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STUDY OF PHASES IN U-10wt%Zr ALLOY BY NEUTRON DIFFRACTION

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Acta Metallurgica Sinica(English Letters) 1995年第3期8卷 174-180页

作者： XIE Guoqiang YANG Jijian ZHANG Baisheng LI Wendan(china Institute of atomic {2., {3.) china Inst of atomic {2. Beijing China

U 10wt%Zr alloy has been analysed by neutron diffraction method to determine the constituent phases and their crystal *** collected diffraction data are processed using Rietveld' s profile technique (with program“ Fullprof ”). Four phases,α-U,δ, γand α Zr, in the alloy at room temperature and the corresponding volume fractions as well their structural parameters are obtained from the data analysis, For the δ-phase, a partially ordered unusual hexagonal structure of the modified C3.(AlB2. type is confirmed.

关键词： U-10wt%Zr alloy neutron diffraction δ-phase

Threading dislocation density comparison between GaN grown on the patterned and conventional sapphire substrate by high resolution X-ray diffraction

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Science china(Physics,Mechanics & Astronomy) 2010年第3期53卷 465-468页

作者： ZHANG YuChao1, XING ZhiGang2. MA ZiGuang2. CHEN Yao2. DING GuoJian2. XU PeiQiang2. DONG ChenMing3. CHEN Hong2.& LE XiaoYun1 1 School of Physics and Nuclear energy Engineering, Beihang University, {2. 100190, china 2.Renewable energy Laboratory, Institute of Physics, Chinese Academy of Sciences, {2. 100190, china 3.School of Information and Communication, Tianjin Polytechnic University, Tianjin 3.0160, china 1. School of Physics and Nuclear energy Engineering Beihang University Beijing 100190 China2. Renewable Energy Laboratory Institute of Physics Chinese Academy of Sciences Beijing 100190 China3. School of Information and Communication Tianjin Polytechnic University Tianjin 300160 China

GaN epifilms are grown on the patterned sapphire substrates (PSS) (0001) and the conventional sapphire substrates (CSS) (0001) by metal-organic chemical vapor deposition (MOCVD) using a novel two-step growth. High resolution X-ray diffraction (HR-XRD) is used to investigate the threading dislocation (TD) density of the GaN epifilms. The TD density is calculated from the ω-scans full width at half maximum (FWHM) results of HR-XRD. The edge dislocation destiny of GaN grown on the PSS is 2.7×108 cm-2. which is less than on the CSS. This is confirmed by the results of atomic force microscopy (AFM) measurement. The lower TD destiny indicates that the crystalline quality of the GaN epifilms grown on the PSS is improved compared to GaN epifilms grown on the CSS. The residual strains of GaN grown on the PSS and CSS are compared by Raman Scattering spectra. It is clearly seen that the residual strain in the GaN grown on PSS is lower than on the CSS.

关键词： GaN patterned sapphire substrate threading dislocation XRD

An N/4 fixed-point duality quantum search algorithm

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中国科学：物理学、力学、天文学英文版 2010年第9期53卷 1765-1768页

作者： HAO Liang1,LIU Dan2.& LONG GuiLu1,3.1Key Laboratory for atomic and Molecular NanoSciences and Department of Physics,Tsinghua University,{2. 100084,china 2.chool of Sciences,Dalian Nationalities University,Dalian 116600,china 3.singhua National Laboratory for Information Science and Technology,{2. 100084,china 1. Key Laboratory for atomic and Molecular NanoSciences and Department of Physics Tsinghua University Beijing 100084 China2. School of Sciences Dalian Nationalities University Dalian 116600 China3. Tsinghua National Laboratory for Information Science and Technology Beijing 100084 China

Here a fixed-point duality quantum search algorithm is *** algorithm uses iteratively non-unitary operations and measurements to search an unsorted *** the marked item is found,the algorithm stops *** algorithm uses a constant non-unitary operator,and requires N/4 steps on average(N is the number of data from the database) to locate the marked *** implementation of this algorithm in a usual quantum computer is also demonstrated.

