Temperature dependence of charge transferred by dislocation in Kcl: Ba crystals

Abstract

The electrical charge assosiated with dislocation motion in KCl:Ba has been studied within the interval from 77 to 292K using on indentation method. The comparison of the potential difference values at 77 and 292K was performed on condition that the impression diagonals were roughly equal. The kinetics of the potential change was studied.     

Characterization of Metal Shells with Internal Coating by the Method of Nonstationary Thermography

Russian Physics Journal -     

Using arc-excitation atomic emission spectrometry in studying the microelement composition of bottom sediments

A procedure is developed for the simultaneous determination of trace metals in river, sea, and lake bottom sediments by atomic emission spectrometry. A present-day scenario using a new system of spectrum record and universal buffer mixtures ensures sufficiently reliable results of analysis of samples of complex composition.     

Photosensitizing Antivirals

Antiviral action of various photosensitizers is already summarized in several comprehensive reviews, and various mechanisms have been proposed for it. However, a critical consideration of the matter of the area is complicated, since the exact mechanisms are very difficult to explore and clarify, and most publications are of an empirical and “phenomenological” nature, reporting a dependence of the antiviral action on illumination, or a correlation of activity with the photophysical properties of the substances. Of particular interest is substance-assisted photogeneration of highly reactive singlet oxygen (¹O₂). The damaging action of ¹O₂ on the lipids of the viral envelope can probably lead to a loss of the ability of the lipid bilayer of enveloped viruses to fuse with the lipid membrane of the host cell. Thus, lipid bilayer-affine ¹O₂ photosensitizers have prospects as broad-spectrum antivirals against enveloped viruses. In this short review, we want to point out the main types of antiviral photosensitizers with potential affinity to the lipid bilayer and summarize the data on new compounds over the past three years. Further understanding of the data in the field will spur a targeted search for substances with antiviral activity against enveloped viruses among photosensitizers able to bind to the lipid membranes.     

Kinetic features of the deformation of solids in nano-and microscopic volumes

The deformation dynamics of nanovolumes in crystalline, quasicrystalline, and amorphous solids is studied experimentally using continuous nanoindentation with a resolution of 0.1 nm. The elastic limits of some materials are determined in a nanocontact region. A jumplike transition to a plastic flow (which is equivalent to a drop in yield in uniaxial macroscopic tests) is revealed and studied. The dynamics and statistics of an unstable plastic flow in strain-aging alloys are analyzed. The specific features of a local stress-strain curve associated with a phase transformation under an indenter and with microcrack nucleation are revealed. The load-carrying ability of a material upon nanocontact loading is shown to be many times its macroscopic yield strength and to approach the theoretical ultimate strength even in plastic materials. The relaxation processes occurring in submicrovolumes after unloading are found to induce an elastic aftereffect that is much larger than that in macroscopic tests. In Si and Ge single crystals, the effect of a jumplike increase in the cracking resistance with the strain rate is detected.     

Effect of the shape of the light pulse on the optical breakdown threshold of transparent dielectrics

The problem concerning the nonsteady heating by a light pulse of arbitrary shape, of an insulated metallic microparticle located in a transparent dielectric, is solved. The effect of the shape of the heating pulse on the nature of heating up of the inclusion is investigated. The results of the paper can be used for the experimental verification of the heat-conductivity theory of breakdown of solid transparent dielectrics.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 77–81, February, 1979.In conclusion, the authors thank V. A. Gorshkov for assistance in carrying out the calculations.     

Self-oscillatory heterogeneous recombination of hydrogen atoms and nonequilibrium desorption of molecules from the surface (Teflon)

The channel of the accommodation of the energy of a heterogeneous chemical reaction (recombination of hydrogen atoms) related to vibrational V-V exchange between excited chemical reaction products and adsorption layer molecules (H₂O, HDO, D₂O, and H₂) was studied by the method of modulated molecular beams. The chemical reaction was found to proceed in an oscillatory mode caused by the nonequilibrium character of its elementary steps. The participation of adsorbed molecules in accommodation was studied by analyzing nonequilibrium desorption of these molecules. An isotope effect was observed in nonequilibrium desorption. The kinetic mechanism of the reaction and the micromechanism of elementary reaction events, which determine the “physical” mechanism of catalysis in the system under study, are discussed.