bluuebunny/crossref_metadata_2025_split huggingface dataset:
Magnetic nanoparticles in biocatalysis
Authors: Grebennikova O , Sviridova I , Matveeva V , Sulman M 
Published: October 2020

Abstract
The properties of enzymatic systems based on horseradish root peroxidase immobilized on magnetic particles were studied. Magnetic Fe3O4 nanoparticles were synthesized by co-precipitation. Then, horseradish root peroxidase was immobilized on their surface in two ways by covalent crosslinking. For this purposes, in the first case, Fe3O4 was sequentially treated with tetraethoxysilane, 3-minopropyltriethoxysilane, glutaraldehyde and HRP. In the second case, before immobilization of HRP, 3-minopropyltriethoxysilane, glutaraldehyde and HRP were sequentially deposited onto the support surface. The activity of the synthesized biocatalysts was evaluated spectrophotometrically in the oxidation reaction of 2,2’-azino-bis (3-ethylbenzothiazolin-6-sulfonate) ammonium with hydrogen peroxide. The kinetic parameters K

m
and V

max
were also calculated for all types of catalysts, including native HRP. Among all biocatalytic systems, the best values, compared with the native enzyme (K

m
= 4 mmol/L and V

max
= 12.6 · 10−4, mmol/L·s), were obtained for the first type of biocatalyst (K

m
= 5 mmol / L and V

max
= 2.5 · 10−4, mmol/L·s). It was also determined that the optimum pH is 7.2.
Cyclic Scheduling for Parallel Processors with Precedence Constrains
Authors: Grigoreva N 
Published: October 2020

Abstract
The goal of this paper is to prepare algorithms of the cyclic scheduling problem, in which some set of jobs V is to be repeated an infinite number of times. We consider the multiprocessors problem when a set of jobs is done on identical parallel processors. Cyclic scheduling problems arise (for example) in manufacturing, timesharing of processors in embedded systems. The goal is to find a periodic schedule that minimizes the cycle time under precedence constraints. Although the problem is NP-hard, we show that the special case, where the precedence graph G is a tree or there are only two processors and all jobs have a unit processing time, can be solved in polynomial time.
Investigation of fine metal films of the Ni-Al system by physical methods
Authors: Ishkov A , Malikov V 
Published: October 2020

Abstract
The article describes the results of investigations of ultrathin Ni-Al films, obtained by the resistive method of thermal evaporation and having characteristic islands sizes of 700-1000 nm with a film thickness of about 500 nm. The work presents a method for producing a film using an installation for creating a high vacuum and subsequent film deposition. Investigations of the obtained film sample were carried out with the help of an optic microscope, a scanning probe microscope and a Fourier analyzer. Kinetic characteristics and relief of the film, characteristic islands sizes are established, the search for regularities in the island structure of films is carried out, and its electrical conductivity is determined.
Study of a secondary power source with hysteresic control, comparison of theory and practice
Authors: Ivanov A D 
Published: October 2020

Abstract
This article presents the comparison of the operation of the model and the prototype of a secondary power source with hysteresic control. The principles of operation of this type of control are considered. Timing diagrams and oscillograms of the model and prototype are presented. Comparison results are presented. On the basis of the prototype, theoretical principles of the operation of hysteresic control are confirmed.
Computer simulation of the multiplicative method for the formation of digital spectrozonal images
Authors: Kalitov M A , Kornyshev N P 
Published: October 2020

Abstract
The article discusses the features of the formation of digital spectrozonal images corresponding to narrow registration zones. TIt analyses the processes of signal transformations with the multiplicative method of forming digital spectrozonal images. The results of computer modeling are discussed with the aim of qualitative and quantitative comparison of images obtained with differential and multiplicative digital spectrozonal imaging. An example of images of test objects obtained by the differential and multiplicative method from the original digital spectrozonal images is given.
Temperature field of SiC – refractometric detector under conditions of visualization of a heated gas stream
Authors: Karachinov V A , Djerenov I G , Evstigneev D A 
Published: October 2020

