Results 21 to 30 of about 13,996 (117)
±800 kV直流输电线路正极性侧带电作业电位转移放电特性研究
Dianci bileiqi, 2020 为明确±800 kV直流输电线路带电作业电位转移放电特性,考虑强电场作用下粒子产生、运动和消散过程,构建了基于流体力学理论的电位转移流注放电模型,计算并分析了放电过程中的电场强度、流注发展速度和电流密度随时间的变化规律,以及不同转移距离下的放电电流。结果表明:在电位转移放电过程中,随着放电时间的增加,流注头部电场强度减小、流注发展速度加快、电流密度增大;电位转移棒与导线间的放电电流随着电位转移距离的减小而增大;确定了±800 kV输电线路在正极性导线侧带电作业时最佳电位转移距离为0. 45 m左右。
周晨梦 +7 more
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Dianci bileiqi, 2022 笔者针对钢结构变电站直击雷防护，对雷击过程中变电站接地特性进行研究，相较于通过避雷带引下线接地的现行方案，在采用钢柱直接接地情况下，地表电位升最大值下降幅度达到26.5%。钢结构变电站的导体网络对于具有大量高频分量的雷电流具有明显的电感效应，地表电位升峰值时刻超前于雷电流约5μs。雷电流散流集中于注流点附近的4～5条引下线或者连接线，总散流占比超过90%,相比现行方案，通过钢柱接地的方案散流更加集中于注流点附近的4条连接线，距离注流点最近的连接线分流占比达到了55.19 ...
李凡 +5 more
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International Journal of Applied Linguistics, Volume 36, Issue 2, Page 1450-1460, May 2026.ABSTRACT Online tutoring platforms (OTPs) are an increasingly popular way for learners to study languages and for teachers to earn money. On many OTPs, individual teachers are responsible for attracting potential students via self‐branding. While scholarship has examined OTP teachers’ self‐branding practices and identified some of the most popular self‐
Wenjing Zeng, Nate Ming Curran
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Zhongshan Daxue xuebao. Yixue kexue ban, 2007 [目的]采用单光子发射计算机断层扫描（SPECT）技术测定抑郁症患者的局部脑血流（rCBF）,与正常对照比较脑血流灌注变化,并观察抑郁症症状与患者脑血流灌注的关系。[方法]以18例未经抗抑郁治疗的抑郁症患者为研究对象,19名正常人作为对照组,分别行SPECT检查。[结果]未经治疗的抑郁患者SPECT脑血流低灌注发生率为72.2%;重症抑郁患者100%存在脑血流低灌注;抑郁组患者双侧额叶、颞叶的rCBF较对照组显著下降（P〈0.01～0.05）,左顶叶、右基底节rCBF也明显降低（P〈0.05 ...
贾艳滨, 黄立安, 徐伊, 徐浩
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Focusing Events, Agenda Setting, and Narrative Numbing
Review of Policy Research, Volume 43, Issue 3, May 2026.ABSTRACT Focusing events are important in understanding policy change, as demonstrated in Birkland's work on agenda setting, the multiple streams framework, and the narrative policy framework. These frameworks emphasize the role of focusing events in drawing public attention to broader issues.
Megan K. Warnement Wrobel +1 more
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Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT Nickel‐based superalloys (Ni‐based superalloys) have attracted extensive attention in laser additive manufacturing (LAM) due to their capability to directly fabricate complex and high‐performance structural components. However, the rapid melting and solidification inherent to LAM result in intense thermal cycling, which induces high residual ...
Tianxiang Lin +9 more
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Dianci bileiqi湿度影响空气间隙负极性流注放电微观过程，建立棒-板空气间隙负流注放电流体模型以及试验平台。记录放电图像，对比其发展通道宽度及发光强度；测量湿度为40%、50%、60%、70%、80%条件下负极性流注放电电流及，从宏观角度对不同湿度情况下的参量进行对比分析。在数值计算中模拟湿度为0%、30%、60%、90%条件下空气间隙负极性流注放电起始、发展及击穿过程，从微观角度分析水分子对负极性流注放电特性参数的影响规律。研究发现：在棒-板电极结构下，湿度增大促进负极性流注发展。湿度每增大30 ...
王清尘 +5 more
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Dianci bileiqi, 2018 在热力学模型基础上,考虑了空间电荷屏蔽作用的二次电晕起始过程,认为流注茎（电晕区与流注-先导转化区）温度达到1 500 K同时二次电晕起始即新生迎面先导起始。并且根据纹影仪对先导通道根部的观测结果,流注茎假设为类圆锥状。通过Comsol软件对地面高大建筑物尖端处上行正极性先导的始发过程进行了数值模拟研究,并分析了锥形流注茎和二次电晕起始过程对先导始发过程的影响。最终得到了锥形流注茎长度与流注茎半径的关系,证明了随着电流的注入,根部优先转化为先导;计算的建筑物尖端处在最大半径（R=0.24 mm ...
王梦寒
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Rare Metals, Volume 45, Issue 4, April 2026.ABSTRACT The development of neuromorphic electronics with visual perception and adaptive capability is highly desirable for advancing artificial vision systems. Herein, we have demonstrated a dual‐plasticity adaptive phototransistor based on IGZO nanofibers that exhibits the perception and dynamic adaptation behavior of rod and cone cells to varying ...
Shanshan Jiang +5 more
wiley +1 more source
Huli yanjiu, 1997 通过对５０个一次性引流袋实际注水量与引流袋标量刻度的对照观察，发现一次性引流袋标量与实际注水量有差异。当注入３００ｍｌ以下水量时，引流袋内标量多数大于实际量，而注入３００ｍｌ以上水量时，引流袋标量明显少于实际量。提示：临床护士对于要求准确记录出入量的患者，测量引流量时一定要用量杯测量，以避免误差。
徐金美 +3 more
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