Kinematics and Physics of Celestial Bodies最新文献

{"title":"Impact of a Disc and Drag Forces on the Existence Linear Stability of Equilibrium Points and Newton-Raphson Basins of Attraction","authors":"S. Yousuf, R. Kishor","doi":"10.15407/kfnt2022.03.076","DOIUrl":"https://doi.org/10.15407/kfnt2022.03.076","url":null,"abstract":"Abstract This paper presents a study of zero velocity curves, linear stability analysis and basins of attraction corresponding to the equilibrium points in the Sun-Jupiter system with asteroid belt and β-Pictoris system with dust belt, respectively under the influence of perturbing factors in the form of Poynting-Robertson drag (P-R drag), solar wind drag and a disc, which is rotating about the common center of mass of the system. Zero velocity curves are obtained and it is observed that in the presence of perturbing factors, the prohibited regions of the motion of infinitesimal mass get disturbed. Again, linear stability and effects of perturbing factors are analyzed for the triangular equilibrium points. It is noticed that because of P-R drag, triangular equilibrium points become unstable within the stability range. Finally, the Newton-Raphson basins of attraction corresponding to the equilibrium points are computed and it is found that in the presence of the disc, geometry of the basins of attraction gets change, whereas the effects of remaining perturbing factors on the structure of basins of attraction are very small.","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"38 1","pages":"166-180"},"PeriodicalIF":0.5,"publicationDate":"2022-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48045412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Kamchatka Meteoroid Effects in the Geomagnetic Field","authors":"L. F. Chernogor","doi":"10.3103/S0884591322010032","DOIUrl":"10.3103/S0884591322010032","url":null,"abstract":"<p>The data acquired at ten geomagnetic observatories (Paratunka, Magadan, Yakutsk, and Khabarovsk (the Russian Federation); Memambetsu, Kanoya, and Kakioka (Japan); Cheongyang (Republic of Korea); Shumagin and College (USA)) during the Kamchatka meteoroid event of December 18, 2018, and on the reference days of December 17 and 19, 2018, have been used to analyze temporal variations in the geomagnetic field components. The distance <i>r</i> from the observatories to the site of explosive energy release by the meteoroid varied from 1.001 to 4.247 Mm. The passage of the Kamchatka meteoroid through the magnetosphere and atmosphere was accompanied by variations mainly in the <i>H</i> geomagnetic field component. The magnetic effect from the magnetosphere was observed to occur twice, 51 and 28 min prior to the meteoroid explosion; the amplitude of the disturbances in the geomagnetic field did not exceed 0.2–1 nT, and the durations were observed to be approximately 20 and 10 min, respectively. Alternating peaks in the level of the <i>H</i> component were observed to lag behind the meteoroid explosion by 8 to 13 min for <i>r</i> from 1.001 to 4.247 Mm. The amplitude of the oscillations varied with increasing <i>r</i> from ~0.5 to ~0.1 nT, while the duration of the magnetic effect from the ionosphere varied in the 16–25-min range for all distances. The apparent speed of propagation in this group of disturbances that were of MHD nature was observed to be approximately 10 km/s. In the second group of disturbances, the time lag increased with increasing distance within the distance range mentioned above from 56 to 218 min. The duration of the disturbance was approximately 16–65 min, the apparent speed was 336 m/s, and the period was 5–10 min. This disturbance in the magnetic field was caused by an atmospheric gravity wave propagating from the meteoroid explosion. The theoretical models for the magnetic effects observed are presented and theoretical estimates are performed. The observations are in agreement with the estimates.