偏心圆柱形电容器的电场

利用复数坐标系ｚ平面的分式线性变换，讨论了偏心圆柱形电容器内的电场分布，概括了平行圆柱形电极间电场分布的一般性结论。     

椭圆柱形电容器的电场及其耐压能力

利用复坐标系上的儒可夫斯基变换,分析椭圆柱形电容器内的电场分布,给出其内部的电势和场强分布表达式,并在场强分布矢量式的基础上,通过MATLAB数据处理软件的数值计算功能进行数值模拟,研究椭圆柱形电容器相对于圆柱形电容器耐压能力的变化情况.     

球形、圆柱形电容器电阻的一种简易求法

给出一种球形、圆柱形电容器电阻的求法，加深对电阻定义和串并联电路电阻关系的理解．     

电容器组耐压值的计算

电容器的用途非常广泛．如提高功率因数、滤波、耦合、调谐、旁路、选频以及电火花加工等．在实际工作中，会遇到电容器的电容量不合适或额定工作电压(习惯称“耐压”)不符合要求的情况，这就要用电容器组，以满足实际工作的需要．几个电容器串联并联或混联成电容器组后，其耐压值需要计算．下面介绍电容器组耐压值的计算方法．     

非平行板电容器的电容和电场的计算

本文采用保角变换的方法计算非平行板电容器的电容和场强,本方法与以往所见的方法不同,它简洁、严谨。     

匹配型保偏光纤自动对轴技术

The auto alignment technique is studied for the PM fiber (PMF) of matching refractive index(MRI). The polarization observation by lens effect tracing technique(POL) is introduced. Based on the POL,an auto alignment system is designed and its performance is then tested. Different light intensity distribution characteristic is found on the different observation surfaces in a series of experients. The widest range of adjustment is achieved when the observation surface corresponds to a light intensity distribution with five characteristic points. This means it is easier to focus.The five point method is presented after analysis of the curves of the five characteristic points with respect to the azimuth angle of the optical fiber.By comparison with the POL,this method is easier to be realized and has higher measurement accuracy,so it is suitable for auto alignment system.     

非平行板电容器电容和电场的两种计算方法之讨论

介绍求解非平行板电容器电容和电场的两种计算方法,一种是从平行板电容器的概念入手的求解方法,另一种是利用电场能量和电容器的能量公式,解出非平行板电容器的电容和电场分布.通过对上述两种方法的讨论,指出第二种方法,严格、简捷易懂,图像清晰,且颇具新意.     

异轴圆柱形电阻器的电阻

利用复变函数保角变换 ,将平行轴圆柱形电阻器变换为同轴圆柱形电阻器 ,并对电阻进行了计算和详细讨论     

有缺陷的平行板电容器内的电场

利用复数坐标系上的保角变换和利用势的拉普拉斯方程分别讨论了带有半圆柱形凸出疤和半球形凸出疤两种有缺陷的平行板电容器内的电场分布,进而得出一些有益的结论     

Acoustic field outside a cylindrical region excited from inside

We present the results of numerical calculation of the acoustic field distribution in a structure consisting of three cylindrically symmetrical, infinitely long coaxial regions with identical constant density. The media in the inner and outer regions have the same sound velocity which is different from that in the intermediate region. In the inner region, a harmonic pressure source is located. Expressions for the acoustic fields in each region are derived and the field distribution in the outer region is determined. The numerical analysis is performed at the distances corresponding to the near field of the source. Characteristic features of the field structure as a function of the source frequency, the sizes of the system, and the acoustic parameters of the medium are determined. The results obtained can be used in geophysical prospecting for characterization of boreholes, in acoustic logging of wells, and in the problems of noise control near industrial and power plants.     

