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Wyszukujesz frazę "Zhang, H. W." wg kryterium: Autor


Tytuł:
Fibre Number of the Cross-section of Ringspun Yarn and its Strength Prediction Model
Liczba włókien w przekroju poprzecznym przędzy obrączkowej i model dla przewidywania jej wytrzymałości
Autorzy:
Zhang, H. W.
Li, Y. L.
Powiązania:
https://bibliotekanauki.pl/articles/232277.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych
Tematy:
ring-spun yarn
yarn incross section
fibre number
yarn twist
yarn strength predication model
przędza obrączkowa
wytrzymałość przędzy
model wytrzymałości przędzy obrączkowej
masa liniowa
Opis:
A calculation equation of the fibre number on the cross-section of ring-spun yarn was deduced theoretically and verified with test data of 20 representative pure cotton ring spun yarns. The equation is practical and convenient to use by substituting the yarn count, yarn twist, and fibre decitex. On the basis of the above equation, a yarn strength predication model was established. The revising functions of yarn count and twist to yarn strength were deduced in practical tests of the strength of 20 commonly used ring-spun yarns, and were used to revise the yarn strength predication model obtained. Substituting the fibre decitex, fibre strength, yarn count, yarn twist and yarn strength can be precisely calculated with this model.
Przeprowadzając teoretyczne rozważania autorzy opracowali matematyczny wzór dotyczący liczby włókien w przekroju poprzecznym przędzy obrączkowej. We wzorze tym uwzględnili oddziaływanie: kształtu przekroju poprzecznego włókien i przędzy, masy liniowej włókien i przędzy, gęstości właściwej włókien i przędzy. Zaproponowane równanie pozwala projektować zamienniki przędzy pod względem ich masy liniowej (tex), liczby skrętu i masy liniowej włókien (tex). Traktując rozpatrywane równanie jako punkt wyjścia autorzy opracowali model przewidywania wytrzymałości przędzy. Otrzymane zależności teoretyczne zweryfikowano poprzez badania eksperymentalne. Przebadano 20 powszechnie stosowanych przędz obrączkowych. Opracowane modele pozwalają precyzyjnie obliczyć wytrzymałość przędzy obrączkowej.
Źródło:
Fibres & Textiles in Eastern Europe; 2014, 6 (108); 38-40
1230-3666
2300-7354
Pojawia się w:
Fibres & Textiles in Eastern Europe
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Fuzzy method and neural network model parallel implementation of multi-layer neural network based on cloud computing for real time data transmission in large offshore platform
Autorzy:
Zhang, H..
Qin, W.
Powiązania:
https://bibliotekanauki.pl/articles/259083.pdf
Data publikacji:
2017
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
parallel implementation
multi-layer neural network
cloud computing
Opis:
With the rapid development of electronic technology, network technology and cloud computing technology, the current data is increasing in the way of mass, has entered the era of big data. Based on cloud computing clusters, this paper proposes a novel method of parallel implementation of multilayered neural networks based on Map-Reduce. Namely in order to meet the requirements of big data processing, this paper presents an efficient mapping scheme for a fully connected multi-layered neural network, which is trained by using error back propagation (BP) algorithm based on Map-Reduce on cloud computing clusters (MRBP). The batch-training (or epoch-training) regimes are used by effective segmentation of samples on the clusters, and are adopted in the separated training method, weight summary to achieve convergence by iterating. For a parallel BP algorithm on the clusters and a serial BP algorithm on uniprocessor, the required time for implementing the algorithms is derived. The performance parameters, such as speed-up, optimal number and minimum of data nodes are evaluated for the parallel BP algorithm on the clusters. Experiment results demonstrate that the proposed parallel BP algorithm in this paper has better speed-up, faster convergence rate, less iterations than that of the existed algorithms.
Źródło:
Polish Maritime Research; 2017, S 2; 39-44
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Semi-analytical solution of optimization on moon-pool shaped WEC
Autorzy:
Zhang, W. C.
Liu, H. X.
