bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of defect structure and indicator of transition to critical state of material
Authors: Damaskinskaya E E , Panteleev I A , Korost D V 
Published: December 2019

Abstract
A feature that allows one to estimate the degree of criticality of the state of the material subjected to the mechanical load has been identified. Two independent non-destructive methods, i.e., acoustic emission (AE) and X-ray computed microtomography (CT), were used at each stage of sample loading. It was found that the energy distribution of AE signals did not always obey to the Guttenberg-Richter law. It was also found that the type of energy distribution of AE signals could be used as an indicator of the state of a deformed material. The exponential function pointed to a non-critical state; the power-law function indicated that the damage accumulation process had passed to the “dangerous” stage. This feature can be used as a physical basis for a new method of non-destructive testing which will allow one to reveal “dangerous” (requiring replacement or repair) spatial regions of objects (constructions, pipelines, etc.).
Polydisperse bubble flows: a study of the bubble cloud evolution by CFD methods
Authors: Chernyshev A S , Schmidt A A 
Published: December 2019

Abstract
The evolution of a polydisperse bubble cloud is analyzed by means of computational fluid dynamics. Gravity-driven bubble flows in a column with a circular cross-section as well as a downward flow in a long vertical pipe are numerically investigated. A method employed in the simulations is based on the Euler-Euler description of the multiphase medium. An inhomogeneous multiple-size group (MUSIG) model is used to describe the bubble size distribution. The formulated approach provides detailed description of the bubble flow structure including variation of the bubble size distribution.
The small parameter method in the problem of the lateral surface shape of the vertical liquid bridge between planes
Authors: Galaktionov E V , Galaktionova N E , Tropp E A 
Published: December 2019

Abstract
The article is devoted to the study of the shape of the vertical liquid bridge between two solid planes with take into account the gravity force. The variation problem statement is given. The parametric form of solution presentation is used. The solution is constructed as a series in powers of a small Bond number. An algorithm for finding zeroth and the subsequent approximations is proposed. A non-uniqueness of the solution is detected. There may be several different profiles of its lateral surface for a fixed height of the liquid bridge. The dependence of the solutions number on the liquid bridge height has been analyzed.
Numerical aspects of wall-distance computation for turbulence modeling
Authors: Kolmogorov Dmitry K. 
Published: December 2019

Abstract
Numerical aspects of the PDE-based approaches to computing the distance-function involved in many RANS models are discussed focusing on solving Eikonal equation written in advection-diffusion form. This approach is implemented and tested within the in-house structured multi-block general purpose CFD code. A technique which allows considerable increasing the robustness of the numerical procedure is proposed and tested on a set of generic 2D geometries (NACA4412 and 30P30N 3-element airfoils, backward-facing step) and more complex 3D configurations (Stanford diffuser and Common Research Model of commercial aircraft). It is shown that this technique permits to avoid convergence problems typically observed for the Eikonal-type equation and to compute the distance-function for all of the tested configurations. The results obtained show high efficiency of the technique and its potential for turbulence computations of industrial flows.
Kelvin probe force gradient microscopy of WSe2 monolayers on Ni
Authors: Borodin B R , Benimetskiy F A , Nyapshaev I A , Alekseev P A 
Published: December 2019

Abstract
This work presents the results of an investigation of WSe2 thin layers on the Ni film by Scanning Probe Microscopy (SPM) methods. To determine surface potential, Kelvin probe force gradient microscopy (KPFGM) was used. Dependences of the surface potential and work function on the number of monolayers of the structure are presented. The band structure and type of doping of the WSe2 monolayer on the Ni film were determined. These data can be important for measuring the number of WSe2 layers by KPFGM and for designing nanodevices because the work function and the surface potential have a strong influence on the operation of such devices.
The effect of post-growth interruption on the formation of InGaAs/GaAs quantum dots obtained by MOVPE
Authors: Salii R A , Mintairov S A , Nadtochiy A M , Nevedomskiy V N , Kalyuzhnyy N A 
Published: December 2019

