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PIXE and INAA studies on ancient potteries from Guangfulin relics in shanghai

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Progress in Natural Science:Materials International 2007年第11期17卷 1348-1356页

作者： Lin Jiawei1, Cheng Huansheng1, Zhang Zhengquan1, Zhang Bin1, Feng Songlin2. Song Jian3, Gao Menghe4 and Zhu Dan1(1. Applied Ion Beam Physics Laboratory, Key Laboratory of the Ministry of Education, Institute of Modern Physics, Fudan University, shanghai 2.0433, china 2. Key Laboratory of Nuclear Analytical Techniques, Institute of High Energy Physics, Beijing 100039, china 3. shanghai Museum, shanghai 2.0003, china 4. Department of Cultural Heritage and Museology, Fudan University, shanghai 2.0433, china) Applied Ion Beam Physics Laboratory Institute of Modern Physics Fudan University Shanghai 200433 China Key Laboratory of Nuclear Analytical Techniques Institute of High Energy Physics Beijing 100039 China shanghai Museum Shanghai 200003 China Department of Cultural Heritage and Museology Fudan University Shanghai 200433 China

This paper reports the study of ancient potteries unearthed from the Guangfulin site in shanghai. From the external features of these potteries, archeologists can classify them into two different cultural types: Liangzhu culture (local culture) and a new culture which might be derived elsewhere, but they can not recognize whether they were produced in the same place. Proton induced X-ray emission (PIXE) and instrumental neutron activation analysis (INAA) were used to measure the chemical compositions of the samples and the results were analyzed using multivariate statistics. We found that the two methods can complement each other and their database can be mutually referenced in the study of ancient potteries. Experimental results show that the compositions of the potteries from the two cultural types are different, which means that the materials for ancient potteries of new culture originate from elsewhere. This supports the archaeologists’ speculation that a group of ancient people migrated to shanghai from some other places 4000 years ago.

关键词： PIXE INAA factor analysis Guangfulin ancient pottery

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 shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai China Department of Civil Engineering Shanghai University 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.

Mechanical and Experimental Study of Sprinkling Water Cooling System on Roof of shanghai Expo Theme Pavilion

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湖南大学学报（自然科学版） 2009年第S1期36卷 156-159页

作者： ZHAO Hui-zhong1,HUANG Chen1,LI Wei-xiang2.SHI Jin-yue2.TAO Si-yuan1,WANG Qian1,WANG Yu-qing1,ZHANG Min3(1.College of Urban Construction and Environment Engineering,University of {2. for Science and Technology,{2. 2.0093,{2. 2.Architectural Design & Research Institute of Tongji University,{2. 2.0092.{2. 3.College of Food Science Technology,{2. Ocean University,{2. 2.1306,{2.) College of Urban Construction and Environment Engineering University of Shanghai for Science and Technology Shanghai 200093 China Architectural Design and Research Institute Tongji University Shanghai 200092 China College of Food Science Technology Shanghai Ocean University Shanghai 201306 China

Based on the similarity theory,a scale effect model of the spraying water cooling system of shanghai expo Theme Pavilion's roof was set *** to the typical weather conditions in shanghai city,different models were analyzed on solar radiation,and different heat transfer amount was *** the following conclusions could be made:At the sunny day of summer in shanghai,the temperature of inner roof with sprinkling system descended about 3 ℃,and the air conditioning load of the whole Theme Pavilion descend more than 32. kW.

关键词： shanghai expo large space atrium solar radiation roof sprinkling system similarity theory prototype

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, {{2. {2. shanghai University, shanghai {2.1800, {{2. 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.

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.{2. 2. School of Transportation Engineering,Tongji University,shanghai 2.0092.{2. Department of Civil Engineering Shanghai University Shanghai China School of Transportation Engineering Tongji University Shanghai 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.

