正相依随机变量的不变原理

对于最大协方差系数以多项式速率下降的正相依随机变量，Birkel给出了矩的上界估计．利用这一结果，Birkel建立了一个泛函中心极限定理．本文首先在最大协方差系数以对数速率下降的条件下给出了相同的矩的上界估计．进一步，基于这个较弱的条件，证明了Birkel的结论仍然成立．     

GRCA(1)模型中误差方差自加权估计的渐近分布

考虑随机系数自回归模型Y_t =Φ_ty_t-1+ u_t,其中 Φ_t为随机系数,u_t为随机误差。在允许Φ_t与u_t相依以及Eu_t无穷的条件下,构造了误差方差的自加权估计,并证明了该估计的渐近正态性。最后通过数值模拟,说明 自加权估计的稳健和有效性。     

Stability of <Emphasis Type="Italic">C</Emphasis>-regularized Semigroups

Let T = (T(t))t≥0 be a bounded C-regularized semigroup generated by A on a Banach space X and R(C) be dense in X. We show that if there is a dense subspace Y of X such that for every x ∈ Y, σu(A, Cx), the set of all points λ ∈ iR to which (λ - A)^-1 Cx can not be extended holomorphically, is at most countable and σr(A) N iR = Ф, then T is stable. A stability result for the case of R(C) being non-dense is also given. Our results generalize the work on the stability of strongly continuous senfigroups.     

On copositive approximation in some classical spaces of sequences

In this paper the author writes a simple characterization for the best copositive approximation in c; the space of convergent sequences, by elements of finite dimensional Chebyshev subspaces, and shows that it is unique.     

On the Existence of Positive Periodic Solutions for Neutral Functional Differential Equation with Multiple Deviating Arguments

By means of an abstract continuation theory for κ-set contraction and continuation theorem of coincidence degree principle, some criteria are established for the existence of positive periodic solutions of following neutral functional differential equation dN/dt=N(t)[α(t)-β（t)N(t)-∑j=1^n bj(t)N(t-σj(t))-∑i=1^mci(t)N‘(t-γi(t)0].     

N粒子W纠缠态的隐形传输

提出使用纠缠交换的方法,采用N对二粒子非最大纠缠态作为量子通道来传输N粒子W纠缠态的方案。传输过程中,发送者对自己所拥有的粒子进行Bell基测量,并将测量结果通过经典通道通知接收者,接收者根据所获取的信息对她的粒子实行相应的幺正变换以恢复最初待传输的粒子态,从而,成功实现该隐形传输。文章还以三粒子的传输为例作了详细介绍。     

紧致带边黎曼流形上的Ricci形变

研究n维紧致带边流形的Ricci形变问题，得到在如下拼脐奈件下｜W｜^2＋｜V｜^2≤1/3（n-2）｜U｜^2,则（M，g）在Ricci流下可形变为（M，g∞），使得（M，g∞）具有常正曲率和全测地边界．     

一个三角不等式的推广

文 [1]证明了“若α ,β ,γ为正锐角 ,且ｓｉｎ2 α ｓｉｎ2 β ｓｉｎ2 γ =1,求证 :α β γ <π2 ”后 ,作了本题的上界估计 .若α ,β ,γ为正锐角 ,且ｓｉｎ2 α ｓｉｎ2 β ｓｉｎ2 γ =1,求证α β γ≤ 3ａｒｃｓｉｎ 13.文 [1]未对其进行证明 ,现将该不等式作如下推广 .定理　若α1,α2 ,… ,αｎ(ｎ≥ 3)为正锐角 ,且 ｎｉ=1ｓｉｎ2 αｉ=1,则 ｎｉ=1αｉ≤ｎａｒｃｓｉｎ 1ｎ.引理　若α1,α2 ,… ,αｎ(ｎ≥ 2 )均为正锐角 ,并且它们的两两之和也为正锐角 ,则ｓｉｎ2 1ｎ ｎｉ=1αｎ≤ 1ｎ ｎｉ=1ｓｉｎ2 αｉ.证　 …