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Chinese Physics B 2013年第6期22卷 549-552页

作者： m y Ali j Poulter Department of mathematics Faculty of ScienceMahidol University

In this work we study the correlation function of the ground state of a two-dimensional fully frustrated Ising model as well as spin glass. The Pfaffian method is used to calculate free energy and entropy as well as the correlation function. We estimate the exponent of spin correlation function for the fully frustrated model and spin glass. In this paper an overview of the latest results on the spin correlation function is presented.

关键词： spin glass correlation function exponent square lattice

Fluctuation theorem for entropy production at strong coupling

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Chinese Physics B 2020年第1期29卷 175-180页

作者： y y Xu j Liu m Feng Faculty of Science Kunming University of Science and TechnologyKunming 650500China Faculty of mechanical and Electrical Engineering Kunming University of Science and TechnologyKunming 650500China State Key Laboratory of magnetic Resonance and Atomic and molecular Physics Wuhan Institute of Physics and MathematicsChinese Academy of SciencesWuhan 430071China School of Physics and microelectronics Zhengzhou UniversityZhengzhou 450001China

Fluctuation theorems have been applied successfully to any system away from thermal equilibrium,which are helpful for understanding the thermodynamic state *** investigate fluctuation theorems for strong coupling between a system and its reservoir,by path-dependent definition of work and heat satisfying the first law of *** present the fluctuation theorems for two kinds of entropy *** is the informational entropy production,which is always non-negative and can be employed in either strong or weak coupling *** other is the thermodynamic entropy production,which differs from the informational entropy production at strong coupling by the effects regarding the *** find that,it is the negative work on the reservoir,rather than the nonequilibrium of the thermal reservoir,which invalidates the thermodynamic entropy production at strong *** results indicate that the effects from the reservoir are essential to understanding thermodynamic processes at strong coupling.

关键词： fluctuation theorem entropy production strong coupling

Nonlinear static and dynamic responses of an electrically actuated viscoelastic microbeam

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Acta mechanica Sinica 2009年第2期25卷 211-218页

作者： y.m.Fu j.Zhang College of mechanics and Aerospace Hunan University

On the basis of the Euler-Bernoulli hypothesis, nonlinear static and dynamic responses of a viscoelastic microbeam under two kinds of electric forces [a purely direct current （DC） and a combined current composed of a DC and an alternating current] are studied. By using Taylor series expansion, a governing equation of nonlinear integro-differential type is derived, and numerical analyses are performed. When a purely DC is applied, there exist an instantaneous pull-in voltage and a durable pull-in voltage of which the physical meanings are also given, whereas under an applied combined current, the effect of the element relaxation coefficient on the dynamic pull-in phenomenon is observed where the largest Lyapunov exponent is taken as a criterion for the dynamic pull-in instability of viscoelastic microbeams.

关键词： mEmS Viscoelastic microbeam Nonlineardynamics

Quantified evaluation of particle shape effects from micro-to-macro scales for non-convex grains

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Particuology 2016年第2期14卷 23-35页

作者： y. yang j.F. Wang y.m. Cheng Department of Civil and Environmental Engineering The Hong Kong Polytechnic University Hong Kong China Department of Civil and Architectural Engineering City University of Hong Kong Hong Kong China

Particle shape plays an important role in both the micro and macro scales responses of a granular assem- bly. This paper presents a systematic way to interpret the shape effects of granular material during quasi-static shearing. A more suitable shape descriptor is suggested for the quantitative analysis of the macroscale strength indexes and contact parameters for non-convex grains, with special consid- eration given to the peak state and critical state. Through a series of numerical simulations and related post-processing analysis, particle shape is found to directly influence the strain localisation patterns, microscale fabric distributions, microscale mobilisation indexes, and probability distribution of the nor- malised contact normal force. Additionally, the accuracy of the stress-force-fabric relationship can be influenced by the average normal force and the distribution of contact vectors. moreover, particle shape plays a more important role than do the confining pressures in determining the friction angle. Strong force chains and the dilation effect are also found to be strongly influenced by the high confinin~ oressure.

关键词： Quantitative analysis Shape factor Statistical analysis micro-macro indexes

ON THE IDENTIFICATION OF RESIDUAL ImPACT PROPERTIES OF mATERIALS By ACOUSTO-ULTRASONICS——A PATTERN RECOGNITION APPROACH

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Acta mechanica Sinica 1995年第1期11卷 34-43页

作者： G.j.molina y.m.Haddad Dept.of mechanical Engineering University of OttawaOttawaCanada K1N 6N5

This paper deals with the application of Acousto-ultrasonics,in con- junction with Pattern Recognition and Classification techniques,to the identification of residual impact properties of a class of polymeric material,namely,Polyvinylchlo- ride(PVC).PVC specimens of different low-energy repeated impact damage states are processed by Acousto-ultrasonics(AU)to retrieve AU signals in the form of dig- italized *** AU signals are grouped as distinct classes,each pertaining to a known level of repeated impact *** features of these AU signals are used to build Pattern Recognition(PR)*** classifiers are used to identify unknown damage states in other PVC specimens by classifying the re- trieved AU signals as belonging to one of the *** obtained results indicate that Acousto-ultrasonics in combination with Pattern Recognition and Classification techniques can be used for the quantitative non-destructive identification of damage states in PVC specimens of unknown low-energy repeated impact conditions.

