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A quasi-local mass for 2.spheres with negative Gauss curvature

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Science China mathematics 2008年第9期51卷 1644-1650页

作者： ZHANG Xiao institute of mathematics, {2. of mathematics and Systems Science, chinese academy of sciences, beijing 100080, China 1. institute of mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100080 China

We extend our previous definition of quasi-local mass to 2.spheres whose Gauss curvature is negative, and prove its positivity.

关键词： general relativity quasi-local mass positivity 53C2. 53C50 83C60

Study of the circulation theory of the cooling system in vertical evaporative cooling generator

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Science China(Technological sciences) 2006年第3期49卷 358-364页

作者： YU Shunzhou1, CAI Jing2. GUO Chaohong1 & GU Guobiao1 1. institute of Electrical Engineering, chinese academy of sciences,{2., China 2. beijing Changcheng institute of Metrology and Measurement, beijing 100095, China institute of Electrical Engineering Chinese Academy of Sciences Beijing 100080 China beijing Changcheng institute of Metrology Measurement Beijing 100095 China

The article briefly states the current development of evaporative cooling generator; its advantages comparing with generators of traditional cooling. Vertical evaporative cooling generator, which adopts Close-Loop-Self-Cycle with no-pump; free convection boil in the hollow stator bar, is one of the great developments in generator design. This article emphasizes the importance of cooling system in generator; expatiates the circulation theory in two aspects, energy; flow;; analyzes the essential reason, motivity; stability of Close-Loop-Self-Cycle. The article points out that the motivity of the circulation is the heat absorbed by coolant. After absorbing heat the coolant will have the ability of doing work because of the phase change. In another words, it is the buoyancy causing by density difference leads to the Close-Loop-Self-Cycle. This conclusion is validated by experimental data.

关键词： vertical evaporative cooling generator, cooling system, circulation theory.

Accuracy of Multivariable Refinable Functions and Two-Scale Similarity Transform

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Acta Mathematica Sinica,English Series 2000年第2期16卷 271-276页

作者： Qiuhui Sheng Silong Peng institute of mathematics,{2. of mathematics and Systems sciences,chinese {2. of sciences,beijing 100080,P.R.China institute of mathematics Academy of Mathematics and Systems Sciences Chinese Academy of Sciences Beijing 100080 P. R. China

In this paper,we prove that if two multiresolutions satisfy a relation,then they have the same accuracy in the multivariate FSI case.

关键词： Accuracy Symbol function Two-scale similarity transform

Assessing the Carrying Capacity of Tourist Resorts: An Application of Tourists’ Spatial Behavior Simulator Based on GIS and Multi-Agent System

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Wuhan University Journal of Natural sciences 2005年第4期10卷 779-784页

作者： ZHANG Ren-jun 1,2.1. institute of Mountain Hazards and Environment, chinese academy of sciences, Chengdu 610041, Sichuan, China 2. Graduated School of the chinese academy of sciences, beijing 100039, China chinese academy of {2. Institute of Mountain Hazards and Environment Chengdu Sichuan China (GRID:grid.9227.e) (ISNI:***) Graduated School of the chinese academy of sciences Beijing China (GRID:grid.9227.e) (ISNI:***)

Based on the study of visitors' individual spatial behaviors, a tourists'spatial behavior simulator (TSBS) to assess the carrying capacity of tourist resorts was developed,TSBS employs GIS (Geographic Information System) to manage the spatial data,and Multi-Agent systemto simulate the actions of individual visitors. By utilizing TSBS, visitors' travel patterns such aslocation, cost, and state can be analyzed and predicted. Based on this analysis and prediction, themodel of assessing the carrying capacity of resorts is built. Our results show that TSBS will be aneffective tool to accurately assess the carrying capacity of tourist resorts.

关键词： tourist resort carrying capacity TSBS GIS Multi-Agent simulator

Integrated precise orbit determination of Shenzhou IV unmanned spacecraft

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Science China(Technological sciences) 2004年第5期47卷 518-525页

作者： L Congmin1,2. GU Yidong3, LIN Baojun3 & GUO Jiong3 1. Center for Space Science and applied Research, chinese academy of sciences,{2., China 2. Graduate School of the chinese academy of sciences, beijing 100039, China 3. General Establishment of Space Science and Application, chinese academy of sciences,{2., China Correspondence should be addressed to L Congmin 1. Center for Space Science and applied Research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the chinese academy of sciences 100039 Beijing China 3. General Establishment of Space Science and Application Chinese Academy of Sciences 100080 Beijing China

Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2.m.

关键词： Shenzhou IV unmanned spacecraft integrated precise orbit determination GPS SLR USB.

