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The effect of agglomerate on micro-structural evolution in solid-state sintering

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Acta Mechanica Sinica 2012年第5期28卷 1323-1330页

作者： Chao Wang shao-hua Chen State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences

Discrete element method （DEM） is used in the present paper to simulate the microstructural evolution of a planar layer of copper particles during sintering. Formation of agglomerates and the effect of their rearrangement on densification are mainly focused on. Comparing to the existing experimental observations, we find that agglomerate can form spontaneously in sintering and its rearrangement could accelerate the densification of compacts. Snapshots of numerical simulations agree qualitatively well with experimental observations. The method could be readily extended to investigate the effect of agglomerate on sintering in a three- dimensional model, which should be very useful for understanding the evolution of microstructure of sintering systems.

关键词： Solid-state sintering Discrete element method Agglomerate Densification Micro-structural evolution

Experimental and numerical investigation on the gas leakage regime for ventilated tail cavity of an underwater vehicle

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Journal of Hydrodynamics 2023年第1期35卷 46-60页

作者： Xiao-bo Quan shao-hua Cheng College of Shipbuilding Engineering Harbin Engineering UniversityHarbin150001China China Academy of Launch Vehicle Technology Beijing100076China Beijing Institute of Astronautical Systems Engineering Beijing100076China

The objective of this paper is mainly to investigate the ventilated tail cavity flow of an underwater vehicle with focus on the gas leakage regime by experimental and numerical methods.A high-speed camera and pressure measurement system are used to record the cavity flow patterns and pressure behavior,*** numerical simulation is carried out with volume of fluid(VOF)model and Filter-based turbulence model(FBM).Good agreement can be obtained between the experimental and numerical *** are three gas leakage types in the evolution of the intact tail cavity,i.e.,twin-vortex tube entrainment(TVTE),toroidal vortex shedding(TVS)and hybrid twin-vortex tube entrainment and toroidal vortex shedding(TVTE-TVS).With the increase of Fr,the unsteady behavior of the cavity with different gas leakage types becomes more *** internal flow characteristics revealed three distinct regions including the ventilation influence region,the reverse flow region and the high shear flow region and have an important effect on the transition of gas leakage regime.

关键词： Ventilated tail cavity gas leakage regime unsteady behavior internal flow characteristics

Eigen elastic mechanics and its variation principle

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中国有色金属学会会刊：英文版 2001年第2期11卷 281-282页

作者： GUO shao-hua 郭少华 College of Resources Environment and Civil Engineering Central South University

The fundamental equations and the corresponding boundary condition of elastic mechanics under mechanical representation are given by using the conception of eigen space and elastic variation principle. It is proved theoretically that the solution of anisotropic elastic mechanics consists of modal ones, which are obtained respectively from the modal equation of the different subspaces. A simple application is also given.

关键词： anisotropy eigen elastic mechanics variation principle modal equation

Conditional Generation of Multiparticle Entanglement via Cavity QED

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Communications in Theoretical Physics 2009年第11期52卷 835-839页

作者： XIANG shao-hua shao Bin SONG Ke-Hui Department of Physics and Information Engineering Huaihua University Huaihua 418008 China Research Institute of Information Science Huaihua University Huaihua 418008 China Department of Physics Beijing Institute of Technology Beijing 100081 China

We propose a simple scheme to not only generate GHZ states and W states of the multiparticle but also form a new category of multiparticle entangled states by letting the A-type three-level atoms simultaneously interacting with a coherent cavity field followed by the selective measurements on the cavity mode. We investigate the influence of the cavity dissipation on the generated entangled state and discuss the experimental feasibility of our scheme. It is shown that the intensity of the coherent cavity field plays an instructive role in contribution to state preparation process while the cavity decay and the detuning between the atoms and cavity mode result in the deterioration of the generated entangled state.

关键词： multiparticle entanglement gavity QED decoherence

Dynamic Manipulability and Optimization of a Two DOF Parallel Mechanism

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Chinese Journal of Mechanical Engineering 2010年第4期23卷 403-409页

作者： shao hua WANG Jinsong WANG Liping GUAN Liwen Department of Precision Instrument and Mechanology Tsinghua University Beijing 100084 China

The dynamic dexterity is an important issue for manipulator design, some indices were proposed for analyzing dynamic dexterity, but they can evaluate the dynamic performance just at one pose in the workspaee of the manipulator, and can＇t be applied to dynamic design expediently. Much work has been done in the kinematic optimization, but the work in the dynamic optimization is much less. A global dynamic condition number index is proposed and applied to the dynamic optimization design the parallel manipulator. This paper deals with the dynamic manipulability and dynamic optimization of a two degree-of-freedom （DOF） parallel manipulator. The particular velocity and particular angular velocity matrices of each moving part about the part＇s pivot point are derived fi＇om the kinematic formulation of the manipulator, and the inertial force and inertial movement are obtained utilizing Newton-Euler formulation, then the inverse dynamic model of the parallel manipulator is proposed based on the virtual work principle. The general inertial ellipsoid and dynamic manipulability ellipsoid are applied to evaluate the dynamic performance of the manipulator, a global dynamic condition number index based on the condition number of general inertial matrix in the workspace is proposed, and then the link lengths of the manipulator is redesigned to optimize the dynamic manipulability by this index. The dynamic manipulability of the origin mechanism and the optimized mechanism are compared, the result shows that the optimized one is much better. The global dynamic condition number index has good effect in evaluating the dynamic dexterity of the whole workspace, and is efficient in the dynamic optimal design of the parallel manipulator.

