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Radiometric cross-calibration of the CBERS-02 CCD camera with the TERRA MODIS

Science china(Technological sciences) 2005年第S2期48卷 44-60页

作者： LI Xiaoying1,2,3. GU Xingfa1,3.4. MIN Xiangjun5, YU Tao1,3. FU Qiaoyan5, ZHANG Yong1,2,3.& LI Xiaowen1,3.1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of chinese Academy of sciences and beijing Normal University, beijing 100101, china 2. graduate University of chinese Academy of sciences, beijing 10003., china 3. The Center for National Spaceborne Demonstration, beijing 100101, china 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84.14.Avignon, France 5. china Center for Resource Satellite Data and Application, beijing 10083., china 1. State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University 100101 Beijing China 2. graduate University of chinese Academy of sciences 100039 Beijing China 3. The Center for National Spaceborne Demonstration 100101 Beijing China 4. Institut National de la Recherche Agronomique Climat Sol Environnement 84914 Avignon France 5. china Center for Resource Satellite Data and Application 100830 Beijing China

For the application of the CCD camera, the most important payload on CBERS-02, the key is to provide long-term stable radiometric calibration coefficients. Although the vicarious calibration had been proved successful, it had its limitations such as test site requirement and unsuitable for historical data. Cross-calibration is one of the alternative methods, but it needs synchro surface spectrum to achieve spectral band matching factors. Our effort is to probe the influences on these factors. Simulations with a lot of surface spectrum showed that the factors changed with the viewing geometry, atmospheric condition and surface targets. However, simulating with the same viewing geometry and atmospheric condition, the spectral band matching factors of the same or similar surface targets’ spectrum acquired from different dates and different places would like to be consistent to each other within 1%―5%. Thus, the synchro measurement data can be substituted by the same or similar target from other source. Based on this method, using the MODIS as the reference, the cross-calibration was performed for CCD camera. The research demonstrated that the traditional method with single calibration site was inappropriate for CCD camera, since the offsets for its four spectral bands were not zeros. With four calibration sites, these offsets were obtained. And the camera was detected to degrade with dates based on four times of cross-calibrations.

关键词： CBERS-02 CCD camera cross-calibration the spectral band matching factors.

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Fluorescence dynamics of interactions between polyamide PyPyPyβDp and DNA

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Science china Chemistry 2006年第1期49卷 75-80页

作者： ZHANG Huijuan1,2, WANG Jin3. WU Yishi1, YUAN Gu3. AI Xicheng1, WANG Li4.& ZHANG Jianping1 1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Institute of Chemistry, chinese Academy of sciences, {4. 100080,{3. 2. school of Life Science and Technology, {4. Institute of Technology, {4. 100081,{3. 3. College of Chemistry and Molecular Engineering, Peking University, {4. 100080,{3. 4. Center for Condensed Matter Physics, Institute of Physics, chinese Academy of sciences, {4. 100080,{3. Correspondence should be addressed to Ai Xicheng and Zhang Jianping 1. State Key Laboratory for Structural Chemistry of Unstable and Stable Species Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China 2. school of Life Science and Technology Beijing Institute of Technology Beijing 100081 China 3. College of Chemistry and Molecular Engineering Peking University Beijing 100080 China 4. Center for Condensed Matter Physics Institute of Physics Chinese Academy of Sciences Beijing 100080 China

The photophysical properties of the polyamide PyPyPyβDp (PPP) were investigated by means of steady-state absorption and fluorescence spectroscopies, as well as time-resolved fluo-rescence spectroscopy. It was found that the excited-state properties of PPP are very sensitive to solvents. In TKMC buffer PPP exhibited weak fluorescence with a decay time constant of 16 ps, while with the decrease of the solvent polarity PPP showed the blue-shifted peak position, increased inten-sity and lengthened life-time for its fluorescence behavior. In the presence of calf thymus DNA, it was observed that the fluorescence intensity was enhanced and the fluorescence lifetime increased from 16 to 3. ps for PPP, which verified that PPP bound into the minor groove of DNA duplex.

