第二类Stirling数的一些同余式

设k,n为非负整数,S(n,k)表示第二类Stirling数.本文研究了S(n,k)模2的方幂的同余式,首先给出了一类二项式系数模2的同余式,然后利用上述结果得到了S(n,a2~m+b)模2~m的同余式.其表达式均由简单二项式系数组成,其中m≥3,b=0,1,2.这些结果改进了Chan和Manna的结果.     

一类阶为偶数的高斯和显式计算的注记

给出指数2情形下阶数为2l_1~(r1)l_1~(r2)的高斯和的显式计算公式.证明方法直接利用Stickelberger理想分解定理,进而结果独立于其他指数2情形高斯和的结果而成立.     

由勾股定理引发的联想

学完勾股定理后,对"32+42=52"这一结果引发了我的探究兴趣,得到如下结果.1.只有正整数n=4才能使(n-1)2+n2=(n+1)2成立.证明由(n-1)2+n2=(n+1)2化简,得n2-4n=0,于是有n=0或n=4,显然0不是正整数,n=4是唯一的,即3,4,5是唯一的连续正整数勾股数.     

一类非散度型椭圆方程解的局部W~(2,p)正则性

本文得到了一类具有小BMO系数的非散度型椭圆方程解的局部W2,p(p≥2) 正则性结果,并给出了这个结果的一个应用．     

关于弱收敛非负随机变量序列的逆矩

在2 δ阶矩有限时,对一类非负弱收敛随机变量列,给出了成立的充分条件,推广了[2]中的结果并严密了其中主要结果定理3,定理4的证明．     

高连通紧带边流形到欧氏空间的嵌入

周学光在[1]中给出了(m-1)-连通的2m、2m 1、2m 2维差不多闭流形到欧氏空间的嵌入定理.本文是利用[1]中的方法,给出了(m-1)-连通的、边界为(m-2)-连通的2m、2m 1、2m 2维紧带边流形到欧氏空间的嵌入定理,这些结果推广了[1]中的相应结果,且在以下两个方面改进了[1]中的相应结果:     

粤东柘林湾浮游植物与生态因子的灰关联-回归分析

应用灰关联方法对 2 0 0 1年 1 0月至 2 0 0 2年 7月柘林湾海域的海水采样结果进行数据分析 ,在磷酸盐、硅酸盐等 1 1项生态因子中找出影响浮游植物密度的关键因子 .根据这个结果 ,进一步建立了以这些关键因子为自变量的线性回归模型 ,模型最后的分析结果和灰关联分析的结果一致 ,即 Fe、水温、浊度是影响柘林湾浮游植物密度的关键因子 .     

U-统计量渐近正态余项级数的收敛性

的收敛性,并获得了园满的结果,在独立和情况下的同一问题,曾由 Heyde[2]于1966年讨论。本文将反复引用[2]中的结果,本文的主要结果是:     

关于指数丢番图方程$x^2+(3a^2-1)^m=(4a^2-1)^n$

应用Bilu,Hanrot和Voutier关于本原素因子的深刻结果以及二次丢番图方程解的表示的一些精细结果,完全解决了指数型丢番图方程x2 (3a2-1)m=(4a2-1)n当3a2-1是奇素数或奇素数幂时的求解问题．     

关于两个素数和一个素数k次幂的丢番图不等式

令■设λ_1,λ_2,λ_3是不全同号的非零实数,且满足λ_1/λ_2为无理数,则对于任意实数η和ε 0,不等式■有无穷多组素数解p_1,p_2,p_3.该结果改进了Gambini,Languasco和Zaccagnini的结果.     

Orbital stability of solitary waves for Kundu equation

In this paper, we consider the Kundu equation which is not a standard Hamiltonian system. The abstract orbital stability theory proposed by Grillakis et al. (1987, 1990) cannot be applied directly to study orbital stability of solitary waves for this equation. Motivated by the idea of Guo and Wu (1995), we construct three invariants of motion and use detailed spectral analysis to obtain orbital stability of solitary waves for Kundu equation. Since Kundu equation is more complex than the derivative Schrödinger equation, we utilize some techniques to overcome some difficulties in this paper. It should be pointed out that the results obtained in this paper are more general than those obtained by Guo and Wu (1995). We present a sufficient condition under which solitary waves are orbitally stable for 2c₃+s₂υ<0, while Guo and Wu (1995) only considered the case 2c₃+s₂υ>0. We obtain the results on orbital stability of solitary waves for the derivative Schrödinger equation given by Colin and Ohta (2006) as a corollary in this paper. Furthermore, we obtain orbital stability of solitary waves for Chen-Lee-Lin equation and Gerdjikov-Ivanov equation, respectively.     

