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Influencing Factors of Total Factor Energy Efficiency in Bohai Rim Region Based on DEA-Tobit Model 被引量:1
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作者 Weifeng Gong Xiaohong Qi +2 位作者 ChuanhuiWang Wenwen Li Yang Xu 《Energy Engineering》 EI 2022年第4期1663-1679,共17页
Bohai Rim region is an important economic development area and a large carbon emission area in China.It is of great significance to explore the total factor energy efficiency and its influencing factors for the low ca... Bohai Rim region is an important economic development area and a large carbon emission area in China.It is of great significance to explore the total factor energy efficiency and its influencing factors for the low carbon transformation and high-quality development of the Bohai Rim region.Based on the total factor energy efficiency framework,the DDF-DEA model was used to calculate the total factor energy efficiency,and the internal and external differences of the total factor energy efficiency were further analyzed.The internal and external influencing factors were determined by ML index method and classical endogenous growth theory,and then the Tobit panel model was used to empirically analyze the action mechanism of all influencing factors of total factor energy efficiency in the Bohai Rim region.The results show that the pure technical efficiency,scale efficiency and technological progress among the internal influencing factors contribute to the improvement of energy efficiency in the Bohai Rim region.Industrial structure,industrial internal structure and ownership structure inhibit the improvement of energy efficiency.Energy consumption structure and energy endowment also have a negative impact on energy efficiency.Therefore,measures such as promoting technological progress,adjusting economic structure and optimizing energy structure will effectively improve total factor energy efficiency in the Bohai Rim region. 展开更多
关键词 Total factor energy efficiency influencing factors Bohai Rim region dea-tobit model ML index method
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海南自贸港上市公司融资效率的影响因素研究——基于DEA-Tobit模型
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作者 林丽娟 彭其 《南海学刊》 2024年第1期21-31,共11页
发挥资本市场支持海南自贸港高质量发展的作用,提高上市公司质量,需要重点解决好上市公司融资效率问题。以2018—2022年20家海南自贸港上市公司为研究样本,运用DEA-Tobit模型对它们的融资效率进行静态和动态分析,研究影响融资效率的因素... 发挥资本市场支持海南自贸港高质量发展的作用,提高上市公司质量,需要重点解决好上市公司融资效率问题。以2018—2022年20家海南自贸港上市公司为研究样本,运用DEA-Tobit模型对它们的融资效率进行静态和动态分析,研究影响融资效率的因素,结果显示:海南自贸港上市公司的融资效率整体处于较低水平,但呈上升趋势,主要得益于技术进步;宏观经济因素、股权结构和企业成长能力等对融资效率的影响不明显。海南自贸港上市公司可通过强化上市公司管理水平及创新能力,提升上市公司财务管理水平,重视人才与科技的作用,牢抓全面注册制改革发展机遇,加快推进资本市场改革与开放等措施提高融资效率。 展开更多
关键词 海南自贸港 上市公司 dea-tobit模型 融资效率
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福建省专利质量对海洋技术创新效率的影响——基于DEA-Tobit模型的实证研究
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作者 陈思佳 《福建金融管理干部学院学报》 2024年第1期75-84,共10页
海洋技术创新是推动海洋经济转型升级、提升海洋经济高质量发展的重要驱动力,如何提升海洋技术创新效率是当前面临的重要问题。为探讨专利质量是否影响海洋技术创新效率的提升,本文基于2007-2021年海洋统计数据,运用二阶段DEA模型测算... 海洋技术创新是推动海洋经济转型升级、提升海洋经济高质量发展的重要驱动力,如何提升海洋技术创新效率是当前面临的重要问题。为探讨专利质量是否影响海洋技术创新效率的提升,本文基于2007-2021年海洋统计数据,运用二阶段DEA模型测算福建省海洋技术创新效率,综合分析海洋科技研发效率和科技成果转化效率,进一步分析专利质量对海洋技术创新效率的影响。研究结果表明:2007-2021年福建省海洋技术创新整体效率较高,呈上升趋势;分阶段看,海洋科技研发效率总体平均水平低于科技成果转化效率。Tobit模型回归结果表明专利质量的提高对海洋技术创新整体效率及分阶段的研发效率和成果转化效率的提升均具有促进作用。此外,海洋经济规模、海洋产业结构、科研平台数、科研院校专利占比等因素对海洋技术创新效率也具有一定的影响。 展开更多
关键词 专利质量 二阶段DEA模型 TOBIT模型 海洋技术创新效率 福建省
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采用STAMP-24Model的多组织事故分析
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作者 曾明荣 秦永莹 +2 位作者 刘小航 栗婧 尚长岭 《安全与环境学报》 CAS CSCD 北大核心 2024年第7期2741-2750,共10页
