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Wyszukujesz frazę "Wang, Y.-J." wg kryterium: Autor


Tytuł:
Assessing soil environmental capacity on different land uses in a suburban area of Chengdu, China
Autorzy:
Yang, W.-L.
Zhou, W.-Y.
Wan, W.-X.
Gou, S.-Z.
Zhang, J.
Deng, S.-H.
Shen, F.
Wang, Y.-J.
Yang, H.
Luo, L.
Powiązania:
https://bibliotekanauki.pl/articles/207670.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
China
soil pollution
heavy metals
soil
vegetables
Chiny
zanieczyszczenie gleby
metale ciężkie
gleba
warzywa
Opis:
Wenjiang (China) is the area which undertakes high-intensity planting activities. Additionally, the soil environmental capacity has been a hot area of research as it plays a key role in environmental protection planning, environmental impact assessment and sustainable development. In this paper, the static model of soil environmental capacity is employed to investigate the distribution of residual soil environmental capacity in Wenjiang. The results show that the soil environmental capacity of mercury is the largest for industrial land while it is the lowest in garlic-rice planting areas; the soil environmental capacity of arsenic is the largest in city construction land while it is the lowest in ecological conservation zone; the soil environmental capacity of lead is the largest in city construction land while it is the lowest in garlic-rice planting areas; and the soil environmental capacity of chromium is the largest in city construction land while it is the lowest in garlic-rice planting areas.
Źródło:
Environment Protection Engineering; 2019, 45, 2; 55-67
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Automation detection of driver fatigue using visual behavior variables
Automatyczna ocena zmęczenia kierowcy z wykorzystaniem wizualnych zmiennych zachowania
Autorzy:
Wang, Y.
Ma, J.
Powiązania:
https://bibliotekanauki.pl/articles/231258.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
czas jazdy
zachowania wizualne
poziom zmęczenia
skala senności Stanford
czynnik prognostyczny
zmęczenie kierowcy
driving duration
visual behaviors
fatigue level
Stanford sleepiness scale
predictor
driver fatigue
Opis:
To examine the correlation of driver visual behaviors and subjective levels of fatigue, a total of 36 commercial drivers were invited to participate in 2-h, 3-h, and 4-h naturalistic driving tests during which their eye fixation, saccade, blinking variables, and self-awareness of their fatigue levels were recorded. Then, one-way ANOVA was applied to analyze the variations of each variable among different age groups over varying time periods. The statistical analysis revealed that driving duration had a significant effect on the variation of visual behaviors and feelings of fatigue. After 2h of driving, only the average closure duration value and subjective level of fatigue had an increase of one-fifth or more. After 4h of driving, however, all these variables had a significant change except for the number of saccades and pupil diameter measurements. Particularly, driver saccadic eye movement was more sensitive to driving fatigue, and the elderly were more likely to be affected by the duration of the drive. Finally, a predictor of driver fatigue was determined to detect the real-time level of fatigue and alert at the critical moment.
Kierowcy zawodowi spędzają długie godziny za kierownicą i szybciej odczuwają zmęczenie podczas prowadzenia pojazdu. Z tego powodu, identyfikacja poziomu zmęczenia w czasie rzeczywistym ma kluczowe znaczenie dla zapewnienia bezpieczeństwa ruchu drogowego i zapobiegania wypadkom, w szczególności w odniesieniu do osób zajmujących się dalekobieżnym transportem komercyjnym. Łącznie 26 kierowców zawodowych w czterech grupach wiekowych zostało zaproszonych do udziału w naturalistycznym egzaminie na prawo jazdy, podczas którego każdy uczestnik został poproszony o ukończenie 2-godzinnych, 3-godzinnych i 4-godzinnych zadań związanych z prowadzeniem pojazdu, obejmujących przerwę na odpoczynek, na trzech drogach ekspresowych w Shandong, Chiny, celem zarejestrowania zmiennych skupienia wzroku, ruchu gałek ocznych i mrugania oczami, jak również subiektywnego poziomu zmęczenia. Następnie, zastosowano jednoczynnikową analizę wariancji w celu przeanalizowania zmienności każdego wizualnego wskaźnika według grup wiekowych w czasie, a analiza statystyczna wykazała, że nieprzerwana jazda ma istotny wpływ na zmiany wskaźników wizualnych i zgłaszany poziom zmęczenia. Po 2 godzinach prowadzenia pojazdu, zarówno średnia wartość czasu zamknięcia, jak i średni subiektywny poziom zmęczenia uległy znacznej zmianie. Po 4 godzinach prowadzenia pojazdu, wszystkie wizualne wskaźniki kierowcy, inne niź średnia liczba ruchów gałek ocznych i średnia średnica źrenicy, uległy znaczącej zmianie. Z drugiej strony, zmiana poziomu zmęczenia jest dodatnio związana ze zmianą średnicy źrenicy, czasem skupienia wzroku, częstotliwościmrugania, czasem mrugania i czasem zamknięcia. Z drugiej strony, zmiana poziomu zmęczenia była ujemnie związana z ilością skupień wzroku, kątem poszukiwań, liczbą ruchu gałek ocznych, szybkością ruchu gałek ocznych i amplitudą ruchu gałek ocznych. Mówiąc dokładniej, ruch gałek ocznych kierowcy był bardziej czuły na poziom zmęczenia podczas jazdy, a u osób starszych występowało większe prawdopodobieństwo, że wpłynie to na długość jazdy w zmienności zachowań wizualnych i uczucie zmęczenia. W przypadku kierowców zawodowych, przepisy ruchu drogowego powinny ściśle kontrolować długość nieprzerwanej jazdy, a osoby starsze powinny zyskać więcej czasu na odpoczynek. Wreszcie, czynnik prognostyczny zmęczenia kierowcy został określony poprzez zmianę współczynnika wizualnych zmiennych, w celu wykrycia poziomu zmęczenia i ostrzegania w krytycznym momencie, w czasie rzeczywistym.
Źródło:
Archives of Civil Engineering; 2018, 64, 2; 175-185
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On some existence results of mild solutions for nonlocal integrodifferential Cauchy problems in Banach spaces
Autorzy:
Yang, Y.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/256027.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
integrodifferential equations
nonlocal initial condition
completely continuous operator
Schaefer fixed point theorem
mild solution
Opis:
In this paper, we study a class of integrodifferential evolution equations with nonlocal initial conditions in Banach spaces. Existence results of mild solutions are proved for a class of integrodifferential evolution equations with nonlocal initial conditions in Banach spaces. The main results are obtained by using the Schaefer fixed point theorem and semigroup theory. Finally, an example is given for demonstration.
Źródło:
Opuscula Mathematica; 2011, 31, 3; 443-455
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analog Circuit Fault Classification Using Improved One-Against-One Support Vector Machines
Autorzy:
Cui, J.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/220569.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analog circuit
fault classification
Support Vector Machines Classifier
fault dictionary
kernel parameter
Opis:
This paper presents a novel strategy of fault classification for the analog circuit under test (CUT). The proposed classification strategy is implemented with the one-against-one Support Vector Machines Classifier (SVC), which is improved by employing a fault dictionary to accelerate the testing procedure. In our investigations, the support vectors and other relevant parameters are obtained by training the standard binary support vector machines. In addition, a technique of radial-basis-function (RBF) kernel parameter evaluation and selection is invented. This technique can find a good and proper kernel parameter for the SVC prior to the machine learning. Two typical analog circuits are demonstrated to validate the effectiveness of the proposed method.
Źródło:
Metrology and Measurement Systems; 2011, 18, 4; 569-582
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Existence results for mild solutions of impulsive periodic systems
Autorzy:
Yang, Y.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/254901.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
impulsive periodic systems
T0-periodic PC-mild solution
Horn’s fixed point theorem
existence
Opis:
By applying the Horn's fixed point theorem, we prove the existence of T0-periodic PC-mild solution of impulsive periodic systems when PC-mild solutions are ultimate bounded.
Źródło:
Opuscula Mathematica; 2012, 32, 3; 601-616
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-permeable layer formation during seed development in Elymus nutans and Elymus sibiricus
Autorzy:
Zhou, J.
Wang, Y.
Trethewey, J.
Powiązania:
https://bibliotekanauki.pl/articles/57994.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
semi-permeable layer
formation
seed development
Elymus nutans
Elymus sibiricus
TEM analysis
seed coat
plant embryo
protective function
mechanical damage
pathogen attack
Źródło:
Acta Societatis Botanicorum Poloniae; 2013, 82, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Visual Detection Method of Longitudinal Crack Based on Computer Image Processing During Slab Continuous Casting
Autorzy:
Liu, Y.
Wang, X.
Sun, Y.
Du, F.
Gao, Y.
Wang, F.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/351636.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
longitudinal crack
visual detection
image processing
continuous casting
Opis:
Based on the mould temperature measured by thermocouples during slab continuous casting, a difference of temperature thermograph is developed to detect slab cracks. In order to detect abnormal temperature region caused by longitudinal crack, the suspicious regions are extracted and divided by virtue of computer image processing algorithms, such as threshold segmentation, connected region judgement and boundary tracing. The abnormal regions are then determined and labeled with the eight connected component labeling algorithm. The boundary of abnormal region is also extracted to depict characteristics of longitudinal crack. Based on above researches, longitudinal crack with abnormal temperature region can be detected and is different from other abnormalities. Four samples of temperature drop are picked up to compare with longitudinal crack on the abnormal region formation, length, width, shape, et al. The results show that the abnormal region caused by longitudinal crack has a linear and vertical shape. The height of abnormal region is more than the width obviously. The ratio of height to width is usually larger than that of other temperature drop regions. This method provides a visual and easy way to detect longitudinal crack and other abnormities. Meanwhile it has a positive meaning to the intelligent and visual mould monitoring system of continuous casting.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 2; 673-680
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation on different behavior and mechanism of Ca(II) and Fe(III) adsorption on spodumene surface
Autorzy:
Yu, F.
Wang, Y.
Wang, J.
Xie, Z.
Powiązania:
https://bibliotekanauki.pl/articles/110230.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
spodumene surface
calcium ions
iron ions
adsorption mechanism
DFT calculation
Opis:
Behavior and mechanism of Ca2+ and Fe3+ adsorption on spodumene surface were investigated by micro flotation tests, zeta potential measurements, and density functional theory (DFT) calculation methods. The micro flotation tests showed that Ca2+ and Fe3+ activated the flotation of spodumene remarkably. However, the effect of Fe3+ was more significant than that of Ca2+. Additionally, Fe3+ significantly changed the zeta potential of spodumene while Ca2+ showed a little change. Meanwhile, the calculated adsorption energy of Fe3+ on spodumene surface was much greater than that of Ca2+ indicating that Fe3+ is more apt to be adsorbed on spodumene surface than Ca2+. The value of bond population in Ca-O illustrated that the bond of Ca-O consists of partial covalent proportion and some ionic component. On the contrary, the bond of Fe-O showed a relatively strong covalent property. The partial density of states (PDOS) of free Ca/Fe and the reacted O atom on spodumene (110) surface before and after the adsorption showed that Fe 3d orbital and O 2p orbital formed hybridization. The density of states (DOS) near the Fermi level of spodumene surface after adsorption with Fe3+ was much stronger than that with Ca2+.
Źródło:
Physicochemical Problems of Mineral Processing; 2014, 50, 2; 535-550
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of vinasse and silica mud on the performance of thermophilic fermentation of brewery sludge from brewery waste substrates
Autorzy:
Xin, Y.
Shen, J.
Wang, B.
Zhu, X.
Wang, Y.
Wang, G.
Chen, Q.
Powiązania:
https://bibliotekanauki.pl/articles/950042.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
brewery waste
anaerobic digestion
thermophilic fermentation
odpady browarnicze
fermentacja beztlenowa
fermentacja termofilna
Opis:
The anaerobic digestion of mixing brewery sludge with vinasse and silica mud at various ratios under thermophilic conditions was explored. Vinasse, silica mud and beer sludge (the sludge from the treatment of beer wastewater) are the main solid wastes of the beer production. Uncontrolled decom-position of these wastes could cause large-scale contamination of soil, water, and air. The results of the investigation showed that the optimal ratio of beer sludge and vinasse was 1:1 under total solids of 10%, producing the highest amount of gas of 1.34 cm3/g within 24 h and 4.06 cm3/g in 10 days. The silica mud weakened the fermentation process and reduced the gas production, and the concentration of total organic carbon, total nitrogen and volatile solids decreased during the digestion. For the mixture of brewery sludge and vinasse, the content of the total organic matter in the biogas manure was more than 60% and the value of pH was 6.5 after the anaerobic digestion, indicating that the manure can be used as an organic fertilizer.
Źródło:
Environment Protection Engineering; 2017, 43, 2; 119-127
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Adjustable Thermal Insulations of Tibetan Clothing by Manikin Testing
Ocena możliwości zmian izolacji cieplnej ubiorów tybetańskich przy wykorzystaniu manekina
Autorzy:
Guo, X F
Wang, Y Y
Li, J
Powiązania:
https://bibliotekanauki.pl/articles/232266.pdf
Data publikacji:
2013
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
Tibetan clothing
style
thermal insulation
clothing area factor
thermal manikin
ubiór tybetański
styl
izolacja cieplna
przewodzenie ciepła
manekin termiczny
Opis:
The thermal insulation of clothing needs to be easily adjusted in an unsteady environment, but this is extremely difficult for most clothing. To reveal the effect of different styles of Tibetan clothing on their thermal property, the total thermal insulations of Tibetan clothing in three typical styles were measured using a thermal manikin. The clothing area factors (fcl) of the Tibetan clothing and body surface area covered by a Tibetan robe were tested with a photographic method. The results showed the following: 1) For similar insulation, fcl of Tibetan clothing is about 0.23 bigger than that of western clothing, estimated from ISO 11079; 2)the style of Tibetan clothing significantly affects the fcl (p < 0.05, fcl = 1.229 + 0.007 BSAC) and the intrinsic thermal insulation (p < 0.05, Icl = 0.166 + 0.016 BSAC); 3)the adjustable thermal insulation of Tibetan clothing proved its adaptability to the large air temperature difference environment on the Tibetan plateau ,which should be valuable for the product development of clothing used in a unsteady environment.
Odzież powinna umożliwiać zmianę jej przewodności cieplnej w niestabilnym środowisku, jednak dla większości odzieży jest to niezwykle trudne. W celu określenia wpływu różnych stylów ubiorów tybetańskich na ich właściwości termiczne określono całkowitą izolację termiczna dla trzech typowych stylów odzieży tybetańskiej przy zastosowaniu manekina termicznego. Wpływ konfiguracji ubioru sprawdzono metodą fotograficzną za pomocą termowizji, określając jednocześnie powierzchniowy współczynnik okrycia ciała fcl. Wykazano, że 1) przy podobnej izolacji fcl ubiorów tybetańskich jest o 0.23 większy od ubiorów zachodnich (ISO11079); 2) styl ubiorów tybetańskich znacząco wpływa na fcl jak i wewnętrzną izolacje cieplną; 3) możliwość regulacji izolacji termicznej tybetańskiego ubioru zapewnia zdolność przystosowania się do dużych różnic temperatury otoczenia na płaskowyżu tybetańskim. Wyniki badań mogą znaleźć zastosowanie w projektowaniu odzieży noszonej w niestabilnym środowisku.
Źródło:
Fibres & Textiles in Eastern Europe; 2013, 1 (97); 87-91
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spare parts allocation optimization in a multi-echelon support system based on multi-objective particle swarm optimization metod
Optymalizacja alokacji części zamiennych w wieloszczeblowym systemie wsparcia na podstawie metody wielokryterialnej optymalizacji rojem cząstek
Autorzy:
Wang, Y.
Zhao, J.
Jia, X.
Tian, Y.
Powiązania:
https://bibliotekanauki.pl/articles/301801.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
MOPSO
części zamienne
alokacja
optymalizacja
prawdopodobieństwo wsparcia
spare parts
allocation
optimization
support probability
Opis:
Optymalizacja alokacji części zamiennych w wieloszczeblowym systemie wspomagania stanowi trudne zagadnienie, które wymaga optymalizacji nieliniowej funkcji celu oraz zmiennych całkowitych. W niniejszej pracy, opracowano wielokryterialny model optymalizacyjny, który maksymalizuje prawdopodobieństwo wsparcia i minimalizuje jego koszty. W celu rozwiązania problemu optymalizacyjnego, wykorzystano ulepszoną metodę wielokryterialnej optymalizacji rojem cząstek (MOPSO). W metodzie tej wykorzystano techniki redukcji wymiarów oraz wielokryterialnej optymalizacji algorytmowej, które mogą poprawić efektywność metody MOPSO. Zasady proponowanej metody zilustrowano przykładem numerycznym.
Spare parts allocation optimization in a multi-echelon support system presents a difficult problem which involves non-linear objective function and integer variables to be optimized. In this paper, a multi-objective optimization model was developed, which maximizes support probability and minimizes support costs. In order to solve the optimization problem, an improved multi-objective particle swarm optimization (MOPSO) method was utilized. In this method, techniques of dimensions reduction and rules-based multi-objective optimization were employed, which can improve the efficiency of MOPSO method. A numerical example was given to show the performance of proposed method.
Źródło:
Eksploatacja i Niezawodność; 2014, 16, 1; 29-36
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Designing a Mixed Evaluating System for Green Manufacturing of Automotive Industry
Projektowanie mieszanego system oceny zielonej produkcji dla przemysłu samochodowego
Autorzy:
Cao, Y.
You, J.
Wang, R.
Shi, Y.
Powiązania:
https://bibliotekanauki.pl/articles/371839.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Komitet Człowiek i Środowisko PAN
Tematy:
SBSC
GM
index system of automotive industry
GA
BPANN
zielona produkcja
system wskaźników przemysłu motoryzacyjnego
Opis:
The article proposed, from a sustainable development perspective, an index system based on Sustainability Balanced Scorecard (SBSC), including the main index of Financial, Internal process, Customer, Learning and growth, Social and the sub- index which comprised 28 indexes to evaluate the Green Manufacturing (GM) of automotive industry. Based on the index system, an evaluation model integrates by back-propagation artificial neural network (BPANN) and genetic algorithm (GA) was introduced. Using established model and indicators evaluated GM in four automotive companies; the key result of the evaluated show that: China’s automotive manufacturing enter-prises still have big room for improvement in respect of customer satisfaction, resource consumption, community service, low-carbon activities etc., so the strategy and management activities that put much pressure on these respect are necessary.
W artykule zaproponowano wykorzystanie systemu wskaźników opartych na Zrównoważonej Karcie Wyników (Sustainability Balanced Scorecard – SBSC). Zgodnie z koncepcją rozwoju zrównoważonego uwzględniono na-stępujące główne wskaźniki: finansowy, procesów wewnętrznych, klienta, wzrostu i uczenia się, społeczny, a także 28 podwskaźników. Celem była ocena Zielonej Produkcji (Green Manufacturing – GM) w przemyśle mo-toryzacyjnym. Wprowadzono model oceny oparty na systemie wskaźników, łączący propagację wsteczną sztucz-nej sieci neuronowej (back-propagation artificial neural network – BPANN) oraz algorytm genetyczny (genetic algorithm – GA). Za pomocą wybranego modelu i wskaźników dokonano oceny Zielonej Produkcji w czterech firmach motoryzacyjnych. Wyniki wskazują, że chińskie przedsiębiorstwa motoryzacyjne mają jeszcze dużo do poprawy w kwestii satysfakcji klienta, zużycia zasobów, pracy społecznej, działań niskoemisyjnych, itp. Ko-nieczne jest zatem obranie strategii oraz gospodarki, które kładą nacisk na wymienione kwestie.
