介电系数

In some materials with periodic variation of dielectric constants and light within a certain frequency range shows exponential decay due to destructive interference and cannot propagate. This phenomenon is called photonic bandgap and this kind of structures is called photonic crystals.

介电系数周期性排列的材料，部分波段会因破坏性干涉呈指数衰减，导致无法在此结构上传播，此现象称为光子能隙，此类具有介电系数周期性排列的结构则称为光子晶体。

The possible mechanician of the dielectrical relaxation effect in a low temperature and moisture absorption is analysed and discussed with SEM, especially from the measured result of the relaxation character complex permittivity ε′,ε of dry and mo...

本研究特别从干燥与吸湿薄膜低温松弛特性——复介电系数ε′、ε测量结果，利用SEM分析与讨论了吸湿低温介电松弛效应可能的机理，并用扩展Debye松弛理论给予理论解释。计算了松弛活化能。

The effective permittivity can be used to describe the molecular polarization of the mixture in the reaction and consequently be used to calculate the transmission and absorption of microwave in the reaction mixture.

由于等效介电系数常常被用来描述在化学反应中微波的吸收和传输情况，因而，化学反应中反应物的等效介电系数就成为微波化学研究的关键问题之一。

Luneberg lens is a spherical lens which its permittivity varies with normalized radial coordinates. It is fabricated by using different homogeneous dielectric centrically layered media. The lens can focus a parallel beam of rays from any direction exactly at a point on the surface. If it is made by adding a reflecting surface "metallic cap", it is called Luneberg lens reflector. It can reflect incident wave into plane wave in incoming direction. It is usually applied in antenna, radar reflector,satellite-based, and mobile-communucation.

龙伯球透镜为一种介电系数与半径成一固定比例的球形透镜，大部分是由数层不同介电系数介电质组合而成，而其主要特性能够把入射波聚焦到球表面一点，假使在透镜表面处镀上一圆锥角金属层即为龙伯球透镜反射器，能把入射波依平面波的型态反射回原入射端，通常用於天线、雷达、卫星通讯、军事等方面。

This thesis with cold-shrink 25kV cable terminal connector components as the main structure, used finite element analysis method to simulate the following situations (1) with different thickness of stress relief material (2) with different relative permittivity of stress relief material,(3) different geometries of the stress cone ,(4) of a grounding embedded electrode to monitor effects of electrical stress grading.

中文摘要本文以25kV冷缩式电缆终端接头元件为主要架构，使用有限元素分析法模拟(1)电应力缓解材料的厚度改变(2)电应力缓解材料的相对介电系数改变(3)不同的应力锥几何尺寸(4)埋置接地电极时的电场与电位分布状况。

The good performance is related to the low work-function metal, Ytterbium, makes the threshold voltage lower successfully and small equivalent oxide thickness by high κ dielectric material.

这些良好的特性是因为拥有低功函数的镱可以成功的将临界电压降低，还有高介电系数介电层闸极可以得到较薄的等效氧化层厚度。

The electrodes consist of improved interdigital structures, and the polypyrrole is coated on the interdigital electrodes. The sensing principle of the sensor is based on the dielectric constant change when the sensing film absorbs or desorbs vapor.

湿度感测器的电极为改良式的梳状结构，并将聚吡咯滴覆於电极间，当成介电层，其感测原理为当聚吡咯吸附及释放水汽时，会造成材料内部介电系数的改变，使电容产生变化。

In this dissertation, we demonstrated a low voltage, fast speed and good data retention MONOS memory device with high work function IrOx metal gate, novel high-k AlN trapping layer and HfAlO blocking layer.

高介电系数介电质的使用，不仅可以有效降低操作电压，同时也可以将电压有效的跨在薄二氧化矽穿遂层以增加编码和抹写速度。

Disadvantage of this device is high voltage, in order to reduce the operating voltage to achieve the purpose of actual use, screening of high dielectric constant material as the dielectric layer material is topic of future research.

缺点是工作电压偏高，需要进一步筛选出介电系数高的物质来作为介电绝缘层材料，以便降低工作电压，达到实际可以使用的目的。

In this thesis, the radiation principle and the structure of slot antenna are studied and the impacts on its performance of every structure parameter in a slot antenna design are analyzed. On this foundation, a design plan of planar slot array antennas is proposed. The design has some structural feature as follows:(1) with different dielectric layers and microstrip line structure to guide the electromagnetic wave effectively;(2) the feeding network formed of microstrip line can match with the radiating slots expediently;(3) in order to increase the bandwidth of the antenna, the wider slot and branched feeding microstrip line are adopted to form a double resonance.

本文对缝隙辐射的原理、缝隙天线的结构作了探讨，分析了缝隙天线设计中各结构参数对其性能的影响，并在此基础上提出一种平面型缝隙天线的设计方案，它具有以下的特点：(1)采用分层结构，以不同的介电系数和微带线结构形成对电磁波的有效引导；(2)利用微带线构成馈电网络可以方便地与辐射缝隙进行匹配；(3)增大缝隙的宽度，并利用馈电微带线的枝节形成双谐振，以增加天线的带宽。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。