Journal of Physical Studies最新文献_第6页

X-ray spectral features and classification of selected QSOs 选定qso的x射线光谱特征和分类

IF 0.5

Journal of Physical Studies Pub Date : 2021-10-14 DOI: 10.30970/jps.25.4901

L. Zadorozhna, A. Tugay, Nadiia Pulatova, Oleh Maluy

{"title":"X-ray spectral features and classification of selected QSOs","authors":"L. Zadorozhna, A. Tugay, Nadiia Pulatova, Oleh Maluy","doi":"10.30970/jps.25.4901","DOIUrl":"https://doi.org/10.30970/jps.25.4901","url":null,"abstract":"We present the results of a systematic analysis of the XMM-Newton spectra of nearby optically bright QSOs. The objects have been selected from X-ray Galaxy Catalog Xgal20. It is a catalog of 1172 manually identi(cid:28)ed and classi(cid:28)ed galaxies, obtained as a cross-correlation between the 4XMM-DR9 catalog and the Hyper-Linked Extragalactic Databases and Archives (HyperLeda) with an X-ray (cid:29)ux greater than F ≥ 10 − 13 erg / ( cm 2 · s ) . The goal of this work is to characterize the X-ray spectral properties of selected QSOs in the 0.1 (cid:21) 10 keV energy band. The majority of the sources (6 out of 11) are classi(cid:28)ed as radio-quiet QSOs. We studied optical spectra, hardness ratios and performed X-ray spectral (cid:28)ts for the 10 brighter sources. In most cases, the power law model with absorption is good enough to simulate observed continua. However, the details of the spectrum in some sources signi(cid:28)cantly complicate the model for (cid:28)tting. The majority of sources have steep spectra Γ > 2 . 1 . Extremely steep photon index ( ∼ 2 . 4 − 2 . 5 ) in our sample occurs for three radio-loud type I quasars. We detected Fe K α line for two radio-loud type II quasars. We (cid:28)nd no strong evidence for spectral hardening above 2 keV either for quasars, of type I, or for the obscured type II. For each quasar its type was established both based on the features and details of observed X-ray spectrum and previous data.","PeriodicalId":43482,"journal":{"name":"Journal of Physical Studies","volume":"197 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77714467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Generation of magnetic fields by thermomagnetic effects in a nonuniformly rotating layer of an electrically conductive fluid 在导电流体的非均匀旋转层中由热磁效应产生的磁场

IF 0.5

Journal of Physical Studies Pub Date : 2021-04-21 DOI: 10.30970/JPS.25.2401

M. Kopp, K. Kulik, A. Tur, V. Yanovsky

{"title":"Generation of magnetic fields by thermomagnetic effects in a nonuniformly rotating layer of an electrically conductive fluid","authors":"M. Kopp, K. Kulik, A. Tur, V. Yanovsky","doi":"10.30970/JPS.25.2401","DOIUrl":"https://doi.org/10.30970/JPS.25.2401","url":null,"abstract":"In this paper, the generation of magnetic fields in a nonuniformly rotating layer of finite thickness of an electrically conducting fluid by thermomagnetic (TM) instability. This instability arises due to the temperature gradient $nabla T_0$ and thermoelectromotive coefficient gradient $nablaalpha $. The influence of the generation of a toroidal magnetic field by TM instability on convective instability in a nonuniformly rotating layer of an electrically conductive fluid in the presence of a vertical constant magnetic field ${bf{B}}_0 | {rm OZ}$ is established. As a result of applying the method of perturbation theory for the small parameter $ epsilon = sqrt {(textrm {Ra}-textrm {Ra}_c) / textrm {Ra}_c} $ of supercriticality of the stationary Rayleigh number $textrm {Ra}_c$ a nonlinear equation of the Ginzburg-Landau type was obtained. This equation describes the evolution of the finite amplitude of perturbations. Numerical solutions of this equation made it possible to determine the heat transfer in the fluid layer with and without TM effects. It is shown that the amplitude of the stationary toroidal magnetic field noticeably increases with allowance for TM effects.","PeriodicalId":43482,"journal":{"name":"Journal of Physical Studies","volume":"238 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76108816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Acoustic waves in a turbulent giant molecular cloud taking into account the correlations of gravitational field 考虑引力场相关性的湍流巨分子云中的声波

