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numerical Dissipation in Shock Capturing Schemes

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Numerical Dissipation in Shock Capturing Schemes

第四届海峡两岸计算流体力学学术研讨会

作者： KunXu Mathematics Department,Hong Kong University of Science and Technology, Clear Water.bay, Kowloon, Hong Kong

＜正＞ Even though many shock capturing schemes have been successfully developed in past decades, the analysis of the numerical dissipative mechanism in them are inadequate. In this paper, we are going to introduce the kinematic and dynamic origion of the numerical dissipation and distinguish their roles in the capturing of numerical shock waves. At end, the gas-kinetic scheme will be introduced, where the kinematic and dynamic dissipation have both been accounted for in its numerical discretization, [this work was supported by the research grant council of Hong Kong].

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Acoustic metamaterials with negative and zero refractive indices

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Acoustic metamaterials with negative and zero refractive ind...

2011年全国压电和声波理论及器件应用研讨会

作者： Che Ting Chan Hong Kong University of Science and Technology,Clear Water.bay.Hong Kong

＜正＞Acoustic metamaterials are composite materials in which the effective density and bulk modulus can be tuned by using resonating units embedded inside a host,and the effective values of density and bulk modulus are discussed in the sense of an effective medium *** the technique of transformation optics,we will show that acoustic metamaterials can achieve novel wave manipulation effects such as invisible *** cloaking effect can be achieved using acoustic metamaterials that either enclose or do not enclose the object to be cloaked. In particular,if acoustic metamaterials with negative modulus and negative density are available,we can do "remote cloaking",in the sense that we can make an object undetectable without touching it.

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Discrete Modeling of Fluid-Particle Interaction in Granular Media

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Discrete Modeling of Fluid-Particle Interaction in Granular ...

2012颗粒材料计算力学会议

作者： Zhao Ji-Dong Shan TongHong Kong University of Science and Technology,Clear Water.bay,Hong Kong

This paper presents a coupled Computational Fluid Dynamics(CFD) and Discrete Element Method(DEM)approach to model the interaction between fluid and granular particles and its impact to relevant *** force and buoyancy force are considered to be the interaction forces exchanged between consecutiveDEM simulations and CFD *** numerical tool is verified by benchmarking simulations of thesettlement of single particle into water and the classic one-dimensional consolidation *** both cases goodagreements are found between the numerical predictions and the analytical *** have further applied thenumerical tool to the simulation of sand pile formed in water and debris flow into water *** varioussimulations demonstrate that the influence of fluid-particle interaction is well captured by the proposed method.

关键词： granular media fluid-particle interaction coupled CFD-DEM granular flow

MECHAnICAL PErTUrBATIOn InDUCED MOLECULAr ALIGnMEnTS In A SIDE-CHAIn LIQUID CrYSTALLInE POLYACETYLEnE, POLY{10-[4-(4'-METHOXYPHEnOXY-CArBOML)PHEnOXYCArBOnYL]-1-DECYnE}

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Chinese Journal of Polymer Science 1999年第3期17卷 289-294页

作者： Ben-zhong Tang Xiang-xing Kong Xin-de Feng Department of Chemistry, Hong Kong University of Science & Technology, Clear Water.bay, Kowloon, Hong Kong, China Department of Polymer Science & Engineering, College of Chemistry, Peking University, Beijing 100871, China Department of Chemistry Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong Department of Polymer Science and Engineering College of Chemistry Peking University Beijing 100871 China

A new liquid crystalline polyacetylene containing a phenyl benzoate mesogen (5) is synthesized,whose mesomorphic properties are found to be easily 'tunab1e' by simple mechanical perturbation. Thepolymerization of 10- [ 4 - (4' -methoxyphenoxycarbonyl )phenoxycarbonyl] - 1 -decyne (4 ) in itiated by theWCl_6-Ph_4Sn/dioxane complex yields polymer 5 with a M_w of 28400. The molecular structure of 5 ischaracterized by nMr, Ir, and UV spectroscopy and its liquid crystalline behavior is investigated by DSC,POM, and XrD analysis. Upon mechanical perturbation, 5 exhibits unusual agitation-induced high-strengthdisclinations, shear-induced inversion walls, and solidification-induced banded textures. Such phenomenahave been observed in the main-chain liquid crystalline polymers with rigid backbones, but have seldom beenreported for the side-chain liquid crystalline polymers with flexible backbones, suggesting that the rigidpolyacetylene backbone of 5 plays a constructive role in inducing the novel molecular alignments.

