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Wyświetlanie 1-53 z 53
Tytuł:
Inhibiting effect of citric acid on the floatability of serpentine activated by Cu(II) and Ni(II) ions
Autorzy:
Huang, Jun-wei
Zhang, Cheng-qiang
Powiązania:
https://bibliotekanauki.pl/articles/110224.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
copper ion
nickel ion
serpentine
floatation
activation
inhibiting
Opis:
The laboratory researches about the inhibiting effect of citric acid on the flotation performance of serpentine activated by Cu2+ and Ni2+ were carried out through micro flotation tests, zeta potential measurements, collector adsorption capacity measurements and solution chemistry analysis. The flotation results showed that Cu2+ and Ni2+ could remarkably activate the flotation of serpentine when the pH value was more than 6, however, this activation could be effectively weakened by adding citric acid. Zeta potential measurement and adsorption capacity measurement indicated that the presence of citric acid could prevent the adsorption of Cu2+ and Ni2+, and therefore reduce the adsorption amount of potassium butyl xanthate on serpentine surface. Furthermore, solution chemical analysis of the flotation system showed that copper hydroxide Cu(OH)2(s) and the nickel hydroxide Ni(OH)2(s) were the main component in the pH range of 9 to 10, which adsorbed onto serpentine surface and made it activated; while the citric acid could effectively prohibit the formation of these metal hydroxide in slurry so as to inhibit the activation impact.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 4; 960-968
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of ecological restoration patterns on runoff and sediment in an abandoned coal mine of Southern China
Autorzy:
Li, Hao
Chen, Wenbo
Zhang, Cheng
He, Lei
Liang, Haifen
Li, Haifeng
Liu, Dingpu
Powiązania:
https://bibliotekanauki.pl/articles/28407391.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
citrus fruit
soil conservation
vegetation
Jiangxi Province
ecological restoration
coal mine
owoce cytrusowe
ochrona gleby
wegetacja
Prowincja Jiangxi
renowacja ekologiczna
kopalnia węgla
Opis:
Evaluating the ecological economic benefits of different ecological restoration patterns in abandoned mines is important in ecological restoration study. Taking the abandoned coal mine in Luoshi Township of Fengcheng county, Jiangxi province, as a case, 4 different ecological restoration patterns (grapefruit with grass vegetation – Pattern I, pine with grass vegetation – Pattern II, grapefruit – Pattern III, and bare slope – Pattern IV) have been conducted to study the runoff and sediment yield under natural rainfall conditions. The results showed that the ecological restoration patterns and rainfall intensity can significantly affect runoff and sediment yield which increased as rainfall intensity increased: Pattern IV > Pattern III > Pattern II > Pattern I. For the optimal ecological restoration with Pattern I, the average runoff and sediment reduction was 59.01 and 77.1%, respectively, in all rainfall intensities. Multivariate analysis of variance (MANOVA) showed that runoff and sediment were significantly affected by ecological restoration pattern and rainfall intensity (P < 0.05). Correlation analysis of runoff and sediment yields indicated that the reduction effect on sediment yield increased with the decrease of runoff, and the relationships between runoff and sediment at different ecological restoration patterns could be fitted with a linear function. Moreover, the vegetation configuration that combines fruit farming with grass can be not only beneficial to control soil and water conservation but produce considerable economic and ecological benefits.
Źródło:
Environment Protection Engineering; 2023, 49, 4; 29--44
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient phosphate removal in swine wastewatewater using Fe-Mn-modified pyro/hydrochar from swine manure
Autorzy:
Zhu, Fanglun
Zhang, Cheng
Shan, Shengdao
Yuan, Wenqiao
Pawłowski, Artur
Song, Chengfang
Cao, Yucheng
Li, Yongfu
Wangj, Junjie
Qian, Jinyao
Powiązania:
https://bibliotekanauki.pl/articles/2032865.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
phosphate adsorption
pig
water eutrophication
biochar
swine manure
adsorpcja fosforanów
trzoda chlewna
eutrofizacja wód
biowęgiel
obornik świński
Opis:
Phosphorus in wastewater is one of the main causes of water eutrophication. Phosphorus removal from swine wastewater is always a challenge. To achieve on-site recycling of swine farm waste, the low-cost pyro/hydrochars and their Fe-Mn-modified form were prepared from swine manure as an efficient adsorbent for phosphate removal. The results showed that the phosphate removal efficiency of unmodified pyro/hydrochars was less than 7.77%, which was significantly increased to 58.21–83.76% for the Fe-Mn-modified-pyro/hydrochars. The maximum adsorption capacity of pyrochar was found on the Fe-Mn-modified-pyrochar (PC-600M) with a surface area of 102.03 m2/g and a micropore volume of 0.25 cm3/g. The PC-600M exhibited high adsorption capacity (26.07 mg/g) in a low concentration of phosphate (50 mg/dm3), and its removal efficiency reached up to 83.76% within 24 hours. Furthermore, the adsorption of phosphate on biochars without modification (HC-210 and PC-600) was validated using a first-order kinetic model, and the adsorption of phosphate on modified biochars (HC-210M and PC-600M) was well described by the second-order kinetic model and Langmuir isotherm. In addition, there is no significant difference in the adsorption of phosphorus between pyrochars and hydrochars, but the preparation cost of hydrochars is lower than that of pyrochars. It was confirmed that the low-cost Fe-Mn-modified pyro/hydrochar from swine manure had potential for efficient phosphate removal in wastewater treatment and would facilitate value-added utilization of swine manure.
Źródło:
Environment Protection Engineering; 2021, 47, 3; 83-101
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ezetimibe prevents myocardial remodeling in an obese rat model by inhibiting inflammation
Autorzy:
Li, Xiao-Xing
Zhao, Lang
Chang, Ying
Liu, Bao-Shan
Xu, Feng
Zhang, Cheng
Ji, Xiao-Ping
Chen, Yu-Guo
Li, Chuan-Bao
Powiązania:
https://bibliotekanauki.pl/articles/1038380.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
obese
inflammation
remodeling
ezetimibe
IL-6
Opis:
Inflammation plays an important role in the development of many obesity-related diseases. This study aimed to investigate the effect of ezetimibe on inflammation and myocardial remodeling in obese rats. A rat model of obesity was established, and myocardial damage was examined by transmission electron microscopy and Masson staining. Twenty obese rats were divided into two groups (n=10): obese group and ezetimibe group. Ten SD rats were used as controls. Western blot was performed to monitor the expression of P-p38MAPK and interleukin (IL)-6. Immunohistochemical staining was used to monitor the expression of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1. In the obese rats group, we observed increased inflammatory factors and myocardial hypertrophy. In contrast, the ezetimibe group exhibited decreased expression of inflammatory factors and an improvement in myocardial remodeling compared to the obese group. Mechanistically, we found that ezetimibe decreased P-p38MAPK, IL-6, intercellular adhesion molecule-1, and vascular cell adhesion molecule-1 levels in the hearts of the obese rats. Taken together, these results indicate that ezetimibe may improve myocardial remodeling in obese rats by inhibiting inflammation.
Źródło:
Acta Biochimica Polonica; 2018, 65, 3; 465-470
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Existence criteria for positive solutions of a nonlinear difference inequality
Autorzy:
Cheng, Sui
Zhang, Guang
Powiązania:
https://bibliotekanauki.pl/articles/1208008.pdf
Data publikacji:
2000
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
Sturm type comparison theorem
limit comparison theorem
nth order linear difference equation
eventually positive solution
eventually positive nonincreasing solution
neutral difference equation
nonlinear delay difference inequality
Opis:
This paper is concerned with a class of nonlinear difference inequalities which include many different classes of difference inequalities and equations as special cases. By means of a Riccati type transformation, necessary and sufficient conditions for the existence of eventually positive solutions and positive nonincreasing solutions are obtained. Various type of comparison theorems are also derived as applications, which extends many theorems in the literature.
Źródło:
Annales Polonici Mathematici; 2000, 73, 3; 197-220
0066-2216
Pojawia się w:
Annales Polonici Mathematici
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Asymptotic dichotomy for nonoscillatory solutions of a nonlinear difference equation
Autorzy:
Zhang, Guang
Cheng, Sui
Powiązania:
https://bibliotekanauki.pl/articles/1338877.pdf
Data publikacji:
1999
Wydawca:
Polska Akademia Nauk. Instytut Matematyczny PAN
Tematy:
difference equation
eventually positive solution
asymptotic dichotomy
Opis:
A nonlinear difference equation involving the maximum function is studied. We derive sufficient conditions in order that eventually positive or eventually negative solutions tend to zero or to positive or negative infinity.
Źródło:
Applicationes Mathematicae; 1998-1999, 25, 4; 393-399
1233-7234
Pojawia się w:
Applicationes Mathematicae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SIRT3-SOD2-ROS pathway is involved in linalool-induced glioma cell apoptotic death
Autorzy:
Cheng, Yanhao
Dai, Chao
Zhang, Jian
Powiązania:
https://bibliotekanauki.pl/articles/1038661.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
linalool
glioma
apoptotic cell death
SIRT3
SOD2
Opis:
Glioma is the most prevalent type of adult primary brain tumor and chemotherapy of glioma was limited by drug-resistance. Linalool is an acyclic monoterpene alcohol possessing various pharmacological activities. The present study was conducted to evaluate the effect of linalool on glioma cell growth. The effect of linalool on cell viability in U87-MG cells was investigated and the results showed that linalool significantly reduced cell viability in a concentration- and time-dependent manner. In addition, exposure of the cells to linalool resulted in a concentration-dependent increase of TUNEL-stained cells, indicating the occurrence of apoptotic cell death. Linalool decreased mitochondrial oxygen consumption rate, increased the expression of Bax and Bak, reduced the expression of Bcl-2 and Bcl-xl, and increased the activities of caspase 3 and caspase 9, leading to increase of apoptosis. Linalool resulted in a concentration-dependent decrease of SOD activity but had no significant effect on mRNA and protein expression of SOD2. Moreover, linalool resulted in a significant increase of the expression of acetylated SOD2. The mRNA and protein expression of SIRT3 was significantly inhibited by linalool. Immunoblot analysis showed that there was an evident protein/protein interaction between SOD2 and SIRT3 under normal condition. Linalool treatment significantly decreased the interaction between SOD2 and SIRT3. Overexpression of SIRT3 significantly inhibited linalool-induced increase of mitochondrial ROS production and apoptotic cell death, and decrease of cell viability. In summary, the data demonstrated that linalool exhibited inhibitory effect on glioma cells through regulation of SIRT3-SOD2-ROS signaling.
