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The FAST all sky HI survey(FASHI):The first release of catalog

Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 112-133页

作者： Chuan-Peng Zhang Ming Zhu Peng Jiang Cheng Cheng Jing Wang Jie Wang Jin-Long Xu Xiao-Lan Liu Nai-Ping Yu Lei Qian Haiyang Yu Mei Ai Yingjie Jing Chen Xu Ziming Liu Xin Guan Chun Sun Qingliang Yang menglin huang Qiaoli Hao FAST Collaboration Guizhou Radio Astronomical Observatory Guizhou UniversityGuiyang 550000China National Astronomical Observatories Chinese Academy of Sciences(CAS)Beijing 100101China Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesCASBeijing 100101China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China

The FAST All Sky HI survey(FASHI)was designed to cover the entire sky observable by the Five-hundred-meter Aperture Spherical radio Telescope(FAST),spanning approximately 22000 square degrees of declination between-14°and+66°,and in the frequency range of 1050-1450 MHz,with the expectation of eventually detecting more than 100000 HI *** August 2020 and June 2023,FASHI had covered more than 7600 square degrees,which is approximately 35%of the total sky observable by *** has a median detection sensitivity of around 0.76 m Jy beam-1and a spectral line velocity resolution of~6.4 km s-1at a frequency of~1.4 *** of now,a total of 41741 extragalactic HI sources have been detected in the frequency range 1305.5-1419.5 MHz,corresponding to a redshift limit of z■*** cross-matching FASHI sources with the Siena Galaxy Atlas(SGA)and the Sloan Digital Sky Survey(SDSS)catalogs,we found that 16972(40.7%)sources have spectroscopic redshifts and 10975(26.3%)sources have only photometric *** of the remaining 13794(33.0%)HI sources are located in the direction of the Galactic plane,making their optical counterparts difficult to identify due to high extinction or high contamination of Galactic stellar *** on current survey results,the FASHI survey is an unprecedented blind extragalactic H I *** has higher spectral and spatial resolution and broader coverage than the Arecibo Legacy Fast ALFA Survey(ALFALFA).When completed,FASHI will provide the largest extragalactic HI catalog and an objective view of HI content and large-scale structure in the local universe.

关键词： surveys redshifts galaxies telescope radio lines HI line

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对外投资政策、逆向技术溢出与技术依赖对创新绩效的影响效应

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经济问题探索 2024年第5期 149-167页

作者：黄梦琳李富有西安交通大学经济与金融学院西安710061

对外投资是经济全球化背景下重要战略,创新绩效是企业持续发展的主要动力,对外投资产生逆向技术溢出提升企业创新绩效,对外投资同时伴随技术依赖不利于企业创新长期发展。对外投资政策是直接调节对外投资,间接影响逆向技术溢出与技术依... 详细信息

对外投资是经济全球化背景下重要战略,创新绩效是企业持续发展的主要动力,对外投资产生逆向技术溢出提升企业创新绩效,对外投资同时伴随技术依赖不利于企业创新长期发展。对外投资政策是直接调节对外投资,间接影响逆向技术溢出与技术依赖对创新绩效作用的关键因素。本文以对外投资为门槛分析其对创新绩效的分效应,采用PSTR模型估计得知,随着对外投资水平提高,中区制、高区制地区逆向技术溢出、技术依赖对创新绩效影响显著但方向相反。采用面板固定效应模型分析总效应,逆向技术溢出与技术依赖的交互作用抑制企业创新绩效的提高,同时对外投资政策力度发挥抑制效应,政策连续性、政策稳定性发挥激励效应。从高技术行业与其他行业、不同企业性质和企业规模角度进行异质性分析,通过投资方式、创新意愿、创新能力、创新动机、创新合作对创新绩效进行机制检验,并提出改善对外投资政策及提升创新绩效的有关建议。

关键词：政策力度政策连续性政策稳定性逆向技术溢出技术依赖创新绩效

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Earth-abundant photovoltaic semiconductor NaSbS2 in the rocksalt-derived structure:A first-principles study

