Results 21 to 30 of about 7,369 (142)
油纸绝缘套管作为变电站内极为重要的电力设备之一,其绝缘状态对于电力系统的安全稳定运行至关重要。频域介电谱法可实现套管绝缘状态的无损检测,但传统扫频测试耗费时间长,为频域介电谱的现场应用带来不便。文中提出一种冲击电压激励下变压器套管介电响应快速测量方法,利用冲击电压信号中包含的丰富频率分量作为激励信号,获取套管末屏响应电流并进行数据处理与计算,从而得到频域介电响应信息。文中基于扩展德拜模型,搭建冲击电压激励下介电响应仿真平台,并利用任意波形发生器、高压功率放大器等设备搭建实验测试平台 ...
张璐 +5 more
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Uncovering correlates of decline and critical refuges for a threatened terrestrial mammal
Abstract Globally, the geographic ranges of numerous species are contracting. Identifying spatiotemporal patterns of threat impact can illuminate why species decline in some parts of their range but persist in others. We developed a correlative approach to identify species’ response thresholds and locate ecological refuge areas associated with ...
Natalya M. Maitz +5 more
wiley +1 more source
ABSTRACT This study investigates how the learner‐related factors of language dominance, encompassing language history, proficiency, use, and attitude, modulate congruency effects in multi‐word unit (MWU) processing among early bilinguals. Seventy Cantonese–Putonghua bilinguals completed lexical decision tasks measuring reaction time and accuracy for ...
Mingjia Cai, Yuan Liang
wiley +1 more source
Read the free Plain Language Summary for this article on the Journal blog. Abstract Wildfires are disrupting and regenerating forces in nature that affect all ecosystem components. However, the impact of wildfires on soil multitrophic biodiversity and the resulting consequences for ecosystem multifunctionality (EMF) remain poorly understood.
Juan Zhou +6 more
wiley +1 more source
Jellyfish blooms restructure plankton dynamics and trophic linkages in coastal waters
Read the free Plain Language Summary for this article on the Journal blog. Abstract Jellyfish blooms are increasing globally in frequency and intensity, introducing complex ecological interactions, yet the mechanisms by which they alter ecosystem structure remain poorly characterized due to a lack of sustained field observations.
Pengpeng Wang +4 more
wiley +1 more source
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
doaj
ABSTRACT Information processing is a fundamental part of policy making and is all the more critical in modern policy making environments characterized by information abundance. Using Punctuated Equilibrium Theory (PET) as a lens, this study investigates how city governments process and apply externally generated knowledge to address environmental ...
Rachel M. Krause +4 more
wiley +1 more source
利用CDEGS中HIFREQ模块建立某500 kV酒杯塔模型,计算了塔顶注入点、横担各处等的频率响应,结合矢量匹配法并对频率响应特性进行拟合,并对该杆塔的频率特性进行了分析。研究表明:UHV杆塔在10 MHz以内,存在多个谐振峰,且主要集中在数十万赫兹至10 MHz之间,高频部分阻抗响应较大,达数百欧姆,计算雷击响应时不宜忽略;矢量匹配法拟合效果好,频率响应函数经适当变换,可植入相应反正软件中计算线路绕击过电压等。
陈文广 +7 more
doaj
Read the free Plain Language Summary for this article on the Journal blog. Abstract Studies have shown that organisms may adjust metabolic rates in response to thermal variability, highlighting metabolic plasticity as a key adaptive mechanism. Understanding the extent of metabolic plasticity of an organism is key to predicting its adaptation to climate
Qian Hu +6 more
wiley +1 more source
频率响应分析法是现场用于检测电力变压器内部机械缺陷的重要方法。目前有几种不同的、用于分析频率响应法结果的方法,其中最常用的就是利用数值指标(如相关系数、均方差等)得出不同频响曲线之间的差异性。然而,传统的数值指标都只使用了频率响应结果的幅值,其对于变压器绕组微小变形的检测灵敏度不够理想。因此,文中提出了一种同时考虑频率响应结果幅值和相位的数值指标及一种改进传统数值指标的方法;然后通过实验得到了不同轴向微小变形程度绕组的频率响应数据;最后将不同的数值指标应用于实验所得数据并进行了对比试验 ...
刘云鹏, 程槐号, 胡焕
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