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Study on the two and three-parameter working stability regions of 3.-TZP suspension

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Science China(Technological Sciences) 2006年第5期49卷 547-568页

作者： CHEN Youqiang1, 2. ZHANG Xinni3. CHEN Sha’ou3.& QI Ping3.1. department of Chemistry, Qingdao university, Qingdao 2.6071, China 2. department of Chemistry, {3., beijing 100084, China 3. department of physics, Qingdao university, Qingdao 2.6071, China department of Chemistry Qingdao University Qingdao China department of Chemistry Tsinghua University Beijing China department of physics Qingdao University Qingdao China

We determined the variation tendency of viscosity (η) at various solids load- ing (α) for 3.-TZP suspension as a function of dispersant concentration (Cw) using vis- cosity measurement, measured the diameter of particles as a function of Cw in very dilute suspension using light scattering method, and obtained the surface features of the sedi- ment of suspension with different Cw using SEM. We also discussed the influence of the microstructure of adsorbed polymer layers on particles and their interactions in the dis- persing medium on the stability of suspension. Then two different stable states and two different unstable states for 3.-TZP suspension were given. Accordingly, the (Cw, η), (Cw, α), and (α, η) two-parameter, and (Cw, α, η) three-parameter stability maps were con- structed. Based on the DLVO theory calculations, the dispersant concentration, particle distance (r), and interparticle potential energy (VT) maps with various solids loading for 3.-TZP aqueous suspension were also constructed. In (Cw, r) two-parameter coordinate system, the stable motion region map for particles was established. The Cw, α, and VT,max (the highest potential energy) surface of the potential barrier map was obtained through calculation and simulation on the basis of the surfaces of Cw, r, VT maps introduced above. The (Cw, α) two-parameter stability map was then obtained from the Cw, α, VT,max map. The results showed that this theoretical map can qualitatively prove the experimentally obtained results—the existence of different dispersed states of particles in suspension system and the variation tendency of suspension stability with changing each parame- ter—were reasonable.

关键词： 3.-TZP, suspension, stability, DLVO theory, interparticle potential energy.

Inconsistency between WMAP data and released map

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Chinese Science Bulletin 2010年第10期55卷 907-909页

作者： LIU Hao1 & LI TiPei1,2.3.1 Key Laboratory of Particle astrophysics,Institute of High Energy physics,Chinese Academy of Sciences,{2. 100049,China {3. of physics & Center for astrophysics,tsinghua university,beijing 100084,China 3.department of engineering physics & Center for astrophysics,tsinghua university,beijing 100084,China Key Laboratory of Particle astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China department of physics & Center for {2. Tsinghua University Beijing China department of engineering {2. & Center for {3. Tsinghua University Beijing China

A remarkable inconsistency between the calibrated differential time-ordered data (TOD) of the Wilkinson Microwave Anisotropy Probe (WMAP) mission,which is the input for map-making,and the cosmic microwave background (CMB) temperature maps published by the WMAP team is revealed,indicating that there must exist a serious problem in the map making routine of the WMAP *** inconsistency is easy to be confirmed without the use of WMAP map-making *** view of the importance of this issue for cosmology study,we invite readers to check it by themselves.

关键词：威尔金森微波各向异性探测器 WMAP 地图制作宇宙微波背景有序数据制作软件 TOD CMB

Constraints on Cardassian universe from Gamma ray bursts

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Science China(physics,Mechanics & Astronomy) 2010年第9期53卷 1720-1725页

作者： WANG TaiShan1 & LIANG Nan2.1 department of physics & Center for {2.,{3.,beijing 100084,China 2.department of Astronomy,beijing Normal university,beijing 100875,China department of physics & Center for {2. Tsinghua University Beijing China department of Astronomy Beijing Normal University Beijing China

