2021 год
| № | Название статьи | Авторы | Название журнала | Краткая аннотация | Ссылка |
| 1 | Exponential distribution of lifetimes for transient bursting states in coupled noisy excitable systems | Albanbay, N., Medetov, B., Zaks, M.A. |
Chaos Q1 in Mathematical Physics |
The phenomenon of transient bursting, caused by additive noise in a set of two coupled FitzHugh-Nagumo oscillators, is studied by direct numerical integration and by measurements in the analog electronic circuit. In the parameter region where the unique global attractor of the deterministic system is the state of rest, introduction of low or moderate intensity fluctuations into the voltage dynamics results in the onset of a transient bursting state: sequences of intermittent bursts (patches of spikes), followed by ultimate relaxation to the equilibrium. Like genuine deterministic bursting, this behavior has its origin in the slow-fast character of the underlying dynamics. Trajectories that in the deterministic variant would converge to the state of rest can, under the action of noise, escape the local basin of attraction of the equilibrium and experience a bursting episode, before being dynamically reinjected into the region around the equilibrium. Under frozen parameter values and fixed noise intensity, the number of bursts preceding the ultimate decay strongly varies for different realizations of the additive random signal. The average duration of the transient bursting stage, bounded for weak noise, diverges when the intensity of fluctuations is raised. For sufficiently large ensembles of realizations, the lifetimes of transient bursting states, both in simulations and in the analog circuit, obey the exponential distribution. We relate this distribution to the probability for a stochastic trajectory to temporarily escape from the local basin of attraction of the equilibrium. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85114711096&origin=resultslist&sort=plf-f |
| 2 | Intelligent autonomous street lighting system based on weather forecast using LSTM | Tukymbekov, D., Saymbetov, A., Nurgaliyev, M., ...Dosymbetova, G., Svanbayev, Y. Kuttybay N. |
Energy Q1 in Engineering |
Existing traditional street lighting systems are characterized by a high level of energy consumption compared to automated intelligent systems that offer different operating modes depending on traffic and power system load. The most promising energy sources systems are hybrid installations that switch the load to the grid in adverse weather conditions. Such systems may increase the energy efficiency of the street lighting system, but they are not completely autonomous. In this case, the most important problem is to provide the street lighting system with energy in adverse weather conditions. In this paper, an autonomous street lighting system with adaptive energy consumption based on weather forecast was shown. The proposed street lighting system is completely independent of traditional power sources and is completely powered by solar panels. The main energy consumers of a street lighting system are lamps. The consumption of lamps can be changed to the minimum brightness level required by outdoor lighting standards. Forecasts of energy generation by solar panels can be obtained using LSTM. It is based on weather and solar radiation forecasts data for the coming days. The brightness levels of lamps are calculated and changed using the methods proposed in this paper. The probability of reaching the critical level of batteries does not exceed 0.10% and fluctuates around 0.05% most of the time when simulating for 1000 days under random weather conditions. Simulation of energy consumption by the street lighting system using the proposed method shows stable and sustainable performance in Almaty, Kazakhstan. The obtained results in this work can be used for designing autonomous street lighting and outdoor lighting systems. | https://www.scopus.com/record/display.uri?eid=2-s2.0-85106395161&origin=resultslist&sort=plf-f |
| 3 | Physical processes during the formation of silicon-lithium p-i-n structures using double-sided diffusion and drift methods | Saymbetov, A., Muminov, R., Japashov, N., Zholamanov, B., Jing, Z. Nurgaliyev, M Kuttybay N. |
Materials Q2 in Materials Science |
In this paper, we described a method of double-sided diffusion and drift of lithium-ions into monocrystalline silicon for the formation of the large-sized, p-i-n structured Si(Li) radiation detectors. The p-i-n structure is a p-n junction with a doped region, where the “i-region” is between the n and the p layers. A well-defined i-region is usually associated with p or n layers with high resistivities. The p-i-n structure is mostly used in diodes and in some types of semiconductor radiation detectors. The uniqueness of this method is that, in this method, the processes of diffusion and drift of lithiumions, which are the main processes in the formation of Si(Li) p-i-n structures, are produced from both flat sides of cylindrical-shaped monocrystalline silicon, at optimal temperature (T = 420◦C) conditions of diffusion, and subsequently, with synchronous supply of temperature (from 55 to 100◦C) and reverse bias voltage (from 70 to 300 V) during drift of lithium-ions into silicon. Thus, shortening the manufacturing time of the detector and providing a more uniform distribution of lithium-ions in the crystal volume. Since, at present, the development of manufacturing of large-sized Si(Li) detectors is hindered due to difficulties in obtaining a uniformly compensated large area and time-consuming manufacturing process, the proposed method may open up new possibilities in detector manufacturing. | https://www.scopus.com/record/display.uri?eid=2-s2.0-85114868997&origin=resultslist&sort=plf-f |
