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

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science china(physics,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 physics, {3. Academy of sciences, lanzhou 73.000, china 2 Department of modern physics, lanzhou University, lanzhou 73.000, china 3.Department of physics, Xianyang Normal College, Xianyang 712000, china institute of modern physics Chinese Academy of Sciences Lanzhou China Department of modern physics Lanzhou University Lanzhou China Department of physics Xianyang Normal College Xianyang China

The X-ray spectra of Nb surface induced by Arq+ (q =16,17) ions with the energy range from 10 to 20 keV/q were studied by the optical spectrum technology. The experimental results indicate that the multi-electron excitation occurred as a highly charged Ar16+ ion was neutralized below the metal surface. The K shell electron of Ar16+ 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 Ar17+ is three magnitude orders larger than that of Ar16+.

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

Compression behavior of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(22.5) bulk metallic glass up to 24 GPa

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science china(physics,Mechanics & Astronomy) 2005年第3期48卷 319-324页

作者： LI Gong 1, 2 , ZHAN Zaiji 2 , LIU Jing 3., YUN Jinku 1 , sUN Liling 2 , LIU Riping 1 , ZHANG Jun 2 & WANG Wenkui 1, 2 1. Key Laboratory of Metastable Materials science and Technology, Yanshan University, Qinhuangdao 066004, china 2. Center for Condensed Matter physics, institute of physics, chinese Academy of sciences, Beijing 100080, china 3. BsRF, institute of High Energy physics, chinese Academy of sciences, Beijing 10003., china Key Laboratory of Metastable Materials science and Technology Yanshan University Qinhuangdao China Center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences Beijing China BsRF Institute of High Energy Physics Chinese Academy of Sciences Beijing China

The compression of a Zr41Ti14Cu12.5Ni10Be22.5 bulk metallic glass (BMG) is investigated at room temperature up to 24 GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.

Impacts of permafrost changes on alpine ecosystem in Qinghai-Tibet Plateau

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science china Earth sciences 2006年第11期49卷 1156-1169页

作者： WANG Genxu1,3., LI Yuanshou2 , WU Qingbai2 & WANG Yibo3.1. institute of Mountain Hazards and Environment, chinese Academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research institute, chinese Academy of sciences, lanzhou 73.000, china 3. Resource and Environment school, lanzhou University, lanzhou 73.000, china institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Resource and Environment school Lanzhou University Lanzhou China Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou China

Alpine cold ecosystem with permafrost environment is quite sensitive to climatic changes and the changes in permafrost can significantly affect the alpine ecosystem. The vegetation coverage, grassland biomass and soil nutrient and texture are selected to indicate the regime of alpine cold ecosystems in the Qinghai-Tibet Plateau. The interactions between alpine ecosystem and permafrost were investigated with the depth of active layer, permafrost thickness and mean annual ground temperature (MAGTs). Based on the statistics model of GPTR for MAGTs and annual air temperatures, an analysis method was developed to analyze the impacts of permafrost changes on the alpine ecosystems. Under the climate change and human engineering activities, the permafrost change and its impacts on alpine ecosystems in the permafrost region between the Kunlun Mountains and the Tanggula Range of Qinghai-Tibet Plateau are studied in this paper. The results showed that the per- mafrost changes have a different influence on different alpine ecosystems. With the increase in the thickness of active layer, the vegetation cover and biomass of the alpine cold meadow exhibit a significant conic reduction, the soil organic matter content of the alpine cold meadow ecosystem shows an exponential decrease, and the surface soil materials become coarse and gravelly. The alpine cold steppe ecosystem, however, seems to have a relatively weak relation to the permafrost environment. Those relationships resulted in the fact that the distribution area of alpine cold meadow decreased by 7.98% and alpine cold swamp decreased by 28.11% under the permafrost environment degradation during recent 15 years. In the future 50 years the alpine cold meadow ecosystems in different geomorphologic units may have different responses to the changes of the permafrost under different climate warming conditions, among them the alpine cold meadow and swamp ecosystem located in the low mountain and plateau area will have a relatively

关键词： permafrost environment, alpine cold ecosystem, statistics relationship, climate change, impacts, Qinghai-Tibet Plateau.

