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IMAGING IN HIGH energy ASTRONOMY

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空间科学学报 1998年第S1期18卷 12-20页

作者： LI Ti-pei (institute of High Enerpy physics, The chinese academy of sciences,{3.)

Space research is usually costly, and this restricts participation of developing countries. With traditional techniques one must construct high resolution instrument,more and more complicated and expensive, to obtain high resolution results from space observations. It is a difficult task to make observations with both high sensitivity and high resolution. Applying advanced inversion technique, one can subtract more information from old data in public domain,and, furthermore, conduct high sensitive and high-resolution experiments with low-cost low-resolution instruments. So developing and applying data analysis technique is of great importance for developing countries to do basic space *** this paper we summarize efforts of chinese scientists in recent years along this direction on imaging in space high energy astronomy.

关键词： Space astronomy Astronomical satellite Imaging

Virtualities of quark and gluon in QCD vacuum

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Science china(physics,Mechanics & Astronomy) 2008年第10期51卷 1439-1447页

作者： ZHOU LiJuan1, QIN SongMei2, WU Qing3.& MA WeiXing4 1 Collaboration Group of Hadron physics and Non-perturbative QCD Study, Guangxi University of Tech- nology, Liuzhou 545006, china 2 Department of physics, Guangxi University, Nanning 540003. china 3.Department of physics, Qingdao University, Qingdao 266071, china 4 institute of High energy physics, chinese academy of sciences, beijing 100049, china 1. Collaboration Group of Hadron physics and Non-perturbative QCD Study Guangxi University of Technology Liuzhou 545006 China 2. Department of physics Guangxi University Nanning 540003 China 3. Department of physics Qingdao University Qingdao 266071 China 4. institute of High energy physics Chinese Academy of Sciences Beijing 100049 China

The non-local vacuum condensates of quantum chromodynamics (QCD) describe the distributions of quarks and gluons in the non-perturbative QCD vacuum state. Physically, this means that vacuum quarks and gluons have a nonzero mean-squared momentum in the vacuum, called virtuality. The quark virtuality is given by the ratio of the local quark-gluon mixed vacuum condensate to the quark local vacuum condensate. The gluon virtuality is expressed by gluon vacuum condensates and four-quark vacuum condensates. We study the two virtualities by solving Dyson-Schwinger Equations and calculating quark and gluon vacuum condensates. Our theoretical results for quark virtuality are in good agreement with many other theoretical model predictions such as QCD sum rules and lattice QCD calculations. Our calculation on gluon virtuality is initial and the results are quite interesting.

关键词： quark gluon virtuality QCD vacuum condensate non-perturbative QCD

Prediction method for October 2003.solar storm

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Science china(Technological sciences) 2006年第5期49卷 629-640页

作者： XIE Yanqiong1, 2, 3. WEI Fengsi1, FENG Xueshang1 & ZHONG Dingkun1, 2 1. State Key Laboratory of Space Weather, Center for Space Science and Applied Research, chinese academy of sciences, beijing 100080, china 2. Graduate School, chinese academy of sciences, beijing 10003., china 3. institute of Meteorology, PLA University of Science and Technology, Nanjing 211101, china State Key Laboratory of Space Weather Center for Space Science Applied Research Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Beijing 100039 China institute of Meteorology PLA University of Science Technology Nanjing 211101 China

Aiming at two intense shock events on October 28 and 29, 2003. this paper presents a two-step method, which combines synoptic analysis of space weather ——“observing” and quantitative prediction ——“palpating”, and then uses it to test predictions. In the first step of “observing”, on the basis of observations of the solar source surface magnetic field, interplanetary scintillation (IPS) and ACE spacecraft, we find that the propagation of the shocks is asymmetric relative to the normal direction of their solar sources, and the Earth is located near the direction of the fastest speed and the greatest energy of the shocks. As the two fast ejection shock events, the fast explosion of coronal mass of the extremely high temperature, the strong magnetic field, and the high speed background solar wind are also helpful to their rapid propagation. In the second step of “palpating”, we adopt a new membership function of the fast shock events for the ISF method. The predicted results show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8% and 6.7%; and for the magnetic disturbance magnitude, the relative errors are 4.1% and 3.1%, re- spectively. Furthermore, the comparison among the predicted results of our two-step method with those of five other prevailing methods shows that the two-step method is advantageous. The results tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction precision.

关键词： solar storm, interplanetary shock, interplanetary scintillation, two-step method, ISF method.