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Progress in Natural Science:Materials International 2019年第6期29卷 322-328页

作者： Xian Zhang menglin huang Peng Xu Chen-Min Dai Zenghua Cai Dan Han Shiyou Chen Key Laboratory of Polar Materials and Devices (MOE) and Department of Optoelectronics East China Normal University Department of Physics China Three Gorges University Collaborative Innovation Center of Extreme Optics Shanxi University

NaSbS2was recently proposed as a novel photovoltaic semiconductor with earth-abundant component elements,but its fundamental material properties have not been well *** systematical first-principles calculations for its electronic,optical and defect properties were carried out in the present study,and the results show that:i)NaSbS2in the rocksalt-derived structure has a quasi-direct band gap and thus may have long minority carrier lifetime;ii) its absorption coefficients are as high as 10~4～10~5 cm-1for the visible light and almost isotropic despite that the structure is distorted relative to the high-symmetry rocksalt structure;iii) the effective masses of the electron and hole carriers are anisotropic with much larger values along the z direction than in the x-y plane,and hence the orientational control of thin films should be important for enhancing the photovoltaic performance;iv) the valence and conduction band edges of NaSbS2are close to those of CuGaSe2) so the n-CdS/pCuGaSe2device structure can be inherited to form the n-CdS/p-NaSbS2solar cells;v) the acceptor defects (NaSbantisites and Na vacancies) have very high concentration,making the synthesized NaSbS2always be p-type;vi)the S-rich condition can suppress the formation of deep-level donor defects (S vacancies and SbNaantisites) and therefore should be adopted for fabricating high-efficiency NaSbS2solar cells.

关键词： NaSbS2 Photovoltaic semiconductor Optical absorption coefficients Defects First-principles calculation

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DASP: Defect and Dopant ab-initio Simulation Package

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Journal of Semiconductors 2022年第4期43卷 82-95页

作者： menglin huang Zhengneng Zheng Zhenxing Dai Xinjing Guo Shanshan Wang Lilai Jiang Jinchen Wei Shiyou Chen Key Laboratory of Computational Physical Sciences(MOE) and State Key Laboratory of ASIC and SystemSchool of MicroelectronicsFudan UniversityShanghai 200433China

In order to perform automated calculations of defect and dopant properties in semiconductors and insulators, we developed a software package, the Defect and Dopant ab-initio Simulation Package(DASP), which is composed of four modules for calculating:(ⅰ) elemental chemical potentials,(ⅱ) defect(dopant) formation energies and charge-state transition levels,(ⅲ) defect and carrier densities and(ⅳ) carrier dynamics properties of high-density defects. DASP uses the materials genome database for quick determination of competing secondary phases when calculating the elemental chemical potential that stabilizes compound semiconductors. DASP calls the ab-initio software to perform the total energy, structural relaxation and electronic structure calculations of the defect supercells with different charge states, based on which the defect formation energies and charge-state transition levels are calculated. Then DASP can calculate the equilibrium densities of defects and electron and hole carriers as well as the Fermi level in semiconductors under different chemical potential conditions and growth/working temperature. For high-density defects, DASP can calculate the carrier dynamics properties such as the photoluminescence(PL) spectrum and carrier capture cross sections which can interpret the deep level transient spectroscopy(DLTS). Here we will show three application examples of DASP in studying the undoped GaN, C-doped GaN and quasi-one-dimensional SbSeI.

关键词： defect dopant first-principles calculations carrier dynamics

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Defect physics of the quasi-two-dimensional photovoltaic semiconductor GeSe

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Chinese Physics B 2022年第11期31卷 60-66页

作者：闫赛超魏金宸王珊珊黄梦麟吴宇宁陈时友 Key Laboratory of Polar Materials and Devices(MOE)and Department of Electronics East China Normal UniversityShanghai 200241China State Key Laboratory of ASIC and System School of MicroelectronicsFudan UniversityShanghai 200433China

