Results 41 to 50 of about 37,045 (159)

三相五柱变压器负载直流偏磁计算分析

open access: yesGaoya dianqi, 2023
在中国大容量的电力传输中,大多数采用三相五柱变压器,由于三相五柱变压器中零序磁路的存在导致直流入侵后磁路会发生严重饱和。为深入研究三相五柱变压器直流偏磁问题,搭建磁场有限元仿真模型,并配合变压器YNyn0联结的外电路方程进行耦合,通过在原边侧中性点输入不同大小的直流电流,首次模拟直流偏磁对三相五柱变压器负载下的影响。文中通过计算变压器原、副边电流和励磁电流波形与空载直流偏磁进行对比,并重点分析尖顶波处的变压器磁场分布,发现直流入侵对负载下副边绕组电流影响较小,原边电流随着直流电流增大发生一定程度的畸变 ...
郭苏鑫, 王泽忠, 梁书原
doaj  

Effects of restoration practices on biodiversity in temperate and boreal forests

open access: yesConservation 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

Improving efficiency in conservation planning by modeling species‐specific responses to threat abatement

open access: yesConservation Biology, EarlyView.
Abstract Reversing ongoing biodiversity loss requires effectively managing anthropogenic threats. Although conservation actions can mitigate these threats, prioritizing and targeting such actions remain challenging because species respond differently depending on the nature of the threats and their biological traits.
Camila Guerrero‐Pineda   +3 more
wiley   +1 more source

Comparative species distribution model framework for marine conservation and its application to loggerhead turtles in the Mediterranean

open access: yesConservation Biology, EarlyView.
Abstract Modeling species distributions in dynamic pelagic environments remains challenging, particularly for wide‐ranging and highly mobile species when there is limited guidance on model performance. This limitation constrains the effective use of species distribution models (SDMs) in marine conservation, where robust and transferable predictions are
E. Pasanisi   +32 more
wiley   +1 more source

Genomics‐informed management of ex situ populations

open access: yesConservation Biology, EarlyView.
Abstract The European Association of Zoos and Aquariums (EAZA) manages insurance populations for hundreds of species through its EAZA ex situ programs (EEPs). EEPs help safeguard against extinction in the wild and provide source populations for genetic rescue programs.
Cock van Oosterhout   +8 more
wiley   +1 more source

基于小波变换的2013年芦山MS7.0地震前姑咱台钻孔应变异常时频分析

open access: yesDizhen xuebao, 2019
2013年4月20日芦山MS7.0地震前,四川省姑咱台四分量YRY-4型钻孔应变仪记录到显著的高频应变畸变信号。为了避免该畸变信号的高频部分在时频演化过程中发生频率混叠现象,同时便于讨论同一研究频段内震前更早记录到的弱应变异常时段与显著应变异常时段的相关性,本文对2012年1月1日至2013年4月20日期间姑咱台的钻孔应变数据进行了时频分析,并使用时域分段的小波变换方法,在局部时频谱中提取了应变异常,分析了各应变异常的频率相关性。结果表明,研究频段内存在两个峰值频率 ...
Weichen Zhang   +4 more
doaj   +1 more source

Optimizing biodiversity offsetting for habitat succession and colonization dynamics

open access: yesConservation Biology, EarlyView.
Abstract Biodiversity offsetting aims to compensate for ecological losses from development through conservation and restoration. However, its long‐term outcomes under repeated impact–offset cycles remain uncertain. Using a conceptual forest succession model, we evaluated how offset outcomes are affected by interactions among compensation scale ...
Konstans Wells   +4 more
wiley   +1 more source

How endorser attributes influence conservation communication

open access: yesConservation Biology, EarlyView.
Abstract Conservation communication often uses the celebrity endorsement strategy. However, robust evidence regarding its effectiveness is still limited. More importantly, practitioners do not have guidelines for selecting an ideal endorser because there is no clear consensus on what endorser attributes are most critical.
Xia He, Tien Ming Lee
wiley   +1 more source

Learning Styles, Engagement and Anxiety in AI‐Mediated Writing: A Multimodal Feedback Study

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Artificial intelligence (AI) tools now permeate English academic writing. However, evidence on how feedback modalities align with student differences and with psychological mechanisms remains limited. Prior work often reduced learning styles to simple matches with delivery modes and treated learning engagement and writing anxiety as peripheral.
Yi Ren   +3 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

open access: yesGaoya 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  

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