关于有界对称域上的混合范数空间

本文研究了Ｃｎ中有界对称域Ω上的混合范数空间Ｈ（ｐ，ｑ，　）其中０＜ ｐ＜　，０＜ｑ＜　，　是正规函数，给出了Ω上全纯函数ｆ的分数导数ｆ［β］和 分数积分ｆ［β］属于（ｐ，ｑ，）的等价条件。应用这些结果，就两种情形０＜ｐ≤２， ０＜ｑ＜　和２≤ｐ＜，０＜ｑ＜ ，用全纯函数ｆ的展式中的系数，分别给出了 ｆ　Ｈ（ｐ，ｑ，）的必要条件和充分条件，并证明了多调和函数ｕ组成的混合范数空 间ｈ（ｐ，ｑ，）（０＜ｐ，ｑ＜　）是自共轭的．     

G~p空间的乘子

本文描述了空间Gp（1≤p＜∞）到空Gq,Aq,Hq和(p≤q≤∞）的乘子的特征．Gp（0＜p≤1）到lq（p≤q＜∞）,Gp（0＜P＜∞）到l∞的乘子的特征也被刻画.     

Cn单位球上的一类Hilbert值函数的收敛性

本文主要研究了Cn单位球上Hilbert值Dμ,q函数的收敛性,得到了若f=∑α≥0xαzα∈Dμ,q,q＞(2n)/(μ),则φ(z)=∑α≥0‖xα‖zα∈Lipγ,其中0＜μ＜1(n=1)或0＜μ＜2(n＞1).此外还得到若f∈Dμ,q,q＞(2n)/(μ),则对几乎所有的{εα}有fω(z)∈H∞,其中0＜μ＜1(n=1)或0＜μ＜2(n＞1).在此过程中,我们利用了Banach空间几何学和Rademacher函数序列的知识.     

指数和的不等式

指数和的不等式是指形如∑ｎｉ＝１ａｉｂｒｉ≤∑ｎｉ＝１ａｉｂｉ（１）的不等式，其中０＜ａ１＜…＜ａｎ＜∞，０＜ｂ１＜…＜ｂｎ＜∞，（ｒ１，ｒ２，…，ｒｎ）是（１，２，…，ｎ）的任何置换．今年春节过后不久，陈希孺院士向他的学生们指出一个挑战性的问题：对...     

序列[nc]上多维除数函数的和

设[θ]表示θ的整数部分,k≥2,dk(n)为除数函数.证明了当实数c满足1＜c＜3849/3334时,Σn≤x dk([nc])具有渐近公式,从而改进了吕广世和翟文广的结果(1＜c＜495/433),而且当k=2时,实数c的范围可以改进到1＜c＜391/335.     

1997年高考24题的深刻背景

文［１］介绍了１９９７年高考（理科）２４题的命题思想，其最初形式为给定二次多项式ｆ（ｘ）＝ａｘ２＋ｂｘ＋ｃ，ａ＞０，设０＜ｘ１＜ｘ２＜１ａ，满足ｆ（ｘｉ）＝ｘｉ，ｉ＝１，２，证明：当０＜ｘ＜ｘ１时，（１）ｘ＜ｆ（ｘ）＜ｘ１；（２）存在０＜ｑ＜１，使得...     

整函数插值序列的稳定性

本文证明了指数π型整函数Bπ，p，1＜p＜∞中某些实插值序列的稳定性，从而证明了存在一个和p有关的正常数δp，使得当sup|uj－j＜δp，u0＝0时，｛Gj（x）｝j∈Z为Bπ，p，1＜p＜∞的一组无条基，其中并且我们还证得是Bπ，p，1＜p＜∞的一组稳定的无条件基．     

不等式a/b

金明烈 《中学数学》1999,(8)

二阶奇异椭圆方程的Dirichlet问题

对二阶奇异椭圆方程-△u 1/uα-λuP=0的Dirichlet问题(λ＞0,0＜P＜1)证明了当α≥1时无解存在,当0＜α＜1时存在极小解;并对较一般的奇异方程给出了一个存在性结果.     

