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Level Set interface treatment and its application in Euler method

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science china(Physics,Mechanics & Astronomy) 2010年第2期53卷 227-236页

作者： WU KaiTeng1,2,HAO Li3,WAng Cheng4 & ZHAng Li1,2 1 Numerical Simulation Sichuan Higher School Key laboratory,Neijiang Normal University,Neijiang 641112,china 2 College of Mathematics and information science,Neijiang Normal University,Neijiang 641112,china 3 College of science,beij.ng University of Civil Engineering and Architecture,beij.ng 100044,china 4 State Key laboratory of Explosion science and technology,beij.ng Institute of technology,beij.ng 100081,china 1. Numerical Simulation Sichuan Higher School Key laboratory Neijiang Normal University Neijiang 641112 China2. College of Mathematics and Information Science Neijiang Normal University Neijiang 641112 China3. College of Science Beijing University of Civil Engineering and Architecture Beijing 100044 China4. State Key Laboratory of Explosion Science and Technology Beijing Institute of Technology Beijing 100081 China

Level Set interface treatment method is introduced into Euler method,which is employed for interface treatment method for multi-materials. Combined with the ghost fluid method,the moving interface is tracked. Fifth-order WENO spatial discretization and third-order TVD Runge-Kutta time discretization methods are used. Shock-wave action on bubble,implosion and velocity field Shock effect bubbles; implosion and velocity field are simulated by means of LS-MMIC3D programmed by C++. Nu-merical results show that the Level Set interface treatment method is effective and feasible for multi-material interface treatment in comparison with the WENO method.

关键词： Euler method Level Set method shock-wave action on bubble implosion numerical simulation

Expression profiles and transactivation analysis of a novel ethylene-responsive transcription factor gene GhERF5 from cotton

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Progress in Natural science:Materials International 2009年第5期19卷 563-572页

作者： Longguo Jin, Bo Huang, Hui Li, Jinyuan Liu laboratory of Molecular Biology and MOE laboratory of Protein science, Department of Biological sciences and Biotechnology, tsinghua University, beij.ng 100084, china [a]laboratory of Molecular Biology and MOE laboratory of Protein science Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China

Plant AP2/EREBP transcription factors play important roles in plant development and in plant responses to biotic and abiotic stresses. A novel gene for ethylene-responsive element binding protein (EREBP), designated GhERF5, which encodes a protein of 255 amino acids, was isolated by RACE-PCR from cotton (Gossypium hirsutum) seedlings. Sequence alignment revealed that GhERF5 contains a typical AP2/ERF domain, and belongs to the B3 subgroup of the ERF subfamily. Particle bombardment assay showed that GhERF5 functions as an in vivo transcription activator in tobacco cells, and it is located in the nuclei of onion epidermis cells. Semi-quantitative RT-PCR revealed that the expression of GhERF5 was highly and rapidly induced when plants were treated with exogenous ethylene, abscisic acid (ABA), salt, cold and drought. Promoter analysis indicated that there are conserved cis-acting elements induced by these stresses in the 50-upstream region of the GhERF5 gene. These results suggest that the GhERF5 gene might play an important role in cotton response to ethylene, ABA and environmental stresses.

关键词： Ethylene-responsive element binding factor (ERF) Abiotic stresses Nuclear localization Transactivation Gossypium hirsutum

Microstructures and characteristics of deep trap levels in ZnO varistors doped with Y_2O_3

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science china(Technological sciences) 2009年第12期52卷 3668-3673页

作者： LIU Jun 1 ,HU Jun 1 ,HE JinLiang 1 ,LIN YuanHua 2 &LOng WangCheng 1 1State Key laboratory of Power Systems,Department of Electrical Engineering,tsinghua University,beij.ng 100084,china 2State Key laboratory of New Ceramics and Fine Processing,Department of Material science and Engineering,tsinghua University, beij.ng 100084,china 1. State Key laboratory of Power Systems Department of Electrical Engineering Tsinghua University Beijing 100084 China 2. State Key laboratory of New Ceramics and Fine Processing Department of Material Science and Engineering Tsinghua University Beijing 100084 China

In this paper discussions on ZnO based varistor ceramics doped with different ratios of Y2O3 are *** on the phase and microstructures of the samples indicates that an additional phase is detected in the samples doped with Y2O3,and the average grain size of the specimens decreases from about 9.2μm to 4.5μm,with an increase in the addition of Y2O3 from 0 mol%to 3 mol%.The corresponding varistor’s voltage gradient markedly increases from 462 V/mm to 2340 V/mm,while the nonlinear coefficient decreases from 22.3 to 11.5,***,the characteristics of deep trap levels in these ZnO samples are investigated by measuring their dielectric *** trap energy level and capture cross section evaluated by relaxation peak of the Cole-Cole plot vary slightly as the addition of Y2O3 *** traps may be ascribed to the intrinsic defects of ZnO lattice.