Źródło:
Acta Biochimica Polonica; 2017, 64, 2; 343-350
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Is Chinas Textile Industry Still a Labour-Intensive Industry?
Czy chiński przemysł tekstylny nadal jest przemysłem pracochłonnym?
Autorzy:
Zhang, Jianlei
He, Lin
Cheng, Longdi
Powiązania:
https://bibliotekanauki.pl/articles/1419851.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
textile industry
labour-intensive industry
factor intensity classification
capital-labour intensity
technology intensity
przemysł tekstylny
przemysł pracochłonny
klasyfikacja intensywności czynników
kapitałochłonność
intensywność technologii
Opis:
Is China's textile industry (CTI) still a laboor-intensive one? To answer this question, this study measures the capital-labour intensity and technology intensity of CTI and its subsectors during 2006-2018, then applies factor intensity classification and cluster analysis to identify their industrial attributes. The results show that CTI and its sub-sectors are still the labour- and non-technology-intensive. All the indexes of capital-labour intensity and technology intensity of CTI and its sub-sectors are below 100, lower than the average of industry sectors, indicating that they are not separate from the category of labour-intensive industry and still heavily dependent on labour. And cluster analysis verifies the industrial classification results. So CTI still needs to keep on increasing its capital intensity and technology intensity to achieve the goal of industrial transformation and upgrading in the future.
Czy chiński przemysł tekstylny nadal wymaga dużego nakładu pracy? Aby odpowiedzieć na to pytanie zbadano kapitałochłonność i intensywność technologiczną chińskiego przemysłu tekstylnego i jego podsektorów w latach 2006-2018, a następnie zastosowano klasyfikację intensywności czynników i analizę skupień w celu określenia ich atrybutów przemysłowych. Wyniki pokazały, że chiński przemysł tekstylny i jego podsektory nadal są pracochłonne i nie wymagają dużej ilości technologii. Wszystkie wskaźniki kapitałochłonności i technologiczno-pracochłonności chińskiego przemysłu tekstylnego i jego podsektorów kształtują się poniżej 100, czyli są niższe od średniej dla sektorów przemysłu, co wskazuje, że nie są one oddzielone od kategorii przemysłu pracochłonnego. Analiza skupień weryfikuje wyniki klasyfikacji przemysłowej. Chiński przemysł tekstylny nadal musi zwiększać swoją kapitałochłonność i intensywność technologii, aby osiągnąć cel, jakim jest transformacja przemysłowa i modernizacja w przyszłości.
Źródło:
Fibres & Textiles in Eastern Europe; 2021, 1 (145); 13-16
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Neuro-adaptive cooperative control for high-order nonlinear multi-agent systems with uncertainties
Autorzy:
Peng, Cheng
Zhang, Anguo
Li, Junyu
Powiązania:
https://bibliotekanauki.pl/articles/2055174.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
multiagent system
radial basis function
RBF neural network
sliding mode control
cooperative control
system wieloagentowy
radialna funkcja bazowa
sieć neuronowa RBF
sterowanie ślizgowe
Opis:
The consensus problem for a class of high-order nonlinear multi-agent systems (MASs) with external disturbance and system uncertainty is studied. We design an online-update radial basis function (RBF) neural network based distributed adaptive control protocol, where the sliding model control method is also applied to eliminate the influence of the external disturbance and system uncertainty. System consensus is verified by using the Lyapunov stability theorem, and sufficient conditions for cooperative uniform ultimately boundedness (CUUB) are also derived. Two simulation examples demonstrate the effectiveness of the proposed method for both homogeneous and heterogeneous MASs.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2021, 31, 4; 635--645
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structural Changes and Growth Factors of China’s Textile Industry: 1997-2012
Zmiany strukturalne i czynniki wzrostu chińskiego przemysłu tekstylnego w latach 1997-2012
Autorzy:
Zhang, J.
Liu, Y.
Cheng, L.
Powiązania:
https://bibliotekanauki.pl/articles/234180.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
China’s textile industry
structural change
growth factors
structural decomposition analysis
przemysł włókienniczy w Chinach
zmiana strukturalna
czynniki wzrostowe
analiza rozkładu strukturalnego
Opis:
In this study, the Input-Output Structural Decomposition Analysis (I-O SDA) method is adopted to analyze the structural change in China's textile industry during 1997-2012 and to measure the contribution rate of the growth factors (consumption, investment, inventory, exports and imports) affecting change in its gross output. Then the key factors and main driving forces promoting textile industry development are figured out. The results show that China's textile industry has experienced great change both in scale and structure. Among the growth factors, the contribution rate of exports is the largest, followed by investment, consumption, imports and inventory. The textile industry still relies heavily on exports, investment and consumption, while the contribution rate of imports is relatively small. In addition, technological change makes a positive contribution with technological innovation. Among the industrial sectors, the cotton& chemical fibre textile industry holds dominance, with the textile manufactured goods industry exhibiting tremendous development, the growth of the knitted textile industry fluctuating, and the wool textile industry and hemp& silk textile industry progressing slowly. Finally relevant policy suggestions are proposed to promote the balanced and coordinated development of China's textile industry.
W celu analizy strukturalnej zmian chińskiego przemysłu tekstylnego w latach 1997-2012 oraz pomiaru czynników wzrostu tj. konsumpcji, inwestycji, rezerw, eksportu i importu wpływających na zmianę wielkości produkcji globalnej zastosowano metodę analizy strukturalnej rozkładów międzygałęziowych (IO SDA). Następnie ustalono kluczowe czynniki i główne siły wspierające rozwój przemysłu włókienniczego. Wyniki pokazują, że przemysł włókienniczy w Chinach przeszedł wielką zmianę zarówno pod względem skali, jak i struktury. Wśród czynników wzrostu największy udział ma eksport, a następnie inwestycje, konsumpcja, import i rezerwy. Przemysł włókienniczy w dalszym ciągu w dużym stopniu opiera się na eksporcie, inwestycjach i konsumpcji, podczas gdy udział importu jest stosunkowo niewielki. Ponadto zmiana technologiczna ma pozytywny wpływ na innowacje. Spośród sektorów przemysłowych dominuje przemysł włókien bawełnianych i chemicznych, a przemysł tekstylny stale się rozwija, rozwój dziewiarstwa podlega fluktuacjom, a rozwój przemysłu włókien wełnianych, konopnych i jedwabnych postępuje powoli . Autorzy sformułowali pewne sugestie mające na celu promowanie zrównoważonego i skoordynowanego rozwoju chińskiego przemysłu tekstylnego.
Źródło:
Fibres & Textiles in Eastern Europe; 2018, 2 (128); 20-25
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heating control of heated twin radiosonde humidity sensor based on DMC
Autorzy:
Sun, N.
Zhang, Y.
Zhang, W
Cheng, E.
Liu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/260018.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
DMC
twin heated humidity sensor
expanded responsible curve
heating control
Opis:
In order to effectively solve condensation and icing problems of radiosonde in low-temperature environment at high altitude, humidity sensor heated automatic alternately to remove pollution and improve the measurement accuracy. Heat experiments obtained the curve of rising temperature and responsible time on heated twin humidity sensor in normal temperature and pressure, by expanded responsible curve to obtain heated model of twin heated humidity sensor and by the analysis of heating model, use DMC and PID control for heating respectively. Simulation results show that the DMC control meets the practical requirements of measure at high altitude.
Źródło:
Polish Maritime Research; 2016, S 1; 52-58
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mathematical Model of Embedded Temperature Sensing Fabric Heat Transmission
Matematyczny model przepływu ciepła w tkaninie z umieszczonym w niej czujniku temperatury
Autorzy:
Zhang, R.
Deng, N.
Cheng, B.
Zhang, S.
Wu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/949451.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
temperature sensing fabric
mathematical model
surface contact thermal resistance
testing system
temperature value
tkanina
czujnik temperatury
model matematyczny
oporność termiczna
system testowania
wartość temperatury
Opis:
In order to explore effect factors in the measurement of temperature sensing fabric, a heat transmission mathematical model of temperature sensing fabric was established. The concept of surface contact thermal resistance associated with the material thermal conductivity, fabric layer number and yarn linear density between the fabric and sensor was proposed in the model, whose surface contact thermal resistance was produced in the process of fabric heat transmission. Some test samples were woven to prove the rationality of the model. The results demonstrated that the value measured would be influenced by the performances of surface contact thermal resistance, which was consistent with the derivation of the theoretical model. The raw material, fabric layer number and yarn linear density of temperature sensing fabric had a great effect on the measurement value. The correlation coefficient reached more than 0.988 among the experimental and theoretical values, respectively, which proved that the heat transmission mathematical model of temperature sensing fabric could be applied in the research of this fabric.
Opracowano matematyczny model przepływu ciepła przez tkaninę zawierającą wbudowane czujniki temperatury w celu określenia wpływu poszczególnych czynników na przebieg pomiarów. Brano pod uwagę oporność termiczną styku czujników z tkaniną związaną z przewodnością termiczną materiału, ilość warstw i masę liniową przędz w obrębie tkaniny i czujników. Uzyskane współczynniki korelacji pomiędzy wartościami eksperymentalnymi i teoretycznymi przekraczały 0,988 co potwierdza, że opracowany przez nas matematyczny model przepływu ciepła w tkaninie pomiarowej można zastosować w tego typu badaniach.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 5 (119); 73-79
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Surface modification of fly ash spheroidal particles and their application in the adsorption of phosphorus and chromium(VI) from single and competitive solute systems
Autorzy:
Chen, Chen
Cheng, Ting
Zhang, Xiao
Zhang, Minte
Lv, Ruiyang
Powiązania:
https://bibliotekanauki.pl/articles/2032957.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
fly ash
Langmuir isotherm
adsorption phosphorus
popiół lotny
izoterma Langmuira
adsorpcja fosforu
Opis:
This work focuses on the surface modification of fly ash spheroidal particles and their application in phosphorus and chromium(VI) adsorption. The results show that through surface modification, amorphous silica-alumina gels precipitated on the spheroidal particle surface (by which the microsurface area of the reaction products is effectively enlarged) and the surface zeta potential was changed to fit for adsorbing anions. During the adsorption experiment (single and competitive solute systems), chromium(VI) was easier to adsorb. The surface zeta potential and the existence of competitive ions should be recognized as two important factors affecting adsorption efficiency. A higher temperature could improve the adsorption efficiencies of the two solute systems. The fitting results of the pseudo-second-order model (single and competitive solute systems) show better agreement than those of the pseudo-first-order model at every temperature. The Langmuir adsorption isotherm equation can better simulate the adsorption process in single solute sy039stems, but only the chromium(VI) adsorption process can be fitted by the competitive Langmuir adsorption isotherm in competitive solute systems.
