一类连续半鞅型随机微分方程解的随机稳定性

本文利用Ｌｙａｐｕｎｏｖ函数方法，讨论了时齐Ｄｏｌｅａｎｓ－Ｄａｄｅｒ－Ｐｒｏｔｔｅｒ方程ｄＸ＿ｔ＝σ（Ｘ＿ｔ）ｄＭ＿ｔ＝ｂ（Ｘ＿ｔ）ｄＡ＿ｔ＋（（Ｍ＿ｔ）为连续局部平方可积鞅；（Ａ＿ｔ）为连续有限变差过程）平凡解的随机稳定性。本文建立了随机稳定性的判定定理并给出了相应的Ｌｙａｐｕｎｏｖ函数的一种具体形式。     

关于2－因指数群

如果有限群Ｇ的每个极大子群的指数的质因子个数（重因式按重数计算）都小于或等于ｎ，则称Ｇ为ｎ－因指数群。本文用单群分类定理证明了定理设Ｇ为非可解２－因指数群，则Ｃ／Ｓ（Ｇ）同构于下列形式的群之一：Ｎ＿１×Ｎ＿２×…×Ｎ＿ｔ其中Ｎ＿ｉ∈｛Ａ＿５，Ｓ＿５，Ａ＿６，Ｓ＿６，Ａ＿７，Ｓ＿７｝，Ｎ＿１，Ｎ＿２，…，Ｎ＿ｔ两两不同，ｔ＝１，２，３，４，５，６．     

ON THE MINIMUM FEASIBLE GRAPH FOR FOUR SETS

ＯＮＴＨＥＭＩＮＩＭＵＭＦＥＡＳＩＢＬＥＧＲＡＰＨＦＯＲＦＯＵＲＳＥＴＳＸＵＹＩＮＦＥＮＧＡＮＤＦＵＸＩＡＯＢＩＮＧＡｂｓｔｒａｃｔ：ＧｉｖｅｎａｃｏｍｐｌｅｔｅｇｒａｐｈｗｉｔｈｖｅｒｔｅｘｓｅｔＸａｎｄｓｕｂｓｅｔｓＸ＿１，Ｘ＿２，．．．，Ｘ＿ｎ...     

两分子饱和反应系统的全局稳定性

两分子饱和反应系统的全局稳定性赵振海（大连理工大学应用数学系，１１６０２４）本文讨论了下列系统的全局稳定性：其中Ｊ＿１，Ｊ＿２，Ａ，Ｂ为非负常数，当；Ｊ＿１＞（１＋１／Ｂ）Ｊ＿２时，系统（１）有唯一正平衡点Ｒ（ｘ，ｙ），其中（１）当Ｊ＿１－３Ｊ＿２≥...     

非自治系统的周期解

本文在齐次线性系统ｘ＝Ａ（ｔ）ｘ的解均为ω周期解的条件下，给出了非自治系统ｘ＝Ａ（ｔ）ｘ＋ｇ（ｔ，ｘ）。     

L－fuzzy集网的R－收敛性质

本文在ＬＦ拓扑空间中建立了Ｌ－ｆｕｚｚｙ集网的弱收敛（Ｒ－收敛）概念，应用文［４］中的Ｒ－闭包，系统讨论了它们的性质，证明了等式ＲｌｉｍＡ＿ｎ＝∧（∨Ａ＿ｍ）＿Ｒ和ＲｌｉｍＡ＿ｎ＝Ａ＿ｎ＝∧（∨Ａ＿ｍ）＿Ｒ并且给出了Ｌ－ｆｕｚｚｙ集网与其子网之间的关系。     

逐次有理L_2逼近

逐次有理Ｌ_２逼近潘杰（合肥工业大学）ＳＵＣＣＥＳＳＩＶＥＲＡＴＩＯＮＡＬＬ＿２－ＡＰＰＲＯＸＩＭＡＴＩＯＮ￥ＰａｎＪｉｅ（ＨｅｆｅｉＵｎｉｖｅｒｓｉｔｙｏｆＴｅｃｈｎｏｌｏｇｙ）Ａｂｓｔｒａｃｔ：Ｌｅｔｆｕｎｃｔｉｏｎｆ∈Ｌ２［ａ，ｂ］，ｒａｔｉｏ?..     

