Results 21 to 30 of about 25,659 (229)

Study on Measurement for Dielectric Property of Microwave Dielectric Resonator [PDF]

open access: yes, 2016
微波介质陶瓷材料是近几十年发展起来的一种新型的功能电子陶瓷,主要用于微波频段电路中完成一种或多种功能的陶瓷材料,是制造微波介质谐振器和滤波器的关键材料,它具有高介电常数,低介电损耗,温度系数小等优良性能适用于制造多种微波元器件,能满足微波电路小型化,集成化,高可靠性,低成本的要求。在电子对抗,导航,通信,雷达,家用卫星直播电视接收器和移动电话中得到了广泛应用。 微波介质陶瓷材料是电介质材料的一种,具有电介质材料的基本性质。其介电性能可用介电常数ε_r^',品质因数Q(或损耗角正切 ...
李学漪
core  

Oxygen Vacancy Engineering of Ultrafine ZnAl2O4 Nanoparticles as a Robust Protective Layer for Dendrite‐Free and Long‐Lifespan Aqueous Zn Metal Anodes

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Aqueous zinc‐ion batteries (AZIBs) hold great promise for safe and sustainable energy storage, but their commercialization is impeded by severe Zn dendrite growth and interfacial instability. To address these challenges, we propose a defect engineering strategy employing ultrafine ZnAl2O4 (ZAO) nanoparticles (∼5 nm) with oxygen vacancy defects
Yilun Ren   +9 more
wiley   +1 more source

Electronic structures and thermoelectric properties of several wide-band-gap semiconductors [PDF]

open access: yes, 2016
由于化石能源的飞速消耗以及人类在应用化石能源过程中造成的环境污染,开发清洁可持续的新能源成为研究热点,热电作为新能源开发中的一员,在研究中遇到的主要问题是材料的热电转换效率难以提高。本文的主要工作是以第一性原理为基础,以SiC,GaN,ZnO等几种宽禁带半导体为对象,研究宽禁带半导体材料结构变化与其热电效率高低的关系。通过Quantumespresso和WIEN2k计算材料的电子结构,再用Boltztrap软件计算材料的热电性质,我们可以比较不同结构的同种化合物热电性质的变化情况,并找出定性的规律 ...
黄政
core  

Electronic Modulation of CoNi Nanoparticles by N‐Doped Carbon for Efficient Lignin Hydrogenolysis to Aromatic Monomers

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Cost‐effective and efficient non‐noble‐metal catalysts for selective lignin hydrogenolysis remain elusive, representing a significant challenge in biorefinery. Here, we prepared a nitrogen‐doped carbon supported CoNi bimetallic catalyst, which was successfully derived from zeolitic imidazolate framework (ZIF) via high‐temperature pyrolysis ...
Xingwei Luo   +3 more
wiley   +1 more source

Three-Dimensional Nanostructured Anode Materials and Their Properties for Lithium-ion Battery [PDF]

open access: yes, 2010
开发新型高容量电极材料是发展新一代锂离子电池的核心,其中金属氧化物和Sn基合金材料具有很高的容量是研究的热点之一。然而金属氧化物和Sn基合金材料在锂离子的嵌脱过程中都发生巨大的体积变化,使容量的快速衰减,从而导致其循环性能很差。因此,如何减小或抑制材料由于锂离子的嵌脱引起的体积变化所带来的容量快速衰减是一个极大的挑战。 针对金属氧化物和Sn基合金材料存在的上述问题,本论文通过构筑三维结构(包括三维纳米带阵列结构和三维多孔结构)纳米材料来显著提高它们的循环寿命。三维结构纳米材料电极具有以下优点:(1 ...
柯福生
core  

Ionic‐Liquid‐Assisted Synthesis of NiTe/CoTe Heterostructure With Te Vacancies in N, P, and F Co‐Doped Hollow Carbon Nanorods for Efficient Alkaline Hydrogen Evolution and High‐Performance Flexible Supercapacitors

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Low conductivity, slow ion‐diffusion, and limited reactive sites are common problems in electrocatalysts and electrode materials. In this study, a complex NiTe–CoTe heterojunction with abundant Te vacancies embedded in N, P, and F co‐doped hollow carbon nanorods (NiTe1−x–CoTe1−x/NPFC) was fabricated via a simple ionic liquid‐assisted ...
Mingjie Yi   +7 more
wiley   +1 more source

高压侧感应取能电源的研究

open access: yesGaoya dianqi, 2013
由于绝缘需要,高压监测设备的电源无法由低压侧直接供给,因此,研究经高压侧取能的供电技术十分必要,而电源供能的稳定性与长期性是对其性能提出的要求。以电流互感器电磁感应取能为基础,引入C8051F021单片机构建电源控制电路,从提高电源自适应能力的角度尝试解决上述问题。该电路的取能部分、过流保护部分及后备电源部分均能由单片机通过对采样点信号进行分析而得到有效控制,可分别解决一次电流宽范围变化下的可靠取能问题,即大电流下的过流保护问题,以及欠电流下的供能问题。这使供电电源能够有效应对不稳定的电流状况,具备长期、
肖波   +5 more
doaj  

Simulation and Process Optimization Research of CuInGaSe2 Thin Film Solar Cells [PDF]

open access: yes, 2015
人类对能源消费的不断增加,传统化石能源的快速消耗导致环境恶化加剧,雾霾等恶劣气候频发,严重影响人类的身体健康和生存,寻找可再生清洁能源成为全球共同追求的目标。太阳能是一种可持续的清洁能源,受到科学家的热衷追捧,而光伏产业作为无污染的新能源产业获得世界各国青睐而得到广泛应用。 以中国光伏产业为代表的发展中国家,其新能源产业以前所未有的速度发展,对世界新能源产业做出巨大贡献,但是由于发达国家的贸易“双反”政策及国内市场开发不足导致以晶硅为主的中国光伏产业遇冷,而薄膜太阳电池却未受到双反的限制。铜铟镓硒 ...
陈文志
core  

石墨烯/聚乙烯醇/聚偏氟乙烯基纳米复合薄膜的介电性能

open access: yes, 2016
石墨烯由于具有良好的力学性能、高的电子传递能力以及相对较低的生产成本等优势而受到广泛关注,但现在多将其直接分散在聚合物中提高聚合物的介电性能. 本工作中,制备出了还原氧化石墨烯/PVA/聚偏氟乙烯(PVDF)的三相纳米复合薄膜. 首先把聚乙烯醇(PVA)和氧化石墨烯(GO)分散于二甲基亚砜(DMSO)中,得到PVA非共价键修饰的GO,再将PVDF溶于该混合液体中,通过溶液浇注以及低温加热过程得到三相纳米复合薄膜.
冯奇   +5 more
semanticscholar   +1 more source

Electrolyte With Functionalized Boron Nitride Nanosheets for Dendrite‐Free Lithium Metal Anodes

open access: yesRare Metals, Volume 45, Issue 3, March 2026.
ABSTRACT Lithium metal batteries (LMBs) are regarded as promising candidates for the next‐generation high‐energy‐density storage systems due to their unparalleled theoretical energy density and low redox potential. However, the commercialization of LMBs is tremendously plagued by the barbaric growth of lithium dendrite and the intricate decomposition ...
Ji Zhou   +5 more
wiley   +1 more source

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