检索结果-南通市图书馆

An interpolating boundary element-free method (IBEFM) for elasticity problems

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2010年第4期53卷 758-766页

作者： REN HongPing 1 , CHENG YuMin 2.& ZHANG Wu 1 1 School of Computer Engineering and Science, shanghai university, shanghai 2.0072. China 2.shanghai Institute of Applied Mathematics and Mechanics, shanghai university, shanghai 2.0072. China 1. School of Computer Engineering and Science Shanghai University Shanghai 200072 China2. Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai 200072 China

The paper begins by discussing the interpolating moving least-squares (IMLS) method. Then the formulae of the IMLS method obtained by Lancaster are revised. On the basis of the boundary element-free method (BEFM), combining the boundary integral equation method with the IMLS method improved in this paper, the interpolating boundary element-free method (IBEFM) for two-dimensional elasticity problems is presented, and the corresponding formulae of the IBEFM for two-dimensional elasticity problems are obtained. In the IMLS method in this paper, the shape function satisfies the property of Kronecker δ function, and then in the IBEFM the boundary conditions can be applied directly and easily. The IBEFM is a direct meshless boundary integral equation method in which the basic unknown quantity is the real solution to the nodal variables. Thus it gives a greater computational precision. Numerical examples are presented to demonstrate the method.

关键词： moving least-squares (MLS) approximation interpolating moving least-squares (IMLS) method boundary integral equation meshless method boundary element-free method (BEFM) interpolating boundary element-free method (IBEFM) elasticity problem

Phylogeographic analysis of human papillomavirus 58

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2009年第12期52卷 1164-1172页

作者： LI YanYun1, LI ZuoFeng2. HE YiFeng1, KANG Yu1, ZHANG XiaoYan1, CHENG MingJun1, ZHONG Yang2. 3· & XU CongJian1· 1 Obstetrics and Gynecology Hospital of fudan university, shanghai 2.0011, China 2.shanghai Bioinformation Research Center, shanghai 2.02.5, China 3 School of Life Sciences, fudan university, shanghai 2.0433, China Obstetrics and Gynecology Hospital of fudan university Shanghai 200011 China shanghai Bio-information Research Center Shanghai 200235 China School of Life Sciences Fudan University Shanghai 200433 China

Human papillomavirus 58 (HPV58) is one type of HPV with high risk of causing cervical cancer. Unusually high prevalence of HPV58 has been reported in Asia, Africa and some other areas. However, due to the scattered distribution of global data, in addition to the lack of data of some HPV58 high-incidence nations and regions, like China's Mainland, a comprehensive analysis of the global geographical distribution of HPV58 remains blank so far. In this study, HPV58 from the human cervical cancer tissue was detected in China's Mainland, and 14 new HPV58-E6/L1 gene sequences were obtained. Moreover, phylogeographic analysis has been conducted combining the HPV58 sequences that have been deposited in GenBank since 1985. The study result shows that the sequences detected from the shanghai, Jiangsu and Sichuan areas are homologous with those found in the past from Hong Kong and Xi'an, China, as well as Japan and other Southeast Asian areas. Furthermore, Western Africa is considered to be the "root" source of the HPV58 variant, while China's Mainland and Southeast Asia are "transit points" and the new sources of HPV58 after receiving the isolates from the "root" source; like HPV16 and HPV18, the HPV58 might also be one of the major HPV types associated with the development and spread of cervical cancer.

关键词： human papillomavirus 58 (HPV58) cervical cancer phylogeography molecular evolution

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

在线全文

学校读者我要写书评

暂无评论

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 university, 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

Approximation to functions of several variables by superpositions of functions of fewer variables

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1997年第4期42卷 351-352页

作者： CHEN Tianping and CHEN Hong1. Department of Mathematics, fudan university,{2., China 2. Sun Microsystems, Sunnyvill, CA95050. US Depamnent of Mathematics Fudan University Shanghai China Sun Microsystems Sunnyvill USA

RECENTLY, the approximation to continuous functions by the superposition of a fixed function attracts some mathematicians and engineers, because it is a basic problem in neural networks and wavelets analysis. In a series of papers, we discussed the approximation to continuous functions of several variables by the superposition of a fixed continuous function of one variable. In this letter, we announce several theorems concerned with the approximation to func-

关键词：化石感知脚气主场袭人角山公行五金跳时心场

Recent developments of nanoparticle-based enrichment methods for mass spectrometric analysis in proteomics

在线全文

学校读者我要写书评

暂无评论

Science China chemistry 2010年第4期53卷 695-703页

作者： ZHANG LiJuan, LU HaoJie & YANG PengYuan Department of chemistry and Institutes of Biomedical Sciences,{2., shanghai 2.0433, China 1. Department of chemistry and Institutes of Biomedical Sciences Fudan University Shanghai 200433 China

In proteome research, rapid and effective separation strategies are essential for successful protein identification due to the broad dynamic range of proteins in biological samples. Some important proteins are often expressed in ultra low abundance, thus making the pre-concentration procedure before mass spectrometric analysis prerequisite. The main purpose of enrichment is to isolate target molecules from complex mixtures to reduce sample complexity and facilitate the subsequent analyzing steps. The introduction of nanoparticles into this field has accelerated the development of enrichment methods. In this review, we mainly focus on recent developments of using different nanomaterials for pre-concentration of low-abundance peptides/ proteins, including those containing post-translational modifications, such as phosphorylation and glycosylation, prior to mass spectrometric analysis.

