bluuebunny/crossref_metadata_2025 huggingface dataset:
Meteorite hazard model for a space mission to Mars
Authors: Demina N Y , Andreev A O , Nefedyev Y A
Published: December 2021

Currently, for the world’s space agencies, the robotic exploration of Mars is one of the most important tasks. One of the necessary stages for the implementation of this mission is the development and addition of new information to the State standard “Meteoric substance, spatial distribution model”. Until now, the State Standard has been more detailed in comparison with the American analogue (developed by NASA) and the European one. The standard is a mandatory document in the design of spacecraft. It should be noted that modeling of meteor hazard at a distance from Earth to Mars is a complex problem, since the analysis of the meteor population in near-Earth space does not give a complete picture of the propagation of meteoroids along the Earth-Mars route. Moreover, the further the trajectory of the spacecraft from the Earth’s orbit is, the less the number of near-Earth meteorites becomes. That is, objects that have the same orbital parameters with small bodies crossing the Earth’s orbit. The only way to solve this problem is to build an interpolation regression model, which is based on measurements from the Earth’s surface and observations of space missions. For this purpose, the density of sporadic meteoroids was transformed from the space mission coordinate system to the ground one. This was done in order to analyze meteorite observations by the Mariner 4 and Pioneer 10 spacecrafts. The results of the work made it possible to obtain new data for the spatial distribution of meteoroids on the Earth-Mars path. According to a comparison of our data with the data on the density of space debris in the previous works the most safe for space flights are normalization conditions of distributions of the elements of the orbits of meteoric bodies P(Z, e, i) < 60.
Composition of the lunar mantle for lower mantle high-velocity seismic model
Authors: Kronrod E V , Kronrod V A , Kuskov O L , Nefedyev Y A , Andreev A O
Published: December 2021

We investigated models of the internal structure of initially homogeneous Moon differentiated as a result of partial melting, using data on seismic velocities according to the seismic models assume the zonal structure of the lunar mantle is a model of the Moon which was obtained with using the array processing methods of high velocities in the lower mantle. As a result of inversion of gravity (mass, moment of inertia), seismic (P- and S-waves velocities) and petrological (balance ratios) data, the Monte Carlo method was used to reconstruct the chemical composition and internal structure of the Moon. The phase composition and physical properties of the mantle were obtained with Gibbs free energy minimization method and equations of state in the five-component system CaO-FeO-MgO-Al2O3-SiO2. For all models, possible values of seismic velocities and concentrations of the main oxides in three zones of the mantle were obtained, satisfying the geochemical and geophysical constraints and the possible sizes of the Fe-10%S core were determined. It was found that the lunar mantle chemical composition (concentration of FeO, Al2O3 and CaO) differs depending on the mantle zone. Constraints on the values of seismic velocities in the lower mantle and the most probable size of the lunar core were determined: VP ≤ 8.45 km/s; Fe-10%S core radius is ∼360 km.
3D printing technologies for creating models and nozzles in an aerodynamic shock tunnel experiment
Authors: Kotov M A , Monakhov N A , Poniaev S A , Popov P A , Tverdokhlebov K V
Published: December 2021

The features of 3D printing method for rapid prototyping and manufacturing of models for a pulsed high-speed gas-dynamic experiment are considered. Modern additive technologies allow the production of models. The basic properties of the materials and the advantages of 3D printing methods are described. The structure and properties of the obtained models can be unattainable using traditional manufacturing techniques. The design of the wind tunnel nozzle block is considered, which provides for the production of profiled contours using 3D printing. The advantages and disadvantages of use of such units on the shock tube are considered.
Search for possible connections of the h-Virginids meteor shower with near-Earth asteroids
Authors: Sergienko M V , Sokolova M G , Andreev A O , Nefedyev Y A
Published: December 2021

Asteroids and comets are the oldest objects in the Solar System and contain the initial matter that existed at the moment of its formation. By studying those small celestial bodies one may describe the processes taking place at the early stages and conditions of the formation of the Solar System. The study of the genetic relationships (using metrics based on orbital elements) of meteor showers with parent bodies (asteroids and comets) can be used to develop the theory of evolutionary processes that took place at the time of the formation of the solar system. In this work, we have studied the genetic relationships of the small meteor shower of the h-Virginids (HVI) with the near-Earth asteroids of the Apollo group. An author’s multi-factor method is applied, which implies the use of D-criterion by Drummond, metric by Kholshevnikov, Tisserand’s parameter, μ and ν quasi-stationary parameters of the restricted three-body problem, and the analysis of the orbit’s perihelion longitude π. The observational base includes television catalogues meteor orbits that are in the public domain: Meteoroid Orbit Database v2.0 (2010–2012) (CAMS) and the European meteor network EDMOND (2001–2016) catalogues. As a result of this study, the orbit of the h-Virginids (HVI), according to the values of Tisserand’s parameter, was found to be transitional, and thus, it was impossible to identify whether it was of cometary or of asteroid type. Using the author’s method, the asteroids 2001SZ269 and 2014HD19 were distinguished. The 2001SZ269 asteroid was distinguished as a candidate having a possible connection with the h-Virginids’ parent body.
FNS-parameterization of human magnetoencephalograms for the diagnosis of photosensitive epilepsy
Authors: Khairullina R R , Demin S A , Yunusov V A , Panischev O Y
Published: December 2021

