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Experimental measurement of the electrical conductivity of single crystal olivine at high temperature and high pressure under different oxygen fugacities

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Progress in Natural Science:Materials International 2006年第4期16卷 387-393页

作者： DAI Lidong, LI Heping, LIU Congqiang, CUI Tongdi, SHAN Shuangming, YANG Changjun, LIU Qingyou and DENG Heming Laboratory of the Earth’s Interior Materials and Fluid Geochemistry, institute of Geochemistry, chinese academy of sciences, Guiyang 550002, china Graduate School of the chinese academy of sciences, beijing 100039, china institute of Geochemistry, chinese academy of sciences, Guiyang 550002, china Guizhou University, Guiyang 550004, china Laboratory of the Earth's Interior Materials and Fluid Geochemistry Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China Graduate School of the chinese academy of sciences Beijing 100039 China institute of Geochemistry chinese academy of sciences Guiyang 550002 China Guizhou University Guiyang 550004 China

At 1.0-4.0 GPa and 1123.1473.K and under oxygen fugacity-controlled conditions (Ni + NiO, Fe + Fe3.4, Fe + FeO and Mo+ M0O2 buffers), a YJ-3.00t Model six-anvil solid high-pressure apparatus and a Sarltron-1260 Impedance/Gain-Phase analyzer were employed to conduct an in situ measurement of the electrical conductivity of single crystal olivine. Experimental results showed that: (1) within the range of experimentally selected frequencies (103.106 Hz), the electrical conductivity of the sample is of great dependence on the frequency; (2) with the rise of temperature ( T), the electrical conductivity (σ) will increase, and the Arrenhius linear relationship is established between lgσ and 1/T; (3. under the control of oxygen buffer Fe+ Fe3.4, with the rise of pressure, the electrical conductivity tends to decrease whereas the activation enthalpy and independent-of-temperature preexponential factor tend to increase, with the activation energy and activation volume of the sample estimated at (1. 25 ± 0.08) eV and (0.105 ±0.025) cm3.mol, respectively; (4) under given pressure and temperature conditions, the electrical conductivity tends to increase whereas the activation energy tends to decrease with increasing oxygen fugacity; and ( 5) the mechanism of electrical conduction of small polarons can provide insight into the behavior of electrical conduction of olivine under high pressure and high temperature.

关键词： olivine high temperature and high pressure electrical conductivity oxygen fugacity small polaron.

Isospin-dependent relativistic microscopic optical potential in the Dirac Brueckner-Hartree-Fock method

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Science china(physics,Mechanics & Astronomy) 2004年第2期47卷 189-198页

作者： RONG Jian1 & MA Zhongyu1,2,3.1. china institute of Atomic energy, {3. 102413. china 2. Center of Nuclear Theoretical physics, National Laboratory of Heavy Ion Accelerator of Lanzhou, Lan-zhou 73.000, china 3. institute of Theoretical physics, chinese academy of sciences, {3. 100080, china Correspondence should be addressed to Rong Jian (email: jrong@***) 1. china institute of Atomic energy 102413 Beijing China 2. Center of Nuclear Theoretical physics National Laboratory of Heavy Ion Accelerator of Lanzhou 730000 Lanzhou China 3. institute of Theoretical physics Chinese Academy of Sciences 100080 Beijing China

The relativistic microscopic optical potential in the asymmetric nuclear matter is studied in the framework of the Dirac Brueckner-Hartree-Fock method. A new decomposition of the Dirac structure of the nuclear self-energy in nuclear matter is adopted. The self-energy of a nucleon with E > 0 in nuclear matter is calculated with the G matrix in the Hartree-Fock approach. The optical potential of a nucleon in the nuclear medium is identified with the nucleon self-energy. The energy and asymmetric parameter dependence of the relativistic optical potentials for proton and neutron are discussed. The resulting Schroedinger equivalent potentials have reasonable behaviors of the energy dependence. The asymmetric parameter dependence of relativistic optical potentials and Schroedinger potentials are emphasized.

关键词： Dirac Brueckner Hartree-Fock, relativistic microscopic optical potential, asymmetric nuclear matter, isospin-dependence.