Abstract
As part of a computer experiment using the finite element method, a technique was developed for visualizing the temperature morphology of the temperature field of a refractometric detector based on single-crystal silicon carbide when interacting with an air stream heated to temperatures T = 400 ÷ 1300 C. It is noted that the maximum values of the detector surface temperature at angles of attack of the stream φ = 0 ÷ 90 degrees turned out to be 5-6 times less than the temperature of the air flow. Experimental studies using methods of brightness television pyrometry showed satisfactory agreement with model concepts.
Specific features of the physicochemical properties of welded titanium nickelide
Authors: Khlopkov E A , Burkhovetskiy V V , Kurushkin D V , Ostropiko E S , Chernyavskaya N V , Shkuratov B E , Lyubomudrov S A , Vyunenko Yu N 
Published: October 2020

Abstract
The paper analyzes the strength characteristics of welded joints made of TiNi alloy with a shape memory effect. Comparison of the level of tensile strength of welded samples made by the TIG method in an Ar and He medium was carried out using a universal machine Instron 5985. The study of the material structure was carried out on longitudinal sections using a JSM-6490LV electron microscope. The analysis of the chemical composition of the material under study in local volumes was carried out using an INCA Penta FETx3 energy dispersive attachment. The calorimetric parameters of the original and welded samples were obtained using a differential scanning calorimeter METTLER TOLEDO 822e.
The effect of molecular structure on the O – NO2 bond dissociation energy and the activation energy of the radical decay of cellotriose nitrates
Authors: Khrapkovskii G M , Garifzianova G G , Egorov D L , Chachkov D V 
Published: October 2020

Abstract
The molecular structure was determined using the method B3LYP/6-31+G(2df, p), and the dissociation energies of the O – NO2 bond in dimethylcellobiose and cellotriose nitrates were calculated. It has been established that the O – NO2 bonds attached to the secondary carbon atom at C2 are the least strong in cellotriose nitrates. With an increase in the degree of substitution, a slight decrease in the dissociation energy of radical decay is observed. The results can be used to discuss the mechanism of thermal decomposition of cellulose nitrates.
Two-alternative optimization of moderate batch data processing
Authors: Kolnogorov A V 
Published: October 2020

Abstract
We consider optimization of moderate batch data processing in the framework of Bernoulli two-armed bandit problem with indefinite control horizon. We assume that there are two alternative processing methods with different a priori unknown efficiencies which are caused by different reasons including those related to legislation. One has to find the most efficient method and to provide its predominant usage. The arising batches of data with close properties have moderate and possibly uncertain sizes. The problem is considered in minimax setting. According to the main theorem of the game theory minimax risk and minimax strategy are searched for as Bayesian ones corresponding to approximately the worst-case prior distribution concentrated on the finite set of parameters. Numerical experiments show that this approach provides good approximations of minimax strategy and minimax risk.
Non-stationary model of incompressible viscoelastic Kelvin-Voigt fluid of higher order in the Earth’s magnetic field
Authors: Kondyukov A O , Sukacheva T G 
Published: October 2020

Abstract
This work is aimed at studying a higher-order model of magnetohydrodynamics in regards to external effects on a fluid. The first initial boundary value problem for a system of higher-order Kelvin-Voigt equations in the Earth’s magnetic field is considered. The study was carried out in the framework of the theory of Sobolev type semilinear equations. The existence of quasistationary semitrajectories of the indicated problem is proved and its phase space is described.
Study of surface processes of functionalized composite structures por-Si/Ag by the method of edge wet angle
Authors: Koshevoi V L , Timchenko A V , Pleshanov I M , Denisenko R S , Bazylo S S , Belorus A O 
Published: October 2020

Abstract
In this work, we studied the functionalized por-Si/Ag composite structures by the contact angle method using the “Contact Angle Measurement System JGW-360A”. The hydrophobic / hydrophilic properties of the studied structures were analyzed. Were studied changes in surface functional groups with various functionalization methods. Wetting gulls were also determined for different series of samples: porous silicon (θ ≈ 580), a porous matrix with a silver layer (θ ≈ 340), and a porous matrix functionalized by electro-thermal diffusion (θ ≈ 410). Were drawn the conclusions about the effect of oxide phases on the hydrophobic/hydrophilic properties of the studied samples.
Modeling and investigation of temperature fields at phase boundaries in powder mixtures undergoing melting and chemical transformation
Authors: Malikov V , Ishkov A , Shegolev A 
Published: October 2020

