基于传输线技术的零平均折射率(zero-n-)带隙的实验研究

基于传输线方法,制备了含左手材料和右手材料的一维光子晶体.通过仿真软件ADS的模拟和矢量网络分析仪的测量,研究了光子晶体的传输特性.实验结果表明:由左手材料和右手材料构成的一维光子晶体具有零平均折射率(zero-n-)带隙,这一带隙处于左手通带和右手通带之间.zero-n-带隙分别由零平均介电常量和零平均磁导率决定,进而对晶格尺度不敏感.     

Curvature Estimates for Strongly Stable Domains on Surfaces with Constant Mean Curvature in Space Forms

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圆柱坐标系中弹性力学的哈密顿正刚方程及其哈密顿单元…

给出圆柱坐标系中弹性力学的哈密顿形式体系，用有限元法得到了哈密顿单元的半解析解，可用于求解复合材料叠层圆柱曲板问题。     

A NEW FINITE DIFFERENCE METHOD FOR COMPUTING SOUND FIELD IN LINED DUCTS

This paper presents a new finite difference method to calculate problems of sound propagation in linedducts.The MacCormack time-split explicit scheme has been used to solve the basic equations for determiningthe acoustic pressure and velocity.The problems of sound propagation in 3-D rectangular ducts have beensolved successfully by use of this scheme with the making of an approach to the acoustic boundary conditions.The finite difference schemes for full grid points and the stability condition of the method are also given in thepaper.This new method needs less storage and is more stable.Moreover,it is easier to program and debug,and,especially,is suitable for computing 3-D sound field.     

链间超交换相互作用下spin-Peierls梯子模型的基态行为

采用Lanczos数值计算方法研究了具有链间海森堡相互作用和链间Dzyaloshinskii-Moriya(DM)相互作用spin-Peierls梯子模型的基态行为.分析了链间海森堡相互作用和链间DM相互作用对系统二聚化的影响.结果发现，这两种链间作用都不利于系统的二聚化，会造成系统基态二聚化的减小，这说明随着系统维度的增大，系统的各向相互作用会限制系统的二聚化，甚至会破坏系统的二聚化相. 关键词： spin-Peierls模型 海森堡相互作用 DM相互作用 二聚化     

Hilbert空间中广义变分不等式和Wiener-Hopf方程(英文)

In this paper,we consider the solvability of generalized variational inequalities involving multi-valued relaxed monotone operators in the framework of Hilbert spaces.Our results mainly improve the corresponding results announced by Verma[R U Verma,Generalized variational inequalities involving multivalued relaxed monotone operators,Appl Math Lett,1997,10：107-109]and many others.     

Super scattering phenomenon in active spherical nanoparticles

Localized surface electromagnetic resonances in spherical nanoparticles with gain are investigated by using the Mie theory. Due to the coupling between the gain and resonances, super scattering phenomenon is raised and the total scattering efficiency is increased by over six orders of magnitude. The dual frequency resonance induced by the electric dipole term of the particle is observed. The distributions of electromagnetic field and the Poynting vector around nanoparticles are provided for better understanding different multipole resonances. Finally, the scattering properties of active spherical nanoparticles are investigated when the sizes of nanoparticles are beyond the quasi-static limit. It is noticed that more highorder multipole resonances can be excited with the increase of the radius. Besides, all resonances dominated by multipole magnetic terms can only appear in dielectric materials.     

频率变化的压缩态光场与原子的相互作用

研究了频率随时间变化的压缩态光场与二能级原子的相互作用，主要讨论了光场频率随时间作正弦调制和脉冲调制两种典型情况下原子布居数反转随时间的演化特性.当光场频率随时间作正弦调制时，不仅光场频率调制，而且压缩态的压缩系数和压缩相位均对原子布居数反转的崩塌-回复过程有影响.当光场频率随时间作脉冲调制时，脉冲调制的突变使各拉比振荡之间的相干性发生改变，并在原子布居数反转随时间演化过程中诱导出新的崩塌-回复过程，尤其在脉冲出现的区间内，原子布居数反转表现出持续的小幅快速振荡，这与压缩态的压缩系数无关. 关键词： Jaynes-Cummings模型 压缩态 原子布居数反转