bluuebunny/crossref_metadata_2025_split huggingface dataset:
Air fleet endowment using methods of decision under certainty
Authors: Balasa R , Costea M L , Andrei A G , Apostol E I , Semenescu A 
Published: February 2021

Abstract
This study presents how to develop the information used during the decision-making process regarding the endowment of the Romanian air fleet with fighter aircraft, where after the analysis, we have as a result the appropriate model for the requirements and criteria for modernization and reorganization of the fleet. This analysis is performed by mathematical methods under certainty by the moments method or the Deutch Martin method. The first step of the method is to normalize the consequence matrix by linear transformations. It is taken into account that the four chosen criteria are of maximum. The moments method optimally generates clear results regarding the purchase of fighter aircraft that contribute to the development of the fleet.
Impact of healthcare innovation on the population’s well-being in Russia
Authors: Arkhipova M , Rogovchenko V 
Published: February 2021

Abstract
The article is devoted to the study of innovative activity in healthcare and its impact on the welfare of Russia’s population, depending on the respondents’ region of residence. Inclusion of various components of the population’s well-being is based on the author’s algorithm for calculating the composite index which includes 21 indicators within 5 sub-indices. To test the hypothesis about the presence of a statistically significant relationship between the level of development of innovations in healthcare and the well-being of the population, as well as in order to highlight innovative factors that affect the well-being of the population, the classical econometric tools and machine learning methods are considered. It allows choosing the most accurate model to describe the studied process and identifying the hidden links between the well-being of the regional population in Russia and their innovative activity. The results of evaluating different models made it possible to choose the Random Forest Regression algorithm in favor of compared Linear Regression Model and the Gradient Boosting Regression technique using control on deferred data. The obtained results of the work can be used in monitoring the state and level of innovative development of the healthcare sector at various levels, in the development of regional and municipal projects and programs to improve the healthcare system.
Study of russian households income differentiation with various inequality measures
Authors: Sirotin V P , Alexeeva K V 
Published: February 2021

Abstract
The article reviews modern income inequality measure such that Gini index and its modification, Zenga index and Davydov, their advantages and disadvantages. The reviewed indices are applied to the household’s income data for different regions in the Russian Federation from 2014 to 2018. The indices studied showed different level of income inequality in regions compared, thus the tendency is the same – income inequality decreases for all type of inequality studied. Russian regions become more similar in terms of income inequality, while income inequality itself tends to decrease in most regions.
The use of return on equity as a criterion for stock selection in the Indian equity markets
Authors: Saha A 
Published: February 2021

Abstract
As per Dorsey, companies with a sustainable competitive advantage tend to outperform the market benchmarks over time. Companies which have a durable competitive advantage compared with their competitors manage to compound capital at attractive rates of return and such companies tend to grow sales and profits predictably and generate substantial free cash flows. This reflects in their share prices over time. In this paper we have used a measure of Return on Equity as an indicator that a company has a sustainable competitive advantage, and have studied the equity performance of such companies as compared with market performance. We find that companies which have attained Return on Equity greater than 15% each year for the past ten years tend to outperform the market benchmarks over the next five years.
Ab initio study of MgO under pressure using quasi-harmonic approximation
Authors: Burov A S , Minakov D V , Levashov P R 
Published: February 2021

Abstract
We examine the dependence of the Gibbs free energy and entropy on pressure and density along MgO isotherm 300 K. Some theoretical works have previously predicted a drastic drop of entropy along MgO isotherms by analyzing existing experimental data and extrapolating them to high pressures. We present first-principle calculations of thermodynamic properties of MgO under pressure using density functional theory and quasi-harmonic approximation. The robustness of our calculations is verified by comparing the calculated and experimental phonon dispersion curves. The comparison with available diamond anvil cell experimental data is also provided. Our estimate for the B1–B2 phase transition is in good agreement with other experimental and theoretical studies. However, our results for entropy along isotherm 300 K do not agree with previous theoretical estimates based upon the integration of thermal expansion coefficient and isothermal bulk modulus by volume.
Equations of state for CaSiO3 phases based on the Helmholtz free energy
Authors: Sokolova T S , Dorogokupets P I 
Published: February 2021

