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Scenario simulation and forecast of land use/cover in northern china

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Chinese science Bulletin 2008年第9期53卷 1401-1412页

作者： LI YueChen 1,2,3.& HE ChunYang 3.1 college of Geographical science, Chongqing normal {3., Chongqing 400047, china 2 college of Resources and Environmental science, Chongqing {3., Chongqing 400044, china 3.college of Resources science & technology, beijing normal university,{13., china college of Geographical science Chongqing Normal University Chongqing 400047 China college of Resources and Environmental science Chongqing University Chongqing 400044 China college of Resources science & technology Beijing Normal University Beijing 100875 China

Modeling land use/cover scenario changes and its potential impacts on structure and functions of ecosystem in typical regions are helpful to understanding the interactive mechanism between land use/cover system and ecosystem. Based on the analysis of the existing land use/cover simulation and forecast models, a land use/cover scenario dynamics model by the integration of System Dynamics (SD) model, Back Propagation Neural Network (BPNN) and Cellular Automata (CA) model is developed with land use/cover scenario changes in northern china in the next 3. years and simulated in this paper. The model is to simulate the land use/cover scenario demands by using a SD model at first, and then allocating the land use scenario patterns at the local scale with the considerations of land use/cover suitability, inheritance ability and neighborhood effect by using BPNN-CA model to satisfy the balance between land use/cover scenario demands and supplies. It integrates the advantages of SD, BPNN and CA. Macro-driving factors and the micro-spatial pattern are also fully taken into account. The BPNN simplifies the identification of the factors’ weights used in CA model and improves the reliability of the simulation results. The simulation accuracy of the model developed in this paper was found to be about 74%. It suggests that the model has the ability to reflect the complexity of land use/cover system at different scales to some extent and it is a useful tool for assessing the potential impacts of land use system on ecosystem. The simulated results also indicate that the urban land, water area and forest will increase significantly, and farmland and unable land will decrease gradually. Obvious land use/cover changes will take place in the farming-pastoral zone and the southeast area of northern china.

关键词：土地利用中国北方细胞自动机系统动力学

Optimal reactions for the synthesis of superheavy nucleus ^(270)Hs

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science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 641-648页

作者： LIU Zuhua1,3.& BAO Jingdong1,2 1. Key Laboratory of Beam technology and Material Modification of Ministry of Education, beijing normal university, beijing 100875,{3. 2. Physics Department, beijing normal university, beijing 100875,{3. 3.{3. Institute of Atomic Energy, beijing 102413.{3. Key Laboratory of Beam technology Material Modification of Ministry of Education Beijing Normal University Beijing 100875 China Physics Department Beijing Normal University Beijing 100875 China china Institute of Atomic Energy Beijing 102413 China

The superheavy nucleus 270Hs is expected to be a “double-magic” deformed nucleus. We have calculated its cross sections of evaporation residue for the reactions 248Cm(26Mg,4n)270Hs, 244Pu(3.Si,4n)270Hs, 23.U(3.S,4n)270Hs and 226Ra(48Ca,4n)270Hs using a two-parameter Smoluchowski equation. It is found from our results that 226Ra(48Ca,4n)270Hs and 23.U(3.S,4n)270Hs are two optimal reactions for the synthesis of the superheavy nucleus 270Hs due to their large negative Q-values.

关键词： diffused fusion barrier,Smoluchowski equation,superheavy nuclei.

ENERGY FLOWS IN COMPLEX ECOLOGICAL SYSTEMS:A REVIEW

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Journal of Systems science & Complexity 2009年第3期22卷 345-359页

作者： Jiang ZHANG Department of Systems science,School of Management,beijing normal {3.,beijing 100875,china. Department of Systems science School of Management Beijing Normal University Beijing 100875 China

Energy flow drives the complex systems to *** allometric scaling as the universalenergy flow pattern has been found in different scales of ecological *** reflects the generalpower law relationship between flow and *** underlying mechanisms of energy flow patterns areexplained as the branching transportation networks which can be regarded as the result of systematicoptimization of a biological target under *** flows in the ecological system may bemodelled by the food web model and population dynamics on the *** paper reviews thelatest progress on the energy flow patterns,explanatory models for the allometric scaling and modellingapproach of flow and network evolution dynamics in ***,the possibility of generalizingthese flow patterns,modelling approaches to other complex systems is discussed.