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"38 1","pages":"25 - 48"},"PeriodicalIF":0.5,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5538745","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Results of Observations of Wave Motions in the Solar Facula","authors":"N. G. Shchukina,&nbsp;R. I. Kostik","doi":"10.3103/S0884591322010056","DOIUrl":"10.3103/S0884591322010056","url":null,"abstract":"<p>The results of spectropolarimetric and filter observations of the facular region in the lines Fe I 1564.3, Fe I 1565.8 nm, Ba II 455.4 nm, and Ca II H 396.8 nm obtained near the center of the solar disk at the German Vacuum Tower Telescope (Tenerife, Spain) are discussed. It is shown that the facular contrast at the center of the Ca II H line increases more slowly as the magnetic field strength increases and, then it begins to decrease if the field increases further. It is concluded that the reason for such behavior is the nonlinear height dependence of the line source function due to the deviation from the local thermodynamic equilibrium. It is found that waves propagating both upward and downward can be observed in any area of the facula, regardless of its brightness. In bright areas with a strong magnetic field, upward waves predominate, while downward waves are more often observed in less bright areas with a weak field. It is shown that the facular contrast measured at the center of the Ca II H line correlates with the power of wave velocity oscillations. In bright areas, it increases with the power regardless of the direction in which the waves propagate. In facular regions with decreased brightness, the opposite dependence is observed for both types of waves. In turn, the power of wave velocity oscillations is sensitive to the field strength magnitude. In the magnetic elements of the facula with increased brightness, the stronger the field, the higher the power of oscillations of both upward and downward waves. In areas with decreased brightness, the inverse dependence is observed. It is concluded that the contrast increase with the increase in the power of wave velocity oscillations observed in bright areas of the facula can be considered as evidence that these areas look bright not only because of the Wilson depression but also because of the heating of the solar plasma by the waves.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"38 1","pages":"49 - 60"},"PeriodicalIF":0.5,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5078709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geomagnetic Effect of the Solar Eclipse of June 10, 2021","authors":"L. F. Chernogor","doi":"10.3103/S0884591322010020","DOIUrl":"10.3103/S0884591322010020","url":null,"abstract":"<p>A solar eclipse (SE) pertains to rare high-energy natural phenomena. For instance, a change in the internal (thermal) energy of the air in a layer only 100 m in height attains 10¹⁸ J while the power of the process is on the order of terawatts. The energy of the processes produced by the SE in the upper atmosphere and geospace is significant. For instance, the thermal energy of the ionospheric plasma in a volume of ~10¹⁹ m³ decreases by 10¹¹ J. The magnetic field in a volume of ~10²¹ m³ decreases by 50 nT, and its energy by 10¹⁵ J. SEs are accompanied by disturbances in all subsystems of the Earth–atmosphere–ionosphere–magnetosphere system. Disturbances in the upper atmospheric and ionospheric parameters act to inevitably produce geomagnetic field variations. At present, geophysicists have no consensus on how SE manifests itself in the geomagnetic field. The available data are inconsistent. Most of the researchers believe that the geomagnetic effect of SE exists. In some cases, the temporal variations in the geomagnetic field, as a whole, repeat the changes in the illumination of the Earth’s surface; in other cases, they may be ahead or delayed by ~1 hour in relation to the changes in illumination. Most often, the geomagnetic effect is studied in the region of the total SE where it should be the most pronounced. The further the observatory is located from the umbra, the more difficult it is to relate the magnetic variations to the SE. Finding the response of the geomagnetic field to the SE is a complicated task. A possible response is “masked” by variations of another nature. Moreover, the magnitude and sign of the geomagnetic field disturbance significantly depend on the state of space weather, season, local time, location of the magnetic observatory, and, of course, the magnitude of the eclipse. Therefore, the study of the effect of SEs on the geomagnetic field remains an important task. The purpose of this study is to present the results of analysis of temporal variations in the geomagnetic field observed by the International Real-Time Magnetic Observatory Network (INTERMAGNET) during the SE of June 10, 2021. The main feature of this eclipse was that the SE was annular (maximum magnitude M_max ≈ 0.943). The annular SE occurred on