Abstract
Equations of state for the CaSiO3 phases are constructed using a thermodynamic model based on the Helmholtz free energy. The proposed thermodynamic formalism is allowed us to calculate the full set of thermodynamic properties of minerals in a wide range of temperatures and pressures. The proposed equations of state are constructed with a small number of fitting parameters and reliably represent the properties of studied minerals under T–P or T–V parameters.
Computation of molecular spectra and thermodynamic functions for diatomic ideal gases using interatomic potentials
Authors: Maltsev M A , Morozov I V , Osina E L 
Published: February 2021

Abstract
A method for calculation of the thermodynamic properties of diatomic ideal gases using interatomic interaction potentials is discussed. For instance the computation of thermodynamic functions such as heat capacity, entropy and reduced Gibbs energy in the temperature range 298.15–10 000 K is shown for diatomic argon compounds.
The effect of atomic polarization on the diffusion coefficient of oxygen ions in cubic zirconia
Authors: Savilov T M , Lankin A V , Norman G E 
Published: February 2021

Abstract
We study single crystal zirconia using molecular dynamics method. We calculate the diffusion coefficient of oxygen ions in the temperature range from the occurrence of diffusion at our calculation parameters to the loss of stability of the crystal. In the potential of interatomic interactions, in addition to conventional terms, we introduce into our model the interaction due to the polarization of atoms. These interactions turned out to be crucial for the correspondence between the calculations and available experimental data.
Metastable shock waves in the region of their ambiguous representation
Authors: Konyukhov A V , Levashov P R , Likhachev A P 
Published: February 2021

Abstract
The behavior of perturbed shocks belonging to Hugoniot segments with ambiguous representation of the shock-wave discontinuity is considered. The segments are adjacent to the region of the shock wave instability L > 1 + 2M from the side of greater and lower pressure. Here, L is the D’yakov parameter and M is the post-shock Mach number. The model equation of state is used. For the constructed Hugoniot curve, the ambiguity sections are overlapped by the shock wave neutral stability regions. The three-dimensional simulations with varying post-shock parameters and perturbation intensity are performed. It is shown that shock waves considered are metastable: for any intensity of the shock wave, there are intervals of the perturbation threshold values inside of which the shock is neutrally stable or unstable. Neutral stability is characterized by the weak damping of secondary waves occurring as result of the perturbation.
Calculation of the optimal corrugation of the plate surface for explosive welding
Authors: Shutov A V , Sultanov V G 
Published: February 2021

Abstract
This article suggests profiling the surface of one of the welded plates in a special way during explosion welding. The principle and method of calculating the profile of the plate based on the materials and welding speeds of the plates are given. It is assumed that such profiling of the surface of the plate will allow to obtain more durable welded joints and even perform welding at a speed below the minimum collision speed for welding plates with smooth surfaces. As an example, a full calculation of plate profiling for specific collision parameters of welded plates is given.
Laser ablation of a multilayer target with layers of nanometer thickness
Authors: Khokhlov V A , Ashitkov S I , Inogamov N A , Komarov P S , Parshikov A N , Petrov Yu V , Romashevsky S A , Struleva E V , Tsygankov P A , Zhakhovsky V V 
Published: February 2021

Abstract
Multilayer products made of ultra-thin layers are widely used in modern science and technology. Laser exposure is used as one of the promising methods of processing such products. In this regard, we study the ablation of a layered target. A physical model is constructed, numerical simulation is performed, and experiments are carried out. The experiments were conducted with two different lasers and various diameters of the focal spot. To estimate the absorbed energy the reflection coefficient was measured. The results of calculations and experiments are consistent with an accuracy of about 10%. This allowed us to refine the model of two-temperature states and determine the strength of nickel. It is explained why, with an increase in the absorbed fluence, first the upper layer breaks in the multilayer.
The role of geometry in the generation of a shock wave by a femtosecond laser pulse
Authors: Shepelev V V , Inogamov N A , Fortova S V 
Published: February 2021

