bluuebunny/crossref_metadata_2025 huggingface dataset:
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

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

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

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

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.
The destruction of pure metal cathodes during the initiation of direct current arc
Authors: Sargsyan M A , Tereshonok D V , Gadzhiev M Kh , Tyuftyaev A S , Shcherbakov V V
Published: February 2021

In this work, the behavior of cathodes made from pure tungsten and pure hafnium in the direct current electric arc at 200 A and in atmospheric pressured argon medium was investigated. The research was focused on the processes happening with the cathodes during the arc initiation phase (first 100 ms after the power input). The processes of rapid cathode destruction were registered, and can be characterized as the destruction of the cathode in liquid phase due to electro-magnetic forces. Characteristic times of the whole process were recorded, as well as the changes in temperature fields on the cathodes surfaces and the rate of mass loss for both types of cathodes. It has been shown that the initial destruction of the cathode plays a major role in the cathodes resource life.
A low-temperature plasma generator working on nitrogen–propane mixture
Authors: Gadzhiev M Kh , Tyuftyaev A S , Kulikov Yu M , Sargsyan M A , Yusupov D I , Son E E
Published: February 2021

A low-temperature plasma generator of a mixture of nitrogen and propane has been developed, with the possibility of supplying propane to the cathode region, to the arc burning zone, and also to the plasma stream below the arc binding zone. The maximum propane flow rate for a given plasmatron design and plasma-forming nitrogen flow rate, at which the arc is stable, was determined. When propane is supplied into the arc binding zone, the decay products are deposited mainly on the electrodes, and when it’s supplied to the anode after the arc binding, the decomposition products are deposited mainly at the anode exit. The study of the microstructure and analysis of the phase composition of the decomposition products of propane were performed.
Modeling of destructive interaction of hot jet and solid plate
Authors: Muruganandam T M , Son E E , Gadzhiev M Kh , Vetchinin S P
Published: February 2021

Based upon the results of a literature review, a set of physical parameters suitable for quantitative comparison in experimental and numerical studies is determined. The review showed the feasibility of modeling the process of the outflow of an immersed jet of inert gas into the surrounding space and the evolution of a free shear layer formed by hot and cold gases to analyze the process of convective and diffusion transport of various types of particles. In the model formulation we consider the problem of solid destruction by a melt of the same substance, as well as by a nitrogen stream at high temperature. The test simulation of the problems of two-phase interaction of a immersed jet of molten liquid and hot gas, on the whole, qualitatively showed the reproduction of the main characteristics of the flow: the generation of large-scale vortices around the jet in the induction zone, the oscillations of the jet when it collides with an obstacle, and the shape of the cavity formed.
Ion composition of nitrogen plasma jet with carbon admixture
Authors: Kavyrshin D I , Chinnov V F , Korshunov O V , Sargsyan M A , Khromov M A , Shcherbakov V V
Published: February 2021

With the aim of studying nitrogen plasma flow impacting graphite surfaces, we investigated the evolution of a plasma jet moving from the nozzle of the plasma torch to the target. The motion is accompanied by a decrease in temperature from 10 to 7 kK with a loss of ≈ 60% of the deposited energy and an increase in the density of carbon-containing impurities with partial preservation of the local thermodynamic equilibrium. The main reactions are thermal processes of the formation and decomposition of molecules, dissociative recombination and recharging of nitrogen ions. In the presence of carbon impurities, this set is supplemented with the substitution reaction C + N2 ↔ CN + N, electron-collision processes of stepwise ionization and recombination, and a whole ion-molecular cascades of reloads and substitutions. It has been established that a small admixture of carbon (∼ 0.1%) manifests itself only in ion-molecular kinetics, increasing the electron concentration, determining the ionic composition of the plasma, and thereby violating the equilibrium between its neutral and charged components. This leads, in particular, to the recombination nonequilibrium distribution of carbon atoms over electronic states. Other carbon-containing impurities (CN and C2) are not significant.
Investigating wire breakage during EDM with fractographic analysis
Authors: Bredgauer Iu O , Polonyankin D A , Fedorov A A , Blesman A I , Linovsky A V , Postnikov D V
Published: February 2021

