Results 31 to 40 of about 3,114 (118)
Dianci bileiqi, 2021 在变电站的实际运行中,当发生线路单相接地故障时,架空地线将会分流部分故障电流,故在CDEGS中建立了变电站A及其连通的3座变电站,形成电力系统模型,仿真得到了变电站A在运行过程中单相接地故障时的入地电流,用以指导变电站A的接地网设计,校核初始设计的接地网不能满足接触电压安全限值要求,故对初始设计的接地网进行优化设计,优化的接地网设计使线路单相接地故障时站内接触电压、跨步电压均能满足安全要求。结果表明试验方法具有较好的接地网设计指导作用,具有工程实际应用指导价值。
伍振园 +5 more
doaj
US Foreign Policy and the Gulf States: Changing Dynamics in a Multipolar World
World Affairs, Volume 188, Issue 4, Winter 2025.ABSTRACT This article focuses on US foreign policy toward the Gulf from Obama's Pivot to Asia to the initial period of the second Trump administration. It situates the role of the US within the broader context of the global energy transition and the Gulf states as geopolitical actors in a multipolar world order.
Steven Wright
wiley +1 more source
Dianci bileiqi, 2013 为确保风电场电气设备和工作人员人身安全,接地设计需要有合格的接地电阻值、接触电压和跨步电压值。在接地电阻满足安全值的情况下,如果接地设计不合理,地面上还是可能产生超过允许值的接触电压和跨步电压。降低接触和跨步电压的一般方法是增设水平接地网和在地表铺设高阻率土壤层,但风电机组所处自然环境特殊,受地形限制,不易过多扩大接地网面积。在不增加接地网总长度的情况下采用不等间距法布置地网导体,或者改变地基与接地网的相对位置可显著降低地表最大接触电压,提高地网安全水平 ...
宋景博 +4 more
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International Journal of Applied Linguistics, Volume 35, Issue 3, Page 1482-1494, August 2025.ABSTRACT While previous research has established nominal complexity as a key indicator of grammatical complexity, its multi‐dimensional manifestation in constrained varieties remains underexplored. This study investigates the distribution of complex nominal structures in constrained spoken English varieties, specifically English as a Second Language ...
Jiaxin Chen, Yao Yao, Dechao Li
wiley +1 more source
Gaoya dianqi, 2010 采用近似分析方法推导出在水平接地网接地导体周围人工改善土壤后水平接地网的等效接地导体半径,结合已有的均匀土壤中水平接地网接地电阻及最大接触电压的计算公式,提出人工改善土壤后水平接地网接地电阻及最大接触电压的计算方法,并通过分析得出:人工改善土壤对降低接地网接地电阻的作用甚微,但能有效降低接地网的最大接触电压。
刘渝根 +3 more
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Politics &Policy, Volume 53, Issue 3, June 2025.ABSTRACT The literature has established that the politics of the welfare state are often shaped by perceptions of deservingness based on the behaviors and characteristics of target populations as well as their race and ethnicity. How are public attitudes affected when confronted with target populations along these two dimensions simultaneously?
Simon F. Haeder
wiley +1 more source
Dianci bileiqi, 2015 针对现有的规程法、电磁暂态仿真程序等对耐雷水平的计算过程中都尚未考虑线路运行时工频电压的影响,为了准确评估接触网受雷击后的影响,根据接触网雷击过电压的产生途径,将其分为3种类型,分别建立等值电路,然后结合规程法,推导了计及工频电压后接触网耐雷水平的计算公式,并利用该公式计算了常见高速铁路接触网的耐雷水平,最后分析了工频电压对接触网耐雷水平的影响。结果表明:接触网耐雷水平是关于工频电压的函数,随工频电压的变化而变化,在接触网防雷设计中,需以耐雷水平的最小值为评估依据。
杨昱鑫, 张友鹏
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Integrative Conservation, Volume 4, Issue 1, Page 10-19, March 2025.Brief summary: Urbanization is leading to “Nature‐deficit Disorder” that threatens children's health and the sustainable development of humanity. This study implements a new solution—the Mini Botanical Garden, which integrates some of the functions of botanical gardens into community green spaces to popularize nature education in the city.
Aoqi Zhang +6 more
wiley +1 more source
Gaoya dianqi, 2019 为获取波动载荷下弓网滑动电接触载流特性,利用FCH-03型销盘式滑动电接触摩擦磨损试验机模拟弓网接触状态,进行强电流密度、不同速度与波动接触压力条件下的浸金属碳/铜对磨实验。根据实验数据获得载流效率、载流稳定性在不同条件下的特性规律,并针对影响受流的运行速度、接触电流、波动接触压力等因素作出深入的机理分析及电弧能量干扰相关性分析。研究表明:载流效率随接触压力振幅的增大而减小,随接触压力频率的增大呈较小的增大趋势。载流稳定性随接触压力振幅的增大而减小。低速时基本不随接触压力频率变化 ...
陈忠华, 刘福升, 回立川, 时光
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Can reducing learning costs improve public support for means‐tested benefit programs?
Policy Studies Journal, Volume 53, Issue 1, Page 135-157, February 2025.Abstract This study investigates how efforts to reduce learning costs of means‐tested public benefit programs impact public support of these programs and perceived deservingness of program beneficiaries. Focusing on the Supplemental Nutrition Assistance Program (SNAP) in the United States, a well‐known means‐tested public benefit program, we integrate ...
Gregory Porumbescu +2 more
wiley +1 more source