bluuebunny/crossref_metadata_2025_split huggingface dataset:
A search for transient events in Konus-Wind data
Authors: Kozlova A V , Svinkin D S , Lysenko A L , Ulanov M V , Tsvetkova A E , Frederiks D D 
Published: December 2019

Abstract
We present the search for and classification of hard X-ray and soft γ-ray transient events in the archive of continuous (waiting-mode) Konus-Wind observations. We found ∼ 26 000 transient events; among them, ∼ 12 000 are solar flares (∼ 10 times as much as observed in triggered mode); and ∼ 5 000 are gamma-ray bursts (GRBs) or soft gamma repeaters (SGRs) confirmed by other space missions (∼ 2 times as much as detected in triggered mode). The remaining ∼ 9 000 events include Galactic transients, unconfirmed GRBs and possible solar flares. We discuss the application of developed techniques for GRBs accompanied by supernovae, high-energy neutrinos and sources of gravitational waves.
Studying the γ-ray pulsar J1932+1916 and its pulsar wind nebula with Chandra
Authors: Medvedev O D , Karpova A V , Shibanov Yu A , Zyuzin D A , Pavlov G G 
Published: December 2019

Abstract
We report on the results of Chandra X-ray observations of the γ-ray radio-quiet pulsar J1932+1916. We confirm the previous detection of the pulsar counterpart and its pulsar wind nebula in X-rays from low spatial resolution data obtained by Suzaku and Swift. The Chandra data with much better spatial resolution resolved the fine structure of the nebula in the pulsar vicinity, which can be interpreted as jets bent by the ram pressure. The size of this compact part is about 30″, and it is surrounded by a weak asymmetric diffusive emission extended up to ≈2.′8. The X-ray spectra of the pulsar, the compact and extended parts of the nebula can be described by the power-law models with photon indexes of

0

.44

−
0.61

+
0.57

,
2

.34

−
0.79

+
0.95

and

2.14

−
0.31

+
0.32

, respectively. The actual pulsar’s X-ray flux is several times weaker than it was obtained with Suzaku and Swift where it was dominated by the unresolved nebula. We discuss possible associations of J1932+1916 with the nearby supernova remnant G54.4−0.3.
FNS-parameterization of non-stationarity effects in the solar activity dynamics
Authors: Demin S A , Panischev O Yu , Latypov R R , Timashev S F 
Published: December 2019

Abstract
In paper we present the findings of analyzing the non-stationary effects to a solar activity dynamics. Within the framework of Flicker-Noise Spectroscopy (FNS) we study the Zurich series of Wolf numbers from 1849 to 2009. According to the FNS methodology the properties of complex system evolution are manifested in the low frequency component (the “resonant” part of the signal) of time signal and contain in the specific sets of the frequencies. For another thing the signal also has the high frequency component (“chaotic” part) including the noise and the different types of short time irregularities. The FNS methodology allows to discover the intermittency phenomena in studied dynamics by analyzing the behavior of the nonstationarity factor. We will show that the maximum value of this parameter corresponds the maximum of Wolf number i.e. the solar activity.
The gamma quanta absorption due to interaction to the thermal bremsstrahlung of hot gas in spheroidal galaxy cluster
Authors: Popov A N , Barsukov D P , Ivanchik A V 
Published: December 2019

Abstract
The interaction of high energy gamma quantum to thermal bremsstrahlung photons of hot intracluster gas with producing electron-positron pair is considered. It is supposed that gas temperature and electron number density have spheroidal distribution in galaxy cluster. The dependence of optical depth on eccentricity and orientation of spheroid is considered.
Megaelectronvolt astronomy with HERMES: spectroscopy, polarimetry, and synergies with fast Cherenkov arrays
Authors: Krassilchtchikov A M , Bykov A M , Eremin V K , Kholupenko E E , Nesterenok A V , Vasilyev G I 
Published: December 2019