This work presents the results of parameterization of magnetoencephalogram signals from healthy subjects and a patient with photosensitive epilepsy. Diagnostic criteria were established during the extraction of resonant and high-frequency (chaotic) components of the initial time signals. It is shown that an increase in the intensity of the chaotic components of the studied signals in the high-frequency region leads to a violation of cross-correlation relationships and a decrease in the level of manifestation of frequency-phase synchronization. The discovered signs of photosensitive epilepsy will contribute to the development of new methods for the diagnosis and medical control of this disease based on Flicker-Noise Spectroscopy.
Molecular modeling of post-diffusion stage of biotissue optical clearing under effect of iohexol aqueous solution
Authors: Shagautdinova I T , Likhter A M , Berezin K V , Dvoretsky K N , Nechaev V V , Tuchin V V
Published: December 2021

Interaction of iohexol (Omnipaque), an X-Ray contrast agent, with a mimetic peptide of collagen (GPH)3 as one of the main components of biological tissues has been studied with the use of methods of classical molecular dynamics (GROMACS). Complex molecular modeling of the post-diffusion stage of optical clearing allowed to evaluate such parameters as the average number of hydrogen bonds, formed between the clearing agent and collagen per unit time, and the immersion agent’s effect on changes in the collagen peptide volume. The obtained results are compared with similar results for glycerol, a polyatomic alcohol, and with the existing experimental data on the efficiency of optical clearing of these immersion agents.
Study of low-temperature exposure on biotissue using an elongated cryoapplicator
Authors: Pushkarev A V , Andreev N A
Published: December 2021

The article presents the results of a study of low-temperature exposure on animal biological tissue using the novel prototype of a liquid nitrogen cryoapplicator. The data obtained are compared with the cryoapplicator characteristics cooled by nitrogen dioxide that are currently used for the atrial fibrillation treatment. Data analysis confirmed the liquid nitrogen cryoapplicators effectiveness and made it possible to highlight their advantages.
Surface modification of polyimide film in the barrier discharge for cellular technologies
Authors: Kamalov A M , Celujko K S , Kolbe K A , Smirnova N V , Borisova M E , Bondarenko P N , Vaganov G V , Didenko A L , Yudin V E
Published: December 2021

In this work, the surface of polyimide films of PMDA-ODA was modified using a barrier discharge in order to optimize their biological properties when interacting with a culture of human dermal fibroblasts. The optimal modes of processing films in a gas discharge, which allows to increase the proliferative activity of cells, are found.
Protein secondary structure analysis of serum from patients with oncohematological diseases
Authors: Mikhailets E S , Chernyshev D A , Telnaya E A , Plotnikova L V , Garifullin A D , Kuvshinov A Y , Voloshin S V , Polyanichko A M
Published: December 2021

One of the promising approaches for diagnosing oncohematological diseases is infrared spectroscopy of blood serum. In this work secondary structure of blood serum proteins of patients with multiple myeloma, chronic lymphocytic leukemia and healthy donors was studied using IR spectroscopy. As a result of the study, it was found that the secondary structure of blood serum proteins in patients with chronic lymphocytic leukemia does not change in comparison with healthy donors. In contrast, patients with multiple myeloma have significant differences in the secondary structure composition of serum proteins compared to healthy donors. We conclude, that IR spectroscopy makes it possible to distinguish serum of healthy donors and patients with multiple myeloma, leading to the potential applicability of this approach to the diagnosis of multiple myeloma.
Possibility of Raman spectroscopy method use for evaluation of periodontitis-affected tooth enamel before and after open curettage
Authors: Timchenko P E , Timchenko E V , Bazhutova I V , Frolov O O , Volova L T , Ionov A Y
Published: December 2021

The results of the research of enamel of periodontitis-affected teeth before and after open curettage are presented in the work. The Raman spectroscopy method was used as an evaluation method of curettage influence on tooth enamel. Chemometric analysis of the Raman spectra of tooth enamel before and after curettage was made. Spectral changes of tooth enamel were detected. It was found that after the procedure of open curettage spectral changes occur in tooth enamel related to the changes in mineral composition and organic matrix forming.
Physical model for effects of microwaves on nucleoids in living cells: role of carrier frequency, modulation and DC and AC magnetic field
Authors: Matronchik A Y , Belyaev I Y
Published: December 2021

The effect of static and alternating magnetic fields on the conformation of nucleoids in cells of different types is considered. The model of slow and nonuniform rotation of the charged DNA domain is used. An equation is obtained for the resonance frequencies of the alternating magnetic field.
Analytical determination of DNA melting characteristic parameters using the optimal degree polynomial regression model
Authors: Belov D A , Bulyanitsa A L , Korneva N A , Aldekeeva A S , Belov Yu V
Published: December 2021

The article describes a new technique for determining two main parameters of DNA melting: the melting temperature Tm
and the temperature melting range ΔT, based on the plotting of an approximating polynomial function for the DNA melting curve. An algorithm is proposed for reducing the melting curve to approximation by the fourth degree polynomial function in accordance with the physical aspect of the DNA melting process. The correctness of the optimal degree choice from the condition of minimizing the value of the Akaike’s information criterion corrected has been confirmed. Analytical expressions for calculating the values of Tm
and ΔT are given oriented to a polynomial function of the fourth degree. Results comparison of applying the proposed and well-known techniques based on the experimental data is performed. The advantages of the new technique are revealed.
Cathodoluminescence of carbon-related defects in hexagonal boron nitride
Authors: Petrov Yu V , Vyvenko O F , Gogina O A , Bolotin K , Kovalchuk S , Watanabe K , Taniguchi T
Published: December 2021