Primary scientific results of Chang'E-1 lunar mission

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Science china Earth sciences 2010年第11期53卷 1565-1581页

作者： OUYANG ZiYuan1,2, LI ChunLai1, ZOU YongLiao1, ZHANG HongBo1, Lü Chang1, LIU JianZhong1, LIU JianJun1, ZUO Wei1, SU Yan1, WEN WeiBin1, BIAN Wei1, ZHAO BaoChang3. WANG JianYu4, YANG JianFeng3. CHANG Jin5, WANG HuanYu6, ZHANG XiaoHui7, WANG ShiJin7, WANG Min1, REN Xin1, MU LingLi1, KONG DeQing1, WANG XiaoQian1, WANG Fang1, GENG Liang1, ZHANG ZhouBin1, ZHENG Lei1, ZHU XinYing1, ZHENG YongChun1, LI JunDuo1, ZOU XiaoDuan1, XU Chun1, SHI ShuoBiao1, GAO YiFei1 & GAO GuanNan1 1 National Astronomical Observatories, chinese academy of sciences, beijing 100012, china 2 {3. of Geochemistry, chinese academy of sciences, Guiyang 550002, china 3.Xi’an {3. of Optics and Precision Mechanics, chinese academy of sciences, Xi’an 710119, china 4 Shanghai {3. of Technical physics, chinese academy of sciences, Shanghai 200083. china 5 Purple Mountain Observatory, chinese academy of sciences, Nanjing 210008, china 6 {3. of High energy physics, chinese academy of sciences, beijing 100049, china 7 Center for Space Science and Applied Research, chinese academy of sciences, beijing 100190, china 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China2. Institute of Geochemistry Chinese Academy of Sciences Guiyang 550002 China3. Xi’an Institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an 710119 China4. Shanghai Institute of Technical Physics Chinese Academy of Sciences Shanghai 200083 China5. Purple Mountain Observatory Chinese Academy of Sciences Nanjing 210008 China6. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China7. Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China

The strategic plan for the development of the unmanned chinese Lunar Exploration Program is characterized by three distinct stages: "orbiting around", "landing on" and "returning from" the Moon. The first chinese lunar probe, Chang'E-1, which was successfully launched on October 24th, 2007 at Xichang Satellite Launch Center, and guided to crash on the Moon on March 1st, 2009, at 52.3.°E, 1.50°S, in the north of Mare Fecunditatis, is the first step towards the "orbiting around" stage. The Chang'E-1 mission lasted 495 days, exceeding the expected life-span by about four months. A total of 1.3. TB raw data was received from Chang'E-1. It was then processed into 4 TB scientific data products at various levels. Many scientific results have been obtained by analyzing these data, including especially the "global lunar image from the first chinese lunar explora- tion mission". All scientific goals of Chang'E-1 have been achieved. It provides much useful materials for further advances of lunar {3. and planetary chemistry. Meanwhile, these results will serve as a firm basis for future chinese lunar missions.

关键词： lunar orbiter Chang’E-1 scientific data results

Photosynthesis for Food,Fuel and the Future

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Journal of Integrative Plant Biology 2010年第8期52卷 I0001-I0001,695-697页

作者： Congming Lu institute of Botany chinese academy of sciences china Issue Editor institute of Botany chinese academy of sciences china

Photosynthesis is a process that converts solar energy to chemical energy in many different organisms, ranging from plants to bacteria. Photosynthesis provides all the food we eat and all the fossil fuel we use. Photosynthesis has long been studied in order to understand its underlying mechanisms and then to apply this knowledge to the production of energy and food for the needs of our society. The 15th International Congress on Photosynthesis will be held in {3. from August 22 to 27, 2010. It will feature eminent plenary speakers and state-of-the-art symposium speakers who are at the cutting edge of discovery in their fields and provide an exciting scientific program which will cover the breadth and depth of photosynthesis from molecular to global. To celebrate this congress, Journal of Integrative Plant Biology （JIPB） publishes a special issue on photosynthesis which includes reviews of the recent progress on the various aspects of photosynthesis.

关键词： Photosynthesis for Food,Fuel and the Future OEC

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 {3. Astrophysics Lab., institute of High {3. physics, chinese academy of sciences, beijing 10003.)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

Single crystal β-Ga_2O_3. Cr grown by floating zone technique and its optical properties

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Science china(Technological sciences) 2007年第1期50卷 51-56页

作者： ZHANG JunGang1, 2, LI Bin3. XIA ChangTai1, XU Jun1, DENG Qun4, XU XiaoDong1, WU Feng1, XU WuSheng4, SHI HongSheng4, PEI GuangQing1, 2 & WU YongQing1,2 1 Shanghai institute of Optics and Fine Mechanics, chinese academy of sciences, Shanghai 201800, china 2 Graduate School of the chinese academy of sciences, beijing 10003., china 3.Shanghai institute of Applied physics, chinese academy of sciences, Shanghai 201800, china 4 GE (china) Research and Development Center Co. Ltd., Shanghai 201203. china 1. Shanghai institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800 China 2. Graduate School of the chinese academy of sciences Beijing 100039 China 3. Shanghai institute of Applied physics Chinese Academy of Sciences Shanghai 201800 China 4. GE (china) Research and Development Center Co. Ltd. Shanghai 201203 China

β-Ga2O3. Cr single crystals were grown by floating zone technique. Absorption spectra and fluorescence spectra were measured at room temperature. The values of field splitting parameter Dq and Racah parameter B were obtained by the peak values of absorption spectra. The value 10Dq/B=23.14 manifests that in β-Ga2O3.crystals Cr3. ions are influenced by low energy crystal field. After high temperature annealing in air, the Cr3. intrinsic emission was enhanced and the green lumines-cence disappeared. The strong and broad 691 nm emission was obtained at 420 nm excitation due to the electron transition occurred from 4T2 to 4A2. The studies manifest that the β-Ga2O3.crystals have the potential application for tunable laser.