Źródło:
Environment Protection Engineering; 2020, 46, 3; 39-59
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method of Structure Design and Heat Treatment of an Integrated Consolidation Sensor and Embedded Temperature Sensing Fabric
Metoda projektowania struktury zintegrowanego czujnika temperatury wbudowanego w tkaninę
Autorzy:
Zhang, R.
Deng, N.
Cheng, B.
Wu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/949452.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
temperature sensing fabric
structure design
partial heat treatment
fabric testing
temperature value
tkanina
czujnik temperatury
częściowa obróbka cieplna
testy tkanin
wartość temperatury
Opis:
In order to solve the problem of temperature sensors easily slipping and improve the precision of temperature measurement in temperature sensing fabric, a specially designed fabric was developed. In this paper, the fabric comprised plain and multi-layered fabric. Sensors were embedded into the multi-layered fabric. The multi-layered fabric was treated by partial heat treatment to make the temperature sensors be fixed to the fabric. The temperature sensing fabrics were measured before and after the partial heat treatment. The results showed that during the heat treatment, the number of fabric layers and fabric organization had an effect on temperature measurement, and the values measured after partial heat treatment were closer to the true value than without treatment. In addition, with an increase in the number of fabric layesr, the values measured were closer to the real value. And the measurement results were closer to the true value when the multi-layered fabric’s organizational structure was plain.
Dla uzyskania hybrydowego elementu pomiarowego opracowano taką strukturę tkaniny aby móc umieścić w niej czujniki temperatury. Wielowarstwową tkaninę poddano odpowiedniej obróbce termicznej umożliwiającej zamocowanie czujników w tkaninie. Stwierdzono, że ilość warstw tkaniny i ich rozmieszczenie ma wyraźny wpływ na uzyskiwaną dokładność pomiaru temperatury. Przy zwiększeniu ilości warstw wzrastała dokładność pomiaru.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 5 (119); 68-72
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Growth, proline content and proline-associated gene expression of autotetraploid Betula platyphylla responding to NaHCO3 stress
Autorzy:
Mu, H.
Lin, L.
Zhang, Q.
Tang, X.
Zhang, X.
Cheng, G.
Powiązania:
https://bibliotekanauki.pl/articles/41683.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
plant growth
proline content
stress response
gene expression
autotetraploid
Betula platyphylla
birch
Sodium bicarbonate
plant stress
Opis:
Plant breeders have focused much attention on polyploid trees because of their resistance for forestry. To evaluate the impact of intraspecies genome duplication on NaHCO3 stress, a series of Betula platyphylla autotetraploids and diploids were generated from the same family. The growth, proline content and proline-associated gene expression of these autotetraploid individuals were compared with those diploid trees. Autotetraploids were superior in injury index and relative growth of height and base diameter compared to diploids. The proline content was higher in autotetraploid individuals compared to diploids. Gene expression data revealed autotetraploids were generally higher expression in BpP5CS1, BpP5CS2, Bp- P5CR1, BpP5CR2, BpP5CR3 and BpOAT and were lower expression in BpProDH and BpP5CDH compared to diploid trees. These results shed light on resistance variation in birch autotetraploidization and polyploidy breeding as a new approach for genetic improvement of birch trees.
Źródło:
Dendrobiology; 2016, 75
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamical modeling and coupling characteristic analysis of the multistage gears system in a continuous miner
Autorzy:
Lu, Wenjia
Zhang, Yimin
Cheng, Hongchuan
Yang, Zhou
Powiązania:
https://bibliotekanauki.pl/articles/279213.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
planets
multistage gear
continuous miner
acceleration
Opis:
The lumped parameter method is adopted to establish a dynamic model of two stage planets and multistage fixed-shaft gears in which the effect of coupling shaft section radius on the system in a continuous miner is considered. The acceleration test of the system proves the accuracy of the proposed model. With the increase of cross section size of the coupled shaft, the influence of the first stage meshing frequency on the second stage planetary system is enhanced. The acceleration decreases gradually with the increase of the size of coupled carrier. It is shown that the modeling by considering the coupled size contributes to reduction of the vibration level.
Źródło:
Journal of Theoretical and Applied Mechanics; 2020, 58, 1; 45-58
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of control parameters on synchronization stability of virtual synchronous generator
Autorzy:
Zhang, Yanxia
Cheng, Yachao
Liu, Kaixiang
Han, Yue
Powiązania:
https://bibliotekanauki.pl/articles/2172794.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
control parameter
frequency modulation coefficient
phase plane method
synchronization stability
virtual synchronous generator
Opis:
Different from the synchronization mechanism of synchronous generators, the non-synchronous generators must be synchronized with the grid through a controller. Generally, the virtual synchronous generator (VSG) control strategy is adopted for this purpose. In view of the current situation, where the control loops are not comprehensively considered in the research of the synchronization stability of the VSG, this paper considers multiple control loops, such as active frequency loops, virtual governors, power filters and current constraint control, to establish the mathematical model of the VSG and infinite system. On this basis, the correlation formula between power angle difference and control parameters is deduced. Adopting the phase plane method, the influence of different control loops and their parameters on the transient synchronization stability is analyzed. Finally, a setting principle of the frequency modulation coefficient of virtual governors is proposed, which not only meets the response speed of control systems, but also has good control performance.
Źródło:
Archives of Electrical Engineering; 2022, 71, 4; 811--828
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study on the flowback of a carboxymethyl hydroxypropyl guar gum fracturing fluid with good temperature resistance
Autorzy:
Dai, Xiaodong
Li, Lei
Zhang, Xin
Cheng, Zhensong
Powiązania:
https://bibliotekanauki.pl/articles/2200830.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
fracturing fluid
backflow rate
injection pressure
displacement direction
proppant wettability
Opis:
For unconventional oil and gas reservoirs such as shale oil and gas as well as tight oil and gas, hydraulic fracturing generally enhances oil recovery. However, the flowback rate of the residual fracturing fluid is low. The residual fracturing fluid in the fracture or the rock ma- trix can reduce relative permeability of oil and gas, and the production rate will decrease. Therefore, it is necessary to study the factors that affect the flowback rate of the fracturing fluid. Most previous studies used the slot model, and viscous and capillary forces explain stable discharge in porous media. The conclusions were only a primarily qualitative analysis. The factors from experimental studies were not comprehensive, and they did not consider the influence of gravity. There are few studies on unstable drainage in porous media un- der different displacement directions. This paper presents a carboxymethyl hydroxypropyl guar gum fracturing fluid with good temperature resistance, and a fracturing fluid flowback experiment is carried on. The effects of the displacement direction, injection pressure, inter- facial tension, fracturing fluid viscosity, and proppant wettability on the flowback rate are analyzed. The research results can provide formulation of the on-site construction scheme.
Źródło:
Journal of Theoretical and Applied Mechanics; 2022, 60, 4; 733--744
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ustalanie harmonogramu obsługi dla systemu wieloelementowego: podejście oparte na stochastycznych sieciach Petriego oraz algorytmie genetycznym
Maintenance scheduling for multi-unit system: a stochastic Petri-net and genetic algorithm based approach
Autorzy:
Zhang, T.
Cheng, Z.
Liu, Y. J.
Guo, B.
Powiązania:
https://bibliotekanauki.pl/articles/301668.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
ustalanie harmonogramu obsługi
system wieloelementowy
sieć Petriego
algorytm genetyczny
minimalny przekrój niezdatności
maintenance scheduling
multi-unit system
Petri net
genetic algorithm
deterioration
minimal cut set
Opis:
Częste czynności obsługowe prowadzą do niskiej gotowości systemu oraz wymagają dużych nakładów pieniężnych. W systemie wieloelementowym całkowity czas i koszt obsługi można obniżać łącząc ze sobą czynności obsługowe niektórych elementów. Dlatego też konieczne jest planowanie zoptymalizowanego harmonogramu czynności obsługowych. W artykule zaproponowano model symulacyjny optymalizacji harmonogramu obsługi oparty na stochastycznych sieciach Petriego uwzględniający niepewność zarówno procesu deterioracji jak i procesu obsługi elementów systemu. Algorytm genetyczny wykorzystano do opracowania terminarza czynności obsługowych, który pozwalałby na minimalizację kosztów całkowitych w przyjętym horyzoncie planowania przy uwzględnieniu całkowitego czasu obsługi, stanu elementów, strat wynikających z cyklu życia oraz wykonalności rozwiązania. Ponadto opisano techniki zastosowane w celu zmniejszenia wysiłku obliczeniowego potrzebnego do wykonania analizy. W końcowej części pracy przedstawiono studium przypadku.
Frequent maintenance activities would cause low system availability and require large sums of money. For a multi-unit system, maintenance activities of some units can be combined together to reduce the total maintenance possession time and cost. Therefore, an optimized timetable of the maintenance activities is needed to be planned. Considering the uncertainties in both the deterioration and maintenance process of the units in a system, this paper advances a stochastic Petri-net based simulation optimization model for maintenance scheduling. The genetic algorithm is used to get the solution of the timetable of the maintenance activity schedule such that the overall cost is minimized in a planning horizon taking into account total maintenance possession time, unit condition, life cycle loss and solution feasibility. Some techniques used to reduce the computational effort required to perform the analysis are also described. A case study is given in the end.