Abstract
Sensitive observations of energetic space phenomena in the 0.3 – 10 MeV range are needed to investigate a number of hot issues of modern astrophysics and cosmology. With the advanced technology of thick double sided silicon strip detectors (Si-DSSDs) it is possible to construct a space-borne gamma-ray telescope with sensitivity 30-100 times better than that of CGRO/COMPTEL. Synergies of MeV range observations from space with GeV-TeV range spectra to be obtained with future fast and sensitive imaging atmospheric Cherenkov arrays (CTA, TAIGA-IACT, ALEGRO) would allow one to reveal complex mechanisms of energy conversion in transient gamma-ray objects, in particular, sources of gamma-ray bursts. In this short note we briefly outline most demanding objectives of 0.3 – 10 MeV range astronomy and present a schematic view of HERMES gamma-ray spectrometer being developed at the Ioffe Institute.
Isotopic imprint of the Solar system encounter with interstellar gas cloud around 660 BC (2610 BP)
Authors: Pavlov A K , Blinov A V , Frolov D A , Konstantinov A N , Koudriavtsev I V , Ogurtsov M G , Ostryakov V M , Vasilyev G I 
Published: December 2019

Abstract
We analyse the long lived radionuclide data (14C, 10Be and 36Cl) in tree rings and Greenland ice cores referred to the 660 BC event. The hypotheses of solar superflare impact on the atmosphere and Solar system collision with small sized dense interstellar cloud are considered. Decisive role in clarifying the situation is the experimental data on other isotope content available in ice for the periods under discussion. The data on 10Be and 36Cl (GRIP and NGRIP stations in Greenland) during the 660 BC event favour the second hypothesis. Various assumptions on the relationship between isotope production and deposition rates in the atmosphere are considered.
Experimental modeling of subsurface gas traps on Mars
Authors: Tsurkov D A , Pavlov A K , Shubina A S , Kuleshov D O 
Published: December 2019

Abstract
Methane seasonal variation observable by MSL mission and possible variations of atmospheric mass on timescale (105-106 years) are among the most intriguing problems in Mars exploration. These variations are connected with hypothetical biosphere activity in the subsurface Martian soil and existence of liquid water on the Martian surface within modern era. Stability of liquid water on surface request higher atmospheric pressure in comparing to modern value. CO2 cannot loss with known mechanisms of atmospheric escape. Therefore, the main part of necessary CO2 must be buried in upper layers of the Martian soil. Local and seasonal time variable sources and fast methane destruction are needed to explain high seasonal variations of methane concentration in air at the Martian surface. Gas reservoirs, containing biogenic or abiogenic methane could be possible seasonal sources of methane as well. In this work we experimental study stability of the gas reservoirs covered of mixture of regolith and water ice with perchlorates. Thickness of covered regolith layer was about 10mm. In experimental runs we increased a temperature of gas traps and monitored a possible diffusion of gases through the isolated layer with mass spectrometer. The gas traps stay stable at gas pressure up to 1 bar. We did not discover any diffusion process before mechanical destruction of reservoirs at gas pressure over 1 bar. In this work we show that the big subsurface gas reservoirs can exist for a long time before cracking due to slow process of the water ice sublimation by climate and seasonal variation of subsurface temperature.
Primordial 4He abundance refinement using sample of SDSS DR15 galaxies
Authors: Kurichin O A , Ivanchik A V , Klimenko V V 
Published: December 2019

Abstract
We present spectroscopic data on metal-deficient HII regions from dwarf galaxies of the Local Volume on the basis of Sloan Digital Sky Survey (SDSS) Data Release 15 observations. Using the data on the intensities of the optical emission lines of the HII regions, one can determine their chemical composition, as well as other physical properties, such as temperature and electron density. Oxygen abundance (and thus the metallicity) of the source is determined using direct method by using strong [OIII] lines. Here we present only sources with oxygen abundance below 12 + logO/H = 8.5. These data is used to determine primordial helium abundance, which value should be determined with as little errors as possibles. The main way to reduce errors is to use the spectroscopic data of the highest quality possible. On the other hand one can statistically decrease evaluation errors by using large dataset. Main focus of this paper is studying if we can decrease errors in Yp
determination by combining HeBCD sample with SDSS spectra of lower quallity.
Spectroscopic examination of dentine and gingival fluids and their diagnostic capability for the preventive treatment of pathology carious processes in dentine
Authors: Seredin P V , Goloshchapov D L , Ippolitov Yu A , Vongsvivut J 
Published: December 2019

