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A Method Combining Numerical Analysis and Limit Equilibrium Theory to Determine Potential Slip Surfaces in Soil Slopes

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Journal of Mountain Science 2011年第5期8卷 718-727页

作者： XIAO Shiguo YAN Liping CHENG Zhiqiang Department of Geological Engineering Southwest Jiaotong University Chengdu 610031 China los angeles Department of Water and Power Los Angeles USA Department of Applied Mechanics and Engineering Southwest Jiaotong University Chengdu 610031 China

This paper describes a precise method combining numerical analysis and limit equilibrium theory to determine potential slip surfaces in soil slopes. In this method, the direction of the critical slip surface at any point in a slope is determined using the Coulomb’s strength principle and the extremum principle based on the ratio of the shear strength to the shear stress at that point. The ratio, which is considered as an analysis index, can be computed once the stress field of the soil slope is obtained. The critical slip direction at any point in the slope must be the tangential direction of a potential slip surface passing through the point. Therefore, starting from a point on the top of the slope surface or on the horizontal segment outside the slope toe, the increment with a small distance into the slope is used to choose another point and the corresponding slip direction at the point is computed. Connecting all the points used in the computation forms a potential slip surface exiting at the starting point. Then the factor of safety for any potential slip surface can be computed using limit equilibrium method like Spencer method. After factors of safety for all the potential slip surfaces are obtained, the minimum one is the factor of safety for the slope and the corresponding potential slip surface is the critical slip surface of the slope. The proposed method does not need to pre-assume the shape of potential slip surfaces. Thus it is suitable for any shape of slip surfaces. Moreover the method is very simple to be applied. Examples are presented in this paper to illustrate the feasibility of the proposed method programmed in ANSYS software by macro commands.

关键词： Soil slope Stress field Potential slip surface Slope stability Factor of safety Numerical analysis Limit equilibrium method ANSYS software

FRACTURE TOUGHNESS OF ORDERED INTERMETALLIC COMPOUNDS FROM SMALL DISKSHAPED SPECIMENS

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中国有色金属学会会刊：英文版 1999年第S1期9卷 106-116页

作者： Alan J.Ardell Department of Materials Science and Engineering, University of California, los angeles, CA 90095 1595, U.S.A.

The miniaturized disk bend test(MDBT) can be used to measure the fracture toughness at “infinite" crack length, K ∞, of ordered intermetallic compounds. The specimens tested are disks 3 mm in diameter and typically range in thickness from 250 to 400 μm. A Vickers indentation is impressed within ±10 μm of the center of a metallographically polished disk under a known load, F . The specimen is then subjected to biaxial loading, with the indented side in tension, and tested to failure. In completely brittle intermetallics the fracture stress, σ f, is calculated using a standard formula and measured experimentally as a function of F . When plasticity intervenes prior to fracture it is necessary to calculate the stress using finite element modeling (FEM), the FEM program NIKE2D has been used. Whether or not the specimens deform plastically, the resulting data on σ f vs F are analyzed using established equations of fracture mechanics in conjunction with an empirical rising R curve equation that characterizes the increase in fracture resistance, K R( c ), with crack length, c . Results are presented on several ordered intermetallic compounds. These include Ni 3Ge and Ti 5Si 3, which exhibit no ductility prior to fracture, and NiAl and a complex TiAl alloy, which both exhibit limited ductility before fracturing. The values of K ∞ determined with the MDBT are in very good agreement with values of K IC measured using conventional methods.