Track Fading and Its Applications in Archaeology, Tectonics and Geothermal Chronology in china

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Journal of Earth Science 2013年第4期24卷 645-651页

作者：郭士伦袁万明陈宝流黄慰文刘顺生 Department of Nuclear physics China Institute of Atomic Energy School of Earth sciences and Resourses China University of Geosciences Department of Radioisotopes China Institute of Atomic Energy institute of Vertebrate Paleontology and Paleoanthropology Chinese Academy of Sciences Guangzhou institute of Geochemistry Chinese Academy of Sciences

Track fading is a basic phenomenon in track science and has been the source of informa- tion in geosciences. This article summarizes the knowledge of track fading and gives some examples of successful applications of track fading in archaeology, tectonics and geothermal chronology in china. The applications of track fading are classified into 5 modes：（1） mode of complete fading （annealing）; （2） mode of partial fading; （3. use of the dependence of track fading on time and temperature; （4） use of the differences of track fading between coexisting minerals; and （5） use of fading-reduced track length. Track fading mechanisms hints that scientists in geothermal chronology should adopt microprobes for quantitative elemental analysis to determine the detailed chemical compositions of each mineral grain or at least of the grains from each position of geological structures in order that one becomes well aware of the relation between the track fading behavior and chemical compositions of the mineral used.

关键词： track fading archaeology tectonics geothermal chronology.

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, beijing 100190,{3. 2 Renewable energy Laboratory, institute of physics, chinese academy of sciences, beijing 100190,{3. 3.School of Information and Communication, Tianjin Polytechnic University, Tianjin 3.0160,{3. 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

X（3.72） and Bound State Problem of D0*0（0 D*0）

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原子核物理评论 2009年第S1期 16-21页

作者： LIU Yan-rui1,LIU Xiang2,3.DENG Wei-zhen2 (1 institute of high energy physics,chinese academy of {3.,beijing 100049,china 2 Department of physics,Peking University,beijing 100871,china 3.Centro de Física Terica,Departamento de Física,Universidade de Coimbra,P-3.04-516,Coimbra,Portugal)

We have performed a dynamical calculation of the bound state problem of D0D*0 by considering the pion and sigma meson exchange potential. Our preliminary analysis disfavors the molecular interpretation of X(3.72) if we use the experimental D*Dπ coupling constant g=0.59 and a reasonable cutoff around 1 GeV,which is the typical hadronic scale. In contrast,there probably exists a loosely bound S-wave BB* molecular state. Such a molecular state would be rather stable since its dominant decay mode is the radiative decay through B*→Bγ.

关键词： X(3.72) bound state molecule

Distributions of arsenic and essential elements in pinna of arsenic hyperaccumulator Pteris vittata L.

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Science china(Life sciences) 2005年第1期48卷 18-24页

作者： CHEN Tongbin, HUANG Zechun, HUANG Yuying & LEI Mei Laboratory of Environmental Remediation, institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, {3. 100101, china Laboratory of Synchrotron Radiation, institute of high energy physics, chinese academy of sciences, beijing 100039, china Laboratory of Environmental Remediation Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing100101 China Laboratory of Synchrotron Radiation Institute of High Energy Physics Chinese Academy of Sciences Beijing100039 China

The distributions of arsenic and 6 essential elements in the pinna of As hyperaccumulator, Pteris vittata L., were studied using synchrotron radiation X-ray fluorescence (SRXRF). Significant correlation between the distribution and mobility of the elements revealed that SRXRF study on the elemental distribution was feasible to inspect the transportations of elements in plants. The distribution of As in the pinna showed that As had great abilities to be transported in xylem vessels and from xylem to mesophyll. The distribution of K, one of the most mobile elements in plants, was similar to that of As, whereas the distributions of Fe and Ca with less mobility in plants were almost opposite to that of As in the pinna.

关键词： hyperaccumulator, chinese brake (Pteris vittata L.), arsenic, element, distribution, SRXRF.