Wire electrical discharge machining (WEDM) is widely used in various fields of production. Its disadvantages include a relatively low productivity rate caused by wire breakages among other factors. In this article, the method of fractographic analysis is used to study a wire that has undergone a breakage during machining. The results indicate that the tool–electrode is subjected to mechanical tension followed by a ductile fracture. The most probable reason of wire breakages is a decrease in the wire cross–section, which can be caused by an electrodes short circuit.
Heat-mass exchange processes dynamics in fires in multi-apartment buildings and its impact on safe people evacuation probability
Authors: Khrapsky S F , Bedrina E A
Published: February 2021

The urgency of people safe evacuation problem from small and medium storeys typical residential sectional type multi-apartment buildings, which in accordance with current regulatory requirements are not equipped with technical means of fire detection and notification of residents, are not equipped with active smoke ventilation systems and do not have effective structural evacuation solutions is shown. Based on modern software systems, numerical experimental studies were conducted to assess the dynamics impact (intensity rate impact) of heat and mass exchange combustion processes on the people evacuation parameters and the corresponding rate of increase dangerous factors for human viability in fire. The time intervals available to residents for safe and timely evacuation are calculated, depending on the typical residential premises fire load characteristic quantity. Taking into account the results obtained, practical measures aimed at improving the people safety in fires in residential multi-apartment buildings are proposed for implementation.
Road roller operator’s vibroprotection system improvement
Authors: Korchagin P A , Teterina I A , Korchagina E A
Published: February 2021

The article reflects the results of the theoretical and experimental studies aimed to reduce dynamic influences on a road roller operator’s workplace by changing the design parameters of the ‘supporting surface – road roller – operator’ dynamic system. The results of the experimental studies on the modernized hinged tie rods construction are presented. The rigidity coefficients of the springing elements of the hinged tie rod ends are determined. The dependence of the rigidity coefficient on the deformation value of the hinged tie rod ends is graphically presented. A comparative analysis of the experimental studies results aimed at determining the value of the dynamic influences on an operator’s workplace (a cabin floor and a seat) carried out with a road three-axle three-wheeler roller with plant and modernised hinged tie rods. The transmission coefficients from the internal combustion engine to the cabin floor and the operator’s seat are obtained at small, medium and high engine speeds, with a vibration exciter switched on and off. The conclusions on the legal use of the modernised hinged tie rod structure as a component of the vibroprotection system of a road roller operator have been drawn.
Roller vibroprotection mechanism with a quasi-zero stiffness section
Authors: Korytov M S , Shcherbakov V S , Titenko V V , Pochekueva I E
Published: February 2021

A new numerical method for designing the profile of the support surface for moving the vibration protection mechanism pressure roller for the operator’s seat in road and construction machines has been developed. The roller vibration protection mechanism of the type under consideration provides for the required force characteristic with a quasi-zero stiffness section of a given long length. This advantage of the roller vibration protection mechanism makes it possible to recommend it for application in vibroprotection systems for road and construction machinery operators. Difficulties in creating such mechanisms are caused by the nonlinear nature of the system of algebra-differential equations that describe the relationship between the static force characteristic and the geometry of the mechanism support profile. That is why it is difficult to obtain a solution in the analytical form of a support surface profile and requires a numerical solution. As an example of the efficiency of the proposed method, we obtained a support surface profile for a roller vibration protection mechanism with a given force characteristic in the form of a three-segment spline with 0.1 meters length quasi-zero stiffness section. The developed method lets us use the specified parameter values as the initial data. In the Simscape Multibody application of the MATLAB system, a simulation model of a dynamic vibration protection mechanism system was developed. It allows simulating movements and studying the modes of this mechanism at the design stage. We give an example of the time dependencies of the mechanism points coordinates obtained using a simulation dynamic model for damped free vibrations.
Vibration protection system with nonlinear elastic and damping characteristics
Authors: Korytov M S , Shcherbakov V S , Titenko V V , Pochekueva I E
Published: February 2021