Źródło:
Eksploatacja i Niezawodność; 2012, 14, 3; 256-264
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bounded-abstaining classification for breast tumors in imbalanced ultrasound images
Autorzy:
Guan, Hongjiao
Zhang, Yingtao
Cheng, Heng-Da
Tang, Xianglong
Powiązania:
https://bibliotekanauki.pl/articles/330479.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
breast ultrasound image
reliable diagnosis
abstaining classification
imbalanced dataset
ultrasonografia piersi
diagnoza wiarygodna
zbiór danych niezrównoważony
Opis:
Computer-aided breast ultrasound (BUS) diagnosis remains a difficult task. One of the challenges is that imbalanced BUS datasets lead to poor performance, especially with regard to low accuracy in the minority (malignant tumor) class. Missed diagnosis of malignant tumors can cause serious consequences, such as delaying treatment and increasing the risk of death. Moreover, many diagnosis methods do not consider classification reliability; thus, some classifications may have a large uncertainty. To resolve such problems, a bounded-abstaining classification model is proposed. It maximizes the area under the ROC curve (AUC) under two abstention constraints. A total of 219 (92 malignant and 127 benign) BUS images are collected from the First Affiliated Hospital of Harbin Medical University, China. The experiment tests BUS datasets of three imbalance levels, and the performance contours are analyzed. The results demonstrate that AUC-rejection curves are less affected by class imbalance than accuracy-rejection curves. Compared with the state-of-the-art, the proposed method yields a significantly larger AUC and G-mean using imbalanced BUS datasets.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2020, 30, 2; 325-336
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Influence of cutting parameters and tool edge geometries on the machinability of AlSi aisi 52100 steel in hard whirling
Autorzy:
Song, Shuquan
Zhang, Yu
Cheng, Jiangtao
Zhang, Hao
Guan, Xiangyu
Zuo, Dunwen
Shen, Xiaoqiang
Powiązania:
https://bibliotekanauki.pl/articles/38905217.pdf
Data publikacji:
2023
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
hard whirling
cutting edge radius
cutting parameters
machinability
Opis:
The synergistic effect of prepared tool edge and cutting parameters in hard whirling is still unclear, limiting its application in producing large precision ball screws. This paper aims to reveal the effect mechanism of cutting parameters and edge geometries in the whirling process to improve the stability of ball screw quality. A novel cutting force measurement strategy is proposed, and a systematic study of cutting force, surface quality and tool wear is implemented. The results show that small feed (less than 0.15 mm) and high cutting speed (more than 180 m/min) can ensure machining efficiency and improve surface quality. The machining quality can be improved when the edge radius is 10 µm, and the chamfer size is 0.1 mm × 20◦ . The tool with a 30 µm edge radius has a low probability of early failure, but the later wear is severe and timely sharpening is recommended. This study could guide cutting parameters and edge geometry optimization to improve the stability of the quality in hard whirling.
Źródło:
Engineering Transactions; 2023, 71, 3; 399-417
0867-888X
Pojawia się w:
Engineering Transactions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A geometric accuracy design method of multi-axis NC machine tool for improving machining accuracy reliability
Metoda projektowania i poprawy niezawodności dokładności obróbczej wieloosiowej obrabiarki NC wykorzystująca pojęcie dokładności geometrycznej
Autorzy:
Cai, L.
Zhang, Z.
Cheng, Q.
Liu, Z.
Gu, P.
Powiązania:
https://bibliotekanauki.pl/articles/301459.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
machine tool
geometric error
accuracy distribution
machining accuracy reliability
multi-body system theory
obrabiarka
błąd geometryczny
rozkład dokładności
niezawodność dokładności obróbki
teoria układów wielomasowych
Opis:
The reliability of machining accuracy is of great significance to performance evaluation and optimization design of the machine tools. Different geometric errors have various influences on the machining accuracy of the machine tools. The main emphasis of this paper is to propose a generalized method to distribute geometric accuracy of component for improving machining accuracy reliability under certain design requirements. By applying MBS theory, a comprehensive volumetric model explaining how individual errors in the components of a machine affect its volumetric accuracy (the coupling relationship) was established. In order to reflect the ability to reach the required machining accuracy, the concept of machining accuracy reliability is proposed in this paper. Based on advanced first order and second moment (AFOSM) theory, reliability and sensitivity with single failure modes were obtained and the model of machining accuracy reliability and the model of machining accuracy sensitivity with multiple failure modes were developed. By taking machining accuracy reliability as a measure of the ability of machine tool and taking machining accuracy sensitivity as a reference of optimizing the basic parameters of machine tools to design a machine tool, an accuracy distribution method of machine tools for improving machining accuracy reliability with multiple failure modes was developed and a case study example for a five-axis NC machine tool was used to demonstrate the effectiveness of this method. It is identified that each improvement of the geometric errors leads to a decrease in the maximum values and mean values of possibility of failure, and the gaps among reliability sensitivity of geometric parameter errors improved also decreased. This study suggests that it is possible to obtain the relationships between geometric errors and specify the accuracy grades of main feeding components of mechanical assemblies for improving machining accuracy reliability.
Niezawodność w zakresie dokładności obróbki ma wielkie znaczenie dla oceny funkcjonowania oraz projektowania optymalizacyjnego obrabiarek. Różne błędy geometryczne mają różny wpływ na dokładność obrabiarek. Głównym celem niniejszej pracy jest zaproponowanie uogólnionej metody rozkładu dokładności geometrycznej elementów składowych obrabiarki, pozwalającej na poprawę niezawodności w zakresie dokładności obróbczej przy spełnieniu pewnych wymagań projektowych. Dzięki zastosowaniu teorii układów wielomasowych MBS, opracowano kompleksowy model wolumetryczny, który wyjaśnia, w jaki sposób pojedyncze błędy występujące w elementach składowych obrabiarki wpływają na jej dokładność wolumetryczną (relacja sprzężeń). Zaproponowane w prezentowanym artykule pojęcie niezawodności dokładności obróbki odnosi się do możliwości uzyskania przez urządzenie wymaganej dokładności obróbki W oparciu o zaawansowaną teorię estymacji momentów AFOSM (Advanced First Order and Second Moment therory), obliczono niezawodność i czułość dla przypadku wystąpienia pojedynczej przyczyny uszkodzenia oraz opracowano model niezawodności dokładności obróbki oraz model czułości dokładności obróbki dla przypadku wystąpienia wielu przyczyn uszkodzeń. Przyjmując niezawodność dokładności obróbki za miarę poprawnego działania obrabiarki oraz przyjmując czułość dokładności obróbki za punkt odniesienia dla optymalizacji projektowej podstawowych parametrów obrabiarek, opracowano metodę, opartą na rozkładzie dokładności obrabiarki, mającą na celu poprawę niezawodności dokładności obróbki dla przypadku wystąpienia wielu przyczyn uszkodzeń. Skuteczność metody wykazano na przykładzie pięcio-osiowej obrabiarki NC. Stwierdzono, że każda korekta błędu geometrycznego prowadzi do spadku maksymalnych i średnich wartości możliwości wystąpienia uszkodzenia oraz zmniejsza rozstęp między poszczególnymi czułościami niezawodnościowymi skorygowanych błędów parametrów geometrycznych. Przedstawione badania wskazują, że możliwe jest ustalenie związku pomiędzy błędami geometrycznymi oraz określenie stopni dokładności głównych elementów składowych zespołów mechanicznych odpowiedzialnych za ruch posuwowy obrabiarki w celu poprawy niezawodności dokładności obróbki.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 1; 143-155
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utilization of N-carboxymethyl chitosan as a selective depressant for talc in flotation of chalcopyrite
Autorzy:
Liu, Cheng
Feng, Qiming
Shi, Qing
Zhang, Wencai
Song, Shaoxian
Powiązania:
https://bibliotekanauki.pl/articles/110512.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
chalcopyrite
talc
flotation separation
N-carboxymethyl chitosan
Opis:
Flotation separation of chalcopyrite from talc is difficult because of the natural hydrophobicity of two minerals. In this work, the flotation separation of chalcopyrite from talc using N-carboxymethyl chitosan as a depressant for talc was studied. The micro-flotation results indicated that the flotation separation of chalcopyrite from talc cannot be realized effectively at pH 9 with low concentration of N-carboxymethyl chitosan, in the presence of calcium ions, talc was more efficiently depressed by N-carboxymethyl chitosan, while the chalcopyrite recovery was not influenced. Contact angle, zeta potential and adsorption results showed that Ca2+ and CaOH+ absorbed on the talc surface and increased the absorption amount of N-carboxymethyl chitosan on the mineral surface, and increased hydrophilicity of talc surface, resulting the selective depression for talc in chalcopyrite flotation.
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 1; 108-115
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Intelligent fault diagnosis of rolling bearings based on continuous wavelet transform-multiscale feature fusion and improved channel attention mechanism
Autorzy:
Zhang, Jiqiang
Kong, Xiangwei
Cheng, Liu
Qi, Haochen
Yu, Mingzhu
Powiązania:
https://bibliotekanauki.pl/articles/24200817.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
deep learning
continuous wavelet transform
improved channel attention mechanism
multi-conditions
convolutional neural network
Opis:
Accurate fault diagnosis is critical to operating rotating machinery safely and efficiently. Traditional fault information description methods rely on experts to extract statistical features, which inevitably leads to the problem of information loss. As a result, this paper proposes an intelligent fault diagnosis of rolling bearings based on a continuous wavelet transform(CWT)-multiscale feature fusion and an improved channel attention mechanism. Different from traditional CNNs, CWT can convert the 1-D signals into 2-D images, and extract the wavelet power spectrum, which is conducive to model recognition. In this case, the multiscale feature fusion was implemented by the parallel 2-D convolutional neural networks to accomplish deeper feature fusion. Meanwhile, the channel attention mechanism is improved by converting from compressed to extended ways in the excitation block to better obtain the evaluation score of the channel. The proposed model has been validated using two bearing datasets, and the results show that it has excellent accuracy compared to existing methods.
Źródło:
Eksploatacja i Niezawodność; 2023, 25, 1; art. no. 16
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Dynamic response of a base-isolated concrete rectangular liquid-storage structure under large amplitude sloshing
Dynamiczna odpowiedź prostokątnej struktury magazynowania substancji ciekłych z wykorzystaniem betonu izolacyjnego
Autorzy:
Cheng, X.
Li, D.
Li, P.
Zhang, X.
Li, G.
