Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "Li, Bo" wg kryterium: Autor

  Lista filtrów
Wyrównaj
Wyświetlanie 1-25 z 27
Tytuł:
Forecasting Yield Curves in an Adaptive Framework
Autorzy:
Chen, Ying
Li, Bo
Powiązania:
https://bibliotekanauki.pl/articles/483285.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
interest rates
functional principal component analysis
local parametric model
Nelson-Siegel model
Opis:
Forecasting yield curves with regime switches is important in academia and financial industry. As the number of interest rate maturities increases, it poses difficulties in estimating parameters due to the curse of dimensionality. To deal with such a feature, factor models have been developed. However, the existing approaches are restrictive and largely based on the stationarity assumption of the factors. This inaccuracy creates non-ignorable financial risks, especially when the market is volatile. In this paper, a new methodology is proposed to adaptively forecast yield curves. Specifically, functional principal component analysis (FPCA) is used to extract factors capable of representing the features of yield curves. The local AR(1) model with time-dependent parameters is used to forecast each factor. Simulation and empirical studies reveal the superiority of this method over its natural competitor, the dynamic Nelson-Siegel (DNS) model. For the yield curves of the U.S. and China, the adaptive method provides more accurate 6- and 12-month ahead forecasts.
Źródło:
Central European Journal of Economic Modelling and Econometrics; 2011, 3, 4; 237-259
2080-0886
2080-119X
Pojawia się w:
Central European Journal of Economic Modelling and Econometrics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Preparation of grape pomace powders and analysis of their nutritive compositions
Autorzy:
Lou, Wenjuan
Li, Bo
Grevtseva, Nataliya
Powiązania:
https://bibliotekanauki.pl/articles/1833735.pdf
Data publikacji:
2021
Wydawca:
Centrum Badań i Innowacji Pro-Akademia
Tematy:
nutritional content
polyphenolic content
grape seeds
grape skin
grape pomace
antioxidative activity
wartości odżywcze
zawartość polifenoli
pestki winogron
skórka winogron
wytłoki z winogron
aktywność antyoksydacyjna
Opis:
Grape pomace (GP) is produced in large amounts worldwide, leading to waste of resources and environmental pollution. Using grapes grown in eastern China, the main nutrients and polyphenols in grape seeds (GS), skin (GSK), and GP powders were determined by conventional chemical composition analysis and HPLC-MS/MS. The antioxidative activity of a GP polyphenol extract was identified using DPPH and hydroxyl radical scavenging assays and reducing power assay. GSK and GP contained less total dietary fiber than GS. The total polyphenolic content of GS was significantly higher than that of GSK and GP. The hydrogen- and electron-donating activities of the GP polyphenol extract were superior to those of vitamin C.
Źródło:
Acta Innovations; 2021, 39; 22--31
2300-5599
Pojawia się w:
Acta Innovations
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Statistical Optimization of Underwater Lower-Frequency Sound Insulation for Locally Resonant Sonic Material Using Genetic Algorithm
Autorzy:
Yuan, Bo
Chen, Yong
Tan, Bilian
Li, Bo
Powiązania:
https://bibliotekanauki.pl/articles/177461.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
underwater acoustic
sound insulation
local resonance
statistical optimization
global optimum
Opis:
The locally resonant sonic material (LRSM) is an artificial metamaterial that can block underwater sound. The low-frequency insulation performance of LRSM can be enhanced by coupling local resonance and Bragg scattering effects. However, such method is hard to be experimentally proven as the Best optimizing method. Hence, this paper proposes a statistical optimization method, which first finds a group of optimal solutions of an object function by utilizing genetic algorithm multiple times, and then analyzes the distribution of the fitness and the Euclidean distance of the obtained solutions, in order to verify whether the result is the global optimum. By using this method, we obtain the global optimal solution of the low-frequency insulation of LRSM. By varying parameters of the optimum, it can be found that the optimized insulation performance of the LRSM is contributed by the coupling of local resonance with Bragg scattering effect, as well as a distinct impedance mismatch between the matrix of LRSM and the surrounding water. This indicates coupling different effects with impedance mismatches is the Best method to enhance the low-frequency insulation performance of LRSM.
