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Lattice distortion and magnetic property of high entropy alloys at low temperatures

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Journal of Materials Science & Technology 2022年第9期104卷 236-243页

作者： Yuan-Yuan Tan zhong-Jun Chen Ming-Yao Su Gan Ding Min-Qiang Jiang Zhou-Can Xie Yu Gong Tao wu zhong-hua wu Hai-Ying Wang Lan-Hong Dai State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China Institute of High Energy Physics Chinese Academy of Sciences&GraduateUniversity of Chinese Academy of SciencesBeijing 100049China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China Zhejiang Institute of Mechanical&Electrical Engineering Hangzhou 310053China State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

Deformation mechanisms and magnetic properties of medium and high entropy alloys(MEA/HEAs)closely relate to lattice distortion and are strongly temperature-dependent,in particular,at low temperature ***,little attention has been paid to the evolution of lattice distortion with temperature decreasing and its effects on deformation behavior and magnetic state *** this work,we carry out in situ synchrotron radiation based X-ray powder diffraction(SR-XRD)experiments from 293 to 123 K aiming for determining lattice distortion evolutions of Cr Co Ni MEA,Cr Fe Co Ni and Cr Mn Fe Co Ni *** measurements at corresponding low temperatures and cryogenic ranges are further *** in situ SR-XRD results demonstrate a general reduction of lattice distortion magnitude with temperature decreasing,which shows a similar tendency with that of reported stacking fault energy(SFE)*** is thus suggested that lattice distortion reduction possibly makes a critical contribution to deformation mechanism *** magnetic measurement results show a clear ferromagnetic transition of Cr Fe Co Ni HEA when temperature is below 173 ***,no obvious magnetic state transition is observed for Cr Co Ni MEA and Cr Mn Fe Co Ni *** present findings on lattice distortion evolutions will pave the way for designing targeted HEAs with particular properties.

关键词： High entropy alloy Lattice distortion Magnetic property Low temperature In situ SR-XRD

Silicon PIN photodiode applied to acquire high-frequency sampling XAFS spectra

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Nuclear Science and Techniques 2022年第7期33卷 15-24页

作者： Yun-Peng Liu Lei Yao Bing-Jie Wang Jia-Jun zhong Hao Wang Li-Xiong Qian zhong-Jun Chen Guang Mo Xue-Qing Xing Wei-Fan Sheng zhong-hua wu Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing100049China

Experimental techniques based on SR facilities have emerged with the development of synchrotron radiation(SR)***,detector miniaturization has become significant for the development of SR experimental *** this study,the miniaturization of a detector was achieved by coupling a commercial silicon PIN photodiode(SPPD)into a beamstop,aiming for it not only to acquire X-ray absorption fine structure(XAFS)spectra,but also to protect the subsequent two-dimensional detector from high-brilliance X-ray radiation damage in certain combination *** mini SPPD detector coupled to a beamstop was used as the rear detector in both the conventional sampling scheme and novel high-frequency(HF)sampling scheme to collect the transmission XAFS *** ion chambers were also used to collect the transmission XAFS spectra,which were used as the *** XAFS spectra were quantitatively analyzed and compared;the results demonstrated that the XAFS spectra collected by this SPPD in both the conventional sampling scheme and HF sampling scheme are *** study provides a new detector-selection scheme for the acquisition of the quick-scanning XAFS(QXAFS)and HF sampling XAFS *** SPPD detector presented in this study can partially meet the requirements of detector miniaturization.

