The Astrophysical Journal Supplement Series最新文献

{"title":"Multimode δ Sct stars from the Zwicky Transient Facility Survey","authors":"Qi Jia, Xiaodian Chen, Shu Wang, Licai Deng, Yangping Luo and Qingquan Jiang","doi":"10.3847/1538-4365/ad4da6","DOIUrl":"https://doi.org/10.3847/1538-4365/ad4da6","url":null,"abstract":"We obtain the largest catalog of multimode δ Sct stars in the northern sky to date using the Zwicky Transient Facility (ZTF) Data Release 20. The catalog includes 2254 objects, of which 2181 are new to our study. Among these multimode δ Sct stars, 2142 objects are double-mode δ Sct, while 109 objects are triple-mode δ Sct and three are quadruple-mode δ Sct. By analyzing the light curves in the r and g bands of the ZTF, we determine the basic parameters of multimode δ Sct stars, including the periods and amplitudes. Periods are checked by comparison with the Optical Gravitational Lensing Experiment catalog of double-mode δ Sct stars. On the Petersen diagram, multimode δ Sct stars form six sequences. We find that in Galactic coordinates, the periods of 1O/F double-mode δ Sct stars at high latitudes are shorter than those of 1O/F double-mode δ Sct stars in the disk, due to metallicity variations. In the future, our catalog can be used to establish the period–luminosity relation and the period–metallicity relation of double-mode δ Sct stars, and to study the Galactic structure.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527980","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":"Stellar X-Ray Activity and Habitability Revealed by the ROSAT Sky Survey","authors":"Henggeng Han, Song Wang, Chuanjie Zheng, Xue Li, Kai Xiao and Jifeng Liu","doi":"10.3847/1538-4365/ad4b17","DOIUrl":"https://doi.org/10.3847/1538-4365/ad4b17","url":null,"abstract":"Using the homogeneous X-ray catalog from ROSAT observations, we conducted a comprehensive investigation into stellar X-ray activity–rotation relations for both single and binary stars. Generally, the relation for single stars consists of two distinct regions: a weak decay region, indicating a continued dependence of the magnetic dynamo on stellar rotation rather than a saturation regime with constant activity, and a rapid decay region, where X-ray activity is strongly correlated with the Rossby number. Detailed analysis reveals more fine structures within the relation: in the extremely fast-rotating regime, a decrease in X-ray activity was observed with increasing rotation rate, referred to as supersaturation, while in the extremely slow-rotating region, the relation flattens, mainly due to the scattering of F stars. This scattering may result from intrinsic variability in stellar activities over one stellar cycle or the presence of different dynamo mechanisms. Binaries exhibit a similar relation to that of single stars while the limited sample size prevented the identification of fine structures in the relation for binaries. We calculated the mass-loss rates of planetary atmospheres triggered by X-ray emissions from host stars. Our findings indicate that for an Earthlike planet within the stellar habitable zone, it would easily lose its entire primordial H/He envelope (equating to about 1% of the planetary mass).","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504883","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":"TESS Light Curves of Cataclysmic Variables. IV. A Synoptic View of Eclipsing Old Novae and Novalike Variables","authors":"Albert Bruch","doi":"10.3847/1538-4365/ad43ec","DOIUrl":"https://doi.org/10.3847/1538-4365/ad43ec","url":null,"abstract":"Based mainly on the months-long 2 minutes time-resolution light curves observed by the Transiting Exoplanet Survey Telescope (TESS) space mission of 48 eclipsing old novae and novalike variables (commonly referred to as NLs) selected from the Ritter & Kolb catalog, a synoptic view of some basic properties of these systems is provided. The supraorbital variations exhibit a large diversity of behavior. Data taken from the literature and many additional eclipse epochs measured in the TESS and in AAVSO light curves are used to update the orbital ephemerides of 21 targets. The large majority of these suffer period variations which defy current theoretical understanding. Orbital waveforms are constructed and, if possible, their variation over time is studied, revealing some common characteristics but also substantial differences between individual systems. The dependence of the eclipse depth on the out-of-eclipse flux reveals that in all systems a fraction of the light source responsible for the out-of-eclipse variations escapes eclipse and is probably located in the outer disk regions. In systems exhibiting superhumps, both eclipse width and epoch are modulated with the accretion disk precession period. This suggests an expansion and contraction of the eclipsed light source, as well as a periodic shift of its light center as a function of the accretion disk precession phase. The dependence of the orbital and superhump waveforms on the disk precession phase is also examined but does not lead to a consistent picture. Two cataclysmic variables are newly identified as eclipsing. Attention is drawn to specific peculiarities in some of the target stars.