实四元数体上的Patel-Toda不等式及改进

本文证明了一些自共轭实四元数矩阵的不等式,推广、改进了Hermitian矩阵的Patel-Toda不等式。     

冯子振生平三考

元代重要作家冯子振,其生平资料十分零散,故其生平行迹鲜为人知,并时见误说.本文对冯子振的字号、籍贯和行迹进行考证,纠谬补阙,或能有益于元代文学的研究.     

都市化与农民的终结 —— 广州南景村经济变迁研究

在田野调查和文献资料的基础上,文章追踪研究了南景这个因杨庆先生的著作而在海外中国研究中颇具影响的学术名村,描述了它五十年后经济生活的基本形貌.从城郊聚落到都市村庄的南景,失去了昔日固守的田园,土地和房屋的出租成了村社、宗族和家庭经济的生存之本.其变迁轨迹不仅是珠江三角洲地区乡村都市化的代表,也承载了传统农民终结的历程.     

“创优似竞赛”溯源

"创优似竞赛"是许渊冲先生提出的观点,译界对此褒贬不一.本文旨在对该观点进行追根溯源,进而对其内涵以及翻译中的译文与原文、译者与原作者、翻译与创作的关系问题作出探讨."创优似竞赛"的翻译观,既是许先生个人经验所出,又是中外翻译理论的结晶,蕴涵着深刻的道理,值得译界重视.     

Trace of the Variance-Covariance Matrix in Natural Exponential Families

In this article, we introduce the notion of trace variance function which is the trace of the variance-covariance matrix. Under some conditions, we prove that this trace variance function characterizes the Natural Exponential Family (NEF). We apply this characterization in order to estimate the distribution which belongs to some NEFs. Therefore, we introduce the estimator of this trace variance function. We give the asymptotic properties of this estimator. Finally, we illustrate our results using a simulation study.     

微量元素与人体健康关系研究的回顾与展望

目前,已有大量的基础医学实验研究和临床观察资料表明,人体患有各种疾病时体内的某些微量元素含量存在着显著的异常,这一现象已引起了国内外学者的广泛关注。本文根据近年国外的文献报道 概述了微量元素的生理作用及与人体健康关系的研究进展,并报道了应用各种仪器测定微量元素的方法。     

论贾平凹散文《月迹》独特的抒情视角

贾平凹的散文《月迹》之所以在文学史上数不清的写月名篇中显得那样独特,是因为它全新的抒情视角.具体表现为：新奇、纯真的儿童视角,无私、柔软的母爱视角和超脱、睿智的全知视角.《月迹》中独特的抒情视角使得该文在追寻月迹的行踪中始终弥漫着淡雅恬静的、融诗情画意哲理为一体的古诗意境.     

Trace pursuit variable selection for multi-population data

Variable selection is a very important tool when dealing with high dimensional data. However, most popular variable selection methods are model based, which might provide misleading results when the model assumption is not satisfied. Sufficient dimension reduction provides a general framework for model-free variable selection methods. In this paper, we propose a model-free variable selection method via sufficient dimension reduction, which incorporates the grouping information into the selection procedure for multi-population data. Theoretical properties of our selection methods are also discussed. Simulation studies suggest that our method greatly outperforms those ignoring the grouping information.     

Characteristic polynomials of the information matrices of balanced fractional 3m factorial designs of resolution v

An explicit expression for the characteristic polynomial of the information matrix M_T of a balanced fractional 3^m factorial (3^m-BFF) design T of resolution V is obtained by utilizing the algebraic structure of the underlying multidimentional relationship. Also by using of the multidimensional relationship algebra, the trace and the determinant of the covariance matrix of the estimates of effects are derived.