arXiv - PHYS - Space Physics最新文献_第3页

Analyzing the Sequence of Phases Leading to the Formation of the Active Region 13664, with Potential Carrington-like Characteristics 分析导致活动区 13664 形成的阶段序列，以及潜在的卡林顿式特征

arXiv - PHYS - Space Physics Pub Date : 2024-09-06 DOI: arxiv-2409.04408

Paolo Romano, Abouazza Elmhamdi, Alessandro Marassi, Lidia Contarino

{"title":"Analyzing the Sequence of Phases Leading to the Formation of the Active Region 13664, with Potential Carrington-like Characteristics","authors":"Paolo Romano, Abouazza Elmhamdi, Alessandro Marassi, Lidia Contarino","doi":"arxiv-2409.04408","DOIUrl":"https://doi.org/arxiv-2409.04408","url":null,"abstract":"Several recurrent X-class flares from Active Region (AR) 13664 have triggered\u0000a severe G5-class geomagnetic storm between May 10 and 11, 2024. The morphology\u0000and compactness of this AR closely resemble the active region responsible for\u0000the famous Carrington Event of 1859. Although the induced geomagnetic currents\u0000produced a value of the Dst index, probably, an order of magnitude weaker than\u0000that of the Carrington Event, the characteristics of AR 13664 warrant special\u0000attention. Understanding the mechanisms of magnetic field emergence and\u0000transformation in the solar atmosphere that lead to the formation of such an\u0000extensive, compact and complex AR is crucial. Our analysis of the emerging flux\u0000and horizontal motions of the magnetic structures observed in the photosphere\u0000reveals the fundamental role of a sequence of emerging bipoles at the same\u0000latitude and longitude, followed by converging and shear motions. This temporal\u0000order of processes frequently invoked in magnetohydrodynamic models -\u0000emergence, converging motions, and shear motions - is critical for the storage\u0000of magnetic energy preceding strong solar eruptions that, under the right\u0000timing, location and direction conditions, can trigger severe space weather\u0000events at Earth.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":"48 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178399","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

Statistical Characteristics of the Proton Isotropy Boundary 质子各向同性边界的统计特征

arXiv - PHYS - Space Physics Pub Date : 2024-09-06 DOI: arxiv-2409.04488

Colin Wilkins, Vassilis Angelopoulos, Anton Artemyev, Andrei Runov, Xiao-Jia Zhang, Jiang Liu, Ethan Tsai

{"title":"Statistical Characteristics of the Proton Isotropy Boundary","authors":"Colin Wilkins, Vassilis Angelopoulos, Anton Artemyev, Andrei Runov, Xiao-Jia Zhang, Jiang Liu, Ethan Tsai","doi":"arxiv-2409.04488","DOIUrl":"https://doi.org/arxiv-2409.04488","url":null,"abstract":"Using particle data from the ELFIN satellites, we present a statistical study\u0000of 284 proton isotropy boundary events on the nightside magnetosphere,\u0000characterizing their occurrence and distribution in local time, latitude\u0000(L-shell), energy, and precipitating energy flux, as a function of geomagnetic\u0000activity. For a given charged particle species and energy, its isotropy\u0000boundary (IB) is the magnetic latitude poleward of which persistently isotropic\u0000pitch-angle distributions ($J_{prec}/J_{perp}sim 1$) are first observed to\u0000occur. This isotropization is interpreted as resulting from magnetic field-line\u0000curvature (FLC) scattering in the equatorial magnetosphere. We find that proton\u0000IBs are observed under all observed activity levels, spanning 16 to 05 MLT with\u0000$sim$100% occurrence between 19 and 03 MLT, trending toward 60% at dawn/dusk.\u0000These results are also compared with electron IB properties observed using\u0000ELFIN, where we find similar trends across local time and activity, with the\u0000onset in $geq$50 keV proton IB occurring on average 2 L-shells lower, and\u0000providing between 3 and 10 times as much precipitating power. Proton IBs\u0000typically span $64^circ$-$66^circ$ in magnetic latitude (5-6 in L-shell),\u0000corresponding to the outer edge of the ring current, tending toward lower IGRF\u0000latitudes as geomagnetic activity increases. The IBs were found to commonly\u0000occur 0.3-2.1 Re beyond the plasmapause. Proton IBs typically span $<$50 keV to\u0000$sim$1 MeV in energy, maximizing near 22 MLT, and decreasing to a typical\u0000upper limit of 300-400 keV toward dawn and dusk, with peak observed isotropic\u0000energy increasing by $sim$500 keV during active intervals. These results\u0000suggest that FLC in the vicinity of IBs can provide a substantial depletion\u0000mechanism for energetic protons, with the total nightside precipitating power\u0000from FLC-scattering found to be on the order of 100 MW, at times $geq$10 GW.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223598","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