安全生产事故往往由多组织交互、多因素耦合造成,事故原因涉及多个组织。为预防和遏制多组织生产安全事故的发生,基于系统理论事故建模与过程模型(Systems-Theory Accident Modeling and Process,STAMP)、24Model,构建一种用于多组织事... 安全生产事故往往由多组织交互、多因素耦合造成,事故原因涉及多个组织。为预防和遏制多组织生产安全事故的发生,基于系统理论事故建模与过程模型(Systems-Theory Accident Modeling and Process,STAMP)、24Model,构建一种用于多组织事故分析的方法,并以青岛石油爆炸事故为例进行事故原因分析。结果显示:STAMP-24Model可以分组织,分层次且有效、全面、详细地分析涉及多个组织的事故原因,探究多组织之间的交互关系;对事故进行动态演化分析,可得到各组织不安全动作耦合关系与形成的事故失效链及管控失效路径,进而为预防多组织事故提供思路和参考。 展开更多
关键词 安全工程 系统理论事故建模与过程模型(STAMP) 24model 多组织事故 原因分析
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基于改进24Model-ISM-SNA建筑工人不安全行为关联路径研究
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作者 赵平 刘钰 +1 位作者 靳丽艳 王佳慧 《工业安全与环保》 2024年第7期37-40,共4页
建筑施工现场环境复杂,为有效控制不安全行为发生,基于行为安全“2-4”模型对360份具有代表性的建筑安全事故调查报告进行分析,提取出22个不安全行为的主要影响因素。利用灰色关联分析方法(GRA)改进的集成ISM-SNA模型,将不安全行为风险... 建筑施工现场环境复杂,为有效控制不安全行为发生,基于行为安全“2-4”模型对360份具有代表性的建筑安全事故调查报告进行分析,提取出22个不安全行为的主要影响因素。利用灰色关联分析方法(GRA)改进的集成ISM-SNA模型,将不安全行为风险因素划分为表层、过渡层与深层,然后对风险因素进行可视化分析、中心度分析及凝聚子群分析,揭示了各致因因素间的关联关系和传导路径。结果表明,建筑工人不安全行为影响因素可划分成7级3阶的多级递阶结构,安全意识、现场监管、外部环境是建筑工人不安全行为的关键影响因素,同时现场监管和隐患排查到位能有效降低不安全行为的发生。 展开更多
关键词 建筑工人 不安全行为 24model 解释结构模型(ISM) 社会网络分析(SNA)
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基于24Model-D-ISM的地铁站火灾疏散影响因素研究
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作者 孙世梅 张家严 《中国安全科学学报》 CAS CSCD 北大核心 2024年第4期153-159,共7页
为预防地铁站火灾事故,深入了解地铁站火灾人员疏散影响因素间的内在联系与层次结构,基于第6版“2-4”模型(24Model)分析63起地铁站火灾疏散事故,充分考虑各个因素之间的交互作用,提取19个影响地铁站人员疏散的关键因素,建立地铁站火灾... 为预防地铁站火灾事故,深入了解地铁站火灾人员疏散影响因素间的内在联系与层次结构,基于第6版“2-4”模型(24Model)分析63起地铁站火灾疏散事故,充分考虑各个因素之间的交互作用,提取19个影响地铁站人员疏散的关键因素,建立地铁站火灾人员疏散影响因素指标体系;采用算子客观赋权法(C-OWA)改进决策试验与评价实验法(DEMATEL),确定地铁站火灾人员疏散的重要影响因素;在此基础上,采用解释结构模型(ISM)分析各个因素间的层次结构及相互作用路径,构建地铁站火灾人员疏散影响因素的多级递阶结构模型。研究结果表明:疏散引导、恐慌从众行为、人员拥挤为地铁站火灾人员疏散的关键影响因素;地铁站火灾人员疏散受表层因素、中间层因素、深层因素共同作用的影响,其中,疏散教育与培训、设施维护与检查、疏散预案等因素是根源影响因素,重视根源影响因素的改善有利于从本质上预防和控制事故的发生。 展开更多
关键词 “2-4”模型(24model) 决策试验与评价实验法(DEMATEL) 解释结构模型(ISM) 地铁站 火灾疏散 影响因素
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金融助推体育产业发展的效率测算及影响因素研究——基于DEA-Tobit模型的实证分析
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作者 邓丰 李海珍 朱伟 《四川体育科学》 2024年第2期113-119,共7页
经济新常态背景下,金融业在推动体育产业发展上起到重要作用,研究二者之间的关系对促进金融-体育系统协调发展具有重要意义。本文以我国2007-2023年上市体育公司金融支持效率为研究对象,采用DEA-BCC模型测算金融支持效率,Tobit面板模型... 经济新常态背景下,金融业在推动体育产业发展上起到重要作用,研究二者之间的关系对促进金融-体育系统协调发展具有重要意义。本文以我国2007-2023年上市体育公司金融支持效率为研究对象,采用DEA-BCC模型测算金融支持效率,Tobit面板模型进行影响因素分析,检验结果显示:我国金融支持体育产业效率均大于0.6,但整体呈波动式走向;东部地区和主板市场金融支持体育产业的发展水平具有一定的代表,且与全样本走势基本一致;企业属性、股权集中度对金融支持体育产业效率有显著的促进作用,企业规模、宏观经济风险会显著抑制金融支持效率,融资约束则对其具有负向不显著影响;对所有样本进行分地区、分市场回归依然得到相似的结论。最后,本文从政府、金融监管当局、体育企业自身提出一定的建议,以促进金融支持体育产业效率的提升。 展开更多
关键词 体育产业 金融支持效率 影响因素 dea-tobit模型 实证分析
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基于DEA-Tobit模型的华东地区公共体育服务效率研究
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作者 张永婷 赵亮 +2 位作者 欧宇轩 许智威 张笑涵 《山东体育科技》 2024年第3期8-14,共7页
公共体育服务是政府为满足公民体育需求所提供的一种体育服务措施,而效率评价是衡量其发展的重要手段。科学的公共体育服务效率评价,能够客观清晰地反映公共体育服务发展情况。构建DEA模型对2016—2018年我国华东地区六省一市的公共体... 公共体育服务是政府为满足公民体育需求所提供的一种体育服务措施,而效率评价是衡量其发展的重要手段。科学的公共体育服务效率评价,能够客观清晰地反映公共体育服务发展情况。构建DEA模型对2016—2018年我国华东地区六省一市的公共体育服务效率评价指标进行测算分析,并运用Tobit模型进行实证检验,探究可能对公共体育服务效率带来影响的外部因素。结果显示:(1)华东地区2016—2018年公共体育服务综合效率值为0.931,纯技术效率值为0.992,规模效率值为0.937,规模报酬呈现递减趋势;(2)地区经济发展水平、人口密度和体育管理人员规模与公共体育服务效率呈正相关,与受教育水平呈负相关。根据研究结果分析华东地区公共体育服务效率问题与差距,提出以下对策建议:减少区域短板,促进协同发展;调整资源配置,提升供给质量;健全监督机制,完善管理体系。 展开更多
关键词 公共体育服务 效率 数据包络分析法 DEA模型 TOBIT模型
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基于DEA-Tobit模型的中国体育公共服务财政支出效率及其影响因素研究
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作者 余喆 陆元兆 《吉林体育学院学报》 2024年第1期69-77,共9页
