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Wyszukujesz frazę "Xu, H." wg kryterium: Autor


Tytuł:
Memoryless equilibrium strategies in multilevel decision processes of discrete-time descriptor systems
Autorzy:
Xu, H.
Mizukami, K.
Kobara, M.
Powiązania:
https://bibliotekanauki.pl/articles/205573.pdf
Data publikacji:
1998
Wydawca:
Polska Akademia Nauk. Instytut Badań Systemowych PAN
Tematy:
gra dynamiczna
description system
discrete-time system
dynamics games
memoryless equilibrium strategies
Opis:
Applying a general theorem developed by Basar (1981), providing a set of sufficient conditions for a triple of strategies to be in hierarchical equilibrium, to games in normal (strategic) form, we study three-player Stackelberg games for linear quadratic discrete-time descriptor systems with three levels of hierarchy in decision making. We derive explicitly sufficient conditions for the existence of the memoryless hierarchical equilibrium strategies for the player (called P[sub 1]) at the top of the hierarchy, and for the player (called P[sub 2]) at the second level of the hierarchy. Since the resulting hierarchical equilibrium strategies do not depend on the memory information, P[sub 1]'s original optimal team cost remains the tight (attainable) lower bound for P[sub 1]'s cost function no matter whether the players at the lower levels of hierarchy act or not at the last two (or one) stages. Moreover, the resulting strategies have the advantages of simpler structure and higher credibility. A numerical example is solved to illustrate the validity of the results.
Źródło:
Control and Cybernetics; 1998, 27, 1; 81-103
0324-8569
Pojawia się w:
Control and Cybernetics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fixed final time optimal adaptive control of linear discrete-time systems in input-output form
Autorzy:
Zhao, Q.
Xu, H.
Jagannathan, S.
Powiązania:
https://bibliotekanauki.pl/articles/91798.pdf
Data publikacji:
2013
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
fixed final time
discrete-time linear system
adaptive control
adaptive regulation
input/output form
Opis:
In this paper, the fixed final time adaptive optimal regulation of discrete-time linear systems with unknown system dynamics is addressed. First, by transforming the linear systems into the input/output form, the adaptive optimal control design depends only on the measured outputs and past inputs instead of state measurements. Next, due to the time-varying nature of finite-horizon, a novel online adaptive estimator is proposed by utilizing an online approximator to relax the requirement on the system dynamics. An additional error term corresponding to the terminal constraint is defined and minimized overtime. No policy/value iteration is performed by the novel parameter update law which is updated once a sampling interval. The proposed control design yields an online and forward-in-time solution which enjoys great practical advantages. Stability of the system is demonstrated by Lyapunov analysis while simulation results verify the effectiveness of the propose approach.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2013, 3, 3; 175-187
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of the effect of variable compression ratios performance on opposed piston 2-stroke engine
Autorzy:
Alqahtani, A.
Wyszynski, M. L.
Mazuro, P.
Xu, H.
Powiązania:
https://bibliotekanauki.pl/articles/133658.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Naukowe Silników Spalinowych
Tematy:
opposed-piston
AVL BOOST
VCR
compression ratio
numerical simulation
tłok przeciwbieżny
stopień sprężania
symulacja numeryczna
Opis:
Numerous skills involving the introduction of (OP) opposed piston engine have been developed in the recent past. Indeed, novel techniques can help to improve the performance of the engine. The aim of this paper is to model and simulate a simple single-cylinder two-stroke opposed-piston engine and minimise fuel consumption and heat loss, using the software programme AVL BOOST™. AVL BOOST is an engine modelling software, which analyses the performance of a modelled single cylinder two-stroke opposed-piston engine by changing desired parameters. In order to meet this aim, experimental results from a unique engine are used to make a comparison with the results obtained from AVL BOOST model. Six combinations of compression ratios (12, 13.5, 15, 16.5, 18 and 19.5) are analysed in this study with the engine speed running at 420 rpm and 1500 rpm. In addition to the compression ratios, the effect of stroke-to-bore (S/B) ratios on OP2S performance is investigated. Various values of S/B ratios, whilst maintaining a constant swept volume, port geometry and combustion timing, and their effect on fuel consumption and heat loss are analysed in this study. A comparison between the two engine speeds with increasing combinations of compression ratios, and the S/B ratios revealed minimal differences in peak pressure, peak temperature, IMEP, ISFC, indicated efficiency and total heat loss. Detailed analyses of these parameters are highlighted in discrete sections of this paper.
Źródło:
Combustion Engines; 2017, 56, 4; 97-106
2300-9896
2658-1442
Pojawia się w:
Combustion Engines
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of quinoline from aqueous solutions by lignite, coking coal and anthracite. Adsorption isotherms and thermodynamics
Autorzy:
Xu, H.
