关于Hamltion线图的一个结果

设Ｇ是一个简单图，(?)ｅ∈Ｅ（Ｇ），定义ｅ＝ｕｖ在Ｇ中的度ｄ（ｅ）＝ｄ（ｕ）＋ｄ（ｖ），其中ｄ（ｕ）和ｄ（ｖ）分别为ｕ和ｖ的度数。若连通图Ｇ的每个桥都有一个端点度数为１，则称Ｇ是几乎无桥的图。本文的主要结果是：设Ｇ是ｐ≥２阶几乎无桥的简单连通图，且Ｇ≠Ｋ_{１，ｐ－１}若对任何无公共顶点的两边ｅ₀及ｅ₁，ｄ（ｅ₀）＋ｄ（ｅ₁）≥ｐ＋４，则Ｇ有一个Ｄ－闭迹，从而Ｇ的线图Ｌ（Ｇ）是哈密顿的。     

关于图Kn-H2n+i(i=1,2)的升分解

Ｙｏｕｓｅｆ．Ａｌａｖｉ等人在文献［１］中定义了一种新分解（Ａｓｃｅｎｄｉｎｇ Ｓｕｂｇｒａｐｈ Ｄｅｃｏｍｐｏｓｉ－ ｔｉｏｎ），即“升分解”，并且猜想：任意有正整数条边的图都可以升分解．本文证明了下面两个结 论： １．Ｋ_n-H_2n+1可以升分解，其中Ｈ_2n+1为含有２ｎ＋１条边的Ｋ_n的子图； ２．Ｋ_n-H_2n+2可以升分解，其中Ｈ_2n+2为含有２ｎ＋     

图中含有D—闭迹的一个充分条件

设Ｇ是一个简单图，Ｌ＝ｕ１ｕ２…ｕｔ是Ｇ中的一个路，定义Ｌ的度ｄ（Ｌ）＝∑ｔｉ＝１ｄ（ｕｉ），其中ｄ（ｕｉ）为ｕｉ在Ｇ中的度数．本文证明了：若Ｇ是ｎ≥３阶几乎无桥的简单连通图，ＧＫ１，ｎ－１，且对Ｇ中任何两个无公共点的二长路Ｌ１，Ｌ２，有ｄ（Ｌ１）＋ｄ（Ｌ２）≥２ｎ－１，则Ｇ有一个Ｄ－闭迹，从而Ｇ的线图Ｌ（Ｇ）是Ｈａｍｉｌｔｏｎ图．     

2-阶邻域连通无爪图的Hamilton性

设Ｇ是无爪图．对ｘ∈Ｖ（Ｇ），若Ｇ［Ｎ（ｘ）］不连通，则存在ｙｉ∈Ｖ（Ｇ）－｛ｘ｝（ｉ－１，２），使｜Ｎ（ｙｉ）∩Ｋｉ（ｘ）｜≥２，且｜Ｎ（ｙｉ）∩Ｎ（Ｋｉ＋１（ｘ））｛ｘ｝｜≥２（ｉ模２），那么称无爪图Ｇ是强２－阶邻域连通的，其中Ｋ１（ｘ），Ｋ２（ｘ）分别表示Ｇ［Ｎ（ｘ）］的两个分支．本文证明了：连通且强２－阶邻域连通的无爪图是Ｈａｍｉｌｔｏｎ图．     

一类泛圈图

本文证明了如果 Ｇ 是 ２ 连通无爪图, Ｇ 不是圈,ｎ＝ ｜ Ｖ（ Ｇ）｜≥９, Ｇ 的每个导出子图 Ａ都满足φ（ａ１,ａ２ ）,且 Ｇ 中不含同构于 Ｚ＋２ 的导出子图,则 Ｇ是泛圈图     

三角形蛇图的调和性

称有ｅ条边的简单图Ｇ为调和图，若存在单射ｈ：Ｖ（Ｇ）→Ｚ_ｅ，Ｚ_ｅ是模ｅ的整数群，其导出映射ｈ^*：Ｅ（Ｇ）→Ｚ_ｅ；ｈ^*（ｖｖ）≡ｈ（ｎ）＋ｈ（ｖ）（ｍｏｄｅ），ｎ，ｖ∈Ｖ（Ｇ）是一个双射，称ｈ为Ｇ的一个调和标号三角形蛇图是一个其所有块都是三角形且其块－割点图为一条路的连通图。本文证明了具有ｔ个块的三角形蛇图足调和的，当且仅当ｔ≠２（ｍｏｄ４）。     

关于二部图K(m,n)-2的色唯一性

设Ｋ（ｍ，ｎ）－２表示从完全二部图Ｋ（ｍ，ｎ）中删去任意２条边所得之图．本文证明了：１．若ｎ≥ｍ≥３，且ｎ＋ｍ＞(（ｎ－ｍ）^２＋８)^1/2＋１/２（ｎ－ｍ）^２＋４，则Ｋ（ｍ，ｎ）－２是色唯一图；２．当ｍ≥３时，Ｋ（ｍ，ｍ）－２，Ｋ（ｍ，ｍ＋１）－２和Ｋ（ｍ，ｍ＋２）－２均是色唯一图．     

关于积流形的P－形式上的Laplace算子谱

本文讨论了积流形的Ｐ－形式上Ｌａｐｌａｃｅ算子谱的唯一性问题，在紧Ｋａｃｈｌｅｒ流形乘积和紧Ｓａｓａｋｉ流形乘积的两类积流形中，ＣＰ^ｎ×ＣＰ^ｎ和Ｓ^２ｎ＋１（１）×Ｓ^２ｎ＋１（１）是Ｐ－形式上Ｌａｐｌａｃｃｅ算子谱特征。     

关于余直径的一个充分条件

本文给出了一个关于长圈和长路的新的充分条件．主要结果是：设在３－连通图Ｇ中，任一对距离为２的顶点ｕ，ｖ，都满足ｍａｘ｛ｄ（ｕ），ｄ（ｖ）｝≥ｍ/２，那么ｄ^＊（Ｇ）≥ｍｉｎ｛ｎ－１，ｍ－２｝．     

关于Witt向量之序列

对出现于公式Π_ｎ≥１１/(１＋ｄ_ｎｔ^ｎ／ｎ！)＝（１－ｔ）ｅ^ｔ中的整数ｄ_ｎ给出了精确估计     

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.