GeSe has recently emerged as a photovoltaic absorber material due to its attractive optical and electrical properties as well as earth abundancy and low ***,the efficiency of GeSe thin-film solar cells(TFSCs)is still low compared to the Shockley–Queisser *** defects are believed to play important roles in the electrical and optical properties of GeSe thin ***,we perform first-principles calculations to study the defect characteristics of *** results demonstrate that no matter under the Ge-rich or Se-rich condition,the Fermi level is always located near the valence band edge,leading to the p-type conductivity of undoped *** Se-rich condition,the Ge vacancy(V_(Ge))has the lowest formation energy,with a(0/2–)charge-state transition level at 0.22 eV above the valence band *** high density(above 10^(17)cm^(-3))and shallow level of VGeimply that it is the p-type origin of *** Se-rich growth condition,Seihas a low formation energy in the neutral state,but it does not introduce any defect level in the band gap,suggesting that it neither contributes to electrical conductivity nor induces non-radiative *** addition,Gei introduces a deep charge-state transition level,making it a possible recombination ***,we propose that the Se-rich condition should be adopted to fabricate high-efficiency GeSe solar cells.

关键词： GeSe bulk point defect concentration photovoltaic

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First-principles exploration of defect-pairs in GaN

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Journal of Semiconductors 2020年第3期41卷 23-31页

作者： He Li menglin huang Shiyou Chen Key Laboratory of Polar Materials and Devices(MOE)and Department of Electronics East China Normal UniversityShanghai 200241China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China

Using first-principles calculations,we explored all the 21 defect-pairs in GaN and considered 6 configurations with different defect-defect distances for each defect-pair.15 defect-pairs with short defect–defect distances are found to be stable during structural relaxation,so they can exist in the GaN lattice once formed during the irradiation of high-energy particles.9 defect-pairs have formation energies lower than 10 eV in the neutral *** vacancy-pair VN–VN is found to have very low formation energies,as low as 0 eV in p-type and Ga-rich GaN,and act as efficient donors producing two deep donor levels,which can limit the p-type doping and minority carrier lifetime in ***–VN has been overlooked in the previous study of defects in *** of these defect-pairs act as donors and produce a large number of defect levels in the band *** formation energies and concentrations are sensitive to the chemical potentials of Ga and N,so their influences on the electrical and optical properties of Ga-rich and N-rich GaN after irradiation should differ *** results about the defect-pairs provide fundamental data for understanding the radiation damage mechanism in GaN and simulating the defect formation and diffusion behavior under irradiation.

关键词： GaN first-principles calculations radiation damage defect-pairs point defects

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基于Prompt学习的无监督关系抽取模型

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计算机应用 2023年第7期43卷 2010-2016页

作者：黄梦林段磊张袁昊王培妍李仁昊四川大学计算机学院成都610065 四川大学“医学+信息”中心成都610041

无监督关系抽取旨在从无标签的自然语言文本中抽取实体之间的语义关系。目前,基于变分自编码器(VAE)架构的无监督关系抽取模型通过重构损失提供监督信号来训练模型,这为完成无监督关系抽取任务提供了新思路。针对此类模型无法有效地理... 详细信息

无监督关系抽取旨在从无标签的自然语言文本中抽取实体之间的语义关系。目前,基于变分自编码器(VAE)架构的无监督关系抽取模型通过重构损失提供监督信号来训练模型,这为完成无监督关系抽取任务提供了新思路。针对此类模型无法有效地理解上下文信息、依赖数据集归纳偏置的问题,提出基于Prompt学习的无监督关系抽取(PURE)模型,其中包括关系抽取和链接预测两个模块。在关系抽取模块中设计了上下文感知的Prompt模板函数以融入上下文信息,并将无监督关系抽取任务转换为掩码预测任务,从而充分利用预训练阶段获得的知识完成关系抽取。在链接预测模块中则通过预测关系三元组中的缺失实体提供监督信号联合训练两个模块。在两个公开真实关系抽取数据集上进行了大量实验,得到的结果表明PURE模型能有效利用上下文信息并且不依赖数据集归纳偏置,相较于目前最优的基于VAE架构的模型UREVA(Variational Autoencoder-based Unsupervised Relation Extraction model)在NYT数据集上的B-cubed F1指标上提升了3.3个百分点。