Abstract
IR-spectra of the samples of the dentine and gingival fluids obtained with the use of synchrotron radiation can be applied for the diagnostics of the pathological processes of the caries character in a dentine. Vibrations within the range of 2100-2050 cm−1 observed in the spectra of dentine and gingival fluids characteristic of thiocyanates mean the development of the carious pathology. At the same time vibration modes of the carboxyl group of a complex ether detected within the range of 1765 – 1725 cm−1 in the spectra of dentine and gingival fluids certainly confirm the development of caries in dentine. These spectrometric signatures can be certainly and reliably detected also in the gingival fluid, indicating at the fact that the changes proceeding in its molecular composition are referred just to the development of pathological processes in the deep dental tissues.
Raman spectroscopic characterization of anti-diabetic drug metformin hydrochloride
Authors: Bayramov F B , Toporov V V , Chakchir O B , Anisimov V N , Rud V Yu , Glinushkin A P , Bairamov B H 
Published: December 2019

Abstract
Raman scattering spectra of metformin hydrochloride, one of the most widely used oral anti-diabetic drugs which also possesses anti-aging and anti-tumor properties, have been obtained by high-resolution and high-sensitivity Raman-scattering technique. It is established that rather narrow (4–10 cm–1) spectral lines of molecular vibrations are observed in of the metformin hydrochloride pressed powder sample in the important spectral range of 50–1700 cm–1. These “fingerprints” can be applied to reveal which chemical bonds produce spectral components corresponding to the vibrations of particular functional groups and the presence of crystalline state of the metformin hydrochloride without evidence of an amorphous phase. This observation makes the metformin hydrochloride as promising model system for development and application as molecular biosensors.
Investigation of the structural reorganization of micromycetes in hypomagnetic fields
Authors: Panina L K , Bogomolova E V , Dmitriev S P , Dovator N A 
Published: December 2019

Abstract
Using the experimental setup that allows the Earth’s magnetic field to be screened up to 1-100 nT, we found features of the microscopic fungi growth pattern, namely, the appearance of spiral growth instead of fractal. A hypothesis was put forward on the participation of a charged protein cluster - Spitzenkorper, located in the apical zone of cells, in the reorganization of fungal growth.
Analysis of stochasticity of gene expression in single cells of Mycoplasma gallisepticum
Authors: Rumyantseva N A , Vedyaykin A D , Khodorkovskii M A , Vishnyakov I E , Fisunov G Yu 
Published: December 2019

Abstract
Genetically identical organisms under the same conditions usually have differences in the level of expression of the same genes. This phenomenon is called genetic noise, and it is characteristic of all organisms. In this paper, we studied the stochasticity of gene expression in Mycoplasma gallisepticum at the level of single cells using fluorescence microscopy. The results show that M. gallisepticum demonstrates high level of variations in gene expression: even in case of strong promoters and ribosome-binding sites, some cells demonstrate negligible expression level. Such a high stochasticity in gene expression may have significant impact on the life of this reduced bacterium.
Analysis of the effectiveness of the stages of the concentration of genetic material
Authors: Petrov D G , Antifeev I E , Germash N N , Makarova E D 
Published: December 2019

Abstract
The effect of the efficiency of the stages of concentration and purification of DNA / RNA and their contribution to the efficiency of the whole process is shown. It is shown that the use of an alternating magnetic field to control the magnetic sorbent inside a liquid sample allows not only to cover the entire volume of the sample, but also to change the liquid reagents in the working chamber, thus high rates of speed and efficiency of the DNA extraction process can be achieved. Based on the data obtained earlier in studying the effect of temperature and ultrasound on the efficiency of DNA extraction, a method is proposed for increasing the efficiency of nucleic acid extraction and concentration using an alternating magnetic field.
Investigation of noise influence on calculation of fractal dimension
Authors: Kondrashov A V , Ustinov A B , Volobuev E S , Drozdovskii A V , Kalinikos B A 
Published: December 2019

