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Wyszukujesz frazę "Chen, L." wg kryterium: Autor


Tytuł:
Thermal decomposition characterization of supergene potassium-jarosite and sodium-jarosite minerals from the northern Tibetan Plateau, China
Autorzy:
Chen, L.
Powiązania:
https://bibliotekanauki.pl/articles/949691.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
potassium-jarosite
sodium-jarosite
thermogravimetric analysis
X-ray diffraction
Opis:
The thermal decomposition of supergene potassium-jarosite and sodium-jarosite samples from the weathering profiles of sulfide deposits in the northern Tibetan Plateau, China, was investigated. Electron microprobe, scanning electron microscopy, and X-ray diffraction analyses indicated the presence of nearly pure potassium-jarosite and sodium-jarosite. Thermogravimetric analysis of the potassium-jarosite sample revealed mass losses of 11.39 wt% at 443.0 °C, 20.99 wt% at 688.3 °C, and 3.18 wt% at 779.3 °C. The thermogravimetric analysis of sodium-jarosite revealed mass losses of 11.72 wt% at 447.5 °C, 21.32 wt% at 682.6 °C, and 3.70 wt% at 716.5 °C. The results provide no evidence for water-molecule loss below 400 °C, as has been reported previously for natural potassium-jarosite and sodium-jarosite. Thermal-decomposition mechanisms have been proposed for potassium-jarosite and sodium-jarosite based on X-ray diffraction analyses of samples obtained at distinct points along the respective thermal decomposition processes. A comparison of the thermal analysis patterns of potassium-jarosite and sodium-jarosite indicates that sodium-jarosite undergoes the initiation of lattice destruction at a higher temperature.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 2; 459-466
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Toxicity of antimony, gallium, and indium toward a teleost model and a native fish species of semiconductor manufacturing districts of Taiwan
Autorzy:
Yang, J.-L.
Chen, L.-H.
Powiązania:
https://bibliotekanauki.pl/articles/13555.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Źródło:
Journal of Elementology; 2018, 23, 1
1644-2296
Pojawia się w:
Journal of Elementology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Apparel Design Safety and Production Criteria and Models
Bezpieczne projektowanie i produkcja odzieży – kryteria i modele
Autorzy:
Chen, L.
Yan, X.
Gao, C.
Powiązania:
https://bibliotekanauki.pl/articles/234142.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
apparel safety
safety attributes
design
production model
safety evaluation
bezpieczeństwo odzieży
atrybuty bezpieczeństwa
projektowanie
produkcja modelu
ocena bezpieczeństwa
Opis:
A safe apparel design and production (SADP) model was proposed as a system to guide the development of safe apparel. An objective analysis of user needs and examination of safe nutrients used in apparel design uncovered through related technical regulations/standards induction and recall case analysis led to the development of apparel safety needs criteria. The criteria were then translated into apparel safety attributes and used in the development of the SADP model. A theoretical evaluation model remained to be developed for apparel safety purposes using multi-part disassembly. It is hierarchically structured in accordance with apparel safety attributes, and demonstrates how the apparel design safety criteria was used by a design team or an industry worker. By the introduction of the apparel design safety evaluation model, a further shift to pro-action and to the prevention of losses will be made possible. The research also demonstrates the application of the SADP model to a textile product design problem.
Zaproponowano kilka modeli bezpiecznego projektowania i produkcji odzieży jako systemu pozyskiwania odzieży bezpiecznej. Przeprowadzono obiektywną analizę potrzeb użytkownika, jak również stosowanych w projektowaniu i produkcji części składowych wyposażenia i odzieży. Doprowadziło to do opracowania kryteriów bezpieczeństwa projektowania i użytkowania.
Źródło:
Fibres & Textiles in Eastern Europe; 2016, 6 (120); 32-38
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
HRTF Adjustments with Audio Quality Assessments
Autorzy:
Yao, S. N.
Chen, L. J.