为探究我国体育公共服务财政支出效率及其存在问题,选取2013—2021年中国31个省份的面板数据,利用CCR、BCC和Malmquist模型进行效率评价,并构建Tobit模型分析其影响因素。研究表明:体育公共服务财政支出综合效率不高,波动较大,规模效率... 为探究我国体育公共服务财政支出效率及其存在问题,选取2013—2021年中国31个省份的面板数据,利用CCR、BCC和Malmquist模型进行效率评价,并构建Tobit模型分析其影响因素。研究表明:体育公共服务财政支出综合效率不高,波动较大,规模效率普遍高于纯技术效率,地区间存在“中部>西部>东部”的异质性特征;除江西和西藏外均存在投入和产出冗余现象;全要素生产率前期波动大,后期趋于稳定;外部影响因素中,人均GDP、人口密度、财政自主权、体育管理人员比例与体育公共服务财政效率呈正相关,未通过显著性检验,城镇化率为负相关且通过显著性检验。据此提出加快财税改革、完善转移支付、加快供给侧改革、坚持新发展理念等发展建议,以期推动体育公共服务高质量发展。 展开更多
关键词 体育公共服务 财政支出效率 dea-tobit模型 影响因素
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基于DEA-Tobit模型的生猪产业绿色发展效率研究
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作者 常静霞 《饲料研究》 CAS 北大核心 2024年第3期176-181,共6页
近年来,生猪产业绿色化取得长足进展。为了解生猪产业绿色发展效率变化情况及相关影响因素,研究首先通过DEA模型对生猪产业绿色发展效率进行测算,研判样本期内生猪产业绿色发展效率变化情况;再利用面板Tobit模型分析生猪产业绿色发展效... 近年来,生猪产业绿色化取得长足进展。为了解生猪产业绿色发展效率变化情况及相关影响因素,研究首先通过DEA模型对生猪产业绿色发展效率进行测算,研判样本期内生猪产业绿色发展效率变化情况;再利用面板Tobit模型分析生猪产业绿色发展效率的影响因素。结果表明:从时间维度观察,生猪产业绿色发展效率在研究期间展现出波动上升的趋势,而在2019年之后,这一趋势则趋于稳定并持续上升。若从空间角度审视,内蒙古、黑龙江等9个省份在生猪产业绿色发展效率方面的提升最为显著。进一步分析动态效率,我们发现规模效率在推动生猪产业绿色发展效率提升中起到了关键作用。此外,资源禀赋、经济发展水平、环境规制、开放程度、交通通达度和规模化水平等要素,均对生猪产业绿色发展效率产生了显著的正向影响,为其提升提供了强大的驱动力。资源禀赋、经济发展水平、环境规制、开放程度、交通通达度和规模化水平均可显著正向提升生猪产业绿色发展效率。因此,应从释放区域资源禀赋、差异化落实环境规制和推动规模化养殖等方面提高生猪产业绿色发展效率。 展开更多
关键词 dea-tobit模型 生猪产业 绿色发展 全要素生产率
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耦合优化蚁群算法与P-Median model的选址模型设计
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作者 顾梓程 胡新玲 《现代电子技术》 北大核心 2024年第3期109-114,共6页
为节省城建部门对于公共体育设施的投入成本以及提高城市人民生活质量,以运动场所优化选址为例,提出一种新型设施选址模型。该模型主要基于P-Median model(最小化阻抗模型)根据需求点数量从全部候选设施选址中选择设施空间位置,让用户... 为节省城建部门对于公共体育设施的投入成本以及提高城市人民生活质量,以运动场所优化选址为例,提出一种新型设施选址模型。该模型主要基于P-Median model(最小化阻抗模型)根据需求点数量从全部候选设施选址中选择设施空间位置,让用户达到离自己最近设施距离成本总和最小的目的,对选址的基本原则和实际情况提出要求,构造目标函数用于优化后蚁群算法求解进行选址工作。优化蚁群算法实现基于Python语言模块,通过改进蚁群原始信息素,提升原有算法的收敛速度,求出目标函数最优解,可以很好地模拟对于运动场所的选址。用二者耦合进行优势互补所设计的选址模型来搜寻研究区蚁群信息素浓度残留最大的栅格像元,从而确定未被已有设施点服务半径覆盖的最佳设施点建立位置。实验结果表明,该新型选址模型相较于最小化阻抗模型与最大化覆盖模型,新增优化设施点使整体服务半径覆盖率分别高出10.42%和6.95%,适合求解较为精确且小规模空间下的选址问题。 展开更多
关键词 蚁群算法 P-Median model 选址模型 GIS 运动场所 位置分配 PYTHON
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Anisotropic time-dependent behaviors of shale under direct shearing and associated empirical creep models 被引量:1
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作者 Yachen Xie Michael Z.Hou +1 位作者 Hejuan Liu Cunbao Li 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第4期1262-1279,共18页
Understanding the anisotropic creep behaviors of shale under direct shearing is a challenging issue.In this context,we conducted shear-creep and steady-creep tests on shale with five bedding orientations (i.e.0°,... Understanding the anisotropic creep behaviors of shale under direct shearing is a challenging issue.In this context,we conducted shear-creep and steady-creep tests on shale with five bedding orientations (i.e.0°,30°,45°,60°,and 90°),under multiple levels of direct shearing for the first time.The results show that the anisotropic creep of shale exhibits a significant stress-dependent behavior.Under a low shear stress,the creep compliance of shale increases linearly with the logarithm of time at all bedding orientations,and the increase depends on the bedding orientation and creep time.Under high shear stress conditions,the creep compliance of shale is minimal when the bedding orientation is 0°,and the steady-creep rate of shale increases significantly with increasing bedding orientations of 30°,45°,60°,and 90°.The stress-strain values corresponding to the inception of the accelerated creep stage show an increasing and then decreasing trend with the bedding orientation.A semilogarithmic model that could reflect the stress dependence of the steady-creep rate while considering the hardening and damage process is proposed.The model minimizes the deviation of the calculated steady-state creep rate from the observed value and reveals the behavior of the bedding orientation's