Powiązania:
https://bibliotekanauki.pl/articles/230249.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
chlupotanie cieczy
amplituda duża
trzęsienie ziemi
struktura prostokątna
substancja ciekła
magazynowanie
nieliniowość
odpowiedź dynamiczna
liquid sloshing
large amplitude
earthquake
rectangular structure
liquid substance
storage
nonlinearity
dynamic response
Opis:
Considering concrete nonlinearity, the wave height limit between small and large amplitude sloshing is defined based on the Bernoulli equation. Based on Navier-Stokes equations, the mathematical model of large amplitude sloshing is established for a Concrete Rectangle Liquid-Storage Structure (CRLSS). The results show that the seismic response of a CRLSS increases with the increase of seismic intensity. Under different seismic fortification intensities, the change in trend of wave height, wallboard displacement, and stress are the same, but the amplitudes are not. The areas of stress concentration appear mainly at the connections between the wallboards, and the connections between the wallboard and the bottom.
Gdy amplituda chlupotania cieczy jest zbliżona do częstotliwości drgań struktury magazynowania substancji ciekłych (CRLSS), wówczas osiągamy rezonans i możemy zaobserwować silne zjawisko nieliniowe. Szkoda jest znacznie większa niż chlupotanie o małej amplitudzie. Obecnie brak jest odpowiedniego raportu na temat badań dynamicznej odpowiedzi struktury magazynowania substancji ciekłych z wykorzystaniem betonu izolacyjnego (CRLSS) z chlupotaniem o dużej amplitudzie, a wpływ materiałów betonowych nie jest brany pod uwagę. W związku z tym, w niniejszej pracy, w oparciu o równanie Bernoulliego, otrzymano ograniczone wysokości fali o dużej amplitudzie chlupotania oraz małej amplitudzie chlupotania. Na podstawie równań Naviera-Stokesa ustanowiono matematyczny model chlupotania o dużej amplitudzie i zbadano odpowiedź sejsmiczną CRLSS podczas chlupotania o dużej amplitudzie. Rozważając równanie Bernoulliego i zadowalający stan, chlupotanie substancji ciekłej jest liniowe, a nieliniowy kwadratowy człon jest lekceważony. W stałym i płynnym interfejsie, struktura magazynowania substancji ciekłych spełnia warunki ciągłości przemieszczania i równowagi siły oddziaływań. Właściwość mechaniczna gumowego zabezpieczenia izolacyjnego została opisana w oparciu o konstytutywną relacje modelu Mooney-Rivlin.
Źródło:
Archives of Civil Engineering; 2017, 63, 1; 33-45
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Maintenance strategy decision for avionics system based on cognitive uncertainty information processing
Decyzja w zakresie strategii utrzymania ruchu układu elektroniki lotniczej w oparciu o przetwarzanie informacji związanych z niepewnością kognitywną
Autorzy:
Tu, J.
Sun, C.
Zhang, X.
Pan, H.
Cheng, R.
Powiązania:
https://bibliotekanauki.pl/articles/301723.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
avionics system
vague sets
prospect theory
maintenance strategy
multicriteria decision making
układ elektroniki lotniczej
zbiory nieostre
teoria perspektywy
strategia utrzymania ruchu
wielokryterialne podejmowanie decyzji
Opis:
Proper maintenance schedule is required to improve avionics systems reliability and safety. A decision approach to maintenance strategy remains a longstanding challenge in avionics system. With regard to fault diagnosis and equipment maintenance of avionics system, in which the equipment fault information are complex and uncertainty, a multi criteria of decision making method for avionics system based on cognitive uncertainty information processing is proposed to be used in the maintenance strategy decision. Firstly, vague set with three-parameters is introduced to make up for the shortage of the original vague set in expressing fuzzy information, a linguistic variables describing the qualitative indexes into three parameter vague of interval number is proposed. At the same time, due to risk psychological factors of maintenance policymakers that cause cognitive uncertainty are introduced into the maintenance decision process, and a prospect value function of three parameters vague interval value is defined based on prospect theory and the formula for measuring the distance between vague interval value, and a non-linear model of equipment maintenance policies can be established. The implementing process of maintenance policy decision for avionics system based on cognitive uncertainty information processing is given in this paper, and a ranking of the maintenance alternatives is determined. Finally, A specific example of decision of maintenance strategies in avionics system with the application of the proposed method is given, showing that the reliability centered maintenance strategy is the most suitable for avionics system.
Doskonalenie niezawodności i bezpieczeństwa układów elektroniki lotniczej wymaga odpowiedniego harmonogramu działań obsługowych. Podejście decyzyjne do strategii utrzymania ruchu od dawna pozostaje wyzwaniem w systemach awioniki. W odniesieniu do diagnozy uszkodzeń i konserwacji urządzeń systemów elektroniki lotniczej, w których informacje o usterkach urządzeń są złożone i obarczone niepewnością, zaproponowano metodę wielokryterialnego podejmowania decyzji opartą na przetwarzaniu informacji związanych z niepewnością kognitywną, którą można stosować przy podejmowaniu decyzji dotyczących strategii utrzymania ruchu. Po pierwsze, wprowadzono nieostry zbiór trzech parametrów, które pozwalają na wyrażenie wartości liczbowej zaproponowanych zmiennych lingwistycznych opisujących wskaźniki jakościowe, jako wartości z przedziału nieostrego. Jednocześnie, do pojęcia procesu decyzyjnego dotyczącego utrzymania ruchu wprowadzono pojęcie ryzyka związanego z powodującymi niepewność poznawczą czynnikami psychologicznymi kierującymi osobami podejmującymi decyzje obsługowe. Zdefiniowano także funkcję oceny dla wartości z przedziału nieostrego trzech parametrów na podstawie teorii perspektywy i wzór do pomiaru odległości między wartościami z przedziału nieostrego, oraz ustalono nieliniowy tryb polityki konserwacji sprzętu. W artykule zaprezentowano proces implementacji decyzji w zakresie polityki konserwacji układów elektroniki lotniczej w oparciu o przetwarzanie informacji związanych z niepewnością kognitywną, stworzono też ranking dostępnych alternatyw w zakresie utrzymania ruchu. Na koniec, zaprezentowano konkretny przykład decyzji w zakresie strategii konserwacji układów elektroniki lotniczej z zastosowaniem proponowanej metody, pokazując, że strategia utrzymania ruchu oparta na niezawodności jest najbardziej odpowiednia dla układów awioniki.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 2; 297-305
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Population diversity maintenance in brain storm optimization algorithm
Autorzy:
Cheng, S.
Shi, Y.
Qin, Q.
Zhang, Q
Bai, R.
Powiązania:
https://bibliotekanauki.pl/articles/91571.pdf
Data publikacji:
2014
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
brainstorm
optimization algorithm
convergence
divergence
brainstorm optimization
BSO
swarm intelligence
BSO algorithm
Opis:
The convergence and divergence are two common phenomena in swarm intelligence. To obtain good search results, the algorithm should have a balance on convergence and divergence. The premature convergence happens partially due to the solutions getting clustered together, and not diverging again. The brain storm optimization (BSO), which is a young and promising algorithm in swarm intelligence, is based on the collective behavior of human being, that is, the brainstorming process. The convergence strategy is utilized in BSO algorithm to exploit search areas may contain good solutions. The new solutions are generated by divergence strategy to explore new search areas. Premature convergence also happens in the BSO algorithm. The solutions get clustered after a few iterations, which indicate that the population diversity decreases quickly during the search. A definition of population diversity in BSO algorithm is introduced in this paper to measure the change of solutions’ distribution. The algorithm’s exploration and exploitation ability can be measured based on the change of population diversity. Different kinds of partial reinitialization strategies are utilized to improve the population diversity in BSO algorithm. The experimental results show that the performance of the BSO is improved by part of solutions re-initialization strategies.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2014, 4, 2; 83-97
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of lizardite on talc flotation using carboxymethyl cellulose as a depressant
Autorzy:
Deng, Jie
Yang, Siyuan
Zhang, Wencai
Liu, Cheng
Li, Hongqiang
Powiązania:
https://bibliotekanauki.pl/articles/1449414.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
talc
lizardite
flotation
CMC
magnesium ion
Opis:
The effect of lizardite on talc flotation when using carboxymethyl cellulose (CMC) as a depressant was studied by micro-flotation experiments and adsorption measurements, zeta-potential measurements, magnesium ion dissolution analysis, and solution chemistry calculation. The results for the micro-flotation experiments showed that the addition of lizardite further decreased the floatability of talc at pH 8.5 when using CMC as the depressant. The mechanism was that magnesium ions dissolved from lizardite lattice, then formed hydrolyzed species of magnesium cations and interacted with talc surfaces, which promoted CMC adsorption, and thus decreasing talc floatability.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 702-709
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dynamic angle metrology system based on fibre-optic gyroscope and rotary table
Autorzy:
Chen, Lei
Zhou, Yilan
Zhang, Dengwei
Shu, Xiaowu
Liu, Cheng
Powiązania:
https://bibliotekanauki.pl/articles/220999.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
circular grating angle encoder
fibre-optic gyroscope
dynamic angle metrology
Opis:
Dynamic angle measurement (DAM) plays an important role in precision machining, aerospace, military and artificial intelligence. Because of its advantages including high sensitivity, solid state and miniaturization, fibre-optic gyroscope (FOG) has great application prospects in the field of DAM. In this paper, we propose a dynamic angle metrology method based on FOG and a rotary table to evaluate the DAM accuracy with FOG. The system synchronously collects data from the FOG and rotary table, and analyses the DAM accuracy of the FOG for different sway conditions compared with that of the angle obtained from the rotary table. An angle encoder in the rotary table provides absolute or incremental angular displacement output with angular displacement measurement accuracy of 10′′ (0:0028°) and angular displacement repeat positioning accuracy of 3′′ (0:00083°), and can be used as an angle reference. The experimental results show that the DAM accuracy of the FOG is better than 0:0028° obtained with the angular encoder, and the absolute DAM accuracy of the FOG is better than 0:0048° for given conditions. At the same time, for the multi-path signal synchronization problem in the metrology field, this paper proposes a signal delay measurement method combining test and algorithm procedures, which can control a delay within 25 μs.
