Results 61 to 70 of about 23,510 (147)

中国历史上的虎(Panthera tigris)亚种名称及分布地

open access: yes野生动物学报, 2016
根据对中国200万年以来虎的分布变迁系统研究,表明中国历史上分布的虎在生态环境变迁过程中曾产生9个亚种,它们的出现与部分灭绝的亚种并不在同一时间。文中不仅对新增虎亚种进行考证,而且对大部分虎亚种的形态、栖息地、分布地区进行梳理,明确它们的古今分布状况及分布界线,还提出规范各虎亚种名称的具体建议。
文榕生 张明海
doaj  

Biodiversity‐driven spatial conservation planning to delineate temporally stable regions

open access: yesConservation Biology, EarlyView.
Abstract The accelerating loss of biodiversity underscores the critical need for effective conservation strategies, particularly in the face of climate change and anthropogenic pressures. We devised a conservation planning framework that adopts a temporal stacking approach to species distribution models and landscape connectivity analyses. These models
Mattia Iannella   +5 more
wiley   +1 more source

染污复合绝缘子交流电场特性研究

open access: yesGaoya dianqi, 2010
为了揭示复合绝缘子在污秽潮湿环境中运行时的电场分布特性,笔者基于复合绝缘子的污闪理论,研究了绝缘污秽电场模型和计算方法,采用污层表面电导率和模拟导电污层的电阻层边界条件,应用有限元电场计算软件ElecNet对复合绝缘子污秽电场进行了交流时谐电场计算分析,比较了污层沿绝缘子轴向均匀分布和不均匀分布两种情况下的绝缘子电场分布,分析了污层表面电导率大小(即不同的污秽度)以及污层分布状态对绝缘子表面电场分布的影响。得出,当伞裙上表面电导率高于下表面时,沿泄漏路径的电位分布线性度降低 ...
王仲奕, 王琪, 陈青
doaj  

Drivers of bat researchers’ intent to adopt field hygiene practices

open access: yesConservation Biology, EarlyView.
Abstract Infectious disease is a growing threat to wildlife, with zoonotic transmission most likely at the human–wildlife interface. One underappreciated activity at this interface is fieldwork with wild animals, but associated risks can be mitigated through field hygiene (FH) practices, such as using personal protective equipment and other appropriate
Joanna L. Coleman   +6 more
wiley   +1 more source

800 kV MOA电位分布数值分析和测量

open access: yesGaoya dianqi, 2009
针对800 kV氧化锌避雷器(MOA)的电位分布,笔者从数值仿真和试验两个方面进行分析。首先,采用有限元法及ANSYS分析了无并联电容时800 kV MOA的电位分布,得到了所有氧化锌组件(MOR)的电压偏差和每单元内MOR所占电压的百分比,并同时求出各法兰之间的部分电容和对地电容。并联电容后将MOA的"静电场"问题转化为"电路"问题,用节点电压法求出并联电容后的电位分布和MOR的电压偏差。接下来,采用自行研制的光纤测量系统对800 kV MOA的电位分布进行了实测,得出了流过MOR的电流分布曲线 ...
岳亚丽, 江少成, 张源斌
doaj  

Overlap of nonbreeding wandering albatrosses with fisheries and implications for colony‐specific population trajectories at South Georgia

open access: yesConservation Biology, EarlyView.
Abstract Bycatch in fisheries is one of the most serious threats to pelagic seabirds, causing major population declines. Mitigation measures can reduce bycatch substantially, but many fisheries fail to apply best practices, and seabird mortality remains high.
V. Warwick‐Evans   +2 more
wiley   +1 more source

尼龙网方格沙障的风沙流颗粒分布特征

open access: yesShuitu Baochi Xuebao, 2016
为了探讨塔克拉玛干沙漠腹地风沙流结构特征及尼龙网方格沙障对风沙流颗粒的分异作用,于2015年4月—2015年6月,选取裸沙地和沙障2种下垫面,利用集沙仪对地表风沙流进行观测,分析了尼龙网沙障对风沙流结构和沙粒粒径分布的分异过程。结果表明:(1)风沙流结构在裸沙地符合指数分布(y=321.025e-10.16x,R2=0.94),在沙障前部和中部分别表现出“象鼻”效应特征和近似于倒置的“象鼻”;沙障的设置,明显减少了近地面(0~42 cm)的输沙量。(2)在裸沙地 ...
黎小娟, 李, 丁新原
doaj  

Research on the properties of the Boolean difference and Boolean E-derivative on special logic functions(特殊逻辑函数布尔差分及布尔e-导数的性质研究)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2013
布尔差分和布尔e-导数是组合电路故障检测和布尔函数密码学性质研究的一种有效工具.从线性函数、冗余函数、自反函数、自双反函数、部分自反函数、部分自双反函数的定义出发,讨论了这些特殊布尔函数布尔差分和布尔e-导数的性质,并给出了相应的证明,为方便快捷地实现故障检测和密码学函数的构造奠定理论基础.
FANGWei-jie(方伟杰)   +2 more
doaj   +1 more source

Providing regular and frequent maps of losses and gains of farmland birds based on European monitoring data

open access: yesConservation Biology, EarlyView.
Abstract Knowledge of species distributions is essential for informing policies on nature conservation and restoration. However, updating them on a regular basis and doing so in a harmonized manner at the international level is difficult. The European Bird Census Council integrated national monitoring data covering 5 years to update farmland bird ...
Sergi Herrando   +54 more
wiley   +1 more source

Attainment Pairing Effects on Cognitive Conflict in Technology‐enhanced EFL Cooperative Tasks

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT This study examines how attainment pairing (high‐high versus high‐low versus low‐low attainment) impacts English as a Foreign Language (EFL) learner engagement during technology‐enhanced cooperative writing tasks. Seventy‐eight Chinese university learners formed 39 dyads (13 pairs per group) via Tencent Meeting.
Ying Liu, Allen Thurston
wiley   +1 more source

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