查询词典 dielectric

The electric field integral equation of a dielectric cylinder irradiated at a given direction by radar electromagnetic wave is solved using MOM to obtain the polarization current of the dielectric cylinder.

引言目标识别、隐身与反隐身等的研究在当今有着重要的军事价值，其基础就是复杂目标的电磁散射特性分析。

The vertical electric field of the buried layer is enhanced due to the low k of the dielectric buried layer at the drain side,the electric field in the drift region is modulated by the compound dielectric layer with different k values,and both increase the breakdown voltage of the device.

CDL SOI结构利用漏端低k介质增强埋层纵向电场，具有不同k值的复合介质埋层调制漂移区电场，二者均使耐压提高。

The results show that glass ceramics with thermal expansion coefficient of 5.11×10^(-6)℃, major phase of α-cordierite and ε=5.5, tan σ=2.1×10^(-4) can be prepared by the addition of 3.6% alkalis (Li2O+Na2O), and Li2O occupies 1.8%. With Li2O substitution for Na2O, spontaneous crystallization is obviously enhanced, and temperature of the first crystallization peak decreases from 950℃ to nearly 900℃, but the crystallization temperature of the second peak was not varied. With the increase of Li2O content, mixed alkali effect can be observed from the thermal expansion coefficient and dielectric loss curve which decreases first and then increases. Dielectric constant decreases monotonously with the increase of Li2O content.

研究结果表明：Li2O和Na2O总含量为3.6%，其中Li2O含量为1.8%时，微晶玻璃以α-堇青石为主晶相，热膨胀系数为5.11×10^(-6)℃，微波频率下介电常数ε为5.5，介电损耗tanσ为2.1×10^(-4)；随着Li对Na的取代，玻璃的析晶能力增强，初始析晶峰温度从950℃降至900℃左右，但没有降低第二析晶峰温度；随着Li2O含量增加，热膨胀系数及介电损耗都出现明显的混合碱效应，曲线呈现先降低后升高的变化趋势；样品的介电常数随Li2O含量增加单调降低。

The results show that glass ceramics with thermal expansion coefficient of 5.11×106 ℃, major phase of α-cordierite and εr=5.5, tan σ=2.1×104 can be prepared by the addition of 3.6% alkalis(Li2O+Na2O), and Li2O occupies 1.8%. With Li2O substitution for Na2O, spontaneous crystallization is obviously enhanced, and temperature of the first crystallization peak decreases from 950 ℃ to nearly 900 ℃, but the crystallization temperature of the second peak was not varied. With the increase of Li2O content, mixed alkali effect can be observed from the thermal expansion coefficient and dielectric loss curve which decreases first and then increases. Dielectric constant decreases monotonously with the increase of Li2O content.

研究结果表明：Li2O和Na2O总含量为3.6%，其中Li2O含量为1.8%时，微晶玻璃以α-堇青石为主晶相，热膨胀系数为5.11×106 ℃，微波频率下介电常数ε r为5.5，介电损耗tan σ为2.1×104；随着Li+对Na+的取代，玻璃的析晶能力增强，初始析晶峰温度从950 ℃降至900 ℃左右，但没有降低第二析晶峰温度；随着Li2O含量增加，热膨胀系数及介电损耗都出现明显的混合碱效应，曲线呈现先降低后升高的变化趋势；样品的介电常数随Li2O含量增加单调降低。

Performed tests based on seven kinds of important structural parameters which were wall thickness, shielding thickness, the radial wall shielding insertion depth, the width of the radial electrode, the electrode width, the relative dielectric constant of wall material and filler shield relative dielectric constant, and studied on structural parameters and the corresponding performances by RBF neural network, the optimization based on PSO was performed with the regression model.

