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Research on nonlinear constitutive relationship of permanent deformation in asphalt pavements

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Science china(Physics,Mechanics & Astronomy) 2006年第6期49卷 671-682页

作者： PENG Miaojuan1 & XU Zhihong2 1. Department of Civil Engineering,Shanghai University,Shanghai 200072,china 2. School of Transportation Engineering,Tongji University,Shanghai 200092,china 1. Department of Civil Engineering Shanghai University Shanghai 200072 China 2. School of Transportation Engineering Tongji University Shanghai 200092 China

To predict correctly the rut depths in asphalt pavements,a new nonlinear viscoelastic-elastoplastic constitutive model of permanent deformation in asphalt pave-ments is presented. The model combines a generalized Maxwell model with an elasto-plastic one. Then from the creep theory,the linear and nonlinear constitutive equations of the generalized Maxwell model are obtained. From the nonlinear finite element method for the rutting of the asphalt pavement,the rut depths of 4 asphalt-aggregate mixtures are obtained. And the results are compared with the ones from the finite element method by SHRP and the experiments by SWK/UN. The results in this paper are better than the ones by SHRP,and agree with the ones of the experiment by SWK/UN. This shows that the nonlinear viscoelastic-elastoplastic constitutive model,which is presented in this paper for the rutting of the asphalt pavement,is effective. The properties,such as nonlinear elastic-ity,plasticity,viscoelasticity and nonlinear viscoelasticity,which affect the rutting of an asphalt pavement,can be shown in the model. And the characteristics of the permanent deformation of the asphalt pavement can be presented entirely in the model.

关键词： asphalt pavement,permanent deformation,nonlinear viscoelastic-elastoplastic constitutive relationship,generalized Maxwell model,creep compliance.

Syndepositional Fault Controlling on Depositional Filling of the Third Member of Shahejie Formation in Beitang Sag

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Journal of Earth Science 2009年第6期20卷 949-958页

作者：黄传炎王华肖敦清陈思王家豪廖远涛 Faculty of Earth Resources China University of Geosciences State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Key Laboratory of Tectonics and Petroleum Resources of Ministry of Education China University of GeosciencesWuhan Research Institute of Exploration and Development PetroChina Dagang Oilfield Company

In the continental lake basin whose structures were extraordinarily active, tectonism is an important factor in controlling the sequence and the depositional filling of the basin. This article reports the assemble patterns of syndepositional fault in the third member of Shahejie （沙河街） Formation in Beitang （北塘） sag. The results show that the comb-shape fracture system and the fracture transformation zone were developed in Beitang sag. These assemble patterns obviously controlled the sand-body and spatial distribution of sedimentary system. However, the steep slope belt of fault terrace, the multistage slope belt and the low uplift gentle slope belt controlled the development of sequence styles. Analyses of the spatial-temporal relationship of the assemble pattern of syndepositional faults and the sedimentary system help predict the favorable exploration zone.

关键词： Beitang sag syndepositional fault structural slope break zone the third member of Shahejie Formation.

COMPOSITIONAL HETEROGENEITY OF ETHYLENE OXIDE-BUTYLENE TEREPHTHALATE SEGMENTED COPOLYMER

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Chinese Journal of Polymer Science 1999年第3期17卷 271-280页

作者： De-zhu Ma Dong-sheng Li Ming-chuan Zhao Mo-zhen Wang Ran Ye Xiao-lie Luo Department of Polymer Science and Engineering, University of Science and Technology of china, Hefei 230026, china Univ Sci & Technol china Dept Polymer Sci & Engn Hefei 230026 Peoples R China

A series of ethylene oxide-butylene terephthalate (EOBT) segmented copolymers with different soft segment length and hard segment content were synthesized. The compositional heterogeneity was studied by solvent extraction. The results show that the compositional heterogeneity increases when soft segment length and hard segment content increase. The compositional heterogeneity is also reflected in the crystallization behavior and morphology of soft and hard segment in EOBT segmented copolymer. The more compositional heterogeneous the EOBT segmented copolymer is, the more different the morphology and the crystallization behavior between separated fractions. Compared with ethylene oxide-ethylene terephthalate (EOET) segmented copolymer, compositional heterogeneity in EOBT segmented copolymer is weaker. But the compositional heterogeneity in EOBT segmented copolymer with long soft segment and high hard segment content is still obvious.

关键词： ethylene oxide-butylene terephthalate segmented copolymer compositional heterogeneity crystallizability morphology

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Communications in Nonlinear Science and Numerical Simulation 1999年第3期4卷 186-190页

作者： Guoqian CHEN and J. H. W. LEE(Centre for Environmental Sciences, Peking University, Beijing 100871, china) (Department of Civil Engineering, University of Hong Kong, Hong Kong, china) Centre for Environmental Sciences Peking University Beijing 100871 China Department of Civil Engineering University of Hong Kong Hong Kong China

IntroductionThethermal,abodyofbuoyalfluidinafluidwithwhichitcanmixandgivennamebygliderpilotstothosemassesofwarmairrisingfromhotgroundwarmedbysunshineinwhichtheycansoar,***],duetoi... 详细信息

IntroductionThethermal,abodyofbuoyalfluidinafluidwithwhichitcanmixandgivennamebygliderpilotstothosemassesofwarmairrisingfromhotgroundwarmedbysunshineinwhichtheycansoar,***],duetoi...

