Results 41 to 50 of about 216,068 (211)
Zhejiang Daxue xuebao. Lixue ban, 2003 七子花是我国特有的单种属珍稀濒危植物,为国家二级重点保护野生植物,主要分布于浙江、安徽和湖北,而浙江是其分布中心.作者在野外调查的基础上,分析了浙江省七子花的地理分布特点、种群数量和群落类型.结果显示:浙江有七子花分布的群落总面积为54.28公顷,保存有七子花约近3万株(丛),并集中分布在临安等5个县市.七子花分布的群落类型较多,但未见于常绿阔叶林中,反映了七子花是在人类长期干扰下勉强生存.但是,七子花对非生物环境的适应幅度较宽,其种群的生存和发展还是有希望的.最后,根据七子花的资源现状 ...
YUJian(俞建) +4 more
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Policy Studies Journal, EarlyView.Abstract We integrate the study of policy design and diffusion theoretically and empirically to advance each and raise novel research questions. We argue that policy dissemination is an important rationale in the design of model legislation and present a theory for how each of the five elements of design map onto the policy innovation attribute of ...
Joshua M. Jansa, Daniel J. Mallinson
wiley +1 more source
野生动物学报, 1994 貉貉（ＮｙｃｔｅｒｅｕｔｅｓＰｒｏｃｘｏｎｏｉｄｅｓＧｒａｙ）属于食肉目犬科。主要分布于亚洲东南部。在原苏联分布在黑龙江流域、乌苏里江流域向北分布到萨哈林半岛。在中国分布在东北、华北、华中、华南和西南地区一直延伸到越南北部。在日本和朝鲜半岛也有分布。...
高犁为
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Kongjian kexue xuebao利用范艾伦卫星2014年至2018年观测的高精度电子能谱数据, 统计分析了不同辐射带高能电子能谱类型的时空分布特征. 结果表明, 辐射带电子能谱主要被分为三类: 指数分布能谱、幂律分布能谱和反转能谱. 指数分布能谱通常在等离子体层以外占主导地位. 幂律分布能谱通常在磁暴的主相出现在高L处, 并逐渐转移到低L处. 在地磁活动平静时期, 幂律分布能谱在高L处存在时间更长, 占比更多.
王 建行 +7 more
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Institutions, in time: Designing feedback pathways for shared infrastructure transitions
Policy Studies Journal, EarlyView.Abstract Electric utilities, challenged by a rapidly unfolding energy transition, use many informal institutions to bridge across technologies and sectors. Little is known, however, about how electric utility systems and other polycentric systems' institutions‐in‐use vary and evolve over time.
Matthew Grimley +6 more
wiley +1 more source
Powerful representation of the poor? German welfare associations' narrative advocacy during COVID‐19
Policy Studies Journal, EarlyView.Abstract The COVID‐19 pandemic sparked unprecedented experimentation in the German social assistance system, leading to changes previously considered impracticable by policymakers. This included a sanctions moratorium, easier access to benefits, and temporary cash transfers, all of which were advocated by welfare associations—key organized interests ...
Christopher Smith Ochoa
wiley +1 more source
Research on Face Load Distribution for Narrow Helioal Gears
Jixie chuandong, 1994 本文用三维边界元程序计算了窄斜齿轮在不同接触线上的载荷分布，分析了齿轮齿面载荷的分布规律。同时还计算出齿轮副的平均刚度ｋｎ１和载荷分布系数Ｋβ计算结果表明荷载分布规律与轴向重合度εβ及传动比有关，载荷分布系数Ｋβ在１．０４至１．２３之间。
王宪法
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野生动物学报, 2023 为了解全球海蛇（Hydrophiinae）的地理分布格局对陆上温度的响应，进一步研究其生存环境与分布丰度模式的关系。从GBIF网站收集全球71种海蛇地理分布信息，划分全球海蛇的高中低丰度区，并划分海蛇的“广布种”和“特有种”，用GIS技术建立物种丰富度模式，获取气候变量数据，对分布丰度和陆上温度生态位宽度进行统计分析。结果显示：有8个区域可被定义为“高丰度区”，22种海蛇可被定义为“广布种”。在高丰度区，部分海蛇加宽陆上温度生态位，部分则收窄生态位；1个物种的局部陆上温度生态位存在地理变异 ...
王湘君 +4 more
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Vibrio cholerae non-O1 non-O139の血清型分布, その毒素産生性および新血清型の追加について
, 1997 A total of 1898 strains of Vibrio cholerae non-O1 non-O139, which had been collected worldwide for the past 3 year period of 1994-1996, were serogrouped.
Shiro Yamai +3 more
semanticscholar +1 more source
Guangtongxin yanjiu, 2020 文章对布里渊光时域分析（BOTDA）分布式光纤传感系统中的偏振效应机理及受激布里渊散射的矢量模型分析进行了阐述。对目前国内外的研究现状,从受激布里渊散射效应中偏振相关布里渊增益谱分析、控制偏振态以及抑制偏振衰落技术等方面进行了详细介绍。布里渊光纤传感系统矢量建模分析和偏振态控制技术具有很好的研究前景,对未来研究中利用偏振态的敏感特性进行分布式传感光纤的温度、应变和振动信息测量及抑制偏振衰落来提高光纤传感系统空间分辨率都具有参考价值。
尚秋峰, 李玉洁
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