The Astrophysical Journal Letters最新文献

{"title":"exoALMA. I. Science Goals, Project Design, and Data Products","authors":"Richard Teague, Myriam Benisty, Stefano Facchini, Misato Fukagawa, Christophe Pinte, Sean M. Andrews, Jaehan Bae, Marcelo Barraza-Alfaro, Gianni Cataldi, Nicolás Cuello, Pietro Curone, Ian Czekala, Daniele Fasano, Mario Flock, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Iain Hammond, Thomas Hilder, Jane Huang, John D. Ilee, Andrés F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Giuseppe Lodato, Cristiano Longarini, Ryan A. Loomis, Frédéric Masset, Francois Menard, Ryuta Orihara, Daniel J. Price, Giovanni Rosotti, Jochen Stadler, Leonardo Testi, Hsi-Wei Yen, Gaylor Wafflard-Fernandez, David J. Wilner, Andrew J. Winter, Lisa Wölfer, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc43b","DOIUrl":"https://doi.org/10.3847/2041-8213/adc43b","url":null,"abstract":"Planet formation is a hugely dynamic process requiring the transport, concentration, and assimilation of gas and dust to form the first planetesimals and cores. With access to observations with extremely high spatial and spectral resolution at unprecedented sensitivities, it is now possible to probe the planet-forming environment in detail. To this end, the exoALMA Large Program targeted 15 large protoplanetary disks, ranging between ∼1″ and ∼7″ in radius, and mapped the gas and dust distributions. 12CO J = 3–2, 13CO J = 3–2, and CS J = 7–6 molecular emission was imaged at high angular ( ) and spectral (∼100 m s−1) resolution, achieving a surface brightness temperature sensitivity of ∼1.5 K over a single channel, while the 330 GHz continuum emission was imaged at 90 mas resolution and achieved a point source sensitivity of ∼40 μJy beam−1. These observations constitute some of the deepest observations of protoplanetary disks to date. Extensive substructure was found in all but one disk, traced by both dust continuum and molecular line emission. In addition, the molecular emission allowed for the velocity structure of the disks to be mapped with excellent precision (uncertainties of the order of 10 m s−1), revealing a variety of kinematic perturbations across all sources. From this sample it is clear that, when observed in detail, all disks appear to exhibit physical and dynamical substructure indicative of ongoing dynamical processing due to young, embedded planets, large-scale (magneto)hydrodynamical instabilities or winds.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884732","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}

{"title":"exoALMA. XVI. Predicting Signatures of Large-scale Turbulence in Protoplanetary Disks","authors":"Marcelo Barraza-Alfaro, Mario Flock, William Béthune, Richard Teague, Jaehan Bae, Myriam Benisty, Gianni Cataldi, Pietro Curone, Ian Czekala, Stefano Facchini, Daniele Fasano, Misato Fukagawa, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Jane Huang, John D. Ilee, Andrés F. Izquierdo, Kazuhiro Kanagawa, Eric W. Koch, Geoffroy Lesur, Cristiano Longarini, Ryan A. Loomis, Ryuta Orihara, Christophe Pinte, Daniel J. Price, Giovanni Rosotti, Jochen Stadler, Gaylor Wafflard-Fernandez, Andrew J. Winter, Lisa Wölfer, Hsi-Wei Yen, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc42d","DOIUrl":"https://doi.org/10.3847/2041-8213/adc42d","url":null,"abstract":"Turbulent gas motions drive planet formation and protoplanetary disk evolution. However, empirical constraints on turbulence are scarce, halting our understanding of its nature. Resolving signatures of the large-scale perturbations driven by disk instabilities may reveal clues on the origin of turbulence in the outer regions of planet-forming disks. We aim to predict the observational signatures of such large-scale flows, as they would appear in high-resolution Atacama Large Millimeter/submillimeter Array observations of CO rotational lines, such as those conducted by the exoALMA Large Program. Post-processing 3D numerical simulations, we explored the observational signatures produced by three candidate (magneto)hydrodynamical instabilities to operate in the outer regions of protoplanetary disks: the vertical shear instability (VSI), the magnetorotational instability (MRI), and the gravitational instability (GI). We found that exoALMA-quality observations should capture signatures of the large-scale motions induced by these instabilities. Mainly, flows with ring, arc, and spiral morphologies are apparent in the residuals of synthetic velocity centroid maps. A qualitative comparison between our predictions and the perturbations recovered from exoALMA data suggests the presence of two laminar disks and a scarcity of ring- and arc-like VSI signatures within the sample. Spiral features produced by the MRI or the GI are still plausible in explaining observed disk perturbations. Supporting these scenarios requires further methodically comparing the predicted perturbations and the observed disks’ complex dynamic structure.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884398","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}

