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

Low-frequency dynamics of disordered XY spin chains and pinned density waves: from localized spin waves to soliton tunneling

A long-standing problem of the low-energy dynamics of a disordered XY spin chain is re-examined. The case of a rigid chain is studied where the quantum effects can be treated quasiclassically. It is shown that as the frequency decreases, the relevant excitations change from localized spin waves to two-level systems to soliton-antisoliton pairs. The linear-response correlation functions are calculated. The results apply to other periodic glassy systems such as pinned density waves, planar vortex lattices, stripes, and disordered Luttinger liquids.Comment: (v2) Major improvements in presentation style. One figure added (v3) Another minor chang

Radiation-induced hydrogen transfer in metals

The paper presents processes of hydrogen (deuterium) diffusion and release from hydrogen-saturated condensed matters in atomic, molecular and ionized states under the influence of the electron beam and X-ray radiation in the pre-threshold region. The dependence is described between the hydrogen isotope release intensity and the current density and the electron beam energy affecting sample, hydrogen concentration in the material volume and time of radiation exposure to the sample. The energy distribution of the emitted positive ions of hydrogen isotopes is investigated herein. Mechanisms of radiation-induced hydrogen transfer in condensed matters are suggested

Electron spin resonance detection and identification of nitrogen centers in nanodiamonds

Individual nitrogen centers N0 and nitrogen pairs N 2 + have been detected and identified in natural diamond nanocrystals by means of the high-frequency electron spin resonance method. The N0 nitrogen centers have been observed in synthetic diamond nanocrystallites with a size of less than 10 nm produced by high-temperature high-pressure sintering of detonation nanodiamonds. Thus, the possibility of the stable state of impurity nitrogen atoms in diamond nanoparticles has been demonstrated. © 2009 Pleiades Publishing, Ltd

Rarefactions and large time behavior for parabolic equations and monotone schemes

We consider the large time behavior of monotone semigroups associated with degenerate parabolic equations and monotone difference schemes. For an appropriate class of initial data the solution is shown to converge to rarefaction waves at a determined asymptotic rate.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46470/1/220_2005_Article_BF01229452.pd

Non-thermal response of YBCO thin films to picosecond THz pulses

The photoresponse of YBa2Cu3O7-d thin film microbridges with thicknesses between 15 and 50 nm was studied in the optical and terahertz frequency range. The voltage transients in response to short radiation pulses were recorded in real time with a resolution of a few tens of picoseconds. The bridges were excited by either femtosecond pulses at a wavelength of 0.8 \mu m or broadband (0.1 - 1.5 THz) picosecond pulses of coherent synchrotron radiation. The transients in response to optical radiation are qualitatively well explained in the framework of the two-temperature model with a fast component in the picosecond range and a bolometric nanosecond component whose decay time depends on the film thickness. The transients in the THz regime showed no bolometric component and had amplitudes up to three orders of magnitude larger than the two-temperature model predicts. Additionally THz-field dependent transients in the absence of DC bias were observed. We attribute the response in the THz regime to a rearrangement of vortices caused by high-frequency currents

Writing Russia's future: paradigms, drivers, and scenarios

The development of prediction and forecasting in the social sciences over the past century and more is closely linked with developments in Russia. The Soviet collapse undermined confidence in predictive capabilities, and scenario planning emerged as the dominant future-oriented methodology in area studies, including the study of Russia. Scenarists anticipate multiple futures rather than predicting one. The approach is too rarely critiqued. Building on an account of Russia-related forecasting in the twentieth century, analysis of two decades of scenarios reveals uniform accounts which downplay the insights of experts and of social science theory alike