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504884","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":"Microlensing Optical Depth and Event Rate toward the Large Magellanic Cloud Based on 20 yr of OGLE Observations","authors":"Przemek Mróz, Andrzej Udalski, Michał K. Szymański, Mateusz Kapusta, Igor Soszyński, Łukasz Wyrzykowski, Paweł Pietrukowicz, Szymon Kozłowski, Radosław Poleski, Jan Skowron, Dorota Skowron, Krzysztof Ulaczyk, Mariusz Gromadzki, Krzysztof Rybicki, Patryk Iwanek, Marcin Wrona and Milena Ratajczak","doi":"10.3847/1538-4365/ad452e","DOIUrl":"https://doi.org/10.3847/1538-4365/ad452e","url":null,"abstract":"Measurements of the microlensing optical depth and event rate toward the Large Magellanic Cloud (LMC) can be used to probe the distribution and mass function of compact objects in the direction toward that galaxy—in the Milky Way disk, the Milky Way dark matter halo, and the LMC itself. The previous measurements, based on small statistical samples of events, found that the optical depth is an order of magnitude smaller than that expected from the entire dark matter halo in the form of compact objects. However, these previous studies were not sensitive to long-duration events with Einstein timescales longer than 2.5–3 yr, which are expected from massive (10–100 M⊙) and intermediate-mass (102–105M⊙) black holes. Such events would have been missed by the previous studies and would not have been taken into account in calculations of the optical depth. Here, we present the analysis of nearly 20 yr long photometric monitoring of 78.7 million stars in the LMC by the Optical Gravitational Lensing Experiment (OGLE) from 2001 through 2020. We describe the observing setup, the construction of the 20 yr OGLE data set, the methods used for searching for microlensing events in the light-curve data, and the calculation of the event detection efficiency. In total, we find 16 microlensing events (13 using an automated pipeline and three with manual searches), all of which have timescales shorter than 1 yr. We use a sample of 13 events to measure the microlensing optical depth toward the LMC τ = (0.121 ± 0.037) × 10−7 and the event rate Γ = (0.74 ± 0.25) × 10−7 yr−1 star−1. These numbers are consistent with lensing by stars in the Milky Way disk and the LMC itself, and they demonstrate that massive and intermediate-mass black holes cannot comprise a significant fraction of the dark matter.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141504885","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":"T-ReX: The Tarantula—Revealed by X-Rays","authors":"Leisa K. Townsley, Patrick S. Broos and Matthew S. Povich","doi":"10.3847/1538-4365/ad435c","DOIUrl":"https://doi.org/10.3847/1538-4365/ad435c","url":null,"abstract":"The Tarantula Nebula (30 Doradus, 30 Dor) is the most important star-forming complex in the Local Group, offering a microscope on starburst astrophysics. At its heart lies the exceptionally rich young stellar cluster R136, containing the most massive stars known. Stellar winds and supernovae have carved 30 Dor into an amazing display of arcs, pillars, and bubbles. We present first results and advanced data-processing products from the 2 Ms Chandra X-ray Visionary Project, “The Tarantula—Revealed by X-rays” (T-ReX). The 3615 point sources in the T-ReX catalog include massive stars, compact objects, binaries, bright pre-main-sequence stars, and compact young stellar (sub)clusters in 30 Dor. After removing point sources and excluding the exceptionally bright supernova remnant N157B (30 Dor B), the global diffuse X-ray maps reveal hot plasma structures resolved at 1–10 pc scales, with an absorption-corrected total-band (0.5–7 keV) X-ray luminosity of 2.110 × 1037 erg s−1. Spatially resolved spectral modeling provides evidence for emission lines enhanced by charge-exchange processes at the interfaces. We identify a candidate for the oldest X-ray pulsar detected to date in 30 Dor, PSR J0538-6902, inside a newly resolved arcuate X-ray wind nebula, the Manta Ray. The long temporal baseline of T-ReX allowed monitoring of dozens of massive stars, several showing periodic variability tied to binary orbital periods, and captured strong flares from at least three low-mass Galactic foreground stars.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527981","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 R2D2 Deep Neural Network Series Paradigm for Fast Precision Imaging in Radio Astronomy","authors":"Amir Aghabiglou, Chung San Chu, Arwa Dabbech and Yves Wiaux","doi":"10.3847/1538-4365/ad46f5","DOIUrl":"https://doi.org/10.3847/1538-4365/ad46f5","url":null,"abstract":"Radio-interferometric imaging entails solving high-resolution high-dynamic-range inverse problems from large data volumes. Recent image reconstruction techniques grounded in optimization theory have demonstrated remarkable capability for imaging precision, well beyond CLEAN’s capability. These range from advanced proximal algorithms propelled by handcrafted regularization operators, such as