Zhang, X. W.
Zhang, L.
Powiązania:
https://bibliotekanauki.pl/articles/963397.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
wave energy
eigenfunction expansion
moon pool
conversion ability
optimization
Opis:
In order to effectively extract and maximize the energy from ocean waves, a new kind of oscillating-body WEC (wave energy converter) with moon pool has been put forward. The main emphasis in this paper is placed on inserting the damping into the equation of heaving motion applied for a complex wave energy converter and expressions for velocity potential added mass, damping coefficients associated with exciting forces were derived by using eigenfunction expansion matching method. By using surface-wave hydrodynamics, the exact theoretical conditions were solved to allow the maximum energy to be absorbed from regular waves. To optimize the ability of the wave energy conversion, oscillating system models under different radius-ratios are calculated and comparatively analyzed. Numerical calculations indicated that the capture width reaches the maximum in the vicinity of the natural frequency and the new kind of oscillating-body WEC has a positive ability of wave energy conversion.
Źródło:
Polish Maritime Research; 2016, S 1; 25-31
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of preparation method on the performance of PtSn/Al2O3 &enspcatalysts for acetic acid hydrogenation
Autorzy:
Zhang, K.
Zhang, H.
Ma, H.
Ying, W.
Fang, D.
Powiązania:
https://bibliotekanauki.pl/articles/779525.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Pt-Sn catalysts
preparation method
acetic acid hydrogenation
XPS
CO-FTIR
Opis:
PtSn/Al2O3 &enspcatalysts with a given loading of 1 wt% Pt and 1 wt% Sn were prepared by co-impregnation or successive impregnation with aqueous solutions of Pt, Sn precursors and a commercial alumina. The catalysts were characterized by N2 &enspadsorption, H2-TPR (H2&ensp temperature-programmed reduction), H2-pulse chemisorption, XPS (X-ray photoelectron spectroscopy) and CO-FTIR (Fourier transform infrared spectroscopy), and tested in the hydrogenation of acetic acid. The results showed that the preparation method affected both the chemical properties and their performance in the hydrogenation of acetic acid. Sn enrichment on the catalysts surface was observed on the co-impregnated catalyst and catalyst in which the Pt precursor had been loaded first. It was found that the modification of Pt was a function of the sequence of Sn addition as revealed by CO-FTIR. Co-impregnated catalyst showed the highest activity and ethanol selectivity.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 1; 11-17
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reliability based analysis and design of a tripod offshore wind turbine structure assuring serviceability performance
Autorzy:
Zhang, J.
Kang, W. H.
Zhang, C.
Sun, K.
Powiązania:
https://bibliotekanauki.pl/articles/259493.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
offshore wind turbine
tripod foundation
serviceability limit state
statistical correlation analysis
reliability analysis
Opis:
Typical tripod foundations are designed using deterministic computational models according to relevant standards and codes. However, for more cost-safety balanced design, uncertainties in significant parameters should be considered in preliminary design to ensure meeting a specific probabilistic safety target in the context of the complex configuration of a tripod structure. In this article, uncertainties associated with design parameters and modelling errors are considered using Monte Carlo simulations, in order to determine the key structural design parameters, and to determine the optimal balance between design parameters and design requirements. A Spearman rank-order correlation based analysis is carried out to understand the effects of design variables on maximum deformation, total weight, and natural frequency, and to have insight about important design parameters for improvement of a preliminary design. It is found that the tower diameter has the most significant effect on the maximum displacement on the hub as validated through engineering case studies. In addition, a statistical framework, which identifies influential design parameters and provides reliability evaluation, is proposed for the structural design of a tripod OWT system. The design cases considered in this study indicate that a simple deterministic design check cannot guarantee the required reliability level of the structure, and the cost-safety balance can be achieved by a reliability analysis with the consideration of the uncertainties in the structure.
Źródło:
Polish Maritime Research; 2018, 4; 139-148
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal configurations of wave energy converter arrays with a floating body
Autorzy:
Zhang, W.