关键词： environmental fluid mechanics thermal turbulence modeling

Finite time L_1 Approach for Missile Overload Requirement Analysis in Terminal Guidance

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Chinese Journal of Aeronautics 2009年第4期22卷 413-418页

作者： Ji Denggao,He Fenghua,Yao Yu Control and Simulation Center,Harbin Institute of Technology,Harbin 150080,china [a]Control and Simulation Center Harbin Institute of Technology Harbin 150080 China

This article analyzes the problem about the missile overload requirement in a homing terminal guidance under various engagement scenarios. An augmented proportional navigation guidance （APNG） model is introduced on the basis of linear kinematics. To analyze the peak-to-peak performance of the terminal guidance system, a new finite time L1 performance measure for a linear time-varying （LTV） continuous system is proposed. Then, according to the idea of the adjoint system, a novel method for computing the L1 norm of a linear continuous system is first derived. Within the finite time L1 framework, the quantitative relation between the guidance loop dynamics and the maximum missile-target maneuver ratio is offered. This relation is expressed in the form of graphs and formulas that can be used to synthesize some of the major subsystem specifications for the missile guidance system. The illustrative examples show that a significant performance improvement is achieved with the proposed guidance loop dynamics.

关键词： finite time Lx-induced norm performance time varying systems missile overload requirement terminal guidance

Research on Some Questions About Selection of Independent Variables

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Systems Science and Systems Engineering 2002年第4期11卷 471-478页

作者： TAO Jing-xuanDept of Management Science and Engineering, china Institute of Metrology, Hangzhou 310034, china Dept of Management Science and Engineering China Institute of Metrology tangzhou 310034 China

The paper studies four methods about selection of independent variables in multivariate analysis. In general condition, advanced statistical method and backward statistical method could not obtain the best subset of independent variables. It is possibly affected by the orders of variables or associations among variables. When multicollinearity is presented in a set of explanatory variables-abnormal state, it is not effective to use the method, although stepwise regression and optimum selecting method of total subsets is widely used.;According to this case, the paper proposes a new method which combines deleting variables with ingredient analysis and is used in research and science practically.;The important characteristic of this paper is that it gives some examples to support each conclusion.

关键词： selection of independent variables multicollinearity stepwise regression subset of variables

CORRECTION METHODS FOR STEADY INCOMPRESSIBLE FLOWS

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Journal of Computational Mathematics 1999年第4期17卷 419-424页

作者： Jian Li(State Key Laboratory of Scientific and Engineering Computing, ICMSEC, Chinese Academy of Sciences, Beijing 100080, china) 中科院计算数学与科学工程计算所科学与工程计算国家重点实验室北京

Correction methods for the steady semi-periodic motion of incompressible fluid are investigated. The idea is similar to the influence matrix to solve the lack of vorticity boundary conditions. For any given boundary condition of the vorticity, the coupled vorticity-stream function formulation is solved. Then solve the governing equations with the correction boundary conditions to improve the solution. These equations are numerically solved by Fourier series truncation and finite difference method. The two numerical techniques are employed to treat the non-linear terms. The first method for small Reynolds number R equals 0-50 has the same results as that in M. Anwar and S.C.R. Dennis' report. The second one for R greater than 50 obtains the reliable results. (Author abstract) 4 Refs.

关键词： incompressible flow vorticity stream function numerical solution

Fuzzy Multi-Objective Decision Model of Supplier Selection with Preference Information

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Journal of Systems Engineering and Electronics 2001年第1期12卷 34-41页

作者： Chen Zhixiang School of Management, Zhongshan University, Guangzhou 510275, P. R. china Ma Shihua & Chen Rongqiu School of Management, Huazhong University of Science & Technology, Wuhan 430074, R R. china School of Management Zhongshan University Guangzhou 510275 P. R. China School of Management Huazhong University of Science & Technology Wuhan 430074 P. R. China

Supplier selection is a multi-objective decision problem, which must be considered many objectives, some objectives are qualitative, and others are quantitative. Meanwhile, manufacturer has preference for different suppliers. In this paper, a new multi-objective decision model with preference information of supplier is established. A practical example of supplier selection problem utilizing this model is studied. The result demonstrates the feasibility and effectiveness of the methods proposed in the paper.

关键词： Multi-objective Supplier selection FuzZy membership degree.

A study of the microbial mineralization in submarine black smoker chimneys from the Okinawa Trough

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Acta Oceanologica Sinica 2009年第2期28卷 87-95页

作者： FENG Jun LI Jianghai CHU Fengyou National Earthquake Response Support Service China Earthquake Adiministration Beijing 100049 China School of Earth and Space Sciences Peking University Beijing 100871 China Second Institute of Oceanography State Oceanic Administration Hangzhou 310012 China

Large amounts of microfossil records discovered in the seafloor black smoker chimney are reported from the Okinawa Trough. They are well preserved and can be divided into four types of filamentous microfossils. It suggests that the fossils may be derived from sulfur or iron oxidation chemolithotrophic prokaryotes and fungi. Based on the comparison studies of the microbial mineralization processes, two steps of biomineralization were hypothesized：（1） biology controlled mineralization; and （2） biology induced mineralization. At the early stage of the mineralization, the biology controlling mineralization is dominating; at the later stage, the biology inducing mineralization is the main mechanism. The composition of the fluids and the species of the microbes will determine the types of the minerals formed.

关键词： microfossils biomineralization black smoker Okinawa Trough