Źródło:
Problemy Ekorozwoju; 2016, 11, 1; 73-86
1895-6912
Pojawia się w:
Problemy Ekorozwoju
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fractional nonlocal integrodifferential equations of mixed type with time-varying generating operators and optimal control
Autorzy:
Wang, J.
Wei, W.
Yang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/254750.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
fractional integrodifferential equations of mixed type
time-varying generating operators
nonlocal conditions
fixed point theorem
existence
optimal control
Opis:
In this paper, a class of fractional integrodifferential equations of mixed type with time-varying generating operators and nonlocal conditions is considered. Using a contraction mapping principle and Krasnoselskii's fixed point theorem via Gronwall's inequailty, the existence and uniqueness of mild solution are given. The existence of optimal pairs of systems governed by fractional integrodifferential equations of mixed type with time-varying generating operators and nonlocal conditions is also presented.
Źródło:
Opuscula Mathematica; 2010, 30, 2; 217-234
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nonlocal impulsive problems for fractional differential equations with time-varying generating operators in Banach spaces
Autorzy:
Wang, J.
Yang, Y.
Wei, W.
Powiązania:
https://bibliotekanauki.pl/articles/255546.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
nonlocal conditions
impulsive equations
fractional differential equations
time-varying generating operators
PC-mild solution
Opis:
In this paper, we study the existence and uniqueness of the PC-mild solution for a class of impulsive fractional differential equations with time-varying generating operators and nonlocal conditions. By means of the generalized Ascoli-Arzela Theorem given by us and the fixed point theorem, some existence and uniqueness results are obtained. Finally, an example is given to illustrate the theory.
Źródło:
Opuscula Mathematica; 2010, 30, 3; 361-381
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On some impulsive fractional differential equations in Banach spaces
Autorzy:
Wang, J.
Wei, W.
Yang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/255610.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
fractional differential equations with impulses
nonlinear impulsive singular version of the Gronwall inequality
PC-mild solutions
existence
Opis:
This paper deals with some impulsive fractional differential equations in Banach spaces. Utilizing the Leray-Schauder fixed point theorem and the impulsive nonlinear singular version of the Gronwall inequality, the existence of PC-mild solutions for some fractional differential equations with impulses are obtained under some easily checked conditions. At last, an example is given for demonstration.
Źródło:
Opuscula Mathematica; 2010, 30, 4; 507-525
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On nonlocal problems for fractional differential equations in Banach spaces
Autorzy:
Dong, X.
Wang, J.
Zhou, Y.
Powiązania:
https://bibliotekanauki.pl/articles/255742.pdf
Data publikacji:
2011
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
nonlocal problems
fractional differential equations
existence
generalized singular Gronwall inequality
fixed point method
Opis:
In this paper, we study the existence and uniqueness of solutions to the nonlocal problems for the fractional differential equation in Banach spaces. New sufficient conditions for the existence and uniqueness of solutions are established by means of fractional calculus and fixed point method under some suitable conditions. Two examples are given to illustrate the results.
Źródło:
Opuscula Mathematica; 2011, 31, 3; 341-357
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical analysis of internal flow phenomena in a multi-blade centrifugal fan
Autorzy:
Wang, J.
Ou, Y.
Wu, K.
Powiązania:
https://bibliotekanauki.pl/articles/1964163.pdf
Data publikacji:
2005
Wydawca:
Politechnika Gdańska
Tematy:
multi-blade centrifugal fan
internal flow field
CFD
Opis:
A three-dimensional, steady, incompressible, turbulent flow field inside a multi-blade centrifugal fan used in an air-conditioner has been analyzed numerically. Reynolds-averaged Navier-Stokes equations with the standard k-epsilon turbulence model have been discretized by the finite volume method. The calculation results have shown complex three-dimensional characteristics of the flow, especially in the blade passages near the shroud side. The results have revealed a boundary layer separating the flow from the leading edge on the blade suction surface, the flow's reversal from the high pressure region inside the volute to the low pressure region near the impeller inlet, the flow's recirculation near the shroud side, a jet-wake pattern at the rotor exit, pressure fluctuation on the blade surface, etc. Some of the numerical results agree well with previous experiment.
Źródło:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2005, 9, 2; 245-256
1428-6394
Pojawia się w:
TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology and developmental traits of the trilobite Changaspis elongata from the Cambrian Series 2 of Guizhou, South China
Autorzy:
Du, G.-Y.
Peng, J.
Wang, D.-Z.
Wang, Q.-J.
Wang, Y.-F.
Zhang, H.
Powiązania:
https://bibliotekanauki.pl/articles/22906.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Opis:
The morphology and ontogeny of the trilobite Changaspis elongata based on 216 specimens collected from the Lazizhai section of the Balang Formation (Stage 4, Series 2 of the Cambrian) in Guizhou Province, South China are described. The relatively continuous ontogenetic series reveals morphological changes, and shows that the species has seventeen thoracic segments in the holaspid period, instead of the sixteen as previously suggested. The development of the pygidial segments shows that their number gradually decreases during ontogeny. A new dataset of well-preserved specimens offers a unique opportunity to investigate developmental traits after segment addition is completed. The ontogenetic size progressions for the lengths of cephalon and trunk show overall compliance with Dyar’s rule. As a result of different average growth rates for the lengths of cephalon, trunk and pygidium, the length of the thorax relative to the body shows a gradually increasing trend; however, the cephalon and pygidium follow the opposite trend. Morphometric analysis across fourteen post-embryonic stages reveals growth gradients with increasing values for each thoracic segment from anterior to posterior. The reconstruction of the development traits shows visualization of the changes in relative growth and segmentation for the different body parts. The new dataset and growth gradient of the trunk suggest that the thoracic segment growth dynamics of early Cambrian to Silurian trilobites follow the same general continuous, steady-state growth gradient decreasing from posterior to anterior.
Źródło:
Acta Palaeontologica Polonica; 2019, 64, 4
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
New specimens of the multituberculate mammal Sphenopsalis from China: Implications for phylogeny and biology of taeniolabidoids
Autorzy:
Mao, F.-Y.
Wang, Y.-Q.
Meng, J.
Powiązania:
https://bibliotekanauki.pl/articles/20957.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
new specimen
multituberculate mammal
mammal
Sphenopsalis
China
phylogenesis
biology
taeniolabidoid
Mammalia
Multituberculata
Taeniolabidoidea
Paleogene
Erlian Basin
Inner Mongolia
Opis:
Multituberculates are the most diverse and best known group of Mesozoic mammals; they also persisted into the Paleogene and became extinct in the Eocene, possibly outcompeted by rodents that have similar morphological and presumably ecological adaptations. Among the Paleogene multituberculates, those that have the largest body sizes belong to taeniolabidoids, which contain several derived species from North America and Asia and some species with uncertain taxonomic positions. Of the known taeniolabidoids, the poorest known taxon is Sphenopsalis nobilis from Mongolia and Inner Mongolia, China, represented previously by a few isolated teeth. Its relationship with other multituberculates thus has remained unclear. Here we report new specimens of Sphenopsalis nobilis collected from the upper Paleocene of the Erlian Basin, Inner Mongolia, China, during a multi-year field effort beginning in 2000. These new specimens document substantial parts of the dental, partial cranial and postcranial morphologies of Sphenopsalis, including the upper and lower incisors, partial premolars, complete upper and lower molars, a partial rostrum, fragments of the skull roof, middle ear cavity, a partial scapula, and partial limb bones. With the new specimens we are able to present a detailed description of Sphenopsalis, comparisons among relevant taeniolabidoids, and brief phylogenetic analyses based on a dataset consisting of 43 taxa and 102 characters. In light of the new evidence, we assess the phylogenetic position of Sphenopsalis and re-establish the family Lambdopsalidae. The monophyly of Taeniolabidoidea is supported in all our phylogenetic analyses. Within Taeniolabidoidea the Asian lambdopsalids and the North American taeniolabidids represent two significantly different trends of adaptations, one characterized by shearing (lambdopsalids) and the other by crushing and grinding (taeniolabidids) in mastication, which supports their wider systematic separation, as speculated when Sphenopsalis was named.
Źródło:
Acta Palaeontologica Polonica; 2016, 61, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On the stability of first order impulsive evolution equations
Autorzy:
Wang, J.
Feckan, M.
Zhou, Y.
Powiązania:
https://bibliotekanauki.pl/articles/255727.pdf
Data publikacji:
2014
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
first order
impulsive evolution equations
Ulam-Hyers-Rassias stability
Opis:
In this paper, concepts of Ulam-Hyers stability, generalized Ulam-Hyers stability, Ulam-Hyers-Rassias stability and generalized Ulam-Hyers-Rassias stability for impulsive evolution equations are raised. Ulam-Hyers-Rassias stability results on a compact interval and an unbounded interval are presented by using an impulsive integral inequality of the Gronwall type. Two examples are also provided to illustrate our results. Finally, some extensions of the Ulam-Hyers-Rassias stability for the case with infinite impulses are given.
Źródło:
Opuscula Mathematica; 2014, 34, 3; 639-657
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of flotation behavior and mechanism of cervantite activation by copper ions
Autorzy:
Wang, J.
Wang, Y.
Fu, K.
Xu, L.
Wang, Z.
Sun, H.
Xiao, J.
Powiązania:
https://bibliotekanauki.pl/articles/110228.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
cervantite
copper ions
activation mechanism
Opis:
Copper-ion activation plays a highly important role in cervantite (Sb2O4) flotation. Without metal-ion activation, cervantite cannot be floated by sodium oleate. In this study, flotation tests were conducted to study the effect of Cu2+ on the flotation behaviours of cervantite and quartz (SiO2) as the main gangue mineral. Metal-ion adsorption capacities, zeta potentials, solution chemistry and X-ray photoelectron spectra were analyzed to study the adsorption behavior and mechanism of copper ions and sodium oleate interaction with the minerals surfaces. The results demonstrate that under weakly acidic conditions, cervantite can be flotated and separated from quartz by the addition of copper ions. The reason is that copper ions can be selectively adsorbed on the cervantite surface under weakly acidic conditions, thereby promoting the adsorption of sodium oleate onto the cervantite surface by chemical adsorption. Conversely, copper ions are weakly adsorbed on quartz surfaces below pH 6.1, and sodium oleate cannot be adsorbed on quartz surfaces by chemical adsorption. The hydroxy copper species are integral to the selective activation of cervantite over quartz.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 814-825
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Poprawa aproksymacji lokalnej średniej w rozkładzie na mody empiryczne dla celów detekcji uszkodzeń przekładni
Improvement of local mean approximation in empirical mode decomposition for gear fault detection
Autorzy:
Wang, Y.
Zuo, M. J.
Lei, Y.
Fan, X.
Powiązania:
https://bibliotekanauki.pl/articles/301082.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
rozkład na mody empiryczne
interpolacja Hermite'a
funkcja sklejana 3-ego stopnia
aproksymacja średniej wartości obwiedni
okienkowana średnia lokalna
detekcja uszkodzeń przekładni
empirical mode decomposition
Hermite interpolation
cubic spline
envelope mean approximation
windowed local mean
gear fault detection
Opis:
Rozkład na mody empiryczne (EMD) to adaptacyjna metoda przetwarzania sygnału w połączonej dziedzinie czasu i częstotliwości, która jest całkowicie sterowana przez same dane. Metody interpolacji funkcjami sklejanymi trzeciego stopnia (cubic spline interpolation) używa się do aproksymacji średniej lokalnej w procesie przesiewu EMD. Niniejsza praca bada podejścia do poprawy aproksymacji średniej lokalnej w celu otrzymania lepszych charakterystyk EMD. Do aproksymacji średniej wartości obwiedni (envelope mean approximation) zastosowano metodę zmodyfi kowanej monotonicznej interpolacji Hermite'a funkcjami sklejanymi (modifi ed monotone piecewise Hermite interpolation, MMPHI), jako że wykazuje ona przewagę nad metodą funkcji sklejanych trzeciego stopnia. Zbadano również jeden z typów bezpośredniej aproksymacji lokalnej średniej, tzw. podejście okienkowanej średniej lokalnej (windowed local mean, WLM), i pokazano jego zalety w wykrywaniu impulsów.
Empirical mode decomposition (EMD) is an adaptive time-frequency domain signal processing method that is completely driven by data itself. The cubic spline interpolation method has been used to approximate the local mean in the sifting process of EMD. This study explores approaches to improve local mean approximation to obtain better EMD performance. A modifi ed monotone piecewise Hermite interpolation (MMPHI) method is applied to envelope mean approximation, because it demonstrates advantages over the cubic spline method. A type of direct approximation of the local mean, i.e., the windowed local mean (WLM) approach, is also investigated and its merit in identifying impulses is demonstrated.
Źródło:
Eksploatacja i Niezawodność; 2010, 2; 59-66
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Improved Robust Kalman Filter in Data Fusion for PPP/INS Tightly Coupled Positioning System
Autorzy:
Li, Z.
Yao, Y.
Wang, J.
Gao, J.
Powiązania:
https://bibliotekanauki.pl/articles/221374.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
PPP/INS tightly coupled positioning
robust filter
IGG scheme
Mahalanobis distance
Opis:
A robust Kalman filter improved with IGG (Institute of Geodesy and Geophysics) scheme is proposed and used to resist the harmful effect of gross error from GPS observation in PPP/INS (precise point positioning/inertial navigation system) tightly coupled positioning. A new robust filter factor is constructed as a three-section function to increase the computational efficiency based on the IGG principle. The results of simulation analysis show that the robust Kalman filter with IGG scheme is able to reduce the filter iteration number and increase efficiency. The effectiveness of new robust filter is demonstrated by a real experiment. The results support our conclusion that the improved robust Kalman filter with IGG scheme used in PPP/INS tightly coupled positioning is able to remove the ill effect of gross error in GPS pseudorange observation. It clearly illustrates that the improved robust Kalman filter is very effective, and all simulated gross errors added to GPS pseudorange observation are successfully detected and modified.
Źródło:
Metrology and Measurement Systems; 2017, 24, 2; 289-301
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Trophic connectivity between intertidal and offshore food webs in Mirs Bay, China
Autorzy:
Ning, J.
Du, F.
Wang, X.
Wang, L.
Li, Y.
Powiązania:
https://bibliotekanauki.pl/articles/47613.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
intertidal zonation
offshore zone
food web
different habitat
trophic interaction
stable isotope
carbon isotope composition
Mirs Bay
China
Źródło:
Oceanologia; 2019, 61, 2
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Distribution and role of the genus Oithona (Copepoda: Cyclopoida) in the South China Sea
Autorzy:
Wang, L.
Du, F.
Wang, X.
Li, Y.
Ning, J.
Powiązania:
https://bibliotekanauki.pl/articles/47786.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
Oithona
Copepoda
Cyclopoida
temperature
hydrological factor
phytoplankton
ichthyoplankton
South China Sea
Oithona plumifera
Oithona similis
Opis:
The relationships between the small cyclopoid copepod Oithona and hydrological factors, phytoplankton and ichthyoplankton were evaluated using the data obtained in the central South China Sea (SCS) in summer 2014. The genus abundance ranged from 6.00 ind. m3 to 93.75 ind. m3 with high abundance band occurring in the branch of SCS Monsoon Jet. The lower temperature and higher salinity in the surface water of the band than other zones indicated that deep water intrusion was a positive factor for aggregation of the genus. The community structure of the genus was dominated by Oithona plumifera and Oithona similis made up 97% of the genus abundance associated with Oithona tenuis. The result of db-RDA analysis showed that the community structure of the genus was affected by temperature, Chl a, larval fishes and fish spawns, and temperature was the most important limiting factor. The result of GAMs analysis showed that abundance of O. tenuis, and copepodites were affected by Chl a, larval fishes and fish spawns; abundance of O. similis was affected by Chl a and fish spawns; and abundance of O. plumifera was affected by Chl a and larval fishes. Therefore, we suggest that the branch of SCS Monsoon Jet and deep water intrusion favor aggregation of plankton in the central SCS in summer. We confirm that the temperature is the limiting factor to the reproduction of the genus Oithona in tropic seas and the genus Oithona is a food-web linker between primary production and larval fishes in the central SCS.
Źródło:
Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chitosan Modified Corn Starch and Its Application as a Glass Fibre Sizing Agent
Skrobia kukurydziana modyfikowana chitozanem i jej zastosowanie jako środka klejącego włókien szklanych
Autorzy:
Wang, Y.
Li, J.
Li, H.
Wang, X.
Lei, H.
Huo, J.
Powiązania:
https://bibliotekanauki.pl/articles/232005.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
glass fiber
sizing agent
corn starch
chitosan
modification
włókno szklane
środki klejące
skrobia kukurydziana
chitozan
modyfikacja
Opis:
Chitosan-modified corn starch was prepared and then applied as a glass fiber sizing agent. The effect of the chitosan on starch-based emulsion, film and sized glass fiber was studied. When 5 % of the chitosan was added, the overall performance of the modified film-forming agent was optimal. The viscosity, surface tension and zeta potential of the sizing agent were 44.99 mPa·s, 51.29 mN·m-1 and 4.5 mV, respectively. The modified sizing agent could easily spread over the surface of glass fibre, and conglutinated to the glass surface firmly. The tensile strength and stiffness of modified-starch glass fiber reached 0.43 N·tex-1 and 4.96 cm. Glass fiber with good overall performance was obtained.
W pracy przygotowano skrobię kukurydzianą modyfikowaną chitozanem, a następnie zastosowano ją jako środek klejący włókien szklanych. Określono lepkość, napięcie powierzchniowe i potencjał zeta środka klejącego. Zmierzono wytrzymałość na rozciąganie i sztywność zmodyfikowanego włókna szklanego. Stwierdzono, że modyfikacja skrobi chitozanem powoduje poprawienie jej właściwości jako środka klejącego. Modyfikacja zwiększyła przyczepność skrobi do włókien i poprawiła ich właściwości mechaniczne.
Źródło:
Fibres & Textiles in Eastern Europe; 2017, 3 (123); 112-120
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation separation of cervantite from quartz
Autorzy:
Wang, J.
Hua, Y.
Yu, S.
Xiao, J.
Xu, L.
Wang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/110941.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cervantite
quartz
dodecylamine
flotation
density functional theory
Opis:
Flotation separation of cervantite (Sb2O4) from quartz was investigated using dodecylamine (DDA) as a collector. Experiments were conducted on single minerals and on a synthetic mixture of quartz and cervantite. Flotation separation mechanisms were investigated using the zeta potential technique, solution chemistry principles, density functional calculations and Fourier Transform Infrared (FT-IR) spectroscopy. The results indicated that DDA, primarily in the form of molecules, exhibited excellent performance in flotation of cervantite and quartz at pH 10.5. The adsorption energy of the DDA molecules on the cervantite surface was greater than the adsorption energy of water molecules, while the adsorption energy of DDA on the quartz surface was less than the adsorption energy of water molecules. DDA molecules can be adsorbed on the quartz surface to a certain extent, but it was difficult for the same molecule to be adsorbed on the cervantite surface in the pulp. This resulted in flotation of quartz. DDA molecules were adsorbed on quartz not only through physical adsorption but also by hydrogen bonding. However, cervantite could not be floated at pH 10.5 since adsorption of DDA molecules occurred through weak physical bonds on cervantite.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1119-1132
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A fully coupled solid and fluid model for simulating coal and gas outburst with DEM and LBM
W pełni zintegrowany model oddziaływania pomiędzy cieczą a ciałem stałym do symulacji wyrzutów węgla i gazu metodą elementów dyskretnych i metodą siatkową Boltzmanna
Autorzy:
Wang, Y. C.
