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数字普惠金融、融资约束与中小企业投资效率

科学管理研究 2024年第1期42卷 106-114页

作者：李梁殷凤春盐城师范学院商学院江苏盐城224007

通过构建异质性随机前沿模型,利用北京大学数字普惠金融指数市级数据和上市公司财务数据,探究数字普惠金融对中小企业融资约束和融资不确定性的作用,从而估算出投资效率。研究发现:我国中小企业在投资时面临显著的融资约束,融资约束的... 详细信息

通过构建异质性随机前沿模型,利用北京大学数字普惠金融指数市级数据和上市公司财务数据,探究数字普惠金融对中小企业融资约束和融资不确定性的作用,从而估算出投资效率。研究发现:我国中小企业在投资时面临显著的融资约束,融资约束的存在使得实际投资水平比最优投资水平低了30%-40%,平均投资效率仅为64%,且投资效率存在明显的异质性特征。数字普惠金融的发展能缓解中小企业融资约束,提高投资效率,这一作用在东部地区和非国有企业样本中更加显著。但是,数字普惠金融的发展同时也增加了中小企业的融资不确定性,加剧了金融市场风险。研究为数字普惠金融的发展缓解中小企业融资约束,提升投资效率提供了经验证据,为如何更好地发挥金融市场对中小企业的支持作用,促进经济高质量发展提供了理论依据和政策启示。

关键词：数字普惠金融融资约束投资效率异质性随机前沿模型中小企业

Design of hadronic calorimeter for DarkSHINE experiment

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Nuclear Science and Techniques 2024年第9期35卷 155-167页

作者： Zhen Wang Rui Yuan Han-Qing Liu Jing Chen Xiang Chen Kim Siang Khaw Liang Li Shu Li Kun Liu Qi-Bin Liu Si-Yuan Song tong Sun Xiao-Long Wang Yu-Feng Wang Hai-Jun Yang Jun-Hua Zhang Yu-Lei Zhang Zhi-Yu Zhao chun-Xiang Zhu Xu-Liang Zhu Yi-Fan Zhu Tsung-Dao Lee Institute Shanghai Jiao Tong University1 Lisuo RoadShanghai 201210China Institute of Nuclear and Particle Physics School of Physics and Astronomy800 Dongchuan RoadShanghai 200240China Key Laboratory for Particle Astrophysics and Cosmology(MOE) Shanghai Key Laboratory for Particle Physics and Cosmology(SKLPPC)Shanghai Jiao Tong University800 Dongchuan RoadShanghai 200240China Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Fudan UniversityShanghai 200443China Institute of Modern Physics Fudan UniversityShanghai 200443China

The sensitivity of the dark photon search through invisible decay final states in low-background experiments relies sig-nificantly on the neutron and muon veto efficiencies,which depend on the amount of material used and the design of the detector *** paper presents the optimized design of the hadronic calorimeter(HCAL)used in the DarkSHINE experiment,which is studied using a GEANT4-based simulation *** geometry is optimized by comparing a traditional design with uniform absorbers to one that uses different thicknesses at different locations on the detector,which enhances the efficiency of vetoing low-energy neutrons at the sub-GeV *** overall size and total amount of material used in the HCAL are optimized to be lower,owing to the load and budget requirements,whereas the overall performance is studied to satisfy the physical objectives.

关键词： Hadronic calorimeter GEANT4 simulation Neutron background Scintillation detector Dark photon

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局部凸起在V形钝前缘模型中的降热特性研究

力学学报 2024年第4期56卷 915-927页

作者：李帅姜振华张珊尹同阎超北京航空航天大学航空科学与工程学院北京100191

三维内转式进气道的唇口结构通常存在复杂的激波干扰及严酷的气动热载荷,严重威胁高超声速飞行器的性能与安全.在6.0马赫的高超声速流动中,以V形钝前缘模型为研究对象,设计了局部凸起的被动流动控制降热方案.采用数值模拟手段,首先研究... 详细信息

