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Scale effects of leaf area index inversion based on environmental and disaster monitoring satellite data

Science China Earth sciences 2010年第S1期53卷 92-98页

作者： ZHANG Hao1,LI XiaoWen1,2,CAO ChunXiang1,YANG Hua2,GAO MengXu1,3.ZHENG Sheng1,3.XU Min1,3.XIE DongHui2,JIA HuiCong1,JI Wei1,ZHAO Jian1,3.CHEN Wei1,3.& NI XiLiang1,3.1 State Key Laboratory of Remote Sensing Science,Jointly Sponsored by Institute of Remote Sensing Applications,chinese academy of sciences and{3. Normal university,beijing 100101,China 2 State Key Laboratory of Remote Sensing Science,Jointly Sponsored by{3. Normal university and Institute of Remote Sensing Applications of chinese academy of sciences,beijing 100875,China 3.graduate university of chinese academy of sciences,beijing 100049,China State Key Laboratory of Remote Sensing Science Jointly Sponsored by Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing China State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing Applications of Chinese Academy of Sciences Beijing China graduate university of chinese{3. of sciences Beijing China

The spatial distribution of sub-pixel components has an impact on retrieval accuracy,and should be accounted for when inverting a three-dimensional adiative transfer model to retrieve leaf area index(LAI).To investigate this effect,we constructed three realistic scenarios with the same LAI values and other properties,except that the simulated plants had different *** implemented the radiosity method to subsequently produce synthetic bidirectional reflectance factor(BRF) datasets based upon these simulated *** inversion was conducted using these data,which showed that spatial distribution affects retrieval *** inversion was also conducted for LAI based on charge-coupled device(CCD) data from the Environment and Disaster Monitor Satellite(HJ-1),which depicted both forest and drought-resistant crop land *** showed that heterogeneity in coarse-resolution remote sensing data is the main error source in LAI *** spatial distribution of global fractal dimension index,which can be used to describe the area of sub-pixel components and their spatial distribution modes,shows good consistency with the coarse resolution LAI inversion error.

关键词： HJ-1 leaf area index scale effect spatial distribution

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Testing local realism in P → VV decays

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Science China(Physics,Mechanics & Astronomy) 2010年第5期53卷 870-875页

作者： LI JunLi1 & QIAO CongFeng1,2 1Department of Physics,graduate university of chinese{3. of sciences,beijing 100049,China 2Theoretical Physics Center for Science Facilities(TPCSF),chinese{3. of sciences,beijing 100049,China Department of Physics Graduate University of Chinese Academy of Sciences Beijing China Theoretical Physics Center for Science Facilities (TPCSF) Chinese Academy of Sciences Beijing China

It was found that the vector meson pair from the pseudoscalar decays can form an entangled *** this work we give out detailed explanations on the polarization correlation of the two entangled vector *** is demonstrated that an experimental test of the Clauser-Horne inequality can be carried out through measuring the azimuthal distribution of four pseudoscalars in the cascade decay ηc→ VV →(PP)(PP),and the measurement of this process is feasible with the current running experiments in tau-charm ***,a brief discussion on the polarization correlation of the two vector mesons from B → VV decays is also presented.

关键词： nonlocality test high energy experiment meson decays

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fMRI time series analysis based on stationary wavelet and spectrum analysis

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Progress in Natural Science:Materials International 2006年第11期16卷 1171-1176页

作者： ZHI Lianhe~ 1,2,3., ZHAO Xia~4, SHAN Baoci~1**, PENG Silong~5, YAN Qiang~1, YUAN Xiuli~1 and TANG Xiaowei~ 1,6 (1. Key Laboratory of Nuclear Analysis Techniques, Institute of High Energy Physics, chinese academy of sciences,{3., China 2. graduate School of chinese academy of sciences,{3., China 3. Department of Physics, Zhoukou Normal university, Zhoukou 466100, China 4. Research Imaging Center, university of Texas Health Science Center, San Antonio, Texas 78229, USA 5. National ASIC Design and Engineering Center, Institute of Automation, chinese academy of sciences,{3., China 6. Department of Physics, Zhejiang university, Hangzhou 3.0027, China) Key Laboratory of Nuclear Analysis Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 China graduate School of chinese academy of{3. Beijing 100049 China Department of Physics Zhoukou Normal University Zhoukou 466100 China Research Imaging Center University of Texas Health Science Center San Antonio TX 78229 United States National ASIC Design and Engineering Center Institute of Automation Chinese Academy of Sciences Beijing 100049 China Department of Physics Zhejiang University Hangzhou 310027 China

