模型论中的拓扑学方法

本文利用拓扑学方法研究了ω-范畴理论的性质,并对模型个数问题进行了讨论.     

与三个数论函数有关的两个方程的解

讨论了与数论函数Euler函数φ(m),函数Ω(m)和函数ω(m)相关联的两个方程φ(m)=2~(Ω(m)+ω(m))3~(Ω(m)+ω(m))与φ(m)=2~(Ω(m)-ω(m))3~(Ω(m)-ω(m))的可解性,利用这三个数论函数的相关性质以及初等方法,给出这两个方程的解,其中函数Ω(m)为m的质因子个数函数,函数ω(m)为m的相异质因子个数函数.     

拟信息基,ω-代数Cpo,和SFP domain

G.Sam b in引入了(代数)信息基的概念,并证明了代数Scott D om a in范畴和信息基范畴是等价的.B.R.C.Bedrega l给出了ω-代数cpo和SFP dom a in的刻划.而G.Q.Zhang通过序结构给出了SFP dom a in的刻划.本文将引入了拟信息基的概念并给出了ω-代数cpo和SFP dom a in的刻划.     

关于Erds和Ivi的一个问题

令ω(n)表示正整数n的不同素因子的个数,Ω(n)表示正整数n的全部素因子的个数.本文到到了下面两个结果:■     

两个数论函数及其方程

对于任意给定的自然数n,著名的Eu ler函数φ(n)定义为不大于n且与n互素的正整数的个数.ω(n)表示n的所有不同素因子的个数.本文研究了方程φ(n)=2ω(n)的可解性,并给出了该方程的所有正整数解.     

一个包含Euler函数的方程

对任意自然数n≥1,著名的Euler函数ψ(n)定义为不大于n且与n互素的正整数的个数.本文的主要目的是研究方程ψ(ψ(ψ(n)))=2ω(n)的可解性,其中ω(n)表示n的所有不同素因子的个数,并给出了该方程的所有正整数解.     

Lω-空间的ω-Lindeloef性质

在Lω-空间中引入ω-Lindeloef性质和ω-Lindeloef空间等概念，给出了其等价刻画，并证明它保持L-拓补空间中许多良好的性质，如闭遗传性、L-好的推广、被连续的L值Zadeh型函数所保持。此外，引入了ω-紧性的概念，研究了其若干性质。     

关于高维非自治系统周期解的判据

本文利用拓扑度的理论，研究了ｎ阶非线性系统ｘ＝ｐ（ｔ）ｘ＋μｈ（ｔ，ｘ）得到，若系统（＊）对应的齐次方程ｘ＝ｐ（ｔ）ｘｄ无非平凡ω周期解，系统（＊）的ω周期解存在及其个数的重要判据。     

ω-非常凸空间与ω-非常光滑空间

本文研究了ω-非常凸空间和ω-非常光滑空间的问题.利用局部自反原理和切片证明了ω-非常凸空间和ω-非常光滑空间的对偶关系,讨论了ω-非常凸空间和ω-非常光滑空间与其它凸性和光滑性的关系,给出了ω-非常凸空间与ω-非常光滑空间的若干特征刻画,所得结果完善了关于Banach空间凸性与光滑性理论的研究.     

关于ω-强凸空间的一点注记

本文研究了关于ω-强凸空间和ω-强光滑空间的问题.利用Banach理论的方法,证明了ω-强凸空间和ω-强光滑空间是一对对偶概念,并讨论了ω-强光滑性与其它光滑性之间的关系,用切片统一刻画了ω-强凸空间与ω-强光滑空间的特征,完善了ω-强凸空间及其对偶空间的研究.     

Hereditary torsion classes of s-systems

Torsion classes and their corresponding quasi-filters in S-systems will be investigated. Torsion theory, in particular the hereditary torsion theory of S-systems will be characterized by the conguences defined on a semigroup S. A number of results on torsion theory of semigroups in the literature will be generalized and extended.     