高维非自治系统非平凡周期解的存在性

本文利用非线性泛函分析中锥的理论，讨论了ｎ维非自治系统ｘ＝Ａ（ｔ）ｘ＋ｇ（ｔ，ｘ）ｘ∈Ｒ＾ｎ产工得到了系统（１）存在非平凡ω周期解的充分条件。     

关于有限Abel群直接因子的平均数

对于有限Ａｂｅｌ群Ｇ，ｔ（Ｇ）定义为其直接因子的个数，在［５］中，Ｅ．Ｋｒａｔｚｅｌ对于和式得到一渐近公式，对应余项为△＿１（ｘ）．本文利用Ｅ．Ｆｏｕｖｒｙ和Ｈ　．Ｉｗａｎｉｅｃ的方法，得到了关于△＿１（ｘ）的一个新的估计，改进了Ｈ．Ｍｅｎｚｅｒ等人的结果．     

EXISTENCE OF WEAK SOLUTIONS OF 2－D EULER EQUATIONS WITH INITIAL VORTICITY ω_0∈E（log~＋L）~α（α＞0）

ＥＸＩＳＴＥＮＣＥＯＦＷＥＡＫＳＯＬＵＴＩＯＮＳＯＦ２－ＤＥＵＬＥＲＥＱＵＡＴＩＯＮＳＷＩＴＨＩＮＩＴＩＡＬＶＯＲＴＩＣＩＴＹω＿０∈Ｅ（ｌｏｇ￣＋Ｌ）￣α（α＞０）ＪＩＵＱＵＡＮＳＥＮ（ＩｎｓｔｉｔｕｔｅＯｆＡｐｐｌｉｅｄＭａｔｈｅｍａｔｉｃｓ，ｔ...     

T＊-extension of Lie Sup ertriple Systems

In this article,we study the Lie supertriple system(LSTS)T over a field K admitting a nondegenerate invariant supersymmetric bilinear form(call such a T metrisable).We give the definition of T_ω~*-extension of an LSTS T,prove a necessary and sufficient condition for a metrised LSTS(T,φ)to be isometric to a T~*-extension of some LSTS,and determine when two T~*-extensions of an LSTS are"same",i.e.,they are equivalent or isometrically equivalent.     

Cartesian closed categories of FƵ-domains

A subset system Z assigns to each partially ordered set P a certain collection Z（P） of subsets. In this paper, a new kind of subset systems called directable subset systems is introduced. For a directable subset system Z, the concepts of FZ-way-below relation and FZ-domain are introduced. The well-known Scott topology is naturally generalized to the Z-level and the resulting topology is called FZ-Scott topology, and the continuous functions with respect to this topology are characterized by preserving the suprema of directed Z-sets. Then, we mainly consider a generalization of the cartesian closedness of the categories DCPO of directed complete posets, BF of bifinite domains and FS of FS-domains to the Z-level. Corresponding to them, it is proved that, for a suitable subset system Z, the categories FZCPO of Z-complete posets, FSFZ of finitely separated FZ-domains and BFFZ of bifinite FZ-domains are all cartesian closed. Some examples of these categories are given.     

Global Existence and Blow-up for a Parabolic System with Nonlinear Boundary Conditions

This paper deals with the global existence and blow-up of positive solutions to the systems: u_t = ∇(u^∇u) + u¹ + v^a v_t = ∇(v^n∇v) + u^b + v^k in B_R × (0, T) \frac{∂u}{∂η} = u^αv^p, \frac{∂v}{∂η} = u^qv^β on S_R × (0, T) u(x, 0) = u_0(x), v(x, 0} = v_0(x) in B_R We prove that there exists a global classical positive solution if and only if l ≤ l, k ≤ 1, m + α ≤ 1, n + β ≤ 1, pq ≤ (1 - m - α)(1 - n - β),ab ≤ 1, qa ≤ (1 - n - β) and pb ≤ (1 - m - α).     

