Results 31 to 40 of about 7,248 (178)

Fabrication‐Driven Oxidation Pathways in Y/Hf‐Modified High‐Entropy Alloys: From Elemental Segregation to Oxide Homogeneity

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT This study elucidates the oxidation mechanisms governing Y/Hf‐doped AlCoCrFeNiTi high‐entropy alloys (HEAs) and reveals the pivotal role of fabrication processes in dictating high‐temperature oxidation behavior. We demonstrate that casting and spark plasma sintering (SPS) promote Y/Hf segregation, resulting in heterogeneous oxide formation and
Huaqing Yi   +5 more
wiley   +1 more source

谐波电流下油浸式配电变压器负载损耗及绕组热点温度分析

open access: yesGaoya dianqi, 2018
为了研究电流畸变情况下油浸式配电变压器负载损耗和绕组热点温度的变化规律,基于IEEE StdC57.110中的绕组涡流谐波损耗因子和杂散谐波损耗因子,并考虑绕组在谐波电流下的集肤效应会增强,定义了绕组电阻谐波损耗因子,从而建立了变压器在谐波电流下负载损耗计算模型。考虑到绕组涡流损耗密度分布不均对绕组热点温度的影响,利用文中所建立的变压器在谐波电流下负载损耗计算模型修正了IEEE Std C57.110:2008的绕组热点温度计算公式。分析结果表明,谐波电流会引起较大的额外负载损耗,谐波畸变率为40 ...
周卫华   +7 more
doaj  

Studies on Ships’ History of Taiwan Stiraits in Qing Dynasty [PDF]

open access: yes, 2015
台湾内属后,海洋运输,是大陆与台湾之间往来联系的唯一纽带。台湾船舶发展史,贯穿了整个台湾的发展历程。本文作者在阅读《明清宫藏台湾档案汇编》中大量有关台湾海峡海洋运输的档案后,通过资料分析、列表格的方法,来介绍清朝时期台湾船舶的相关历史。本文主要是从台湾的海洋交通体系、船只损耗情形、船只修造的相关内容,以及对当时出现在台湾海峡的商船管理等方面来展开的。 台湾与大陆的交流均通过船舶进行。清朝初期,郑成功占据厦门、台湾对抗清廷,大力发展台厦之间、台湾与东南亚各国间的贸易外来,船舶往来频繁。康熙收复台湾之后 ...
陈静
core  

Enhanced Low‐Frequency Microwave Absorption and Corrosion Resistance of FeSiAl Using Low‐Melting‐Point Glass Phase Coatings

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT This study developed a FeSiAl@LMPGP composite material to address the demand for low‐frequency electromagnetic absorption. Through controllable heat treatment, FeSiAl particles and PbO nanoparticles self‐assembled into a high‐density Mott–Schottky heterointerface structure, which exhibited a significant built‐in electric field (BIEF) effect ...
Yuqi Wang   +5 more
wiley   +1 more source

The Research and Design of Planar Lens Antenna Based Metamaterial Surface [PDF]

open access: yes, 2015
平面透镜天线因为其制作工艺简单、成本低、易于大批量生产、一致性好等优点,有很大的应用市场,越来越受到工程师的青睐。本文主要是研究平面透镜天线的应用,用平面贴片透镜天线替代三维透镜天线,用平面龙伯透镜天线替代三维龙伯透镜天线,仿真和测试结果都比较好,在一定程度上改进了现有的研究成果。 在平面贴片透镜天线的研究上,本文研究了只需要一种贴片单元,只需要改变贴片大小和单元极化方向,就可以获得360◦的全相位相应,而传输系数|S11|只改变2dB。之后设计了一款有96个贴片单元组成的平面贴片透镜天线 ...
熊小平
core  

In Situ MOF Pyrolysis Construction of Hierarchical Porous Co‐Nanoparticles/Carbon Cloth Composites for Enhanced Electromagnetic Wave Shielding and Absorption

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT The development of high‐performance electromagnetic protection materials integrating broadband absorption and effective shielding capabilities is hindered by challenges in simultaneously optimizing multiple electromagnetic properties through conventional material designs.
Changlong Du   +9 more
wiley   +1 more source

Microstructures and Performances of Novel Three-dimensional Porous Titanium Anodes [PDF]

open access: yes, 2016
钛阳极在湿法冶金、阴极保护、电解铜箔、铝电极箔和电化学合成丁二酸等领域具有广泛的应用。钛阳极一般要由钛基体和活性涂层两部分组成,目前,析氧用钛阳极的涂层材料是以贵金属铱的氧化物为主要成分,这种涂层材料具有低的析氧电位和长的使用寿命。但是,铱的价格昂贵,用量大,造成电极成本过高,因此,有必要研究和开发非贵金属涂层,以逐步取代贵金属涂层。此外,钛基体只起到传导电流和稳定尺寸的作用,并没有发挥出钛阳极的整体功效,如何设计出更好的基体材料,把涂层的性能完全发挥出来,也是目前急需解决的问题 ...
范亚卓
core  

MXene‐Based Electromagnetic Attenuation Materials in Microwave and Terahertz Bands

open access: yesRare Metals, Volume 45, Issue 2, February 2026.
ABSTRACT MXenes exhibit considerable potential for developing high‐performance electromagnetic (EM) shielding and absorption materials operating across microwave and terahertz frequencies, due to their tunable surface chemistry and exceptional charge carrier transport properties.
Guozheng Zhang   +9 more
wiley   +1 more source

光纤熔接施工中降低光纤接头熔接损耗的措施

open access: yesGuangtongxin yanjiu, 2000
介绍光纤接头熔接损耗的概念及其测量方法、影响熔接损耗的主要因素以及降低熔接损耗的方法 .
杨大伟
doaj  

Control strategy research for PV DC microgrid with hybrid storage system [PDF]

open access: yes, 2016
以光伏、风电等可再生能源为主的分布式发电技术因为其随机性、不稳定性,对配电网潮流改变带来的安全性等问题,其发展得到一定的制约。微电网被广泛认为是解决分布式发电技术应用瓶颈的有效解决方案,而直流微电网以直流形式传输电能,控制结构简单,不需考虑频率和相位,系统损耗小,效率高,也更加适合越来越多的直流电器的接入,因此具有很强的推广实用价值。本文在研究了直流微电网的国内外研究发展现状、架构,以及包括控制技术、储能技术、保护技术等关键技术基础上,对包含有蓄电池和超级电容器在内的光伏直流微电网系统进行了研究 ...
杨贇
core  

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