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Anomalous magnetotransport in LaMn_(1-x)Te_xO_3

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Science china(physics,Mechanics & Astronomy) 2009年第7期52卷 987-992页

作者： TAN GuoTai1,2, CHEN ZhengHao3.& ZHANG XiaoZhong4,5 1 Key Laboratory of Beam Technology & Materials Modification of the Ministry of Education, Institute of Low energy Nuclear physics, beijing Normal University, beijing 100875, china 2 beijing Radiation Center, beijing 100875, china 3.Laboratory of Optical physics, Institute of physics, chinese academy of sciences, beijing 100080, china 4 Key Laboratory of Advanced Materials of the Ministry of Education, Department of Materials Science and Engineering, Tsinghua University, beijing 100084, china 5 beijing National Center for Electron Microscopy, Tsinghua University, beijing 100084, china Key Laboratory of Beam Technology & Materials Modification of the Ministry of Education Institute of Low Energy Nuclear Physics Beijing Normal University Beijing China beijing Radiation Center Beijing China Laboratory of Optical physics Institute of Physics Chinese Academy of Sciences Beijing China Key Laboratory of Advanced Materials of the Ministry of Education Department of Materials Science and Engineering Tsinghua University Beijing China beijing National Center for Electron Microscopy Tsinghua University Beijing China

The LaMn1-xTexO3.δ (x=0.1, 0.2, 0.3. were synthesized using solid-state reaction method for the first time. X-ray photoemission spectrum (XPS) shows that in the samples the Te ions have a valence of Te4+, and Mn3. ions are partly converted into Mn2+ and Mn4+ due to the excess oxygen and Te doping. The magnetotransport associated with Mn2+, Mn3. and Mn4+ was investigated. The experimental results show that the samples are insulator at 0 T when the amount of Mn3. is much larger or less than the sum of Mn2+ and Mn4+; by contrast, the samples display metal to insulator transition with increasing temperature when the amount of Mn3. is close to the sum of Mn2+ and Mn4+. These anomalous magnetotransport behaviors were analyzed in the frame of the double-exchange (DE) mechanism.

关键词： colossal magnetoresistance La-Te-Mn-O magnetotransport

β-delayed proton decays near the proton drip line

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Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 257-267页

作者： XU Shuwei 1 , LI Zhankui 1 , XIE Yuanxiang 1 , HUANG Wenxue 1 , SHU Nengchuan 2 , CHEN Yongshou 2 , XU Furong 3., WANG Kun 4 , PAN Qiangyan 1 , WANG Xudong 1 , YU Yong 1 & XING Yebing 1 1. Institute of Modern physics, chinese academy of sciences, Lanzhou 73.000, china 2. Nuclear physics Department, china Institute of Atomic energy, beijing 102413. china 3. Department of Technical physics, Peking University, beijing 100871, china 4. Shanghai Institute for Nuclear Research, Shanghai 201800, china Institute of Modern physics Chinese Academy of Sciences Lanzhou China Nuclear physics Department China Institute of Atomic Energy Beijing China Department of Technical physics Peking University Beijing China Shanghai Institute for Nuclear Research Shanghai China

We briefly reviewed the experimental study on a-delayed proton decays near the proton drip line published by our group during the period of 1996―2004, namely the first observation of the a-delayed proton decays of 9 new nuclides in the rare-earth region and the new measurements of a-delayed proton decays of 5 nuclides in the mass ～90 region near the N = Z line with the aid of the “p-?” coincidence in combination with a He-jet tape transport system. In the meantime some important experimental technique details were supplemented. The experimental results, including the half -lives, spins, parities, deformations and production reaction cross sections for the 14 nuclei were summarized and compared with the current nuclear-model predictions, and then the following points were represented. (1) The experimental half-lives for 85Mo and 92Rh as well as the predicted “waiting point” nuclei 89Ru and 93.d are 5―10 times longer than the theoretical predictions given by M?ller et al. using a macroscopic-microscopic model. It considerably influences the predictions of the abundances of the nuclides produced in the rp-process. (2) The current-model predictions are not consistent with the experimental assignments of the spins and parities for the proton drip-line nuclei 142Ho and 128Pm. However, the nuclear potential energy surface (PES) calculated by using a Woods- Saxon-Strutinsky method reproduced the experimental results. (3. The Alice code overestimated the production reaction cross sections of the studied 9 rare-earth nuclei by one order of magnitude or two, while HIVAP code overestimated them by one order of magnitude approximately.

