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Photosynthetically active radiation retrieval based on HJ-1A/B satellite data

science china Earth {2. 2010年第S1期53卷 81-91页

作者： li li1,xin xiaozhou1,{2.,2.& liu qinhuo1 1 state key laboratory of remote Sensing science,institute of remote Sensing applications,chinese academy of sciences,beijing 100101,china 2.Zhejiang Climate Center,Hangzhou 310017,china 1. state key {2. of remote Sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China2. Zhejiang Climate Center Hangzhou 310017 China

Photosynthetically active radiation(PAR) is essential for plant photosynthesis and carbon cycle,and is also important for meteorological and environmental *** advance china's disaster and environmental monitoring capabilities,the HJ-1A/B satellites have been placed in Earth *** of their environmental monitoring objectives is the study of *** simulated direct solar,scattered and environment radiation between 400 and 700 nm under different atmospheric parameters(solar zenith angle,atmospheric water vapor,atmospheric ozone,aerosol optical thickness,surface elevation and surface albedo),and then established a look-up table between these input parameters and *** on the look-up table,we used HJ-1A/B aerosol and surface albedo outputs to derive the corresponding *** of inversed instantaneous and observed PAR values using HJ-1 Heihe experimental data had a root mean square error of 2..2.W m-2.with a relative error of 5.9%.The root mean square error for accumulated daily PAR and observed values was 0.49 MJ m-2.with a relative error of 3.5%.Our approach improved significantly the computational efficiency,compared with using directly radiation transfer *** also studied the sensitivity of various input parameters to photosynthetically active radiation,and found that solar zenith angle and atmospheric aerosols were sensitive PAR *** albedo had some effect on PAR,but water vapor and ozone had minimal impact on PAR.

关键词： Photosynthetically active radiation 6S HJ-1A/B satellites

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Cotton pixel identification with CBERS-02.CCD data based on spectral knowledge

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science china(Technological {2.) 2005年第S2期48卷 129-144页

作者： li Jing1,2.3, liu {2.,3, liu Qiang1, CHEN liangfu1, BO Junhua3 & li Shaokun3 1. state key laboratory of remote Sensing science, IRSA, chinese academy of sciences, {12. 100101, china 2. Graduate University of chinese academy of sciences, {12. 100049, china 3. The key Oasis Eco-agriculture laboratory of xinjiang Production and Construction Corps, Shi Hezi 832.00, china 1. state key {2. of remote Sensing science IRSA Chinese Academy of Sciences 100101 Beijing China 2. Graduate University of chinese academy of sciences 100049 Beijing China 3. The key Oasis Eco-agriculture laboratory of {2.jiang Production and Construction Corps 832000 Shi Hezi China

In this paper the in-situ experiment data are collected from the Spectral library to estimate the possible values of the primary structural parameters in each cotton growing season by statistics. Based on these values the spectra of the cotton major growing seasons were simulated and analyzed using the canopy reflectance model, SAILH. In this way we also simulated the cotton pixel spectra corresponding to CBERS-02.CCD and took them as the reference spectra for spectra fitting. Then No.143 Regiment of No.8 Agricultural Division of xinjiang Production and Construction Corps (XPCC) was chosen as the study area, and two spectra fitting methods, Mahalanobis distance and spectra angle, were used to identify cotton pixel from CBERS-02.CCD image of the study area. At last we analyzed the effect of the calibration coefficients error on cotton identifying. The results showed that within 4% error the spectral angle classifier can still have a good performance.

关键词： CBERS-02 cotton pixel identification spectra fitting.

