Hermite-Fejr插值算子的平均收敛准则

给出了一个有用的判断Ｈｅｒｍｉｔｅ－Ｆｅｊéｒ插值算子Ｈｎ（ｆ,ｘ）平均收敛准则,即Ｈｎ（ｆ,ｘ）依范数收敛于ｆ（ｘ）的充分必要条件是：Ｈｎ（ｆ,ｘ）一致有界（对一切ｎ）并且Ｈｎ（ｆ,ｘｋ）依范数收敛于ｘｋ（ｋ＝１,２）．     

三角插值中的线性求和问题

本文通过选取求和因子构造出和式型三角插值多项式Ｈｎ（ｆ，ｒ，ｘ）（ｒ为奇自然数），使其在全实轴上一致地收敛到以２π为周期的连续函数ｆ（ｘ），且Ｈｎ（ｆ，ｒ，ｘ）对Ｃｎ２π（ｌ≤ｒ）连续函数类的逼近均达到最佳收敛阶．Ｈｎ（ｆ，ｒ，ｘ）的饱和阶为１／ｎ（ｒ＋１），饱和函数类为ｆ（ｒ）（ｘ）∈Ｌｉｐｍｌ．     

关于Hermite-Fejer插值过程的平均收敛

文［１］讨论了某些非Ｗ－过程的插值算子的加权平均逼近的收敛性和收敛阶．如记Ｈｎ（ｆ；ｘ）为以第二类Ｃｈｅｂｙｓｈｅｖ多项式Ｕｎ（ｘ）的零点作为插值节点，区间［－１，１］上的函数ｆ（ｘ）的Ｈｅｒｍｉｔｅ－Ｆｅｊｅｒ插值算子，［１］中证得：定理Ａ当０＜ｐ...     

一类指数型整函数值算子的逼近性质

设（Ｕσｆ）（ｘ）＝Σ↓ｋ∈Ｚｆ（Ｘｋ）Ａσ（Ｘ－Ｘｋ），Ｘｋ＝２ｋπ／σ，ｋ∈Ｚ，σ〉０，ｆ是Ｒ上的有界函数，而Ａσ（ｙ）＝２／σ∫σ０ｓｉｎ＾ｍ（σ－Ｘ）ｈ／ｓｉｎ＾ｍ（σ－Ｘ）ｈ＋ｓｉｎ＾ｍｘｈｃｏｓｘｙｄｘ，ｍ为奇自然数，０〈ｈ〈π／σ，本文研究了此插值算子的收敛与饱和问题。     

关于区间上的单峰扩张自映射

设ｆ是区间Ｉ＝［０，１］上的扩张的单峰函数，λ是ｆ的扩张常数。又设Ｋ≥３是奇数，ｎ≥３是整数，λｋ是方程ｘ＾ｋ－２ｘ＾ｋ－２－１＝０的最大实根，μｎ是方程ｘ＾ｎ－２ｘ＾ｎ－１＋１＝０的最大实根，本文用较简单的方法证明了，当λ≥λＫ时，ｆ中含有Ｋ－周期轨道，当λ≥μｎ时，ｆ中含有相对于自身的ＲＬ＾ｎ－２Ｃ型单峰周期轨道。此外，本文还讨论了一类方程ｘ＾ｎη（ｘ）＝ζ（ｘ）的根的极限度最性质。     

小波级数的Bouligand维数

本文讨论了小波级数ｆ（ｘ）－Σｊ≥０Σｋ≥ｘＣｊｋΨｊｋ＾λ（ｘ）的上、下Ｂｕｏｌｉｇａｎｇｄ维数，在小波级数Ψ满足一定的条件下，给出了与Ｗｅｉｅｒｓｔｒａｓｓ函数相应的结果。     

关于有界二元密度函数的一个公式

设Ｆ（ｘ，ｙ）是二元连续型分布函数，ｆ（ｘ，ｙ）是其密度函数，本文的目的是给出公式α＾２Ｆ（ｘ，ｙ）／αｘαｙ＝ｆ（ｘ，ｙ）成立的一个充分条件。     

带Hilbert核奇异积分方程的Galerkin方法

该文讨论了以下形式的奇异积分方程其中ａ（ｘ），ｂ（ｘ），ｆ（ｘ），（ｘ）∈Ｈ（２π），ｋ（ｘ，ｔ）关于ｘ，ｔ也∈Ｈ（２π）的数值解法．在Ｌ２模下，得出了逼近解的存在性和收敛性；当ｆ（Ｘ），ｋ（ｘ，ｔ）∈Ｈμ２π，μ＞时，逼近解在最大模下一致收敛到精确解；当ｆ（ｐ）（Ｘ），ｋ（ｘ，ｔ）∈Ｈμ２π时，逼近解对精确解的逼近阶．     