关键词： Liquid crystals Side-chain liquid crystalline polymers Polyacetylenes High-strength disclinations Inversion walls Banded textures Molecular alignments

Effects of harvesting on productivity of bay leaf tree(Cinnamomum tamala nees & Eberm):Case from Udayapur district of nepal

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Journal of Forestry research 2014年第1期25卷 163-170页

作者： Dyutiman Choudhary S.P Kala n.P Todaria S.Dasgupta M.Kollmair International Centre for Integrated Mountain Development (ICIMOD) HnB Garhwal University

Cultivation of bay leaves （Cinnamomum tamalanees ＆ Eberm） to fulfil household income needs is a long established practice in Udayapur district of nepal. The practices adopted by farmers for.bay leaf harvesting have not, however, been validated by scientific investigation for their sustainability. To investigate the impacts of harvesting on the yield of branch, leaves and biomass of leaves, a two-year research project was conducted in farm fields at Kopche village of routa VDC in Udayapur district, nepal. Four different harvesting treatments, the orien-tation and the order of branches were taken as independent variables to test their effects on number of branches, leaves and biomass of leaves. Orientation, harvesting treatments and order of branches had a significant effect on the number of branches, but not on the number of leaves or biomass （fresh and dry weight） of leaves in the year of harvest. Between two consecutive harvests there was no significant difference in the num-ber of branches, leaves or biomass. Lower two-thirds portion of the trees produced the largest number of leaves and branches of the fourth order in both years. Therefore, lower two-thirds portion of the trees were suitable for harvesting. Our findings support farmer experience that no change in productivity of leaves is observed when harvesting each year. For long term sustainability, harvesting should be conducted without debarking of trees or damage to branches. Our findings could be extrapolated to and tested in other areas with different access and user rights where the rota-tion for harvest is fixed or regulated without research evidence.

关键词： agro forestry tree leaf harvesting yield management practices sustainable development

一个基于Web的安全电子商务系统的组合模型(英文)

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计算机工程 1999年第S1期25卷 147-151页

作者：梅杰香港科技大学计算机系

虽然已经有人提出了一些电子商务系统安全问题的解决方案，有些安全问题仍然需要关注：如：拒绝服务攻击、持续入侵和缺乏安全技能。信息安全系统专家从黑客角度考虑信息安全问题具有重要的意义。首先介绍了信息安全系统的组合模型，并... 详细信息

虽然已经有人提出了一些电子商务系统安全问题的解决方案，有些安全问题仍然需要关注：如：拒绝服务攻击、持续入侵和缺乏安全技能。信息安全系统专家从黑客角度考虑信息安全问题具有重要的意义。首先介绍了信息安全系统的组合模型，并提出了影响基于Web的电子商务系统的安全问题，其中主要从网络和系统安全等角度进行讨论。提出了针对基于Web电子商务系统的安全方莫决的设计方法，并给出了解决有关安全问题的方法。对一个自行开发的黑客入侵防范系统进行案例研究，并改进了组合模型，试图设计一个安全电子商务系统的原型。

关键词：组合模型电子商务 Internet安全 Web安全黑客

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土地情结

世界建筑导报 2012年第4期27卷 10-11页

作者： richard Leplastier Lovett bay PSA事务所

家：这里没有路,只有船。这是个水上社区。大概在1974年,独自一人静静地坐在这破败的甲板上。远望着海湾,风吹在水面上,微微荡漾,波光粼粼。砂洲–这一时间和潮汐的时钟,展示着完美的力量。思绪慢慢游荡开来。一条姜黄色的博德牧羊犬的... 详细信息

