Results 51 to 60 of about 11,284 (195)

氧化锌非线性电阻片用无机高阻层的研究

open access: yesDianci bileiqi, 2006
研究了氧化锌非线性电阻片侧面用无机高阻层在4/10大电流冲击和2ms方波电流冲击作用下的破坏机理。认为影响电阻片耐受大电流冲击能力的关键之一是无机高阻层本身的绝缘强度,之二是无机高阻层和电阻片之间膨胀系数的配合问题,并通过试验指出,侧面绝缘层的膨胀系数应比ZnO陶瓷小0.5×10-6/℃~1.5×10-6/℃。影响电阻片耐受方波电流冲击能力的关键是无机高阻层和电阻片本体反应后所形成的中间层的稳定性。研制的无机高阻层可满足φ32mm×35mm、梯度为240V/mm的电阻片65kA大电流冲击的要求 ...
高奇峰   +3 more
doaj  

Multiscale Study of a Synergistic System in Carbon‐Coated Multimetal‐Based Selenides Toward Rapid and Highly Stable Sodium Storage

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
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

直流机电暂态仿真建模及与电磁暂态仿真的对比

open access: yesGaoya dianqi, 2018
对直流输电的机电暂态仿真模型进行了深入研究。推导了适用于整流侧和逆变侧的换流器通用数学模型,分析了换相失败的判断方法,同时对逆变侧定关断角控制器的模拟方法进行了详细分析。在机电暂态仿真软件中搭建了含有直流输电详细模型的测试系统。为了深入分析直流输电机电暂态模型的精确度,以直流输电逆变侧不同程度的故障对比了机电暂态仿真结果与电磁暂态仿真结果。结果表明:机电暂态仿真计算是理想化的,它对换相失败临界点的判断与电磁暂态仿真存在偏差;在发生换相失败故障时,机电暂态模型响应曲线与电磁暂态模型基本一致 ...
李威   +8 more
doaj  

Dual Synergistic Effects in a Ce‐Modified MnO2/MnO Heterostructure Enabling Outstanding Acidic Oxygen Evolution

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT The development of highly efficient and stable nonprecious metal electrocatalysts for the acidic oxygen evolution reaction (OER) is crucial to advance proton exchange membrane (PEM) water electrolysis. In this work, a dual synergistic strategy was proposed by constructing a Ce‐modified MnO2/MnO heterostructure.
Chuanbin Li   +7 more
wiley   +1 more source

换流站机具施工人员安全防护研究

open access: yesGaoya dianqi, 2014
直流输电工程与交流输变电工程不同,直流设备周围的电场为直流静电场和空间离子流场的综合场。但是,目前,国内直流输电工程的检修作业人员安全防护基本参照同等电压等级的交流输变电工程进行。当现场使用大型机具进行带电施工和检修时,由于机具的进入,作业现场的直流综合场和空间离子流分布会影响检修作业人员的安全防护效果。因此,笔者针对直流换流站的现场实际布置情况,对换流站典型施工区域有/无机具条件下的直流合成电场和离子流密度进行了测试。测试结果表明,有大型机具存在时,由于机具本体的屏蔽作用 ...
蔡焕青   +7 more
doaj  

Bimetallic Mo/Fe‐Doped CoP2 Nanoleaf Array as a Bifunctional Electrocatalyst for Overall Water Splitting

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT The development of efficient and stable bifunctional catalysts remains a key challenge for green hydrogen production via electrochemical water splitting. In this study, a bimetallic Mo/Fe‐doped CoP2 nanoleaf array anchored on carbon cloth (Mo, Fe‐CoP2@CC) was synthesized from zeolitic imidazolate framework‐L (ZIF‐L) via an ion‐exchange and low‐
Xiangqun Zeng   +6 more
wiley   +1 more source

Broad‐Spectral Response Lead Halide Perovskite Solar Cells Through Integration of Multifunctional Organic Bulk‐Heterojunction and Quantum‐Cutting Downconversion Materials

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Expanding near‐infrared (NIR) spectral response and utilizing ultraviolet (UV) photons are effective strategies for enhancing the power conversion efficiency (PCE) of lead halide perovskite solar cells (PSCs). However, the range of NIR spectral response extension and the utilization of UV light for devices are not enough, and the loss of ...
Li He   +9 more
wiley   +1 more source

Commande à haute performance et sans capteur mécanique du moteur synchrone à aimants permanents [PDF]

open access: yes, 2008
Les moteurs synchrones à aimants permanents sont de plus en plus utilisés dans les servo-méchanisme grâce à leurs performances supérieures aux autres moteurs à courants alternatifs.
Zheng, Zedong
core  

Sodiumation of Biomass‐Derived Quinones Enables High‐Rate and Long‐Life Cathodes for Sodium‐Ion Batteries

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Biomass‐derived quinones are promising green and sustainable cathode materials for sodium‐ion batteries (SIBs), yet their practical application is hindered by poor cycling stability due to dissolution in conventional electrolytes. Herein, we demonstrate that sodiumation is an effective strategy to enhance both rate capability and cycling ...
Xinyue Zhu   +4 more
wiley   +1 more source

基于有限元分析的双馈异步发电机定子绕组匝间短路故障诊断研究

open access: yesGaoya dianqi, 2012
笔者基于有限元分析软件Maxwell 2D建立了双馈异步发电机的仿真模型,通过改变模型中短路匝数和短路电阻的大小来模拟电机的不同短路情况,对不同情况下的电机进行仿真计算得出:定子发生匝间短路故障后,会在定子中产生负序电流,并随着故障严重程度的增加而增大,同时负序电流会受到电源不对称的影响,在用负序电流进行故障诊断时,需要补偿这些非电机故障因素的影响,同时负序电流也会受到电机负载情况的影响,且随着负载的增大负序电流有微弱增大。另外,定子发生匝间短路故障后,定子三相电流不再对称,故障相电流恒最大 ...
张志新, 马宏忠, 钱雅云, 程俊
doaj  

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