influence on the steady-creep rate.The applicability of the five classical empirical creep models is quantitatively evaluated.It shows that the logarithmic model can well explain the experimental creep strain and creep rate,and it can accurately predict long-term shear creep deformation.Based on an improved logarithmic model,the variations in creep parameters with shear stress and bedding orientations are discussed.With abovementioned findings,a mathematical method for constructing an anisotropic shear creep model of shale is proposed,which can characterize the nonlinear dependence of the anisotropic shear creep behavior of shale on the bedding orientation. 展开更多
关键词 Rock anisotropy Direct shear creep Creep compliance Steady-creep rate Empirical model Creep constitutive model
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Mshpy23:a user-friendly,parameterized model of magnetosheath conditions 被引量:1
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作者 Jaewoong Jung Hyunju Connor +3 位作者 Andrew Dimmock Steve Sembay Andrew Read Jan Soucek 《Earth and Planetary Physics》 EI CSCD 2024年第1期89-104,共16页
Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind−Magnetosphere−Ionosphere Link Explorer(SMILE)will observe magnetosheath and its boundary motion in soft X-rays for understanding magnetopause reconnectio... Lunar Environment heliospheric X-ray Imager(LEXI)and Solar wind−Magnetosphere−Ionosphere Link Explorer(SMILE)will observe magnetosheath and its boundary motion in soft X-rays for understanding magnetopause reconnection modes under various solar wind conditions after their respective launches in 2024 and 2025.Magnetosheath conditions,namely,plasma density,velocity,and temperature,are key parameters for predicting and analyzing soft X-ray images from the LEXI and SMILE missions.We developed a userfriendly model of magnetosheath that parameterizes number density,velocity,temperature,and magnetic field by utilizing the global Magnetohydrodynamics(MHD)model as well as the pre-existing gas-dynamic and analytic models.Using this parameterized magnetosheath model,scientists can easily reconstruct expected soft X-ray images and utilize them for analysis of observed images of LEXI and SMILE without simulating the complicated global magnetosphere models.First,we created an MHD-based magnetosheath model by running a total of 14 OpenGGCM global MHD simulations under 7 solar wind densities(1,5,10,15,20,25,and 30 cm)and 2 interplanetary magnetic field Bz components(±4 nT),and then parameterizing the results in new magnetosheath conditions.We compared the magnetosheath model result with THEMIS statistical data and it showed good agreement with a weighted Pearson correlation coefficient greater than 0.77,especially for plasma density and plasma velocity.Second,we compiled a suite of magnetosheath models incorporating previous magnetosheath models(gas-dynamic,analytic),and did two case studies to test the performance.The MHD-based model was comparable to or better than the previous models while providing self-consistency among the magnetosheath parameters.Third,we constructed a tool to calculate a soft X-ray image from any given vantage point,which can support the planning and data analysis of the aforementioned LEXI and SMILE missions.A release of the code has been uploaded to a Github repository. 展开更多
关键词 MAGNETOSHEATH PYTHON modelING
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Development and validation of a prediction model for early screening of people at high risk for colorectal cancer 被引量:1
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作者 Ling-Li Xu Yi Lin +3 位作者 Li-Yuan Han Yue Wang Jian-Jiong Li Xiao-Yu Dai 《World Journal of Gastroenterology》 SCIE CAS 2024年第5期450-461,共12页