三维内转式进气道的唇口结构通常存在复杂的激波干扰及严酷的气动热载荷,严重威胁高超声速飞行器的性能与安全.在6.0马赫的高超声速流动中,以V形钝前缘模型为研究对象,设计了局部凸起的被动流动控制降热方案.采用数值模拟手段,首先研究了局部凸起方案的降热能力以及降热原理,然后初步优化了局部凸起的位置、高度以及宽度等关键设计参数,最后分析了优化后的局部凸起方案的攻角、侧滑角及马赫数的适用性.研究结果表明:上游凸起边缘形成的斜激波与主马赫反射结构形成的透射激波发生干扰,能够减弱其冲击壁面的强度,实现降热的目的;驻点凸起通过改变超声速射流的对撞角度,能够降低其对撞的强度,实现降热的目的.原始方案的降热能力约为37.75%,在对局部凸起的关键设计参数进行初步优化后,优化方案的降热能力将提升至44.60%.设计工况下的优化方案具有良好的攻角适用性,而高度可变的优化方案可以较好地适用于有侧滑角及高马赫数的流动.在研究范围内,高度可变的优化局部凸起方案的降热能力均高于20%.

关键词：内转式进气道 V形钝前缘气动热流动控制局部凸起

电动汽车用多相电驱重构型车载充电系统关键技术综述

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中国电机工程学报 2024年第13期44卷 5281-5296,I0022页

作者：於锋殷琪皓佟明昊张千帆南通大学电气工程学院江苏省南通市226019 南京理工大学机械工程学院江苏省南京市210094 哈尔滨工业大学电气工程及自动化学院黑龙江省哈尔滨市150001

电驱重构型车载充电系统为电动汽车电气部分提供了一种全新轻量化设计思路,旨在利用电驱单元分时执行电驱与充电2种变流功能。相较于三相电驱系统,多相电驱系统具有输出转矩平滑、容错性能强等诸多优势特性。鉴于此,该文首先归纳现有并... 详细信息

电驱重构型车载充电系统为电动汽车电气部分提供了一种全新轻量化设计思路,旨在利用电驱单元分时执行电驱与充电2种变流功能。相较于三相电驱系统,多相电驱系统具有输出转矩平滑、容错性能强等诸多优势特性。鉴于此,该文首先归纳现有并网式多相电驱重构型车载充电系统的拓扑结构与控制策略,并介绍其容错运行方案;然后,着重分析太阳能电动汽车用多能量端口电驱重构型车载充电系统的工作原理与控制策略;最后,总结全文并对多相电驱重构型车载充电系统的发展方向进行展望。

关键词：电驱重构型车载充电系统电动汽车多相电机太阳能电动汽车关键技术

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Global status and trends in hepatitis B virus DNA mutation research from 2003 to 2022:A comprehensive bibliometric view

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Portal Hypertension & Cirrhosis 2024年第1期3卷 14-21页

作者： Ming Li Xiaoming Xu Yong Liu Minxin Mao Yu Geng Shengxia yin Xin tong Chao Wu Jie Li Department of Infectious Diseases Nanjing Drum Tower Hospital Clinical College of Nanjing University of Chinese MedicineNanjingJiangsuChina Department of Infectious Diseases Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingJiangsuChina Department of Laboratory Medicine Nanjing Drum Tower HospitalAffiliated Hospital of Medical SchoolNanjing UniversityNanjingJiangsuChina Institute of Viruses and Infectious Diseases Nanjing UniversityNanjingJiangsuChina

Aims:Hepatitis B virus(HBV)is an enveloped DNA virus belonging to the Hepadnaviridae *** is a significant contributor to the prevalence of chronic liver disease on a global *** in HBV DNA can affect the diagnosis,treatment,and prognosis of patients with chronic hepatitis *** numerous studies on HBV DNA mutations have been conducted,few bibliometric studies have been performed to *** study aimed to analyze changes in scientific output to gain a better understanding of the current research status and identify potential new research directions in the field of HBV DNA ***:Relevant studies published between 2003 and 2022 were retrieved from the Web of Science Core Collection *** version 6.1.R6 was used to construct network maps to evaluate collaborations among countries,institutions,authors,journals,and ***:In total,1508 publications over the past 20 years were obtained,mainly from China,the United States,and *** major research institutions in China included the University of Hong Kong,Fudan University,and Peking *** Ching Lung was the most productive author,whereas Anna Suk-Fong Lok was the most frequently co-cited *** keyword“HBsAg”was the strongest burst keyword in recent years,indicating possible future study ***:This bibliometric analysis intuitively revealed the overall research status of HBV DNA mutations,providing valuable information for researchers,funding agencies,and policymakers to explore the current research status,research hotspots,and new directions for future research.