Abstract
An important component of the process of hardening parts by induction surfacing is the heating of hard alloy and flux particles in the surfacing charge. The article describes complex studies on measuring and modeling temperatures at phase boundaries in complex melting and thermoreactive powder mixtures. To register the temperature in the process of induction surfacing, it is proposed to use the XA-microthermocouple method and the method of thermal indication using SHS compositions. The data of numerical modeling and solution of the non-stationary problem of heat conduction in the selected model of composite contact materials are presented. The developed methods of complex registration of temperature in the process of induction surfacing make it possible to determine the melting temperatures of the surfacing charge and its individual components, as well as the surface of the part.
Pseudo-random sequences with non-maximal length realized according to the Galois scheme based on the primitive polynomial in degree
Authors: Pesoshin V A , Kuznetsov V M , Kuznetsova A S 
Published: October 2020

Abstract
We consider homogeneous and nonhomogeneous pseudo-random sequences of non-maximal length formed by Galois generator based on characteristic polynomial in degree. We discovered periodic polynomial structures in degree in general form and on characteristic examples. We presented and applied the decimation method of periodic sequences, giving their decomposition on elementary M-sequences and constant components. We solved the tasks of analyzing of the diversity of generated sequences, which are organized and ordered from elements of direct and inverse M-sequences, and zero and one constants. We have obtained a general analytical relationship between decimation results and probabilistic properties. We discovered conditions for forming equal probability properties of the resulting sequences and determined the boundary relations of the generator parameters with the initial task of the minimum order of elementary M-sequences.
Potential curves companions and the forecast of critical parameters
Authors: Petrik G G 
Published: October 2020

Abstract
Here, new results obtained by modeling intermolecular interactions are presented. A third special point, the inflection point, is introduced in the potential curve (PC) description. General relations are obtained that refer to the coordinates of the minimum and inflection by the PC – and the indices n and m, that determine the shape of individual contributions to Mie potentials (n-m). The new approach applies to 10 globule molecules in the analysis of potentials restored from data on the properties of substances (second virial coefficient and viscosity) using standard methods. The analysis revealed several problems, the source of which turned out to be data characteristics for WF6 molecules. As a result, a new concept has been introduced of PC – companions, which characterize each object. Calculations of the coordinates of the inflection points of PC companions and their comparison with critical parameters showed that one of them (PC with a large value of n) better predicts the critical temperature, and the other (PC with a lower value of n) predicts a critical volume. The results obtained, of fundamental interest, raise new questions.
Hybrid magnetoelectric converter
Authors: Petrov R V , Kuzmin E V , Leontiev V S , Sokolov O V , Bichurin M I 
Published: October 2020

Abstract
The article is devoted to the study of a hybrid magnetoelectric voltage converter. The article deals with the magnetoelectric structure of the converter with its design features. The measuring stand with the calculation of the converter parameters is also described and the measurement results are given. In the manufacture of the ME element, materials such as piezoelectric PZT and magnetostrictive amorphous alloy Metglas were used. ME is a layered element, which consists of a PZT plate with electrodes applied to the lateral surfaces and one or more Metglas layers. The Metglas plates are connected to the piezoelectric using an adhesive bond. In experimental studies, the number of Metglas layers varied from one to three. The article discusses the design of the converter and the choice of the most optimal of the ones under study. As a result of the study, the lowest indicators were found for a converter without a core, the more Metglas layers, the better the characteristics of the converter. The ME element at the resonant frequency converts energy much better (the conversion power was about 130 μW) than the design of a conventional converter, and also a hybrid converter based on a series switching circuit gives an even greater gain in energy conversion (the conversion power was about 180 μW).
Modelling of microwave magnetoelectric effect in a laminate of ferrite and piezoelectric bimorphs
Authors: Petrov V M , Saplev A F 
Published: October 2020