Hexagonal boron nitride is a wide band gap semiconductor exhibiting various luminescence bands in visible and near ultraviolet range, which can be used as single photon source. The luminescence band with zero phonon line at 4.1 eV is commonly ascribed to the carbon impurity introduced during crystal growth. In this paper we provide experimental evidence that carbon-related luminescent centers can be introduced in hBN by local electron irradiation in the chamber of scanning electron microscope at room temperature that can be used as a technique for the nanofabrication of single photon source devices with desired pattern.
Development and synthesis of orthophosphate single crystals of YPO4 and LuP4 activated with Er3+
Authors: Silantieva E A , Zamoryanskaya M V , Burakov B E
Published: December 2021

Crystals of xenotime-structured phosphates doped with erbium had been grown from molybdate flux at a temperature 1220 ° C followed by slow cooling. The crystals synthesized had been studied using X-ray diffraction and electron probe microanalysis in combination with optical microscopy and luminescence studies.
Engineering of defects in fast neutron irradiated synthetic diamonds
Authors: Khomich A A , Kovalev A I , Khmelnitsky R A , Khomich A V , Popovich A F , Ralchenko V G
Published: December 2021

Chemical vapor deposited (CVD) diamonds have been irradiated with fast reactor neutrons at fluencies F = 1·1018 and 3 · 1018 cm-2 and then heated at temperatures up to 1600 °C. The processes of annealing in and annealing out of various complexes of intrinsic defects responsible for vibrational and electron-vibrational bands in the IR absorption spectra have been studied in detail. Some tens of local vibrational modes and zero-phonon lines with rather small width caused by numerous complexes of intrinsic defects were observed in the 400-11000 cm-1 range.
Simulation of heat transfer processes during the growth of crystals of the NiFeGaCo alloy
Authors: Vasil’ev M G , Krymov V M , Nosov Yu G , Bakholdin S I
Published: December 2021

Long crystals of NiFeGaCo alloy with shape memory effect, including magnetically controlled ones, were obtained by the methods of Czochralski and Stepanov. A strong influence on the properties of crystals of dendritic formations, especially noticeable in the initial part of the crystal, has been revealed. In order to optimize the growth experiments, the heat transfer process in the thermal growth zone was simulated. It is shown that the formation of dendrites is due to a change in heat transfer during growth, which leads to an increase in the axial temperature gradient near the crystallization front as the crystal grows. This fits into the framework of the classical concepts of the transition from dendritic growth to normal growth.
Measurements of pyroelectric coefficients of BT and BST ceramics
Authors: Burovikhin A P , Mylnikov I L , Dedyk A I , Belyavskiy P Yu , Pavlova Yu V , Pakhomov O V , Ivanov A A
Published: December 2021

In the work, the field and temperature dependencies on the pyroelectric coefficients of ceramic capacitor structures were measured. Barium titanate (BT) and solid solutions of barium-strontium titanate (BST) were investigate. At temperatures range from 20 °C to 30 °C, the values of the pyroelectric coefficients of the BST ceramics (p) 10-5 - 10-4 C/m2 K exceeded p for the BT ceramics by an order. The developed measurement technique made it possible to carry out direct pyroelectric coefficients measurements and determine the polarization initial state of the samples, regardless of their phase state.
The influence of conformational defects on the development of structural phase transition in tetracosane C24H50
Authors: Gureva S A , Marikhin V A , Myasnikova L P , Volchek B Z , Medvedeva D A
Published: December 2021

The kinetics of the first-order solid-state structural transition in monodisperse n-alkanes samples of even tetracosane C24H50 was studied by FTIR spectroscopy. The existence of many irregular conformers in solid phases of tetracosane, the concentration of which reaches a maximum when approaching the melting temperature, has been demonstrated. The existence of these defective molecules promotes transitions between different rotator phases in the solid state.
The nanostructuring of ultra-high-molecular-weight polyethylene in thermal and mechanical fields as revealed by DSC
Authors: Myasnikova L P , Borisov A K , Boiko Yu M , Borsenko A P , Drobot’ko V F , Egorov V M , Ivankova E M , Radovanova E I , Marikhin V A
Published: December 2021

The ultra-high-molecular-weight polyethylene reactor powders are widely used for the actively developing solvent-free method for producing high-strength high-modulus PE filaments, which includes the compaction and sintering of a powder followed by orientational hardening. To find an appropriate regime of the technological process, it is important to know how the nanostructure changes when transforming from a powder to a precursor for hardening. Nanocrystalline lamellae are characteristics of the powder structure. For the first time, the DSC technique was used to follow changes in the thickness distribution of lamellae in ultra-high-molecular-weight polyethylene reactor powder on its way to a precursor for orientation hardening. It was found that the percentage of thick (>15 nm) and thin (10 nm) lamellae in compacted samples and those sintered at temperatures lower than the melting temperature of PE (140°C) remains nearly the same. However, significant changes in the content of lamellae of different thicknesses were observed in the samples sintered at 145°C with subsequent cooling under different conditions. The influence of the lamellae thickness distribution in precursors on the mechanical characteristics of oriented filaments was discussed.
Investigation of electrolysis-related modification of graphene films in biosensors
Authors: Eliseyev I A , Usikov A S , Lebedev S P , Roenkov A D , Puzyk M V , Makarov Yu M , Gushchina E V , Oganesyan G A , Voronina A A , Shabunina E I , Shmidt N M
Published: December 2021

