The Astrophysical Journal最新文献_第6页

Spectral Line Search in Bright Gamma-Ray Bursts Observed by Fermi/GBM

The Astrophysical Journal Pub Date : 2025-04-14 DOI: 10.3847/1538-4357/adc00b

Tong-Lei Liao, Yan-Qiu Zhang, Wang-Chen Xue, Shuo Xiao, Shao-Lin Xiong, Xi-Lu Wang, Hua Feng, Chao Zheng, Yue Wang, Jia-Cong Liu, Chen-Wei Wang, Jiao-Jiao Yang, Mei-Xin Hong, Zheng-Huo Jiang, Yang Lai and Xi-Hong Luo

{"title":"Spectral Line Search in Bright Gamma-Ray Bursts Observed by Fermi/GBM","authors":"Tong-Lei Liao, Yan-Qiu Zhang, Wang-Chen Xue, Shuo Xiao, Shao-Lin Xiong, Xi-Lu Wang, Hua Feng, Chao Zheng, Yue Wang, Jia-Cong Liu, Chen-Wei Wang, Jiao-Jiao Yang, Mei-Xin Hong, Zheng-Huo Jiang, Yang Lai and Xi-Hong Luo","doi":"10.3847/1538-4357/adc00b","DOIUrl":"https://doi.org/10.3847/1538-4357/adc00b","url":null,"abstract":"The recently reported discoveries of emission lines with power-law decay from ∼37 to ∼6 MeV in the gamma-ray burst (GRB) 221009A have greatly contributed to probing the physics of GRBs, which also raises the natural question of whether there are more emission lines in bright GRBs. In this work, we search for emission lines in the top 30 highest fluence GRBs in the Gamma-Ray Burst Catalog observed by the Fermi/Gamma-ray Burst Monitor. Although no new lines are confirmed, there are a portion of GRBs that seem to show emission line features in their spectra with mean values of 61 keV, 110 keV, and 2.1 MeV, respectively. However, considering that the redshifts of these GRBs are different, the observed emission line features have almost identical central energy, thus the ∼110 keV spectral line should be caused by instrumental effects rather than GRB or other astronomical sources. The ∼61 keV and ∼2.1 MeV are comparable to 57.6 keV and 2.2 MeV, which are spectral lines confirmed to come from the excited energy level of 127I and the neutron capture line, respectively, as reported by previous studies. Our findings indicate that various effects may produce emission line-like features in the GRB spectrum and caution should be taken to carefully identify whether they are from GRB, other astronomical sources, or instrumental effects. Finally, the lack of spectral lines searched in other bright GRBs implies the special radiation mechanism of the spectral lines in GRB 221009A.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143836988","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

Deuterated Polycyclic Aromatic Hydrocarbons in the Interstellar Medium: Constraints from the Orion Bar as Observed by the James Webb Space Telescope

The Astrophysical Journal Pub Date : 2025-04-14 DOI: 10.3847/1538-4357/adbd11

X. J. Yang and Aigen Li

{"title":"Deuterated Polycyclic Aromatic Hydrocarbons in the Interstellar Medium: Constraints from the Orion Bar as Observed by the James Webb Space Telescope","authors":"X. J. Yang and Aigen Li","doi":"10.3847/1538-4357/adbd11","DOIUrl":"https://doi.org/10.3847/1538-4357/adbd11","url":null,"abstract":"The gas-phase abundances of deuterium (D) in the local interstellar medium exhibit considerable regional variations. Particularly, in some regions the gas-phase D abundances are substantially lower than the primordial D abundance generated in the Big Bang after subtracting the astration reduction caused by the Galactic chemical evolution. Deuterated polycyclic aromatic hydrocarbon (PAH) molecules have been suggested as a potential reservoir of the D atoms missing from the gas phase. Recent observations from the James Webb Space Telescope’s Near Infrared Spectrograph have revealed how widespread deuterated PAHs are in the Orion Bar through their aliphatic C–D emission at 4.65 μm and possibly aromatic C–D emission at 4.4 μm as well. To examine the viability of deuterated PAHs as the D reservoir, we model the infrared emission spectra of small PAH molecules containing various aromatic and aliphatic D atoms in the Orion Bar. We find that small deuterated PAHs exhibit a noticeable emission band at 4.4 or 4.65 μm even if they contain only one aromatic or aliphatic D atom. We derive ND,ali/NH ≈ 3.4%, the deuteration degree of PAHs measured as the number of aliphatic D atoms (relative to H), from the observed intensity ratios of the 4.65 μm band to the 3.3 μm aromatic C–H band. The deuteration degree for aromatically deuterated PAHs is less certain as C–N stretch also contributes to the observed emission around 4.4 μm. If we attribute it exclusively to aromatic C–D, we derive an upper limit of ≈14% on the deuteration degree, which is capable of accounting for an appreciable fraction of the missing D budget.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143832362","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