Impact of land-use change on hydrological processes in the Maying River basin, china

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science china Earth sciences 2006年第10期49卷 1098-1110页

作者： WANG Genxu1,3. ZHANG Yu2, LIU Guimin2 & CHEN Lin3.1. institute of Mountain Hazards and Environment, chinese Academy of sciences, Chengdu 610041, china 2. Cold and Arid Regions Environmental and Engineering Research institute, chinese Academy of sciences, lanzhou 73.000, china 3. Resource and Environment school, lanzhou University, lanzhou 73.000, china institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu China Resource and Environment school Lanzhou University Lanzhou China Cold and Arid Regions Environmental and Engineering Research institute Chinese Academy of Sciences Lanzhou China

since the 1960s, dramatic changes have taken place in land-use patterns characterized by the persistent expansion of cultivated land and a continuous decrease in natural woodland and grassland in the arid inland river basins of china. It is very important to assess the effects of such land-use changes on the hydrological processes so vital for water resource management and sustainable development on the catchment scale. The Maying River catchment, a typical arid inland watershed located in the middle of the Hexi Corridor in northwest china, was the site chosen to investigate the hydrological responses to land-use changes. The annual runoff, base flow, maximum peak flow, and typical seasonal runoff in both spring and autumn flood periods were selected as the variables in the hydrological processes. statistical-trend analysis and curvilinear regression were utilized to detect the trends in hydrological variables while eliminating the climatic influence. The relationship between cultivated land-use and hydrological variables was analyzed based on four periods of land-use variation data collected since 1965. A runoff model was established composed of two factors, i.e., cultivated land use and precipitation. The impact of land use changes, especially in the large ar- eas of upstream woodland and grassland turned into cultivated lands since 1967, has resulted in a mean annual runoff decrease of 28.12%, a base flow decline of 3..3.%, a drop in the maximum peak discharge of 3..77%, and mean discharge decreases in spring and autumn of 3..05% and 24.87% respectively, of which the contribution of cultivated land expansion to the influence of annual runoff amounts to 77%-80%, with the contribution to the influence of spring discharge being 73.-81%, and that to the influence of base flow reaching 62%-65%. Thus, a rational regulation policy of land use patterns is vitally important to the sustainable use of water resources and the proper development of the entire catchment.

关键词： land-use change, arid inland river catchment, hydrological process, impact, Maying River.

X-ray spectra induced by ^(129)Xe^(q+) impacting the metal surface

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science china(physics,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 1institute of modern physics,{3. Academy of sciences,lanzhou 73.000,china 2Department of physics,Xianyang Normal University,Xianyang 712000,china 3.epartment of modern physics,lanzhou University,lanzhou 73.000,china 4Department of Applied physics,Xi’an Jiaotong University,Xi’an 710049,china institute of modern physics Chinese Academy of Sciences Lanzhou China Department of physics Xianyang Normal University Xianyang China Department of modern physics Lanzhou University Lanzhou China Department of Applied physics Xi’an Jiaotong University China

Using the slow highly charged ions 129 Xe q+ (q=25,26,27;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 10-8and 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 1.3.×10-18s based on Heisenberg uncertainty relation.

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

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

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science china(physics,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 Wenlong11. institute of modern physics, {3. Academy of sciences, lanzhou 73.000, china 2. Department of physics, Xianyang Normal University, Xianyang 712000, china 3. Department of modern physics, lanzhou University, lanzhou 73.000, china 4. Department of Applied physics, Xi’an Jiaotong University, Xi’an 710049, china institute of modern physics Chinese Academy of Sciences Lanzhou China Department of physics Xianyang Normal University Xianyang China Department of modern physics Lanzhou University Lanzhou China Department of Applied physics 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 Ar16+ion, with electronic con-figuration 1s2 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.