Huagn, G.
Li, X.
Gao, L.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/110016.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quinoline adsorption
coking coal
adsorption isotherms
thermodynamics
Opis:
Based on the concept of circular economy, a novel method of industrial organic wastewater treatment by using adsorption on coal is introduced. Coal is used to adsorb organic pollutants from coking wastewaters. After adsorption, the coal would be used for its original purpose, its value is not reduced and the pollutant is thus recycled. Through systemic circulation of coking wastewater zero emissions can be achieved. Lignite, coking coal and anthracite were used as adsorbents in batch experiments. The quinoline removal efficiency of coal adsorption was investigated. The coking coal and anthracite exhibited properties well-suited for adsorption onto both adsorbents. The experimental data were fitted to Langmuir and Freundlich isotherms as well as Temkin, Redlich–Peterson (R-P) and Dubinin-Radushkevich (D-R) models. Both Freundlich Isotherm and D-R model provided reasonable models of the adsorption process. The thermodynamic parameters of quinoline adsorption on coking coal were calculated. The thermodynamic parameters indicated that the adsorption process is exothermic and is a physical adsorption. The △S° value indicated that the adsorption entropy decreased because the adsorbate molecule was under restrictions after it adsorption on the coal surface. The coal adsorption method for removing refractory organic pollutants is a great hope for achieving zero emission waste water for a coking plant.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 214-227
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Pretreatment of coking wastewater by an adsorption process using fine coking coal
Autorzy:
Gao, L.
Li, S.
Wang, Y.
Gui, X.
Xu, H.
Powiązania:
https://bibliotekanauki.pl/articles/110417.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
coking coal
coking wastewater
adsorption
COD
phenol
Opis:
A new technique for pretreatment of coking wastewater is introduced based on the concept of circular economy. Coal is fed into a coking system after adsorption. This study validates the feasibility of using coking coal to adsorb organic pollutants in coking wastewater. The sorption kinetics and equilibrium sorption isotherms of coking coal for removal of chemical oxygen demand (COD) and phenol from coking wastewater was also discussed in this paper. Gas chromatograph/mass spectroscopy (GC/MS) was used to detect changes in the quality of coking wastewater. The results showed that when coking coal dosage was 120 g/dm3, 65% of COD and 34% of phenol in waste water can be removed after 40 min of agitation. The surface functional groups of coking coal before and after adsorption were observed with a Fourier transform infrared spectrometer. The kinetics of COD and phenol adsorption from coking wastewater by coking coal fitted the pseudo second-order model. The adsorption process of coking coal can be classified into two categories, namely, rapid and slow. The Freundlich isotherm provided a better fit with all adsorption isotherms than the Langmuir isotherm. Coking coal could be a suitable low-cost adsorbent for recalcitrant organic pollutants.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 422-436
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characteristics of the staminate flower and pollen from autotetraploid Betula platyphylla
Autorzy:
Lin, L.
Yao, Q.
Xu, H.
Mu, H.
Jiang, J.
Powiązania:
https://bibliotekanauki.pl/articles/41710.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Opis:
Comparison of the staminate flower and pollen of Betula platyphylla between autotetraploid and diploid individuals may reveal the reason for cross sterility when an autotetraploid male parent is crossed with a diploid female parent. Staminate flowers and pollen from seven autotetraploid individual trees were examined. The morphologies of the staminate flower and pollen and pollen germination of these autotetraploid individuals were compared with diploid trees. The structure of the staminate flower did not differ between autotetraploids and diploids, whereas the size of the staminate flower was larger in the autotetraploids compared with the diploids. The mean diameter and pore depth of the pollen were significantly larger in autotetraploid individuals compared with diploids, and several abnormalities in pollen morphology were found commonly amongst pollen from the autotetraploid trees. The germination rate of pollen from autotetraploids was significantly inferior to that of diploids and there was a significant negative correlation between germination rate and the percentage of abnormal pollen. These results demonstrate that the autotetraploid should not be chosen as the male parent to obtain hybrid triploid progenies because the pollen is abnormal and results in low fertility despite its large size. The results provide important information for selecting and distributing parent strains with the aim of building seed orchards of triploid birch trees.
Źródło:
Dendrobiology; 2013, 69
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy feature of a multi-flow column flotation process
Autorzy:
Cheng, G.
Yu, Y.
Ma, L.
Xia, W.
Xu, H.
