Results 1 to 10 of about 1,452,452 (183)
Gaoya dianqi, 2020 频率响应分析法是检测电力变压器绕组变形的常用诊断方法之一。近年来,频率响应分析法的检测流程趋向标准化,但寻求合适的算法对频响曲线数据进行量化分析仍需深入研究。文中将频响曲线数据的量化分析看作一个概率分类问题,提出了应用欧氏距离分析诊断变压器绕组变形程度和类型的新方法。研究结果表明,欧氏距离分析能够有效地对变压器绕组变形程度进行诊断,且与先前研究提出的数学指数方法相比,该方法对变形程度的诊断结果具有更高的线性度。同时,在检测频段分段后获取子频段的欧氏距离分布的基础上 ...
张重远 +6 more
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Gaoya dianqi, 2020 变压器是电网最为核心的设备,绕组变形是变压器主要的故障类型之一,频率响应分析法（frequency response analysis, FRA）是目前广泛应用的绕组变形检测方法。为提高绕组变形分类诊断的性能,文中提出基于粒子群算法优化支持向量机（particle swarm optimization-support vector machine, PSO-SVM）的变压器绕组变形分类方法,采用数学统计方法提取频率响应曲线的特征参量,并输入到支持向量机模型进行训练,利用粒子群算法优化支持向量机模型参数 ...
刘伟 +4 more
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Equine Veterinary Journal, EarlyView.Abstract Background Persistent breeding‐induced endometritis (PBIE) is a common reason for mares failing to establish pregnancy. Objective To examine the hypothesis that advancing mare age and embryo donor status predispose to PBIE and compromise fertility.
Tom Stout +3 more
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Equine Veterinary Journal, EarlyView.Abstract Background The middle conchal sinus (MCS) (ethmoidal sinus) remains one of the least understood equine paranasal compartments. Despite recognition of its involvement in sinonasal disease, disorders of the MCS often remain underdiagnosed in the absence of computed tomographic (CT) imaging due to limited anatomical understanding and challenges ...
J.‐B. Pavard +3 more
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Beyond Universalism: A Contextual Approach to Comparative Public Administration
Public Administration and Development, EarlyView.ABSTRACT In this essay, I advocate for a contextual approach to comparative public administration, arguing that effective governance reform requires moving away from universal models to embrace local political, socioeconomic, and institutional realities.
XiaoHu Wang
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Wildlife Letters, EarlyView.Human‐caused leopard deaths in Sri Lanka averaged 9.65 ± 4.5 records year−1 over 17 years (2008–2024; n = 164), with records highly clustered in the central highland mosaic ecosystem. Mortality was dominated by adult males and driven primarily by snaring in plantation landscapes, and indicating an increase approximately 0.7–0.8 deaths per year.
Sanjaya Weerakkody +11 more
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Jianzhu Gangjiegou Jinzhan, 2022 施工过程对大跨复杂结构的受力及变形影响显著，针对施工中复杂钢结构存在大量预制构件的特点，提出可模拟预制构件行为的无形变单元结构非线性施工分析方法。基于PEP梁柱单元理论，提出了无形变单元刚度矩阵的计算方法、单元施工分析激活步骤及“一单元一构件”的建模方法。通过大跨结构施工分析算例，与传统生死单元与分步建模法计算结果对比，证明不考虑累积施工变形对预制构件影响的传统施工模拟方法会低估结构关键部位的内力和变形，导致不安全的设计结果。所提出方法可准确模拟预制构件对其余结构部分的影响及其相互作用，施工分析步骤简单，
刘耀鹏, 张紫娟, 白睿, 陈绍礼
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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
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Gaoya dianqi, 2017 通过试验研究了频率响应分析法检测变压器绕组变形。首先分析了频率响应分析法检测变压器绕组变形的基本原理。建立了频率响应分析法试验平台,分析了影响频率响应分析法检测绕组变形结果的主要因素。结合相关系数法对两个典型算例变压器绕组进行了变形诊断分析。通过对变压器的频率响应测试数据比较分析,结果表明了用频率响应分析法判断变压器绕组变形仍存在一定的局限性。
张海军, 王曙鸿, 刘艳琴
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Functional Ecology, EarlyView.Read the free Plain Language Summary for this article on the Journal blog. Abstract Decomposition is the transformation of dead organic matter into its inorganic constituents. In most biomes, decomposition rates can be accurately predicted with simple mathematical models, but these models have long under‐predicted decomposition in globally extensive ...
Heather L. Throop +8 more
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