Abstract
Laser exposure at a sufficient intensity creates a shock wave (SW), propagating in the irradiated target. The process is used in many technological applications. As a result of femtosecond exposure, a warmed up layer with a thickness of d
T ∼ 0.1 μm occurs. The radius of the heating spot R
L varies from values of the order of a micron (focusing on the diffraction limit) up to tens or hundreds of microns depending on the experiment. As you can see, R
L ≫ d
T, therefore one-dimensional motion with a plane surface is generated. The quasi-plane SW stage ends when the SW moves away from the target surface to a depth of about RL. Then the stage of quasi-hemispherical propagation begins. The paper analyzes the transition from plane to hemispherical SW. The motion of the “wings” of a hemispherical wave on the target surface bordering on a gas or vacuum is investigated. Theoretical estimates and numerical simulation results are presented. Analysis of the movement of the “wings” on the surface is important for experimental diagnostics of phenomena inside the target.
Electron thermal conductivity of nickel and aluminum in solid and liquid phases in two-temperature states
Authors: Petrov Yu V , Inogamov N A , Khokhlov V A , Migdal K P 
Published: February 2021

Abstract
Analytical expressions for the electron thermal conductivity of nickel and aluminum are presented. The thermal conductivity depends on the electronic and ionic temperatures, density and phase of the substance (solid or liquid). The expressions obtained can be used in hydrodynamic calculations of the ablation of these metals or multilayer targets made from them. We consider the case when ablation is caused by the action of ultrashort laser pulses.
Modeling of electronic and phonon thermal conductivity of silicon in a wide temperature range
Authors: Koroleva O N , Demin M M , Mazhukin A V , Mazhukin V I 
Published: February 2021

Abstract
In the present article, using the methods of mathematical modeling, the thermal conductivity of silicon was obtained in a wide temperature range (0.3 ≼ T ≼ 3 kK), including the region of semiconductor-metal phase transformations. As it is known, there are two mechanisms of heat transfer in a solid: elastic lattice vibrations and free electrons, therefore, in the study of the thermal conductivity of silicon, the lattice and electronic components were taken into account. The lattice (phonon) thermal conductivity in this work was determined within the framework of the atomistic approach. The Stillinger–Weber and Kumagai–Izumi–Hara–Sakai interaction potentials were used for modeling. The results of the comparison of the phonon thermal conductivity obtained from the simulation results with the used interaction potentials are presented. The modeling of the thermal conductivity of the electronic subsystem of silicon with intrinsic conductivity in this work is based on the use of the quantum statistics of the electron gas using the Fermi–Dirac integrals. The total thermal conductivity of silicon, obtained as the sum of the electronic and phonon components, is compared with the experimental data.
X-ray radiography based on the phase-contrast imaging with using LiF detector
Authors: Makarov S S , Pikuz T A , Buzmakov A V , Chernyaev A P , Mabey P , Vinci T , Rigon G , Albertazzi B , Casner A , Bouffetier V , Kodama R , Katagiri K , Kamimura N , Umeda Y , Ozaki N , Falize E , Poujade O , Togashi T , Yabashi M , Yabuuchi T , Inubushi Y , Miyanishi K , Sueda K , Manuel M , Gregori G , Koenig M , Pikuz S A 
Published: February 2021

Abstract
An x-ray radiography technique based upon phase contrast imaging using a lithium fluoride detector has been demonstrated for goals of high energy density physics experiments. Based on the simulation of propagation an x-ray free-electron laser beam through a test-object, the visibility of phase-contrast image depending on an object-detector distance was investigated. Additionally, the metrological capabilities of a lithium fluoride crystal as a detector were demonstrated.
Restoring size of detonation nanodiamonds from small-angle x-ray scattering of polychromatic synchrotron radiation beam
Authors: Rubtsov I A , Ten K A , Pruuel E R , Kashkarov A O , Zubavichus Ya V , Peters G S , Veligzhanin A A 
Published: February 2021