Population-size-dependent branching processes in Markovian random environments

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Chinese Science Bulletin 1998年第8期43卷 635-638页

作者： WANG Hanxing 1 and DAI Yonglong 2.1. Department of Mathematics, shanghai University, shanghai 2.1800, {2. 2. Department of Mathematics, Zhongshan University, Guangzhou 5102.5, {2. Department of Mathematics Shanghai University Shanghai China Department of Mathematics Zhongshan University Gunngzhou China

A branching model {Z n} n≥0is considered where the offspring distribution of the population’s evolution is not only dependent on the population size, but also controlled by a Markovian environmental process {ξ n} n≥0. For this model, asymptotic behaviour is studied such as limn→∞Z n and limn→∞Z n/m n in the case that the mean m k, θof the offspring distribution converges to m>1 as the population size k grows to ∞. In the case that {ξ n} n≥0is an irreducible positive recurrent Markov chain, certain extinction (i.e. P(Z n=0 for some n)=1) and noncertain extinction (i.e. P(Z n=0 for some n)<1) are studied.

关键词： Markov chains in random environments stochastic population models branching processes.

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 and Mechanics Shanghai University Shanghai China Department of Building Engineering Xi’an University of Technology Xi’an 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.

Study of ozone “weekend effect” in shanghai

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Science china Earth Sciences 2008年第9期51卷 1354-1360页

作者： TANG WenYuan1↑, ZHAO ChunSheng1, GENG FuHai1,2. PENG Li2. ZHOU GuangQiang2. GAO Wei2. XU JianMing2.& TIE XueXi2.3 1 Department of Atmospheric Science, School of Physics, Peking University, Beijing 100871, china 2.Atmospheric Chemistry Laboratory of shanghai Meteorological Bureau, shanghai 2.0030, china 3 Atmospheric Chemistry Division, NCAR, Boulder CO 80301, USA Department of Atmospheric Science School of Physics Peking University Beijing China Atmospheric Chemistry Laboratory of shanghai Meteorological Bureau Shanghai China Atmospheric Chemistry Division NCAR Boulder USA

Analysis of observed ozone data in 2.06 from five monitoring sites (Xujiahui, Chongming, Baoshan, Pudong, Jinshan) in shanghai reveals that ozone (O_3) concentrations in Xujiahui are higher at week-ends than those on weekdays, despite the fact that emissions of ozone precursor substances, such as oxides of nitrogen (NOx), carbon monoxide (CO) and volatile organic compounds (VOCs) are lower at weekends than those on weekdays. The possible chemical cause of ozone "weekend effect" is that NO_2.NO ratio increases at weekends by 2..61% compared with those on weekdays. In addition, because of an average 12.13% reduction in NOx (NO + NO_2. in the early morning (05:00-09:00) at weekends compared with that on weekdays, the ozone inhibition period ends 0.5 h earlier at weekends resulting in the longer duration of ozone accumulation and the higher ozone production rate. The rate of ozone production is a function of VOCs and NOx in the atmosphere. VOCs/NOx ratio in Xujiahui is 4.55 at weekends, and 4.37 on weekdays, belonging to the "NOx-limited". The increasing VOCs/NOx ratio at weekends leads to ozone enhancement from 73 ppbv to 80 ppbv, which are consistent with ozone "weekend effect" in Xujiahui. Furthermore, combining with MICAPS cloud amount data, the fact that ozone "weekend effect" in Xujiahui weakens gradually along with the increasing of cloud amount indicates that ozone photochemical production leads to ozone "weekend effect" in Xujiahui of shanghai.

关键词： shanghai ozone photochemical pollution "weekend effect"

Monte Carlo calculation method on low energy electronscattering in polybasic medium

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Chinese Science Bulletin 1998年第2期43卷 171-174页

作者： TAN Zhenyu 1 and HE Yancai 2.1. College of Electric Power, Shandong University of Technology, Jinan 2.0061, {2. 2. shanghai Institute of Ceramics, Chinese Academy of Sciences, shanghai 2.0050, {2. College of Electric Power Shandong University of Technology Jinan China shanghai Institute of Ceramics Chinese Academy of Sciences Shanghai China

A novel Monte Carlo method of simulating low energy electron (LEE) scattering in polybasic medium is presented. The Mott cross section is adopted to describe the elastic scattering of LEE, and a mean cross section idea is proposed instead of usual determination of the scattering center. The Joy’’s modified Bethe equation is used to calculate energy loss of LEE. The scattering processes of LEE in bulk PMMA have been simulated. And the electron backscattering coefficients, the electron interaction range and energy dissipation distribution of LEE in bulk PMMA have been calculated and compared with those calculated by the method of determining scattering center.

关键词： low_energy electron scattering Monte Carlo method cross_section.