| 4 | Dual-axis schedule tracker with an adaptive algorithm for a strong scattering of sunbeam | Saymbetov, A., Mekhilef, S., Kuttybay, N., ...Dosymbetova, G., Svanbayev, Y. Nurgaliyev, M |
Solar Energy Q1 in Materials Science |
The efficiency of photovoltaic panels is one of the main challenges of solar energy today. The sharp decline in solar cell performance in cloudy weather is the most significantlimiting factor for the transition to a green economy. As a result, today's priority task is the development of various algorithms to improve the performance of solar cells in cloudy weather. This paper compares the performance of dual-axis schedule tracker and dual-axis schedule tracker with an adaptive algorithm for a strong scattering of the sun's rays by clouds. A comparative analysis of the manufactured trackersoperation in adverse weather conditions was performedand with the use of small solar panels, an effective method was proposed for determining the minimum flow of solar energy entering the surface of photovoltaic installations with strong cloud scattering. The developed dual-axis method of tracking the sun is 41% more efficient than the dual-axis schedule tracker. The energy produced by trackers with high-power panels for three months in the previous threeyears was also estimated using availablemeteorological data in Almaty, Kazakhstan. The results obtained can be used to design solar trackers in areas with a high probability of intensesolar energy scattering on clouds. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85108003152&origin=resultslist&sort=plf-f |
| 5 | Period bouncer cataclysmic variable EZ Lyn in quiescence | Amantayeva, A., Zharikov, S., Page, K.L., Khokhlov, S., Ibraimov, M. |
Astrophysical Journal Q1 in Physics and Astronomy |
We report the study of the accretion disk structure of the period bouncer cataclysmic variable EZ Lyn (SDSS J080434.20+510349.2) in quiescence based on our new time-resolved photometric and spectroscopic observations and data extracted from archives. The object magnitude now is V = 17.95(5), close to its brightest before the first superoutburst in 2006. We confirmed the presence of the small eclipse in the optical light curve. The spectra obtained in quiescence at different epochs look similar. However, the contribution of the disk and intensities of emission lines are strongly varied. We singled out pure accretion disk spectra and found that the Balmer decrement Hα:Hβ:Hγ:Hδ = 1.61:1.0:0.76:0.59 is comparable with one at bright accretion disks in longer period cataclysmic variables. The decrement suggests that emission lines are excited collisionally in an optical thin part of the disk with average density and temperature of logN0 = 12.5(2) and T = (10–15) × 103 K. Based on the photometric data and our modeling techniques, we redetermined the mass of MWD = 0.85(1) Me and the current effective temperature TWD,eff = 11,250(50) K of the white dwarf. The secondary has mass of M2 = 0.042(14) Me. The system inclination is 79.0°(2). The mass accretion rate is about M » (0.3–3.0) ´ 10-12 M⊙ yr-1. The disk luminosity, together with results from light-curve modeling, suggests a low effective temperature ∼2500 K of the continuum emitting region, where also the spiral arm pattern is hosted. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85115938228&origin=resultslist&sort=plf-f |
| 6 | Extended HNCO, SiO, and HC3N emission in 43 southern star-forming regions | He, Y.-X., Henkel, C., Zhou, J.-J., ...Komesh, T., Sailanbek, S. |
Astrophysical Journal, Supplement Series Q1 in Space and Planetary Science |
We have selected 43 southern massive star-forming regions to study the spatial distribution of HNCO 404-303, SiO 2-1, and HC3N 10-9 line emission and to investigate their spatial association with the dust emission. The morphology of HNCO 404-303 and HC3N 10-9 agrees well with the dust emission. HC3N 10-9 tends to originate from more compact regions than HNCO 404-303 and SiO 2-1. We divided our sources into three groups: those in the Central Molecular Zone (CMZ), those associated with bubbles (Bubble), and the remaining sources, which are termed "normal star-forming regions"(NMSFR). These three groups, subdivided into three different categories with respect to line widths, integrated intensities, and column densities, hint at the presence of different physical and chemical processes. We find that the dust temperature Td, and the abundance ratios NHNCO/NSiO and NHNCO/NHC3N show a decreasing trend toward the central dense regions of CMZ sources, while NHC3N/NSiO moves in the opposite direction. Moreover, a better agreement is found between Td and NHC3N/NSiO in Bubble and NMSFR category sources. Both outflow and inflow activities have been found in eight of the 16 bubble and NMSFR sources. The low outflow detection rate indicates either that in these sources the SiO 2-1 line wing emission is below our sensitivity limit or that the bulk of the SiO emission may be produced by the expansion of an H II region or supernova remnant, which has pushed molecular gas away, forming a shock and yielding SiO |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85101657393&origin=resultslist&sort=plf-f |
| 7 | Effects of non-vanishing dark matter pressure in the Milky Way Galaxy | Boshkayev, K., Konysbayev, T., Kurmanov, E., Mutalipova, K., Zhumakhanova, G. |
