Results 51 to 60 of about 35,610 (162)
Gaoya dianqi, 2017 接地模拟试验是实现接地网参数预测与接地特性分析的基本方法。一些接地材料如柔性石墨复合接地材料、离子接地体以及接地模块等在进行接地模拟试验时,其部分相似项并不能按照相似条件进行缩比,使得接地网原型的预测误差较大。针对此问题,笔者首先阐述了接地模拟试验的畸变相似模型,分析接地模拟试验中畸变相似项的来源,然后提出畸变系数与畸变项敏感度的概念。最后通过仿真实例和实际接地模拟试验,分析不同土壤电阻率与模型相似比条件下,接地模拟试验对接地体直径畸变项与接地体电阻率畸变项的敏感度 ...
高晓东 +5 more
doaj
Habitat and spatial trends of U.K. wintering waterbird populations over 50 years
Conservation Biology, EarlyView.Abstract The United Kingdom is an important wintering ground for millions of waterbirds. Most U.K. wintering waterbird populations increased between 1970 and the mid‐1990s, but declined thereafter. We examined U.K. population indices in 46 wintering waterbird species in two 25‐year periods, 1970–1994 and 1995–2019, to identify which waterbird groups ...
Blaise Martay +8 more
wiley +1 more source
Changes in the transformative potential of action proposals in Finnish Red Lists from 1986 to 2019
Conservation Biology, EarlyView.Abstract Red lists provide critical knowledge regarding biodiversity decline, especially in Finland, where broad assessments have been made regularly since the 1980s. They deliver information on the threat status of species and ecosystems, propose actions to guide conservation policy, and have the potential to spur transformative change.
Anni Arponen +4 more
wiley +1 more source
Uncovering correlates of decline and critical refuges for a threatened terrestrial mammal
Conservation Biology, EarlyView.Abstract Globally, the geographic ranges of numerous species are contracting. Identifying spatiotemporal patterns of threat impact can illuminate why species decline in some parts of their range but persist in others. We developed a correlative approach to identify species’ response thresholds and locate ecological refuge areas associated with ...
Natalya M. Maitz +5 more
wiley +1 more source
500 kV罗平站主变加装中性点限流电抗器电磁暂态研究及设备选型
Gaoya dianqi, 2017 随着电网的发展,部分自耦变压器中压侧电抗常接近于零,导致变压器220 kV侧发生近区单相或两相接地时,故障穿越电流已接近甚至超过变压器可承受短路电流的极限值,为限制罗平站220 kV单相或两相短路电流水平、改善主变运行环境,拟在主变中性点加装限流电抗器。采用最新EMTPE程序,通过对主变接入限流电抗后短路电流水平、过电压及绝缘配合等电磁暂态特性研究,提出了500 kV罗平站主变中性点限流电抗器阻抗选取原则及限流效果、工频及操作过电压水平、流经主变中性点电抗器的工频稳态及暂态电流水平 ...
王典浪, 李东, 杨晓维, 皮天满
doaj
How identity bias affects perceptions of conservation messages on social media
Conservation Biology, EarlyView.Abstract Public support is essential for conservation, as public opinion can influence decision‐making and policy. Therefore, understanding whether bias toward conservationists due to their identity (identity bias) affects their perceived credibility and support for their recommendations is important.
Lauren F. Rudd +4 more
wiley +1 more source
Effects of restoration practices on biodiversity in temperate and boreal forests
Conservation Biology, EarlyView.Abstract Several restoration practices are used to mitigate and compensate for the negative effects of large‐scale forestry on biodiversity in temperate and boreal forests. A comprehensive synthesis of the benefits of these practices across taxa is missing. We conducted a systematic review and meta‐analysis on this topic.
Malin Tälle +2 more
wiley +1 more source
四川大学学报. 自然科学版, 1980 这是熟知的,两个相互等价的(即可经行列式为±1的整系数齐次线性变换互变的)实系数n元二次型f和g,对变元的所有整数值来说,表数相同(即凡能由f以整变元表出之数均可由型g以整变元表出,反之亦真).但是,相反的结论是否能够成立呢?亦即是否表数相同的二次型一定是等价的呢?这是基本而古老的问题.1830年,Legendre曾未加证明地断言,表数相同的二元恒定二次型必等价.1895年,Bauer曾就有相同行列式的真本原整系数恒定二元二次型这一特殊情形证明了Legendre的断言.
柯召, 郑德勋
doaj
Psychometric framework for coexistence with large carnivores
Conservation Biology, EarlyView.Abstract Human–carnivore coexistence is essential for biodiversity conservation, yet measuring the attitudes and behaviors that support it remains methodologically challenging. We developed psychometric scales to assess willingness to coexist with carnivores and the underlying beliefs of this coexistence through an iterative expert elicitation process ...
Benjamin Ghasemi +14 more
wiley +1 more source