四元数自共轭矩阵和的特征值的不等式

本文将Wietandt关于复自共轭矩阵的特征值和的变分特征以及和的特征值的不等式推广到四元数体上，由此还给出了复自共轭矩阵的主对角元与特征值的优化关系的Schur定理、复矩阵的主对角元的模与奇异值的优化关系的Fan定理在四元数体上的推广.     

四元数矩阵凸函数及其不等式

本文推广复矩阵凸函数及其性质到四元数体上矩阵，并且得到关于四元数矩阵凸函数的一些不等式．     

四元数矩阵方程∑A~iXB_i=E

设ＨＦ为域Ｆ上广义四元数可除代数，其中ｃｈａｒＦ≠２．应用伴随矩阵与矩阵表示方法，本文得到ＨＦ上矩阵方程∑ｋｉ＝０ＡｉＸＢｉ＝Ｅ有解或有唯一解的几个充要条件，并且给出了几个解的公式．     

关于四元数矩阵之迹的几个定理

R.Rellman对两个正定实矩阵建立了与Cauchy—Schwarz不等式相类似的结果,引起人们的关注,对Rellman不等式进行深入的研究.但对四元数矩阵之迹的研究至今未见.如所熟知,四元数体的非交换性,已经给四元数代数理论的研究带来了巨大的困难,它也必然影响到四元数矩阵迹的性质.事实上,关于实(或复)矩阵的几个简单性质:     

两类四元数矩阵偶的GH合同标准形

该文给出两类四元数矩阵偶〈A，B１〉与〈A，B２〉的ＧＨ 合同标准形，其中A为半正定自共轭阵，B１ 为斜自共轭阵，B２ 为自共轭阵．由此分别得到（广义）半正定与正定四元数矩阵的ＧＨ合同标准形，以及矩阵同时对角化问题的若干个结果．     

四元数体上的矩阵及其优化理论

本文引入了四元数体 Q 上的广义双随机矩阵,给出了它与优化的关系.由此,我们得出了四元数矩阵奇异值的一些重要不等式,特别是得出了四元数矩阵的和与积的奇异值不等式.我们还讨论了四元数自共轭矩阵的和与积的特征值等.推广了复数域上矩阵的许多著名结果.     

分裂四元数矩阵的奇异值分解及应用

利用i-共轭重新定义了分裂四元数矩阵的共轭转置,在此基础上借助复表示和友向量研究了分裂四元数矩阵的奇异值分解,并利用所得结果解决了分裂四元数矩阵的极分解和分裂四元数矩阵方程AXB-CYD=E.     

关于四元数自共轭矩阵乘积迹和特征值的几个定理

给出四元数自共轭矩阵乘积迹的几个定理及特征值之界的几个新估计，在四元数体上改进和推广了文［１－１２］的相应结果     

四元数矩阵的惯性定理与稳定性

本文给出了四元数矩阵惯性的定义,讨论了四元数体上Lyapunov矩阵方程的唯一解,推广了一般惯性定理、Lyapunov稳定性定理、Carlson-Schneider定理、Stein稳定性定理等一些重要的结果到四元数矩阵,同时得出了四元数体上稳定矩阵的一些判别条件.     

四元数向量和矩阵的秩

在四元数和四元数向量、矩阵空间上引入三种不同的实表示法则，将四元数列向量的左右线性相关性问题转换成实数域上向量的线性相关问题，由此获得用实矩阵的秩代替四元数矩阵列左秩和列右秩计算方法，同时得出四元数矩阵可逆的一些充要条件和一些新的四元数行列式定义．     

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).     

Instructions for Authors

<正>Submission Authors must use LaTeX for typewriting,and visit our website www.actamath.com to submit your paper.Our address is Editorial Office of Acta Mathematica Sinica,Academy of Mathematics and Systems Science,Chinese Academy of Sciences,Beijing 100190,P.R.China.     

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

正August 10-14,2015Beijin,China The 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