Abstract
In this paper we investigate in details the influence of the noise intensity on the result of the fractal dimension calculation. The fractal dimension of multidimensional torus is considered as an analysis object. Sum of a number of harmonic signals with irrational ratio of their frequencies and noise signal allows to construct partially destructed torus. It is shown that the presence of the noise leads to increase of the fractal dimension. Value of the increase depends on the relation between noise intensity and harmonics intensity.
Anomalous thermal expansion of iron borate crystals FeBO3 near the Néel point
Authors: Zamkovskaya A , Maksimova E , Nauhatsky I 
Published: December 2019

Abstract
Study of the anomalous behavior of the linear thermal expansion coefficient near the antiferromagnetic phase transitions in iron borate crystals FeBO3 are reported. The lattice parameters and volume of FeBO3 have been measured in the temperature range 25–300˚C by the X-ray diffraction method. The thermal expansion is evidently sharply anisotropic and spike near the Néel temperature.
Issues of TRIM program as a tool for developing a silicon detectors radiation degradation scenario
Authors: Mitina D , Verbitskaya E , Eremin V 
Published: December 2019

Abstract
The presented study is focused around the TRIM program issues and its applications for prediction of silicon detectors degradation under heavy ions of 40Ar. Results of the simulations of low-energy ion (53.4 MeV) and high-energy ion (1.62 GeV) irradiation are demonstrated. Experimental data for silicon p+-n-n+ detectors irradiated by the low energy are also presented. Reliability of TRIM simulations application for studying silicon detectors degradation under heavy ion irradiation is discussed.
Observation of internal multiplication of nonequilibrium charge in irradiated silicon detectors at a temperature of 1.9K
Authors: Shepelev A , Eremin V , Verbitskaya E 
Published: December 2019

Abstract
The development of modern high-energy physics is a powerful incentive for the progress of its experimental base. The use of semiconductor devices is standard for large accelerators and experimental setups at LHC, CERN, and perspective as sensors for monitoring beam loss and radiation fields in superconducting magnets and accelerating resonators operating at superfluid helium temperature (1.9 K). In these problems, the optimal type of radiation sensor is a compact silicon detector, the use of which in harsh radiation environment in combination with helium temperatures is a non-trivial task. The most important characteristics of such devices are the distribution of the electric field in the volume and the parameters of charge carrier transport, which determines the detector signal. The study considers specific kinetics of charge collection in silicon detectors at a temperature of 1.9 K in situ irradiated by relativistic hadrons.
Computer simulation of phases consisting of Be, B and Li atoms and calculating their elastic properties using quantum mechanical calculation
Authors: Schigartsov A A , Fofanov A D 
Published: December 2019

Abstract
Chemical elements of groups 1 and 2 have the most pronounced properties in their periods. There is something unique about each of them, inciting substantial interest, especially regarding light-weight alloys of these elements. Young’s modulus to density ratio of beryllium is six times higher than that of steel. Heat-resistance of Be is 600°C. The combination of these physicochemical properties makes beryllium alloys specifically applicable in aerospace. Simulation of material properties is one of the main missions for materials science. Elastic properties are the easiest to calculate compared to other mechanical properties. Elastic properties are characterized by the fifth-fourth digits of the total cluster energy. Here we present the results of the calculation of the elastic constants of hexagonal and cubic beryllium and cubic lithium boride. The calculations were based on the density functional theory (DFT). The results obtained by different techniques (quantum chemical, semi-empirical) and data from the literature were compared.
Construction of the collision integral kernels for the hard spheres model
Authors: Bakaleinikov L A , Flegontova E Yu , Tropp E A 
Published: December 2019

Abstract
Recurrence procedure for constructing kernels of the integral operators arising in expansion of the nonlinear Boltzmann collision integral in Legendre polynomials is realised in “Mathematica” system for the hard spheres gas. All the kernels with increasing indices corresponding to the Legendre polynomials indices are subsequently calculated up to sum of indices equal to 40. The main features of the kernels as functions of their indices are considered. The kernels can be used to solve the nonlinear Boltzmann equation in strongly anisotropic case.
Exchange energy in diamagnetically diluted iron borate-based crystals
Authors: Seleznyova K , Mogilenec Yu , Strugatsky M , Yagupov S , Kliava J 
Published: December 2019