Źródło:
Archives of Acoustics; 2019, 44, 2; 365-374
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of oat β-glucan on in vitro digestion characteristics of set-type yogurt
Autorzy:
Qu, Xiaoqing
Li, Bo
Yang, Wei
Nazarenko, Yuliya
Powiązania:
https://bibliotekanauki.pl/articles/2142863.pdf
Data publikacji:
2022
Wydawca:
Centrum Badań i Innowacji Pro-Akademia
Tematy:
oat beta-glucan
yogurt
in vitro digestion
antioxidative activity
cholesterol solubility
beta-glukan z owsa
jogurt
trawienie in vitro
aktywność antyoksydacyjna
rozpuszczalność cholesterolu
Opis:
The main objective of the study was to evaluate the effect of added 0.3% (w/w) oat β-glucan (OG) in set-type yogurt on its protein digestion using an in vitro gastrointestinal model. During gastric digestion phase, the amount of soluble proteins and peptides increased to 25% and 40% for control yogurt (yogurt without OG) and 0.3% OG yogurt, respectively. Buccal digestion has little effect on the structure of yogurts, while large spherical vesicles were formed for both control yogurt and 0.3% OG yogurt after gastric digestion. The presence of 0.3% OG promoted the hydrolysis of yogurt in the gastric digestion phase and caused higher antioxidant activity. Compared with that of control yogurt, the inhibition of cholesterol solubility of 0.3% OG yogurt showed no differences after buccal digestion but significantly higher after gastrointestinal digestion (21.3% for gastric and 22.7% for intestinal digestion). Overall, this study enhances the understanding of digestion characteristics of 0.3% OG-fortified set-type yogurt and provides a theoretical basis for the development of this kind of dairy products.
Źródło:
Acta Innovations; 2022, 43; 5-14
2300-5599
Pojawia się w:
Acta Innovations
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Muscle fatigue related to human posture using a brush cutter for landscape gardening: a preliminary study
Autorzy:
Yang, Wanying
Li, Bo
Li, Shusen
Zhang, Yanlin
Yang, Hongze
Powiązania:
https://bibliotekanauki.pl/articles/2082518.pdf
Data publikacji:
2022-06-20
Wydawca:
Instytut Medycyny Pracy im. prof. dra Jerzego Nofera w Łodzi
Tematy:
working posture
muscle activity
occupational diseases
ergonomics of work
agriculture and forestry
brush cutter
Opis:
Background: Brush cutters are widely used in Chinese landscape gardening and agricultural laboring which leads the operators being exposed to many risks. Low back pain (LBP) is particularly common and can lead to substantial personal, community and financial burdens. The aim of the presented study was to measure the activity and function of each torso muscle of the operator when using the bush cutter, so as to evaluate the muscle injury of the operator during using several common brush cutters for different landscape tasks. Material and Methods: The human postures of 6 workers using 2 types of brush cutters in the 3 working conditions were recorded and measured by using a surface electromyography (sEMG) system and a camera. The test results were compared by t-test and sign test. The effect of human posture on the sEMG signal of trunk muscles in different working condition were analyzed by ANOVA. Results: In the 3 working conditions, except for the left trapezius muscle, the muscle load of operating the backpack brush cutter is higher than that of operating side-mounted brush cutter. When operating the side-mounted backpack brush cutter, the force on both sides of the trapezius muscle is uneven, the load of the left trapezius muscle is >25%, and the maximum value is >30%. Conclusions: The results highlighted significant differences in the effects of different working postures on the muscle activities of workers’ trunk. Safe operation standards should therefore be taken to protect the exposed workers and to improve the industrial design of irrigation cutters to prevent the occurrence of occupational diseases.
Źródło:
Medycyna Pracy; 2022, 73, 3; 201-207
0465-5893
2353-1339
Pojawia się w:
Medycyna Pracy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Coal permeability change caused by mining-induced stress
Autorzy:
Zhang, Lulu
Li, Bo
Wei, Jianping
Wen, Zhihui
Ren, Yongjie
Powiązania:
https://bibliotekanauki.pl/articles/89077.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Wydział Geoinżynierii, Górnictwa i Geologii. Instytut Górnictwa
Tematy:
mining-induced stress
permeability
unloading path
sensitivity index
effective stress
Opis:
To study coal permeability evolution under the influence of mining actions, we conducted a sensitivity index test on permeability to determine the influence of axial and confining stresses on coal permeability. Loading and unloading tests were performed afterward, and the differences between loading and unloading paths in terms of strain and permeability were studied. A permeability evolution model was built in consideration of absorption swelling and effective stress during modeling. An effective stress calculation model was also built using axial and confining stresses. The calculation results of the two models were compared with experimental data. Results showed that permeability were more sensitive to confining stress than axial stress, and effective stress placed a large weight on confining stress. Large axial and radial deformations at peak strength were observed during unloading. In the unloading phase, the permeability of coal began to increase, and the increment was enhanced by large initial axial stress when confining stress was loaded. permeability sensitivity to axial and confining stresses were used to explain these permeability changes. The calculation results of the models fitted the experimental data well. Therefore, the proposed models can be used to calculate effective stress on the basis of axial and confining stresses and describe permeability change in coal under the influence of mining actions.