Constraints on the original Cardassian model and the modified polytropic Cardassian model are examined from the recently derived 42.gamma-ray bursts(GRBs) data calibrated with the method that can avoid the circularity *** results show that GRBs can be an optional observation to constrain the Cardassian *** the GRBs data with the newly de-rived size of baryonic acoustic oscillation peak from the Sloan Digital Sky Survey(SDSS),and the position of the first acoustic peak of the Cosmic Microwave Background radiation(CMB) from Wilkinson Microwave Anisotropy Probe(WMAP),we find Ωm0=0.2.+0.02.0.02.n=0.06+0.07-0.08(1σ) for the original Cardassian model,and Ωm0=0.2.+0.2.-0.02.n=-0.09+0.2.-1.91,β=0.82.2.10-0.62.1σ) for the modified polytropic Cardassian model.

关键词： Cardassian Gamma ray burst Cosmic Microwave Background baryonic acoustic oscillation

A MESSAGE-DRIVING FORMALISM FOR MODELING AND SIMULATION OF MULTI-AGENT SUPPLY CHAIN SYSTEMS

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Journal of Systems Science and Systems engineering 2011年第4期20卷 385-399页

作者： Wenzhe TAN1 Yueting CHAI2.Yi LIU3.1department of Automation, tsinghua university, {2., {3., China 2.0} of Automation, tsinghua university, {2., {3., China 3.1} of Automation, tsinghua university, {2., {3., China department of Automation Tsinghua University Beijing China

To acquire a competitive advantage in the expanding market, manufacturing enterprises should be able to manage their supply chains as effectively as possible. It is now becoming popular to model supply chains as multi-agent systems and use discrete event simulation to learn more about their behaviors or investigate the implications of alternative configurations. In order to enhance the computational efficiency and keep the simulation credibility, this paper proposes a message-driving formalism for the simulation of multi-agent supply chain systems. Through the message-driving formalism, the problem of shared variables is addressed and the parallel operation of agents is implemented. Simulation experiments with a prototype implementation show that the message-driving formalism is able to provide credible results in significantly less simulation time.

关键词： Supply chain multi-agent system modeling and simulation parallel discrete event simulation message-driving formalism

Density-functional formula for strongly correlated systems

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Progress in Natural Science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1*, HAN Rushan2.and CHEN Nanxian1(1. department of physics, {2., {3., China 2. department of physics, Peking university, beijing 100871, China) Dept. of Phys. Tsinghua Univ. Beijing 100084 China Dept. of Phys. Peking Univ. Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.

Solving the input data in error correc-tion of optical fabrication by finite Fourier coefficient algorithm

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Science China(Technological Sciences) 2006年第1期49卷 50-60页

作者： CHENG Haobo1,2. SUN Guozheng3.& FENG Zhijing2.1. department of Optical {3., {2. Institute of Technology, {2. 100081, China 2. department of Precision Instruments and Mechanology, tsinghua university, beijing 100084, China 3. China North Industries Group Corporation, {2. 100089, China department of Optical engineering Beijing Institute of Technology Beijing China department of Precision Instruments and Mechanology Tsinghua University Beijing China China North Industries Group Corporation Beijing China

A free-form lens (FFL) is a special surface that is difficult to be fabricated. FFL are usually fabricated by computer-controlled optical surfacing (CCOS) technique. During CCOS, the material removal amount is determined by the unit removal function (URF) convoluting with the input data――the dwell time. When the removal amount and the URF are known, how to solve the input data involves the special algorithm――deconvolution. Usually, the input data are solved by virtue of low pass filter or iterative methods. However, an approximation solution would destroy the machining stability nec-essary to perform precisely CCOS. In this paper, to solve the input data, a new method that is based on the finite Fourier coefficient is put forward. It can give a continuous and accurate solution for fabricating choice. Several parameters are simulated, which influ-ence the process of CCOS, and evaluating on the effect of the method is also carried out. Experimental results verify that this method is suitable for guiding the manufacturing of high precision FFL.

