A planar left-handed metamaterial based on electric resonators

A planar left-handed metamaterial(LHM) composed of electric resonator pairs is presented in this paper.Theoretical analysis,an equivalent circuit model and simulated results of a wedge sample show that this material exhibits a negative refraction pass-band around 9.6GHz under normal-incidence and is insensitive to a change in incidence angle.Furthermore,as the angle between the arm of the electric resonators and the strip connecting the arms increases,the frequency range of the pass-band shifts downwards.Consequently,this LHM guarantees a relatively stable torlerence of errors when it is practically fabricated.Moreover,it is a candidate for designing multi-band LHM through combining the resonator pairs with different angles.     

广义极分解

本文使用下列符号:C~(m×n)表示m×n复矩阵的集合,C_r~(m×n)表示秩为r的m×n复矩阵的集合,A~H和A~+分别表示矩阵A的共轭转置和Moore-Penrose广义逆,|| ||_2表示向量的Euclid范数和矩阵的谱范数,|| ||_F表示Frobenius范数,R(A)表示A的列     

基于单面金属结构的二维宽带左手材料

利用将磁谐振器与共面短金属导线相结合的思想,设计了一种基于单面金属结构的二维左手材料. 理论分析与仿真结果均表明该结构在某一频段同时具有负等效磁导率和负等效介电常数,并且相对左手带宽达到36%. 此外,该结构具有良好的容错能力,短金属导线宽度的变化对整体结构的谐振频率及通带宽度影响很小,这不仅有利于实际加工而且对于设计红外及太赫兹频率范围下的左手材料具有参考价值. 关键词： 左手材料 磁谐振器 宽频带 容错性     

连通的开口和闭口谐振环构成的磁超材料设计

在已有的磁超材料和左手材料结构中,负等效磁导率主要通过开口谐振环、平行短金属线对或者它们的变形结构来实现. 这些结构要求入射电磁波的电场方向平行于基板. 针对这一特点,利用将开口和闭口的谐振环相连通的思想,设计出了入射电磁波的电场方向垂直于基板型的三维磁超材料,并予以实验验证. 该对称结构中金属线线宽的变化对磁谐振频率影响很小,有利于实际的加工和应用. 同时,该结构对于设计三维以及具有极化无关、均匀各向同性等特点的磁超材料和左手材料具有参考价值. 关键词： 磁超材料 谐振环 电场方向     

Precision Higgs physics at the CEPC

The discovery of the Higgs boson with its mass around 125 GeV by the ATLAS and CMS Collaborations marked the beginning of a new era in high energy physics.The Higgs boson will be the subject of extensive studies of the ongoing LHC program.At the same time,lepton collider based Higgs factories have been proposed as a possible next step beyond the LHC,with its main goal to precisely measure the properties of the Higgs boson and probe potential new physics associated with the Higgs boson.The Circular Electron Positron Collider(CEPC)is one of such proposed Higgs factories.The CEPC is an e~+e~- circular collider proposed by and to be hosted in China.Located in a tunnel of approximately 100 km in circumference,it will operate at a center-of-mass energy of 240 GeV as the Higgs factory.In this paper,we present the first estimates on the precision of the Higgs boson property measurements achievable at the CEPC and discuss implications of these measurements.     

输出反馈极点配置问题的一个算法

在线性多变量控制理论中,存在一个代数特征值反问题——输出反馈极点配置问题。问题叙述如下: 问题PAO.给定A∈R~(n×n),B∈R_m~(n×m),C∈R_p~(p×n)和?={λ_1,λ_2,…,λ_n},?在复共轭下封闭.求K∈R~(m×p),使得A+BKC具有事先给定的特征值λ_1,λ_2,…,λ_n。 [2]和[5]等证明了     

关于鲁棒的输出反馈极点配置问题的算法

本文使用下列符号:R~(n×m):所有n×m实矩阵的全体;R_r~(n×m):所有秩为r的n×m实矩阵的全体;||·||_2:向量的欧氏范数和矩阵的谱范数;||·||_F:矩阵的Frobenius范数;