Powiązania:
https://bibliotekanauki.pl/articles/109768.pdf
Data publikacji:
2017
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
flotation column
turbulent kinetic energy
turbulent dissipation rate
bubble
Opis:
A cyclonic-static micro-bubble flotation column (FCSMC) has been widely used in mineral separation. FCSMC includes countercurrent, cyclone and jet flow mineralization zones in a single column. In this study, the energy feature of the three different zones was compared. The turbulent flow was evaluated in terms of the turbulent kinetic energy (k) and the turbulent dissipation rate (ε). An appropriate computing model was determined by comparing the flow field value measured by PIV with the results of the Fluent numerical simulation. Jet flow separation exhibited the maximum k and ε values among the three columns, whereas counter-current separation displayed the minimum values. The high circulating volumetric flowrate means great energy input and turbulent intensity. The higher turbulent dissipation rate, the smaller the bubble is. The better performance of the FCSMC was mainly attributed to the multiple mineralization steps. The floatability of mineral particles gradually decreases with an increase in flotation time, the mineralization energy gradually increased to overcome the decrease in mineral floatability. By contrast, the countercurrent was beneficial for recovering the coarse particles, and the jet flow was beneficial for recovering the fine particles.
Źródło:
Physicochemical Problems of Mineral Processing; 2017, 53, 2; 1266-1284
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption mechanism of sodium oleate on titanium dioxide coated sensor surface using quartz crystal microbalance with dissipation
Autorzy:
Fan, G.
Liu, J.
Cao, Y.
Feng, L.
Xu, H.
Powiązania:
https://bibliotekanauki.pl/articles/110014.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
QCM-D
TiO2 coated sensor surface
sodium oleate
adsorption mechanism
Opis:
Quartz Crystal Microbalance with Dissipation (QCM-D) was firstly applied to investigate the adsorption mechanism of sodium oleate on TiO2 coated sensor surface. The effects of pH value, sodium oleate concentration, and temperature on TiO2 coated sensor surface were evaluated systematically using the QCM-D technique. Zeta potential, surface tension, adsorption isotherms, and adsorption thermodynamics were employed to characterize the adsorption process. The results showed the advantages of QCM-D on the investigation of the adsorption process. Additionally, the electrostatic equilibrium adsorption data was well matched to the Langmuir isotherm. Based on the thermodynamic analysis, adsorption was a spontaneous and endothermic physisorption process.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 2; 597-608
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Expression analysis of multifunctional RNA-binding protein hnRNP K during development of mammalian testis
Autorzy:
Xu, H.
Zhang, P.
Li, R.
Wu, W.
Wang, S.
Xu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/2087724.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hnRNP K
testis development
spermatogenesis
pig
rat
Źródło:
Polish Journal of Veterinary Sciences; 2018, 21, 2; 343-352
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of gas holdup on the efficiency of cyclonic-static microbubble flotation column for oily wastewater treatment
Autorzy:
Ning, K.
Huang, G.
Xu, H.
Wu, L.
Li, X.
Wang, Y.
Powiązania:
https://bibliotekanauki.pl/articles/208139.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
bubble columns
efficiency
flotation
wastewater treatment
oil water separation
kolumna flotacyjna
efektywność
flotacja
oczyszczanie ścieków
separacja wody
Opis:
A cyclonic-static microbubble flotation column of a novel construction was used in oil-water separation fields and has high efficiency for oil-water separation. The gas holdup is a key parameter for the evaluation of the performance of a flotation column. The gas holdup, closely related to the bubble size, bubble velocity and superficial gas velocity, is one of the most important parameters characterizing the hydrodynamics of a bubble column. The effect of gas holdup in a cyclonic-static microbubble flotation column was investigated. In addition, several operating parameters such as the circulating pressure, superficial gas velocity, and frother consumption were also investigated. The gas holdup was positively correlated to the superficial gas velocity. The gas holdup of clean water and oil wastewater increased along with the increase of the frother consumption. The separation mechanism of cyclonic-static microbubble flotation column was analyzed.
Źródło:
Environment Protection Engineering; 2018, 44, 2; 5-17
0324-8828
Pojawia się w:
Environment Protection Engineering
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:
Dynamic expression profile of DNA methyltransferases in rat testis development
Autorzy:
Xu, H.X.
Qin, J.Z.
Zhang, K.Y.
Zeng, W.X.
Powiązania:
https://bibliotekanauki.pl/articles/31635.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
DNA methyltransferases (Dnmts) are unique and perform specific functions during male germ cell development. To further characterize the significance of Dnmts in the events leading to production of spermatozoa, we investigated whether the expression patterns in Dnmt1, Dnmt3a, Dnmt3b and Dnmt3l were apparent in rat testes at different time points during development. The qRT-PCR results showed that expression levels of Dnmt3a and Dnmt3l were abundant before birth and were present at the highest levels in testes tissue at 18.5 days postcoitus (dpc), and gradually decreased from day 0 postpartum (dpp) to 90 dpp. Expression of Dnmt1 and Dnmt3b reached a peak after birth (P <0.01), and then gradually reduced until adulthood. Western blotting and immunolocalization analysis of Dnmt3a and Dnmt3b further confirmed the differential expression and localization of the two proteins during rat testis development. The dynamic expression profile of Dnmts implies specific and potentially nonredundant roles for each of these enzymes in the developing rat testis.
