Higher spin gauge theories in any dimension

Some general properties of higher spin gauge theories are summarized, with the emphasize on the nonlinear theories in any dimension. To cite this article: M.A. Vasiliev, C. R. Physique 5 (2004).

Résumé

Des propriétés générales des théories de jauge de grands spins sont présentées, en insistant particulièrement sur les théories non-linéaires en dimensions diverses. Pour citer cet article : M.A. Vasiliev, C. R. Physique 5 (2004).     

"信号与系统"网络课件的设计与实现

随着网络技术在教育中应用的广泛与深入,发展网络教学已成为趋势。《信号与系统》网络课件灵活地穿插使用自主学习型．自测辅导型．互动式授课型课件,借助计算机完成异步自主．同步互动等以发展个性化的学习。本文介绍了《信号与系统》网络课件的设计思路、总体结构,讨论了系统导航、检索、问题讨论。专题辅导以及测试等主要功能,并对系统的开发环境及实现技术如多媒体处理技术、数据库开发技术、CCS、PHP技术等作了简要说明。     

英国兰开夏大学的物理实验教学

简要介绍了英国兰开夏大学的物理实验教学和成绩评定方法,分析了其特色,可以看出该大学较重视学生创造性综合能力的培养.     

利用教育技术开发远程职业教育的思考

科技的进步,职业教育的改革已迫在眉睫,利用教育技术开发远程职业教育已势在必行,从远程职业教育教学系统开发和远程职业教育的应用平台出发,阐述了职业教育改革中的一种思路。     

计算机数补码表示法辨析

计算机数补码表示法是计算机相关课程教学的重要知识点,现有教材在计算机数补码表示法描述中是雷同的.但是,笔者认为这存在一定问题,主要是补码的求解方法和补码的表示范围没有阐述清楚.参考若干资料,总结出计算机数补码几种求解方法,通过具体分析,有助于学生理解计算机数补码的表示法的本质,为计算机后序相关课程的学习打下良好的基础.     

中国电信远程教育工程设计浅探

介绍多媒体技术在远程教育中的应用，中国电信远程教育教育网的组成方式。提出了对网络的环境要求、系统设计、平面设计、设备要求等问题。     

Higher rank numerical ranges and low rank perturbations of quantum channels

For a positive integer k, the rank-k numerical range Λk(A) of an operator A acting on a Hilbert space H of dimension at least k is the set of scalars λ such that PAP=λP for some rank k orthogonal projection P. In this paper, a close connection between low rank perturbation of an operator A and Λk(A) is established. In particular, for 1?r<k it is shown that Λk(A)⊆Λk−r(A+F) for any operator F with rank(F)?r. In quantum computing, this result implies that a quantum channel with a k-dimensional error correcting code under a perturbation of rank at most r will still have a (k−r)-dimensional error correcting code. Moreover, it is shown that if A is normal or if the dimension of A is finite, then Λk(A) can be obtained as the intersection of Λk−r(A+F) for a collection of rank r operators F. Examples are given to show that the result fails if A is a general operator. The closure and the interior of the convex set Λk(A) are completely determined. Analogous results are obtained for Λ_∞(A) defined as the set of scalars λ such that PAP=λP for an infinite rank orthogonal projection P. It is shown that Λ_∞(A) is the intersection of all Λk(A) for k=1,2,…. If A−μI is not compact for all μ∈C, then the closure and the interior of Λ_∞(A) coincide with those of the essential numerical range of A. The situation for the special case when A−μI is compact for some μ∈C is also studied.     

Nanoscale Science and Technology at Los Alamos National Laboratory

Research in the emerging field of nanoscale science and technology has grown steadily at Los Alamos National Laboratory since 1990. This article summarizes some of this work, examining research highlights within the seven key categories of nanoscience in which Los Alamos has ongoing projects, capabilities, and facilities: (1) Materials and chemistry, (2) Theory and modeling, (3) Bioscience, (4) Investigative tools and facilities, (5) Sensors and devices, (6) Synthesis and fabrication, and (7) Education and outreach. Future research horizons are indicated throughout while institutional strategies for advancing nanoscale science are summarized at the end.     

面向创新教育的经济数学建模教学研究

本文较深刻地分析了经济数学建模教学在高校人才培养中的作用；明确了经济数学建模教学是经济数学课程教学改革的突破口、切入点；同时，对如何开展经济数学建模教学提出了建议．