关键词： Allometric scaling energy flow flows in complex systems food web.

Implementation of a multiple round quantum dense coding using nuclear magnetic resonance

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science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 706-715页

作者： ZHANG Jingfu1, XIE Jingyi2, WANG Chuan1, DENG Zhiwei3. LU Zhiheng4, & LONG Guilu1,5 1. Key Laboratory For Quantum Information and Measurements of MOE, Department of Physics, Tsinghua university, beijing 100084,china 2. Department of Materials {3. and Engineering, beijing normal university, beijing 100875, china 3. Testing and Analytical Center, beijing normal university, beijing 100875,china 4. Department of Physics, beijing normal university, beijing 100875, china 5. Key Laboratory For atomic and Molecular Nano{3.s, Tsinghua university, beijing 100084,china 1. Key Laboratory For Quantum Information and Measurements of MOE Department of Physics Tsinghua University 100084 Beijing China 2. Department of Materials science and Engineering Beijing Normal University 100875 Beijing China 3. Testing and Analytical Center Beijing Normal University 100875 Beijing China 4. Department of Physics Beijing Normal University 100875 Beijing China 5. Key Laboratory For Atomic and Molecular Nanosciences Tsinghua University 100084 Beijing China

A multiple round quantum dense coding scheme based on the quantum phase estimation algorithm is proposed and implemented in a three qubit nuclear magnetic resonance (NMR) quantum computer. Using an m + 1 qubit system, Bob can transmit one of 2m+1 messages to Alice, through manipulating only one qubit and exchanging it between Alice and Bob for m rounds. The information capacity is enhanced to m + 1 bits as compared to m bits in a classical scheme. The scheme has been demonstrated in NMR system, and the experimental results show a good agreement between theory and experiment.

关键词： quantum dense coding, multiple round, nuclear magnetic resorance

Developing land use scenario dynamics model by the integration of system dynamics model and cellular automata model

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science china Earth sciences 2005年第11期48卷 1979-1989页

作者： HE Chunyang, SHI Peijun, CHEN Jin, Li Xiaobing, PAN Yaozhong, LI Jing, LI Yuechen & LI Jinggang Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education of china, beijing normal university college of Resources {3. & technology, beijing normal university, beijing 100875, china 1. Key Laboratory of Environmental Change and Natural Disaster Ministry of Education of China Beijing Normal University China 2. college of Resources science & technology Beijing Normal University 100875 Beijing China

Modeling land use scenario changes and its potential impacts on the structure and function of the ecosystem in the typical regions are helpful to understanding the interactive mechanism between land use system and ecological system. A Land Use Scenario Dynamics (LUSD) model by the integration of System Dynamics (SD) model and Cellular Automata (CA) model is developed with land use scenario changes in northern china in the next 20 years simulated in this paper. The basic idea of LUSD model is to simulate the land use scenario de-mands by using SD model at first, then allocate the land use scenario patterns at the local scale with the considerations of land use suitability, inheritance ability and neighborhood effect by using CA model to satisfy the balance between land use scenario demands and supply. The application of LUSD model in northern china suggests that the model has the ability to reflect the complex behavior of land use system at different scales to some extent and is a useful tool for assessing the potential impacts of land use system on ecological system. In addition, the simulated results also indicate that obvious land use changes will take place in the farming-pastoral zone of northern china in the next 20 years with cultivated land and urban land being the most active land use types.

关键词： system dynamics, cellular automata, scenario, land use, model

Theoretical analysis of alloy multiplying factor by the empirical electron theory of solids and molecules

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science china(Technological sciences) 2007年第6期50卷 807-814页

作者： SONG YuePeng1,2, LIU GuoQuan2, LI ZhiLin3. FENG ChengMing1 1 Mechanical and Electronic Engineering college, Shandong Agricultural university, Tai’an 271018, china 2 college of Materials science and Engineering, university of science and technology, beijing 100083. china 3.college of Material science and Engineering, beijing university of Chemical technology, beijing 100029, china Mechanical Electronic Engineering college Shandong Agricultural University Tai’an 271018 China college of Materials science Engineering University of Science technology Beijing 100083 China college of Material science Engineering Beijing University of Chemical Technology Beijing 100029 China