Źródło:
Polish Journal of Veterinary Sciences; 2015, 18, 3
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of quinoline from aqueous solutions by lignite, coking coal and anthracite. Adsorption kinetics
Autorzy:
Xu, H.
Wang, Y.
Huagn, G.
Fan, G.
Gao, L.
Li, X.
Powiązania:
https://bibliotekanauki.pl/articles/110664.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
quinoline adsorption
coking coal
kinetics
adsorption activation energy
coal adsorption
Opis:
Basing on the concept of circular economy, a novel method of industrial organic wastewater treatment by using adsorption on coal is introduced. Coal is used to adsorb organic pollutants from coking wastewaters. After adsorption, the coal would be used in its original purpose, as its value was not reduced and the pollutant was reused. Through the systemic circulation of coking wastewater zero emissions can be achieved. Lignite, coking coal and anthracite were used as adsorbents in batch experiments. The quinoline removal efficiency of coal adsorption was investigated. Both the coking coal and anthracite exhibited properties well-suited for quinoline adsorption removal. The experimental data were fitted to the pseudo-first- order and pseudo-second-order kinetic equations as well as intraparticle diffusion and Bangham models. An attempt was made to find the rate-limiting step involved in the adsorption processes. Both boundary-layer diffusion and intraparticle diffusion are likely involved in the rate-limiting mechanisms. Effect of pH on coal adsorptions by coking coal was investigated. The process of quinoline adsorption on coal was researched. The coal adsorption method for removing refractory organic pollutants is a great hope for achieving wastewater zero emission for coking plants.
Źródło:
Physicochemical Problems of Mineral Processing; 2016, 52, 1; 397-408
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kinetic research of quinoline, pyridine and phenol adsorption on modified coking coal
Autorzy:
Sun, X.
Xu, H.
Wang, J.
Ning, K.
Huang, G.
Yu, Y.
Ma, L.
Powiązania:
https://bibliotekanauki.pl/articles/110365.pdf
Data publikacji:
2018
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
adsorption kinetics
modification
coking coal
coking wastewater
Opis:
Adsorption is widely used in wastewater treatment. In this work, the removal of quinoline, pyridine and phenol from coking wastewater by using modified coking coal, which was treated by four different modification methods i.e. acidification sodium hydroxide (5 mol/dm3), hydrochloric acid (5 mol/dm3) and acetic acid (5 mol/dm3) and low-temperature (105 oC) oxidation, was investigated. The modified coal was characterized by the surface area analysis, SEM, total acidity and basicity and FT-IR. The results showed that the surface area from high to low follows the order: modification with acetic acid, modification with hydrochloric acid, raw coal, modification with sodium hydroxide and modification with low-temperature. Experimental data were fitted to pseudo-first-order, pseudo-second-order and intra-particle diffusion. The adsorption of all followed pseudo-second-order kinetics. The result showed that the removal efficiency of coal modified by hydrochloric acid and acetic acid are higher than raw coal, while modified by sodium hydroxide and low-temperature are lower than raw coal., The coal modified by hydroxide acid had the best adsorption capacity.
Źródło:
Physicochemical Problems of Mineral Processing; 2018, 54, 3; 965-974
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D Simulation of Warp Knitted Structures with a New Algorithm Based on NURBS
Symulacja 3D struktur dzianych z zastosowaniem algorytmu opartego na algorytmie NURBS
Autorzy:
Xu, H Y
Chen, N L
Jiang, J H
Jin, L X
Wang, Z X
Powiązania:
https://bibliotekanauki.pl/articles/232913.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
warp knitted stitch
three-dimensional simulation
NURBS
joint of stitches
MATLAB
ścieg osnowy tkaniny
struktura dzianin
symulacja trójwymiarowy
algorytm NURBS
wspólne szwów
oprogramowanie Matlab
Opis:
In order to obtain a three-dimensional computer simulation of warp knitted structures with more flexibility and realism, a new algorithm using Matlab was developed by NURBS based on empirical geometrical loop models. With the principles of NURBS curves, once the values of data points are known, the control points with two coincidence points at the start and end points can be uncomplicatedly calculated by Matlab. Then the NURBS curve of a single typical stitch can be simulated flexibly by Matlab. A new typical stitch selected from two stitches simulated directly by the new method is redefined to improve the joint of neighboring stitches, and it is found that there are two types of redefined typical warp knitted stitches judged by whether the two under lap on the same side or not. Based on the redefined typical warp knitted stitch, two warp knitted structures are simulated regardless of the loop offset, and all the joints of stitches are smooth.