Xue, S.
Xie, J.
Powiązania:
https://bibliotekanauki.pl/articles/348657.pdf
Data publikacji:
2012
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
wyrzut węgla i gazu
oddziaływanie ciecz-ciało stałe
metoda elementów dyskretnych
metoda siatkowa Boltzmanna
coal and gas outbursts
solid-fluid coupling
Discrete Element Method
lattice Boltzmann method
Opis:
In this paper, we present a fully coupled solid-fluid code which is developed to model the whole process of coal and gas outbursts. The Discrete Element Method is used to model the deformation and fracture of solid, while Lattice Boltzmann Method models fluid flow, including free flow and Darcy flow. These two methods are coupled in a two-way process: the solid part provides a moving boundary condition and transfers momentum to the fluid, and the fluid exerts a dragging force to the solid. Gas desorption occurs at solid-fluid boundary, and gas diffusion is implemented in the solid code where particles are assumed as porous material. Some preliminary simulations are carried out to validate the code.
W niniejszej publikacji prezentujemy w pełni zintegrowany kod oddziaływania pomiędzy cieczą a ciałem stałym, opracowany do modelowania całego procesu wyrzutów węgla i gazu. Metoda elementów dyskretnych stosowana jest do modelowania deformacji i pęknięcia ciała stałego, podczas gdy metoda siatkowa Boltzmanna - do modelowania przepływu cieczy, w tym przepływu swobodnego i przepływu zgodnie z prawem Darcy'ego. Te dwie metody połączone są w procesie dwukierunkowym: część stała zapewnia warunki ruchomej granicy rozdziału, przenosząc pęd do cieczy, a ciecz wywiera opór na ciele stałym. Desorpcja gazu występuje na granicy oddziaływania pomiędzy cieczą a ciałem stałym, a do rozproszenia gazu dochodzi w kodzie ciała stałego, gdzie cząsteczki traktowane są jako materiał porowaty. Prowadzone są wstępne symulacje w celu sprawdzenia poprawności kodu.
Źródło:
AGH Journal of Mining and Geoengineering; 2012, 36, 3; 377-384
1732-6702
Pojawia się w:
AGH Journal of Mining and Geoengineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The kurtosis parameter of partially coherent controllable dark hollow beams in free space
Autorzy:
Li, J.
Wang, W W
Lai, Y
Powiązania:
https://bibliotekanauki.pl/articles/173815.pdf
Data publikacji:
2014
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
kurtosis parameter
partially coherent controllable dark hollow beams
free space
Opis:
Based on the extended Huygens–Fresnel principle and the definition of second-order moments of the Wigner distribution function, the analytical expression for the kurtosis parameter of partially coherent controllable dark hollow beams in free space is derived, and used to study the influence of beam parameters on the kurtosis parameter. It is shown that the kurtosis parameter increases with increasing the wavelength and the waist width, or decreasing the scaling factor, however, the effect of the beam order and the spatial correlation length on the kurtosis parameter depends on the propagation distance. The results can be interpreted physically.
Źródło:
Optica Applicata; 2014, 44, 4; 533-543
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, Structure and Energetic Properties of a Catenated N6, Polynitro Compound: 1,1’-Azobis(3,5-dinitropyrazole)
Autorzy:
Li, Y.-N.
Shu, Y.-J.
Wang, Y.-L.
Wang, B.-Z.
Zhang, S.-Y.
Bi, F.-Q.
Powiązania:
https://bibliotekanauki.pl/articles/358573.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic compound
1,1’-azobis(3,5-dinitropyrazole)
synthesis
energetic properties
Opis:
A nitrogen-rich, polynitro energetic compound with an N,N-azo linkage, 1,1’-azobis(3,5-dinitropyrazole) (ABDNP), has been synthesized by an oxidative coupling reaction of 1-amino-3,5-dinitropyrazole with different oxidizing agents. The target compound was characterized by IR spectroscopy, 1H and 13C nuclear magnetic resonance spectroscopy, elemental analysis, mass spectra, X-ray diffraction and differential scanning calorimetry (DSC). The DSC results show that 1,1’-azobis(3,5-dinitropyrazole) decomposes at a relatively high onset temperature (202.9 °C), which indicates that 1,1’-azobis(3,5-dinitropyrazole) has acceptable thermal stability. The energetic properties were obtained, with a measured density and heat of formation matched by theoretically computed values based on the B3LYP method.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 2; 321-335
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seismic damage behaviour of aeolian sand reinforced concrete columns with I-shaped structural steel
Autorzy:
Wang, Y. H.
Wang, H. Y.
Wang, Y. P.
Zhao, M.
Qi, J.
Huo, G. Z.
Liu, P. Q.
Powiązania:
https://bibliotekanauki.pl/articles/1849772.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
piasek eoliczny
słup żelbetowy
stal konstrukcyjna
przekrój I
zachowanie
uszkodzenie sejsmiczne
model uszkodzenia
aeolian sand
column
I-shaped steel
structural steel
seismic damage
behaviour
damage model
Opis:
To promote the application of aeolian sand resources for steel-concrete composite structures, an aeolian sand reinforced concrete column with I-shaped structural steel is proposed in this study. Four specimens are designed and manufactured with different replacement rates of aeolian sand. The seismic behaviour and damage evolution process of the specimens are studied by low-cycle repeated loading tests. Based on the test results, the mechanical characteristics, failure modes, hysteresis curves, skeleton curves, energy dissipation capacity, displacement ductility, and stiffness degradation of the specimens with different replacement rates of aeolian sand are analysed. In addition, the effects of the design parameters on the seismic behaviour of the specimens are also studied. The results show that the indexes of the seismic behaviour can be significantly improved by adding steel. Moreover, a revised damage model is proposed, to better reflect the evolution law of seismic damage of aeolian sand reinforced concrete columns with steel. The proposed model can provide an important reference for seismic damage assessment of the columns.
Źródło:
Archives of Civil Engineering; 2020, 66, 4; 633-650
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biomass-biogas recycling technique studies of municipal food waste disposal: a reviw
Badania nad technologiami odzysku biogazu z biomasy z żywnościowych odpadów komunalnych: przegląd
Autorzy:
Jin, Y
Wen, J
Nie, Y
Chen, H
Wang, G
Powiązania:
https://bibliotekanauki.pl/articles/1819373.pdf
Data publikacji:
2012
Wydawca:
Politechnika Koszalińska. Wydawnictwo Uczelniane
Tematy:
solid-liquid system
anaerobic digestion
leachate recirculation
methane production
activated sludge
retention time
performance
hydrolysis
water
stabilization
biomasa
fermentacja beztlenowa
odpady komunalne
recycling odpadów spożywczych
Opis:
Źródła energii znalazły się w centrum zainteresowania pod względem prawnym, etycznym, społecznym i gospodarczym z powodu rosnących problemów środowiska. Powszechnie wiadome, że nieodnawialne źródła energii są w coraz większym stopniu zastępowane innymi, które są odnawialne i mniej zanieczyszczające, z wykorzystaniem technologii mających na celu zrównoważony rozwój. Utylizacja stałych odpadów żywnościowych jest wciąż poważnym problemem dla wielu społeczności. Technologia beztlenowej fermentacji jest możliwa do zastosowania przy przetwarzaniu organicznych odpadów stałych i łączy odzysku materiału oraz produkcję energii. Recykling odpadów spożywczych w procesie beztlenowa fermentacja na biogaz, zawiesinę biogazu oraz nawóz organiczny jest podstawowym zadaniem utylizacji bioodpadów komunalnych. Bazując na sortowaniu odpadów spożywczych, technologia ta może zlikwidować zanieczyszczenia z odpadów spożywczych, w odniesieniu do ich źródeł. Z jednej strony złagodzić presję na środowisko pochodzące z spożywczych odpadów komunalnych oraz uniknąć wtórnego zanieczyszczenia, osiągnąć zasadę „3R” (Reduce, Reuse, Recycle) w gospodarce odpadami jeszcze bardziej. Zasada ta wprowadza zasady technik, przewagę technologiczną oraz postęp w dziedzinie badań nad beztlenową fermentacją. Fermentacja beztlenowa dzieli się na mokrą i suchą. W porównaniu z oczywistymi zaletami fermentacji na mokro, jest jeszcze wiele braków w procesie fermentacji suchej. Ostatecznie stwierdzono, że technologia suchej fermentacji do produkcji metanu zmieniła tradycyjne podejście do fermentacji. W pewnym sensie, usuwanie i recykling odpadów spożywczych jest w przybliżeniu podobny do zgazowania komunalnych odpadów spożywczych, co może zamienić odpady w majątek, który ludzkość może wykorzystać do zarządzania w metropoliach. I zdecydowanie rekomenduje się fermentację typu etanolowego jako najbardziej obiecujący typ acydyfikacyjny.
Źródło:
Rocznik Ochrona Środowiska; 2012, Tom 14; 21-55
1506-218X
Pojawia się w:
Rocznik Ochrona Środowiska
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on quantifying the hydrophilicity of leached coals by FTIR spectroscopy
Autorzy:
Wang, J.
He, Y.
Yang, Y.
Xie, W.
Ling, X.
Powiązania:
https://bibliotekanauki.pl/articles/110191.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chemical-structural properties
macerals
hydrophilicity
functional group
Opis:
Surface properties play important roles in characterization of structural parameters and the hydrophilicity index. Accurate analysis of the macerals rather than the average properties of the macerals and minerals are crucial for these parameters and indexes. In order to improve the accuracy of analyzing coal surface property, HF/HCl acid leaching was applied to eliminate the interference of minerals. FTIR was used to characterize the differences in surface chemical composition between raw and processed coal. Moreover, each functional group was analyzed quantitatively. Based on these quantitative data, the structural parameters and hydrophilicity indexes were calculated. From the results of FTIR, the peaks of mineral cover up the types of the organic peaks, such as -COOH and aromatic CH stretching. In addition, they decrease the intensity of the peak such as C=C and aromatics CHx out-of-plane deformation in the spectra of raw coals. However, it provided the accurate types and contents of organic functional groups of the macerals after acid leaching. The structural parameter results indicate that the values cannot reflect the coal ranks through the surface properties of raw coals while they show a good relationship with the degree of coalification in the analysis of processed coals. Besides, the hydrophilicity indexes are verified by the natural floatability of coal macerals of the processed coals. It is also found that the processed lignite coal cannot be floated despite elimination of the hydrophilic minerals. The main reason of hard-to-float property of lignite coal lies in a strong hydrophilicity of macerals.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 227-239
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of small uav position and attitude with reliable in-flight initial alignment for MEMS inertial sensors
Autorzy:
Wang, D.
Dong, Y.
Li, Q.
Wu, J.
Wen, Y.
Powiązania:
https://bibliotekanauki.pl/articles/221716.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
MEMS
INS
GNSS
in-flight alignment
unmanned aerial vehicle
Opis:
The advance of MEMS-based inertial sensors successfully expands their applications to small unmanned aerial vehicles (UAV), thus resulting in the challenge of reliable and accurate in-flight alignment for air-borne MEMS-based inertial navigation system (INS). In order to strengthen the rapid response capability for UAVs, this paper proposes a robust in-flight alignment scheme for airborne MEMS-INS aided by global navigation satellite system (GNSS). Aggravated by noisy MEMS sensors and complicated flight dynamics, a rotation-vector-based attitude determination method is devised to tackle the in-flight coarse alignment problem, and the technique of innovation-based robust Kalman filtering is used to handle the adverse impacts of measurement outliers in GNSS solutions. The results of flight test have indicated that the proposed alignment approach can accomplish accurate and reliable in-flight alignment in cases of measurement outliers, which has a significant performance improvement compared with its traditional counterparts.
Źródło:
Metrology and Measurement Systems; 2018, 25, 3; 603-616
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Traffic fatalities prediction based on support vector machine
Autorzy:
Li, T.
Yang, Y.
Wang, Y.
Chen, C.
Yao, J.
Powiązania:
https://bibliotekanauki.pl/articles/223743.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
traffic accident
support vector machine
SVM
particle swarm optimization (PSO)
PSO
prediction model
optimal parameters
wypadek drogowy
Particle Swarm Optimization
model prognostyczny
optymalne parametry
Opis:
To effectively predict traffic fatalities and promote the friendly development of transportation, a prediction model of traffic fatalities is established based on support vector machine (SVM). As the prediction accuracy of SVM largely depends on the selection of parameters, Particle Swarm Optimization (PSO) is introduced to find the optimal parameters. In this paper, small sample and nonlinear data are used to predict fatalities of traffic accident. Traffic accident statistics data of China from 1981 to 2012 are chosen as experimental data. The input variables for predicting accident are highway mileage, vehicle number and population size while the output variables are traffic fatality. To verify the validity of the proposed prediction method, the back-propagation neural network (BPNN) prediction model and SVM prediction model are also used to predict the traffic fatalities. The results show that compared with BPNN prediction model and SVM model, the prediction model of traffic fatalities based on PSO-SVM has higher prediction precision and smaller errors. The model can be more effective to forecast the traffic fatalities. And the method using particle swarm optimization algorithm for parameter optimization of SVM is feasible and effective. In addition, this method avoids overcomes the problem of “over learning” in neural network training progress.
Źródło:
Archives of Transport; 2016, 39, 3; 21-30
0866-9546
2300-8830
Pojawia się w:
Archives of Transport
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of accuracy of simple methods for design and analysis of a blazed phase grating microstructure
Autorzy:
Wang, W.
Jing, X.
Zhao, J.
Li, Y.
Tian, Y.
Powiązania:
https://bibliotekanauki.pl/articles/173533.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
grating
effective medium theory
scalar diffraction theory
Opis:
In order to precisely analyze and design the transmittance characteristics of a blazed grating, the validity of both the scalar diffraction theory and the effective medium theory is quantitatively demonstrated. By making a comparison of diffraction efficiencies calculated by the two simplified methods and Fourier modal method, the accuracy can be obtained. It is found that when the normalized period is more than three wavelengths of the incident light, the scalar diffraction theory is useful to calculate the transmittance of the blazed grating within the error of less than 3%. The validity of the scalar diffraction theory increases when the normalized period increases. Importantly, by considering the Fresnel reflection effect, the validity of scalar diffraction theory can be significantly enhanced. Furthermore, when no higher-order diffraction waves appear and only zeroth order diffraction wave propagates, the effective medium theory is accurate to compute the diffraction efficiency within the difference of less than 1% between the zeroth order effective medium theory and Fourier modal method. The polarization characteristics of the validity of effective medium theory are also quantitatively demonstrated. The validity of the two simplified theories is dependent on not only the normalized period of surface microstructure but also the normalized groove depth.
Źródło:
Optica Applicata; 2017, 47, 2; 183-198
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vertical transmission of PCV2b to fetuses in sows intramuscularly infected with PCV2b
Autorzy:
Wang, N.D.
Li, J.J.
Wang, A.B.
Zhu, Z.
Chang, Y.
Mao, Y.
Zan, Y.
Wang, Z.F.
Deng, Z.B.
Powiązania:
https://bibliotekanauki.pl/articles/31535.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
In order to investigate whether PCV2b can be transmitted across the placenta in sows thereby causing vertical infection of fetuses, six sows in 75 day of pregnancy were either intramuscularly inoculated with a PCV2b culture supernatant (n = 4) or mock infected with cell culture supernatant (n = 2). At parturition, 3 newborn piglets from each litter were randomly selected and euthanatized prior to suckling. Samples of the mesenteric lymph nodes, spleens, kidneys, hearts and lungs were collected for PCR, histopathological and immunohistochemical assays. The results showed that the newborn piglets from PCV2b-infected sows had histopathological lesions in the tested tissues. Moreover, PCV2b antigen and DNA were detected as well. These findings therefore suggested that porcine circovirus type 2b can be transmitted across the placenta of sows, thereby leading to PCV2b vertical infection of the fetuses.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 3
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Molecular cloning, recombinant expression, and purification of osteocalcin in sika deer (Cervus nippon) antler
Autorzy:
Li, X.
Liu, M.
Bai, X.
Li, Y.
Zhao, Y.
Wang, S.
Wang, J.
Powiązania:
https://bibliotekanauki.pl/articles/2087587.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cervus nippon
osteocalcin
molecular cloning
expression
purification
Źródło:
Polish Journal of Veterinary Sciences; 2019, 1; 143-150
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Enzymatic Polishing and Reactive Dyeing of Cotton Fabric in One Bath
Enzymatyczne polerowanie i reaktywne barwienie bawełnianych tkanin w systemie stosowania jednej kąpieli
Autorzy:
Wang, P.
Hong, Y.
Ding, Y.
Cui, L.
Yuan, J.
Wang, Q.
Fan, X.
Powiązania:
https://bibliotekanauki.pl/articles/232210.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
cotton fabric
neutral cellulase
reactive dye
one-bath method
colour strength
tkanina bawełniana
celulaza
reaktywne barwienie
metoda jednej kąpieli
siła koloru
Opis:
Cellulase has the ability to remove fuzz-fibres from cellulosic textiles, which endows fabric with a glabrous appearance and soft handle. In this paper, the combined uses of bio-polishing and reactive dyeing in one bath were carried out, aiming at shortening the treatment time and reducing the overall consumption of water and energy as well. The properties of cotton fabrics before and after the combined treatments were investigated, including the colour strength, colour fastnesses and tearing strength. The results indicated that the colour fixing agent of soda had noticeable inhibiting effects on cellulase activity. Meanwhile reactive dyes might react with cellulase proteins under alkaline conditions, resulting in decelerating influences on the dye-fibre covalent reactions. The acceptable one-bath process consisted of bio-polishing and dyeing of cotton in neutral solution, followed by dye fixation under alkaline conditions. Compared to polishing and dyeing in two baths, the one-bath method endowed fabric with a bit lower colour strength.
Celulaza ma zdolność do usuwania włosków zmechacenia z tekstyliów celulozowych, co pozwala na osiągnięcie gładkiej powierzchni o delikatnym chwycie. W pracy badano sumaryczny efekt biopolerowania i reaktywnego barwienia przeprowadzanych w jednej kąpieli. Metoda ta ma na celu skrócenie czasu obróbki i zredukowanie ogólnego zapotrzebowania na wodę i energię. Badano właściwości tkanin bawełnianych przed i po obróbce. Między innymi badano nasycenie kolorem, trwałość koloru i wytrzymałość na rozrywanie. Wyniki wskazują, że soda jako środek utrwalający kolor ma zauważalny wpływ na hamowanie działania celulazy. Porównując metodę równoczesnego polerowania i barwienia z metodą, gdzie obydwie obróbki stosowane są indywidualnie stwierdzono, że w metodzie równoczesnej obróbki uzyskuje się nieco niższe nasycenie koloru.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 1 (109); 109-113
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Emergence and complete genome of Senecavirus A in pigs of Henan Province in China, 2017
Autorzy:
Wang, H.B.
Tian, B.
Lv, H.L.
Wang, F.
Zhang, T.
Wang, C.Y.
Zhang, Y.D.
Dong, J.J.
