bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studying the fractal properties of Ceres
Authors: Mubarakshina R R , Andreev A O , Nefedyev Y A , Arkhipova A A , Kronrod E V , Demina N Y 
Published: December 2021

Abstract
Currently, the asteroid Ceres belongs to small celestial bodies with the most well-known physical parameters. The study of the structural and real properties of Ceres is an urgent and modern task, the solution of which will make it possible to develop the evolutionary theory of a minor planet. In this work, the fractal properties of the dwarf planet Ceres were analyzed using data from the Dawn space mission. Using the expansion in a harmonic series in spherical functions the height parameters of the structural model of Ceres, a 3D model of Ceres was constructed. The analysis showed that the resulting system has a complex multiparameter fractal configuration. The study of such objects requires the use of harmonic multiparameter methods. Multivariate fractal analysis allows to represent systems similar to the Ceres model in the form of a spectrum of fractal dimensions. The advantage of fractal analysis is the ability to explore local areas of the physical surface. In this work, the Minkowski algorithm was used for this purpose. At the final stage, an overdetermined system was solved for various local areas of topocentric information in order to postulate a model that takes into account external measures. Fractal dimensions D are determined for local regions and the entire model of the planet. Fractal dimensions vary from 1.37 to 1.92 depending on the longitude and latitude of Ceres. The main results are as follows: 1) the structure of the Ceres surface varies more strongly in longitude; 2) the structure of Ceres is smoother in latitude; 3) the coefficient of self-similarity changes rather quickly in longitude, which indicates that different local regions of the minor planet were formed under the influence of various physical processes. It is necessary to emphasize that the resulting fractal dimensions are significantly scattered both in longitude and latitude of Ceres. This fact confirms the presence of a complex structure in the spatial model of a minor planet. This also applies to the actual physical surface of Ceres. The results of the work allow us to conclude that fractal modeling can give independent values of the fractal dimension both for the entire model of Ceres and for its local macrostructural regions.
Long-term evolution of coronal holes on the Sun and occurrence frequencies of magnetic storms with gradual commencements
Authors: Veretenenko S , Ogurtsov M , Obridko V , Tlatov A 
Published: December 2021

Abstract
Long-term evolution of areas with open configuration of magnetic field (coronal holes) on the Sun reconstructed on the basis of H-alpha synoptic charts for the period 1887-2016 was studied and compared with annual occurrence frequencies of magnetic storms with gradual (GC) commencements. It was found that correlation between yearly values of coronal hole (CH) areas and sunspot numbers with no time shift is negative and not strong, but increases up to ∼0.6-0.7 when CH areas are delayed by 4-5 years relative to sunspot numbers. Temporal variations of CH areas in the Northern and Southern hemispheres are characterized by dominant ∼11-year periodicities; however, they differ significantly on the multidecadal time scale. The wavelet spectra of CH areas in the Southern hemisphere, unlike those in the Northern one, reveal persistent periodicities of ∼30-35 years on the studied time interval. Similar periodicities of ∼30-35 years are observed in annual occurrences of GC magnetic storms which are caused by high-speed streams of solar wind from coronal holes. The results of cross wavelet analysis of annual occurrence frequencies of GC magnetic storms and areas of coronal holes revealed common periodicities ∼11, ∼35 and ∼60 years which confirmed a close link of these storms with the evolution of large-scale magnetic fields on the Sun.
The use of the formalism of the complex electrical module in the monitoring of oncological diseases
Authors: Salnikova Zh A , Castro R A 
Published: December 2021

Abstract
The article discusses the use of the formalism of a complex electrical module to determine the relaxation parameters α, β, τ of blood serum. Approximating formulas for the real and imaginary components of the electrical modulus, obtained from the Havrilyak-Negami equation, are given. The assumption is made that for healthy organisms the parameters α, β, τ are constant (or change insignificantly), and for cancer patients they change, and the more the disease develops, the more these parameters change. It is also assumed that the activation energies Ea
of macromolecules in the composition of blood serum are different for healthy and diseased organisms. Thus, the study of the dynamics of changes in the parameters α, β, τ, Ea
can be used in the monitoring of oncological diseases.
Analysis of infrared spectra of blood serum of patients with multiple myeloma
Authors: Chernyshev D A , Mikhailets E S , Telnaya E A , Plotnikova L V , Garifullin A D , Kuvshinov A Y , Voloshin S V , Polyanichko A M 
Published: December 2021

