For the scattering field caused by the finite - length conducting and permeable cylinder , the boundary condition that the normal component of electrical strength is zero in conducting medium , i . e . en = 0 , was used to determine the separation constant of boundary value problem in the past 以往含有有限长导电导磁圆柱体散射场的求解，大都根据导电媒质中电场强度法向分量为零，即e _ n = 0 ，这一边界条件来确定边值问题中分离常数的取值。
The conclusion that ez is more important during the breakdown of rf ion source is made out by comparing ez and e 6 before breakdown , and then , the breakdown criterion of rf ion source is deduced , and the relation between breakdown voltage and pressure is analyzed too 通过比较击穿前高频电场的轴向和幅向分量，得出了轴向电场在高频离子源击穿中起主要作用的结论，并进而推导出了高频离子源的击穿判据，得出了气体击穿时离子源击穿电压和放电管内气压的关系。
First according to the fact that tangential components of the evolution do not affect the geometric shape of the evolving curves , we introduce the evolution equation of geometric quantities for the general planar curves . then we describe the work of gage - hamilton briefly . last we consider a special curvature flow of curve which evolves with speed function of the principal curvatures along the inner norm and show that convexity of the curve is kept and its length and area are contracted if the initial closed curve is smooth and convex . so the final shape of the curve will be a point in finite time 首先根据曲线在切向分量上发展是不影响曲线的发展形状，我们引入了曲线的一些几何变量的发展方程；其次我们简要地回顾gage - hamilton研究曲线发展的一般步骤；最后我们考虑沿曲线的内法线以曲率的函数为发展速度的一类特殊的曲线族，证明了在初始曲线为凸的闭平面简单曲线条件下，曲线将保持凸的，并且它的面积和周长将同时收缩，并在有限时间内成为一个点。
In this part , pga , pgv and pgd are studied , the main results are as follows : 1 ) in general , pga decrease with depth and can reach maximum at surface ; the pga ratio with depth of downhole / surface is affected by magnitude and ground pga value , the bigger the magnitude and pga value , the smaller the pga decrement with depth ; the decrement with depth is much more significant in near - surface than that in deep downhole 加速度峰值沿深度的变化与地震的大小和场地条件有关。对于土层场地，一般说来，随着震级和地表pga的增大，加速度峰值沿深度的下降梯度减小。对于“土层基岩”型场地，基岩面处的水平分量约是地表的1 3 . 7 ，竖向分量约是地表的1 3 . 2 。
The main achievements are as follows : the theory models of defect mfl field are set up ; based on the magnetic dipole model and finite element model , the distribution of defect mfl field is simulated in the dissertation ; the component of flux density ( magnetic filed ) parallel to the surface of pipe is detected by a circumferential array of hall probes ; the factors including defect geometry parameters , defect surface angle and shape , pipe material , field intensity , vehicle velocity , background magnetization , operating pressure and remanent magnetization and so on influence the mfl signal characteristics 采用霍尔元件作为缺陷漏磁检测传感器，获得管道轴截面漏磁场切向分量的漏磁信号；研究了缺陷外形尺寸、缺陷倾角和形状、管道材质和磁化强度、检测仪移动速度、管道背底磁场、管内压力和剩磁对漏磁信号的影响。提出了各通道增益放大、各路漏磁信号偏离调整、波形微分、数字滤波和平滑等漏磁信号预处理方法；分析了等空间采样的漏磁信号转换为等时间采样信号的必要性，研究了漏磁信号的小波去噪方法。
Considering that the ferrite core is often made from good permeable material , the dissertation presents the condition that the normal component of the magnetic field strength is zero approximately at the inside surface of good permeable material , i . e . bn = 0 to determine the eigenvalues for the separation constant . during the solving process , the solenoid coil is supposed to be wound closely by infinite symmetrical delta - coils 考虑到磁芯通常是由导磁性能非常好的软磁材料构成，本文提出利用靠近良导磁材料内侧磁场强度法向分量近似为零，即b _ n 0 ，这一边界条件，来确定边值问题中的本征值。
A combined recognition feature extraction method based on vehicle target contour is given . this kind of recognition feature includes global shape features and local statistic features of target contour ’ s horizontal and vertical part . it can be used in visible light and infrared situation , and it has good stability and consistency even if the illumination and texture changed 基于这些特点,本文给出一种基于车辆目标轮廓的组合识别特征提取方法,所提取的组合特征包括以车辆目标轮廓为基础的全局形状矩特征和以车辆目标轮廓纵横向分量为基础的局部统计特征,该方法具有较强的稳定性和一致性。
According to the effective field expression which has been derived in former , the phenomenon that the tangential component of magnetic leakage field has maximum value and the normal component of magnetic leakage field acquires zero value at the stress concentration zone of positive magnetostriction ferromagnetism materials under the application of tensile stress and negative magnetostriction ferromagnetism materials under the application of compressive stress is explained theoretically through analyzing and discussing 根据所得到的地磁场中受力铁磁性材料有效场表达式，通过分析讨论，解释了受拉力作用的正磁致伸缩铁磁材料和受压力作用的负磁致伸缩材料在应力集中处漏磁场切向分量出现最大值、同时法向分量为零值的现象。
We often ignore the effect of vertical ground motion in general structure seismic design . in current seismic design code there is only one design response spectrum for horizontal ground acceleration , whereas the corresponding vertical design response spectrum equals that the horizontal design response spectra times 65 % , the characteristic period of vertical design response spectrum is assumed to be same as that of horizontal component 一般认为,地震动竖向分量的强度约为水平分量的1 / 2 ~ 2 / 3 ,故在普通建筑物的抗震设计和分析中常常忽略竖向地震动的影响,而我国现阶段抗震设计规范中也只给出了水平向设计反应谱。
Value , and the current density and intensity versus the substorm phases . moreover , the characteristics of substorm current wedge are given special attention . it is found that the density and intensity of facs reach their peak during the expansion phase , the onset of the expansion phase is triggered when imf is changed to southward from northward or the southward imf decreases , and the positions of onset are most likely to be at the edge of plasma sheet near the earth 值分布以及场向电流强度和密度随亚暴位相的变化，并着重分析了亚暴电流楔的特征。结果表明，亚暴膨胀相的场向电流强度和密度都达到极大值亚暴的膨胀相是由行星际磁场转向或南向分量变小触发的，其起始位置很可能位于近地等离子体片内边缘。