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Estimating surface evapotranspiration using combined MODIS and CBERS-02.data

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science china(Technological {2.) 2005年第S2期48卷 145-160页

作者： xin xiaozhou1,2. liu {2., TANG Yong1,3, TIAN Guoliang1, GU xingfa1, li Xiaowen1,2. ZHENG Hongsheng4 & CHEN Jiayi4 1. state key laboratory of remote Sensing science, institute of remote Sensing applications, {12., beijing 100101, china 2. Research Center for remote Sensing and GIS, Department of Geography, beijing Normal University, beijing 100875, china 3. Graduate University of {12., beijing 100039, china 4. Department of Atmospheric Physics, Peking University, beijing 100871, china 1. state key {2. of remote Sensing science Institute of Remote Sensing Applications Chinese Academy of Sciences 100101 Beijing China2. Research Center for Remote Sensing and GIS Department of Geography Beijing Normal University 100875 Beijing China3. Graduate University of Chinese Academy of Sciences 100039 Beijing China4. Department of Atmospheric Physics Peking University 100871 Beijing China

Spatial scale error is one of the most serious problems in the estimates of land surface heat fluxes of sensible and latent from satellite-borne data such as MODIS 1km resolution reflectance and emissive data. One of the feasible and economic ways to decrease the spatial scale error is to use high resolution land use class data together with the MODIS data. CBERS-02.data were used to produce land use class of Baiyangdian area, Hebei Province, china in the autumn of 2.04. The area ratio of each class in MODIS pixel was calculated, and used to derive the heat fluxes of the mixed pixel. The results showed that the estimated heat fluxes of soil, sensible and latent have been changed remarkably after using the high resolution land class data. It could be concluded from the comparison between simulated and ground-measured fluxes as well as the theoretical analysis that high resolution land class data are useful to diminishing the scale error of heat fluxes estimated from low resolution satellite data.

关键词： surface evapotranspiration spatial scale error MODIS CBERS land class.

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Controllable Ring-opening Polymerization ofδ-Valerolactone Catalyzed by Quinolinyl-Urea/MTBD Systems

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chinese Journal of Polymer science 2024年第8期42卷 1103-1110页

作者： xin-Yu liu {2.ang Zhu su-Yun Jie Bo-Geng {2. state key {2. of Chemical Engineering College of Chemical and Biological EngineeringZhejiang UniversityHangzhou 310058China

Due to their excellent biocompatibility and biodegradability,aliphatic polyesters are widely used in the biomedical,packaging and agricultural fields,which are usually accessed by the ring-opening polymerization(ROP)of lactones and the catalysts particularly play an important *** a series of quinolinyl-urea catalysts have been synthesized via the reaction between isocyanate and aminoquinoline with an amino group at different substitution positions and *** combination with 7-methyl-1,5,7-triazabicyclo[4,4,0]dec-5-ene(MTBD)as a cocatalyst and benzyl alcohol(BnOH)as an initiator,1-(3,5-bis(trifluoromethyl)phenyl)-3-(quinolin-3-yl)urea(3-QU)was observed to be most active for the ROP ofδ-valerolactone(δ-VL).The polymerization conditions were optimized by varying the type of organic base,catalyst concentration and reaction *** changing the ratio of[M]_0/[I],linear polyvalerolactones(PVLs)with different molecular weights and narrow molecular weight distribution were *** kinetic and chain extension experiments were carried out to prove the"living"/controllable *** the NMR experiments were used to support the proposal of possible mechanism.

关键词： Quinolinyl-urea Ring-opening polymerization PVL

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A highly reduced Mo_(74) polyoxometalate featuring high proton conductivity accessed by building block strategy

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science china Chemistry 2024年第3期67卷 862-868页

作者： Shi-Yi liu Xue-xin {2. Wei-Chao Chen Kui-Zhan Shao xin-Long Wang Chao Qin Zhong-Min su key laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Department of ChemistryNortheast Normal UniversityChangchun 130024China state key {2. of supramolecular Structure and Materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction *** we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2.H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(2.)ⅥO_(2.2.(OH)_({2.(SO_(4))_(6)]·46H_(2.O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton ***,high proton conductivity(2.04×10^(-2.S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting *** result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.

