Статьи журнала - Сибирский аэрокосмический журнал
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Статья научная
The priority of the military-industrial complex (MIC) in the economy of the Russian Federation is determined by the role of the defense industry in the technical and technological modernization of economy rather than by the magnitude of military production. Organizing high-technology and competitive production is possible only on condition that MIC is provided with qualified employees who possess high intellectual and creative potential. At the same time, the requirements for the management mechanisms relating to the formation and development of human capital are increased either. The paper presents the results of a study of one of the subsystems of human capital management, which is the system of motivation and stimulation of employees ' innovative activity. The study was conducted at a large enterprise of military-industrial complex Open Joint Stock Company “Krasnoyarsk Machine-Building Plant” by an anonymous survey of employees. The respondents included managers, specialists and workers. The aim of the study is to investigate the motives of employees for innovative activity and organizational and managerial factors of stimulation. The results show that material factors and motives largely affect the innovative activity of employees. As a results of the survey, it was also found that additional measures are needed to create a favourable environment for innovative activity, mainly by removing barriers associated with financing and organizing innovative activity. The results received in the survey enable the company administration to adjust the applied tools and methods of the system of motivation and stimulation of employees' innovative activity to improve its efficiency, which subsequently leads to the development of innovative activity at an enterprise. The formulated principles allow to form a system of motivation and stimulation of innovative activity, focusing on the development of human capital at enterprises of MIC.
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Статья научная
Solar cells based on AIIIBV materials in solar arrays are the main energy sources for most modern spacecraft. In spite of the fact that high characteristics have already been achieved, the work for improving solar cells is being continued due to the growth of energy consumption by spacecraft. One of the directions is decreasing solar radiation reflection by solar cell surface due to the deposition of antireflec- tion coating (ARC). In the article we show the results of the study of ARC (Ta2O5 / SiO2). We have presented the results of spectral and thickness calculations by special software of ARC on the triple junc- tion (InGaP / InGaAs / Ge) solar cell taking into account cell structure as well. We have performed the experiment of ARC on the glass-substrate to confirm the manufacturability of the process. ARC deposition has been made by electron-beam evaporation in vacuum. The results of investigation of spectral char- acteristics of samples obtained by a spectrophotometer confirm the uniformity of covering without relation to the sam- ple position in a machine. Spectral characteristic calculations for glass-substrate coincide with experimental data. The results of studying spectral characteristics of ARC on a solar cell demonstrate good correspondence with experimental data. The electric characteristics measured by the solar simulator (AM0) before and after the ARC cover- ing on the experimental samples show the increase of short-circuit current up to 122 mA and the rise of efficiency up to 7.5 %. We have demonstrated the results of scanning electron microscopic investigation of ARC on the different positions of solar cells.
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Study of carbide formation in the plasma of a low-pressure pulsed arc discharge
Статья научная
We examine the influence of pressure and gas mixture composition on the preparation of nanomaterials via vacuum arc sputtering of titanium cathodes in carbon-containing media. The formation of carbide phases in various gaseous atmospheres is accompanied by the formation of the low-temperature phase α-Ti (hcp lattice), characteristic of pure titanium. Carbide formation in the plasma synthesis of TiC nanoparticles is determined by the C/H ratio in the molecules of the hydrocarbons used. To raise the yield of carbon-rich carbide phases and reduce the percentage of the residual metal in the resulting nanopowders, it is necessary to use hydrocarbons with a large C/H ratio, for example, benzene and acetylene.
