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International Journal of disaster Risk Science 2022年第1期13卷 100-113页

作者： Sai Leung ng Graduate Institute of Earth Science Chinese Culture UniversityTaipei 11114TaiwanChina

This study adopted an extended theory of planned behavior to understand how risk perception affected disaster preparedness *** intercept survey(N=286)was conducted at a typhoon-prone district of Hong Kong,China in 2019,then the data were analyzed using structural equation *** results indicated that risk perception and intention of preparedness were predictors of disaster preparedness *** perception significantly affected intention of preparedness and the effect was partially mediated by subjective *** perception also significantly affected attitude and perceived behavioral control,but attitude and perceived behavioral control were not significantly correlated with intention of *** only may this study supplement the existing literature of disaster preparedness toward typhoons,but also it provides insights for the planning and management of natural hazards and disaster risk reduction in Hong Kong,China.

关键词： disaster preparedness behaviour Hong Kong,China Risk perception Structural equation modelling Theory of planned behaviour Typhoon preparedness

Transit Network design:a Hybrid Enhanced Artificial Bee Colony Approach and a Case Study

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International Journal of Transportation Science and Technology 2013年第3期2卷 243-260页

作者： y.Jiang W.y.Szeto T.M.ng department of Civil Engineering The University of Hong KongHong KongP.R.China

A bus network design problem in a suburban area of Hong Kong is *** objective is to minimize the weighted sum of the number of transfers and the total travel time of passengers by restructuring bus routes and determining new frequencies.A mixed integer optimization model is developed and was solved by a Hybrid Enhanced Artificial Bee Colony algorithm(HEABC).A case study was conducted to investigate the effects of different design parameters,including the total number of bus routes available,the maximum route duration within the study area and the maximum allowable number of bus routes that originated from each *** model and results are useful for improving bus service policies.

关键词： Transit network design Artificial bee colony algorithm Heuristic

The role of AVdR in linear cascade testing

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航空动力学报 2007年第6期22卷 933-944页

作者： Wing F.ng department of Mechanical Engineering Virginia Polytechnic Instituteand State University

Linear cascade testing plays an important role in the research and development of turbomachinery and is widely used over the *** ideal cascade model of a turbomachinery blade row is *** actual linear cascade testing,the flow through the test section converges due to the development of the boundary layer and secondary flow along the sidewall surfaces of the test *** velocity density ratio(AVdR) is adopted to account for the deviation of the tested cascade flow from the ideal 2d *** numerous published cascade works,the influence of AVdR on cascade performance is seen to be complicated with many affecting factors,such as those related to cascade/blade geometry and flow ***,controlling AVdR is limited by the facility ***,real blade-to-blade flow in turbomachines is usually associated with AVdR greater than unity due to limited span of blades between the hub and shroud such that cascade testing without reducing AVdR could be favored *** these facets add complexity and diversification to the *** current paper reviews previous studies and results on *** understanding on the role of AVdR and recommendations on how to deal with it in linear cascade testing are provided.

关键词：线性叶栅试验轴向速度密度比空气流动叶栅特性

Rotating electroosmotic flow of an Eyring fluid

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Acta Mechanica Sinica 2017年第2期33卷 295-315页

作者： Cheng Qi Chiu-On ng department of Mechanical Engineering The University of Hong Kong Hong Kong China

A perturbation analysis is presented in this paper for the electroosmotic (EO) flow of an Eyring fluid through a wide rectangular microchannel that rotates about an axis perpendicular to its own. Mildly shear-thinning rheology is assumed such that at the leading order the problem reduces to that of Newtonian EO flow in a rotating channel, while the shear thinning effect shows up in a higher-order problem. Using the relaxation time as the small ordering parameter, analytical solutions are deduced for the leading- as well as first-order problems in terms of the dimensionless debye and rotation parameters. The velocity profiles of the Ekman-electric double layer (EdL) layer, which is the boundary layer that arises when the Ekman layer and the EdL are comparably thin, are also deduced for an Eyring fluid. It is shown that the present perturbation model can yield results that are close to the exact solutions even when the ordering parameter is as large as order unity. By this order of the relaxation time parameter, the enhancing effect on the rotating EO flow due to shear-thinning Eyring rheology can be significant.