BACKGROUND Colorectal cancer(CRC)is a serious threat worldwide.Although early screening is suggested to be the most effective method to prevent and control CRC,the current situation of early screening for CRC is still... BACKGROUND Colorectal cancer(CRC)is a serious threat worldwide.Although early screening is suggested to be the most effective method to prevent and control CRC,the current situation of early screening for CRC is still not optimistic.In China,the incidence of CRC in the Yangtze River Delta region is increasing dramatically,but few studies have been conducted.Therefore,it is necessary to develop a simple and efficient early screening model for CRC.AIM To develop and validate an early-screening nomogram model to identify individuals at high risk of CRC.METHODS Data of 64448 participants obtained from Ningbo Hospital,China between 2014 and 2017 were retrospectively analyzed.The cohort comprised 64448 individuals,of which,530 were excluded due to missing or incorrect data.Of 63918,7607(11.9%)individuals were considered to be high risk for CRC,and 56311(88.1%)were not.The participants were randomly allocated to a training set(44743)or validation set(19175).The discriminatory ability,predictive accuracy,and clinical utility of the model were evaluated by constructing and analyzing receiver operating characteristic(ROC)curves and calibration curves and by decision curve analysis.Finally,the model was validated internally using a bootstrap resampling technique.RESULTS Seven variables,including demographic,lifestyle,and family history information,were examined.Multifactorial logistic regression analysis revealed that age[odds ratio(OR):1.03,95%confidence interval(CI):1.02-1.03,P<0.001],body mass index(BMI)(OR:1.07,95%CI:1.06-1.08,P<0.001),waist circumference(WC)(OR:1.03,95%CI:1.02-1.03 P<0.001),lifestyle(OR:0.45,95%CI:0.42-0.48,P<0.001),and family history(OR:4.28,95%CI:4.04-4.54,P<0.001)were the most significant predictors of high-risk CRC.Healthy lifestyle was a protective factor,whereas family history was the most significant risk factor.The area under the curve was 0.734(95%CI:0.723-0.745)for the final validation set ROC curve and 0.735(95%CI:0.728-0.742)for the training set ROC curve.The calibration curve demonstrated a high correlation between the CRC high-risk population predicted by the nomogram model and the actual CRC high-risk population.CONCLUSION The early-screening nomogram model for CRC prediction in high-risk populations developed in this study based on age,BMI,WC,lifestyle,and family history exhibited high accuracy. 展开更多
关键词 Colorectal cancer Early screening model High-risk population Nomogram model Questionnaire survey Dietary habit Living habit
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24Model与LCM原因因素定义对比研究
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作者 袁晨辉 傅贵 +1 位作者 吴治蓉 赵金坤 《中国安全科学学报》 CAS CSCD 北大核心 2024年第1期27-34,共8页
为探究损失致因模型(LCM)原因因素定义与事故致因“2-4”模型(24Model)存在的异同和优缺点,梳理2个模型各层面原因和结果的定义,对比定义内容及其对事故原因分析等安全实务的指导作用,并以一起瓦斯爆炸事故为例加以实证分析,获得二者分... 为探究损失致因模型(LCM)原因因素定义与事故致因“2-4”模型(24Model)存在的异同和优缺点,梳理2个模型各层面原因和结果的定义,对比定义内容及其对事故原因分析等安全实务的指导作用,并以一起瓦斯爆炸事故为例加以实证分析,获得二者分析结果之间的差异。研究结果表明:LCM是首个将管理因素纳入事故致因分析的一维事件序列模型,可明确各层面原因因素的定义和因素间的逻辑关系,但部分定义存在交叉重复的问题,并没有揭示安全工作指导思想等深层次事故致因因素;24Model作为系统性事故致因模型,对各类因素的定义均以组织为主体,描述事件、事故、安全的概念内涵,划分个体安全动作、安全能力和组织安全管理体系的类别并给出含义解析,探究组织安全文化层面的问题并以32个元素体现;2个模型的事故原因分析方法均建立在对各层级原因因素定义的基础上,并适用于模型理论体系本身。 展开更多
关键词 “2-4”模型(24model) 损失致因模型(LCM) 事故致因模型 原因因素定义 对比研究
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Oxygen tension modulates cell function in an in vitro three-dimensional glioblastoma tumor model 被引量:1
