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Vinnichenko Maxim Ya., Firsov Dmitry A., Mashko Marina O., Shterengas Leon, Belenky Gregory L., Vorobjev Leonid E.

Electron recombination and capture in laser nanostructures with InGaAsSb/AlGaAsSb quantum wells

Published in category «Condensed matter physics»

Time dynamics of photoluminescence intensity was studied in InGaAsSb/AlGaAsSb quantum wells with different compositions of the barrier solid solution. The charge carrier capture time in quantum wells, the energy relaxation times, the lifetime related to resonant Auger recombination were estimated. It was shown that under certain design of nanostructures the resonant Auger recombination can be observed. The influence of temperature and structure design on the Auger recombination rate is discussed.

Views: 2028 Comments: 0

Shaganov Anton P., Filimonov Alexey V., Koroleva Ekaterina Yu., Fotiadi Alexander E.

The formation of polar nanoregions and nanodomains in SBN-61 single-axis relaxors

Published in category «Condensed matter physics»

The paper is devoted to application of a synchrotron radiation scattering method to the analysis of domain structure ofSr0.6Ba0.4Nb2O6 (SBN) samples. It is experimentally established that at high temperature there are polarizing centers of the varied size in the SBN-61 samples, with center distances down to the units of micron. Domain structure formation in SBN-61 is accompanied by partial disordering caused by increasing of polarization fluctuations. The polarization in the volume of the samples in question was correlated, and a direction of preferred correlation can change depending on the general ordering.

Views: 1923 Comments: 0

Yurova Valentina A., Fedortsov Alexander B., Klimchitskaya Galina L., Churkin Yuri V.

The Casimir force pressure onthe dielectric layer in nanoscale solid-state multilayer Al - SiO2 - Si structures

Published in category «Condensed matter physics»

The calculation of the dispersion forces pressure value on the dielectric layer in solid-state multilayer Al - SiO2 - Sistructure widely used in electronic components production is presented. It is shown that the pressure increases sharply in the nanometer range of the dielectric thickness and at the thickness of 1 nm reaches the value of 8 MPa. The calculation results do not depend on the dielectric permittivity model of the structure matters.

Views: 1613 Comments: 0

Lamkin Ivan A., Menkovich Ekaterina A., Tarasov Sergey A.

Ultraviolet photodiodes on the basis of the contactsof metal and aluminum-nitride gallium solid solutions

Published in category «Condensed matter physics»

The paper considers the problem of creating high-quality ohmic and rectifying contacts to AlGaN solid solutions with a high degree of Al. The basic problems connected with creating ultraviolet photosensitive structures based on the contact metal - AlGaN solid contacts are presented.

Views: 1227 Comments: 0

Radchuk Natalia B., Ushakov Alexander Yu.

Optical properties of transition metals nanocomposites

Published in category «Condensed matter physics»

The paper contains results of investigation of transition metals nanocomposites on the basis of arabinogalactan. Absorption spectra, optical activity and methods of nanocomposites synthesis are considered.

Views: 1225 Comments: 0

Kvashenkina Olga E.

Features of electronic phase transition in VO2

Published in category «Condensed matter physics»

The details of several stages of the thermal metal-semiconductor phase transition (MSPT) in vanadium dioxide films are experimentally studied. The idea of a joint and coherent coexistence of the two components of MSPT - the electronic and structural components - is substantiated. The problem of the type of metal-semiconductor phase transition in vanadium dioxide is discussed.

Views: 1009 Comments: 0

Basalkevich Tatiana M., Talnishnikh N.A., Shmidt Natalia P.

Development features of degradation processes in high-power blue InGaN/GaN light-emitting diodes

Published in category «Experimental technique and devices»

The paper describes the features of degradation processes, the current-voltage characteristics, electroluminescence spectra and external quantum efficiency. The reasons for the rapid development of degradation processes in high-power blue InGaN /GaN light-emitting diodes, complicating the prediction of their service life, are elucidated.

Views: 1867 Comments: 0

Gonchar Igor V., Ivanov A.S., Fedortsov Alexander B.