Variation of Dense Gas Mass–Luminosity Conversion Factor with Metallicity in the Milky Way

The Astrophysical Journal Pub Date : 2025-04-14 DOI: 10.3847/1538-4357/adbf8d

Sudeshna Patra, Neal J. Evans, Kee-Tae Kim, Mark Heyer, Andrea Giannetti, Davide Elia, Jessy Jose, Jens Kauffmann, Manash R. Samal, Agata Karska, Swagat R. Das, Gyuho Lee and Geumsook Park

{"title":"Variation of Dense Gas Mass–Luminosity Conversion Factor with Metallicity in the Milky Way","authors":"Sudeshna Patra, Neal J. Evans, Kee-Tae Kim, Mark Heyer, Andrea Giannetti, Davide Elia, Jessy Jose, Jens Kauffmann, Manash R. Samal, Agata Karska, Swagat R. Das, Gyuho Lee and Geumsook Park","doi":"10.3847/1538-4357/adbf8d","DOIUrl":"https://doi.org/10.3847/1538-4357/adbf8d","url":null,"abstract":"HCN and HCO+ are the most common dense gas tracers used both in the Milky Way and external galaxies. The luminosity of HCN and HCO+J = 1 → 0 lines are converted to a dense gas mass by the conversion factor, αQ. Traditionally, this αQ has been considered constant throughout the Galaxy and in other galaxies, regardless of the environment. We analyzed 17 outer Galaxy clouds and five inner Galaxy clouds with metallicities ranging from 0.38 Z⊙ to 1.29 Z⊙. Our analysis indicates that αQ is not constant; instead, it varies with metallicity. The metallicity-corrected αQ derived from the HCN luminosity of the entire cloud is almost three times higher in the outer Galaxy than in the inner Galaxy. In contrast, HCO+ seems less sensitive to metallicity. We recommend using the metallicity-corrected dense gas conversion factors and for extragalactic studies. Radiation from nearby stars has an effect on the conversion factor of a similar magnitude as that of the metallicity. If we extend the metallicity-corrected scaling relation for HCN to the Central Molecular Zone (CMZ), the value of becomes one-third to one-half of the local values. This effect could partially account for the low star formation rate per dense gas mass observed in the CMZ.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"69 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143832364","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

A Systematic NLTE Study of Very Metal-poor Stars with Metallicity down to −4.3 dex. I. Global Stellar Parameters Based on High-resolution Spectra

The Astrophysical Journal Pub Date : 2025-04-14 DOI: 10.3847/1538-4357/adc127

Jianrong Shi, Gang Zhao, Shuai Liu, Zeming Zhou, Haining Li, Hongliang Yan, Sofya Alexeeva, Huawei Zhang, Wako Aoki, Tadafumi Matsuno, Jingkun Zhao, Huiling Chen and Yufu Shen