Powiązania:
https://bibliotekanauki.pl/articles/2087575.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Senecavirus A
vesicular disease
phylogenetic analysis
Źródło:
Polish Journal of Veterinary Sciences; 2019, 1; 187-190
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermodynamic and Electronic Properties of $OsB_2$ from First-Principles Calculations
Autorzy:
Cheng, Y.
Yang, J.
Wang, Y.
Ji, G.
Chen, X.
Powiązania:
https://bibliotekanauki.pl/articles/1365243.pdf
Data publikacji:
2014-05
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.15.Mb
61.50.Ks
67.25.de
71.20.-b
Opis:
The pressure induced phase transitions of $OsB_2$ from the orthorhombic structure (Orth) to the hexagonal structure (Hex) is investigated by using ab initio plane-wave pseudopotential density functional theory, together with quasi-harmonic Debye model. We find that the pressure-induced phase transition occurs at 2.8 GPa and 12.5 GPa by local density approximation and general gradient approximation, respectively. It is predicted that $OsB_2$ has no phase transition temperature from the Orth structure to the Hex structure. Moreover, the dependences of the relative volume V/$V_0$ on the pressure, thermal expansion coefficient α on the pressure and temperature are also successfully obtained. The electronic properties including energy band, total and partial density of states and electron density difference for two structures are also analyzed. The Mulliken charges and Bond populations for both Orth and Hex structures are also obtained.
Źródło:
Acta Physica Polonica A; 2014, 125, 5; 1186-1190
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of a 20 kJ Sparker for High Resolution Ocean Seismic Survey
Autorzy:
Sun, Y.
Gao, Y.
Yan, P.
Wang, J.
Yuan, W.
Wu, H.
Wang, Y.
Wan, P.
Zhao, G.
Powiązania:
https://bibliotekanauki.pl/articles/1807914.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.80.Wq
43.30.+m
Opis:
An ocean sparker with a stored energy of 20 kJ was developed for high resolution ocean seismic survey. The sparker is mainly composed of a high voltage high frequency charging supply, energy storage capacitors, a discharging switch and discharging electrodes. The H-bridge inverter and series resonant mode were adopted in the charging supply, and a dry high voltage transformer was used to improve the safety and maintenance, the average charging rate exceeded 4 kJ/s. An optical fiber connected between the high voltage system and the control system was used to isolate high voltage and transmit the high voltage signal. The high voltage electrodes of the discharging electrodes consisted of several hundreds of electrodes. The experimental results show that the sparker can be operated at repetition rates of 12 shots/min, and can meet the expected design requirements. Further field tests will be done in the near future.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1059-1061
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Health index synthetization and remaining useful life estimation for turbofan engines based on run-to-failure datasets
Synteza wskaźników stanu technicznego oraz ocena pozostałego okresu użytkowania silników turbowentylatorowych z wykorzystaniem zbiorów danych o pracy do czasu uszkodzenia
Autorzy:
Shi, J.
Li, Y.
Wang, G.
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/301447.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
hierarchical clustering
relevance vector machine
run-to-failure
remaining useful life
health indices
prognostics
grupowanie hierarchiczne
maszyna wektorów istotnych
praca do czasu uszkodzenia
pozostały okres użytkowania
wskaźnik stanu technicznego
prognostyka
Opis:
Turbofan engines will gradually degrade until failure occurs or life ends if without maintenance. Reliable degradation assessment and remaining useful life (RUL) estimation make sense on both aviation safety and rational maintenance decisions. This paper proposes a data-driven prognostic method on the premise of run-to-failure (RtF) data which are multivariate sensory data collected from the engines operating from normal to failure. After necessary pre-processing to the data, clustering analysis is executed to generate the clusters which represent the multi-states of the degradation process. The failure state cluster is extracted, and then the distance between the pre-processed data and the cluster is calculated. Therefore, one-dimensional time series are generated and defined as the health indices. Afterwards the degradation models are built based on the health indices. Finally, the RUL of a testing unit can be estimated by similarity analysis with the models. Hierarchical clustering (HC) and relevance vector machine (RVM) are the main algorithms employed in this paper. To validate the proposition, a case study is performed on turbofan engines data from Prognostics Center of Excellence (PCoE) at NASA Ames Research Center, and sufficient comparisons were given.
Silniki turbowentylatorowe niepoddane konserwacji ulegają stopniowej degradacji aż do czasu wystąpienia uszkodzenia lub zakończenia cyklu życia. Rzetelna ocena degradacji oraz pozostałego okresu użytkowania (RUL) mają wpływ zarówno na bezpieczeństwo maszyn lotniczych jak i racjonalne podejmowanie decyzji dotyczących utrzymania ruchu. W artykule zaproponowano sterowaną danymi metodę prognostyczną opartą na danych o pracy do czasu uszkodzenia (run-to failure, RTF), które są wielowymiarowymi danymi sensorycznymi zbieranymi podczas normalnej pracy silnika aż do jego uszkodzenia. Po niezbędnej wstępnej obróbce danych, przeprowadzono analizę skupień w celu wygenerowania skupień reprezentujących multi-stany procesu degradacji. Wyodrębniono klaster stanów uszkodzenia, a następnie obliczono odległość między wstępnie przetworzonymi danymi a wyodrębnionym klastrem. Następnie wygenerowano jednowymiarowe szeregi czasowe, które zdefiniowano jako wskaźniki stanu technicznego. Na podstawie tych wskaźników zbudowano modele degradacji. Wreszcie, w oparciu o analizę podobieństwa do opracowanych modeli oceniono RUL jednostki testowej. Główne algorytmy zastosowane w niniejszym opracowaniu to algorytmy grupowania hierarchicznego (HC) oraz maszyny wektorów istotnych (RVM). Aby zweryfikować zaproponowaną w pracy metodę, przeprowadzono studium przypadku z wykorzystaniem danych dot. silników turbowentylatorowych pochodzące z Prognostic Center of Excellence (PCoE) przy NASA Ames Research Center oraz przedstawiono odpowiednie porównania.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 4; 621-631
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integrated decision on spare parts ordering and equipment maintenance under condition based maintenance strategy
Zintegrowany system decyzyjny dotyczący zamawiania części zamiennych i utrzymania ruchu urządzeń w ramach strategii utrzymania zależnej od bieżącego stanu technicznego
Autorzy:
Wang, Y.
Zhao, J.
Cheng, Z.
Yang, Z.
Powiązania:
https://bibliotekanauki.pl/articles/301823.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
spare parts
inventory control
ordering
condition based maintenance
Monte Carlo simulation
części zamienne
kontrola zapasów
zamówienia
utrzymanie zależne od bieżącego stanu technicznego
symulacja Monte Carlo
Opis:
Aiming to optimize the equipment maintenance and the spare parts ordering management jointly, a comprehensive decision model under condition based maintenance (CBM) policy is presented for a single equipment system with continuous and random deterioration. In this model, the equipment deterioration is a continuous Gamma process under a continuous condition monitoring, and the spare parts inventory is controlled by spare parts support probability. Firstly, a spare part support probability model was developed to determine the optimal spare parts stock level S, which is set to meet the requirement of a predetermined stockout probability. Secondly, the equipment replacement and spare parts ordering decision is made to optimize the equipment replacement and spare parts ordering jointly, which is based on the equipment deterioration leveland total operating cost of the system. Thirdly, an integrated decision simulation model is presented for evaluating cost rate, availability and stockout probability. Finally, a numerical example is given to illustrate the performance of this model. The results show that the optimal preventive maintenance threshold obtained from the proposed decision model can satisfy the spare parts support requirements under (S-1, S) inventory control strategy.
Dążąc do jednoczesnej optymalizacji utrzymania ruchu urządzeń i zarządzania zamówieniami części zamiennych, zaproponowano kompleksowy model decyzyjny w ramach strategii utrzymania zależnej od bieżącego stanu technicznego (CBM) przeznaczony dla systemów z pojedynczym urządzeniem i ciągłym oraz losowym zużyciem. W niniejszym modelu, zużycie urządzenia jest ciągłym procesem Gamma z ciągłym monitorowaniem stanu, podczas gdy zapasy części zamiennych są kontrolowane poprzez prawdopodobieństwo wsparcia w zakresie części zamiennych. Po pierwsze, opracowano model prawdopodobieństwa wsparcia w zakresie części zamiennych w celu określenia optymalnego poziomu zapasów części zamiennych S, ustalonej aby spełnić wymogi określonego prawdopodobieństwa braku dostępności. Po drugie, przeprowadzono proces decyzyjny dotyczący wymiany urządzenia i zamawiania części zamiennych w celu jednoczesnej optymalizacji wymiany urządzenia i zamawiania części zamiennych, w oparciu o poziom zużycia urządzenia i całkowity koszt działania systemu. Po trzecie, zaprezentowano zintegrowany symulacyjny model decyzyjny dla oceny poziomu kosztów, dostępności i prawdopodobieństwa jej braku. Zasady niniejszego modelu zilustrowano przykładem numerycznym. Wyniki pokazują, że optymalny próg konserwacji zapobiegawczej uzyskany za pomocą proponowanego modelu decyzyjnego może spełnić wymagania dotyczące części zamiennych w ramach (S-1, S) strategii kontroli zapasów.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 4; 591-599
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Renewable warranty policy for multiple-failure-mode product considering different maintenance options
Polityka odnawiania gwarancji dla produktówo mnogich przyczynach uszkodzeń uwzględniająca różne opcje obsługi
Autorzy:
Li, X.
Jia, Y.
Wang, P.
Zhao, J.
Powiązania:
https://bibliotekanauki.pl/articles/301949.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
multiple failure modes
renewing warranty
preventive maintenance
warranty cost
product availability
upgrading maintenance
mnogie przyczyny uszkodzeń
odnowienie gwarancji
obsługa profilaktyczna
koszty gwarancji
gotowość produktu
konserwacja modernizacyjna
Opis:
Along with the advancement of manufacturing techniques, the quality of the spares for product is likely to be improved during the warranty period. There can be two types of spares, i.e. low-quality spares and high-quality spares for replacement maintenance. And the manufacturers (customers) may have to decide whether or not to provide (buy) the warranty considering upgrading maintenance. This paper presents a renewing warranty policy considering three maintenance options for products with multiple failure modes. The cost and availability models of these maintenance options are proposed. Of these options, upgrading maintenance is taken into account with the assumption that the warrantied item will be upgraded one time during the warranty cycle. After upgrading maintenance, the high-quality spares are used to replace the failed item. By minimizing the ratio between cost and availability of the product, the optimal upgrading opportunity is obtained. In the numerical example, the results of these options are presented. Monte Carlo simulation results are compared with the analytical results to demonstrate the correctness and efficiency of the proposed models considering upgrading maintenance. The renewing warranty policy considering upgrading maintenance policy is compared with the one without considering upgrading maintenance. The results show that the former is better than the latter in some cases. The sensitivity of the cost model and availability model to different parameters is analyzed at last.
Wraz z postępem techniki produkcji, wzrasta prawdopodobieństwo, że jakość części zamiennych do produktu ulegnie poprawie w przeciągu okresu gwarancyjnego. Istnieją dwa rodzaje części zamiennych: części zamienne niskiej i wysokiej jakości. Producenci (klienci) mogą być zmuszeni podjąć decyzję czy objąć produkt gwarancją (wykupić gwarancję) zapewniającą konserwację modernizacyjną. W artykule przedstawiono politykę odnawiania gwarancji z uwzględnieniem trzech różnych opcji obsługi produktów narażonych na mnogie przyczyny uszkodzeń. Zaproponowano modele kosztów i gotowości dla omawianych opcji obsługi. Spośród badanych opcji, do dalszej analizy wybrano konserwację modernizacyjną zakładającą, że element podlegający gwarancji zostanie poddany jednokrotnej modernizacji podczas cyklu gwarancyjnego. Po wykonaniu konserwacji modernizacyjnej, uszkodzony element zastępuje się częściami zamiennymi wysokiej jakości. Minimalizując stosunek kosztów do gotowości produktu, uzyskuje się optymalną możliwość modernizacji Przykład numeryczny przedstawia wyniki uzyskane dla omawianych opcji. Wyniki symulacji Monte Carlo porównano z wynikami analitycznymi w celu wykazania prawidłowości i efektywności proponowanych modeli uwzględniających konserwację modernizacyjną. Politykę odnawiania gwarancji uwzględniającą konserwację modernizacyjną porównano z polityką, która takiej konserwacji nie uwzględnia. Wyniki pokazują, że pierwsza z tych opcji jest w niektórych przypadkach korzystniejsza od drugiej. Badania wieńczy analiza czułości modelu kosztów i modelu gotowości na różne parametry.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 4; 551-560
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-Objective Optimization of Acoustical Properties of PU-Bamboo-Chips Foam Composites
Autorzy:
Jiang, Y.
Chen, S.
Wang, D.
Chen, J.
Powiązania:
https://bibliotekanauki.pl/articles/177709.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
vehicle sound package
sound absorption coefficient
transmission loss
Taguchi method
Opis:
In this study, an effective optimization approach was proposed to improve acoustical behaviors of PU foams. The important parameters of PU foams: content of water, silicone oil and catalyst A1 were chosen and their effects on sound absorption coefficient and transmission loss of PU foams were studied by using Taguchi methods. In addition, bamboo chips were incorporated into PU foams as fillers to improve the acoustical properties of PU foams. Four controlled factors: the content of water, silicone oil, catalyst A1 and bamboo chips with three levels for each factor were chosen and Taguchi method based on orthogonal array L9 (34) was employed to conduct the experiments. Based on the results of Taguchi’s orthogonal array L9 (34), signal-to noise (S/N) analysis was used and developed to determine an optimal formulation of PU-bamboo-chips foam composites.
Źródło:
Archives of Acoustics; 2017, 42, 4; 707-714
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Fluorescence Characteristic of a Complex Probe οf CdSe Quantum Dots Coupling with Thiazole Orange
Autorzy:
Fei, X.
Jia, G.
Wang, J.
Gu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/1537765.pdf
Data publikacji:
2010-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.63.Kv
78.55.-m
78.67.-n
Opis:
CdSe quantum dots were synthesized using thioglycolic acid as stabilizer in aqueous solution under $N_{2}$. The UV-vis spectrometry and fluorescence spectra indicate that the bimodal quantum dots were formed and the optical band gaps are about 650 nm and 750 nm, respectively. The quantum dots coated with TO were prepared in room temperature, and the fluorescence characteristic was studied. The result showed that the peak shift of quantum dots fluorescence spectra can mainly be due to the change of the capping layer, resulting in the confinement energy change. This is vital for the investigating on of the forming process and mechanisms of the combination of thiazole orange dye and quantum dots.
Źródło:
Acta Physica Polonica A; 2010, 117, 6; 949-952
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Compositions of Al-Based Quasicrystals Interpreted by Cluster Formulae
Autorzy:
Chen, H.
Qiang, J.
Wang, Y.
Dong, C.
Powiązania:
https://bibliotekanauki.pl/articles/1372748.pdf
Data publikacji:
2014-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.44.Br
36.40.-c
71.20.Lp
Opis:
It is known previously that bulk metallic glass compositions satisfy cluster formulae $[cluster](glue atom)_{1, 3}$ of 24 valence electrons as deduced from our cluster-resonance model. In the present work, it is further shown that compositions of Al-based binary and ternary quasicrystals are also explained by 24-electron cluster formulae of the types $[icosahedron](glue atom)_{0, 1}$, where the icosahedral cluster is identified from a corresponding crystalline approximant according to dense atomic packing and cluster isolation criteria, and the glue atom site is either vacant for an icosahedral quasicrystal or equal to one for a decagonal quasicrystal. Ternary quasicrystals are formulated with the same formulae as their basic binary ones but the icosahedron shell sites are substituted by third elements. The 24-electron cluster formulae are then the chemical and electronic structural units of quasicrystals, mimicking the molecular formulae of chemical substances.
Źródło:
Acta Physica Polonica A; 2014, 126, 2; 446-448
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Orchards on Eroded Uplands of Southeast China: Sustainability or Abandonment?
Sady na zerodowanych wyżynach płd.-wsch. Chin: zrównoważoność czy problem?
Autorzy:
Wang, C.
Yang, Y.
Pang, W.
Hong, J.
Powiązania:
https://bibliotekanauki.pl/articles/371226.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Komitet Człowiek i Środowisko PAN
Tematy:
soil erosion
rural livelihoods
sustainability
cost benefit analysis
China
erozja gleb
poziom życia rolników
zrównoważoność
analiza kosztów i korzyści
Chiny
Opis:
Orchard development on eroded uplands is considered as a successful method in integrating soil erosion treatment with economic development in many developing countries. However, much attention focused on its present achievements without thinking over the economic viability over long plantation duration. Orchards that have not been intensified seem to be threatened by complete abandonment. To illustrate the economic viability and sustain-ability of orchard management, we have deliberately focused on a case study in Southeast China. The results of economic viability based on a cost-benefit analysis showed that orchard management was barely economically sustainable. Their viability is assured if reduced labor costs and increased fruit price are accepted. Based on these results, recommendations are made to prevent the abandonment of orchards on degraded uplands and to preserve its environmental benefits.
Tworzenie sadów na zerodowanych wyżynach w wielu krajach rozwijających się jest traktowane jako metoda udanie łączącą zintegrowane przeciwdziałanie erozji gleb z rozwojem ekonomicznym. Niestety, zbyt mocno podkreśla się znacznie szybkich osiągnięć, bez rozważania kontekstu wieloletniej opłacalności takich działań. Sady, których nie poddano modyfikacjom, opuszczono. By zilustrować ekonomiczną sensowność i zrównoważoność zarządzania sadami, wybrano jako case study obszar płd.-wsch. Chin. Rezultaty oceny opartej na analizie kosztów i korzyści wykazały, że zarządzanie sadami okazuje się być słabo ekonomicznie zrównoważone. Opłacalność zostałaby zapewniona w przypadku obniżenia kosztów pracy i podniesienia cen owoców. Na podstawie przeprowadzonych badań przedstawiono rekomendacje, których uwzględnienie umożliwiłoby zaprzestanie procederu rezygnacji z prowadzenia sadów na terenach zdegradowanych wyżyn i utrzymanie korzyści środowiskowych.
Źródło:
Problemy Ekorozwoju; 2016, 11, 2; 37-43
1895-6912
Pojawia się w:
Problemy Ekorozwoju
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Process Model of Building Sustainable Competitive Advantage for Multinational Enterprises:An Empirical Case Study
Model procesu budowania zrównoważonej przewagi konkurencyjnej dla przedsiębiorstw międzynarodowych:studium przypadku
Autorzy:
Shan, M.
You, J.
Wang, Y.
Liu, H.
Powiązania:
https://bibliotekanauki.pl/articles/371328.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Komitet Człowiek i Środowisko PAN
Tematy:
multinational enterprises
MNEs
corporate social responsibility
corporate environmental behavior
corporate legitimacy
sustainable development
przedsiębiorstwo międzynarodowe
społeczna odpowiedzialność biznesu
wpływ biznesu na środowisko
legalność biznesu
rozwój zrównoważony
Opis:
Multinational enterprises (MNEs) are the leading entities in the process of global economic integration, whose international expansion would be regulated and constrained by environmental issues. Drawing on theories of corporate social responsibility, corporate environmental behavior and legitimacy, this paper establishes a grounded process model that has both theoretical and practical significance. The model reveals that development of sustainable competitive advantage of MNEs is a gradual process that is dependent on the corporate environmental behavior and the legitimation of their behaviors. Via a real in-depth case study of Badische Anilin-Soda-Fabrik (BASF), one of the largest chemical companies in the world, the application and effectiveness of the proposed process model are demonstrated. Also, implications of this model and future directions for both research and practice are indicated.