Powiązania:
https://bibliotekanauki.pl/articles/950215.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
HRTF
PEAQ
cone of confusion
headphones
surround
Opis:
There are an increasing number of binaural systems embedded with head-related transfer functions (HRTFs), so listeners can experience virtual environments via conventional stereo loudspeakers or head- phones. As HRTFs vary from person to person, it is difficult to select appropriated HRTFs from already existing databases for users. Once the HRTFs in a binaural audio device hardly match the real ones of the users, poor localization happens especially on the cone of confusion. The most accurate way to obtain personalized HRTFs might be doing practical measurements. It is, however, expensive and time consuming. Modifying non-individualized HRTFs may be an effort-saving way, though the modifications are always accompanied by undesired audio distortion. This paper proposes a flexible HRTF adjustment system for users to define their own HRTFs. Also, the system can keep sounds from suffering intolerable distortion based on an objective measurement tool for evaluating the quality of processed audio.
Źródło:
Archives of Acoustics; 2013, 38, 1; 55-62
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance Prediction and Irreversibility Analysis of a Thermoelectric Refrigerator with Finned Heat Exchanger
Autorzy:
Meng, F.
Chen, L.
Sun, F.
Powiązania:
https://bibliotekanauki.pl/articles/1493399.pdf
Data publikacji:
2011-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.-a
05.60.Cd
05.70.Ln
Opis:
A developed model of commercial thermoelectric refrigerators with finned heat exchanger is established by introducing finite time thermodynamics. A significant novelty is that physical properties, dimension parameters, temperature parameters and flow parameters are all taken into account in the model. Numerical studies and comparative investigation on the performance of a typical commercial water-cooling thermoelectric refrigerator which consists of 127 thermoelectric elements, are performed for cooling load and coefficient of performance. The results show that the maximum cooling load is 2.33 W and the maximum coefficient of performance is 0.54 when the cooling temperature difference is 10 K. Comparing the simulation results of several models, it is found that the heat convection of the heat exchanger and the heat leakage through the air gap are the main factors, which cause irreversibility and decrease the performance. Moreover, the performance can be improved by optimizing the length and cross-section area of thermoelectric elements. The model and calculation method may be applied to not only the analysis and performance prediction of practical thermoelectric refrigerators, but also the design and optimization of heat exchangers.
Źródło:
Acta Physica Polonica A; 2011, 120, 3; 397-406
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Endoreversible Four-Reservoir Chemical Potential Transformer with Diffusive Mass Transfer Law
Autorzy:
Xia, D.
Chen, L.
Sun, F.
Powiązania:
https://bibliotekanauki.pl/articles/1493376.pdf
Data publikacji:
2011-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.Ln
82.60.Lf
Opis:
The performance of an isothermal endoreversible four-reservoir chemical potential transformer, in which the mass transfer between the mass reservoir and the working medium obeys diffusive law, is analyzed and optimized in this paper. The relation between the rate of energy pumping and the coefficient of performance of the isothermal chemical potential transformer is derived by using finite-time thermodynamics. Moreover, the optimal operating regions and the influences of some parameters on the performance of the cycle are studied. The results obtained herein can provide some new theoretical guidelines for the optimal design of a class of apparatus such as mass exchangers, as well as electrochemical, photochemical, and solid-state devices, and the fuel pumps for solar-energy conversion systems.
Źródło:
Acta Physica Polonica A; 2011, 120, 3; 378-383
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Endoreversible Modeling and Optimization of a Multistage Heat Engine System with a Generalized Heat Transfer Law via Hamilton-Jacobi-Bellman Equations and Dynamic Programming
Autorzy:
Xia, S.
Chen, L.
Sun, F.