{"title":"A Systematic NLTE Study of Very Metal-poor Stars with Metallicity down to −4.3 dex. I. Global Stellar Parameters Based on High-resolution Spectra","authors":"Jianrong Shi, Gang Zhao, Shuai Liu, Zeming Zhou, Haining Li, Hongliang Yan, Sofya Alexeeva, Huawei Zhang, Wako Aoki, Tadafumi Matsuno, Jingkun Zhao, Huiling Chen and Yufu Shen","doi":"10.3847/1538-4357/adc127","DOIUrl":"https://doi.org/10.3847/1538-4357/adc127","url":null,"abstract":"Very metal-poor (VMP) stars provide a record of the chemical composition and dynamics of the early Galaxy. Based on the high-resolution and high signal-to-noise ratio spectra from the Subaru Telescope for 103 VMP stars, in this series of papers we homogeneously investigate the nonlocal thermodynamic equilibrium (NLTE) abundances of important astrophysical elements. This sample covers a wide metallicity range from [Fe/H] ∼ −1.7 dex down to −4.3 dex, including 13 objects with [Fe/H] ≤ −3.0 dex. Here, we present a set of homogeneous stellar atmospheric parameters, including the effective temperature, surface gravity, metallicity, and microturbulence velocity with the spectroscopic method, and the NLTE line formation for both Fe i and Fe ii in the classical one-dimensional model atmospheres have been considered. The NLTE effects of the Fe i lines range from ∼0.03 dex to ∼0.3 dex, and increase with decreasing metallicity. In addition, they depend on the surface gravity, which generally increases with decreasing . The largest NLTE effects can be found for the giants of ∼ 2.5 dex. For dwarfs and subgiants, our final effective temperatures are consistent with those derived from the TIRFM scales of A. Alonso et al. with a mean difference of 7.1 ± 100.2 K, while for giants, our results are slightly lower than those from the TIRFM scales of A. Alonso et al. with a mean difference of −69.5 ± 94.1 K. For dwarfs and subgiants, the spectroscopically derived surface gravity is consistent with that estimated based on the Gaia DR3 parallax; however, for giants, the former leads to a 0.2 dex lower surface gravity.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"108 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143832426","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

The Merging Galaxy Cluster Environment Affects the Morphology of Radio Active Galactic Nuclei

The Astrophysical Journal Pub Date : 2025-04-14 DOI: 10.3847/1538-4357/adbb5e

Mary Rickel, Emily Moravec, Yjan A. Gordon, Martin J. Hardcastle, Jonathon C. S. Pierce, Lawrence E. Bilton and Ian D. Roberts

{"title":"The Merging Galaxy Cluster Environment Affects the Morphology of Radio Active Galactic Nuclei","authors":"Mary Rickel, Emily Moravec, Yjan A. Gordon, Martin J. Hardcastle, Jonathon C. S. Pierce, Lawrence E. Bilton and Ian D. Roberts","doi":"10.3847/1538-4357/adbb5e","DOIUrl":"https://doi.org/10.3847/1538-4357/adbb5e","url":null,"abstract":"It has previously been found that the galaxy cluster environment can affect the fueling and evolution of active galactic nuclei (AGN). This work examines the effect of the merging cluster environment on the properties of radio AGN by comparing the radio morphology of cluster members in a sample of four merging and eight relaxed galaxy clusters at low redshift (z < 0.2). Using 144 MHz data from the LOFAR Two-meter Sky Survey and Zooniverse, we classify the radio morphology of the radio-detected cluster members using the following morphology classes: compact, compact extended, extended, jetted, and disturbed. We find that the merging cluster environment has a statistically significant, higher population proportion of disturbed (bent and head tail) sources, indicating that the merging environment can affect the morphology of cluster radio AGN. We also investigate the number of AGN that are detected in the radio data only and the number that are detected in both the radio and optical data in mergers and nonmergers. We find that the merging cluster environment has a higher population proportion of AGN that are identified only as radio AGN compared to AGN that are identified as both radio and optical AGN. Overall, we find that the merging environment affects certain radio AGN (disturbed and only radio-identified AGN), but not all.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"121 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143832359","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

Modeling the UV/Optical Light Curve of Re-brightening Tidal Disruption Events

The Astrophysical Journal Pub Date : 2025-04-14 DOI: 10.3847/1538-4357/adc005

Shiyan Zhong

引用次数: 0

EPOCHS. XI. The Structure and Morphology of Galaxies in the Epoch of Reionization to z ∼ 12.5

