齐型空间上的Lipschitz函数与Littlewood－Paley g－函数

在θ阶正规齐型空间上，如果算子列｛Ｓｋ｝ｋ∈Ｚ是恒等逼近，Ｄｋ＝Ｓｋ－Ｓｋ－１；本文给出一个用｛Ｄｋ｝ｋ∈Ｚ表达的ｆ∈Ｌｉｐα（Ｌｉｐｓｃｈｉｔｚ函数类，０＜α＜θ）的充分必要条件．作为其推论得到，对于ｆ∈ＬＩｐα，其Ｌｉｔｔｌｅｗｏｏｄ－Ｐａｌｅｙｇ函数ｇ（ｆ）（Ｘ）或者处处为无穷大，或者在Ｌｉｐα上有界．     

球上Bloch函数的导数与α－Carleson测度

设ｆ是Ｂ＝｛Ｚ∈Ｃｎ；｜ｚ｜＜１｝上的全纯函数，Ｒｍｆ是高阶径向导数，而Ｄｓｆ（ｓ＞０）是ｆ的ｓ阶分数次导数，本文证明ｆ是Ｂｌｏｃｈ函数当且仅当ｓｕｐ｛｜Ｒｍｆ（ｚ）｜（１－｜ｚ｜２ｍ｜＜＋∞或者　作为相关的结果，我们用Ｂｌｏｃｈ函数的积分性质刻划了α－Ｇａｒｌｅｓｏｎ测度，另一方面我们得到了Ｂｌｏｃｈ函数关于α－Ｃａｒｌｅｓｍ测度的新特征．     

Littlewood－Paley的g_λ~＊函数与面积函数在Lip_α（R~n）

本文证明，对于Ｌｉｐｓｃｈｉｔｚ空间Ｌｉｐα（Ｒｎ）的函数ｆ，若相应Ｌｉｔｔｌｅｗｏｏｄ－Ｐａｌｅｙ的ｇ函数的ｇ（ｆ）（ｘ）（或面积函数Ｓ（ｆ）（ｘ））在Ｒｎ中一点有限，则它必处处有限，并且作为Ｌｉｐα（Ｒｎ）上的算子，ｇ和Ｓ在一定意义下有界，这对一切α，０＜α＜１，和适当的λ成立．     

几类不具有捏制轨道系列完整性的单峰函数族

本文证明，存在着由单峰函数构成的Ｃｏ－函数族｛ｆλ），｛ｇλ｝及具有下列性质：（ｉ）各ｆλ均是分段线性的单峰平顶函数，各ｇλ及均是Ｃ∞－单峰平顶函数．但族｛ｆλ｝，｛ｇλ｝及均非一致平顶；（ｉｉ）族｛ｆλ｝及｛ｇλ｝均满足一致的Ｌｉｐｓｃｈｉｔｚ条件，但在峰顶处均非一致地可微；（ｉｉｉ）族在峰顶处一致地可微，但不满足一致的Ｌｉｐｓｃｈｉｔｚ条件；（ｉｖ）当０≤λ≤７／８时捏制序列Ｋ（ｆλ），Ｋ（ｇλ）及以均不大于ＲＬＣ，当７／８＜λ－≤１时Ｋ（ｆλ），Ｋ（ｇλ）及Ｋ均不小于ＲＬＬ（ＲＬＲ）∞，因而族｛ｆλ｝，｛ｇλ｝及均不具有捏制轨道系列的完整性．本文的结果解答了文［５］中提出的两个猜测．     

亚纯函数的不动点与拟正规族

本文研究了亚纯函数的不动点与拟正规族的关系，得到了以下结果：设F 是区域Ｄ内的亚纯函数族，ｑ是一个非负整数．如果对任意的ｆ∈Ｆ存在自然数ｋ＝ｋ（ｆ）＞１使得ｆ的 ｋ次迭代ｆ～ｋ在 Ｄ内最多有 ｑ个不动点，则Ｆ是 Ｄ内阶至多为ｍａｘ｛４，ｑ＋３｝的拟正规族．     