June 10, 2021 with a commencement time 08:12:20 UT over Canada. The Moon’s shadow moved across the Atlantic Ocean, Greenland, the Arctic Ocean, the North Pole, and the northern parts of Europe and Asia. A partial SE occurred in Mongolia and China, and it ceased at 11:33:43 UT. The annularity was observed from 10:33:16 to 10:36:56 UT over Greenland. The analysis of the geomagnetic effect was based on the INTERMAGNET database. The data were processed with 1-min temporal resolution and 0.1-nT level resolution, and temporal variations in the <i>X</i>, <i>Y</i>, and <i>Z</i> components recorded at 15 magnetic observatories were studied","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"38 1","pages":"11 - 24"},"PeriodicalIF":0.5,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5538766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparison of Ground-Based and Satellite Geomagnetic Pulsations during Substorms","authors":"L. V. Kozak,&nbsp;B. A. Petrenko,&nbsp;E. E. Grigorenko,&nbsp;E. A. Kronberg","doi":"10.3103/S0884591322010044","DOIUrl":"10.3103/S0884591322010044","url":null,"abstract":"<p>Magnetic field pulsations in the magnetosphere and the time of their detection and location on the Earth’s surface are analyzed. Measurements of magnetic field fluctuations from fluxgate magnetometers of the Cluster II satellites and measurements from ground-based magnetometers in the auroral oval region are used. The substorms on August 13, 2019, are examined. In particular, two substorms and flapping motions of the magnetotail current sheet are analyzed. The measurements from ground-based observatories are selected using the 3DView software, a tool for the visualization of spacecraft position with associated geomagnetic tail field lines. A continuous wavelet transform is used to identify geomagnetic pulsations, and an integrated representation in two frequency bands, 45–150 s (Pc4/Pi2) and 150–600 s (Pc5/Pi3), is considered to determine the pulsation type and estimate the observed shifts between the pulsations recorded in the Earth’s magnetotail and in the auroral oval region. Correlated Pi2 and Pc5 pulsations in the auroral region and in the magnetotail are detected. The magnitude of detected pulsations depends on the relative position of ground-based magnetometers and the projection of the field line on which the spacecraft are located. Based on the time delay between the maxima of geomagnetic pulsations at the Earth’s surface in relation to disturbances in the magnetosphere, the velocity of disturbance propagation along the magnetic field line is estimated.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"38 1","pages":"1 - 10"},"PeriodicalIF":0.5,"publicationDate":"2022-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"5075962","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Convection Effect in the Surface Atmosphere of Solar Eclipses of March 20, 2015, and June 10, 2021","authors":"L. F. Chernogor","doi":"10.3103/S0884591321060039","DOIUrl":"10.3103/S0884591321060039","url":null,"abstract":"<p>The parameters of geophysical fields and numerous parameters of the Earth–atmosphere–ionosphere–magnetosphere system significantly change during a solar eclipse (SE). In particular, the planet surface temperature decreases, the convection and turbulent processes slow down, and the air temperature near the ground reduces. The inhomogeneous structure of the surface air layer notably changes, and the role of temperature fluctuations in this layer and, consequently, the role of fluctuations in the air refractive index shrink. The purposes of this work are to analyze the observations of solar limb quivering during the two last partial SE that took place near the city of Kharkiv on March 20, 2015, and June 10, 2021, and the estimates of the statistical parameters governing air convection. The SE effects in the surface air layer were observed with the optical AFR-2 chromospheric-photospheric telescope at the V.N. Karazin Kharkiv National University Astronomical Observatory 70 km to southeast of Kharkiv. The quivering of the solar limb was measured on the days of SEs (March 20, 2015, and June 10, 2021) and on the reference days in order to determine the basic parameters of the atmospheric convection. The variations in the convection parameters are qualitatively similar to variations in illumination of the Earth’s surface and in the air temperature in the surface air layer. In the summertime, all convection parameters are a factor of ~2 higher than in the springtime. The SE effect on atmospheric convection was considerably weaker on June 10, 2021, than on March 20, 2015, because of insignificant magnitude of the former SE (0.11 vs. 0.54) and the clouds which screened the solar disk, which appreciably suppressed atmospheric convection. The comparative study of convection during seven SEs in 1999–2021 has shown that the magnitude of the effect strongly depends on the season, local time, cloud thickness, the tropospheric weather, and the magnitude of a solar eclipse.