The Astrophysical Journal Pub Date : 2025-04-13 DOI: 10.3847/1538-4357/adb968

Lewi Westcott, Christopher J. Conselice, Thomas Harvey, Duncan Austin, Nathan Adams, Fabricio Ferrari, Leonardo Ferreira, James Trussler, Qiong Li, Vadim Rusakov, Qiao Duan, Honor Harris, Caio Goolsby, Thomas J. Broadhurst, Dan Coe, Seth H. Cohen, Simon P. Driver, Jordan C. J. D’Silva, Brenda Frye, Norman A. Grogin, Nimish P. Hathi, Rolf A. Jansen, Anton M. Koekemoer, Madeline A. Marshall, Rafael Ortiz III, Nor Pirzkal, Aaron Robotham, Russell E. Ryan, Jake Summers, Christopher N. A. Willmer, Rogier A. Windhorst and Haojing Yan

{"title":"EPOCHS. XI. The Structure and Morphology of Galaxies in the Epoch of Reionization to z ∼ 12.5","authors":"Lewi Westcott, Christopher J. Conselice, Thomas Harvey, Duncan Austin, Nathan Adams, Fabricio Ferrari, Leonardo Ferreira, James Trussler, Qiong Li, Vadim Rusakov, Qiao Duan, Honor Harris, Caio Goolsby, Thomas J. Broadhurst, Dan Coe, Seth H. Cohen, Simon P. Driver, Jordan C. J. D’Silva, Brenda Frye, Norman A. Grogin, Nimish P. Hathi, Rolf A. Jansen, Anton M. Koekemoer, Madeline A. Marshall, Rafael Ortiz III, Nor Pirzkal, Aaron Robotham, Russell E. Ryan, Jake Summers, Christopher N. A. Willmer, Rogier A. Windhorst and Haojing Yan","doi":"10.3847/1538-4357/adb968","DOIUrl":"https://doi.org/10.3847/1538-4357/adb968","url":null,"abstract":"We present a structural analysis of 520 galaxy candidates at 6.5 < z < 12.5 with a signal-to-noise ratio of >10σ in the F444W filter taken from the EPOCHS v1 sample, consisting of uniformly reduced deep JWST NIRCam data covering the CEERS, JADES GOODS-S, NGDEEP, SMACS-0723, GLASS, and PEARLS surveys. We use standard software to fit single Sérsic models to each galaxy in the rest-frame optical and extract their parametric structural parameters (Sérsic index, half-light radius, and axis ratio) and Morfometryka to measure their nonparametric concentration and asymmetry parameters. We find a wide range of sizes for these early galaxies, with galaxy sizes overall continuing to become progressively smaller in the high-redshift regime, following kpc. We further find a galaxy size–mass correlation up to z ∼ 12, with galaxies of a given mass also becoming smaller. Using nonparametric methods, we find that galaxy merger fractions, classified through asymmetry parameters, at these redshifts remain consistent with those in the literature, maintaining a value of fm ∼ 0.12 ± 0.07 showing little dependence with redshift when combined with the literature at z > 4. We find that galaxies that are smaller in size also appear rounder, with an excess of high axis ratio objects. Finally, we artificially redshift a subsample of our objects to determine how robust the observational trends we see are, determining that the observed trends are due to real evolutionary effects, rather than being a consequence of redshift effects.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143827731","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

Cosmological Simulations of Stellar Halos with Gaia Sausage–Enceladus Analogs: Two Sausages, One Bun?

The Astrophysical Journal Pub Date : 2025-04-13 DOI: 10.3847/1538-4357/adbe31

Dylan Folsom, Mariangela Lisanti, Lina Necib, Danny Horta, Mark Vogelsberger and Lars Hernquist