关键词： polyoxometalate building block molybdenum highly reduced state proton conduction

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Post-earthquake assessment of building damage degree using liDAR data and imagery

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science china(Technological {2.) 2008年第S2期51卷 133-143页

作者： li ManChun1,CHENG liang1,2.GONG JianYa2.{2. YongXue1,CHEN ZhenJie1,li FeiXue1,CHEN Gang1,CHEN Dong1 & SONG XiaoGang3 1 Department of Geographic Information science,Nanjing University,Nanjing 2.0093,china 2.state key laboratory of Information Engineering in surveying,Mapping and remote Sensing,Wuhan University,Wuhan 430079,china 3 state key laboratory of Earthquake Dynamics,institute of Geology,china Earthquake Administration,beijing 10002.,china Department of Geographic Information science Nanjing University Nanjing 210093 China state key {2. of Information Engineering in surveying Mapping and Remote Sensing Wuhan University Wuhan 430079 China state key {2. of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China

Various methods have been developed to detect and assess building's damages due to earthquakes using remotely sensed *** the launch of the high resolution sensors such as IKONOS and QuickBird,it becomes rea{2.stic to identify damages on the scale of individual *** the low accuracy of the results has often led to the use of visual interpretation ***,it is very difficult to estimate the degree of building damage(*** damage,moderate damage,or severe damage) in detail using the existing ***,a novel approach integrating {2.DAR data and high resolution optical imagery is proposed for evaluating building damage degree *** approach consists of two steps:3D building model reconstruction and rooftop patch-oriented 3D change ***,a method is proposed for automatically reconstructing 3D building models with precise geometric position and fine details,using pre-earthquake {2.DAR data and high resolution ***,focusing on each rooftop patch of the 3D building models,the pre- and post-earthquake {2.DAR points belonging to the patch are collected and compared to detect whether it was destroyed or not,and then the degree of building damage can be identified based on the ratio of the destroyed rooftop patches to all rooftop *** novelty of the proposed approach is to detect damages on the scale of building's rooftop patch and rea{2.ze quantitative estimation of building damage degree.

关键词： post-earthquake assessment building damage degree rooftop patch liDAR imagery

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Quantitative estimation of the shrub canopy LAI from atmosphere-corrected HJ-1 CCD data in Mu Us Sandland

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science china Earth {2. 2010年第S1期53卷 26-33页

作者： CHEN Wei1,2,CAO ChunXiang1,HE QiSheng1,2,GUO HuaDong3,ZHANG Hao1,2,li RenQiang4,ZHENG Sheng1,2,XU Min1,2,GAO MengXu1,2,ZHAO Jian1,2,li Sha1,NI Xiliang1,2,JIA HuiCong1,JI Wei1,TIAN Rong1,2,liu Cheng1,2,ZHAO Yuxing5 & li JingLu6 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 100049,china 3 Center for Earth Observation and Digital Earth,chinese academy of sciences,beijing 100190,china 4 china key laboratory of Ecological Network Observation and Modeling,institute of Geographical sciences and Natural Resources Research,chinese academy of sciences,beijing 100101,china 5 Ordos Forestry Sand Control science institute,Dongsheng 017000,china 6 Inner Mongolia Biomass Thermoelectricity limited Company,Wushen 017300,china 1. state key {2. 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 100049 China 3. Center for Earth Observation and Digital Earth Chinese Academy of Sciences Beijing 100190 China 4. china key {2. of Ecological Network Observation and Modeling Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China 5. Ordos Forestry Sand Control science institute Dongsheng 017000 China 6. Inner Mongolia Biomass Thermoelectricity limited Company Wushen 017300 China