Przeprowadzono symulację komputerową struktur dzianin w wymiarze 3D, opracowując w tym celu nową procedurę opartą na algorytmie NURBS. Do tego celu wykorzystano oprogramowanie MATLAB. Symulację 3D przeprowadzono w oparciu o procedury numeryczne umożliwiające wykreślenie przestrzennych figur geometrycznych opisujących strukturę dzianin. Symulowano kształt oczek zamkniętych i otwartych podstawowych splotów kolumienkowych trykotu, sukna i aksamitu. W oparciu o 8 punktów referencyjnych zorientowano konfigurację pętli oczka i łącznika w postaci przestrzennej linii eliptycznej. Do zapisu struktury splotu kształtu oczek wykorzystywano aparat matematyczny w postaci macierzy.
Źródło:
Fibres & Textiles in Eastern Europe; 2015, 1 (109); 57-60
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Finite Element Modeling for the Uni-Axial Tensile Behaviour of Metallic Warp-Knitted Fabric
Zastosowanie metody elementów skończonych (FEM) do przewidywania jednoosiowego rozciągania dzianin metalicznych
Autorzy:
Xu, H.-Y.
Jiang, J.-H.
Chen, N.-L.
Lin, F.-B.
Shao, H.-Q.
Powiązania:
https://bibliotekanauki.pl/articles/231781.pdf
Data publikacji:
2018
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
warp-knitted fabric
finite element analysis
tensile behavior
metallic
TexGen
dzianina osnowowa
analiza elementów skończonych
proces rozciągania
dzianina metaliczna
Opis:
The finite element analysis method (FEM), for its advantages of lower time and economic costing in predicting the mechanical properties of fabrics, was applied to warp-knitted fabrics. In this paper, two bar warp-knitted fabric knitted with wires was used as reflecting mesh antennas. Firstly the loop unit of the metallic warp-knitted fabric was simulated in 3-D by TexGen software. Secondly the 3-D loop unit model was inputted into ABAQUS software to form a model of the metallic warp-knitted fabric sheet for uni-axial tension analysis. Thirdly numerical results were obtained after setting the parameters in ABAQUS. Finally numerical results were verified by uni-axial tensile experiments on the metallic warp-knitted fabric. The results showed that the simulation was in good agreement with the experimental tensile process, where the transfer of yarns between loops when in low fabric elongation and in yarn elongation when in high fabric elongation were simulated by FEM of warp-knitted fabric in the tensile process. Also the same trend of tensile force was found in experiment and FEM results. Therefore it can be concluded that FEM can be used to predict the mechanical properties of warp-knitted fabric with a complex structure.
Do przewidywaniu mechanicznych właściwości dzianin metalicznych zastosowano metodę elementów skończonych (FEM). Symulacji 3D dzianin dokonano przy użyciu dwóch rodzajów oprogramowania: TexGen i ABAQU. Wyniki symulacji zweryfikowano eksperymentalnie. Stwierdzono, że symulacja charakteryzowała się zgodnością z eksperymentalnie przeprowadzonym procesem rozciągania. Na podstawie wyników stwierdzono, że metoda elementów skończonych (FEM) może być z powodzeniem wykorzystywana do przewidywania mechanicznych właściwości dzianin o złożonej strukturze.
Źródło:
Fibres & Textiles in Eastern Europe; 2018, 2 (128); 49-54
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stability control of propeller Autonomous Underwater Vehicle based on combined sections method
Autorzy:
Qi, D.
Feng, J.
Liu, A.
Hu, J.
Xu, H.
Li, Y.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/259119.pdf
Data publikacji:
2015
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
propeller AUV
dynamic model
stability control
simulation
Opis:
Learning from the motion principle of quadrotor, a symmetric propeller AUV, which has small size and low velocity is designed. Compared with the AUV equipped with rudders, it has better maneuverability and manipulation at low velocity. According to the Newton-Euler method, the 6 DOF kinematic model and dynamic model of the propeller AUV are established. A stability controller that consists of 3 different PID controllers is designed. It makes the depth and attitude angle as trigger conditions, and the relevant controller is chosen in different moving process. The simulation experiments simulate ideal motion state and disturbed motion state, and experiments results show that the stability controller based on combined sections method can make the best of mature technology of PID, and meet the control requirements in different stages. It has a higher respond speed and accuracy, improving the stability of the propeller AUV under the disturbance of complex ocean currents.