关键词： fixed-point search algorithm duality quantum computing the N4 duality search algorithm

Probing Nuclear Symmetry energy with Giant Dipole Resonances in Finite Nuclei

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原子核物理评论 2009年第S1期26卷 181-184页

作者： CAO Li-gang1,3.MA Zhong-yu2.3.(1 Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 73.000,china 2.china Institute of atomic {3.,beijing 102.13.china 3.Center of Theoretical Nuclear Physics,National Laboratory of Heavy Ion Research Facility in Lanzhou,Lanzhou 73.000,china) Institute of Modern Physics Chinese Academy of SciencesLanzhou 730000China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China china Institute of atomic {2. Beijing 102413China Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Research Facility in LanzhouLanzhou 730000China

The relationship between the centroid energies of the isovector giant dipole resonance of finite nuclei and the symmetry energy has been studied. It is found the excitation energies of the dipole resonance in finite nuclei are correlated linearly with the symmetry energy at and below the saturation density. This linear correlation leads to the symmetry energy at the saturation density at the interval 3..0 MeV ≤ S(ρ0) ≤ 3..0 MeV,and the symmetry energy at ρ = 0.1 fm-3.at the interval 2..2.2..5 MeV. It is proposed that a precise measurement of the dipole mode in nuclei could set up an important constraint on the equation of state for nuclear matter.

关键词： symmetry energy dipole resonance Pygmy resonance

Phase transition in the Zr_(60)Al_(15)Ni_(2.) bulk metallic glass subjected to rolling at room temperature

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Science china(Technological Sciences) 2006年第6期49卷 655-662页

作者： YAN Zhijie1, 2. LI Jinfu1, ZHOU Yaohe1 & WU Yanqing3.1. State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai 2.003., {2. 2. School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 03.02., {2. 3. School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 2.003., {2. State Key Laboratory of Metal Matrix Composites School of Materials Science Engineering Shanghai Jiao Tong University Shanghai 200030 China School of Materials Science Engineering Taiyuan University of Science Technology Taiyuan 030024 China School of Environmental Science Engineering Shanghai Jiao Tong University Shanghai 200030 China

The microstructure evolution of the Zr60Al15Ni2. metallic glass during rolling at room temperature is investigated by X-ray diffraction (XRD), differential scanning calorimetry (DSC); high-resolution transmission electron microscopy (HREM). The results show that the values of full width at half maximum (FWHM) of the XRD patterns; exothermic enthalpy ΔH of DSC plots do not monotonically change with the variation of deformation degrees . As is not large than 2.%, the values of FWHM; ΔH are lower than that of the as-cast state. When reaches 3.%, the values of FWHM; ΔH become larger than that of the as-cast state, while their values begin to decrease again as reaches about 85%. These results indicate that the reversible transitions between ordered; disordered atomic configurations occur during rolling, which is further verified by the HREM images. The reversible phase transition can be explained by the competition between the diffusion controlled reordering; shear-induced disordering during rolling.

关键词： metallic glasses, plastic deformation, phase transformations, shear bands.

Study for ^(2.8)Th reduction in thermal reactor with Th-U fuel cycls

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Nuclear Science and Techniques 1999年第1期10卷 48-50页

作者： XU Xiaoqin (china Institute of atomic {2., {3. 102.1s) china Institute of atomic {2. Beijing 102413 China

By using computer code WIMS/CENDL, the effects of some parameters, core configuration such as fuel element structure, neutron flux and burn-up, are discussed in this paper. It is shown that high neutron flux, small fuel rod diameter, large volume ratio of coolant to fuel, seed-blank heterogeneous core arrangement and 2.0} Pa chemical separation are necessary for reducing 2.8Th production in reactor.