关键词： ZnO varistors Y2O3 electrical properties deep trap levels

Nonvolatile resistive switching memories-characteristics,mechanisms and challenges

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Progress in Natural science:Materials International 2010年第1期20卷 1-15页

作者： Feng PAN,Chao CHEN,Zhi-shun WAng,Yu-chao YAng,Jing YAng,Fei ZEng laboratory of Advanced Materials,Department of Materials science and Engineering, tsinghua University,beij.ng 100084,china tsinghua Univ Adv Mat Lab Dept Mat Sci & Engn Beijing 100084 Peoples R China

This review presents a summary of current understanding of the resistive switching materials and devices which have inspired extraordinary interest all over the *** various switching behaviors and different conductive mechanisms are involved in the field,the resistive switching effects can be roughly classified into filament type and interface type according to their conducting behavior in low resistance *** those filament based systems,the migration of metallic cations and oxygen vacancies, characterization of the filament as well as the role of Joule heating effects are discussed in *** to the interface based system, we describe the methods of modulating interface barrier height such as using different electrodes,inserting a tunnel *** is demonstrated that the switching mechanism can transform from one to another along the change of some specific *** also give an overview on the latest developments in multilevel storage and the resistive switching in organic *** this paper,the solutions to address the sneak current problems in crossbar structure are discussed.

关键词： resistive switching nonvolatile memory RRAM filament redox reaction

Implementation of a multiple round quantum dense coding using nuclear magnetic resonance

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science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 706-715页

作者： ZHAng Jingfu1, XIE Jingyi2, WAng Chuan1, DEng Zhiwei3, LU Zhiheng4, & LOng Guilu1,5 1. Key laboratory For Quantum information and Measurements of MOE, Department of Physics, tsinghua University, beij.ng 100084,china 2. Department of Materials science and Engineering, beij.ng Normal University, beij.ng 100875, china 3. Testing and Analytical Center, beij.ng Normal University, beij.ng 100875,china 4. Department of Physics, beij.ng Normal University, beij.ng 100875, china 5. Key laboratory For atomic and Molecular Nanosciences, tsinghua University, beij.ng 100084,china 1. Key laboratory For Quantum information and Measurements of MOE Department of Physics Tsinghua University 100084 Beijing China 2. Department of Materials science and Engineering Beijing Normal University 100875 Beijing China 3. Testing and Analytical Center Beijing Normal University 100875 Beijing China 4. Department of Physics Beijing Normal University 100875 Beijing China 5. Key laboratory For Atomic and Molecular Nanosciences Tsinghua University 100084 Beijing China

A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2m+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment.

关键词： quantum dense coding, multiple round, nuclear magnetic resorance

Response synchronization: New progress in brain-visual information processing

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Chinese science Bulletin 1999年第16期44卷 1447-1458页

作者： ZHAO Songnian, XIOng Xiaoyun, YAO Guozheng and GUO Aike1. State Key laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry , Institute of Atmospheric Physics , Chinese Academy of sciences , beij.ng 100029, china 2. Commission of the national Natural science Foundation of china , beij.ng 100083, china 3. The Center of information science , Peking University, beij.ng 100871, china 4. Open laboratory of Visual information Processing , Institute of Biophysics , Chinese Academy of sciences , beij.ng 100101, china State Key laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Commission of the national Natural science Foundation of china Beijing China The Center of information science Peking University Beijing China Open laboratory of Visual information Processing Institute of Biophysics Chinese Academy of Sciences Beijing China

Studies on brain-vision have entered a new stage, after the stimulus-induced y synchronized oscillation of neuron group activities have been discovered in cat primary visual cortex. Naturally, how to understand the visual system became a very important methodological problem. From aspects such as information processing, nonlinear dynamics and neuronal network, some primary problems in vision studies have been deeply discussed, which are

关键词： neuron group (neural population) synchro-oscillation computational theory of vision response synchroniza-tion.

