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Helmholtz equation and non-singular boundary elements applied to multi-disciplinary physical problems

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Communications in Theoretical Physics 2022年第8期74卷 18-34页

作者： Evert Klaseboer qiang sun Institute of High Performance Computing 1 Fusionopolis WaySingapore 138632Singapore Australian Research Council Centre of Excellence for Nanoscale BioPhotonics School of ScienceRMIT UniversityMelbourneVIC 3001Australia

The famous scientist Hermann von Helmholtz was born 200 years *** complex physical wave phenomena in engineering can effectively be described using one or a set of equations named after him:the Helmholtz *** this has been known for a long time,from a theoretical point of view,the actual numerical implementation has often been hindered by divergence-free and/or curlfree *** is further a need for a numerical method that is accurate,reliable and takes into account radiation conditions at *** classical boundary element method satisfies the last condition,yet one has to deal with singularities in the *** review here how a recently developed singularity-free three-dimensional boundary element framework with superior accuracy can be used to tackle such problems only using one or a few Helmholtz equations with higher order(quadratic)elements which can tackle complex curved *** are given for acoustics(a Helmholtz resonator among others)and electromagnetic scattering.

关键词： acoustics Helmholtz cavity electromagnetics scattering boundary integral method

A Non-Singular Boundary Element Method for Interactions between Acoustical Field Sources and Structures

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Advances in Applied Mathematics and Mechanics 2023年第4期15卷 831-851页

作者： qiang sun Australian Research Council Centre of Excellence for Nanoscale Biophotonics School of ScienceRMIT UniversityMelbourneVIC 3001Australia

Localized point sources(monopoles)in an acoustical domain are implemented to a three dimensional non-singular Helmholtz boundary element method in the frequency *** allows for the straightforward use of higher order surface elements on the boundaries of the *** will been shown that the effect of the monopole sources ends up on the right hand side of the resulting matrix *** carefully selected examples are studied,such as point sources near and within a concentric spherical core-shell scatterer(with theoretical verification),near a curved focusing surface and near a multi-scale and multi-domain acoustic lens.

关键词： Acoustic monopoles acoustic lens boundary integral method quadratic elements

Highly sensitive tuning of lattice thermal conductivity of graphenelike borophene by fluorination and chlorination

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Nano Research 2020年第4期13卷 1171-1177页

作者： Tingwei Li Ge Nie qiang sun Department of Materials Science and Engineering Peking UniversityBeijing 100871China State Key Laboratory of Coal-based Low Carbon Energy ENN Science&Development Co.Ltd.Langfang 065001China Center for Applied Physics and Technology Peking UniversityBeijing 100871China

Boron-based 2D materials are of current ***,graphene-like geometry is unstable for B due to the electron deficiency,which can be stabilized by introducing H,F and ***,using density functional theory combined with phonon Boltzmann transport equation,we perform systematic studies on how the functionalization changes the lattice thermal conductivity(LTC).We find that when going from hydrogenation to fluorination and chlorination,the LTC along zigzag direction changes from 367.6 to 211.3 and 43.0 W/(rrvK),while the corresponding values in armchair direction are 279.6,198.9,and 41.6 W/(m·K),*** huge differences imply the sensitivity of LTC to functionalization,which can be attributed to the enhanced anharmonicity as revealed by analyzing group velocity,Gruneisen parameter,anharmonic scattering rates,and three-phonon scattering space.

关键词： graphene-like borophene lattice thermal conductivity fluorination chlorination calculation

A constraint-weaving approach to points-to analysis for AspectJ

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Frontiers of Computer Science 2014年第1期8卷 52-68页

作者： qiang sun Yuting CHEN Jianjun ZHAO Department of Computer Science and Engineering and School of Software Shanghai Jiao Tong University Shanghai 200240 China State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing 100190 China

Points-to analysis is a static code analysis tech- nique that establishes the relationships between variables of references and allocated objects. A number of points-to analysis algorithms have been proposed for procedural and object-oriented languages like C and Java, while few of them can be used for AspectJ as we know so far. One main rea- son is that Aspect/is an aspect-oriented language which im- plements the separation of crosscutting concerns by advices, pointcuts, and inter-type declarations, while a points-to anal- ysis of AspectJ programs may be imprecise because any as- pect woven into the base code may change the points-to rela- tions in the program and thus a conservative analysis has to be taken in order to handle the aspects. In this paper, we pro- pose a context-sensitive points-to analysis technique called AJPoints for AspectJ. Similar to the weaving mechanism for AspectJ, AJPoints obtains the constraints and templates on the points-to relations for the base code and the aspects, re- spectively, but weaves and solves them in an iterative manner in order to cross the boundary between the base code and the aspects. We have implemented AJPoints on abc AspectJ compiler and evaluated it by using twelve AspectJ benchmark programs. The experimental can achieve a high precision pectJ programs. results show that our technique about points-to relations in As-

关键词： points-to analysis context-sensitive analysis,AspectJ

NECESSARY AND SUFFICIENT CONDITION FOR GLOBAL CONTROLLABILITY OF A CLASS OF AFFINE NONLINEAR SYSTEMS

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Journal of Systems Science & Complexity 2007年第4期20卷 492-500页

作者： Yimin sun Shengwei MEI qiang LU Department of Electrical Engineering Tsinghua University Beijing 100084 China

In this paper, we investigate the global controllability of a class of n-dimensional affine nonlinear systems with n- 1 controls and constant control matrix. A necessary and sufficient condition for its global controllability has been obtained by using the methods recently developed. Furthermore, we generalize the above result to a class of affine nonlinear systems with a block-triangular-like structure. Finally, we will give three examples to show the applications of our results.

