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Temperature in High Temperature SHPB Experiments

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Transactions of Tianjin University 2008年第B10期14卷 536-539页

作者：邓志方谢若泽颜怡霞李思忠黄西成 Institute of Structural mechanics China Academy of Engineering Physics

As an experimental technique, it’s desired that the temperature in specimen is uniform in high temperature split Hopkinson pressure bar (SHPB) experiments. However, the temperature in specimen decreases and the temperature of bars increases when specimen starts to contact with bars, which induces the nonuniform temperature distribution in specimen, and may result in inac-curacy of experimental results. In this paper, the temperature distributions of specimen and bars in high temperature SHPB experiments were investigated while the specimen was heated alone. Firstly, the temperature history of specimen was measured at different initial temperatures by ex-periments, then simulation was carried out. Simulation results were consistent with experimental results by adjusting the thermal contact coefficient between specimen and bars. By this way, the thermal contact coefficient and simulation results were validated, and the proper cold contact times of specimen and bars in high temperature SHPB experiments were discussed. Finally, the results were compared with those in references.

关键词： high temperature SHPB experiment heat transfer thermal contact coefficient cold contact time

New numerical algorithms in SUPER CE/SE and their applications in explosion mechanics

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Science china(physics,{2. & Astronomy) 2010年第9期53卷 237-243页

作者： WANG Gang1,2.WANG JingTao1 & LIU KaiXin1,3 1 LTCS and College of engineering,Peking University,Beijing 100871,china 2.LHD,Institute of {2.,Chinese academy of Sciences,Beijing 100190,china 3 Center for Applied physics and Technology,Peking University,Beijing 100871,china 1. LTCS and College of engineering Peking University Beijing 100871 China2. LHD Institute of Mechanics Chinese Academy of Sciences Beijing 100190 China3. Center for Applied Physics and Technology Peking University Beijing 100871 China

The new numerical algorithms in SUPER/CESE and their applications in explosion mechanics are studied. The researched al-gorithms and models include an improved CE/SE (space-time Conservation Element and Solution Element) method,a local hybrid particle level set method,three chemical reaction models and a two-fluid model. Problems of shock wave reflection over wedges,explosive welding,cellular structure of gaseous detonations and two-phase detonations in the gas-droplet system are simulated by using the above-mentioned algorithms and models. The numerical results reveal that the adopted algorithms have many advantages such as high numerical accuracy,wide application field and good compatibility. The numerical algo-rithms presented in this paper may be applied to the numerical research of explosion mechanics.

关键词： new algorithm SUPER CE/SE numerical simulation explosion mechanics

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Effect of rare earths on phase transformation in as-cast ZA2. alloy dur-ing compressive creep

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Rare Metals 2003年第4期22卷 259-264页

作者： WEIXiaowei SHENBaoluo DepamnentofAppliedphysics UniversityofElectronicScienceandTechnologyofChinaChengdu610045China DeparlanentofMetalScience SichuanUniversityChengdu610065China

The effect of the mixed rare earths of Ce on the phase transformation in ascast ZA 2. alloy during compressive was investigated under 37 MPa and at 160 deg C by X-raydiffraction technique and SEM. The results showed that the as cast microstructure of ZA 2.-RE alloyconsisted of a dendritic Al-rich alpha' surrounded by Zn-rich beta' phase, interdendritic epsilonphase and Zn-rich eta phase together with a complex Z phase which was a complex constitute compound,(RE,Cu)Al_5Zn_(16), dispersed in crystal interfaces or branch crystal interfaces and stable duringcompressive creep test at 160 deg C. The phase transformations of ZA 2.-RE alloy, decomposition ofbeta' phase arid four transformation, were delayed by the addition of rare earths, also the lamellarstructure and the spheroidized structure in ZA 2.-RE alloy were finer than in ZA 2. alloy duringcompressive creep test at 160 deg C at the same creep time, and the compressive creep resistance ofZA 2.-RE alloy was higher than that of ZA 2. alloy.