Truncation error calculation based on Richardson extrapolation for variable-step collaborative simulation

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science china(information sciences) 2011年第6期54卷 1238-1250页

作者： ZHAng HeMing 1 , LIAng SiLu 2 , SOng ShiJi 1 & WAng HongWei 3 1 Department of Automation, TNList, tsinghua University, beij.ng 100084, china 2 Computer and information Management Center, tsinghua University beij.ng 100084, china 3 Engineering Design Centre, Engineering Department, Cambridge University, Cambridge CB2 1PZ, UK 1. Department of Automation TNList Tsinghua University Beijing 100084 China2. Computer and Information Management Center Tsinghua University Beijing 100084 China3. Engineering Design Centre Engineering Department Cambridge University Cambridge CB2 1PZ UK

Collaborative simulation is an effective approach to performing simulation analysis for complex systems by integrating models developed for different engineering disciplines. Collaborative simulation issues include the modeling of coupled multidisciplinary systems, and the simulation running time integration of these models that are solved parallelly. Estimation of the local truncation error of coupling models is the key to solve multidisciplinary collaborative simulation problem, which is actually used to restrict the simulation step. This paper presents a variable-step method based on Richardson extrapolation for calculating the local truncation error to solve collaborative simulation problem of multidisciplinary coupling models. Formulas for estimating the local truncation error are derived through theoretical analysis by using integration methods and interpolation technologies, respectively. The simulation experiments are illustrated to validate the accuracy and efficiency of proposed collaborative simulation algorithm in comparison with the usual combinative algorithm.

关键词： multidisciplinary systems collaborative simulation variable-step algorithm error estimation

Communication network designing:Transmission capacity,cost and scalability

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science china(information sciences) 2012年第11期55卷 2454-2465页

作者： ZHAng GuoQiang1,2,3 & ZHAng GuoQing1 1Institute of Computing technology,Chinese Academy of sciences,beij.ng 100190,china 2School of Computer science and technology,Nanjing Normal University,Nanjing 210046,china 3Provincial Key laboratory for Computer information Processing technology,Soochow University,Suzhou 215000,china 1. Institute of Computing technology Chinese Academy of Sciences Beijing 100190 China2. School of Computer Science and Technology Nanjing Normal University Nanjing 210046 China3. Provincial Key Laboratory for Computer Information Processing Technology Soochow University Suzhou 215000 China

Despite the growing number of works centering around the traffic dynamics on complex networks,these researches still have some common shortcomings,e.g.,too simple traffic flow model and lack of considerations for the designing cost and scalability *** paper builds on a more realistic traffic flow model,and offers a holistic view on the network designing *** addition to the extensively studied transmission capacity,this paper takes designing cost and scalability as two other designing objectives,and presents a quantitative study of how different designing choices independently and collectively influence these objectives by the introduction of a cartesian coordinate *** is shown that different kinds of network topologies display different shapes of achievable solution spaces and exhibit different abilities to achieve cost-effective and scalable *** particular,we find the philosophy underlying empirical network designing and engineering today fails to meet the cost-effective and scalable designing requirements,and propose a cost-effective and scalable designing scheme for BA-like networks,i.e.,the efficient routing combined with effective betweenness based link bandwidth *** addition,when designing a thoroughly new network from the beginning,we find that ER network is a good candidate to achieve cost-effective and scalable designing in most settings.

关键词： cost-effective communication network designing network transmission efficiency network topology traffic dynamics next generation network scalable network designing

Deformation reinforcement theory and its application to high arch dams

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science china(Technological sciences) 2008年第S2期51卷 32-47页

作者： YAng Qiang,LIU YaoRu,CHEN YingRu & ZHOU WeiYuan State Key laboratory of Hydroscience and Hydraulic Engineering,tsinghua University,beij.ng 100084,china 1. State Key laboratory of Hydroscience and Hydraulic Engineering Tsinghua University Beijing 100084 China

In this paper,the deformation reinforcement theory(DRT) proposed by the authors is elaborated with a new definition of instability that an elasto-plastic structure is not stable if it cannot satisfy simultaneously equilibrium condition,kinematical admissibility and constitutive equations under the prescribed *** from the definition,a proof is established to the principle of minimum plastic complementary energy for failured *** is revealed that the principle of mini-mum plastic complementary energy results in relaxed constitutive equations,especially,yield *** is demonstrated with case studies that many key issues in arch dam design,e.g.,global stability,dam-toe reinforcement,dam-toe cracking,dam-abut-ment reinforcement,can be well solved within the framework of the deformation reinforcement *** structural global stability can be described by the curve of the plastic complementary energy vs overloading *** unbalanced-forces obtained by elasto-plastic FEM can be used as the basis of analysis of global stability,dam-heel cracking,dam-toe anchorage and reinforcement of faults of high arch dams and their foundations.

关键词： high arch dams global stability reinforcement unbalanced force plastic complementary energy