The leaf area index(LAI) is an important ecological parameter that characterizes the interface between vegetation canopy and the *** addition,it is used by most process-oriented ecosystem *** paper investigates the potential of HJ-1 CCD data combined with linear spectral unmixing and an inverted geometric-optical model for the retrieval of the shrub LAI in Wushen Banner of Inner Mongolia in the Mu Us ***(Moderate Resolution Atmospheric Radiance and Transmittance Model) was used for atmospheric *** was extracted using the threshold of the normalized difference vegetation index,with which water bodies and farmland were separated,in combination with a vegetation map of the People's Republic of china(1:1000000).Using the geometric-optical model,we derive the per-pixel reflectance as a simple linear combination of two components,namely sunlit background and *** fraction of sunlit background is related to the shrub *** the support of HJ-1 CCD data,we employ linear spectral unmixing to obtain the fraction of sunlit background in an atmospherically corrected HJ *** addition,we use the measured shrub canopy structural parameters for shrub communities to invert the geometric-optical model and retrieve the pixel-based shrub *** total,18 sample plots collected in Wushen Banner of Inner Mongolia are used for *** results of the shrub LAI show good agreement with R2.of 0.817 and a root-mean-squared error of 0.173.

关键词： shrub leaf area index inversion HJ-1 data geometric-optical model MODTRAN Mu Us Sandland

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Application of ensemble kalman filter to geophysical parameters retrieval in remote sensing:A case study of kernel-driven BRDF model inversion

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science china Earth {2. 2006年第6期49卷 632-640页

作者： QIN Jun1, YAN Guangjian1, liu Shaomin1, liANG Shunlin2. ZHANG Hao1, WANG Jindi1 & li Xiaowen1 1. state key laboratory of remote Sensing science, School of Geography and remote Sensing, Research Center for RS&GIS, beijing Normal University, beijing 100875, {12. 2. Department of Geography, 2.81 Lefrak Hall, University of Maryland, College Park, MD2.742. USA 1. state key {2. of remote Sensing science School of Geography and Remote Sensing Research Center for RS&GIS Beijing Normal University Beijing 100875 China 2. Department of Geography 2181 Lefrak Hall University of Maryland College Park MD20742 USA

The use of a priori knowledge in remote sensing inversion has great implications for en{2.ring the stability of inversion process and reducing uncertainties in retrieved re{2.lts, especially under the condition of in{2.fficient observations. Common optimization algorithms have difficulties in providing posterior distribution and thus cannot directly acquire uncertainties in inversion re{2.lts, which is of no benefit to remote sensing application. In this article, ensemble Kalman filter (EnKF) has been introduced to retrieve {2.rface geophysical parameters from remote sensing observations, which has the capability of not merely obtaining inversion re{2.lts but also giving its posterior distribution. To show the advantage of EnKF, it is compared to standard MODIS AMBRALS algorithm and highly effi-cient global optimization method SCE-UA. The inversion abilities of kernel-driven BRDF models with different kernel combinations at several main cover types are emphatically discussed when observa-tions are deficient and a priori knowledge is introduced into inversion.

关键词： remote sensing inversion, a priori knowledge, posterior distribution, ensemble kalman filter, BRDF, kernel-driven model, albedo.

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Exceptional electrostrain with minimal hysteresis and superior temperature stability under low electric field in KNN-based lead-free piezoceramics

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Journal of Advanced Ceramics 2024年第3期13卷 364-372页

作者： Huan liu Yijin Hao Ziqi Yang Tianyi Feng Bin su {2. Zhang Mengping Xue Bo-Ping Zhang Jing-Feng li beijing Municipal key {2. of New Energy Materials and Technologies School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China state key {2. of New Ceramics and Fine Processing School of Materials Science and EngineeringTsinghua UniversityBeijing 100084China