Cosmic ray north-south anisotropy: rigidity spectrum and solar cycle variations observed by ground-based muon detectors 宇宙射线南北各向异性：地面μ介子探测器观测到的刚度谱和太阳周期变化

arXiv - PHYS - Space Physics Pub Date : 2024-09-05 DOI: arxiv-2409.03182

M. Kozai, Y. Hayashi, K. Fujii, K. Munakata, C. Kato, N. Miyashita, A. Kadokura, R. Kataoka, S. Miyake, M. L. Duldig, J. E. Humble, K. Iwai

{"title":"Cosmic ray north-south anisotropy: rigidity spectrum and solar cycle variations observed by ground-based muon detectors","authors":"M. Kozai, Y. Hayashi, K. Fujii, K. Munakata, C. Kato, N. Miyashita, A. Kadokura, R. Kataoka, S. Miyake, M. L. Duldig, J. E. Humble, K. Iwai","doi":"arxiv-2409.03182","DOIUrl":"https://doi.org/arxiv-2409.03182","url":null,"abstract":"The north-south (NS) anisotropy of galactic cosmic rays (GCRs) is dominated\u0000by a diamagnetic drift flow of GCRs in the interplanetary magnetic field (IMF),\u0000allowing us to derive key parameters of cosmic-ray propagation, such as the\u0000density gradient and diffusion coefficient. We propose a new method to analyze\u0000the rigidity spectrum of GCR anisotropy and reveal a solar cycle variation of\u0000the NS anisotropy's spectrum using ground-based muon detectors in Nagoya,\u0000Japan, and Hobart, Australia. The physics-based correction method for the\u0000atmospheric temperature effect on muons is used to combine the different-site\u0000detectors free from local atmospheric effects. NS channel pairs in the\u0000multi-directional muon detectors are formed to enhance sensitivity to the NS\u0000anisotropy, and in this process, general graph matching in graph theory is\u0000introduced to survey optimized pairs. Moreover, Bayesian estimation with the\u0000Gaussian process allows us to unfold the rigidity spectrum without supposing\u0000any analytical function for the spectral shape. Thanks to these novel\u0000approaches, it has been discovered that the rigidity spectrum of the NS\u0000anisotropy is dynamically varying with solar activity every year. It is\u0000attributed to a rigidity-dependent variation of the radial density gradient of\u0000GCRs based on the nature of the diamagnetic drift in the IMF. The diffusion\u0000coefficient and mean-free-path length of GCRs as functions of the rigidity are\u0000also derived from the diffusion-convection flow balance. This analysis expands\u0000the estimation limit of the mean-free-path length into $le200$ GV rigidity\u0000region from $<10$ GV region achieved by solar energetic particle observations.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178406","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

Exploring the magnetic and thermal evolution of a coronal jet 探索日冕喷流的磁和热演变

arXiv - PHYS - Space Physics Pub Date : 2024-09-05 DOI: arxiv-2409.03484

Sushree S Nayak, Samrat Sen, Arpit Kumar Shrivastav, R. Bhattacharyya, P. S. Athiray