关键词： Affine nonlinear systems block-triangular-like structure global controllability vector field

Rapid hydrate formation and efficient gas separation based on aqueous solid carrier

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Chinese Journal of Chemical Engineering 2024年第10期74卷 127-132页

作者： Haibo Liu qiang sun Xiaodong Liu Du sun Guangjin Chen China Oilfield Services Limited Sanhe 065201China State Key Laboratory of Heavy Oil Processing China University of Petroleum-BeijingBeijing 102249China Tarim Oilfield Branch of China National Petroleum Corporation Korla 841000China

The long hydrate induction time and limited gas-liquid contact area leads to slow hydrate formation rate and low water-hydrate conversion *** media are often used to promote hydrate formation because of their large specific surface ***,we used 3A molecular sieve as a water-carrying solid in this work,and investigated the dynamic renewal of the gas-liquid interface and its effect on hydrate *** formation kinetics of ethane hydrate was first measured in an aqueous molecular sieve *** the separation of(H_(2)+CH_(4)+C_(2)H_(6)+C_(3)H_(8))gas mixture was conducted via hydrate *** results show that the formation rate and gas storage capacity of ethane hydrate can be greatly improved by using aqueous molecular *** with a pure water system under the same temperature and pressure,aqueous molecular sieve has obvious advantages in separation effect and energy consumption for separating gas mixtures.

关键词： Hydrate Formation kinetics Gas storage capacity Gas separation Aqueous molecular sieve

Tree-based differential evolution algorithm for QoS multicast routing

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The Journal of China Universities of Posts and Telecommunications 2011年第4期18卷 76-81页

作者： KONG sun CHEN Zeng-qiang Department of Automation Nankai University Tianjin 300071 China

Differential evolution （DE） algorithm has attracted more and more attention due to its fast optimization performance and good stability. When DE algorithm is applied into multi-constrained multicast routing optimization problem, a common solution to such problem is to merge the paths into a tree after finding paths from the source node to each destination node. This method maybe obtains the better result, but it can consume a lot of computational time. To solve the problem, a tree-based DE algorithm is introduced in this paper. The central operations of the algorithm are realized with tree structure. This method saves the time of finding paths and integrating them to construct a multicast tree. The experiments show that the proposed algorithm can achieve higher success rate than several common algorithms with much smaller running time for different networks.

关键词： quality of service (QoS) multicast routing DE tree structure

Generalized Hybrid Nanofluid Model with the Application of Fully Developed Mixed Convection Flow in a Vertical Microchannel

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Communications in Theoretical Physics 2019年第8期71卷 903-911页

作者： Hang Xu qiang sun State Key Laboratory of Ocean Engineering School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong University Shanghai 200240 China Particulate Fluids Processing Centre Department of Chemical Engineering The University of Melbourne Parkville VIC 3010 Australia

The fully developed mixed convection hybrid nanofluid flow in a vertical microchannel is examined in *** simplified hybrid model that omits the nonlinear terms due to the interaction of different nanoparticle volumetric fractions is derived and compared with the existing *** generalized model describing hybrid nanofluid suspended with multiple kinds of solid particles is *** argument that the corresponding nanofluid solutions obtained by the homogenous model can be recovered from the results of the regular problems through simple arithmetic operations is *** in similarity form for this flow problem are formulated by means of a set of similarity *** effects of various parameters on important physical quantities are analyzed and discussed.

关键词： hybrid nanofluid vertical channel mixed convection slippery effect

Molecular mechanisms underlying cell-in-cell formation:core machineries and beyond

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Journal of Molecular Cell Biology 2021年第5期13卷 329-334页

作者： Zubiao Niu Meifang He qiang sun Laboratory of Cell Engineering Institute of BiotechnologyBeijing 100071China Laboratory of General Surgery The First Affiliated HospitalSun Yat-sen UniversityGuangzhou 510080China Research Unit of Cell Death Mechanism Chinese Academy of Medical Sciences2020RU009Beijing 100071China

Although cell-in-cell structures(CICs),with one or more cells present inside another cell,had been identified for a century,it was not until recent years that scientists started to uncover their pivotal roles in multiple biological processes,primarily via mediating the death of internalized ***,considerable progresses were made on deciphering the mechanisms underlying their formation based on different *** was one of the best investigated CIC models,where cell internalization was coordinately driven by adherens junction and contractile ac-tomyosin,the two spatially polarized and complementary core elements that were coupled by mechanical ring,a recently identified core ***,an expanding group of factors were found capable of regulating CIC formation by targeting these core *** elucidation of the molecular machinery controlling CIC formation enables synthetic engineering of cells used for clinical and research purposes。

关键词： mechanisms beyond complementary