Results 31 to 40 of about 9,857 (139)
目前,国内外对模块化多电平换流器(modular multilevel converter,MMC)的运行特性的研究主要集中在换流器环流产生机理及其抑制、换流器输出电压及电流谐波特性等方面的分析,未对换流器功率模块电容对换流器调制度的影响进行过多研究。文中从换流器的基本原理出发,详细分析了功率模块电容对换流器调制度的影响,分析表明换流器桥臂中的n次谐波电流会在功率模块电容上产生n-1、n、n+1次电流谐波,进而在功率模块电容上产生n-1、n、n+1次电压波动 ...
任成林 +5 more
doaj
ABSTRACT The design of nanoparticles confined in hollow N‐doped carbon structures is crucial for improving the oxygen reduction reaction (ORR) kinetics, yet achieving this remains a significant challenge. In this work, hollow porous nitrogen‐doped carbon encapsulated FeP/Fe2P (H‐FeP/Fe2P) were successfully constructed via a templating method combined ...
Li‐Xia Wang +8 more
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In Situ Uniform Lithium Enrichment for Dense, High‐Performance LLZO Solid Electrolytes
ABSTRACT A major challenge in garnet‐type Li7La3Zr2O12 (LLZO) system all‐solid‐state electrolytes is the high porosity that typically remains after sintering, which compromises ionic conductivity and degrades battery cycling performance. To address this, we propose an innovative strategy to achieve uniform lithium enrichment on the surface of ...
Yi‐Yang Xiao +8 more
wiley +1 more source
ABSTRACT Vanadium oxides are deemed competitive cathode candidates for aqueous zinc‐ion batteries (AZIBs), benefited from their high theoretical capacity and multiple crystalline structures. However, the sluggish reaction kinetics, poor reversibility, and high solubility have hindered the practical application.
Xiaoyu Fan +7 more
wiley +1 more source
本文叙述了ZnO避雷器用阀片的电性能的均匀性。使用热像法是评价均匀性的一种简单而实用的方法,它是通过对喷涂有金属的ZnO阀片的表面的红外线辐射热照像,用试验获得均匀性和通流容量之间的关系。具有相同均匀性系数δ的阀片,击穿前的通流容量与交流短时过电压的波幅大小和持续时间的长短无关。还提出了交流短时过电压有允许极限的考虑。
李瑞田
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ABSTRACT Existing literature largely agrees that authoritarian regimes establish channels for political participation to gather valuable information on citizens' anti‐regime sentiments and policy preferences and to supervise lower‐level bureaucrats and firms.
Anton Bogs
wiley +1 more source
通过对某线110 k V有缺陷的线路避雷器进行绝缘电阻、泄漏电流及局放测试,并解体对其中泄漏电流不合格的电阻片进行干燥处理,干燥前后发现不合格的电阻片泄漏电流变化不大,为找出问题所在,提出通过测量避雷器电阻片电容量与额定值相比较的方法,对不合格的电阻片进行电容量测量,测试结果显示:不合格的电阻片电容量均超过其额定值的20%,表明这些电阻片已经劣化,找出了造成该线路避雷器炸裂的原因并非电阻片受潮,而是电阻片本身劣化所致。
邱太洪 +5 more
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Beyond Motivation: Modeling the Predictive Role of L2 Pride in Informal Digital Learning of English
ABSTRACT This study investigates the role of second language (L2) pride—an understudied affective factor—in shaping learners’ language learning motivation and involvement with informal digital learning of English (IDLE). Drawing on questionnaire data from 1388 Chinese university EFL students, the study employs structural equation modeling to examine ...
Minlin Minny Zou +3 more
wiley +1 more source
复合式避雷器是一种特殊结构的超高压避雷器。它主要用来解决阀片和间隙通流容量不足、灭弧能力低的矛盾,使避雷器的通流容量增加,以满足超高压系统对避雷器的要求。复合式避雷器的关键元件是并联间隙。它在一定的冲击电流下必须可靠动作,使避雷器冲击残压保持在规定值以下 ...
张雨时, 龙淑范
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换流变压器作为直流输电技术的核心设备,其宽频模型对于系统暂态仿真具有重要意义,目前设备宽频建模依赖于其宽频特性的测量。然而特高压换流变压器入口电容大,基于时域法的宽频特性测量目前尚无满足要求的宽频脉冲发生器。文中设计的脉冲发生器通过增加中储电容、陡化开关、调波电感等手段大幅提高了脉冲输出的高频分量,通过增加调波电容提高了频谱分析的平整性,在携带入口电容为10.4 n F的±800 kV特高压换流变压器负载时,可输出幅值35 kV、上升沿320 ns、振荡周期800 ns的高压脉冲,频谱分析显示在1 ...
黄冬冬, 李江涛, 何双, 朱毅
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