关键词： Electroosmotic flow Eyring fluid Rotating channel

On the time development of dispersion in electroosmotic flow througha rectangular channel

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Acta Mechanica Sinica 2012年第3期28卷 631-643页

作者： Suvadip Paul Chiu-On ng department of Mechanical Engineering The University of Hong Kong

This is an analytical study on the time develop- ment of hydrodynamic dispersion of an inert species in elec- troosmotic flow through a rectangular channel. The objec- tive is to determine how the channel side walls may affect the dispersion coefficient at different instants of time. To this end, the generalized dispersion model, which is valid for short and long times, is employed in the present study. An- alytical expressions are derived for the convection and dis- persion coefficients as functions of time, the aspect ratio of the channel, and the debye-Htickel parameter representing the thickness of the electric double layer. For transport in a channel of large aspect ratio, the dispersion may undergo several stages of transience. The initial, fast time develop- ment is controlled by molecular diffusion across the narrow channel height, while the later, slower time development is governed by diffusion across the wider channel breadth. For a sufficiently large aspect ratio, there can be an interlude between these two periods during which the coefficient is nearly steady, signifying the resemblance of the transport to that in a parallel-plate channel. Given a sufficiently long time, the dispersion coefficient will reach a fully-developed steady value that may be several times higher than that with- out the side wall effects. The time scales for these periods of transience are identified in this paper.

关键词： Taylor dispersion. Electroosmotic flow. Gener-alized dispersion model

Remodeling of astrocyte secretome in amyotrophic lateral sclerosis:uncovering novel targets to combat astrocyte-mediated toxicity

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Translational Neurodegeneration 2022年第1期11卷 84-97页

作者： Winanto ng Shi-yan ng Institute of Molecular and Cell Biology A*STAR Research EntitiesSingapore 138673Singapore

Amyotrophic lateral sclerosis(ALS)is an adult-onset paralytic disease characterized by progressive degeneration of upper and lower motor neurons in the motor cortex,brainstem and spinal *** neuron degeneration is typically caused by a combination of intrinsic neuronal(cell autonomous)defects as well as extrinsic(non-cell autonomous)factors such as astrocyte-mediated *** are highly plastic cells that react to their microenvironment to mediate relevant *** neurodegeneration,astrocytes often turn reactive and in turn secrete a slew of factors to exert pro-inflammatory and neurotoxic *** efforts have been carried out to characterize the diseased astrocyte secretome over the years,revealing that pro-inflammatory chemokines,cytokines and microRNAs are the main players in mediating neuronal *** metabolomic technologies mature,these studies begin to shed light on neurotoxic metabolites such as secreted *** this focused review,we will discuss changes in the astrocyte secretome during *** particular,we will discuss the components of the reactive astrocyte secretome that contribute to neuronal death in ALS.

关键词： Motor neuron disease Astrocyte Astrocyte-mediated toxicity Secretome

Jetting-based bioprinting:process,dispense physics,and applications

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Bio-design and Manufacturing 2024年第5期7卷 771-799页

作者： Wei Long ng Viktor Shkolnikov Singapore Centre for 3d Printing(SC3dP) School of Mechanical and Aerospace EngineeringNanyang Technological University(NTU)Singapore 639798Singapore HP Inc. Palo AltoCA 94304USA

Jetting-based bioprinting facilitates contactless drop-on-demand deposition of subnanoliter droplets at well-defined positions to control the spatial arrangement of cells,growth factors,drugs,and biomaterials in a highly automated layer-by-layer fabrication *** to its immense versatility,jetting-based bioprinting has been used for various applications,including tissue engineering and regenerative medicine,wound healing,and drug development.A lack of in-depth understanding exists in the processes that occur during jetting-based *** review paper will comprehensively discuss the physical considerations for bioinks and printing conditions used in jetting-based *** first present an overview of different jetting-based bioprinting techniques such as inkjet bioprinting,laser-induced forward transfer bioprinting,electrohydrodynamic jet bioprinting,acoustic bioprinting and microvalve ***,we provide an in-depth discussion of various considerations for bioink formulation relating to cell deposition,print chamber design,droplet formation and droplet ***,we highlight recent accomplishments in jetting-based *** present the advantages and challenges of each method,discuss considerations relating to cell viability and protein stability,and conclude by providing insights into future directions of jetting-based bioprinting.