IF 0.5

Journal of Physical Studies Pub Date : 2021-02-28 DOI: 10.30970/JPS.25.1903

Îëåñÿ Ãîí÷àðà, ïðîñï. Ãàãàðiíà

{"title":"Acoustic waves in a turbulent giant molecular cloud taking into account the correlations of gravitational field","authors":"Îëåñÿ Ãîí÷àðà, ïðîñï. Ãàãàðiíà","doi":"10.30970/JPS.25.1903","DOIUrl":"https://doi.org/10.30970/JPS.25.1903","url":null,"abstract":"A hydrodynamic model for the description of small acoustic oscillations in a turbulent giant molecular cloud is constructed by averaging the Euler equation over Reynolds, taking into account the turbulence of a self-consistent gravitational (cid:28)eld that has zero (cid:28)rst moment and nonzero second moment in equilibrium. It is shown that, in addition to the Reynolds turbulent stress tensor, the momentum (cid:29)ow tensor includes the second correlation moment of the gravitational (cid:28)eld strength, both potential and vortex, for which the time equation is obtained from the Einstein equations in non-relativistic approximation. After linearization, this equation is ∂ t (cid:104) g i g k (cid:105) = ( ∂ k v i + ∂ i v k − 2 ∂ l v l δ ik ) (cid:10) g 2 (cid:11) 0 / 6 , where ∂ t ant ∂ i are the time and spatial derivatives, v i is the mass velocity component, (cid:10) g 2 (cid:11) 0 is the square of a self-consistent gravitational (cid:28)eld strength equilibrium value. Two transverse and longitudinal branches of acoustic oscillations in a homogeneous isotropic cloud are obtained. Zeroing of the transverse oscillations velocity gives a limiting condition for the stability of the giant molecular cloud (cid:10) v 2 (cid:11) 0 − (cid:10) g 2 (cid:11) 0 / (8 πGρ 0 ) ≥ 0 , where (cid:10) v 2 (cid:11) 0 is the mean square turbulent velocity, G is the gravitational constant, ρ 0 is the equilibrium density value. Thus, the doubled energy density of the turbulent motion must be greater than the gravitational (cid:28)eld energy density. It is shown that the thermal motion does not a(cid:27)ect the stability of the system. For the spherical shape of the cloud, the radius of the giant molecular cloud is obtained, which is consistent with observational data.","PeriodicalId":43482,"journal":{"name":"Journal of Physical Studies","volume":"3 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80201513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Bound-state solutions of the modified Klein–Gordon and Schrödinger equations for arbitrary l-state with the modified Morse potential in the symmetries of noncommutative quantum mechanics 非对易量子力学对称性中任意l态修正Morse势的修正Klein-Gordon方程和Schrödinger方程的束缚态解

IF 0.5

Journal of Physical Studies Pub Date : 2021-02-23 DOI: 10.30970/JPS.25.1002

A. Maireche

{"title":"Bound-state solutions of the modified Klein–Gordon and Schrödinger equations for arbitrary l-state with the modified Morse potential in the symmetries of noncommutative quantum mechanics","authors":"A. Maireche","doi":"10.30970/JPS.25.1002","DOIUrl":"https://doi.org/10.30970/JPS.25.1002","url":null,"abstract":"In this work, approximate analytical solutions of both modi(cid:28)ed Klein(cid:21)Gordon equation and Schr(cid:4)odinger equation in noncommutative relativistic and nonrelativistic three-dimensional real space have been explored by using the Pekeris approximation scheme to deal with the centrifugal term, Bopp’s shift method and standard perturbation theory. We present the bound-state energy equation with a newly proposed potential called the modi(cid:28)ed Morse potential under the condition of equal scalar and vector potentials. The potential is a superposition of the Morse potential and some exponential radial terms. The aim of combining these potentials is to have an extensive application. We show that the new energy depends on the global parameters ( Θ c and σ c ) characterizing the noncommutativity space-space and the potential parameter ( D e , r e , α ) in addition to the Gamma function and the discreet atomic quantum numbers ( j, l, s, m ) . The present results are applied in calculating both the energy spectrum for a few heterogeneous (LiH, HCl, NO) and homogeneous (H 2 , I 2 , O 2 ) diatomic molecules. We have also discussed some special cases of physical importance.","PeriodicalId":43482,"journal":{"name":"Journal of Physical Studies","volume":"4 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78861281","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 22