Unbounded connected component of the positive solution set of nonlinear operator equation and its applications

In this paper, by using global bifurcation theories we obtain some results for structure of positive solution set of some nonlinear equations with parameters. As a result, we obtain some existence results for positive solutions of the nonlinear operator equation. The main result can be applied to various of differential boundary value problems to obtain the existence results for positive solutions without the assumption that the nonlinearities are positone.     

Structure of positive solution sets of sub-linear semi-positone operator equations

In this paper, first we obtain some results on the structure of the positive solution set of a nonlinear operator equation. Then using these results, we obtain some existence results for positive solutions of nonlinear operator equations. We use global bifurcation theories to show our main results.     

ON HYPERSTABILITY OF THE BIADDITIVE FUNCTIONAL EQUATION

We present results on approximate solutions to the biadditive equation f(x+y,z-w) + f(x-y,z+w) = 2f(x,z)-2f(y,w)on a restricted domain. The proof is based on a quite recent fixed point theorem in some function spaces. Our main results state that,under some weak natural assumptions,functions satisfying the equation approximately(in some sense) must be actually solutions to it. In this way we obtain inequalities characterizing biadditive mappings and inner product spaces.Our outcomes are connected with the well known issues of Ulam stability and hyperstability.     

Improved Strichartz estimates for a class of dispersive equations in the radial case and their applications to nonlinear Schrödinger and wave equations

We prove some new Strichartz estimates for a class of dispersive equations with radial initial data. In particular, we obtain the full radial Strichartz estimates up to some endpoints for the Schrödinger equation. Using these estimates, we obtain some new results related to nonlinear problems, including small data scattering and large data LWP for the nonlinear Schrödinger and wave equations with radial critical initial data and the well-posedness theory for the fractional order Schrödinger equation in the radial case.     

(2+1)维浅水波方程的新精确解

对(2+1)维浅水波方程的现有解进行了推广.应用CK方法对方程进行求解,得到方程的Backlund变换公式,将已知解代入公式,求得一些新的精确解,从而推广了浅水渡方程的解.     

The Sparre Andersen Risk Process with Investment and Debit Interest

In this paper, we study absolute ruin problems for the Sparre Andersen risk process with generalized Erlang()-distributed inter-claim times, investment and debit interest. We first give a system of integro-differential equations with certain boundary conditions satisfied by the expected discounted penalty function at absolute ruin. Second, we obtain a defective renewal equation under some special cases, then based on the defective renewal equation we derive two asymptotic results for the expected discounted penalty function when the initial surplus tends to infinity for the light-tailed claims and heavy-tailed claims, respectively. Finally, we investigate some explicit solutions and numerical results for generalized Erlang(2) inter-claim times and exponential claims.     

Estimates of low Sobolev norms of solutions for some nonlinear evolution equations

In this work we obtain results on the estimates of low Sobolev norms for solutions of some nonlinear evolution equations, in particular we apply our method for the complex modified Korteweg-de Vries type equation and Benjamin-Ono equation.     

常利率下Erlang(2)风险模型的罚金折现期望

本论文研究了常利率下E rlang(2)的风险模型,得到了关于罚金折现期望满足的积分表达式、积分-微分方程以及L-S变换满足的微分方程,并且考虑了一些特殊情况.     

Entire functions sharing one polynomial with their derivatives

In this paper, we study the growth of solutions of ak-th order linear differential equation and that of a k + 1-th order linear differential equation. From this we affirmatively answer a uniqueness question concerning a conjecture given by Brück in 1996 under the restriction of the hyper order less than 1/2, and obtain some uniqueness theorems of a nonconstant entire function and its derivative sharing a finite nonzero complex number CM. The results in this paper also improve some known results. Some examples are provided to show that the results in this paper are best possible.