Electric field computation inside a rectangular petrol tank

In the paper was developed a hybrid method (analytic–numeric) for the electric field computation inside a rectangular petrol tank. For this problem it will be assumed a static state and all the computations will be developed in a Cartesian coordinate system. Two regions will be delimitated: first one is the free space and second one is the liquid electro-statically charged (petrol) inside the tank.For solving the Laplace equation in the first region, variable separation method will be applied and the electric potential will be determined. In the second region the Poisson equation will be solved, assuming a particular solution and then the electric potential will be obtained. To determine the constants from the potential expressions the zero potential condition at the tank surface and the continuity conditions at the separation surface was considered. Using mathematical manipulations (series development, numerical approximations etc.) an ill conditioned matrix system (23 × 23) resulted. This system will be numerically solved/discussed using a developed MathCad algorithm. The condition number of the coefficients matrix is being computed and the regularization methods applied to the system will be discussed.     

接地导体薄圆筒内线电荷的电场

利用复数坐标系z上的保角变换,计算接地导体薄圆筒内线电荷的电势和场强的分布,并利用数学软件MATLAB绘制出电场线与等势线(面)图.     

On the magnetization of a thin-walled cylindrical sheath with a magnetic field from the Rayleigh range inside

In terms of the general theory of magnetization of thin-walled sheaths, magnetization of a thin-walled indefinitely long circular cylindrical sheath that is placed in an external magnetic field and experiences the action of an internal magnetic field from the Rayleigh range is considered. It is shown that the solution of the problem can be reduced to solving infinite sets of nonlinear equations in the coefficients of Fourier series representing the components of the magnetization and internal magnetic field strength that are averaged over the thickness of the sheath and tangent to its surface. Approximate solutions to these sets of equations are obtained, and expressions for the coefficients multiplying the first terms of the series are given.     

Electric field distribution and effective nonlinear AC and DC responses of graded cylindrical composites

The perturbation method is used to study the localization of electric field distribution and the effective nonlinear response of graded composites under an external alternating-current (AC) and direct-current (DC) electric field E_app = E₀ (1+sin ωt). The dielectric profile of the cylindrical inclusions is modeled by function ε_i (r) = C_k r^k (r ≤ a), where r is the radius of the cylindrical inclusion, and C_k, k, a are parameters. In the dilute limit, the local potentials and the effective nonlinear responses at all harmonics are derived. Meanwhile, the general effective nonlinear responses are also derived and compared with the effective nonlinear responses at harmonics under the AC and DC external field. It is found that the effective nonlinear AC and DC responses at harmonics can be calculated by those of the general effective nonlinear of the graded composites under the external DC electric field. Moreover, the obtained local electrical fields show that the electrical field distribution in the cylindrical inclusions is controllable, and the maximum of the electric field inside the cylinder is at its center.     

有限长均匀带电薄圆柱面的电场

由场的叠加原理,导出了有限长均匀带电薄圆柱面电势和电场的级数表达式.     

Theoretical investigation of the possibility of isotope separation during motion of charged particles in the electromagnetic field of a cylindrical capacitor and a linear current flowing along its axis

A characteristic feature of the trajectories of charges moving in constant axisymmetric radial electric and azimuthal magnetic fields, whose strengths are inversely proportional to the center from the symmetry axis is the exponential dependence of the turning points on the parameters of motion. This leads to a noticeable difference in the trajectories for isotope ions, which makes it possible to obtain a new method for their electromagnetic separation. The trajectories of isotopes being separated are studied theoretically. The conditions under which the trajectories are closed and form toroidal surfaces (storage vortex rings) have been determined earlier. These results are given for convenience in analyzing another problem, associated with the formation of such ionic toroidal vortex surfaces (stable in Wood’s sense) during a streak lightning discharge in the atmosphere (ball lightning model).     

凹圆柱面内的波和回音壁

本文结合回音壁的声学特点分析了凹圆柱面内有关的波。当声源接近于凹面时,产生沿表面传播的波,文中给出声场的径向分布。文中还给出线源情形下各反射波的表示式和得到一次反射声焦散面的图解法。