检索结果-南通市图书馆

维普期刊数据库博看期刊

Factors influencing particle agglomeration during solid-state sintering

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2012年第3期28卷 711-719页

作者： Chao Wang shao-hua Chen State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of Sciences100190 BeijingChina

Discrete element method （DEM） is used to study the factors affecting agglomeration in three-dimensional copper particle systems during solid-state sintering. A new parameter is proposed to characterize agglomeration. The effects of a series of factors are studied, including particle size, size distribution, inter-particle tangential viscosity, tem- perature, initial density and initial distribution of particles on agglomeration. We find that the systems with smaller particles, broader particle size distribution, smaller viscos- ity, higher sintering temperature and smaller initial density have stronger particle agglomeration and different distribu- tions of particles induce different agglomerations. This study should be very useful for understanding the phenomenon of agglomeration and the micro-structural evolution during sin- tering and guiding sintering routes to avoid detrimental ag- glomeration.

关键词： Solid-state sintering Discrete element simula-tion. Agglomeration. Densification

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

疏棉状嗜热丝孢菌脂肪酶LipTL的酶学性质及脱胶应用研究

在线全文

学校读者我要写书评

暂无评论

食品与发酵工业 2025年第1期51卷 41-46页

作者：邵化单明明王琼波徐瑞敏陈曦魏涛郑州轻工业大学食品与生物工程学院河南郑州450001 漯河医学高等专科学校食品营养系河南漯河462002

酶法脱胶技术在油脂精炼行业应用潜力巨大,磷脂酶是酶法脱胶技术中的主要用酶,但因现有磷脂酶资源在底物选择性、温度稳定性方面难以满足工业脱胶工艺的要求,限制了磷脂酶在油脂精炼行业中的大规模应用。研究表明,来自疏棉状嗜热丝孢菌(... 详细信息

酶法脱胶技术在油脂精炼行业应用潜力巨大,磷脂酶是酶法脱胶技术中的主要用酶,但因现有磷脂酶资源在底物选择性、温度稳定性方面难以满足工业脱胶工艺的要求,限制了磷脂酶在油脂精炼行业中的大规模应用。研究表明,来自疏棉状嗜热丝孢菌(Thermomyces lanuginosus)的脂肪酶(LipTL)具有水解磷脂的功能。该研究利用大肠杆菌构建LipTL的基因工程菌,对LipTL进行异源表达,探究LipTL的酶学性质和油脂脱胶效果。序列比对显示,该酶与磷脂酶A1具有高度相似性;SDS-PAGE结果表明,LipTL分子质量约为30 kDa;LipTL的最适温度为55℃、最适pH值为9.0,在55℃条件下处理2 h仍能保持90%以上的相对活力。LipTL在脱胶反应6 h后,将大豆油和花生油的残磷量分别降至5.2、4.9 mg/kg,具有良好的脱胶效果。该研究结果证实该脂肪酶可用于油脂脱胶,不仅为酶法脱胶提供新的酶源,也为该酶的后续改造提供了研究基础。

关键词：疏棉状嗜热丝孢菌脂肪酶酶法脱胶同源建模酶学性质

Conditional Generation of Multiparticle Entanglement via Cavity QED

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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