关键词： polyamide (PPP), calf thymus DNA (ctDNA), time-resolved fluorescence spectroscopy, recognition dynamics.

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Improvement of the SLP simulation in the coupled AGCM-ocean surface wave model

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chinese Science Bulletin 2005年第20期50卷 2397-2400页

作者： YU Weidong1, 2, 3. LI Zhaoxin4.& YUAN Yeli3.1. Institute of Oceanology, chinese Academy of sciences, Qingdao 266071,{4. 2. {3. school of chinese Academy of sciences, beijing 10004.,{4. 3. Laboratory of Marine Science and Numerical Modeling, First Institute of Oceanography, State Oceanic Administration, Qingdao 266061,{4. 4. LMD/CNRS, Univ. Paris 6, Paris, France Institute of Oceanology Chinese Academy of Sciences Qingdao 266071 China graduate school of chinese Academy of {3. Beijing 100049 China Laboratory of Marine Science and Numerical Modeling First Institute of Oceanography State Oceanic Administration Qingdao 266061 China LMD/CNRS Univ. Paris 6 Paris France

The coupled atmosphere-ocean general circulation models (CGCM) are nowbecoming the indispensable tools for the climate study. However, most models still suffer fromunrealistic simulations. One problem is the troublesome climate drift. It may come from someunresolved aspects. One possibility is the poor air-sea surface flux description now adopted inCGCM. The commonly used solution for this problem is the so-called flux correction. To deal with it,Hasslemann proposed an alternative solution of prospect. That is to incorporate the ocean surfacewave model into this coupled GCM system so as to establish a coupled atmosphere-wave-ocean *** necessity is clearly seen from the recent field experiment that air-sea momentum flux dependsstrongly on the sea state. So the explicit calculation of the air-sea flux with the aid of the oceansurface wave model is highly desired. Theoretical progress has provided feasibility to such ideaand experiments have been conducted. Recent work also reveals that coupling ocean surface wave modelwith oceanic general circulation model can result in much better reproduction of the upper oceanthermal structure. This further strengthens our belief in the final realization of the coupledatmosphere-wave-ocean modeling system.

关键词：大气海洋循环模式气象学 SLP模拟

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Thermal analysis of the baffle structure of the Solar Space Telescope

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Science china(Physics,Mechanics & Astronomy) 2010年第9期53卷 1755-1764页

作者： LI Rong1,2,3.& WANG Sen1,3.1 National Astronomical Observatories,chinese Academy of sciences,{4. 100012,{3. 2 graduate University of chinese Academy of sciences,{4. 10004.,{3. 3.Key Laboratory of Solar Activity,National Astronomical Observatories of chinese Academy of sciences,{4. 100012,{3. 1. National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Key Laboratory of Solar Activity National Astronomical Observatories of Chinese Academy of Sciences Beijing 100012 China

The SST(Space Solar Telescope) is an astronomical telescope with a primary mirror of 1 m in *** observes the sun with a small view field to ensure that its high spatial resolution imaging has 0.1″-0.15″ and high SNR(signal to noise ratio).Surrounding the small view field is still the sun,which is an intense source of both heat and stray *** baffles(the main baffle,the aperture,and the outer baffle),which are used to eliminate the stray light,will change the thermal flux in the SST and will weaken the effect of the thermal control *** this study,the compatibility analysis of the thermal effect of baffle structures in SST is *** GCF(Geometry Composing Function) and BRDF(Bidirectional Reflectance Distribution Function),which are two inherent related parameters in the compatibility analysis,are *** objective and method of the compatibility analysis are *** the thermal analysis software,the temperature fields are calculated for different lengths of the main baffle,different radii of apertures,different lengths of the outer baffle with a 3. tilt angle and 16' tilt angle,and different tilt angles of the outer baffle with a 200 mm length.A series of configurations and sizes of the baffles are studied with the goals of both thermal control and elimination of stray *** design of the baffle structure of SST is achieved:the main baffle of length 4.00 mm,the internal shield of radius 4.4.mm,the outer baffle of length 200 mm,and the outer baffle of tilt angle 3. are successfully *** paper presents the relationship between the thermal control design and stray light elimination plan in the *** aims of the optimal design of the baffle structure of SST are *** thoughts and methods of the optimal analysis are also useful for similar optical telescopes designed for solar observation.

