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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 2.0072.china 2. School of Transportation Engineering,tongji university,shanghai 2.0092.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.

中国政治经济学年度发展报告（2.2.）（下）

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政治经济学评论 2024年第3期 90+207-208页

作者： Center for Studies of Contemporary Political Economy,Research institute for 2.st-Century Marxism,Nankai university·university of Chinese Academy of Social Science Center for Teaching and Research on Capital,Renmin university of china National institute of Socialist Political Economy with Chinese Characteristics,Renmin university of china 南开大学·中国社会科学院大学2.世纪马克思主义研究院当代政治经济学研究中心中国人民大学《资本论》教学与研究中心中国人民大学全国中国特色社会主义政治经济学研究中心

编者按2.2.年，高质量发展扎实推进，新质生产力加快形成，我国经济总体回升向好，圆满实现发展主要预期目标。为针对性地破解经济恢复发展中的难题，聚焦推进中国式现代化进程中的重点、难点问题，中国政治经济学界开展系统深入研究，...

编者按2.2.年，高质量发展扎实推进，新质生产力加快形成，我国经济总体回升向好，圆满实现发展主要预期目标。为针对性地破解经济恢复发展中的难题，聚焦推进中国式现代化进程中的重点、难点问题，中国政治经济学界开展系统深入研究，取得系列代表性成果。为准确刻画学界研究进展和轨迹，推动中国经济学理论体系的构建和完善，本刊精选议题如期奉上《中国政治经济学年度发展报告（2.2.）》。自2.10年起，本刊连续十四年发布《中国政治经济学年度发展报告》，“年度发展报告”专栏已成为本刊标志性特色栏目。2.2.年报告聚焦12.专题，分为（上）（下）两篇，其中专题1—6于报告（上）篇刊登，专题7—12.报告（下）篇刊登。2.2.年报告（下）选题如下：

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Boundary element-free method for elastodynamics

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Science china(Physics,Mechanics & Astronomy) 2005年第6期48卷 641-657页

作者： CHENG Yumin1 & PENG Miaojuan2.1. shanghai institute of Applied Mathematics and Mechanics, shanghai university, shanghai 2.0072. china 2. Department of Civil Engineering, shanghai university, shanghai 2.0072. china 1. shanghai institute of Applied Mathematics and Mechanics Shanghai University 200072 Shanghai China 2. Department of Civil Engineering Shanghai University 200072 Shanghai China

The moving least-square approximation is discussed first. Sometimes the method can form an ill-conditioned equation system, and thus the solution cannot be obtained correctly. A Hilbert space is presented on which an orthogonal function system mixed a weight function is defined. Next the improved moving least-square approximation is discussed in detail. The improved method has higher computational efficiency and precision than the old method, and cannot form an ill-conditioned equation system. A boundary element-free method (BEFM) for elastodynamics problems is presented by combining the boundary integral equation method for elastodynamics and the improved moving least-square approximation. The boundary element-free method is a meshless method of boundary integral equation and is a direct numerical method compared with others, in which the basic unknowns are the real solutions of the nodal variables and the boundary conditions can be applied easily. The boundary element-free method has a higher computational efficiency and precision. In addition, the numerical procedure of the boundary element-free method for elastodynamics problems is presented in this paper. Finally, some numerical examples are given.

关键词： moving least-square approximation, improved moving least-square approximation, elastodynamics, boundary integral equation, meshless method, boundary element-free method, Fourier eigen transform.

Transverse patterns and spatiotemporal instability of a photorefractive oscillator

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Chinese Science Bulletin 1997年第9期42卷 724-729页

作者： ZHUANG Jun and TAN Weihan1. shanghai institute of Optics and Fine Mechanics, Chinese Academy of Sciences, shanghai 2.1800, china 2. shanghai university, shanghai 2.1800, china shanghai institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai China shanghai university Shanghai China

IN time realm,instability and chaos phenomena of a nonlinear optical system have been dis-cussed *** recent years,as much interest was attracted to the transverse ef-fects in nonlinear optics,the study was developed t... 详细信息

关键词： photorefractive oscillator spatiotemporal instability transverse patterns.

