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3D building modeling,organization and application in digital city system

中国科学：技术科学英文版 2010年第S1期53卷 134-142页

作者： YANG Xue 1,WENG JingNong 1,2.XIA YuBin 2.WU Lun 3 & SUI ZhengWei 3 1 College of Software,Beihang university,beijing 100191,China 2.College of Computer,Beihang university,beijing 100191,China 3 Institute of Remote Sensing and GIS,peking university,beijing 100871,China College of Software Beihang University Beijing China College of Computer Beihang University Beijing China Institute of Remote Sensing and GIS Peking University Beijing China

The real world is a three-dimensional(3D)space requiring that 3D geospatial information applications be developed in alignment with the observer’s visual and perceptive ***,3D building model data are required in a wide range of areas such as urban planning,environmental protection,real estate management and emergency *** the same time,the development of Web service[LU1]technologies allows the possibility of the widely distributed 3D geospatial data on the web.3D city building model with its related information is an important part in the construction of a digital city system,and has become a staple resource on the web *** view of the hierarchical representation of a 3D building model,an abstract of a 3D building model based on structure details is studied,and a novel representation approach named 3D transparent building hierarchical model is presented in this *** approach fully uses both the existing 3D modeling technologies and CAD constructing mapping *** the spatial relationship description,structural components inside a building can be represented and integrated as hierarchical models in a unified 3D *** addition,based on the characteristics of the 3D building model data,a service-oriented architecture and Web service technologies for 3D city building models are *** aim of the approach is that 3D city building models can be used as a kind of data resource service on the web,and can also exist independently in various different web applications.

关键词： 3D modeling 3D transparent building hierarchical models China Star web services

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Inclusive　Minimal　Surfacein　G2.n1

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北京大学学报(自然科学版) 1996年第3期 3-7页

作者： MO Miaohuan (department of Mathematics, peking university, {2., 100871)

刻划了从Ｒｉｅｍａｎｎ面到复Ｇｒａｓｓｍａｎｎ流形的具有拓扑度＞２ｎ（ｇ－１）或′阶有限的一切可兼极小浸入。

关键词：可兼极小浸入 Riemann面复Grassmann流形

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A new enzymatic method for determination of E. coli

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Chinese Chemical Letters 1999年第10期10卷 849-850页

作者： Yun Xiang CI Tian Le LI(department of Chemistry, peking university. {2.) department of Chemistry Peking University Beijing 100871 China

beta-Galactosidase, a kind of endoenzyme in E. coli cells. can be released by the pore-forming action of colicin El. and E. coli can be detected rapidly by enzymatic method.

关键词： E-coli colicin E1 enzymatic method

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REGULARITY OF SOLUTIONS TO THE DIRICHLET PROBLEM FOR DEGENERATE ELLIPTIC EQUATION

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Chinese Annals of Mathematics,Series B 2003年第4期24卷 529-540页

作者： CHEN YEMIN School of Mathematics, peking university, beijing 100871, China. School of Mathematics Peking University Beijing 100871 China

In this paper, the author studies the regularity of solutions to the Dirichlet problem forequation Lu = f, where L is a second order degenerate elliptic operator in divergence form inΩ, a bounded open subset of Rn (n... 详细信息

关键词： Regularity Dirichlet problem Degenerate Weighted spaces

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Lactonization of 5-Phenylfuran-4-arylcarbinol-3-carboxylic Acids under the Catalysis of Boron Trifluoridc Etherate

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Chinese Chemical Letters 1999年第2期10卷 103-104页

作者： Xiao Ping NIE Xiu Lin YE (department of Chemistry, peking university． {2.， 100871) department of Chemistry Peking University Beijing 100871 China

?-Phenyl－4－aroylfuran－3－carboxylic acids were reduced in aqueous alkaline solutions ofNaBH4 to afford hydroxy acids in excellent yields． Under the catalysis of boron trifluoride etherate，the hydroxy acids were c... 详细信息

关键词： Lactonization boron trifluoride etherate hydroxy acid

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The LIL Convergence for Stationary Linear Random Field

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Acta Mathematica Sinica,English Series 1996年第4期12卷 385-397页

作者： He Shuyuan department of Probability and Statistics peking university {2., 100871 China department of Probability and Statistics Peking University Beijing China

Let Y={Y_n;n∈N^2. be a stationary linear random field generated by a two- dimensional martingale difference. Where N^2.denotes the two dimensional integer lattice. The main purpose of this paper is to obtain the LIL ... 详细信息

关键词： Stationary linear random field 1/4 Martingale difference LIL convergency.

