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Pole assignment in descriptor periodic systems

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Science china Mathematics 2005年第10期48卷 1309-1332页

作者： FAN Hung-Yuan~1.LIN Wen-Wei~1.& XU Shufang~2.1. Department of Mathematics,Tsing Hua {1.,Hsinchu 30043,china {2.,School of Mathematical Sciences,peking university,Beijing 1.0871.china 1. Department of Mathematics Tsing Hua University 30043 Hsinchu China 2. lmam School of Mathematical Sciences Peking University 100871 Beijing China

In this paper a pole assignment problem is considered for the descriptor linear discrete-time periodic systems, which is using the periodic proportional-derivative feedback to modify a given system such that the closed loop system has a specified selfconjugate set of eigenvalues. It is shown that the complete reachability of an open loop periodic system is equivalent to the possibility of assigning an arbitrary set of the eigenvalues to the system by choosing the suitable periodic proportional-derivative feedback.A computational approach is also proposed to solve the problem, which uses the reliable numerical techniques based on the orthogonal transformations. Numerical examples are presented to illustrate the effectiveness of the proposed approach.

关键词： descriptor linear periodic system, pole assignment, proportional and derivative feedback, numerical method, periodic Schur decomposition.

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灵光独耀:沈宗灵与中国法理学

中国法律评论 2024年第4期 149-154页

作者： peking university Law School 北京大学法学院

在其诸多弟子的追忆中,沈宗灵先生一生专心治学、淡泊名利,由此常常对世事保持一种有意的疏离。“灵光独耀,迥脱根尘”,或许便是这位法理学大家的灵魂写照。壹“经国济民”:沈宗灵的早年岁月1.2.年2.2.日,沈宗灵出生于浙江杭州的一个... 详细信息

在其诸多弟子的追忆中,沈宗灵先生一生专心治学、淡泊名利,由此常常对世事保持一种有意的疏离。“灵光独耀,迥脱根尘”,或许便是这位法理学大家的灵魂写照。壹“经国济民”:沈宗灵的早年岁月1.2.年2.2.日,沈宗灵出生于浙江杭州的一个商人家庭,后随家人迁居上海。

关键词：沈宗灵淡泊名利法理学浙江杭州灵光

Density-functional formula for strongly correlated systems

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Progress in Natural Science:Materials International 2005年第5期15卷 395-401页

作者： WANG Huaiyu1.*, HAN Rushan2.and CHEN Nanxian1.1. Department of Physics, Tsinghua {1., Beijing 1.0084, china 2. Department of Physics, {2., Beijing 1.0871, china) Department of Physics Tsinghua University Beijing 100084 China Department of Physics Peking University Beijing 100871 China

Density functional method is applied for strongly correlated systems. Based on the assumption that the systems are composed of electrons in singly-occupied orbitals and those in doubly-occupied orbitals, a set of self-consistent equations are obtained by standard variation procedure. The equations consist of two parts. One part is to solve the wave functions of the electrons in singly-occupied orbitals and the other is to solve the wave functions of the electrons in doubly-occupied orbitals. The physical meanings of the terms appearing in the equations are discussed.

关键词： density-functional theory strongly correlated systems doubly-occupied orbital two-particle wave function self-consistent equations.

Management Communication in university’s Digital Library

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上海交通大学学报 2003年第S1期37卷 250-254页

作者： LIU Yuan fang 1. LIN Li 2.(1. Library of Dalian {1. of Technology, Dalian 1.602., china 2. 2. st Century Development and Research Center, Dalian 1.602.)

Digital library is a process of exploiting more scientific methods to construct a social knowledge network. It represents an “extension” from a traditional library. The core and essence is to build a favorable surroundings for knowledge accumulation, knowledge transfer and knowledge communication. Management communication covers information transfer and organization cooperation. Compared with traditional library, the management communication in digital library shoulders the commitment to support knowledge innovation. On the basis of analysis of the connotation of digital library, this paper analysed the aspects of management communication, including communicators, communication styles, contents, channels and outer communication, all of which tries to construct an integrated model of management communication in a digital library and turns a library into an actual “knowledge fountain”.

关键词： university’s digital library knowledge management management communication

Two applications of generalized Carleson measures to meromorphic Besov-type spaces

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Chinese Science Bulletin 1998年第15期43卷 1260-1264页

作者： TAN Haiou 1.and XIAO Jie 2.1. Department of Mathematics, Wuyi {1., Jiangmen 52.02., china 2. School of Mathematical Sciences, {2., Beijing 1.0871, china Department of Mathematics Wuyi University Jiangmen China School of Mathematical Sciences Peking University Beijing China

The generalized Carleson measures are used to characterize the meromorphic Besov_type spaces and to explore some inclusions between these spaces.

关键词： generalized Carleson measures meromorphic Besov_type spaces.

