弱纵向外电场对磁化等离子体中哨声波的影响

本文以等离子体动力论为基础讨论存在纵向外电场时磁化等离子体的哨声波。由于外电场的影响,等离子体偏离平衡态。取电子稳态分布函数为局域的麦克斯韦分布,用沿无扰轨道积分方法求出系统的介电张量,并分别用介电张量的厄米部份和反厄米部份分析哨声的色散关系和增长率。对于波矢在以电场方向为轴顶角为2c锥角范围内的哨声,外电场的作用使波增长;波矢在此锥角范围之外,外电场的作用使其衰减。波的增长率随频率增高而增大,随波矢倾角增大而减小。ee时,波矢与外电场平行对应的最大增长率与等离子体密度成正比,与磁场强度成反比。文中还给出了以电离层F层作背景参数的数值计算结果。     

电场对胆甾相液晶的作用

用统计物理的方法讨论了胆甾相液晶在垂直螺旋轴方向的电场作用下螺旋结构的变化，得到了螺距ｈ和阈值电场强度Ｅｃ的近似表达式。结果表明：ｈ和Ｅｃ与场强、液晶的本征螺距、液晶分子结构及温度等有关     

静电场对向列相液晶的影响

用统计物理的方法讨论了外加静电场对向列相液晶的影响。结果表明，电场诱导的向列相取向序参量、双折射和向列相—各向同性相的相变温度的改变是场强的偶函数，在电场较弱时与场强平方成正比。     

ELECTRIC FIELD MICROSENSOR BASED ON THE STRUCTURE OF PIEZOELECTRIC INTERDIGITATED CANTILEVER BEAMS

This paper presents the design, fabrication, and preliminary experimental result of an electric field microsensor based on the structure of piezoelectric interdigitated cantilevers with staggered vertical vibration mode. The working principle of this electric field microsensor is demonstrated, and the induced charges and structural parameters of this microsensor are simulated by the finite element method. The electric field microsensor was fabricated by Micro-Electro Mechanical Systems(MEMS) technique. Each cantilever is a multilayer compound structure(Al/Si3N4/ Pt/PZT/Pt/ Ti/SiO 2/Si), and Piezoelectric, PieZ oelectric ceramic Transducer(PZT)(PbZ rxTi(1–x)O3) layer, prepared by sol-gel method, is used as the piezoelectric material to drive the cantilevers vibrating. This electric field microsensor was tested under the DC electric field with the field intensity from 0 to 5×104 V/m. The output voltage signal of the electric field microsensor has a good linear relationship to the intensity of applied electric field. The performance could be improved with the optimized design of structure, and reformative fabrication processes of PZT material.     

磁场中布里奇曼法生长碲镉汞晶体的缺陷腐蚀分析

用化学腐蚀方法研究了磁场中布里奇更法生长碲镉汞晶体的位错和亚晶界，在施加磁场的样品中观察到分布较为均匀的位错和较少的亚晶界，这可能是由于在生长过程中施加了磁场对组分分凝和组分过冷起到了一定的抑制作用。     

应用等离子体化学反应的高频离子源中气压对引出金属离子和卤素离子含量的影响

高频离子源中等离子体化学反应引出金属和卤素离子的实验中,存在一个规律性的东西。那就是,放电室内的气压在工作范围内变化时,离子束中金属离子和卤素离子的含量也都随之改变。当气压升高时,金属离子的百分比增大,卤素离子的百分比减小;反之,金属离子的比率下降,而卤素离子的比率上升。本文对这样一个事实进行了一些讨论。     

无摩擦基板上液晶薄层的分子场理论

采用分子场近似，通过Ｌｅｂｗｏｈｌ－Ｌａｓｈｅｒ模型研究无摩擦基板上的液晶薄层，给出了出现向列相对液晶薄层中的子分子取向状态的向列相－各向同性相转变，讨论了基板诱导的取向序（包括双轴序）以及介面区中的双轴一单轴相变。     

A NEW METHOD FOR SOLVING DYADIC GREEN''''S FUNCTION OF ELECTROMAGNETIC FIELD

A new method for solving electromagnetic field boundary value problem is given.Byusing this method,the boundary value problem of the vector wave equation can be transformedinto the independent boundary value problem of scalar wave equations and the two additionalvector differential operations.All the dyadic Green's functions got by eigenfunction expansionof the dyadic Green's function can be got by this method easily and some of the dyadic Green'sfunctions for complex systems which are very difficult to get by the ordinary method have beengot by this new method.The dyadic Green's function for a dielectric loaded cavity is one of thegiven examples.     

激光辐照加电场激发对滇稻的育种研究

我们用激光辐照加电场激发处理了滇稻种子，通过室内育秧和田间试验，发现在出苗率，有效分蘖和结实率等方面均优于单纯激光处理的稻种。     

ELECTROMAGNETIC ENERGY FLOW PATTERN ON THE AXIS OF A CIRCULAR DISK BY TRANSIENT EXCITATION

The exact energy flow pattern on the axis of a circular disk by transient excitation is presented in this paper. It has been shown that non-decaying region does not appear when the source is chosen to be a rectangular pulse, on the contrary, there exists a uprising region on the axis when the width of the pulse is less than a/c. After reaching its maximum value point, the energy decays slowly until the law of r-2 is met. The scale of the uprising region is dependent upon the size of the antenna and the width of the pulse. It has also been shown that there exists a oscillatory region near the source for a harmonic excitation, and the amplitude is also uprising, which is quite different compared with the conclusion drawn by S. Silver(1949). Finally, the phenomenon of energy uprising in time domain is explained and some problems about the electromagnetic missiles are also expounded.