Źródło:
Polish Maritime Research; 2015, S 1; 157-162
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Combustion Characteristics and Mechanism of Boron-based, Fuel-rich Propellants with Agglomerated Boron Powder
Autorzy:
Xu, H. -X.
Pang, W.-Q.
Guo, H.-W.
Zhao, F.-Q.
Wang, Y.
Sun, Z.-H.
Powiązania:
https://bibliotekanauki.pl/articles/358733.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
analytical chemistry
boron-based fuel-rich solid propellants
agglomerated boron powder
combustion performance
combustion mechanism
Opis:
In order to extend the burning rate of boron-based, fuel-rich solid propellants with agglomerated boron powder, the effects of the boron content, the AP content, and of the magnesium powder content, on the burning rate and pressure exponent have been studied systematically. It has been shown that when the AP content is constant, the burning rate of the propellants increases with an increase in the agglomerated boron content. Furthermore, the burning rate and pressure exponent increase with increasing the contents of AP and magnesium powder. By means of single colour frame amplification photography and combustion wave tests, the combustion mechanism of these propellants has been investigated. It has been shown that the flame of the propellants becomes brighter by increasing the AP content, the dT/dxcp and dT/dxgp of the propellant FR-5 being around 6815 and 5789 °C/mm respectively, higher than those of FR-4, resulting in greater burning rates. The Ts of these propellants is above 683 °C, which is higher than the decomposition peak temperatures of agglomerated boron powder and of propellants (about 649 °C), which indicates that agglomerated boron powder is partially oxidized on the combustion surface, and the heat released from it may be beneficial to the combustion of the propellants.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 4; 575-587
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of injection pressure and strategy in a Jaguar V6 diesel engine
Autorzy:
Abdullah, N. R.
Mamat, R.
Rounce, P.
Wyszynski, M. L.
Tsolakis, A.
Xu, H. M.
Tian, G.
Powiązania:
https://bibliotekanauki.pl/articles/242414.pdf
Data publikacji:
2009
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
combustion
emissions
injection strategies
premixed combustion
ignition delay
Opis:
In recent years, the improvement of engine performance and emissions has become an extremely important concern. This study focuses on the injection strategy based on the injection pressure (IP) and duration between pilot injection and the main injection (dMI) using a multi cylinder common rail multiple injections diesel engine. The study was designed to produce improvements in fuel mixing via the injection strategy, to reduce the main ignition delay. This would contribute to a minimum amount of fuel burnt in the premixed combustion phase, leading to a reduction in emissions. Recent evidence shows that premixed combustion is significant in the controlling of emissions of nitrogen oxides (NOx) and soot. Six different IPs combined with a short and long dMI were compared in the attempt to improve engine performance and emissions. The engine performance was measured in terms of brake specific fuel consumption, ignition delay, heat release and peak in-cylinder pressure and emissions, specifically nitrogen oxides (NOx), total unburned hydrocarbons (THC), carbon monoxide (CO) and smoke emissions for each engine test condition. The evidence from this study shows that the effect of IP is more dominant than dMI in terms of peak cylinder pressure, heat release, brake specific fuel consumption and emissions. However, the dMI shows a strong effect at a higher engine speed.
Źródło:
Journal of KONES; 2009, 16, 2; 9-22
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation into particulate size distributions in the exhaust gas of diesel engines fuelled with biodiesel blends
Autorzy:
Chuepeng, S.
Theinnoi, K.
Xu, H. M.
Wyszynski, M. L.
York, A. P. E.
Hartland, J. C.
Qiao, J.
Powiązania:
https://bibliotekanauki.pl/articles/248072.pdf
Data publikacji:
2008
Wydawca:
Instytut Techniczny Wojsk Lotniczych
Tematy:
biodiesel
PM
combustion
diesel
PM size distribution
Opis:
Particulate matter (PM) size distributions in the exhaust gas of biodiesel blend fuelled diesel engines have been studied by experimenting firstly on a single cylinder equipped with a pump-line-injector injection system and secondly for comparison on a V6 DI engine equipped with a common rail fuel injection system. Both engines were operated with a biodiesel (RME) blend of B30 and ultra low sulphur diesel fuel (ULSD). Several engine load conditions with and without exhaust gas recirculation (EGR) were selected. Particulate number concentrations vs. the electrical mobility equivalent diameter were examined using a fast differential mobility spectrometer. The effect of engine operating conditions including EGR rates on particulate emissions has been investigated. It is found that PM sizes from combustion of B30 without EGR operation are generally smaller than those from ULSD while number concentrations are higher. This can result in lower PM mass estimates for the B30 case if due care is not taken. When EGR is applied to control nitrogen oxides emissions, both the total PM number and mass are increased and shifted toward the larger sizes for both fuels used in the test. The calculated total PM mass from B30 combustion is lower than in the ULSD case for all the tested engine operating conditions.
