Results 1 to 10 of about 17,578 (115)
Shuitu Baochi Xuebao, 2020 以北京市漫水河流域为研究对象，对漫水河1956-2016年年降雨量、年径流系数变化特征及径流系数突变性进行分析，以2000-2016年代表现状下垫面条件，采用主成分分析法分析了时段降雨量和年降雨量对年径流系数的影响，并建立了年径流系数与主要降雨因子的线性主成分回归模型及基于LM（Levenberg—Marquardt）算法的BP神经网络模型。结果表明：漫水河流域年径流系数在过去的61年间呈极显著下降趋势，年径流系数从1956年到上世纪70年代初、上世纪70年代末到80年代末 ...
王少丽 +5 more
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Dianci bileiqi, 2020 10 kV配电线路耐雷水平较低,雷击跳闸事故频繁。而杆塔分流系数对线路的耐雷水平至关重要。根据某山区大跨越10 kV线路参数,利用ATP-EMTP软件建立10 kV线路仿真模型,量化分析线路避雷器装设前后对杆塔分流系数的影响,以及改变避雷器接地电阻大小后,杆塔分流系数的变化规律。仿真结果表明:雷电流10 kA时,装设避雷器后杆塔分流系数降低了72.38%,且避雷器接地电阻降低一半,则杆塔分流系数可至少降低20.9%。最后通过对该10 kV线路进行具体改造,大大提高了线路的耐雷水平。
曾程 +4 more
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Gaoya dianqi, 2022 合理控制高压断路器的关合和开断时刻可以在一定程度上降低系统中的暂态过程，选相关合和开断一直是高压断路器在工程应用中的关注点。文中通过等效电路建立了高压交流断路器不同期短路关合过程计算的数值分析模型，可以计算得到任意时刻的全电流、断口电压、交流分量电流和直流分量电流。通过验算国家标准GB/T 30846—2014第4.102规定的短路关合峰值系数验证了计算模型的正确性，并计算了中性点有效接地系统不同期短路关合的峰值系数。最后，应用两个算例分析与讨论了中性点有效接地系统和非有效接地系统中断路器的选相关合技术，
李志新, 吴限, 苑婷, 毛武平
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Inferring alternative ecosystem states with field survey data
Methods in Ecology and Evolution, EarlyView.Abstract Many ecosystems potentially exhibit alternative stable states, where distinct states can coexist under identical environmental conditions. While simulation models have generated key hypotheses in alternative stable states theory, they often rely on scale‐free parameters disconnected from real ecosystems.
Ning Chen +10 more
wiley +1 more source
Emerging applications of large language models in ecology and conservation science
Conservation Biology, EarlyView.Abstract Large language models (LLMs) mark a major development in artificial intelligence, with potentially transformative implications for ecology and conservation science. Built on advanced deep‐learning architectures, these models can support a wide range of tasks. We reviewed emerging applications of LLMs, drawing on the wider scientific literature
Christos Mammides +5 more
wiley +1 more source
Evaluating the use of taxonomy in the IUCN Red List
Conservation Biology, EarlyView.Abstract Taxonomy defines the units that conservationists strive to preserve for future generations. However, the discovery of new species and the taxonomic revision of existing species affect conservation efforts. Despite the importance of taxonomy for a species’ conservation, there is currently no overview of how those leading species extinction risk
Stephen T. Garnett +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
Policy Studies Journal, Volume 54, Issue 3, August 2026.Abstract Studies of lobbying typically look at the extent to which interest groups realize political goals on issues they actively lobby for. Little is known, however, about the extent to which interest groups attain their political goals without making an active lobbying effort.
Marcel Hanegraaff +2 more
wiley +1 more source
Dianci bileiqi, 2008 提出一种能够在现场直接测试避雷线分流电阻的方法,建立了计算避雷线分流系数的实用数学模型,并对建立的数学模型和实测及相关数据进行分析、计算,推导出了较为实用的、简便的计算避雷线分流系数的近似计算式。计算结果表明:所测变电站接地网的接地电阻Rg越大,避雷线分流系数Ke1越大;否则,Ke1就越小。而避雷线分流系数Ke1,线路前10级杆塔接地电阻平均值Rav,线路平均档距Lav越大,避雷线分流系数Ke1越小;否则,Ke1就越大。
李德超 +4 more
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Rare Metals, Volume 45, Issue 7, July 2026.ABSTRACT Heteroatom coordination regulation is an effective strategy to enhance Fenton‐like catalysis of single atom catalysts, yet its impact on the local microenvironment of active sites still requires in‐depth investigation. Herein, Cl2–Fe–NC catalysts with axial Cl coordination are prepared.
Jing‐Hao Yan +6 more
wiley +1 more source