Bitsadze-Samarskii type problem for the integro-differential diffusion-wave equation on the Heisenberg group

This paper deals with the fractional generalization of the integro-differential diffusion-wave equation for the Heisenberg sub-Laplacian, with homogeneous Bitsadze-Samarskii type time-nonlocal conditions. For the considered problem, we show the existence, uniqueness and the explicit representation formulae for the solution

PECULIARITIES OF THE DETERMINATION OF THE TEMPERATURE OF A FREELY BURNING ARC DISCHARGE FROM SELF-REVERSED RESONANCE SPECTRAL LINES OF ATOMS.

The results of calculations of the nonuniformity parameter M, used in determining the plasma temperature by Bartels' method, for self-reversed Na I 589. 0/589. 6 nm and Al I 308. 2 nm lines, emitted by an arc discharge burning freely in air, are presented. The calculations were performed for models of the positive column of the arc taking into account the ionization of atoms and the changes in the broadening of the lines in the radial direction. The effect of these factors in calculations of M are discussed

Spectroscopic diagnostics of a strongly inhomogeneous optically thick plasma. Part 2. Determination of atom concentration and variations of different physical values in the plasma cross-section using asymmetric self-reversed emission and absorption lines

The possibility of determining electron impact half-width and electron concentration, atom concentration and radial distributions of different physical values using the profiles of asymmetric self-reversed emission and absorption lines simultaneously and sequentially recorded over the plasma cross-section is examined. © 1995

Spectroscopic diagnostics of a strongly inhomogeneous optically thick plasma. Part 1. The formation of asymmetric self-reversed emission and absorption lines: determination of electron impact half-width and electron concentration

An analysis has been carried out of the profiles of asymmetrically self-reversed emission lines and of absorption lines using various models for inhomogeneous optically thick plasmas. Conditions of impulsing discharge, exploding wires, sparks, plasma jets, laser ablation of a target, etc. were considered. The possibility of determining electron impact half-width and electron concentration from the wings of asymmetrically self-reversed lines is considered. © 1995 Elsevier B.V. All rights reserved

Geometry-induced reduction of the critical current in superconducting nanowires

Reduction of the critical current in narrow superconducting NbN lines with sharp and rounded bends with respect to the critical current in straight lines was studied at different temperatures. We compare our experimental results with the reduction expected in the framework of the London model and the Ginsburg-Landau model. We have experimentally found that the reduction is significantly less than either model predicts. We also show that in our NbN lines the bends mostly contribute to the reduction of the critical current at temperatures well below the superconducting transition temperature

A wavelet-based technique for eliminating noise from optical spectra

In the paper we deal with the removal of noise from an optical spectral line of Cu I (330.79 nm: 4P12F0 - 4d14G). For this purpose we use wavelet denoising algorithm along with the minimal energy criterion that allows one to effectively divide the signal into "useful" and parasite components. This approach is tested on an example of reconstruction of a Lorenzian profile blurred by a random fractal noise