关键词： dynamic manipulability dynamic optimization parallel manipulator

Seismic performance evaluation of steel frame-steel plate shear walls system based on the capacity spectrum method

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第3期9卷 322-329页

作者： Jian-hua shao Qiang GU Yong-kang SHEN College of Civil Engineering Hohai University Nanjing 210098 China Department of Civil Engineering Suzhou University of Science and Technology Suzhou 215011 China

This paper presents some methods that the standard acceleration design response spectra derived from the present China code for seismic design of buildings are transformed into the seismic demand spectra, and that the base shear force-roof displacement curve of structure is converted to the capacity spectrum of an equivalent single-degree-of-freedom （SDOF） system. The capacity spectrum method （CSM） is programmed by means of MATLABT.0 computer language. A dual lateral force resisting system of 10-story steel frame-steel plate shear walls （SPSW） is designed according to the corresponding China design codes. The base shear force-roof displacement curve of structure subjected to the monotonic increasing lateral inverse triangular load is obtained by applying the equivalent strip model to stimulate SPSW and by using the finite element analysis software SAP2000 to make Pushover analysis. The seismic performance of this dual system subjected to three different conditions, i.e. the 8-intensity frequently occurred earthquake, fortification earthquake and seldom occurred earthquake, is evaluated by CSM program. The excessive safety of steel frame-SPSW system designed according to the present China design codes is pointed out and a new design method is suggested.

关键词： Steel frame-steel plate shear walls (SPSW) system Capacity spectrum method (CSM) Seismic demand spectrum Base shear force-roof displacement Seismic performance evaluation

Teleportation of Atomic States in a Vacuum-Induced Environment

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Communications in Theoretical Physics 2009年第1期51卷 60-64页

作者： LIU Jin shao Bin IANG shao-hua ZOU Jian Department of Physics School of Science Beijing Institute of Technology Beijing 100081 China Department of Physics and Electronic Information Science Huaihua University Huaihua 418008 China

We present a scheme for teleporting atomic state through a dissipative quantum channel induced by spontaneous emission and investigate the destructive effect of the atomic decay on the success probability and the fidelity of teleportation associated to different channels. It is found that there exists an optimal channel to realize faithful teleportation.

关键词： quantum teleportation Bell-state measurement unitary transformation

Microwave-assisted Preparation of Temperature Sensitive Poly(N-isopropylacrylamide) Hydrogel with Improved Responsive Properties

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Chinese Chemical Letters 2006年第3期17卷 361-364页

作者： shao hua SHI Li Jian LIU Department of Polymer Science College of Chemistry and Molecular Science Wuhan University Key Laboratory of Biomedical Polymers （Wuhan University） Ministry of Education Wuhan 430072 R ＆ D Center Nhwa Pharmaceutical Group Xuzhou 221007

Poly（N-isopropylacrylamide）-based hydrogel was prepared under microwave irradiation The hydrogel thus prepared, comparing with that prepared by thermal heating method, exhibits faster swelling and shrinking kinetics. The improved responsive properties are due to the more heterogeneous and porous networks formed under microwave irradiation.

关键词： Microwave poly(N-isopropylacrylamide) hydrogel fast response.

Approximate and Conditional Teleportation of an Unknown Atomic-Entangled State Without Bell-State Measurement

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Communications in Theoretical Physics 2007年第2期47卷 253-256页

作者： CHEN Chang-Yong LI shao-hua Department of Physics and Information Engineering Hunan Institute of Humanities Science and Technology Loudi 417000 China State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Wuhan Institute of Physics and Mathmatics the Chinese Academy of Sciences Wuhan 430071 China Department of Communication and Controlling＇ Engineering Hunan Institute of Humanities Science and Technology Loudi 417000 China

A scheme for approximately and conditionally teleporting an unknown atomic-entangled state in cavity QED is proposed. It is the novel extension of the scheme of [Phys. Rev. A 69 （200,I） 06,1302], where the state to be teleported is an unknown atomic state and where only a time point of system evolution and the corresponding： fidelity implementing the telèportation are given. In fact, there exists multi-time points and the corresponding fidelities, which are Shown in this paper and then are used to realize the approximate and conditional teleportation of the unknown atomic-entangled state. Naturally, our scheme does not involve the Bell-state measurement or an additional atom, which is required in the Bell-state measurement, only requiring one single-mode cavity. The scheme may be generalized to not only the teleportation of the cavity-mode-entangled-state by means of a single atom but also the teleportation of the unknown trapped-ion-entangled-state in a linear ion trap and the teleportation of the multi-atomic entangled states included in generalized GHZ states.

关键词： teleportation Bell-state measurement cavity QED Rydberg state