Erratum to: Several Articles in JETP Letters Published Online First

JETP Letters - An Erratum to this paper has been published: https://doi.org/10.1134/S0021364022330013     

In situ FTIR investigation of adsorption properties of sub-micron Cu2O-doped RuO2 sensing electrode of planar potentiometric pH sensor

In situ Fourier transform infrared spectroscopy (FTIR) was used to study adsorption properties of 20?mol% Cu₂O-doped RuO₂ sensing electrode (SE) screen-printed on the platinised alumina substrate of the planar electrochemical pH sensor and subsequently sintered at 800?°C. Morphology and properties of developed SEs were characterized by X-ray diffraction, scanning electron microscopy, atomic force microscopy and FTIR techniques. It was shown that both Cu₂O doping and changes in the sintering condition of the SE affected morphology and adsorption spectra of 20?mol% Cu₂O-doped RuO₂. Fundamental vibration frequencies of ruthenium?Coxygen bond at a temperature of 23?°C as well as region above fundamental frequencies for the sub-micron 20?mol% Cu₂O-doped RuO₂-SE were identified.     

Photoluminescence of single quantum wires and quantum dots

The results of a study into the photoluminescence spectra of a set of quantum dots based on GaAs enclosed in AlGaAs nanowires are presented. The steady state and time resolved spectra of photoluminescence under optical excitation both from an array of quantum wires/dots and a single quantum wire/dot have been measured. In the photoluminescence spectra of single quantum dots, emission lines of excitons, biexcitons and tritons have been found. The binding energy of the biexciton in the studied structures was deduced to be 8 meV.     

A Mathematical Model for Hysteretic Two-Phase Flow in Porous Media

We develop a mathematical model for hysteretic two-phase flow (of oil and water) in waterwet porous media. To account for relative permeability hysteresis, an irreversible trapping-coalescence process is described. According to this process, oil ganglia are created (during imbibition) and released (during drainage) at different rates, leading to history-dependent saturations of trapped and connected oil. As a result, the relative permeability to oil, modelled as a unique function of the connected oil saturation, is subject to saturation history. A saturation history is reflected by history parameters, that is by both the saturation state (of connected and trapped oil) at the most recent flow reversal and the most recent water saturation at which the flow was a primary drainage. Disregarding capillary diffusion, the flow is described by a hyperbolic equation with the connected oil saturation as unknown. This equation contains functional relationships which depend on the flow mode (drainage or imbibition) and the history parameters. The solution consists of continuous waves (expansion waves and constant states), shock waves (possibly connecting different modes) and stationary discontinuities (connecting different saturation histories). The entropy condition for travelling waves is generalized to include admissible shock waves which coincide with flow reversals. It turns out that saturation history generally has a strong influence on both the type and the speed of the waves from which the solution is constructed.     

Influence of impurity and indentation time on dislocation rosettes

It has been shown that the impurity type and indentation time affect appreciable on dislocation rosettes of NaCl single crystals. It was established that the growth of indentation diagonal was not practically followed by the increase of the dislocation zone size. This phenomenon connected with the cross slip processes, which are perhaps more intensive for prolonged indentation time and high temperatures. The assumption is made that the two mechanisms of responsible for indentation formation the movement of dislocations and their multiplication by the cross slip.     

Deflection of IR-radiation in n-InSb in the presence of temperature-electrical instability in a magnetic field

The formation of an S-shaped volt-ampere characteristic (VAC) during the heating of a specimen of n-type indium antimonide by a dc electric current in the presence of an external magnetic field is considered. In the calculation of the VAC the temperature dependences of the band gap width, the carrier density, the mobility, and the heat conductivity are taken into account. The angle of deflection of IR-radiation in indium antimonide is calculated using the density distribution over the cross section of the specimen derived from the integration of heat conductivity equation. The experimental and theoretical dependences of the deflection angle on the current are in agreement in order of magnitude and indicate that it is possible to use the temperature instability for the construction of laser radiation deflectors in the IR range.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 11, pp. 35–40, November, 1984.The authors are grateful to V. L. Bonch-Bruevich and I. P. Zvyagin for useful discussion and valuable critical remarks.     

The cubic algorithm

A nongradient algorithm for nonlinear nonconvex Lipschitzian optimization problems is proposed.     

Toward a theory of diffraction by the boundary of a highly reflective medium with periodically modulated characteristics

The problem of diffraction by simultaneously existing surface-profile and impedance gratings in the presence of resonance with a surface electromagnetic wave is examined. The problem is solved in an impedance approximation (Leontovich boundary condition) using Rayleigh's hypothesis. The solution method is based on the distinguishing of resonance fields, for which a finite system of equations is constructed. A proposed regular procedure for exclusion of nonresonance fields makes it possible to obtain a solution with any accuracy for any polarization of the incident radiation and orientation of the gratings. Specific results are given in a principal approximation for the case of several resonances in the first-order spectra.Scientific-Industrial Organization Metrology. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika, Vol. 35, Nos. 3, 4, pp. 234–245, March–April, 1992.     

Autoionization of Excitons in Organic Solar Cells

It has been shown that in addition to the conventional mechanism of photovoltaic effect in organic solar cells (OSCs), which is the ionization of molecular excitons on impurities, a new mechanism is possible in nanoscale cells, namely, tunneling autoionization in a strong electric field of the pn junction. Its quantum yield for molecular excitons and charge-transfer excitons becomes higher than for ionization on impurities with a cell length of less than 20–25 or 60–80 lattice periods (~10 and ~25 nm), respectively. The possibility of creating cascades of series-connected OSCs with a quantum yield close to 1 on the basis of the new mechanism is discussed.