Źródło:
Metrology and Measurement Systems; 2019, 26, 3; 497-504
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A self-scheduling strategy of virtual power plant with electric vehicles considering margin indexes
Autorzy:
Jiao, Fengshun
Deng, Yongsheng
Li, Duo
Wei, Bo
Yue, Chengyan
Cheng, Meng
Zhang, Yapeng
Zhang, Jiarui
Powiązania:
https://bibliotekanauki.pl/articles/949880.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
electric vehicle (EV)
response time margin (RTM)
scheduling strategy
state of charge margin (SOCM)
virtual power plant (VPP)
Opis:
From the perspective of a virtual power plant (VPP) with electric vehicles (EVs), a self-scheduling strategy considering the response time margin (RTM) and state of charge margin (SOCM) is proposed. Firstly, considering the response state of the state of charge (SOC) and charge-discharge state of EVs, a VPP based response capacity determination model of EVs is established. Then, RTM and SOCM indexes are introduced on the basis of the power system scheduling target and the EV users’ traveling demands. The RTM and SOCM indices are calculated and then are used to generate a priority sequence of responsive EVs for the VPP. In the process of the scheduling period and rolling iteration, the scheduling schemes of the EVs in the VPP for multiple time periods are determined. Finally, the VPP self-scheduling strategy is validated by taking an VPP containing three kinds of EV users as an example. Simulation results show that with the proposed strategy, the VPP is able to respond to the scheduling power from the power system, while ensuring the traveling demands of the EV users at the same time.
Źródło:
Archives of Electrical Engineering; 2020, 69, 4; 907-920
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetics of photoelectrocatalytic degradation of diclofenac using N, S co-doped TiO2 nano-crystallite decorated TiO2 nanotube arrays photoelectrode
Autorzy:
Cui, Y.
Deng, X.
Ma, Q.
Zhang, H.
Cheng, X.
Li, X.
Xie, M.
Cheng, Q.
Li, B.
Powiązania:
https://bibliotekanauki.pl/articles/207955.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
effluents
nanotubes
sodium sulfate
sulfur compounds
yarn
photoelectrocatalytic degradation
ścieki
nanorurki
siarczan sodu
związki siarki
przędza
Opis:
As a non-steroidal anti-inflammatory drug, diclofenac, was commonly used as analgesic, antiarthritic and antirheumatic, and has frequently been detected in municipal wastewater treatment plants (MWTPs) effluents and demonstrated to be potentially environmental risk on human beings. In the present study, N, S co-doped TiO2 nano-crystallites decorated TiO2 nano-tube arrays (N, S-TiO2 NCs/TiO2 NTAs) photoelectrode was used to degrade diclofenac containing wastewater. In addition, the effects of some critical parameters including initial pH, external positive potential, sodium sulfate concentration and initial diclofenac concentration on the photoelectrocatalytic (PEC) degradation of diclofenac containing wastewater and dynamic characteristics were investigated systematically. Results showed that N, S-TiO2 NCs/TiO2 NTAs photoelectrode exhibited high PEC efficiency for the degradation of diclofenac, in which the PEC processes fitted well with the Langmuir–Hinshelwood (L–H) model. Furthermore, external additional anions such as Cl, ClO and NO3 – played an important role in inhibiting the degradation of diclofenac. Also, the N, S-TiO2 NCs/TiO2 NTAs photoelectrode possessed good stability for consecutive applications for degradation of diclofenac, which could potentially be utilized in wastewater treatment.
Źródło:
Environment Protection Engineering; 2018, 44, 2; 117-130
0324-8828
Pojawia się w:
Environment Protection Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Acquisition of the Surface Morphology of Ruled Gratings with a Microscope Objective
Autorzy:
Li, Z.
Ma, L.
Liu, C.
Zhang, M.
Chen, X.
Cheng, C.
Powiązania:
https://bibliotekanauki.pl/articles/1189791.pdf
Data publikacji:
2015-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
42.30.Kq
42.87.-d
42.79.Dj
42.40.Kw
Opis:
In this paper, an optical microscope objective with large numerical number is inserted into a Mach-Zehnder interferometer, and this system is adopted to detect the surface morphologies of two ruled transmission gratings with area scale to a micrometer. The object waves transmitting from the gratings interfere with spherical reference wave, and the interferograms constructed are recorded by a high-resolution CCD. The surface maps of the gratings are retrieved from the interferograms, and the results are confirmed by the measurement with an atomic force microscope, with detection errors in nanometer scale. This work provides an optical non-destructive method for precise detection of small-area sophisticated object surfaces with an optical microscope objective.
Źródło:
Acta Physica Polonica A; 2015, 127, 6; 1630-1633
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of bubble-particle interactions in a column flotation process
Autorzy:
Cheng, G.
Shi, C.
Yan, X.
Zhang, Z.
Xu, H.
Lu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/109635.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
particle
bubble
column flotation
collision
attachment
detachment
Opis:
Bubble-particle interactions play an important role in flotation. This study examines the behaviour of bubble clusters in a turbulent flotation cell. Particularly, the bubble-particle interaction characteristics in flotation are investigated. The bubble size in a flotation column was measured using an Olympus i-SPEED 3 high-speed camera. Relationships between the circulating volume, bubble size and bubble terminal velocity were discussed. Probabilities of collision, attachment, detachment and acquisition between bubbles and particles in different circulating volumes were calculated based on the flotation kinetic theory. Using the extended Derjaguin–Landau–Verwey–Overbeek (EDLVO) theory, the relationship between the potential energy and distance in bubble-particle interaction was analysed. The results demonstrated that as the circulating volume increased, the bubble size and velocity decreased. When the circulating volume increased from 0.253 to 0.495 m3/h, the bubble diameter decreased from 511 to 462 μm, and the corresponding bubble velocity decreased from 43.1 to 37.5 mm/s. When the circulating volume remained constant as the particle size increased, probabilities of collision, attachment, detachment and acquisition increased. When the particle size remained constant as the circulating volume increased, these probabilities also increased. At a constant circulating volume as the particle size increased, the absolute value of the total potential energy between the particle and bubble increased. When the distance between the bubble and particle was 30 nm, the energy barrier appeared.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 1; 17-33
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved resonant thermal converter based on micro-bridge resonator
Autorzy:
Dong, L.
Han, J.
Zhang, P.
Zhao, Z.
Cheng, B.
Han, D.
Powiązania:
https://bibliotekanauki.pl/articles/220878.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermoelectric transfer difference
micro-bridge resonator
thermal converter
bifilar heater
Opis:
This paper presents the design, fabrication and testing of an improved thin-film thermal converter based on an electro-thermally excited and piezo-resistively detected micro-bridge resonator. The resonant thermal converter comprises a bifilar heater and an opposing micro-bridge resonator. When the micro-bridge resonator absorbs the radiant heat from the heater, its axial strain changes, then its resonant frequency follows. Therefore the alternating voltage or current can be transferred to the equivalent DC quantity. A non-contact temperature sensing mechanism eliminates heat loss from thermopiles and reduces coupling capacitance between the temperature sensor and the heater compared with traditional thin-film thermal converters based on thermopiles. In addition, the quasi-digital output of the resonant thin-film thermal converter eliminates such problems as intensity fluctuations associated with analogue signals output by traditional thin-film thermal converters. Using the fast-reversed DC (FRDC) method, the thermoelectric transfer difference, which determines the frequency-independent part of the ac-dc transfer difference, is evaluated to be as low as 1.1 · 10-6. It indicates that the non-contact temperature sensing mechanism is a feasible method to develop a high-performance thermal converter.
Źródło:
Metrology and Measurement Systems; 2018, 25, 4; 715-725
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Anonymous traffic classification based on three-dimensional Markov image and deep learning
Autorzy:
Tang, Xin
Li, Huanzhou
Zhang, Jian
Tang, Zhangguo
Wang, Han
Cai, Cheng
Powiązania:
https://bibliotekanauki.pl/articles/27311448.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
anonymous network
traffic classification
three-dimensional Markov image
output self-attention
deep learning
sieć anonimowa
klasyfikacja ruchu
trójwymiarowy obraz Markowa
samouwaga wyjściowa
uczenie głębokie
Opis:
Illegal elements use the characteristics of an anonymous network hidden service mechanism to build a dark network and conduct various illegal activities, which brings a serious challenge to network security. The existing anonymous traffic classification methods suffer from cumbersome feature selection and difficult feature information extraction, resulting in low accuracy of classification. To solve this problem, a classification method based on three-dimensional Markov images and output self-attention convolutional neural network is proposed. This method first divides and cleans anonymous traffic data packets according to sessions, then converts the cleaned traffic data into three-dimensional Markov images according to the transition probability matrix of bytes, and finally inputs the images to the output self-attention convolution neural network to train the model and perform classification. The experimental results show that the classification accuracy and F1-score of the proposed method for Tor, I2P, Freenet, and ZeroNet can exceed 98.5%, and the average classification accuracy and F1-score for 8 kinds of user behaviors of each type of anonymous traffic can reach 93.7%. The proposed method significantly improves the classification effect of anonymous traffic compared with the existing methods.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 4; art. no. e145676
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of multi-objective fruit fly optimisation algorithm based on population Manhattan distance in distribution network reconfiguration
Autorzy:
Tang, Minan
Zhang, Kaiyue
Wang, Qianqian
Cheng, Haipeng
Yang, Shangmei
Du, Hanxiao
Powiązania:
https://bibliotekanauki.pl/articles/1841286.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Chebyshev chaotic mapping
distributed generation
distribution network reconfiguration
fuzzy decision method
Pareto optimal
pmdMOFOA
population Manhattan distance
Opis:
In order to optimise the operation state of the distribution network in the presence of distributed generation (DG), to reduce network loss, balance load and improve power quality in the distribution system, a multi-objective fruit fly optimisation algorithm based on population Manhattan distance (pmdMOFOA) is presented. Firstly, the global and local exploration abilities of a fruit fly optimisation algorithm (FOA) are balanced by combining population Manhattan distance (PMD) and the dynamic step adjustment strategy to solve the problems of its weak local exploration ability and proneness to premature convergence. At the same time, Chebyshev chaotic mapping is introduced during position update of the fruit fly population to improve ability of fruit flies to escape the local optimum and avoid premature convergence. In addition, the external archive selection strategy is introduced to select the best individual in history to save in external archives according to the dominant relationship amongst individuals. The leader selection strategy, external archive update and maintenance strategy are proposed to generate a Pareto optimal solution set iteratively. Lastly, an optimal reconstruction scheme is determined by the fuzzy decision method. Compared with the standard FOA, the average convergence algebra of a pmdMOFOA is reduced by 44.58%. The distribution performance of non-dominated solutions of a pmdMOFOA, MOFOA, NSGA-III and MOPSO on the Pareto front is tested, and the results show that the pmdMOFOA has better diversity. Through the simulation and analysis of a typical IEEE 33-bus system with DG, load balance and voltage offset after reconfiguration are increased by 23.77% and 40.58%, respectively, and network loss is reduced by 57.22%, which verifies the effectiveness and efficiency of the proposed method.