One of the leading areas of improving the road construction machines is to increase the comfort and safety of the human operator by reducing vibration effects. Therefore, the most simple and available way to implement this direction is applying the passive vibration isolation of a human operator’s seat. Vibration protection mechanisms of such seats typically have one translational degree of freedom. Studying the single degree of freedom vibration protection systems under the various external influences, in particular, with kinematic excitation of base displacements is a relevant topic of investigations. The research objective is to develop a mathematical model of a vibration protection system with variable stiffness and damping coefficients of a vibration isolator, as well as to optimize the mathematical model parameters. The following problems were solved: the development of the calculation model, the compilation of the model differential equations system, the description of the dependences of the stiffness force and damping coefficient of the vibration protection system using two-point Hermite splines. A type of the kinematic excitation characterized by one parameter - a constant base velocity, the evaluation criterion of the system response to this kinematic excitation - the maximum object acceleration and the integral criterion for assessing the system response to a spectrum or excitation range at the different speeds were proposed. The parameters specifying the type of the dependences of the stiffness force and damping coefficient of the vibration isolator were optimized by the integral criterion. The results are represented in the form of the mathematical model formulas, displacements and accelerations graphs and optimized values of the system parameters.
Experimental investigations of the parameters of liquid evaporation process under acoustic-vacuum exposure
Authors: Trushlyakov V I , Lesnyak I Y , Novikov A A
Published: February 2021

Experimental investigations of the process of liquid evaporation under conditions of acoustic-vacuum exposure were conducted. Based on the obtained values of the evaporating liquid mass and the liquid vapor pressure in a closed container, a resonance effect is revealed. The emergence of the resonance effect is characterized by the active boiling of the liquid when the frequency of the system “steam-gas mixture + cupola + vacuum chamber + liquid layer” coincides with the frequency of the acoustic exposure under conditions of reduced external pressure. To measure the vapor pressure of the liquid, a cupola was introduced into the experimental stand, which makes it possible to increase the vapor pressure of the liquid and register its value with the equipment used. The calibration characteristic of laboratory scales is obtained as a dependence of the change of cargo weight on the pressure values in the vacuum chamber. Using the obtained calibration characteristic of laboratory scales operating under acoustic-vacuum exposure, the values of liquid mass change are obtained at different values of external pressure in the vacuum chamber. The results obtained can be applied in the field of acoustic-vacuum drying and cleaning of different surfaces.
Influence of the charging pressure of the hydraulic pneumatic accumulator of the communal machine control device on the pressure force of the brushed working body
Authors: Tsekhosh S I , Ignatov S D , Shcherbakov VS , Kvasov I N
Published: February 2021

The article is devoted to the actual problem of increasing the efficiency of cleaning the roadway with a communal machine. To increase the cleaning efficiency, it is necessary to provide the required pressing force and thus the required area of the contact spot between the brush pile and the surface to be cleaned, which can be done by using a position control device for the brush working equipment.

Research methods. In the process of research were used the following methods: analysis, synthesis, ascent from the abstract to the concrete. The results of the study of the influence of the parameters of the control device on the criterion of the efficiency of the working process of the communal machine are presented.

Results. As a result of the analysis of the process of interaction of the brush working equipment with the surface being cleaned, the dependences connecting the standard deviation of the pressing force of the brush working equipment to the surface to be cleaned from the required value, taking into account the wear of the pile and the charging pressure of the hydraulic pneumatic accumulator, were revealed, their approximation was carried out, and the regression equation was obtained.

Conclusions. The studies carried out made it possible to obtain regression equations which are used to determine the optimal value of the standard deviation of the pressing force from the required one for different degrees of wear of the pile, depending on the charging pressure of the hydraulic pneumatic accumulator. The research results can be applied in the design of automatic control systems for the position of the working bodies of construction and road machines.
Load distribution factor along the power transmission lines as a factor in choosing a voltage class
Authors: Bogachkov I M , Khamitov R N
Published: February 2021

Gas fields differ from industrial enterprises by long power transmission lines with low electrical loads (low density), which grow many times during the life cycle. Power supply to gas well clusters is carried out according to the scheme - “main circuit with one through line with transformer substations distributed along the line”. The distribution of transformer substations along the transmission line affects the voltage loss, and, consequently, the choice of voltage class. The purpose of the research is to quantify the distribution of transformer substations along the power line to develop a mathematical model for calculating the optimal voltage class. To achieve this goal, the following tasks are solved: five power supply schemes are built for gas well clusters; electric moments are calculated for each scheme; the load distribution coefficient is determined. The problems were solved using an experimental-theoretical method (analysis and synthesis) and a software product – Mathcad. As a result, the coefficient is calculated in the work - for even load distribution, when placing the entire load at the end of the line and when placing the load at the beginning of the line.
Kinematic model of the parallel approximation method
Authors: Dubanov A A , Ausheev T V
Published: February 2021