平均单叶函数的相邻系数

设ｆ（ｚ）＝ｚ＋Σａｎｚ＾ｎ为单位园｜ｚ｜＜１内解析且平均单叶，记其族为Ｍ又设｛ｆ（ｚ）／ｚ｝＾λ＝１＋Σ＾∞ｎ＝１Ｄｎ（λ），λ＞０，本文说明了：定理一 若ｆ∈Ｍ，λ＞０，则：Σ＾∞ｋ＝１｛｜｜Ｄｋ（λ）｜－｜Ｄｋ－１（λ）｜｜／ｄｋ（λ）｝＾２≤Ａｎ，ｎ＝２，３，…其中Ａ为绝对常数。ｄｋ（ｈ）＝ｈ（ｈ＋１）…（ｈ＋ｋ－１）／ｋ！当λ＝１／２，ｆ∈ｓ时为Ｉ．Ｖ．Ｍｉｌｍ所证明。定理二 若ｆ∈Ｍ并     

Z_2不变的C~∞函数芽的典型形式

Ｗｈｉｔｎｅｙ关于偶函数的结果给出了一个变元且在Ｚ_２群｛±１｝下不变的Ｃ~∞函数芽的典型形式：如果ｆ∈Ｅ_１且ｆ（－ｘ）＝ｆ（ｘ）,则存在ｈ∈Ｅ_１使得ｆ（ｘ）＝ｈ（ｘ~２）．该文将借助Ｍａｌｇｒａｎｇｅ预备定理和有关的计算,得出Ｒ~ｎ在原点且在群｛±Ｉ_ｎ｝下不变的Ｃ∞函数芽的典型形式．     

一类指数型整函数插值算子的逼近性质

设（Ｕσｆ）（ｘ）＝∑ｋ∈Ｚｆ（Ｘｋ）Ａσ（Ｘ－Ｘｋ）,Ｘｋ＝２ｋπσ,ｋ∈Ｚ,σ＞０,ｆ是Ｒ上的有界函数,而Ａσ（ｙ）＝２σ∫σ０ｓｉｎｍ（σ－Ｘ）ｈｓｉｎｍ（σ－Ｘ）ｈ＋ｓｉｎｍｘｈｃｏｓｘｙｄｘ,ｍ为奇自然数,０＜ｈ＜πσ,本文研究了此插值算子的收敛与饱和问题．     

星形函数族的一个子族的极值点与支撑点

设Ｆ（｛ｎ｝）＝｛ｆ（ｚ）：ｆ（ｚ）在｜ｚ｜＜１内解析，ｆ（ｚ）＝ｚ－∞ｎ＝１ａｎｚｎ，ａｎ≥０，＋∞ｎ＝２ｎａｎ≤１｝，则Ｆ（｛ｎ｝）是星形函数族的一个子族．许多学者研究了这个函数族．设Ｍ＝｛ｆ（ｚ）：ｆ（ｚ）在｜ｚ｜＜１内解析，ｆ（ｚ）＝ｚ－∞ｎ＝１ａｎｚｎ，ａｎ≥ａｎ＋１≥０，＋∞ｎ＝２ｎａｎ≤１｝．在本文中我们找出了函数族Ｍ的极值点与支撑点．     

Littlewood—Paley的gλ函数与面积函数在Lipα（R^n）上的有界性

本文证明，对于Ｌｉｐｓｃｈｉｔｚ空间Ｌｉｐａ（Ｒ＾ｎ）的函数ｆ，若相应Ｌｉｔｔｌｅｗｏｏｄ－Ｐａｌｅｙ的ｇλ函数ｇλ（ｆ）（ｘ）（或面积函数Ｓ（ｆ）（ｘ））在Ｒ＾ｎ中一点有限，则它必处处有限，并且作为Ｌｉｐａ（Ｒ＾ｎ）上的算子，ｇλ和Ｓ在一定意义下有界，这对一切ａ，０＜ａ＜１，和适当的λ成立。     

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.     

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.     

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.     

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     

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     

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).     

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.     

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.