Electromagnetic radiation and variations in the conductivity of muscovite specimens during dehydration

The authors give experimental results on the measurement of electromagnetic radiation and electrical conductivity of muscovite specimens during heating or cooling in the temperature range from 20 to 600°C. It was established that at some temperatures there were variations in the electrical conductivity with the attendant onset of pulsed electromagnetic radiation in the radio-frequency range from 247.5 kHz to 35.8 MHz. The oscillations in the conductivity and the maximum intensity of electromagnetic radiation coincide with the boiling points of weakly bound water at about 100°C, the electrical activity of centers on the surface of micas (20–450°C), the temperatures of crystallization of muscovite in a hydrothermal process from 480 to 160°C, and phase transitions at 550–590°C. The electromagnetic radiation is probably due to fluctuations in the defects in the mineral under thermal excitation and adhesion processes as a result of dehydration of the muscovite.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 1, pp. 27–33.     

电磁力控制湍流边界层分离圆柱绕流场特性数值分析

在亚临界区高雷诺数Re=1.4×105下,采用脱体涡模拟结合湍流分离的方法对弱电解质中电磁力作用下湍流边界层分离圆柱绕流场及其升(阻)力特性进行了数值模拟和分析.结果表明,电磁力可以提高圆柱体湍流边界层内的流体动能,延缓圆柱体湍流边界层的流动分离,减弱圆柱体湍流绕流场中在流向和展向上大尺度漩涡的强度,减小圆柱体阻力时均值及其升力脉动幅值.当电磁力作用参数大于某个临界值后,湍流边界层流动分离消失,在圆柱体尾部产生射流现象,从而电磁力对圆柱体产生净推力作用,出现负阻力现象,而且升力脉动幅值接近于零,出现圆柱体升力消失现象.     

Separation of variables in the stationary Schrödinger equation

The problem of separation of variables in the stationary Schrödinger equation is considered for a charge moving in an external electromagnetic field. On the basis of the definition formulated, necessary and sufficient conditions are found for separation of variables in equations of elliptic type to which the stationary Schrödinger equation belongs. Application of general theorems made it possible to enumerate all types of electromagnetic fields and systems of coordinates in which separation of variables in the stationary Schrödinger equation is possible. Systems of ordinary differential equations which the wave function in the separated variables satisfies are written down to explicit form.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 45–50, August, 1972.     

Special Stäckel electrovac spacetimes

Classification of all electrovac specetimes permitting the separation of variables in the Hamilton-Jacobi equation for a charged test particle is carried out. This separation requires the existence of a complete set consisting of Killing’s vectors and tensors of a special kind. Every complete set defines its own type of metric and electromagnetic potential in the separable coordinate system. There exist seven types of separation of variables for electromagnetic spaces. For every type an additional classification is carried out by transformation of coordinates without any disturbance of the separation conditions, the gradient transformation of electromagnetic potential and the conformal-constant transformation of metric. The key step in solving the problem is the extraction of an autonomous subsystem which determines the metric from only the Einstein-Maxwell equations for every type of separation of variables. Representatives of all classes of metrics and electromagnetic potential are given for every type of separation of variables with the exception of the spaces found in the well-known work by Carter. The problem is solved in terms of metric formalism. The classes of electrovac spacetimes obtained are found to be related to Petrov’s classification.     

Way of detecting an electromagnetic earthquake precursor

A way of detecting an electromagnetic earthquake precursor is suggested. Detection is carried out with a device composed of a vertical electrical antenna and a toroidal magnetic antenna located on the Earth’s surface. It is shown that the detector is the most sensitive to the radiation of an electrical dipole inside the lithosphere that is oriented normally to the Earth’s surface. Such a pattern allows one to detect electromagnetic precursors by the method suggested.     

Blind phase retrieval and source separation of electromagnetic fields

Blind source separation of two electromagnetic fields is investigated. The difficulty of this task lies in the fact that only the power, which is the square of the sum of the electromagnetic fields, can be directly measured; the cross term of the electromagnetic fields is inevitable, and a strong correlation occurs in blind deconvolution. However, the relative phase is physically different from the field intensities, and, hence, extracting the phase during separation seems inconceivable. Our results demonstrate that the intensities and the relative phase of two electromagnetic waves can be determined with eigenvalue problem formalism even when the mixing processes are completely unknown.     

