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THE CHARACTERISTICS OF GREAT COSMIC RAY STORM EVENTS IN MARCH 1989

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天文研究与技术 1990年第4期 115-119页

作者： Ye Zonghai, Xiao Shaoyu and Xue Shunshengcenter for space science and applied research, chinese academy of {3.s, beijing 100080, china

The characters of cosmic ray ray Forbush decrease caused by solar flares in March 1989 are analyzed in this paper. The relationship between the cosmic ray intensity variations and the characters of solar flares and ge... 详细信息

关键词： meson cosmic anisotropy characters storm latitude neutron burst proton ionization

A fingerprint identification algorithm by clustering similarity

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science china(Information sciences) 2005年第4期48卷 437-451页

作者： TIAN Jie, HE Yuliang, CHEN Hong & YANG Xin center for Biometric research and Testing (CBRT), Key Laboratory of Complex Systems and Intelligence science, Institute of Automation, {3. academy of sciences, Graduate School of the {3. Acad- emy of sciences, beijing 100080, china center for Biometric research and Testing (CBRT) Key Laboratory of Complex Systems and Intelligence Science Institute of Automation Chinese Academy of Sciences Graduate School of the Chinese Academy of Sciences Beijing China

This paper introduces a fingerprint identification algorithm by clustering similarity with the view to overcome the dilemmas encountered in fingerprint identification. To decrease multi-spectrum noises in a fingerprint, we first use a dyadic scale space (DSS) method for image enhancement. The second step describes the relative features among minutiae by building a minutia-simplex which contains a pair of minutiae and their local associated ridge information, with its transformation-variant and invariant relative features applied for comprehensive similarity measurement and for parameter estimation respectively. The clustering method is employed to estimate the transformation space. Finally, multi-resolution technique is used to find an optimal transformation model for getting the maximal mutual information between the input and the template features. The experimental results including the performance evaluation by the 2nd International Verification Competition in 2002 (FVC2002), over the four fingerprint databases of FVC2002 indicate that our method is promising in an automatic fingerprint identification system (AFIS).

关键词： dyadic scale space (DSS) minutia-simplex multi-resolution comprehensive similarity.

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,{3. 2 Graduate School of the chinese academy of sciences, beijing 10003.,{3. 3.Shanghai Institute of applied Physics, chinese academy of sciences, Shanghai 201800,{3. 4 GE (china) research and Development center Co. Ltd., Shanghai 201203.{3. Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai China Graduate School of the chinese academy of sciences Beijing China Shanghai Institute of applied Physics Chinese Academy of Sciences Shanghai China GE (china) research and Development center Co. Ltd. Shanghai 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.

Applications of synchrotron-based X-ray techniques in environmental science

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science china Chemistry 2010年第12期53卷 2529-2538页

作者： LUO Lei & ZHANG ShuZhen State Key Laboratory of Environmental Chemistry and Ecotoxicology research center for Eco-Environmental sciences,{3. academy of sciences,beijing 100085,china State Key Laboratory of Environmental Chemistry and Ecotoxicology research center for Eco-Environmental sciences Chinese Academy of Sciences Beijing China

Synchrotron-based X-ray techniques have been widely applied to the fields of environmental science due to their element-specific and nondestructive properties and unique spectral and spatial resolution *** techniques are capable of in situ investigating chemical speciation,microstructure and mapping of elements in question at the molecular or nanometer scale,and thus provide direct evidence for reaction mechanisms for various environmental *** this contribution,the applications of three types of the techniques commonly used in the fields of environmental research are reviewed,namely X-ray absorption spectroscopy (XAS),X-ray fluorescence (XRF) spectroscopy and scanning transmission X-ray microscopy (STXM).In particular,the recent advances of the techniques in{3. are elaborated,and a selection of the applied examples are provided in the field of environmental ***,the perspectives of synchrotron-based X-ray techniques are *** their great progress and wide application,the techniques have revolutionized our understanding of significant geo-and bio-chemical *** is anticipatable that synchrotron-based X-ray techniques will continue to play a significant role in the fields and significant advances will be obtained in decades ahead.

关键词： synchrotron spectroscopy spectromicroscopy environmental science

Apply Spatially Variant Apodization to SAR/INSAR Image Processing

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Apply Spatially Variant Apodization to SAR/INSAR Image Proce...

A comparative analysis on two solar proton events

2007 Asian and Pacific Conference on Synthetic Aperture Radar(APSAR 2007)

作者： Wenshuai Zhai Yunhua Zhang center for space science and applied research chinese academy of {3.s beijing 100080

Spatially Variant Apodization （SVA） is one of nonlinear apodization methods used for sidelobe control in SAR/ISAR or optical imagery while maintaining mainlobe resolution unchanged. In this paper,we apply SVA to process RADARSAT image and show that by using SVA one can get better resolution compared with using classic windowing techniques such as Hamming,etc. Also,we investigate the impact of SVA for phase sensitive applications and find that SVA can be used to enhance coherence of image pair for INSAR. SIR-C/X X-band experimental data are processed to demonstrate the significant effect of SVA.