Źródło:
Archives of Electrical Engineering; 2021, 70, 2; 307-323
1427-4221
2300-2506
Pojawia się w:
Archives of Electrical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using high level roadway to control gas emission in a longwall mining face – numerical simulation study
Autorzy:
Ma, Yongzhen
Cheng, Jianwei
Zhang, Rui
Wang, Zui
Ran, Dezhi
Sheng, Shuping
Zhang, Jufeng
Si, Junhong
Yu, Zhaoyang
Powiązania:
https://bibliotekanauki.pl/articles/2203351.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
symulacja numeryczna
wentylacja górnicza
kopalnia węgla
high level roadway
gob
numerical simulation
u+hLR ventilation method
Opis:
With the increase of coal mining depth, the gas content in coal seams could also become larger and larger, which could suddenly cause an inrush of gas into the longwall mining face. It is very dangerous for miners’ safety in the underground. The U-shaped ventilation pattern of longwall mining face that underground coal mines currently use is not enough to deliver sufficient air quantities to dilute gases in mining faces, which could result in the gas concentration over the required celling limit by government laws. Thus, the mine must stop production. In this paper, the high level roadway (HLR) is designed and the U + HLR new ventilation pattern is proposed to control gas emission in a longwall mining face. Using computational fluid dynamics simulation (CFD) software, the flow field and gas transportation in the mine gob are studied. The optimized ventilation parameters are summarized. It is found that the best vertical distance of the HLR is 35 m over the coal seam and the horizontal distance is 25 m from the air return roadway. It is recommended that the negative suction pressure design of the high level roadway should be ranged from 9000 Pa to 10000 Pa. Based on the study outcomes, the gas emission could be well controlled in mining faces and avoid any gas disaster accidents.
Źródło:
Archives of Mining Sciences; 2022, 67, 4; 715--728
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on mine seal stability under explosion load and ground pressure in underground coal mines
Autorzy:
Cheng, Jianwei
Song, Wanting
Jing, Yi
Zhang, Xixi
Korzec, Marek
Borowski, Marek
Wang, Yue
Powiązania:
https://bibliotekanauki.pl/articles/218944.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kopalnia węgla
symulacja numeryczna
dłutowanie
seals in underground coal mines
numerical simulation
slotting
ground pressure
roof to floor moving convergence
damage level
Opis:
The mine seals in coal mines with a good impact resistance and air tightness are mainly used to isolate abandoned mining areas from active workings. For one thing, it can prevent the leakage of harmful gases, such as toxic gas from abandoned areas. For another, once an underground mine explosion happens, it can effectively block the spread of the explosion between the abandoned mining areas and the active workings. Hence, it is of great significance to study the explosion-proof performance and mechanical properties of the mine seals. First of all, the effect of slotting on the stability of the seals in coal mines under explosion load was explored in this study. By numerical simulations, the mechanical response characteristics of the seals with or without cutting a slot under the explosion load were compared in detail. The results show that slotting improved the stress concentration at the contact surface of surrounding rock by transferring partial impact received by mine seals to the surrounding rocks, thus, to achieve the effect of buffering explosion impact. Besides, such effect will be enhanced with increasing cutting depth into rock, and will stabilize when the depth is 20 cm. On this basis, the mechanical properties and damage of the seals constructed by different materials (standard brick and #C40 concrete) under the explosion load were compared. It was found that once a slot was set, the maximum deformation of the concrete seal was reduced, while the maximum deformation of the brick seal increased. Since the non-deformability of the concrete seal is obviously stronger than that of the brick seal, with the impact resistance stronger than that of the brick seal, the concrete seal is more suitable for slotting. Moreover, the damage of the seals in underground coal mines under the strata ground pressure was studied; the results of which show that the damage state under the ground pressure can be divided into 3 levels, i.e. no damage, minor damage and rapid development of damage. Meanwhile, it was found that the prestressed structure fordem by the ground pressure at the level of no damage can enhance the protective effect of the seals in coal mines. However, when the ground pressure was further developed, the seal itself was destroyed and the protective effect was lost. In addition, the influence of roof to floor moving convergence, a deformation parameter of the roadway, on the seals was also investigated. The results show that the ground pressure and roof-to-floor convergence act on the seals in coal mines in the same way, thus roof to floor moving convergence can replace the ground pressure to analyze other related mechanical properties of the seals in coal mines in the future researches.
Źródło:
Archives of Mining Sciences; 2020, 65, 1; 71-87
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Revealing the core transcriptome modulating plant growth phase in Arabidopsis thalianaby RNA sequencingand coexpression analysis of the FHY3 FAR1 mutant
Autorzy:
Wang, W.
Zhao, G.
Wu, S.
Hua, W.
Zhang, T.
Ruan, R.
Cheng, Y.
Powiązania:
https://bibliotekanauki.pl/articles/2130692.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Botaniczne
Tematy:
weekly transcriptome analysis
plant development
different expression genes
(DEGs)
immune response
Opis:
Plants must continually calibrate their growth in response to the environment throughout their whole life cycle. Revealing the regularity of plant early growth and development is of great significance to plant genetic modification. It was previously demonstrated that loss of two key light signaling transcription factors, FHY3 and FAR1, can cause a stunted stature in the plant adult stage, and numerous defense response genes can be continuously activated. In this study, we performed a time-course transcriptome analysis of the early 4 weeks of leaf samples from wild plants and their fhy3 and far1 transcription factors. By comparative transcriptome analysis, we found that during the early 4 weeks of plant growth, plants primarily promoted morphogenesis by organizing their microtubules in the second week. In the third week, plants began to trigger large- scale defense responses to resist various external stresses. In the fourth week, increased photosynthetic efficiency promoted rapid biomass accumulation. Weighted gene coexpression network analysis of FHY3 and FAR1 revealed that the two light signaling transcription factors may be originally involved in the regulation of genes during embryonic development, and in the later growth stage, they might regulate gene expression of some defense-related genes to balance plant growth and immunity. Remarkably, our yeast two-hybrid and bimolecular fluorescence complementation experiments showed that FAR1 interacts with the immune signaling factor EDS1. Taken together, this study demonstrates the major biological processes occurring during the early 4 weeks of plant growth. The light signaling transcription factors, FHY3 and FAR1, may integrate light signals with immune signals to widely regulate plant growth by directly interacting with EDS1.
Źródło:
Acta Societatis Botanicorum Poloniae; 2020, 89, 2
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and kinetic study of zinc leaching from metallurgical slag by 5-sulfosalicylic acid
Autorzy:
Wang, Long
Gao, Hanyu
Song, Shimin
Xue, Na
Zhang, Jinxia
Yang, Siyuan
Liu, Cheng
Powiązania:
https://bibliotekanauki.pl/articles/1447397.pdf
Data publikacji:
2021
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
zinc metallurgical slag
5-sulfosalicylic acid
leaching kinetics
resource recover
Opis:
As an organic acid with the characters of low corrosivity and extensive source, 5-sulfosalicylic acid (5-SSA) was firstly utilized as a potential leaching reagent for the recovery of zinc from metallurgical slag. Effects of stirring speed, leaching temperature, 5-SSA concentrations and size fraction on the leaching zinc leaching rate were investigated. A zinc leaching efficiency of 94.2% was achieved under the appropriate operating conditions (450 rpm of stirring speed, 50 ℃ of leaching temperature, 0.3 mol/L of 5-SSA concentration and d90=65 µm of size fraction), indicating that 5-SSA was an excellent leaching reagent of zinc oxide. SEM-EDS and specific surface aperture analyzer further reveal the well-developed micropores and cracks from zinc metallurgical slag, which could be assigned to the removal of zinc oxide encapsulated in the sample. In addition, the leaching kinetics of zinc metallurgical slag in the 5-SSA was studied. It was found that the surface chemical reaction model satisfactorily predicted the zinc leaching rate. A reaction kinetic equation was finally established for the zinc leaching rate.
Źródło:
Physicochemical Problems of Mineral Processing; 2021, 57, 3; 8-20
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A BIM technology-based underwater structure damage identification and management method
Autorzy:
Li, Xiaofei
Su, Rongrong
Cheng, Peng
Sun, Heming
Meng, Qinghang
Song, Taiyi
Wei, Mengpu
Zhang, Chen
Powiązania:
https://bibliotekanauki.pl/articles/2204531.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
building information modeling
underwater structural disease
damage identification
deep learning
modelowanie informacji o budynku
identyfikacja uszkodzeń
uczenie głębokie
uszkodzenie podwodnej konstrukcji
Opis:
With the continuous development of bridge technology, the condition assessment of large bridges has gradually attracted attention. Structural Health Monitoring (SHM) technology provides valuable information about a structure's existing health, keeping it safe and uninterrupted use under various operating conditions by mitigating risks and hazards on time. At the same time, the problem of bridge underwater structure disease is becoming more obvious, affecting the safe operation of the bridge structure. It is necessary to test the bridge’s underwater structure. This paper develops a bridge underwater structure health monitoring system by combining building information modeling (BIM) and an underwater structure damage algorithm. This paper is verified by multiple image recognition networks, and compared with the advantages of different networks, the YOLOV4 network is used as the main body to improve, and a lightweight convolutional neural network (Lite-yolov4) is built. At the same time, the accuracy of disease identification and the performance of each network are tested in various experimental environments, and the reliability of the underwater structure detection link is verified.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2023, 71, 2; art. no. e144602
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Aspherical, sphero-cylindrical, toroidal, and ellipsoidal surfaces for designing astigmatic spectacle lenses with axis orientation
Autorzy:
Xiang, Huazhong
Wang, Peng
Zheng, Zexi
Zheng, Gang
Chen, Jiabi
Wang, Cheng
Zhang, Dawei
Zhuang, Songlin
Powiązania:
https://bibliotekanauki.pl/articles/27310110.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
toric
astigmatism
spherocylinder
aspheric
ellipsoidal surface
Opis:
In this paper, formulas for aspherical, sphero-cylindrical, toroidal, and ellipsoidal surfaces with astigmatic axes are derived. Based on this, four types of curved surfaces were designed to correct astigmatism with axis, and, subsequently, the lenses were simulated, fabricated, and measured. A total of ten spectacle lenses in two groups were designed. Those in the first group used identical optical parameters. The spherical and cylindrical powers and maximum and minimum edge thicknesses of aspherical, sphero-cylindrical, and ellipsoidal surfaces were compared. The results indicated that the power of the lens constructed using the toroidal surface was more accurate than those of the other three lenses. Moreover, the minimum edge thickness of the toroidal surface was 1.2%, 4.98%, and 4.87% lower than those of the aspherical, sphero-cylindrical, and ellipsoidal surfaces, respectively. The powers and edge thicknesses of toroidal surfaces with different diopters were compared in the second group. The minimum and maximum edge thicknesses were observed to be reduced by 8.97% and 6.05%, respectively, corresponding to the conic constants obtained via ray tracing. The conclusion will be significant for clinical ophthalmology and optical design for the patients with astigmatism.