{"title":"exoALMA. IV. Substructures, Asymmetries, and the Faint Outer Disk in Continuum Emission","authors":"Pietro Curone, Stefano Facchini, Sean M. Andrews, Leonardo Testi, Myriam Benisty, Ian Czekala, Jane Huang, John D. Ilee, Andrea Isella, Giuseppe Lodato, Ryan A. Loomis, Jochen Stadler, Andrew J. Winter, Jaehan Bae, Marcelo Barraza-Alfaro, Gianni Cataldi, Nicolás Cuello, Daniele Fasano, Mario Flock, Misato Fukagawa, Maria Galloway-Sprietsma, Himanshi Garg, Cassandra Hall, Andrés F. Izquierdo, Kazuhiro Kanagawa, Geoffroy Lesur, Cristiano Longarini, Francois Menard, Ryuta Orihara, Christophe Pinte, Daniel J. Price, Giovanni Rosotti, Richard Teague, Gaylor Wafflard-Fernandez, David J. Wilner, Lisa Wölfer, Hsi-Wei Yen, Tomohiro C. Yoshida and Brianna Zawadzki","doi":"10.3847/2041-8213/adc438","DOIUrl":"https://doi.org/10.3847/2041-8213/adc438","url":null,"abstract":"The exoALMA Large Program targeted a sample of 15 disks to study gas dynamics within these systems, and these observations simultaneously produced continuum data at 0.9 mm (331.6 GHz) with exceptional surface brightness sensitivity at high angular resolution. To provide a robust characterization of the observed substructures, we performed a visibility space analysis of the continuum emission from the exoALMA data, characterizing axisymmetric substructures and nonaxisymmetric residuals obtained by subtracting an axisymmetric model from the observed data. We defined a nonaxisymmetry index and found that the most asymmetric disks predominantly show an inner cavity and consistently present higher values of mass accretion rate and near-infrared excess. This suggests a connection between outer disk dust substructures and inner disk properties. The depth of the data allowed us to describe the azimuthally averaged continuum emission in the outer disk, revealing that larger disks (both in dust and gas) in our sample tend to be gradually tapered compared to the sharper outer edge of more compact sources. Additionally, the data quality revealed peculiar features in various sources, such as shadows, inner disk offsets, tentative external substructures, and a possible dust cavity wall.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884727","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}

{"title":"Biases from Missing a Small Planet in High Multiplicity Systems","authors":"C. Alexander Thomas, Lauren M. Weiss and Matthias Y. He","doi":"10.3847/2041-8213/adcba1","DOIUrl":"https://doi.org/10.3847/2041-8213/adcba1","url":null,"abstract":"In an era when we are charting multiple planets per system, one might wonder the extent to which “missing” (or failing to detect) a planet can skew our interpretation of the system architecture. We address this question with a simple experiment: starting from a large, homogeneous catalog, we remove planets and monitor how several well-defined metrics of the system architecture change. We first perform this test on a catalog of observed exoplanets. We then repeat our test on a catalog of synthetic planetary systems with underlying hyperparameters that have been fit to reproduce the observed systems as faithfully as possible (though imperfectly). For both samples, we find that the failure to detect one or more planets tends to create more irregularly spaced planets, whereas the planet mass similarity and coplanarity are essentially unaffected. One key difference between the synthetic and observed data sets is that the observed systems have more evenly spaced planets than the observation-bias-applied synthetic systems. Since our tests show that detection bias tends to increase irregularity in spacing, the even spacing in the observed planetary systems is likely astrophysical rather than the result of the Kepler missions’ inherent detection biases. Our findings support the interpretation that planets in the same system have similar sizes and regular spacing and reinforce the need to develop an underlying model of planetary architectures that reproduces these observed patterns.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143884733","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}