关键词： bibliometrics DNA hepatitis B virus mutation

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小胶质细胞表型和功能研究进展

中国药理学通报 2024年第3期40卷 410-415页

作者：魏晓佟郭瑞张启春南京中医药大学药学院江苏南京210023 南京中医药大学医学院·整合医学学院江苏南京210023

小胶质细胞是中枢神经系统的常驻髓系来源免疫细胞,参与大脑的先天性和获得性免疫反应。在健康和病理下的脑组织功能维持中,小胶质细胞发挥保护或损伤性作用,此取决于细胞的表型和功能。传统的小胶质细胞分型借鉴外周的巨噬细胞的促炎... 详细信息

小胶质细胞是中枢神经系统的常驻髓系来源免疫细胞,参与大脑的先天性和获得性免疫反应。在健康和病理下的脑组织功能维持中,小胶质细胞发挥保护或损伤性作用,此取决于细胞的表型和功能。传统的小胶质细胞分型借鉴外周的巨噬细胞的促炎和抗炎表型,因此也被称为“脑巨噬细胞”。随着新的技术和研究方法的发展,越来越多的小胶质细胞表型被发现,新发现的小胶质细胞表型通常具有疾病、脑区和功能的特异性,为研究特定疾病的发生发展的病理学过程并发展相应的干预措施提供了重要依据。该文就小胶质细胞表型和功能研究的最新进展进行回顾性综述,分析了小胶质细胞谱系构成及其异质性功能。

关键词：小胶质细胞表型功能疾病相关小胶质细胞白质相关小胶质细胞髓样细胞触发受体2

Performance in the Fundamentals of Laparoscopic Surgery: Does it reflect global rating scales in the Objective Structured Assessment of Technical Skills in porcine laparoscopic surgery?

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Asian Journal of Urology 2024年第3期11卷 443-449页

作者： Ho Yee Tiong Wei Zheng So Jeremy Yuen-chun Teoh Shuji Isotani Gang Zhu Teng Aik Ong Eddie Shu-yin Chan Peggy Sau-Kwan Chu Kittinut Kijvikai Ming Liu Bannakji Lojanapiwat Michael Wong Anthony Chi-Fai Ng Yong Loo Lin School of Medicine Department of SurgeryNational University of SingaporeSingapore S.H.Ho Urology Centre Department of SurgeryThe Chinese University of Hong KongHong KongChina Department of Urology Juntendo University Graduate School of MedicineTokyoJapan Department of Urology National University HospitalSingapore Department of Urology Beijing United Family HospitalBeijingChina Department of Surgery University of Malaya Specialist CentreKuala LumpurMalaysia Division of Urology Department of SurgeryTuen Mun HospitalHong Kong Department of Urology Ramathibodi HospitalMahidol UniversitySalayaThailand Department of Urology Beijing HospitalBeijingChina Department of Urology Chiangmai Ram HospitalChiang MaiThailand International Urology Fertility&Gynaecology CentreSingapore

Objective:To correlate the utility of the Fundamentals of Laparoscopic Surgery(FLS)manual skills program with the Objective Structured Assessment of Technical Skills(OSATS)global rating scale in evaluating operative ***:The Asian Urological Surgery Training and Educational Group(AUSTEG)Laparoscopic Upper Tract Surgery Course implemented and validated the FLS program for its usage in laparoscopic surgical ***’basic laparoscopic skills were assessed using three different training models(peg transfer,precision cutting,and intra-corporeal suturing).They also performed live porcine laparoscopic surgery at the same *** surgery skills were assessed by blinded faculty using the OSATS rating ***:From March 2016 to March 2019,a total of 81 certified urologists participated in the course,with a median of 5 years of post-residency *** differences in task time did not reach statistical significance,those with more surgical experience were visibly faster at completing the peg transfer and intra-corporeal suturing FLS ***,they took longer to complete the precision cutting task than participants with less *** OSATS scores correlated weakly with all three FLS tasks(peg transfer time:r=0.331,r^(2)=0.110;precision cutting time:r=0.240,r^(2)=0.058;suturing with intracorporeal knot time:r=0.451,r^(2)=0.203).Conclusion:FLS task parameters did not correlate strongly with OSATS globing rating scale *** FLS task models demonstrated strong validity,it is important to assimilate the inconsistencies when benchmarking technical proficiency against real-life operative competence,as evaluated by FLS and OSATS,respectively.