Particle in a uniform field in a noncommutative space with preserved time reversal and rotational symmetries 非交换空间中具有时间反转和旋转对称性的均匀场中的粒子

IF 0.5

Journal of Physical Studies Pub Date : 2021-02-19 DOI: 10.30970/JPS.25.2002

Kh. P. Gnatenko, Kh. I. Stakhur, A. V. Kryzhova

引用次数: 0

Nonlinear wave dynamics of a disperse granular layer stimulated by an inwards moving piston 由向内运动活塞刺激的分散颗粒层的非线性波动动力学

IF 0.5

Journal of Physical Studies Pub Date : 2021-02-16 DOI: 10.30970/JPS.25.1401

S. Mykulyak, S. Skurativskyi

引用次数: 1

Increasing the efficiency of modeling the energy characteristics of nanoclusters 提高纳米团簇能量特性建模的效率

IF 0.5

Journal of Physical Studies Pub Date : 2021-02-05 DOI: 10.30970/JPS.25.1001

O. Vasylenko, V. Reva, V. Pogosov

{"title":"Increasing the efficiency of modeling the energy characteristics of nanoclusters","authors":"O. Vasylenko, V. Reva, V. Pogosov","doi":"10.30970/JPS.25.1001","DOIUrl":"https://doi.org/10.30970/JPS.25.1001","url":null,"abstract":"Context. The paper presents a computational scheme and a number of techniques for increasing the e(cid:30)ciency of mathematical modeling of the energy characteristics of metal clusters with vacancies. The object of the research is the process of calculating wave functions and (cid:28)nding eigenvalues using the Numerov and the shooting methods. local density approximation for calculating the energy characteristics of nanoclusters. At the simulation stage, the one-electron wave function was calculated by (cid:16)stitching(cid:17) it from two parts at an empirically selected point with normalization before and after the procedure. A number of techniques have been developed to improve the quality of the simulation: calculating the optimal step, limiting changes in the electrostatic pro(cid:28)le, managing the resulting data arrays, etc. For calculations on a supercomputer, the distribution between the (cid:29)ows was carried out. Results. At the modeling stage, economic models of the metal sphere with a vacancy in the center were developed. For the simulation stage, a method of stable two-sided calculation of the wave function using the shooting and the Numerov methods with the optimal step has been developed. The full computational scheme for the simulation is implemented in C ++ for calculation on a PC and on a supercomputer. The simulation results were compared with the ab-initio calculation data and experimental data for Cs, Rb, K, Na, Li, Mg, and Al clusters with and without vacancies (calculation error < 15%). Conclusions. The developed computational scheme and modeling technique allow increasing the simulation e(cid:30)ciency and obtaining adequate energy characteristics of metal spherical nanoclusters with and without vacancies. Further research might focus on the modi(cid:28)cation of models and simulation techniques for the study of layered nanoscale systems.","PeriodicalId":43482,"journal":{"name":"Journal of Physical Studies","volume":"27 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83193274","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Approximate evaluation of the duration of the orbital motion of artificial Earth satellites taking into account light pressure 考虑光压力的人造地球卫星轨道运动持续时间的近似计算