关键词： microstructure change compressive creep rare earths ZA 2. alloy

Fast Z-Pinch,A New Approach for Promising Fusion Energy

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工程科学（英文版） 2007年第4期5卷 36-44页

作者： Peng Xianjue,Hua Xinsheng(china academy of {2. physics,mianyang Sichuan 62.900,china)

The basic concept of fast Z-pinch,and late progress in fast Z-pinch plasma research as HEDP and ICF research,especially as an approach for high yield low-cost fusion energy research,are summarized in this *** possible... 详细信息

关键词： fast Z-Pinch implosion HEDP ICF fusion energy

Study on the thermal stability and electrical properties of the high-k dielectrics (ZrO_2. _x(SiO_2._(1-x)

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Science china(Technological Sciences) 2009年第8期52卷 2222-2226页

作者： Lü ShiCheng1,2. YIN Jiang1,2. XIA YiDong2.3, GAO LiGang2.3 & LIU ZhiGuo2.3 1 Department of physics, Nanjing University, Nanjing 2.0093, china 2.National Laboratory of Solid Sate Micro{2.s, Nanjing University, Nanjing 2.0093, china 3 Department of Materials Science and engineering, Nanjing University, Nanjing 2.0093, china 1. Department of physics Nanjing University Nanjing 210093 China 2. National Laboratory of Solid Sate Microstructures Nanjing University Nanjing 210093 China 3. Department of Materials Science and engineering Nanjing University Nanjing 210093 China

(ZrO2.x(SiO2.1-x (Zr-Si-O) films with different compositions were deposited on p-Si(100) substrates by using pulsed laser deposition technique. X-ray photoelectron spectra (XPS) showed that these films remained amorphous after annealing at 800℃ with RTA process in N2.for 60 s. The XPS spectra indi- cated that Zr-Si-O films with x=0.5 suffered no obvious phase separation after annealing at 800℃, and no interface layer was formed between Zr-Si-O film and Si substrate. While Zr-Si-O films with x >0.5 suffered phase separation to precipitate ZrO2.after annealing under the same condition, and SiO2.was formed at the interface. To get a good interface between Zr-Si-O films and Si substrate, Zr-Si-O films with bi-layer structure (ZrO2.0.7(SiO2.0.3/(ZrO2.0.5(SiO2.0.5/Si was deposited. The electrical properties showed that the bi-layer Zr-Si-O film is of the lowest equivalent oxide thickness and good interface with Si substrate.

关键词： high-k dielectric film pulsed laser deposition pseudo ternary alloy

Mechanically Driven Alloying and Structural Evolution of Nanocrystalline Fe_(60)Cu_(40) Powder

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Journal of Materials Science & Technology 1997年第4期13卷 354-358页

作者： Yuanda DONG and Xueming MA(School of Materials Science and engineering, Shanghai University, Shanghai 2.0072. china)Yuanzheng YANG(Dept. of Mechanical engineering(2., South china University of Technology, Guangzhou 510641, china)Fangxin LIU and Genmiao WA School of Materials Science and engineering Shanghai University Shanghai 200072 China Dept. of Mechanical engineering(2. South China University of Technology Guangzhou 510641 China Lab. of structure Analysis University of Science and Technology of China Hefei 230026 China

