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Land cover changes based on plant successions: Deforestation, rehabilitation and degeneration of forest in the upper Dadu River watershed

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Science china Earth sciences 2005年第12期48卷 2214-2230页

作者： YAN Jianzhong1,2.3. ZHANG Yili1, BAI Wanqi1, LIU Yanhua4, BAO Weikai5, LIU Linshan1, 2.& ZHENG Du1 1. institute of Geographic {3. and Natural Resources Research, Chinese Academy of {3., beijing 100101, china 2. Graduate School of the Chinese Academy of {3., beijing 10003., china 3. College of Resources and Environment, Southwest Agricultural University, Chongqing 400716, china 4. The Ministry of Science and Technology, P. C. china, beijing 100862. china 5. Chengdu institute of Biology, Chinese Academy of {3., Chengdu 610041, china institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Graduate School of the Chinese Academy of sciences Beijing China College of Resources and Environment Southwest Agricultural University Chongqing China The Ministry of Science and Technology P. C. China Beijing China Chengdu institute of Biology Chinese Academy of Sciences Chengdu China

To link regional land use/cover changes with environmental effects, land cover changes are required to reflect vegetation successions, whereas the land cover classification systems commonly used nowadays cannot serve this purpose. In this paper, a new land cover classification system is established in which land covers are classified by the vegetation succes-sions, taking Zamtang County, Barkam County and Jinchuan County in the upper Dadu River watershed as a study area. Using multi-temporal remote sensing images, the land cover data of 1967, 1986 and 2.00 are obtained by means of integration of unsupervised classification and visual interpretation methods. The database facilitates the study of land use/cover changes, en-vironmental effects and ecological construction. Land cover changes reflect the main ecological processes in the upper Dadu River watershed. The landscape composed mainly of grasslands, wildwoods and alpine scrubs in 1967 was changed to that of grasslands, secondary forests, al-pine scrubs, fragmentary wildwoods, artificial forests, secondary scrubs in 2.00, meanwhile, the landscape got more fragmentized. The total area of the forests decreased by 9.43.. Study results have shown the process of restoration of logged areas in forest centers. From 1967 to 2.00, only 6.86 percents of logged areas were converted to shrubs, meadows or crop-lands, and the rest were converted into artificial forests or secondary forests. So the ecological shelter functions will be restored, stage by stage. Firewood collection, charcoal production and overgrazing are the three major triggers for the extensive degradation of alpine oak forests, Sa-bina tibetica forests and meadows. The arid valley grasslands expanded too. The degradation of vegetation in the southern slopes impairs ecological shelter functions and affects livelihood of local residents, so it is essential to find effective measures for ecological restoration and recon-struction. Field investigations have found

关键词： land use/cover classification, upper Dadu River watershed, vegetation successions, GIS, RS.

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On conformal measures for infinitely renormalizable quadratic polynomials

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Science china Mathematics 2005年第10期48卷 1411-1420页

作者： HUANG Zhiyong~1 JIANG Yunping~(2.3. & WANG Yuefei~3.1. School of information,Renmin University of china,{2. 100872.china 2. Department of Mathematics,Queens College,City University of New York,NY 113.7,USA Department of Mathematics,Graduate School,City University of New York,New York,NY 10016,USA 3. Academy of Mathematics and Systems Science,Chinese Academy of sciences,{2. 100080,china School of information Renmin University of China Beijing China Department of Mathematics Queens College City University of New York NY USA Department of Mathematics Graduate School City University of New York New York USA Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing China

We study a conformal measure for an infinitely renormalizable quadratic polynomial. We prove that the conformal measure is ergodic if the polynomial is unbranched and has complex bounds. The main technique we use in t... 详细信息

关键词： Julia set, conformal measure, three-dimensional puzzle, infinitely renormalizable quadratic polynomial.

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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 {2., beijing 100093. china) 2.(Graduate University of Chinese Academy of {2., beijing 100049, china) 3.(Center for Documentation and information, institute of Botany, Chinese Academy of {2., beijing 100093. china) 4 (Zhejiang Normal University, Jinhua 3.0}004, china) 5 (Research Center of Systematic and Evolutionary Botany, institute of Botany, Chinese Academy of {2., beijing 100093. china) (State Key laboratory of Vegetation and Environmental Change Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (Graduate University of Chinese Academy 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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Communication network designing:Transmission capacity,cost and scalability

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Science china(information {2.) 2012年第11期55卷 2454-2465页

作者： ZHANG GuoQiang1,2.3.& ZHANG GuoQing1 1institute of Computing Technology,Chinese Academy of sciences,{2. 100190,china 2.chool of Computer Science and Technology,Nanjing Normal University,Nanjing 2.0046,china 3.rovincial Key laboratory for Computer information processing Technology,Soochow University,Suzhou 2.5000,china institute of Computing Technology Chinese Academy of Sciences Beijing China School of Computer Science and Technology Nanjing Normal University Nanjing China Provincial Key laboratory for Computer information {2. Technology Soochow University Suzhou China