{"title":"Exploring the magnetic and thermal evolution of a coronal jet","authors":"Sushree S Nayak, Samrat Sen, Arpit Kumar Shrivastav, R. Bhattacharyya, P. S. Athiray","doi":"arxiv-2409.03484","DOIUrl":"https://doi.org/arxiv-2409.03484","url":null,"abstract":"Coronal jets are the captivating eruptions which are often found in the solar\u0000atmosphere, and primarily formed due to magnetic reconnection. Despite their\u0000short-lived nature and lower energy compared to many other eruptive events,\u0000e.g. flares and coronal mass ejections, they play an important role in heating\u0000the corona and accelerating charged particles. However, their generation in the\u0000ambience of non-standard flare regime is not fully understood, and warrant a\u0000deeper investigation, in terms of their onset, growth, eruption processes, and\u0000thermodynamic evolution. Toward this goal, this paper reports the results of a\u0000data-constrained three-dimensional (3D) magnetohydrodynamics (MHD) simulation\u0000of an eruptive jet; initialized with a Non-Force-Free-Field (NFFF)\u0000extrapolation and carried out in the spirit of Implicit Large Eddy Simulation\u0000(ILES). The simulation focuses on the magnetic and dynamical properties of the\u0000jet during its onset, and eruption phases, that occurred on February 5, 2015 in\u0000an active region NOAA AR12280, associated with a seemingly three-ribbon\u0000structure. In order to correlate its thermal evolution with computed\u0000energetics, the simulation results are compared with differential emission\u0000measurement (DEM) analysis in the vicinity of the jet. Importantly, this\u0000combined approach provides an insight to the onset of reconnection in\u0000transients in terms of emission and the corresponding electric current profiles\u0000from MHD evolutions. The presented study captures the intricate topological\u0000dynamics, finds a close correspondence between the magnetic and thermal\u0000evolution in and around the jet location. Overall, it enriches the\u0000understanding of the thermal evolution due to MHD processes, which is one of\u0000the broader aspects to reveal the coronal heating problem.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223414","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

Mixed Source Region Signatures Inside Magnetic Switchback Patches Inferred by Heavy Ion Diagnostics 重离子诊断法推断出的磁回转斑块内部的混合源区特征

arXiv - PHYS - Space Physics Pub Date : 2024-09-05 DOI: arxiv-2409.03645

Yeimy J. Rivera, Samuel T. Badman, Michael L. Stevens, Jim M. Raines, Christopher J. Owen, Kristoff Paulson, Tatiana Niembro, Stefano A. Livi, Susan T. Lepri, Enrico Landi, Jasper S. Halekas, Tamar Ervin, Ryan M. Dewey, Jesse T. Coburn, Stuart D. Bale, B. L. Alterman

{"title":"Mixed Source Region Signatures Inside Magnetic Switchback Patches Inferred by Heavy Ion Diagnostics","authors":"Yeimy J. Rivera, Samuel T. Badman, Michael L. Stevens, Jim M. Raines, Christopher J. Owen, Kristoff Paulson, Tatiana Niembro, Stefano A. Livi, Susan T. Lepri, Enrico Landi, Jasper S. Halekas, Tamar Ervin, Ryan M. Dewey, Jesse T. Coburn, Stuart D. Bale, B. L. Alterman","doi":"arxiv-2409.03645","DOIUrl":"https://doi.org/arxiv-2409.03645","url":null,"abstract":"Since Parker Solar Probe's (Parker's) first perihelion pass at the Sun, large\u0000amplitude Alfv'en waves grouped in patches have been observed near the Sun\u0000throughout the mission. Several formation processes for these magnetic\u0000switchback patches have been suggested with no definitive consensus. To provide\u0000insight to their formation, we examine the heavy ion properties of several\u0000adjacent magnetic switchback patches around Parker's 11th perihelion pass\u0000capitalizing on a spacecraft lineup with Solar Orbiter where each samples the\u0000same solar wind streams over a large range of longitudes. Heavy ion properties\u0000(Fe/O, C$^{6+}$/C$^{5+}$, O$^{7+}$/O$^{6+}$) related to the wind's coronal\u0000origin, measured with Solar Orbiter can be linked to switchback patch\u0000structures identified near the Sun with Parker. We find that switchback patches\u0000do not contain distinctive ion and elemental compositional signatures different\u0000than the surrounding non-switchback solar wind. Both the patches and ambient\u0000wind exhibit a range of fast and slow wind qualities, indicating coronal\u0000sources with open and closed field lines in close proximity. These observations\u0000and modeling indicate switchback patches form in coronal hole boundary wind and\u0000with a range of source region magnetic and thermal properties. Furthermore, the\u0000heavy ion signatures suggest interchange reconnection and/or shear driven\u0000processes may play a role in their creation.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223599","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