Propagation of radiation in a plasma situated in a gravitational field

Weak electromagnetic and gravitational fields in a plasma situated in a strong gravitational field, are studied using linearized, general-relativistic, kinetic equations. A tensor operator is constructed for the electrical conductivity of a plasma in a gravitational field, which is a general-relativistic generalization of the electrical conductivity of a homogeneous plasma. Similar tensor operators, which allow one to determine the energy-momentum tensor and the vector current, induced by electromagnetic and gravitational fields in a plasma, are also obtained.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 9, pp. 57–62, September, 1976.     

Characteristics of the electromagnetic wave field far away from the radiation source

A solution to the Sommerfeld problem of the far (in terms of wavelengths) field of a vertical electrical dipole placed at the interface between two media has been found. The characteristics of a surface electromagnetic wave that propagates over a medium with highly inductive surface impedance δ have been determined. The spatial characteristics of the wave are expressed through the real and imaginary parts of impedance δ. It has been proved that the surface electromagnetic wave is the major contributor to the electromagnetic field of the ground wave in the case of highly inductive radio paths.     

车辆强电磁脉冲环境适应性研究

近年来,随着大量用频设备的广泛应用,使得空间电磁环境日益复杂。复杂多变的电磁环境不仅会影响车辆的运用效能,而且会威胁车辆的生存能力。电磁环境对车辆的影响不可低估,尤其是强电磁脉冲,其破坏能力远远超过一般的电子干扰,会引起车辆的电子、电气元件的失效或损伤,严重影响着车辆机动与安全性能的有效发挥。将以某车辆为对象,较为系统地介绍车辆可能遭遇的强电磁脉冲环境、强电磁脉冲防护思路、车辆电磁环境效应分析以及采取的具体防护加固措施,以期提升车辆强电磁环境适应能力。     

带状螺旋线研究中的坐标变换

分析了带状螺旋线行波管中电磁场分量在柱坐标系下的Floquet形式，证明适当的坐标变换是电磁场分量写成变量分离形式的充分条件.螺旋带平面展开后，应用坐标变换得到的电磁场分量变量分离形式是去除面电流分布假设的理论基础.计算并分析了一个典型结构的色散和耦合阻抗，计算结果与实验结果有很好的一致. 关键词： 螺旋带 坐标变换 色散 耦合阻抗     

Electromagnetic response of a layered composite insulator to pulsed mechanical excitation

A double electrical layer is found to make a major contribution to the electromagnetic response of a layered composite material. The effective charge density in the double electrical layer forming at the cementgypsum interface is estimated to be 4 × 10^?9 C/cm².     

Autaptic modulation-induced neuronal electrical activities and wave propagation on network under electromagnetic induction

Based on an improved HR neuron model, the effects of electrical and chemical autapses on the firing activities of single neurons are studied, and the wave propagation in forward feedback neural network is also discussed by considering autapstic regulation under different intensities of electromagnetic induction. It is found that the electrical activities of single neuron can be changed by exerting excitatory or inhibitory of electrical and chemical autapses. With different feedback gains of electromagnetic induction current, membrane potential shows the oscillatory solutions and steady states. Under the condition of different autapse or electromagnetic induction, the propagation of electrical activities caused by the central neuron is transformed in the forward feedback network. Moreover, the spatial synchronization of the network will be changed by choosing different coupling intensities and feedback gains. It is proved that the electrical and chemical autapses play a significant role in firing modes of single neuron and the wave propagation of the forward feedback networks under the electromagnetic induction.     

Dielectric effect and electrical relaxation in mica crystals

Results are given of an investigation of the dielectric state and electrical relaxation in crystals of dioctahedral muscovite mica. By comparing experimental and theoretical data for the spectra of thermostimulated depolarization (TSD) currents, the temperature dependences of the conductivity during linear heating log = f(1/T) and results of a study of the transfer of the electrical relief during contact under pressure between polarized and nonpolarized crystals, a conclusion is drawn concerning the drift mechanism of relaxation of the dielectric state in mica.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 10, pp. 99–101, October, 1991.     

Search for a correlation between the extremely low-frequency earth's electromagnetic field and periodic gravitational fields of astrophysical origin

To detect periodic gravitational fields of astrophysical orgiin, the extremely low-frequency (ELF) natural Earth's electromagnetic field is used together with the wide capabilities of the experimental test field of Vladimir State University. The emphasis is on an analysis of spectra of the electrical component of the Earth's electromagnetic field in the range of ELF gravitational-wave emission of double pulsars. A problem of developing a method and means for experimental verification of the interrelation between the extremely low-frequency Earth's electromagnetic field and the gravitational-wave emission of double pulsars is formulated. Vladimir State University. Translated from Izvestiya Vysshikh Uchebhykh Zavedenii, Fizika, No. 6, pp. 36–42, June, 2000.     