Despite the growing number of works centering around the traffic dynamics on complex networks,these researches still have some common shortcomings,e.g.,too simple traffic flow model and lack of considerations for the designing cost and scalability *** paper builds on a more realistic traffic flow model,and offers a holistic view on the network designing *** addition to the extensively studied transmission capacity,this paper takes designing cost and scalability as two other designing objectives,and presents a quantitative study of how different designing choices independently and collectively influence these objectives by the introduction of a cartesian coordinate *** is shown that different kinds of network topologies display different shapes of achievable solution spaces and exhibit different abilities to achieve cost-effective and scalable *** particular,we find the philosophy underlying empirical network designing and engineering today fails to meet the cost-effective and scalable designing requirements,and propose a cost-effective and scalable designing scheme for BA-like networks,i.e.,the efficient routing combined with effective betweenness based link bandwidth *** addition,when designing a thoroughly new network from the beginning,we find that ER network is a good candidate to achieve cost-effective and scalable designing in most settings.

关键词： cost-effective communication network designing network transmission efficiency network topology traffic dynamics next generation network scalable network designing

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Research progress on Drosophila visual cognition in china

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Science china(Life sciences) 2010年第3期53卷 374-384页

作者： GUO AiKe1,2.ZHANG Ke1,PENG YueQin1 & XI Wang1 1 institute of Neuroscience,State Key laboratory of Neuroscience,Shanghai institutes for Biological sciences,Chinese Academy of sciences,Shanghai 2.003.,china 2.State Key laboratory of Brain and Cognitive Science,institute of biophysics,Chinese Academy of sciences,beijing 100101,china institute of Neuroscience State Key Laboratory of Neuroscience Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai China State Key laboratory of Brain and Cognitive Science Institute of Biophysics Chinese Academy of Sciences Beijing China

visual cognition,as one of the fundamental aspects of cognitive neuroscience,is generally associated with high-order brain functions in animals and ***,as a model organism,shares certain features of visual cognition in common with mammals at the genetic,molecular,cellular,and even higher behavioral *** learning and memory to decision making,Drosophila covers a broad spectrum of higher cognitive behaviors beyond what we had *** with powerful tools of genetic manipulation in Drosophila,an increasing number of studies have been conducted in order to elucidate the neural circuit mechanisms underlying these cognitive behaviors from a genes-brain-behavior *** goal of this review is to integrate the most important studies on visual cognition in Drosophila carried out in {3.'s Mainland during the last decade into a body of knowledge encompassing both the basic neural operations and circuitry of higher brain function in ***,we consider a series of the higher cognitive behaviors beyond learning and memory,such as visual pattern recognition,feature and context generalization,different feature memory traces,salience-based decision,attention-like behavior,and cross-modal leaning and *** discuss the possible general gain-gating mechanism implementing by dopamine-mushroom body circuit in fly's visual *** hope that our brief review on this aspect will inspire further study on visual cognition in flies,or even beyond.

关键词： visual invariance recognition visual memory traces feature and context generalization selective attention cross-modality memory integration salience-based decision making

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配对螺旋样纤维(PHF)-Tau与神经细胞的死亡

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生物化学与生物物理进展 2001年第4期28卷 441-443页

作者：聂春来视觉信息加工开放实验室

神经纤维缠结 (neurofibrillarytangles ,NFT)是老年性痴呆病的重要病理特征 ,人类神经tau分子聚集形成的配对螺旋样纤维 (pairedhelicalfilaments ,PHF)是NFT的主要成分 .最近研究表明 ,PHF与神经细胞的坏死和程序化死亡密切相关。

关键词：神经tau 氧自由基配对螺旋样纤维老年性痴呆病神经细胞死亡

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An ID-based authenticated dynamic group key agreement with optimal round

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Science china(information {2.) 2012年第11期55卷 2542-2554页

作者： TENG JiKai1,2.WU ChuanKun1 & TANG ChunMing3.1State Key laboratory of information Security,{2. of Software of Chinese Academy of sciences,beijing 100090,china 2.raduate University of Chinese Academy of sciences,beijing 100049,china 3.aculty of Mathematic and information Science,Guangzhou University,Guangzhou 510006,china State Key laboratory of information Security Institute of Software of Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of sciences Beijing China Faculty of Mathematic and information Science Guangzhou University Guangzhou China

Group key agreement protocols are crucial for achieving secure group *** are designed to provide a set of users with a shared secret key to achieve cryptographic goal over a public *** group membership changes,the session key should be refreshed efficiently and *** previous group key agreement protocols need at least two rounds to establish or refresh session *** this paper,a dynamic authenticated group key agreement(DAGKA) protocol based on identity-based cryptography is *** making use of the members' values stored in previous sessions,our Join and Leave algorithms reduce the computation and communication costs of *** the proposed protocol,Setup and Join algorithms need one *** session key can be refreshed without message exchange among remaining users in Leave algorithm,which makes the protocol more *** security is proved under decisional bilinear Diffie-Hellman(DBDH) assumption in random oracle model.