Powiązania:
https://bibliotekanauki.pl/articles/1504513.pdf
Data publikacji:
2011-06
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
05.70.-a
05.60.Cd
05.70.Ln
Opis:
A multistage endoreversible Carnot heat engine system operating between a finite thermal capacity high-temperature fluid reservoir and an infinite thermal capacity low-temperature environment with a generalized heat transfer law [q ∝ ( Δ $(T^{n}))^{m}$] is investigated in this paper. Optimal control theory is applied to derive the continuous Hamilton-Jacobi-Bellman equations, which determine the optimal fluid temperature configurations for maximum power output under the conditions of fixed initial time and fixed initial temperature of the driving fluid. Based on the general optimization results, the analytical solution for the case with Newtonian heat transfer law [q ∝ Δ(T)] is further obtained. Since there are no analytical solutions for the other heat transfer laws, the continuous Hamilton-Jacobi-Bellman equations are discretized and the dynamic programming algorithm is adopted to obtain the complete numerical solutions of the optimization problem, and the relationships among the maximum power output of the system, the process period and the fluid temperature are discussed in detail. The results show that the optimal high-temperature fluid reservoir temperature for the maximum power output of the multistage heat engine system with Newtonian and linear phenomenological [q ∝ Δ $(T^{-1})$] heat transfer laws decrease exponentially and linearly with time, respectively, while those with the Dulong-Petit [q∝$(Δ T)^{1.25}$], radiative [q∝ Δ $(T^4)$] and [q∝$(Δ(T^4))^{1.25}$] heat transfer laws are different from the former two cases significantly.
Źródło:
Acta Physica Polonica A; 2011, 119, 6; 747-760
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized integrated importance measure for system performance evaluation: application to a propeller plane system
Uogólniona miara zintegrowanej ważności komponentów jako narzędzie oceny wydajności systemu: zastosowanie w odniesieniu do układu śmigłowca
Autorzy:
Dui, H.
Chen, L.
Wu, S.
Powiązania:
https://bibliotekanauki.pl/articles/301830.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
wydajność systemu
miara ważności
rozkład Weibulla
szybkość przejścia
system performance
importance measure
Weibull distribution
transition rate
Opis:
Miara zintegrowanej ważności (IIM) pozwala oceniać szybkość zmian wydajności systemu powstałych w wyniku przejścia elementu systemu z jednego stanu do drugiego. IIM pozwala rozważać scenariusze, w których szybkość przejścia elementu z jednego stanu do drugiego jest stała. Jest to jednak sprzeczne z założeniem degradacji, zgodnie z którym wydajność systemu obniża się, w związku z czym, szybkość przejścia może z upływem czasu ulegać zwiększeniu. Rozkład Weibulla opisuje żywotność danego elementu, co wykorzystuje się w wielu różnych zastosowaniach technicznych do modelowania złożonych zbiorów danych. W przedstawionej pracy, rozszerzono IIM uzyskując nową miarę ważności, która pozwala rozważać scenariusze, w których szybkość przejścia elementu z jednego stanu do drugiego w wyniku degradacji jest zależną od czasu funkcją rozkładu Weibulla. Przyjęto, że warunkowy rozkład prawdopodobieństwa elementu przebywającego w pewnym stanie jest rozkładem Weibulla, gdzie dany jest kolejny stan do którego ma przejść dany element. Badania nad nową miarą ważności umożliwiają identyfikację najważniejszych elementów podczas trzech różnych okresów czasu życia systemu, co odpowiada charakterystyce rozkładów Weibulla. Dla ilustracji, wyprowadzono pewne właściwości probabilistyczne i zastosowano rozszerzoną miarę ważności do analizy przykładu rzeczywistego układu śmigłowca.
The integrated importance measure (IIM) evaluates the rate of system performance change due to a component changing from one state to another. The IIM simply considers the scenarios where the transition rate of a component from one state to another is constant. This may contradict the assumption of the degradation, based on which system performance is degrading and therefore the transition rate may be increasing over time. The Weibull distribution describes the life of a component, which has been used in many different engineering applications to model complex data sets. This paper extends the IIM to a new importance measure that considers the scenarios where the transition rate of a component degrading from one state to another is a time-dependent function under the Weibull distribution. It considers the conditional probability distribution of a component sojourning at a state is the Weibull distribution, given the next state that component will jump to. The research on the new importance measure can identify the most important component during three different time periods of the system lifetime, which is corresponding to the characteristics of Weibull distributions. For illustration, the paper then derives some probabilistic properties and applies the extended importance measure to a real-world example (i.e., a propeller plane system).