Abstract
In this work, the study of formation regimes of In0.8Ga0.2As quantum dots on GaAs surface by metallorganic vapour-phase epitaxy has been carried out. The influence of post-growth interruption after the quantum dots deposition on the optical and physical properties of the formed objects has been investigated. It has been established that the interruption time of 2-5 seconds is optimal for the In0.8Ga0.2As/GaAs material system and growth conditions. For the chosen interruption time, the quality of formed quantum dots and their physical sizes were estimated using transmission electron microscopy: lateral size is 10 – 20 nm, height is not exceeding 5 nm and concentration is ∼9.8·1010 cm−2.
Structural transformation of the BiSbTeSe2 topological insulator during Co laser MBE deposition
Authors: Kaveev A.K. , Suturin S.M. , Golyashov V.A. , Kokh K.A. , Tereshchenko O.E. 
Published: December 2019

Abstract
The studies of the structural transformation of BiSbTeSe2 topological insulator during Co deposition were carried out. It was shown that Co, being deposited on BiSbTeSe2(0001) at 330°C, substantially modifies topmost part of the substrate. Reciprocal space mapping studies using RHEED data analysis reveal formation of the well-ordered layer with the modified composition and crystalline structure. It was found that this layer consists of three orthorhombic structural domains oriented at 120° to each other. Each domain has Pmnn space group characteristic fot CoTexSe2-x. The lattice parameters and epitaxial relations were found.
Laser plasma plume parameters for cascade fission of metal micro- and nanodroplets
Authors: Bormatov A A , Kozhevin V M 
Published: December 2019

Abstract
The cascade fission under the action of Coulomb forces of metal droplets charged up to the Rayleigh limit in a vacuum has been well studied and it is widely used in vacuum technology. Experimental works using the laser electrodispersion method showed that such a division can be carried out in the plasma of a laser plasma plume during the process of nanosecond ablation of metals. The previously published analytical model made it possible to work out requirements for plasma parameters, at which droplets can be divided to nanometer scales, but the limits of applicability of this model were not known. In this paper we present a more accurate numerical model for charging metal droplets in a laser plasma plume, which was used to obtain laser plasma parameters for implementation of cascade metal droplet fission. A comparison with the results obtained using the analytical model is presented.
Study of the influence of the ZnO:Al polycrystalline film morphology on the silver nanoparticles formation
Authors: Shirshneva-Vaschenko E V , Sokura L A , Baidakova M V , Yagovkina M A , Snezhnaia Zh G , Shirshnev P S , Romanov A E 
Published: December 2019

Abstract
The paper presents the results of the optical and structural properties studies of samples consisting of ZnO:Al (AZO) oxide films with an intermediate silver nanoparticles layer. Obtaining samples were carried out by the method of sol-gel technology using different types of composition, and the conditions for drying and final annealing of the samples were varied. The study of the samples optical properties consisted of the optical absorption spectra measurements, and their structural properties were determined by X-ray diffraction and small-angle X-ray scattering. Comparison of data obtained from measurements of optical and structural properties of samples confirmed the results obtained from modeling in the Comsol Multiphysics software. X-ray diffraction demonstrated that the AZO films have a polycrystalline structure and are highly textured in the [002] direction. Zinc oxide grains are 10-15 nm. Silver nanoparticles are the comparable with AZO grains and have dimensions of several tens of nanometers. An increase in the annealing temperature of the films leads to a redistribution of silver nanoparticles in the AZO film, the distance between the particles increases. Consequently, the effect of the plasmon eigenmodes of the nanoparticles prevails over the effect of the system of particles oscillations interacting with each other. The analysis of the coatings obtained by the method of small-angle X-ray scattering showed that nanoparticles in the AZO film form an ordered structure.
Effect of Langmuir coating on the localization of excitonic polarization in CdS surface layer
Authors: Korolkova K A , Novak V R , Sel’kin A V 
Published: December 2019

Abstract
Low temperature (T=2K) optical reflection spectra have been studied for the organic-semiconductor structures prepared by deposition of Langmuir-Blodgett films on CdS surface. The spectra are measured in the resonant spectral range of the A

n=1 exciton state in CdS. Theoretical analysis of the spectra is carried out with an account of the spatial dispersion effects and the exciton-free surface “dead” layer. The conclusion has been drawn of the interface localization of the Wannier-Mott exciton due to organic film deposition on the crystal surface.
Investigation of resistive switching effect in nanocrystalline TiO2 thin film for neuromorphic system manufacturing
Authors: Dukhan D D , Tominov R V , Avilov V I , Zamburg E G , Smirnov V A , Ageev O A 
Published: December 2019

Abstract
Effect of resistive switching in TiO2 thin film was investigated. It was shown, resistive switching from high resistance state (HRS) to low resistance state (LRS) has occurred at 3.2±0.2 V, and from LRS to HRS at -2.8±0.5 V. Endurance test shown that HRS decreased from 42.31±5.26 kΩ to 26.45±6.14 kΩ, LRS increased from 2.25±1.15 kΩ to 3.45±1.18 kΩ. HRS/LRS coefficient has decreased from 18.8 to 7.6. Time-stability of TiO2 surface charge was investigated. It was shown, that voltage decreased from 320±21 to 22±5 mV during 90 minutes and square side increased from 3.43±0.12 to 4.12±0.14 µm during 90 minutes. The results can be useful for neuromorphic systems manufacturing based on nanocrystalline TiO2 films.
Effect of iron intercalation on graphene/SiC electronic structure
Authors: Lobanova E Yu , Pronin I I 
Published: December 2019

Abstract
Graphene-based materials are of great interest for spintronics devices. In the present paper, the effect of intercalated iron on the electronic structure of the graphene/4H-SiC(0001) system has been studied in the frame of density functional theory. It is shown that the most energetically favorable position of intercalated Fe atoms corresponds to their location between the buffer layer and the top Si layer of the substrate. Insertion of Fe atoms into the system leads to the spin polarization of the electronic states of carbon. Another effect is that the buffer layer becomes flat and bilayer graphene forms in the system.
Effect of radiation with low degree coherence on the photoinduced light scattering excitation in lithium niobate crystals
Authors: Maksimenko V A 
Published: December 2019

Abstract
Laser radiation with irregular wavefront erases noisy photorefractive gratings in lithium niobate crystals doped with iron. We investigated noisy photorefractive gratings recording and erasing via observing the photoinduced light scattering in LiNbO3:Fe crystal. Also the effect of the incoherent light on the photoinduced light scattering excitation is considered in the paper.
Polariton Bose condensation in microcavity in high magnetic fields
Authors: Kochereshko V P , Platonov A V , Filosofov N G , Savvidis P , Tsintzos S I , Hatzopoulos Z , Besombes L , Mariette H 
Published: December 2019

Abstract
The dependences of the exciton-polariton photoluminescence spectra on the intensity of optical excitation and external magnetic fields are investigated in cylindrical mesas based on high-quality microcavities. It was found that with an increase of the intensity of optical excitation above a certain threshold at sufficiently large magnetic field or with an increase of magnetic fields at constant optical excitation, the distribution of exciton-polaritons over Zeeman sublevels becomes substantially non-Boltzmannian.
Transverse magneto-optical Kerr effect in magnetoplasmonic waveguide structures based on Fe3O4
Authors: Pavlov S I , Pevtsov A B , Dyakov S A , Yavsin D A , Spitzer F , Akimov I , Verbin S Y , Tikhodeev S G , Gippius N A , Nashchekin A V , Bayer M 
Published: December 2019

Abstract
In this study transverse magneto-optical Kerr effect in transmission for the magnetite thin film with gold grating on top was examined theoretically and experimentally. The magnetite films with thickness of 200 nm were fabricated by the laser electrodispersion technique. Arrays of gold stripes with 600 nm period and 350 nm and 500 nm stripe widths were created by lift-off e-beam lithography. It was shown experimentally that the TMOKE enhancement in structures with 350 nm width is attributed to SPP excitation on gold-magnetite surface. TMOKE value δ reaches magnitude of ±5·10−3 at the wavelengths 790 nm and 860 nm at light incidence angles of 8-10° and 12-13°, respectively. In case of 500 nm stripe width, SPP excitation is poor, however δ reaches magnitude of ±6.6·10−3 at angles of incidence more than 20°, that can be associated with the quasiguided mode resonance in such structure.
Observation of magnetization transfer in spin-exchange collisions of cesium and rubidium atoms
Authors: Dmitriev S P , Dovator N A , Kartoshkin V A , Okunevich A I 
Published: December 2019

Abstract
Spin exchange is one of the effective processes for obtaining spin-polarized atoms. Such mechanism of spin polarization is usually used to transmit and observe the longitudinal (along magnetic field) component magnetization of atoms. However, spin-exchange collisions can also lead to the transfer of the transverse component of magnetization, which occurs when the atoms involved in the collisions are exposed to an alternating resonant magnetic field. This article describes experiments to observe the transmission of transverse magnetization between alkali metal atoms 133Cs and 85Rb in spin-exchange collisions. The calculation of the spin exchange in a mixture of Cs and Rb under magnetic resonance conditions gave a qualitative agreement with the experimental results.
The method of polarization filtering for implementation of the optical manipulator
Authors: Shostka N V , Karakchieva O S , Sokolenko B V , Shostka V I 
Published: December 2019

Abstract
The ability to capture and transport micro-objects with the help of light is one of the topical studies in modern optics. Optical tweezers perform manipulations with colloidal and aerosol nano- and microparticles, living cells, individual molecules and atoms, which is widely used in modern science. Optical traps, created on the basis of singular beams, allow capturing live microorganisms for further study using optical microscopy. Such traps have important practical characteristics, such as maintaining a minimum of intensity on the beam axis, which allows to avoid unwanted overheating of the captured object, as well as to keep the object in transverse coordinates. On the other hand, for many practical purposes it is necessary to limit the transmission of the captured object in the longitudinal direction. Finding ways to generate such three-dimensional traps is currently one of the priorities of world optics. In presented work it is shown that polarized vector beams, formed after uniaxial crystal, create bottle beam with dark centre and by varying geometrical and polarization parameters of experimental set-up it is possible to control the bottle beam properties.
The effect of optical density of the flowing liquid on the measurement error of its refractive index
Authors: Grebenikova N M , Davydov V V 
Published: December 2019

Abstract
The main factors responsible for measurement errors in the determining of the refractive index of the flowing fluid are considered. It was found, that the most significant effect on the measurement error have changes in optical density and temperature of the investigated flowing fluid, scattering of radiation in cuvette transducer and wedge shape of the cuvette glass. A new design of differential refractometer has been developed to study the influence of the optical density values of the flowing fluid on the measurement errors. The results of experimental studies are presented.
Investigation of photoelectric properties of CuO / PZT heterostructures in the visible and near IR regions
Authors: Kochunov K.V. , Konoplev G.A. , Mukhin N.D. , Chigirev D.A. 
Published: December 2019

Abstract
The method of formation of copper oxide / lead zirconate titanate (CuO/PZT) heterostructures using RF magnetron sputtering of chemically pure grade copper oxide powder on prepolarized ferroelectric ceramic substrate is considered; the direction of polarization was parallel with the copper oxide film plane. The short-circuit photocurrent in the CuO/PZT samples with different thicknesses under irradiation in the visible and near IR regions was measured. The spectral dependences of the photocurrent were estimated. The maximum photoresponse of the structures was observed at the wavelength of 515 nm.
Spectral dependencies of multijunction solar cells in a wide range of temperatures
Authors: Levina S A , Mintairov M A , Filimonov E D , Shvarts M Z 
Published: December 2019

Abstract
In this paper, triple-junction solar cells of various middle junction thickness are studied. It is shown that in samples with thin layers, an optical coupling between the top and the bottom subcell is possible as well as a direct leakage of external radiation through the middle one. True values of the spectral dependences of the external quantum efficiency are calculated in accordance with the corrective method. The proposed method reveals some difference in the negative contribution of the luminescence and the positive signal results from the light penetration.
An investigation of the generalized model of pyroelectric thermal IR detectors
Authors: Popov A V , Ilyichev E A , Demin G D 
Published: December 2019

Abstract
In our work, a compact model of an infrared radiation detector based on a LiTaO3 pyroelectric material (lithium tantalate) is presented. Based on the developed model, the time-dependent characteristics of the pyroelectric current, voltage and the surface temperature of such detector were calculated. The obtained results can be used in the development of detectors of thermal images of objects operating in the wavelength range from 3 to 15 μm.
Investigation of the converse flexoelectric effect in KTaO3 using the interferometric microscopy method
Authors: Obozova E D , Polushina A D , Zalesskii V G , Syrnikov P P 
Published: December 2019

Abstract
The inhomogeneous strain induced by an external electric field (the converse flexoelectric effect) has been studied in thin KTaO3 single crystal plates by a scanning interferometric microscopy method. It has been shown that the type of inhomogeneous strain (spherical and cylindrical bending) is determined by the direction of the applied field along [001] and [011] crystallographic directions.
Influence of voltage pulse rise-time on initiation and propagation of fast ionization waves in extended capillaries
Authors: Eliseev S , Timshina M , Samokhvalov A , Letunovskaya M , Smirnov A , Sergushichev K , Kalinin N , Belsky D , Burtsev V 
Published: December 2019

Abstract
Creating stable and efficient compact X-ray sources based on fast capillary discharges that do not incorporate preliminary ionization circuits poses additional restrictions on parameters of voltage pulses and capillary geometry. Applying a voltage pulse with a rise rate of the order of 1 kV/ns results in gradual breakdown of non-ionized gas in the capillary which takes the form of an ionization wave that initiates at the powered electrode and propagates with typical velocities of 1 cm/ns. After the wave reaches the grounded electrode, a plasma channel with gradually increasing conductivity is formed. The current onset therefore appears only after a certain time delay after beginning of the voltage pulse. The ratio between the delay and the applied voltage rise-time will eventually influence the current rise rate that defines plasma heating and compression. It is therefore necessary to have the ability to estimate this delay time for a given capillary geometry and understand its dependence on the properties of a voltage pulse. In this work numerical simulations of fast ionization waves created in an extended Al2O3 capillary filled with nitrogen at 2 Torr were performed for cases of voltage pulses of negative polarity with rise-times varying in the range 10-50 ns. The numerical model was based on fluid approach with drift-diffusion approximation for charged particle fluxes. Influence of voltage rise-time on initiation and propagation of a fast ionization wave as well as on consequent rate of current rise is investigated.
Fast scanning probe for the Globus-M2 tokamak
Authors: Tokarev V A , Gusev V K , Khromov N A , Patrov M I , Petrov Yu V , Sakharov N V , Minaev V B , Varfolomeev V I , Telnova A Yu , Shegolev P B , Bakharev N N , Kurskiev G S , Kiselev E O 
Published: December 2019

Abstract
A fast scanning probe which can penetrate inside the separatrix during discharge was developed for Globus-M2. The probe has been designed to move various sensor pins into the scrape-off layer. The driving force is provided by a crank-slider mechanism which is ensured maximum linear speed about 4 m/s. The paper presents probe head and drive system description.
Investigation of plasma jet sources with high kinetic energy
Authors: Goryainov V Yu , Voronin A V , Gusev V K , Novokhatsky A N , Ponyaev S A 
Published: December 2019

Abstract
Results of coaxial and rail electromagnetic accelerators investigation with pulsed gas puffing and different shapes and lengths of electrodes are presented. The influence of an additional magnetic field on accelerator parameters was studied. The method for plasma jet parameters controlling was developed with the use of a piezo-sensor and infrared camera. The plasma jet pressure dependences on the accelerator length and polarity of the electrode voltage, as well as on the distance from accelerator were derived in experiments on the plasma gun test bench. Coaxial plasma gun with the electrode length 220 mm, negative polarity of the central electrode voltage and focusing insert placed into the initial part of the accelerator proved to be most effective. At the output of the accelerator deuterium plasma jet was obtained with flow velocity up to 160 km/s and pressure up to 2 MPa.