家：这里没有路,只有船。这是个水上社区。大概在1974年,独自一人静静地坐在这破败的甲板上。远望着海湾,风吹在水面上,微微荡漾,波光粼粼。砂洲–这一时间和潮汐的时钟,展示着完美的力量。思绪慢慢游荡开来。一条姜黄色的博德牧羊犬的突然出现,

关键词：土地牧羊犬水面

nanoscale Transport of Dipolar Fluids in a rotating Electric Field

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Nanoscale Transport of Dipolar Fluids in a Rotating Electric...

第十届全国流变学学术会议

作者： FAnG Angbo~(**) (Department of Physics,Hong Kong University of Science and Technology, Clear Water.bay,Kowloon,Hong Kong) Department of Physics Hong Kong University of Science and Technology Clear Water Bay Kowloon Hong Kong

＜正＞We investigate nanoscale transport of dipolar *** generalizing Onsager’s principle of least dissipation of energy to fluid system with microstructure,we derive via a variational approach the hydrodynamic equations including the generalized navier-Stokes equation,the macroscopic balance equation of intrinsic angular momenta carried by fluid molecules,and the dipolar relaxation equations in the presence of external ***,the generalized boundary conditions are *** the bulk equations,the translation-rotation coupling characterized by the vortex viscosity plays a central role for the exchange of angular momenta between the orbital part and the intrinsic spinning ***, interfacial translation-rotation coupling is important for nanochannels and is properly taken into account by our generalized boundary conditions.

关键词： nanochannels navier-Stokes equation Dipolar fluids Boundary conditions

Validation of a radioimmunoassay-based fecal corticosteroid assay for richardson＇s ground squirrels Urocitellus richardsonii and behavioural correlates of stress

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Current Zoology 2014年第5期60卷 591-601页

作者： James F. HArE Calen r rYAn Chris EnrIGHT Laura E. GArDInEr Lindsay J SKYnEr Charlene n. BErKVEnS W. Gary AnDErSOn Department of Biological Sciences University of Manitoba Winnipeg MB Canada R3T 2N2 Assiniboine Park Zoo Winnipeg MB Canada R3R 2N7 Present Address: School of Applied Science Bay of Plenty Polytechnic Tauranga 3112 New Zealand

We validated a radioimmunoassay-based method quantifying fecal glucocorticoid metabolites (FGMs) from captive male and female richardson’s ground squirrelsUrocitellus richardsonii. Blood samples were drawn to explore the correlation between plasma cortisol and FGM concentrations. We also injected groups of squirrels with normal saline (CTL; control), adre-nocorticotropic hormone (ACTH; stimulating adrenal activity), or dexamethasone (DEX; suppressing adrenal activity). Potential correlations between stress and behaviour were explored through quantification of fecal pellet production and the intervention necessary to elicit defecation, as well as the behaviour of subjects in the context of handling. Changes in plasma cortisol concentration between capture (baseline), and following handling (stress-induced) were also quantified for free-living squirrels. While glucocorticoid concentrations recovered from feces during our captive-animal study were not well correlated with plasma cortisol concentrations, and uncorrelated with defecation or behaviour, FGM concentrations did reflect the activation of the hypothalamic-pituitary-adrenal (HPA) axis. FGM concentrations increased significantly during initial captivity, but declined to baseline level as individuals acclimated to the novel environment. Injection of subjects with ACTH increased FGMs above baseline, confirming activation of the HPA axis. Plasma cortisol concentrations increased significantly with induced stress, indicating that capture and handling activated the glucocorticoid stress response even among previously handled, free-living subjects. Our findings validate a non-invasive tool that will afford new insight into the physiological processes underlying social, reproductive and antipredator behaviour of richardson’s ground squirrels.

关键词：糖皮质激素放射免疫法行为松鼠粪便验证基础 richardson