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"37 6","pages":"284 - 292"},"PeriodicalIF":0.5,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4890251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Statistical Analysis of the Orbital Motion of Selected Artificial Earth Satellites during Solar Cycle 24","authors":"A. I. Bilinsky,&nbsp;O. A. Baran,&nbsp;M. I. Stodilka,&nbsp;Ye. B. Vovchyk,&nbsp;M. M. Koval’chuk","doi":"10.3103/S0884591321060027","DOIUrl":"10.3103/S0884591321060027","url":null,"abstract":"<p>A statistical analysis of selected parameters of solar activity and orbital motion of artificial Earth satellites (AES’s) during solar cycle 24 is carried out. Inactive satellites, launch vehicle (LV) stages, and their debris moving mainly in low orbits are studied. Different analysis algorithms are applied to the time series of the solar radio flux <i>F</i>_10.7 and the calculated deceleration rate <i>dP</i>/<i>dt</i> of the investigated space objects (SOs): their annual statistical indices are estimated, these parameters are studied for periodicity (wavelet analysis), and a test additive decomposition into trend and seasonal components is performed. It is found that the satellite deceleration rate in the vicinity of the solar maximum (2012–2014) increases by a factor of ten. For the solar radio flux <i>F</i>_10.7 and the kinematic parameter <i>dP</i>/<i>dt</i> of SOs 06073 and 31117, seasonal changes, cyclicity with a period of 27 days, etc. are confirmed. A clear anticorrelation between the trends of the corresponding parameters within –0.73…‒0.95 for SO 31117 during 2011–2018 and –0.82…–0.95 for SO 37794 during 2012–2018 is observed.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"37 6","pages":"310 - 325"},"PeriodicalIF":0.5,"publicationDate":"2021-12-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4890599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dynamic Falling of the Chelyabinsk Meteoroid: Sizes, Radiation, and Destruction","authors":"L. F. Chernogor,&nbsp;Yu. B. Mylovanov","doi":"10.3103/S0884591321050056","DOIUrl":"10.3103/S0884591321050056","url":null,"abstract":"<p>The purpose of this paper is to obtain refined altitude–time dependences of radiation intensity and mass of the Chelyabinsk meteoroid during the fall, determine the size of the bolide, and build a model of destruction with an estimate of the fragment distribution parameters by mass. The study into the impact of large celestial bodies on the environment is an urgent task for forecasting environmental consequences. The radiation intensity was calculated using the time dependence of the bolide’s brightness and E. Epic’s empirical formula. The Stefan–Boltzmann law and M. Planck’s formula were used for the radiation model of a perfect black body in a limited range of wavelengths. A method was found to determine the size of the bolide according to published observations from the video recorder. For the construction of the model of continuous fragmentation, an adapted equation of individual fragments' motion was used. Three types of mass distribution of fragments were tested: logarithmically normal, power-law, and uniform. As a result of the numerical simulation, the contribution of radiation energy was determined. It was shown that 21% of the kinetic energy of a meteoroid was spent on radiation. The variations in the mass, altitude–time dependences of the bolide size, and the parameters for different distributions of fragments by mass were calculated. The diameter of the bolide head reached 2 km, and the length of the tail was 3.5–4 km. It was found that the results of fragmentation are described at the initial stage of motion by the power-law distribution, while the distribution is lognormal in denser layers of the atmosphere. The characteristics of the swarm of stone fragments that may have followed the meteoroid were estimated. The length of the swarm reached 30 km, the maximum mass of the swarm was estimated at 400 t, and the radiation energy was 0.6% relative to the initial kinetic energy of the meteoroid.