Źródło:
Journal of KONES; 2008, 15, 3; 75-82
1231-4005
2354-0133
Pojawia się w:
Journal of KONES
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis and Characterization of a High Energy Combustion Agent (BHN) and Its Effects on the Combustion Properties of Fuel Rich Solid Rocket Propellants
Autorzy:
Pang, W.-Q.
Zhao, F.-Q.
Xue, Y.-N.
Xu, H.-X.
Fan, X.-Z.
Xie, W.-X.
Zhang, W.
Lv, J.
Deluca, L. T.
Powiązania:
https://bibliotekanauki.pl/articles/358474.pdf
Data publikacji:
2015
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
fuel rich solid propellant
BHN
DSC
TG-DTG
burning rate
combustion properties
Opis:
A high energy combustion agent (tetraethylammonium decahydrodecaborate, BHN) was prepared by means of an ion exchange reaction (IER), and the prepared samples were characterized by the advanced diagnostic techniques of Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC) etc. The effects of BHN particles on the hazard and combustion properties of fuel rich solid propellants were investigated. The results showed that the BHN samples and fuel rich propellants containing BHN particles can be prepared successfully and solidified safely. The peak temperature of thermal decomposition and the heat of decomposition of the BHN samples prepared were 305.8 °C and 210.9 J•g-1 at a heating rate of 10 K•min-1, respectively. The burning rate and pressure exponent of fuel rich solid propellants decreases with increases in the fraction of BHN particles in the propellant formulation. Compared with the reference formulation (sample BP-1), the burning rate of the propellant with 10% mass fraction of BHN particles (sample BP-4) had decreased 30% at 3.0 MPa, and the pressure exponent had dropped from 0.44 to 0.41.
Źródło:
Central European Journal of Energetic Materials; 2015, 12, 3; 537-552
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Intervalley Transfer of Electrons in ZnS-Type Thin Film Electroluminescent Devices
Autorzy:
Zhao, H.
Wang, Y.
Xu, Z.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/2011094.pdf
Data publikacji:
1999-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
72.20.-i
78.60.-b
Opis:
Based on the calculation about intervalley scattering rates in ZnS, the intervalley transfer process in ZnS-type thin film electroluminescent devices is investigated through the Monte Carlo simulation. The transient time of intervalley transfer is about 0.2-0.3 ps, it coincides with that of electron average energy. Intervalley distribution shifts to high valleys as the electric field increased. The electron kinetic energy distributions in different valleys are also gained. We propose that high valleys could store energies, which could prolong the decay of the electron average energy as the field was removed. These results could be used as the basic data on the study of electroluminescent process and the citation of valley parameters in analytic models should be carefully considered.
Źródło:
Acta Physica Polonica A; 1999, 96, 3-4; 475-482
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analytical Band Model in Monte Carlo Simulation of Electric Transport in ZnS Thin Film Electroluminescent Devices
Autorzy:
Zhao, H.
Wang, Y.
Xu, X.
Powiązania:
https://bibliotekanauki.pl/articles/2014087.pdf
Data publikacji:
2000-07
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
78.60.-b
72.20.-i
Opis:
In this paper, an analytical band model is introduced in Monte Carlo simulation of electric transport process in thin film electroluminescent devices. The band structure of ZnS calculated from the empirical pseudopotential method is fitted by using polynomials. The density of states and scattering rates are also calculated from these polynomials. Based on these results, the electric transport process in ZnS-type thin film electroluminescent devices is simulated through the Monte Carlo method. By comparison with others, this model is as fast as the nonparabolic model and as accurate as the full band model. Furthermore, the influence of the band model on the simulation results is also investigated. We show that the dispersion relation and density of states are all important in the simulation.
Źródło:
Acta Physica Polonica A; 2000, 98, 1-2; 123-130
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A reliability analysis method of cloud theory – Monte Carlo based on performance degradation data
Oparta na teorii chmury i modelu Monte Carlo metoda analizy niezawodnościowej danych o obniżeniu charakterystyk
Autorzy:
Yang, H.
Xu, G.
Fan, X.