Current distribution and stability of LTS/HTS hybrid superconducting conductors

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Science china(Technological sciences) 2010年第7期53卷 2000-2007页

作者： GUAN XiaoJin1,2, WANG YinShun1 & ZHOU WeiWei3.1 Key Laboratory of HV and EMC beijing, North china Electric Power University, beijing 102206, china 2 Department of physics, Baoding University, Baoding 071000, china 3.institute of Electrical Engineering, chinese academy of sciences, beijing 100190, china 1. Key Laboratory of HV and EMC beijing North China Electric Power University Beijing 102206 China2. Department of Physics Baoding University Baoding 071000 China3. Institute of Electrical Engineering Chinese Academy of Sciences Beijing 100190 China

Current distribution and stability of a hybrid LTS/HTS superconductor, consisting of multifilamentary NbTi/Cu and Bi2223.Ag tapes, were numerically analyzed according to power-law models. The results showed that most of current passed through the LTS and the current increased in the HTS with temperature rise when the transport current was below the critical current of the hybrid conductor. The quench propagation velocity of the hybrid conductor was smaller but its minimum quench energy was larger than those of LTS conductors, indicating that the stability of the hybrid superconducting conductor was effectively improved and a high engineering current density was simultaneously achieved. Finally, a hybrid sample, made by soldering Bi2223.Ag tape onto NbTi/Cu conductor, was prepared and tested successfully at helium temperature. The experimental results qualitatively agreed with the simulated ones.

关键词： distribution hybrid conductor minimum quench energy quench propagation velocity n value stability

Observation of signature inversion in the πh_(9/2)(×)νi_(13.2) oblate band

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Science china(physics,Mechanics & Astronomy) 2005年第4期48卷 442-449页

作者： XIE Chengying1,2, ZHOU Xiaohong1,2, ZHANG Yuhu1, GUO Yingxiang1, LEI Xiangguo1, ZHENG Yong1, LIU Minliang1, SONG Litao1, WANG Hualei1, YU Haiping1, GUO Wentao 1, LUO Peng1, WU Zhijun1, ZHU Lihua3.& WU Xiaoguang3.⒈ institute of Modern physics, chinese academy of sciences, Lanzhou 73.000,{3. ⒉ Graduate School of the chinese academy of sciences, beijing 100049,{3. ⒊ institute of Atomic energy Research, beijing 102413.{3. institute of Modern physics Chinese Academy of Sciences Lanzhou China Graduate School of the chinese academy of sciences Beijing China institute of Atomic energy Research Beijing China

high-spin states in 190Tl have been studied via the 160Gd(3.Cl, 5nγ) reaction. The level scheme, consisting of the π h9 /2 νi13.2 oblate band and a cascade with character of single particle excitations, has been established. Spin values have been firmly assigned to the oblate band in 190Tl, resulting in low-spin signature inversion in the π h9 /2 νi13.2 oblate band for the first time. Based on the similarity of the level structure in doubly odd Tl nuclei, spin values for the oblate bands in 192―200Tl should be re-assigned, and a consistent low-spin signature inversion has occurred in these oblate deformed nuclei. The low-spin signature inversion phenomena can be interpreted qualitatively by using the 2-quasiparticle plus rotor model including p-n residual interactions.

关键词： deformed odd-odd 190Tl, oblate rotational bands, signature inversion, 2-qp+rotor model.

Systematic study of survival probability of excited superheavy nuclei

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Science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 109-113页

作者： XIA ChengJun1, SUN BaoXi1, ZHAO EnGuang2,3.& ZHOU ShanGui2,3.1College of Applied sciences, beijing University of Technology, beijing 100124,{3. 2institute of Theoretical physics, chinese academy of sciences, beijing 100190,{3. 3.enter of Theoretical Nuclear physics, National Laboratory of Heavy Ion Accelerator, Lanzhou 73.000,{3. chinese Acad Sci Inst Theoret Phys Beijing 100190 Peoples R China beijing Univ Technol Coll Appl Sci Beijing 100124 Peoples R China Ctr Theoret Nucl Phys Natl Lab Heavy Ion Accelerator Lanzhou 730000 Peoples R China

The stability of excited superheavy nuclei (SHN) with 100 Z 13. against neutron emission and fission is investigated by using a statistical model. In particular, a systematic study of the survival probability against fission in the 1n-channel of these SHN is made. The present calculations consistently take the neutron separation energies and shell correction energies from the calculated results of the finite range droplet model which predicts an island of stability of SHN around Z = 115 and N = 179. It turns out that this island of stability persists for excited SHN in the sense that the calculated survival probabilities in the 1n-channel of excited SHN at the optimal excitation energy are maximized around Z = 115 and N = 179. This indicates that the survival probability in the 1n-channel is mainly determined by the nuclear shell effects.

关键词： survival probability superheavy elements island of stability neutron emission fission