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作者 Sen Wang Siqi Yao +8 位作者 Na Pei Luge Bai Zhiyan Hao Dichen Li Jiankang He J.Miguel Oliveira Xiaoyan Xue Ling Wang Xinggang Mao 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第3期307-319,共13页
Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor ... Hypoxia is a typical feature of the tumor microenvironment,one of the most critical factors affecting cell behavior and tumor progression.However,the lack of tumor models able to precisely emulate natural brain tumor tissue has impeded the study of the effects of hypoxia on the progression and growth of tumor cells.This study reports a three-dimensional(3D)brain tumor model obtained by encapsulating U87MG(U87)cells in a hydrogel containing type I collagen.It also documents the effect of various oxygen concentrations(1%,7%,and 21%)in the culture environment on U87 cell morphology,proliferation,viability,cell cycle,apoptosis rate,and migration.Finally,it compares two-dimensional(2D)and 3D cultures.For comparison purposes,cells cultured in flat culture dishes were used as the control(2D model).Cells cultured in the 3D model proliferated more slowly but had a higher apoptosis rate and proportion of cells in the resting phase(G0 phase)/gap I phase(G1 phase)than those cultured in the 2D model.Besides,the two models yielded significantly different cell morphologies.Finally,hypoxia(e.g.,1%O2)affected cell morphology,slowed cell growth,reduced cell viability,and increased the apoptosis rate in the 3D model.These results indicate that the constructed 3D model is effective for investigating the effects of biological and chemical factors on cell morphology and function,and can be more representative of the tumor microenvironment than 2D culture systems.The developed 3D glioblastoma tumor model is equally applicable to other studies in pharmacology and pathology. 展开更多
关键词 HYPOXIA GLIOMA Three-dimensional glioma model In vitro
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基于DEA-Tobit两阶段模型的我国物流企业运营绩效研究
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作者 孔訸炜 谢家平 +1 位作者 陈启楠 梁玲 《上海管理科学》 2024年第2期74-80,共7页
我国物流企业运营的关键是提升物流效率,而提升其效率的第一步是需要明确究竟哪些因素影响了物流效率。论文以此为目的,选取我国60多家物流上市企业为决策单元,收集2016—2018年的面板数据,运用DEA-Tobit两阶段模型,对我国物流上市企业... 我国物流企业运营的关键是提升物流效率,而提升其效率的第一步是需要明确究竟哪些因素影响了物流效率。论文以此为目的,选取我国60多家物流上市企业为决策单元,收集2016—2018年的面板数据,运用DEA-Tobit两阶段模型,对我国物流上市企业的“投入-中间产出-最终产出”的两个过程进行DEA效率测算,并用Tobit回归对影响运营绩效的因素进行了分析,进而打开影响物流企业运营绩效的黑箱。研究发现,有一半以上的物流企业在两个阶段中的投入有很大部分是无效的,并且导致我国物流企业整体运营效率低下的原因很可能出在第二阶段的运营上,而且也实证验证了地区经济发展水平、地区物流周转效率、企业高学历员工和负债率对物流企业运营绩效的影响。根据研究结论,分别从政策和企业层面提出了优化我国物流企业资源配置和提高运营效率的策略建议。 展开更多
关键词 DEA两阶段模型 TOBIT模型 物流企业 运营效率测评
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Effects of mesenchymal stem cell on dopaminergic neurons,motor and memory functions in animal models of Parkinson's disease:a systematic review and meta-analysis 被引量:3
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作者 Jong Mi Park Masoud Rahmati +2 位作者 Sang Chul Lee Jae Il Shin Yong Wook Kim 《Neural Regeneration Research》 SCIE CAS CSCD 2024年第7期1584-1592,共9页
Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse ... Parkinson’s disease is chara cterized by the loss of dopaminergic neurons in the substantia nigra pars com pacta,and although restoring striatal dopamine levels may improve symptoms,no treatment can cure or reve rse the disease itself.Stem cell therapy has a regenerative effect and is being actively studied as a candidate for the treatment of Parkinson’s disease.Mesenchymal stem cells are considered a promising option due to fewer ethical concerns,a lower risk of immune rejection,and a lower risk of teratogenicity.We