关键词： identity-based cryptography dynamic group key agreement provably secure admissible pairing

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The correspondence between the concepts in description logics for contexts and formal concept analysis

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Science china(information {2.) 2012年第5期55卷 1106-1122页

作者： MA Yue 1,2.SUI YueFei 1 & CAO CunGen 1 1 Key laboratory of Intelligent information {2.,institute of Computing Technology,Chinese Academy of sciences,beijing 100190,china 2.Graduate University of Chinese Academy of sciences,beijing,china Key laboratory of Intelligent information {2. Institute of Computing Technology Chinese Academy of Sciences Beijing China Graduate University of Chinese Academy of sciences Beijing China

Formal concept analysis (FCA) and description logic (DL) are meant to be formalizations of concepts.A formal concept in the former consists of its intent and extent,where the intent is the set of all the attributes shared by each object in the extent of the concept,and the extent is the set of all the objects sharing each property in the intent of the concept.A concept in the latter formalization is simply a concept name,the interpretation of which is a subset of a *** consider the correspondence between concepts in both formalizations,a multi-valued formal context must be represented both as a knowledge base and as a model of the DL for contexts,where concepts are decomposed into tuple concepts C,interpreted as a set of tuples and value concepts V,interpreted as a set of attribute-value *** show that there is a difference between the interpretation of concepts R.V /R.C and the Galois connection between the extent/intent of formal concepts in *** to the Galois connection,there should be concepts of the form + R.V and + R.C inter-preted in FCA,and hence the logical language L for DL is extended to be L + together with + as a constructor so that + R.V and + R.C are well-defined ***,according to the interpretation in DL there should be pseudo concepts in FCA so that the interpretation of concepts R.V /R.C is the extent/intent of pseudo *** correspondence between formal concepts and concepts in L +,and between pseudo concepts and concepts in L are presented in this paper.

关键词： description logic formal concept analysis concept attribute/role

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Entropy product measure for multipartite pure states

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Science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 606-615页

作者： CAO Wancang1,2. LIU Dan2. PAN Feng3.& LONG Guilu2.4 1. Department of Physics, Chifeng College, Chifeng 02.001, china 2. Key laboratory for Quantum {2. and Measurements, Department of Physics, Tsinghua University, beijing 100084, china 3. Department of Physics, Liaoning Normal University, Dalian 11602., china 4. Key laboratory for Atomic and Molecular Nano-{13., Tsinghua University, beijing 100084, china Correspondence should be addressed to Long Guilu Department of Physics Chifeng College Chifeng China Key laboratory for Quantum information and Measurements Department of Physics Tsinghua University Beijing China Department of Physics Liaoning Normal University Dalian China Key laboratory for Atomic and Molecular Nano-sciences Tsinghua University Beijing China

An entanglement measure for multipartite pure states is formulated using the product of the von Neumann entropy of the reduced density matrices of the constituents. Based on this new measure, all possible ways of the maximal entanglement of the triqubit pure states are studied in detail and all types of the maximal entanglement have been compared with the result of ‘the average entropy’. The new measure can be used to calculate the degree of entanglement, and an improvement is given in the area near the zero entropy.

关键词： multipartite pure state von Neumann entropy entanglement measure

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Fusion tracking in color and infrared images using joint sparse representation

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Science china(information {2.) 2012年第3期55卷 590-599页

作者： LIU HuaPing1,2.3.& SUN FuChun1,2.3.1Department of Computer Science and Technology, Tsinghua University, beijing 100084, {3. 2.tate Key {2. of Intelligent Technology and Systems, beijing 100084, {3. 3.singhua National {2. for information Science and Technology, beijing 100084, {3. Department of Computer Science and Technology Tsinghua University Beijing China State Key laboratory of Intelligent Technology and Systems Beijing China Tsinghua National laboratory for information Science and Technology Beijing China

Currently sparse signal reconstruction gains considerable interest and is applied in many fields. In this paper, a similarity induced by joint sparse representation is designed to construct the likelihood function of particle filter tracker so that the color visual spectrum and thermal spectrum images can be fused for object tracking. The proposed fusion scheme performs joint sparse representation calculation on both modalities and the resultant tracking results are fused using min operation on the sparse representation coefficients. In addition, a co-learning approach is proposed to update the reference templates of both modality and enhance the tracking robustness. The proposed fusion scheme outperforms state-of-the-art approaches, and its effectiveness is verified using OTCBVS database.

关键词： joint sparse representation fusion tracking color image infrared image

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