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Study of consolidation features for fragmentally nanostructured hard metal composites
Статья научная
The results of experimental studies combined with modeling and prediction methods for the properties of hard metal composites show that modification with additives of ceramic nanoparticles and composite powders (WC-Co) allows to control microstructure parameters and provides the increase in binding durability and the level of physicomechanical properties of a hard alloy in general. Simultaneous complex application of submicrocrystalline WC carbides coated with Co layer and alloying additives of Al2O3 nanoparticles - grain growth inhibitors of the main phase, can be consid- ered as the most perspective direction of nanostructured hard metal with increased hardness, strength and crack resis- tance production. The coating of carbide particles with a binder layer is an effective starting method that allows to ob- tain a volumetric billet with maintaining the unique properties of the initial nanopowders and ensures a uniform distri- bution of the phases (WC, Co, Al2O3). Such a multiphase fragmented nanostructured composite is characterized by additional heterogeneity, determined by differences in size and elastic phases properties. By combining the sizes and properties of the phase components in such a heterogeneous composite, it is possible to provide an increase in the frac- ture energy, i. e., Palmkvist crack resistance up to 16-18 MPa m1/2 (due to inhibition on nanoparticles inclusions, stress reliefs and changes in intercrystalline crack trajectory, its length decrease). Based on the proposed stereological mod- els and the experimentally established relationships between composition and microstructure parameters, the required volume concentrations of nanoparticles additives and composite powders (WC-Co) were determined.
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Study of hydrodynamics features in the apparatuses with movable nozzle
Статья научная
Apparatuses for the heat and mass transfer processes must be designed so that they have a maximum contact sur- face. Classification of heat-mass exchange apparatuses provides geometric features of the apparatus and the hydrodynamic condition they create. However, the main trend which remains dominant in the design of such apparatus is to create a thin film of liquid on the surface of the nozzle. The work was aimed at choosing the solution in which the MN of the heat-mass exchange apparatuses can be used to implement the contact handling process of gases and liquids with density values clarification of the nozzle elements (ρnе) and the column dynamic height (Нст) and obtain the specified calculated dependences which describe the hydrody- namics and mass transfer in the apparatuses with a movable nozzle, that is to create bases for engineering calculations. Research methods were theoretical study and experimental studies on heat and mass transfer devices with movable nozzle. The best ranger for mass transfer processes implementation is that of ρneІІ (ρ = 200-700 kg/m3), which is distin- guished by a wide working area according to wg, acceptable values of fluid withdrawal and a relatively small dynamic layer height. Within the described mode, we can distinguish the area wg @ 4.7-6.0 m/s, where there is no dependence of Hp on wg. Specified calculated dependence obtained which describes the hydrodynamics and heat and mass transfer in the apparatuses with a movable nozzle.
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Study of structural properties of bismuth pyrostannate by Raman and IR spectroscopy
Статья научная
Chromium-substituted bismuth pyrostannates with a pyrochlore structure were synthesized by the solid-phase reaction method. The X-ray structural analysis performed at room temperature showed that the samples Bi2(Sn1-xCrx)2O7, x = 0; 0.05, 0.1 are single-phase and belong to the Pc monoclinic structure. Polymorphic transformations of the synthesized samples were studied by Raman and IR spectroscopy. IR spectra were obtained at the temperature range 110-525 K and frequencies 350-1100 cm-1. Raman spectra were measured at room temperature at frequencies of 100-3000 cm-1. Heterovalent substitution of Sn4+ for Cr3+ modifies the spectra of pure Bi2Sn2O7. The crystal structure of Bi2Sn2O7 consists of two oxygen sublattices: SnO6 and Bi2O'. Chromium ions substituted tin ions in the SnO6 oxygen octahedra, distorting the local structure in the vicinity of bismuth ions. Phonon modes are softening in the vicinity of phase transitions. А shift of the phase boundaries of polymorphic transitions is observed for Bi2(Sn1-хCrх)2O7, x = 0.05, 0.1. The frequencies of stretching vibration modes were determined from IR and Raman spectra. The substitution of chromium for tin ions resulted in the appearance of two new modes at frequencies of 581 and 822 cm-1 in the Raman spectra. The absence of an inversion center in the crystal structure of Bi2(Sn1-xCrx)2O7 is confirmed by Raman spectroscopy. IR spectra of chromium-substituted samples consist of complex lines, which decompose into 2 and 3 Lorentzian lines. The softening and broadening of optical absorption modes are associated with the electronic contribution. Impurity states of electrons form polarons.