Źródło:
Eksploatacja i Niezawodność; 2017, 19, 2; 279-286
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Temperature-dependent Shock Initiation of CL-20-based High Explosives
Autorzy:
Pi, Z.
Chen, L.
Wu, J.
Powiązania:
https://bibliotekanauki.pl/articles/358764.pdf
Data publikacji:
2017
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
CL-20
shock initiation
heated explosive
phase transitions
numerical simulation
Opis:
To investigate the effects of temperature on the shock initiation characteristics of hexanitrohexaazaisowurtzitane (CL-20), shock initiation experiments on heated C-1 explosive (94% epsilon phase CL-20, and 6% binder, by weight) were performed at temperatures of 20 °C, 48 °C, 75 °C, 95 °C, 125 °C, 142 °C, and 175 °C. An explosive driven flyer device was used to initiate the C-1 charges and manganin pressure gauges were embedded in the C-1 specimen to record the pressure changes with time. Our results show that C-1 becomes more sensitive as the temperature is increased from 20 °C to 95 °C. The ε to γ phase transition in CL-20 occurs at 125 °C; C-1 with CL-20 in the γ phase at 142 °C is less shock sensitive than C-1 with CL-20 in the ε phase at 95 °C or 75 °C. Compared with C-1 at 142 °C, C-1 at 175 °C shows a dramatic increase in shock sensitivity. An ignition and growth reactive flow model was used to simulate the shock initiation of C-1 at various temperatures, and the parameters were obtained by fitting the experimental data. With this parameter set, the shock initiation characteristics of C-1 for temperatures between 20 °C and 175 °C can be derived.
Źródło:
Central European Journal of Energetic Materials; 2017, 14, 2; 361-374
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An LPV pole-placement approach to friction compensation as an FTC problem
Autorzy:
Patton, R. J.
Chen, L.
Klinkhieo, S.
Powiązania:
https://bibliotekanauki.pl/articles/331466.pdf
Data publikacji:
2012
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
układ liniowy niestacjonarny
detekcja uszkodzeń
diagnostyka uszkodzeń
liniowa nierówność macierzowa
lokowanie biegunów
friction
linear parameter varying
fault detection
fault diagnosis
linear matrix inequality
pole placement
Opis:
The concept of combining robust fault estimation within a controller system to achieve active Fault Tolerant Control (FTC) has been the subject of considerable interest in the recent literature. The current study is motivated by the need to develop model-based FTC schemes for systems that have no unique equilibria and are therefore difficult to linearise. Linear Parameter Varying (LPV) strategies are well suited to model-based control and fault estimation for such systems. This contribution involves pole-placement within suitable LMI regions, guaranteeing both stability and performance of a multi-fault LPV estimator employed within an FTC structure. The proposed design strategy is illustrated using a nonlinear two-link manipulator system with friction forces acting simultaneously at each joint. The friction forces, regarded as a special case of actuator faults, are estimated and their effect is compensated within a polytope controller system, yielding a robust form of active FTC that is easy to apply to real robot systems.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2012, 22, 1; 149-160
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A systematic approach for solving the great circle track problems based on vector algebra
Autorzy:
Chen, C. L.
Powiązania:
https://bibliotekanauki.pl/articles/260175.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
great circle
vector algebra
multiple products
spherical trigonometry
Opis:
A systematic approach, based on multiple products of the vector algebra (S-VA), is proposed to derive the spherical triangle formulae for solving the great circle track (GCT) problems. Because the mathematical properties of the geometry and algebra are both embedded in the S-VA approach, derivations of the spherical triangle formulae become more understandable and more straightforward as compared with those approaches which use the complex linear combination of a vector basis. In addition, the S-VA approach can handle all given initial conditions for solving the GCT problems simpler, clearer and avoid redundant formulae existing in the conventional approaches. With the technique of transforming the Earth coordinates system of latitudes and longitudes into the Cartesian one and adopting the relative longitude concept, the concise governing equations of the S-VA approach can be easily and directly derived. Owing to the advantage of the S-VA approach, it makes the practical navigator quickly adjust to solve the GCT problems. Based on the S-VA approach, a program namely GCTPro_VA is developed for friendly use of the navigator. Several validation examples are provided to show the S-VA approach is simple and versatile to solve the GCT problems.
