Том 81, № 1 (2017)

The model of a polarization-preserving anisotropic mirror is proposed. The mirror is a plane boundary of a metal–dielectric nanocomposite that consists of silver spheroidal nanoparticles dispersed in a transparent matrix. The dependence of reflection spectra on the shape of the nanoparticles is studied. It is shown that in one region of the spectrum, the mirror preserves the sign of polarization in the reflected light.

The impact disordered coating has on the energy level excitation of its molecules via a cascade mechanism under the effects of terahertz pulses with a small number of periods is investigated. It is shown that the presence of a disordered structure can reduce the intensities of spectral lines induced by the cascade process even if the structure is behind the medium.

The problem of generating the entangled states of two parametrically coupled quantum oscillators at finite temperatures is considered. For coherent pumping, an analytical expression describing the behavior of logarithmic negativity is obtained using the Heisenberg–Langevin formalism. The expression also describes the attaining of a long nonzero steady-state value of logarithmic negativity. It is shown numerically that pumping noise limits the lifetime of entanglement in the system.

The dynamics of electrons in a multiwave Cherenkov oscillator are analyzed, based on the results from numerical modeling. It is shown that a flux of charged particles moving contrary to the initial beam is formed at the moment of generating a radiation pulse in an oscillator. The basic parameters of this backward beam are given.

The single-particle electron energy spectrum and total electron energy spectra of a hydrogenically passivated central fragment of a coordination compound of rhodium with an aurophile terpyridine derivative (CCRATD) in different charge states ranging from–3e to +3e are obtained. The electron transport characteristics for a single-electron molecular transistor based on a CCRATD molecule are calculated and analyzed.

Longitudinal and transverse high-frequency conductivities of a graphene superlattice placed in an additional dc electric field are calculated. It is shown that in a sufficiently strong transverse field, the dependence of the longitudinal high-frequency conductivity of the superlattice on the ac field frequency changes. This effect is explained by the nonadditivity of the electronic spectrum of the investigated structure.

A plasma equation of state in a gas domain is derived from Saha model accounting for ion cores. Calculations for Cu are performed using the stiff ion core model for densities of up to 10⁶ g/cm³. A compressible ion core model is also developed. The Tomas–Fermi model is applied to condensed plasma. Both models are unified into a thermodynamically consistent equation of state.

Modern surface wave–based approaches to the deep sounding of the Earth are compared, along with results from reconstructing deep structure of the Hawaiian plume, obtained by phase and amplitude methods. Ways of further improving these methods are proposed.

An experiment on sound propagation in a shallow natural pond covered with an ice layer is described. The results from processing the experimental data are presented. It is found that the sound propagates along the ice-covered water layer and at the pond’s bottom. The corresponding velocities are determined.

The radiation force generated upon the scattering of a quasi-Gaussian acoustic beam on a homo-geneous elastic sphere in a fluid is investigated. It is shown that the force depends nonmonotonically on the ratio between the sphere’s diameter and the beam’s waist. For a given beam power, the radiation force has its maximum value when the diameters are roughly egual to each other. This is due to the resonant excitation of shear waves on the sphere’s surface under the impact of acoustic wave in the surrounding fluid.

The results from in situ and post-exposure studies of the effect an electron beam has on the optical characteristics of a tellurium dioxide single crystal are presented. The acoustooptical material is irradiated with electrons having an energy of 5 MeV. The transmission and absorption spectra of the paratellurite crystal are measured at different absorbed radiation doses. The dose dependence of the intensity of light with a wavelength of 357 nm transmitted through the crystal is determined.

Features of thermal bar development in a fresh water reservoir during ice cover melting are investigated by means of mathematical modeling. It is shown that the presence of water with the temperature of maximum density (4°C) leads to two opposite effects. On the one hand, a thermal bar forms near the shore and moves to the center of the water basin; on the other hand, an eddy arises near the ice edge, which slows down the process.

A procedure for recurrent increasing of the order of accuracy is described for the FDTD method. This approach does not require any modification of the standard equations. As a test problem, Gaussian pulse propagation in free space is considered. Calculations with increasing of the accuracy order up to six are performed. A posteriori asymptotically precise error estimate for the numerical solution is obtained.

The generality of synergetic principles in the processes of autowave self-organization in active media makes allows us to apply a model that describes evolving physicochemical and biophysical systems based on a modified system of FitzHugh–Nagumo equations for the development of a spatiotemporal stock market model with motive Elliott waves as its most common pattern.