Latitudinal dependence of variations in the frequencies of solar oscillations above the acoustic cut-off 声学截止频率以上太阳振荡频率变化的纬度依赖性

arXiv - PHYS - Space Physics Pub Date : 2024-09-05 DOI: arxiv-2409.03574

Laura Jade Millson, Anne-Marie Broomhall, Tishtrya Mehta

{"title":"Latitudinal dependence of variations in the frequencies of solar oscillations above the acoustic cut-off","authors":"Laura Jade Millson, Anne-Marie Broomhall, Tishtrya Mehta","doi":"arxiv-2409.03574","DOIUrl":"https://doi.org/arxiv-2409.03574","url":null,"abstract":"At high frequencies beyond the acoustic cut-off, a peak-like structure is\u0000visible in the solar power spectrum. Known as the pseudo-modes, their\u0000frequencies have been shown to vary in anti-phase with solar magnetic activity.\u0000In this work, we determined temporal variations in these frequencies across the\u0000solar disc, with the aim of identifying any potential latitudinal dependence of\u0000pseudo-mode frequency shifts. We utilised nearly 22 years of spatially resolved\u0000GONG data for all azimuthal orders, $textit{m}$, for harmonic degrees 0 $leq$\u0000$textit{l}$ $leq$ 200, and determined shifts using the resampled periodogram\u0000method. Periodogram realisations were created from overlapping, successive\u0000216d-long segments in time, and cropped to 5600-6800$mu$Hz. Cross-correlation\u0000functions were then repeatedly generated between these realisations to identify\u0000any variation in frequency and the uncertainty. We categorised each mode by its\u0000latitudinal sensitivity and used this categorisation to produce average\u0000frequency shifts for different latitude bands (15$^circ$ and 5$^circ$ in\u0000size) which were compared to magnetic proxies, the $F_{mathrm{10.7}}$ index\u0000and GONG synoptic maps. Morphological differences in the pseudo-mode shifts\u0000between different latitudes were found, which were most pronounced during the\u0000rise to solar maximum where shifts reach their minimum values. At all\u0000latitudes, shift behaviour was strongly in anti-correlation with the activity\u0000proxy. Additionally, periodicities shorter than the 11-year cycle were\u0000observed. Wavelet analysis was used to identify a periodicity of four years at\u0000all latitudes.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178403","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

Electron shock drift acceleration at a low-Mach-number, low-plasma-beta quasi-perpendicular shock 低马赫数、低等离子体β准垂直冲击下的电子冲击漂移加速度

arXiv - PHYS - Space Physics Pub Date : 2024-09-05 DOI: arxiv-2409.03174

Ao Guo, Quanming Lu, San Lu, Zhongwei Yang, Xinliang Gao

引用次数: 0

Emergence of two inertial sub-ranges in solar wind turbulence: dependence on heliospheric distance and solar activity 太阳风湍流中两个惯性子范围的出现：与日光层距离和太阳活动有关