Źródło:
Mining Science; 2019, 26; 203-222
2300-9586
2353-5423
Pojawia się w:
Mining Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On path-quasar Ramsey numbers
Autorzy:
Li, Binlong
Ning, Bo
Powiązania:
https://bibliotekanauki.pl/articles/747260.pdf
Data publikacji:
2014
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Opis:
Let \(G_1\) and \(G_2\) be two given graphs. The Ramsey number \(R(G_1,G_2)\) is the least integer \(r\) such that for every graph \(G\) on \(r\) vertices, either \(G\) contains a \(G_1\) or \(\overline{G}\) contains a \(G_2\). Parsons gave a recursive formula to determine the values of \(R(P_n,K_{1,m})\), where \(P_n\) is a path on \(n\) vertices and \(K_{1,m}\) is a star on \(m+1\) vertices. In this note, we study the Ramsey numbers \(R(P_n,K_1\vee F_m)\), where \(F_m\) is a linear forest on \(m\) vertices. We determine the exact values of \(R(P_n,K_1\vee F_m)\) for the cases \(m\leq n\) and \(m\geq 2n\), and for the case that \(F_m\) has no odd component. Moreover, we give a lower bound and an upper bound for the case \(n+1\leq m\leq 2n-1\) and \(F_m\) has at least one odd component.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica; 2014, 68, 2
0365-1029
2083-7402
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the Influencing Factors of the Acoustic Performance of the Muffler Considering Acoustic-structural Coupling
Autorzy:
Zhao, Bo
Li, He
Powiązania:
https://bibliotekanauki.pl/articles/31339942.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
acoustic performance
muffler
acoustic-structural coupling
transmission loss
mode
optimisation
Opis:
In the calculation of the acoustic performance of mufflers, the walls of mufflers are usually treated rigidly without considering the acoustic-structural coupling, but the results so calculated differ significantly from the actual situation. Based on the basic equations, the article derives the finite element equations of the muffler system while considering the acoustic-structural coupling effect and theoretically analyses the connection between the acoustic-structural coupling system and the structural and acoustic modes. The structural and acoustic modes of the muffler are calculated and the reasons for the mutation of the transmission loss curve of the muffler when the acoustic-structural coupling is considered are analysed. The results show that the acoustic-structural coupling is the result of the interaction between the structure and the air inside the expansion chamber under acoustic excitation, which manifests mutations in the sound pressure inside the muffler in some frequency bands. Then, using a single-chamber muffler as an example, the transmission loss is used to characterise the performance of the muffler. The effects of different factors such as shell thickness, structure, porous media material lining, and restraint method on the acoustic-structural coupling effect of the muffler are analysed, and the structure of a double-chamber muffler is successfully optimised according to the conclusions.
Źródło:
Archives of Acoustics; 2022, 47, 4; 479-490
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heavy Subgraphs, Stability and Hamiltonicity
Autorzy:
Li, Binlong
Ning, Bo
Powiązania:
https://bibliotekanauki.pl/articles/31341693.pdf
Data publikacji:
2017-08-01
Wydawca:
Uniwersytet Zielonogórski. Wydział Matematyki, Informatyki i Ekonometrii
Tematy:
heavy subgraphs
hamiltonian graphs
closure theory
Opis:
Let G be a graph. Adopting the terminology of Broersma et al. and Čada, respectively, we say that G is 2-heavy if every induced claw (K1,3) of G contains two end-vertices each one has degree at least |V (G)|/2; and G is o-heavy if every induced claw of G contains two end-vertices with degree sum at least |V (G)| in G. In this paper, we introduce a new concept, and say that G is S-c-heavy if for a given graph S and every induced subgraph G′ of G isomorphic to S and every maximal clique C of G′, every non-trivial component of G′ − C contains a vertex of degree at least |V (G)|/2 in G. Our original motivation is a theorem of Hu from 1999 that can be stated, in terms of this concept, as every 2-connected 2-heavy and N-c-heavy graph is hamiltonian, where N is the graph obtained from a triangle by adding three disjoint pendant edges. In this paper, we will characterize all connected graphs S such that every 2-connected o-heavy and S-c-heavy graph is hamiltonian. Our work results in a different proof of a stronger version of Hu’s theorem. Furthermore, our main result improves or extends several previous results.