关键词： baffle the main baffle the outer baffle GCF BRDF

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Optimization of mathematical models for thematic maps

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Science china(Technological sciences) 2010年第S1期53卷 15-24页

作者： QI QingWen1,ZHANG An1,JIANG LiLi1,ZOU XiuPing2,XU Li3.& CHENG Xi1,4.1 Institute of Geographical sciences and Natural Resources Research,chinese Academy of sciences,{3. 100101,china 2 Institute of Policy and Management,chinese Academy of sciences,{3. 100080,china 3.Taishan University,Taian 271021,china 4.graduate University of chinese Academy of sciences,{3. 10004.,china chinese Acad Sci Inst Geog Sci & Nat Resources Res Beijing 100101 Peoples R China chinese Acad Sci Inst Policy & Management Beijing 100080 Peoples R China Taishan Univ Tai An 271021 Shandong Peoples R China chinese Acad Sci Grad Univ Beijing 100049 Peoples R China

The thematic map is a major class of maps designed to demonstrate particular features or concepts,functioning as an indispensable tool in geographical *** process of thematic mapping is one into which geographical research goes deeply and *** key activity and course of thematic map production is the use of mathematical models to create thematic data ***,the selection and optimization of mathematical models is in the forefront of thematic map *** theoretical foundations,mechanisms and methods of mathematical model optimization are expounded in this paper,including two approaches,the phase by phase mode and the multi-aim scheme balance *** studies in eco-environment mapping and emergency mapping are described and analyzed,with a hierarchical analysis method being used in the model optimization for eco-environment fragility and sensitivity assessment mapping in Beibuwan (Guangxi) District,the dynamic system (DS) method being used in the model optimization for ecological security adjustment mapping in Xishuang Banna,Yunnan province,and the multi-phase mode being used in the models for forest fire and infectious diseases mapping.

关键词： thematic map mathematic model optimization

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Absolute radiometric calibration of CBERS-02 IRMSS thermal band

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Science china(Technological sciences) 2005年第S2期48卷 72-90页

作者： ZHANG Yong1,2,3. GU Xingfa1,3.4. YU Tao1,3. ZHANG Yuxiang5, CHEN Liangfu1,3. LI Xiaoying1,2,3. LI Xiaowen1,3.& HE Liming6 1. State Key Laboratory of Remote Sensing Science, Jointly Sponsored by the Institute of Remote Sensing Applications of chinese Academy of sciences and beijing Normal University, beijing 100101, china 2. graduate University of chinese Academy of sciences,{14., china 3. The Center for National Spaceborne Demonstration, beijing 100101, china 4. Institut National de la Recherche Agronomique, Climat Sol Environnement, 84.14.Avignon, France 5. National Satellite Meteorological Center, beijing 100081, china 6. State Environmental Protection Administration, beijing 100029, china chinese Acad Sci Inst Remote Sensing Applicat State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China beijing Normal Univ State Key Lab Remote Sensing Sci Beijing 100101 Peoples R China chinese Acad Sci Grad Univ Beijing 100039 Peoples R China Ctr Natl Spaceborne Demonstrat Beijing 100101 Peoples R China INRA F-84914 Avignon France Natl Satellite Meteorol Ctr Beijing 100081 Peoples R China State Environm Protect Adm Beijing 100029 Peoples R China