Liu, H.
Zhang, X.
Zhang, L.
Ashraf, M. A.
Powiązania:
https://bibliotekanauki.pl/articles/260084.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
wave energy
cylinder array
power take-off
hydrodynamic analysis
Opis:
An array of floating point-absorbing wave energy converters (WECs) is usually employed for extracting efficiently ocean wave energy. For deep water environment, it is more feasible and convenient to connect the absorbers array with a floating body, such as a semi-submersible bottom-moored disk, whose function is to act as the virtual seabed. In the present work, an array of identical floating symmetrically distributed cylinders in a coaxial moored disk as a wave energy device is proposed The power take-off (PTO) system in the wave energy device is assumed to be composed of a linear/nonlinear damper activated by the buoys heaving motion. Hydrodynamic analysis of the examined floating system is implemented in frequency domain. Hydrodynamic interferences between the oscillating bodies are accounted for in the corresponding coupled equations. The array layouts under the constraint of the disk, incidence wave directions, separating distance between the absorbers and the PTO damping are considered to optimize this kind of WECs. Numerical results with regular waves are presented and discussed for the axisymmetric system utilizing heave mode with these interaction factors, in terms of a specific numbers of cylinders and expected power production.
Źródło:
Polish Maritime Research; 2016, S 1; 71-77
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and simulative study on accumulator function in the process of wave energy conversion
Autorzy:
Zhang, W.
Liu, Y.
Luo, H.
Xue, G.
Zhang, J.
Powiązania:
https://bibliotekanauki.pl/articles/259862.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
wave energy converter
AMESim simulation
accumulator
experimental verification
Opis:
In this paper, a floating-buoy wave energy converter using hydrostatic transmission system is studied. The entire work progress of wave energy power generation device is introduced, and the hydraulic transmission principles are emphasized through the simulation to verify the feasibility of design principle of hydraulic transmission system. The mathematical model of the accumulator is established and applied in the AMEsim simulation. The simulation results show that the accumulator plays an important role in the wave power hydraulic transmission system and that the correct configuration of accumulator parameters can improve the rapidity and stability of the system work. Experimental results are compared with the simulation results to validate the correctness of the simulation results. This would provide a valuable reference to the optimal design of wave power generation.
Źródło:
Polish Maritime Research; 2016, 3; 79-85
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Morphology of the invasive amphiphyte Alternanthera philoxeroides under different water levels and nitrogen concentrations
Autorzy:
Ding, W.
Zhang, H.
Zhang, F.
Wang, L.
Cui, S.
Powiązania:
https://bibliotekanauki.pl/articles/19911.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2014, 56, 2
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thermal Expansion of Explosive Molecular Crystals: Anisotropy and Molecular Stacking
Autorzy:
Qian, W.
Zhang, C.
Xiong, Y.
Zong, H.
Zhang, W.
Shu, Y.
Powiązania:
https://bibliotekanauki.pl/articles/358262.pdf
Data publikacji:
2014
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
energetic material
anisotropic thermal expansion
molecular stacking
molecular dynamics simulation
density functional theory method
Opis:
Molecular dynamics simulations of three typical explosive crystals, octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX), 1,1-diamino-2,2- dinitroethene (FOX-7) and 1,3,5-triamino-2,4,6-trinitrobenzene (TATB), were carried out under NPT ensemble and selected force field. The equilibrium structures at elevated temperatures were obtained, which show that the stacking behaviour of the molecules does not change with temperature. The coefficient of thermal expansion (CTE) values were calculated by linear fitting methods, and the results show that the CTE values are close to the experimental results and are anisotropic. The total energies of the cells expanding along each single crystallographic axis were calculated by the periodic density functional theory method, indicating that the energy change rates are anisotropic, and correlation equations of the energy change vs. CTE values were established. The essence of the anisotropy of the explosive crystal’s thermal expansion was compared and elucidated.
Źródło:
Central European Journal of Energetic Materials; 2014, 11, 1; 59-81
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EGTA, a calcium chelator, affects cell cycle and increases DNA methylation in root tips of Triticum aestivum L.
