基于体硅工艺的微夹持器设计

为克服静电致动微夹持器夹持力小、运动范围小的弱点,设计并研制了一种基于体硅工艺的微夹持器。建立了S形柔性夹持臂力学模型,借助有限元方法进行结构优化、夹持臂模态分析以及静电驱动器对微操作对象影响的估算。研制成一种大深宽比梳状静电驱动微夹持器,释放了等效长度达5.470mm的柔性夹持臂。该夹持器采用了导电型并接地连接的柔性微夹持臂,可防止静电对操作的影响,柔性结构有效解决了静电力小与硅材料的弹性模量高之间的矛盾,使微夹持器的夹持力输出大大增加。     

圆平行板电容器极板电流磁场的数值计算

用数值计算的方法研究了圆平行板电容器极板上电流的磁场，求出传导电流(极板电流 馈线电流)产生的磁场，并与使用全电流环路定律在忽略边缘效应的条件下的计算结果作比较。     

静电梳齿驱动器静电-结构耦合的仿真分析

采用降阶建模为静电梳齿驱动执行器开发了一个二维有限元模型,将梳齿驱动器简化为一组等价的集总参数单元,各单元均体现了对应器件的静动态特性和输入输出特性,降阶得到的模型降低了计算的复杂程度,提高了计算的速度.对采用降阶模型法所建立的模型仿真,得出梳齿驱动执行器的驱动位移、静电力与结构参数和所施加电压关系的仿真结果.该方法能以较快的速度求解静电-结构耦合问题,所得结果与有限元解相比较,最大位移误差小于5%.     

具有挠曲电效应的纳米电介质变分原理及控制方程

纳米电介质具有较强的挠曲电效应,并且该效应与大的应变梯度相耦合．在纳米尺度,静电力不能被忽略．我们基于电学焓,建立了可考虑应变及极化梯度效应以及静电力影响的纳米电介质变分原理．由此变分原理,导出了其控制方程,给出了广义静电应力的表达式．广义静电应力由两部分组成,一部分为与极化及应变有关的Maxwell应力,另一部分为与极化梯度及应变梯度有关的应力．我们的工作为研究纳米电介质中的力电耦合问题提供了基础．     

光电-静电复合驱动MEMS悬臂梁挠度分析

针对P LZT陶瓷光致形变直接驱动响应速度较慢的问题,提出了一种光电-静电复合驱动MEMS悬臂梁的新型驱动方式.阐述了光电-静电驱动悬臂梁的驱动机理,并建立了光电-静电驱动悬臂梁的静态模型;利用平行板电容器原理,推导出光电-静电复合驱动悬臂梁的挠度与静电力之间的微分方程,并得到悬臂梁自由端挠度的解析表达式;建立了光电-...     

静电悬浮微机械加速度计设计

设计了一种基于静电悬浮原理的微机械加速度计。它采用三明治结构的微敏感元件,电容式位移检测方案及静电力悬浮控制方案。着重对敏感元件的主要结构设计、参数的选取、支承静电力的计算以及量程极限、精度极限等问题进行了分析,表明在目前技术条件下,可以实现量程约5g,精度为10-5g的悬浮微加速度计。设计并加工出一种圆环形结构的敏感元件,已实现了Z轴方向的静电悬浮及加速度测量,证明设计方案是可行的,进一步研究可实现三轴悬浮加速度计。     

静电陀螺寻北仪静电力干扰的仿真分析

以静电陀螺仪为核心部件的静电陀螺寻北仪是一种高精度的寻北仪器,其中静电力干扰是主要干扰源之一。本文针对静电陀螺寻北仪中的静电力干扰进行仿真分析。图形仿真结果直观地表明了转子的二次谐波、三次谐波,沿ｘ轴、ｙ轴相对电极的面积差,沿ｘ轴、ｙ轴的电极错位以及转子中心相对电极中心的偏移对干扰力矩影响的性质及大小。仿真结果可作为结构及系统设计的参考。     

电源电动势定义的讨论

现行电磁学教材对电源电动势的定义为:把单位正电荷从电源的负极经电源内部移动到正极时非静电力所作的功。用公式ε=表示,并指出,电源的电动势反映电源非静电力作功的本领。是表征电源本身的特征量,它具有一定的数值,与外电路的性质以及是否接通都没有关系。笔者认为此定义值得商榷。     

基于有限元分析的静电探测器电极设计

根据静电理论,研究了利用旋叶式三维静电探测器对空中目标进行测向的方法.根据三维静电探测器测得的三路信号可实时给出目标方位角和俯仰角.分析了感应电极叶片数量与感应电流幅值之间的关系,应用有限元分析软件ANSYS对静电探测器电极结构进行了设计仿真计算,对不同叶片数的探测电极的感应电荷变化量进行仿真,分析了边缘效应的影响.根据计算结果给出了静电探测器电极的优化设计参数,为旋叶式三维静电探测器电极设计提供基础和指导.     

变截面微梁的变形分析

考虑静电力边缘效率的影响,导出了静电力微梁的耦合控制方程,并借助打靶法和迭代修正齐次扩容精细积分法提出了一种分析两端固支变截面微梁变形的半解析方法。与文献值的比较表明,本文方法具有较高的精度,并采用该方法分析了边缘效应和截面的几何尺寸对微梁变形的影响。     

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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