关键词： proton drip line, β-delayed proton decay, He-jet tape transport system, "p-γ" coincidence, spin, parity, deformation, production reaction cross section.

Microorganisms desulfurization of coal

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Journal of Environmental sciences 1993年第1期5卷 83-89页

作者： Zhong Huifang and Li YaqinInstitute of Microbiology, chinese academy of sciences, beijing 100080, china

A culture of Thiobacillus ferrooxidans strain T-4, isolated from Song Zao Coal Mining, china, is able to use pyrite from coal as a source of energy. The bacterial culture solution with 108 -109 cells/ml, pH 1.55 - 1.70 was employed in the nine coal samples with -200 mesh have been studied at initial pH 1.7.3.℃ , 20-3.% coal pulp density. The bacterial removal sulfur from coal in samples 3. 4, 6 and 7 were reduced to 1.05 - 1.3.% and 86.11% of pyritic sulfur can be removed in 4-24 hours.

关键词： Thiobacillus ferrooxidans microorganisms desulfurization.

Fabrication of atomically smooth SrRuO_3.thin films by laser molecular beam epitaxy

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Science china(physics,Mechanics & Astronomy) 2008年第7期51卷 745-749页

作者： LIU GuoZhen1, HE Meng1, JIN KuiJuan1, YANG GuoZhen1, Lü HuiBin1, ZHAO Kun2, ZHENG ShiJian3.& MA XiuLiang3.1 beijing National Laboratory for Condensed Matter physics, Institute of physics, {3., beijing 100080, china 2 Department of Mathematics and physics, china University of Petroleum, beijing 102249, china 3.Shenyang National Laboratory for Materials Science, Institute of Metal Research, {3., Shenyang 110016, china beijing National Laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China Department of Mathematics and physics China University of Petroleum Beijing China Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang China

high-quality SrRuO3.(SRO) thin films and SrTiO3.SRO bilayer were grown epitaxially on SrTiO3.(STO)(001) substrates by laser molecular beam epitaxy. The results of in situ observation of reflection high-energy electron diffraction and ex situ X-ray diffraction θ -2θ scan indicate that the SRO thin films have good crystallinity. The measurements of atomic force microscopy and scan tunneling microscopy reveal that the surface of the SRO thin film is atomically smooth. The resistivity of the SRO thin film is 3.0 μΩ·cm at room temperature. Furthermore, the transmission electron microscopy study shows that the interfaces of STO/SRO and SRO/STO are very clear and no interfacial reaction layer was observed. The experimental results show that the SRO thin film is an excellent electrode material for devices based on perovskite oxide materials.

关键词： SrRuO3 thin film laser molecular beam epitaxy surface morphology

Entropy of Dilatonic Black Hole due to Arbitrary Spin Fields

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chinese Journal of Astronomy and Astrophysics 2001年第4期1卷 357-364页

作者： You-Gen Shen and Chang-Jun Gao (Shanghai Astronomical Observatory, chinese academy of sciences, Shanghai 20003. National Astronomical Observatories, chinese academy of sciences, beijing 100012 Institute of Theoretical {3., chinese academy of Scienc Shanghai Astronomical Observatory Chinese Academy of Sciences Shanghai 200030 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 Institute of Theoretical physics Chinese Academy of Sciences Beijing 100080

Using the membrane model based on the brick-wall model, we calculate the free energy and entropy of dilatonic black hole due to arbitrary spin fields. The result shows that the entropy of scalar field and the entropy ... 详细信息

关键词： black hole physics - entropy - spin

Calibrating the HXMT collimators using diffuse illumination

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 36-39页

作者： HAN Dong1,JIN YongJie1,WU Mei2 & ZHANG Zhi1 1 Department of Engineering physics & Center for Astrophysics,Tsinghua University,beijing 100084,{3. 2 Key Laboratory of Particle Astrophysics,Institute of high energy physics,chinese academy of sciences,beijing 100049,{3. Department of Engineering physics & Center for Astrophysics Tsinghua University Beijing China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China

We propose a new method to calibrate the HXMT collimators by measuring the optical point spread function(PSF) of the hard X-ray modulation telescope(HXMT).The light transmission of the collimator at different viewing angles with a camera and a diffuse backlight placed behind the collimator is *** method is much easier to accomplish than measuring the PSF with a parallel optical *** experimental results are very consistent with the *** PSF of the collimator of the high energy X-ray telescope on HXMT is found to be in good agreement with the design,with accuracy better than 1 arcmin.