performed a meta-analysis to evaluate the therapeutic effects of mesenchymal stem cells and their derivatives on motor function,memory,and preservation of dopamine rgic neurons in a Parkinson’s disease animal model.We searched bibliographic databases(PubMed/MEDLINE,Embase,CENTRAL,Scopus,and Web of Science)to identify articles and included only pee r-reviewed in vivo interve ntional animal studies published in any language through J une 28,2023.The study utilized the random-effect model to estimate the 95%confidence intervals(CI)of the standard mean differences(SMD)between the treatment and control groups.We use the systematic review center for laboratory animal expe rimentation’s risk of bias tool and the collaborative approach to meta-analysis and review of animal studies checklist for study quality assessment.A total of 33studies with data from 840 Parkinson’s disease model animals were included in the meta-analysis.Treatment with mesenchymal stem cells significantly improved motor function as assessed by the amphetamine-induced rotational test.Among the stem cell types,the bone marrow MSCs with neurotrophic factor group showed la rgest effect size(SMD[95%CI]=-6.21[-9.50 to-2.93],P=0.0001,I^(2)=0.0%).The stem cell treatment group had significantly more tyrosine hydroxylase positive dopamine rgic neurons in the striatum([95%CI]=1.04[0.59 to 1.49],P=0.0001,I^(2)=65.1%)and substantia nigra(SMD[95%CI]=1.38[0.89 to 1.87],P=0.0001,I^(2)=75.3%),indicating a protective effect on dopaminergic neurons.Subgroup analysis of the amphetamine-induced rotation test showed a significant reduction only in the intracranial-striatum route(SMD[95%CI]=-2.59[-3.25 to-1.94],P=0.0001,I^(2)=74.4%).The memory test showed significant improvement only in the intravenous route(SMD[95%CI]=4.80[1.84 to 7.76],P=0.027,I^(2)=79.6%).Mesenchymal stem cells have been shown to positively impact motor function and memory function and protect dopaminergic neurons in preclinical models of Parkinson’s disease.Further research is required to determine the optimal stem cell types,modifications,transplanted cell numbe rs,and delivery methods for these protocols. 展开更多
关键词 ANIMAL animal experimentation mesenchymal stem cells models Parkinson’s disease stem cell transplantation
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Assessing the Performance of CMIP6 Models in Simulating Droughts across Global Drylands 被引量:1
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作者 Xiaojing YU Lixia ZHANG +1 位作者 Tianjun ZHOU Jianghua ZHENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第2期193-208,共16页
Both the attribution of historical change and future projections of droughts rely heavily on climate modeling. However,reasonable drought simulations have remained a challenge, and the related performances of the curr... Both the attribution of historical change and future projections of droughts rely heavily on climate modeling. However,reasonable drought simulations have remained a challenge, and the related performances of the current state-of-the-art Coupled Model Intercomparison Project phase 6(CMIP6) models remain unknown. Here, both the strengths and weaknesses of CMIP6 models in simulating droughts and corresponding hydrothermal conditions in drylands are assessed.While the general patterns of simulated meteorological elements in drylands resemble the observations, the annual precipitation is overestimated by ~33%(with a model spread of 2.3%–77.2%), along with an underestimation of potential evapotranspiration(PET) by ~32%(17.5%–47.2%). The water deficit condition, measured by the difference between precipitation and PET, is 50%(29.1%–71.7%) weaker than