The low signal to noise ratio (SNR) of functional MRI (fMRI) prefers more sensitive data analysis methods. Based on stationary wavelet transform and spectrum analysis, a new method with high detective sensitivity was developed for analyzing fMRI time series, which does not require any prior assumption of the characteristics of noises. In the proposed method, every component of fMRI time series in the different time-frequency scales of stationary wavelet transform was discerned by the spectrum analysis, then the components from noises were removed using the stationary wavelet transform, finally the components of real brain activation were detected by cross-correlation analysis. The results obtained from both simulated and in vivo visual experiments illustrated that the proposed method has much higher sensitivity than the traditional cross-correlation method.

关键词： fMRI stationary wavelet transform spectrum analysis data analysis.

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Nitrogen isotopic composition of plant-soil in the Loess Plateau and its responding to environmental change

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chinese Science Bulletin 2009年第2期54卷 272-279页

作者： LIU WeiGuo1,2 & WANG Zheng1,3.1 State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, chinese academy of sciences, Xi’an 710075, China 2 Xi’an Jiaotong{3., School of Human Settlement and Civil Engineering, Xi’an 710049, China 3.graduate{3. of chinese academy of sciences, beijing 100049, China State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Xi’an China School of Human Settlement and Civil Engineering Xi’an Jiaotong University Xi’an China graduate university of chinese{3. of sciences Beijing China

The nitrogen isotope of soil is of emerging significance as an indicator of climatic change and biogeochemical cycle of nitrogen in nature systems. In this paper, the nitrogen content and isotopic composition of modern ecosystems from arid and semiarid Loess Plateau in northwestern China, including plant roots and surface soil, were determined to investigate trends in δ15N variation of plant roots and soil along a precipitation and temperature gradient in northwestern China under the East Asian Monsoon climate condition. The δ15N values of surface soil from the study area vary from ?1.2‰ to 5.8‰, but from -5.1‰ to 1.9‰ in the plant roots. Our results indicate that (1) although the isotopic compositions of both plant roots and surface soil change with a similar trend along the climate gradient, the apparent nitrogen difference between plant roots and soil existed, with -δ15N values ranging from 0.3. to 7.2‰ with average of 4.1‰; and (2) mean annual precipitation (MAP) is the dominant factor for isotopic composition of plant-soil nitrogen in the Loess Plateau, and the δ15N values are less correlated with MAT; we suggest that nitrogen isotopic composition of soil is a potential tracer for environmental changes.

关键词：氮同位素物理性质化学性质环境论

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Floral organogenesis of Delavaya toxocarpa (Sapindaceae;Sapindales)

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Journal of Systematics and Evolution 2009年第3期47卷 237-244页

作者： 1,2,3.i-Min CAO 1Nian-He XIA 1(Institute of Economic Botany, South China Botanical Garden, chinese academy of sciences, Guangzhou 510650, China) 2(Department of Life sciences, Hengyang Normal university, Hengyang 421008, China) 3.graduate university of chinese academy of sciences, beijing 100049, China) (Institute of Economic Botany South China Botanical Garden Chinese Academy of Sciences Guangzhou 510650 China) (Department of Life sciences Hengyang Normal University Hengyang 421008 China) (graduate university of chinese{3. of sciences Beijing 100049 China)

The floral organogenesis and development of Delavaya toxocarpa Franch. (Sapindaceae) were studied under scanning electron microscope and light microscope to determine its systematic position within Sapindaceae. Flowers arise in terminal thyrses. The sepal primordia initiate in a spiral (2/5) sequence, which are not synchronous. The flve petal primordia initiate almost synchronously and alternate with sepal primordia. Eight stamens initiate almost simultaneously and their differentiation precedes that of the petals. The last formed petal and one stamen initiate from a common primordium. Mature stamens curve inwards and cover the ovary in bud. The gynoecium begins as a hemispheric primordium on which two carpellary lobes arise simultaneously. Later in development a single gynocium is formed with two locules and two ovules per locule. Floral morphology suggests a closer affinity with Sapindaceae, although certain features of floral ontogenesis are similar to those observed in certain members of the former Hippocastanaceae, such as Handeliodendron.