Źródło:
Discussiones Mathematicae Graph Theory; 2017, 37, 3; 691-710
2083-5892
Pojawia się w:
Discussiones Mathematicae Graph Theory
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Flotation separation of enargite from complex copper concentrates by selective surface oxidation
Autorzy:
Li, Tangfei
Zhang, Yansheng
Zhang, Bo
Jiao, Fen
Qin, Wenqing
Powiązania:
https://bibliotekanauki.pl/articles/110698.pdf
Data publikacji:
2019
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
mineralogy
enargite
selective surface oxidation
froth flotation
EDTA extraction
Opis:
In previous study, the promising results of separating enargite from non-arsenic copper sulfides were obtained using selective surface oxidation in pure mineral systems. However, this technology was not well understood in real ores or concentrates. In this study, the flotation separation of enargite from complex copper concentrates by selective surface oxidation was investigated. The effects of regrinding, pulp pH, NaClO concentration, conditioning time and flotation time on separation of enargite from NECu minerals were studied. The mineralogical characteristics of the flotation feed and products were showed as an instructive tool to understand the separation results. According to the results of EDTA extraction, the possible mechanism for separation of enargite from NECu minerals is that enargite is more resistant to oxidized compared to NECu minerals. The following order for the oxidation of NECu minerals and enargite is obtained: chalcopyrite (chalcocite, digenite)> enargite (covellite).
Źródło:
Physicochemical Problems of Mineral Processing; 2019, 55, 4; 852-864
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Life Prediction Mechanism of Ladle Composite Structure Body Based on Simulation Technology
Autorzy:
Li, Gongfa
Jiang, Du
Sun, Ying
Jiang, Guozhang
Tao, Bo
Powiązania:
https://bibliotekanauki.pl/articles/353596.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
ladle life prediction
initiative maintenance
crack propagation
thermal shock method
Opis:
Ladle plays an important role in the metallurgical industry whose maintenance directly affects the production efficiency of enterprises. In view of the problems such as low maintenance efficiency and untimely maintenance in the current ladle passive maintenance scheme, the life prediction mechanism for ladle composite structures is established which bases on the stress analysis of steel shell and ladle lining in the production process, combining conventional fatigue analysis and extended fracture theory. The mechanism is accurate and effective according to the simulation results. Through which, the useful life of steel shell can be accurately predicted by detecting the crack length of it. Due to the large number of factors affecting the life of the lining of the ladle, it is difficult to accurately predict the life of the ladle lining, so a forecasting mean based on the thermal shock method is proposed to predict the service life of the ladle lining in this paper. The life prediction mechanism can provide data support and theoretical guidance for the active maintenance of the ladle, which is the prerequisite for scientifically formulating ladle initiative maintenance program.
Źródło:
Archives of Metallurgy and Materials; 2019, 64, 4; 1555-1562
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Research on creep-fatigue model of anchored jointed rock mass
Autorzy:
Song, Yang
Fan, Bo
Li, Yong-Qi
Wang, He-Ping
Powiązania:
https://bibliotekanauki.pl/articles/2200878.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
shear creep
anchored jointed rock mass
fractional order
fatigue load
damage
Opis:
To explore the mechanical response of anchored rock mass with an interaction of fatigue and creep, this paper selects the fatigue amplitude and fatigue frequency as influencing factors to carry out a fatigue-creep experiment of the anchored rock mass. Based on fractional order theory and binary perturbation theory, a new fractional order creep model is constructed. The results show that compared with the Burgers model, the newly proposed creep model can better describe the whole process of creep deformation of the anchored jointed rock mass under fatigue loading.
Źródło:
Journal of Theoretical and Applied Mechanics; 2023, 61, 1; 163--173
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Physics-of-failure and computer-aided simulation fusion approach with a software system for electronics reliability analysis
Metoda i oprogramowanie do analizy niezawodności urządzeń elektronicznych oparte na połączeniu metodologii fizyki uszkodzeń i symulacji komputerowej
Autorzy:
Sun, Bo
Li, Yu
Wang, Zili
Li, Zhifeng
Xia, Quan
Ren, Yi
Feng, Qiang
Yang, Dezhen
Qian, Cheng
Powiązania:
https://bibliotekanauki.pl/articles/301540.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
physics of failure
reliability analysis
electronics
prognostics and health management
computeraided simulation
software system
fizyka uszkodzeń
analiza niezawodności
urządzenia elektroniczne
prognostyka i zarządzanie zdrowiem
symulacja komputerowa
system oprogramowania
Opis:
Electronics, such as those used in the communication, aerospace and energy domains, often have high reliability requirements. To reduce the development and testing cost of electronics, reliability analysis needs to be incorporated into the design stage. Compared with traditional approaches, the physics of failure (PoF) methodology can better address cost reduction in the design stage. However, there are many difficulties in practical engineering applications, such as processing large amounts of engineering information simultaneously. Therefore, a flexible approach and a software system for assisting designers in developing a reliability analysis based on the PoF method in electronic product design processing are proposed. This approach integrates the PoF method and computer-aided simulation methods, such as CAD, FEM and CFD.The software system integrates functional modules such as product modeling, load-stress analysis and reliability analysis, which can help designers analyze the reliability of electronic products in actual engineering design. This system includes software and hardware that validate the simulation models. Finally, a case study is proposed in which the software system is used to analyze the filter module reliability of an industrial communication system. The results of the analysis indicate that the system can effectively promote reliability and can ensure the accuracy of analysis with high computing efficiency.