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来源： cnki会议评论

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chinese science Bulletin 2007年第1期52卷 47-51页

作者： LE GuiMing1,2,3.4, HAN YanBen2 & ZHANG YiJun3.1 Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites, china Meteorological Administration, beijing 100081, china 2 National Astronomical Observatories, {3. academy of sciences, beijing 100012, china 3.{3. academy of Meteorological sciences, china Meteorological Administration, beijing 100081, china 4 National center for space Weather, china Meteorological Administration, beijing 100081, china Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites China Meteorological Administration Beijing China National Astronomical Observatoires Chinese Academy of Sciences Beijing China chinese academy of Meteorological sciences China Meteorological Administration Beijing China

This paper presents a comparative analysis on the two Solar Proton Events (SPE), which occurred on 14 July 2000 (Bastille Day) and 28 October 2003.(28OCT03. respectively. It is found that although the peak flux of the latter seemed to be greater than that of the former based on geostationary observations, the maximum intensities of the energetic protons (>10 MeV and 3. MeV) during the Bastille Day event were all higher than those of the 28OCT03.event according to the interplanetary observations. Further analysis indicated that the quantity of the seed particles, which could be accelerated to the energies exceeding 10 and 3. MeV by the Coronal Mass Ejection (CME)-driven shock on 14 July 2000, was far larger than that of the 28OCT03.event. In the Bastille Day case, when the CME approached to the height around 14 R⊙, the CME-driven shock would reach its maximum capacity in accelerating the solar en- ergetic protons (>100 MeV). In contrast, on 28 October 2003. when CME approached to the height about 58R⊙, the CME-driven shock reached its highest potential in accelerating the solar energetic protons of the same category. At this moment, the peak flux (>100 MeV) was about 155 pfu, which was much lower than 3.5 pfu measured on 14 July 2000. This demonstrated that in the Bastille Day event, the quantity of the seed particles, which could be accelerated to the energy beyond 100 MeV, was significantly larger than its counterpart in the 28OCT03.case. Therefore, the peak flux of an SPE event depends not only on the interplanetary intensity of the solar energetic particles, but also on the velocity of the associated CME-driven shock, and the quantity of the seed particles as well as on the interplanetary magnetic en- vironment. This paper also reveals that the magnetic sheath associated with ICME on 28 October 2003.captured a large number of solar energetic protons, including those having energy greater than 100 MeV.

关键词：太阳质子 CME 太阳耀斑太阳系

基于星敏感器的星光折射卫星自主导航方法研究

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系统工程与电子技术 2004年第3期26卷 353-357页

作者：李琳琳孙辉先中国科学院空间科学与应用研究中心北京100080

研究了基于星光折射量测进行自主确定卫星姿态及轨道的方法。这种导航方案利用高精度的CCD星敏感器,结合星光穿越大气的较精确的数学模型,来间接敏感地平,从而实现对卫星的精确定位和定姿。为了说明所提导航方案的有效性,采用推广卡尔... 详细信息

研究了基于星光折射量测进行自主确定卫星姿态及轨道的方法。这种导航方案利用高精度的CCD星敏感器,结合星光穿越大气的较精确的数学模型,来间接敏感地平,从而实现对卫星的精确定位和定姿。为了说明所提导航方案的有效性,采用推广卡尔曼滤波算法,结合模拟的测量数据对自主定轨进行了仿真。仿真结果表明,定轨精度优于100m。还分析比较了采样周期、星敏感器精度、恒星数目等因素对定轨精度的影响。总结了其变化规律,可用于提高卫星自主定轨精度。

关键词：卫星自主导航星敏感器星光折射角推广卡尔曼滤波

A Decision Support System for Economic Development and Price Reform

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Journal of Systems Engineering and Electronics 1993年第1期4卷 65-73页

作者： Hu Lequn, Yang Shetang and Zhang WenzhongInstitute of System science, Academia Sinica, beijing, 100080Zhu JunNational Information {3. of china, beijing, 100072 Institute of System science Academia Sinica Beijing 100080 National Information center of china Beijing 100072

In this paper, we present a real decision support system applied to china's macroeconomic management. The structure, design and functions of the system are discussed, and the problems occurring in designing and making... 详细信息

关键词： Decision support system System analysis Interactive method Macroeconomic management Price reform.

TRULY BALANCED PULSE GENERATOR USING MICROWAVE TRANSISTOR AND SRD

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Journal of Electronics(china) 2011年第1期28卷 141-144页

作者： Xie Yifang Xiong Weiming Centre for space science and applied {3. Chinese Academy of Sciences Beijing 100190 China

A novel efficient circuit for Ultra-WideBand(UWB) balanced sub-nanosecond monocycle pulse generation is *** pulse generator employs wideband bipolar transistor,step recovery diodes,Schottky diodes,and simple charging and discharging *** transient analysis and design of the circuit are presented along with their operating *** pulse generator produces truly balanced monocycle pulse with 500 ps pulse-width and 800 mV peak *** generated monocycle pulse also has very symmetrical positive and negative portions and low ringing *** presented pulse generator can be used as both a transmitter feeding UWB balanced antennas without broadband baluns and a balanced switching pulse generator that used in UWB receiver.

关键词： Balanced monocycle pulse generator Ultra-WideBand(UWB) Microwave bipolar transistor Step Recovery Diode(SRD)