This article considers a model of the pursuit problem using the parallel approach method. The purpose of this article is to modify the method of parallel approach in order to take into account the case when the pursuer’s speed vector is not directed at the target at the pursuit beginning moment. In addition, in the model discussed in the article, the pursuer cannot instantly change the movement direction. That is, the condition is imposed that the pursuer’s trajectory curvature radius cannot be less than a certain value. The proposed method is based on the fact that the pursuer, choosing a step at the iteration stage, will try to follow the predicted trajectories. Based on the materials of the article, we have written the test program that calculates the pursuer’s trajectory, taking into account the conditions set out. The completed animated image visualizes the change in the coordinates of the pursuer, the target, and the predicted trajectories from time to time.
Kinematic model of the pursuit problem on a plane by the chase method
Authors: Dubanov A A , Ausheev T V
Published: February 2021

This article considers a kinematic, geometric model of the pursuit problem on a plane by the chase method, where the pursuer cannot instantly change the direction of movement, while moving at a constant modulo speed. The initial speed of the pursuer is not directed at the target when the pursuit begins. In order for the speed vector of the pursuer to be directed at the target after some time, we have developed a method that is based on following the trajectory that connects the pursuer and the target. This trajectory takes into account the inertia of the pursuer in the sense that the radius of curvature of the trajectory is not less than a certain threshold value. Based on the materials of this article, test programs were written and an animated image was made.
Geometric modeling of torse surfaces in BN-calculus
Authors: Konopatskiy E V , Bezditnyi A A , Litvinov A I
Published: February 2021

The paper presents a general approach to geometric modelling of torse surfaces in BN-calculus, based on the definition of the torse as the geometric location of tangents to its edge of return. In this paper, a method for determining the curves – edges of the return of the torse surface, using the geometric properties of the point definition of the curve in plane and spatial simplices, is proposed in general form. Examples of constructing geometric models of torse surfaces, for which algebraic and transcendental spatial curves were used as the return edge, are given.
Automatic classification method of the speaker’s emotional state by voice
Authors: Koshekov K T , Kobenko V Yu , Anayatova R K , Savostin A A , Koshekov A K
Published: February 2021

This article addresses the problem of developing an effective method for automatically classifying the aviation personnel emotions (announcer) by voice. To this end, it is possible to create a dictatorial independent algorithm capable of performing a multi-grade classification of the seven emotional states of a person (joy, fear, anger, sadness, disgust, surprise and neutrality) on the basis of a set of 48 informative features. These features are formed from the digital recording of the speech signal by calculating Mel Frequency Cepstral coefficient and the main tone frequency for individual recording frames. The increase of informativeness and the reduction of the dimension for the Mel Frequency Cepstral coefficient is achieved by processing said coefficients with the aid of a deep, convergent neural network. The model of the classifier is realized by means of logistic regression, which was trained on the basis of emotionally colored English speech samples by these informative features. As a result of the training on the test sample, the correct recognition response accuracy is equal to 0.96. The inventive solution can be used for improving human-machine interfaces, as well as in the field of aviation, medicine, marketing etc.
Optimization of passive activator parameters for printing machines
Authors: Litunov S N , Toschakova Yu D , Yurkov V Yu
Published: February 2021

This paper is devoted to the mathematical calculation and experimental researching of ink apparatus using in printing machines. We show the existence of structuring process in ink boxes and the formation of so-called quasi-solid in the printing ink. Our geometric model is based on the mathematical problem of covering some planar domains by the set of circles. All circles belong to one-parameter family and it is a special feature of the problem. Using this model we get the method of calculation some optimal dimensions of passive activators using for destruction the quasi-solid. Calculations are based on experimental data and it is achieved by variation of several parameters. In this paper we describe the system with only one passive activator but there exist the opportunity to optimize the system with several ones. Software realization is not given in the paper but it is based on the algorithms that are described. Experimental data were received with using real equipments and materials of printing industry. Specifically, we investigated the generating of quasi-solids in the ink boxes and we got some results for using the passive activators.
Setting of the Dupin cyclide by three straight lines and sphere
Authors: Salkov N A
Published: February 2021

