关于两类函数方程的连续解与解析解

在本文中,我们首先考察了一类非齐次线性函数方程 φ[f(x)]=g(x)φ(x)+F(x), 在所谓的“不定情况”下,给出了连续解存在唯一性条件及其稳定性条件,并讨论了它的属于数λ的正规解的存在性问题。另外,本文还藉助优级数法给出一类非线性函数方程 f[φ(x)]=φ(ax)+F(x) 的局部解析解的存在唯一性定理。     

Harry-Dym方程及其解

本文研究了三类Harry-Dym方程的初值问题,证明了解的存在性与正则性,梅造了特解,还举例说明不同的初值问题分别对应于全直线、半直线或有限区间上KdV方程的定解问题。     

非一致椭圆型方程的广义Green函数

该文我们证明了一类齐次线性非一致椭圆型方程广义Ｇｒｅｅｎ函数的存在性和唯一性，并得到了广义Ｇｒｅｅｎ函数的一性性质，推广和发展了Ｇｒｕｔｅｒ，Ｍ．和Ｗｉｄｍａｎ，ｋ．ｏ［２］的相应结果，而且我们证明广义Ｇｒｅｅｎ函数唯一性的方法与［２］中的方法完全不同．     

一类拟线性抛物方程解的性质

本文给出了一类拟线性抛物方程初边值问题的解的存在唯一性，本文还给出了解所满足的“能量”等式，从而证明了解关于时间变量的连续性。     

AN IMPROVEMENT OF A RESULT OF IVOCHKINA AND LADYZHENSKAYA ON A TYPE OF PARABOLIC MONGE-AMP\`ERE EQUATION

For the initial-hotmdary value problem about a type of parabolic Monge-Ampere equation of the form (IBVP): {-Dtu + (deD^2xu)^1/n = f(x,t), (x,t) ∈ Q = Ω×(0,T)}, u(x,t) =Ф(x,t)(x,t) ∈δpQ}, where Ω is a bounded convex domain in R^n, the result in [4] by Ivochkina and Ladyzheokaya is improved in the sense that, under assumptions that the data of the problempossess lower regularity and satisfy lower order compatibility conditions than than in [4], the existence of classical solution to (IBVP) is still established (see Theorem 1.1 below). This cannot be reallzed by only using the method in [4]. The main additional effort the authors have done is a kind of nonlinear perturbation.     

抛物型薛定谔方程的最优正则性估计(英文)

本文通过特征化抛物型薛定谔算子t-Δ+V的域,探讨了抛物型薛定谔方程u/t-Δu+Vu=f在Orlicz空间中的最优正则性估计,并且对空间的维数没有限制.     

GLOBAL EXISTENCE FOR A SEMILINEAR DIFFERENTIAL SYSTEM

In this paper, a semilinear elliptic-parabolic PDE system which arises in a two dimensional groundwater flow problem is studied. Existence and uniqueness results are established via the L^p - L^q a priori estimates and the inverse function theorem.     

The G Class of Functions and Its Applications

Abstract In this paper, we introduce the concept of the G class of functions of the parabolic class, and show the H?lder continuity of the G class of functions. The introduction of this concept contributes to the proof of the regularity and existence of the solution for the first boundary problem of parabolic equation in divergence form. Project supported by NNFC (79790130) and ZJPNFC(198013) and STDF of Shanghai     

APPLICATION OF THE G CLASS OF FUNCTIONS IN THE PARABOLIC CLASS

§1　IntroductionIn[1],wehaveintroducedtheconceptoftheGclassoffunctionsintheparabolicclass,andhaveprovedtheHldercontinuityofthiskindoffunctions.Theintroductionoftheconceptcontributestotheproofoftheregularityandexistenceofthesolutionforthefirstboundaryvalueproblemofparabolicequationindivergenceform.Here,weconsidertheapplicationsoftheGclassoffunctionsintheparabolicclasstothefirstboundaryvalueproblemofparabolicequation.Asweknow,ithasreceivedextensivestudyforthefirstboundaryvalueproblemofthefoll…     

一类常微分方程解的存在唯一性及其应用

提出并证明了一类常微分方程解的存在唯一性成立的一个充要条件,并给出了多项式形式增长函数的一列上界.最终将此结果应用到证明一类倒向随机微分方程的唯一解问题.     

一类抛物方程组解的存在唯一性及关于耦合函数的连续依赖性

利用上、下解方法讨论了抛物方程组解的存在唯一性,并证明了解关于耦合函数的连续依赖性,同时给出了误差估计．     

一类对称函数的Schur凸性及其应用

对x=(x_1,…,x_n)∈[0,1)~n∪(1,+∞o)~n,定义对称函数■其中r∈N,i_1,i_2,…,i_n为非负整数.研究了F_n(x,r)的Schur凸性、Schur乘性凸性和Schur调和凸性.作为应用,用控制理论建立了一些不等式,特别地,给出了高维空间的一些新的几何不等式.     

单叶解析函数的几个子族之间的关系及应用

在复平面单位圆盘内引入了β型螺形甬数族S<,β>的一个子类S<'β>,<,α>函数族,研究了S<'β>,<,α>族与解析函数族S*,S*(α),K,K(α)及S<,β>之间的关系,利用得到的关系式对S<'β>,<,α>族的第二项系数进行了精确估计,同时得到了K(a)族的第二、三项系数的关系式和S<,β>,族的一个积分表...     

复合函数极限的应用

利用复合函数极限的运算法则给出收敛数列与其子列的关系、海涅定理以及数列重排的另一种证明,把三个重要的定理归结为复合函数极限的应用,将大学数学里三个重要但理解起来相对困难的定理纳入统一简单的框架.     

A Certain Class of Weighted Approximations for Integrable Functions and Applications

A certain class of weighted approximations, which extends the results of Masjed-Jamei [6] is introduced for integrable functions and some of upper bounds are obtained for the absolute value of the errors of such approximations in two L¹[a, b] and L^∞[a, b] spaces. As the main motivation for introducing the aforesaid class, it is shown that many new inequalities can be generated from the given error bounds. Some illustrative examples are presented in this sense. Moreover, by using the obtained error bounds, a nonstandard type of three-point weighted quadrature rules is introduced and its error bounds are computed.     

一类对称函数的Schur凸性与应用

对x=（x₁,x₂,…,x_n）∈R₊ⁿ及r∈{1,2,…,n},定义了对称函数F_n（x,r）=F_n（x₁,x₂,…,x_n;r）=∑_1≤i12…r≤n(∏₍j=1 x_ij/₁+x_ij^1/r,其中i₁,i₂,…,i_n是正整数.本文讨论了F_n（x,r）的Schur凸性、Schur几何凸性和Schur调和凸性,并借助于控制理论建立了若干不等式.     

Characterizations and Applications of Prequasi-Invex Functions

In this paper, two new types of generalized convex functions are introduced. They are called strictly prequasi-invex functions and semistrictly prequasi-invex functions. Note that prequasi-invexity does not imply semistrict prequasi-invexity. The characterization of prequasi-invex functions is established under the condition of lower semicontinuity, upper semicontinuity, and semistrict prequasi-invexity, respectively. Furthermore, the characterization of semistrictly prequasi-invex functions is also obtained under the condition of prequasi-invexity and lower semicontinuity, respectively. A similar result is also obtained for strictly prequasi-invex functions. It is worth noting that these characterizations reveal various interesting relationships among prequasi-invex, semistrictly prequasi-invex, and strictly prequasi-invex functions. Finally, prequasi-invex, semistrictly prequasi-invex, and strictly prequasi-invex functions are used in the study of optimization problems.