By introducing the distribution probability of structural units in austenite contain- ing alloying elements and considering its effects on phase transformation, this paper establishes a calculation model of distribution probability of structural units. A new valence electron structure (VES) parameter-transformation effect coefficient of alloying elements (HL), is defined and then studied both theoretically and ex- perimentally. The relationship between the parameter HL and the multiplying factor (the quenching capability factor) of alloying elements is studied. The results indi- cate that the two parameters (HL and the quenching capability factor) have the same variation characteristic and substance feature. Therefore, the multiplying factor virtually expresses the relative quantity of structural units in the alloying elements-containing austenite.

关键词： multiplying factor (the quenching capability factor), empirical electron theory of solids and molecules, transformation effect coefficient of alloying elements, structural units in austenite containing alloying elements

Compactness of the commutators of parabolic singular integrals

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science china Mathematics 2010年第10期53卷 2633-2648页

作者： CHEN YanPing1 & DING Yong2,3.1Department of Mathematics and Mechanics,university of science and technology {3.,{3. 100083.china 2School of Mathematical science,{3. normal university,{3. 100875,china 3.aboratory of Mathematics and Complex Systems (BNU),Ministry of Education of{13.,{3. 100875,china 1. Department of Mathematics and Mechanics University of Science and Technology Beijing Beijing 100083 China2. School of Mathematical Science Beijing Normal University Beijing 100875 China3. Laboratory of Mathematics and Complex Systems (BNU) Ministry of Education of China Beijing 100875 China

In this paper,the authors prove that the commutator [b,T] of the parabolic singular integrals is a compact operator on Lp(Rn)(1 < p < ∞) if and only if b ∈ VMO(Rn,ρ).The result is substantial improvement and extens... 详细信息

关键词： parabolic singular integrals commutators compactness BMO VMO

Functional central limit theorem for super α-stable processes

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science china Mathematics 2004年第6期47卷 874-881页

作者： HONG WenmingDepartment of Mathematics, beijing normal university, beijing 100875, china 1. Department of Mathematics Beijing Normal University 100875 Beijing China

A functional central limit theorem is proved for the centered occupation time process of the super α-stable processes in the finite dimensional distribution sense. For the intermediate dimensions α < d < 2α (0 < α ≤ 2), the limiting process is a Gaussian process, whose covariance is specified; for the critical dimension d= 2α and higher dimensions d < 2α, the limiting process is Brownian motion.

关键词： super α-stable processes occupation time central limit theorem evolution equation

Study on NDVI-T_s space by combining LAI and evapotranspiration

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science china Earth sciences 2006年第7期49卷 747-754页

作者： HAN Lijuan1,2,3. WANG Pengxin4, YANG Hua1,2,3. LIU Shaomin1,2,3.& WANG Jindi1,2,3.1. Research Center for Remote Sensing and GIS, School of Geography, beijing normal university, beijing 100875, china 2. State Key Laboratory of Remote Sensing {3., beijing 100875, china 3. beijing Key Laboratory for Remote Sensing of Environment and Digital Cities, beijing 100875, china 4. Department of Information Management, college of Information and Electronic Engineering, china Agricultural university, beijing 100083. china 1. Research Center for Remote Sensing and GIS School of Geography Beijing Normal University Beijing 100875 China 2. State Key Laboratory of Remote Sensing science Beijing 100875 China 3. beijing Key Laboratory for Remote Sensing of Environment and Digital Cities Beijing 100875 China 4. Department of Information Management College of Information and Electronic Engineering China Agricultural University Beijing 100083 China

This paper focuses on interpreting the different spatial relationships between NDVI and Ts, a triangular or a trapezoid, and on analyzing transformation conditions, the physical and ecological meanings of the vegetation index-surface temperature space as well. Further, we use the Tempera-ture-Vegetation Dryness Index (TVDI) to explain the existent meaning of a triangular space after NDVI reaches its saturated state by employing the relationships between NDVI, LAI and evapotranspiration. The specific relations between NDVI and Ts are useful for describing, validating and updating land surface models.

关键词： NDVI, land surface temperature, evapotranspiration, leave area index.