Over the past few years, interest in Dupin cyclides has re-emerged: they can be used both in mechanical engineering and in construction, for covering the spans of civil buildings and in temple architecture; the properties of the Dupin cyclide can be widely used in computer graphics. The article considers a method for setting of Dupin cyclides using three lines and a sphere, which greatly the possibilities for the construction of these surfaces, especially when it is necessary to cut compartments of a certain size from them and to dock them.
Methods of investigation and elimination of systematic errors in the realization of pseudo-random variables with heavy-tailed distributions
Authors: Zadorozhnyi V N , Zakharenkova T R , Pagano M
Published: February 2021

Shifts arising in generation of random variables, which are obtained by transformation of standard random numbers, with heavy-tailed distributions are investigated. The formula for calculation of deterministic moments shift for a random variable via a discretization spacing of used standard pseudo-random numbers is derived. The deterministic shift is calculated for a mean value of random variables that have the Pareto distribution and realized by the widely accepted inversion technique. The shift calculation results are verified and confirmed experimentally by means of the rapid Monte-Carlo technique – stratification method. By an example of the average queue length calculation, it is demonstrated how the shifts within distributions in queueing systems affect the queueing properties. The universal method for the realization of non-shifted random variables with heavy-tailed distributions, ARAND method, is developed and investigated. The method is based on the use of uniformly distributed between one and zero pseudo-random variables having a variable discretization spacing and represented in floating-point format.
Application a cubic spline to calculate derivatives in the presence of a boundary layer
Authors: Blatov I A , Zadorin A I
Published: February 2021

The problem of calculating the derivatives of a function with large gradients given at the grid nodes is considered. The decomposition of the function into regular and singular components is assumed. Such decomposition takes place in the presence of an exponential boundary layer. The case of the Bakhvalov mesh is considered. The error in calculating the derivatives based on the differentiation of the interpolating cubic spline is estimated. Error estimates are obtained taking into account uniformity in a small parameter.
Modelling and construction of curriculum optimization algorithms in order to improve the effectiveness of management of the educational process
Authors: Guts A K , Senkovskaya A A , Furayeva I I
Published: February 2021

This article discusses the principles of influence on improving the management of the educational process of a university from the perspective of analysis and optimization of work plans. Mathematical models are presented for optimizing working curricula separately for the first and senior courses, taking into account such factors as the contingent of students, the classroom fund of the university. Different approaches to the analysis of curricula for the first and senior courses are demonstrated. The basic functions of an automated system that implements the formulated models for the analysis of curricula are described.
On Hybrid Evolutionary Algorithms for Scheduling Problem with Tardiness Criterion
Authors: Kovalenko Yu V
Published: February 2021

We present hybrid algorithms based on various metaheuristics for the scheduling problem with one machine and total weighted tardiness criterion. We research operators and algorithmic mechanisms provided in the literature. Advantages and disadvantages of the considered approaches are identified and analyzed. Some of the stated properties are common for scheduling problems on permutations.
Analysis of the influence of the geometry of the input part of the matrix on the formation of the edge part of the cylindrical bill
Authors: Pasynkov A A , Larin S N , Platonov V I
Published: February 2021

The formation of an uneven geometry of the end part of cylindrical products is quite common after the implementation of drawing of sheet blanks. It occurs due to the imbalanced orientation of the crystallographic structure of the material, that is, due to the anisotropy of the mechanical properties. As different elements of the sheet bill have different speed of movement relative to the tool during the drawing, so-called scallops, or protrusions, appear. This causes a problem during the production, since it takes additional time and resources to bring the geometry of the products to the norm. Therefore, the actual task is to minimize this phenomenon. The article discusses an approach to eliminating or minimizing scallop formation by means of scientifically grounded selection of the geometry of the input part of the matrix. The influence of geometry parameters on the uneven geometry of products and their stress state is described.
The methods and approaches to computer networks simulation using virtual network infrastructure
Authors: Podsadnikov A V , Rozov K V , Kratov S V
Published: February 2021

