Results 31 to 40 of about 1,430,791 (187)
高压断路器进出线的复合空心绝缘子主体长约8~10 m,弹性模量远小于瓷绝缘子。复合空心绝缘子在强风下会产生风偏,风偏量受风速大小和工作自身弹性模量影响。大幅风偏是否会引起复合空心绝缘子内外电场强度的畸变,劣化内外绝缘鲜有研究。由于高压复合空心绝缘子成本高,投运时间短,退运下来的样品较少。文中采用有限元分析的方法模拟强风工况,进行电场计算。针对750 kV断路器复合空心绝缘子在强风下振动的1阶模态振型,计算绝缘关键区域的电场强度,阐明风偏对接地屏蔽电极附近的电场畸变的危害最大,并给出了风速阈值 ...
张楠 +7 more
doaj
Growing Demand and Uneven Supply: Eight Years of Nature Education in China 需求增长与供给不均:中国自然教育八年发展回顾
ABSTRACT This study examines the role of nature education in advancing conservation and sustainability in China between 2014 and 2023. Drawing on national survey reports and historical–comparative methods, it analyses the dynamics of public demand, institutional supply, and practitioner capacity.
Qi Yunxi, Lyu Xiang, Huang Yu
wiley +1 more source
ABSTRACT Reliable operation of high‐performance magnetostrictive devices, composed of the giant magnetostrictive material (GMM), that is, the TbDyFe alloy, critically depends on an optimally tailored bias magnetic field. Sufficient intensity and uniformity are essential to induce the ideal initial strain in the GMM, enabling peak reciprocating output ...
Jinan Yu +12 more
wiley +1 more source
介绍了高压直流输电线路导线表面最大场强和线路电磁环境参数的计算方法。针对±660 kV直流输电线路,分析了导线表面最大场强对地面合成电场、地面离子流密度、无线电干扰和可听噪声的影响,得出正极导线电压在620680 kV之间变化时,随着导线表面最大场强的增大,地面合成电场和地面离子流密度分别增加1.2倍和2.8倍;导线表面最大场强对无线电干扰和可听噪声的影响相对较小,分别增加17%和0.3%。±660 kV直流输电线路在额定电压范围内运行时,电磁环境指标不会超出《高压直流架空送电线路技术导则》的规定。
袁海燕, 庄燕飞, 姚金霞, 刘民
doaj
Fermi Surface Structure Revealed by Quantum Oscillations in Half‐Heusler Semimetal LuAuSn
ABSTRACT The Fermi surface structure in the half‐Heusler semimetallic compound LuAuSn was systematically investigated using quantum oscillation studies of high‐quality single crystals and first‐principles calculations. Clear bulk quantum oscillation signals were observed for multiple complementary physical properties, including magnetization, Hall ...
Yue Lu +12 more
wiley +1 more source
APPLICATION OF SUPER-MICRO TESTER IN MEMS BONDING STRENGTH TEST
研制微力学测试仪,对微电子机械系统中键合结构的强度进行测试.最大载荷为1.4 N,在载荷量程为450 mN时仪器的最高分辨力为10 μN.采用键合在玻璃基底上的硅悬臂梁作为试样.为模拟横力剪切破坏和扭转破坏工况,用微力学测试仪分别在悬臂梁的固定端和自由端施加载荷至试样破坏.测得相应的破坏载荷并计算出最大剪应力.对破坏残骸的显微观察发现,存在玻璃开裂和硅开裂2种失效模式.该技术为微电子机械系统(micro-electro-mechanical system,MEMS)键合结构的强度表征提供一种有效方法 ...
郇勇 +4 more
core +1 more source
ABSTRACT The development of sodium‐ion batteries (SIBs) is limited by slow charge transfer kinetics and large material volume changes caused by the large radius of Na+. Leveraging the excellent physicochemical properties and unique heterostructures of metal selenides, ultrafine hetero‐CuFeSe2‐CoSe2 nanoparticles are in situ wrapped by ...
Ying Zhu +5 more
wiley +1 more source
气体绝缘变电站(gas insulated substation,GIS)中隔离开关的倒闸操作会产生强烈的瞬态空间电磁场,对变电站中电子设备形成电磁干扰,威胁其运行。为此,文中提出采用时域有限积分法计算GIS空间电磁场分布,考虑由于隔离开关操作对GIS造成的空间电磁暂态过程。文中计算并分析了550 kV GIS中空间环境中的电场和磁场,分别计算和分析传导耦合和辐射耦合下电磁强度在不同距离,不同高度的分布特性和规律(GIS线路内电磁强度随线路长度的变化,以及电磁强度距离GIS线路高度的变化)。计算结果表明,
赵雪 +4 more
doaj
ABSTRACT The construction of p–n homojunctions represents a promising strategy for effective solar‐driven photocatalytic hydrogen evolution, owing to their inherent advantages of superior lattice matching and minimized charge transfer resistance. However, this approach remains largely unexplored.
Yueqiang Lin +6 more
wiley +1 more source