{"title":"Cosmological Simulations of Stellar Halos with Gaia Sausage–Enceladus Analogs: Two Sausages, One Bun?","authors":"Dylan Folsom, Mariangela Lisanti, Lina Necib, Danny Horta, Mark Vogelsberger and Lars Hernquist","doi":"10.3847/1538-4357/adbe31","DOIUrl":"https://doi.org/10.3847/1538-4357/adbe31","url":null,"abstract":"Observations of the Milky Way’s stellar halo find that it is predominantly comprised of a radially biased population of stars, dubbed the Gaia Sausage–Enceladus, or GSE. These stars are thought to be debris from dwarf galaxy accretion early in the Milky Way’s history. Though typically considered to be from a single merger, it is possible that the GSE debris has multiple sources. To investigate this possibility, we use the IllustrisTNG50 simulation to identify stellar accretion histories in 98 Milky Way analogs—the largest sample for which such an identification has been performed—and find GSE-like debris in 32, with two-merger GSEs accounting for a third of these cases. Distinguishing single-merger GSEs from two-merger GSEs is difficult in common kinematic spaces, but differences are more evident through chemical abundances and star formation histories. This is because single-merger GSEs are typically accreted more recently than the galaxies in two-merger GSEs: the median infall times (with 16th and 84th percentiles) are and Gyr ago for single- and two-merger scenarios, respectively. The systematic shifts in abundances and ages that occur as a result suggest that efforts in modeling these aspects of the stellar halo prove ever-important in understanding its assembly.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143827733","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

Transition from Vortical to Alfvénic-like Fermi Electron Acceleration in Magnetic Reconnection with Increasing Guide Field

The Astrophysical Journal Pub Date : 2025-04-13 DOI: 10.3847/1538-4357/adbc60

C. Crawford, H. Che, G. P. Zank and A. O. Benz

引用次数: 0

Simultaneous Multiwavelength Observations of the Repeating Fast Radio Burst FRB 20190520B with Swift and FAST

The Astrophysical Journal Pub Date : 2025-04-13 DOI: 10.3847/1538-4357/adbef0

Zhen Yan, Wenfei Yu, Kim L. Page, Jie Lin, Di Li, Chenhui Niu, Casey Law, Bing Zhang, Shami Chatterjee, Xian Zhang and Reshma Anna-Thomas

{"title":"Simultaneous Multiwavelength Observations of the Repeating Fast Radio Burst FRB 20190520B with Swift and FAST","authors":"Zhen Yan, Wenfei Yu, Kim L. Page, Jie Lin, Di Li, Chenhui Niu, Casey Law, Bing Zhang, Shami Chatterjee, Xian Zhang and Reshma Anna-Thomas","doi":"10.3847/1538-4357/adbef0","DOIUrl":"https://doi.org/10.3847/1538-4357/adbef0","url":null,"abstract":"Among several dozen known repeating fast radio bursts, those precisely localized offer the best opportunities to explore their multiwavelength counterparts, which are key to uncovering their origins. Here we report our X-ray, ultraviolet (UV), and optical observations with the Swift satellite of the repeating FRB 20190520B, in coordination with simultaneous radio observations with the Five-hundred-meter Aperture Spherical radio Telescope (FAST). Our aim was to detect potentially associated multiwavelength bursts and identify any persistent multiwavelength counterparts to the associated persistent radio source (PRS). While a total of 10 radio bursts were detected by FAST during the Swift observations, we detected no X-ray, UV, or optical bursts in accompany with the radio bursts. We obtained the energy upper limits (3σ) on any multwavelength bursts as follows: 5.03 × 1047 erg in the hard X-ray band (15–150 keV), 7.98 × 1045 erg in the soft X-ray band (0.3–10 keV), and 4.51 × 1044 erg in the U band (3465 Å), respectively. The energy ratio between soft X-ray (0.3–10 keV) and radio emission of the bursts is constrained as <6 × 107, and the ratio between optical (U band) and radio as <1.19 × 106. We detect no multiwavelength counterpart to the PRS. The 3σ luminosity upper limits are 1.04 × 1047 (15–150 keV), 8.81 × 1042 (0.3–10 keV), 9.26 × 1042 (UVW1), and 2.54 × 1042 erg s−1 (U), respectively. We show that the PRS is much more radio-loud than representative pulsar wind nebulae, supernova remnants, extended jets of Galactic X-ray binaries, and ultraluminous X-ray sources, suggestive of boosted radio emission of the PRS.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"39 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143827735","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