Near infrared lights emission of ^(40)Ar^(16+) impacting on metal surfaces

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science china(physics,Mechanics & Astronomy) 2009年第7期52卷 1021-1026页

作者： ZHANG XiaoAn1,2, XIAO GuoQing2, YANG ZhiHu2, WANG Li1 & ZHAN WenLong2 1 Department of physics, Xianyang Normal University, Xianyang 712000, china 2.institute of modern physics, {3. Academy of sciences, lanzhou 73.000, china Department of physics Xianyang Normal University Xianyang China institute of modern physics Chinese Academy of Sciences Lanzhou China

The highly charged ion 40Ar16+ with the velocity (kinetic energy EK=150 keV, velocity V=8.5×105 m/s) smaller than Bohr velocity (VBohr=2.9×106 m/s) was found to hove impacts on the surfaces of metals Ni, Mo, Au and Al, and the Ar atomic infrared light lines and X-rays spectra were simultaneously measured. The experimental results show that the highly charged ion that captures electrons is neutralized, and the multiply-excited hollow atom forms. The hollow atom cascade decay radiates lights from infrared to X-ray spectrum. The intensity of infrared lights shows that the metallic work functions play an important role in the neutralization process of highly charged ions during their interaction with metallic surfaces, which verifies the classical over-the-barrier model.

关键词： infrared light lines X-ray neutralization highly charged ions

Anomalous Phenomena in E<18 keV Hydrogen Ion Beam Implantation Experiments on Pd and Ti

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chinese journal of nuclear physics 1997年第4期19卷 244-249页

作者： Wang Tieshan~(1) Piao Yubo~(2) Hao Jifang~(1) Wang Xuezhi~(2) Jin Genming~(1) Niu Zhanqi~(2) (1)institute of modern physics,the {3. Academy of sciences,lanzhou 73.000 (2)Department of modern physics of lanzhou University,lanzhou 73.000 中科院近代物理所甘肃兰州兰州大学现代物理系甘肃兰州

Implantation experiments of low energy（1 keVmax1.2 mA/cm2)and lowbeam density(Jmin0.02 mA/cm2).Palladium and titanium foils（plates）are bombarded withproton and deuteron beams in order to compare the atomic and nucl... 详细信息

Implantation experiments of low energy（1 keVson hydrogen loaded metals are performed with high beam density(Jsub>maxsub>1.2 mA/cmsup>2sup>)and lowbeam density(Jsub>minsub>0.02 mA/cmsup>2sup>).Palladium and titanium foils（plates）are bombarded withproton and deuteron beams in order to compare the atomic and nuclear interactions between dif-ferent ion beams.X-ray and charged particles are measured,and neutron and gamma doses arealso monitored during the implantation *** anomalous peak in X-spectra,whoseenergy is about four times the beam energy,is observed during the high beam density *** peak moves from about 40 keV to 62 keV and FWHM reduces rapidly,while thebeam energy and intensity *** wide peak with over twice the beam energy is mea-sured in experiment with low beam *** is located between 16 keV and 3. keV,and itspeak energy increases with the increase of implantation dose（implantation time）.some anoma-lous intensities of neutrons correlated with a charged particle peak（2.93.3.85 MeV）are alsoobserved in the deuteron-palladium *** highest neutron intensity reaches about8×10sup>4sup> n/s,while the beam energy and intensity are about 15 keV and 1.0 mA,respectively.

关键词： Hydrogen ion beam Low energy Implantation Palladium and titanium foils

Global analysis theory of climate system and its applications

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chinese science Bulletin 2003年第10期48卷 1034-1039页

作者： LI Jianping1,2 & CHOU Jifan2,3.1. LAsG, institute of Atmospheric physics, chinese Academy of sciences, Beijing 100029,{3. 2. Department of Atmospheric sciences, lanzhou University, lanzhou 73.000,{3. 3. Training Center for{3. Meteorological Administration, Beijing 100081,{3. LAsG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China Department of Atmospheric sciences Lanzhou University Lanzhou 730000 China Training Center for china Meteorological Administration Beijing 100081 China

The idea and main theoretical results of the global analysis theory of climate system are briefly summarized in this paper. A theorem on the global behavior of climate system is given, i.e. there exists a global attractor in the dynamical equations of climate, any state of climate system will be evolved into the global attractor as time increases, indicating the nonlinear adjustment process of climate system to external forcing. The different effects of external forcing, dissipation and nonlinearity on the long-term behavior of solutions are pointed out, and some main applications of the global analysis theory are also introduced. Especially, three applications, the adjustment and evolution processes of climate, the principle of numerical model design and the optimally numerical integration, are discussed.

关键词：整体分析理论气侯体系应用不定性计算法则气侯科学数字模型