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Retrieving crop leaf area index by assimilation of MODIS data into a crop growth model

Science China Earth Sciences 2010年第5期53卷 721-730页

作者： WANG DongWei1,2,3, WANG JinDi1,2 & LIANG ShunLin4 1 State Key Laboratory of Remote Sensing Science, Jointly Sponsored by Beijing Normal university and Institute of Remote Sensing Applications, CAS, Beijing 100875, China 2 School of geography, Beijing Key Laboratory of Environmental Remote Sensing and Digital City, Beijing Normal university, Beijing 100875, China 3 Haihe River Water Conservancy Commission, Tianjin 300170, China 4 department of geography, university of Maryland, College Park, MD 20742, USA 1. State Key Laboratory of Remote Sensing Science Jointly Sponsored by Beijing Normal University and Institute of Remote Sensing Applications CAS Beijing 100875 China2. School of Geography Beijing Key Laboratory of Environmental Remote Sensing and Digital City Beijing Normal University Beijing 100875 China3. Haihe River Water Conservancy Commission Tianjin 300170 China4. Department of Geography University of Maryland College Park MD 20742 USA

Leaf area index (LAI) is an important parameter in monitoring crop growth. One of the methods for retrieving LAI from remotely sensed observations is through inversion of canopy reflectance models. Many model inversion methods fail to account for variable LAI values at different crop growth stages. In this research, we use the crop growth model to describe the LAI changes with crop growth, and consider a priori LAI values at different crop growth stages as constraint information. The key approach of this research is to assimilate multiple canopy reflectance values observed at different growth stages and a priori LAI values into a coupled crop growth and radiative transfer model sequentially using a variational data assimilation algorithm. Adjoint method is used to minimize the cost function. Any other information source can be easily incorporated into the inversion cost function. The validation results show that the time series of MODIS canopy reflectance can greatly reduce the uncertainty of the inverted LAI values. Compared with MODIS LAI product at Changping and Shunyi Counties of Beijing, this method has significantly improved the estimated LAI temporal profile.

关键词： inversion leaf area index crop growth model time series MODIS

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Recent Developments on Quantum Molecular Dynamics

Recent Developments on Quantum Molecular Dynamics

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第九届全国化学动力学会议

作者： Dong Hui Zhang Center for Theoretical & Computational Chemistry and State Key Laboratory of Chemical Reaction Dynamics, Dalian Institute of Chemical Physics, Dalian, China & department of Computational Science, national university of singapore, singapore, 119260

＜正＞In this talk, I will first briefly present some recent developments made in our group on studying chemical reaction dyanmics in gas-phase, including qunatum reaction dynamics for the F + H2, F + HD reactions on ...

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Geometric construction of energy-minimizing Bézier curves

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Science China(Information Sciences) 2011年第7期54卷 1395-1406页

作者： XU Gang 1,4,5,WANG GuoZhao 2 & CHEN WenYu 2,3 1 Institute of Graphics and Image,Hangzhou Dianzi university,Hangzhou 310018,China 2 department of Mathematics,Zhejiang university,Hangzhou 310027,China 3 School of Computer Engineering,Nanyang Technological university,639798,singapore 4 Galaad,INRIA Sophia-Antipolis,2004 Route des Lucioles,06902,France 5 State Key Lab of CAD & CG,Zhejiang university,Hangzhou 310027,China Institute of Graphics and Image Hangzhou Dianzi University Hangzhou China Galaad INRIA Sophia-Antipolis Sophia Antipolis France State Key Lab of CAD & CG Zhejiang University Hangzhou China department of Mathematics Zhejiang University Hangzhou China School of Computer Engineering Nanyang Technological University Singapore Singapore

Modeling energy-minimizing curves have many applications and are a basic problem of Geometric *** this paper,we propose the method for geometric design of energy-minimizing B′ezier ***,the necessary and sufficient condition on the control points for B′ezier curves to have minimal internal energy is *** on this condition,we propose the geometric constructions of three kinds of B′ezier curves with minimal internal energy including stretch energy,strain energy and jerk *** some control points,the other control points can be determined as the linear combination of the given control *** compare the three kinds of energy-minimizing B′ezier curves via curvature combs and curvature plots,and present the collinear properties of quartic energy-minimizing B′ezier *** also compare the proposed method with previous methods on efficiency and ***,several applications of the curve generation technique,such as curve interpolation with geometric constraints and modeling of circle-like curves are discussed.