Adjoint method for the optimum planning of industrial pollutant sources

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Science China Earth sciences 2005年第8期48卷 1270-1279页

作者： LIU Feng1,2. HU Fei2.& ZHU Jiang2.1. College of Environmental sciences, Peking University, beijing 100871, China 2. LAPC, {2. of Atmospheric Physics, chinese academy of sciences, beijing 10002., China 1. College of Environmental sciences Peking University 100871 Beijing China 2. LAPC Institute of Atmospheric Physics Chinese Academy of Sciences 100029 Beijing China

The optimum planning of industrial pollutant sources, which optimizes the economic object without violating environmental constraints, is an important and hard task to be conquered. In this paper, an adjoint method is developed to solve the problem. The penalty function is in-troduced to deal with the environmental inequality constraints, and Lagrange function is con-structed to derive the adjoint equation and the gradient of the object function. In this means, the gradient of the object function can be calculated by solving the adjoint equation, and the infor-mation from the gradient is used to make the object function descend and approach to an optimal solution after some iterations. A two-dimensional, simplified model is used for numerical experi-ments. The theoretical derivations are verified by the results of the experiments. Furthermore, the adjoint method is shown to be of excellent convergence and efficiency, which is adaptive to the fast development of air quality numerical models and super computers.

关键词： optimum planning, industrial pollutant sources, adjoint equation, penalty function, gradient.

On the ratio of different norms of caloric functions and related eigenfunctions of an integral operator

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Science China mathematics 2012年第8期55卷 1597-1612页

作者： DING YuTao 1,2.& ZHANG LiQun 1,2.1 institute of mathematics,{2. of mathematics and Systems Science,chinese {2. of sciences,beijing 100190,China 2.Hua Loo-Keng Key Laboratory of mathematics,chinese {2. of sciences,beijing 100190,China 1. institute of mathematics Academy of Mathematics and Systems Science Chinese Academy of Sciences Beijing 100190 China2. Hua Loo-Keng Key Laboratory of Mathematics Chinese Academy of Sciences Beijing 100190 China

We investigate the ratio of L 1 and L 2.norms of the Cauchy problem solutions of heat equations with compact support initial *** related asymptotic behavior of the eigenvalues and eigenfunctions of certain integral op... 详细信息

关键词： integral operators eigenvalues heat equation

Comparison of eastern paleo-Tethyan ophiolites and its geodynamic significance--Evidence from Dur'ngoi ophiolite

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Science China Earth sciences 2004年第4期47卷 378-384页

作者： CHEN Liang1,2. SUN Yong1,2. PEI Xianzhi2. Feng Tao2.& Zhang Guowei2.1. Open Laboratory of Continental Dynamics, Ministry of Education, Northwest University, Xi抋n 710069, China 2. institute of Geology and Geophysics, chinese academy of sciences, {2. 10002., China Open Laboratory of Continental Dynamics Ministry of Education Northwest University Xi’an 710069 China institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China

Nd-Pb isotopic geochemistry of metabasalt from Dur抧goi ophiolite, Qinghai Prov-ince, NW China reveals the presence of DMM mixing with EMII components in its upper mantle source, which is comparable with present Indian MORB. Comparisons indicate that the geo-chemistry, chronology and source characteristics of Dur抧goi ophiolite coincide with Pa-leo-tethyan ophiolites from 揝anjiang?area. Together with evidences from regional geology in adjacent areas, this study proves that independent paleo-tethyan basins evolved contemporarily, the dynamics of which is attributed to the interaction of mantle plume with over-riding lithosphere.

关键词： ophiolite, Paleo-Tethys, DUPAL anomaly, Indosinian movement.

Effect of rock mass structure and block size on the slope stability——Physical modeling and discrete element simulation

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Science China(Technological sciences) 2005年第z1期48卷 1-17页

作者： LI Shihai1, LIAN Zhenzhong1,2.& J. G. Wang3 1. institute of Mechanics, chinese academy of sciences,{2., China 2. Graduate School, chinese academy of sciences, beijing 100060, China 3. Tropical Marine Science institute, National University of Singapore, Singapore 1192.0 chinese Acad Sci Inst Mech Beijing 100080 Peoples R China chinese Acad Sci Grad Sch Beijing 100060 Peoples R China Natl Univ Singapore Trop Marine Sci Inst Singapore 119260 Singapore

This paper studies the stability of jointed rock slopes by using our improved three-dimensional discrete element methods (DEM) and physical modeling. Results show that the DEM can simulate all failure modes of rock slopes with different joint configurations. The stress in each rock block is not homogeneous and blocks rotate in failure development. Failure modes depend on the configuration of joints. Toppling failure is observed for the slope with straight joints and sliding failure is observed for the slope with staged joints. The DEM results are also compared with those of limit equilibrium method (LEM). Without considering the joints in rock masses, the LEM predicts much higher factor of safety than physical modeling and DEM. The failure mode and factor of safety predicted by the DEM are in good agreement with laboratory tests for any jointed rock slope.

关键词： rock masses, slope stability, DEM simulation, block size effect, joints configuration effect, limit equilibrium method.