Results 21 to 30 of about 13,612 (123)
, 2020 本发明提供一种高硬度高电导率梯度结构Cu‑Cr合金触头的制备方法，包括如下步骤：选择Cr含量在20～60wt.％的两块Cu‑Cr合金基材分别作为静端和动端；将激光原位设备的激光参数调整至等于或大于常规激光扫描时参数的1/3，然后使激光器产生连续激光对静端表面层进行激光扫描；将激光参数调整至等于或低于常规激光扫描时参数的1/3，然后使激光器产生连续激光对动端表面层进行激光扫描，扫描完成后取下动端；以两块熔覆层厚度不同的触头组成方式来作为同一真空灭弧室的静端和动端，且静端的熔覆层厚度大于动端的熔覆层厚度 ...
何秀丽 +5 more
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Gaoya dianqi, 2006 研究了杯状纵磁真空灭弧室的极限电流开断能力与触头直径和触头开距间的规律,建立便于设计时应用的计算公式。从合成回路上开断能力的试验结果出发,将三维有限元法对杯状纵磁触头的纵向磁场的计算结果引入到开断能力与触头直径和触头开距的关系式中,初步得到极限电流开断能力与触头直径和触头开距的关系为I=k×D2×Bz0.4,式中k是系数。该式的物理意义是开断能力随触头直径的增加而增大,随触头开距的增加而减小。
刘志远, 王仲奕, 张炫, 王季梅
doaj
Robust metrics for quantifying and comparing resistance and recovery in experimental studies
Methods in Ecology and Evolution, Volume 17, Issue 1, Page 6-14, January 2026.Abstract Various indices have been developed to experimentally quantify resistance and recovery (two components of engineering resilience) in response to anthropogenic and natural disturbances. This diversity complicates the selection of appropriate metrics for comparing resilience across ecosystems and studies.
Zewei Zhuang +2 more
wiley +1 more source
Gaoya dianqi, 2011 风能作为可再生的绿色能源,将成为以分布式发电为特征的智能电网的重要组成部分。然而现有电力系统抗风电扰动能力差是影响风电产业发展的关键性制约。采用分频输电技术可解决上述风电并网问题,而分频输电会造成断路器开断短路电流时有较长的燃弧时间,从而引起断路器的开断能力降低。笔者综述了分频输电对真空断路器开断能力的影响。Slade研究指出当系统频率降低时,真空断路器的短路电流开断能力的降低与频率降低倍数的平方根有关,即ix（f1）/ix（f2）=（f1/f2）～（1/2）。对于采用横向磁场触头,触头直径为62 ...
刘志远
doaj
World Medical &Health Policy, Volume 17, Issue 4, Page 912-920, December 2025.ABSTRACT In Brazil, the healthcare system is based on the provision of a public system that offers free and universal services to all citizens, supplemented by private initiative. Evaluating user satisfaction plays an important role in identifying improvements and promoting organizational changes that benefit everyone involved.
Patrícia Silva Bazoni +8 more
wiley +1 more source
Gaoya dianqi, 1984 在户外高压开关中,有些产品没有灭弧装置,但却要求具备在大气中开断一定数值的小电流的能力。例如,空载变压器自切开关、隔离开关等都属此类。长期以来,这些产品的开断能力试验,大多是在试验室里进行的。但有时在户外现场试验中发现,往往与试验里测得的结果不一致。分析认为,此类开关开断小电流的能力 ...
艾克郑
doaj
World Water Policy, Volume 11, Issue 4, Page 1048-1064, November 2025.ABSTRACT Groundwater governance is complex due to several externalities associated with groundwater being an invisible natural resource tied to the land with millions of extractors and limited means of exclusion. The paper traces the evolution of groundwater irrigation in India and the corresponding change in groundwater laws and policies to address ...
Anindita Sarkar, Amrita Sarkar
wiley +1 more source
Gaoya dianqi, 2016 文中讨论了在探索选择六氟化硫（SF6）替代气体的过程中关于气体开断能力研究的重要性,并对气体开断能力的评估进行了阐述。简要总结了目前工业界对SF6替代气体开断试验的结果。以N2和CO2为例,从理论上分析了其开断性能劣于SF6的原因,初步建立了喷口电弧中气体开断能力与物性参数间的关系,为理解SF6替代气体开断机理及选择判据的建立提供理论依据。
阎究敦, 张权, 曹昆
doaj
Integrative Conservation, Volume 4, Issue 3, Page 277-286, September 2025.This study provides an innovation to address the challenge in accessibility to samples and genetic markers in Snow leopard conservation genetic studies. We performed next‐generation sequencing (NGS) on 19 fecal samples obtained from the eastern Qinghai‐Tibet Plateau, and successfully assembled 17 complete mitogenome sequences (~16,720 bp) and ...
Chen Cheng +7 more
wiley +1 more source
Gaoya dianqi, 2012 综述了SF6断路器极限开断能力以及介质开断能力的数值预测方法的最新研究进展。电流过零前200 ns的电弧电导（G200）是判断断路器热开断能力的一个重要参数,为计算G200,对电弧特性进行模拟,在燃弧阶段采用磁流体动力学模型,而在接近电流零区采用Mayr模型,从而建立相应的电路模型来确定电弧时间常数和电弧功率损耗系数等参数,以分析高压断路器的热开断能力。为判断电击穿能力,需要根据电弧过零时灭弧室内的每一点的压力和温度值,确定对应点的临界击穿场强分布Ec,同时计算在暂态恢复电压作用下灭弧室内的电场分布Ea,
牟京卫 +5 more
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