关键词： Silicon PIN photodiodes Beamstop XAFS High frequency sampling

ON THE EXPLICIT COMPACT SCHEMES II: EXTENSION OF THE STCE/CE METHOD ON NONSTAGGERED GRIDS ON THE EXPLICIT COMPACT SCHEMES II: EXTENSION OF THE STCE/CE METHOD ON NONSTAGGERED GRIDS

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Journal of Computational Mathematics 2000年第5期18卷 467-480页

作者： hua-zhong Tang , hua-mu wu (State Key Laboratory of Scientific and Engineering Computing, Institute of Computational Mathematics, Chinese Academy of Sciences, Beijing 100080, China) 中科院计算数学所科学与工程计算国家重点实验室北京 100080

This paper continues to construct and study the explicit compact (EC) schemes for conservation laws. First, we axtend STCE/SE method on non-staggered grid, which has same well resolution as one in [1], and just requires half of the computational works. Then, we consider some constructions of the EC schemes for two-dimensional conservation laws, and some 1D and 2D numerical experiments are also given.

关键词： Conservation laws Compact scheme Shock-Capturing method Euler equations.

Small Angle X-ray Scattering Study of PS Conformation in Tetrahydrofuran Solvent with Gas Anti-solvent

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Chinese Chemical Letters 2000年第12期11卷 1093-1094页

作者： Dan LI Zhi Min LIU Guan Ying YANG Qing HUO Bu Xing HAN Yi LIU zhong hua wu Bao zhong DONG Center for molecular sciences Institute of chemistryChinese Academy of ScienceBeijing 100080 Chemical Engineering College Beijing Union UniversityBeijing 100023 Institute of High Energy Physics Chinese Academy of ScienceBeijing 100039

Small angle X-ray scattering (SAXS) was used to study the effect of dissolved CO2 on the conformation of polystyrene (PS) in PS/tetrahydrofuran(THF) solution at 308.15 K and at pressures up to 3 MPa. The cloud pressure and the expansion curve of the solution were also determined. The dependence of the conformation on pressure was discussed.

关键词： small angle X-ray scattering polystyrene THF CO2 conformation

Research of Trap and Electron Density Distributions in the Interface of Polyimide/Al2O3 Nanocomposite Films Based on IDC and SAXS

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Chinese Physics Letters 2017年第4期34卷 116-119页

作者： Yuan-Yuan Liu Jing-hua Yin Xiao-Xu Liu Duo Sun Ming-hua Chen zhong-hua wu Bo Su Key Laboratory of Engineering Dielectric and Its Applications (Ministry of Education) Harbin University of Science and Technology Harbin 150080 Harbin Cambridge College Harbin 150069 Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049

The distributions of traps and electron density in the interfaces between polyimide （PI） matrix and Al2O3 nanoparticles are researched using the isothermal decay current and the small-angle x-ray scattering （SAXS） tests. According to the electron density distribution for quasi two-phase mixture doped by spherical nanoparticles, the electron densities in the interfaces of PI/Al2O3 nanocomposite films are evaluated. The trap level density and carrier mobility in the interface are studied. The experimental results show that the distribution and the change rate of the electron density in the three layers of interface are different, indicating different trap distributions in the interface layers. There is a maximum trap level density in the second layer, where the maximum trap level density for the nanocomposite film doped by 25 wt% is 1.054 × 10^22 eV·m^-3 at 1.324eV, resulting in the carrier mobility reducing. In addition, both the thickness and the electron density of the nanocomposite film interface increase with the addition of the doped Al2O3 contents. Through the study on the trap level distribution in the interface, it is possible to further analyze the insulation mechanism and to improve the performance of nano-dielectric materials.

关键词： AI PI Research of Trap and Electron Density Distributions in the Interface of Polyimide/Al2O3 Nanocomposite Films Based on IDC and SAXS IDC Al

Application of the Robust Approach and Finite Element Analysis in Door System Static Design

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International Journal of Plant Engineering and Management 2010年第2期15卷 111-116页

作者： LI Chao zhong Zhi-hua ZHU wu State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Changsha410082 P. R. China

The robust design approach based on Taguchi＇s design of experiment （DOE） coupled with the traditional finite element analysis （FEA） is applied to the static design of a sedan door. This method aims at shortening the design period, reducing the calculation cost and improving the competitive competence. First, the pe^ormance re- quirements, the control factors and the corresponding levels are determined to design a DOE table. Second, based on the schemes from the DOE table, sensitive control factors are distinguished from the results of the FEA method. Finally, the optimum design is chosen after comparisons and analyses of these performance response graphs. Performance results of the optimum design indicate that the application of the robust approach and FEA can greatly im- prove the quality of the door system, satisfy the requirements of products, underline the design purpose and shorten the design period.