Abstract
Multiple myeloma (MM) is a serious disease that is difficult to diagnose especially at early stage. Infrared spectroscopy is a promising approach for diagnosing MM. The principal component analysis (PCA) allows us to reduce the dimension of the data and keep only the important variables. In this study, we apply principal components analysis to infrared (IR) spectra of blood serum from healthy donors and multiple myeloma patients. As a result of the analysis by PCA, it was possible to visualize the separation of patient’s and donor’s samples into two clusters. The result indicates that this method is potentially applicable for diagnosis of multiple myeloma.
Generation in the regime with three resonance frequencies
Authors: Oparina Yu S , Savilov A V 
Published: December 2021

Abstract
If the group velocity of the wave is close to the bunch velocity, the bunch placed in the maximumum of the radiated pulse. It provides high effeciency of the electron-wave interaction. However, there are other factors related to particle dynamics, which have strong influence on the radiation process. In this paper the regime with three resonance frequencies is discussed. By varying the phase size of the electron bunch, the generation conditions at each of the frequencies can be changed. There are results for the spontaneous coherent super-radiative undulator emission in the terahertz frequency range from a short (as compared to the wavelength of the radiated wave) dense electron bunch. As a result, an electron bunch radiates two pulses with amplitudes of the radiated fields ∼ 10-70 MV/m.
Non-equilibrium methods for synthesis and modification of gallium oxide
Authors: Nikolskaya A A , Korolev D S , Mikhaylov A N , Mullagaliev T D , Chigirinsky Yu I , Belov A I , Nezhdanov A V , Trushin V N , Nikolichev D E , Almaev A V , Giulian R , Kumar M , Tetelbaum D I 
Published: December 2021

Abstract
Synthesis and modification of gallium oxide as a wide-bandgap semiconductor is a topical task in the fields of power electronics, UV detectors, gas sensors, telecommunication. In the present work, the Ga2O3 films deposited on sapphire substrates by magnetron sputtering have been studied. The influence of deposition parameters and subsequent annealing on the structure and optical properties of the synthesized films is analyzed. Ion doping of magnetron-deposited films with silicon is carried out by the ion implantation method. It is shown by the Raman scattering and optical transmission spectroscopy that ion irradiation leads to the disordering of the crystal structure, but subsequent annealing results in a partial recovery of the structure. Hall-effect measurements for irradiated and then annealed films do not reveal the formation of a conducting layer. Apparently, this is due to the fact that the main contribution to the resistance is made by grain boundaries in the magnetron-deposited films.
In-situ estimation of defect volume from parameters of acoustic emission signals
Authors: Damaskinskaya E E , Hilarov V L , Panteleev I A , Korost D V , Damaskinskii K A 
Published: December 2021

Abstract
By using two methods of nondestructive testing, i.e., acoustic emission (AE) measurements and X-ray computed microtomography (CT), an experimental study of defect accumulation during a uniaxial compression of a natural heterogeneous material was carried out. A joint analysis of the AE and CT data revealed a correspondence between energy characteristics of the acoustic emission accompanying defect formation and volume of defects. It is shown that the dependence of the total energy of AE signals on the defect volume is linear, which is consistent with the phenomenological dependences for earthquake focuses obtained earlier. The linear dependence was used to estimate the average defect size. It is shown that, regardless of the assumed defect shape, its average linear size does not exceed 100 μm.
Prediction of radiation degradation of Si detectors irradiated by relativistic ions of different masses
Authors: Mitina D , Verbitskaya E , Eremin I , Fadeeva N 
Published: December 2021

Abstract
The presented paper is focused around radiation damage of silicon material under the different ions irradiation. The ion total energy range is 0.7 GeV for 7Li to 208 GeV for 208Pb. The results of TRIM modeling for the set of six ions are presented. The extracted information about vacancy production allows making first assumptions of the Si degradation dependence on mass and energy of the incident ion.
Raman scattering and luminescence in single crystals of the amino acid glycine C2H5NO2 with an admixture of croconic acid C5H2O5
Authors: Balashova E V , Smirnov A N , Davydov Yu V , Krichevtsov B B , Starukhin A N 
Published: December 2021

