Results 11 to 20 of about 3,108 (119)
中国铁路接触网腕臂绝缘子冬季面临“雪闪”问题,研究多种积雪条件下,对平、斜安装腕臂绝缘子的电场特性影响,为绝缘子选型及优化提供理论依据。以QBG-25型棒式瓷绝缘子为研究对象,建立有限元电场模型,分析温度、积雪厚度、融雪覆冰厚度及污秽类型对绝缘子电场特性的影响。仿真结果表明:当温度低于0℃时,绝缘子电场强度随温度的降低先增大后减小,在-2℃时电场强度达到峰值;积雪厚度对电场强度影响呈现先增长后减小的变化趋势,各个伞裙电场强度与伞裙表面积雪形态有关,表面积雪程度严重但未完全覆盖时,电场强度畸变最严重 ...
李刚, 李彦哲, 李宝学
doaj
输电线路运行时导线表面的电场强度是影响导线覆冰及其电晕放电过程的重要因素,但现有文献的研究对象多为交流输电线路。为适应中国直流输电线路的建设浪潮,文中在电晕笼中采用人工带电模拟覆冰的方法研究了覆冰电场强度对导线雨凇覆冰形态以及电晕损失特性的影响规律。研究表明:覆冰电场强度对导线雨淞覆冰形态具有显著的影响,覆冰时导线表面电场强度越高,形成的雨淞覆冰导线的覆冰重量和冰凌长度越小、冰凌间距越大、覆冰厚度呈先增大后减小的规律。高覆冰电场强度下形成的雨淞覆冰导线的电晕损失更小,此外 ...
张海兵 +4 more
doaj
针对GIS隔离开关操作时电子式互感器内部电磁干扰问题,文章首先对电子式互感器进行了结构建模,基于偶极子天线的辐射理论模型对电子式互感内部的三维电磁场分布规律和强度开展分析,最终得到电子式互感器内部不同时刻的电磁场强度及其分布规律:在电磁骚扰产生0.5~2.5μs内电子式互感器内部电场强度较大,在3μs之后电场逐渐减小,在相同频率下,y轴方向电场最强,x轴方向磁场最强。
成林 +6 more
doaj
为调控直流稳态与极性反转工况下直流气体绝缘输电线路(HVDC GIL)绝缘子的沿面电场分布,分别设计了稳态梯度(ST-SFGM)绝缘子与极反梯度(PR-SFGM)绝缘子。迭代优化后的SFGM绝缘子涂层电导率恒定,厚度沿r坐标方向减小。电场仿真结果表明,直流稳态工况下均匀绝缘子的最大电场出现在高压三结合点附近,强度为4.25 kV/mm。ST-SFGM绝缘子与PR-SFGM绝缘子的直流电场分布较为均匀,最大电场强度分别下降54.6%与62.1%。极性反转工况下,均匀绝缘子与ST ...
姚航, 杜伯学, 梁虎成, 董佳楠
doaj
ABSTRACT Dielectric polymers commonly suffer from severe performance degradation above 150°C, hindering advanced power systems. Herein, we demonstrate a polyetherimide (PEI) nanocomposite that overcomes this by mimicking the gradient architecture of nacre and bamboo, incorporating a continuous vertical gradient of fluorinated boron nitride nanosheets ...
Jian Wang +8 more
wiley +1 more source
Structural Modulation of Magnetic Softness in Fe‐Based Amorphous Alloys via Pulse Current Training
ABSTRACT Fe‐based amorphous alloys, despite their intrinsically low magnetocrystalline anisotropy, suffer from quasi‐dislocation dipoles and localized stress fields that impede domain‐wall motion and increase coercivity. Here, we introduce pulse current training (PCT) as an energy‐efficient technique to overcome these limitations in a Fe76Si9B10P5 ...
Shumin Ye +13 more
wiley +1 more source
ABSTRACT Composite materials hold significant potential for abrasive sealing, yet composite materials used for abrasive sealing fall short in service durability under extreme environments. Here, a controllable strategy for adjusting pore structure is proposed, aiming to design a YSZ(ESP)/BN@ZrO2‐polyester coating with hybrid micron/nanometer ...
Shuang Yu +8 more
wiley +1 more source
ABSTRACT The rapid expansion of data‐intensive applications has highlighted the fundamental limitations of traditional CMOS‐based von Neumann architectures, particularly in terms of power efficiency, latency, and flexibility. Spin logic devices utilizing spin–orbit torque (SOT) present a promising pathway for nonvolatile, low‐power, and in‐memory ...
Ke‐Yi Wu +5 more
wiley +1 more source
采用动态蒙特卡罗模拟方法,模拟半柔性大分子链在电场作用下穿越纳米孔道进入球腔的输运过程.主要研究电场强度及半柔性大分子链的刚性强度对穿孔过程的影响.发现:平均穿孔时间τ随电场强度的增大而减小,τ与链的长度N满足标度关系τ〜Nα,并且电场强度E和弯曲能b对标度指数有显著影响.研究结果表明,当电场强度为中等时,刚性弱和刚性强的大分子的穿孔过程是完全不同的.研究半柔性大分子链穿越微孔的行为,有助于更深入认识生物大分子在生命体内的输运过程.
MAYuansui(马源穗) +3 more
doaj +1 more source
ABSTRACT The Janus structure of ZnIn2S4 (ZIS) endows it with an intrinsic built‐in electric field that effectively drives photogenerated charge separation. However, this very structure also renders the predominant (001) facet (In–S termination) catalytically inert due to its low electron density and high energy barrier for the hydrogen evolution ...
Qingao Zhou +8 more
wiley +1 more source