Przedsiębiorstwa międzynarodowe stanowią wiodące podmioty w procesie globalnej integracji gospodarczej, których ekspansja międzynarodowa powinna uwzględniać regulacje i ograniczenia związane z ochrona środowiska. Niniejszy artykuł, opierając się na teorii społecznej odpowiedzialności biznesu, jego wpływowi na środowisko i legalności działania, przedstawia model istotny zarówno z poziomu teorii, jak i praktyki. Model ten pokazuje, że budowanie zrównoważonej przewagi konkurencyjnej przedsiębiorstw międzynarodowych jest procesem stopniowym, zależnym od podejścia do środowiska. Zastosowanie i skuteczność proponowanego modelu wykazano na przykładzie jednego z największych zakładów chemicznych na świecie, którym jest Badische Anilin-Soda-Fabrik (BASF). Zaproponowano także przyszłe kierunki badań, tak w kontekście naukowym, jak i praktycznym.
Źródło:
Problemy Ekorozwoju; 2015, 10, 1; 67-78
1895-6912
Pojawia się w:
Problemy Ekorozwoju
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Convergence Analysis of Inverse Iterative Neural Networks with L₂ Penalty
Autorzy:
Wen, Y.
Wang, J.
Huang, B.
Zurada, J. M.
Powiązania:
https://bibliotekanauki.pl/articles/108754.pdf
Data publikacji:
2016
Wydawca:
Społeczna Akademia Nauk w Łodzi
Tematy:
neural networks
gradient descent
inverse iterative
monotonicity
regularization
convergence
Opis:
The iterative inversion of neural networks has been used in solving problems of adaptive control due to its good performance of information processing. In this paper an iterative inversion neural network with L₂ penalty term has been presented trained by using the classical gradient descent method. We mainly focus on the theoretical analysis of this proposed algorithm such as monotonicity of error function, boundedness of input sequences and weak (strong) convergence behavior. For bounded property of inputs, we rigorously proved that the feasible solutions of input are restricted in a measurable field. The weak convergence means that the gradient of error function with respect to input tends to zero as the iterations go to infinity while the strong convergence stands for the iterative sequence of input vectors convergence to a fixed optimal point.
Źródło:
Journal of Applied Computer Science Methods; 2016, 8 No. 2; 85-98
1689-9636
Pojawia się w:
Journal of Applied Computer Science Methods
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vibrational Properties of Sundatang Soundboard
Autorzy:
Batahong, R. Y.
Dayou, J.
Wang, S.
Lee, J.
Powiązania:
https://bibliotekanauki.pl/articles/176904.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sundatang
frequency response function
impact testing
mode shape
Opis:
This paper presents the measurement of vibrational properties of sundatang soundboard. Sundatang is a plucked stringed traditional musical instrument that is popular among the Kadazandusun communities in Sabah, Malaysia. The vibrational properties of the soundboard are measured using CADA-X impact hammering system in a condition where the instrument is without any string. There are two types of sundatang used in this study; one made from acacia and the other from vitex wood. In this measurement, frequency response functions (FRFs) and modal parameters of the top plate and back plate of this instrument are obtained. It is found that in free edge, fundamental frequency of both plates of acacia sundatang is greater than the vitex sundatang in a range of 112 Hz to 230 Hz. However, in clamped edge (attached to its ribs), it was modified to a lower frequency and closer to each other in the range of 55 Hz to 59 Hz. Another finding is the detection of the excitation of similar mode shape at different resonance frequencies. This phenomenon is termed as Different State of Mode (DSM) which is observed may be because the number of testing points is not enough. Findings of this study provide important information to the study of quality development of this instrument.
Źródło:
Archives of Acoustics; 2014, 39, 2; 177-187
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Early Cambrian origin of thylacocephalan arthropods
Autorzy:
Vannier, J
Chen, J.Y.
Huang, D.Y.
Charbonnier, S.
Wang, X.Q.
Powiązania:
https://bibliotekanauki.pl/articles/23320.pdf
Data publikacji:
2006
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
fauna
thylacocephalan arthropod
Lagerstatte
Zhenghecaris shankouensis
China
arthropod
Arthropoda
Early Cambrian
Cambrian
paleontology
Opis:
Zhenghecaris shankouensis gen. et sp. nov. is one of the largest “bivalved” arthropods of the Lower Cambrian Maotianshan Shale fauna. Its non−mineralized carapace was dome−like, laterally compressed, armed with rostral features, and probably enclosed the entire body of the animal. Zhenghecaris was provided with elliptical stalked lateral eyes. The carapace design, external ornament and visual organs of Zhenghecaris suggest affinities with the Thylacocephala, an extinct (Lower Silurian to Upper Cretaceous) group of enigmatic arthropods whose origins remain poorly understood. The bivalved arthropodsIsoxys and Tuzoia (Lower and Middle Cambrian) are two other potential thylacocephalan candidates making this group of arthropods a possible new component of Cambrian marine communities. Zhenghecaris, Isoxys, and Tuzoia are interpreted as nektonic animals that probably inhabited the lower level of the water column in shallow shelf settings at depths of perhaps 100–150 m or less. Their feeding mode either in the water column (e.g., mesozooplankton) or on the substrate (e.g., small epibenthos, detritus) is uncertain, although some of these arthropods were possibly mid−water predators (e.g., Isoxys with raptorial appendages).
Źródło:
Acta Palaeontologica Polonica; 2006, 51, 2
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption behavior of surfactants on lignite particles with different densities in aqueous medium
Autorzy:
Wang, J.
He, Y.
Wen, B.
Ling, X.
Xie, W.
Wang, S.
Powiązania:
https://bibliotekanauki.pl/articles/110538.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
interfacial surface free energy
adsorption
lignite
surfactant
Washburn equation
Opis:
Lignite is well known for its strong hydrophilicity and hard-to-float properties. However, the surface free energy of the solid is made up of two components, that is the Lifshitz-van der Waals and acid-base interaction energy. Differences in these two components between the low ash (lower density) and high ash fraction (higher density) provide a benefit for improving the separation efficiency through introducing surfactants in flotation. In this paper, thermodynamic characterization of three density lignite fractions was measured by a Washburn dynamic method. Combining the Washburn equation and Van Oss-Chaudhury-Good theory, the surface free energy components of three samples were calculated according to the wetting process by n-hexane, diiodomethane, deionized water and ethylene glycol. The Lifshitz-van der Waals part of surface free energy reduced with the coal density increase, especially between fractions of -1.45 g/cm3 and 1.45-1.80 g/cm3, while the Lewis base part increased slightly. The interfacial interaction free energies between the surfactant and lignite in aqueous medium indicated that the low hydrophilic index benefited for the stronger adsorption intensity. Increase of the surfactant Lifshitz-van der Waals component increases the adsorptive intensity on lower density lignite and the repulsive intensity on higher density lignite, which is beneficial for separation.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 996-1008
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Filtration approach to mitigate indoor thoron progeny concentration
Autorzy:
Wang, J.
Meisenberg, O.
Chen, Y.
Karg, E.
Tschiersch, J.
Powiązania:
https://bibliotekanauki.pl/articles/148751.pdf
Data publikacji:
2010
Wydawca:
Instytut Chemii i Techniki Jądrowej
Tematy:
filtration
thoron progeny
potential alpha energy concentration (PAEC)
equilibrium equivalent concentration (EEC)
mitigation
Opis:
This study investigates filtration of air as potential mitigation method of thoron progeny exposure. The experiments were conducted in a model room (volume 7.1 m3) which was equipped with a pump and an HEPA (high efficiency particulate air) filter. Filtration at a rate of 0.2, 0.4, 0.5 and 0.8 h–1 during 88 h proved an effective practice in reducing the total indoor thoron decay product concentration. The results indicate that 0.4–0.8 h–1 filtration rate had almost the same filtration efficiency in decreasing the total thoron EEC (equilibrium equivalent concentration) by 97 per cent while 80 per cent of total thoron EEC were reduced by 0.2 h–1 filtration rate; meanwhile, the unattached thoron EEC rose significantly by 190, 270, 290 per cent, respectively under 0.4–0.8 h–1 filtration rate, whereas 0.2 h–1 filtration rate increased unattached thoron EEC by 40 per cent. The aerosol number size distribution variation reveals that filtration operation removes smaller particles faster or earlier than the larger ones. The annual effective dose calculated was reduced by 91–92 per cent at a filtration rate of 0.4–0.8 h–1 while 75 per cent reduced at 0.2 h–1 filtration rate after 88 h filtration process.
Źródło:
Nukleonika; 2010, 55, 4; 445-450
0029-5922
1508-5791
Pojawia się w:
Nukleonika
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel in-phase disposition SPWM pulse allocation strategy for cascaded H-bridge inverter
Autorzy:
Zhang, Y.
Xiong, J.
Kong, L.
Wang, X.
Powiązania:
https://bibliotekanauki.pl/articles/141155.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
in-phase disposition SPWM
Inverter
CHB
THD
Opis:
A novel in-phase disposition (IPD) SPWM pulse allocation strategy applied to a cascaded H-bridge (CHB) converter is presented in this paper. The reason causing the power of the CHB converter imbalance is analyzed according to the traditional structure, the conception of power imbalance degree is introduced and the principle of the novel in-phase disposition SPWM allocation strategy is deduced in detail. The new pulse allocation scheme can ensure the power balance in 3/4 cycles through interchanging the PWM pulse sequence of the different CHB cell, meanwhile it makes the full advantage of the IPD control strategy, lower the total harmonic distortion (THD) of line voltage compared to a carrier phase shifted (CPS) control strategy, which is verified by theoretical derivation. A seven-level cascaded inverter composed by three H-bridge cells is taken as the example. The simulation and experiment is performed. The results indicate the validity of the analysis and verify the effectiveness of the proposed SPWM allocation strategy.
Źródło:
Archives of Electrical Engineering; 2018, 67, 2; 361--375
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On a method to authenticate and verify digital streams
Autorzy:
Wysocki, B.J.
Wang, Y.
Safavi-Naini, R.
Powiązania:
https://bibliotekanauki.pl/articles/309279.pdf
Data publikacji:
2002
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
authentication algorithms
hash chains
signing digital streams
Markov modelling
Gilbert-Elliott channels
Opis:
Recently, digital streams have become widely used to make audio, video, and other media available in real-time over the Internet. As with other transmission methods, the recipient needs to have a possibilty to verify the source and authenticity of the received information. Several techniques have been proposed to deal with this issue. Most of them are vulnerable to packet losses or they introduce unacceptable computational and/or communication overheads. Some of the graph-based techniques provide immunity to burst losses of certain length. However, these techniques are not immune to the loss of packets containing signatures or occasional burst of lengths greater than the assumed one. In the paper, we propose a modification to one of the graph-based techniques that introduces immunity to the loss of packets containing signatures, without introducing any additional overheads.
Źródło:
Journal of Telecommunications and Information Technology; 2002, 2; 45-52
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical Prosperities of Ag-ZnO Composition Nanofilm Synthesized by Chemical Bath Deposition
Autorzy:
Wang, Y.
Yao, J.
Jia, G.
Lei, H.
Powiązania:
https://bibliotekanauki.pl/articles/1505423.pdf
Data publikacji:
2011-03
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Lm
78.66.Hf
78.55.Et
68.37.Hk
Opis:
Ag-ZnO composite thin films were prepared on glass substrates by chemical bath deposition at lower temperature. The samples were characterized by X-ray diffraction, scanning electron microscopy, photoluminescence and the optical transmission spectra. The morphology analysis showed that Ag nanoparticles were not deposited on the ZnO nanorods surface but on the glass substrate. The influence of the reaction time on the size and density of Ag nanoparticles was studied, the results showed that the reaction time played an important role in determining of the optical characteristics. There were two obvious photoluminescence peaks located at about 395 nm and 471 nm, respectively. The blue emission centered at 471 nm can be ascribed to the electron transition from $Zn_{i}$ to $V_{Zn}$.
Źródło:
Acta Physica Polonica A; 2011, 119, 3; 451-454
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modeling and experimental investigation of a controllable rotary fluid damper
Autorzy:
Cao, X.
Zhou, J.
Yu, M.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/38697102.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
controllable damper
rotary damper
parametric modeling
sensitivity analysis
damper design
Opis:
Controllable rotary fluid damper (CRFD) is an efficient and cheap energy dissipation device, which is used to reduce the impact of vibration in mechanical systems. In this paper, the CRFD controlled by a servo motor is developed to reduce the effects of vibrations in the helicopter flight control system. The dynamic mechanical characteristic of the CRFD is experimentally investigated by the MTS machine. Due to the complex factors such as high shear thinning rate and compressibility of the damping medium, inertia of moving parts and internal friction, the CRFD studied has highly nonlinear hysteresis characteristics. The accuracy of the damper modeling is of great significance for designing effective vibration reduction methods. Therefore, a new generalized viscous–nonlinear elastic model is proposed to track the mechanical characteristics of CRFD. On the basis of parameter sensitivity analysis, the proposed generalized viscous–nonlinear elastic model is modified. According to the identification results of the modified model, the main parameters are fitted as polynomial functions of motor rotation angle. Through error analysis between analytical torques and experimental torques, it is concluded that the modified generalized viscous–nonlinear elastic model has the smallest error compared with Kwok and Maxwell models, which indicates that the proposed modified model can accurately describe the mechanical characteristics of the CRFD under different working conditions.
Źródło:
Archives of Mechanics; 2023, 75, 4; 493-516
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the start-up of natural bio-film colonization of constructed rapid infiltration system
Autorzy:
Xu, W.
Yang, J.
Wang, J.
Jian, Y.
Tang, M.
Powiązania:
https://bibliotekanauki.pl/articles/259259.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Constructed Rapid Infiltration System
start-up of natural bio-film colonization
removal rate
COD
Opis:
Abstract: this paper studied the start-up of natural bio-film colonization under the conditions where wet-to-dry ratio was 1:6, hydraulic load was 0.8m3/m2·d, and water temperature was 100C-150C, it took 25d in total to become mature, after the success of bio-film colonization, the removal rate of COD and NH4+-N can be stabilized at 80%, and the removal rate of NH4+-N can reach 90% above. The microorganism was divided into the following stages during bio-film colonization:1. Reversible adhesion of cell on the surface of the carrier, 2.Irreversible adhesion of cell on the surface of the carrier, 3.Division of cell adhering to the surface of the carrier and formation of microcolony adhering to the surface of the carrier, 4.Growth of microcolony adhering to the surface of the carrier to be mature bio-film with three-dimensional structure. The process of natural bio-film colonization can be judged comprehensively according to removal rate of NH4+-N and COD, effluent pH as well as color of microbial film.
Źródło:
Polish Maritime Research; 2016, S 1; 32-35
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of recent coastline evolution due to marine reclamation projects in the Qinzhou Bay
Autorzy:
Yan, Y.
Zhang, Z.
Wang, C.
Zhang, L.
Huang, Y.
Zhang, J.
Powiązania:
https://bibliotekanauki.pl/articles/258862.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Qinzhou Bay
marine reclamation
remote sensing
geospatial analysis
coastline evolution
Opis:
Intense marine reclamation activities bring obvious benefits, meanwhile, these activities also influence the coastal natural formation, hydrodynamic processes and water environment etc. In order to investigate the exact influence in the Qinzhou Bay brought by marine reclamation behaviors in recent years, based on the remote sensing image data in the Qinzhou Bay in 2006, 2008, 2009, 2012 and 2014, with the help of GIS and RS software, the thesis interprets Qinzhou Bay coastline and artificial reclamation by man-machine interaction and makes quantitative analysis in the Qinzhou Bay coast evolution recently. The results show: (1) Qinzhou Bay coastal morphology change degree was strong in 2006 - 2012 and the coastline changed greatly. Originally part of the natural shore segments which had twists and turns were gradually filled into artificial coast, the coast constantly advanced to the sea, coastline became regular and straight; (2) The change degree of coastline was relatively small in 2006-2008, the average artificial coastline increased 8.86 km/a, the average artificial reclamation area was 20.79 km2 /a; in 2008-2012, the change range of coastline was the greatest, coastline changed most severely, the average artificial coastline increased 16.07 km/a, the average artificial reclamation area was 58.52 km2 /a; however, in 2012-2014, coastline change degree relatively slowed, the average artificial coastline increased 4.04 km per year, the average artificial reclamation area was 3.464 km2 /a. (3) Compared to the studies of predecessors, the innovation of this paper is that it is the first to carry out the detailed research on coastline evolution caused by reclamation engineerings of the Qinzhou Bay, then formed the change results on coastline that caused by intense human activities in the Qinzhou Bay, provided the area of the marine environment protection with full and accurate data.
Źródło:
Polish Maritime Research; 2017, S 2; 188-194
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of Magnetic Core in Magnetic Pulse Compression System
Autorzy:
Zhang, D.
Yan, P.
Sun, Y.
Wang, J.
Zhou, Y.
Pan, R.
Powiązania:
https://bibliotekanauki.pl/articles/1807880.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
07.05.Tp
42.65.Re
75.60.Ej
Opis:
In order to obtain the characteristics of magnetic core under ≈0.5-5 μs saturation time, a one-stage magnetic pulse compression circuit without external demagnetization circuits which are commonly used in magnetic compressors is designed. The current through the core is calculated by voltage across the resistive load, and the loop voltage is picked up with a single wire loop and integrated by software. B-H curves are derived from the measured voltage and current wave forms. B-H curves show that the core loss is in inverse proportion to the time to saturation, whereas the percentile core loss decreases as the charging energy increases. While the eddy current loss and dissipated energy are in direct proportion to dB/dt. The low inductance of magnetic switch indicates that the core is saturated and behaves as an air core. By applying custom characteristics to each stage in Pspice simulation, more practical energy transfer in magnetic pulse compression and the effects of leakage current are presented.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1001-1003
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental Study of Clothing Tactile Comfort Based on Electro-neurophysiology
Eksperymentalne badanie komfortu dotykowego odzieży na podstawie elektroneuro fizjologii
Autorzy:
Wang, Y
Zhao, M M
Yu, M
Li, J
Powiązania:
https://bibliotekanauki.pl/articles/231787.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
tactile
clothing
electromyography
electroencephalography
dotykowy comfort odzieży
elektromiografia
elektroencefalografia
Opis:
Electromyography (EMG) and electroencephalography (EEG) methods were used to evaluate the reaction of human skin to tactile stimuli evoked by textiles. The peak value of the EMG and energy percentage of the weave of the EEG when the subjects came into contact with 9 kinds of fabrics were selected for tests and next clothing was made on their basis. They were utilized as two important evaluating indexes. Statistical analysis was carried out to verify the correlation between the data obtained from objective measurements and the subjective measurements. The results showed that when the subjects came into contact with thicker, heavier and stiffer fabrics, the peak values of the myoelectric potential induced were higher. When clothing with a higher mass density was worn, energy percentages of the weave at both the left and right occipitalia were higher.