Abstract
Single crystals of the amino acid glycine (Gly) C2H5NO2 doped with croconic acid (CA) C5H2O5 were synthesized by evaporation from an aqueous solution. The crystals grow in the form of hexagonal pyramids or thin plates. Analysis of polarized Raman scattering spectra (excitation wavelength of 532 nm) measured at room temperatures showed that crystals in the form of pyramids corresponded to γ-polymorph (γ-Gly), and crystals in the form of plates to α-polymorph of glycine (α - Gly). The presence of croconic acid molecules in the crystals is confirmed by the change in their color from white in pure Gly crystals to light or dark yellow, characteristic of CA crystals, as well as the presence of weak lines corresponding to CA in the Raman spectra. In single crystals of both Gly:CA polymorphs, strong green luminescence significantly exceeding the intensity of Raman scattering is observed in the range 400 - 700 nm with a maximum at 510 nm (2.44 eV) upon excitation at λ= 325 nm.
Study of the effect of nitrogen and hydrogen on the structure and magnetic properties of (Sm, Er)2Fe17 alloys
Authors: Tereshina I S , Veselova S V , Akimova O V , Paukov M A , Karpenkov A Yu , Argunov E V , Verbetsky V N 
Published: December 2021

Abstract
Materials based on the Sm2Fe17 compound with nitrogen have great potential for the manufacture of highly efficient permanent magnets. The initial, nitrided, and hydrogenated alloys based on the Sm2Fe17 intermetallic compound with partial substitution of erbium atoms for samarium atoms Sm1.2Er0.8Fe17(H, N)x have been studied by X-ray phase analysis and scanning electron microscopy. Nanopowders of Sm1.2Er0.8Fe17N2 were obtained by mechanical grinding. The grinding time was varied from 0 to 60 minutes. The magnetic hysteresis properties of all powder samples were studied in static magnetic fields up to 7 T, as well as in pulsed magnetic fields up to 60 T. The strength of the intersublattice exchange interaction was estimated. The obtained values λ are valid only for the explored concentration of Sm/Er ions.
Photo-e.m.f. at a metal/layered n-InSe semiconductor contact under heating conditions of current carriers by an electric field
Authors: Abdinov A S , Babayeva R F 
Published: December 2021

Abstract
The features of the photo-e.m.f. are experimentally studied on the metal/n-InSe contact under conditions of heating the current carriers by an electric field in the temperature range of T0
=77÷350 K. The dependences of the photo-e.m.f. (Uph
) value have been measured in the absence of

(

U

p
h

0

)

and under the condition of heating the current carriers

(

U

p
h

E
^

)

, as well as the value of

Δ

U

p
h

=
(

U

p
h

E
^

-U

p
h

0

)

from the wavelength (λ) and light intensity (I), heating electric field strength (Ê), time (τ), temperature (T0
), the initial value of the dark resistivity (ρD0 at 77K) n-InSe. It has been established that the heating of current carriers by an electric field significantly affects the magnitude and behavior of the photo-e.m.f. characteristics on the metal/n-InSe contact. The nature of this effect depends on T0,ρD0, I. The value of

U

p
h

E
^

significantly exceeds the value of

U

p
h

0

. With an increase in Ê, the value of AUph increases linearly (ΔUph~Ê) at relatively small Ê, and the dependence of ΔUph
(Ê) reaches saturation at higher Ê. The value of ΔUph
decreases with increasing
ρD0
, at relatively small Ê. With an increase in
ρD0
, the relaxation time of the photo-e.m.f. also increases when turned off the pulse of the electric field. The obtained experimental results are explained on the basis of the dependence of the photo-e.m.f. on the metal/n-InSe contact on the effective temperature of heated current carriers (Te
), considering the effect of the spatial inhomogeneity of n-InSe crystals on the photo-e.m.f. and on the process of heating the current carriers.
Regular electrically charged objects in Nonlinear Electrodynamics coupled to Gravity
Authors: Dymnikova Irina , Galaktionov Evgeny 
Published: December 2021