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"37 5","pages":"241 - 262"},"PeriodicalIF":0.5,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4553758","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Attenuation of Evanescent Acoustic-Gravitational Modes in the Earth’s Thermosphere","authors":"O. K. Cheremnykh,&nbsp;A. K. Fedorenko,&nbsp;E. I. Kryuchkov,&nbsp;D. I. Vlasov,&nbsp;I. T. Zhuk","doi":"10.3103/S0884591321050044","DOIUrl":"10.3103/S0884591321050044","url":null,"abstract":"<p>The attenuation of the acoustic-gravitational nondivergent <i>f</i><b><i>-</i></b>mode and inelastic γ<b><i>-</i></b>mode in the Earth’s upper atmosphere due to viscosity and thermal conductivity is studied. To analyze the attenuation, a system of hydrodynamic equations is used, including the modified Navier–Stokes and heat transfer equations. These modified equations take into account the contribution of the background density gradient to the transfer of energy and momentum by waves. Dispersion equations are obtained for <i>f-</i> and γ<i>-</i>modes in an isothermal dissipative atmosphere. It is shown that viscosity and thermal conductivity have little effect on the frequency of these modes under typical conditions in the thermosphere. Expressions are obtained for the damping decrements of the <i>f-</i> and γ-modes. It was established that the decrement of the γ<i>-</i>mode attenuation is almost an order of magnitude higher in the Earth’s thermosphere than the corresponding decrement of the <i>f-</i>mode. It is also found that the attenuation of the <i>f-</i>mode does not depend on the thermal conductivity but is due only to the dynamic viscosity and increases with an increase in the relative contribution of the bulk viscosity. The dissipation of the γ<i>-</i>mode is caused by dynamic viscosity and thermal conductivity and does not depend on the bulk viscosity. The time variation of the perturbation amplitudes for the <i>f-</i> and γ<i>-</i>modes at different heights of the thermosphere is considered. The characteristic attenuation times of the <i>f-</i> and γ<i>-</i>modes at different heights depending on the wavelength, as well as at different levels of solar activity, are calculated. The boundary heights in the thermosphere above which the <i>f-</i>and γ<i>-</i>modes cannot exist due to dissipation are determined.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"37 5","pages":"221 - 229"},"PeriodicalIF":0.5,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4558285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Pole Coordinates and Length of Day from Laser Ranging of Low Earth Orbiters","authors":"V. Ya. Choliy","doi":"10.3103/S0884591321050068","DOIUrl":"10.3103/S0884591321050068","url":null,"abstract":"<p>This article is devoted to determining Earth’s Orientation Parameters (EOP) from reprocessing of the Laser ranging observations of the specially designed satellites. These are laser geodynamics satellites Lageos and Etalon and Low Earth Orbiters Lares, Ajisai, Starlette, and Stella. New software was created by the author and a new approach was proposed to analyze each model of geodynamics phenomena; a transformation or process was first tested separately and only then included into the package. The main attention was paid to the analysis of the possibility to use Laser Ranging data to Low Earth Orbiters for EOP determination. It was shown that, despite the much lower Lares’s orbit (height is 700 km) than the Lageos’s orbit (7000 km), the resulting EOP series from Lares data have the same precision in general. It was achieved by new software and a new author approach to the study of the models. Final EOP data sets were computed at the same time by a combination of raw EOPs from each satellite or from the combination of the conditional equations. In the latter case, the precision of the final solution is 10–15% better. It allows us to recommend Low Earth orbiters for geodynamics on a permanent basis.</p>","PeriodicalId":681,"journal":{"name":"Kinematics and Physics of Celestial Bodies","volume":"37 5","pages":"263 - 268"},"PeriodicalIF":0.5,"publicationDate":"2021-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"4557859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}