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Studies on BEPC upgrade from pretzel to double-ring

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Science China(physics,Mechanics & Astronomy) 2010年第11期53卷 2084-2089页

作者： ZHANG Chuang institute of high energy physics,Chinese Academy of Sciences,Beijing 100049,China institute of high energy physics Chinese Academy of Sciences Beijing China

physics opportunity in the charm and τ energy region calls for higher luminosity of the Beijing Electron-Positron Collider (BEPC).The BEPC has experienced continuous improvement since its completion in ***,as a major upgrading project of the BEPC,aims at enhancing its luminosity of factor 30–100,following the principle of "one machine,two purposes" as adopted in BEPC,so that both high energy physics and synchrotron radiation experiments can be carried out with *** the BEPC to BEPCII,the double-ring scheme with multi-bunch e +-e-collision in the large crossing angle was studied in comparison with the single-ring pretzel *** the dedicated synchrotron radiation operation,artful "bridges" are designed to connect two halves of the outer ring in both the southern and the northern crossing *** paper reviews the studies on the BEPC upgrade from pretzel to double-ring structure of BEPCII.

关键词： collider storage ring high energy physics synchrotron radiation

ABUNDANCE PATTERNS OF REFRACTORY SIDEROPHILE ELEMENTS OF FE-NI METALLIC GRAINS IN C3V CHONDRITES

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Science in China,Ser.B 1986年第3期29卷 326-336页

作者：柴之芳 institute of high energy physics Academia Sinica Beijing

A lot of Fe-Ni metallic grgins in the inclusions from the Allende and Leoville chondrites were studied on the concentration patterns of some refractory siderophile elements, Os, Ir, Ru, Re, W, Mo and Pt, using neutron activation analysis. Our experimental results show that the grains studied in this work can be roughly classified into two types: equilibrium and non-equilibrium grains. This probably reflects their distinction in the fractionation and condensation processes of the solar system. Or the so-called non-equilibrium grains might be the relics from the supernovae *** experiments were carried out on microgram level.

关键词： Ru ABUNDANCE PATTERNS OF REFRACTORY SIDEROPHILE ELEMENTS OF FE-NI METALLIC GRAINS IN C3V CHONDRITES Re Pt ppm work SRM

Timing in the Time Domain: Cygnus X-1

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Chinese Journal of Astronomy and Astrophysics 2001年第4期1卷 313-332页

作者： Ti-Pei Li (Department of physics and Center for Astrophysics, Tsinghua University, Beijing 100084 high energy Astrophysics Lab., institute of high energy physics, Chinese Academy of Sciences, Beijing 100039)E-mail:litp@*** Department of physics and Center for Astrophysics Tsinghua University Beijing 100084 High Energy Astrophysics Lab. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100039

Quantities characterizing temporal property, e.g., power density, coherence, and time lag, can be defined and calculated directly in the time domain without using the Fourier transformation. Spectral hardness, variability duration, and correlation between different characteristic quamtities on different time scale can be studied in the time domain as well. The temporal analysis technique in the time domain is a powerful tool, particularly in studying rapid variability on short time scales (or in high frequencies). Results of studying variabilities of X-rays from Cyg X-1 with the analysis technique in the time domain and RXTE data reveal valuable clues to understanding production and propagation processes of X-rays and structure of accretion disk in the black hole system.

关键词： methods: data analysis - stars: individual (Cygnus X-1) - X-rays: stars

Transport　of　atmospheric　trace　elements　and　dust－soil　to　the　Western　Pacific　Ocean

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Journal of Environmental Sciences 1996年第4期8卷 460-465页

作者： Yang Shaojin Chen Bingru Yang Yinan(institute of high energy physics,Chinese Academy of Sciences,Beijing 100080,China) institute of high energy physics Chinese Academy of Sciences Beijing 100080 China

Atmospheric aerosol and rainwater samples collected in the different Western Pacific area were analyzed by instrumental neutron activation and proton induced X-ray emission to (1) determine the atmospheric concentrations of trace elements over the Western Pacific and (2) to esti mate the atmospheric deposition of trace elements and dust-soil material to this region. high abundance of pollutant and crustal elements relative to oceanic sources was observed. Some characteristics of marine atmosphere relating to long-range transport of crustal and anthropogenic elements from continent to the remote ocean are discussed. The total dust-soil particle mass is estimated to be 0. 066-1.2 μg/m￣3 over the Western Pacific Ocean areas. Atmospheric inputs of dust-soil particles control the marine particle concentrations of crustal elements. In addition, the characteristics of marine rain water are discussed.

关键词： dust-soil marine rain-water atmospheric trace elements.

