检索结果-南通市图书馆

The fundamental solution of the Keldysh typeoperator

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2009年第9期52卷 1829-1843页

作者： CHEN ShuXing School of Mathematical Sciences, fudan university, shanghai 200433, china 1. School of Mathematical Sciences Fudan University Shanghai 200433 China

In this paper we discuss the fundamental solution of the Keldysh type operator $ L_\alpha u \triangleq \frac{{\partial ^2 u}} {{\partial x^2 }} + y\frac{{\partial ^2 u}} {{\partial y^2 }} + \alpha \frac{{\partial u}} {{\partial y}} $ , which is a basic mixed type operator different from the Tricomi operator. The fundamental solution of the Keldysh type operator with $ \alpha > - \frac{1} {2} $ is obtained. It is shown that the fundamental solution for such an operator generally has stronger singularity than that for the Tricomi operator. Particularly, the fundamental solution of the Keldysh type operator with $ \alpha < \frac{1} {2} $ has to be defined by using the finite part of divergent integrals in the theory of distributions.

关键词： mixed type equation Keldysh operator fundamental solution finite part of divergent integral 35M10 35A08

Hydrogenation of CO over carbides of tungsten

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of chemistry 1992年第1期10卷 5-9页

作者： QIN,Dai-Yi GAO,Zi department of chemistry,fudan university,shanghai 200433 QIU,Yue-Ming DONG,Shu-Zhong department of Modern Physics,fudan university,shanghai 200433 1department of chemistry Fudan University Shanghai 2004332Department of Modern Physics Fudan University Shanghai 200433

CO hydrogenation on tungsten carbides has been *** methanation activities of tungsten carbides are comparable to that of supported Group VIII metal ***- programmed thermal desorption spectra of CO on tungsten carbide ... 详细信息

关键词： Hydrogenation of CO over carbides of tungsten CO over

A categorical interpretation of Yetter-Drinfel'd modules

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1999年第9期44卷 771-778页

作者： KAN Haibin and WANG ShuanhongInstitute of Mathematics , fudan university , shanghai 200433 , china department of Mathematics , Henan Normal university, Xinxiang 453002, china Institute of Mathematics Fudan Univrrsity Shanghai China Dcpartment of Mathematics Henun Normal University Xinxiang China

It is known that any strict tensor category （C, I） can determine a strict braided tensor category Z （ C）, the centre of C. When A is a finite Hopf algebra, Drinfel’d has proved that Z（AM） is equivalent to D（A）M as a braided tensor category, where AM is the left A-module category, and D （A） is the Drinfel’d double of A. This is the categorical interpretation of D （A）.Z（4M） is proved to be equivalent to the Yetter-Drinfel’ d module category AY D4 as a braided tensor category for any Hopf algebra A. Furthermore, for right A-comodule category MA , Z（MA） is proved to be equivalent to the Yetter-Drinfel’ d module category AY D4 as a braided tensor category. But, in the two cases, the Yetter-Drinfel’ d module category AY DA has different braided tensor structures.

关键词： Yetter-Drinfel’d module tensor category equivalence.

Plateau of α-function and c-minimal homoclinic orbits

在线全文

学校读者我要写书评

暂无评论

Science china Mathematics 2006年第7期49卷 922-931页

作者： LI Xia & CUI Xiaojun department of Mathematics, university of Science and Technology of Suzhou, Suzhou 215009, china Mathematical Research Institute, fudan university, shanghai 200433, china 1. department of Mathematics University of Science and Technology of Suzhou Suzhou 215009 China 2. Mathematical Research Institute Fudan University Shanghai 200433 China

We consider the construction of the plateau of the α-function in a hyperbolic and positive definite Lagrangian system, and link the boundries of the α-function's plateau with the distribution of c-minimal homoclinic... 详细信息

关键词： α-function, β-function, plateau, Aubry sets.

Catalytic hydrolysis of CFC-12 over solid acid Ti(SO_4)_2

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2000年第4期11卷 311-314页

作者： Zhen MA Wei Ming HUA Yi TANG Zi GAO (department of chemistry. fudan university. shanghai 200433) department of chemistry Fudan University Shanghai 200433 China

The catalytic hydrolysis of dichlorodifluoromethane (CFC-12) was investigated over solid acid Ti(SO_4)_2. The catalytic activity decreased with the calcination temperature. When space velocity was 6 1 h^(-1) g-cat^(-1). the CPC-12 conversion at 310C over Ti(SO_4)_2 calcined at 350C remained about 98.5% during 360 h on stream. and the selectivity to by-products remained zero. The findings enlarged the scope of traditional catalyst systems for the CFCs decomposition.

关键词： Chlorofluorocarbons. catalytic decomposition. solid acid Ti(SO_4)_2.

SIMULATION OF FLUID-SOLID INTERACTION ON WATER DITCHING OF AN AIRPLANE BY ALE METHOD

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2011年第5期23卷 637-642页

作者： HUA Cheng FANG Chao CHENG Jin department of Mechanics and Engineering Science Fudan University Shanghai 200433 China School of Mathematical Sciences Fudan University Shanghai 200433 China

Ditching is considered as one of the important aspects of safety performances of airplanes. It is related primarily with the fluid-solid interaction, whose studies mainly depend on experiments at the present time. Numerical and analytical methods for fluid-solid interaction by using 3-D full scale airplane＇s model will reduce the dependence on the expensive model tests. Numerical studies can be used to estimate the safety of ditching and provide a reference for the crashworthiness design. This article proposes a 3-D dynamical structural model after the real shape of an airplane and an Arbitrary Lagrange-Euler （ALE） fluid-field model, to simulate the fluid-solid interactions caused by low speed ditching. The simulation is based on interaction computational methods, within LS-DYNA nonlinear finite-element code. The results of pressure distributions and accelerating time histories of the airplane＇s subfloor are discussed in the context of the safety of ditching, and the simulation results and the analytical methods are verified.