Urządzenia elektroniczne, na przykład te używane w łączności, lotnictwie i energetyce, często muszą spełniać wysokie wymagania dotyczące niezawodności. Aby zmniejszyć koszty rozwoju i testowania tego typu urządzeń, należy opracować metodę analizy niezawodności, którą można wykorzystywać już na etapie projektowania. Metodologia fizyki uszkodzeń (PoF) pozwala, lepiej niż tradycyjne podejścia, rozwiązywać problemy związane z niezawodnością już na etapie powstawania projektu. Jednak jej zastosowanie w praktyce inżynierskiej nastręcza wielu trudności, związanych, między innymi, z koniecznością jednoczesnego przetwarzania dużych ilości informacji inżynieryjnych. W związku z tym, w przedstawionej pracy zaproponowano elastyczne podejście oraz system oprogramowania, które mogą być wykorzystywane przez projektantów do opracowania analizy niezawodności produktu elektronicznego w opaciu o PoF na etapie projektowania. Podejście to stanowi połączenie metody PoF i metod symulacji komputerowej, takich jak CAD, FEM i CFD. System oprogramowania zawiera moduły funkcjonalne, takie jak modelowanie produktu, analiza obciążeń, analiza niezawodności i inne, które mogą wspomagać projektantów w analizie niezawodności projektowanych przez nich produktów elektronicznych. Na system ten, oprócz oprogramowania składa się także sprzęt komputerowy, który służy do walidacji modeli symulacyjnych. W artykule przedstawiono studium przypadku, w którym zaproponowany system oprogramowania wykorzystano do analizy niezawodności modułu filtra wykorzystywanego w systemie łączności przemysłowej. Wyniki analizy pokazują, że opracowane oprogramowanie skutecznie poprawia niezawodność urządzeń jak też zapewnia dokładność analizy przy jednoczesnej wysokiej wydajności obliczeniowej.
Źródło:
Eksploatacja i Niezawodność; 2020, 22, 2; 340-351
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Role of different lignin systems in polymers: mechanical properties and thermal stability
Autorzy:
Hasan, Gvlmira
Musajan, Dilhumar
Hou, Gong-bo
He, Mingyu
Li, Ying
Yimit, Mamatjan
Powiązania:
https://bibliotekanauki.pl/articles/779443.pdf
Data publikacji:
2020
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
lignin
mechanical properties
thermal stability
polymer
Opis:
Lignin was used to study the mechanical properties and thermal stability of polymers. The lignin was blended with three kinds of polymers, and the addition of lignin was 0.5 wt%. Under the condition of thermal oxidation, the thermal stability of lignin/polymer samples varies with the structure of lignin. The effects of lignin on the mechanical properties and thermal stability of the polymers were investigated by oxidation induction time (OIT), rheological properties, mechanical properties and differential scanning calorimetry (DSC). The results show that the effect of lignin on the thermal properties of polymer samples is 2~3oC. It can be inferred that lignin can effectively improve the interaction between polymer molecular chain segments, and improve the crystallization rate and rigidity to a certain extent, so it can be seen that lignin has good compatibility and thermal stability.
Źródło:
Polish Journal of Chemical Technology; 2020, 22, 4; 10-16
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Metal Oxides on the Thermal Decomposition Kinetics and Mechanisms of HAN/PVA Based Propellants
Autorzy:
Hu, Song-qi
Liu, Xue-li
Liu, Lin-Lin
Kang, Bo
Zhang, Yan
Powiązania:
https://bibliotekanauki.pl/articles/27787991.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
HAN/PVA-based propellant
metal oxides
catalytic behaviour
kinetic parameters
Opis:
The thermal decomposition processes of HAN/PVA-based propellants have been investigated using a simultaneous thermogravimetric analysis (TGA) – differential scanning calorimetry (DSC), coupled with Fourier-Transform Infrared Spectroscopy (FTIR) and Mass Spectrometry (MS) system. The activation energy (Ea), pre-exponential factor A and reaction mechanism function f(α) of the decomposition processes have been determined by non-isothermal and Malek methods. The results showed that the decomposition process of an HAN/PVA sample occurs mainly in the temperature range 202.2~220.1 °C, with a mass loss, heat release and Ea of about 84.8%, 1474.18 and 88.76 kJ·mol–1, respectively. Of the seven metal oxides studied as catalysts, Al2O3, V2O5 and Fe2O3 have significant catalytic effects on an HAN/PVA-based propellant, in lowering the decomposition temperature, with Ea changing from 88.8 to 83.7, 85.6 and 113.6 kJ·mol–1, respectively. The f(α) of both HAN/PVA and HAN/PVA/Al2O3 samples can be expressed as f(α) = (1 – α)2, whereas f(α) = α or f(α) = α/2 fit well for the HAN/PVA/V2O5 and HAN/PVA/Fe2O3 samples.
