广义Petersen图的宽直径

Generalized Petersen graphs are commonly used interconnection networks,and wide diameter is an important parameter to measure fault-tolerance and efficiency of parallel pro- cessing computer networks.In this paper,we show that the diameter and 3-wide diameter of generalized Petersen graph P (m,a) are both O( m 2a ),where a ≥ 3.     

关于序半群理想的根

Let S be an ordered semigroup.In this paper,we characterize ordered semigroups in which the radical of every ideal（right ideal,bi-ideal） is an ordered subsemigroup（resp.,ideal,right ideal,left ideal,bi-ideal,interior ideal） by using some binary relations on S.     

含有割点的图的最小特征值

Let ψ be a certain set of graphs.A graph is called a minimizing graph in the set ψ if its least eigenvalue attains the minimum among all graphs in ψ.In this paper,we determine the unique minimizing graph in ψn,where ψn denotes the set of connected graphs of order n with cut vertices.     

一类限制m元over-分拆同余式

We discuss a family of restricted m-ary overpartition functions bm,j （n）, which is the number of m-ary overpartitions of n with at most i ＋ j copies of the non-overlined part m^i allowed, and obtain a family of congruences for bm,lm-1 （n）.     

推出-拉回图上的覆盖性同态

In a pushout-pullback diagram,which consists of four morphisms f : A → B,g : A → C,α : C → D and β : B → D,we give some relations among the covers of these four modules.If kerf ∈ I(L ),then g : A → C is L -covering if and only if β : B → D is L -covering.If every module has an L -precover and kerf ∈ I(L ),then A and C have isomorphic L -precovers if and only if B and D have isomorphic L -precovers.     

两类广泛递归序列的动力特性

We investigate the dynamics of two extensive classes of recursive sequences:xn+1=c∑ k ∑xn-ioxn-i1…xn-i2j+f(xn-io,xn-i1,…,xn-i2k)j=0(i0,i1,…,i2j)∈A2j/c∑ k ∑xn-ioxn-i1…xn-i2j-1+c+f(xn-io,xn-i1,…,xn-i2k)j=1(i0,i1,…,i2j)∈A2j-1 and xn+1=c∑ k ∑xn-ioxn-i1…xn-i2j-1+c+f(xn-io,xn-i1,…,xn-i2k)j=1(i0,i1,…,i2j)∈A2j-1/c∑ k ∑xn-ioxn-i1…xn-i2j+f(xn-io,xn-i1,…,xn-i2k)j=0(i0,i1,…,i2j)∈A2j We prove that their unique positive equilibrium x = 1 is globally asymptotically stable.And a new access is presented to study the theory of recursive sequences.     

$\delta$-拼挤流形中的2-调和子流形

We study biharmonic submanifolds in δ-pinched Riemannian manifolds, and obtain some sufficient conditions for biharmonic submanifolds to be minimal ones.     

有限域上的本原最优正规元

Let q be a prime or prime power and Fqn the extension of q elements finite field Fq with degree n(n1).Davenport,Lenstra and Schoof proved that there exists a primitive element α∈ Fqn such that α generates a normal basis of Fqn over Fq.Later,Mullin,Gao and Lenstra,etc.,raised the definition of optimal normal bases and constructed such bases.In this paper,we determine all primitive type I optimal normal bases and all finite fields in which there exists a pair of reciprocal elements α and α-1 such that both of them generate optimal normal bases of Fqn over Fq.Furthermore,we obtain a sufficient condition for the existence of primitive type II optimal normal bases over finite fields and prove that all primitive optimal normal elements are conjugate to each other.     

一类带有快扩散项的半导体方程的弱解存在性

In this paper, we consider the transient drift-diffusion model with fast diffusion term. This problem is not only degenerate but also singular. We present the existence result for the Neumann boundary value problem with general nonlinear diffusivities.     

R~n上Plate方程全局吸引子的正则性和有限维性

研究了无界区域Rn上Plate方程全局吸引子的正则性和有限分形维性.该方程的全局吸引子在相空间H2(Rn)×L2(Rn)的存在性已在先期文章建立,现在进一步证明该全局吸引子具有更好的正则性,即它是H4(Rn)×H2(Rn)的有界集并具有有限分形维数.