Results 31 to 40 of about 216,068 (211)
Exploring gaps, biases, and research priorities in the evidence for reptile conservation actions
Conservation Biology, EarlyView.Abstract With over 21% of reptile species threatened with extinction, there is an urgent need to ensure conservation actions to protect and restore populations are informed by relevant, reliable evidence. We examined the geographic and taxonomic distribution of 707 studies that tested the effects of actions to conserve reptiles synthesized in ...
Oliver Speight +9 more
wiley +1 more source
Graphic method calculating Boolean difference based on K-map(基于K图的布尔差分计算的图形方法)
Zhejiang Daxue xuebao. Lixue ban, 2002 基于K图和降维K图,讨论了计算逻辑函数的一阶布尔差分和二阶布尔差分的图形方法.实例表明该方法具有直观、简单等特点,并且它能给出布尔差分的最简与/或式.
YUDang-jun(余党军) +2 more
doaj +1 more source
Predictions of southern migration timing in coastal sharks under future ocean warming
Conservation Biology, EarlyView.Abstract Projected redistribution of marine species due to ocean warming may undermine current conservation efforts. Yet, there have been few studies on how ocean warming may alter migration timing. Across 5 years of acoustic telemetry data (2018–2022), we determined environmental drivers of southward migration timing for 6 migratory shark species from
Maria H. Manz +16 more
wiley +1 more source
中介效应的点估计和区间估计：乘积分布法、非参数Bootstrap和MCMC法
, 2012 针对中介效应ab的抽样分布往往不是正态分布的问题,学者近年提出了三类无需对ab的抽样分布进行任何限制且适用于中、小样本的方法,包括乘积分布法、非参数Bootstrap和马尔科夫链蒙特卡罗（MCMC）方法。采用模拟技术比较了三类方法在中介效应分析中的表现。结果发现：1）有先验信息的MCMC方法的ab点估计最准确;2）有先验信息的MCMC方法的统计功效最高,但付出了低估第Ⅰ类错误率的代价,偏差校正的非参数百分位Bootstrap方法的统计功效其次,但付出了高估第Ⅰ类错误率的代价;3 ...
方杰, 张敏强
semanticscholar +1 more source
Conservation Biology, EarlyView.Abstract Identifying refugia from emerging threats is vital to ensure the persistence of rare and threatened species, but modeling habitat distribution for these species is challenging and the role of people in refuge management is rarely considered. Myrtle rust is an emerging infectious disease that represents a grave threat to the rare wetland tree ...
Sarah M. Herbert +7 more
wiley +1 more source
, 2012 利用电弧离子镀技术在不锈钢基体上制备了(Ti,Al)N涂层,研究了N_2分压改变对涂层残余应力沿层深分布及相关力学性能的影响.结果表明,低N_2分压下,(Ti,Al)N涂层残余应力沿层深分布较均匀,随N_2分压的增加,涂层应力沿层深呈"钟罩型"分布,且全膜厚的应力值也明显增大;通过对涂层生长结构及微观成分分析,初步探讨了应力分布机理.随N_2分压的增加,涂层硬度会显著增加,而膜/基结合力则大幅下降;采用改变N_2分压工艺制备(Ti,Al)N涂层,可有效调整涂层残余应力沿层深分布趋势,改善其力学性能 ...
赵升升 +4 more
semanticscholar +1 more source
野生动物学报, 2010 根据2008～2009年实地考察研究结果,着重就该区2种有蹄类动物的分布、种群数量以及有关问题作概要性探讨。调查研究结果表明:（1）老虎台盘羊分布区盘羊平均密度=8.49/8=1.06只/km2,黑英山盘羊分布区盘羊平均密度=5.34/3=1.78只/km2。整个分布区盘羊种群数量1 488只,其中,老虎台分布区种群数量=480×1.06=509只,黑英山分布区种群数量=550×1.78=979只。（2）老虎台北山羊分布区北山羊平均密度=14.59/5=2.92只/km2 ...
阿布力米提·阿布都卡迪尔 +5 more
doaj
International Journal of Applied Linguistics, EarlyView.ABSTRACT While previous research has established nominal complexity as a key indicator of grammatical complexity, its multi‐dimensional manifestation in constrained varieties remains underexplored. This study investigates the distribution of complex nominal structures in constrained spoken English varieties, specifically English as a Second Language ...
Jiaxin Chen, Yao Yao, Dechao Li
wiley +1 more source
, 2011 9-羰基-10,11-去氢泽兰酮为紫茎泽兰（Eupatorium adenophorum）的主要致肝脏毒性成分及杀虫的生物活性成分。从紫茎泽兰叶片中分离提纯得到9-羰基-10,11-去氢泽兰酮（Euptox A）标准品,建立了高效液相色谱法测定紫茎泽兰中Euptox A含量的分析方法。采用C18反相色谱柱,柱温30°C,以甲醇-水（60：40,v/v）为流动相、流速为0.8 mL.min–1、检测波长为255 nm进行测定。Euptox A在紫茎泽兰中的添加回收率为97.3%–103.7%,检测限为0 ...
白洁 +6 more
semanticscholar +1 more source
New Phytologist, EarlyView.Summary The importance of marine angiosperms, or seagrasses, as foundation species for marine coastal ecosystems is in marked contrast to their low species number of only 70 described taxa. Seagrass species tend to have very similar overall morphologies dictated by hydrodynamic forces of the ocean environment.
Xiaomei Zhang +14 more
wiley +1 more source