Based on the laboratory calibration before launch of CBERS-02 IRMSS thermal infrared channel, the onboard blackbody calibration, the radiometric cross- calibration against TERRA MODIS corresponding channel and the in-flight field calibration at Lake Qinghai: water surface radiometric calibration test site of china on Aug. 17, 2004.are carried out in this research. When making onboard blackbody calibration of CBERS-02 IRMSS, it is necessary to understand inside structures and light path in IRMSS camera and receive and process calibration blackbody signals at normal and high temperatures. Onboard blackbody calibration results of each detector are very important to relative radiometric calibration of images processing and absolute radiometric calibration of each detector. In-flight field calibration mainly contains field experiments, obtaining synchronous images, spectrum marching and MODTRAN radiative transmi- ssion computation. Radiometric cross-calibration of CBERS-02 IRMSS thermal band against TERRA MODIS selected 6 times synchronous images of two sensors passing through Lake Qinghai and Lake Taihu from August to December, 2004.to compute the cross calibration data. Combining the in-flight field calibration and radiometric cross calibration data, the absolute radiometric calibration coefficients are calculated by the linear regression method. This new calibration model can obviously control the radiometric calibration uncertainties aroused by the single point method used in the in-flight calibration of CBERS-02 IRMSS, this kind of sensors cannot receive the cosmic background radiation. In this research, the radiometric calibration coefficients obtained through the linear regression model are 8.53.(gain, unit: DN/W m?2sr?1μm?1) and 4..92 (offset, unit: DN).

关键词： CBERS-02 IRMSS thermal band in-flight field calibration onboard blackbody calibration cross calibration.

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Applications of URANS on predicting unsteady turbulent separated flows

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Acta Mechanica Sinica 2009年第3期25卷 319-324页

作者： Jinglei Xu Huiyang Ma Department of Physics, graduate University of the chinese Academy of sciences, 10004. {3.,{4. Department of Physics Graduate University of the Chinese Academy of Sciences 100049 Beijing China

Accurate prediction of unsteady separated turbulent flows remains one of the toughest tasks and a practi cal challenge for turbulence modeling. In this paper, a 2D flow past a circular cylinder at Reynolds number 3.900 is numerically investigated by using the technique of unsteady RANS （URANS）. Some typical linear and nonlinear eddy viscosity turbulence models （LEVM and NLEVM） and a quadratic explicit algebraic stress model （EASM） are evaluated. Numerical results have shown that a high-performance cubic NLEVM, such as CLS, are superior to the others in simulating turbulent separated flows with unsteady vortex shedding.

关键词： URANS Nonlinear eddy viscosity turbulencemodel ,Separated flows Circular cylinder

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A 12-bit multichannel ADC for pixel detectors in particle physics and nuclear imaging

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Science china(Technological sciences) 2010年第5期53卷 1208-1214页

作者： WEI Wei1,2,3.WANG Zheng1,3.& ZHAO JingWei1,3.1 Institute of High Energy Physics,chinese Academy of {4.,beijing 10004.,{3. 2 graduate University of chinese Academy of {4.,beijing 10004.,{3. 3.Key Lab of Nuclear Detection Technology and Nuclear Electronics of chinese Academy of {4.,beijing 10004.,{3. 1. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. Key Lab of Nuclear Detection Technology and Nuclear Electronics of Chinese Academy of Sciences Beijing 100049 China

Modern pixel detectors in nuclear and particle physics experiments and also in nuclear imaging,starve for highly integrated application specified integrated circuit(ASIC),whereas in china the study of ASIC still stays far away from practical *** lack of ASIC strictly limits the research and development of domestic high energy physics field.A 12-bit multichannel ADC designed for high density readout is introduced as a major candidate for solution.A precise model is discussed and the simulation fully agrees with the model,which indicates a key principle of *** is performed according to the given rule,and novel layout techniques are carried *** results in all aspects are also obtained,showing an excellent real performance,which satisfies the practical requirement.