关键词： HXMT collimator point spread function Monte Carlo simulation diffuse illumination

An SGS Model and Its Application

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Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 87-90页

作者： Zhengtong XIE Jiachun LI (Institute of Mechanics, chinese academy of sciences, beijing 100080, china) Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

Based on the turbulent energy and structure function model, a subgridstress model named transitional structure function (TSF) is proposed, which exhibitsmore satisfactory performance than the previous one when applied in turbulent flow withinand above forest *** time and horizontal averaged statistics such as mean verticalprofiles of wind velocity, Reynolds stress, turbulent kinetic energy etc., and instantaneousfields as well are in general agreement with earlier observations, at least in a qualitativesense.

关键词： Large-Eddy simulation SGS model turbulent flow canopy

Exploration of combined adjustment laws about IGV,stator and rotational speed in off-design conditions in an axial compressor

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中国科学：技术科学英文版 2010年第4期53卷 969-975页

作者： HU YanMing1,2 & NIE ChaoQun1 1 Key Laboratory of Advanced energy and Power Technology,Institute of Engineeting Thermophysics,chinese {3. of Science,beijing 100190,china 2 Graduate School of chinese academy of sciences,beijing 100190,china Key Laboratory of Advanced energy and Power Technology Institute of Engineeting Thermophysics Chinese Academy of Science Beijing China Graduate School of chinese academy of sciences Beijing China

Experimental investigations are performed in a three-stage low-speed axial compressor with variable inlet guide vanes(IGV) and adjustable *** characteristics of the compressor,especially the efficiency and stall margin,are analyzed in design and off-design operation conditions by adjusting stagger angles of IGV and stators as well as changing the rotational *** experimental results show that the off-design performance of the multistage axial compressor is improved by restaggering of IGV and stators related to rotational *** the background of engineering applications,digital signal processing(DSP) technique is used to realize online adjustment of stagger angles according to the corresponding relations between incidence angles of rotor and rotational speed.

关键词： axial compressor IGV surge DSP techniques off-design

Enhancement of magnetism of Zn0.95Co0.05O films by p-type Cu+ doping

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Progress in Natural Science:Materials International 2011年第1期21卷 31-35页

作者： Wei-chang HAO~(1,5),Jian-jun LI~2,Huai-zhe XU~3.Jia-ou WANG~4,Tian-min WANG~1 1.Center of Materials physics and Chemistry,Beihang University,beijing 100083.china 2.Department of Materials Science and Engineering, Anhui University of Science and Technology,Huainan 23.001,china 3.Department of physics,Beihang University,beijing 100083.china 4.beijing Synchrotron Radiation Facility,Institute of high energy physics, chinese academy of sciences,100049,china 5.Key Laboratory of Micro-nano Measurement,Manipulation and physics, Ministry of Education,Beihang University,beijing 100191,china Center of Materials physics and Chemistry Beihang University Beijing 100083 China Key Laboratory of Micro-nano Measurement Manipulation and Physics Ministry of Education Beihang University Beijing 100191 China Department of Materials Science and Engineering Anhui University of Science and Technology Huainan 232001 China Department of physics Beihang University Beijing 100083 China beijing Synchrotron Radiation Facility Institute of High Energy Physics Chinese Academy of Sciences 100049 China

Zn0.95Co0.05O and Zn0.91Co0.05Cu0.04O thin films were fabricated on Si（111） substrate by the reactive magnetron sputtering method at different O-Ar *** characterizations by X-ray diffractometry（XRD）,X-ray photo-electronic spectrum（XPS）, and electron paramagnetic resonance（EPR） indicate that the doped Cu ions substitute the Zn2+ions in the ZnO *** doped Cu ions are in Cu+and Cu2+mixture valence *** ferromagnetism of the Zn0.91Co0.05Cu0.04O film increases gradually the increasing Cu+ions *** results indicate that the increase of ferromagnetism is not owing to the magnetic contribution of Cu+ions themselves,but owing to the enhancement of magnetic interaction between Co ions,which suggests that p-type doping of Cu+ions plays an important role in mediating the ferromagnetic coupling between Co ions.

关键词： Zn0.95Co0.05O films Zn0.91Co0.05Cu0.04O films magnetic semiconductors magnetic coupling co-doping