该方法以敏感场整体灵敏度大小等系统性能为优化目标，基于管壁厚度、屏蔽层厚度、径向屏蔽插入管壁深度、径向电极宽度、电极宽度、管壁材料的相对介电常数、屏蔽层填充物相对介电常数7种重要的结构参数进行试验。应用RBF神经网络对多组结构参数以及对应的系统性能指标进行学习，得到回归模型，并应用粒子群算法进行寻优。

From the theory of dielectric breakdown, the mathematic method was used to describe the whole course during which the dielectric captured the electric charges that was immitted by electrode.

从电介质的击穿机理出发，用数学方法描述了电极注入电荷被介质捕获的全过程，详细分析了电介质的击穿特性并得出了电击穿现象的理论公式，通过同成分铌酸锂晶体和掺锌铌酸锂晶体的极化和击穿实验对理论分析的结果进行了验证，试验现象与理论分析吻合较好。

An oxide coating is formed on the surface of the aluminum powder after the surface passivation treatment, so as to efficiently avoid the formation of leakage conductance due to mutual contact between eclectically-conducting additives and thereby to reduce the dielectric loss of the material. The composite material has high dielectric constant, low density and good flexibility. The production method of the composite material has the advantages of simple and controllable process, low hot-pressing temperature, energy conservation and environmental protection.

铝粉经过钝化处理，表面形成一层氧化物包覆层，有效地避免了导电添料因相互接触而形成漏电导，降低了材料的介电损耗；复合材料介电常数高，密度低，加工简单，并具有良好的柔韧性；复合材料的制备方法工艺易控简单、热压温度低、节能环保。

In this paper, by means of finding the solutions of Maxwells equitions which have a tensor dielectric permittivity,the wave equitions were obtained in rotation dielectric under the condition of longitudinal direct current magnetic field.

本文求解张量介质电常数条件下的麦克斯韦方程，导出了纵向场作用下旋光材料的波动方程。由于电场与磁场是互相耦合不能单独存在，因而引入了孪生标量波的概念，并证明了该标量波满足亥姆霍兹方程。

In this thesis, there are two types of varactors used in the VCO: one is the Philips' BB135 p-n junction capacitor; the other is Al/HfO2/Si capacitor with HfO2 dielectric. Because the dielectric constant of HfO2 is larger than that of SiO2, the capacitance of Al/HfO2/Si capacitor will be larger than that of MOS capacitor with the same thickness and area. Therefore, there will be larger unit voltage for adjusting the ratio of the capacitance values of the capacitors.

在本论文实验的VCO电路中之可变电容有2种：一种是飞利浦厂商所提供型号为BB135之P-N接面电容；第二种是自制的Al/HfO2/Si电容是使用二氧化铪（HfO2）来做为电容的介电材料，因为HfO2介电常数比氧化矽（SiO2）大，目的是要在相同厚度以及面积下，就可以有较大的电容值，希望能藉此有较大的单位电压改变电容值的比值。

The aim of this thesis is to explore new MWDC with cation-deficient perovskite structure in A_5B_4O_(15) system. According to the characteristic of A_5B_4O_(15) perovskite structure, series of new titanates / tantalates Ba_(5-x)La_xTi_xTa_(4-x)O_(15)(x=1~3) were prepared, characterized. The dielectric properties were measured. Furthermore, the effects of Nb~(5+) substitution Ta~(5+) at B-site in Ba_3La_2Ti_2Ta_2O_(15) ceramic on structure and dielectric properties were studied.

本论文的主要目的是在A_5B_4O_(15)系列中探索新型类钙钛矿结构高性能微波介质陶瓷，进行了Ba_(5-x)La_xTi_xTa_(4-x)O_(15)(x=1～3)系列钛钽酸盐陶瓷的制备、结构与介电性能研究工作，并研究了材料Ba_3La_2Ti_2Ta_2O_(15)的B位Nb~(5+)离子取代Ta~(5+)离子对材料结构和介电性能的影响。

This one mode pays close attention to network credence foundation of the businessman very much.

这一模式非常关注商人的网络信用基础。

Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.

扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。