关键词： curve design minimal energy geometric construction interpolation with constraints circle-like curves

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Complete solving of explicit evaluation of Gauss sums in the index 2 case

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Science China Mathematics 2010年第9期53卷 2525-2542页

作者： YANG Jing1,2 & XIA LingLi3,1department of Mathematical Sciences,Tsinghua university,Beijing 100084,China 2Division of Mathematical Sciences,School of Physical and Mathematical Sciences,Nanyang Technological university,637371,singapore 3Basic Courses department,Beijing Union university,Beijing 100101,China 1. department of Mathematical Sciences Tsinghua University Beijing 100084 China2. Division of Mathematical Sciences School of Physical and Mathematical Sciences Nanyang Technological University 637371 Nanyang Singapore3. Basic Courses Department Beijing Union University Beijing 100101 China

Let p be a prime number,N be a positive integer such that gcd(N,p) = 1,q = pf where f is the multiplicative order of p modulo *** χ be a primitive multiplicative character of order N over finite field *** paper studies the problem of explicit evaluation of Gauss sums G(χ) in the "index 2 case"(i.e.[(Z/NZ):] = 2).Firstly,the classification of the Gauss sums in the index 2 case is ***,the explicit evaluation of Gauss sums G(χλ)(1 λ N-1) in the index 2 case with order N being general even integer(i.e.N = 2r·N0,where r,N0 are positive integers and N0 3 is odd) is ***,combining with the researches before,the problem of explicit evaluation of Gauss sums in the index 2 case is completely solved.

关键词： Gauss sum Stickelberger’s theorem Stickelberger congruence Davenport-Hasse lifting formula Davenport-Hasse product formula

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Intracellular Glutathione Detection using MnO2-Nanosheet-Modified Upconversion Nanoparticles

Intracellular Glutathione Detection using MnO2-Nanosheet-Mod...

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中国化学会第28届学术年会

作者： Renren Deng 1,Xiaogang Liu 1,2 1 department of Chemistry,national university of singapore,singapore 117543 2 Institute of Materials Research and Engineering,3 Research Link,singapore 117602

＜正＞We report a novel design,based on a combination of lanthanide-doped upconversion nanoparticles and manganese dioxide nanosheets,for rapid,selective detection of glutathione in aqueous solutions and living *** th...

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Geomorphologic evolution and environmental changes in the Shaluli Mountain region during the Quaternary

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Chinese Science Bulletin 2005年第1期50卷 52-57页

作者： ZHOU Shangzhe1,2, XU Liubing1, CUI Jianxin1, ZHANG Xiaowei1 & ZHAO Jingdong1 1. national Laboratory of Western China’s Environmental Systems of Ministry of Education of China and department of geography, Lan- zhou university, Lanzhou 730000, China 2. department of geography, South China Normal university, Guang- zhou 510631, China national Laboratory of Western China''s Environmental Systems of Ministry of Education of China and department of geography Lanzhou University Lanzhou 730000 China department of geography South China Normal University Guangzhou 510631 China

Geologic and geomorphologic evidence from the Shaluli Mountain indicates that the planation surface that formed in the Late Tertiary disintegrated during the Late Pliocene-Early Quaternary. At the same time, rift ba- sins appeared on some parts of the planation surface, and began to accumulate fluvial-lacustrine sediment. These are interpreted as being the response of this region to Phase-A of the Qingzang Tectonic Movement. After this, the Shaluli Mountain continued to rise in several pulses. Faulting and incision by some large tributaries of the Jinsha and Yalong Rivers resulted in several rift river valleys and the earliest terraces. Generally, the planation surface in this region had been uplifted to about 3500—3700 m a.s.l. no later than 550—600 ka BP, after the Kunlun-Huanghe Tectonic Move- ment, and coupled with global glacial climate, and resulted in the earliest glaciation recognized so far in the Hengduan Mountains. At the same time, loess was deposited in the Ganzi area of the northern Shaluli Mountain. During the last glacial period, the Shaluli Mountain approached its present altitude and developed several large ice caps, such as the Daocheng Ice Cap and Xinlong Ice Cap, as well as several huge valley glaciers. These paleoglaciers produced some of the most spectacular glacial topography on the Tibetan Pla- teau.

