检索结果-南通市图书馆

Science china(Technological Sciences) 2010年第3期53卷 633-644页

作者： GE JuHong & XU Jian School of Aerospace Engineering and Applied Mechanics,tongji university,shanghai 200092,china 1. School of Aerospace Engineering and Applied Mechanics Tongji University Shanghai 200092 China

The bidirectional associative memory (BAM) neural network with four neurons and two delays is considered in the present paper.A linear stability analysis for the trivial equilibrium is firstly employed to provide a possible critical point at which a zero and a pair of pure imaginary eigenvalues occur in the corresponding characteristic equation.A fold-Hopf bifurcation is proved to happen at this critical point by the nonlinear *** coupling strength and the delay are considered as bifurcation parameters to investigate the dynamical behaviors derived from the fold-Hopf *** dynamical behaviours are qualitatively classified in the neighbourhood of the fold-Hopf bifurcation point by using the center manifold reduction (CMR) together with the normal *** bifurcating periodic solutions are expressed analytically in an approximate *** validity of the results is shown by their consistency with the numerical simulation.

关键词： codimension-two bifurcation time delay solution classification unfolding centre manifold

REGULARITY RESULTS FOR SOME QUASI-LINEAR ELLIPTIC SYSTEMS INVOLVING CRITICAL EXPONENTS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of mathematics,Series B 2005年第1期26卷 119-126页

作者： HUYEXIN LIJUAN departmentofmathematics ShanghaiJiaotongUniversityShanghai200240China departmentofmathematics ShanghaiJiaotongUniversityShanghai200240China.

The authors show the regularity of weak solutions for some typical quasi-linear elliptic systems governed by two p-Laplacian operators. The weak solutions of the following problem with lack of compactness are proved t... 详细信息

关键词： Elliptic equation system p-Laplacian operator Critical Sobolev exponent Regularity

Mechanisms of antiprostate cancer by gum mastic:NF-κB signal as target

在线全文

学校读者我要写书评

暂无评论

Acta Pharmacologica Sinica 2007年第3期28卷 446-452页

作者： Mei-lan HE~(2,4) Ang LI~2 Chun-su XU~2 Shun-li WANG~3 Meng-jie ZHANG~2 Hua GU~2 Yao-qin YANG~3 Hui-hong TAO~3 ~2Institute of Cancer Research,Life Science and Technology School,tongji university,shanghai 200092,china ~3Cellular Morphology Center,Medical School,tongji university,shanghai 200092,china Institute of Cancer Research Life Science and Technology School Tongji University Shanghai 200092 China Cellular Morphology Center Medical School Tongji University Shanghai 200092 China

Aim:To study the effect of gum mastic,a natural resin,on the proliferation ofandrogen-independent prostate cancer PC-3 cells,and further investigate themechanisms involved in this regulatory system,taking nuclear factor κB(NF-κB)signal as the ***:3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazoliumbromide(MTT)assay and a flow cytometer were used to detect the effect of gummastic on the proliferation of PC-3 ***,reporter gene assay,RT-PCR,andWestern blotting were carried out to study the effects of gum mastic on the NF-κBprotein level and the NF-κB signal *** expression of genes involved inthe NF-κB signal pathway,including cyclin D1,inhibitors of κBs(IκBα),andphosphorylated Akt(p-AKT),were *** addition,transient transfectionassays with the 5×NF-κB consensus sequence promoter was also used to test theeffects of gum ***:Gum mastic inhibited PC-3 cell growth and blockedthe PC-3 cell cycle in the G1 *** mastic also suppressed NF-κB activity inthe PC-3 *** expression of cyclin D1,a crucial cell cycle regulator and anNF-κB downstream target gene,was reduced as ***,gum masticdecreased the p-AKT protein level and increased the IκBα protein ***:Gum mastic inhibited the proliferation and blocked the cell cycleprogression in PC-3 cells by suppressing NF-κB activity and the NF-κB signalpathway.

