Results 91 to 100 of about 1,579,839 (226)
, 2000 报道我国内陆水体单殖吸虫的宿主特异性的研究。研究表明单殖吸虫有很强的宿主特异性 ,但不同种类的特异性有很大的差别。从目前已有的记录来看 ,60 %以上的单殖吸虫只有 1种宿主 ,约 75%的单殖吸虫的宿主仅为 1属 ,超过97%的单殖吸虫的宿主在 1科之内。没有 1种单殖吸虫可寄生于超过 3个科的宿主中 ,但大钩指环虫可在 2 3属 33种宿主中寄生。在科和属特异性水平上 ,以锚首虫科和指环虫科单殖吸虫的特异性较强 ,三代虫科次之 ,双身虫科最弱 ;而在种特异性水平上 ...
夏晓勤,王伟俊,姚卫建
core
Effects of climate change on marine biodiversity on the western Atlantic coast
Conservation Biology, EarlyView.Abstract The current climate crisis, driven by greenhouse gas emissions, threatens global biodiversity, including that in marine ecosystems. However, projections for the western Atlantic Ocean that jointly quantify species richness and endemism while accounting for spatially biased and incomplete occurrence data remain limited.
Ubirajara Oliveira +33 more
wiley +1 more source
Dianci bileiqi, 2019 交流金属氧化物避雷器（简称MOA）的工作特性完全依赖于其V-A特性,由于V-A特性对温度的敏感性,导致多柱并联避雷器暂态过程中柱间负荷应力分布极不均匀,运行中出现过多起损坏事故。本文搭建了试验平台对多柱避雷器不同温度下的V-A特性进行了深入研究。研究结果表明:MOA的V-A特性具有明显的温度特性,在0～1 200 A电流区具有明显的负温度系数,在>1 200 A非线性区具有正温度系数。暂态温升中避雷器柱间电流分布不均匀系数远大于静态,从而导致阻抗处于极小值的柱吸收更多的能量 ...
蔡汉生, 廖传民, 郭洁, 徐迪
doaj
, 2002 在垃圾焚烧余热锅炉中，垃圾灰熔融特性是决定灰沉积危害程度的最重要特性之一。本研究通过测定垃圾灰的成分、灰熔点，系统分析垃圾灰熔融特性与其成分的关系，以及垃圾灰与低熔点煤灰在熔融特性与成分之间的区别 ...
阎常峰, 林伯川
core
Conservation Biology, EarlyView.Abstract Targets 1 and 3 of the Kunming–Montreal Global Biodiversity Framework (KMGBF) require actions to focus on areas of importance for biodiversity—a prerequisite for reversing biodiversity loss and halting human‐induced extinctions as set out in the Mission and Goals of the KMGBF.
Felicia A. Collins +6 more
wiley +1 more source
Guangtongxin yanjiu, 2014 针对利用阶跃响应法测试光电探测元件频率响应时存在无法获得相频特性的问题,文章通过Multisim软件建立了与实际器件参数一致的等效电路,根据相频特性中相位差与时间差之间的关系,提出了一种同时测量幅频特性和相频特性的频率响应测量方法,仿真测量的幅频特性结果与传统阶跃响应法的测量结果一致。光电二极管的相频特性对高速接收系统的设计具有重要影响。
李子强, 吕辉, 杨涛
doaj
Conservation Biology, EarlyView.Abstract Protected areas cannot halt biodiversity loss in isolation; integrating them with surrounding human‐dominated landscapes is critical. However, this integration is challenged by substantial landscape heterogeneity at protected area borders, making it difficult to determine cross‐border changes in ecosystem service provision.
Alberto González‐García +7 more
wiley +1 more source
Zhongguo shiyan zhenduanxue, 2010 目的分析孤立性甲状腺结节的CT表现,评价CT扫描在孤立性甲状腺结节良恶性鉴别诊断中的价值。方法与病理结果对照分析75例孤立性甲状腺结节的CT表现特点。结果在结节边缘不清、微小钙化等方面,良恶性结节有显著性差异 ...
蒋元文, 王薇, 周宏伟, 张云亭
doaj
International Journal of Applied Linguistics, EarlyView.ABSTRACT Studies on classroom interactions suggest that displaying affiliation through linguistic and multimodal resources could promote positive emotions like enjoyment, thereby enhancing engagement and enthusiasm in second/foreign language learning.
Karen C. K. Choi, Kevin W. H. Tai
wiley +1 more source