正交电磁场中粒子束的质量聚焦及粒子轨迹

<正>交电磁场中粒子的运动轨迹在拐点处按指数规律变化,使不同质量离子的轨迹有明显区别,由此可创建新的电磁核素分离法。从牛顿运动方程出发,基于单粒子轨道法阐述被分离核素在正交电磁场中的运动规律,重点找出轨迹的拐点。给出了多质量粒子束在正交电磁场中的质量聚焦特性,以Li离子为例,应用MATLAB模拟粒子束的运动轨迹,结果表明正交电磁场中可实现多质量束流的质量分离。总结出粒子轨迹方程的特点,为多质量束流分离结构的工程化实现提供参数。研究成果可应用到质量分离器、质谱分析仪及材料提纯等装置的研制中,同时对于特殊位形电磁场控制多质量束流等相关领域的研究亦有一定的参考价值。     

Solutions of the Dirac equation and Green's electron function in an external electromagnetic field of special form

A complete orthonormal set of c-numerical solutions of the Dirac equation is constructed and integral representations are obtained for the Green's electron function in an external electromagnetic field representing the combination of a longitudinal electrical wave and a plane wave being propagated in one direction (along the x₃ axis).     

Effects of temperature and electromagnetic induction on action potential of Hodgkin–Huxley model

Based on an improved the Hodgkin–Huxley (HH) neuron model which is driven by the electromagnetic induction, the effects of temperature and electromagnetic induction on the action potential of neuron are investigated by numerical computations. It is very interesting that, under the fixed condition of electromagnetic induction, there is a region for the electrical activity of neuron in the external current and temperature parameters plane, the region of electrical firing is similar to the Arnold’ tongue-like structure, and the Arnold’ tongue originates from the nonlinear variation of temperature with the increasing of threshold external current. The effects of temperature and electromagnetic induction on neuronic electrical activity are respectively discussed by using numerical simulations. Our results provide new insights into the roles of temperature in the improved HH neuron model, the existence of Arnold’ tongue-like structure might give some insights for the treatment of neurological diseases such as the epilepsia.     

Autowave dynamics of the magnetic flux in nonideal type-II superconductors with different current-voltage characteristics

An analysis was performed of the processes of penetration of a macroscopic electromagnetic field into superconducting media with different current-voltage characteristics induced by a variable external magnetic field or by carrier transport. It has been shown that even if a finite electrical voltage arises in the superconductor before the critical current is reached, the magnetic flux, as in the critical state model, penetrates into the superconductor at a finite rate as a characteristic electromagnetic wave. At its front, a special condition is fulfilled; namely, a smooth transition to the nonperturbed value of the strength of the electric field induced by an external perturbation. Formulas are given for the calculation of the penetration rate of the electromagnetic field into a superconductor. For corroboration of the formulated relationships, the study was compared with corresponding numerical calculations.     

Electrodynamics of hyperbolically accelerated charges V. The field of a charge in the Rindler space and the Milne space

We describe the electromagnetic field of a uniformly accelerated charge in its co-moving Rindler frame. It is shown that the electrical field lines coincide with the trajectories of photons. The self force of a charged particle at rest in Rindler space, and the increase of its weight due to its charge, is calculated. The general case of an accelerated charge in Rindler space is also considered. It is shown that the electrical field inside a uniformly charged spherical shell can be used as a measure of it 4-acceleration. A result that has earlier been deduced in a different way by Fugmann and Kretzschmar is confirmed, namely that the intensity of radiation from a point charge instantaneously at rest in an accelerated frame is proportional to the square of the relative acceleration of the charge and the observer. In particular it is shown that a freely falling charge in Rindler space radiates in accordance with Larmor’s formula. In this case the radiation energy is taken from the Schott energy. The energy of the electromagnetic field is analysed from the point of view of the Hirayama-separation, which generalizes the Teitelboim-separation to non-inertial frames, of the field in a bound part and an unbound part. A detailed account, with reference to the Rindler frame, of the field energy and particle energy is given for the case of a charge entering and leaving a region with hyperbolic motion. We also consider the electromagnetic field of a uniformly accelerated charge with reference to the Milne frame, which covers a different part of spacetime than the Rindler frame. The radiating part of the electromagnetic field is found in the Milne sector of spacetime.