In this work, the modification of the surface parameters of graphene chips after electrolysis treatment in a NaClO4 aqueous solution has been studied. Two electrolysis modes have been analysed. In the first one, a negative potential (-0.2 V) is applied to the graphene chips, while in the second one the potential is positive (0.8 V). Investigation using a number of techniques including atomic force microscopy, Kelvin probe force microscopy, Raman spectroscopy, measurements of current-voltage characteristics and low-frequency noise has shown that the electrolysis mode with application of a positive potential on graphene chips decreases the 1/f noise and allows one to obtain a uniform surface potential distribution while leaving the graphene structure undamaged. The results of this study help to understand the efficiency and reproducibility of the procedure for electrolysis treatment of graphene chips.
Influence of the magnetic field on the formation and properties of polyvinyl alcohol - multi-walled carbon nanotube nanocomposites
Authors: Vasin S V , Efimov M S , Nizametdinov A M , Sergeev V A
Published: December 2021

The effect of a magnetic field on the polymerization process and the electrophysical characteristics of polyvinyl alcohol (PVA) films with the inclusion of multiwalled carbon nanotubes (MWCNTs) was studied. Using SEM micrographs, it was shown that the films obtained under the action of a magnetic field have a more homogeneous structure, while a significant number of MCNT agglomerations are present in the control samples. In the study of the conductivity at direct and alternating current, it was found that the films obtained in a magnetic field have a conductivity that significantly exceeds the conductivity of the control samples. It has been shown that the use of a magnetic field during polymerization has a noticeable effect on the properties and characteristics of nanocomposite films based on PVA and MWCNTs.
Clustering in thin silver films upon heating
Authors: Kazakov V A , Razina A G , Smirnov A V , Vasilev A I
Published: December 2021

The kinetics of the formation of silver clusters Ag from nanoscale continuous films of Ag on the surface of silicate glass and composite structures from films of Ag with carbon in the form of a continuous film and individual nanoparticles upon annealing in air at temperatures up to 670K is investigated. In the course of the work, the dependences of the surface morphology of silver clusters and absorption spectra in the visible wavelength range were obtained by the methods of atomic force microscopy and optical spectrophotometry.
Construction of barrier heterostructures based on carbon and organometallic compounds
Authors: Mazinov A S , Gurchenko V S , Tyutyunik A S , Ilina V Y , Dmitriev A I
Published: December 2021

This paper presents the results of using hybrid-organic zinc complex C24H24N6O3Zn as a component for creating fullerene C60-based heterostructures. The synthesis technique of the complex compound, the microscopy of the film surfaces obtained, their optical and luminescence properties are described in the paper. The introduction of zinc complex to fullerene shows that there occurs a potential barrier at the active layer interface. The obtained thin-film structures have rectifying light volt-ampere characteristics.
Development of techniques for the formation of a planar electric vacuum diode based on an array of CNTs synthesized at the edge of the Co-Nb-N-(O) film
Authors: Eritsyan G S , Gromov D G , Dubkov S V , Kitsyuk E P , Savitskiy A I , Dudin A A
Published: December 2021

This work shows the possibility of forming a planar diode structure based on carbon nanotubes formed on a catalytic alloy film Co-Nb-N-(O). The paper presents a technological route for the formation of a planar diode structure Si/SiO2/Si3N4/Co-Nb-N-(O)/SiO2 and studies the emission characteristics. The current-voltage characteristic of the obtained diode structure in the Fowler-Nordheim coordinates is close to linear in the range from 15 to 22 V, which confirms the phenomenon of electron emission.
III-V nanostructures with different dimensionality on silicon
Authors: Reznik R R , Kotlyar K P , Gridchin V O , Ilkiv I V , Khrebtov A I , Samsonenko Yu B , Soshnikov I P , Kryzhanovskaya N V , Leandro L , Akopian N , Cirlin G E
Published: December 2021

The possibility of AlGaAs nanowires with GaAs quantum dots and InP nanowires with InAsP quantum dots growth by molecular-beam epitaxy on silicon substrates has been demonstrated. Results of GaAs quantum dots optical properties studies have shown that these objects are sources of single photons. In case of InP nanowires with InAsP quantum dots, the results we obtained indicate that nearly 100% of coherent nanowires can be formed with high optical quality of this system on a silicon surface. The presence of a band with maximum emission intensity near 1.3 μm makes it possible to consider the given system promising for further integration of optical elements on silicon platform with fiber-optic systems. Our work, therefore, opens new prospects for integration of direct bandgap semiconductors and singlephoton sources on silicon platform for various applications in the fields of silicon photonics and quantum information technology.
Plasma enhanced chemical vapor deposition of gallium phosphide at low temperature
Authors: Uvarov A V , Morozov I A , Baranov A I , Maximova A A , Vyacheslavova E A , Kudryashov D A , Gudovskikh A S
Published: December 2021