Dependence of binaural loudness summation on interaural level difference and frequency for pure tones

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Science china(Physics,Mechanics & Astronomy) 2010年第5期53卷 834-841页

作者： ZHANG Jie & MAO DongXing institute of Acoustics,tongji {2.,shanghai 2.0092.china 1. institute of Acoustics Tongji University Shanghai 200092 China

Most of the existing loudness models are based on the diotic listening hypothesis,though human beings always hear in dichotic listening *** this situation,the arithmetic mean of loudness at both ears is usually taken as the approximate value of overall perceived loudness,unaffected by the interaural level difference(ILD).The present work investigated the overall perceived loudness for pure tones in dichotic listening conditions through a subjective *** experimental procedures and systematic errors were investigated to prove the accuracy of the subjective *** results showed that fluctuation was insignificant in the low frequency range,while apparent fluctuation of overall loudness could be observed at a high *** overall loudness deviated from the arithmetic mean value as the ILD became larger.A revised model for overall loudness in dichotic listening conditions was *** proposed model and experiment are consistent.

关键词： dichotic listening subjective experiment interaural level difference overall perceived loudness loudness model

A complex variable meshless method for fracture problems

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Science china(Physics,Mechanics & Astronomy) 2006年第1期49卷 46-59页

作者： CHENG Yumin1 & LI Jiuhong2.1. shanghai institute of Applied Mathematics and Mechanics, shanghai university, shanghai 2.0072. china 2. Department of Building Engineering, Xi’an university of Technology, Xi’an 710048, china shanghai institute of Applied Mathematics Mechanics Shanghai University Shanghai 200072 China Department of Building Engineering Xi’an University of Technology Xi’an 710048 China

Based on the moving least-square (MLS) approximation, the complex variable moving least-square approximation (CVMLS) is discussed in this paper. The complex variable moving least-square approximation cannot form ill-conditioned equations, and has greater precision and computational efficiency. Using the analytical solution near the tip of a crack, the trial functions in the complex variable moving least-square approxi- mation are extended, and the corresponding approximation function is obtained. And from the minimum potential energy principle, a complex variable meshless method for fracture problems is presented, and the formulae of the complex variable meshless method are obtained. The complex variable meshless method in this paper has greater precision and computational efficiency than the conventional meshless method. Some examples are given.

关键词： moving least-square approximation, complex variable moving least-square approximation, meshless method, complex variable meshless method, fracture.

Fracture analysis of a functionally graded interfacial zone between two dissimilar homogeneous materials

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Science china(Physics,Mechanics & Astronomy) 2006年第5期49卷 540-552页

作者： CHENG Zhanqi1,2.& ZHONG Zheng1 1. School of Aerospace Engineering and Applied mechanics, tongji university, shanghai 2.0092. china 2. College of Civil Engineering, Zhengzhou {2., Zhengzhou 450002. china 1. School of Aerospace Engineering and Applied mechanics Tongji University Shanghai 200092 China 2. College of Civil Engineering Zhengzhou University Zhengzhou 450002 China

In this paper the plane elasticity problem for a functionally graded interfacial zone containing a crack between two dissimilar homogeneous materials has been considered. It is assumed that in the interfacial zone the reciprocal of the shear modulus is a linear function of the coordinate, while Possion’s ratio keeps constant. By utilizing the Fourier transformation technique and the transfer matrix method, the mixed boundary problem is reduced to a system of singular integral equations that are solved numerically. The influences of the geometric parameters and the graded parameter on the stress intensity factors are investigated. The numerical results show that the graded parameters, the thickness of interfacial zone, the crack size and location have significant effects on the stress intensity factors.

关键词： functionally graded material interfacial zone fracture stress intensity factor

Explicit Analytical Solutions for the Shearingand Radial Stresses in Curved Beams

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Communications in Nonlinear Science and Numerical Simulation 1999年第2期4卷 151-156页

作者： Aiming YU+ Xiangrong LI+++ (tongji university,{2.)++ (shanghai university, shanghai 2.0072. china) tongji university Shanghai 200092 China shanghai university Shanghai 200072 China

The shearing stresses in curved beams can be solved explicitly from anintegral equation, which is obtained by differentiation & integral manipulations. Twonovel formulae for shearing & radial stresses are also presented in the paper. The resultsof an example reveal that the shearing & radial stresses arrive at their maximum valuesslightly below the centroid of the section.

关键词： curved beam shearing stress radial stress integral equation

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 100871, china 2. Laboratory of Marine Geology,{2., shanghai 2.0092. china 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, 2.7, 2.1, 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 1146.