The article is devoted to the problem of computer networks simulation in educational process. The article examines the current state of affairs in this area. The analysis of the existing software for computer networks simulation is performed. The practical example of Cisco Packet Tracer software using for computer network simulation as part of the Computer Networks training course is provided.
A heuristic for a special case of the generalized assignment problem with additional conditions
Authors: Zaozerskaya Lidia
Published: February 2021

We consider the following variant of the generalized assignment problem (GAP). There are a set of agents and a set of jobs for which a single resource use. Each job is to assign to one and only one agent subject to the constraints on the capacity and loading of agents. The resource expense for executing any job is independent of the agents choice unlike the profit from the job. Each job has a certain type (or color). For every agent, the maximum possible number of the job types given. It is necessary to find a feasible assignment of agents to jobs so that all jobs were completed and total profit was maximized. Finding a feasible solution to this problem is NP-hard. We present a heuristic algorithm based on the ideas of random search and local improvement of solutions. Used the mixed-integer programming (MIP) relaxation and variables fixing, we construct a set of integer linear programming (ILP) subproblems similar to the original problem and solve them by the general MIP solver. The results of a computational experiment for tasks with random initial data are presented.
Gesture recognition system based on electromyography signals
Authors: Kabanov A A , Nikonova G V
Published: February 2021

The subject of the study is a gesture recognition system based on an electromyography signal for controlling anthropomorphic prostheses. As a result of the work, signals were received and written to files, software was developed for processing and filtering signals, as well as for recognizing gesture patterns. The resulting system will allow to determine various hand movements based on the electromyography signal and control anthropomorphic prostheses. The resulting system will allow to determine various hand movements based on the electromyography signal and control anthropomorphic prostheses.
Intelligent system functioning for thermophysical measurements in an uncertain measuring situation
Authors: Selivanova Z M , Kurenkov D S , Varepo L G , Trapeznikova O V
Published: February 2021

In the conditions of production under the influence of external and internal factors, the functioning of an intelligent system for thermophysical measurements is associated with the uncertainty of the measuring situation. As a result, the accuracy and efficiency of determining the thermal properties of study subjects – thermal insulation materials - decrease. The study purpose is to achieve the required accuracy and efficiency of the qualitative property parameters of the studied objects in non-destructive control under the uncertainty of the measuring situation, which is important and relevant. A formalized states description of the intelligent system for thermophysical measurements is proposed, taking into account the structure of the system, information and measurement situations, the materials under study, and control signals. The mathematical model has been developed to describe the functioning of an intelligent system under conditions of uncertainty and its application in the operation of the system. An intelligent system of thermophysical measurements with a reconfigurable structure adapting to the measuring situation has been developed. The study results are obtained using the theory of systems, well-known methods of thermal conductivity and methods of artificial intelligence. Experimental results of operating the intelligent system for thermophysical measurements in conditions of uncertainty are presented. They confirm the increase in the accuracy of determining the qualitative properties of the objects under study.
The method of processing data of mass spectrometric analysis of vacuum medium of quartz resonator-thermostats
Authors: Belousov K A , Strunin V I , Khudaibergenov G Zh , Yarosh A M
Published: February 2021

The theoretical and practical development of gas environmental analysis with the usage of a complex based on a residual gas analyzer is briefly presented. The data of technological search of annealing, degassing and sealing modes of quartz resonators and generators with participation of authors are summarized. The gas flow rate was estimated from the mass spectra. The method of measurement of working parameters of products, as well as estimation of operating time resource is proposed. Measurement of quartz resonator-thermostats (QRT) parameters is performed using serial technologies.
Average lifetimes of a metastable state at low barrier in the overdamped regime
Authors: Chushnyakova M V , Gontchar I I
Published: February 2021

Thermal decay of a metastable state is a process revealing itself in particular in the contemporary single-molecule pulling experiments. Unfortunately, some approaches used for the interpretations of these experiments in the literature are incorrect and misleading. We prove this statement in the present work. For this aim, the most important characteristic of the decay process which is the average lifetime of a Brownian particle in a metastable state is considered. For this state two typical potentials are used: the Lennard-Jones and cubic potentials. We concentrate on the case of strong friction (overdamped regime) and low barrier since these conditions are typical for the mentioned experiments. We calculate the average lifetimes using five approaches, including dynamical modeling, and compare them with each other.
Solid solutions of hetero- and homo-substitution of the AIIIBV-CdTe, AIIBVI-CdTe systems. Physical and chemical properties
Authors: Kirovskaya I A , Ekkert A O , Ekkert R V , Chernous N V , Kropotin O V , Kraseninin V I
Published: February 2021

In the regions of mutual solubility of the initial binary compounds (InP and CdTe, ZnS and CdTe), according to the specifically developed methods, solid solutions of the InP-CdTe, ZnS-CdTe systems have been obtained, certified based on the results of X-ray, micro-, submicroscopical, UV, infrared studies as substitutional solid solutions with a cubic sphalerite structure.

