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Role of gallium wetting layer in high-quality ZnO growth on sapphire (0001) substrates

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Science china(physics,Mechanics & Astronomy) 2004年第5期47卷 612-620页

作者： ZENG Zhaoquan1,3. WANG Yong2, DU Xiaolong1, MEI Zengxia1, KONG Xianghe3. JIA Jinfeng1, XUE Qikun1 & zhang Ze2, 4 1. State Key Laboratory for Surface physics, institute of physics, Chinese Academy of Sciences, beijing 100080, china 2. Laboratory of Electron Microscopy, institute of physics, Chinese Academy of Sciences, beijing 100080, china 3. College of physics and Engineering, Qufu Normal University, Qufu 273.65, china 4. beijing University of Technology, beijing 100022, china State Key Laboratory for Surface physics Institute of Physics Chinese Academy of Sciences Beijing China College of physics and Engineering Qufu Normal University Qufu China Laboratory of Electron Microscopy Institute of Physics Chinese Academy of Sciences Beijing China beijing University of Technology Beijing China

A Ga wetting layer was used to modify the surface structure of sapphire (0001) substrate to prepare high-quality ZnO film by radio frequency plasma-assisted molecule beam epitaxy. We found that this Ga layer plays a crucial role in eliminating 3. rotation domains, controlling polarity and decreasing defect density in ZnO epilayers, as demonstrated by in situ reflection high energy electron diffraction, ex situ high resolution X-ray diffraction and high resolution cross-sectional transmission electron microscopy. Zn-polar film of ZnO was determined by convergent beam electron diffraction. A Ga bilayer model is proposed to understand the effects of the Ga wetting layer on high-quality ZnO growth.

关键词： Ga wetting layer, sapphire, polarity, defect density, zinc oxide, rf-MBE, RHEED, HRXRD, TEM, CBED.

Exploration of microscopic physical processes of Z-pinch by a modified electrostatic direct implicit particle-in-cell algorithm

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Chinese physics B 2024年第9期33卷 433-442页

作者： Kaixuan Li Cheng Ning Ye Dong chuang Xue institute of Applied physics and Computational Mathematics Beijing 100088China

For investigating efficiently the stagnation kinetic-process of Z-pinch,we develop a novel modified electrostatic implicit particle-in-cell algorithm in radial one-dimension for Z-pinch simulation in which a small-angle cumulative binary collision algorithm is *** our algorithm,the electric field in z-direction is solved by a parallel electrode-plate model,the azimuthal magnetic field is obtained by Ampere’s law,and the term for charged particle gyromotion is approximated by the cross product of the averaged velocity and magnetic *** simulation results of 2 MA deuterium plasma shell Zpinch,the mass-center implosion trajectory agrees generally with that obtained by one-dimensional MHD simulation,and the plasma current also closely aligns with the external *** phase space diagrams and radial-velocity probability distributions of ions and electrons are *** main kinetic characteristic of electron motion is thermal equilibrium and oscillation,which should be oscillated around the ions,while that of ion motion is implosion *** the region of stagnation radius,the radial-velocity probability distribution of ions transits from the non-equilibrium to equilibrium state with the current increasing,while of electrons is basically the equilibrium *** the initial ion density and current peak are not high enough,the ions may not reach their thermal equilibrium state through collisions even in its stagnation phase.

关键词： Z-pinch particle-in-cell ion heating charged particle collisions

Si-doped Li_(6)PS_(5)I with enhanced conductivity enables superior performance for all-solid-state lithium batteries

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Chinese Chemical Letters 2024年第10期35卷 479-484页

作者： Liang Ming Dan Liu Qiyue Luo Chaochao Wei Chen Liu Ziling Jiang Zhongkai Wu Lin Li Long zhang Shijie Cheng chuang Yu State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Scienceand TechnologyWuhan430074China School of Chemistry and Chemical Engineering Huazhong University of Science and TechnologyWuhan 430074China State Grid Hubei Electric Power Research institute Wuhan 430077China College of physics and energy Fujian Normal UniversityFuzhou 350117China

Lithium argyrodites Li_(6)PS_(5)X(X=Cl,Br,I)show great potential as solid electrolytes for solid-state lithium batteries due to their high Li-ion conductivities and excellent electrode ***,the relatively low conductivity of Li_(6)PS_(5)I(10^(-6)m S/cm)compared to the other two compositions limits its ***,Si-doped Li_(6.5)P_(0.5)Si_(0.5)S_(5)I electrolyte is designed and synthesized with superior high conductivity of 3.6 mS/*** characterization proves the increase due to the anion disorder and volume expansion caused by ***,the poor interfacial stability between layered oxide cathode Li Ni_(0.6)Co_(0.2)Mn_(0.2)O_(2)and Li_(6.5)P_(0.5)Si_(0.5)S_(5)I inhibits its battery *** introducing Li_(3.InCl6electrolyte in the configuration,the corresponding battery delivers high initial discharge capacity of 150.2m Ah/g and superior cyclability during 250 cycles at 0.5 *** work offers design strategy to obtain Li_(6)PS_(5)I-based electrolytes for high performance solid-state batteries.

