磁各向异性媒质中振荡电四极子辐射功率的角分布

振荡电四极子在磁各向异性媒质中辐射时，功率的角分布较为复杂.通过缜密的数学推导得到了磁各向异性媒质中电四极子沿极轴振荡时，其辐射功率角分布的表达式.当媒质为各向同性时，计算结果与预期的结果相吻合，从而验证了推导结果的正确性.     

几类常见媒质电磁散射问题的统一描述

工程实践中,经常遇到线性或非线性媒质、各向同性或各向异性媒质、色散或非色散媒质、无耗或有耗媒质、无磁或有磁媒质以及导体或介质等几类不同目标的电磁散射问题,却尚未形成统一的理论描述。尝试利用体等效原理,由麦克斯韦方程组导出了这几类问题的一般形式,通过设定一些特定参数,即可得到前述的具体问题,以期为该领域的应用研究奠定理论基础。几个散射算例初步证实了本文理论框架的普适性。     

基于Z变换法对双负媒质传播散射的FDTD分析

文章研究了分析双负媒质电磁散射规律的一种方法,双负媒质是介电系数和磁导系数均为负值的介质材料.引入色散Drude模型后,本构关系在时域成为卷积关系,因此将Z变换理论应用到双负媒质中的时域有限差分(FDTD)中,使FDTD可计算双负媒质中电磁波的散射和传播.该文对麦克斯韦方程做了修改,并给出双负媒质中介电系数和磁导系数均为频率函数的FDTD表达式.最后,数值仿真了电磁波与双负媒质平板的相互作用;计算了覆盖了双负媒质金属柱的电磁散射,探讨了双负媒质在隐身技术方面的应用前景.     

旋波媒质中无散并矢格林函数和电波辐射

应用文献[1]的方法给出了旋波媒质中电磁场矢量的无散并矢格林函数的普遍形式，然后由此构造出旋波媒质中辐射场的无散磁矢势，并且以电偶极辐射为例，进一步研究了旋波媒质中电磁波的辐射问题。     

位于导电媒质中的平行板电容器

本文给出位于寻电媒质中充电平行板电容器内的电磁场分布情况、结论是:虽然板间电场随时间按指数规津衰减、但磁汤为零,电容器放电过程中,电场能的减少全部转化为导电媒质的焦耳热。     

一维非均匀各向异性媒质传播特性的SMM分析

给出了一种用于分析一维非均匀各向异性媒质传播特性的新数值技术．该技术将原来的各向异性媒质等效成具有圆极化本征模的各向同性媒质,从而将一维非均匀各向同性媒质中的散射矩阵技术推广到各向异性媒质问题的分析当中．计算机模拟结果显示,这种新的分析技术所得的分析结果与近似方法所得的结果完全一致,     

应用改进的ADI-FDTD方法对微带结构进行数值仿真

为了改进微波电路设计的数值仿真方法，在各向异性媒质条件下，将交替方向隐式算法用于时域有限差分方法，直接求解时域麦克斯韦方程，把二阶色散Lorentz媒质吸收边界条件推广到单轴各向异性情形、验证了色散媒质吸收边界的吸收效果比Mur和完全匹配层吸收边界更有效．通过对低通滤波器、贴片天线、线谐振器和螺旋电感等典型微带结构的数值仿真，验证了新提出方法的有效性．     

各向异性媒质中三维涡流场的等效源法

提出计算各向异性媒质中三维涡流场的等效源法。该法是将各向异性媒质中涡流场问题转化为附加等效源的各向同性媒质中涡流场问题。还提出实现等效源法的迭代算法，该算法是用通常的求解各向同性媒质中涡流场的方法（如有限元法、边界元法、模拟源法等）迭代计算附加等效源的各向同性媒质中涡流场。文中还给出了等效源迭代算法的收敛条件。由于每次迭代都可以利用计算各向同性场的中间结果，所以迭代计算所需的机时不多。文中给出了计算实例。     

各向异性磁介质中三维同轴电缆的自感

在高频信号的传输过程中，传输线的分布电感和分布电容不容忽视，以磁各向异性的毕奥-萨伐尔定律，以及由此定律而求出的在各向异性磁介质中载流直导线磁场，作为论述该研究的基础，从而由公式εL|dI/dt|，求出在各向异性磁介质中有一定横截面的同轴电缆的分布电感。     

关于旋波媒质中谱域电并矢格林函数

将旋波媒质中电并矢格林函数方程分解为无旋和无散部分，提出了一种在旋波媒质中推导谱域电并矢格林函数无散分解式的新方法，而旋波媒质中谱域电并矢格林函数无旋分解式则和通常非旋波媒质中无旋分解式完全一样。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with     

Journal of Donghua University ( English Edition) Contents of Volume 31

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