关键词： ditching fluid structure interaction Arbitrary Lagrange-Euler (ALE) finite element method

Dispersion of Soluble Matters in Newton-dipolar Stratified Fluid and Effects of Peripheral Layer

在线全文

学校读者我要写书评

暂无评论

Communications in Nonlinear Science and Numerical Simulation 1998年第4期3卷 236-241页

作者： Zhangji LU, Shousheng DONG, Yu SHEN and Guangping ZHENG (department of Mechanics and Engineering Science, fudan university, shanghai 200433,china)(department of Physics, East china Normal university, shanghai 200062, china) Dept. of Mechanics and Eng. Science Fudan University Shanghai 200433 China department of Physics East China Normal University Shanghai 200062 China

In the paper, the dispersion law and the concentration distributions of soluble matters in Newton-dipolar fluids flowing through a circular tube have been investigated. Main results are: (1) for the dependence of M on A (or H), the completely opposite trends are obtained in the cases with and without the peripheral layer. (2) effects of δ on　M have the minimum values near 8=0.85-0.9. (3) various models such as couple stress,micropolar, dipolar, Newton-newtonian, Newton-couple stress and Newton-micropolar　model etc. are all special cases of Newton-dipolar fluid (where Mz=0). WhenMz≠ 0,however, there are evident differences between the Newton-dipolar fluid and the Newtoncouple stress fluid, the Newton-micropolar fluid.

关键词： dipolar fluid dispersion effects of a peripheral layer tube flow of complex fluid

TOEPLITZ C-ALGEBRA OVER THE L-SHAPED DOMAIN IN C^m

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 1996年第3期17卷 325-334页

作者： XU SHENGZHI CHEN XIAOMAN YAN SHAOZONG(Institute of Mathematics, fudan university, shanghai 200433, china) Institute of Mathematics Fudan University Shanghai 200433 China

The authors investigate the Toeplitz C-algebra over the L-shaped domain in Cn by thegroupoid approach, and successfully parameterise the unit space of the groupoid associated tothe Toeplitz C-algebra.

关键词： L-shaped domain Toeplitz C-algebra Parameterization

Identification and Characterization of glnA Promoter and its Corresponding Trans-regulatory Protein GlnR in the Rifamycin SV Producing Actinomycete,Amycolatopsis mediterranei U32

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2006年第12期38卷 831-843页

作者： Hao YU~(1&) Wen-Tao PENG~1 Yang LIU~1 Ting WU~2 Yu-Feng YAO~1 Ming-Xue CUI~1 Wei-Hong JIANG~1 Guo-Ping ZHAO~(1,3,4*) 1 Laboratory of Molecular Microbiology,Institute of Plant Physiology and Ecology,shanghai Institutes for Biological Sciences,Chinese Academy of Sciences,shanghai 200032,china 2 department of Medicinal chemistry,School of Pharmacy,fudan university,shanghai 200032,china 3 State Key Laboratory of Genetic Engineering & department of Microbiology,School of Life Science,fudan university,shanghai 200433,china 4 Laboratory of Disease and Health Genomics,Chinese National Human Genome Center at shanghai,shanghai 201203,china Laboratory of Molecular Microbiology Institute of Plant Physiology and Ecology Shanghai Institutes for Biological Sciences Chinese Academy of Sciences Shanghai 200032 China department of Medicinal chemistry School of Pharmacy Fudan University Shanghai 200032 China State Key Laboratory of Genetic Engineering & department of Microbiology School of Life Science Fudan University Shanghai 200433 China Laboratory of Disease and Health Genomics Chinese National Human Genome Center at Shanghai Shanghai 201203 China

The genetic requirements for the transcription of glnA,encoding the major glutaminesynthetase in a rifamycin SV-producing Amycolatopsis mediterranei strain,U32,were *** experiments showed that the promoter of U32 glnA （pglnA） was likely to have two transcriptioninitiation sites:P1and P2,located 157 and 45 nucleotides （nt） upstream of the translational start codon,*** mobility shift and DNase I footprinting analyses revealed a 30 bp cis-element locatedat 45 to 75 nt downstream of P1,or 38 to 68 nt upstream of *** sequence of the cis-element displayedhigh similarity to the corresponding regions of pglnA from Streptomyces coelicolor and *** as a reporter gene,the expression levels of U32 pglnA and its deletion derivatives under differentnitrogen-source conditions were analyzed by detecting the catechol dioxygenase activities in ***54,*** J508 and *** FS10 （glnR mutant）.These in vivo studies showed that theactivation of U32 pglnA in *** required GlnR,and its binding to the U32 pglnA was furtherconfirmed by the gel mobility shift *** and heterologous expression of the U32 glnR allowed usto detect the in vitro interaction between the U32 GlnR and the corresponding pglnA *** shown by in vivo glnR inactivation and complementation indicated that GlnR is essential for theactive transcription of glnA in U32.

关键词： glnA promoter cis-element glnR Amycolatopsis mediterranei