Paleoceanographic evolution recorded in the northern South china Sea since 4 Ma

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Science china Earth Sciences 2005年第12期48卷 2166-2173页

作者： HUANG Baoqi1.2. JIAN Zhimin2.& WANG Pinxian2.1. School of Earth and Space Sciences, peking university, Beijing 1.0871, {2. 2. Laboratory of Marine Geology, Tongji university, Shanghai 2.0092. {2. 1. School of Earth and Space Sciences Peking University 100871 Beijing China 2. Laboratory of Marine Geology Tongji University 200092 Shanghai China

Upper water structure over the last 4 million years in the northern South china Sea (SCS) was reconstructed by sea surface temperature (SST) and primary productivity estimated by changes in the abundance of planktonic foraminifer, planktonic foraminifer transfer function, and the accumulation rate of benthic foraminifera. Results of SST and primary productivity show that SST gradually decreased since 4 Ma, but differential seasonal temperature and primary productivity increased in steps mainly at about 3.1. {1.7, {1.1. 1.6, 0.9 and 0.5 Ma. Comparison with tectonics and orbital variations indicates that phased rising of the Tibet since 3.6 Ma, closing of Panama and Indonesian seaways, and orbital changes were responsible for the changes of upper water structure in the SCS, respectively.

关键词： northern South china Sea, upper water structure, Late Pliocene, planktonic foraminifer, ODP 1.46.

The numerical method for three-dimensional impact with friction of multi-rigid-body system

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 102-118页

作者： ZHAO Zhen1.2. LIU Caishan2.& CHEN Bin2.1. Beijing Institute of Graphic Communication, Beijing 1.2.00, china 2. Department of Mechanics & Engineering Science, peking university, Beijing {2., china Beijing Institute of Graphic Communication Beijing 102600 China Department of Mechanics & Engineering Science Peking University Beijing 100871 China

The differential equations for planar impacts reduce to an algebraic form, and can be easily solved. For three dimensional impacts with friction, there is no closed-form solution, and numerical integration is required due to the swerve behavior of tangential impulse during collisions. The dynamic governing equations in the impact process are built up in impulse space based on the Lagrangian equation in this paper. The coefficient of restitution defined by Poisson is used as the condition of impact termination. A valid nu- merical method for solving three-dimensional frictional impact of multi-rigid body system is established. The singular cases of tangential movement in sticking point are especially noticed and analyzed. Several examples are present to reveal the different kinds of tan- gential movement modes varied with the normal impulse during collision.

关键词： multi-rigid body, impact, friction.

Integrative inversion of land surface component temperature

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Science china Earth Sciences 2005年第11期48卷 2011-2019页

作者： FAN Wenjie1.& XU Xiru1.2.1. Institute of Remote Sensing and Geographical Information System, {1., Beijing 1.0871, {2. 2. Center of Remote Sensing and GIS of Beijing Normal university, Beijing 1.0875, {2. 1. Institute of Remote Sensing and Geographical Information System Peking University 100871 Beijing China 2. Center of Remote Sensing and GIS of Beijing Normal {1. 100875 Beijing China

In this paper, the row winter wheat was selected as the example to study the com-ponent temperature inversion method of land surface target in detail. The result showed that the structural pattern of row crop can affect the inversion precision of component temperature evi-dently. Choosing appropriate structural pattern of row crop can improve the inversion precision significantly. The iterative method combining inverse matrix was a stable method that was fit for inversing component temperature of land surface target. The result of simulation and field ex-periment showed that the integrative method could remarkably improve the inversion accuracy of the lighted soil surface temperature and the top layer canopy temperature, and enhance inver-sion stability of components temperature. Just two parameters were sufficient for accurate at-mospheric correction of multi-angle and multi-spectral thermal infrared data: atmospheric trans-mittance and the atmospheric upwelling radiance. If the atmospheric parameters and component temperature can be inversed synchronously, the really and truly accurate atmospheric correction can be achieved. The validation using ATSRII data showed that the method was useful.

关键词： components temperature, inverse pattern, atmospheric correction

Analysis on the long term discharge of a catchment

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Journal of Environmental Sciences 2000年第3期12卷 279-285页

作者： HONG Lin 1. TAKASE Keiji 2. SATO Koichi 2.(1. Wuhan university of Hydraulic and Electric Engineering, Wuhan 430072. china 2. Ehime university, Japan) Wuhan university of Hydraulic and Electric Engineering Wuhan 430072 China Ehime university Japan

In this study, the characteristics of the long term discharge of a Terraced Paddy Field Catchment are studied. 2.Kind of Tank Models are proposed and used to simulate the discharge of the catchment. The characteristics of the model simulations of the discharge of the catchment are analyzed and compared with those of a forest catchment.

关键词： long term discharge model simulation terraced paddy field catchment