arXiv - PHYS - Space Physics Pub Date : 2024-09-04 DOI: arxiv-2409.03090

Shiladittya Mondal, Supratik Banerjee, Luca Sorriso-Valvo

{"title":"Emergence of two inertial sub-ranges in solar wind turbulence: dependence on heliospheric distance and solar activity","authors":"Shiladittya Mondal, Supratik Banerjee, Luca Sorriso-Valvo","doi":"arxiv-2409.03090","DOIUrl":"https://doi.org/arxiv-2409.03090","url":null,"abstract":"The solar wind is highly turbulent, and intermittency effects are observed\u0000for fluctuations within the inertial range. By analyzing magnetic field spectra\u0000and fourth-order moments, we perform a comparative study of intermittency in\u0000different types of solar wind measured during periods of solar minima and a\u0000maximum. Using eight fast solar wind intervals measured during solar minima\u0000between 0.3 au and 3.16 au, we found a clear signature of two inertial\u0000sub-ranges with $f^{-3/2}$ and $f^{-5/3}$ power laws in the magnetic power\u0000spectra. The intermittency, measured through the scaling law of the kurtosis of\u0000magnetic field fluctuations, further confirms the existence of two different\u0000power laws separated by a clear break. A systematic study on the evolution of\u0000the said sub-ranges as a function of heliospheric distance shows correlation of\u0000the break scale with both the turbulence outer scale and the typical ion\u0000scales. During solar maximum, we analyzed five intervals for each of Alfv'enic\u0000fast, Alfv'enic slow and non-Alfv'enic slow solar wind. Unlike the case\u0000during the solar minima, the two sub-ranges are no longer prominent and the\u0000Alfv'enic slow wind is found to be in an intermediate state of turbulence\u0000compared to that of the fast wind and the usual non-Alfv'enic slow wind.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178400","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

Toward Realistic Solar Flare Models: An explicit Particle-In-Cell solver in the DISPATCH framework 实现逼真的太阳耀斑模型：DISPATCH 框架中的显式粒子单元求解器

arXiv - PHYS - Space Physics Pub Date : 2024-09-04 DOI: arxiv-2409.02493

Michael Haahr, Boris V. Gudiksen, Åke Nordlund

{"title":"Toward Realistic Solar Flare Models: An explicit Particle-In-Cell solver in the DISPATCH framework","authors":"Michael Haahr, Boris V. Gudiksen, Åke Nordlund","doi":"arxiv-2409.02493","DOIUrl":"https://doi.org/arxiv-2409.02493","url":null,"abstract":"Context. Simulating solar flares, which involve large-scale dynamics and\u0000small-scale magnetic reconnection, poses significant computational challenges.\u0000Aims. This study aims to develop an explicit Particle-In-Cell (PIC) solver\u0000within the DISPATCH framework to model the small-scale kinetic processes in\u0000solar corona setting. This study in the first in a series with the ultimate\u0000goal to develop a hybrid PIC-MHD solver, to simulate solar flares. Methods. The\u0000PIC solver, inspired by the PhotonPlasma code, solves the Vlasov-Maxwell\u0000equations in a collisionless regime using explicit time-staggering and\u0000spatial-staggering techniques. Validation included unit tests, plasma frequency\u0000recovery, two-stream instability, and current sheet dynamics. Results.\u0000Validation tests confirmed the solver's accuracy and robustness in modeling\u0000plasma dynamics and electromagnetic fields. Conclusions. The integration of the\u0000explicit PIC solver into the DISPATCH framework is the first step towards\u0000bridging the gap between large and small scale dynamics, providing a robust\u0000platform for future solar physics research.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178413","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

Observed Fluctuation Enhancement and Departure from WKB Theory in Sub-Alfvénic Solar Wind 亚阿尔费尼太阳风中观测到的波动增强和与 WKB 理论的偏离

arXiv - PHYS - Space Physics Pub Date : 2024-09-04 DOI: arxiv-2409.02612

David Ruffolo, Panisara Thepthong, Peera Pongkitiwanichakul, Sohom Roy, Francesco Pecora, Riddhi Bandyopadhyay, Rohit Chhiber, Arcadi V. Usmanov, Michael Stevens, Samuel Badman, Orlando Romeo, Jiaming Wang, Joshua Goodwill, Melvyn L. Goldstein, William H. Matthaeus

引用次数: 0