Abstract
The article discusses the magnetoelectric (ME) effect in a layered structure of ferrite and two piezoelectric bimorphs. Proposed theoretical model predicts a giant microwave ME coupling at the coincidence of high-order harmonics of electromechanical resonance and ferromagnetic resonance for the ferrite. In such structures, ME interaction is known to be a result of mechanical strains. Using two piezoelectric bimorphs results in the excitation of high-order harmonic modes that are suppressed in ferrite-piezoelectric bilayers. ME coefficient of 300 V/(cm·Oe) at 5 GHz is predicted for the fifth resonance mode in the laminate of yttrium-iron garnet and two langatate bimorphs. The phenomenon can be used for the realization of ME interaction based microwave devices.
Collective excitations of the quantum rotation motion of methane molecules in the solid state
Authors: Prokhorov A Yu , Leont’eva A V , Dmitriev Yu A 
Published: October 2020

Abstract
The present study is aimed at elucidating of specific quantum mechanical properties of solid methane suggesting contribution of collective effects to the rotational motion of molecules. Analysis of NMR and EPR low temperature experiments of pure and doped solid methanes gives strong evidence of the hindered quantum rotation of CH4 and CD4 molecules even at liquid helium temperatures.
Acid-base properties of the surface of zinc oxide powders subjected to milling in the attritor
Authors: Pronin I A , Yakushova N D , Sychev M M , Komolov A S , Mjakin S V , Karmanov A A , Averin I A , Moshnikov V A , Korotcenkov G 
Published: October 2020

Abstract
Using the method of acid-base indicators adsorption, the influence of mechanical stresses and defects, arising in the milling process, on the surface properties of ZnO powders is analyzed. An explanation of the changes in acid-base properties is given.
Quantification of nonlinear interdependence in complex systems dynamics: simulations and applications
Authors: Pyko N S , Pyko S A , Mikhailov V N , Bogachev M I 
Published: October 2020

Abstract
In our work we studied the nonlinear interdependence metric quantifying the mutual dynamics of two stochastic data series. This metric is based on the calculation of the Euclidean distances between points belonging to the trajectories of these series in the state-space. Using surrogate data as an example, the sensitivity of the metric to the autocorrelation properties of the studied data series, as well as to the amplitude and phase randomization, are investigated. We also considered the application of this metric to the analysis of backscatter signals in sea surface monitoring. We suggest that the nonlinear interdependence metric may be useful as a complementary indicator for the sea wave structure quantification and modeling.
Acoustic excitations in a non-ideal one-dimensional superlattice with anisotropic impurity layers
Authors: Rumyantsev V V , Fedorov S A , Gumennyk K V , Paladyan Yu A , Zavorotnev Yu D 
Published: October 2020

Abstract
The virtual crystal approximation is used to study the specifics of propagation of acoustic excitations through a non-ideal one-dimensional superlattice. Numerical modeling is performed to evaluate the dependence of the lowermost acoustic band gap in a two-sublattice phonon crystal (disordered in composition and widths of constituent layers) on impurity layer concentration.
Fluctuation criteria of applicability of the Gibbs ensemble method to nanosized objects
Authors: Samsonov V M , Talyzin I V , Samsonov M V 
Published: October 2020

Abstract
Fluctuations of energy egr;

E
in the canonical ensemble and of temperature egr;

T
in the micro-canonical one have been evaluated theoretically as well as employing the isothermal and adiabatic molecular dynamics (MD), respectively. MD experiments were performed on Au NPs in the size range from 1.0 to 15.0 nm. As secondary results, MD data on the temperature dependence of the heat capacity of Au NPs are also obtained and analyzed. Theoretical evaluations of egr;

E
and egr;

T
satisfactory or, in some cases, very well agree with our MD results on Au NPs. We have found that egr;

T
is by about two orders of magnitude higher than egr;

E
. However, even for very small NPs (nanoclusters) consisting of 55 atoms egr;

T
is of order of 10 % only. So, a conclusion is made on applicability of both the Gibbs ensemble method and the notion of temperature in its conventional sense to NPs.
On phase diagrams for Au-Si nanosystems: thermodynamic and atomistic simulations
Authors: Samsonov V M , Kartoshkin A Yu , Talyzin I V , Vasilyev S A , Kaplunov I A 
Published: October 2020