关键词：地形学环境变化 Shaluli山脉展平面西藏高原 ESR-年代测定

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A RE-VISIT TO THE FORMULATION OF THE FINITE ELEMENT METHOD INSPIRED BY MESHFREE TECHNIQUES

A RE-VISIT TO THE FORMULATION OF THE FINITE ELEMENT METHOD I...

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庆祝中国力学学会成立50周年暨中国力学学会学术大会’2007

作者： LIU GR~(*,+,1)) HAN X~(**,2)) *(Center for ACES,department of Mechanical Engineering,national university of singapore,9 Engineering Drive 1,117576,singapore) +(singapore-MIT Alliance,E4-04-10,4 Engineering 3,117576,singapore) **(College of Mechanical and Automobile Engineering,Hunan university,Changsha,410082,China)

The finite element method is the most popular computational method for solving mechanics problems in *** is very well developed,widely used and technically very ***,this does not mean that further development is *** t...

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Issues of the Holocene transgression on the southern plain of the Changjiang Delta

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Acta Oceanologica Sinica 1988年第4期7卷 578-590页

作者： Yan Qinshang and Hong Xueqing department of geography, East China Normal university, Shanghai, China Dept. of geography East China Normal Univ. Shanghai China. China

The paper deals with the question of Holocene transgression on the southern plain of the Changjiang *** the beginning of the transgression, the paleovalleys of the Changjiang and Qiantang Rivers were covered by sea water at *** shoreline of 8000-7500 yr BP coincided with the -7m isobath of paleotopography. Sea level had already been the present level about 7000-6500 years ago, and the Holocene transgression reached its maximum extent. During the period, the Changjiang and Qiantang Rivers and the Dongtiaoxi valley were turned into estuaries; the eastern area of Shanghai became a shallow sea; some of the bays and lagoons were distributed on the Hang-Jia-Hu and Tao-Ge Plain; the hilly region around the Taihu Lake was coastal marsh and freshwater swamp. Gangshen on the west of Shanghai was formed 7000-4000 yr BP, and during the last 4000 years, the eastern coastal plain of Shanghai advanced quickly toward the sea, and partial clear land of the western Taihu Lake was enclosed and charged into a fre

关键词： Ho Issues of the Holocene transgression on the southern plain of the Changjiang Delta

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The Role of Aga Khan Rural Support Programme in Rural Development in the Karakorum, Hindu Kush & Himalayan Region: Examples from the Northern Mountainous Belt of Pakistan

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Journal of Mountain Science 2007年第4期4卷 331-343页

作者： Fazlur-Rahman department of geography Urban & Regional Planning University of Peshawar University Town 25100 Peshawar NWFP Pakistan

Pakistan is predominantly a mountainous country where rural development activities are characterised by inconsistency, politically motivated short-term projects without proper feedback. Since the inception of the country, the top-down approach has been followed, and the same development plans that were formulated for the plain areas have been extended to the mountains without any modification. In doing so, neither the participation of the local communities was cared for, nor the mountain specificities were considered in the planning process. Moreover, the representation of the local inhabitants was improper and contradictory to the facts. This biased approach has been one of the main causes for the failure of development projects carried out by different agencies of the Government. Contrary to the perception of the state authorities, the mountain communities proved to be more open to accept new approaches and demonstrated the capacity and capability of being a dependable development partner. In this paper, a detailed account of the Aga Khan Rural Support Programme （AKRSP） has been presented to assess and evaluate the approach followed by this non-governmental organisation （NGO）, and the response of the local inhabitants as collaborators in the development process. The achievements of the AKRSP from project planning, implementation and monitoring can be adopted as a model for rural development not only in the plains, but also in the mountainous areas of the developing countries in the world.

关键词： Rural development mountains northern Pakistan Aga Khan Rural Support Programme village organisations

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THE ECOLOGICAL DISASTERS IN NINGXIA AND THE COUNTERMEASURES

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干旱区资源与环境 1993年第Z1期7卷 118-121页

作者： Mi Wenbao Li Longtang geography department of Ningxia university

Ningxia lies in the midland of China, along the upper and middle of the Yellow *** south of the region belongs to the Loess Plateau and the north of it is Part of theMongolian plateau. The main feature of the climate in the whole region is dry or half *** ecological enviroment is in a very delicate state and human activities have made itworse. The severe consequences are widely-spread various types of ecological disasters.

关键词： NingXia Elologic Disaster Water and Soil Loss Sandification Salinization

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