关键词： gum mastic prostate cancer NF-κB signal

BLOCKWISE PERTURBATION THEORY FOR 2×2 BLOCK MARKOV CHAINS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Computational mathematics 2000年第3期18卷 305-312页

作者： Jun-gong Xue Wei-guo Gao (department of mathematics, Fudan university, shanghai, 200433, china) 复旦大学上海 200433

Let P be a transition matrix of a Markov chain and be of the form P = qq@. The stationary distribution πT is partitioned conformally in the form (π1T, π2T). This paper establish the relative error bound in πiT (i ... 详细信息

关键词： Blockwise perturbation Markov chains stationary distribution error bound

STEADY-STATE SOLUTIONS FOR A ONE-DIMENSIONAL NONISENTROPIC HYDRODYNAMIC MODEL WITH NON-CONSTANT LATTICE TEMPERATURE

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2008年第3期28卷 479-488页

作者：黎野平 department of mathematics Xianning College

A one-dimensional stationary nonisentropic hydrodynamic model for semiconductor devices with non-constant lattice temperature is studied. This model consists of the equations for the electron density, the electron current density and electron temperature, coupled with the Poisson equation of the electrostatic potential in a bounded interval supplemented with proper boundary conditions. The existence and uniqueness of a strong subsonic steady-state solution with positive particle density and positive temperature is established. The proof is based on the fixed-point arguments, the Stampacchia truncation methods, and the basic energy estimates.

关键词： Steady-state nonisentropic hydrodynamic model semiconductor subsonic

FLOATING QUANTIZATION EFFECTS ON MULTIRATE SAMPLED-DATA NONLINEAR CONTROL SYSTEMS

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Scientia 2007年第3期27卷 635-644页

作者：余宏旺汪志鸣 department of mathematics East China Normal University

In this article, floating quantization effects on multirate sampled-data control systems are studied. It shows that the solutions of multirate digital feedback control systems with nonlinear plant and with floating quantization in the controller are uniformly ultimately bounded if the associated linear systems consisting of linearization of the plant and controller with no quantization are Schur stable. Moreover, it also shows that the difference between the response of multirate digital controllers without quantizers and the same plant with floating quantization in the controllers can be made as small as desired by selecting proper quantization level.

关键词： Multirate sampled-data control systems quantization Schur stable uniformly ultimately bounded

REFINED CONNECTIVITY PROPERTIES OF ABELIAN CAYLEY GRAPHS

在线全文

学校读者我要写书评

暂无评论

Chinese Annals of mathematics,Series B 1998年第4期19卷 409-414页

作者： LI QIAOLIANG (department of Applied mathematics, shanghai Jiaotong university, shanghai 200030, chinaPresend in department of mathematics, Hunan Normal university, Changsha 410082, china.)LI QIAO (department of Applied mathematics, shanghai Jiaotong Univ shanghai Jiao Tong Univ Dept Appl Phys Shanghai 200030 Peoples R China Hunan Normal Univ Dept Math Changsha 410082 Peoples R China

Restricted edge connectivity of a graph G is defined to be the minimum size |U| of a set U of edges such that G-U is disconnected and G-U contains no trivial component K1. The high order edge connectivity Ni, i1, is the number of edge outsets of size i. TO determine all Ni, i 1, for a general graph is NP-hard. In this paper, the authors evaluated the restricted edge connectivity and the high order edge connectivity Ni, 1 i -1, for any connected Abelian Cayley graphs explicitly.

