关于一类矩阵的平方根公式

从性质C1/2C1/2=C出发,在不求过渡矩阵的前提下,利用Sherman-Morrison公式得到了非负定矩阵A=aaT+bbT的平方根表示,进而解决了一类特殊矩阵方程X2=A的求解问题.其中a,b是Rn中的n维非零列向量.     

Complete genome sequence of Salmonella enterica serovar Typhimurium LT2.

Salmonella enterica subspecies I, serovar Typhimurium (S. typhimurium), is a leading cause of human gastroenteritis, and is used as a mouse model of human typhoid fever. The incidence of non-typhoid salmonellosis is increasing worldwide, causing millions of infections and many deaths in the human population each year. Here we sequenced the 4,857-kilobase (kb) chromosome and 94-kb virulence plasmid of S. typhimurium strain LT2. The distribution of close homologues of S. typhimurium LT2 genes in eight related enterobacteria was determined using previously completed genomes of three related bacteria, sample sequencing of both S. enterica serovar Paratyphi A (S. paratyphi A) and Klebsiella pneumoniae, and hybridization of three unsequenced genomes to a microarray of S. typhimurium LT2 genes. Lateral transfer of genes is frequent, with 11% of the S. typhimurium LT2 genes missing from S. enterica serovar Typhi (S. typhi), and 29% missing from Escherichia coli K12. The 352 gene homologues of S. typhimurium LT2 confined to subspecies I of S. enterica-containing most mammalian and bird pathogens-are useful for studies of epidemiology, host specificity and pathogenesis. Most of these homologues were previously unknown, and 50 may be exported to the periplasm or outer membrane, rendering them accessible as therapeutic or vaccine targets.     

京沪高速铁路北京至沧州段桥梁工程施工与创新

针对京沪高速铁路北京至沧州段桥梁工程特点，重点介绍了代表性特殊结构桥梁的施工方法、区域性地面沉降地区桥梁工后沉降的控制措施，以及保证350 km/h无砟轨道高平顺性的施工技术创新措施。     

基于在场价值提升的高校课堂吸引力重构研究

大学课堂是高校教育的前沿阵地,因此大学课堂缺乏吸引力势必会影响课堂实践、师生和谐和教育的良性循环。针对部分教师、学生的不作为及高等教育机制和体制的弊端,应从提升师生的在场价值出发,重构大学课堂吸引力。一是从根本上扭转教学为辅的高等教育体制;二是打破教师主导课堂的传统模式,创新教师—学生的互动模式,构筑"多联、互动、发展"的课堂和"教师—学生—高校—社会"四位一体的育人环境,培养良好的育人机制。     

方以智《东西均·反因》思想发微

明末清初思想家方以智阐言天地间之至理乃相因者皆极相反,现象世界的万事万物皆相待而生,因缘而起,由此以显现象事物之空性,泯除视现象之物为实有的执持.同时,为了破除对道体的执定,进而阐明了反因即正因、用中一贯、不落两边的精微义理,方以智融贯儒释道三教归一的思想大旨由此得以确立.     

Product Family Hierarchical Associated Design and Its Hierarchical Optimization

After reviewing the literature and methodology-related issues within the field of product family design, a deficiency in the current design and development of product family is pointed out. The concept of hierarchical associated design is proposed in this article, according to the deficiency~ and the methods and models for realizing the notion above are described. A two-dimensional analytical model is constructed based on the composing levels and developing processes of product family. The optimization models to hierarchical associated design problems are grouped into two categories： overall-local and key-subordinate. The algorithms of the models are discussed in this paper     

双向交互式有线电视系统的几个关键问题

介绍和分析了建立双向交互式有线电视系统所要解决的关键问题 ,并提出了具体的解决方法 ,重点是回传噪声的抑制及调制方式的选择。本文为CATV网的改造提供了依据     

信息空间的数学模型

本提出了信息空间的概念，定义了它的结构，在该结构上讨论了信息运算，分类，查询及其应用。     

短码长LT码的快速信度传播解码法

无码率码在广播传输中使用时,信道质量突然下降会导致较大突发性错误并使解码器解码效率降低.为改善此情况,文中提出在短码长LT码解码中采用快速信度传播(FBP)解码法.该方法基于交换启发式原理,对接收到的信号立即进行处理,并快速转化为三角矩阵,不仅提高了解码的成功率而且提高了解码速率.由分析和仿真实验可知:FBP解码法的解码成功率较传统的高斯消元解码法和信度传播解码法有极大的提高;当信源信号长度为128b时,FBP解码法的解码成功率较传统的信度传播解码法有大幅提高;FBP解码法的解码计算复杂度与解码耗时都优于高斯消元解码法.     

H∞ tracking design for a class of decentralized nonlinear systems via fuzzy adaptive observer

imulation results substantiate the effectiveness of the proposed scheme.