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Flooding 1990s along the Yangtze River, has it concern of global warming?

Journal of Geographical Sciences 2001年第1期11卷 43-52页

作者： GONG Dao-yi1, ZHU Jin-hong2. WANG Shao-wu2.(1. Key Laboratory of Environmental Change and Natural Disaster, Institute of Resources Science, beijing Normal university, beijing 100875, China 2. department of geophysics, peking university, beijing 100871, Key Laboratory of Environmental Change and Natural Disaster Institute of Resources Science Beijing Normal University Beijing China department of geophysics Peking University Beijing China

There were a series of severe floods along the middle to lower reaches of the Yangtze River (Changjiang River) in China during the 1990s. The extensive summer (June, July and August) precipitation is mostly responsible for the flooding. The summer rainfall in the 1980s and the 1990s is much higher than that in the previous 3 decades. The means for 1990–1999 is +87.62.mm above normal, marked the 1990s the wettest decade since the 1950s. Six stations with a time span of 1880–1999 are selected to establish century-long rainfall series. This series also shows that the 1990s is the wettest decade during the last 12. years. In the wettest 12.years, four occurred in the 1990s (1991, 1996, 1998 and 1999). Both global and China’s temperature show there is a relative lower air temperature during the 1960–1970s, and a rapid warming in the 1980–1990s. Comparisons of rainfall between 1960–1979 and 1980–1999 show there are dramatic changes. In the cold period 1960–1979, the summer rainfall along the Yangtze River is 3.8 % to 4.7 % below the normal, during the warm period 1980–1999, over 8.4 % to 18.2.% of summer rainfall occurs. Over the whole eastern China, the summer rainfall shows opposite spatial patterns from the 1960–1970s to 1980–1990s. The consistent trend toward more rainfall with global warming is also presented by the greenhouse scenario modeling. A millennial Drought/flood Index for the middle to lower reaches of the Yangtze River showed that although the surplus summer rainfall in the 1990s is the severest during the past 150 years, it is not outstanding in the context of past millennium. Power spectra of the Drought/flood Index show significant interdecadal periods at 33.3 and 11.8 years. Thus, both the natural interdecadal variations and the global warming may play important roles in the frequent floods witnessed during the last two decades.

关键词： summer rainfall Yangtze River global warming interdecadal variation

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我国脉冲星观测研究的进展和前景

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天文学进展 1999年第3期17卷 236-243页

作者：吴鑫基张晋王娜中国科学院-北京大学联合北京天体物理中心中国科学院乌鲁木齐天文站乌鲁木齐830011

介绍了脉冲星观测研究的意义，国际上所取得的重大成就和脉冲星观测最主要的技术问题。分析了我国脉冲星观测研究的现状和潜力、存在的问题和美好的前景。对正在执行的由中、澳、英合作的“利用乌鲁木齐２５ｍ射电望远镜在１８ｃｍ ...

介绍了脉冲星观测研究的意义，国际上所取得的重大成就和脉冲星观测最主要的技术问题。分析了我国脉冲星观测研究的现状和潜力、存在的问题和美好的前景。对正在执行的由中、澳、英合作的“利用乌鲁木齐２５ｍ射电望远镜在１８ｃｍ波段上进行脉冲星脉冲到达时间的观测研究”项目，就其课题意义、接收系统的技术改造和观测灵敏度等进行了介绍。展望了ＦＡＳＴ

关键词：脉冲星观测脉冲到达时间射电望远镜

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THE PHYSICAL ENTROPY OF SINGLE CONSERVATION LAWS

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Journal of Computational Mathematics 1998年第5期16卷 437-444页

作者： (department of Mathematics, peking university,{2., China) beijing Univ Dept Math Beijing 100871 Peoples R China

By means of the comparisons with the formulas in statistical mechanics and thermodynamics, in this paper it is demonstrated that for the single conservation law partial derivative(t)u + partial derivative(x)f(u) = 0, if the flux function f(u) is convex (or concave), then, the physical entropy is S = -f(u); Furthermore, if we assume this result can be generalized to any f(u) with two order continuous derivative, from the thermodynamical principle that the local entropy production must be non-negative, one entropy inequality is derived, by which the O.A. Olejnik's famous E- condition can be explained successfully in physics.

关键词： conservation laws entropy entropy production

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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 university, {2. 100084, China 2. department of Physics, peking university, beijing 100871, 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.

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Interdecadal variations in global climate and earth rotation rate

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Chinese Science Bulletin 1997年第18期42卷 1557-1560页

作者： QIAN Weihongdepartment of geophysics,{2., beijing 100871, China department of geophysics Peking University Beijing 100871 China

A science plan for future 15 a, 'A Study of Climate Variability and Predictability'(CLIVAR), was published by WMO in 1996. As the plan treated interdecadal climatic variability as a sub-plan, it showed that this problem is very important. By the implementation of 'Tropical Ocean and Global Atmosphere' (TOGA) 10-a plan during 1985—1994, the interdecadal variability that occurred in ENSO (El Nino/Southern Oscillation) ocean-atmosphere interaction has been found. This variability made the traditional ENSO prediction pattern useless

关键词： interdecadal variation climate prediction sea surface temperature earth rotation rate.

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THE FUNCTION d_k(n) AT CONSECUTIVE INTEGERS

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Chinese Annals of Mathematics,Series B 1999年第4期20卷 473-478页

作者： MENG ZAIZHAO(department of Mathematics, peking university,{2., China) peking Univ Dept Math Beijing 100871 Peoples R China

Let dk(n) denote the k-fold iterated divisor function (k ≥ 2.. It is proved that for sufficiently large x) dk(n) = dk(n + 1) holds for >> x(log log x)-3 integers n ≤x.

关键词： Divisor function Multiplicative function Congruence

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The regular representation and regular covariant representation of crossed products of Woronowicz C^(*)-algebras

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Science China Mathematics 2005年第9期48卷 1245-1259页

作者： ZHANG Xiaoxia~(1,2. & GUO Maozheng~(1,3) 1. School of Mathematical Sciences,peking university,{2. 100871,China 2. department of Mathematics,Yantai university,Yantai 2.4005,China 3. LMAM,peking university,{2. 100871,China 1. School of Mathematical Sciences Peking University 100871 Beijing China 2. department of Mathematics Yantai University 264005 Yantai China 3. LMAM Peking University 100871 Beijing China

In this paper,it is shown that the regular representation and regular covariant representation of the crossed products A×α G correspond to the twisted multiplicative unitary operators,where A is a Woronowicz C~*-algebra acted upon by a discrete group ***,it is also shown that the regular covariant C~*-algebra is the Woronowicz C~*-algebra which corresponds to a multiplicative ***,an explicit description of the multiplicative unitary operator for C(SU_q(2. )×α (?) is given in terms of those of the Woronowicz C~*-algebra C(SU_q(2. ) and the discrete group G.

关键词： multiplicative unitary operator, Woronowicz C*-algebra, crossed product.

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Neuroimaging studies of self-reflection

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Progress in Natural Science:Materials International 2004年第4期14卷 10-16页

作者： ZHU Ying(department of Psychology, peking university,{2., China) peking Univ Dept Psychol Beijing 100871 Peoples R China

This paper reviews some basic findings and methodological issues in neuroimaging studies of self-referential processing. As a general rule, making judgments about one’s self, inclusive of personality trait adjectives or current mental states (person’ s preferences, norms, aesthetic values and feeling) uniformly generates medial prefrontal activations, regardless of stimulus materials (words or pictures) and modality (visual or auditory). Cingulate activations are also observed in association with most self-referential processing. Methodological issues include treating self-referential processing as either representing one’s own personality traits or representing one’s own current mental states. Finally, self-referential processing could be considered as implement of "I think therefore I am" approach to neuroimaging the self.

关键词： self self-referential processing medial prefrontal cortex cingulate brain image.

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Empirical rheological law of multiphase rocks:Energy minimizing approach independent of bound theory

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Chinese Science Bulletin 2003年第22期48卷 2496-2500页

作者： ZANG Shaoxian, JIANG Yan & WEI Rongqiang department of geophysics,{2., beijing 100871, China department of geophysics Peking University China

Based on energy minimizing approach of bound theory, the influence of the distribution of constituent minerals on rheological property of rocks is discussed. Energy minimizing approach independent of the bound theory is advanced after the constraint condition is improved. The strength of four multiphase rocks is calculated with the new empirical rheological law. Results indicate that the new law has a reasonable physical explanation and fits the experimental data very well.

关键词：流变学能量最小化法多相岩石地质学

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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 {2., peking university, beijing 100871, China 1. Institute of Crustal Dynamics China Earthquake Administration Beijing 100085 China 2. department of geophysics Peking University Beijing 100871 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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