关键词： application specified integrated circuit high density readout Wilkinson ADC multi-channel ADC

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Responses of soil respiration in non-growing seasons to environmental factors in a maize agroecosystem,Northeast china

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chinese Science Bulletin 2010年第24期55卷 2723-2730页

作者： LI RongPing1,2,3. ZHOU GuangSheng1,4.& WANG Yu1,3.1 State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, chinese Academy of sciences, {4. 100093.{3. 2 Institute of Atmospheric Environment,{3. Meteorological Administration, Shenyang 110016,{3. 3.graduate University of chinese Academy of sciences, {4. 10004.,{3. 4.chinese Academy of Meteorological sciences, {4. 100081,{3. State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China Institute of Atmospheric Environment China Meteorological Administration Shenyang 110016 China graduate University of chinese Academy of sciences Beijing 100049 China chinese Academy of Meteorological sciences Beijing 100081 China

Based on continuous three-year measurements (from 2004.to 2007) of eddy covariance and related environmental factors, environmental controls on variation in soil respiration (Rs) during non-growing season were explored in a maize agroecosystem in Northeast china. Our results indicated that during non-growing seasons, daily Rs was 1.08-4.08 g CO2 m-2 d-1, and the lowest occurred in late November. The average Rs of non-growing season was 4.6.06 ± 20.01 g CO2 m-2, accounting for 11% of the gross primary production (GPP) of the growing season. Additionally, at monthly scale, the lowest value of Rs appeared in January or February. From the beginning to the end of non-growing season, daily Rs tended to decrease first, and then increase to the highest. There was a significant quadratic curve relationship between Rs and soil temperature at 10 cm depth when soil temperature was more than 0°C (P3.%-70%. When soil water content was more than 0.1 m3.m-3. soil moisture at 10 cm depth was significantly parabolically correlated with Rs (P3.-79%. Meanwhile, the standard error of regression estimation between the values of prediction and observation for Rs could reach 2.7%-11.8%. Rs in non-growing season can account for 22.4. of Rs in growing season, indicating that it plays a critical role in assessing the carbon budget in maize agroecosystem, Northeast china.

关键词：中国东北地区农田生态系统生长季节土壤呼吸环境因素玉米土壤含水量反应

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Identification and removal of block ambiguities in sea surface wind field with scatterometers

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Science china Earth sciences 2009年第2期52卷 242-249页

作者： CHEN KeHai1,2, XIE XueTong3.& FANG Yu4.1 South china Sea Institute of Oceanology, chinese Academy of sciences, Guangzhou 5103.1, china 2 graduate University of chinese Academy of sciences, beijing 10004., china 3.school of Electronic Science and Engineering, National University of Defense Technology, Changsha 4.0073. china 4.The Institute of Remote Sensing and GIS, Peking University, beijing 100871, china 1. South china Sea Institute of Oceanology Chinese Academy of Sciences Guangzhou 510301 China 2. graduate University of chinese Academy of sciences Beijing 100049 China 3. school of Electronic Science and Engineering National University of Defense Technology Changsha 410073 China 4. The Institute of Remote Sensing and GIS Peking University Beijing 100871 China

The solution of the current wind retrieval algorithm for scatterometers has several wind vector ambi-guities, due to the bi-harmonic relationship between normalized backscattering cross section and the relative wind direction and the existence of the measurement error. In order to remove the ambiguities for a unique wind field, a circular median filter approach (CMF) is usually adopted. But under the con-dition for clustering distribution of the false ambiguities in some local areas, the CMF fails and thus engenders block ambiguities, which degrade the precision of the retrieved wind field. For such a situation, a technique of identification and removal of the block ambiguities is presented to further optimize the retrieved wind field after CMF. It is demonstrated in experiment that this technique can identify and remove most of the block ambiguities.

关键词： scatterometer block ambiguity identification and removal

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