Characteristics of air particulate matter and their sources in urban and rural area of Beijing, China

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Journal of Environmental Sciences 2000年第4期12卷 402-409页

作者： YANG Shao jin, DONG Jin quan, CHENG Bing ru (institute of high energy physics, Chinese Academy of Sciences, Beijing 100080, China) institute of high energy physics Chinese Academy of Sciences Beijing 100080 China

During October 1993 and March 1996, the samples of fine and coarse air particulate matter have been collected at representative urban and rural site of Beijing with the Gent Stacked Filter Unit Sampler. Instrumental neutron activation analysis (INAA) and proton induced X ray emission (PIXE) method were used to determine the elemental composition of the particulate matter. Average elemental concentrations and enrichment factors were calculated for the fine and coarse size fractions. Based on the particulate matter data obtained at urban and rural site together with the chemical constituents of the aerosol from the different sources are discussed. The results show that the relative particulate mass and elemental concentrations of crustal and pollutant elements in the air particulate matter collected over the urban are higher than rural and winter heating period are higher than in ordinary season. Beijing atmosphere is polluted by aerosols from regional and faraway sources. It was noticed that the toxic or harmful elements such as As, Sb, Pb, Cu, Ni, S and Zn were mainly enriched in fine particles with diameter less than 2 μm. A receptor model was used to assess the relative contribution of major air pollution sources at receptor sites in Beijing. Trace elements were used as the markers for the above assessment. Factor analysis method was used to identify possible emission sources of air particles. The major sources of dust soil, coal burning, motor vehicle emission, industry emission and refuse incineration were identified.

关键词： atmospheric particulate matter urban rural source aerosol

Control of Melt Structures on Cu-Au Mineralization in Basic-Ultrabasic Complexes of Northern China

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Acta Geologica Sinica(English Edition) 2000年第4期74卷 786-794页

作者： YUAN Wanming institute of high energy physics, Chinese Academy of Sciences, Beijing 100080and MO Xuanxue China University of Geoscienses, Beijing 100083 Chinese Acad Sci Inst High Energy Phys Beijing 100080 Peoples R China China Univ Geosci Beijing 100083 Peoples R China

Based on systematic analyses of 72 samples of different basic-ultrabasic rocks, the present paper discusses the relationship between melt structure and Cu and Au mineralization. It is found that if the NBO/T, NBO, M2+, FeO and MgO values are relatively high and the T, M3+, Fe2O3 and CaO values are low the basic-ultrabasic melt will be favourable to Cu (Ni) mineralization, but if the former are low and the latter are high it is favourable to Au metallization. Cu ions occupy dominantly octahedra in basic-ultrabasic melt and the higher the NBO/T, NBO and M2+ values, the more the octahedra in the melt. Au element mainly takes the form of Au+ ions in basic-ultrabasic melt and the Au+ ions constitute tetrahedral sites together with Fe3+ ions. Therefore, low M2+ and high Fe3+, i.e. high oxygen fu-gacity, can promote the enrichment of Au+ ions and Au mineralization. Components NT (other than Au+), Al2O3 and SiO2 in basic-ultrabasic melt have no effect on metallogenetic species. As mentioned above, in relevant diagrams distribution areas of the characteristic values of ore-free melt and those of ore-forming melt are overlapped in different degrees, which possibly indicates that not all the magmas have mineralizing ability. It can be well distinguished whether basic-ultrabasic rocks are favourable to Cu or Au mineralization or they are just ore-free rocks by analysing integrated diagrams of the characteristic values of the magmatic melt structure.

关键词： melt structure Cu-Au mineralization basic-ultrabasic complex

The Daya Bay Reactor Neutrino Experiment

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Bulletin of the Chinese Academy of Sciences 2012年第2期26卷 117-122页

作者： CAS institute of high energy physics

On Aug.15, 201l, a new large-scale scientific facility in China, Daya Bay Reactor Neutrino Experiment, started to operate. It is located in Daya Bay Nuclear Power Plant in Guangdong Province, around 50kin to both Hong Kong and Shenzhen City. The main scientific goal is to precisely determine the neutrino mixing angle 013 by detecting neutrinos from the reactors at different distances.

关键词：中微子实验反应堆大亚湾中微子探测深圳市核电厂广东省混合角

Zhao Zhongyao: A Pioneer of Nuclear Research in China

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Bulletin of the Chinese Academy of Sciences 2002年第2期16卷 118-124页

作者： institute of high energy physics, CAS institute of high energy physics CAS

　　On June 4, 2002, a centennial meeting was held in Beijing in commemoration of the late Professor Zhao Zhongyao (C.Y. Chao, 1902 -1998), a famous physicist and a pioneer of experimental physics and high-energy phys... 详细信息

关键词： A Pioneer of Nuclear Research in China Zhao Zhongyao

Effects of cosmological constant on motion of UHECR particles

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Science China(physics,Mechanics & Astronomy) 2005年第1期48卷 44-56页

作者： CHEN Shaoxia & CHANG Zhe institute of high energy physics, Chinese Academy of Sciences, Beijing 100039, China Graduate School of Chinese Academy of Sciences, Beijing 100039, China institute of high energy physics Chinese Academy of Sciences Beijing 100039 China Graduate School Chinese Academy of Sciences Beijing 100039 China

Recent astronomical observations manifest that about two-thirds of the whole energy in the Universe is contributed by a small positive cosmological constant A (> 0). Then, an asymptotically de Sitter spacetime is premised naturally. However, physics in the de Sitter spacetime is very different from that in the Minkowski spacetime. As the first step, a covariant formalism of the kinematics in the de Sitter spacetime is presented here. By solving exactly the equations of motion for a field, we obtain the dispersion relation of a free particle. It is noticed that the dispersion relation is dependent on the degree of freedom of angular momentum of the particle. We show the threshold anomaly of the ultra high energy cosmic ray disappears naturally in the framework of the de Sitter kinematics.

关键词： ultrahigh energy cosmic ray, cosmological constant, curved spacetime.