Abstract
Phase diagrams for Au-Si nanosystems were calculated by using thermodynamic simulation (NANOCALPHAD methodology) and molecular dynamics (MD). Thermodynamic simulations have been carried out for two Au-Si nanosystems: (i) a solid (crystalline) Si or Au nanoparticle (NP) contacting with an Au-Si nanodroplet of the same radius; (ii) a cylindrical Si nanowire (nanowhisker) with an Au-Si nanodroplet on its butt. We have found that the eutectic temperature of the first system decreases in comparison with the bulk eutectic temperature, and the position of the eutectic point slightly shifts to a lower value of the molar fraction of Si that agree with MD results obtained on another system, i.e. on spherical Au-Si NPs. Contrary to the first system, the eutectic temperature of the second one, i.e. of the system “Si nanowhisker -- Au-Si nanodroplet” increases in comparison with the bulk phase diagram. An explanation of such a result is proposed and discussed.
Computer simulation of dealloying in Cu-Pt nanoparticles
Authors: Sdobnyakov N Yu , Samsonov V M , Kolosov A Yu , Myasnichenko V S , Savina K G , Vasilyev S A , Ershov P M , Grigoryev R E , Bogdanov S S , Sokolov D N 
Published: October 2020

Abstract
Two basic alternative atomistic simulation methods (molecular dynamics and Monte-Carlo) have been used to reproduce the dealloying phenomenon in Cu-Pt nanoalloys. Using the Gupta (tight-binding) potential, we simulated nanoparticles consisting initially of 1500 Cu and 1500 Pt atoms. The involved programs propose search and following removing Cu atoms with the lowest specific binding energies. We have found that as a result of dealloying the particle surface layer is really enriched with Pt atoms. However the particle core keeps in general the structure of the initial nanoalloy. This effect is especially noticeable in molecular dynamics simulation. We have also established that dealloying results in formation of a defected particle structure (vacancies, first of all). Presumably, just such an effect yields the porous structure of bigger Cu-Pt particles in laboratory experiments on dealloying.
Profiles of ion-doped layers on gallium arsenide
Authors: Seleznev B I , Fedorov D G , Zhelannov A V 
Published: October 2020

Abstract
We studied the concentration profiles of charge carriers that are characteristic for ion-doped layers (IDL) used in the manufacturing of field-effect transistors with a Schottky barrier (FTS) on gallium arsenide. Silicon was used as a dopant in the formation of n- and n+ -n layers on GaAs. During annealing of the IDL, SiO2 films were used as protective coatings. The impurity content and silicon distribution in the IDL were estimated by the SIMS method. Profiles of ion-doped layers were calculated by the LSB method. The method for measuring of surface concentration consists in the constant chemical etching of thin layers of gallium arsenide and the measurement of surface electrophysical characteristics. The experimental concentration profiles for GaAs are not Gaussian, but have wide “tails” due to channeling effects in crystals and the influence of chromium. The modes of ion implantation are considered, which form IDL with a sharper profile of the concentration of charge carriers in the “tail”.
A comparative analysis of magnetic properties and microstructure of high coercivity Sm(CoCuFe)5 quasi-binary alloys in the framework of fractal geometry
Authors: Semenova E M , Lyakhova M B , Kuznetsova Yu V , Karpenkov D Yu , Ivanova A I , Karpenkov A Yu , Ivanov D V , Antonov A S , Sdobnyakov N Yu 
Published: October 2020

Abstract
The results of the micro- and nanostructures investigation of Sm(CoCuFe)5 alloys by means of scanning electron and atomic force microscopy are presented. It was shown that sequential high- and low-temperature heat treatments lead to the formation of a homogeneous microstructure with nanoscale compositional heterogeneities. Such a structure provides a coercive filed of up to 32 kOe. The coercivity and remanent magnetization of the samples in the temperature range from 300 to 700 K linearly decrease. The predominant coercivity mechanism in these materials is pinning on nanoscale inhomogeneities with an increased copper concentration. The fractal dimension of the surface of the Sm(CoCuFe)5 alloy metallographic specimen was determined at different stages of heat treatments. The comparative analysis of magnetic properties and microstructure in the framework of fractal geometry was carried out.
Simulation of the mirror descent algorithm on distributions with different variances
Authors: Shiyan D N , Kolnogorov A V 
Published: October 2020

Abstract
In this article, we consider the operation of the mirror descent algorithm in a random environment in which the distributions of one-step incomes have close expectations and different variances. Particular attention is paid to the version of the algorithm for batch processing which allows one to achieve better processing time without increasing losses. The results of numerical modeling of the operation of the algorithms are presented.