关键词： Abelian Cayley graph Restricted edge connectivity High order edge connectivity

Highest weight representations of a Lie algebra of Block type

在线全文

学校读者我要写书评

暂无评论

Science china mathematics 2007年第4期50卷 549-560页

作者： Yue-zhu WU & Yu-cai SU department of mathematics, shanghai Jiaotong university, shanghai 200240, china department of mathematics, Qufu Normal university, Qufu 273165, china department of mathematics, university of Science and Technology of china, Hefei 230026, china 1. department of mathematics Shanghai Jiaotong University Shanghai 200240 China 2. department of mathematics Qufu Normal University Qufu 273165 China 3. department of mathematics University of Science and Technology of China Hefei 230026 China

For a field $\mathbb{F}$ of characteristic zero and an additive subgroup G of $\mathbb{F}$ , a Lie algebra B(G) of the Block type is defined with the basis {L α,i , c | α ∈ G ?1 ≤ i ∈ ?} and the relations [L α,i , L β,j ] = ((i + 1)β ? (j + 1)α)L α+β,i+j + αδ α, ?β δ i+j,?2 c, [c, L α,i ] = 0. Given a total order ? on G compatible with its group structure, and any Λ ∈ B(G) 0 * , a Verma B(G)-module M(Λ, ?) is defined, and the irreducibility of M(Λ, ?) is completely determined. Furthermore, it is proved that an irreducible highest weight B(?)-module is quasifinite if and only if it is a proper quotient of a Verma module.

关键词： Verma modules Lie algebras of Block type irreducibility 17B10 17B65 17B68

The Geometric Structure of Strange Attractors in the Lozi Map

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2期3卷 67-71页

作者： Yongluo CAO and Zengrong LIU* (department of mathematics, Suzhou university,Suzhou 215006, china) *(department of mathematics, shanghai university,shanghai 200072, china) (E mail: ***) department of mathematics Suzhou University Suzhou 215006 China department of mathematics Shanghai University Shanghai 200072 China

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｐａｓｔｔｗｏｄｅｃａｄｅｓ，ｔｈｅｓｔｒａｎｇｅａｔｒａｃｔｏｒｓｉｎｔｈｅｆｉｅｌｄｏｆｎｏｎｌｉｎｅａｒｓｃｉｅｎｃｅｄｒａｗｓｔｈｅａｔｅｎｔｉｏｎｏｆｍａｎｙｓｃｉｅｎｔｉ... 详细信息

ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｔｈｅｐａｓｔｔｗｏｄｅｃａｄｅｓ，ｔｈｅｓｔｒａｎｇｅａｔｒａｃｔｏｒｓｉｎｔｈｅｆｉｅｌｄｏｆｎｏｎｌｉｎｅａｒｓｃｉｅｎｃｅｄｒａｗｓｔｈｅａｔｅｎｔｉｏｎｏｆｍａｎｙｓｃｉｅｎｔｉｓｔｓ．Ｉｎｐａｒｔｉｃｕｌａｒ，...

关键词： strange attractor transversal homoclinic point weak transversal homoclinic point

The geodetic numbers of graphs and digraphs

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china mathematics 2007年第8期50卷 1163-1172页

作者： Chang-hong LU~(1,2) 1 department of mathematics,East china Normal university,shanghai 200062,china 2 Institute of Theoretical Computing,East china Narnal university,shanghai 200062,china 1. department of mathematics East China Normal University Shanghai 200062 China 2. Institute of Theoretical Computing East China Narnal University Shanghai 200062 China

For every two vertices u and v in a graph G, a u-v geodesic is a shortest path between u and v. Let I(u, v) denote the set of all vertices lying on a u-v geodesic. For a vertex subset S, let I(S) denote the union of all I(u, v) for u, v ∈ S. The geodetic number g(G) of a graph G is the minimum cardinality of a set S with I(S) = V (G). For a digraph D, there is analogous terminology for the geodetic number g(D). The geodetic spectrum of a graph G, denoted by S(G), is the set of geodetic numbers of all orientations of graph G. The lower geodetic number is g ?(G) = minS(G) and the upper geodetic number is g +(G) = maxS(G). The main purpose of this paper is to study the relations among g(G), g ?(G) and g +(G) for connected graphs G. In addition, a sufficient and necessary condition for the equality of g(G) and g(G × K 2) is presented, which improves a result of Chartrand, Harary and Zhang.

关键词： convex set digraph distance geodesic geodetic number 05C12 05C20