The dependence of the quality of a screened layered spherical resonator on its geometric and electrodynamic parameters is studied in the case of a three-layer dielectric filling on the basis of a mathematical model constructed in the paper.
Show AbstractThe minimum distance between conjugate points on a geodesic with the curvature given by a random renewal process is estimated. It is shown that, in the zero-curvature limit, the problem is reduced to analysis of the intersection of the level by a certain diffusion process with reflection.
Show AbstractControlled 2D dissipative tunneling in systems of coupled quantum molecules is studied in the quasi-classical (instanton) approximation. It is shown that, with allowance for the electron tunneling trajectory bifurcation, the effect of two-particle wave function blocking in a system of coupled quantum molecules is observed when the radii of quantum dots (making up the quantum molecules) coincide. If the influence of a thermostat medium is neglected, blocking is replaced by a “kink” in the tunneling probability as a function of the asymmetry parameter of quantum molecules.
Show AbstractThe relationship is considered between the topology of a domain on which the boundary-value problem for the equation $\Delta v+\lambda v=f$ is stated and that of the corresponding Sobolev space. The Jones theorem is generalized so as to make it closer to the Weyl-von Neumann theorem.
Show AbstractThe fundamental mechanism of energy loss from a Gaussian beam scattered by the edge of a corner reflector is considered. An independent calculation is performed to estimate the relative losses for different polarizations with allowance for the Goos-Hanchen shift effect. For the angle of incidence $\alpha=\pi/4$, the relative energy losses by waves polarized along the reflector’s edge and normally to this direction are estimated at ($(W_\textbf{diff}/W_\textbf{inc})_E\simeq7.03(\lambda_0/a)$) and $(W_\textbf{diff}/W_\textbf{inc})_H\simeq3.82(\lambda_0/a)$, respectively, where $\lambda_0$ is the wavelength in free space and $a$ is the effective radius of the beam.
Show AbstractBuffer performance of mitochondria in intracellular calcium signaling is studied in relation to the amount of cytosolic calcium-binding proteins and calcium ion fluxes across the plasma membrane of the cell.
Show AbstractFrequency dependences are obtained of the conductivity in Langmuir films of modified vanadyl phthalocyanine in vacuum and under the conditions of adsorption of donor and acceptor molecules. It is found that, upon the adsorption of NO$_2$ and CH$_4$O molecules, the film conductivity at $f<10$ kHz increases by several orders of magnitude. It is shown that, in vacuum and upon adsorption of acceptor molecules, the dominant charge transfer mechanism is the hopping of holes via localized states. In the case of adsorption of donor molecules, the ionic conductivity mechanism appears to prevail.
Show AbstractIn terms of the full nonlocal theory, an expression for the form factor of a smooth nonlocal model potential in an elementary metal is computed.
Show AbstractA theory of the helix-coil transition in solutions containing a denaturing agent is proposed. It is shown that, if the transition is induced by an increase in the concentration of the denaturant, the range of the conformational transition narrows with a growing activity of the agent. In contrast, if the transition is induced by temperature variation, addition of a denaturant makes the transition broader, the more so for a higher activity of the agent. The results of the computation agree with published experimental data.
Show AbstractFluorescence spectroscopy with the application of fluorescent molecular probes is used to determine the temperature ranges in which vitrification of the surface layer of polystyrene with different molecular masses typically occurs. It is found that the surface vitrification temperature is significantly lower than the bulk values. The results of the study are in good agreement with the data obtained earlier using an independent technique.
Show AbstractA technique of statistical wavelet analysis is proposed and tested for applicability to the data of radio sounding of the ionosphere by navigation signals of the global positioning system. Important advantages of wavelet analysis over spectral analysis are demonstrated, including performance under short-term fault conditions.
Show AbstractOn the basis of an elaborated theory and numerical computation, it is inferred that typhoons and hurricanes can originate in a region filled by convective turbulent mesovortices.
Show AbstractThe data obtained on the ACTIVE, SAMPEX, and TIROS-N satellites are used to study the dynamics of low-energy (from tens of keV to several MeV) proton fluxes in the region of the geomagnetic equator (${L<1.15}$) at low altitudes (up to 1000 km). The dependence of the fluxes on the local magnetic time is presented. A number of magnetic disturbances in November–December 1978 are analyzed to illustrate the dependence of the flux on the geomagnetic activity level. The results obtained allow the conclusion that the ring current is one of the main sources of protons at low altitudes in near-equatorial latitudes.
Show AbstractA model of acoustic gravity wave propagation is developed and a numerical algorithm for solving the corresponding hydrodynamics equations is elaborated. Behavior of the waves in the upper atmospheric layers is studied in relation to the parameters of the ground-based sources.
Show AbstractThe clock rate in the spaceborne OSIRIS instrument has been studied. It is shown that the relativistic and gravitational effects should be controlled to within 0.1% to obtain the required accuracy of astrometric measurements.
Show AbstractNumerical simulation of self-modulation lasing regimes has been carried out for a СО$_2$ laser with transverse flow of the active medium through an unstable resonator with inhomogeneous internal pumping. Two types of steady-state self-modulation oscillation differing in the feedback mechanism were observed. The type of lasing regime and the conditions of its realization depend both upon the pumping profile and upon the composition and pressure of the working mixture, which makes it generally possible to control temporal characteristics of lasing.
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