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Molecular Dynamics Simulation of Behaviours of Non-Polar Droplets Merging and Interactions with Hydrophobic Surfaces

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Journal of Bionic Engineering 2008年第4期5卷 271-281页

作者： y.y. yan c.y. Ji School of the Built Environment University of Nottingham Nottingham NG7 2RD UK

This paper presents a molecular dynamics simulation of the behaviours of non-polar droplets merging and also the fluid molecules interacting with a hydrophobic surface. Such behaviours and transport phenomena are popular in general microchannel flow boiling and two-phase flow. The droplets are assumed to be composed of Lennards-Jones type molecules. Periodic boundary conditions are applied in three coordinate directions of a 3-D system, where there exist two liquid droplets and their vapour. The two droplets merge when they come within the prescribed small distance. The merging of two droplets apart from each other at different initial distances is tested and the possible larger （or critical） non-dimensional distance, in which droplets merging can occur, is discussed. The evolution of the merging process is simulated numerically by employing the Molecular Dynamics （MD） method. For interactions with hydrophobic solid wall, a system with fluid confined between two walls is used to study the wetting phenomena of fluid and solid wall. The results are compared with those of hydrophilic wall to show the unique characteristics of hydrophobic interactions by microscopic methods.

关键词： molecular dynamics simulation mist flow droplets merging hydrophobic wetting

cyclic stress-controlled tests on offshore clay

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Journal of Rock Mechanics and Geotechnical Engineering 2017年第2期9卷 376-381页

作者： S.y. Thian c.y. Lee Department of civil Engineering Jalan Ikram-UnitenUniversiti Tenaga NasionalKajang43000Malaysia

One of the main concerns in cyclic behavior of soft clay is gradual degradation with the progression of loading cycle.A series of cyclic constant-volume direct simple shear(cDSS) loading tests was performed on Malaysia offshore clay to study its undrained *** testing program consists of stresscontrolled tests with cyclic shear ratio ranging from 0.34 to 0.83 at different overconsolidation ratios(OcRs).For a given cyclic stress ratio in stress-controlled tests,the accumulated cyclic strain and pore water pressure increase with elevated number of *** heavily overconsolidated clay specimens,the negative cyclic pore water pressure is generated followed by positive cyclic pore water pressure as cyclic tests *** post-cyclic strength of offshore clay specimens is reduced by undrained cyclic stresscontrolled loading.

关键词： Offshore clay cyclic degradation Undrained cyclic loading Shear strength Pore pressure Overconsolidation ratio(OcR)

PREDIcTION FOR FORMING LIMIT OF AL2024T3 SHEET BASED ON DAMAGE THEORy USING FINITE ELEMENT METHOD

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Acta Mechanica Solida Sinica 2006年第2期19卷 174-180页

作者： Tang c.y. Fan Jianping Tsui c.P. Department of Industrial and Systems Engineering The Hong Kong Polytechnic University Hong Kong China School of civil Engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China

This paper presents the application of anisotropic damage theory to the study of forming limit diagram of A12024T3 aluminum alloy sheet. In the prediction of limiting strains of the aluminum sheet structure, a finite element cell model has been constructed. The cell model consists of two phases, the aluminum alloy matrix and the intermetallic cluster. The material behavior of the aluminum alloy matrix is described with a fully coupled elasto-plastic damage constitutive equation. The intermetallic cluster is assumed to be elastic and brittle. By varying the stretching ratio, the limiting strains of the sheet under biaxial stretching have been predicted by using the necking criterion proposed. The prediction is in good agreement with the experimental findings. Moreover, the finite element cell model can provide information for understanding the microscopic damage mechanism of the aluminum alloy. Over-estimation of the limit strains may result if the effect of material damage is ignored in the sheet metal forming study.