关键词： Delavaya toxocarpa Franch. floral organogenesis Hippocastanaceae Sapindaceae.

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The establishment of crystal position look-up table for positron emission tomography with block detectors

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Science China(Technological sciences) 2009年第8期52卷 2418-2423页

作者： CHAI Pei1,2 & SHAN BaoCi1 1 Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, chinese academy of sciences,{3., China 2 graduate university of chinese academy of sciences,{3., China Key Laboratory of Nuclear Analytical Techniques Institute of High Energy Physics Chinese Academy of Sciences Beijing China graduate university of chinese{3. of sciences Beijing China

A method has been developed to establish the crystal position look-up table for positron emission tomography with block detectors. It is based on the principle that the counts in crystal position histogram obey the Gaussian mixture model (GMM). This method has taken full consideration of the characteristics of the GMM and the detector itself. The experimental results have proved that it is simple, reliable, and universal.

关键词： positron emission tomography position look-up table 2-D position histogram

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Features and distribution patterns of chinese endemic seed plant species

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Journal of Systematics and Evolution 2011年第2期49卷 81-94页

作者： 1,2,3.Ji-Hong HUANG 1,4 Jian-Hua CHEN 5 Jun-Sheng YING 1 Ke-Ping MA 1 (State Key Laboratory of Vegetation and Environmental Change, Institute of Botany, chinese academy of sciences,{3. 100093. China) 2 (graduate university of chinese academy of sciences, beijing 100049, China) 3.(Center for Documentation and Information, Institute of Botany, chinese academy of sciences,{3. 100093. China) 4 (Zhejiang Normal university, Jinhua 3.1004, China) 5 (Research Center of Systematic and Evolutionary Botany, Institute of Botany, chinese academy of sciences,{3. 100093. China) (State Key Laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (graduate university of chinese{3. of sciences Beijing 100049 China) (Center for Documentation and Information Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Zhejiang Normal university Jinhua 321004 China) (Research Center of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China)

We compiled and identified a list of chinese endemic seed plant species based on a large number of published references and expert reviews. The characters of these seed plant species and their distribution patterns were described at length. China is rich in endemic seed plants, with a total of 14 93. species (accounting for 52.1% of its total seed plant species) belonging to 1584 genera and 191 families. Temperate families and genera have a significantly higher proportion of endemism than cosmopolitan and tropical ones. The most primitive and derived groups have significantly higher endemism than the other groups. The endemism of tree, shrub, and liana or vine is higher than that of total species; in contrast, the endemism of herb is lower than that of total species. Geographically, these chinese endemic plants are mainly distributed in Yunnan and Sichuan provinces, southwest China. Species richness and proportion of these endemic plants decrease with increased latitude and have a unimodal response to altitude. The peak value of proportion of endemism is at higher altitudes than that of total species and endemic species richness. The proportions of endemic shrub, liana or vine, and herb increase with altitude and have a clear unimodal curve. In contrast, the proportion of tree increases with altitude, with a sudden increase at ～4000 m and has a completely different model. To date, our study provides the most comprehensive list of chinese endemic seed plant species and their basic composition and distribution features.

关键词： biodiversity conservation distribution pattern endemism flora of China seed plants.

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Relationship between Surface Pollen and Modern Vegetation in Southwestern China

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Journal of Mountain Science 2010年第2期7卷 176-186页

作者： PAN Tao DAI Erfu and WU Shaohong Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China graduate university of chinese{3. of sciences BeO'ing 100049 China Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing 100085 China