{"title":"Anisotropic Turbulent Flows Observed in Above-the-loop-top Regions during Solar Flares","authors":"Xiaoyan Xie, Chengcai Shen, Katharine K. Reeves, Bin Chen, Xiaocan Li, Fan Guo, Sijie Yu, Yuqian Wei and Chuanfei Dong","doi":"10.3847/2041-8213/adc91b","DOIUrl":"https://doi.org/10.3847/2041-8213/adc91b","url":null,"abstract":"Solar flare above-the-loop-top (ALT) regions are vital for understanding solar eruptions and fundamental processes in plasma physics. Recent advances in three-dimensional (3D) magnetohydrodynamic (MHD) simulations have revealed unprecedented details on turbulent flows and MHD instabilities in flare ALT regions. Here, for the first time, we examine the observable anisotropic properties of turbulent flows in ALT by applying a flow-tracking algorithm on narrow-band extreme-ultraviolet images that are observed from the face-on viewing perspective. First, the results quantitatively confirm the previous observation that vertical motions dominate and that the anisotropic flows are widely distributed in the entire ALT region with the contribution from both upflows and downflows. Second, the anisotropy shows height-dependent features, with the most substantial anisotropy appearing at a certain middle height in ALT, which agrees well with the MHD modeling results where turbulent flows are caused by Rayleigh–Taylor-type instabilities in the ALT region. Finally, our finding suggests that supra-arcade downflows (SADs), the most prominently visible dynamical structures in ALT regions, are only one aspect of turbulent flows. Among these turbulent flows, we also report the antisunward-moving underdense flows that might develop due to MHD instabilities, as suggested by previous 3D flare models. Our results indicate that the entire flare fan displays group behavior of turbulent flows where the observational bright spikes and relatively dark SADs exhibit similar anisotropic characteristics.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143872737","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}

{"title":"Discovery of a Radio Megahalo in the Cluster PLCKG287.0+32.9 Using the uGMRT","authors":"Sameer Salunkhe, Ramananda Santra and Ruta Kale","doi":"10.3847/2041-8213/adc396","DOIUrl":"https://doi.org/10.3847/2041-8213/adc396","url":null,"abstract":"We report the discovery of a radio megahalo in the merging cluster PLCKG287.0+32.9, based on upgraded Giant Metrewave Radio telescope (uGMRT) observations at frequencies 300–850 MHz. The sensitive radio observations provide a new window to study the complex physics occurring in this system. Apart from significant detections of the known diffuse radio emission in the cluster, we detect the central diffuse emission to a much larger extent of ∼3.2 Mpc, reaching the R500 of the cluster. The radial surface brightness profile shows a distinct flattening beyond ∼0.5R500, dividing the emission into inner and outer components. This outer envelope shows a steep spectral index (≲−1.5) and emissivity ∼20 times lower than the inner component, confirming the megahalo characteristics. The radial profile of the spectral index also distinguishes the steep spectrum megahalo emission. Our observational results align with recent numerical simulations, showing megahalo emission oriented along the merger axis and the reacceleration of electrons driven by late-stage merger-induced turbulence. This is the first detection of a radio megahalo at a frequency higher than the LOFAR 144 MHz, opening the possibilities for more discoveries and spectral studies to understand their origin.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866970","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}

{"title":"On the Origin of Long-term Modulation in the Sun’s Magnetic Activity Cycle","authors":"Chitradeep Saha, Suprabha Mukhopadhyay, Dibyendu Nandy","doi":"10.3847/2041-8213/adc91e","DOIUrl":"https://doi.org/10.3847/2041-8213/adc91e","url":null,"abstract":"One of the most striking manifestations of orderly behavior emerging out of complex interactions in any astrophysical system is the 11 yr cycle of sunspots. However, direct sunspot observations and reconstructions of long-term solar activity clearly exhibit amplitude fluctuations beyond the decadal timescale, which may be termed as supradecadal modulation. Whether this long-term modulation in the Sun’s magnetic activity results from nonlinear mechanisms or stochastic perturbations remains controversial and a matter of active debate. Utilizing multimillennial-scale kinematic dynamo simulations based on the Babcock–Leighton paradigm—in the likely (near-critical) regime of operation of the solar dynamo—we demonstrate that this supradecadal modulation in solar activity cannot be explained by nonlinear mechanisms alone; stochastic forcing is essential for the manifestation of observed long-term fluctuations in the near-critical dynamo regime. Our findings substantiate some independent observational and theoretical investigations and provide additional insights into temporal dynamics associated with a plethora of natural phenomena in astronomy and planetary systems arising from weakly nonlinear, nondeterministic processes.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863011","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}