Źródło:
Central European Journal of Energetic Materials; 2021, 18, 3; 322-338
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Gastrodin ameliorates spinal cord injury via antioxidant and anti-inflammatory effects
Autorzy:
Du, Fangtao
Wang, Xiaoning
Shang, Bo
Fang, Jifeng
Xi, Yuting
Li, Aijuan
Diao, Yenze
Powiązania:
https://bibliotekanauki.pl/articles/1038788.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
spinal cord injury
gastrodin
inflammation
oxidative stress
Nrf2
Opis:
Spinal cord injury (SCI) is one of the most severe traumatic injuries that results in dysfunction of limbs and trunk below the damaged section. Recent studies have shown that gastrodin (GAS) could improve the recovery of SCI. In the current study, we aimed to examine the possible mechanism underlying the effect of GAS on recovery of SCI in rats. In rats with SCI, GAS improved locomotor functions and decreased permeability of blood-spinal cord barrier, as illustrated by increase of Basso-Beattie-Bresnahan scores and decrease of Evans blue leakage. In addition, GAS inhibited inflammation, as evidenced by decrease of proinflammatory cytokines, including tumor necrosis factor α (TNFα) and interleukin-1β (IL-1β) in rats following SCI. Moreover, increase of TBARS content and decrease of glutathione (GSH) content and superoxide dismutase (SOD) activities in SCI rats were inhibited by GAS. Furthermore, GAS enhanced mRNA expression of nuclear factor (erythroid-derived 2)-like 2 (Nrf2), catalytic subunit of γ-glutamylcysteine ligase (GCLc) and modified subunit of γ-glutamylcysteine ligase (GCLm). The data suggested that GAS may promote the recovery of SCI through the enhancement of Nrf2-GCLc/GCLm signaling pathway, and subsequent improvement of oxidative stress and inflammation, resulting in decrease of permeability of BSCB and improved recovery of locomotor function in rats with SCI. The results have provided novel insights into GAS-related therapy of SCI and associated neurodegenerative diseases.
Źródło:
Acta Biochimica Polonica; 2016, 63, 3; 589-593
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization dependent high refractive index metamaterial with metallic dielectric grating structure in infrared band
Autorzy:
Li, Jianmin
Chen, Peng
Fang, Bo
Cai, Jinhui
Zhang, Le
Wu, Yinglai
Jing, Xufeng
Powiązania:
https://bibliotekanauki.pl/articles/2172825.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
metamaterial
high refractive index
infrared band
Opis:
According to the theory of high refractive index of metamaterials, a composite structure of metal dielectric grating was designed to achieve high refractive index in infrared band. Based on the S-parameter inversion algorithm, we extracted the effective permittivity, the effective permeability, and the effective refractive index of the designed metamaterial. By changing the geometric parameters of the composite grating metamaterial structure, the effective refractive index of the designed metamaterial reaches more than 8.0 at the infrared resonance frequency. This is a high refractive index that many natural materials cannot achieve. It is noteworthy that the metamaterial structure has obvious polarization sensitivity. The metamaterial structure has both high refractive index and wideband zero refractive index properties when different polarized light is incident. At the same time, we further investigate the influence of metamaterial geometric parameters on the effective refractive index of metamaterials. Also, we propose a double grating metamaterial structure to obtain more degrees of freedom of metamaterial on the effective refractive index.