两类正规化双全纯映照子族齐次展开式的精细估计

本文考虑C~n中单位多圆柱上和一般复Banach空间中单位球上的正规化双全纯α(0■α＜1)次的殆β(-π/2＜β＜π/2)型螺形映照以及α(0＜α＜1)次的β(-π/2＜β＜π/2)型螺形映照f(其中x=0是f(x)-x的k+1阶零点),研究了它们的构造,并得到其齐次展开式的精细估计．所得的结果推广了以前相应的结论．     

RECENT PROGRESS ON SPHERICAL HARMONIC APPROXIMATION MADE BY BNU RESEARCH GROUP ——In memory of Professor Sun Yongsheng

As early as in 1990, Professor Sun Yongsheng, suggested his students at Beijing Normal University to consider research problems on the unit sphere. Under his guidance and encouragement his students started the research on spherical harmonic analysis and approximation. In this paper, we incompletely introduce the main achievements in this area obtained by our group and relative researchers during recent 5 years （2001-2005）. The main topics are： convergence of Cesaro summability, a.e. and strong summability of Fourier-Laplace series; smoothness and K-functionals; Kolmogorov and linear widths.     

Boundedness for commutators of multipliers on Hardy type spaces

In this paper, we study the commutators generalized by multipliers and a BMO function. Under some assumptions, we establish its boundedness properties from certain atomic Hardy space Hb^p（R^n） into the Lebesgue space L^p with p 〈 1.     

A unified approach to certain problems of best local approximation

In this paper we study best local quasi-rational approximation and best local approximation from finite dimensional subspaces of vectorial functions of several variables. Our approach extends and unifies several problems concerning best local multi-point approximation in different norms.     

Towards Excellence in Science Chinese Academy of Sciences

<正>May 26,2014,Beijing Science is a human enterprise in the pursuit of knowledge.The scientific revolution that occurred in the 17th Century initiated the advances of modern science.The scientific knowledge system created by     

THE 8~(th) INTERNATIONAL CONGRESS ON INDUSTRIAL AND APPLIED MATHEMATICS

<正>August 10-14,2015Beijing,ChinaThe International Congress on Industrial and Applied Mathematics(ICIAM)is the premier international congress in the field of applied mathematics held every four years under the auspices of the International Council for Industrial and Applied Mathematics.From August 10 to 14,2015,mathematicians,scientists     

Bounds for the zeros of polynomials

Let P(z)=∑↓j=0↑n ajx^j be a polynomial of degree n. In this paper we prove a more general result which interalia improves upon the bounds of a class of polynomials. We also prove a result which includes some extensions and generalizations of Enestrǒm-Kakeya theorem.     

Boundedness of commutators related to Marcinkiewicz integrals on hardy type spaces

In this paper, the authors study the boundedness of the operator [μΩ, b], the commutator generated by a function b ∈ Lipβ(Rn)(0 ＜β≤ 1) and the Marcinkiewicz integrals μΩ, on the classical Hardy spaces and the Herz-type Hardy spaces in the case Ω∈ Lipα(Sn-1)(0 ＜α≤ 1).     

Generalization of the interaction between Haar approximation and polynomial operators to higher order methods

In applications it is useful to compute the local average empirical statistics on u. A very simple relation exists when of a function f（u） of an input u from the local averages are given by a Haar approximation. The question is to know if it holds for higher order approximation methods. To do so, it is necessary to use approximate product operators defined over linear approximation spaces. These products are characterized by a Strang and Fix like condition. An explicit construction of these product operators is exhibited for piecewise polynomial functions, using Hermite interpolation. The averaging relation which holds for the Haar approximation is then recovered when the product is defined by a two point Hermite interpolation.     

Jacobi polynomials used to invert the laplace transform

Given the Laplace transform F(s) of a function f(t), we develop a new algorithm to find an approximation to f(t) by the use of the classical Jacobi polynomials. The main contribution of our work is the development of a new and very effective method to determine the coefficients in the finite series expansion that approximation f(t) in terms of Jacobi polynomials. Some numerical examples are illustrated.