Information on the multicomponent diamond-like semiconductors has been supplemented, including first-ever determined values of the average size (dav), the mean number (nav) of the predominant particles in the systems components, their forbidden bandwidth values and the surface structure.

The acid-base properties of the obtained solid solutions surfaces and binary components of the systems, which are assigned to the weak-acid region (pHiso <7), have been studied. Prognosis concerning the increased activity of such surfaces towards the main gases have been made and proved. The concentration dependences of the studied bulk and surface properties have been established. They possess both smooth and extreme nature. The influence on the dependence type by the degree of difference in the values of the forbidden bandwidth of the initial binary components has been confirmed. The reverse trends in changes with the composition of density (ρr) and pHiso have been substantiated.

The connection between the concentration dependences of bulk and surface properties has been revealed. The possibility of using such connection for a faster, more efficient search for the advanced materials for semiconductor gas analysis and, in particular, for the manufacture of sensors for the main gases trace contamination.
Solid solutions of the InAs-AIIBVI heterosystems. Bulk, surface physical and chemical properties
Authors: Kirovskaya I A , Kopylova E N , Umanskiy I Y , Bukashkina T L , Krasheninin V I
Published: February 2021

Using specifically developed methods, solid solutions of the InAs-AIIBVI (AIIB-ZnS, CdTe) systems have been obtained. In accordance with the results of X-ray studies in combination with the results of micro, submicroscopical studies, they were certified as solid substitution solutions with a cubic sphalerite structure; information on crystal-chemical and structural properties has been obtained; the elemental compositions have been determined, which substantially coincide with the given molar ones. The acid-base properties of the solid solutions surfaces and binary components of the systems revealing a weak-acid character and increased activity towards main gases have been studied. The consistent patterns of changes in bulk and surface properties with a change in composition have been established which obey mainly to a statistical law as applied to the InAs-CdTe system and with extreme manifestations as applied to the InAs-ZnS system, which have been substantiated. The connections between the consistent patterns, the influence of bulk properties (in particular, the forbidden bandwidth, the electronegativity difference) on the surface properties have been revealed. The objectives for the search of the advanced materials for the sensor technology, based on more accessible information on bulk properties, have been set. The practical guidelines have been given on the use of the obtained materials for the manufacture of measuring cells for the main gases trace contamination.
Synthesis and physicochemical inverstigation of hydroxyapatite and wollastonite composite granules
Authors: Shevchenko A E , Solonenko A P , Blesman A I , Polonyankin D A , Chikanova E S
Published: February 2021

Creation of osteoinductive materials based on biocompatible synthetic salts, with a sufficiently high strength and porosity, with the shape which allow filling bone defects with various shapes and sizes is an actual task of modern biomaterial science. In this work, a series of granular materials were obtained from synthetic powders with various proportions of hydroxyapatite and wollastonite using a suspension technology based on the principle of immiscible liquids. Ceramic particles have a spherical shape, microhardness at least 17 HV and open porosity about 50 %. These materials can be used for reparation of bone defects of various locations, shapes and sizes in surgical dentistry, traumatology and orthopaedics.
Experimental research of reagent capsulation process at various methods of carbon dioxide supply
Authors: Shtripling L O , Kholkin E G , Kalinin Yu V , Merkulov V V
Published: February 2021

The article considers some features of the reagent encapsulation method at low temperatures. A setup layout has been created to measure temperature of the encapsulated material while reagent encapsulating. During the experiment, the duration of maintaining the temperature for preparing the next portion was determined. Methods for supplying carbon dioxide to the unit during reagent encapsulation were compared. As a result of the experiment, a more profitable way of supplying carbon dioxide to the unit was determined.
Immobilization of Catalase Using PAES-C Polymer for Wastewater Biological Treatment Research
Authors: Bi Haiyan , Tian Jiaying , Fu Ye , Wang Dazhi , Cai Weijie
Published: February 2021