关键词： optical fabrication, computer controlled optical surfacing, free-form lens, finite Fourier coefficient, error correction.

A SINGLE-PERIOD INVENTORY SYSTEM WITH A GENERAL S-SHAPED UTILITY AND EXPONENTIAL DEMAND

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Journal of Systems Science and Systems engineering 2010年第2期19卷 227-236页

作者： Wei GENG1 Xiaobo ZHAO2.Deng GAO3.department of Industrial engineering,{2.,{3.,China department of Industrial engineering Tsinghua University Beijing China

We discuss a single-period inventory system with a general S-shaped utility function and exponential demand. It is shown that there exists a state-dependent order-up-to policy to be optimal. Behaviors of optimal polic... 详细信息

关键词： Inventory S-shaped utility function order-up-to policy

Gas kinetic algorithm for flows in Poiseuille-like microchannels using Boltzmann model equation

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Science China(physics,Mechanics & Astronomy) 2005年第4期48卷 496-512页

作者： LI Zhihui1,2. ZHANG Hanxin1 & FU Song2.⒈ National Laboratory for CFD, Hypervelocity Aerodynamics Institute,China Aerodynamics Research and Development Center,Mianyang 62.000,China {3. of engineering Mechanics,{2.,{3.,China National Laboratory for CFD Hypervelocity Aerodynamics Institute China Aerodynamics Research and Development Center Mianyang China department of engineering Mechanics Tsinghua University Beijing China

The gas-kinetic unified algorithm using Boltzmann model equation have been extended and developed to solve the micro-scale gas flows in Poiseuille-like micro-channels from Micro-Electro-Mechanical Systems (MEMS). The numerical modeling of the gas kinetic boundary conditions suitable for micro-scale gas flows is presented. To test the present method, the classical Couette flows with various Knudsen numbers, the gas flows from short microchannels like plane Poiseuille and the pressure-driven gas flows in two-dimensional short microchannels have been simulated and compared with the approximate solutions of the Boltzmann equation, the related DSMC results, the modified N-S solutions with slip-flow boundary theory, the gas-kinetic BGK-Burnett solutions and the experimental data. The comparisons show that the present gas-kinetic numerical algorithm using the mesoscopic Boltzmann simplified velocity distribution function equation can effectively simulate and reveal the gas flows in microchannels. The numerical experience indicates that this method may be a powerful tool in the numerical simulation of micro-scale gas flows from MEMS.

关键词： Boltzmann model equation, discrete velocity ordinate method, finite-difference scheme, Couette flow, Poiseuille flow, gas flow in short-microchannel.

Influence of magnetic current on the ground state entanglement in an isotropic transverse XY chain

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Progress in Natural Science:Materials International 2007年第10期17卷 1147-1151页

作者： Liu Dan1,2., Zhang Yong3.and Long Guilu1,2.1. Key Laboratory for Atomic and Molecular NanoSciences, and department of {3., {2., {3., China 2. Center of Quantum Information Science and Technology, tsinghua National Laboratory for information Science and Technology, {3., China 3. Institute of {3., School of Sciences, beijing university of Posts and Telecommunications, beijing 100876, China) Key Laboratory for Atomic and Molecular NanoSciences Department of Physics Tsinghua University Beijing 100084 China Center of Quantum Information Science and Technology Tsinghua National Laboratory for Information Science and Technology Beijing 100084 China Institute of physics School of Sciences Beijing University of Posts and Telecommunications Beijing 100876 China

We study the ground state entanglement in a three-qubit XY chain under the influence of a magnetization current. It is found that the ground state changes from a W state to a disentangled state as the magnetic field varies. When the Lagrange multiplier λ>3. namely under a strong magnetic current, the ground state holds onto a W state for a large range of the magnetic field strength. A phase transition to the magnetization-current phase occurs under a certain condition.

关键词： Heisenberg-XY chain magnetic-current phase transition.