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Study of tribological properties of plasma-modified UHMWPE
Статья научная
The results of studying of nanocomposite materials based on ultra-high-molecular-weight polyethylene filled with copper oxide nanopowder produced in plasma of low-pressure arc discharge are presented. The process of the vacuum-plasma synthesis of powdered composite mixtures, which involves the treatment of powders of the polymer matrix material in a device for synthesizing nanopowders at low temperatures, is described. The results of the experimental study of the specimens are presented.
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Sustainable development of the agro-economic system: essence, terms and concepts
Статья научная
Conceptual apparatus and terminological special features in the question of the sustainable development of the agro-economic of systems are examined. The ways of transition to the sustainable development are revealed: planning and organizing of development of the agro-economic systems; improvement of social and economic conditions of villagers; development of self-government; production diversification; accelerated development of alternative activities and others.
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System analysis of dynamic problems of anisotropic plasticity theory
Статья научная
Dynamic problems are the least studied area of plasticity theory. These problems arise in various fields of engineering and science, but the complexity of the original differential equations do not allow to develop accurate solutions and correctly solve numerical boundary value problems. This is even more typical of dynamic equations of anisotropic plasticity. Anisotropy reduces the group of symmetries allowed by the equations, and therefore narrows the number of invariant solutions. One-dimensional dynamic plasticity problems are well studied, but two-dimensional problems cause insurmountable mathematical difficulties due to the nonlinearity of the basic equations, even in the isotropic case. The study of the symmetries of the plasticity equations allowed us to find some exact solutions. The most known solution was found by B. D. Annin, who described the unsteady compression of a plastic layer made of isotropic material by rigid plates. Annin's solution is linear in two spatial variables, however, it includes arbitrary functions of time. Symmetries are also used in the proposed work. Point symmetries are first calculated for dynamic plasticity equations in the anisotropic case and are presented in the paper. The Lie algebra generated by the found symmetries appeared to be infinite-dimensional. This circumstance made it possible to apply the method of constructing new classes of nonstationary solutions. Symmetry can transform the exact solution of stationary dynamic equations in non-stationary solutions. The framed solutions include arbitrary functions and arbitrary constants. The outline of the article is as follows: according to the method of Lie group of point symmetries allowed by the equations of anisotropic plasticity is calculated. Two classes of new stationary invariant solutions are framed. These stationary solutions, by means of transformations generated by point symmetries, are transformed into new non-stationary solutions. In conclusion, a new self-similar solution of unsteady equations of anisotropic plasticity is framed; Annin's solution is generalized for the anisotropic case. The framed solutions can be used to describe the compression of plastic material between rigid plates, as well as to test programs, designed to solve anisotropic plastic problems.
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System for processing highly specialized information in distributed networks
Статья научная
A new structure of a system for arranging and control of highly specialized information in corporate systems is proposed. The principle difference of the given structure is that it is capable to process multilinguistic information within one user's inquiry.
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Technique to estimate and forecast life quality of population
Статья научная
The article presents the expediency to apply life quality indicator of efficiency for activity of authorities and also the essence of the estimation technique developed by the author and forecasting of life quality of the population with regional features taken into account.
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Technology of producing fibrous structure wire from chips of aluminum–magnesium–silicon alloys
Статья научная
A technological scheme for processing the scrap of aluminum–magnesium–silicon alloy in the form of friable chips into rods and wire is introduced. This scheme is based on the powder metallurgy methods. The characteristic structure and the level of mechanical properties of the produced wire are denoted.
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Статья научная
A new method for the production of nanomaterials in the plasma of a low-pressure arc discharge is developed and experimentally studied. This method can be used to synthesize nanoparticles 5-10 nm in size with a narrow size distribution. In this method, a low-pressure arc discharge is used to melt a material, to disperse the molten material, to deliver liquid material droplets to the plasma, to cool the liquid nanoparticles forming in the plasma up to their solidification, and to deposit the solidified nanoparticles onto a substrate.