Dla oceny reakcji ludzkiej skóry na dotykowe stymulacje materiałami włóknistymi stosowano elektromiografię (EMG) i elektroencefalografie (EEG). Wartość szczytowa przebiegu EMG oraz procent energii fali EEG w czasie kiedy badane osoby znajdowały się w kontakcie z 9 rodzajami materiałów włókienniczych posłużyła do ich selekcji dla stosowanych testów. Na tej podstawie wykonano odzież przeznaczona dla osób testowanych. Przeprowadzono analizę statystyczna dla zweryfikowania korelacji pomiędzy wynikami uzyskanymi z obiektywnych pomiarów oraz subiektywnych testów. Wyniki wykazały, że kiedy osoby badane znajdowały się w kontakcie z grubszymi i cięższymi i sztywniejszymi materiałami to wartość piku EMG była wyższa. Kiedy ubranie wykonane było z udziałem przędz o wyższej masie liniowej procent energii fali lewej i prawej połówki potylicy był wyższy.
Źródło:
Fibres & Textiles in Eastern Europe; 2014, 4 (106); 102-106
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on the rheological properties of CL-20/HTPB casting explosives
Autorzy:
Li, H.-X..
Wang, J-Y.
An, C.-W.
Powiązania:
https://bibliotekanauki.pl/articles/358310.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
casting explosive
particle gradation
rheological properties
plasticizer
Opis:
The rheological properties of ε-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12hexaazaisowurtzitane (CL-20)/hydroxy-terminated polybutadiene (HTPB) casting explosives with different formulations were tested and analyzed. The effects of both the weight percentage (wt.%) of CL-20 and its particle size, as well as the type and content of plasticizers, on the rheological properties of CL-20/HTPB casting explosives were investigated in detail. The results show that the viscosity and pseudoplasticity of CL-20/HTPB casting explosives increase with increasing wt.% of CL-20 and decreasing particle size. The gradation of CL-20 particle size also affects the rheological properties of the casting explosives. When the mixing ratio of 30 μm to 2 μm particles is 3:1, the viscosity reaches its lowest value and the non-Newtonian index reaches the maximum value of 0.5698. The viscosity, non-Newtonian index and impact sensitivity of the samples studied are clearly decreased by the addition of dioctyl adipate (DOA), dioctyl sebacate (DOS) or dibutyl phthalate (DBP). However, the three plasticizers do not appear to affect the thermal decomposition of CL-20/HTPB casting explosives. With respect to the rheological properties, mechanical properties and sensitivity, DOA is the optimum plasticizer to use in CL-20/HTPB casting explosives.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 2; 237-255
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ground liquefaction and deformation analysis of breakwater structures under earthquakes
Autorzy:
Zhao, J.
Wang, Y.
Yun, G.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/258448.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
breakwater
seismic design
liquefaction
excessive pore pressure ratio
displacement
Opis:
Ground liquefaction and deformation is one of the important causes that damage engineering structures. Chinese current code for seismic design of breakwater is based on the single-level seismic design method as well as code for port and water-way engineering. However, this code can not exactly reflect the seismic performance of breakwater structures which experience different seismic intensities. In this paper, the author used a finite difference software, namely, FLAC3D, to analyze the state and compute seismic responses of breakwater structure. The breakwater foundation’s pore pressure ratio and displacement due to different earthquake have been studied. And the result show that: Smaller earthquakes have little influence on serviceability of the foundation, and severe earthquakes can liquefy some parts of the foundation; In the latter case , obvious changes of pores and foundation displaces can be found. Particularly, when seismic peak acceleration reachs 0.2g, Liquefaction appears in the foundation and mainly concentrated in the upper right side of the structure. In addition, the survey of ultra-hole pressure and displacement values of sand layers of the breakwater, manifests when the ultra pore pressure near 1.0, displacement and overturning structure is relatively large, resulting in varying degrees of damage to the structure. This paper’s research can provide theoretical and designable reference for similar engineering structures.
Źródło:
Polish Maritime Research; 2016, S 1; 109-114
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of thermal treatment on colour and texture of Typha latifolia L.
Autorzy:
Zang, M.
Zhou, Y-H.
Wang, S.
Tang, J.
Powiązania:
https://bibliotekanauki.pl/articles/25390.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Opis:
Through the analysis of the residual activity of peroxidase (POD), chromatic aberration, shear intensity and shear power, the effects of different thermal treatment times at 100°C on the POD, surface colour and texture of Typha latifolia L. were evaluated. The results showed that the activity of POD decreased with the increasing thermal treatment time at 100°C. The regeneration amount of POD increased first for some time and then started to decrease with the treatment time. Thermal treatment times 1.0 and 1.5 min at 100°C exhibited maximum regeneration of POD for the samples stored at 20 and 37°C, respectively. The sample had acceptable texture and surface colour when they were treated at 100°C for 4 min because the POD in the sample was inactivated to an acceptable level.
Źródło:
International Agrophysics; 2012, 26, 2
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Property of 1,4-Diamino-3,6- dinitropyrazolo[4,3-c]pyrazole and Its Derivatives
Autorzy:
Li, Y.-N.
Wang, B.-Z.
Shu, Y.-J.
Zhang, S.-Y.
Lian, P.
Powiązania:
https://bibliotekanauki.pl/articles/358674.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
3,6-dinitropyrazolo[4,3-c]pyrazole (DNPP)
1,4-diamino-3,6- dinitropyrazolo[4,3-c]pyrazole (DADNP)
4,4’-(triaz-1-ene-1,3-diyl)bis(1- amine-3,6-dinitropyrazolo[4,3-c]pyrazole) (TBADNP)
N-amination reaction
synthesis
property
Opis:
A synthetic procedure has been developed for the synthesis of 1,4-diamino- 3,6-dinitropyrazolo[4,3-c]pyrazole (DADNP) via N-amination reaction. Its derivatives, 4,4’-(triaz-1-ene-1,3-diyl)bis(1-amine-3,6-dinitropyrazolo[4,3-c] pyrazole) (TBADNP) and 1,4-dinitramino-3,6-dinitropyrazolo[4,3-c]pyrazole (DNADNP), were first designed and synthesized by the diazotization and nitrification of amino group, and their structures were characterized by IR, 1H NMR, 13C NMR, elementary analysis and MS. The thermal properties of target compounds were studied by means of differential scanning calorimetry (DSC) and thermogravimetry (TG). The thermal decomposition peak temperatures of DADNP, TBADNP and DNADNP are 227, 236 and 288 °C, respectively. Results show that the derivatives of 1,4-diamino-3,6-dinitropyrazolo[4,3-c]pyrazole have better thermal stability.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 2; 321-331
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of dissolved mineral species in quartz flotation and siderite solubility simulation
Autorzy:
Luo, X.
Wang, Y.
Ma, M.
Song, S.
Zhang, Y.
Deng, J.
Liu, J.
Powiązania:
https://bibliotekanauki.pl/articles/109459.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quartz
solubility
siderite
calcium ion
temperature
flotation
Opis:
Quartz is, in most cases, the major gangue mineral found in the iron ores. Although it can be activated by calcium at strong alkaline pH, quartz nevertheless, reports to the concentrate with Fe when the iron ores contain siderite. It causes a poor concentrate grade and separation between quartz and iron minerals. The effect of siderite on reverse anionic flotation of quartz from hematite was studied in our previous investigations. In this work, the effect of siderite dissolution on the quartz recovery in the froth product and the effect of pH, ions and temperature on siderite dissolution were investigated. Microflotation, PHREEQC simulation, solution chemistry calculation and Fourier transform infrared spectroscopy (FTIR) measurements were conducted. It was observed that the dissolved species of siderite exhibited negative impact on quartz flotation. This influence became weak to some extent by either stripping the dissolved species or shortening dissolution time. Siderite was easily dissolved in the presence of calcium ion under strong alkaline conditions and its solubility increased with increasing the calcium ion concentrate and temperature. When the calcium ion was added as an activator of quartz under strong alkaline conditions (pH>9.96), calcium existed mainly in the CaCO3 precipitation form according to the solubility rule in the presence of siderite. This form could adsorb onto quartz surfaces and further the chemical reaction between starch and quartz was monitored by FTIR measurements. This study provides a further supplement for previous study. A potential strategy is suggested that finding a collector used at low temperature or flotation under neutral (or weak alkaline) medium is helpful to the reverse flotation of iron ores containing siderite.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1241-1254
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
System and Method for Simultaneous Measurement of Nitrogen Content and Uniformity of Nitration of Nitrocellulose
Autorzy:
Liu, Y.
Shao, Z.
Wang, W.
Li, W.
Lv, Y.
Sun, J.
Powiązania:
https://bibliotekanauki.pl/articles/358714.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
nitrocellulose
uniformity of nitration
nitrogen content
mixed acid nitration
cotton maturity
Opis:
Nitrocellulose (NC) is a common, commercially available, cellulosederived material and has been functionalized and widely applied in microfluidic technology, immunoassays and biochemical analyses. However, existing testing parameters always fail to completely and accurately reflect its inherent quality. In this study, we have designed and assembled a novel automatic polarizing microscope test system (PMTS) to scientifically test the nitrogen content and uniformity of nitration of NC based on the chromogenic principle of a polarization microscope. The advantages of this system are: (i) the PMTS requires less sample (only a few micrograms); (ii) the test period is shorter and the results can be obtained within 20 min; (iii) the method belongs to the nondestructive testing group, and the NC sample is not burned, dissolved, or damaged; and (iv) this method has increased accuracy, and the deviation of the nitrogen content is less than ±0.05%. The properties of various NC samples prepared by different nitricsulfuric acid systems from raw materials with diverse maturities were determined via PMTS. Five NC samples with different nitrogen contents (10.9%, 11.5%, 11.8%, 12.6% and 13.5%) were tested, and the variance of the corresponding uniformity of nitration of these samples were 3.17, 1.61, 1.15, 1.76, and 2.83. The uniformity of nitration initially decreased and then increased with increasing nitrogen content, and the best uniformity of nitration appeared at a nitrogen content of 12%. We also found that fibre maturity has a positive effect on the uniformity of nitration. This testing device and method, with its cost-effectiveness and field-portability, can significantly improve the accuracy of nitration content and uniformity, and has an important value in practical applications.
Źródło:
Central European Journal of Energetic Materials; 2018, 15, 4; 554-571
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation behaviour and surface characteristic of anosovite in a sodium oleate solution
Autorzy:
Wang, Y.
Wen, S.
Zhang, J.
Wu, D.
Xian, Y.
Shen, H.
Powiązania:
https://bibliotekanauki.pl/articles/110766.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
anosovite
sodium oleate
flotation
adsorption
Opis:
Properties of anosovite in titanium slag, anosovite flotation response in a collector solution of sodium oleate, and adsorption behaviour of sodium oleate on the mineral surface were studied in the present work using XRD, Raman spectra, flotation tests, zeta potential analysis, FTIR and XPS. The results show that the anosovite crystal contains magnesium, and its chemical composition is Mg0.09Ti2.91O5. The chemical bonds on the anosovite surface mainly comprise Ti-O bonds. Micro-flotation tests indicate that anosovite has better floatability at a wide pH range and the recovery reaches 88% at pH=6, when the dosage of sodium oleate is only 4·10−6 mol/dm3. The point of zero charge of anosovite was determined near pH 3.2 by the zeta potential measurement. In the flotation process, chemical adsorption occurs between the carboxyl of sodium oleate and the titanium sites on the anosovite surface.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 714-723
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Study On The Fabrication Of Iron Powder From Forging Scale Using Hydrogen
Próby wytwarzanie proszku żelaza metodą redukcji zgorzeliny pochodzącej z procesów kucia za pomocą wodoru
Autorzy:
Shin, S. M.
Lee, D.-W.
Yun, J.-Y.
Kang, Ch.-Y.
Wang, J.-P.
Powiązania:
https://bibliotekanauki.pl/articles/350946.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
forging scale
hydrogen partial pressure
hematite
iron powder
kucie za pomocą wodoru
hematyt
redukcja zgorzeliny
proszek żelaza
Opis:
This study was conducted to investigate the effect of hydrogen content, temperature, reaction time for the reduction of forging scale which is mainly composed of hematite (Fe2O3). All reductive reactions were performed over the temperature range of 700 to 1200°C as well as 0.1 to 1 atm of hydrogen partial pressures. The results showed that the mechanism for the reduction of iron oxides using hydrogen gas was not a simple process, but proceeded in multiple reduction stages thermodynamically. The iron oxide was almost completely reduced to metallic iron powder with 91 wt.% of iron content in the forging scale at 0.1 atm of hydrogen partial pressure. The content of iron was however found to be increased with increasing hydrogen partial pressure from 0.1 to 1 atm with regardless of temperatures. The metallic iron powder was obtained with the mean size of 100 μm and more porous structure was observed.
Źródło:
Archives of Metallurgy and Materials; 2015, 60, 2B; 1547-1549
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Ships Safety Control System
Autorzy:
Han, X. J.
Meng, X. Y.
Wang, Z. W.
Powiązania:
https://bibliotekanauki.pl/articles/117442.pdf
Data publikacji:
2009
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Safety of Navigation
ships safety
Control System
Ships Safety Control System
Ship Accidents
Human Factor
Control Strategy
Accident Precaution
Opis:
The proportion of main reasons of ships accidents to the whole reasons is discussed in the paper. Among these reasons, human factors are in the majority. So a method to prevent wrong orders sent by a navigator is laid emphasis on. On the basis of this, a ships safety control system is studied. The construction and control principle of the ships safety control system, as well as control strategy, implementation method and key technology are elaborated in the paper.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2009, 3, 1; 19-22
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Organ-level evaluation of the carbon starvation hypothesis in deciduous broad-leaved Catalpa bungei plants undergoing drought-induced mortality
Autorzy:
Qiu, Q.
Wang, J.
Su, Y.
Li, J.
Ma, J.
He, Q.
Powiązania:
https://bibliotekanauki.pl/articles/2078283.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Carbon starvation
Catalpa bungei
Drought
Non-structural carbohydrate (NSC)
Plant mortal-
ity
Opis:
The carbon starvation hypothesis (CSH) is one of the current leading hypotheses regarding the mechanism of plant death, although it has not been sufficiently validated due to a lack of evidence. To help verify the role of carbon starvation in plant mortality, we measured the non-structural carbohydrate (NSC) concentration ([NSC]) in different organs (roots, stems, and leaves) of plants of Catlapa bungei clone 9-1 after the cessation of photosynthesis and death due to drought and in well-watered controls. Drought in- duced the loss of NSC reserves, which was observed in all organs at death, and carbon starvation appeared to begin after the cessation of photosynthesis. The [NSC] dynamics, occurrence time of carbon starvation, and survival time varied among the organs, and even within the same organs at different stem heights. Overall, our findings are compatible with the CSH in that carbon starvation occurs in roots, stems, and leaves and concurs with plant death during prolonged drought.
Źródło:
Dendrobiology; 2018, 80; 48-60
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation and cytological study of collagen/nano-hydroxyapatite/graphene oxide composites
Autorzy:
Wang, J.
Wang, Y.
Liu, D.
Yang, Q.
Huang, C.
Yang, C.
Zhang, Q.
Powiązania:
https://bibliotekanauki.pl/articles/307450.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
nanohydroksyapatyt
tlenek grafitu
mineralizacja
kolagen
nano-hydroxyapatite
graphene oxide
biomimetic mineralization
collagen
Opis:
Biomimetic mineralized composite scaffolds are widely used as natural bone substitute materials in tissue engineering by inducing and assembling bonelike apatite. In this study, the single lamellar structure of graphene oxide (GO) powder was prepared via an improved Hummers’ method. Methods: To better mimic natural bone, the collagen (COL)/Nano-hydroxyapatite (nHA)/graphene oxide (GO) composite material was prepared by simulated body fluid (SBF) method using COL/GO as a matrix template. Hydroxyapatite (HA) with calcium ion deficiency was achieved via biomimetic mineralization, and it had properties closer to those of natural bone than pure HA has. Results: The mineralized COL/nHA/GO composites exhibited loose porous structures, and the connectivity of the holes was good and thus beneficial to the exchange of nutrients and excreted metabolites. Conculsions: Antibacterial and MTT experiment confirmed that the COL/nHA/GO composite material had excellent antibacterial property and biocompatibility. Hence, these results strongly suggested the mineralized COL/nHA/GO composite is a good candidate biomaterial to be applied in bone tissue engineering.
Źródło:
Acta of Bioengineering and Biomechanics; 2018, 20, 4; 65-74
1509-409X
2450-6303
Pojawia się w:
Acta of Bioengineering and Biomechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Crystallization Process of $Fe_{75}Co_5Zr_{10}B_{10}$ Amorphous Alloy
Autorzy:
Sun, Y.
Zuo, B.
Wang, D.
Meng, X.
Liu, J.
Wang, L.
Hua, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1399278.pdf
Data publikacji:
2013-10
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.43.Dq
64.60.My
Opis:
$Fe_{75}Co_5Zr_{10}B_{10}$ amorphous alloy prepared by melt-spinning was annealed at various temperatures. The thermal property and microstructures were investigated by differential thermal analysis, X-ray diffraction, and transmission electron microscopy. The crystallization process of $Fe_{75}Co_5Zr_{10}B_{10}$ amorphous alloy is complex. The α-Fe phase precipitates from the amorphous matrix in the initial stage of crystallization. The α-Mn type (χ) phase precipitates at 570°C, but transforms to α-Fe phase and the Laves C14(λ) phase at higher temperature. In the final stage of crystallization, $Fe_3Zr$, $Fe_2Zr$, and unknown phases are observed and the λ-phase disappears. The α-Fe phase preferentially nucleates after annealing at 530C for 10 min and the χ-phase preferentially nucleates after annealing at 600C for 10 min. The nucleation barrier of χ-phase is larger than that of α-Fe phase. The local structure of χ-phase is more similar to amorphous phase.
Źródło:
Acta Physica Polonica A; 2013, 124, 4; 685-687
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fabrication and Characterization of PMMA/HMX-based Microcapsules via in situ Polymerization
Autorzy:
Jia, X.
Hou, C.
Tan, Y.
Wang, J.
Ye, B.
Powiązania:
https://bibliotekanauki.pl/articles/358134.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
fabrication
characterization
HMX
PMMA
microcapsules
Opis:
Microcapsule technology was applied with nitramine explosives to improve their performance. Polymethyl Methacrylate (PMMA) was selected for the fabrication of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane (HMX) based microcapsules. The PMMA/HMX-based microcapsules were prepared via a facile in situ polymerization of PMMA on the surface of the HMX crystals. Structural characterization of the PMMA/HMX microcapsules was studied systematically by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared (FT-IR) spectroscopy, and their thermal durability as well as their mechanical sensitivities were measured. The results indicated that spherical microcapsules were formed, with PMMA as the capsule wall and HMX as the core material. The SEM results showed that the grains of the PMMA/HMX microcapsules were spherical and that the particle distribution was homogeneous. XRD and FT-IR analyses indicated that the HMX polymorph was preserved in the optimal β-form during the whole preparative process. The DSC results showed that the PMMA/HMX microcapsules had better thermal decomposition performance, and that the apparent activation energy of the microcapsules had increased by 47.3 kJ/mol compared to the recrystallized HMX, and its thermal stability had greatly improved. In addition, the drop height (H50) had increased from 30.45 cm to 58.49 cm, an increase of 65.81%. Thus, microcapsule technology will have a very wide range of applications in reducing the sensitivity of high energy materials in the future.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 3; 559-572
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Rotor power loss in a PM SM by calculation, simulation and measurements, mutual verification of methods
Autorzy:
Vannier, J. C.
Kaczmarek, R.
Wang, Z. Y.
Randria, A.