Highly supersaturated nanocrystalline fcc Fe60Cu40 alloy has been prepared by mechanical alloying of elemental powders. The phase transformation is monitored by X-ray diffraction (XRD),Mossbauer spectroscopy and extended X-ray absorption fine structure (EXAFS). The powder obtained after milling is of single fcc structure with grain size of nanometer order. The Mossbauer spectra of the milled powder can be fitted by two subspectra whose hyperfine magnetic fields are 16 MA/m and 2. MA/m while that of pure Fe disappeared. EXAFS results show that the radial structure function (RSF) of Fe K-edge changed drastically and finally became similar to that of reference Cu K-edge, while that of Cu K-edge nearly keeps unchanged in the process of milling. These imply that bcc Fe really transforms to fcc structure and alloying between Fe and Cu occurs truly on an atomic scale. EXAFS results indicate that iron atoms tend to segregate at the boundaries and Cu atoms are rich in the fcc lattice. Annealing experiments show that the Fe atoms at the interfaces are easy to cluster to α-Fe at a lower temperature, whereas the iron atoms in the lattice will form γ-Fe first at temperature above 350℃, and then transform to bcc Fe

关键词： Mechanically Driven Alloying and Structural Evolution of Nanocrystalline Fe MA Cu Powder Figure

Peculiar dynamical properties of plutonium hydrides

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Progress in Natural Science:Materials International 2006年第3期16卷 248-254页

作者： MENG Daqiao, ZHU Zhenghe, LUO Deli and JIANG Gang (Institute of Atomic and Molecular physics, Sichuan University, Chengdu 610065, china National Key Laboratory of Surface physics and Chemistry, mianyang 62.907, china) [a]Institute of Atomic and Molecular physics Sichuan University Chengdu China [b]National Key Laboratory of Surface physics and Chemistry Mianyang China

In the present work, the structure and spectra of PuH and PuH2.are defined by B3LYP/SDD method, from which the analytic potential energy function of PuH2.is derived. The analysis of quasi-classical molecular reaction dynamics is performed to study the state-state process of Pu(7Fg) + H2.X1∑g+). It is found that the reaction Pu(7Fg)+H2.X1∑g+)→PuH2.X7B1) has no threshold. The simultaneous hydrogenation process of plutonium with the main product of PuH2.is theoretically proved for the first time.

关键词： hydrogenation reaction of plutonium molecular dynamics density functional theory.

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混沌伪随机序列复杂度分析的符号动力学方法

物理学报 2004年第9期53卷 2877-2881页

作者：肖方红阎桂荣韩宇航西安交通大学建筑工程与力学学院西安710049 中国工程物理研究院绵阳610003

通过将混沌伪随机序列看成一个符号序列 ,提出了用符号动力学的方法来分析混沌伪随机序列的复杂度 .以Logistic映射和耦合映射格子系统产生的混沌伪随机序列为例 ,说明了该方法的应用 ,并将计算结果与近似熵ApEn法的计算结果作了比较 .... 详细信息

通过将混沌伪随机序列看成一个符号序列 ,提出了用符号动力学的方法来分析混沌伪随机序列的复杂度 .以Logistic映射和耦合映射格子系统产生的混沌伪随机序列为例 ,说明了该方法的应用 ,并将计算结果与近似熵ApEn法的计算结果作了比较 .结果表明 ,该方法可以有效地判断出不同的混沌伪随机序列的复杂程度。

关键词：通信控制系统混沌伪随机序列符号动力学 Logistic映射

Numerical Simulation on Temperature and Stress Fields in Beryllium During Cutting Process

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Journal of Shanghai Jiaotong university(Science) 2011年第3期16卷 329-332页

作者：董平张鹏程李瑞文 Key Laboratory for Surface physics and Chemistry china academy of engineering physics

The temperature and stress fields in beryllium during high speed cutting process were studied by employing a thermo-mechanically coupled finite element method(FEM).The results show that the temperatures in beryllium increase only a little during the cutting *** of the residual stresses for along and normal to the cutting direction are tensile stresses in the surface of beryllium after *** cutting force and thrust force are about 2.0 and-2.0kN/m at the steady stage,*** main effects of coolant on the cutting process are to decrease the friction coefficient and heat between the tool and the workpiece,so to reduce the temperature,but almost no effects are made for *** study is helpful to enhance the understanding for stress formation and optimize the process parameters of beryllium.

关键词： beryllium temperature field stress field cutting finite element method(FEM)