the SARA family, to hybrid plug-and-play (PnP) algorithms propelled by learned regularization denoisers, such as AIRI. Optimization and PnP structures are however highly iterative, which hinders their ability to handle the extreme data sizes expected from future instruments. To address this scalability challenge, we introduce a novel deep-learning approach, dubbed “Residual-to-Residual DNN series for high-Dynamic-range imaging” or in short R2D2. R2D2's reconstruction is formed as a series of residual images, iteratively estimated as outputs of deep neural networks (DNNs) taking the previous iteration’s image estimate and associated data residual as inputs. It thus takes a hybrid structure between a PnP algorithm and a learned version of the matching pursuit algorithm that underpins CLEAN. We present a comprehensive study of our approach, featuring its multiple incarnations distinguished by their DNN architectures. We provide a detailed description of its training process, targeting a telescope-specific approach. R2D2's capability to deliver high precision is demonstrated in simulation, across a variety of image and observation settings using the Very Large Array. Its reconstruction speed is also demonstrated: with only a few iterations required to clean data residuals at dynamic ranges up to 105, R2D2 opens the door to fast precision imaging. R2D2 codes are available in the BASPLib (https://basp-group.github.io/BASPLib/) library on GitHub.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"3 8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141529049","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":"CO Observations of Early-mid Stage Major Mergers in the MaNGA Survey","authors":"Qingzheng Yu, 清正 余, Taotao Fang, 陶陶 方, Cong Kevin Xu, 聪 徐, Shuai Feng, 帅 冯, Siyi Feng, 思轶 冯, Yu Gao, 煜 高, Xue-Jian Jiang, 雪健 蒋 and Ute Lisenfeld","doi":"10.3847/1538-4365/ad4547","DOIUrl":"https://doi.org/10.3847/1538-4365/ad4547","url":null,"abstract":"We present a study of the molecular gas in early-mid stage major mergers, with a sample of 43 major-merger galaxy pairs selected from the Mapping Nearby Galaxies at Apache Point Observatory survey and a control sample of 195 isolated galaxies selected from the xCOLD GASS survey. Adopting kinematic asymmetry as a new effective indicator to describe the merger stage, we aim to study the role of molecular gas in the merger-induced star formation enhancement along the merger sequence of galaxy pairs. We obtain the molecular gas properties from CO observations with the James Clerk Maxwell Telescope, Institut de Radioastronomie Milimetrique 30 m telescope, and the MaNGA-ARO Survey of CO Targets survey. Using these data, we investigate the differences in molecular gas fraction ( ), star formation rate (SFR), star formation efficiency (SFE), molecular-to-atomic gas ratio ( /MH i), total gas fraction (fgas), and the SFE of total gas (SFEgas) between the pair and control samples. In the full pair sample, our results suggest the of paired galaxies is significantly enhanced, while the SFE is comparable to that of isolated galaxies. We detect significantly increased and /MH i in paired galaxies at the pericenter stage, indicating an accelerated transition from atomic gas to molecular gas due to interactions. Our results indicate that the elevation of plays a major role in the enhancement of global SFR in paired galaxies at the pericenter stage, while the contribution of enhanced SFE in specific regions requires further explorations through spatially resolved observations of a larger sample spanning a wide range of merger stages.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527982","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":"Complex Network View of the Sun’s Magnetic Patches. I. Identification","authors":"Zahra Tajik, Nastaran Farhang, Hossein Safari and Michael S. Wheatland","doi":"10.3847/1538-4365/ad4642","DOIUrl":"https://doi.org/10.3847/1538-4365/ad4642","url":null,"abstract":"Solar and stellar magnetic patches (i.e., magnetic fluxes that reach the surface from the interior) are believed to be the primary sources of a star’s atmospheric conditions. Here, we apply the complex network approach and investigate its efficacy in the identification of these features. For this purpose, we use the line-of-sight magnetograms provided by the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory. We construct the magnetic network following a specific visibility graph condition between pairs of pixels with opposite polarities and search for possible links between these regions. The complex network facilitates the construction of node degrees and PageRank images, and applying the downhill algorithm to node-degree images allows for the grouping of pixels into features corresponding to one-to-one matches with magnetogram patches. This approach promisingly serves to identify the nontrivial morphological structure of the magnetic patches for small and large sizes. We observe that the changes in the features of the node-degree images effectively correspond to the cospatial magnetic patches over time. Through visual assessment, we estimate an