{"title":"The Discovery and Characterization of Earth-crossing Asteroid 2024 YR4","authors":"Bryce T. Bolin, Josef Hanuš, Larry Denneau, Roberto Bonamico, Laura-May Abron, Marco Delbo, Josef Ďurech, Robert Jedicke, Leo Y. Alcorn, Aleksandar Cikota, Swayamtrupta Panda and Henrique Reggiani","doi":"10.3847/2041-8213/adc910","DOIUrl":"https://doi.org/10.3847/2041-8213/adc910","url":null,"abstract":"We describe observations and physical characteristics of Earth-crossing asteroid 2024 YR4, discovered on 2024 December 27 by the Asteroid Terrestrial-impact Last Alert System. The asteroid has semimajor axis a = 2.52 au, eccentricity e = 0.66, inclination i = 3 41, and a ∼0.003 au Earth minimum orbit intersection distance. We obtained g-, r-, i-, and Z-imaging with the Gemini South/Gemini Multi-Object Spectrograph on 2025 February 7 and Y and J imaging with the Keck/Multi-Object Spectrometer for Infrared Exploration on 2025 February 12. We measured a g − i spectral slope of 13% ± 3%/100 nm and color indices g − r = 0.70 ± 0.10, r − i = 0.25 ± 0.06, i − Z = −0.27 ± 0.10, and Y − J = 0.41 ± 0.10. 2024 YR4 has a spectrum that best matches R-type and Sa-type asteroids and a diameter of ∼30–65 m using our measured absolute magnitude of 23.9 ± 0.3 mag and assuming an albedo of 0.15–0.4. The lightcurve of 2024 YR4 shows ∼0.4 mag variations with a rotation period of ∼1170 s. We use photometry of 2024 YR4 from Gemini and other sources taken between 2024 December to 2025 February to determine the asteroid’s spin vector and shape, finding that it has an oblate, ∼3:1 axial ratio and a pole direction of λ, β = ∼ 42∘, ∼−25∘. Finally, we compare the orbital elements of 2024 YR4 with the near-Earth object population model and find that its most likely sources are resonances between the inner and central Main Belt.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"53 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866974","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}

{"title":"Observations of 1/f Noise at Mercury’s Solar Wind Using MESSENGER Data","authors":"Rayta A. Pradata, Sohom Roy, William H. Matthaeus, Jiaming Wang, Rohit Chhiber, Francesco Pecora and Yan Yang","doi":"10.3847/2041-8213/adc9b2","DOIUrl":"https://doi.org/10.3847/2041-8213/adc9b2","url":null,"abstract":"Low-frequency signals having a band-limited scale-invariant power, or “1/f” noise, have been detected in the interplanetary medium and inferred from coronal and photospheric observations. Their origin remains under debate, with the principal issue being whether the signal originates from local processes or has a solar origin, possibly emerging from a superposition of scale-invariant structures. Detection of such interplanetary signals at frequencies as low as a few times 10−6 Hz at distances well within 1 au is important in developing an understanding of this phenomenon, but this is challenging due to a lack of the requisite long-duration data records. Here, we employ magnetic field data from the MESSENGER spacecraft, processed to remove Mercury’s wake, to analyze spectra from a year of data. The 1/f signal is detected down to the lowest expected frequencies, consistent with the observed lognormal distribution of correlation times and the Machlup–Montroll–Shlesinger superposition principle. This supports the hypothesis that the observed 1/f signals have an origin in solar processes, possibly the dynamo, and disfavors local in situ generation, as described in W. H. Matthaeus & M. L. Goldstein and W. H. Matthaeus et al.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143866973","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}

{"title":"Contribution of Alfvénic Waves on the Formation and Deflection of Switchbacks: Insights from Two Decades of WIND Spacecraft Data","authors":"Hui Li, Fanzhuo Dai, Chi Wang, Wence Jiang, Haoyu Li","doi":"10.3847/2041-8213/adc9a9","DOIUrl":"https://doi.org/10.3847/2041-8213/adc9a9","url":null,"abstract":"Switchbacks, characterized by large-angle deflections of the local interplanetary magnetic field relative to the background, are frequently observed throughout the heliosphere and play a crucial role in the solar wind dynamics. Recent studies have highlighted the importance of local generation mechanisms, such as expanding waves, turbulence, velocity shear, and footpoint motion, in the formation of switchbacks. Utilizing nearly two decades of data from the WIND spacecraft near 1 au, we conducted a detailed investigation into the differences between switchbacks and their surrounding environment, focusing on the influence of solar wind conditions on their occurrence rate and deflection degree. Our findings indicate that switchbacks are embedded within Alfvén waves, and their occurrence rate and maximum deflection degree are significantly enhanced during large-amplitude Alfvén waves. Specifically, the occurrence rate of switchbacks during these periods shows no significant correlation with solar wind velocity, suggesting that Alfvén wave activity is the primary driver of switchback formation. Our results further indicate that the evolution of switchbacks is closely related to the evolution of Alfvén waves, and that velocity shear and footpoint motion do not play an additional role in their evolution. These findings provide valuable insights into the dynamics of switchbacks and their relationship with solar wind conditions, contributing to a deeper understanding of the complex interactions within the heliosphere.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143863012","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}