Autorzy:
Zhang, C.
Shi, W.
Ma, K.
Li, H.
Zhang, F.
Powiązania:
https://bibliotekanauki.pl/articles/57455.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Botaniczne
Opis:
In this study, when germinated Triticum aestivum L. seeds were treated with 0, 2, 4 and 6 mM ethyl glycol tetraacetic acid (EGTA), root growth was suppressed and the mitotic index decreased. These inhibitory effects were positively correlated with EGTA concentration. RT-PCR analysis revealed that the expression of several gene markers related to the G1/S transition of the cell cycle were significantly downregulated. Confocal microscopy of Fluo-3/AM-stained roots showed chelation of nearly all of the Ca2+ within the root meristematic regions. Both random amplified polymorphic DNA (RAPD) and coupled restriction enzyme digestion-random amplification (CRED-RA) techniques showed significant increases in the levels of genomic DNA polymorphisms and degree of DNA methylation. The study provides information concerning the impact of Ca²+) chelator, EGTA, on the growth, expression of cell cycle transition marker genes, and changes in DNA structure and methylation in the wheat roots.
Źródło:
Acta Societatis Botanicorum Poloniae; 2016, 85, 3
0001-6977
2083-9480
Pojawia się w:
Acta Societatis Botanicorum Poloniae
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimal design and numerical simulation on fish-like flexible hydrofoil propeller
Autorzy:
Xue, G.
Liu, Y.
Zhang, M.
Zhang, W.
Zhang, J.
Luo, H.
Jia, R.
Powiązania:
https://bibliotekanauki.pl/articles/259984.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
bionics
flexible hydrofoil
phase angle
hydrodynamic coefficient
Opis:
Hydrofoil is widely used in underwater vehicle for the excellent hydrodynamic characteristics. Currently, researches are mostly about the rigid hydrofoil while the flexible hydrofoil, like the caudal fin, has not been studied adequately. In this paper, the fish was regarded as the bionic object. Then the kinematics model to describe the fish swimming was put forward. A fin-peduncle propulsion mechanism was designed based on the kinematics model to achieve the similar sine curve swimming model. The propulsion mechanism was optimized by Matlab to reduc the deviation between the output curve of the fin-peduncle propulsion mechanism and the ideal motion trajectory. Moreover, the motion phase angles among flexible articulations are optimized to reduce fluid resistance and improve propulsive efficiency. Finally, the fish-like hydrofoil oscillation is simulated by fluid-solid coupling method based on the Fluent. It was shown that the optimized flexible fish-like oscillation could generate the motion that follows the similar law of sine. The propulsive efficiency of oscillating hydrofoil propeller is much higher than that of the screw propeller, and the flexible oscillation has higher propulsive efficiency than the rigid oscillation without obvious fluid resistance increase.
Źródło:
Polish Maritime Research; 2016, 4; 59-66
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
One-dimensional isothermal multicomponent diffusion-reaction model and its application to methanol synthesis over commercial Cu-based catalyst
Autorzy:
Lei, K.
Ma, H.
Zhang, H.
Ying, W.
Fang, D.
Powiązania:
https://bibliotekanauki.pl/articles/778972.pdf
Data publikacji:
2015
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
global kinetics
internal effectiveness factor
diffusion-reaction model
methanol synthesis
Opis:
The present work was a study on global reaction rate of methanol synthesis. We measured experimentally the global reaction rate in the internal recycle gradientless reactor over catalyst SC309. The diffusion-reaction model of methanol synthesis was suggested. For model we chose the hydrogenation of CO and CO2 &enspas key reaction. CO and CO2 &enspwere key components in our model. The internal diffusion effectiveness factors of CO and CO2&enspin the catalyst were calculated by the numerical integration. A comparison with the experiment showed that all the absolute values of the relative error were less than 10%. The simulation results showed that decreasing reaction temperature and catalyst diameter were conducive to reduce the influence of the internal diffusion on the methanol synthesis.