一类非线性偏微分方程组的直接解法

根据Hopf-Cole变换法和试探函数法的基本思想,引入一个变换,并把它应用于求解(2+1)维破裂孤子方程组、(2+1)维Nizhnik-Novikov-Vesslov方程组和(2+1)维Broer-Kaup方程组,得到了这三个方程组的许多新的解析解,包括孤波解和奇异行波解.该方法也适用于其它方程组.     

一类非自治Liénard系统的定性研究

研究自治Liénard系统+f(x).x+e(t)g(x)=h(t)解的定性性态.在一定条件下,我们证明了该系统周期解的存在性、局部唯一性和渐近稳定性,所得结果推广了文[2-4]的相应结论.     

Blow-up vs.Global Finiteness for an Evolution p-Laplace System with Nonlinear Boundary Conditions

In this paper, the authors consider the positive solutions of the system of the evolution p-Laplacian equations
with nonlinear boundary conditions
and the initial data （u0, v0）, where Ω is a bounded domain in Rn with smooth boundary δΩ, p 〉 2, h（·,·） and s（·,· ） are positive C1 functions, nondecreasing in each variable. The authors find conditions on the functions f, g, h, s that prove the global existence or finite time blow-up of positive solutions for every （u0, v0）.     

半直线伸缩调制框架集

本文研究右半直线平方可积函数空间L^2(R+)中的一类伸缩调制系.实际问题中时间变量不可取负值,L^2(R+)可模拟因果信号空间.但因R+按加法不能作成一个群,它不容许小波与Gabor系.我们研究L^2(R+)中由特征函数生成的伸缩调制系(MD-系)框架,引入了R+中MD-框架集的概念,利用"伸缩等价"与"基数函数"方法刻画了L^2(R+)中MD-Bessel集与完备集;得到了关于MD-Riesz基集的两个充分条件,并证明了通过对MD-Riesz基集进行有限可测分解可得到MD-框架集.     

Modified Boussinesq System with Variable Coefficients： Classical Lie Approach and Exact Solutions

The Lie-group formalism is applied to investigate the symmetries of the modified Boussinesq system with variable coefficients. We derived the infinitesimals and the admissible forms of the coefficients that admit the classical symmetry group. The reduced systems of ordinary differential equations deduced from the optimal system of subalgebras are further studied and some exact solutions are obtained.     

Almost Everywhere Convergence of Sequences of Cesàro and Riesz Means of Integrable Functions with Respect to the Multidimensional Walsh System

The aim of this paper is to prove the a.e.convergence of sequences of the Cesa`ro and Riesz means of the Walsh–Fourier series of d variable integrable functions.That is,let a=(a1,...,ad):N→Nd(d∈P)such that aj(n+1)≥δsupk≤n aj(k)(j=1,...,d,n∈N)for someδ0 and a1(+∞)=···=ad(+∞)=+∞.Then,for each integrable function f∈L1(Id),we have the a.e.relation for the Ces`aro means limn→∞σαa(n)f=f and for the Riesz means limn→∞σα,γa(n)f=f for any 0αj≤1≤γj(j=1,...,d).A straightforward consequence of our result is the so-called cone restricted a.e.convergence of the multidimensional Ces`aro and Riesz means of integrable functions,which was proved earlier by Weisz.     

ON THE FINITE ELEMENT APPROXIMATION OF SYSTEMS OF REACTION-DIFFUSION EQUATIONS BY p/hp METHODS

We consider the approximation of systems of reaction-diffusion equations, with the finite element method. The highest derivative in each equation is multiplied by a parameter ε∈ （0, 1], and as ε → 0 the solution of the system will contain boundary layers. We extend the analysis of the corresponding scalar problem from [Melenk, IMA J. Numer. Anal. 17（1997）, pp. 577-601], to construct a finite element scheme which includes elements of size O（εp） near the boundary, where p is the degree of the approximating polynomials. We show that, under the assumption of analytic input data, the method yields exponential rates of convergence, independently of ε, when the error is measured in the energy norm associated with the problem. Numerical computations supporting the theory are also presented, which also show that the method yields robust exponential convergence rates when the error in the maximum norm is used.