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The numerical method for three-dimensional impact with friction of multi-rigid-body system

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Science china({1.,Mechanics & Astronomy) 2006年第1期49卷 102-118页

作者： ZHAO Zhen1.2. LIU Caishan2.& chen Bin2.1. Beijing Institute of Graphic Communication, Beijing 1.2.00,{1. 2. department of Mechanics & Engineering Science, Peking university, Beijing 1.0871.{1. Beijing Institute of Graphic Communication Beijing China department of Mechanics & Engineering Science Peking University Beijing China

The differential equations for planar impacts reduce to an algebraic form, and can be easily solved. For three dimensional impacts with friction, there is no closed-form solution, and numerical integration is required due to the swerve behavior of tangential impulse during collisions. The dynamic governing equations in the impact process are built up in impulse space based on the Lagrangian equation in this paper. The coefficient of restitution defined by Poisson is used as the condition of impact termination. A valid nu- merical method for solving three-dimensional frictional impact of multi-rigid body system is established. The singular cases of tangential movement in sticking point are especially noticed and analyzed. Several examples are present to reveal the different kinds of tan- gential movement modes varied with the normal impulse during collision.

关键词： multi-rigid body, impact, friction.

Atomic force microscopy studies of SrTiO_(3)(001.substrates treated by chemical etching and annealing in oxygen

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Science china({1.,Mechanics & Astronomy) 2005年第4期48卷 459-468页

作者： WANG Xu1. FEI Yiyan1. LU Huibin1. JIN Kui-juan1. zhu Xiangdong1.3, {1. zhenghao1. ZHOU Yueliang1.& YANG Guozhen1.1. Beijing National Laboratory for Condensed Matter {12.,Institute of {12.,Chinese Academy of Sciences,Beijing 1.0080,china 2. department of {12.,university of California, Davis,California,USA Beijing National Laboratory for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China department of {1. University of California Davis USA

The SrTiO3 (001. substrates treated by chemical etching in NH4F-buffered HF solution and annealing in oxygen ambient have been studied by an atomic force microscopy (AFM). The SrTiO3 substrates with TiO2.termineted and atomically smooth surfaces and single unit cell steps have been obtained. The surface morphologies of SrTiO3 substrates strongly depend on the treated conditions and the quality of the substrates.

关键词： SrTiO3, AFM, surface morphology, surface defects.

X-ray spectra induced by slow highly charged Ar^(q+) ions in collision with Nb surface

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Science china({1.,Mechanics & Astronomy) 2008年第10期51卷 1463-1469页

作者： YANG ZhiHu1, CUI Ying2. chen XiMeng2. SONG ZhangYong1, SHAO JianXiong2. RUAN FangFang1, ZHANG HongQiang2. DU Juan2. LIU YuWen2. GAO ZhiMing2. ZHANG XiaoAn3, zhu KeXin1, YU DeYang1 & CAI XiaoHong1 1 Institute of Modern {2., Chinese Academy of Sciences, Lanzhou 730000, china 2.department of Modern {2., Lanzhou university, Lanzhou 730000, china 3 department of {2., Xianyang normal College, Xianyang 712.00, china Institute of Modern physics Chinese Academy of Sciences Lanzhou China department of Modern {1. Lanzhou University Lanzhou China department of {1. Xianyang Normal College Xianyang China

The X-ray spectra of Nb surface induced by Arq+ (q =1.,1.) ions with the energy range from 1. to 2. keV/q were studied by the optical spectrum technology. The experimental results indicate that the multi-electron excitation occurred as a highly charged Ar1.+ ion was neutralized below the metal surface. The K shell electron of Ar1.+ was excited and then de-excited cascadly to emit K X-ray. The intensity of the X-ray emitted from K shell of the hollow Ar atom decreased with the increase of projectile kinetic energy. The intensity of the X-ray emitted from L shell of the target atom Nb increased with the increase of projectile kinetic energy. The X-ray yield of Ar1.+ is three magnitude orders larger than that of Ar1.+.

关键词： highly charged ion hollow atom multi-electron X-ray

X-ray spectra induced by ^(1.9)Xe^(q+) impacting the metal surface

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Science china({1.,Mechanics & Astronomy) 2008年第1期51卷 82-89页

作者： ZHANG XiaoAn 1.2.,XIAO GuoQing 1.,YANG ZhiHu 1.,chen XiMeng 3 ,ZHAO YongTao 1., LI FuLi 4 ,WANG Li 1.2.,CUI Ying 3 ,ZHANG HongQiang 3 &ZHAN WenLong 1.1.nstitute of Modern {1.,Chinese Academy of Sciences,Lanzhou 730000,china 2.10} of {1.,Xianyang {12. university,Xianyang 71.000,china 3department of Modern {1.,Lanzhou university,Lanzhou 730000,china 4department of Applied {1.,Xi’an Jiaotong university,Xi’an 71.049,china Institute of Modern physics Chinese Academy of Sciences Lanzhou China department of {1. Xianyang Normal University Xianyang China department of Modern {1. Lanzhou University Lanzhou China department of Applied {1. Xi’an Jiaotong University China

Using the slow highly charged ions 1.9 Xe q+ (q=2.,2.,2.;initial kinetic T0≤4.65 keV/a.u.)to impact Au surface,the Au atomic Mαcharacteristic X-ray spectrum is *** result shows that as long as the charge state of projectile is high enough,the heavy atomic characteristic X-ray can be effectively excited even though the incident beam is very weak(nA magnitude),and the X-ray yield per ion is in the order of 1.-8and increases with the kinetic energy and potential energy of *** measuring the Au Mα-X-ray spectra,Au atomic N-level lifetime is estimated at about 1.33×1.-1.s based on Heisenberg uncertainty relation.