Źródło:
Polish Journal of Chemical Technology; 2015, 17, 1; 103-109
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Process simulation of dimethyl ether synthesis via methanol vapor phase dehydration
Autorzy:
Bai, Z.
Ma, H.
Zhang, H.
Ying, W.
Fang, D.
Powiązania:
https://bibliotekanauki.pl/articles/779378.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
dimethyl ether
methanol dehydration to DME
process simulation
Opis:
The production processes included catalytic dehydration of methanol in an adiabatic fixed-bed reactor and two columns product separations. In this study, the technological process for dimethyl ether (DME) synthesis is built on PRO/II platform based on the combined parameters of the reaction dynamic model for methanol dehydration reaction, the improved NRTL model of the liquid phase, the PR model of vapor phase. In order to validate the proposed model, the simulation results have been compared with the available data from a set of industrial production equipment with a production capacity of 200 000 tonnes per annum. A comparison between the calculated and measured results has proved that these results are satisfactory. The bed height and the volume of the catalytic bed are calculated aim at one million t/a DME yields and while taking account of high-purity DME production. After discussing the influence of feed stage location and reflux ratio for DME product purity, the suitable unit operation conditions are chosen. Accordingly, accurate process simulation results provide the basis and guidance for an improvement and development of the similar industrial device.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 2; 122-127
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Relationship Between Bake Hardening, Snoek-Köster and Dislocation-Enhanced Snoek Peaks in Coarse Grained Low Carbon Steel
Autorzy:
Lin, W.
Zhao, S.
Zhang, H.
Jin, X.
Powiązania:
https://bibliotekanauki.pl/articles/353663.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
low carbon steel
ultra-low carbon bake-hardening (ULC-BH) steel
bake hardening (BH)
Snoek peak
dislocation-enhanced Snoek peak
Snoek-Köster peak
internal friction
Opis:
In the present work, specimens prepared from coarse grained low carbon steel with different prestrains were baked and then, their bake hardening (BH) property and internal friction were determined. TEM was used to characterize the dislocation structure in BH treated samples. The measurements of internal friction in prestrained samples and baked samples were carried out using a multifunctional internal friction apparatus. The results indicate that, in coarse grained low carbon steel, the bake hardening properties (BH values) were negative, which were increased by increasing the prestrain from 2 to 5%, and then were decreased by increasing the prestrain from 5 to 10%. In the specimen with prestrain 5%, the BH value reached the maximum value and the height of Snoek-Köster peak was observed to be the maximum alike. With increasing the prestrain, both of the BH value and Snoek-Köster peak heights are similarly varied. It is concluded that Snoek-Köster and dislocation-enhanced Snoek peaks, caused by the interactions between interstitial solute carbon atoms and dislocations, can be used in further development of the bake hardening steels.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1723-1732
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of boron on ZSM-5 catalyst for methanol to propylene conversion
Autorzy:
Xu, A.
Ma, H.
Zhang, H.
Ying, W.
Fang, D.
Powiązania:
https://bibliotekanauki.pl/articles/777971.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
methanol to propylene
ZSM-5
boron modifi cation
propylene
Opis:
B-ZSM-5 catalysts were prepared by various modification methods with boric acid, including ion-exchange, impregnation and direct synthesis. The catalysts were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), NH3-Temperature Programmed Desorption (NH3-TPD), N2 adsorption-desorption, Fourier Transform Infrared spectrometry (FT-IR), 27Al and 11B MAS NMR spectra. The results revealed that the weak acidity of catalysts was significantly increased by modification. The catalytic activity was measured in a fixed bed at 460°C for methanol to propylene (MTP) reaction. The results of MTP reaction showed a great increment of the propylene selectivity for the boron modified samples, especially for the directly synthesized B-ZSM-5 which also displayed high activity and selectivity towards C2 =-C4 = olefins. It was found that the remarkable selectivity strongly depended on the intensity of weak acidity.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 4; 95-101
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł

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