Źródło:
Optica Applicata; 2023, 53, 3; 377--391
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optical trapping forces of focused circular partially coherent beams on Rayleigh particles
Autorzy:
Yu, Chaoqun
Chen, Fuchang
Zeng, Jun
Huang, Cheng
He, Zhimin
Lin, Huichuan
Zhang, Yongtao
Chen, Ziyang
Pu, Jixiong
Powiązania:
https://bibliotekanauki.pl/articles/2172861.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
tight focusing
radially polarized
circular partially coherent
spherical aberration
optical trapping force
Opis:
The optical trapping forces of tightly-focused radially polarized circular partially coherent beams on Rayleigh particles are theoretically investigated. Numerical calculations are performed to study the optical trapping forces on Rayleigh particles for different initial coherent length of the incident circular partially coherent beams. The results show that the magnitude of the gradient force decreases with the reduction of the initial coherent length of the focused radially polarized circular partially coherent beams, while the balanced position (i.e., the position where the optical trapping forces becomes zero) stays constant. Moreover, the focused spot gradually elongates along the optical axis with the reduction of the initial coherent length, and the axial gradient force on Rayleigh particles also decreases gradually with the reduction of the intensity gradient in axial direction. As there exists an spherical aberrant in the focusing optical system, the focal spot in the direction of the optical axis becomes trumpet-shaped, and the optical trapping forces on Rayleigh particles change as well.
Źródło:
Optica Applicata; 2022, 52, 4; 575--583
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of magnesium hydroxide by modifier-directed hydration and its effect on flame retardancy and mechanical properties of polypropylene
Autorzy:
Wang, Mei Jia
Bai, Li Mei
Zhang, Meng Ting
Ma, Yu Xin
Zhao, Liu Cheng
Li, Shao Ying
Powiązania:
https://bibliotekanauki.pl/articles/27323651.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
modifier
hydration preparation
magnesium hydroxide
polypropylene
Opis:
With the rapid development of the polymer materials industry and the improvement of people's environmental awareness, magnesium hydroxide has been widely used in polymer materials due to its high decomposition temperature, non-toxic smoke suppression, and the advantages of neutralizing harmful gases produced by polymer combustion. However, the conventional preparation methods of magnesium hydroxide exhibit several issues, including high hydrophilicity, elevated polarity, and limited compatibility with polymers. This research proposes an improved method by adding sodium stearate and KH560 modifier, controlling the rate of magnesium oxide and preparing magnesium hydroxide flame retardants using a modifier-directed hydration method. Various characterizations confirmed its morphology, particle size and structure. The magnesium hydroxide exhibits low polarity, small particle size, stable structure and excellent hydrophobicity (with a contact angle of 120.32°, and a free energy of 1.34mN/m). In parallel, the magnesium hydroxide/polypropylene composites demonstrate excellent flame retardancy (LOI of 25%, V-1 grade) and simultaneously enhance the dispersion of magnesium hydroxide within the polypropylene matrix, improving the material's toughness and strength.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 6; art. no. 175706
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Myocardial remodeling in rats with metabolic syndrome: role of Rho-kinase mediated insulin resistance
Autorzy:
Li, Chuan-Bao
Li, Xiao-Xing
Chen, Yu-Guo
Gao, Hai-Qing
Bao, Cheng-Mei
Liu, Xiang-Qun
Bu, Pei-Li
Zhang, Juan
Zhang, Yun
Ji, Xiao-Ping
Powiązania:
https://bibliotekanauki.pl/articles/1039743.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
Rat
Metabolism
Myocardium
Phosphorylation
Insulin resistance
Opis:
Insulin resistance (IR) plays a critical role in metabolic syndrome (MS). Previous studies have demonstrated that activated ROCK is increased in MS patients. However, the effect of Rho-kinase (ROCK) on IR has not been definitely determined. Thus, the aims of the present study were to determine whether ROCK activation induces IR or affects myocardial structure and function, as well as the possible mechanisms underlying this process. Wistar rats fed high fat, high glucose and high salt diet sewed as model of MS and we used transmission electron microscopy, echocardiogram technology, and terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling staining to identify any myocardial damage. The protein levels of MYPT-1 (characteristic of ROCK activation), IRS-1 and AKT were analyzed by immunohistochemistry and Western blotting. In hearts from MS rats, we found increased protein levels of phospho-MYPT-1 and phospho-IRS-1 (Ser307) and decreased phospho-AKT compared to levels in normal rats. In conclusion, the results suggest that ROCK-mediated IR is involved in the development of myocardial impairments in MS rats and that this effect is mediated probably via the IRS-1/PI3-kinase/AKT pathway.
Źródło:
Acta Biochimica Polonica; 2012, 59, 2; 249-254
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on safe disposal of cephalosporins based on kinetic pyrolysis mechanism
Autorzy:
Fan, Jiangxue
Zhang, Meng
Hou, Xiaofei
Wang, Fang
Bai, Mengyuan
Jiao, Ruoxi
Yang, Zhongyu
Duan, Erhong
Cheng, Fengfei
Zhou, Wen
Powiązania:
https://bibliotekanauki.pl/articles/27315672.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Distillation residues
Thermal analysis kinetics
Template “3-2-2”
Template “1+1”
Pyrolysis mechanism
Opis:
Based on the global goals for cleaner production and sustainable development, the pyrolysis behavior of cephalosporin residues was studied by TG-MS method. The influence of full temperature window on the safe disposal of residues was analyzed based on the “3-2-2” and “1+1” of thermal analysis kinetics, and the gas by-products of thermal degradation were monitored. Results showed that the pyrolysis of distillation residues were divided into low and high-temperature zones, including six stages. Maximum error rate (8.55%) by multiple scan rate was presented based on “3-2-2” pattern and maximum total fluctuation (33.7) by single scan rate was presented based on “1+1” pattern, which implied that the comprehensive multi-level comparison method was very reliable. The E value “E” of six stages showed an increasing trend ranging 166.8 to 872.8 kJ/mol. LgA(mean) was 27.28. Most mechanism function of stage 1, 2 were Z-L-T equation (3D), stage 3, 4, 6 were Avrami-Erofeev equation (AE3, AE4, AE2/3) and stage 5 was Reaction Order (O2). In addition, various small molecular micromolecule substances were detected such as C2H4O, C2H6, NH3, CH4, CO2 under full temperature windows and a possible pyrolysis path of residues was provided.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 4; 52--60
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SYBR Green-based real-time polymerase chain reaction assay for detection of porcine parvovirus 6 in pigs
Autorzy:
Sun, P.
Bai, C.X.
Zhang, D.
Wang, J.
Yang, K.K.
Cheng, B.Z.
Li, Y.D.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/2087328.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
porcine parvovirus 6
real-time polymerase chain reaction
SYBR Green
Źródło:
Polish Journal of Veterinary Sciences; 2020, 23, 2; 197-202
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of differential serum expression of three factors and pulmonary function in patients with silicosis
Autorzy:
Zhu, Ying
Duan, Xia Yu
Cheng, Yun Qi
Yao, Xin Jing
Xu, Hong
Zhang, Kui Sheng
Li, Feng Shi
Yang, Fang
Liu, Liang He
Yuan, Xiang Ju
Powiązania:
https://bibliotekanauki.pl/articles/2086531.pdf
Data publikacji:
2021-08-05
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
silicosis
pulmonary function
early diagnosis
ROC
PTPN2
factor B
Opis:
ObjectivesSilicosis is a chronic occupational lung disease. As was previously found by the authors, some proteins increased in the lung tissue of activated rats, and protein tyrosine phosphatase non-receptor type 2 (PTPN2), factor B, and vaccinia-related kinase 1 (VRK1) showed highly differential expressions.Material and MethodsIn this study, serum and bronchoalveolar lavage fluid samples were collected from patients with silicosis and healthy people to verify the expression of PTPN2, factor B, and VRK1. The diagnostic value of differentially expressed proteins for silicosis was judged.ResultsThe expression levels of serum PTPN2, VRK1, and factor B in patients with silicosis were significantly higher than those in the control group (p < 0.01). Higher serum PTPN2 and factor B concentrations significantly and negatively correlated with the ratio of forced expiratory volume in 1 s to forced vital capacity (FEV1/FVC), maximum vital capacity (VCmax), FEV1, and FVC, suggesting that the high expression of PTPN2 and factor B is associated with decreased pulmonary ventilation function and restrictive ventilatory impairment in patients with silicosis. All area under curve (AUC) measurements generated from single detection events were >0.744, with PTPN2 reaching the highest value (0.858). The AUC, sensitivity, and specificity for the combined diagnosis using factor B and PTPN2 were 0.907, 86.91% and 85.07%, respectively, for factor B and PTPN2. The 3 differentially expressed proteins are potential classes of predictive biomarkers for silicosis.ConclusionsRegarding the economy and test practicality, the best diagnostic combination is factor B and PTPN2 for the analysis of AUC, sensitivity and specificity.
Źródło:
International Journal of Occupational Medicine and Environmental Health; 2021, 34, 4; 527-540
1232-1087
1896-494X
Pojawia się w:
International Journal of Occupational Medicine and Environmental Health
Dostawca treści:
Biblioteka Nauki
Artykuł
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