关键词： 3d bioprinting Biofabrication Jetting-based dispense physics Machine learning

Potential Hydrodynamic Performance Enhancement of Hydrokinetic Turbine with Hydrophobic Coatings

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China Ocean Engineering 2021年第6期35卷 924-932页

作者： CHEN Long ng Kai-Wern School of Hydraulic and Environmental Engineering Changsha University of Science and TechnologyChangsha 410114China department of Civil Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia Key Laboratory of Water-Sediment Sciences and Water disaster Prevention of Hunan Province Changsha University of Science and TechnologyChangsha 410114China

Hydrokinetic energy is a promising technology to harness predictable renewable energy from free-flowing water,tides and ocean *** studies have been conducted by researchers and engineers to find out ways to enhance the performance of the hydrokinetic *** current paper reports the experimental study of using hydrophobic coating as an alternative way to improve the performance of hydrokinetic turbine.A hydrophobic coating can lower the friction drag of a surface that is in contact with *** hydrokinetic turbine blade,reduction in friction drag may allow a blade section to have a better lift/drag ratio and have its efficiency *** this study,a formula to predict the pattern of drag reduction over a hydrophobic surface has been *** hydrophobic coatings were applied on NACA 63418 hydrofoils and their performances were *** was found that NACA 63418 hydrofoil with the hydrophobic coatings had its drag reduced by an average of 3%−4.0%.When the coatings were applied on a 350 mm diameter three-bladed turbine,the maximum increment of rotational speed of the turbine was found to be 2.5%.The performance of the two coatings against marine fouling was also *** weight of plate with and without the coatings increased by 10%and 100%,respectively.

关键词： hydrophobic coating hydrokinetic energy marine fouling

Structural and mass transport properties of liquid ytterbium in the temperature range 1123 K–1473 K

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Chinese Physics B 2023年第6期32卷 481-488页

作者： d d Satikunvar N K Bhatt B y Thakore department of Physics Sardar Patel UniversityVallabh VidyanagarGujarat 388120India department of Physics Maharaja Krishnakumarsinhji Bhavnagar UniversityBhavnagarGujarat 364001India

We have studied the structural and atomic transport properties of liquid f-shell yb in the temperature range 1123 K–1473 K. Pair interactions between atoms are derived using a local pseudopotential. The potential parameters are fitted to the phonon dispersion curve at room temperature. The local pseudopotential used in the present study is computationally more efficient with only three parameters, and it is found to be transferable to the liquid phase without changing the *** the various computed properties agree with reported theoretical and experimental findings, the adopted fitting scheme is justified. As a significant outcome of the study, we find that(i) the melting in yb is governed by the Lindemann's law,(ii)the mass transport mechanism obeys the Arrhenius law,(iii) the role of the three-particle correlation function in deriving the velocity autocorrelation function is small,(iv) the mean-square atomic displacement is more sensitive to the choice of interaction potential than the other bulk properties, and(v) liquid yb does not show liquid–liquid phase transition within the studied temperature range. Further, due to the good description of the structural and mass transport properties, we propose that yb remains divalent at reduced density.

关键词： transport properties pseudopotential single-particle dynamics ytterbium

Synthesis and Crystal Structure of Trans-bis(acesulfamato-O)tetraaquazinc(Ⅱ)

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Chinese Journal of Structural Chemistry 2010年第7期29卷 1047-1050页

作者： SAHIN Onur ICBUdAK Hasan B(U|¨)y(U|¨)KG(U|¨)ng(O|¨)R Orhan department of Physics Faculty of Arts and SciencesOndokuz Mayis UniversitySamsunTurkey department of Chemistry Faculty of Arts and SciencesOndokuz Mayis UniversitySamsunTurkey

The title compound, trans-bis（acesulfamato-O）tetraaquazinc（Ⅱ）（I, C8H16N2O12S2Zn）, crystallizes in the triclinic system, space group P1 with a = 5.1638（5）, b = 8.5338（9）, c = 9.9583（9）A, α = 74.325（8）, β = 81.112（7）, γ = 75.800（8）°, V= 407.77（7） A3, Z = 1, F（000） = 236, Rint = 0.085, T= 296 K, the final R = 0.029 and wR = 0.078 for 1832 observed reflections with I〉 2σ（0. The ZnⅡcentre resides on a centre of symmetry and has a distorted octahedral geometry. The basal plane is defined by two carbonyl O atoms of two monodentate trans-oriented acesulfamato ligands and two trans-aqua ligands. The axial positions in the octahedron are occupied by two trans-aqua ligands. Intermolecular O-H…O hydrogen bonds produce R22（8） and R22（16） rings, which lead to two- dimensional polymeric chains.

关键词： crystal structure zinc(Ⅱ) octahedral complex hydrogen bonds