Abstract
The analytical relation between the microscopic a
ex and macroscopic E
dil exchange constants for diluted iron-gallium borates has been obtained. A computer code implementing a calculation of the macroscopic exchange constant for diluted iron-gallium borates has been put forward. A diamagnetically diluted crystal lattice has been generated using Monte-Carlo technique. We have found that the absolute value of the macroscopic exchange constant for diluted iron-gallium borates decreases with decreasing x, following a parabolic law.
Paraxial approximation of the electrostatic potential of a charged nonconducting torus
Authors: Tashayev Y N 
Published: December 2019

Abstract
In an electrostatics it is possible to allocate two kinds of problems: the field determination at an unknown location of the charges, but the given electric potential at the boundaries of the considered region, and the calculation of the potential and components of the electric field strength in a region free of charges from the known spatially-limited electric charge distribution. In this paper, preference has been given to the second formulation, which has been added by the principle of superposition of electric fields. Further, we consider the problem of the distribution of the electrostatic potential over a thin-walled torus, uniformly charged along the surface. The condition of constancy of the surface charge density is realized only when using a torus with dielectric walls. To find the distribution of the electrostatic potential around a non-conducting torus uniformly charged along the surface, the Poisson equation was considered, which solution was represented as a surface integral. In toroidal coordinates, an expression for the electrostatic potential is obtained, which is calculated in terms of the complete elliptic integral of the first kind. The torus potential is explored on presence of a local extreme. The functions of cylindrical coordinates (paraxial approximation) are constructed, approximating the potential and field intensity in the outer region of the torus, and it is proved that the potential has a saddle shape in the region close to the centre. The spatial distribution of the electrostatic potential in the outer region of a uniformly charged along the torus surface has been visualized, using Matlab environment.
Raman spectra of GaSe epitaxial layers grown on GaAs substrates and group-theoretical analysis of their vibrational modes
Authors: Davydov V Yu , Kitaev Yu E , Smirnov A N , Eliseyev I A , Starukhin A N , Avdienko P S , Sedova I V , Sorokin S V 
Published: December 2019

Abstract
A complete group-theoretical analysis of vibrational modes in ε, β, γ-GaSe polytypes has been performed. Raman spectroscopy data obtained on single crystals of ε-GaSe with a subsequent group-theoretical analysis were used to analyze the Raman spectra low-dimensional GaSe structures. Information was obtained on the structural properties of epitaxial layers and arrays of nanorods of the ε-polytype GaSe grown by molecular beam epitaxy on GaAs (001) substrates.
Nanostructures based on functionalized porous silicon for promising solar energy systems
Authors: Smerdov R S , Spivak Yu M , Moshnikov V A 
Published: December 2019

Abstract
The promising application of functionalized composite materials based on porous silicon (PS) for perspective solar energy conversion systems is considered in this paper. PS-based nanostructures are suggested for further realization of photon-enhanced thermionic emission for solar concentrators and thermionic electrodes due to the remarkable properties displayed by these materials. Nanostructured layers functionalized with silver (PS/Ag) are obtained via electrochemical etching and deposition processes. The investigation of acquired materials functionalized with fractal-like silver agglomerates is performed. Electronic absorption spectroscopy is utilized in order to characterize the surface structure of PS/Ag layers. Localized surface plasmon resonance phenomenon taking place within the array of silver nanoparticles is observed. Two distinct absorption bands located in the visible spectrum are detected; their emergence is related to the resonance effect taking place in the two nanoparticle arrays appearing during the synthesis process. The intensity of these bands can be manipulated with synthesis parameters of porous silicon matrix.
Effect of applied electric field on growth morphology of copper phthalocyanine thin films
Authors: Gordeeva A B , Dementev P A , Dunaevskiy M S , Makarenko I V , Pavlov S I 
Published: December 2019

Abstract
The effect of electric field on the initial stages of copper phthalocyanine adsorption on the SiO2 substrate was studied experimentally. The external electric field was applied during thermo-vacuum evaporation of CuPc. Using atomic-force microscopy and scanning electron microscopy, it was found that in the presence of an electric field, the film morphology changes. Instead of randomly oriented elongated crystallites, new form bend-shaped ones are formed on the substrate surface. The paper provides an explanation of the experimentally observed effect of the electric field on the structure of the growing film.