Powiązania:
https://bibliotekanauki.pl/articles/262831.pdf
Data publikacji:
2006
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie
Tematy:
synchronous machine
permanent magnet
eddy current loss
equivalent circuit
Opis:
The subject of the paper is the comparison of four complementary methods of the rotor loss estimation in a PM SM, supplied by a PWM voltage source. An ANSYS based finite element model produces values of W, the magnetic energy stored, and P, the rotor losses. On analytical level the machine is represented by a parallel two elements equivalent circuit for each voltage harmonic. Its parameters are estimated using P and W values. Finally, the eddy current losses representation in the ANSYS code is verified for magnets under study by direct losses measurements. The calculation results are compared with some measured values resulting from analysis and harmonic decomposition of the machine total losses.
Źródło:
Electrical Power Quality and Utilisation. Journal; 2006, 12, 2; 113-116
1896-4672
Pojawia się w:
Electrical Power Quality and Utilisation. Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Compact High Current Vacuum Diode Based on a Ceramic-Metal Welding Interface
Autorzy:
Xun, T.
Zhang, J.
Yang, H.
Wang, Y.
Liu, Z.
Powiązania:
https://bibliotekanauki.pl/articles/1807886.pdf
Data publikacji:
2009-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
52.59.Mv
73.20.-r
84.70.+p
Opis:
For one kind of high current diodes composed of a ceramic-metal welding vacuum interface, the electrical design was presented. For compactness, a radial type insulator and a cone-column anode crust were adopted. The shielding methods around cathode and anode region were applied to mitigate the influence of welding solder to vacuum flashover. Finite Element Analysis (FEA) simulation results indicated that by adjusting the anode outline and shielding shape, the electric fields along the ceramic were well distributed. High voltage test was conducted on a long-pulse accelerator and experimental results confirm the theoretic design: the diode can stably hold on 400 kV and 200 ns voltage pulse.
Źródło:
Acta Physica Polonica A; 2009, 115, 6; 1013-1015
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reliability analysis of the products subject to competing failure processes with unbalanced data
Oparta na niezbilansowanych danych analiza niezawodności produktów podlegających procesom powstawania uszkodzeń konkurujących
Autorzy:
Li, J.
Zhang, Y.
Wang, Z.
Fu, H.
Xiao, L.
Powiązania:
https://bibliotekanauki.pl/articles/1365849.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
reliability evaluation
competing failure model
unbalanced data
interval statistics
ocena niezawodności
model uszkodzeń konkurujących
dane niezbilansowane
statystyki przedziałowe
Opis:
Considering the degradation and catastrophic failure modes simultaneously, a general reliability analysis model was presented for the competing failure processes with unbalanced data. For the degradation process with highly unbalanced data, we developed a linear random-effects degradation model. The model parameters can be estimated based on a simple least square method. Furthermore, to fully utilize the degradation information, we considered the last measured times of the degradation units that had only one or two measured time points as zero-failure data or right-censored data of the catastrophic failure mode. Then the incomplete data set was composed of zero-failure data and catastrophic failure data. To analyze the incomplete data, the definition of the interval statistics was firstly given. The best linear unbiased parameter estimators of catastrophic failure were obtained based on the Gauss-Markov theorem. Then, the reliability function of the competing failure processes was given. The corresponding two-sided confidence intervals of the reliability were obtained based on a bootstrap procedure. Finally, a practical application case was examined by applying the proposed method and the results demonstrated its validity and reasonability.
W pracy przedstawiono ogólny model analizy niezawodności procesów związanych z powstawaniem uszkodzeń konkurujących, który pozwala na wykorzystanie danych niezbilansowanych oraz umożliwia jednoczesne uwzględnienie uszkodzeń wynikających z obniżenia charakterystyk i uszkodzeń katastroficznych. Opracowano liniowy model efektów losowych dla procesu degradacji o wysoce niezbilansowanych danych. Parametry tego modelu można określić na podstawie prostej metody najmniejszych kwadratów. Ponadto, aby w pełni wykorzystać informacje dotyczące obniżenia charakterystyk, dane pochodzące z ostatniego pomiaru jednostek podlegających degradacji, dla których przeprowadzono tylko jeden lub dwa pomiary, rozpatrywano jako dane o zerowym uszkodzeniu lub jako ucięte prawostronnie dane dotyczące uszkodzenia katastroficznego. W ten sposób otrzymano zbiór niepełnych danych składający się z danych o uszkodzeniach zerowych oraz danych o uszkodzeniach katastroficznych. Aby móc przeanalizować uzyskane niepełne dane, podano definicję statystyki przedziałowej. Najefektywniejszy nieobciążony estymator liniowy (BLUE) parametrów uszkodzeń katastroficznych uzyskano na podstawie twierdzenia Gaussa-Markowa. Następnie, podano wzór funkcji niezawodności procesów związanych z powstawaniem uszkodzeń konkurujących. Odpowiednie dwustronne przedziały ufności dla oszacowanej niezawodności uzyskano metodą bootstrapową. Na koniec, przedstawiono przypadek praktycznego zastosowania proponowanej metody, którego wyniki wykazały jej trafność i zasadność.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 1; 98-109
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
De novo sequencing and comparative transcriptome analysis of white petals and red labella in Phalaenopsis for discovery of genes related to flower color and floral differentiation
Autorzy:
Yang, Y.
Wang, J.
Ma, Z.
Sun, G.
Zhang, C.
Powiązania:
https://bibliotekanauki.pl/articles/58306.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
sequencing
RNA sequence
transcriptome
Phalaenopsis
gene
flower
colour
floral differentiation
diversity
Opis:
Phalaenopsis is one of the world’s most popular and important epiphytic monopodial orchids. The extraordinary floral diversity of Phalaenopsis is a reflection of its evolutionary success. As a consequence of this diversity, and of the complexity of flower color development in Phalaenopsis, this species is a valuable research material for developmental biology studies. Nevertheless, research on the molecular mechanisms underlying flower color and floral organ formation in Phalaenopsis is still in the early phases. In this study, we generated large amounts of data from Phalaenopsis flowers by combining Illumina sequencing with differentially expressed gene (DEG) analysis. We obtained 37 723 and 34 020 unigenes from petals and labella, respectively. A total of 2736 DEGs were identified, and the functions of many DEGs were annotated by BLAST-searching against several public databases. We mapped 837 up-regulated DEGs (432 from petals and 405 from labella) to 102 Kyoto Encyclopedia of Genes and Genomes pathways. Almost all pathways were represented in both petals (102 pathways) and labella (99 pathways). DEGs involved in energy metabolism were significantly differentially distributed between labella and petals, and various DEGs related to flower color and floral differentiation were found in the two organs. Interestingly, we also identified genes encoding several key enzymes involved in carotenoid synthesis. These genes were differentially expressed between petals and labella, suggesting that carotenoids may influence Phalaenopsis flower color. We thus conclude that a combination of anthocyanins and/or carotenoids determine flower color formation in Phalaenopsis. These results broaden our understanding of the mechanisms controlling flower color and floral organ differentiation in Phalaenopsis and other orchids.
Źródło:
Acta Societatis Botanicorum Poloniae; 2014, 83, 3
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of selenium on growth, lipid peroxidation and antioxidative enzyme activity in melon (Cucumis melo L.) seedlings under salt stress
Autorzy:
Hu, K.L.
Zhang, L.
Wang, J.T.
You, Y.
Powiązania:
https://bibliotekanauki.pl/articles/58727.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
selenium
plant growth
lipid peroxidation
antioxidative enzyme
enzyme activity
melon
Cucumis melo
seedling
salt stress
Opis:
The objective of this study was to investigate the effect of exogenous selenium (Se) supply (0, 2, 4, 8, 16 μM) on the growth, lipid peroxidation and antioxidative enzyme activity of 100 mM NaCl-stressed melon (Cucumis melo L.) seedlings. Salt stress significantly reduced the growth attributes including stem length, stem diameter, dry weight and increased antioxidative enzyme activity [superoxide dismutase (SOD), peroxidase (POD), catalase (CAT)]. Moreover, the plant exhibited a significant increase in electrolyte leakage and malondialdehyde (MDA) content under NaCl stress. Se supplementation not only improved the growth parameters but also successfully ameliorated the adverse effect caused by salt stress in melon seedlings. However, the mitigation of NaCl-stressed seedlings was different depending on the Se concentration. At lower concentrations (2–8 μM), Se improved growth and acted as antioxidant by inhibiting lipid peroxidation and increasing in SOD and POD enzymes activity under salt stress. At higher concentrations (16 μM), Se exerted diminished beneficial effects on growth. Whereas CAT activity was enhanced. The result indicated that Se supplementation had a positive physiological effect on the growth and development of salt-stressed melon seedlings.
Źródło:
Acta Societatis Botanicorum Poloniae; 2013, 82, 3
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of leaching kinetics of cerussite in sodium hydroxide solutions
Autorzy:
Feng, Q.
Wen, S.
Wang, Y.
Zhao, W.
Deng, J.
Powiązania:
https://bibliotekanauki.pl/articles/110621.pdf
Data publikacji:
2015
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
cerussite
sodium hydroxide
leaching
kinetics
activation energy
Opis:
The leaching kinetics of cerussite in alkaline medium was investigated with respect to experimental variables such as sodium hydroxide concentration, temperature, particle size and stirring speed. The results showed that leaching reagent concentration and reaction temperature exerted significant effects on the extraction of lead, whereas particle size and stirring speed exhibited a relatively moderate effect on the leaching rate. The leaching process followed the kinetic law of the shrinking core model, and the dissolution rates were controlled by the surface chemical reaction with an apparent activation energy value of 43.79 kJ/mol. A corresponding dissolution kinetic equation was also proposed to describe the dissolution reaction. The results indicated that sodium hydroxide could be used as an effective leaching reagent for extracting lead from cerussite.
Źródło:
Physicochemical Problems of Mineral Processing; 2015, 51, 2; 491-500
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Copper adsorption reaction rate and ion exchange ratio during the copper activation of sphalerite
Autorzy:
Liu, J.
Luo, D.
Huang, L.
Wang, Y.
Wen, S.
Powiązania:
https://bibliotekanauki.pl/articles/110651.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
sphalerite
copper activation
solution chemistry
ion exchange ratio
reaction rate
Opis:
A theoretical analysis method of the solution chemistry characteristic of Cu(II) at various pH values was developed. Using such method, the existence form of Cu species and their proportions in aqueous solution can be clearly determined. After that, the copper adsorption and ion exchange ratio (E) during the copper activation of sphalerite were investigated. The results indicated that the copper activation of sphalerite can be divided into two stages, i.e., the fast activation stage (t ≤4 min) and slow activation stage (t >4 min). The general form of the copper adsorption rate was determined as ΓCu=K1ln(t) +Γ1, which is confirmed by the data fitting of the fast activation stage. The lower activation pH results in higher ion exchange efficiency for Cu substituting Zn. For a strong acid pH of 4.1, the E maintains about 1:1 in the entire activation time range and is not dependent on the activation time. However, the value of E is greater than 1 under weak acidic (pH=6.2) and alkaline (pH=9.1) pH conditions and it significantly depends on the activation time. For such conditions, E decreases with increase in the activation time, which supports the ion exchange mechanism, but within short activation time, it is not a 1:1 ion exchange process.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 377-385
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel Approach To Diagnosis Of Analog Circuit Incipient Faults Based On KECA And OAO LSSVM
Autorzy:
Zhang, C.
He, Y.
Zuo, L.
Wang, J.
He, W.
Powiązania:
https://bibliotekanauki.pl/articles/221378.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
analog circuits
incipient fault diagnosis
wavelet transform
kernel entropy component analysis
least squares support vector machine
Opis:
Correct incipient identification of an analog circuit fault is conducive to the health of the analog circuit, yet very difficult. In this paper, a novel approach to analog circuit incipient fault identification is presented. Time responses are acquired by sampling outputs of the circuits under test, and then the responses are decomposed by the wavelet transform in order to generate energy features. Afterwards, lower-dimensional features are produced through the kernel entropy component analysis as samples for training and testing a one-against-one least squares support vector machine. Simulations of the incipient fault diagnosis for a Sallen-Key band-pass filter and a two-stage four-op-amp bi-quad low-pass filter demonstrate the diagnosing procedure of the proposed approach, and also reveal that the proposed approach has higher diagnosis accuracy than the referenced methods.
Źródło:
Metrology and Measurement Systems; 2015, 22, 2; 251-262
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Female mouse model of diabetes mellitus induced by streptozotocin and high-carbohydrate high-fat diet
Autorzy:
Guo, R.
Dong, J.
Wang, D.Q.
Gu, Y.F.
Powiązania:
https://bibliotekanauki.pl/articles/16627528.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
diabetes mellitus
female mouse
pathological analysis
streptozotocin
high-carbohydrate high-fat diet
Opis:
With the improvement of people’s living standards and rapid economic development, the incidence of diabetes mellitus (DM) is increasing in most parts of the world. DM presents an important potential threat to human health. In the present study, a model of diabetes in female mice was established, and fasting blood glucose was detected at week 4, after which the biochemical profiles were evaluated by histopathological analysis. The success rate of modeling in the normal control (NC) group and the low/ middle/high-dose streptozotocin (STZ) group were 0, 0, 25% and 60%, respectively. In the middle-dose and high-dose STZ groups, the liver index was increased significantly compared with the NC group (p<0.05). The blood biochemical indicators of total cholesterol and low density lipoprotein cholesterol in three STZ injection groups were as follows: alanine aminotransferase and aspartate transaminase in middle- and high-dose STZ groups, high-density lipoprotein cholesterol and serum creatinine in the high-dose STZ group, and blood urea nitrogen in the middle-dose STZ group were significantly increased (p<0.05). The level of total triglycerides was lower, obviously, in the high-dose STZ group than in the NC group (p<0.05). The mice showed marked steatosis, green-dyed fiber tissue coloring in varying degrees, and the contour of the hepatic lobules basically disappeared in STZ injection groups. The results suggest that to establish a diabetes model for female ICR mice, the optimum dose of STZ is 100 mg/kg.
Źródło:
Polish Journal of Veterinary Sciences; 2022, 25, 4; 547-555
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Large deformation and stability analysis of a cylindrical rubber tube under internal pressure
Autorzy:
Sang, J.
Xing, S.
Liu, H.
Li, X.
Wang, J.
Lv, Y.
Powiązania:
https://bibliotekanauki.pl/articles/279927.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
large deformation analysis
stability analysis
rubber tube
nonlinear elastic theory
Opis:
Rubber tubes under pressure can undergo large deformations and exhibit a particular nonlinear elastic behavior. In order to reveal mechanical properties of rubber tubes subjected to internal pressure, large deformation analysis and stability analysis have been proposed in this paper by utilizing a modified Gent’s strain energy function. Based on the nonlinear elastic theory, by establishing the theoretical model of a rubber tube under internal pressure, the relationship between the internal pressure and circumferential principal stretch has been deduced. Meanwhile stability analysis of the rubber tube has also been proposed and the relationship between the internal pressure and the internal volume ratio has been achieved. The effects on the deformation by different parameters and the failure reasons of the rubber tube have been discussed, which provided a reasonable reference for the design of rubber tubes.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 1; 177-188
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Interactions between soil water and fertilizer on leaf photosynthesis and delta13C of Catalpa bungei seedlings
Autorzy:
Qiu, Q.
He, Q.
Wang, J.H.
Su, Y.
Ma, J.W.
Wu, J.W.
Li, J.Y.
Powiązania:
https://bibliotekanauki.pl/articles/41431.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
interaction
soil water
fertilizer
leaf
photosynthesis
delta 13 carbon
Catalpa bungei
seedling
Opis:
Our objective was to identify combinations of irrigation and fertiliser application that promoted the photosynthetic productivity and water use efficiency (WUE) of Catalpa bungei. Using response surface methodology based on a rotatable central composite design, we conducted a pot experiment with C. bungei clone 004-1 seedlings. The experiment quantified the effects of interactions between soil water content (W), nitrogen application rate (N), and phosphorus application rate (P) on leaf net photosynthetic rates (Pn), SPAD values (SPAD-502 meter readings of leaf chlorophyll), and carbon isotope composition (δ13C). N had significantly positive effects on the all three leaf parameters, while W had significantly negative effects on leaf δ13C signatures but positive effects on leaf Pn and SPAD values. The magnitude of the N effect exceeded that of the W effect. P had no significant effects on any of the three leaf parameters. The W × N interaction had significant positive effects on Pn and SPAD, but significant negative effects on leaf δ13C. Thus, irrigation and nitrogen application had different effects on seedling growth and WUE, and the two effects were interactive. Catalpa bungei growth was promoted by appropriately increasing nitrogen application and irrigation, but WUE was improved by increasing N and decreasing irrigation. Therefore, strategies for the irrigation and fertilisation of C. bungei plantations should be designed to appropriately balance plant growth and WUE.
Źródło:
Dendrobiology; 2016, 76
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Wzrost i właściwości optyczne kryształu BaGd2 (MoO4)4 domieszkowanego Er3+
Growth and optical properties of Er3+-doped BaGdcrystal 2 (MoO4)4
Autorzy:
Han, S.
Wang, J.
Zhang, H.
Pan, S.
Xv, H.
Wang, Y.
Shen, C.
Powiązania:
https://bibliotekanauki.pl/articles/142191.pdf
Data publikacji:
2013
Wydawca:
Stowarzyszenie Inżynierów i Techników Przemysłu Chemicznego. Zakład Wydawniczy CHEMPRESS-SITPChem
Tematy:
Wytwarzanie kryształów
ciepło właściwe
widmo
czas trwania fluorescencji
crystal growth
specific heat
spectrum
fluorescence lifetime
Opis:
Pojedynczy kryształ BaGd2(MoO4)4 domieszkowany 1% at. Er3+ wyhodowano metodą Czochralskiego. Omówiono szczegóły procedury otrzymywania i wzrostu kryształu. Kryształ ma doskonałą płaszczyznę poślizgu (010), a jego łupliwość czyni go przydatnym jako ośrodek czynny w mikrolaserach. Zmierzono widmo absorpcyjne w zakresie światła widzialnego i bliskiej podczerwieni (NIR) w temperaturze pokojowej. W zakresie od 380 do 1600 nm występuje kilka intensywnych pików absorpcyjnych. Zmierzono również widmo fluorescencyjne wzbudzane za pomocą lampy ksenonowej. Zaobserwowano intensywny pik emisyjny NIR 1536 nm. Czasy trwania fluorescencji 4I13/2 oraz 4I11/2 wyznaczone za pomocą dopasowania krzywej wykładniczej wyniosły odpowiednio 5,85 ms i 112,62 μs. Ciepło właściw Er3+ BaGd2(MoO4)4 w 25°C wynosi 0,471 J g-1 K-1. Na podstawie zmierzonych widm obliczono parametry optyczne na podstawie teorii Judda-Ofelta (J–O).
A 1 at % Er3+ doped BaGd2(MoO4)4 single crystal was grown by the Czochralski method. Details on the preparation and growth procedures were discussed. The crystal has a perfect (010) cleavage plane, and the cleavage character makes the crystal suitable as a gain medium for microchip lasers. The absorption spectrum in the visible and near-infrared (NIR) regions was measured at room temperature. There are several strong absorption peaks in the range from 380 to 1600 nm. The fluorescence spectrum excited by a Xenon lamp was also measured. A strong NIR emission peak located at 1536 nm was observed. The fluorescence lifetimes of 4I13/2 and 4I11/23+:BaGd2(MoO4)4 at 25°C is 0.471 J g-1 K-1. Using the measured spectra, the optical parameters were calculated using the J–O theory.