关键词： robust approach Tagnchi's design door system DOE FEA

Comparison and significance of specific and non-specific cellular immunity in patients with chronic hepatitis B caused by infection with genotypes B or C of hepatitis B virus

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Science China(Life Sciences) 2009年第8期52卷 719-723页

作者： GU XiBing,YANG XiaoJuan,WANG Dong,hua zhong,wu HangYuan,CHEN HaoKun,XU YueQin & LU zhonghua wuxi Hospital for Infectious Diseases,wuxi 214005,China 1. wuxi Hospital for Infectious Diseases Wuxi 214005 China

The present study was designed to investigate possible relationships between the genotypes of hepatitis B virus(HBV) and the HBV-specific cytotoxic T lymphocyte(CTL) *** genotypes,HBV specific CTL HBV DNA and other markers of HBV infection were determined in 138 patients with chronic hepatitis *** results showed that the patients infected with genotype C(n=62) had a significantly lower HBV-specific CTL response than those who were infected with HBV genotype B(P<0.01).HBV DNA titer was higher in patients infected with HBV genotype C than in those infected with HBV geno-type B(P<0.01).Both alanine aminotransferase(ALT) and total bilirubin(TBIL) were higher in HBV genotype C infected patients than in those infected with genotype B(P<0.01 and <0.05,respectively).These results suggest that compared with CHB patients infected with HBV genotype B,the higher HBV DNA level and more severe liver damages in the patients infected with genotype C of HBV may be associated with genotype C of the virus.

关键词： chronic hepatitis B hepatitis B virus(HBV) genotypes specific cytotoxic T lymphocyte

A COMBINED MEASUREMENT SYSTEM FOR UV/V IN SITU SPECTROELECTROCHEMICAL STUDY

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Chinese Chemical Letters 1991年第4期2卷 309-312页

作者： Jin LUO zhong hua LIN Zhao wu TIAN (State Key Laboratory for Physical Chemistry of the Solid Surface,Xiamen University,Xiamen,361005)

A microcomputer-based UV/V in situ spectroelectrochemical measurement system has been *** paper presents a description of the experimental details regarding the methods and equipment.

关键词： UV A COMBINED MEASUREMENT SYSTEM FOR UV/V IN SITU SPECTROELECTROCHEMICAL STUDY

THE RELAXING SCHEMES FOR HAMILION-JACOBI EQUATIONS

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Journal of Computational Mathematics 2001年第3期19卷 231-240页

作者： hua-zhong Tang hua-mu wu (State Key Laboratory of Scientific and Engineering Computing, Institute of Computational Mathematics and Scientific/Engineering Computing, Academy of Mathematics and Systems Sciences, Chinese Academy of Sciences, Beijing 100080,

Hamilton-Jacobi equation appears frequently in applications, e.g., in differential games and control theory, and is closely related to hyperbolic conservation laws[3, 4, 12]. This is helpful in the design of difference approximations for Hamilton-Jacobi equation and hyperbolic conservation laws. In this paper we present the relaxing system for HamiltonJacobi equations in arbitrary space dimensions, and high resolution relaxing schemes for Hamilton-Jacobi equation, based on using the local relaxation approximation. The schemes are numerically tested on a variety of 1D and 2D problems, including a problem related to optimal control problem. High-order accuracy in smooth regions, good resolution of discontinuities, and convergence to viscosity solutions are observed.

关键词： The relaxing scheme The relaxing systems Hamilton-Jacobi equation Hyperbolic conservation laws.