IF 0.5

Journal of Physical Studies Pub Date : 2021-01-29 DOI: 10.30970/JPS.25.1901

M. M. Koval'chuk, Y. Vovchyk, O. Baran, A. Bilinsky, I. P. Laushnyk, M. Stodilka, M. Hirnyak

{"title":"Approximate evaluation of the duration of the orbital motion of artificial Earth satellites taking into account light pressure","authors":"M. M. Koval'chuk, Y. Vovchyk, O. Baran, A. Bilinsky, I. P. Laushnyk, M. Stodilka, M. Hirnyak","doi":"10.30970/JPS.25.1901","DOIUrl":"https://doi.org/10.30970/JPS.25.1901","url":null,"abstract":"A comprehensive research was conducted to establish the in(cid:29)uence of solar pressure on the existence of arti(cid:28)cial Earth satellites in their orbit. Six low-orbit satellites and one satellite with a high-elliptical orbit moving in orbit during 2001(cid:21)2020 were selected for the study. We used the USSTRATCOM database of the satellites’ orbital elements (http://www.space-track.org/), additional data were taken from CalSky (https://www.calsky.com) and TLEtools (https://tletools.readthedocs.io). Taking into account light pressure, we re(cid:28)ned the calculation of the duration of a satellite’s orbital motion, which we had performed earlier [M. M. Koval’chuk, Bull. Natl. Univ. Kyiv. Astron. 55, 39 (2017)], and clari(cid:28)ed the moment of its destruction. Using the proposed method allowed us to reduce the di(cid:27)erence between the calculated and the real lifetime of satellites: for low-orbit satellites, the di(cid:27)erence between the calculated and the real time of their existence in orbit does not exceed ± 1 day, for a satellite with a highly elliptical orbit it is +2 days. Such accuracy is su(cid:30)cient to produce proper forecasts. Thus, consideration of light pressure gives a small correction in the calculations in the case of low-orbit satellites, but this correction can be signi(cid:28)cant for low-mass and large-surface objects moving in medium and high (geostationary) orbits [Ch. Lucking, C. Colombo, C. R. McInnes, Acta Astronaut. 77, 197 (2012)].Keywords:","PeriodicalId":43482,"journal":{"name":"Journal of Physical Studies","volume":"20 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89306086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Groups of meteorites and meteorite-dropping fireballs in asteroidal orbits 成群的陨石和陨石坠落的火球在小行星轨道上

IF 0.5

Journal of Physical Studies Pub Date : 2021-01-01 DOI: 10.30970/jps.25.4902

Y. Gorbanev, N. Konovalova, N. K. Davruqov

引用次数: 1

Optical soliton perturbation and polarization with quadratic--cubic nonlinearity by sine-Gordon equation approach 二次-三次非线性光孤子摄动与偏振

IF 0.5

Journal of Physical Studies Pub Date : 2021-01-01 DOI: 10.30970/JPS.25.2001

Y. Yıldırım, E. Topkara, A. Biswas, H. Triki, M. Ekici, P. Guggilla, S. Khan, M. Belić

{"title":"Optical soliton perturbation and polarization with quadratic--cubic nonlinearity by sine-Gordon equation approach","authors":"Y. Yıldırım, E. Topkara, A. Biswas, H. Triki, M. Ekici, P. Guggilla, S. Khan, M. Belić","doi":"10.30970/JPS.25.2001","DOIUrl":"https://doi.org/10.30970/JPS.25.2001","url":null,"abstract":"This paper recovers a full spectrum of optical solitons that are generated by the combined e(cid:27)ects of dispersion and nonlinearity of the pulse propagation. The quadratic(cid:21)cubic form of the nonlinear refractive index is incorporated in the governing nonlinear Schr(cid:4)odinger equation, which governs the dynamics of the soliton transmission across trans-continental and transoceanic distances. The model is considered with a nonlinear chromatic dispersion that is required to sustain for smooth transmission of soliton pulses in optical (cid:28)bers, couplers, PCF, magneto-optic waveguides, crystals, metamaterials, metasurfaces, birefringent (cid:28)bers, DWDM systems and other form of waveguides. Solitons in birefringent (cid:28)bers as well as solitons in polarization preserving (cid:28)bers are considered. The governing model is treated with Hamiltonian type perturbation terms. The perturbation terms are with full intensity. The model is studied for the intensity count m = 1 . The adopted integration algorithm is the sine-Gordon equation method that reveals single form soliton solutions as well as dual-form soliton solutions. These solitons are dark soliton, singular soliton, bright soliton and combo singular soliton. Also, dark soliton represents a kink/anti-kink solitary wave or a shock wave in (cid:29)uid dynamics. The respective constraint conditions are also in place to guarantee the existence of such solitons.","PeriodicalId":43482,"journal":{"name":"Journal of Physical Studies","volume":"282 1","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77842307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1