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Testing of aluminum-silicon alloys mechanical properties on separately casted specimens
Статья обзорная
The mechanical properties of aluminum alloys before casting into moulds were determined on separately casted control specimens casted in horizontal or vertical forms. A comparison of the mechanical properties (tensile strength t, elongation 8, hardness HB) of 12-mm-diameter individually casted of AK7ch alloy control specimens and its density in the solid state (p) showed that it is necessary to use specimens casted in a horizontal mold for evaluation of castings quality. It was estimated that position of separately casted test samples in the foundry metal form influences the indicators of mechanical properties of aluminium-silicon alloys.
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Testing the algorithm of the “Caterpillar”-SSA method for time series recovery
Статья научная
The basic algorithm of the “Caterpillar”-SSA method is considered and tested.
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The Cayley graphs of finite two-generator burnside groups of exponent 7
Статья научная
For the first time the definition of the Cayley graph was given by the famous English mathematician Arthur Cayley in the XIX century to represent algebraic group defined by a fixed set of generating elements. Now the Cayley graphs are widely used both in mathematics and in applications. In particular, these graphs are used to represent computer networks, including the modeling of topologies of multiprocessor computer systems (MCS) - supercomputers. This is due to the fact that Cayley graphs possess many attractive properties such as regularity, vertex transitive, small diame- ter and degree at a sufficiently large number of vertices in the graph. For example, such a basic network topology as the ”ring”, ”hypercube” and ”torus” are the Cayley graphs. One of the widely used topologies of MCS is a k- dimensional hypercube. This graph is given by a k-generated Burnside group of exponent 2. This group has a simple structure and is equal to the direct product of k copies of the cyclic group of order 2. Now the Cayley graphs of groups of exponent 3, 4, and 5 have already been studied. In this paper we research the Cayley graphs of some finite two- generated Burnside groups of exponent 7. The computation of the diameter of the Cayley graph of a large finite group is a solvable but very difficult problem. In the general case the problem of determining the minimal word in a group is NP-hard ( nondeterministic polynomial ). Thus, in the worst case, the number of elementary operations that must be per- formed to solve this problem is an exponential function of the number of generating elements. Therefore, to effectively solve problems on Cayley graphs having a large number of vertices, it is necessary to use MCS.
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The algorithm for estimating angular rate of spacecraft in survivability mode
Статья научная
The paper discusses the issue of ensuring survivability of Spacecraft (SC) in its long-term autonomous operation in space conditions for cases of critical failure of rate sensors. We presented an autonomous control loop in survivability mode in the form of a functional circuit and a mathematical model of control loop. On the spacecraft engineered by JSC ISS - Reshetnev, failures of an angular-rate sensor took place; these failures reduced a redundancy level and unfailing performance of SC; the failure of a standby angular rate sensor will lead to impossibility to use this mode. We came up with a solution to a problem of potential failures of angular rate sensors for spacecraft in operation in orbit using addi- tional control logic; this solution is the purpose of our work. We developed a mathematical model of control without using an angular rate sensor. We described the model in details and it included estimating the angular rate according to previously generated control actions, calculation of control actions and filtration of evaluation registration accord- ing to measuring of a solar sensor. We showed the purpose of each newly introduced block that gives such advantages as improving the noise immunity of control loop to measurement errors, providing search rotation in the case of failure of all rate sensors. Improved control algorithm was synthesized. Having improved the basic algorithm, we carried out ground and flight tests. We performed mathematical modeling in the environment called GNU Octave. Hybrid modeling was performed on rotary tables equipped with functional models of units and a functional model of onboard control subsystem. We conducted flight tests on real geostationary SC flying in orbit. For each test, we pro- vided description of initial conditions and presented graphs of measurement of angular rate. We carried out all the tests successfully, and the algorithm is applied on the SC engineered by JSC “ISS - Reshetnev Company”.
