Results 91 to 100 of about 29,284 (225)

基于时域介电法的不同材料油纸绝缘特性研究

open access: yesGaoya dianqi, 2018
为研究油浸式变压器中油浸普通牛皮绝缘纸和油浸热稳定绝缘纸的时域介电特性,文中在实验室开展了不同温度下的油纸样品加速热老化试验。通过极化去极化电流法(PDC)获得PDC曲线,根据曲线分析不同类型油纸绝缘在老化过程中的极化特性差异,从PDC曲线中提取电导率并拟合得曲线,探寻能够表征不同类型油纸绝缘老化程度的特征量。结果表明:普通牛皮绝缘纸试样的老化速度快于热稳定绝缘纸,且在老化后期,后者聚合度下降速率变缓更明显;PDC曲线对绝缘材料的变化十分敏感,对于老化时间相同的两种材料 ...
高波   +4 more
doaj  

Investigation of A Low-frequency Piezoelectric and Electrostatic Hybrid Vibration Energy Harvesting Technology [PDF]

open access: yes, 2015
无线传感网络技术的发展要求更持久的供能,传统的电池体积大,寿命短,逐渐无法满足技术进步的需要。能量收集技术可以将环境中的振动能源收集转换为电能,其寿命长,无须更换,实现电子器件的自供能,是一种较为有前景的替代传统电池的技术。 根据线性质量弹簧阻尼系统理论,本文深入分析了两种主要的振动能量收集方式:压电式能量收集及静电式能量收集,分别建立了其数学模型,并在此基础上设计了一种兼具有压电式和静电式收集原理的的复合式振动能量收集器。同时,成功设计了三种非线性复合式能量收集器结构和双电容结构 ...
邓志强
core  

Designing 3d Transition‐Metal Doped g‐C3N4 Monolayer for Enhanced Bifunctional Oxygen Evolution/Reduction Reactions Activity: Defect Physics and Constant‐Potential Study

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Graphitic carbon nitride (g‐C3N4) doped with 3d transition metals (3d‐TM@g‐C3N4) has gained attention as a noble metal‐free alternative for oxygen evolution and reduction reactions (OER/ORR). Yet the key mechanisms driving its performance remain debated, especially across different charge states.
Jing Zhang   +6 more
wiley   +1 more source

变压器油和绝缘纸老化对扩展Debye模型参数的影响研究

open access: yesGaoya dianqi, 2016
为研究变压器油和绝缘纸老化对扩展Debye模型参数的影响,以及确定变压器油换油时间,首先在实验室条件下对油纸绝缘试样进行130℃加速老化试验和PDC试验,然后建立不同试样相对应的扩展Debye模型,深入研究变压器油和绝缘纸老化时扩展Debye模型支路参数的变化规律,最后提出用中间时间常数分支电容变化率作为变压器的换油阈值。结果表明:变压器油主要影响扩展Debye模型时间常数小于500 s的支路参数,随着变压器油老化天数增加,油老化产物会增加油中偶极子组的转向极化及油纸界面极化,去极化电流起始部分幅值增大,
宋臻杰, 杨飞豹, 吴广宁, 高波
doaj  

Pyrolysis‐Engineered Fe/Mn‐ZIF Catalysts: Balancing Activity, Selectivity, and Stability for the Oxygen Reduction Reaction

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Metal oxide‐based catalysts for oxygen reduction reaction (ORR) have drawn great attention in recent years. However, it remains technically challenging for the precise regulation of the overall performance due to the trade‐off effect among the activity, selectivity, and stability of electrocatalysts. Herein, a balancing strategy to control the
Haoran Ma   +7 more
wiley   +1 more source

A first-principles investigation of spin gapless Heusler compounds M2CoA (M = Mn, Ti; A = Al, Si) [PDF]

open access: yes, 2015
M2CoA型Heusler化合物Mn2CoAl、Mn2CoSi、Ti2CoAl和Ti2CoSi具有独特的电子结构和磁学性质。Mn2CoAl是一种自旋无带隙半导体,其电子结构的一个自旋方向存在能带间隙,另一个相反自旋方向的导带和价带边缘在费米能级相接触,呈现无带隙半导体特性。Mn2CoSi、Ti2CoAl和Ti2CoSi被预测为自旋半金属,其电子结构的一个自旋方向存在能带间隙,另一方面,费米能级贯穿半金属相反自旋方向的能带,呈现金属特性。不管是自旋无带隙半导体还是自旋半金属,载流子都具有极高的自旋极化率 ...
林道斌
core  

Cs2SnI6: A Perovskite‐Based Electromagnetic Wave Absorbing Material

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Lead halide perovskites and carbon‐based materials are interesting, high‐performing electromagnetic wave absorbing materials. However, only a few studies have been carried out to examine in detail the electromagnetic wave absorption properties of these materials.
Fei Han   +11 more
wiley   +1 more source

Seawater desalination by ICP on a new microfluidic chip [PDF]

open access: yes, 2015
全球淡水资源匮乏受到越来越多的国家的重视,特别是一些水资源短缺的国 家和地区。海水淡化被认为是获得淡水资源的最佳途径之一。现如今海水淡化方 法发展较为迅速,其中主流技术有反渗透法、电渗析法以及蒸馏法等。 虽然上述三种方法发展较早,技术相对成熟,但能耗大、运营成本高,需要 搭建大型配套设备且不便移动,不易全球推广,特别是在欠发达国家。在淡水资 源短缺急剧严重的今天,寻找一种低能耗、成本低、便携式、使用寿命长、易于 市场推广、适合家庭以及个人使用的新型海水淡化装置迫在眉睫,本文研究设计 ...
葛立凯
core  

Construction of CoP/Mn2P Heterojunctions via One‐Step Phosphorization Coupled With Hollow Hard Carbon Spheres as Supports: Enabling Ultrastable Long‐Cycle Sodium‐Ion Anodes Over a Wide Temperature Range

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Driven by global energy transition and sustainability, sodium‐ion batteries (SIBs) have emerged as key alternatives to lithium‐ion batteries for low‐to‐medium energy storage, because of abundant sodium resources and low cost. However, their commercialization is hindered by the lack of anodes with high capacity, fast kinetics, and long‐term ...
Shuang‐Lin Cai   +13 more
wiley   +1 more source

The model evident study of technical indicators for classification of chemical power(化学电源技术指标分类的模型实证研究)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2009
分别采用因子分析模型和聚类模型对化学电源的技术指标:正极长度、负极长度、隔膜长度、电液量、容量、开路电压、自放电后电压、内阻和重量进行分析,得出正极长度与负极长度参数设计指标联系最紧密,开路电压与自放电后电压性能测试指标联系最紧密.这为化学电源技术指标的分类研究提供理论依据,为化学电源的设计质量控制、组合管理质量控制提供了参考价值,从而促进化学电源的技术进步与发展.
CHENGFu-long(程福龙), WANGBo(汪波)
doaj   +1 more source

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