This article is devoted to the formation and study of the properties of amorphous gallium phosphide layers obtained by plasma-chemical deposition at a temperature of 250 °C. The optical and structural properties of the obtained layers on fused silica and silicon substrates were investigated. The possibility of the formation of a homogeneous amorphous gallium phosphide with a smooth surface at a low temperature and low power of RF plasma was shown.
Influence of plasmon resonance on the luminescence of titanium dioxide thin films doped with rare earth ions
Authors: Łapński M , Czubek J , Drozdowska K , Sadowski W , Kuznetsov V V , Charykov N , Koscielska B
Published: December 2021

In this work the study of the optical properties of europium doped titanium dioxide thin films (TiO2:Eu) enhanced by gold plasmonic nanostructures are presented. Plasmonic platforms were manufactured by thermal annealing of thin film of Au, deposited on a Corning glass substrate. As a result of thermal treatment, gold spherical nanostructures with average dimensions of 50 nm were obtained. Luminescent TiO2:Eu film was deposited by RF magnetron sputtering method, from mosaic target. Morphology of gold nanostructures was investigated by SEM and TEM microscopes, while composition of oxides film was analysed by XPS methods. Luminescence properties were studied on the basis of excitation and emission spectra. Experiments have shown that such structures exhibit interesting luminescent properties and could be potential candidates for optoelectronics applications.
Processes of formation of epitaxial arrays of self-catalytic GaP nanowires on Si (111)
Authors: Fedina S V , Fedorov V V , Berdnikov Yu S , Sapunov G A , Mukhin I S
Published: December 2021

This study is devoted to the investigation of the effect of growth conditions (growth temperature, values of molecular beam fluxes) on the formation of self-catalytic GaP NW on Si(111), namely surface density, orientation and NW morphology. Nanowire arrays were grown on Si (111) by the plasma-assisted molecular beam epitaxy. It was determined that an increase of the temperature and a decrease of the Ga flux, while maintaining the V/III ratio, reduces the inclined NWs and parasitic islands nucleation probability.
Study of electric parameters of thin porous anodic alumina layers
Authors: Muratova E N , Nalimova S S , Bobkov A A , Moshnikov V A
Published: December 2021

Currently, the study of the electric parameters of porous anodic alumina (PAA) layers is of interest for sensor applications (humidity, DNA, etc.). PAA layers are synthesized using electrochemical anodizing of aluminum foil in potentiostatic mode with an aqueous solution of sulfuric acid and glycerin as an electrolyte. The surface morphology of the layers was studied by atomic force microscopy. The electric characteristics were studied using impedance spectroscopy at room temperature and under heating. An increase in the impedance of the heat-treated PAA sample was found, as well as an increase in the impedance with an increase in the measurement temperature. The results are explained by the influence of adsorbed water molecules on the electric characteristics of porous layers.
Model calculations of φ-meson production in small collision systems
Authors: Mitrankova M M , Berdnikov A Ya , Berdnikov Ya A , Kotov D O , Mitrankov Iu M
Published: December 2021

Ultrarelativistic ion collisions provide the unique possibility to study the quark-gluon plasma, a state of matter formed in the universe at the very first moments after the Big Bang. The minimal temperature and baryon density for the quark-gluon plasma formation requires scrutiny, since the signatures of the quark-gluon plasma formation are observed in large systems (such as Au+Au) at

s

N
N

=
200

GeV

, whereas collective effects in p+p collisions are not revealed. The φ-meson production measurements are considered to be a convenient tool to investigate the collision dynamics, as it is sensitive to the quark-gluon plasma effects. To interpret the nuclear modification effects and to study the process of the possible QGP formation the comparison with different theoretical models predictions is needed. This paper presents the comparison of the obtained experimental results on φ-meson production in small collision systems (p+Al, p+Au) at

s

N
N

=
200

GeV

to default and string melting versions of the AMPT model and PYTHIA model predictions. The results indicate that the minimal conditions (temperature and baryon density) for a QGP formation may lie in between in p+Al and p+Au collisions.
Method and stabilization system of position-sensitive spectrometer based on semiconductor strip detector
Authors: Tuboltsev Yu V , Eremin I V , Bogdanov A A , Chichagov Yu V , Eremin V K , Verbitskaya E M
Published: December 2021

The paper proposes a method and its realization for stabilizing the characteristics of a multichannel position-sensitive spectrometer. The device uses a new design of the semiconductor strip detector, which allows a simultaneous injection of stable in time electric charges on all strips. This solution enables the electronics to track changes in the conversion characteristics of all electronic channels including detectors strips, and correct them during the spectrometer operation. In addition, the proposed detector design makes it possible to control the signal propagation along the strips, thus providing an on-line check of the integrity of strips metallization and the quality of their connection with the readout electronics.
Degradation of silicon detectors under long-term irradiation by 252Cf fission products
Authors: Bakhlanov S V , Derbin A V , Drachnev I S , Konkov O I , Kotina I M , Kuzmichev A M , Lomskaya I S , Mikulich M S , Muratova V N , Niyazova N V , Semenov D A , Trushin M V , Unzhakov E V
Published: December 2021