Abstract
We present a brief review of the basic properties of regular electrically charged black holes and electromagnetic solitons, predicted by analysis of regular solutions to dynamical equations of Nonlinear Electrodynamics minimally coupled to Gravity (NED-GR). The fundamental generic feature of regular NED-GR objects is the de Sitter vacuum interiors and the relation of their masses to spacetime symmetry breaking from the de Sitter group. Regular spinning NED-GR objects have interior de Sitter vacuum disk with the properties of a perfect conductor and ideal diamagnetic. The disk is confined by the ring with the superconducting current which provides the non-dissipative source of the electromagnetic fields and of the intrinsic magnetic momentum.
Peculiarities of the memory state formation in thin Ge2Sb2Te5 films
Authors: Fefelov S A , Kazakova L P , Bogoslovskiy N A , Yakubov A O , Bylev A B 
Published: December 2021

Abstract
The current-voltage characteristics of Ge2Sb2Te5 thin films were measured by a sequence of triangular current pulses with an increasing maximum current. Each current pulse forms in the sample a conducting filament with an area proportional to the maximum current in the recording pulse.
Critical behavior of a two-dimensional ferromagnetic film on a non-magnetic substrate
Authors: Belim S V , Bychkov I V , Maltsev I V 
Published: December 2021

Abstract
In this paper, we investigate the behavior of a ferromagnetic (FM) film on a nonmagnetic substrate near the Curie point by the computer simulation. The influence of the substrate is specified using the two-dimensional Frenkel-Kontorova (FK) potential. The study is carried out for a two-dimensional film described by the Ising model. At the first step, we calculate the positions of the substrate’s atoms in the ground state depending on the parameters. The parameters are (i) the ratio of the substrate periods and the crystal lattice of the film; and (ii) the ratio of the substrate potential amplitude to the elasticity coefficient of interatomic interaction. The period ratio determines the system coverage ratio. Minimization of the system’s total energy determines the ground state. Calculations show that the ground state has a periodic structure that differs from a square lattice with a coverage coefficient not equal to unity. We calculate the displacements of atoms from the equilibrium position for systems with a different linear scale.
Method for critical current angular dependencies analysis of superconducting tapes
Authors: Guryev V V , Shavkin S V , Kruglov V S 
Published: December 2021

Abstract
Various applications of superconducting materials require accounting of the critical current anisotropy relative to magnetic field direction - I
c7(θ). However, today there is no sufficiently comprehensive model that takes into account the anisotropy, therefore the angular dependences are usually not analysed, but only described using various mathematical formulas. As a result, the fitting parameters have no physical meaning and it is difficult to correlate the picture with the features of the microstructure. In this paper, we propose a method for analysing the critical current angular dependences based on the anisotropic pinning model. The applicability of this model for conventional superconducting Nb-Ti tapes with one peak in the I
c7(θ) dependence is shown. The possibility of extending this model to analyse the angular dependences of HTS materials is discussed.
Effect of wet KOH etching on structural properties of GaN nanowires grown on patterned SiOx/Si substrates
Authors: Lendyashova V V , Kotlyar K P , Gridchin V O , Reznik R R , Lihachev A I , Soshnikov I P , Cirlin G E 
Published: December 2021

Abstract
The possibility of the controlled removal of GaN nanowires (NWs) from an SiOx inhibitor layer of patterned SiOx/Si substrates has been demonstrated. It has been found that the wet KOH etching preserves the selectively grown GaN NWs on Si surface, whereas the GaN NWs grown on inhibitor SiOx layer are removing. The effect is described by the difference in polarity between GaN NWs grown on a Si surface and NWs grown on a SiOx inhibitor layer.
Effect of SFE on the evolution of crystallographic texture in Cu-Zn alloys subjected to severe plastic deformation
Authors: Zaynullina L I , Sitdikov V D , Sitdikova G F , Alexandrov I V 
Published: December 2021

Abstract
Within the framework of experimental investigations and computer modeling using the viscoplastic self-consistent (VPSC) model of a material plastic flow, the regularities of preferential orientations formation were established, the proportion of certain texture components was estimated, and existing slip systems (SS) and twinning systems (TS) were identified for equal-channel angular pressing (ECAP) of copper alloys depending on the stacking fault energy (SFE).
Spectroscopic evidence of tunnel coupling between CdTe quantum wells in the CdTe/ZnTe heterostructures
Authors: Agekyan V , Filosofov N , Karczewski G , Serov A , Shtrom I , Reznitsky A 
Published: December 2021