关键词： ordered intermetallics Ni 3Ge Ti 5Si 3 TiAl fracture toughness miniature disk bend test

INVESTIGATION ON RESONANT TUNNELING IN GaAs/Al_xGa_(1-x)As DBD USING TUNNELING SPECTROSCOPY

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Journal of Electronics(China) 1990年第1期7卷 70-76页

作者：陈弘毅 K.L.Wang Institute of Microelectronies Tsinghua UniversityBeijing100084 Device Research Laboratory Electrical Engineering DepartmentUniversity of California at Los AngelesLos AngelesCA.90024U.S.A

Experimental investigation on resonant tunneling in various GaAs/AlxGa1-xAsdouble barrier single well structures has been performed by using tunneling spectroscopy atdifferent *** results show that in addition to resonant tunneling via GaAs wellstate confined by AlxGa1-xAs Γ-point barrier there exists resonant tunneling via GaAs well stateconfined by AlxGa1-xAs X-point barrier for both indirect（x>0.4）and direct（x<0.4）cases.

关键词： Resonant tunneling Quantum well Energy band profile

Biological Impact of Type Ⅰ Interferon Induction Pathways beyond their Anti-virus Activity

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Biological Impact of Type Ⅰ Interferon Induction Pathways b...

Heat flow distribution in Chinese continent and its adjacent areas

第六届全国免疫学学术大会

作者： Genhong Cheng Department of Microbiology,Immunology and Molecular Genetics,University of California los angeles,los angeles,CA 90095,USA

In response to most viral and many bacterial infections,mammalian cells produce an array of Type I Interferons,which activate the JAK/STAT pathway and induce a large set of genes involved in innate and adaptive immune...

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Progress in Natural Science:Materials International 2008年第7期18卷 843-849页

作者： Wei Tao a,*, Zhengkang Shena,b a State Key Laboratory of Earthquake Dynamics, Institute of Geology, China Earthquake Administration, Beijing 100029, China b Department of Earth and Space Sciences, University of California, los angeles, CA 90095-1567, USA State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China Department of Earth and Space Sciences University of California Los Angeles CA 90095-1567 USA

Using a compilation of 6980 heat flow measurements, we produce a new heat flow map for the Chinese continent and its adjacent areas. We develop an objective and integrated method to interpolate the heat flow data, taking into account both the uniformity within geological units and coherency of regional heat flow. The geologic units are outlined based on Zhang et al.’s active tectonic block model. Our heat flow model is presented in two formats: a contour map and a heat flow dataset with values on a 1×1° grid for the Chinese continent and its adjacent areas, reflecting detailed variations in some regions. Also provided is a resolution map which helps understand the reliability of the heat flow model. Our results reveal that (1) Heat flows in the eastern part of the Chinese continent are relatively higher than those in the western part except that in the Tibetan Plateau area. (2) Heat flows in the Ordos and North China blocks are around 60 mW/m2, and are 50–55 mW/m2 in South China except for the continental marginal sea regions. (3) Heat flow is the lowest in the Junggar Basin, only 35–45 mW/m2, and is 45–55 mW/m2 in the Tarim Basin. The results of this study provide an important data- set for studies on thermal and rheological structures of the Chinese continent and its adjacent areas.

关键词： Heat flow Chinese continent and its adjacent areas Geological units Contour map Resolution map

TRAF-mediated regulation of immune and inflammatory responses

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Science China(Life Sciences) 2010年第2期53卷 159-168页

作者： WANG YaYa1,ZHANG Peng2,LIU YingFang2 & CHENG GenHong1 1 Department of Microbiology,Immunology & Molecular Genetics,University of California los angeles,609 Charles E.Young Drive East,los angeles,California 90095,USA 2 National Laboratory of Biomacromolecules,Institute of Biophysics,Chinese Academy of Sciences,Beijing 100101,China Department of Microbiology Immunology & Molecular Genetics University of California Los Angeles Los Angeles USA National Laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing China

The tumor necrosis factor (TNF) receptor-associated factor (TRAF) family consists of six mammalian members,and is shown to participate in signal transduction of a large number of receptor families including TNF receptor family (TNFR) and Toll-like receptors-interleukin-1 receptors (TLR-IL-1R) *** receptor activation,TRAFs are directly or indirectly recruited to the intracellular domains of these *** subsequently engage other signaling proteins to activate inhibitor of κB kinase (IKK) complex,TRAF family member-associated NF-κB activator (TANK)-binding kinase 1 (TBK1) and inducible I κB kinase (IKK-i) (also known as IKKε),ultimately leading to activation of transcription factors such as NF-κB and interferon-regulatory factor (IRF) to induce immune and inflammatory responses.