关键词： enrichment nanoparticles mass spectrometry proteomics phosphorylation glycosylation

Application of vertically integrated sampling approach to study of new production via ^(2.4)Th -^(2.8)U disequilibria

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2000年第2期19卷 37-44页

作者： Chen Feizhou1 Huang Yipu2.Chen Min2.(1. College of Fishery Science, shanghai Fisheries university, shanghai 2.0090, China 2. Department of Oceanography, Xiamen university, Xiamen 361005, China) College of Fishery Science Shanghai Fisheries University Shanghai 200090 China

The spatial and temporal distributions of new production vary largely in different sea areas. To understand the level of new production in the sea area studied better, an estimate of new production must be obtained in large spatial and temporal scales. The ~2.4Th/ ~2.8U disequilibrium is an effective method for the study of new production. Two sampling strategies, vertically integrated sampling ap proach based on trapezoidal integration principle and discrete layer sampling approach, were compared in the studies of the xiamen Bay and the northern South China Sea. The scavenging fluxes and removal fluxes of ~2.4Th and the residence times for dissolved and particulate ~2.4Th were calculated. The coinci dent results from two Sampling approach suggest that vertically integrated sampling approach is not only effective and reliable, but also significantly reduces the number and volume of samples. It allows us to study new production by ba ^(2.4)Th - ^(2.8)U disequilibria in large spatial scale.

关键词： New production vertically integrated Sampling approach, ^(2.4)Th - ^(2.8)U disequilibria Xia men Bay northern South China Sea

Direct CP violation in hadronic B decays

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2006年第3期49卷 357-366页

作者： HONG Bihai1,2.& Lü Caidian3 1. Department of Physics, Lishui university, Lishui 32.000,China 2. Department of Physics, shanghai Jiaotong university, shanghai 2.0030, China 3. Institute of High Energy Physics, Beijing 100049,China Department of Physics Lishui University Lishui 323000 China Department of Physics Shanghai Jiaotong University Shanghai 200030 China Institute of High Energy Physics Beijing 100049 China

There are different approaches for the hadronic B decay calculations, recently. In this paper, we upgrade three of them, namely factorization, QCD factorization and the perturbative QCD approach based on kT factorization, using new parameters and full wave functions. Although they get similar results for many of the branching ratios, the direct CP asymmetries predicted by them are different, which can be tested by recent experimental measurements of B factories.

关键词： CP violation hadronic B decay factorization.

The expression of core fucosylated E-cadherin in cancer cells and lung cancer patients: prognostic implications

在线全文

学校读者我要写书评

暂无评论

Cell Research 2004年第5期14卷 423-433页

作者： Fei GENG1, Bi Zhi SHI , Yun Feng YUAN2. Xing Zhong WU1* 1 1Department of Biochemistry and Molecular Biology,{2. Medical Center, shanghai 2.0032. China 2.epartment of Thoracic Surgery, Zhongshan Hospital,{2., shanghai 2.0032. China 1Department of Biochemistry and Molecular Biology Fudan University Medical Center Shanghai 200032 China 1Department of Biochemistry and Molecular Biology Fudan University Medical Center Shanghai 200032 China 2.epartment of Thoracic Surgery Zhongshan Hospital Fudan University Shanghai 200032 China 1Department of Biochemistry and Molecular Biology Fudan University Medical Center Shanghai 200032 China

It is well documented that the glycosylation of E-cadherin is correlated with cancer metastasis, but whether E- cadherin could be core fucosylated remains largely unknown. We found that E-cadherin was core fucosylated in highly metastatic lung cancer cells while absent in lowly metastatic lung cancer cells. Since α-1,6 Fucosyltransferase (α-1,6 FucT) is known to catalyze the reaction of core fucosylation, we investigated the biological function of core fucosylation on E-cadherin by α-1,6 FucT targeted RNAi and transfecting α-1,6 FucT expression vector. As a result, calcium dependent cell-cell adhesion mediated by E-cadherin was strengthened with the reduction of core fucosylation on E- cadherin after RNAi and was weakened with the elevated core fucosylation on E-cadherin after α-1,6 FucT over expression. Our data indicated that α-1,6 FucT could regulate E-cadherin mediated cell adhesion and thus play an important role in cancer development and progression. Computer modeling showed that core fucosylation on E-cadherin could significantly impair three-dimensional conformation of N-glycan on E-cadherin and produce conformational asym- metry so as to suppress the function of E-cadherin. Furthermore, the relationship between the expression of core fucosylated E-cadherin and clinicopathological background of lung cancer patients was explored in lung cancer tissue of patients. It turns out to demonstrate that core fucosylated E-cadherin could serve as a promising prognostic indicator for lung cancer patients.

关键词： Core fucosylated E-cadherin prognosis cancer metastasis RNA interference molecular modeling.

PARAMETERS OF DARBOUX TRANSFORMATION FOR REDUCED AKNS,KAUP-NEWELL AND PCF SYSTEMS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Annals of Mathematics,Series B 1999年第2期20卷 195-204页

作者： ZHOU ZIXIANG(Institute of Mathematics, fudan university, shanghai 2.0433) fudan Univ Inst Math Shanghai 200433 Peoples R China

FOr the integrable system with u(p, q) reduction, there is a well-known sufficient conditionto choose the parameters: the spectral parameters only take two mutually conjugate valuesand the solutions of the Lax pair should satisfy certain orthogonal relations. In this paper, theauthor proves that, for the AKNS system, the Kaup-Newed system and the principal chiralfield (PCF), this condition is also necessary for generic potentials with the u(p, q) *** some other reductions, sufficiency and necessity of more constraints are proved.

关键词： Darboux transformation Spectral parameters u(p q) reduction