关键词：无监督关系抽取 Prompt学习变分自编码器预训练语言模型无监督学习

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“一带一路”背景下健全促进对外投资政策和服务体系研究

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西安交通大学学报（社会科学版） 2023年第6期43卷 78-94页

作者：李富有高莉王坤薛青梅王少辉黄梦琳西安交通大学经济与金融学院陕西西安710061

在深入推进“一带一路”建设背景下,健全促进对外投资政策和服务体系是中国促进对外投资高质量发展、实现高水平对外开放的重要举措,也是坚持和完善中国特色社会主义制度、推进国家治理体系与治理能力现代化的重要体现。以党的十九大、... 详细信息

在深入推进“一带一路”建设背景下,健全促进对外投资政策和服务体系是中国促进对外投资高质量发展、实现高水平对外开放的重要举措,也是坚持和完善中国特色社会主义制度、推进国家治理体系与治理能力现代化的重要体现。以党的十九大、二十大会议精神为指导,研究阐释健全促进对外投资政策和服务体系的理论内涵,比较分析中国促进对外投资政策和服务体系与发达国家的主要区别,深入剖析对外投资政策和服务体系现存的难点问题及其成因。在此基础上,运用文本挖掘技术和问卷调查法构建2013—2022年促进对外投资政策和服务体系的研究数据库,基于政策一致性模型(PMC)和模糊层次分析法(F-AHP)分别构建及评价促进对外投资政策与服务指标体系。实证分析发现,2013—2022年中国促进对外投资政策力度逐年上升,且2018年之前政策调整变化较大,2018年以后政策调整趋于平稳。中国促进对外投资服务体系指数呈逐年上升趋势,但指数分值总体不高。利用向量自回归模型(VAR)和双向固定效应模型分别评价中国促进对外投资政策和服务体系的运行效果,发现中国对外投资政策和服务体系积极促进了对外直接投资、对外承包工程的发展,但是对于对外劳务合作无显著影响。此外,使用空间滞后模型和双向固定效应模型论证了中国对外投资政策和服务体系能够有效促进东道国的技术升级和国民人均收入的增长;提出了健全促进对外投资政策和服务体系改革的实施路径和对策建议。在促进对外投资政策支持体系优化方面,构建促进对外投资政策机构、支持政策和专项政策为一体的促进对外投资政策支持体系,建立“时空立体式”促进对外投资优惠政策体系;健全促进对外投资政策供求平衡与政策协调配合机制,从供给和需求角度切入分析促进对外投资政策供求匹配的作用机制,通过促进对外投资政策组织架构协调、政策内容协调配合及政策利益平衡与利益调整实现各类政策的协调配合;建立促进对外投资政策在面临复杂环境与重大冲突时的动态调整运行机制,实现复杂环境与重大冲突下政策调整的科学性。在促进对外投资服务体系改革方面,通过加强促进对外投资服务支持体系的顶层规划设计,创新服务决策机制;通过创建法治型、服务型、数字型新型对外投资政府服务体系提高对外投资的服务效能;在国家治理体系与治理能力改革框架下,重点推进促进对外投资的系统治理、综合治理、源头治理和依法治理“四个治理”改革,建立对外投资争端治理机制、境外领事保护工作机制、境外经贸园区合作建设机制、对外投资宏观调控机制“四种机制”;健全对外投资风险分析及防范措施以强化公共服务功能。

关键词：对外投资政策对外投资服务体系 “一带一路” 高水平对外开放对外直接投资对外承包工程

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城乡收入流动预测与收入差距:区域及来源结构分析

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经济问题探索 2020年第8期 74-86页

作者：李富有黄梦琳西安交通大学经济与金融学院西安710061

收入流动性与收入差距是影响社会经济稳定发展的基本元素,采用2013年至2018年城乡人均可支配收入指标,首先利用马尔科夫模型预测收入流动性并判断城乡收入差距变化趋势,其次利用门槛效应模型验证城乡收入差距与经济发展水平的关系,最后... 详细信息