关键词： Argyrodite electrolyte Li_(6.5)P_(0.5)Si_(0.5)S_(5)I All-solid-state lithiumbatteries Stability Electrochemical performance

Observation constraints of the hard X-ray modulation telescope HXMT

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 31-35页

作者： LU Yu1,2,zhang WenZhao3.QU JinLu1,SONG LiMing1,GAO Jian3.zhang HongMei4 & OU Ge4 1 Key Laboratory of Particle Astrophysics,{3. of high energy physics,Chinese Academy of Sciences,beijing 1.0049,china 2 Graduate University of Chinese Academy of Sciences,beijing 1.0049,china 3.Department of Astronomy,beijing Normal University,beijing 100875,china 4 Computing Center,{3. of high energy physics,Chinese Academy of Sciences,beijing 1.0049,china Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of Sciences Beijing China Department of Astronomy Beijing Normal University Beijing China Computing Center Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The hard X-ray modulation telescope HXMT is a low orbit X-ray space telescope whose main science goals are to accomplish a hard X-ray all sky survey and to study timing and spectral characteristics of X-ray *** has three kinds of science instruments:the high energy X-ray detector(HE),the medium energy X-ray detector(ME) and the low energy X-ray detector(LE).The observation schedule of HXMT is a key to achieving the science goal of HXMT,and the analysis of the observation constraints is one of the first tasks in making the observation *** paper analyzes how the observation constraints influence the sky visibility and the visible time distribution of X-ray sources and discusses the schedule strategy with regard to the observation constraints.

关键词： HXMT observation constraints sky visibility

Properties of the 3.2^-[521] band in the odd-N rare-earth nuclei

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Science china(physics,Mechanics & Astronomy) 2011年第S1期54卷 37-43页

作者： CHEN Liang1,2, ZHOU XiaoHong1,2, zhang YuHu1, zhang ShuangQuan3.& ZHU LiHua4 1institute of Modern {3., Chinese Academy of Sciences, Lanzhou 73.000, china 2Graduate University of Chinese Academy of Sciences, beijing 1.0049, china 3.tate Key Laboratory of Nuclear {3. and Technology, School of {3., Peking University, beijing 100871, china 4china institute of Atomic {13., beijing 102413. china institute of Modern physics Chinese Academy of Sciences Lanzhou China Graduate University of Chinese Academy of Sciences Beijing China State Key Laboratory of Nuclear physics and Technology School of Physics Peking University Beijing China china institute of Atomic energy Beijing China

high-spin states in 161Er have been studied experimentally via the 150Nd(16O, 5n) reaction at a beam energy of 86 MeV. Three rotational bands built on the 5/2+[642], 3.2-[521], and 11/2-[505] configurations have been extended up to high-spin states, and particularly, the α = -1/2 branch of the ground state 3.2-[521] band has been revised significantly. It is found that signature inversion occurs in the 3.2-[521] band after the band crossing in 161Er. The systematics of the signature inversion associated with the 3.2-[521] configuration in the rare-earth region is discussed. The band properties are analyzed within the framework of a triaxial particle-rotor model, and a triaxial deformation is proposed to the 3.2-[521] band.

关键词： high-spin states signature inversion triaxial particle-rotor model

The flux modulation of INTEGRAL

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 110-113页

作者： CHEN YuPeng,zhang Shu,WANG JianMin,LI TiPei & QU JinLu Laboratory for Particle Astrophysics,institute of {3. energy physics,beijing 1.0049,china Laboratory for Particle Astrophysics Institute of High Energy Physics Beijing China

We have analyzed International Gamma-Ray Astrophysics Laboratory(INTEGRAL) data corresponding to observations of the high mass X-ray binary(HMXB) V03.2+53.during its huge outburst which occurred in 2004-2005,and found that there is a quasi periodic signal with ultra low frequency of roughly 4-5×10-5 Hz in the *** feature is revealed through a series of consistent analyses of imagings and fittings of the energy spectrum for each science window(SCW),and shows up in the corresponding light *** analysis of the power spectrum also provides a hint of a power peak located around 4×10-5 Hz,after subtracting off the linear trend of the light curve,and shows the consistency with the previous analyses.A similar feature shows up in our analysis of the light curve of Crab in hexagonal dithering ***,an instrumental effect on the flux modulation might exist in the INTEGRAL data product of different levels:imaging,spectral fitting and light curve analysis,at least for the observational mode of hexagonal *** an effect is,to our knowledge,not yet available in the current literature.

