Results 1 to 10 of about 12,368 (118)
Gaoya dianqi, 2022 针对高压XLPE电缆缓冲层烧蚀故障频发，缓冲层烧蚀影响因素较多，难以准确评估在运电缆缓冲层状态的情况，提出了一种缓冲层状态模糊综合评估方法。根据缓冲层烧蚀故障机理及带材特性，建立状态评估因子及评估分级标准。在此基础上，采用改进层次分析方法确定评估因子的权重。采用模糊综合评价方法，计算缓冲层状态评估等级隶属度向量。根据最大隶属度原则确定最终评估结果。通过实例计算表明，该评估方法能够对缓冲层状态进行准确评估，有效降低人的主观因素影响，为制定在运高压XLPE电缆缓冲层状态运维管控措施提供了科学依据。
周韫捷 +6 more
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Gaoya dianqi, 2022 输变电设备运行状态评估是电网企业技术管理的重要内容，针对目前电力变压器健康状态评估模型中存在的对状态量单一赋权不合理、实现步骤较为繁琐、算法性能不稳定等问题，文中采用加权秩和比WRSR(weighted rank sum ratio)模型对电力变压器健康状态进行评估，该模型原理简单，易于实现。通过选取电力变压器运行中典型状态量，采用组合赋权的理论对各状态量赋予权值大小，进而计算评估对象的加权秩和比。利用加权秩和比确定待评估对象的概率单位，并将概率单位作为自变量代入回归方程中得到状态评估结果 ...
咸日常 +5 more
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Gaoya dianqi, 2021 电力变压器结构、运行工况复杂,影响其健康状态的因素众多,建立有效的变压器健康状态评估模型对其状态进行准确评估是十分必要的。文中提出一种考虑变压器历史运行工况影响的变压器健康状态评估模型。从油色谱试验、电气试验、油化试验数据及现场评估等方面提取相关重要指标作为定量指标和定性指标,通过主客观组合权重和岭型隶属函数完成基于定量指标的变压器状态初步评估结果;考虑变压器历史工况建立定性指标对初步评估结果进行合理修正,完成对变压器健康状态的评估。最后以宁夏地区1台110 kV主变验证了该评估方法的有效性和准确性 ...
周秀 +7 more
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Wildlife Letters, EarlyView.We used spatially explicit capture‐recapture to estimate jaguar densities in a private reserve in the Colombian Llanos and quantified land cover change in and around the reserve from 2014 to 2024. Densities increased 22% since 2014, while disturbed land cover increased by 39%–54% around the reserve depending on buffer distance. Our study indicates that
Valeria Boron +7 more
wiley +1 more source
Gaoya dianqi, 2020 高压开关柜作为配电网络中应用最广泛、使用数量最多的配电设备之一,为保证高压开关柜稳定运行及电网安全,需要对其状态进行准确评估。文中提出了一种综合赋权与加权秩和比（WRSR）相结合的新的开关柜状态评估方法。首先根据高压开关柜的绝缘状态、电气状态、机械状态和历史记录等信息,建立状态评估体系,运用层次分析法和熵权法相结合分别计算指标主客观权重并实现综合赋权;其次建立基于加权秩和比（WRSR）的开关柜状态评估模型,该模型构建简便,且具有强大的信息统计分析功能,可以实现状态分类及定量评估 ...
吴晗 +5 more
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Gaoya dianqi, 2022 针对变压器本体绝缘状态评估中的状态信息指标的不确定性，文中提出了基于模糊评判理论与DSmT的变压器本体多级绝缘状态评估模型，该模型分为本体绝缘状态等级评估与绝缘缺陷风险等级评估。应用模糊评判理论构建等级评估的隶属度函数模型，选择反映变压器绝缘状态的绝缘类指标参量作为模型的输入，应用熵权法改进的DSmT对指标隶属度进行融合得到最终的等级评估结果，该模型有效克服了等级区间界限值过于绝对化的局限性，解决了传统DST高冲突性证据的融合问题。通过实例验证，该模型的评估结果具有一定的有效性 ...
夏彦卫 +5 more
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Wildlife Letters, EarlyView.Reported annual per‐capita harvest of muskrats (PCHM) decreased as wetland complexity (total number of wetland patches) decreased in 13 state and federal wetland areas in the Midwest, USA. Our results support the hypothesis that regional‐scale declines in the abundance of muskrats are likely associated with the losses to wetland habitats throughout the
Tim L. Hiller +5 more
wiley +1 more source
Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Permafrost thaw is reshaping nutrient dynamics in boreal forests, but its impacts on tree nutrient limitation and functional strategies remain poorly understood. Clarifying these responses is crucial for predicting the response of boreal forests to climate change.
Qiyue Fu +9 more
wiley +1 more source
Drivers of bat researchers’ intent to adopt field hygiene practices
Conservation Biology, EarlyView.Abstract Infectious disease is a growing threat to wildlife, with zoonotic transmission most likely at the human–wildlife interface. One underappreciated activity at this interface is fieldwork with wild animals, but associated risks can be mitigated through field hygiene (FH) practices, such as using personal protective equipment and other appropriate
Joanna L. Coleman +6 more
wiley +1 more source
Taxonomic and functional diversity of urban bees of the world
Conservation Biology, EarlyView.Abstract Bees play a pivotal role in terrestrial environments. Urbanization can affect these organisms and the ecosystem services they provide. However, knowledge of the global diversity of urban bees is limited. Thus, we summarized data on urban bee species identities and occurrences; compared distributions of all bees with those found in urban ...
João C. F. Cardoso +10 more
wiley +1 more source