average false-negative error rate of approximately 1% in identifying small-scale features (one or two pixels in size).","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527885","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":"USmorph: An Updated Framework of Automatic Classification of Galaxy Morphologies and Its Application to Galaxies in the COSMOS Field","authors":"Jie Song, GuanWen Fang, Shuo Ba, Zesen Lin, Yizhou Gu, Chichun Zhou, Tao Wang, Cai-Na Hao, Guilin Liu, Hongxin Zhang, Yao Yao, Xu Kong","doi":"10.3847/1538-4365/ad434f","DOIUrl":"https://doi.org/10.3847/1538-4365/ad434f","url":null,"abstract":"Morphological classification conveys abundant information on the formation, evolution, and environment of galaxies. In this work, we refine a two-step galaxy morphological classification framework (<monospace>USmorph</monospace>), which employs a combination of unsupervised machine-learning and supervised machine-learning techniques, along with a self-consistent and robust data-preprocessing step. The updated method is applied to galaxies with <italic toggle=\"yes\">I</italic>\u0000_mag &lt; 25 at 0.2 &lt; <italic toggle=\"yes\">z</italic> &lt; 1.2 in the COSMOS field. Based on their Hubble Space Telescope/Advanced Camera for Survey <italic toggle=\"yes\">I</italic>-band images, we classify them into five distinct morphological types: spherical (SPH, 15,200), early-type disk (17,369), late-type disk (21,143), irregular disk (IRR, 28,965), and unclassified (UNC, 17,129). In addition, we have conducted both parametric and nonparametric morphological measurements. For galaxies with stellar masses exceeding 10⁹\u0000<italic toggle=\"yes\">M</italic>\u0000_☉, a gradual increase in effective radius from SPHs to IRRs is observed, accompanied by a decrease in the Sérsic index. Nonparametric morphologies reveal distinct distributions of galaxies across the <italic toggle=\"yes\">G</italic>ini−<italic toggle=\"yes\">M</italic>\u0000₂₀ and <italic toggle=\"yes\">C</italic>−<italic toggle=\"yes\">A</italic> parameter spaces for different categories. Moreover, different categories exhibit significant dissimilarity in their <italic toggle=\"yes\">G</italic>\u0000₂ and Ψ distributions. We find morphology to be strongly correlated with redshift and stellar mass. The consistency of these classification results with expected correlations among multiple parameters underscores the validity and reliability of our classification method, rendering it a valuable tool for future studies.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"59 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527886","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":"Reconstructing Intrinsic Stellar Noise with Stellar Atmospheric Parameters and Chromospheric Activity","authors":"Jinghua Zhang, Maosheng Xiang, Jie Yu, Jian Ge, Ji-Wei Xie, Hui Zhang, Yaguang Li, You Wu, Chun-Qian Li, Shaolan Bi, Hong-Liang Yan, Jian-Rong Shi","doi":"10.3847/1538-4365/ad41b6","DOIUrl":"https://doi.org/10.3847/1538-4365/ad41b6","url":null,"abstract":"Accurately characterizing the intrinsic stellar photometric noise induced by stellar astrophysics, such as stellar activity, granulation, and oscillations, is of crucial importance for detecting transiting exoplanets. In this study, we investigate the relation between the intrinsic stellar photometric noise, quantified by the Kepler combined differential photometric precision (CDPP) metric, and the level of stellar chromospheric activity, indicated by the <italic toggle=\"yes\">S</italic>-index of Ca <sc>ii</sc> H K lines derived from LAMOST spectra. Our results reveal a clear positive correlation between the <italic toggle=\"yes\">S</italic>-index and robust rms values of CDPP, with the correlation becoming more significant at higher activity levels and on longer timescales. We have therefore built an empirical relation between the robust rms values of CDPP and the <italic toggle=\"yes\">S</italic>-index as well as <italic toggle=\"yes\">T</italic>\u0000_eff, <inline-formula>\u0000<tex-math>\u0000<?CDATA $mathrm{log}$?>\u0000</tex-math>\u0000<mml:math overflow=\"scroll\"><mml:mi>log</mml:mi></mml:math>\u0000<inline-graphic xlink:href=\"apjsad41b6ieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>\u0000<italic toggle=\"yes\">g</italic>, [Fe/H], and the apparent magnitude, with the <monospace>XGBoost</monospace> regression algorithm, using the LAMOST–Kepler common star sample as the training set. This method achieves a precision of ∼20 ppm for inferring the intrinsic noise from the <italic toggle=\"yes\">S</italic>-index and other stellar labels on a 6 hr integration duration. We have applied this empirical relation to the full LAMOST DR7 spectra database and obtained the intrinsic noise predictions for 1,358,275 stars. The resultant catalog is publicly available and expected to be valuable for optimizing target selection for future exoplanet-hunting space missions, such as the Earth 2.0 mission.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"44 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141527888","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}