The response function of the recoil nuclei in detectors designed for detection of neutrinos or dark matter particles can be determined only through usage of a neutron source with a known energy spectrum. A possible solution for a compact neutron calibration source is a combination of a 252Cf neutron source and a semiconductor detector that detects fission fragments, and thus records the neutron emission moment. This work is devoted to the degradation study of the operating parameters for silicon semiconductor detectors irradiated by fission fragments of the nuclide of 252 Cf. Two types of Si detectors were under investigations - silicon-lithium Si(Li) p-i-n detectors and silicon surface barrier detectors. As a result of the measurements, the maximum permissible radiation doses for the correct operation of both types of detectors and the relation of the received radiation dose to the spectroscopic characteristics of the detectors were determined.
Properties of ρ(770)0, K*(892), ϕ(1020), ∑(1385)±, Λ(1520) and Ξ(1530)0 resonances in heavy-ion collisions at a center of mass energy of

SNN=4-11GeV

and their reconstruction using the MPD detector at NICA
Authors: Ivanishchev D A , Kotov D O , Kryshen E L , Malaev M V , Riabov V G , Riabov Yu.
Published: December 2021

The short-lived hadronic resonances are used to study properties of the hot and dense medium produced in relativistic heavy-ion collisions. Due to their short lifetimes, the resonance yields and masses measured in the hadronic channels are sensitive to rescattering and regeneration effects in the hadronic phase. The measurement of resonances is foreseen in the physical program of the MPD experiment at NICA in heavy-ion collisions at

S

N
N

=
4
-
11

GeV

, in the range of energies where extensive measurements of resonances are not experimentally available. In this contribution, we explore the sensitivity of the ρ(770)0, K*(892), ϕ(1020), ∑(1385)±, Λ(1520) and Ξ(1530)0 resonances measured in the hadronic decay channels to different stages of the heavy-ion collisions at NICA energies and report the feasibility studies for the reconstruction of resonances in the MPD setup
Effect of quantum fluctuations on soliton regimes in microlasers
Authors: Fedorov S V , Rosanov N N , Veretenov N A
Published: December 2021

We present a theoretical investigation of effect of quantum fluctuations on laser solitons. Derivation of the stochastic equation, linearized with respect to quantum perturbations is carried out and the solutions are found. Explicit expressions are obtained for the time dependence of the soliton coordinates and momentum dispersion (variance) for perturbations averaged over the reservoir. It is shown that the dispersion of the soliton momentum becomes constant. It is shown that the dispersion of quantum perturbations tends to infinity near the Andronov-Hopf bifurcation threshold. The magnitude of quantum perturbations near the threshold of the appearance of hysteresis is estimated. It is shown that quantum perturbations do not significantly noise the soliton profile even with a very low intensity tending to zero. The number of photons in such solitons without supporting radiation, can reach unity.
Regime of small number of photons in the cavity for a singleemitter laser
Authors: Larionov N V
Published: December 2021

The model of a single-emitter laser generating in the regime of small number of photons in the cavity mode is theoretically investigated. Based on a system of equations for different moments of the field operators the analytical expressions for mean photon number and photon number variance are obtained. Using the master equation approach the differential equation for the phase-averaged quasi-probability Q is derived. For some limiting cases the exact solutions of this equation are found.
Subcarrier wave quantum key distribution system with gaussian modulation
Authors: Goncharov R , Samsonov E , Kiselev A D
Published: December 2021

The aim of the paper is to describe a well-known quantum key distribution GG02 protocol using multimode coherent states generated on subcarrier frequencies of the optical spectrum. In order to detect signal states, we use a method of coherent detection without the participation of a local oscillator directly but where power from a carrier wave is used as such. Within the framework of the modern GG02 protocol description and the secutity proof against collective attacks, we introduce the necessary amendments to reduce our model to a model of the common system.
Vertical cavity surface emitting lasers of 1.3 μm spectral range based on the InGaAs/InGaAlAs superlattice
Authors: Rochas S S , Karachinsky Ya L , Babichev A V , Novikov I I , Gladyshev A G , Kolodeznyi E S , Kopytov P E , Bougrov V E , Blokhin S A , Blokhin A A , Voropaev K O , Yu Egorov A
Published: December 2021

Vertical-cavity surface-emitting lasers of 1.3 μm spectral range with the active region based on the InGaAs/InGaAlAs superlattice were studied. VCSEL heterostructure was formed by a wafer-fusion of the heterostructure with an active region and two DBRs grown by molecular-beam epitaxy on InP and GaAs substrates respectively. Fabricated VCSELs have shown threshold current below 1.6 mA and frequency of small signal modulation near 9 GHz at 20°C.
Design of electrically driven single-photon source based on intra-cavity contacted microcavity with oxide-confined optical apertures emitting at 1.3 μm
Authors: Blokhin S A , Bobrov M A , Maleev N A , Blokhin A A , Vasyl’ev A P , Kuzmenkov A G , Shchukin V A , Ledentsov N N , Reitzenstein S , Ustinov V M
Published: December 2021

We propose a hybrid microcavity design of a 1.3 μm range electrically driven single-photon source (SPS) consisting of two high-contrast dielectric distributed Bragg reflectors which surround a 3λ-thick semiconductor cavity with two intra-cavity contact layers and four 40-nm-thick oxide-confined apertures. According to 3D finite-difference time-domain modelling, the overall photon-extraction efficiency of ~74% and the Purcell factor of ~13 can be obtained by properly adjusting the position of oxide-confined apertures relative to the electric field of the fundamental optical mode. The studied SPS design also demonstrates a coupling efficiency of up to 13% within numerical aperture 0.12 in contrast to ~5% reached for a conventional semiconductor micropillar.
Intensity noise characteristics of intracavity contacted VCSELs with rhomboidal oxide current aperture for the magnetometric sensor with Cs133 vapor cell used in magnetoencephalography
Authors: Bobrov M A , Blokhin S A , Maleev N A , Blokhin A A , Vasyl’ev A P , Kuzmenkov A G , Ustinov V M , Novikov I I , Ya Karachinskii L
Published: December 2021