Abstract
The photoluminescence (PL) spectra of CdTe/ZnTe double quantum wells (QWs) are studied on a series of samples containing two CdTe layers with nominal thicknesses of 2 and 4 monolayers (ML) in the ZnTe matrix. The QWs were grown in atomic-layer epitaxy and separated by ZnTe spacers with the thicknesses dsp
=40−160 ML. The dependences of the relative intensity of shallow QW1 and deep QW2 PL bands (I1
and I2
, respectively) on the pump intensity (J) when excited by the lasers with different radiation wavelengths are investigated. It is found that in the sample with dsp=40 ML, the ratio Y(J)=I1/I2 depends on J and the shape of the Y(J) dependency changes with the excitation wavelength. In the samples with dsp
> 70 ML Y(J) also changes with the excitation intensity J, but the shape of this dependence is the same for various excitation wavelengths. It is concluded that the energy relaxation in these samples is influenced not only by the tunneling of charge carriers from QW1 to QW2, but also by carrier relaxation at the nonradiative centers, for which the recombination rate is different for shallow and deep QWs.
Study of the optical properties of a NiO/AuNP/NiO nanocomposite film transferred onto a transparent flexible substrate
Authors: Enns Y , Kondrateva A , Komarevtsev I , Kazakin A , Vyacheslavova E , Kuznetsov A , Andreeva V D , Mishin M 
Published: December 2021

Abstract
In this work a technique for optically active nanocomposite structures consisting of an oxide matrix with plasmonic NPs were demonstrated. A nanocomposite film was formed on a silicon substrate by NiO oxide matrix sputtering and gold nanoparticles dewetting. Studies of the morphology, elemental composition, and structure of the nanocomposite using SEM, EDS, XRD methods are presented. The transfer of the film onto a polymer substrate made it possible to study the optical characteristics of the obtained structures. It is shown that formed nanocomposite coatings on a polymer substrate are highly flexible and exhibit excellent mechanical properties.
Wafer fusion technique features for near-IR laser sources
Authors: Rochas S S , Novikov I I , Karachinsky L Ya , Babichev A V , Blokhin S A , Nevedomskii V N , Voropaev K O , Egorov A Yu 
Published: December 2021

Abstract
The paper presents the results of studies of the conditions for the formation of A3B5 compound semiconductors heterointerfaces including InP, InGaAsP and GaAs layers. The heterostructures were grown by molecular-beam epitaxy and were fused by wafer fusion technique. Improvement of planarity and homogeneity over the thickness of heterointerface due to using optimized preliminary preparation of semiconductor wafer surfaces was demonstrated. No additional extended defects such as dislocations were found.
Fabrication and complex investigation of LAFE based on CNT by PECVD with island catalyst
Authors: Chumak M A , Rokacheva A A , Filatov L A , Kolosko A G , Filippov S V , Popov E O 
Published: December 2021

Abstract
This paper presents a study of large area field emitter based on carbon nanotubes grown by PECVD method on Si/SiO2 substrate with Fe catalyst. The catalyst was deposited by CVD on the substrate from ferrocene in the form of islands. The sample creation technology was described and results of the emission properties study were presented. Current-voltage characteristics were registered and tested for compliance with the cold field emission regime. The fluctuation statistic of effective microscopic parameters was constructed. Using data from a computerized field projector, the emission profile of the sample was calculated.
Creation of micro-and nanochannels on the surface of silicon chips by lithography methods and investigation of ion transport in channel
Authors: Afonicheva Polina , Lebedev Denis , Bukatin Anton , Mukhin Ivan , Evstrapov Anatoly 
Published: December 2021

Abstract
We developed a technique for fabrication microfluidic silicon-glass chips with a system of nanochannels connecting two microchannel using traditional optical lithography and a focused ion beam. To investigate the transport phenomena in the nanochannels we experimentally studied their ion conductivity and using optical microscopy confirmed the existence of the diffusion flow through them. The developed method allows us to create systems of nanochannels with on-purpose geometry and controlled sizes. Devices with such nanochannels can be applied in the creation of biosensor devices and for genetic studies.