关键词： TRAF NF-κB type 1 interferon innate immunity

Dynamics and Synchronization of Semiconductor Lasers

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Dynamics and Synchronization of Semiconductor Lasers

WORD PROBLEMS AND THE CENTERS OF ABEL DIFFERENTIAL EQUATIONS

第二届全国复杂动态网络学术论坛

作者： Jia-Ming Liu Electrical Engineering Department.University of California los angeles. los angeles CA 90095. USA

＜正＞A complete picture of the nonlinear dynamics and unidirectionally coupled chaos synchronization of single-mode semiconductor lasers is presented in this paper. Synchronization for chaotic optical communications is *** concepts and theoretical framework are *** results are presented to demonstrate the fundamental *** computations are employed for mapping the dynamical states and for illustrating certain detailed characteristics of the chaotic *** different semiconductor laser systems,namely the optical injection system,the optical feedback system,and the optoelectronic feedback system,that are of most interest for high-bit-rate chaotic optical communications are *** optical injection system is a nonautonomous system that follows a period-doubling route to *** optical feedback system is a phase-sensitive delayed-feedback autonomous system for which all three known routes, namely period-doubling,quasiperiodicity,and intermittency,to chaos can be *** optoelectronic feedback system is a phase-insensitive delayed-feedback autonomous system that follows a quasiperiodicity route to chaotic *** synchronization in unidirectionally coupled configurations is the focus of discussions for chaotic *** optical injection and optical feedback systems,the frequency,phase,and amplitude of the optical fields of both transmitter and receiver lasers are all locked in synchronism when complete synchronization is *** the optoelectronic feedback system,chaos synchronization involves neither the locking of the optical frequency nor the synchronization of the optical *** both optical feedback and optoelectronic feedback systems,where the transmitter is configured with a delayed feedback loop, anticipated and retarded synchronization can be observed as the difference between the feedback delay time and the propagation time from the transmitter laser to the receiver las

关键词： Semiconductor lasers dynamics chaos synchronization and chaotic communications

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Annals of Differential Equations 1995年第4期11卷 392-396页

作者： M.A.M.Alwash(University of California, los angeles, CA 90024, USA)

The approach of word problems is adopted to study the centers of nonautonomous cubic *** answer various questions that arise from this investigation. In *** demonstrate that a recent condition for the existence of a c... 详细信息

关键词： ABEL WORD PROBLEMS AND THE CENTERS OF ABEL DIFFERENTIAL EQUATIONS

Chemistry, Theater, Information and Communications Technology

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Journal of Chemistry and Chemical Engineering 2015年第3期9卷 221-226页

作者： Maria de los angeles Montiel Montoya Celia Sanchez Mendoza Graciela Martinez de Jesus Department of Chemistry National Preparatory School No. 4 National Autonomous University of Mexico Mexico 11870 Mexico Department of Chemistry National Preparatory School No. 8 National Autonomous University of Mexico Mexico 01600 Mexico

Theater play that shows how textiles, make up, hair dyes and music players has changed along the last six decades, especially due to polymers. It is a play that has a historic, chemical and musical side that introduces the use of ICT （information and communications technology）, such as Faeebook, Moodle platform, Web sites, E-mail, Word, Publisher, PowerPoint, Videos and Digital music. Results in the conduct of the students that participated： assertiveness, self-esteem, tolerance, cooperation, responsibility and teamwork, all of them significantly contributed a meaningful learning about the polymers.

关键词： Theater ICT polymer meaningful learning.