关键词：热反应堆钍-铀 2.8钍减少

The Angular Distribution of Light Composite Particle Projectile in Preequilibrium Reactions

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Chinese journal of nuclear physics 1994年第2期16卷 160-169页

作者： Shen Qingbiao(china Institute of atomic {2.,P.O.Box 2.5,{3. 102.13. china Inst of atomic {2. Beijing China

Formulations of double differential cross sections of light composite particleconsidering (1,m) and (2.m) pickup type reactions simultaneously for semi-classicalmulti-step compound and direct processes are *** calculated results of crosssections,spectra,and double differential cross sections indicate that generally the con-tributions of the (2.m) pickup type reactions are about 15%-2.% when the incident en-ergies are below 50 MeV but can become dominant when the incident energies areabove 50 MeV in some region of the outgoing energies and *** forward tenden-cy of the calculated angular distributions by (2.m) configuration is weaker than those by(1,m) *** the reactions of outgoing composite particle with higher inci-dent energy,the multi-step direct process must be considered.

关键词： Preequilibrium Composite particle Double differential cross section

Calculation of triaxial superdeformation in ^(174)Hf

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Science china(Physics,Mechanics & Astronomy) 2007年第5期50卷 553-557页

作者： YU ShaoYing1,2.4, LI XiaoWei2. SHEN CaiWan1,5 & CHEN YongShou3.4 1 School of Science, Huzhou Teachers College, Huzhou 3.3.00, china 2.College of Mathematics, Physics and Information Engineering, Zhejiang Normal University, Jinhua 3.1000, china 3.china Institute of {3. energy, beijing 102.13. china 4 Institute of Theoretical Physics, Chinese Academy of Sciences, beijing 100080, china 5 Center of Theoretical Nuclear Physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lanzhou 73.000, china 1. School of Science Huzhou Teachers College Huzhou 313000 China 2. College of Mathematics Physics and Information Engineering Zhejiang Normal University Jinhua 321000 China 4. Institute of Theoretical Physics Chinese Academy of Sciences Beijing 100080 China 5. Center of Theoretical Nuclear Physics National Laboratory of Heavy Ion Accelerator of Lanzhou Lanzhou 730000 China 3. china Institute of {2. energy Beijing 102413 China

A two-dimensional Total Routhian Surface (TRS) calculation with the fixed hexa- decapole deformation ε4 = 0.03.was carried out for several configurations of 174Hf. Results indicate that the shell corrections have an important contribution to the formation of triaxial superdeformation in 174Hf and some possible configuration assignments are made to the 4 TSD bands experimentally found in 174Hf.

关键词： Total Routhian Surface (TRS), triaxial superdeformation, configuration

Effects of Y2.1 phase contents on the critical current density J_c and microstructural analysis in YBCO bulk superconductors

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Rare Metals 2002年第4期21卷 282-288页

作者： SHA Jianjun, YU Gang, and YU Jinnanchina Institute of atomic {2., P. O. Box 2.5-51, {3. 102.13. china china Institute of atomic {2. P.O. Box 275-51 北京 102413

YBCO bulk superconductors were prepared by the solid state reaction andtop-seed-melt-textured growth (TSMTG) process. By using the AC susceptibility measurement, thecritical transition temperature T_c of samples is 91.5 K for the highest value, and the transitionwidth ΔT_c is less than 1 K. The highest magnetization critical current densities J_c achieved 10~6A/cm^2.under 5 T at 10 K and 1.3.X10^4 A/cm^2.under 2.T at 70 K (H//c), respectively. The resultscombining the SEM observation indicate that doping of Y2.1 particles is more effective in improvingthe growth quality of melt-textured YBCO superconductor and in reducing the micro-cracks ofspecimens. Doping of Y_2._3.powder forms the rod-shaped Y2.1 particles, but doping of Y2.1 particlesdirectly to matrix materials forms the spherical Y2.1 particles mainly. Combining themicrostructures with J_c measurements shows that the interfaces are most important on flux bundlepinning, in which the gradient of free {2. is larger than that of other place between the Y2.1particles and the Y12.0}matrix materials.

关键词： quasi-single domain melt-textured Y2.1 particles critical current density magnetic flux pinning