Powiązania:
https://bibliotekanauki.pl/articles/301128.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
performance degradation
Cloud theory
Monte Carlo method
randomness
fuzziness
obniżenie charakterystyk
teoria chmury
metoda Monte Carlo
losowość
rozmycie
Opis:
Owing to inadequate degradation data, the randomness and the fuzziness of degradation processes, it is difficult to calculate the reliability of product. By investigating performance reliability using degradation data of performance, the authors proposed a method of analyzing reliability of performance degradation data using Monte Carlo principle and cloud theory. First of all, the performance degradation cloud with the degradation amount and the entropy which denotes the possible discrete degree of the degradation data, is generated by using performance degradation data and a cloud theory forward cloud generator. Then, the minimum membership threshold of cloud droplets and the threshold of product failure were set. Meanwhile, the number of cloud droplets that comply with the minimum membership degree and the failure threshold were counted. Finally, the reliability method of performance degradation data was proposed by using the principle of Monte Carlo and the cloud theory. In this work, the cloud theory was introduced to verify the reliability of the performance degradation of the product. The randomness and the fuzziness in the degradation tests are resolved. In addition, due to the limits of degradation test data, the difficulties in calculation of the reliability is resolved using the principle of Monte Carlo, the minimum membership of cloud droplets and its minimum degree are therefore guaranteed. This work provides a new method of simulating the reliability of degradation. The feasibility of the method was validated by an example ensuring a high durability of conveyor belt joints is tantamount to guaranteeing their reliable operation and that the results of research conducted so far fail to provide unambiguous solutions to a number of problems that emerge in this case, it is advisable that advanced studies using computer techniques should be conducted within this area.
Ze względu na niewystarczające dane o degradacji oraz losowość i rozmycie procesów degradacji, obliczanie niezawodności produktu jest zadaniem trudnym. Chcąc badać niezawodność przy użyciu danych dotyczących obniżenia charakterystyk, autorzy zaproponowali metodę analizy danych o obniżeniu charakterystyk wykorzystującą zasady metody Monte Carlo oraz teorii chmury. Po pierwsze, wykorzystując dane o obniżeniu charakterystyk oraz progresywny generator chmur, wygenerowano chmurę obniżenia charakterystyk zawierającą dane na temat stopnia degradacji oraz stopnia entropii, która określa możliwy dyskretny stopień degradacji danych. Następnie, ustalono minimalny próg przynależności punktów chmury oraz próg uszkodzenia produktu. Policzono liczbę punktów chmury które spełniały warunek minimalnego stopnia przynależności oraz progu uszkodzenia. Wreszcie, zaproponowano metodę analizy niezawodnościowej danych o obniżeniu charakterystyk wykorzystującą zasady modelu Monte Carlo oraz teorii chmury. W pracy przedstawiono teorię chmury, która pozwala na weryfikację niezawodności danych of obniżeniu charakterystyk produktu. Rozwiązano w ten sposób problem losowości i rozmycia występujące w badaniach degradacji. Ponadto, przy użyciu metody Monte Carlo, rozwiązano trudności w obliczaniu niezawodności związane z ograniczeniami danych z badań degradacji, co zagwarantowało minimalną przynależność punktów chmury oraz minimalny stopień uszkodzenia. W prezentowanej pracy przedstawiono nową metodę symulacji niezawodności danych o degradacji. Poprawność przedstawionej metody zweryfikowano na podstawie przykładu. Zapewnienie wysokiej trwałości złączy taśmy przenośnikowej jest równoznaczne z zapewnieniem ich niezawodnej pracy, a ponieważ wyniki prowadzonych dotąd badań nie dostarczają jednoznacznych rozwiązań wielu wyłaniających się w tym przypadku problemów, wskazane jest prowadzenie w tym zakresie zaawansowanych badań z użyciem technik komputerowych.
Źródło:
Eksploatacja i Niezawodność; 2015, 17, 3; 435-442
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Development of evaluation system of coastline resource in Dafeng
Autorzy:
Chen, M.
Xu, C.
Chen, H.
Powiązania:
https://bibliotekanauki.pl/articles/259978.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
coastline
Analytic Hierarchy Process
evaluation system
Opis:
Coastline is one type of valuable non-renewable resources. From the perspective of economic theory, it can gather population, promote traffic construction, and then improve the level of international trade. The research object of this paper is the coastline resource in Dafeng area. Firstly, we have a brief summary of the existing coastline evaluation literature, then introduce the location and natural attributes of the coastline resources in Dafeng. Following that, the Analytic Hierarchy Process (AHP) model is used to build the economic evaluation index system based on the characteristics of coastline in Dafeng. Specially, this index system consists of 6 factors, and a total of 41 detailed indicators were chosen including water depth, GDP, etc. On this basis, we use the assignment method to quantify the weight of each index, and calculate the comprehensive score of coastline resource by using the YAAHP software. The final conclusion is as follows: The total score of economic evaluation of coastline resource in Dafeng is 0.87. Therefore, the coastline resource in Dafeng will eventually be constructed a unique coastal economic zone, where the implemented port industrial projects will include shipbuilding, logistics, mechanical processing etc.
Źródło:
Polish Maritime Research; 2017, S 2; 181-187
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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