We demonstrate noise characterization of novel 894.4 nm vertical-cavity surface emitting lasers with intracavity contacts and a rhomboidal oxide current aperture (IC-VCSELs), dedicated to 133Cs D1 line compact optically pumped atomic magnetometers (OPM). The laser relative intensity noise, measured to be -139 dB/Hz at 10 kHz frequency in 1 Hz bandwidth for a laser optical power of 0.8 mW, is decreased with optical power growth. The IC-VCSELs polarization-resolved relative intensity noise is 143 dB/Hz at 10 kHz frequency in 1 Hz bandwidth for 0.8 mW. The emission linewidth of the VCSEL is about 55 MHz. The IC-VCSEL parameters are determined, such as emission linewidth ~ 50-60 MHz, optical power ~ 0.5-1.0 mW, at which the polarization-resolved RIN becomes close to the RIN, which makes it possible to use these lasers in various OPM Mz and Mx schemes. The ultimate sensitivity of OPM was estimated by the ratio of the magnetic resonance to the signal to noise level. It is shown that a OPM based on the IC-VCSELs, assuming magnetic resonance FWHM ~ 1 kHz, can achieve a shot noise-limited sensitivity around 20 fT in 1 Hz bandwidth without any polarization improvements by polarizer or polarization beam splitter cube (PBC). Developed IC-VCSELs is acceptable for use in compact OPM for magnetoencephalography.
Microfabrication of Alkali Vapor MEMS Cells for chip-scale atomic clock
Authors: Kazakin A , Kleimanov R , Komarevtsev I , Kondrateva A , Enns Y , Shashkin A , Glukhovskoy A
Published: December 2021

The technology of MEMS atomic cells containing rubidium or caesium vapors in an atmosphere of neon buffer gas has been developed. Two-chamber silicon cells containing an optical cavity, shallow filtration channels and a technical container for a solid-state alkali source have been implemented in a single-step process of anisotropic wet chemical etching. To prevent significant undercutting of the filtration channels during etching of the through silicon cavities, the shapes of the compensating elements at the convex corners of the silicon nitride mask have been calculated and the composition of the silicon etchant has been experimentally found. The sealing of the cells has been carried out by silicon-glass anodic bonding at a temperature of 250 °C. For this purpose the LK5 glass which has an increased ionic conductivity in comparison with the conventional glass Borofloat 33 was used. The best microfabricated cells allowed us to obtain estimates of the relative instability of the coherent population trapping resonance frequency at the level of 5 · 10-11 at 1 s.
Four-terminal perovskite-silicon tandem solar cells for low light applications
Authors: Nikolskaia A B , Kozlov S S , Vildanova M F , Karyagina O K , Shevaleevskiy O I
Published: December 2021

Here novel high efficient semi-transparent perovskite solar cells (PSCs) based on ZrO2 photoelectrodes were fabricated and were used as top elements in tandem systems with crystalline silicon (c-Si) solar cells in four-terminal configuration. The comparative analysis of photovoltaic parameters measured for PSCs, c-Si solar cells and PSC/c-Si tandem solar cells demonstrated that the use of ZrO2 photoelectrodes allows to improve the PSC performance and to achieve efficiencies for PSC/c-Si tandem solar cell higher than for a standalone c-Si solar cell under varying illumination conditions.
Dielectric and thermal properties of organic ferroelectric (R)-3-quinuclidinol in porous glass
Authors: Milinskiy A Yu , Baryshnikov S V , Charnaya E V , Uskova N I
Published: December 2021

The results of studies of the dielectric constant ε′ and the DTA signal of a new organic ferroelectric (R)-3-quinuclidinol (C7H13NO), embedded in porous glasses with an average pore size of 100 nm, are presented. The phase transition was found to shift to low temperatures by 3 K upon heating and 6 K upon cooling, in comparison with bulk (R)-3-quinuclidinol. A decrease in the phase transition temperature in composites with (R)-3-quinuclidinol nanoparticles is consistent with theoretical models of the influence of size effects on the structural phase transition.
Magnetic and resonance properties of the Y0.5Sr0.5Cr0.5Mn0.5O3 polycrystal
Authors: Patrin G S , Mataev M M , Seitbekova K Zh , Shiyan Ya G , Plekhanov V G
Published: December 2021

The magnetostatic and magnetic resonance properties of the Y0.5Sr0.5Cr0.5Mn0.5O3 polycrystalline system have been experimentally studied. The intracrystalline ferromagnetic interaction turned out to be prevalent while the intercrystalline interaction appears to have antiferromagnetic character. We found that two absorption lines are observed in the spectrum in the magnetic ordering region at T < 80 K. The high-field line corresponds to the interacting parts of polycrystal related to the disordered shells and the low-field peak is system of ferromagnetic particles.
Do we need a non-perturbative theory of Bose-Einstein condensation?
Authors: Zloshchastiev K G
Published: December 2021