二维全空间上线性阻尼Navier-Stokes方程的全局吸引子及其维数估计

本文研究二维全空间上线性阻尼Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程的大时间性态央餐力项ｆ（ｘ）∈（Ｌ＾２（Ｒ＾２）＾２而不需要对ｆ（ｘ）作任何加权限制的条件下,证明了线性阻尼Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程的全局吸引子的存在性,并给出了其Ｈａｕｓｄｏｒｆｆ及Ｆｒａｃｔａｌ维数估计。     

改进的PSB拟牛顿修正矩阵的收敛性

本文在已建立的一类新拟牛顿方程Ｂｋ＋１δｋ＝ｙｋ＝ｙｋ＋θｋ／δｋ＾Ｔｕ的基础上,证明了满足新拟牛顿方程的改进ＰＳＢ算法产生的拟牛顿修正矩阵序列在序列｛ｘｋ｝收敛于ｘ＾＊,｛δｋ｝一致性无关及二阶导数阵连续有界的条件下收敛于海色阵Ｇ（ｘ＾＊）。     

On a class of self-similar processes with stationary increments in higher order Wiener chaoses

We study a class of self-similar processes with stationary increments belonging to higher order Wiener chaoses which are similar to Hermite processes. We obtain an almost sure wavelet-like expansion of these processes. This allows us to compute the pointwise and local Hölder regularity of sample paths and to analyse their behaviour at infinity. We also provide some results on the Hausdorff dimension of the range and graphs of multidimensional anisotropic self-similar processes with stationary increments defined by multiple Wiener–Itô integrals.     

A REPRESENTATION FORMULA RELATED TO SCHR(O)DINGER OPERATORS

Schr(o)dinger operator is a central subject in the mathematical study of quantum mechanics.Consider the Schrodinger operator H = -△ V on R, where △ = d2/dx2 and the potential function V is real valued. In Fourier analysis, it is well-known that a square integrable function admits an expansion with exponentials as eigenfunctions of -△. A natural conjecture is that an L2 function admits a similar expansion in terms of "eigenfunctions" of H, a perturbation of the Laplacian (see [7], Ch. Ⅺ and the notes), under certain condition on V.     

On a class of Riemann surfaces

It is considered the class of Riemann surfaces with dimT1 = 0, where T1 is a subclass of exact harmonic forms which is one of the factors in the orthogonal decomposition of the spaceΩH of harmonic forms of the surface, namely The surfaces in the class OHD and the class of planar surfaces satisfy dimT1 = 0. A.Pfluger posed the question whether there might exist other surfaces outside those two classes. Here it is shown that in the case of finite genus g, we should look for a surface S with dimT1 = 0 among the surfaces of the form Sg\K , where Sg is a closed surface of genus g and K a compact set of positive harmonic measure with perfect components and very irregular boundary.     

CONTENTS OF VOLUME 30

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Instructions for contributions

正Applied Mathematics-A Journal of Chinese Universities,Series B(Appl.Math.J.Chinese Univ.,Ser.B)is a comprehensive applied mathematics journal jointly sponsored by Zhejiang University,China Society for Industrial and Applied Mathematics,and Springer-Verlag.It is a quarterly journal with     

Journal of Mathematical Research with Applications Guide for Authors

正Journal overview:Journal of Mathematical Research with Applications(JMRA),formerly Journal of Mathematical Research and Exposition(JMRE)created in 1981,one of the transactions of China Society for Industrial and Applied Mathematics,is a home for original research papers of the highest quality in all areas of mathematics with applications.The target audience comprises:pure and applied mathematicians,graduate students in broad fields of sciences and technology,scientists and engineers interested in mathematics.     

Staircase transportation problems with superadditive rewards and cumulative capacities

A cumulative-capacitated transportation problem is studied. The supply nodes and demand nodes are each chains. Shipments from a supply node to a demand node are possible only if the pair lies in a sublattice, or equivalently, in a staircase disjoint union of rectangles, of the product of the two chains. There are (lattice) superadditive upper bounds on the cumulative flows in all leading subrectangles of each rectangle. It is shown that there is a greatest cumulative flow formed by the natural generalization of the South-West Corner Rule that respects cumulative-flow capacities; it has maximum reward when the rewards are (lattice) superadditive; it is integer if the supplies, demands and capacities are integer; and it can be calculated myopically in linear time. The result is specialized to earlier work of Hoeffding (1940), Fréchet (1951), Lorentz (1953), Hoffman (1963) and Barnes and Hoffman (1985). Applications are given to extreme constrained bivariate distributions, optimal distribution with limited one-way product substitution and, generalizing results of Derman and Klein (1958), optimal sales with age-dependent rewards and capacities.To our friend, Philip Wolfe, with admiration and affection, on the occasion of his 65th birthday.Research was supported respectively by the IBM T.J. Watson and IBM Almaden Research Centers and is a minor revision of the IBM Research Report [6].