关键词： X-ray source individual V03.2+53

Formation of super-concentrated hydrochloric acid in the third phase in tertiary amine N23.-PtCl_6^(2-)-HCl system and its influences on the Pt microemulsion extraction

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Science china Chemistry 2009年第11期52卷 1825-1834页

作者： HUANG Kun1,CHEN Jing1,zhang ChengFeng1,2,LI ZhiHong3.PAN QingHua1,SUN Yan1,LIU ShaoXuan1,LIU XueXin2,LI WeiHong1,YANG ZhanLan1,WENG ShiFu1,HU TianDou3.XU YiZhuang1 & WU JinGuang1 1 College of Chemistry and Molecular Engineering,Peking University,beijing 100871,china 2 {3. of Chemistry,Chinese Academy of Sciences,beijing 100190,china 3.{3. of high energy physics,Chinese Academy of Sciences,beijing 1.0049,china College of Chemistry and Molecular Engineering Peking University Beijing China institute of Chemistry Chinese Academy of Sciences Beijing China institute of high energy {3. Chinese Academy of Sciences Beijing China

In this paper,we have investigated the formation of the third-phase in tertiary amine(N23.)-PtCl62--HCl system and the microscopic phase structural evolution of platinum-loaded organic phases before and after the occurrence of the *** third-phase is characterized by various spectroscopic techniques,and the small angle X-ray scattering(SAXS) experiments demonstrate the appearance of nano-aggregates,i.e.,water-in-oil reversed micelles,in the third *** experimental results indicate that(1) formation of the third phase is related to the aggregation behaviors of nano-reversed micelles in which a super-concentrated hydrochloric acid formed with the H+ to H2O molar ratio being much higher than that of the conventional 3. wt% saturated hydrochloric acid.(2) The occurrence of the super-concentrated HCl results in a great amount of H+ and Cl-ions enriched and confined within the nano-water pools of W/O reversed micelles in third ***,the coordination behaviors of platinum complex ions in that super-concentrated hydrochloric acid are very different from their corresponding behaviors in bulk aqueous *** is possible that H+ ions participate in the formation of such complexes as HmPtCl6z+ in the super-concentrated hydrochloric acid.(3. The relative contents of various HmPtCl6z+ complexes are different corresponding to the H+ ion concentrations in confined nanowater *** association ability of the acidified tertiary amine N23. molecules(R3.H+) with various HmPtCl6z+ complexes plays an important role in affecting the platinum extraction behaviors.

关键词： solvent extraction third phase super-concentrated hydrochloric acid tertiary amine platinum

GRB 090423.Marking the death of a massive star at z=8.2

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Science china(physics,Mechanics & Astronomy) 2010年第S1期53卷 64-68页

作者： LIN Lin1,LIANG EnWei2 & zhang ShuangNan3.1 Department of physics and Center for Astrophysics,Tsinghua University,{3. 100084,china 2 Department of physics,Guangxi University,Nanning 53.004,china 3.Key Laboratory of Particle Astrophysics,institute of high energy physics,Chinese Academy of Sciences,beijing 1.0049,china Department of physics and Center for Astrophysics Tsinghua University Beijing China Department of physics Guangxi University Nanning China Key Laboratory of Particle Astrophysics Institute of High Energy Physics Chinese Academy of Sciences Beijing China

GRB 090423.is the new high-z record holder of Gamma-ray bursts(GRBs) with *** present a detailed analysis of both the spectral and temporal features of GRB 090423.observed with Swift/BAT and Fermi/*** find that the T90 observed with BAT in the 15-150 keV band is 13.2 s,corresponding to-1.4 s at z=*** once again gives rise to the issue of whether the progenitors of high-z GRBs are massive stars or mergers since the discovery of GRB 080913.at z=*** comparison with the T90 distribution in the burst frame of the current redshift-known GRB sample,we find that it is marginally grouped into the long group(Type II GRBs).The spectrum observed with both BAT and GBM is well fitted by a power-law with exponential cutoff,which yields an Ep=(50.4±7.0) *** event satisfies the Amati-relation well for Type II GRBs within their 3. uncertainty *** results indicate that this event would be produced by the death of a massive *** on the Amati-relation,we derive its distance modulus,which follows the Hubble diagram of the concordance cosmology model at a redshift of-8.2.

关键词： gamma-ray bursts high energy phenomenon cosmology

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 {3., beijing Normal University, beijing 100875, china 2 beijing Radiation Center, beijing 100875, china 3.Laboratory of Optical {3., institute of {3., 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