We recall the experimental data of one-dimensional axial propagation of sound near the center of the Bose-Einstein condensate cloud, which used the optical dipole force method of a focused laser beam and rapid sequencing of nondestructive phase-contrast images. We reanalyze these data within the general quantum fluid framework but without model-specific theoretical assumptions; using the standard best fit techniques. We demonstrate that some of their features cannot be explained by means of the perturbative two-body approximation and Gross-Pitaevskii model, and conjecture possible solutions.
RANS-based design of experimental flow model for investigation of complex curved turbulent wakes subjected to adverse pressure gradient
Authors: Guseva E K , Nikulin D A , Travin A K , Radespiel R , Scholz P
Published: December 2021

Results are presented of a series of RANS computations aimed at creating a new experimental flow model of a curved turbulent wake evolving under adverse pressure gradient. In the course of the computations, key geometric parameters of the model (the angle of attack of a flat plate generating the wake and the shape and the angles of attack of liner foils creating the pressure gradient) were varied in a wide range. The purpose was to find the parameters ensuring desirable features of the flow, namely, a considerable wake curvature and its strong deceleration leading to formation of a large stagnation or even a reversal flow region, on the one hand, and no flow separation either from the flat plate or from the surfaces of the liner foils, on the other hand. As a result, the design satisfying all these demands has been found. This design will be implemented and studied in the framework of recently launched joint German-Russian project “Complex Wake Flows” which presents a continuation of an earlier similar project devoted to symmetric wakes.
Stability features of steady-state solutions for a diode with electron and ion counter-streams
Authors: Bakaleinikov L A , Kuznetsov V I , Flegontova E Yu
Published: December 2021

Stability features of steady-state solutions for a diode with counter-streaming electron and ion flows are studied. For this purpose, the time-dependent problem for an exponential potential perturbation with complex frequency is considered. By linearization of the Poisson equation and electron and ion densities integrodifferential equation for the potential perturbation amplitude is derived. In the case of uniform unperturbed potential distribution an explicit solution of this equation is obtained. Eigen modes of the perturbation are studied. The limiting value of the diode length above which steady state solutions in question are unstable is found. The obtained analytical Eigen modes coincide with the result of numerical simulation of the potential perturbation evolution.
Gas discharge sustained by powerful THz and sub-THz gyrotrons in the mixtures of noble gases with nitrogen
Authors: Sidorov A V , Veselov A P , Razin S V , Barmashova T V , Vodopyanov A V , Luchinin A G , Orlovskiy A A , Glyavin M Yu
Published: December 2021

The discharge propagation velocity towards electromagnetic radiation of sub-THz and THz bands was measured in various noble gases (argon, krypton) mixtures with nitrogen in the wide pressure range (0.1 – 2 atm) for various field intensities into the focal spot (from dozen of kW/cm2 to several MW/cm2). In the experimental setups two different gyrotrons were used. In case of 263 GHz it was CW gyrotron with power up 1 kW, in case of 670 GHz – pulsed gyrotron (20 μs) with power up to 40 kW. In both cases the focusing system provided the size of the focal spot of (2–3)·λ, which ensured the investigation of discharge phenomena in a wide pressure range (0.1 – 2 atm). In both cases discharge appeared in the focal spot spread towards heating radiation into the area with the field intensity much less than one in the focal spot. Velocity of the discharge propagation was measured by using photos from speed camera with small exposure (down to 20 ns) and streak camera. It was demonstrated that discharge velocity increase along with pressure decrease and drops with electric field decrease as it moves away from the focal spot.
On mesh requirements for Large Eddy Simulation with Wall Functions
Authors: Kolmogorov Dmitry K. , Menter Florian , Garbaruk Andrey V.
Published: December 2021

The results of using Large Eddy Simulation with Wall Functions (WFLES) in application to basic wall-bounded flows, such as turbulent boundary layer and channel flow cases are presented. In particular, it is shown that WFLES is suitable for predicting wall bounded flows and provides reasonable accuracy when using appropriate grids. The grid for WFLES should have isotropic cells with size smaller than 10% of the boundary layer thickness. Using coarser grids or anisotropic cells leads to significant reduction of accuracy.
S-, P- and R-striations as attractors for electron phase trajectories in spatially periodic resonance fields
Authors: Golubovskii Yuri , Gurkova Tatiana , Valin Sergei
Published: December 2021

A new point of view on the appearance of S-, P- and R-striations in a positive column of inert gases is proposed, based on a dynamic analysis of the resonance properties of electron phase trajectories in spatially periodic fields. The positive column may be considered as a resonator containing a set of resonant modes. Like a tuning fork, being disturbed, it responds with one of the modes, in particular with of S-, P-, or R-modes or striations, depending on the discharge conditions. The dynamic approach eliminates the difficulties of the kinetic theory associated with the long length of the solution of Boltzmann equation, which is much greater than the length of the positive column.
The analysis of applicability of thermoelectric radiation detectors for heat flux measurements behind a reflected shock wave
Authors: Kotov M A , Shemyakin A N , Solovyov N G , Yu Yakimov M , Glebov V N , Dubrova G A , Malyutin A M , Popov P A , Poniaev S A , Lapushkina T A , Monakhov N A , Sakharov V A
Published: December 2021

The study is devoted to assessing the applicability of the manufactured thermoelectric sensor to measure pulsed heat fluxes in shock-wave processes. It is shown that the created thermoelectric sensor has fast response time and sufficient level of electric signal and can be successfully used in short duration high speed gas dynamic experiments.