Based on the pollen data obtained from thirty-five surface soil samples and investigated vegetation data from seven plant quadrats,the quantitative relationship between surface soil pollen and modern vegetation are studied in the longitudinal range-gorge region (LRGR) in Southwestern China.R-values (referring to pollen assemblages) are calculated with pollen percentage and plant *** coefficients of similarity between pollen and vegetation are *** results show that the pollen assemblages on surface soil of all vegetation zones can basically represent the native vegetation,but the pollen assemblages are not fully according with the *** is due to the influencing factors including pollen preservation ability,pollen production,amount of exotic pollen and pollen *** pollen representation in surface soil is different in families and *** pollen of woody plants such as Pinus,Tsuga,Alnus,Fagus and Castanopsis are over-representative,but those of Quercus,Carpinus Myrica,Elaeocarpaceae,Ericaceae,Theaceae and Llex are underrepresentative;the pollen of herbaceous plants such as Artemisia and Rubiaceae are over-representative,while those of others including Gramineae and Araliaceae are *** R-values of the same taxon pollen in different vegetation zones are different,depending on their distances from the pollen *** coefficients of the similarity between plant communities and pollen assemblages are mostly over 70%,which indicate again that the surface soil pollen and spores assemblages can represent the *** is concluded that there is a good corresponding relationship between surface pollen assemblages and native vegetation in LRGR,and it is of great significance for reconstructing the past vegetation and paleoclimate using quantitative fossil pollen data in this region.

关键词： Longitudinal range-gorge region (LRGR) Pollen assemblage Vegetation R-value Coefficient of similarity

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Validating global hydrological models by ground and space gravimetry

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chinese Science Bulletin 2009年第9期54卷 1534-1542页

作者： ZHOU JiangCun1,2,3. SUN HePing1,2 & XU JianQiao1,2 1 Institute of Geodesy and Geophysics, chinese academy of sciences, Wuhan 43.077, China 2 Key Laboratory of dynamic geodesy, chinese academy of sciences, Wuhan 43.077, China 3.graduate university of chinese academy of sciences, beijing 100049, China Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan China Key Laboratory of dynamic geodesy Chinese Academy of Sciences Wuhan China graduate university of chinese{3. of sciences Beijing China

The long-term continuous gravity observations obtained by the superconducting gravimeters (SG) at seven globally-distributed stations are comprehensively analyzed. After removing the signals related to the Earth's tides and variations in the Earth's rotation, the gravity residuals are used to describe the seasonal fluctuations in gravity field. Meanwhile, the gravity changes due to the air pressure loading are theoretically modeled from the measurements of the local air pressure, and those due to land water and nontidal ocean loading are also calculated according to the corresponding numerical models. The numerical results show that the gravity changes due to both the air pressure and land water loading are as large as 100×10-9 m s-2 in magnitude, and about 10×10-9 m s-2 for those due to the nontidal ocean loading in the coastal area. On the other hand, the monthly-averaged gravity variations over the area surrounding the stations are derived from the spherical harmonic coefficients of the GRACE-recovered gravity fields, by using Gaussian smoothing technique in which the radius is set to be 600 km. Com-pared the land water induced gravity variations, the SG observations after removal of tides, polar mo-tion effects, air pressure and nontidal ocean loading effects and the GRACE-derived gravity variations with each other, it is inferred that both the ground- and space-based gravity observations can effec-tively detect the seasonal gravity variations with a magnitude of 100×10-9 m s-2 induced by the land water loading. This implies that high precision gravimetry is an effective technique to validate the re-liabilities of the hydrological models.

关键词：重力测量水文模型模型验证和空间地面重力变化季节性波动空气压力

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Threshold quantum secure direct communication without entanglement

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Science China(Physics,Mechanics & Astronomy) 2008年第2期51卷 176-183页

作者： YANG YuGuang1,3.& WEN QiaoYan2 1 College of Computer Science and Technology, beijing university of Technology, beijing 100022, China 2 School of Science, beijing university of Posts and Telecommunications, beijing 100876, China 3.State Key Laboratory of Information Security (graduate School of chinese academy of sciences), beijing 100049, China College of Computer Science and Technology Beijing University of Technology Beijing China State Key Laboratory of Information Security (graduate School of chinese academy of{3.) Beijing China School of Science Beijing University of Posts and Telecommunications Beijing China

For the first time, a threshold quantum secure direct communication (TQSDC) scheme is presented. Similar to the classical Shamir's secret sharing scheme, the sender makes n shares, S1, …, Sn of secret key K and each receiver keeps a share secretly. If the sender wants to send a secret message M to the receivers, he en-codes the information of K and M on a single photon sequence and sends it to one of the receivers. According to the secret shares, the t receivers sequentially per-form the corresponding unitary operations on the single photon sequence and ob-tain the secret message M. The shared shares may be reusable if it can be judged that there is no eavesdropper in line. We discuss that our protocol is feasible with current technology.

关键词： quantum secure direct communication threshold secure direct communication quantum secret sharing

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