PAES-C polymer modified by glutaraldehyde (GA) was selected to immobilize the catalase. Infrared spectrum analysis and 1H NMR test the presence of - COOH bond in PAES-C, which favored the cross-linking of PAES-C with catalase. The SEM image showed that its surface had a porous structure, which increased its surface area and provided more active sites for the immobilization of catalase. Indeed, the influence of various factors including GA mass concentration, modification time of GA and carrier, cross-linking time of modified carrier and catalase on the immobilization capacity were deeply investigated. In particular, the achieved optimal conditions for immobilization of catalase were as following: GA mass concentration was set at 1.0wt%, GA modification time was 1.0 h, and the binding time between the modified carrier and the enzyme was 1.0 h. Herein, the findings in this work revealed that PAES-C polymer might be one of the promising candidates for wastewater biological treatment and immobilization of other enzyme.
Analysis on the Characteristics of the Demand for Development and Utilization of Sea Space Resources
Authors: Mamat Gulnigar , Kang Minjie
Published: February 2021

The analysis of the demand characteristics and suitability of elements for the development and utilization of sea space resources is the key content of Marine zoning and planning. Taking Liaoning Province as the research area, this paper analysis the characteristics of the demand for offshore areas through the superposition analysis of the current situation of sea area use and Marine function zoning, and analysis the suitability of the elements of Marine function zoning through the superposition analysis of the Marine function area with the elements of water quality, water depth and coast type. The differences in factor endowment and demand characteristics between regions will provide references for the research on optimal allocation of sea space resources.
Quantitative Evaluation of the Effects of Different Cost Experience Curve on Total Energy Investment Cost: Endogenous VS Exogenous
Authors: Cai Bin , Xia Zimo , Lai Yening , Wen Yan , Song Xiaofang , Xue Feng , Li Zhiyuan
Published: February 2021

Endogenous learning curve (endogenous method) and set value exogenously (exogenous method) are two widely used methods for non-fossil energy cost experience curve in energy transition research based on quantitative model. The difference between endogenous method and exogenous method on total energy investment cost are compared, and the effect of key factors such as the learning rate of endogenous curve, cumulative installation capacity of the electricity supply technology, growth pathway of the electricity supply technology are analyzed. Recommendation for pay more attention to the effects of different cost experience curves on results of quantitative models are made for better decision-making support.
A Large Temperature Difference Thermal Substation (LTDTS) with Electric Heat Pump and Thermal Storage Tank
Authors: Sun Jian , Ma Shicai , Huo Cheng , Ge Zhihua , Zhou Shaoxiang
Published: February 2021

A new thermal substation named LTDTS is presented, which could reduce the return water temperature of primary pipeline to below 30 °C. The capacity of an existing heating pipe could be enlarged by more than 50% without changing its flow rate. The LTDTS with single-stage or two-stage heat pump is experimented, which is compared with simulation results. The LTDTS is recommended for large district heating systems due to advantages of reducing the pipe investment and recovering industrial waste heat for lower energy consumption of heating.
Study on the Synthesis of Charge Transfer Complex of Nifedipine and Tetracyanoethylene
Authors: Tian Lu , Wang Fanbo , Wu Jiang , Lv Yuguang
Published: February 2021

Purposes: To construct a new method for the determination of nifedipine and apply it to the determination of in vitro drugs in order to achieve simple and accurate quantitative detection. Procedures: A charge transfer complex of nifedipine tetracyanoethylene was constructed, and the fluorescence intensity changes of the complex and nifedipine were compared. Screen the effect of drug dosage, reaction time and reaction temperature on the fluorescence intensity of the system. Results: Nifedipine is a substance with its own fluorescence characteristics, but its own fluorescence intensity is not as high as expected. Through the addition of tetracyanoethylene, it is found that the fluorescence intensity of nifedipine has been greatly enhanced, combined with ultraviolet A new absorption peak was found in the spectrum, indicating that the two were successfully complexed. Conclusions: The experiment successfully synthesized the nifedipine charge transfer complex, and constructed a new method for the determination of nifedipine content, which is of great significance for the determination of the content of drugs in vitro.