关键词： pattern recognition acousto-ultrasonics impact damage quantitative non-destructive examination

The ocular toxicity and pharmacokinetics of simvastatin following intravitreal injection in mice

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International journal of Ophthalmology(English edition) 2017年第9期10卷 1361-1369页

作者： Dennis y.tse Seong jae Kim Inyoung Chung Feng He Theodore G.Wensel Samuel m.Wu Department of Ophthalmology Baylor College of MedicineHoustonTX 77030USA School of Optometry the Hong Kong Polytechnic UniversityHong KongChina Department of Ophthalmology Institute of Health SciencesCollege of MedicineGyeongsang National UniversityJinju52727Korea Department of Biochemistry and molecular Biology BaylorCollege of MedicineHoustonTX 77030USA

AIm：To investigate the retinal toxicity and pharmacokinetics of simvastatin intravitreally injected into ***：Forty-eight 6-8-week-old C57BL/6j mice were used in this *** was intravitreally injected into the right eye of each mouse;the left eye was injected with vehicle and was used as a *** dark-adapted electroretinography（ERG）was performed 1 and 7d following *** was examined using a combination of light,fluorescence and electron *** liquid chromatography（HPLC）was used to determine the decay in the retinal simvastatin ***：ERG revealed no significant changes in the simvastatin-injected eyes compared to *** studies showed normal retinal morphology in eyes injected with simvastatin up to a final vitreal concentration of 200μmol/*** significant changes in the number of photoreceptors,bipolar cells or ganglion cells were *** retinal simvastatin concentration decayed exponentially,with a half-life of ***：Intravitreal injection of up to 200μmol/L simvastatin produced no signs of adverse effects in the mouse *** reaches the retina shortly after intravitreal injectionand has a short half-life.

关键词： simvastatin retina electroretinography highperformance liquid chromatography electron microscopy intravitreal injection

First principles insights into oxide/polymer composites: SrTiO_(3) /polyaniline/graphene

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journal of materials Science & Technology 2023年第35期166卷 250-260页

作者： Nathan D.Wood joshua S.tse jonathan m.Skelton David j.Cooke Lisa j.Gillie Stephen C.Parker marco molinari Department of Chemical Sciences School of Applied SciencesUniversity of HuddersfieldHuddersfield HD13DHUK Department of Chemistry University of ManchesterManchester M139PLUK Department of Chemistry University of BathBath BA27AYUK

A detailed computational investigation,based on density functional theory,of the interaction of polyani-line(PANI)and graphene nanoribbons(GNRs)with SrTiO_(3) is *** adsorption of PANI in var-ious oxidation states and co-adsorption with GNRs is found to be thermodynamically ***-sorbed PANI introduces N and C 2p states into the SrTiO_(3) bandgap,while co-adsorption of PANI and GNRs leads to a bridging of the gap and semi-metallic behaviour,thus rendering the electrical properties highly sensitive to the loading of the GNRs/PANI in the *** the lattice dynamics of the composites predicts a 68-88%reduction in the lattice thermal conductivity due to reduced phonon group *** together,these findings provide insight into the growing number of experimental studies highlighting the enhanced thermoelectric performance of oxide-polymer composites and indicate co-adsorption with graphene as a facile direction for future research.

关键词： Polymer/inorganic composites Polyaniline/strontium titanate/graphene nanoribbon composites PANI/GNR/SrTiO_(3)composites Thermoelectric composites Electrical transport Thermal conductivity1 Introduction

Unsupervised learning on scientific ocean drilling datasets from the South China Sea

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Frontiers of Earth Science 2019年第1期13卷 180-190页

作者： Kevin C.tse Hon-Chim CHIU man-yin TSANG yiliang LI Edmund y.LAm Department of Earth Sciences The University of Hong KongPokfulamHong KongChina Department of Geography and Centre for Geo-computation Studies Hong Kong Baptist UniversityKowloon TongHong KongChina Department of Earth Sciences University of TorontoTorontoON M5S 2M8Canada Department of Electrical and Electronic Engineering The University of Hong KongPokfulamHong KongChina

Unsupervised learning methods were applied to explore data patterns in multivariate geophysical datasets collected from ocean floor sediment core samples coming from scientific ocean drilling in the South China *** to studies on similar datasets,but using supervised learning methods which are designed to make predictions based on sample training data,unsupervised learning methods require no a priori information and focus only on the input *** this study,popular unsupervised learning methods including K-means,self-organizing maps,hierarchical clustering and random forest were coupled with different distance metrics to form exploratory data *** resulting data clusters were externally validated with lithologic units and geologic time scales assigned to the datasets by conventional methods. Compact and connected data clusters displayed varying degrees of correspondence with existing classification by lithologic units and geologic time scales.K-means and self-organizing maps were observed to perform better with lithologic units while random forest corresponded best with geologic time *** study sets a pioneering example of how unsupervised machine learning methods can be used as an automatic processing tool for the increasingly high volume of scientific ocean drilling data.

关键词： machine learning unsupervised learning ODP IODP clustering

Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

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Applied mathematics and mechanics(English Edition) 2024年第4期45卷 663-676页

作者： y.ZARE m.T.mUNIR G.j.WENG K.y.RHEE Biomaterials and Tissue Engineering Research Group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of Engineering and Technology American University of the Middle EastEgaila 54200Kuwait Department of mechanical and Aerospace Engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Department of mechanical Engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously *** contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact *** developed model's accuracy is verified through numerous experimental *** further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are ***,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling *** dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/*** increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's ***,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase