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地学前缘 2003年第4期10卷 479-505页

作者： Yong-gang LIDepartment of Earth Sciences ,University of Southern california ,Los Angeles,california 90089,U. S. A. Department of Earth Sciences University of Southern CaliforniaLos Angeles California

美国加利福尼亚州兰德斯和海克特曼恩地区于1992年和1999年先后发生7.4级和7.1级地震,分别在地面产生80km和40km长的断裂带。震后在断裂带布置的密集地震站台记录到明显的断层导波(fault-zone guided waves)。这些导波由断层带内的余震... 详细信息

美国加利福尼亚州兰德斯和海克特曼恩地区于1992年和1999年先后发生7.4级和7.1级地震,分别在地面产生80km和40km长的断裂带。震后在断裂带布置的密集地震站台记录到明显的断层导波(fault-zone guided waves)。这些导波由断层带内的余震和人工震源激发产生,走时在S波之后,但具有比体波更强的振幅和更长的波列,并具有频散特征。通过对2～7 Hz断层导波的定量分析和三维有限差分数字模拟,获得了震深区断裂带的高分辨内部构造图像以及岩石的物理特性。数字模拟结果表明这些断裂带上存在被严重破碎了的核心层,形成低速、低Q值地震波导。核心破碎带宽约100～200 m,其内地震波波速降为周围岩石的40％～50％,Q值约为10～50。根据岩石断裂力学观点,这一低速、低Q值带可被解释为地震过程中处于断层动态断裂前端的非弹性区(或称之为破碎区,相干过程区)。在兰德斯和海克特曼恩断裂带测得的破碎区宽度与断裂带长度之比约为0.005,基本上符合岩石断裂力学预期的结果。观察到的断层导波还显示兰德斯和海克特曼恩地震中多条断层发生滑移和破碎。兰德斯地震时多条阶梯形断层相继断裂;而在海克特曼恩地震中,断裂带南北两端均出现分枝断裂,深处的分枝断裂较地表出现的破裂状况更为复杂。由三维有限元模拟的动态断裂过程表明,?

关键词：断层导波四维地震兰德斯断裂带海克特矿加利福尼亚

华北燕山带:构造、埃达克质岩浆活动与地壳演化(英文)

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地学前缘 2003年第4期10卷 373-384页

作者： Gregory A. DAVIS Department of Earth Sciences, University6 of Southern california, Los Angeles,california 90089-0740 USA Department of Geology , China University of Geosciences , Beijing 100083, China （北京）中国地质大学

埃达克质火成岩在中国东部,包括燕山带是很常见的,一般认为它们是下地壳不均匀的镁铁质岩石及/或富集的上地幔岩石在高压(≥1.5 GPa)下部分熔融的结果。在燕山带内埃达克岩浆的形成有一个很长的时间(约190～80 Ma),然而岩浆活动的峰期... 详细信息

埃达克质火成岩在中国东部,包括燕山带是很常见的,一般认为它们是下地壳不均匀的镁铁质岩石及/或富集的上地幔岩石在高压(≥1.5 GPa)下部分熔融的结果。在燕山带内埃达克岩浆的形成有一个很长的时间(约190～80 Ma),然而岩浆活动的峰期却与约170～130 Ma间有基底岩石卷入的陆壳收缩期相一致。尽管埃达克质岩浆活动的历史很长,但那种把岩浆活动与岩石圈的拆沉效应相联系的模式似乎是不适当的。在该带内,埃达克质与非埃达克质岩浆活动有一部分是同时的,而且在地理分布上也是相间的,这说明了在下地壳和上地幔岩石的部分熔融中成分是相当不均匀的。侏罗纪及白垩纪熔融作用的热源应当是与古太平洋板块俯冲相关的中生代板底垫托的玄武岩浆。除了局部例外,在燕山带,埃达克质岩浆活动的终结和碱性岩浆活动的开始约在130～120 Ma,在此时期收缩作用使东亚大达200万km^2以上的地区发生了NW—SE向的区域性伸展作用。强烈的地壳伸展仅局限于华北克拉通北缘分布的少数几个变质核杂岩中。陆壳的伸展减薄合理地解释了130～120 Ma间发生高压埃达克质熔融条件的终结,尽管还有局部年轻的埃达克火山活动(约120～80Ma)可以在伸展规模有限而厚的地壳依然存在的地区继续出现。燕山区早白垩世的碱性侵入体中的锆石不存在前寒武纪?

关键词：燕山带中国东部中生代构造埃达克质岩浆作用

对逆冲断层一些普遍观念的质疑──以美国西部科迪勒拉及中国华北的野外研究为例(英文)

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地学前缘 1999年第3期6卷 49-66页

作者： Gregory A. Davis(Department of Earth Sciences, University of Southern california Los Angeles,california 90089-0740 USA)

在过去的25年里，由于许多原因，作为最常见、分布也最广泛的地质构造形迹之一，逆冲断层成为倍受关注的科学研究主题。文中指出，关于逆冲断层及其几何学特征的许多普遍认识（或观念），并不像以往文献中所阐述的那样简单。其中之一的... 详细信息

在过去的25年里，由于许多原因，作为最常见、分布也最广泛的地质构造形迹之一，逆冲断层成为倍受关注的科学研究主题。文中指出，关于逆冲断层及其几何学特征的许多普遍认识（或观念），并不像以往文献中所阐述的那样简单。其中之一的"薄皮"冲断构造是受地层控制的，极少有或者没有结晶基底物的卷入。文中主张，"薄皮"一词只有逆冲板片的几何学形态含义，而不应包含地层意义，并列举了一些完全由结晶岩石所构成的薄皮逆冲构造的例子来说明这一主张。近来，逆冲双重构造成为构造文献中的热点。关于逆冲双重构造的成因，引用得最多的是1982年Boyer和Elliot在其重要论文"逆冲断层系统"中所作的解释。他们认为，双重道冲构造是通过在冲断坡底部发生下盘破裂。新生断裂不断向前扩展并进入先存断层下盘的一系列变形过程中逐渐形成的。根据Boyer和Elliot提出的这种变形过程，将形成一个具有平面状顶板断层的边冲双重构造，这个顶板断层只在活动断坡的顶部是主动向前扩展的。依笔者之见，在实际的构造变形当中，是不可能具备形成平顶过冲双重构造的地质条件的。而能对平顶过冲双重构造形成作出最好解释的是反序（out－of－sequence，OOS）边冲断层的发育，即断层向着主冲断层的后方发展，在先存道冲构造的上部?

关键词：断层逆冲断层双重构造反序断层作用

Network platform for remote structural testing and shared use of laboratories

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Progress in Natural Science:Materials International 2005年第12期15卷 1135-1142页

作者： XIAO Yan,HU Qing,GUO Yurong,ZHU Pingsheng and YI Weijian Department of Civil Engineering,University of Southern california,Los Angeles CA90089,USA School of Civil Engineering,Hunan University,Changsha 410082,China FutureNet Technologies Corporation,Monrovia,california,USA,and Nanchang,China Department of Civil Engineering University of Southern California Los Angeles CA90089 USA. School of Civil Engineering Hunan University Changsha 410082 China. FutureNet Technologies Corporation Monrovia California USA. FutureNet Technologies Corporation Nanchang China

This paper presents a network platform developed for remote testing of scaled model or prototype structures and structural *** network platform,NetSLab,was developed based on the client/server concept along with a proposed data model and the communication *** platform is capable of transferring the control and feedback data as well as signals among remotely located structural testing laboratories or computers connected by *** concepts were introduced to develop the platform and to provide relatively easy and friendly interface for applications and further *** and actual tests were successfully carried out at the Hunan University,China and the University of Southern california,*** simulating bridge piers and piles or building substructures were subjected to recorded earthquake ground motions,and the tests were controlled remotely over the Internet using the platform.

关键词： communication protocol data model earthquake simulation Internet remote testing

Characterization of Compact Support of Fourier Transform for Orthonormal Wavelets of L^2(R^d)

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Acta Mathematica Sinica,English Series 2005年第4期21卷 855-864页

作者： Zhi Hua ZHANG (Zhihua ZHANG) Department of Mathematics,University of california,Davis,california.95616,USA Department of Mathematics University of California Davis California 95616 USA

Let{ψμ} be an orthonormal wavelet of L^2（R^d） and the support of a whole of its Fourier transform be Uμsupp{ψμ}=Пi=1^d[Ai, Di]-Пi=1^d（Bi, Ci）, Ai≤Bi≤Ci≤Di. Under the weakest condition that each │ψμ│,... 详细信息

关键词： Orthonormal wavelets Multiresolution analysis Scaling function Compact support

FOUR STEP SCHEME FOR GENERAL MARKOVIAN FORWARD-BACKWARD SDES

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Journal of Systems Science & Complexity 2010年第3期23卷 546-571页

作者： Jin MA Jiongmin YONG Yanhong ZHAO Department of Mathematics University of Southern California Los Angeles CA 90089 USA Department of Mathematics University of Central Florida Orlando FL 32816 USA Department of Mathematics Purdue University West Lafayette IN 47907 USA

This paper studies a class of forward-backward stochastic differential equations (FBSDE)in a general Markovian *** forward SDE represents a large class of strong Markov semimartingales,and the backward generator requires only mild regularity *** authors showthat the Four Step Scheme introduced by Ma,et al.(1994) is still effective in this ***,the authors show that the adapted solution of the FBSDE exists and is unique over any prescribedtime duration;and the backward components can be determined explicitly by the forward componentvia the classical solution to a system of parabolic integro-partial differential *** importantconsequence the authors would like to draw from this fact is that,contrary to the general belief,in aMarkovian set-up the martingale representation theorem is no longer the reason for the well-posednessof the FBSDE,but rather a consequence of the existence of the solution of the decoupling integralpartialdifferential ***,the authors briefly discuss the possibility of reducing the regularityrequirements of the coefficients by using a scheme proposed by *** (2002) to the current case.

关键词： Forward-backward stochastic differential equations Four Step Scheme parabolic integropartial differential equation strong Markov semi-martingales.

Internet-based collaborative pseudo-dynamic testing of multi-span bridge structure

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Progress in Natural Science:Materials International 2009年第5期19卷 623-633页

作者： Dapeng Wang a, Shizhu Tiana, Xinjiang Caia, Yunlei Fan b, Yan Xiaob,c a School of Civil Engineering, Harbin Institute of Technology, Harbin 150090, China b School of Civil Engineering, Hunan University, Changsha 410082, China c Department of Civil Engineering, University of Southern california, Los Angeles, CA 90089, USA [a]School of Civil Engineering Harbin Institute of Technology Harbin 150090 China [b]School of Civil Engineering Hunan University Changsha 410082 China [c]Department of Civil Engineering University of Southern California Los Angeles CA 90089 USA

In this paper, the first Internet-based collaborative pseudo-dynamic testing of a multi-span bridge system in China’s mainland is presented in detail, which has been carried out by the collaboration of Hunan University (HNU), Harbin Institute of Technology (HIT) and Tsinghua University (TU) in China’s mainland, and the University of Southern california (USC) in the USA. The prototype system of Russion River Bridge at Southern california in America is illustrated. Different testing specimens, testing equipments and substructure boundary conditions at HNU and HIT laboratories are described. A network protocol platform for collaborative pseudo-dynamic testing, called NetSLab, and some function modules developed on the use of its standardized interface are introduced. Aiming at the MTS system widely used in structural testing, two approaches are presented to implement the communication interface between NetSLab and testing equipment, respectively, studied by HNU and HIT. The integrated networked testing system and collaborative testing procedures are presented. The testing results manifest that the networked collaborative testing system with powerful capability provides a testing platform with good coordination for complex models or actual structures, and achieves remote sharing of testing equipments.

关键词： Internet-based collaborative pseudo-dynamic testing Multi-span bridge structure Network protocol platform Communication interface Remote sharing of testing equipment

POLES OF ZETA FUNCTIONS OF COMPLETE INTERSECTIONS

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Chinese Annals of Mathematics,Series B 2000年第2期21卷 187-200页

作者： WAN DAQING(Department of Mathematics, University of california, Irvine, CA 92697-3875, USA.) Department of Mathematics University of California Irvine CA 92697-3875 USA

A vanishing theorem is proved for e-adic cohomology with compact support on an affine (singular) complete intersection. As an application, it is shown that for an affine complete intersection defined over a finite field of q elements, the reciprocal "poles" of the zeta function are always divisible by q as algebraic integers. A p-adic proof is also given, which leads to further q-divisibiliy of the poles or equivalently an improvement of the polar part of the AxKatz theorem for an affine complete intersection. Similar results hold for a projective complete intersection.

关键词： Pole Zeta function Complete intersection

QUALIFICATION OF UNCERTAINTY FOR SIMULATING SOLUTE TRANSPORT IN THE HETEROGENEOUS MEDIA WITH SPARSE GRID COLLOCATION METHOD

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Journal of Hydrodynamics 2009年第6期21卷 779-789页

作者： SHI Liang-sheng YANG Jin-zhong State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan 430072 China The Sonny Astani Department of Civil and Environmental Engineering University of Southern California Los Angeles CA 90089 USA

The sparse grid collocation method is discussed to qualify the uncertainty of solute transport. The Karhunen-Loeve （KL） expansion is employed to decompose the log transformed hydraulic conductivity. The head, velocity and concentration fields are represented by the Lagrange polynomial expansion. A sparse grid collocation method is then used to reduce the original stochastic partial differential equations to a set of deterministic equations which is collocated at selected interpolation （collocation） points. The collocation points are constructed by the Smolyak algorithm. The accuracy, efficiency and convergence property of sparse grid collocation method are investigated by numerical experiments. The analysis shows that stochastic collocation strategy helps to decouple stochastic computations, and all the numerical computation is possible to be implemented by existing deterministic finite element codes. The proposed method provides an efficient way to evaluate the uncertainty of the solute transport in the heterogeneous media.

关键词： stochastic partial differential equations collocation method solute transport uncertainty