关键词： forming limit diagram (FLD) anisotropic damage finite element method (FEM) limit strain localized necking elasto-plastic deformation

Revisiting the intraseasonal,interannual and interdecadal variability of tropical cyclones in the western North Pacific

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Atmospheric and Oceanic Science Letters 2018年第2期11卷 198-208页

作者： LI Richard c.y. ZHOU Wen city University of Hong Kong Shenzhen Research Institute Shenzhen China School of Energy and Environment Guy Carpenter Asia-Pacific Climate Impact Center City University of Hong Kong Hong Kong China

This paper reviews the recent progress and research on the variability of tropical cyclones(Tcs) at different time scales. Specific focus is placed on how different types of external forcings or climatic oscillations contribute to Tc variability in the western North Pacific(WNP). At the intraseasonal scale, recent advances on the distinctive impacts of the Madden–Julian Oscillation(MJO), the Quasi-biweekly Oscillation, and the asymmetric MJO modulation under different El Ni?o–Southern Oscillation(ENSO) states, as well as the influences of the Pacific–Japan teleconnection, are highlighted. Interannually, recent progress on the influences of the ENSO cycle, different flavors of ENSO, and impacts of Indian Ocean warming is presented. In addition, the uncertainty concerning interdecadal Tc variations is discussed, along with the recently proposed modulation mechanisms related to the zonal sea surface temperature gradient, the North Pacific Gyre Oscillation, and the Pacific Decadal Oscillation(PDO). It is hoped that this study can deepen our understanding and provide information that the scientific community can use to improve the seasonal forecasting of Tcs in the WNP.

关键词： Tropical cylones intraseasonal oscillation ENSO Pacific-Japan teleconnection

QUENcH IN STABILIZATION OF cu-Zn-Al ALLOy

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中国有色金属学会会刊：英文版 1997年第3期7卷 100-103页

作者： Peng, Kun Tan, Shusong Li, Shutang chung, c.y. Lan, c.W.H. central South Univ of Technology Changsha China

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关键词： shape memory alloy stabilization quenchant

coercivity Enhancement of Nd-Fe-B Thin Film Magnets through Dy Surface Diffusion Process

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Journal of Materials Science & Technology 2011年第9期27卷 826-830页

作者： c.y. you J. Zhu N. Tian Z.X. Lu State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Beijing 100083 China School of Materials Science and Engineering Xi＇an University of Technology Xi＇an 710048 China

The Dy capping layer was deposited at different temperatures on the Nd-Fe-B thin films to investigate the mechanism of the coercivity enhancement through the Dy surface diffusion. The highest coercivity of 2005 kA/m （25.2 kOe） was obtained at the Dy deposition temperature of 460℃, which was significantly higher than the value of 1297 kA/m （16.3 kOe） without Dy capping layer. By performing the transmission electron microscopy （TEM） analysis, it was found that some of the grain boundaries were enriched with Nd element, which could be partly ascribed to the promotion by the Dy surface diffusion. In comparison to the evolution of the spin reorientation temperature of Nd2Fe14B phase after the deposition of the Dy capping layer, it is concluded that structural modification plays a significant role in the coercivity enhancement due to the Dy surface diffusion.

关键词： Nd-Fe-B thin film coercivity enhancement Dy layer Microstructure

Ionic Liquid Mediated Synthesis of Lath Shaped cuO Micro-Assembles as Extremely Stable Anode Material for Lithium-Ion Batteries

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chinese Journal of chemistry 2017年第8期35卷 1299-1304页

作者： Man Wang Ruguang Ma ying Liu c.y. chung yonghong Deng Zhouguang Lu Department of Materials Science and Engineering Southern University of Science and Technology Shenzhen Guangdong 518055 China State Key Laboratory of High Performance ceramics and Superfine Microstrueture Shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai 200050 China Department of Physics and Materials Science City University of Hong Kong 83 Tat Chee Avenue Kowloon Hong Kong China

A novel lath-shaped cuO microassemble consisting of well-c.y.talized ultrafine nanoc.y.tals was prepared by an ionothermal method with the assistance of ionic liquids （ILs, 1-butyl-3-methylimidazolium tetrafluoroborate）. As anode material of lithium ion batteries, the ILs-cuO exhibits high specific capacity, durability and good rate per- formance, superior to bare cuO. At a high current density of 1000 mA·g^-1, after 100 cycles, ILs-cuO still retains a discharge capacity of 483.2 mAh·g^-1. The improved electrochemical performances could be ascribed to the unique microscale lath-shape cuO assembles composed of ultrafine nanostructure.