Abstract
Over the past two decades, LIH SB RAS and BINP SB RAS have jointly conducted experiments on time-resolved (TR) small-angle x-ray scattering (SAXS) with detonating high explosives. The purpose of these experiments is to restore the dynamics of carbon species condensation to diamond nanoparticles by analyzing series of SAXS patterns behind the detonation front measured in real time with fast detectors. This knowledge is crucial for the development of reliable detonation models. In this paper, we compare SAXS patterns of identical nanodiamond samples measured at the TR-SAXS extreme state of matter end-station (BINP SB RAS) in the static mode under realistic conditions simulating fast real-time measurements with polychromatic SR beam and traditional SAXS BioMUR beamline at the Kurchatov Synchrotron Radiation Source (NRC “Kurchatov Institute”) with monochromatic synchrotron radiation (SR) beam. These experiments confirm that the size of scattering inhomogeneities determined in dynamic experiments with single bunch exposure with polychromatic SR beam is correct.
Cell proliferation under intense pulses of terahertz radiation
Authors: Sitnikov D S , Ilina I V , Revkova V A , Konoplyannikov M A , Kalsin V A , Baklaushev V P 
Published: February 2021

Abstract
Terahertz (THz) waves can influence a diverse spectrum of cellular processes. In the present study, we focus on the effect of high-power broadband THz pulses on cell culture. An experimental setup for long-term irradiation of cells with THz pulses with intensities of about 32 GW/cm2 has been developed. Human skin fibroblasts were exposed to THz pulses with a field strength of about 3.5 MV/cm for 90 min. Preliminary results on the THz-induced apoptosis process in cells are presented.
Search for hadronic solar axions
Authors: Akhmatov Z A , Berezin S S , Gavrilyuk Yu M , Gangapshev A M , Derbin A V , Drachnev I S , Kazalov V V , Khokonov A Kh , Kobychev V V , Kuzminov V V , Muratova V N , Panasenko S I , Ratkevich S S , Tekueva D A , Unzhakov E V , Zavrazhnov A Yu 
Published: February 2021

Abstract
Resonance excitation of the 83Kr first nuclear level (E = 9.4 keV) by solar axions formed via the Primakoff mechanism and via an M1-transition in the 83Kr nucleus in the Sun is searched. The γ-and x-ray photons and the conversion and Auger electrons arising from the excited-level relaxation are detected with a proportional counter in the underground low-background facility of Baksan Neutrino Observatory. The following experimental constraint is obtained for the product of the axion-photon coupling constant and the axion mass: |g

Aγ
m

A
| ≼ 6.16 × 10−17. In the framework of the hadronic-axion model, this corresponds to a new axion-mass constraint of mA
≼ 12.6 eV at 95% coincidence level (C.L.). In case of pure hadronic interaction the upper limit for axion-nucleon coupling is

|

g

AN

3

−

g

AN

0

|

≼ 8.3 × 10−7 at 95% C.L., which corresponds to upper limit for hadrionic axion mass: mA ≼ 64 eV at 95% C.L. with the generally accepted values S = 0.5 and z = 0.56.
Singularity-free stable black holes, holding the baryon conservation law in the periodic waveguided multiverse
Authors: Gribov I A 
Published: February 2021

Abstract
Black holes (BHs) are three-dimensional (3D) singularity-free macroscopic defects in the superfluid-crystal-like four-dimensional (4D) periodic waveguided multiverse (PWM) concept by the author, like edge-dislocations in 3D smectic-A liquid crystals. The PWM-co-emergent intrinsically identical ordinary matter (OM), antimatter (AM), dark matter (DM), dark antimatter (DAM) arise in the nearest 3D-waveguids–3D-universes with the co-emergent special relativity, weak Newtonian gravity, the expanded equivalence principle–the expanded general relativity (PWM-GR) foundation, predicting gravity mass symmetry–matter-antimatter antigravity. The PWM-BHs have identical Schwarzschild radii, outer gravity potentials as the GR-BHs, but flat-singularity-free gravity potentials inside. Microscopic PWM-fermions—singularity-free defects-holes in the weightless superfluid PWM-vacuum-medium–form singularity-free, intrinsically physically identical macroscopic defects: OM-BHs, DM-BHs, AM-BHs, DAM-BHs in the nearest 3D-waveguides. The smallest free PWM-BHs have 4.3 solar masses (excluding microscopic Hawking’s GR-BHs never experimentally detected), they are stable—too heavy for gravitational Schwinger-like virtual electron-positron pairs decoupling—unable emit gravitationally repulsive virtual positrons; they also unable emit repulsive PWM-antiphotons, electrostatically confined in the gravitationally polarized PWM-vacuum, preserving its decay, holding the fundamental baryon number conservation law, prohibiting Hawking’s-GR-BHs evaporation. Only plasma-eating, growing PWM-BHs emit thermal positrons, simultaneously absorbing attractive virtual particles. The dominating PWM-DM-pulsars explain relativistic galactic positrons flows excess over electrons.
Distribution function of the ion microscopic field in strongly coupled ultracold plasma: Molecular dynamics simulations
Authors: Bobrov A A , Bronin S Ya , Klyarfeld A B , Korchagin D S , Zelener B B , Zelener B V 
Published: February 2021