Źródło:
Optica Applicata; 2022, 52, 3; 441--460
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of calculation method of pure mode II stress intensity factor of fine-grained concrete using different numerical models
Autorzy:
Zhou, Changlin
Peng, Bo
Deng, An
Gao, Xiaofeng
Li, Yaojia
Zhou, Lei
Zhu, Zheming
Powiązania:
https://bibliotekanauki.pl/articles/1839720.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
fine-grained concrete
critical stress intensity factor
J-integral
anti-symmetrical four-point bending
FEM
XFEM
Opis:
Measuring and calculating methods of critical stress intensity factors (SIFs) have become hot topics which attracted large attention recently. In this work, anti-symmetrical four-point bending tests of cracked fine-grained concrete specimens were conducted experimentally and numerically by using a computer-controlled universal testing machine and ABAQUS code. A comparative study of the calculation method of pure mode II stress intensity factor of a fine-grained concrete was performed by utilizing the conventional finite element method (FEM) in two and three dimensions as well as the extended finite element method (XFEM) in three dimensions. The results show that in three-dimensional models, the crack mode is closest to the pure mode II at the center of specimen thickness. Pure mode II stress intensity factors obtained by SEAM2D and XFEM3D are 1.013 and 1.0617 times that by SEAM3D, respectively. Pure mode II stress intensity factors of the fine-grained concrete obtained by the conventional FEM are more stable than that by XFEM. The number of mesh circles has slight influence on the calculation results of pure mode II stress intensity factor.
Źródło:
Journal of Theoretical and Applied Mechanics; 2021, 59, 2; 251-264
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis of a novel hydroxamic acid flotation collector and its flotation separation of malachite against quartz
Autorzy:
Sun, Xin
Huang, Lingyun
Wu, Dandan
Hu, Bo
Zhang, Mei
Li, Yaming
Tong, Xiong
Powiązania:
https://bibliotekanauki.pl/articles/2146909.pdf
Data publikacji:
2022
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation
collector
malachite
hydroxamic acid
direct flotation
adsorption
Opis:
This paper proposes a promising chelating collector, phenyl propyl hydroxamic acid (BPHA), to directly float malachite for the separation of malachite against quartz. The flotation performance and mechanism was investigated via microflotation tests, as well as through contact angle, Scanning Electron Microscopeand Energy Dispersive Spectrometer (SEM–EDS), zeta potential, adsorption capacity, Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS) analyses. The results of microflotation tests showed that BPHA has a strong ability to collect malachite and a significant selectivity against quartz. The contact angle tests showed that BPHA effectively adsorbed onto the mineral surface and could improve the hydrophobicity of the malachite surface. SEM–EDS and adsorption capacity analyses further indicated that BPHA adsorbed onto the surface of malachite. The FR-IR results suggested that BPHA could react with Cu2+ ions and facilitate strong chemical adsorption onto the surface of malachite. Furthermore, zeta potential and XPS analyses provided clear evidence that BPHA exhibited a stronger affinity for malachite and a weaker interaction with quartz.
Źródło:
Physicochemical Problems of Mineral Processing; 2022, 58, 4; art. no. 149427
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A dynamic model for the heat transfer behavior of a cooling system
Autorzy:
Liu, Wen
Zhang, Chi
Hu, Xiao-Xiong
Cao, Jian-Bo
Liu, Li-Jiao
Ye, Xin-Y
Lin, Li
Qi, Xun-Ji
Powiązania:
https://bibliotekanauki.pl/articles/2050060.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
adsorption system
refrigerating system
desorption
simulation
Opis:
For purposes of studying the heat transfer behavior of various fluids in a refrigeration system, a dynamic model is established, obtained on the basis of analysis concerning the effects of adsorption velocity, adsorbent bed temperature, condensing temperature, and heat transfer fluids, as well as changes of external conditions. It is demonstrated that adsorption velocity increases sharply in the initial phase of adsorption process and gradually declines after reaching a peak value, whereas condensing temperature increases sharply in the initial phase of desorption process and decreases after reaching a peak value with the desorption quantity decreasing. Furthermore, the increase of heat source temperature and the decrease of cooling water temperature can advance the adsorption process. The present study therefore suggests some ways of improving the performance of such a refrigeration system by increasing heat source temperature, decreasing ambient air temperature, increasing return air temperature and decreasing cooling water temperature.
Źródło:
Control and Cybernetics; 2020, 49, 3; 315--332
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Counterion effects on the alkali dissolution mechanism of quartz
Autorzy:
Yao, Yu-yun
Tang, Yun
Yang, Yong
Li, Guo-hui
Wu, Bo
Dai, Wen-zhi
Powiązania:
https://bibliotekanauki.pl/articles/2200337.pdf
Data publikacji:
2023
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quartz
counterion
quantum chemistry
hydrolysis
mechanism
Opis:
In gold ore, quartz plays an important role in mineral formation by acting as the follower. Understanding counterion release, transport, and deposition in alkali solution is a prerequisite for evaluating the potential role of gold separate from quartz deposits in pretreatment. In this work, the aggregation, retention, and release of counterion in alkali solution media were investigated by kinetic research and pure mineral experiments, the correlation and mechanism of these processes were revealed by combining geochemical theory, interaction energy calculation, and quantum chemistry. The results showed that the retention and release of counterion were closely related to the dissolution and corrosion rate of quartz. The NH4+ and Fe2+ with higher mineral affinity reduced the quartz stability, and the dispersion stability and mobility of the quartz were greatly improved by an alkaline substance due to the enhancement of steric hindrance effects. Quantum chemical calculation results show that ammonium ion promotes the dissolution of quartz stronger than ferrous ion, which is mainly reflected in reducing the activation energy required for the formation of transition state (TS1), which can be verified by kinetic calculation. These findings provide essential insight into the extraction of gold coated by quartz as well as a vital reference for the experiment of gold-loaded quartz leaching in mineral processing.
