Results 111 to 120 of about 23,739 (228)
Gaoya dianqi, 2010 针对目前变电站断路器特性试验过程中存在的问题,从是否需要断路器控制电源和测试仪器设计两方面进行了探讨和分析,指出了试验过程中要注意的直流接地问题,以及断路器机械特性和低电压测试仪器设计中可以改进的地方。同时对时间-行程曲线的实际意义进行了分析。
曹阳, 肖辉, 莫臣
doaj
, 2009 应用等效最优控制方法对互连结构体系被动控制器的刚度参数和阻尼参数同时进行了优化,并在此基础上,建立了安装有次结构时有控互连结构体系的动力学模型,研究了控制器参数优化设计结果对次结构楼层反应谱的影响 ...
张建霖, 郝源
core
Powerful representation of the poor? German welfare associations' narrative advocacy during COVID‐19
Policy Studies Journal, EarlyView.Abstract The COVID‐19 pandemic sparked unprecedented experimentation in the German social assistance system, leading to changes previously considered impracticable by policymakers. This included a sanctions moratorium, easier access to benefits, and temporary cash transfers, all of which were advocated by welfare associations—key organized interests ...
Christopher Smith Ochoa
wiley +1 more source
Gaoya dianqi为解决某GIS母线中波纹管的最大压缩位移和疲劳寿命究竟能否同时满足工程指标的难题，应用工程计算和有限元分析分别加以计算，然后通过两种计算结果和实验验证进行比较，以期获得哪种方法更精确可靠。为达此目的，文中给出了工程计算和有限元建模的详细过程。按工程计算方法得到的最大压缩位移结果无法满足工程指标，而有限元分析计算方法，却可以达到工程指标，且有较大的安全裕度。有限元分析还揭示了满足大压缩位移的机理，计算结果符合某GIS工程同时需要的压缩位移和疲劳寿命。经型式试验也验证了模拟的正确性 ...
王玉, 杨知我
doaj
Gaoya dianqi, 2010 OPGW因雷击而断股,不仅会影响到输电线路的安全运行,而且会威胁到电力系统通信和继电保护的可靠性。因此,对OPGW雷击断股的分析和研究就显得尤为重要。笔者采用有限单元法（FEM）分析OPGW遭雷击时的高温情况。首先在对OPGW遭雷击时的能量转换和传递过程分析的基础上建立了温度场的数学模型,并进一步阐述了使用有限单元法对该温度场进行数值求解的空间域和时间域离散过程。分析了雷电电弧弧根的能量功率函数及其影响因素,以此作为OPGW分析温度场的外热源。雷击点的热流分布采用高斯热源模型 ...
崔弘 +4 more
doaj
Research on web stability and human-induced vibration of Concrete filled steel tubular with corrugated steel web composite structure [PDF]
, 2014 波形钢腹板-钢管混凝土组合结构作为一种新型结构，可以发挥钢管混凝土抗压能力强和波形钢腹抗剪能力高的优点，其作为腹板的波形钢还具有自重轻、受力明确、施工方便、美观等优点，使得这种组合结构具有强大的竞争力和广泛的应用前景，作为一种新型结构，前人对其进行的理论与试验研究甚少。为此，本文在侨英人行天桥荷载试验的基础上，建立了该桥的有限元模型，对该桥的波形钢腹板稳定性和人致振动特性进行了有限元分析，并总结规律。本文的工作主要集中在以下几个方面： 通过对侨英人行天桥的荷载试验和有限元分析，结果表明 ...
曾显通
core
Partisans' evaluations of unconstitutional legislative activity
Policy Studies Journal, EarlyView.Abstract In this research note, we examine whether public evaluations of a policy depend on the constitutionality of the process by which that policy was passed. We observe whether people's views depend on accusations that a policy was passed in violation of a state constitution's single subject rule, and whether the effect of that accusation depends ...
Kevin K. Banda +2 more
wiley +1 more source
, 2009 采用在结构顶层设置双向TMD被动控制的方法,对结构在多向地震作用下的振动进行了被动控制的研究.在建立三维结构控制体系的动力学模型后推导出结构-TMD联合动力方程,并以功率谱密度函数矩阵迹的积分为目标函数,利用单纯形法对双向TMD的参数进行优化设计.数值结果表明,利用双向TMD系统对结构进行被动控制的方法是可行且有效的 ...
张建霖, 曾轲
core
Research on the influence of PGA when considering the new Yuping potential seismic source in the Hunan-Guizhou border region [PDF]
This paper collects relevant information on the newly added Yuping potential seismic source in western Huaihua, and analyzed the seismic hazard of the study area based on 1′×1′ grid points.
Gang Hu, Lei Shao
core +1 more source
Policy Studies Journal, EarlyView.ABSTRACT This study examines the evolution of climate change discourse in the United States Congress from 1987 to 2017, employing natural language processing (NLP) techniques to analyze floor speeches. Using a la carte (ALC) word embeddings, we investigate how Democratic and Republican members of Congress frame climate change, focusing on denialist ...
Joseph Charles Van Matre +2 more
wiley +1 more source