关键词： slow highly charged ions characteristic X-ray level lifetime

Analytical Potential Energy Function,Spectroscopic Constants and Vibrational Levels for A^1._u^+ State of Dimer ~7Li_2

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Communications in Theoretical physics 2007年第12期48卷 1081-1087页

作者： SHI De-Heng~1.MA Heng~1.SUN Jin-Feng~(1.2.and zhu Zun-Lue~1.1.College of {1. & Information Engineering,Henan normal university,Xinxiang 453007,china~2.department of {1. & Electron Science,Luoyang normal university,Luoyang 471.2.,china College of physics & Information Engineering Henan Normal University Xinxiang 453007 China department of {1. & Electron Science Luoyang Normal University Luoyang 471022 China

The symmetry-adapted-duster configuration-interaction method is used to investigate the spectroscopicproperties of ~7Li_2.A^1._u^+) over the internuclear distance ranging from 2.4ao to *** complete potential energycurves are calculated at numbers of basis *** the ab initio calculated points are fitted to the analytic MurrellSorbie function and then employed to compute the spectroscopic *** comparison,the spectroscopic constantsreproduced by the potential attained at D95(3df,3pd) are found to be very close to the experiments,a^d the values (T_e,D_e,R_e,ω_e,ω_eχ_e,α_e and B_e) are of 1.732.93 eV,1.1.1.36 eV,0.31. 2. nm,2.1.95 cm^(-1.,1.62. cm^(-1.,0.005 35 cm^(-1.,and0.490 cm^(-1.,*** the potential obtained at D95(3df,3pd),the totally 75 vibrational states are found whenJ=*** vibrational levels,the classical turning points and the inertial rotation constants of the first 68 vibrationalstates are calculated for the first time and compared with the available *** agreement is *** centrifugal distortion constants of the first 32.vibrational states are also reported for the first *** reasonabledissociation limit for ~7Li_2.A^1._u^+) is deduced using the calculated results at present.

关键词： analytic potential energy function harmonic frequency dissociation energy vibrational level classical turning point

Approaches to improving critical current density of YBCO superconducting thick films deposited by electrophoresis

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Science china({1.,Mechanics & Astronomy) 2004年第2期47卷 165-172页

作者： zhu Yabin1.2. ZHOU Yueliang2. LIU Zhen2. WANG Shufang2. {1. zhenghao2. L?Huibin2. YANG Guozhen2. XIAO Ling3, REN Hongtao3, JIAO Yulei3 & zheng Minghui3 1. department of physics, College of Science, Beijing Jiaotong university, Beijing 1.0044, china 2. Laboratory of Optical physics, Institute of physics and Center for Condensed Matter physics, Chinese Academy of Sciences, Beijing 1.0080, china 3. General Research Institute for Nonferrous Metals, Beijing 1.0088, china Correspondence should be addressed to zhu Yabin (email: ybzhu@***) department of {1. College of Science Beijing Jiaotong University Beijing China Laboratory of Optical physics Institute of physics and Center for Condensed Matter physics Chinese Academy of Sciences Beijing China General Research Institute for Nonferrous Metals Beijing China

Fabrication of YBCO superconducting thick films by electrophoresis has been widely reported. However, the value of critical current density (J c) is far from what the practical application requires. The superconducting thick films are obtained using top-seeded melt growth method with different proportional Y2.aCuO5 (Y2.0}) addition. High-pressure oxygen has been used in the annealing process to improve the uniformity of the oxygen content in the superconducting thick films. When 40mol% Y2.0} powder is added to the YBa2.u3O7–5 (Y1.3) powder,J c for the superconducting thick film by approaches described above reaches 7.008×1.3 A/cm2.(77 K, 0 T), which is greater than the value ever reported.

关键词： YBCO thick films, electrophoretic deposition, melt-textured.