收入流动性与收入差距是影响社会经济稳定发展的基本元素,采用2013年至2018年城乡人均可支配收入指标,首先利用马尔科夫模型预测收入流动性并判断城乡收入差距变化趋势,其次利用门槛效应模型验证城乡收入差距与经济发展水平的关系,最后利用空间杜宾模型证明经济发展水平、政府干预、人口流动、市场制度等因素对缩小城乡收入差距的空间溢出作用。得出主要结论:(1)马尔科夫预测模型显示全国、城镇、农村收入五等分占比持续变化,城乡收入流动非固化但收入差距逐渐拉大;(2)门槛效应模型结果表明经济发展水平位于人均生产总值26432. 92元和37552. 55元具有显著的双重门槛效应,随着人均生产总值的提高抑制城乡收入差距作用不断增强;(3)空间杜宾模型结果表明,城镇财产性收入、经济发展水平、市场制度有利于缩小本地区城乡收入差距,而提高农村人均可支配收入降低本地区城乡收入差距并对邻近地区收入差距的缩小具有显著的溢出效应。最后,从收入来源结构调整视角提出改善城乡收入差距的措施。

关键词：收入流动马尔科夫预测门槛效应空间杜宾模型

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Searching for the Nano-Hertz Stochastic Gravitational Wave Background with the Chinese Pulsar Timing Array Data ReleaseⅠ

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Research in Astronomy and Astrophysics 2023年第7期23卷 300-311页

作者： Heng Xu Siyuan Chen Yanjun Guo Jinchen Jiang Bojun Wang Jiangwei Xu Zihan Xue RNicolas Caballero Jianping Yuan Yonghua Xu Jingbo Wang Longfei Hao Jingtao Luo Kejia Lee Jinlin Han Peng Jiang Zhiqiang Shen Min Wang Na Wang Renxin Xu Xiangping Wu Richard Manchester Lei Qian Xin Guan menglin huang Chun Sun Yan Zhu National Astronomical Observatory Chinse Academy of SciencesBeijing 100101China Kavli Institute for Astronomy and Astrophysics Peking UniversityBeijing 100871China Department of Astronomy School of PhysicsPeking UniversityBeijing 100871China Max-Planck institut fúr Radioastronomie Auf Dem HúgelBonnD-53121Germany Hellenic Open University School of Science and Technology26335 PatrasGreece Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Yunnan Astronomical Observatories Chinese Academy of SciencesKunming 650216China Institute of Optoelectronic Technology Lishui UniversityLishui 323000China National Time Service Center Chinese Academy Of SciencesXi'an 710600China Key Laboratory of Radio Astronomy and Technology Chinese Academy of SciencesBeijing 100101China Beijing Laser Acceleration Innovation Center HuairouBeijing 101400China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871China Australia Telescope National Facility CSIRO Space and AstronomyP.O.Box 76Epping NSW 1710Australia

Observing and timing a group of millisecond pulsars with high rotational stability enables the direct detection of gravitational waves(GWs).The GW signals can be identified from the spatial correlations encoded in the times-of-arrival of widely spaced *** Chinese Pulsar Timing Array(CPTA)is a collaboration aiming at the direct GW detection with observations carried out using Chinese radio *** short article serves as a“table of contents”for a forthcoming series of papers related to the CPTA Data Release 1(CPTA DR1)which uses observations from the Five-hundred-meter Aperture Spherical radio ***,after summarizing the time span and accuracy of CPTA DR1,we report the key results of our statistical inference finding a correlated signal with amplitude logA_(c)=-14.4_(-2.8)^(+1.0)for spectral index in the range ofα∈[-1.8,1.5]assuming a GW background(GWB)induced quadrupolar *** search for the Hellings–Downs(HD)correlation curve is also presented,where some evidence for the HD correlation has been found that a 4.6σstatistical significance is achieved using the discrete frequency method around the frequency of 14 n *** expect that the future International Pulsar Timing Array data analysis and the next CPTA data release will be more sensitive to the n Hz GWB,which could verify the current results.

关键词： (stars:)pulsars:general gravitational waves methods:statistical methods:observational

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