关键词： β-Ga2O3. Cr single crystals floating zone technique tunable laser spectrum.

Time of impact of fragment P2 of comet SL 9 on Jupiter

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chinese Science Bulletin 1997年第5期42卷 396-398页

作者： ZHOU Hongnan,QIAN Bochen, HUANG Keliang and LI Qibin1. Department of Astronomy, Nanjing University, Nanjing 210093. china 2. Shanghai Observatory, chinese academy of sciences, Shanghai 20003., china 3. {3. Department, Nanjing Normal University, Nanjing 210097, china 4. beijing Astronomical Observatory, chinese academy of sciences, beijing 100080, china Department of Astronomy Nanjing University Nanjing China Shanghai Observatory Chinese Academy of Sciences Shanghai China physics Department Nanjing Normal University Nanjing China beijing Astronomical Observatory Chinese Academy of Sciences Behijing China

FROM 1994-07-16 to 1994-07-22, 21 fragments of comet SL 9 impacted against Jupiter in succession. During the impact period the impact of fragments D, E, K, N, P2 and S was observed in china. We used a 1.56-m telescope with the CCD camera of Shanghai Observatory to monitor Jupiter and its Galilean Satellites, obtaining 1000 high-quality images at B, V, I wave bands. Our data on optical wave bands are rather complete and valuable in the world. Specially, we got some images of Jupiter, Io and Europa in the impact time of fragment P2 impacting against Jupiter. This will help us understand the precise time, position, depth and energy of the P2’s collision. In this note, we report the impact time of fragment P2 of comet SL 9 and Jupiter. Since the impact of comet SL 9 was expected to take place on the side of Jupiter

关键词： comet comet Shoemaker-Levy 9 impacting against Jupiter impact time.

Electronic structure and magnetism of Fe-doped SiC nanotubes

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Science china(physics,Mechanics & Astronomy) 2010年第9期53卷 1582-1589页

作者： ZHANG WeiHu1,2,3.ZHANG FuChun3.ZHANG ZhiYong4,LU ShuYuan5 & YANG YanNing3.1 Xi’an institute of Optics and Precision Mechanics,chinese academy of {3.,Xi’an 710068,china 2 Graduate University of chinese academy of sciences,beijing 100049,china 3.College of physics and Electronic Information,Yan’an University,Yan’an 716000,china 4 Information Science and Technology Institution,Northwest University,Xi’an 710127,china 5 Department of Telecommunications,Xi’an institute of Posts and Telecommunications,Xi’an 710121,china 1. Xi’an institute of Optics and Precision Mechanics Chinese Academy of Sciences Xi’an 710068 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. College of Physics and Electronic Information Yan’an University Yan’an 716000 China4. Information Science and Technology Institution Northwest University Xi’an 710127 China5. Department of Telecommunications Xi’an Institute of Posts and Telecommunications Xi’an 710121 China

The electronic structure and magnetic properties of Fe-doped SiC nanotubes are investigated by using the first-principles method based on density functional theory(DFT) in the local spin density approximation(LSDA).The calculation results indicate that the SiC nanotube of Fe substitution for C exhibits antiferromagnetism while ferromagnetism features prominently when Fe substitutes *** is a kind of half-metal magnetic *** formation energy calculation results show that the formation energy of ferromagnetic structure is 3.2 eV lower than that of antiferromagnetic *** atoms are more likely to replace Si ***-orbit coupling induces electron spin polarization in the ground ***,the doping Fe atoms make relaxation towards the outside of the tube to some extent and larger geometric distortion occurs when Fe substitutes C,but the whole geometric structure of SiC nanotubes is not damaged due to the *** is revealed in the calculation of energy band structure and density of states that more dispersed distribution of energy levels is produced near the Fermi *** Fe substitution for Si,obviously there are spin-split and intense p-d hybrid effects by Si 3. electron spins and Fe 3. electron spins localized at the exchanging interactions between magnetic transitional metal(TM) *** electronic density results indicate that system magnetic moments are mainly generated by the unpaired 3. electrons of Fe *** these results show that the transition metal doping SiC nanotube could be a potential route to fabricating the promising magnetic materials.

关键词： SiC nanotube the first-principles doped magnetic properties