Źródło:
Polish Maritime Research; 2016, 2; 3-13
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Binary-phase metal-based sandwiched grating with high efficiency
Autorzy:
Wang, B.
Chen, L.
Lei, L.
Zhou, J.
Powiązania:
https://bibliotekanauki.pl/articles/174769.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
binary phase
metal layer
sandwiched grating
Opis:
We describe a novel high efficiency element based on a binary-phase metal-based sandwiched grating, where the binary grating is covered by a dielectric layer and connected by a metal slab on the fused-silica substrate. The modal method is used to optimize the grating duty cycle and period to analyze the feasibility to achieve high efficiency for TE and TM polarizations by effective indices of the modes excited in the grating region. Rigorous coupled-wave analysis (RCWA) is employed to optimize the grating depth and to cover the layer thickness accurately by numerical calculations. It is not easy for the conventional binary grating with a usual duty cycle to achieve high efficiency in the –1st order for TM polarization. For the binary-phase metal-based sandwiched grating, high efficiency can be diffracted into the –1st order for not only TE polarization but also TM polarization. Moreover, the wide fabrication tolerance, the wideband property and the flat surface of easy cleaning should be significant for practical applications in a variety of optical systems.
Źródło:
Optica Applicata; 2013, 43, 3; 607-613
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Polarization-selective beam splitter by a sandwiched grating
Autorzy:
Wang, B
Chen, L
Lei, L
Zhou, J
Powiązania:
https://bibliotekanauki.pl/articles/174875.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
modal method
rigorous coupled-wave analysis (RCWA)
sandwiched grating
high efficiency
beam splitter
Opis:
We describe a polarization-selective beam splitter by a sandwiched grating, which can fulfill the high efficiency element for TE polarization and the two-port output for TM polarization. The modal method and the rigorous coupled-wave analysis (RCWA) are employed together to optimize the polarization-selective beam splitter. According to the modal method, the grating duty cycle and period are discussed to analyze the physical mechanism of such a dual-function element. Using RCWA, grating depth and thickness of the covering layer are accurately optimized to design such a polarization-selective beam splitter. With the optimized grating duty cycle, period, depth and covering layer thickness, TE polarization can be mainly diffracted in the –1st order and two-port output can be achieved for TM polarization in the 0th and the –1st orders. The polarization-selective beam splitter should be a useful element in a variety of applications with advantages of high efficiency, wideband property, and dual functions based on a sandwich grating.
Źródło:
Optica Applicata; 2013, 43, 2; s. 229-236
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
2D Structural Acoustic Analysis Using the FEM/FMBEM with Different Coupled Element Types
Autorzy:
Chen, L.
Zhao, W.
Liu, C.
Chen, H.
Powiązania:
https://bibliotekanauki.pl/articles/176330.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
boundary element method
finite element method
discontinuous boundary elements
acoustic fluid-structure interaction
fast multipole method
Opis:
A FEM-BEM coupling approach is used for acoustic fluid-structure interaction analysis. The FEM is used to model the structure and the BEM is used to model the exterior acoustic domain. The aim of this work is to improve the computational efficiency and accuracy of the conventional FEM-BEM coupling approach. The fast multipole method (FMM) is applied to accelerating the matrix-vector products in BEM. The Burton-Miller formulation is used to overcome the fictitious eigen-frequency problem when using a single Helmholtz boundary integral equation for exterior acoustic problems. The continuous higher order boundary elements and discontinuous higher order boundary elements for 2D problem are developed in this work to achieve higher accuracy in the coupling analysis. The performance for coupled element types is compared via a simple example with analytical solution, and the optimal element type is obtained. Numerical examples are presented to show the relative errors of different coupled element types.
Źródło:
Archives of Acoustics; 2017, 42, 1; 37-48
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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