Results 31 to 40 of about 35,375 (133)
Gaoya dianqi, 2020 精确的变压器深度饱和模型是分析电网过电压暂态过程的基础。而目前端口试验的方法只能得到额定运行时等效电路模型的参数,却无法得到过电压下深度饱和区的参数。该文提出利用数值仿真的方法确定三相变压器深度饱和等效电路模型参数,数值仿真的方法分为两种,包括基于端口数值试验的方法和基于电磁场分布计算磁阻方法。前者通过磁场和电路耦合的方法在变压器的端口设置开路或短路状态以确定等效电路参数,后者利用变压器各部分的磁通和能量的积分结果计算磁阻,再转换得到等效电路参数。计算磁阻的方法更适用于分析拓扑复杂 ...
王迎迎, 袁建生
doaj
World Water Policy, Volume 12, Issue 4, November 2026.ABSTRACT Biochemical oxygen demand (BOD) remains a core indicator of organic pollution in freshwater monitoring, but its role in water policy and practice is changing as water‐quality assessment moves toward predictive, integrative, and decision‐support approaches.
Isadora Favero Roque Cenci +5 more
wiley +1 more source
Gaoya dianqi, 2019 电力变压器是实现电压变换和电能分配的重要电力设备。针对变压器机械故障,振动分析法具备很强的科学性和可行性。文中搭建了基于振动传感阵列的变压器振动测试系统,研究了单相变压器油箱表面振动分布,分别测量绕组在正常状态和故障状态下的油箱振动云图,提取振动云图的方向梯度直方图（HOG）特征,选择支持向量机（SVM）为学习训练方法,形成二类分类器,分辨变压器绕组的正常状态与故障状态。最终提出基于振动云图HOG和SVM的变压器绕组松动故障诊断方法,实验验证该方法有很高的识别率。
朱梓倩 +4 more
doaj
World Water Policy, Volume 12, Issue 4, November 2026.ABSTRACT This paper describes and analyzes recharge practices in Bács‐Kiskun County, Hungary, within what can be categorized as the farmer domain. Such locally embedded aquifer recharge practices remain underexplored in Hungary. Current research and funding largely focus on large‐scale Managed Aquifer Recharge (MAR) interventions emphasizing intended ...
Helen Sundberg, Michael Gilek
wiley +1 more source
Jianzhu Gangjiegou Jinzhan为揭示偏心竖向荷载作用下薄壁箱梁的畸变，基于能量变分原理和箱梁各板件的静力平衡分析，给出优化后箱梁畸变研究的3种方法。推导出各方法研究梯形截面箱梁畸变解析计算式的普遍形式，得到相应的四阶畸变控制微分方程。对各畸变研究方法采用典型数值算例进行验证，研究结果表明：优化后的各畸变研究方法计算的畸变翘曲正应力值与文献数值相差很小，各方法之间误差最大不超过5.39%，方法2和方法3计算结果误差很小可忽略；各方法计算的矩形截面箱梁的畸变扇性坐标值均相等，梯形截面箱梁的畸变扇性坐标值则不同 ...
王兆南, 张元海
doaj +2 more sources
Gaoya dianqi, 2014 为了满足经济效益与社会效益的需要,进一步加强变压器运行的安全性与稳定性,笔者提出了一种对变压器进行状态评估的方法。通过分析变压器运行中各状态量参数,引入基于关联规则的权重计算方法,采用综合分析与变权重评分制的方法,建立起一个较为完善的变压器状态评估体系,以更为准确地评判变压器运行状态的真实工况。实例分析证明,此方法能够为变压器实施状态检修提供有效的参考意见。
谢荣斌 +4 more
doaj
World Water Policy, Volume 12, Issue 4, November 2026.ABSTRACT This article examines how renewable‐energy expansion is changing water–energy bargaining among Iran, Iraq, and Türkiye in the Tigris–Euphrates basin. Much of the existing literature on transboundary water politics focuses on territorial control, upstream–downstream power asymmetries, legal rules, and hydro‐hegemony but gives less attention to ...
Umud Shokri
wiley +1 more source
Gaoya dianqi, 2011 为准确判断电力变压器故障后的绕组变形情况,笔者探究了频响法、短路阻抗法和绕组电容法综合判断变压器绕组变形的依据和规律。通过对故障变压器的理论分析和计算,结合实际的吊罩结果,证实了此3种方法的有机结合有助于准确分析和判断变压器绕组变形程度。
陈巧勇, 任红, 罗平, 王建强
doaj
Policy Studies Journal, Volume 54, Issue 4, November 2026.ABSTRACT The intersection of immigration and welfare has taken a central stage in the politics of social policy and garnered increasing scholarly attention in welfare politics research. While prior research has examined how immigration affects welfare support and welfare generosity in the US, less is known about the determinants of immigrant‐related ...
Ping Xu, Ling Zhu, Sebastian Ege
wiley +1 more source
Policy Studies Journal, Volume 54, Issue 4, November 2026.ABSTRACT This paper examines how governments navigate policy legitimacy during crises through three distinct discursive processes: legitimization, delegitimization, and blame avoidance. Using a sequential mixed‐methods design, the study analyzes Denmark's decision to cull all mink during the COVID‐19 pandemic. The quantitative analysis of 947 newspaper
Olivier Rubin +3 more
wiley +1 more source