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The refined theory of transversely isotropic piezoelectric rectangular beams

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Science China(Physics,Mechanics & Astronomy) 2006年第4期49卷 473-486页

作者： GAO Yang1 & WANG Minzhong2.1. College of Science, China Agricultural university, beijing 100083, China 2. State Key Laboratory for Turbulence and Complex Systems and {2. of Mechanics and Engi- neering Science, peking university, beijing 100871, China College of Science China Agricultural University Beijing China State Key Laboratory for Turbulence and Complex Systems and department of Mechanics and Engineering Science Peking University Beijing China

The problem of deducing one-dimensional theory from two-dimensional theory for a transversely isotropic piezoelectric rectangular beam is investigated. Based on the piezoelasticity theory, the refined theory of piezoelectric beams is derived by using the general solution of transversely isotropic piezoelasticity and Lur'e method without ad hoc assumptions. Based on the refined theory of piezoelectric beams, the exact equations for the beams without transverse surface loadings are derived, which consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beams under transverse loadings are derived directly from the refined beam theory. As a special case, the governing differential equations for transversely isotropic elastic beams are obtained from the corresponding equations of piezoelectric beams. To illustrate the application of the beam theory developed, a uniformly loaded and simply supported piezoelectric beam is examined.

关键词： rectangular beams, the refined theory, piezoelectric, transversely isotropic.

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Dynamic mechanisms of the post-seismic deformation following large events:Case study of the 1999 Chi-Chi earthquake in Taiwan of China

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Science China Earth Sciences 2009年第11期52卷 1813-1824页

作者： ZHU ShouBiao1,2.& CAI YongEn2.1 Institute of Crustal Dynamics, China Earthquake Administration, beijing 100085, China 2.department of Geophysics, {2., beijing 100871, China Institute of Crustal Dynamics China Earthquake Administration Beijing China department of Geophysics Peking University Beijing China

The mechanism of postseismic deformation related to strong earthquakes is important in geodynamics, and presumably afterslip or viscoelastic relaxation is responsible for the postsesimic deformation. The 1999 Chi-Chi, Taiwan of China, earthquake occurred in the region where GPS observation station is most densely deployed in the world. The unprecedented GPS data provides a unique opportunity to study the physical processes of postseismic deformation. Here we assume that the interactions of viscoelastic relaxation, afterslip, fault zone collapse, poroelastic rebound, flow of underground fluids, and all these combined contribute to the surface displacements following the main shock. In order to know the essence of the postseismic deformation after the strong event, fault zone collapse, poroelastic rebound, flow of underground fluids, and so on, are represented equivalently by the variations of the focal medium properties. Therefore, the viscoelastic relaxation, afterslip, and the variations of the equivalent focal medium properties are inverted by applying the GPS temporal series measurement data with viscoelastic finite element method. Both the afterslip rate distribution along the fault and the afterslip evolution with time are obtained by means of inversion. Also, the preliminary result suggests that viscosities of the lower crust and the upper mantle in Taiwan region is 2.7×1018 and 4.2.102. Pa·s, respectively. Moreover, the inversion results indicate that the afterslip contributing to postseismic deformation of 44.6% in 450 days after the Chi-Chi earthquake, with 34.7% caused by the viscous relaxation and 2..7% by other factors such as fault zone collapse, poroelastic rebound, and the flow of liquids.

关键词： mechanism of postseismic deformation viscoelastic finite element method GPS temporal series data Chi-Chi earthquake

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The refined theory of deep rectangular beams based on general solutions of elasticity

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Science China(Physics,Mechanics & Astronomy) 2006年第3期49卷 291-303页

The problem of deducing one-dimensional theory from two-dimensional the- ory for a homogeneous isotropic beam is investigated. Based on elasticity theory, the re- fined theory of rectangular beams is derived by using Papkovich-Neuber solution and Lur’e method without ad hoc assumptions. It is shown that the displacements and stresses of the beam can be represented by the angle of rotation and the deflection of the neutral surface. Based on the refined beam theory, the exact equations for the beam without transverse surface loadings are derived and consist of two governing differential equations: the fourth-order equation and the transcendental equation. The approximate equations for the beam under transverse loadings are derived directly from the refined beam theory and are almost the same as the governing equations of Timoshenko beam theory. In two ex- amples, it is shown that the new theory provides better results than Levinson’s beam the- ory when compared with those obtained from the linear theory of elasticity.

关键词： deep rectangular beams,the refined theory,Papkovich-Neuber solution,Lur'e method,governing equation

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SYNTHESIS AND PROPERTIES OF NEW MESOGEN-JACKETED LIQUID CRYSTALLINE POLYMERS

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Chinese Journal of Polymer Science 2000年第2期18卷 139-148页

作者： Qi-ding Mi Qi-feng Zhou department of Polymer Science & Engineering, College of Chemistry peking university, {2., China 北京大学北京

Some new mesogen-jacketed liquid crystalline polymers (MJLCP) with polymer backbones, spacers, and mesogenic units of different structures were synthesized by radical polymerization. The mesomorphic behavior of these polymers was examined using differential scanning calorimetry (DSC) and polarizing optical microscopy (POM). Their liquid crystallinity is influenced by the variation of polymer backbone, spacer, mesogenic unit and its terminal groups. The results show that 1) a more flexible polymer main-chain is more favorable to the formation of a liquid crystal phase, while 2. a flexible spacer will decrease the 'Jacket Effect' and the liquid crystallinity and 3) a subtle modification of the terminal groups on the mesogenic unit may also have a significant influence on properties of the polymers.

关键词： mesogen-jacketed liquid crystalline polymers polymer backbones spacers mesogenic units liquid crystallinity

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