A fast-operating interferometry device for measuring films thickness over the range from ten to one thousand microns

Published in category «Experimental technique and devices»

A fast-operating laser-interferometric device for measuring the thickness of films which are transparent in visible or infrared ranges is described in this work. The thickness of the films to be investigated is from 10 µm to 1 mm. Measuring frequency is 25 times per second, time of one measurement is 3·10-4 s. This allows measuring the thickness of unstable films including liquid ones. Due to combining two ways of determining the thickness in one device (by the number of peaks in the angular dependence of the laser beam reflectance coefficient, and by the value of this coefficient at a given angle of incidence) the error in determining the thickness is only 150 nm.

Views: 1928 Comments: 0

Zolotov Sergey A., Privalov Vadim E.

The influence of active element geometry on gas discharge laser gain factor

Published in category «Physical electronics»

The article deals with new approaches to increase the gain factor of the laser on the He-Ne mixture by changing the geometry of the active element. The amplification gain and the optimum size of the combined sections of the active elements are calculated.

Views: 1802 Comments: 0

Kovalevsky Dmitry V.

Effects of heterogeneity of potential barriers and lattice finiteness in the Kronig - Penney model

Published in category «Physical electronics»

Using the matrix formalism, the wave functions of continuum states and the energies of surface (Tamm) states are calculated in the modified Kronig - Penney model with a special geometry of the potential (an infinitely high potential barrier at the origin of the coordinates, bounding the region of electron motion to positive semi-axis; the height of the potential delta-barrier / the depth of the potential well closest to the origin of the coordinates differs from the height of all other barriers). Particular attention is paid to the case of size quantization in the lattice of finite length

Views: 1503 Comments: 0

Karaseov Platon A., Karabeshkin Konstantin V.

The features of defect formation in silicon under molecular ion bombardment

Published in category «Physical electronics»

Molecular effect in silicon under molecular ion bombardment over a wide energy range is described. Physical mechanisms for explanation of this phenomenon are suggested. Results of experimental studies and computer simulation of processes occurred in Si under Р+ and PF+4. ion bombardment are presented.

Views: 1878 Comments: 0

Kiesewetter Dmitry V., Savina Alla Yu.

The approximation of Rhodamine dyes fluorescence spectra

Published in category «Physical optics»

Using of different functions for approximation of spectra of fluorescence of Rhodamine has been put forward. The fluorescence spectra of solutions and Rhodamine doped polymeric fibers were measured at different temperatures. The accuracy of approximations was defined.

Views: 1661 Comments: 0

Yuhnev Andrey D., Sinitsyna Darya E.

The blood vessel models: the technology development for makingand following investigation

Published in category «Biophysics and medical physics»

Methods of making the human blood vessel silicon models are considered. The procedure for measurement of model andcarotid artery diameters under pulsating pressure of liquid is described. The results of compliant coefficients determinationare given.

Views: 1773 Comments: 0

Lukashova Olga F., Mokrova Darya V., Kafidova Galina A., Perevoznik Dmitry S.

A noninvasive speckle sensor of blood flow velocity in the microvasculature

Published in category «Biophysics and medical physics»

The peculiarities of a noninvasive speckle blood flow velocity sensor development have been considered. Functional elements within the structure of the sensor were optimized, that permitted to produce its mobile version. Also, Bluetooth radio channel, allowing transmitting informational signal to a personal computer for subsequent processing and storage, was included in the sensor e-frame. Experimental results of the sensor testing are presented.

Views: 1683 Comments: 0

Kapralova Victoria M., Nazarova Elena A., Ivanova Nataliya E., Shadrin Evgeniy B.

Albumin conformational changes as a diagnostic parameter

Published in category «Biophysics and medical physics»

Thermoimpedancemetric curves of human serum albumin aqueous solutions of various concentrations and pH are obtained. It is shown that the globule-coil transition in individual globules is observed and the curve shape reflects albuminconformational changes including changes under the different denaturants influence. The possibility of denaturation kinetics study by means of thermoimpedancemetry is demonstrated. Results obtained allow to expand diagnostic capabilities of cerebrospinal fluid thermoimpedancemetry on the conformational diseases.

Views: 1818 Comments: 0

Khaiyrullin Andrey R., Stepanova Tamara P., Rozhkova Natalia N., Gladchenko Svetlana V.