EXISTENCE OF PERIODIC SOLUTIONS TO A KIND OF HIGHER ORDER FUNCTIONAL DIFFERENTIAL EQUATION WITH TWO DEVIATING ARGUMENTS

In this paper, by the theory of Fourier series, Bernoulli number theory and continu-ation theorem of coincidence degree theory, we study a kind of higher order functional differential equation with two deviating arguments. Some new results on the existence of periodic solutions are obtained.     

具偏差变元的高阶泛函微分方程的周期解存在性问题

利用Fourier级数理论,伯努利数理论和重合度理论研究了一类具偏差变元的高阶泛函微分方程x(m)(t)+(m-1)∑(i=1)aix(i)(t)+f(x(t))+β(t)g(x(t-T(t)))=p(t)的周期解问题,得到了周期解存在的充分条件,有意义的是函数β(t)可变号.     

Euler and number theory

We give an account of the most important results obtained by Euler in number theory, including the main contribution of Euler, application of analysis to problems of number theory. We note an important role played in modern number theory by the function that was introduced by Euler and is called the Riemann zeta function. We also discuss Euler’s works in other fields of science such as function theory and theory of music, as well as the relationship between music and mathematics.     

在微重力条件下无限长方柱中的自然对流*

为了研究在宇宙空间微重力环境中.自然对流对流体运动的影响,将变量展成Grashof的摄动级数,使用摄动理论将Navier-Stokes方程组简化成:关于温度T的Poisson方程,关于流函数ψ的非齐次biharmonic方程.选取一无限长封闭方柱体,假定在柱体边界上预先给定一种线性温度分布,使用数值计算方法求解上述简化方程组,得到各阶流函数和各阶温度值,进而详细地研究了方柱中流体的运动状况,分析和讨论了某些参数,如Grashof数和Prandtl数对流体运动的影响,最后将计算结果与由未简化方程推算的结果进行比较,证实近似方法正确地简化了复杂的流体运动过程,并且可以推广、运用到三维问题上.     

Nielsen equalizer theory

We extend the Nielsen theory of coincidence sets to equalizer sets, the points where a given set of (more than 2) mappings agree. On manifolds, this theory is interesting only for maps between spaces of different dimension, and our results hold for sets of k maps on compact manifolds from dimension (k−1)n to dimension n. We define the Nielsen equalizer number, which is a lower bound for the minimal number of equalizer points when the maps are changed by homotopies, and is in fact equal to this minimal number when the domain manifold is not a surface.As an application we give some results in Nielsen coincidence theory with positive codimension. This includes a complete computation of the geometric Nielsen number for maps between tori.     

不确定性信息处理的集对论思想与方法

集对论从主体与客体联系层次上较好地实现了不确定性信息的整体处理,集对论的同异反集合和联系数等概念弥补了模糊集合论的缺陷。本文从概念上探讨了集对论的基本原理和思想方法,并与模糊集合论做了对比分析,认为集对论体现了认识过程中的辩证思维,因而具有更强的方法论意义。     

Toeplitz operators on generalised H2 spaces

Some aspects are developed of the theory of Toeplitz operators on generalised HardyH ² spaces associated to function algebras. It is shown that a substantial number of results of the classical theory of Toeplitz operators on the circle extend to this situation, although counterexamples are given which show that there are also important differences. Spectral connectedness results are obtained, and a characterisation of invertibility for Toeplitz operators. The Fredholm theory is also studied.     

编序式问卷调查的模糊偏序排序法

讨论了现有的编序式问卷调查排序方法的不足之处;提出了基于模糊偏序关系的编序式问卷调查的排序方法,给出了模糊偏序排序法的数学模型,论证了用模糊偏序关系对编序式问卷调查进行排序是一种较好的方法;并用实例分析了模糊偏序排序法应用于编序式问卷调查的具体操作步骤.     

Exponential Sums and Coding Theory: A Review

This article is a survey of several recent applications of methods from analytic number theory to research in coding theory, including results on Kloosterman codes, binary Goppa codes, and prime phase shift sequences. The mathematical methods focus on exponential sums, in particular Kloosterman sums. The interrelationships with the Weil–Carlitz–Uchiyama bound, results on Hecke operators, theorems of Bombieri and Deligne and the Eichler–Selberg trace formula are reviewed.