关键词： lithium ion batteries anode lath-shaped cuO micro-assembles ionic liquid

Pressure　Loss　Through　Sharp　180　deg　Turn　in　a　Relatively　Short　Two－Pass　Smooth　and　Rib－Roughened　channel

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Journal of Thermal Science 1995年第2期4卷 109-116页

作者： c.y. Zhao W.Q. Tao(School of Energy and Power Engineering, Xi’an Jiaotong University, Xi’an, Shaanxi 710049, china) School of Energy and Power Engineering Xi’an Jiaotong University Xi’an China

The local pressure distributions and resistance coefficients (f1 and f2) through the sharp 180 deg turn in a relatively short (L/De = 4) two-pass smooth and rib-roughened channel were investigated for a Reynolds number range of 1.0 × 103 - 9.0 × 103. The rib pitch-to-height ratios (p/e) were 5,10, and 20. The rib height-to-hydraulic diameter ratios (e/De) were 0.025, 0.050 and 0.10, and the rib angles of attack (α) were 90, 45, 60, -45, and -60 deg. Ribs were installed not only in before and after turn regions but also in turn region. The results show that the resistance coefficients remain approximately constant when Reynolds number is more than 3.0×104. The effects of the rib condguration (rib spacing, rib height, and rib orientation) on the inlet straight duct resistance coefficient (f2) were significant, however, their effects on the overall resistance coefficient (f1) were diluted by the sharp-180 turn. For this relatively short channel (L/De=4), the overall resistance coefficient (f1) was greatly affected by the sharp turn. correlations for the overall resistance (f1) and inlet straight duct resistance coefficient (f2) are presented.

关键词： resistance cofficient rib-roughened channel.

Highly conductive and stable iodine doped argyrodite electrolyte for all-solid-state lithium batteries

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Journal of Energy chemistry 2025年第1期100卷 50-58页

作者： Gaozhan Liu Jing Zhang Jing yang Jinghui chen Xingyue Xiao Xiayin yao Ningbo Institute of Materials Technology and Engineering Chinese Academy of Sciences center of Materials Science and Optoelectronics Engineering University of Chinese Academy of Sciences

Lithium argyrodites with high ionic conductivity and low cost are considered as one of the most prospective solid electrolytes for all-solid-state lithium ***,the poor chemical stability and compatibility with lithium metal limit their ***,Li5.4PS4.4cl1.4I0.2solid electrolyte with high ionic conductivity of 11.49 m S cm-1and improved chemical stability is synthesized by iodine *** ultra-thin Li5.4PS4.4cl1.4I0.2membrane with thickness of 10μm can be obtained by wet coating process,exhibiting a high ionic conductivity of 2.09 mS cm-1and low areal resistance of 1.17Ω***,iodine doping could in-situ form LiI at the lithium/electrolyte interface and improve the critical current density of Li5.4PS4.4cl1.6from 0.8 to 1.35 mA *** resultant LicoO2/Li5.4PS4.4cl1.4I0.2/Li battery shows excellent cycling stability at 1 c,with a reversible specific capacity of 110.1 mA h g-1and a retention of 80.5% after 1000 *** addition,the assembled LicoO2/Li5.4PS4.4cl1.4I0.2membrane/Li pouch cell delivers an initial discharge capacity of 110.4 mA h g-1and 80.5% capacity retention after 100 cycles.

关键词： Argyrodite electrolytes Iodine doping Ionic conductivity Stability All-solid-state lithium battery