Effect of thermal cycling on the stress-strain state of a rotating disk

The effect of repeated thermal cycling on the stress-strain state of a rotating disk is investigated. It is demonstrated that repeated temperature cycling in a given regime nearly doubles the deformation of the rotating disk. This suggests the probability of a major influence of thermal cycling on the deformed state of the rotating disk.Translated From Problemy Prochnosti, No. 1, pp. 57–62, January, 1991.     

Features of the photoconductivity of iodine-doped cotton fibers illuminated in the fundamental absorption range

The photoelectric properties of cotton fibers treated with iodine were studied in the fundamental absorption range. The samples exhibit a sublinear illumination-current characteristic and a long-term relaxation of photoconductivity (PC) after UV irradiation (hν=5 eV) of the iodine-doped fibers. A PC mechanism is proposed which explains both the nonlinear variation of photocurrent with illumination intensity and the PC decay according to a bimolecular recombination law after UV irradiation of the iodine-doped fiber in the fundamental absorption range.     

Characteristics of a descending dispersed-annular flow

Experimental data on the loss of liquid from the surface of a film and the resistance of dispersed-annular flow are presented.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 52, No. 6, pp. 925–929, June, 1987.     

Many-body effects and electron tunneling in metal-insulator-p-type semiconductor structures

Investigation of the tunneling conductivity σ _d(V) of structures made on a highly doped, narrow-gap p-type semiconductor HgCdTe reveals an abrupt increase in this quantity at voltages corresponding to the start of tunneling into the conduction band. It is shown that the observed functions σ _d(V) cannot be described in the framework of a model based on single-particle tunneling. It is proposed that the abrupt increase in σ _d(V) is attributable to tunneling into exciton states. Fiz. Tekh. Poluprovodn. 32, 1069–1072 (September 1998)     

Oxidation of boron silicide and materials based on it

Boron silicide and compounds based on it containing titanium, chromium, nickel, and yttrium and scandium oxides are studied for their oxidation in air from room temperature to 1300°C. It is shown that chromium boride markedly improves the heat resistance of B₄Si over a wide temperature range (700–1300°C) probably as a result chromium-oxide dissolution in borosilicate glass and alteration of its structure. A favorable effect of yttrium and scandium oxides as well of nickel silicide appears at above 100°C as a result of forming complex oxide compounds in the scale.     

A RHEED study of the transition from two-dimensional to three-dimensional growth in the InAs/GaAs system

A specially developed detection system and an analysis of RHEED diffraction patterns were used to investigate the dynamics of transition from two-dimensional to three-dimensional growth mechanism in the heteroepitaxial InAs/GaAs system. An analysis of the dynamics of the diffraction patterns was used for the first time to investigate the dynamics of formation of quantum dots. A time shift in the dynamic behavior of the diffracted intensity for diffraction patterns recorded at different angles was found. This shift is explained in terms of the size differences in the three-dimensional islands at the initial stage of decay of the pseudomorphic layer. InAs/GaAs quantum dots grown under certain conditions produce reflections at 45° relative to the principal reflections. This is evidence for the ordering of islands in the [001] and [010] crystallographic directions. Fiz. Tekh. Poluprovodn. 31, 1230–1232 (October 1997)     

Band of Selective Transmission of Electromagnetic Radiation by an Absorbing Dielectric Layer

Equations for determining the frequency band near the frequency of selective reflectionless transmission of electromagnetic radiation by a layer of an absorbing dielectric which separates two nonabsorbing media with dissimilar optical densities have been obtained. The absorption band of the wave in the dielectric layer as a function of the dielectric properties and thickness of the layer and of the dielectric properties of the separated media has been evaluated.     

Determination of the characteristic length of thickness fluctuations for a tunneling-thin insulator in MIS structures from electrical data

New methods for determining the “correlation length” for thickness fluctuations of a thin insulator film from data obtained in measurements of the electrical characteristics of MIS tunnel structures, i.e., without the use of microscopy, have been suggested and tested. One of these methods relies on statistical processing of electric current data for a random sample of structures. The other technique analyzes abrupt downward changes in current, observed in tests of devices under a sufficiently high bias. The methods have been tested on Al/SiO₂/Si tunnel structures. The resulting estimates of the characteristic scale of thickness fluctuations are compared with the data obtained in direct measurements of this scale for the same oxide layers.