Źródło:
Physicochemical Problems of Mineral Processing; 2023, 59, 1; art. no. 160038
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biochemical characterization of a catalase from Vibrio vulnificus, a pathogen that causes gastroenteritis
Autorzy:
Pei, Jihua
Wang, Haijun
Wu, Limin
Xia, Shenglong
Xu, Changlong
Zheng, Bo
Li, Tianya
Jiang, Yi
Powiązania:
https://bibliotekanauki.pl/articles/1038620.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
catalase
Vibrio vulnificus
kinetics
mutation
gastroenteritis.
Opis:
Vibrio vulnificus is a virulent human pathogen causing gastroenteritis and possibly life threatening septicemia in patients. Most V. vulnificus are catalase positive and can deactivate peroxides, thus allowing them to survive within the host. In the study presented here, a catalase from V. vulnificus (CAT-Vv) was purified to homogeneity after expression in Escherichia coli. The kinetics and function of CAT-Vv were examined. CAT-Vv catalyzed the reduction of H2O2 at an optimal pH of 7.5 and temperature of 35°C. The Vmax and Km values were 65.8±1.2 U/mg and 10.5±0.7 mM for H2O2, respectively. Mutational analysis suggests that amino acids involved in heme binding play a key role in the catalysis. Quantitative reverse transcription-PCR revealed that in V. vulnificus, transcription of CAT-Vv was upregulated by low salinity, heat, and oxidative stresses. This research gives new clues to help inhibit the growth of, and infection by V. vulnificus.
Źródło:
Acta Biochimica Polonica; 2017, 64, 3; 543-549
0001-527X
Pojawia się w:
Acta Biochimica Polonica
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:
Newly identified transcripts of UL4 and UL5 genes of human cytomegalovirus
Autorzy:
Gao, Shuang
Ruan, Shan
Ma, Yanping
Li, Mali
Wang, Lin
Zheng, Bo
Qi, Ying
Sun, Zhengrong
Huang, Yujing
Ruan, Qiang
Powiązania:
https://bibliotekanauki.pl/articles/1039141.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Biochemiczne
Tematy:
HCMV
UL4
UL5
transcript
Opis:
Human cytomegalovirus (HCMV) UL4 and UL5 genes are two members of the RL11 gene family. In an earlier study, three UL4 transcripts of about 1.7, 1.5 and 1.4 kb were found in early and late classes after infection by the Towne strain by nuclease protection and primer extension analyses. In the present study, two UL4 transcripts (1.5 and 1.7 kb) were found by cDNA library screening, Northern blot, 3' and 5' RACE analyses to appear initially in the immediate early phase and one UL4 transcript (1.4 kb) in the late phase in a low-passage clinical isolate. Furthermore, two novel low-abundance UL5 transcripts with the same 3' terminus as the identified UL4 transcripts in the UL4-UL5 gene region were found in late class RNAs.
Źródło:
Acta Biochimica Polonica; 2015, 62, 1; 97-101
0001-527X
Pojawia się w:
Acta Biochimica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Diffraction mechanism of five-port transmission gratings
Autorzy:
Gao, Chenhao
Wang, Bo
Wen, Kunhua
Meng, Ziming
Wang, Qu
Nie, Zhaogang
Xing, Xiangjun
Chen, Li
Lei, Liang
Zhou, Jinyun
Powiązania:
https://bibliotekanauki.pl/articles/1835817.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
1 × 5 splitting
single-groove grating
normal incidence
Opis:
This paper designs a five-port transmission grating under normal incidence. Rigorous coupled-wave approach is used to optimize the grating parameters. The energy of the grating is mainly dispersed to the 0th, ±1st and ±2nd orders. The efficiency of each diffraction order under both polarizations is close to 20%. The modal method is used to describe the propagation mechanism of the two polarized lights in the grating, and the diffraction behavior of the grating is analyzed. In addition, the grating has a wide range of incident characteristics and a large process tolerance. Therefore, this five-port beam splitter with a connecting layer will be a good polarization-independent beam splitting device.
Źródło:
Optica Applicata; 2020, 50, 4; 609-618
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-25 z 27

Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies