bluuebunny/crossref_metadata_2025 huggingface dataset:
CNN-Based Speaker Verification and Speech Recognition in Tibetan
Authors: Gan Zhenye , Yu Yue , Wang Rui , Zhao Xin
Published: December 2020

In recent years, there have a little studies on speaker and speech recognition in Tibetan, which are mainly based on traditional methods of probability statistics. With the development of deep learning, neural networks have been widely used in speaker and automatic speech recognition, which have achieved remarkable results. In this paper, we utilize end-to-end model to study speaker verification and speech recognition in Tibetan. This article uses the ResCNN network for Tibetan speaker verification. In speech recognition, we adopt the DFCNN-CTC structure, where connectionist temporal classification (CTC) directly outputs the probability of sequence prediction without external post-processing. We have made some improvements to the two models. Experiments show that the improved model reduces EER by 3% and WER by 18% in speaker verification and speech recognition, respectively.
SAR image classification method based on improved capsule network
Authors: Yang Zezhou , Jing Shaodi
Published: December 2020

Aiming at the problem that the convolutional neural network is difficult to recognize the posture transformation of the image, which requires a large number of label samples for training. This paper proposes an improved synthetic aperture radar image classification method based on the combination of dilated convolution and capsule network. We use dilated convolution to expand the receptive field while reducing the amount of calculation, and use the capsule network to improve the classification effect when there are fewer training samples. The experimental results show that the proposed method can still achieve high classification performance after the training sample is small and the test sample undergoes pose transformation, and at the same time, it has a low computational load.
Automatic segmentation in fetal ultrasound images based on improved U-net
Authors: Yang Yujie , Yang Pinli , Zhang Bo
Published: December 2020

As an effective way of routine prenatal diagnosis, ultrasound (US) imaging has been widely used in clinical practice. Biosignatures obtained from fetal segmentation contribute to fetal development and health monitoring. However, the artifacts, speckle noises, quality of imaging equipment and other factors make the segmentation of fetal US images extremely challenging. In this paper, aiming to improve the depth of the model, as well as to avoid the vanishing gradient problem and exploding gradient problem, we propose Residual U-net and ASPP U-net based on U-net, which further improves the accuracy of segmentation without increasing the depth of the model. The results of our experiments show that the network proposed in the paper can effectively improve the segmentation accuracy in fetal US images.
Research on automatic defect identification technology of electronic components
Authors: Lijing Yin , Kui Zhang , Yaru Cui , Shengbiao An , Jie Huang
Published: December 2020

Aiming at the problems of low efficiency and low accuracy caused by manual defect detection of electronic components, FCN, SegNet/DeconvNet and DeepLab and other deep learning technologies are studied. Using Caffe, Keras, PyTorch and other frameworks, an automatic defect identification system for electronic components is developed to distinguish qualified products from unqualified ones, so as to realize intelligent defect detection of electronic components. At the same time, the detection accuracy rate is greatly improved, and the quality of electronic components is guaranteed.
Design and Realization of Gaze Gesture Control System for Flight Simulation
Authors: Qiao Yuanyuan , Wang Jihui , Chen Jing , Ren Jie
Published: December 2020

In airplane cockpit, flight crew, display interface, control device and onboard control device constitute a complex human computer interaction system. As a natural interaction way, eye movement can simplify the interaction process of pilots, avoiding mistakes caused by fatigue or distraction. What’s more, since this interactive modality only requires eye movement as input, it can be adapted to some special situations and free the user’s hands. In this paper, we design a gaze gesture interaction system for flight simulation and compare it with the existing prominent interaction methods.
Campus canteen takeaway robot based on Raspberry Pi
Authors: Wu Qiwen , Zhu Tianyin , Zhang Shuai
Published: December 2020

In this era of rapid technological development, the related technologies of intelligent robots have made great progress, and the application scenarios of robots have also expanded from the industrial field to the service field. In order to obtain a more convenient way of dining, more and more people choose to order take-out, especially on campus, takeaway members are everywhere. Aiming at the special group of college students, we proposed a takeaway robot system for campus canteens based on Raspberry Pi. The system is mainly composed of Raspberry Pi, navigation module, obstacle avoidance module, voice module, driving module and applet ordering platform. Users only need to order food on WeChat applet, and the takeaway robot will deliver the food to the target address. The takeaway robot runs safely and stably, and can complete the unmanned delivery of takeaway. The system can help college students save time while eating hygienic canteen takeout, and it can also effectively solve the problem of speeding and hurting people on campus.
The Sobolev approximation for radiation transport with line overlap and continuous opacity
Authors: Nesterenok A V
Published: December 2020

The radiation transport problem in the plane–parallel medium with the large velocity gradient is considered. The Sobolev approximation is used. The effects of continuum absorption and line overlap are taken into account. The photon loss probability functions are calculated and tabulated. Two calculations are performed – for the Gaussian spectral line profile and for the rectangular profile. It is shown that at particular choice of the rectangular profile width the results of the calculations are very close. The evaluated photon loss probability functions may be used in the calculations of energy level populations of OH molecule in the interstellar gas flows.
The influence of positronium photoionization rate on the heating of J0250+5854 polar cap
Authors: Barsukov D P , Vorontsov M V , Morozov I K
Published: December 2020

The influence of positronium photoionization rate on the heating of PSR J0250+5854 polar cap is considered. It is assumed that the polar cap is heated only by reverse positrons accelerated in pulsar diode. It is supposed that pulsar diode is located near the star surface (polar cap model) and operates in the steady state space charge-limited flow regime. The influence of a small-scale magnetic field on the electric field inside the pulsar diode is taken into account. The reverse positron current is calculated in the framework of two models: rapid and gradually screening. To calculate the production rate of electron-positron pairs we take into account only the curvature radiation of primary electrons and its absorption in magnetic field. It is assumed that some fraction of electron-positron pairs may be created in bound state that can later be photoionized by thermal photons from star surface.
Surface energy of nuclear matter above and below neutron drip with the Skyrme-type effective interactions
Authors: Shchechilin N N , Chugunov A I
Published: December 2020

Neutron star crust consists of highly neutron excess nuclei, which are inaccessible for laboratory experiments. In the deepest region of the crust (so-called inner crust, located after the neutron drip) atomic nuclei are immersed into the sea of degenerate unbound neutrons. Study of the crust structure and equation of state in such conditions relies on the theoretical nuclear mass models. In particular, it is convenient to use the compressible liquid drop model, which contains the surface tension term. A thermodynamically consistent description must take into account adsorption of neutrons on the nucleus surface (neutron skin) and dependence of surface tension on matter properties in two-phase equilibrium. We calculate the surface tension of nuclear matter by the extended Thomas-Fermi approach. For this aim, we parametrize the number density profile of the two-phase system by Fermi-Dirac type functions, totally containing 5 parameters, and minimize the thermodynamic potential Ω to obtain equilibrium configuration. We use Skyrme-type nuclear interactions SLy4 and BSk24, fulfilling experimental data of atomic nuclei, observational constraints on the maximal neutron star mass and theoretical calculations of high-density nuclear matter. The results are presented as a function of neutron chemical potential, which is useful for compressible liquid drop models in the inner crust of a neutron star.
Tunka-Grande and TAIGA-Muon scintillation arrays: status and prospects
Authors: Monkhoev R , Astapov I , Bezyazeekov P , Borodin A , Brueckner M , Budnev N , Chernykh V , Chiavassa A , Dyachok A , Fedorov O , Gafarov A , Garmash A , Grebenyuk V , Gress O , Gress T , Grinyuk A , Grishin O , Horns D , Igoshin A , Ivanova A , Kalmykov N , Kazarina Y , Kindin V , Kiryuhin S , Kokoulin R , Kompaniets K , Korosteleva E , Kozhin V , Kravchenko E , Kryukov A , Kuzmichev L , Lagutin A , Lemeshev Y , Lubsandorzhiev B , Lubsandorzhiev N , Mirgazov R , Mirzoyan R , Osipova E , Pakhorukov A , Pan A , Panasyuk M , Pankov L , Petrukhin A , Poleschuk V , Popesku M , Popova E , Porelli A , Postnikov E , Prosin V , Ptuskin V , Pushnin A , Raikin R , Rubtsov G , Ryabov E , Sagan Y , Samoliga V , Sabirov B , Silaev A , Sidorenkov A , Skurikhin A , Slunecka V , Sokolov A , Suvorkin Y , Sveshnikova L , Tabolenko V , Tarashchansky B , Tkachev L , Tluczykont M , Tanaev A , Ternovoy M , Ushakov N , Ustinov K , Vaidyanathan A , Volchugov P , Voronin D , Wischnewski R , Zagorodnikov A , Zhurov D , Yashin I
Published: December 2020

The Tunka-Grande and TAIGA-Muon arrays are the part of a single experimental complex, which also includes the Tunka-133 and TAIGA-HiSCORE (High Sensitivity COsmic Rays and gamma Explorer) wide-angle Cherenkov arrays, TAIGA-IACT array (Imaging Atmospheric Cherenkov Telescope) and Tunka-Rex radio antennas array (Tunka Radio Extension). This complex is located in the Tunka Valley (Buryatia Republic, Russia), 50 km from Lake Baikal. It is aimed at investigating the energy spectrum and mass composition of charged cosmic rays in the energy range 100 TeV - 1000 PeV, searching for diffuse gamma rays above 100 TeV and studying local sources of gamma rays with energies above 30 TeV.

This report outlines 3 key points. The first is a description of the Tunka-Grande and TAIGA-Muon scintillation arrays. The second part presents preliminary results of the search for diffuse gamma rays with energies above 50 PeV according to the Tunka-Grande data. The third part is devoted to the prospects of the search for diffuse gamma rays with energies above 100 TeV using the TAIGA-Muon array.
Constraining of physical conditions in the cold neutral medium using HD/H2 relative abundance
Authors: Kosenko D N , Balashev S A
Published: December 2020

We present constraints on physical conditions in diffuse HD/H2-bearing molecular clouds using measured HD/H2 column density ratio. We used recently published formalism that describes how this ratio changes with ultraviolet field intensity, number density and cosmic ray ionization rate. Out of them the most important parameter is the cosmic ray ionization rate, as it determines the chemistry in neutral medium and is still poorly constrained in ISM. Using the result of absorption line analysis in our Galaxy and in several high-redshift systems we found that value of cosmic ray ionization rate is

1.3

−
0.5

+
1.3

×

10

−
17

s

−
1

in our Galaxy and is few × 10−18 s−1 in DLAs at high redshifts.
Mass spectrometric analysis of the carbon isotope composition in plant leaves via sample gasification using oxidation by yeast
Authors: Kuleshova T E , Pavlova E S , Titov Yu A , Kuzmin A G , Gall N R
Published: December 2020

The paper describes a new developed method of sample gasification using yeast oxidation of monosaccharides in plant tissue for 13C/12C isotope ratio mass spectrometric analysis. Variations in the carbon isotopic composition of the leaf surface have been shown; the δ13C value for chlorophytum varies from -37 ‰ to -32 ‰ from the tip of the leaf to its base. It has been shown first that the spectral composition of radiation affects the ratio of carbon isotopes in plant leaves: the predominance of blue component in the spectrum results in accumulation of heavy 13C isotope up to δ13C = -25 ‰.
Contribution of radiant component to thermal conductivity of the medium
Authors: Shamparov E Yu , Bugrimov A L , Rode S V , Jagrina I N
Published: December 2020

Radiation-conductive heat transfer in a semi-transparent medium has been studied. Two methods for measuring thermal conductivity components are described. Thermal resistance of a remote reflecting surface, the thickness of radiation-conductive relaxation, the depth of penetration of thermal radiation, as well as radiant and conductive components of thermal conductivity of foamed polyethylene were measured using an aluminum foil radiation screen. The dependences of the total thermal conductivity of simple and aluminum-metalized polyester bulk non-woven canvases on the thickness to which it is compressed were measured. Radiant and conductive components of the thermal conductivity of non-woven material are calculated. It is shown how metal nanocoating of fibers reduces radiant thermal conductivity of the material.
Field emission cell with a W-cathode formed by local ion-stimulated deposition
Authors: Shandyba N A , Kolomiytsev A S , Panchenko I V , Jityaev I L
Published: December 2020

This article presents the results of a theoretical study of a field emission cell with a vertically oriented emitter. The field emission cell was formed based on a combination of etched methods with a Ga+ focused ion beam and local ion-stimulated tungsten deposition. The influence of the geometric parameters of the field emission cell on the electric field strength at the emitter top is estimated. It was found that a decrease in the rounding-off radius of the emitter top from 150 to 5 nm leads to an increase in the electric field strength by more than an order of magnitude from 1.28 × 106 to 16 × 106 V/cm. A decrease in the diameter of the field emission cell from 2.5 μm to 900 nm contributes to an increase in the electric field strength by 33.6 % from 3.04 × 106 to 4.58 × 106 V/cm.
Investigation of radiation formation (plasmoid) in the air environment by radar method
Authors: Fadeenko V B , Fadeenko I V , Vasiliev D A , Davydov V V , Rud V Yu
Published: December 2020

The expediency of using the radar method for detecting radiation contamination at long distances is substantiated in this article. The design of a radar for the detecting of small radioactive formations in the air at the long distances is developed. The dependence of the reflection coefficient of microwave radiation on the wavelength for determining the level of radioactive radiation is established. The investigation results of radioactive contamination in the atmosphere are presented.
Influence of wet etching in KOH on defects in silicon nanowires formed by cryogenic dry etching
Authors: Baranov A I , Kudryashov D A , Morozov I A , Uvarov A V , Shugurov K Yu , Gudovskikh A S
Published: December 2020

The work is devoted to exploration of arrays of vertical aligned silicon nanowires (SiNWs) obtained by cryogenic dry etching in ICP mode with height of 4.5-5.5 μm and aspect ratio of 7. It was shown that geometry of nanowires has crucial influence on rate of wet etching in KOH since it is higher for 3D objects than for planar wafer, and the diameter should be the same along the nanowire for controlled wet etching. Wet etching in 4% KOH solution during 30 s allowed to save array of uniformity vertical aligned SiNWs with height of 4 μm and diameter of 500 nm. Such treatment reduced concentration of defects detected by deep-level transient spectroscopy, particularly, it drops as minimum in two times for deep level with £0=0.68-0.74 eV placed near to surface of wafer.
Anomalously low ionization energy of phosphorus atoms in the electric field of silicon p-n junctions in the temperature range 10-20 K
Authors: Shepelev A , Eremin V , Verbitskaya E
Published: December 2020

The work extends the study of the ionization properties of phosphorus atoms as trapping/emission centres in the electric field of silicon p-n junctions operating at low temperatures. The goal is describing the ionization of phosphorus atoms by a single effective parameter, the ionization energy of phosphorus energy levels Eion
. An approach to the study is based on manipulating the space charge concentration Neff
in a nonirradiated silicon p+/n/n+ structure via filling phosphorus donors with electrons supplied by a laser pulse. Extracting the Neff
from the experimental current pulse response shapes recorded at variable temperature and pulse repetition rate allowed building Arrhenius plot for evaluating Eion
in the electric field. This value is shown to be 6.4±1.1 meV that is paradoxically low, being about 7 times less than the referred data.
Development of neural network for automatic calibration of ultrasonic thickness gauge
Authors: Grevtseva A S , Davydov V V , Rud V Yu
Published: December 2020

At article of the main factors rendering of influence on the reliability of material control results by ultrasonic thickness gauge are determined. The necessity of the use of automatic calibration of ultrasonic thickness gauge for reduction of measurement error is justified. The neural network for the realization of automatic device calibration is developed. The received experimental results are presented.
The shape of a vertical liquid bridge between arbitrary convex surfaces in axisymmetric case
Authors: Galaktionov E V , Galaktionova N E , Tropp E A
Published: December 2020

The article is devoted to the study of the lateral surface shape of a vertical liquid bridge of small volume between two arbitrary convex solid surfaces in the axisymmetric case. A variational statement of the original problem is given. The solution is found by the iteration method under the assumption that the Bond number is small. An algorithm for the iterative process is proposed, taking into account the action of gravity. It was found that the maximum number of different profiles of the lateral surface of the liquid bridge corresponding to one selected set of parameters is four. As an example, the problem of the lateral surface shape between a sphere and a plane has been solved.
Calculation of the conductivity of a thin conductive layer taking into account Soffer boundary conditions and isoenergy surface anisotropy of conductor
Authors: Savenko O V , Kuznetsov P A , Kuznetsova I A
Published: December 2020

The task about the conductivity of a thin conductive layer in a longitudinal alternative electric field is solved. The relationship between layer thickness and charge carrier mean free path is arbitrary. The Soffer model is used as boundary conditions for Boltzmann equation. The isoenergy surface of a semiconductor is an ellipsoid of revolution. Analytical expressions are obtained for conductivity tensor components as functions of layer thickness, isoenergy surface anisotropy parameter, electric field frequency, surface roughness parameters, and chemical potential. The limiting cases of a degenerate and non-degenerate electron gas are considered. The dependences of conductivity tensor components on the above parameters are analyzed. The results obtained for cases of a degenerate and non-degenerate electron gas are compared. A comparative analysis of results is made with calculations in the view of diffuse-mirror boundary conditions and with known experimental data.
Anisotropic plasmons in Au/GaAs(001) structures with gold nanoclusters
Authors: Berkovits V L , Kosobukin V A , Ulin V P , Soldatenkov F Y , Alekseev P A
Published: December 2020

The structures Au/GaAs(001) with gold nanoclusters are created by annealing of Au films deposited onto GaAs surface. The samples are diagnosed stepwise by scanning probe microscopy. Using reflectance anisotropy spectroscopy, Au clusters are established to possess plasmons with the in-surface anisotropy. The measured anisotropy spectrum consists of a resonant feature near the energy of 2 eV typical of local plasmons of Au clusters. The results are explained theoretically, and the new spectral feature is assigned to anisotropic plasmons of Au nanoclusters located on GaAs surface.
Fabrication of carbon nanowalls by radio frequency magnetron sputtering of graphite target in argon plasma
Authors: Grudinkin S A , Vinogradov A Ya
Published: December 2020

Vertical carbon nanowalls have been fabricated by RF magnetron sputtering of a graphite target in an argon plasma without hydrogen presence. The effect of deposition parameters such as substrate temperature, argon pressure, deposition time and RF power on the morphology and the structure of carbon nanowalls was investigated by using Raman spectroscopy and atomic force microscopy. The argon ion bombardment of the substrate is crucial for the nucleation and growth of carbon nanowalls. A specific range of RF power and argon pressure values was established at which nanowalls formation is possible. The height of nanowalls produced at minimal RF power increases non-monotonically with the deposition time. It turned out that the nanowalls growth rate has an extremum, after reaching which the growth rate of the thickness of nanowalls increases.
Sn-assisted growth of Ga(In)AsP nanowires from vapor phase in a quasi-closed volume
Authors: Karlina L B , Vlasov A S , Smirnova I P , Soshnikov I P
Published: December 2020

We have shown the possibility of Ga(In)AsP on GaAs (100) nanowire growth in a quasi-closed volume from the vapour phase witn the use of Sn catalyst. We have investigated the dynamics of nanowire formation depending on the growth time at constant V/III ratio given by the process temperature. It is shown that growth of free-standing nanowires is realized through the vapor-liquid-solid mechanism. Based on the Raman scattering data sequential growth of two phases have been shown. Phosphorous concentration in free-stamding nanowires was estimated to be high.
The formation of SiNWs depending on the topology of the metal-catalyst film in the process of metal-assisted chemical etching of c-Si
Authors: Ermina A A , Zharova Yu A , Bolshakov V O , Tolmachev V A
Published: December 2020

The method of metal-assisted chemical etching for obtaining silicon nanowires, which consists of two stages, was studied. The conditions and modes for producing layers at both stages of the implemented technology are established, which include (1) chemical deposition of an array of self-organizing Ag nanoparticles on a Si substrate as a catalyst mask and (2) chemical etching of SiNWs to various depths from 110 to 1200 nm. The optical properties and morphology of a metal-catalyst (Ag) film were studied depending on the deposition time and solution concentration. Spectral ellipsometry was used to characterize the samples at all stages of MACE. Using the measured ellipsometric angles, the dielectric functions were determined, as well as the thicknesses and parameters of the fractions of composite layers in a multilayer model by approximating the effective Maxwell Garnett and Bruggeman medium for two-component layers. Samples with Ag nanoparticles with different morphologies were studied using reflection spectrophotometry in the wavelength range from 200 to 600 nm. The results showed that composite Ag-Si structures are promising for obtaining plasmon effects in both the visible and IR spectral regions.
In-situ WAXS study of the crystal structure of R-BAPB oligoimide during heating
Authors: Ivan’kova E M , Kasatkin I A , Popova E H , Didenko A L , Vaganov G V , Yudin V E , Komarov P V
Published: December 2020

In the process of this work, an oligoimide FT-BAPB-R-BAPB-FT was synthesized, the particles of which consist of numerous lamellas having a semi-crystalline structure. On the DSC thermogram of oligoimide powder, two endo peaks were observed at 281.1°C and 306.4°C. A unique WAXS experiment was performed in-situ by heating the reactor oligoimid powder in a heat chamber. There was no significant difference in the X-ray profiles when the sample was heated. It should be noted that the transformation of the crystalline cell does not occur until the sample melts. It was revealed that the degree of crystallinity decreases during heating. We believe that the low-temperature endopeak is associated with the melting of small crystallites and amorphization of the sample. However, a significant increase in crystal size was found to be a result of recrystallization. Thus, the high-temperature endopic corresponds to the melting of larger crystallites.
The effect of imidization conditions on the structure and properties of fibres from partially crystallized polyimide
Authors: Vaganov G V , Didenko A L , Ivanov A G , Ivan’kova E M , Yudin V E , Borisov I L , Volkov A V
Published: December 2020

In this work, the two-stage process for producing polyimide fiber from polyamic acid (PAA) by wet spinning was used. Polyimide fibers were obtained by thermal and chemical imidization. The effect of the imidization method (chemical and thermal) on morphology, chemical structure, thermal stability and mechanical properties of polyimide fibers was investigated. A number of research methods were used in the work, such as Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calometry (DSC), thermogravimetric analysis (TGA) and determination of strength characteristics.
TEM investigation of microstructure of semipolar GaN layers grown on nano-patterned Si(001) substrates
Authors: Myasoedov A V , Bert N A , Bessolov V N
Published: December 2020

The synthesis of III-nitride binary compounds on commercial standard (001) silicon wafers by vapour-phase epitaxy is one of the promising directions for III-nitride technology development. However, the difference between crystal symmetry of Si(001) and wurzite (0001) surface structures is challenge that hinders the development. A use of silicon substrates with nano-patterned surface is one of the solutions to the problem. In this paper we present a transmission electron microscopy study of polar and semipolar GaN layers grown by halide vapour-phase epitaxy and metalorganic vapour-phase epitaxy on nano-patterned silicon (001) substrate. Crystallographic orientation relationships between the silicon substrate and GaN layers is identified. For GaN layers grown by metalorganic vapour-phase epitaxy an effect of SiC buffer layer synthesized by original growth method on their microstructure and surface morphology is under consideration.
Microstructure and morphology of 2D arrays of Ge quantum dots in a Si/Al2O3 matrix
Authors: Sokura L A , Nevedomskiy V N , Baidakova M V , Levin A A , Belolipetsky A V , Yassievich I N , Ershov A V , Bert N A
Published: December 2020

The paper presents the results of the microstructure and morphology study of two-dimensional Ge QD arrays in a Si/Al2O3 matrix formed by annealing multilayer periodic structures with Ge nanolayers in a Si/Al2O3 matrix. The distinctive features of samples in the series are the location and thickness of the Si barrier layers between Ge and aluminium oxide matrix. X-ray reflectometry and diffractometry and transmission electron microscopy studies have shown that large Al6Ge5 crystallites are formed and the multilayer structure is destroyed after annealing of the multilayer sample Al2O3/Ge without Si. It was found that the presence of Si barrier layers in multilayer Al2O3/Si/Ge structures reduces the interdiffusion of Al and Ge, but Ge1-xSix nanocrystallites are formed as a result of Si and Ge interdiffusion. Thus, the introduction of Si barrier layer into the Al2O3/Ge structure allowed obtaining of two-dimensional arrays of Ge1-xSix nanocrystallites with the penetration of Si up to 0.64.
Production and reconstruction of short-lived ρ(770)0, K*(892)0, ϕ(1020) and Λ(1520) resonances as a function of centrality and energy in Au+Au collisions at NICA
Authors: Ivanishchev D , Kotov D , Malaev M , Riabov V , Ryabov Yu
Published: December 2020

The short-lived resonances have proved to be very useful in the study of heavy-ion collisions at SPS, RHIC, and the LHC. Properties of these particles measured in dominant hadronic decay channels carry a wealth of information about the hadron chemistry and reaction dynamics. Resonances containing one or two strange quarks contribute to the study of the strangeness enhancement phenomenon predicted as a signature of the phase transition to quark-gluon plasma in heavy-ion collisions. Resonance integrated and differential yields are sensitive to the hadron re-scattering and regeneration in the hadronic phase. The resonance production has only scarcely been studied in heavy-ion collisions at NICA energies. These proceedings are devoted to the review of the expected properties of the resonances and their sensitivity to different stages of Au+Au collisions at

s

N
N

= 11 GeV. Results of feasibility studies for reconstruction of ρ(770)0, K*(892)0, ϕ(1020) and Λ(1520) resonances in the MPD experimental setup as a function of collision energy and centrality are presented.
Luminescence of silicon and quartz crystals at mechanical destruction
Authors: Vettegren V I , Ponomarev A V , Mamalimov R I , Scherbakov I P , Kulik V B
Published: December 2020

Spectra and time dependencies of fractoluminescence (FL) signals of silicon (Si) and quartz (SiO2) crystals are obtained when diamond crystals are scratched on their surfaces. Signals are generated when barriers preventing dislocation movement along sliding planes are broken. Simultaneously, the Si and SiO2 crystals break down into nanocrystals (nc). The band 1.62 eV and 2.14 eV corresponds in FL spectra of Si and SiO2 nc accordingly. After the crystals are broken, powders are formed. The size of Si and SiO2 nc in powders was determined by photoluminescence (PL) and Raman spectroscopy.
The possibility of controlling the relaxation rate of color centers in the optical fibers
Authors: Dmitrieva D S , Pilipova V M , Dudkin V I , Davydov V V , Rud V Yu
Published: December 2020

The necessity of method developing for losses compensation in the fiber optic communication lines after irradiation is substantiated. The reasons of appearance of radiation color centers in the optical fiber, which are the main sources of losses in irradiated fiber, are considered. The different methods of the governance of color centers relaxation rate after γ-radiation influence to the optical fiber are researched A method of the relaxation processes rate increasing of color centers is developed. It’s using allows to compensate the negative influence of γ-radiation on the fiber optic communication line of the during data transmission. The received experimental results are presented.
The role of excited discrete atomic states in the formation of quantum vortices in barrier-suppression ionization of hydrogen-like atom by ultrashort laser pulse
Authors: Larionov N V , Smirnovsky A A
Published: December 2020

We theoretically examine the quantum vortices creating through barrier-suppression ionization of two dimensional hydrogen atom by ultrashort laser pulse. We show that for the considered case of ionization, the excited discrete atomic states do not impact on the vortex formation, and the problem can be considered in the single-level atom approximation.
Digital holographic visualization of microparticles retained by an optical spatial trap
Authors: Shostka N V , Sokolenko B V , Karakcheva O S , Prisyazhniuk A V , Voytitsky V I , Poletaev D A , Halilov S I
Published: December 2020

We propose a convenient method for generating optical traps based on a spatially structured beam. The proposed method of optical trap shaping utilizes interference of few Gaussian beams which waists, inclination angles and beam number are chosen for controllable trapping of micron-sized particles in three-dimensional space. In addition to implementing non-contact trapping, optical visualization in all planes was performed with digital holographic microscopy. This method contributes to the accurate localization of the studied specimens inside the cuvette over whole volume.
Effect of saturable absorber in 1.5 μm wafer-fused vertical cavity surface-emitting lasers
Authors: Blokhin S A , Bobrov M A , Maleev N A , Blokhin A A , Vasyl’ev A P , Kuzmenkov A G , Ustinov V M , Gladyshev A G , Babichev A V , Novikov I I , Karachinsky L Ya , Voropaev K O , Ionov A S , Egorov A Yu
Published: December 2020

The static characteristics of 1.5 μm wafer-fused VCSEL with the thin n++-InGaAs/p++-InGaAs/p++-InAlGaAs tunnel junction (TJ) were investigated. The devices with the 8 μm diameter of the buried tunnel junction (BTJ) demonstrate effective single-mode lasing. A rapid increase in the threshold current, accompanied by an abrupt change in the output optical power is observed for devices with BTJ-diameter less than 7 μm. The observed behavior can be explained by increasing in the overlap of the optical mode with the unpumped (passive) part of the active region, which leads to the additional optical absorption. On the one hand, since the high-order transverse modes have the higher optical losses due to larger overlap with the unpumped part of the active region, then lasing via fundamental mode is more preferable even at large size of BTJ region. On the other hand, the reduction of effective index step between the BTJ region and the regions outside BTJ (caused by using small TJ etching depth) and the lateral smoothing of the difference in the height of the surface relief after TJ regrowth results in the significant drop of the transverse optical confinement factor and rise of absorption. Moreover, the absorption effect can be also strongly enhanced by increasing the heatsink temperature due to decreasing in the gain-to-cavity detuning.
Temperature dependence of the optical and electrical properties of long-wavelength InAsSb-based LED heterostructures
Authors: Semakova A A , Romanov V V , Moiseev K D , Bazhenov N L , Mynbaev K D
Published: December 2020

Optical and electrical characteristics of asymmetrical InAs/InAsSb/InAsSbP LED heterostructures with the InSb content in the active layer of 0.15 and 0.16 were studied in the temperature range 4.2 -300 K. At T < 150 K, radiative transitions involving donor-acceptor states in the InAs substrate were observed in electroluminescence spectra, and the presence of these states also showed up in the peculiarities of current-voltage characteristics. A strong effect of the quality of the InAsSb/InAsSbP heterointerface on the characteristics of the heterostructures was observed.
Visual control and data transmission system by Li-Fi technology for patients in a vegetative state/unresponsive wakefulness syndrome and minimally conscious state
Authors: Degtiareva S A , Kondratieva E A , Smirnova I G , Polukhin I S , Andreev Y S , Bougrov V E
Published: December 2020

Due to the development of high technologies, there is a need to use computer systems to support the increasingly complex types of human activities. It provides high accuracy and speed of various research and medical examinations. Taking into account the daily workload of doctors in the Intensive Care Unit, remote medical diagnostics systems are being implemented in many referral hospitals to predict the course of diseases. Decision-making is the result of processing certain information, the medical history patients based on the use of accumulated knowledge. Therefore, it can be concluded that automatic and visual control systems make the diagnosis process more accurate and easier. The aim of the work is to develop an optoelectronic system for visual monitoring and data transmission for patients in a coma by Li-Fi technology.
Spectrum evolution of magnetostatic waves excited through ultrafast laser-induced heating
Authors: Filatov Ia A , Gerevenkov P I , Wang M , Rushforth A W , Kalashnikova A M , Khokhlov N E
Published: December 2020

We study experimentally the influence of the laser-induced temperature gradient on the parameters of propagating magnetostatic surface waves in thin film of the ferromagnetic metallic alloy Galfenol Fe0.81Ga0.19. The material has a pronounced magnetocrystalline anisotropy and exhibits the long-distance propagation of magnetostatic surface waves excited with femtosecond laser pulses. The excitation pulse heats up the sample locally, what leads to the spatial-temporal change of magnetization and anisotropy parameters of the film, and thus excites the magnetostatic surface waves. We show experimentally that the spectrum of the excited waves narrows as they propagate in such a gradient medium. By changing the orientation of external magnetic field with respect to anisotropy axes of the sample, we control whether the low- or high-frequency part of the spin waves spectrum is suppressed.
Structural and dielectric properties of ceramic and thin film multiferroics based on Ba0.5Sr0.5TiO3
Authors: Mylnikov I L , Burovikhin A P , Eskov A V , Dedyk A I , Pavlova Yu V , Belyavskiy P Yu , Semenov A A
Published: December 2020

This paper presents the results of a study of the structural and dielectric properties of barium-strontium titanate (Ba0.5Sr0.5TiO3) with a high concentration of doped manganese ions. It was found that upon the addition of manganese ions, the phase transition point shifts toward lower temperatures. A graph of the dependence of the ceramic lattice parameters on the concentration of manganese ions is presented. It is shown that with an increase in the sintering temperature of ceramics, the dielectric constant of the samples increases.
Micro-photoluminescence of InP/GaInP2 quantum dots structures for topological quantum gates
Authors: Afanasev K M , Vlasov A S , Lebedev D V , Mintairov S A , Kalyuzhnyy N A , Saly R A , Zadiranov Yu M , Mintairov A M
Published: December 2020

Self-organized quantum dots (QD) InP/GaInP2 are natural electronic molecules (EM). They are promising objects for the study of the physics of strongly correlated electronic systems and the creation of quantum logic elements. In this work, we used micro-photoluminescence technique to study the effect of molecular oxygen on emission properties of these QDs and possible reducing their surface density.
Gaussian impurity bands in GaN and weakening of carrier confinement in InGaN/GaN quantum wells
Authors: Bochkareva N I , Ivanov A M , Klochkov AV , Shreter Y G
Published: December 2020

Gaussian impurity bands in GaN responsible for intracenter optical absorption and photoluminescence, give rise to defect-assisted carrier tunneling (hopping) through the barriers in the pn nanostructures with InGaN/GaN quantum wells (QWs). The tunneling injection of majority cariers into the QW results in the current humps and in rapid increase in the radiative recombination efficiency at low enough forward bias. As the bias increases, the carrier confinement in the QW weakens, leading to tunneling injection of minority cariers into the barriers, which results in the emission efficiency saturation and droop.
Experimental studies of the spectral characteristics of a free glow discharge in the wavelength range of 340-440 nm
Authors: Bezverkhnii N O , Monakhov N A , Petrenko M V , Lapushkina T A , Sakharov V A , Poniaev S A , Bobashev S V
Published: December 2020

Non-equilibrium air plasma generated in free glow discharge is characterized by optical emission spectroscopy techniques in the wavelength range of 340–440 nm. The rotational and vibrational temperature are studied as a function of distance from the electrode, to find out differences in the distribution of plasma parameters along with the discharge axis. In this work, the rotational and the vibrational temperature is determined from rovibrational spectra of second positive N2 system. It is observed that

N
2
+

/

N
2

intensity ratio increases from anode to cathode along the discharge axis.
The properties of long-lived ions appearing in plasma diode in a course of nonlinear oscillations
Authors: Bakaleinikov L A , Kuznetsov V I , Flegontova E Yu
Published: December 2020

Nonlinear oscillations may occur in a plasma diode when the ions are reflected from a potential barrier. It was found that long-lived ions are formed in the course of the oscillations of the potential. Based on the proposed analytical model of the oscillations of the potential the reason for the appearance of long-lived ions is elucidated and the main features of their distribution function are revealed. The analytical results are in good agreement with the results of simulation.
Prediction of drag crisis on a circular cylinder using a new algebraic transition model coupled with SST DDES
Authors: Stabnikov A S , Garbaruk A V
Published: December 2020

Flows with massive separation zones are frequent in industrial applications and pose a considerable challenge for contemporary turbulence solving techniques. Accurate prediction of these types of flows can be broken down into two distinct problems: prediction of separation points, which can be addressed by using laminar to turbulent transition models in RANS framework and description of the separated regions, best dealt with by using LES. The present work proposes a new algebraic transition model which is then coupled with the hybrid RANS-LES method DDES with the resulting approach tested on a flow around a circular cylinder on a wide range of Reynolds numbers ranging from sub- to super-critical. Results show that the proposed method is an improvement relative to both RANS and DDES methods and shows promise but requires further development.
Numerical simulation of the interaction of uranium hexafluoride with methane and oxygen in turbulent flame
Authors: Popov P A , Talalov V A , Pashkevich D S , Kambur P S , Kapustin V V , Zimin A R , Alekseev Yu I
Published: December 2020

Model of the uranium hexafluoride conversion in a methane-oxygen turbulent diffusion flame is presented. Model of the weighted sum of grey gases was used to calculate the absorption coefficient of mixture of uranium dioxide particles and carbon dioxide. Radiation heat transfer model was calibrated using available experimental data. A good agreement was obtained between the simulation results and experimental data.
Influence of destruction of the bismuth crystal structure on the features of measuring pulsed heat fluxes using a sensor based on anisotropic thermoelements
Authors: Popov P A , Poniaev S A , Sakharov V A , Reznikov B I , Monakhov N A
Published: December 2020

The results of heat flux measurements using a sensor based on anisotropic thermoelements with defects in the crystal structure during reflection of a shock wave are presented. Using numerical simulation, the influence of the defective layer thickness on the sensor electrical signal and the calculated heat flux is analysed. It is shown that the presence of even a thin defect layer makes it unsuitable for measuring pulsed heat fluxes with a characteristic time of ∼ 1 μs.
Ultrasound temperature control during short-term local heating of a test object by focused ultrasound
Authors: Ivanova Y F , Yukhnev A D , Gataulin Y A , Smirnov E M , Tarkhov D A , Berkovich A E
Published: December 2020

High Intensity Focused Ultrasound (HIFU) is widely used in modern medicine. One of the important applications is the ablation of internal organ tumors under the HIFU heating. During this procedure, it is necessary to monitor the temperature in healthy adjacent tissues. Ultrasound thermometry (UST) is a promising non-invasive method of temperature control. The paper presents implementation of the UST technique in case of short-term local heating. A new algorithm suggested for ultrasound data processing improves the accuracy of the ultrasound thermometry technique to 2 °C.
Testing of a new algebraic laminar-turbulent transition model on a range of airfoils at moderate Reynolds numbers
Authors: Matyushenko A A , Stabnikov A S , Garbaruk A V , Menter F R , Lechner R
Published: December 2020

High quality prediction of laminar-turbulent transition for flow around airfoils is an important task for industrial applications. Prediction of such flows is usually carried out using the RANS framework in combination with transition models. The present study shows the capability of a recently developed algebraic transition model for prediction flows around different airfoils. The results of the model demonstrate satisfactory agreement with the experimental data and with results of existing differential models.
Monte Carlo simulation of mercury ion drift characteristics in an inert gas
Authors: Kurbanismailov V S , Maiorov S A , Ragimkhanov G B , Khalikova Z R
Published: December 2020

The Monte Carlo method calculated and tabulated the diffusion-drift characteristics of mercury ions in three inert gases (He, Ar, Xe) depending on the reduced electric field strength - the average energy of the ions, their longitudinal and transverse temperatures, diffusion coefficients along and across the direction of the field. The velocity distribution function of the ions and the angular dependence of the ions bombarding the surface are investigated
Further development of the Xe laser plasma 11-nm radiation source – new data on laser energy absorption and spectroscopy
Authors: Butorin P S , Kalmykov S G , Maximov V A , Sasin M E
Published: December 2020

Absorption of the laser pulse energy in the plasma has been shown to change from 8.5% at irradiation of a gas-puff target with a beam narrow-focused onto a near-central area of the jet up to 65% at the wide defocused irradiation. An analysis of this phenomenon is based on a hypothesis that plasma density decays significantly during the 10ns laser pulse due to hydrodynamic expansion of the hot plasma. A similarity of the EUV (Extreme UltraViolet) intensity and the laser light absorption as functions of the laser beam diameter suggests a revision of the conventional idea of a strong EUV radiation self-absorption in a cold peripheral shell of the laser plasma whereas the high absorptivity of the laser radiation by the plasma looks like a major feature to gain high efficiency of an EUV source.
Measurements of the plasma parameters at the edge of the FT-2 tokamak and comparison with the gyro-kinetic model
Authors: Kaledina O A , Shatalin S V , Esipov L A , Kouprienko D V , Lashkul S I
Published: December 2020

Diagnostics of a plasma edge is an extremely important field of tokamak physics because this region determines the plasma-surface interaction. In the paper the plasma density, electron temperature and radial electric field at the plasma edge of the FT-2 tokamak are analyzed using the results of probe measurements. The measurements were performed in the experiments conducted with a plasma pinch being in a symmetrical vertical position and were compared with the results derived by the ELMFIRE code simulations to correct the model calculations. The experimental observations are shown to be in a reasonable agreement with the gyro-kinetic model predictions.