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Статья научная
The experimental evaluation of the working process stability with respect to acoustic oscillations in combustion chambers and gas generators of liquid rocket engines is one of the main methods used in rocket engine construction. External and internal disturbing devices using explosive hexogen often lead to the damage to the fire walls and struc- tural elements of the aggregates The disadvantages of traditional external impulse devices also include a considerable wide range of the pressure pulses values generated by them in the combustion chamber with the same value of the sam- ple of the explosive and with the constant parameters of the atmosphere in the combustion chamber, which is due to the scatter of the explosives characteristics. An alternative approach is proposed for creating a pulse effect on the working process in the combustion chamber by exploding an electrical conductor. The disturbing device is made with an explo- sive chamber connected by a channel with the reaction volume of the combustion chamber. In the electro-impulse dis- turbing device a thin wire fastened to isolated electrodes is used instead of the charge of the explosive. As a substance used to create a pressure pulse, this generator uses gas filling the blasting chamber, the mass of which depends on the pressure in the combustion chamber and in the chamber of the electro-impulse perturbative device. If one immediately heats this gas to a temperature of several thousand degrees, one can get a gas that is close in parameters to the com- bustion products of explosives in traditional external impulse devices. Such heating can be carried out by discharging through a wire of an electric capacitor charged to several thousand volts. First, instantaneous (for several microsec- onds) evaporation of the wire, and then through the plasma channel formed at the site of the wire, the final discharge of the capacitor takes place, with virtually all of the energy stored in the capacitor discharged. The plasma temperature in this case, according to different sources, can reach from several tens of thousands to one million degrees. The gas is also heated by adiabatic compression with a shock wave. The metal particles formed after the evaporation of the wire and the condensation of the vapor have a value of several nanometers and, therefore, do not damage the inner layer of the combustion chamber. The methodological bases are considered and the algorithm for estimating the stocks of stability to acoustic vibrations from the reaction of the combustion process to such pulsed artificial disturbances is developed. There have been developed electro-impulse disturbing devices that reduce the risk of damage to the compo- nents of liquid rocket engine assemblies in full-scale and model test, and have an obvious prospect for widespread use.
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The analysis of completed, ongoing and potential missions to the Jupiter system
Статья научная
In the next decade, a significant increase in the intensity of the Jupiter system and its satellites studying with the help of spacecraft is expected. The two Galilean moons - Europe and Ganymede - are particularly interesting since the potential life is possible on these objects, even in a primitive form. Such missions are being developed by ESA (“Jupiter Icy Moon Explorer” (JUICE)), NASA (“Europa Clipper” and “Europa Lander”), Roskosmos (“Laplace-P”) and others. The final goal of the European and Russian projects is the detailed study of Ganymede - the largest satellite both in the Jupiter system and in the entire Solar system. The Russian perspective project “Laplace-P” assumes the creation and launch of two spacecrafts in one launch window. At the heart of the first mission spacecraft is an orbiter. One of its tasks is mapping the surface of Ganymede from the orbit of an artificial satellite and collecting data for selecting a landing site of the second spacecraft - a landing satellite. The project should be based on the launch of a spacecraft from the Baikonur cosmodrome with the help of the Angara-A5 launcher and the KVTK upper stage. When developing the flight scheme it is assumed that in 8 years the spacecrafts should be put into the orbit around Ganymede. The flight trajectory to Jupiter is formed with the help of gravitational maneuvers near the Earth and Venus. The mission of “JUICE” involves the study of Ganymede only from the orbit of an artificial satellite. The article is devoted to comparison of completed, carried out and perspective expeditions to the Jupiter system. If the first mission - “Galileo” - was mainly focused on Jupiter itself, the future missions are aimed at investigations of its satellites. Based on the analysis of the reviewed projects, recommendations are given to improve the efficiency of the Russian “Laplace-P” project. It is established that to improve the efficiency of the Russian mission “Laplace-P” it is recommended both further structural improvement of space vehicles and the development of a trajectory in the Jupiter system based on modern methods of ballistic design.
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Статья научная
The influence of selective circuits of digital-analogue converters at primary pulsed-code conversion on distortion of input signal of coders with audio data compression is considered.
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