Monthly Notices of the Royal Astronomical Society Q1 in Space and Planetary Science |
We consider the possibility that the Milky Way's dark matter halo possesses a non-vanishing equation of state. Consequently, we evaluate the contribution due to the speed of sound, assuming that the dark matter content of the galaxy behaves like a fluid with pressure. In particular, we model the dark matter distribution via an exponential sphere profile in the galactic core, and inner parts of the galaxy whereas we compare the exponential sphere with three widely used profiles for the halo, i.e. the Einasto, Burkert and Isothermal profile. For the galactic core, we also compare the effects due to a dark matter distribution without black hole with the case of a supermassive black hole in vacuum and show that present observations are unable to distinguish them. Finally we investigate the expected experimental signature provided by gravitational lensing due to the presence of dark matter in the core. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85118303500&origin=resultslist&sort=plf-f |
| 8 | Luminosity of accretion disks in compact objects with a quadrupole | Boshkayev, K., Konysbayev, T., Kurmanov, E., ...Malafarina, D., Quevedo, H. |
Physical Review D Q1 in Physics and Astronomy |
We consider the circular motion of test particles in the gravitational field of a static and axially symmetric compact object described by the metric. To this end, we calculate orbital parameters of test particles on accretion disks such as angular velocity (), total energy (), angular momentum (), and radius of the innermost stable circular orbit () as functions of the mass () and quadrupole () parameters of the source. The radiative flux, differential, and spectral luminosity of the accretion disk, which are quantities that can be experimentally measured, are then explored in detail. The obtained results are compared with the corresponding ones for the Schwarzschild and Kerr black holes in order to establish whether black holes may be distinguished from the metric via observations of the accretion disk’s spectrum. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85116372484&origin=resultslist&sort=plf-f |
| 9 | Bound mass of Dehnen models with a centrally peaked star formation efficiency | Shukirgaliyev, B., Otebay, A., Sobolenko, M., Kalambay M..Spurzem, R., Just, A. |
Astronomy and Astrophysics Q1 in Physics and Astronomy |
Context. Understanding the formation of bound star clusters with a low star formation efficiency (SFE) is important for improving our knowledge of the star-formation history of galaxies. In N-body models of star-cluster evolution after gas expulsion, the Plummer model with an outer power law density profile has been used in a broad range of studies. Aims. Here, we study the impact of the density profile slopes on the survivability of the low-SFE star clusters after instantaneous gas expulsion. We compare cases when a stellar cluster exhibits a Plummer profile to those with Dehnen profiles, including cuspy ones of different slopes at the time of formation. Methods. We determined the corresponding density profile of the residual gas for a given global SFE, assuming that our model clusters formed with a constant efficiency per free-fall time and, hence, with a shallower density profile for the gas than that of the stars. We performed direct N-body simulations of evolution of clusters initially in virial equilibrium within the gas potential following gas removal. Results. We find that the violent relaxation lasts no longer than 20 Myr, independently of the density profile power law slopes. Dehnen model clusters survive after violent relaxation with significantly lower SFEs when the global SFE measured within the Jacobi radius or within a half-mass radius. Dehnen γ = 0 model clusters show a similar final bound fraction with the Plummer model clusters if the global SFE is measured within ten scale radii. The final bound fraction increases with the γ values for a given global SFE. Conclusions. We conclude that Dehnen clusters better resist the consequences of the violent relaxation that follows the instantaneous gas expulsion, as compared to the Plummer clusters. Therefore, the shallower the outer density slope of the low-SFE clusters, the better their prospects for survival after gas expulsion. Among the Dehnen clusters, we find that the steeper the inner slope, the higher the bound mass fraction that is retained, following the violent relaxation for a given global SFE. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85117103291&origin=resultslist&sort=plf-f |
| 10 | Preparation and characterization of F-, O-, and N-containing carbon nanoparticles for pH sensing | Lisnyak, V.V., Zaderko, A.N., Mariychuk, R., Mussabek, G.K., Zhylkybayeva, N., Tananiko, O.Y. |
Applied Nanoscience (Switzerland) Q1 in Materials Science (miscellaneous) |