Źródło:
Chemik; 2013, 67, 9; 763-770
0009-2886
Pojawia się w:
Chemik
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal stability and mechanical properties of hybrid materials based on nitrocellulose grafted by aminopropylisobutyl polyhedral oligomeric silsesquioxane
Stabilność termiczna i właściwości mechaniczne materiałów hybrydowych na bazie nitrocelulozy szczepionej oligomerycznym wielofunkcyjnym aminopropyloizobutylosilseskwioksanem
Autorzy:
Yang, X.
Wang, Y.
Li, Y.
Li, Z.
Song, T.
Liu, X.
Hao, J.
Powiązania:
https://bibliotekanauki.pl/articles/945783.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
nitrocellulose
hybrid material
aminopropylisobutyl polyhedral oligomeric silsesquioxane
thermal stability
mechanical properties
nitroceluloza
materiał hybrydowy
oligomeryczny wielofunkcyjny aminopropyloizobutylosilseskwioksan
stabilność termiczna
właściwości mechaniczne
Opis:
The need for improvement in nitrocellulose (NC) storage safety and convenience of application requires an increase in NC thermal stability and enhancement of its mechanical properties. To this aim, hybrid materials were synthesized by grafting NC with aminopropylisobutyl polyhedral oligomeric silsesquioxane (amino-POSS) using isophorone diisocyanate (IPDI) as a crosslinking agent. The structure and elemental composition of the resulting products were confirmed by Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance (1H NMR and 29Si NMR), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). It was found, based on the silicon mapping using energy dispersive X-ray spectroscopy (EDS), that amino-POSS was well dispersed in NC matrix. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) studies showed that hybrid amino-POSS-NC materials have higher thermal decomposition activation energy (Ea) compared to NC control sample. According to TGA results, the temperatures of 5 % weight loss (T5 %) and 50 % weight loss (T50 %) as well as the residual masses at 240 °C (CR240 °C), were increased as a result of NC modification with amino-POSS. As can be seen from the digital and scanning electron microscopy (SEM) images, the char layers of amino-POSS-NC hybrid materials after burning in air became more compact with increasing amino-POSS content. XPS studies have shown an increased content of the graphitized carbon in the char residues of the modified samples. The results of DSC, TGA, SEM and XPS studies have directly proved the enhancement of the thermal stability of amino-POSS-NC hybrid materials. In addition, tensile strengths and Young's moduli of amino-POSS-NC hybrid materials were increased gradually with the amino-POSS content in the uniaxial tensile tests. All these results show that the proposed modification of nitrocellulose improves the safety of manufacture and use of this material.
Poprawa bezpieczeństwa przechowywania nitrocelulozy (NC) wymaga zwiększenia jej stabilności termicznej, a wygoda używania poprawy właściwości mechanicznych. W tym celu zsyntetyzowano materiały hybrydowe, w których NC szczepiono oligomerycznym wielofunkcyjnym aminopropyloizobutylosilseskwioksanem (amino-POSS) stosując jako środek sieciujący izoforonodiizocyjanian (IPDI). Strukturę i skład otrzymanych materiałów potwierdzono za pomocą spektroskopii w podczerwieni z transformatą Fouriera (FT-IR), jądrowego rezonansu magnetycznego (1H NMR i 29SiNMR), dyfraktometrii rentgenowskiej (XRD) oraz spektroskopii fotoelektronów rentgenowskich (XPS). Na podstawie wyników badań mapowania Si, otrzymanych metodą spektroskopii dyspersji energii promieniowania rentgenowskiego (EDS), stwierdzono, że amino-POSS został dobrze zdyspergowany w matrycy NC. Badania stabilności termicznej przeprowadzone za pomocą różnicowej kalorymetrii skaningowej (DSC) wykazały, że materiały hybrydowe typu amino-POSS-NC charakteryzują się większymi wartościami energii aktywacji rozkładu termicznego (Ea) niż próbka kontrolna NC. Zgodnie z wynikami analizy termograwimetrycznej (TGA) wartości temperatury ubytku 5 % (T5 %) i 50% (T50 %) masy próbki oraz pozostałości masy w temperaturze 240 °C (CR240 °C) zwiększały się na skutek modyfikacji NC za pomocą amino-POSS. Według fotografii cyfrowych i fotografii wykonanych metodą skaningowej mikroskopii elektronowej (SEM) warstwy węglowe powstałe po spaleniu materiałów hybrydowych w powietrzu wraz ze zwiększeniem zawartości amino-POSS stawały się coraz bardziej zwarte, a wyniki badań XPS wykazały, że tworzyło się coraz więcej węgla w postaci grafitu. Wszystkie wyniki DSC, TGA, SEM i XPS dowodzą poprawy stabilności termicznej materiałów hybrydowych amino-POSS-NC. Stwierdzono także, że wytrzymałość na rozciąganie i moduł Young'a podczas prób jednoosiowego rozciągania materiałów hybrydowych rosną ze zwiększaniem się zawartości amino-POSS. Wyniki wszystkich przeprowadzonych badań dowodzą, że zaproponowana modyfikacja NC poprawia bezpieczeństwo wytwarzania i użytkowania tych materiałów w porównaniu z niemodyfikowanym NC.
Źródło:
Polimery; 2017, 62, 7-8; 576-587
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on the Mechanism and Kinetics of Polymorphic Transitions of ε CL-20 in Composite Systems
Autorzy:
Guo, X.-Y.
Zhang, P.
Xu, J.-J.
Wang, Z.-H.
Jiao, Q.-J.
Powiązania:
https://bibliotekanauki.pl/articles/358032.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
polymorphic transition
kinetics
activation energy
transition temperature
Opis:
In order to explore the polymorphic transition law for ε-CL-20 in composite systems, the polymorphic transition process of pure ε-CL-20 crystals stimulated by heat was investigated by the X-ray Diffraction (XRD) method, and the kinetic parameters of the polymorphic transition process were calculated (including the apparent activation energy Ea and the pre-exponential factor lnA). Meanwhile the effects of different additives on the polymorphic transition process and kinetics of ε-CL-20 were explored in detail. The experimental results showed that the ε-form tends to transform into the γ- form on heating and that the Ea and lnA for the transition process were 209.97 kJ/mol and 57.47, respectively. The first group of additives clearly promoted the polymorphic transition of ε-CL-20 and lowered the initial transition temperature and the activation energy. The second and third groups of additives inhibited the polymorphic transition of ε-CL-20 and raised the initial transition temperature and the activation energy.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 4; 689-702
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of nitrogen deposition on growth and relationship of Robinia pseudoacacia and Quercus acutissima seedlings
Autorzy:
Ding, W.
Wang, R.
Yuan, Y.
Liang, X.
Liu, J.
Powiązania:
https://bibliotekanauki.pl/articles/41055.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
nitrogen deposition
plant growth
relationship
Robinia pseudoacacia
Quercus acutissima
seedling
positive interaction
nitrogen fixation
facilitation
competition
Opis:
Increased nitrogen deposition and biological invasions may be two crucial consequences of global change. Exotic plants often have adverse effects on native plants. However, there are reports of occasional positive interaction between them. Increased nitrogen deposition enhances nitrogen availability in soil, which may facilitate the growth of some exotic plant and decrease the competitive advantage of native plants because of their adaptation to low-nutrient environments. Consequently, increased nitrogen deposition may regulate the relationship between exotic and native plants. A greenhouse experiment was, thus, conducted to examine the effects of increased nitrogen deposition on the relationship between the native Quercus acutissima and the exotic Robinia pseudoacacia, which are both widely distributed in North China. Seedlings of both species were grown in monoculture and mixture arrangements in a pot experiment with different nitrogen addition levels (i.e., 0, 2, 5, and 10 g N m–2 a–1). Nitrogen addition altered the biomass partitioning of Q. acutissima and R. pseudoacacia seedlings, with more biomass allocated to leaves and less to roots. Although R. pseudoacacia seedlings always had growth predominance over Q. acutissima seedlings, Q. acutissima was not threatened by R. pseudoacacia at the four levels of nitrogen addition during the three-month duration of the experiment. A positive interaction between the seedlings of R. pseudoacacia and Q. acutissima was found, and increased nitrogen deposition did not affect the positive interaction. Further studies are necessary to determine whether or not R. pseudoacacia is harmful to native ecosystems and should be limited for forestation in North China.
Źródło:
Dendrobiology; 2012, 67
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Lifetime prediction of self-lubricating spherical plain bearings based on physics-of-failure model and accelerated degradation test
Prognozowanie czasu pracy samosmarujących łożysk ślizgowych w oparciu o model fizyki uszkodzeń oraz przyspieszone badania degradacji
Autorzy:
Wang, Y.
Fang, X.
Zhang, C.
Chen, X.
Lu, J.
Powiązania:
https://bibliotekanauki.pl/articles/300754.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
accelerated degradation test
self-lubricating spherical plain bearing
lifetime prediction
physicsof-failure model
przyspieszone badanie degradacji
samosmarujące łożysko ślizgowe
prognozowanie czasu pracy
model fizyki uszkodzeń
Opis:
Due to small friction coefficient and no need for lubrication during operation, self-lubricating spherical plain bearings (SSPBs) have been widely used in operation and transmission systems in aerospace, nuclear power plants, and ship equipment and they are key components of these systems. SSPBs failure will directly affect the operational reliability and safety of the equipment; therefore, it is necessary to accurately predict the service life of SSPBs to define reasonable maintenance plans and replacement cycles and to ensure reliability and safety of vital equipment. So far, lifetime prediction of SSPB has been primarily based on empirical formulae established by most important bearing manufacturers. However, these formulae are lack of strong theoretical basis; the correction coefficients are difficult to determine, resulting in low accuracy of lifetime prediction. In an accelerated degradation test (ADT), the load is increased to accelerate the SSPB wear process. ADT provides a feasible way for accurate lifetime prediction of SSPB in a short period. In this paper, wear patterns are studied and methods of wear analysis are presented. Then, physics-offailure model which considers SSPB wear characteristics, structure parameters and operation parameters is established. Moreover, ADT method for SSPB is studied. Finally, lifetime prediction method of SSPBs based on physics-of-failure model and ADT is established to provide a theoretical method for quick and accurate lifetime prediction of SSPBs.
W związku z niskim współczynnikiem tarcia oraz brakiem konieczności smarowania podczas pracy,samosmarujące łożyska ślizgowe (self-lubricating spherical bearings, SSPB) znajdują szerokie zastosowanie w układach pracy oraz układach przełożeń urządzeń w przemyśle lotniczym, elektrowniach jądrowych, oraz na statkach, stanowiąc kluczowe elementy tych układów. Uszkodzenie łożyska SSPB ma bezpośredni wpływ na niezawodność eksploatacyjną oraz bezpieczeństwo sprzętu; dlatego też istnieje konieczność precyzyjnego prognozowania resursu łożysk SSPB, pozwalającego na odpowiednie planowanie konserwacji oraz cykli wymiany , które ma na celu zapewnienie niezawodności i bezpieczeństwa kluczowego sprzętu. Dotychczas czas pracy łożysk SSPB prognozowano przede wszystkim w oparciu o wzory empiryczne podawane przez największych producentów łożysk. Wzory te, jednak, nie mają solidnej podstawy teoretycznej; trudno jest dla nich określić współczynniki korygujące, co zmniejsza trafność prognozowania czasu pracy. W przyspieszonych badaniach degradacji zwiększa się obciążenie celem przyspieszenia procesu zużycia łożysk SSPB. Badania przyspieszone umożliwiają trafne przewidywanie czasu pracy łożysk SSPB w krótkim okresie czasu. W przedstawionej pracy analizowano wzorce zużycia badanych łożysk oraz przedstawiono metody analizy zużycia. Następnie opracowano model fizyki uszkodzeń, który uwzględnia charakterystyki zużycia, parametry konstrukcyjne oraz parametry eksploatacyjne omawianych łożysk ślizgowych. Ponadto rozpatrywano możliwość zastosowania badań przyspieszonych dla tego typu łożysk. W wyniku przeprowadzonych badań, opracowano metodę prognozowania czasu pracy łożysk SSPB opartą na modelu fizyki uszkodzeń oraz badaniach przyspieszonych, która pozwala na szybkie i trafne prognozowanie czasu pracy samosmarujących łożysk ślizgowych.
Źródło:
Eksploatacja i Niezawodność; 2016, 18, 4; 528-538
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Foci for Determining the Insensitivity Features of Nanometer RDX: Nanoscale Particle Size and Moderate Thermal Reactivity
Autorzy:
Wang, Y.
Song, X.
Song, D.
Zhang, J.
Song, K.
Powiązania:
https://bibliotekanauki.pl/articles/358576.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
nanometer RDX
sensitivities
reactivity
hot spots
kinetics
Opis:
In this paper, the reasons why nanometer RDX showed lower sensitivity than micro RDX is discussed. Herein we supposed two factors affect the sensitivity of nanometer RDX. Firstly, according detonation physics models, a nanometer particle size results in small hot spots and a high critical temperature. These features suggested high safety for nanometer RDX based on the hot spot theory. A further factor is the thermal reactivity of nanometer RDX, which considerably affects the safety of nanometer energetic materials. Employing the Kinetic Compensation Effect, we calculated the kinetic parameters of micro and nanometer RDX. The results indicated that there was no obvious distinction between the activation energies of micro and nanometer RDX, which implies almost the same reactivity of micro and nanometer RDX. Incorporating the results of small hot spots, high critical temperature, and the unchanged reactivity of micro and nanometer RDX, we concluded that nanometer RDX should exhibit low sensitivity as an intrinsic feature.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 4; 799-815
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Observation and Control of Interfacial Defects in ZnO/ZnSe Coaxial Nanowires
Autorzy:
Bhutto, W.
Wu, Z.
Cao, Y.
Wang, W.
Kang, J.
Powiązania:
https://bibliotekanauki.pl/articles/1361939.pdf
Data publikacji:
2014-04
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
62.23.Hj
61.46.Km
64.70.Nd
68.35.Ct
Opis:
ZnO/ZnSe coaxial nanowires with different ZnO core diameters were synthesized by using a two-step chemical vapor deposition. The scanning electron microscopy images demonstrated that the coaxial nanowires with small ZnO core diameter had the smoother surface than that with large ZnO core diameter. A coherent ZnSe layer with wurtzite structure was observed in the nanowire interface between the ZnO core and the ZnSe shell by high resolution transmission electron microscopy. This coherent layer is beneficial to reduce the defect density and improve the crystal quality by suppressing the phase transition. It was found that the coherent thickness was significantly related to the ZnO core diameter. For the nanowire with large ZnO core, a thin critical thickness of 2 - 3 nm was obtained. As a result, a layer of zinc blende ZnSe appeared outside the nanowire, and a lot of defects existed in the interface between the ZnSe layers with different phase structures. For the nanowire with small ZnO core, however, the critical thickness increased and a coherent coaxial structure was observed with the same lattice spacing in the ZnO core and the ZnSe shell. To obtain defect-free coaxial nanowire, an optimal structure was also proposed by theoretical calculation.
Źródło:
Acta Physica Polonica A; 2014, 125, 4; 994-996
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Decomposition Kinetics of Hexanitrohexaazaisowurtzitane/Ammonium Perchlorate
Autorzy:
Zhu, Y.-L.
Wang, K.-K.
Shan, M.-X.
Zheng, X.-D.
Jiao, Q.-J.
Wang, J.-S.
Powiązania:
https://bibliotekanauki.pl/articles/358067.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
hexanitrohexaazaisowurtzitane
ammonium perchlorate
thermal analysis
thermal decomposition kinetics
Opis:
The thermal decomposition kinetics of hexanitrohexaazaisowurtzitane/ ammonium perchlorate (HNIW/AP) have been investigated by thermogravimetrydifferential scanning calorimetry-mass spectrometry (TG-DSC-MS) simultaneous analysis. TG showed that there were three weight loss processes for the thermal decomposition of the HNIW/AP mixture. The first was ascribed mainly to the thermal decomposition of HNIW, while the second and third were assigned to that of AP. The presence of AP has little effect on the thermal decomposition process of the HNIW component. The apparent activation energy of the thermal decomposition of the HNIW component, calculated by the Kissinger method, was little changed compared to that of neat HNIW. The addition of HNIW to AP caused the onset and end temperatures of the thermal decomposition to be decreased and the decomposition process to be shortened. The high-temperature and lowtemperature decomposition processes of AP became blurred in the presence of HNIW, and this was supported by the MS results.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 1; 149-159
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Genome size of the diploid hybrid species Hippophae goniocarpa and its parental species, H. rhamnoides ssp. sinensis and H. neurocarpa ssp. neurocarpa (Elaeagnaceae)
Autorzy:
Zhou, X.
Ma, J.
Wang, W.
Gong, N.
Zhang, Y.
Liu, J.
Powiązania:
https://bibliotekanauki.pl/articles/19367.pdf
Data publikacji:
2010
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2010, 52, 2
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fruit biomechanics based on anatomy: a review
Autorzy:
Li, Z.
Yang, H.
Li, P.
Liu, J.
Wang, J.
Xu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/24093.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Opis:
Fruit biomechanics is needed for quality determination, multiscale modelling and engineering design of fruit processes and equipments. However, these determined fruit biomechanics data often have obvious differences for the same fruit or tissue. In order to investigate it, the fruit biomechanics based on anatomy was reviewed in this paper. First, the anatomical characteristics of fruit biomaterials were described at the macroscopic ‘tissue’ level and microscopic ‘cellular’ level. Subsequently, the factors affecting fruit biomechanics based on anatomy and the relationships between fruit biomechanics, texture and mechanical damage were summarised according to the published literature. Fruit biomechanics is mainly affected by size, number and arrangement of cells, quantity and volume of intracellular spaces, structure, thickness, chemical composition and permeability of cell walls, and pectin degradation level and turgor pressure within cells based on microanatomy. Four test methods and partial determined results of fruit biomechanics were listed and reviewed. The determined mechanical properties data of fruit are only approximate values by using the existing four test methods, owing to the fruit biomaterials being non-homogeneous and living. Lastly, further aspects for research on fruit biomechanics were proposed for the future.
Źródło:
International Agrophysics; 2013, 27, 1
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermally Induced Polymorphic Transformation of Hexanitrohexaazaisowurtzitane (HNIW) Investigated by in-situ X-ray Powder Diffraction
Autorzy:
Liu, Y.
Li, S.
Wang, Z.
Xu, J.
Sun, J.
Huang, H.
Powiązania:
https://bibliotekanauki.pl/articles/358065.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HNIW
polymorphism
in situ X-ray diffraction
phase transition
heat stimulation
Opis:
The ε→γ phase transition of HNIW induced by heat was investigated with in situ X-ray powder diffraction (PXRD). The effects of purity, particle size, insensitive additives and the time of isothermal heat treatment on the phase transition were evaluated. It was found that the phase transition is irreversible with changes in temperature, and the two phases can coexist in a certain temperature range. Moreover, the initial phase transition temperature increases with increasing purity and decreasing particle size of HNIW, and thus with the approximate crystal density. The addition of graphite and paraffin wax to HNIW as insensitive additives leads to a decrease in the initial phase transition temperature, but the addition of TATB does not affect the initial phase transition temperature. Thus, TATB is a suitable insensitive additive. Moreover, at the critical temperature, the isothermal time determined the efficiency of the ε- to γ-phase transition. This work lays the foundations for the choice of molding technologies, performance test methods, ammunition storage options, as well as the manufacture of HNIW-based explosive formulations.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 4; 1023-1037
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł

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