Based on a solution of the Fokker-Planck equation, the distribution function of the translational energy is solved for a Rayleigh gas with sources of heavy particles. The nature of disturbances in the equilibrium distribution function caused by the source of the particles is analyzed.
Show AbstractThe article presents a generalization of the root locus method to the class of linear self-regulating systems containing not only elements described by ordinary differential equations with constant coefficients, but also an element described by a one - dimensional heat conduction equation.
Show AbstractCoherent - oscillator radiation is considered. A comparison is made with the radiation of a classical particle, and an estimate is given for the decay probability of the coherent state in the process of spontaneous emission.
Show AbstractThe formation of Sr$^+$ and Ва$^+$ ions in a cooled hollow cathode in a discharge filled with argon and helium is investigated. The concentration of Sr$^+$ and Ва$^+$ ions is determined from the measured absorption coefficients of their resonance lines and also from the solution of the balance equation.
Show AbstractOn the basis of expansion in powers of a small parameter, the chain of Bogolyubov equations for the crystal state is solved. Ah expression is obtained for the s-particle distribution function up to second order, inclusive.
Show AbstractA contactless nondestructive method of determining the concentration of free charge carriers in PbTe and Pb$_{0,8}$ Sn$_{0,2}$Te from the IR reflection spectrum in the wavelength range 20-120 microns is proposed. Theoretical calibration curves are constructed, allowing the charge-carrier concentration in PbTe at T = 300 and 80 К and in Pb$_{0,8}$ Sn$_{0,2}$Te at T = 80К to be determined from the position of the point of inflection of the spectral dependence of the reflection coefficient on the light wavelength. The error of the metod is estimated, and shown to be no more than ±30%.
Show AbstractThe angular distribution of neutrino pairs emitted by a relativistic electron moving in a magnetic field is considered. It is shown that the particles are emitted predominantly in the opposite direction to the magnetic field. This asymmetry directly reflects the nonconservation of spatial parity in the given process. On account of radiation reactive forces, the electron is accelerated in the direction of the magnetic field. Expressions are obtained for the asymmetry parameter of the radiation and the radiation reactive force, depending both on the magnetic field strength and the electron energy and on its polarization.
Show AbstractThe structure of the front of disconnection shock waves in completely ionized plasma is investigated. In the case of nonmagnetized plasma, the shock wavefront at M$_1$>1 consists of a narrow isomagnetic discountinuity, followed by a broad (of the order of the magnetic - field diffusion length) region of Joule dissipation, in which the transverse component of the magnetic field declines from the initial value to zero. At sufficiently large values β=8πnT/ H$^{2}$≫1 the width of the shock wave front is determined again by the scale characteristic of electronic thermal conductivity. For magnetized plasma, the width of the front is of the order of. the characteristic length of electronic thermal conductivity. When M $^{2}$ $_1$ > 4/5, M$^{2}$ $_2$>4/5 an internal ionic shock wave arises in the structure of the front.
Show AbstractA theoretical description is proposed for the process d+p→ π$^({-})$ (0°)$^{+}$ with a primary - deuteron momentum of around 10 GeV/c, allowing both qualitative and quantitative accounts of the cumulative creation of π$^{-}$ mesons to be given. This model is developed on the basis of representation of the given process as a three – particle problem, taking account of two- and three - particle forces. The amplitude of the reaction is represented as a sum of contributions from an infinite series of diagrams, including the peaks of the two- and three-particle interactions. It is shown that, at high energy, the simplest diagrams make an important contribution to the amplitude of the cumulative meson formation. The differential cross section calculated for the formation of π$^{-}$ mesons at 0 in the reaction (d + p) is in good quantitative agreement with experimental data.
Show AbstractThe analytical properties of the refractive indices of normal waves are considered, for the example of normal waves in laminar media and surface waves. It is shown that the possibility of wave transmission through the layer is characterized by the appearance of branching points in functions of the refractive index not lying on the real frequency axis and violating the condition of applicability of dispersion relations of Kramers - Kronig type to normal waves. In the case of surface waves, analogous disruption of analyticity characterizes the possibility of the emission of surface-wave energy into the volume of the medium.