Over the past two decades,(K_(0.5)Na_(0.5))NbO_(3)(KNN)-based lead-free piezoelectric ceramics have made significant ***,attaining a high electrostrain with remarkable temperature stability and minimal hysteresis under low electric fields has remained a significant *** address this long-standing issue,we have employed a collaborative approach that combines defect engineering,phase engineering,and relaxation *** LKNNS-6BZH ceramic,when sintered at T_(sint)=1170℃,demonstrates an impressive electrostrain with a d_(33) value of 0.2.6%and 1379 pm·V^(-1)under 2. kV·cm^(-1),which is comparable to or even surpasses that of other lead-free and Pb(Zr,Ti)O_(3)***,the electrostrain performance of this ceramic remains stable up to a temperature of 12.℃,with the lowest hysteresis observed at 9.73%under 40 kV·cm^(-1).These excellent overall performances are attributed to the presence of defect dipoles involving V′_(A)-V∙∙_(O) and B′_(Nb)-V∙∙O,the coexistence of R-O-T multiphase,and the tuning of the trade-off between long-range ordering and local *** work provides a lead-free alternative for piezoelectric actuators and a paradigm for designing piezoelectric materials with outstanding comprehensive performance under low electric fields.

关键词： lead-free piezoelectric ceramics temperature stability electrostrain potassium sodium niobate low hysteresis

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Study of proton resonances in ^(18)Ne via resonant elastic scattering of ^(17)F+p and its astrophysical implication

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science china(Physics,Mechanics & Astronomy) 2011年第S1期54卷 32-36页

作者： HE JianJun1, HU Jun1,2, XU ShiWei1, CHEN ZhiQiang1, ZHANG XueYing1, WANG JianSong1, YU XiangQing1, ZHANG liYong1,2, li Long1,2, YANG YanYun1,2, MA Peng1,2, ZHANG XueHeng1, HU ZhengGuo1, GUO ZhongYan1, XU xing1,2, YUAN XiaoHua1, LU Wan1,2, YU YuHong1, ZANG YongDong1,2, TANG ShuWen1,2, YE RuiPing1,2, CHEN JinDa1,2, JIN ShiLun1,2, DU ChengMing1,2, WANG ShiTao1,2, MA JunBing1,2, liu LongXiang1,2, BAI Zhen1,2, LEI XiangGuo1, suN ZhiYu1, ZHANG YuHu1, ZHOU XiaoHong1, XU HuShan1, su Jun3, li ErTao3, WANG HongWei4, TIAN WenDong4 & li XiangQing5 1 institute of Modern Physics (IMP), chinese academy of sciences, Lanzhou 730000, china 2 Graduate University of chinese academy of sciences, beijing 100049, china 3 china institute of Atomic Energy (CIAE), beijing 102413, china 4 Shanghai institute of Applied Physics (SINAP), chinese academy of sciences, Shanghai 201800, china 5 School of Physics and state key laboratory of Nuclear Physics and Technology, Peking University, beijing 100871, china 1. institute of Modern Physics (IMP) Chinese Academy of Sciences Lanzhou 730000 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China3. China Institute of Atomic Energy (CIAE) Beijing 102413 China4. Shanghai Institute of Applied Physics (SINAP) Chinese Academy of Sciences Shanghai 201800 China5. School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking University Beijing 100871 China

The proton resonant properties in 18Ne, which determine the reaction rate of the key stellar 14O(α,p)17F reaction, have been studied by using a technique of proton resonant elastic scattering of 17F+p. A 4.2. MeV/nucleon 17F radioactive ion (RI) beam was produced via a projectile-fragmentation reaction, and separated by a Radioactive Ion Beam line in Lanzhou (RIBLL). By bombarding a thick (CH2.n target, the energy spectra of the recoiled protons were mea{2.red by two ΔE-E silicon telescopes at the center-of-mass scattering angles of θc.m.≈175°±5°, θc.m.≈152.±8°, respectively. Several proton resonances in 18Ne were ob served clearly. A further R-matrix analysis of the experimental data is under way to determine the resonant parameters. The present work reports the preliminary re{2.lts briefly.

关键词： resonant reaction reaction rate explosive burning accreting binary systems

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