关键词： TheFundamentalsof Laparoscopic Surgery The Objective Structured Assessment of Technical Skills Laparoscopic training Surgical education Surgical training Urological laparoscopic surgery

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单线态裂分中间态的理论研究进展

物理学进展 2024年第3期44卷 112-122页

作者：童磊张春峰南京大学物理学院南京210093 南京大学南通材料工程技术研究院南通226001

单线态裂分是指有机材料在光激发后,从一个单重态激子转变为两个三重态激子的光物理过程。该过程有望提高光电转换效率,因而受到了广泛的关注。研究发现单线态裂分中存在一个关键的中间态,而如何构建中间态的波函数则是重要的挑战。本... 详细信息

单线态裂分是指有机材料在光激发后,从一个单重态激子转变为两个三重态激子的光物理过程。该过程有望提高光电转换效率,因而受到了广泛的关注。研究发现单线态裂分中存在一个关键的中间态,而如何构建中间态的波函数则是重要的挑战。本文着重介绍了双激发态波函数构建的两类理论模型,而后讨论了振动、轨道和自旋相互作用对中间态形成和解离的影响。最后总结了进一步的理论研究将面临的挑战。

关键词：单线态裂分双激发态电子态耦合交换相关能

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The relationship between the distribution of HBcAg in liver cells and the pathological manifestations of the liver in 429 HBeAg-positive chronic HBV-infected individuals

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Gastroenterology & Hepatology Research 2024年第3期6卷 10-15页

作者： Fan Nie Chang-chun Zeng Guang-Dong tong Mu-Min Shao Xiao-Hua Le Xin Deng Da-Qiao Zhou National Clinical Research Center for Infectious Diseases Shenzhen 518112China Central Laboratory of Shenzhen Longhua District Central Hospital Shenzhen 518112China Hepatology Department of Shenzhen Traditional Chinese Medicine Hospital Shenzhen 518112China Pathology Department of Shenzhen Traditional Chinese Medicine Hospital Shenzhen 518112China Pathology Department of Shenzhen Third People's Hospital Shenzhen 518112China Traditional Chinese Medicine Department of Shenzhen Third People's Hospital Shenzhen 518112China

Background:The natural history of chronic HBV infection is typically characterized by four stages:the immune tolerance period,the immune clearance period,the immune control period,and the immune escape *** stages are associated with the distribution of HBcAg in liver cells;however,this relationship remains a topic of broad debate within the field of liver *** objectively and quantitatively measure the intracellular distribution of HBcAg,this paper aims to design a method referred to as the“layered evaluation method”and to examine its ***:The distribution of HBcAg in liver cells is assessed using Image Pro Plus image processing software,along with calculations of cytoplasmic and nuclear positive staining ***:The findings indicate that the highest proportion of patients exhibited a positive cytoplasmic expression rate ranging from 0-2.5%.More than 40% of the total sample was categorized within the 0-2.5% positive nuclear expression *** HBcAg cytoplasmic positive staining rates were classified into five levels:a cytoplasmic HBcAg positive staining rate of less than 0.05% is designated as level 0,indicating negative expression;a staining rate between 0.05% and 5% is classified as level 1;a rate from 5% to less than 10% is classified as level 2;a rate from 10% to less than 20% is classified as level 3;and a nuclear positivity rate exceeding 20% is classified as level ***:The inflammatory activity grade in these patients was positively correlated with the cytoplasmic distribution of ***,the nuclear distribution rate of HBcAg was significantly higher in the G3 group compared to the other groups.

关键词： distribution of HBcAg pathological manifestations of the liver positive staining rate