Show AbstractOn the basis of athree - dimensional representation of the transmission function of an electrostatic analyzer with cylindrical plates, a method of practical calculation of the basic parameters of an analyzer with a slit diaphragm at the inlet is developed. The characteristics of an analyzer with specified properties are calculated. The characteristics obtained are in good agreement with the results of experimental verification.
Show AbstractFull - scale investigations are performed in the coastal region of the sea. As a result of analyzing the spectra of temperature, flow, velocity, and components of the wind velocity,oscillations at a frequency of 0.40 cycle/hr due to internal waves are discovered.It is suggested that wind is the energy source.
Show AbstractA mathematical model of the variation in oxygen concentration in a fresh-water basin with radiant heating from above is constructed.In the model, the consumption of oxygen, the oxidation of organic material, and the settling of suspended organics to the bottom are taken into account. The diffusion coefficients of oxygen and organic material and also the rate of settling of the organics are regarded as constant. The boundary condition adopted for oxygen at the water surface is the condition of local thermodynamic equilibrium, taking the consumption of oxygen in the oxidation of organic material in the surface film into account. The system of diffusion. equations obtained is solved numerically on a BESM-6 computer. The results of the calculation are compared with experimental data from the Moscow State University thermal basin. The discrepancy between the theoretical and experimental values of the oxygen concentration is no more than 10$. The model may satisfactorily describe the extremal situation when summer heating of the basin coincides with a prolonged period of calm weather.
Show AbstractMethods of integrating systems written in Hamiltonian form are considered. On the basis of the method of canonical transformations, a general solution is obtained. It is shown that an arbitrary function of the coordinates and the momenta, depending on the time in view of the system, may bewritten in the form of P-order edexponentials. As an example, the solution of equations for Airey functions is considered. An algorithm of canonical transformation to mean variables and the Hamiltonian of the mean motion is considered. In the last section, a new derivation is obtained for the equations determining the eigenfunctions and eigenvalues. An algorithm is presented for the solution of the eigenvalue problem and the calculation of an arbitrary function of the matrix elements in all orders with respect to the small parameter.
Show AbstractThe angular correlation function of the reaction of $^{12}$C(p,p'N) with l-GeV protons is investigated. It is shown that the differential cross section increases with departure from the reaction plane. This effect must be taken into account in investigating giant resonances in coincidence experiments.
Show AbstractFor an arbitrary specified background space - time, an action of Fokker type to arbitrary order in the gravitational - interaction constant is constructed for a trial particle interacting with a certain material system characterized by a specified energy - momentum tensor. It is shown that the equations of motion of the trial particle following from this principle are quations of the geodesic line in some effective metric depending on the variables of the system.
Show AbstractThe damping of the lowest mode of surface waves on a liquid sphere as a result of nonlinear interaction with other capillary modes of higher order is investigated. The problem is solved within the framework of the method of Hamiltonian formalism.
Show AbstractPotentials leading to an equidistant spectrum are investigated by the method of the inverse spectral problem. Using a reference potential in the form of a harmonic oscillator with a centrifugal barrier , a class of potentials with equidistant energy levels coinciding with those of the reference potential is found. New eigenfunctions are found . Asymptotic expressions are given for the potential and the wave functions. The case in which an additional level is switched on is investigated. This method of recovering the potential may also be used in the case of arbitrarily positioned energy levels.
Show AbstractAt room temperature , the laws of photosensitivity (PS) change of GaAs (Cr) crystals by spectral and integral bias lighting are investigated. Nonreproducibility of the spectral photoresponse i$_M$ at the intrinsic-PS maximum is found. Since the time relaxation p$_T$(t), μ$_nT$(t) after illumination in the region of the impurity quenching effect (QE) occurs in a matter of days , it may be concluded that deep donors play an important role in the formation of GaAs (Cr) PS and also that compensational inhomogeneity associated with strong filling of the working levels by electrons is present in n samples. It is shown that stimulation effects may be due to liquidation of the inhomogeneity by the illumination, even such as to cause QE by predominant hole generation at larger I.
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