Results 21 to 30 of about 11,903 (114)
Dianci bileiqi, 2021 城际动车组闭合断路器,会引起车载主回路暂态响应,导致高压系统、车体及接地系统产生暂态过电压,继而通过电磁耦合对车载敏感设备造成不良影响。为系统分析城际动车组闭合断路器时的各车暂态过电压特性,从闭合工况下的过电压产生机理出发,建立闭合工况下的过电压仿真模型,得到闭合断路器时的车体过电压的时域及频域特性,并通过试验结果加以验证。结果显示:闭合断路器时,1-4车车体过电压呈对称分布,且头尾车较大,可达2 kV以上,主要高频振荡频率约为800 kHz ...
张天浩 +5 more
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Policy Studies Journal, EarlyView.ABSTRACT Why did Australia go from the White Australia Policy, which excluded non‐whites, to institutionalizing multiculturalism policy in the 1970s? This question defies traditional political ideologies of the major political parties, which had long supported the White Australia Policy. This article is a rare empirical demonstration of the Five‐Thread
Julius C. S. Mok
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Interface Issues of Inorganic Solid‐State Electrolytes in Secondary Magnesium Batteries
Rare Metals, Volume 45, Issue 3, March 2026.ABSTRACT Solid‐state magnesium batteries (SSMBs) have gained significant attention as promising candidates for next‐generation safe energy storage systems because of the abundance of magnesium (Mg) in the earth's crust, superior energy density, and inherent nonflammability.
Jiren Wang +9 more
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Shuitu Baochi Xuebao, 2006 利用1980年、1995年、2000年三期遥感影像，在RS与GIS支持下，解译提取吉林省西部20年草地空间信息，分析该区草地时空动态及其景观格局变化。结果表明：①20年来，草地面积减少40．70％。草地退化严重，主要转化为耕地和盐碱地，转移面积分别达到475799．43hm^2和303182．06hm^2；②20年来．草地总动态度为负，1980～1995年，高覆盖度草地对整体草地变化影响较大；1995-2000年．高、中覆益度草地对草地整体变化影响较大；③20年来，各类草地质心向东北方向偏移 ...
李建平, 赵江洪, 张柏, 张树清
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Review of Policy Research, Volume 43, Issue 2, March 2026.ABSTRACT This study adapts the Multiple Streams Framework (MSF) to explore why COVID‐19 vaccine mandates were applied at sectoral and subnational levels in Vietnam while the central government maintained that vaccination was voluntary. Document analysis reveals that these mandates arose from the effective coupling of the three streams—problem, policy ...
Hang Duong, Katie Attwell
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Rare Metals, Volume 45, Issue 2, February 2026.ABSTRACT With the continuous advancement of materials science and technology, the rare metal gallium has increasingly emerged as a promising alternative to the toxic metal mercury. Although existing research has predominantly focused on the high electrical conductivity and excellent deformability of liquid metal (LM), its intrinsic fluidic property ...
Feifan Guo +6 more
wiley +1 more source
Gaoya dianqi, 2011 为解决工程上变电站接地网故障诊断中建模耗时长、现场工作量大等实际问题,基于特勒根定理及最小二乘法编写可视化接地网故障诊断软件,实现接地网拓扑结构自动生成,并通过串行通讯接口RS-232将现场测量接地引下线端口电阻值自动传输至诊断软件,在输出界面中依据各支路导体电阻增量判断接地网状态。该诊断平台大大提高了接地网故障诊断效率,具有较好工程实用性。
刘渝根 +5 more
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International Journal of Applied Linguistics, Volume 36, Issue 1, Page 522-539, February 2026.ABSTRACT This paper examines the features of metadiscourse across different teacher moves in university linguistics classroom discourse and the teaching strategies reflected in its use. The results reveal that teachers employ diverse metadiscourse during classroom interactions to support student reasoning.
Jingjie Li, Wenjie Hu
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Dianci bileiqi配电网小电阻接地系统的供电可靠性较低，且存在高阻保护拒动的问题，而消弧线圈接地系统又难以选线。针对上述两种接地系统的缺陷，在结合二者各自优势的基础上提出一种中性点动态接地系统。利用中性点电压阈值比较及延时处理对单相接地故障性质进行区分，根据不同类型的故障采用不同的中性点接地方式，从而实现对故障的差异化处理。尤其是在解决高阻接地故障时，通过动作可切换电阻支路的开关来实现零序电流的二次增量，为故障选线提供基础信号。利用Simulink仿真验证该接地系统的可行性，仿真结果表明 ...
黄亚峰 +4 more
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基于故障性质判断法的配电网中性点动态接地成套装置的开发及应用
Dianci bileiqi, 2019 通过对配电网中性点经消弧线圈接地方式,以及小电阻接地方式的特点分析及存在的问题进行了更加深入地研究,并开发研制出了配电网中性点动态接地成套装置。该装置具备消弧线圈接地与小电阻接地方式二者的优点,又能够灵活地解决两者存在的缺点。其功能在于配电网发生单相接地故障时,依据故障特征量和参数,就可以对故障的性质进行智能判断。满足在瞬时性接地故障时,故障点的绝缘水平能够快速恢复,提高了电网供电可靠性;同时在永久性单相接地故障时,能够快速且准确地选出,并切除故障线路,确保了设备和人身安全。经大量实验及运行结果证明 ...
李政洋 +5 more
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