Abstract
The results of calculating the distribution function of the ion-microscopic field at the neutral point of ultracold plasma by the method of molecular dynamics are presented. The calculations are carried out for the model of two-component fully ionized ultracold plasma in a wide range of the Coulomb coupling parameter values. To evaluate the accuracy of the calculations, the distribution function of the ion microscopic field of randomly distributed charged particles was calculated and compared with the exact Holtsmark function. Results obtained for our model can be used for any equilibrium or non-equilibrium strongly coupled plasmas, in which quantum effects are negligible. Comparison with results of other authors is made.
Electrophonic noises from meteors and dust acoustic modulational perturbations
Authors: Morozova T I , Popel S I 
Published: February 2021

Abstract
The article discusses dusty plasmas processes in the Earth’s ionosphere associated with the passages of meteoroids and the spread of the meteor tail. Mechanisms explaining the occurrence of electrophonic noises recorded simultaneously with the passage of meteor bodies are suggested for extremely low frequencies range. It is explained by modulational instability of electromagnetic waves from meteor associated with the dust acoustic mode with characteristic frequencies 0.03–60 Hz. As electromagnetic waves propagate in the dusty plasmas of the meteor tail or in the dusty ionospheric plasmas, dust acoustic waves are excited as a result of the development of modulational instability of electromagnetic waves at characteristic frequencies and as a result, the electromagnetic waves become modulated. At the surface, these perturbations can be converted into sound waves by means of receivers. The growth rates of modulational instability at which the modulational excitation of extremely low-frequency dust acoustic disturbances occur are calculated. The conditions of the development of modulational instability are given. The correlation between observations of ionospheric radio noises and passages of meteors is noticed. Observed data of electrophonic noises include discussing range of frequencies 0.03–60 Hz.
Creation of stable dust structures in strong magnetic fields
Authors: Pavlov S I , Dzlieva E S , Novikov L A , Ivanov A Yu , Yanitsin D V , Polischuk V A , Karasev V Yu 
Published: February 2021

Abstract
When investigating the dusty plasmas in a magnetic field, there are a number of problems in creating stable dust structures. This is particularly evident in stratified discharge at fields above 1000 G. This report discusses the conditions of the experiment under which for the first time it was possible to create the stable dust structure in the glow discharge with fields up to 10 000 G. The areas of stability and instability of the dust trap have been detected depending on discharge parameters such as a gas sort, a pressure, a current and a radius of discharge tube. The conditions of instability are compared with the literary data on the properties of the glow discharge in plasma. The general recommendations for the creation of the stable dust structure are concluded.
Diagnostics of dust trap by the discharge glow in magnetic field
Authors: Novikov L A , Ermolenko M A , Dzlieva E S , Pavlov S I , Polischuk V A , Karasev V Yu 
Published: February 2021

Abstract
In order to understand in detail the physical processes in the dusty plasma in the magnetic field in the stratified discharge, we carried out an experiment to observe the geometry of the glow of standing strata in the neon discharge. Stratified discharge was video recorded in longitudinal magnetic field inside magnetic coil at values of magnetic induction from 0 to 2700 G. As the magnetic field increased, both the configuration of the striation and the intensity of their glow changed. Video recording was carried out by a periscope video camera with the possibility of displaying an image on a computer. The results show a tendency to merge the strata; the head of the striation is lengthened. The suggested interpretation shows the decrease in the longitudinal gradient of the electron temperature, which leads to the decrease in the electron eddy current in the striation and the slight decrease in the rotational velocity of the dust structure.