Speciation of the elements and compositions on the surfaces of dust storm particles:The evidence for the coupling of iron with sulfur in aerosol during the long-range transport

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Chinese Science Bulletin 2005年第8期50卷 738-744页

作者： ZHANG Xingying1.2. zhuANG Guoshun1.2.3, {1. Jianmin2.& XUE Huaxin2.1. Center for Atmospheric Environment Study, department of Chemistry, Beijing normal university, Beijing 1.0875, china 2. Center for Atmospheric Chemistry Study, department of Environ- mental Science and Engineering, Fudan university, Shanghai 2.0433, china 3. LAPC/NZC, Institute of Atmospheric physics, NZC/LAPC, Chinese Academy of Sciences, Beijing 1.002., china Center for Atmospheric Environment Study Department of Chemistry Beijing Normal University Beijing 100875 China Center for Atmospheric Chemistry Study Department of Environmental Science and Engineering Fudan University Shanghai 200433 China LAPC/NZC Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The speciation of the elements on the surface of the particles collected during dust storm and non-dust storm in Beijing and Inner Mongolia was studied by XPS. The ma- jor species of iron on the surface were oxides, sulfate, silicate, FeOOH and minor part sorbed on SiO2.Al2.3. Sulfate is the dominant species of sulfur on the surface. SiO2.and Al2.3 are the main components of Si and Al on the surface respectively. One of the most important findings was that the Fe(II) (FeS and FeSO4) produced could account for up to 44.3% and 45.6% of the total Fe on the surface in the aerosol sample collected at that night and next day of the “peak” time of the dust storm occurring on March 2., 2.02. while Fe2.SO4)3, one of the Fe(III) species on the surface decreased from 67.1. to 49.5% and 48.0% respectively. Both S and Fe en- riched on the surface of aerosol particles. Fe(II) accounted for 1.3%?5.3% of total Fe in bulk aerosol samples during dust storm. These results provided strong evidence to sup- port the hypothesis of the coupling between iron and sulfur in aerosols during the long-range transport, which would have important impact on the global biogeochemical cycle.

关键词：物种形成原理 XPS 大气悬浮物 Fe-S结合粒子集合

Estimating surface evapotranspiration using combined MODIS and CBERS-02.data

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Science china(Technological Sciences) 2005年第S2期48卷 145-160页

作者： XIN Xiaozhou1,2. LIU Qinhuo1, TANG Yong1,3, TIAN Guoliang1, GU Xingfa1, LI Xiaowen1,2. zheng Hongsheng4 & chen Jiayi4 1. State Key Laboratory of Remote Sensing Science, Institute of Remote Sensing Applications, Chinese Academy of Sciences, Beijing 100101,{2. 2. Research Center for Remote Sensing and GIS, department of Geography, Beijing normal university, Beijing 100875,{2. 3. Graduate university of Chinese Academy of Sciences, Beijing 100039,{2. 4. department of Atmospheric physics, Peking university, Beijing 100871,{2. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University Beijing 100875 China Graduate university Chinese Academy of Sciences Beijing 100039 China department of Atmospheric {1. Peking University Beijing 100871 China

Spatial scale error is one of the most serious problems in the estimates of land surface heat fluxes of sensible and latent from satellite-borne data such as MODIS 1.m resolution reflectance and emissive data. One of the feasible and economic ways to decrease the spatial scale error is to use high resolution land use class data together with the MODIS data. CBERS-02.data were used to produce land use class of Baiyangdian area, Hebei Province, china in the autumn of 2.04. The area ratio of each class in MODIS pixel was calculated, and used to derive the heat fluxes of the mixed pixel. The results showed that the estimated heat fluxes of soil, sensible and latent have been changed remarkably after using the high resolution land class data. It could be concluded from the comparison between simulated and ground-measured fluxes as well as the theoretical analysis that high resolution land class data are useful to diminishing the scale error of heat fluxes estimated from low resolution satellite data.

关键词： surface evapotranspiration spatial scale error MODIS CBERS land class.

X-ray spectra induced in highly charged 40Ar^q+ interacting with Au surface

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Science china({1.,Mechanics & Astronomy) 2006年第2期49卷 203-212页

作者： ZHANG Xiao’an1.2. XIAO Guoqing1. YANG Zhihu1. chen Ximeng3, ZHAO Yongtao1. LI Fuli4, ZHANG Yinping1. CUI Ying3, ZHANG Hongqiang3, XU Xu3, SHAO Jianxiong3 & ZHAN Wenlong1.. Institute of Modern {1., Chinese Academy of Sciences, Lanzhou 730000, china 2. department of {1., Xianyang normal {12., Xianyang 71.000, china 3. department of Modern {1., Lanzhou {12., Lanzhou 730000, china 4. department of Applied {1., Xi’an Jiaotong {12., Xi’an 71.049, china Institute of Modern physics Chinese Academy of Sciences Lanzhou China department of {1. Xianyang Normal University Xianyang China department of Modern {1. Lanzhou University Lanzhou China department of Applied {1. Xi’an Jiaotong University Xi’an China

By use of optical spectrum technology, the spectra of X-ray induced by highly charged 40Arq+ ions interacting with Au surface have been studied. The results show that the argon Kα X-ray were emitted from the hollow atoms formed below the surface. There is a process of multi-electron exciting in neutralization of the Ar1.+ion, with electronic con-figuration 1.2.in its ground state below the solid surface. The yield of the projectile Kα X-ray is related to its initial electronic configuration, and the yield of the target X-ray is related to the projectile kinetic energy.

关键词： highly charged ion hollow multi-electron excitation X- ray.