Dipole moments of C60 fullerene in benzene, toluene and orthoxylene

Published in category «Physics of molecules»

The determination of dipole moments of C60 fullerene has been carried out in benzene, toluene and ortoxylene solutionsunder infinite dilution. It was found that dipole moments are 1.0 D, 1.8 D and 2.27 D in toluene, benzene and ortoxylene, respectively.

It means that there are isolated C60 molecules in toluene solution but associated clusters with constant stoichiometry in benzene and ortoxylene solutions.

Views: 1673 Comments: 0

Berdnikov Alexander Ya., Ivanishchev Dmitry A., Kotov Dmitry O., Ryabov Victor G., Ryabov Yuri G., Samsonov Vladimir M.

The measurement of electromagnetical signs of quark-gluon plasma in heavy ion collisions at 62.4 GeV

Published in category «Nuclear physics»

Dilepton spectra in Au+Au collisions at √SNN = 62.4 GeV and calculation of dilepton pair cocktail from known sources have been presented.

Views: 1707 Comments: 0

Pavlov Fedor F.

The calculation of matrix elements for the electromagnetic deuteron current in a formal light description cone

Published in category «Nuclear physics»

The paper investigates the behavior of matrix elements for the electromagnetic deuteron as a function of the momentumtransfer. Matrix elements in question were calculated in the light cone formalism using the criteria for option of matrix elements for the plus-component of the electromagnetic current in the Breit frame.

Views: 1650 Comments: 0

Pavlov Fedor F., Berdnikov Yaroslav A.

Angular condition for matrix elements of the electromagnetic deuteron current

Published in category «Nuclear physics»

The paper is devoted to investigation of Grach-Kondratyuk angular condition. The matrix element of the «plus» component of the electromagnetic current of the deuteron defines four independent functions. Whereas, the matrix element should be expressed in three of the deuteron form factors: the charge, magnetic and quadrupole. This means that there must be additional equation. This equation is called the angular condition. The paper investigates the behavior of this condition as a function of the square of the momentum transfer, and shows its violation.

Views: 1825 Comments: 0

Berdnikov Yaroslav A., Ivanov Alexey E., Kim Victor T., Suetin Daniil P.

Nuclear effects in hadron-nuclear interactions at high energies

Published in category «Nuclear physics»

The process of hard interaction of hadrons with nuclei at high energies is studied, results of modeling of lepton pairs production in hadron-nuclear interactions in the Drell - Yan process are presented. Comparison with experimental data from E772 and E886 collaboration is carried out. Fine matching of HARDPING model with experiment is obtained.

Views: 1800 Comments: 0

Vishnevsky Vyacheslav E., Pustovalova Olga A., Ivanova Olga A., Strecopitova Maria V.

The stability of the stationary polymeasure equilibrium regime

Published in category «Mathematics»

The paper proves the theorems of the stability of the integral manifold of a system of differential equations and the asymptotic stability of the equilibrium regime of a system of differential equations.

Views: 1722 Comments: 0

Pervadchuk Vladimir P., Shumkova Daria B., Dektyarev Dmitry N.

Matters of solvability and derivation of optimization systems in variational problems described by two-dimensional parabolic equations

Published in category «Mathematics»

In this paper we obtain conditions for the solvability of the optimal control of two-dimensional nonlinear equation of parabolic type. In this case the function of optimal control is determined explicitly and depends on the solution of the resulting optimality system.

Views: 1778 Comments: 0

Fedotov Alexey I., Lisin Sergey K.

Using of nonlinear minimization theory for applied problems of design of objects properties

Published in category «Mathematics»

An analysis and a design of objects parameters and their properties have been carried out by application of the minimization theory procedure using experimental data and their restoring. The theory of the best estimation change was taken to extract validly the scientific and technical information from experiments. The strategies for regeneration of experimental dependencieswere developed by means of results representation, experiments deviations and other things.

Views: 1562 Comments: 0

Vasiliev Alexander N., Tarkhov Dmitry A.

Parametrical neural network models of classical and nonclassical problems for heat conduction equation

Published in category «Mathematics»

Problems of mathematical modeling for complex systems are considered in the paper in terms of neural network technique. System parameters are given in some variation intervals. Neural network model of nonstationary temperature field inthe case of both classical and non-classical problem statement is cited as an example. Results of neurocomputing for accurate and noise data are given.

Views: 1677 Comments: 0

Nguyen Van Thang, Arseniev Dmitry G., Belyaev Alexander K.

The stability of motion of the shaft supported by floating ring bearings and its self-oscillation with allowance of lubrication hydrodynamics and centrifugal forces

Published in category «Mechanics»

Our study gives the theoretical representation of the stability of the balance position of the shaft supported by floating ring bearing with allowance of lubrication hydrodynamics and centrifugal force. The basic results are referred to the shortbearing investigation.

Views: 1824 Comments: 0

Zhgutov Vladimir M.

Geometrically nonlinear thermoplasticity mathematic models of shells with the variable thickness

Published in category «Mechanics»

The mathematical deformation models of variable thickness shells (smoothly-variable anb ribbed shells), experiencing either mechanical load or permanent temperature field and taking into account the geometrical nonlinearity, nonlinearelasticity and transverse shear, were developed. There are given refined geometrical proportions for geometrically nonlinear and steadiness problems.

Views: 1533 Comments: 0

Sanin Andrey L., Semyonov E.A.

Quantum Duffing oscillators: free and coupled, noise action

Published in category «Theoretical physics»

The numerical integration of the non-stationary two-dimensional Schrödinger equation was carried out. In the context of quantum wave-packets, dynamical means, Fourier spectra, uncertainty relations, autocorrelators there were studied the dynamical properties for two coupled quantum Duffing oscillators. It is shown that synchronization for identical oscillatorsand partial transmission of the frequency spectrum in non-identical oscillators takes place. It was found that increasing of noise power leads to the amplitude reduction of the complex-shaped oscillations and the expansion of the frequency spectra.

Views: 1558 Comments: 0

Apushkinsky Evgeniy G.

Nonlinear signal spectra transformations

Published in category «Radiophysics»

Echo formation occurs in media consisting of many individual oscillators which are able to interact with the external exciting field and have slightly different frequencies. Each this oscillator is considered as a quadripole transforming the input signals. We show that the delay operation with some conversion of the signals will be carried out if each quadripole transforming, has a nonlinearity, in which the spectrum of its output is connected to the spectrum of the input signal through a nonlinear transformation.

Views: 1687 Comments: 0

Vasil’ev Gennadiy I., Kholupenko Evgeniy E., Yablokov Sergey N., Bayko Denis A., Bykov Andrey M., Krasil’shchikov Alexander M., Pavlov Georgiy G.

The influence of the night-sky background on ground-based observations of gamma-ray bursts in the range between 1 and 10 GeV

Published in category «Astrophysics»

The influence of night-sky background on detecting cosmic gamma-ray bursts and measurements of their light curves with ground-based Cherenkov telescopes in the range between 1 and 10 GeV is considered. It is shown that the probability of registration of Cherenkov flashes from cosmic gamma-quanta decreases significantly at energies less than 3 GeV under the influence of night sky optical background even if the sensitivity of detecting units is better than that of modern Cherenkov telescopes.

Views: 1440 Comments: 0

Uvarov Yuri A., Bykov Andrey M., Pavlov Georgiy G., Levenfish Kseniya P., Kropotina Yuliya A.

Vela pulsar wind nebula: determination of the anisotropy of accelerated particle distribution function

Published in category «Astrophysics»

A geometric model of Vela pulsar wind nebula (PWN) is suggested. The method of determination of leptonic distribution function anisotropy is developed based on the comparison of high resolution roentgen Chandra images of Vela PWN with model predicted images. An angular dependence of distribution function in the nebula rest frame is obtained in the ranges ofangle between particle velocity and pulsar wind direction T: 10q < T < 90q and 130q < T < 160q.

Views: 1646 Comments: 0

Kozhevnikov Nikolay M.

The anniversary session of the Presidium of the Scientific and Methodological Council on Physics of the Ministry of Education and Science of the Russian Federation

Published in category «Chronicle»

The results of the meeting of the Presidium of the Scientific and Methodological Council on Physics dedicated to the 10th anniversary of the Council’s activity in its current make-up are presented. Upon discussing the Council performance report the Presidium passed a number of constructive resolutions.

Views: 1573 Comments: 0