A novel sensing system was designed for pH measurements based on the enhanced and quenched photoluminescence (PL) and UV–Vis absorption of the diluted water solutions of F-, O-, and N-containing carbon nanoparticles (FON-CNPs). These FON-CNPs were solvothermally synthesized, dissolved, ultra-filtrated, and separated by thin-layer chromatography. The total fluorine content in them was found to be 1.2–1.5 mmol per gram. Their TGA showed a total weight loss of 52.7% because of the thermal decomposition and detachment of the surface groups and the partial burning of the functionalized shell on the carbon core at temperatures below 1200 °C. TEM and Raman data confirmed the presence of graphitic structures in the carbon core. From the results of ATR FTIR and UV–Vis spectroscopies, we showed that a carbon shell incorporates different functional groups covering the carbon core. The surface groups of the carbon shell include carboxyl, phenolic, and carbonyl groups. Heterocyclic N-containing and amino groups and trifluoromethyl groups supporting the hydrophobicity were also found. We suggested the possible reasons for the pH responses obtained with the sensing system considering them dependent on the de-protonation of functional groups with pH change. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85101098654&origin=resultslist&sort=plf-f |
| 11 | Corrosion and Mechanical Properties of the Fe-W-Wo2and Fe-Mo-MoO2Nanocomposites | Yar-Mukhamedova, G., Ved', M., Sakhnenko, N., Karakurkchi, A., Yermolenko, I. |
Advances in Materials Science and Engineering Q2 in General Engineering |
Analyzing of composition electrolytic coatings' application for the metal surface protection is considered. It is established that using different components for coatings' modification gives possibility to obtain surfaces with expanding exploitation properties, in particular, with improved wearing and anticorrosion resistance. The new approach for protecting details which are made from cast irons by obtaining two kinds of composition coatings from binary alloys iron-molybdenum and iron-tungsten is proposed. It is found that the modification of iron by refractory metals up to 37 wt. % leads to a noticeable change in the microstructure of the coatings' surface. It is established that the incorporation of refractory metals into the iron matrix is a good way to increase the microhardness of the surface by 2.5-3.5 times and rising of the wear resistance by 40%, as well as decreasing the friction coefficient by 3-4 times in comparison with the cast iron substrate. The research results can be used for surfaces hardening and protection in different industries. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85108425225&origin=resultslist&sort=plf-f |
| 12 | The prolonged gamma ray enhancement and the short radiation burst events observed in thunderstorms at Tien | Shepetov, A., Antonova, V., Kalikulov, O., Mukashev, K. M..Zhukov, V., Gurevich, A |
Atmospheric Research Q1 in Atmospheric Science
|
We report the observation results of the hard radiation flashes which accompanied the lightning discharges above the mountains of Northern Tien Shan. Time series of the counting rate intensity, numerical estimations of absolute flux, and energy distribution of accelerated electrons and of (20−2000) keV gamma rays were obtained at the height of 3700 m a. s. l., immediately within thunderclouds, and in closest vicinity (≲100 m) to discharge region. Two different kinds of radiation emission events are presented here: a relatively prolonged rise of gamma ray intensity with minute-scale duration (the thunderstorm ground enhancement, TGE) which has preceded a negative field variation, and a short sub-millisecond radiation burst, which accompanied a close lightning discharge in thundercloud. It was revealed also an indication to positron generation in thunderclouds at the time of gamma ray emission, as well as modulation of the neutron counting rate in Tien Shan neutron monitor which was operating at a (1.5–2) km order distance from the region of lightning development. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85091258561&origin=resultslist&sort=plf-f |
| 13 | Electrostatic energy analyzer for nanotechnology applications | Guseinov, N.R., Ilyin, A.M. |
Journal of Electron Spectroscopy and Related Phenomena Q2 in Radiation
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Electrostatic energy analyzers are key instruments in the wide field of the Electron Spectroscopy, and the Auger Electron Spectroscopy is one of commonly used technique within this area. The paper presents a new energy analyzer based on combination of a face-field and CMA configurations and some experimental Auger spectra obtained from nanostructures synthesized. The data obtained show that the presented analyzer's energy resolution and design parameters are superior to the data of the well known standard CMA. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85097347019&origin=resultslist&sort=plf-f |
| 14 | Methods of stability control of perovskite solar cells for high efficiency | Muradov, A., Frolushkina, D., Samusenkov, V., Zhamanbayeva, G., Kot, S. |
Energies Q1 in Control and Optimization
|
The increasing demand for renewable energy devices over the past decade has motivated researchers to develop new and improve the existing fabrication techniques. One of the promising candidates for renewable energy technology is metal halide perovskite, owning to its high power conversion efficiency and low processing cost. This work analyzes the relationship between the structure of metal halide perovskites and their properties along with the effect of alloying and other factors on device stability, as well as causes and mechanisms of material degradation. The present work discusses the existing approaches for enhancing the stability of PSC devices through modifying functional layers. The advantages and disadvantages of different methods in boosting device efficiency and reducing fabrication cost are highlighted. In addition, the paper presents recommendations for the enhancement of interfaces in PSC structures. |
https://www.scopus.com/record/display.uri?eid=2-s2.0-85106883894&origin=resultslist&sort=plf-f |