observations. The CMIP6 models show weaknesses in capturing the climate mean drought characteristics in drylands, particularly with the occurrence and duration largely underestimated in the hyperarid Afro-Asian areas. Nonetheless, the drought-associated meteorological anomalies, including reduced precipitation, warmer temperatures, higher evaporative demand, and increased water deficit conditions, are reasonably reproduced. The simulated magnitude of precipitation(water deficit) associated with dryland droughts is overestimated by 28%(24%) compared to observations. The observed increasing trends in drought fractional area,occurrence, and corresponding meteorological anomalies during 1980–2014 are reasonably reproduced. Still, the increase in drought characteristics, associated precipitation and water deficit are obviously underestimated after the late 1990s,especially for mild and moderate droughts, indicative of a weaker response of dryland drought changes to global warming in CMIP6 models. Our results suggest that it is imperative to employ bias correction approaches in drought-related studies over drylands by using CMIP6 outputs. 展开更多
关键词 DROUGHTS hydrothermal conditions DRYLANDS CMIP6 model evaluation
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Cellular interplay to 3D in vitro microphysiological disease model:cell patterning microbiota-gut-brain axis 被引量:1
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作者 Kamare Alam Lakshmi Nair +6 位作者 Souvik Mukherjee Kulwinder Kaur Manjari Singh Santanu Kaity Velayutham Ravichandiran Sugato Banerjee Subhadeep Roy 《Bio-Design and Manufacturing》 SCIE EI CAS CSCD 2024年第3期320-357,共38页
The microbiota-gut-brain axis(MGBA)has emerged as a key prospect in the bidirectional communication between two major organ systems:the brain and the gut.Homeostasis between the two organ systems allows the body to fu... The microbiota-gut-brain axis(MGBA)has emerged as a key prospect in the bidirectional communication between two major organ systems:the brain and the gut.Homeostasis between the two organ systems allows the body to function without disease,whereas dysbiosis has long-standing evidence of etiopathological conditions.The most common communication paths are the microbial release of metabolites,soluble neurotransmitters,and immune cells.However,each pathway is intertwined with a complex one.With the emergence of in vitro models and the popularity of three-dimensional(3D)cultures and Transwells,engineering has become easier for the scientific understanding of neurodegenerative diseases.This paper briefly retraces the possible communication pathways between the gut microbiome and the brain.It further elaborates on three major diseases:autism spectrum disorder,Parkinson’s disease,and Alzheimer’s disease,which are prevalent in children and the elderly.These diseases also decrease patients’quality of life.Hence,understanding them more deeply with respect to current advances in in vitro modeling is crucial for understanding the diseases.Remodeling of MGBA in the laboratory uses many molecular technologies and biomaterial advances.Spheroids and organoids provide a more realistic picture of the cell and tissue structure than monolayers.Combining them with the Transwell system offers the advantage of compartmentalizing the two systems(apical and basal)while allowing physical and chemical cues between them.Cutting-edge technologies,such as bioprinting and microfluidic chips,might be the future of in vitro modeling,as they provide dynamicity. 展开更多
关键词 Microbiota-gut-brain axis Neurodegeneration 3D disease model Organoid Transwell system
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