Results 81 to 90 of about 29,284 (225)

Design of Indoor Base-Station Antennas [PDF]

open access: yes, 2015
随着无线通信的飞速发展,天线的作用越来越重要,根据应用场景的要求,选择合适的天线类型和结构。当前,无论是基站系统还是移动终端设备,小型化、多功能化、高性能等已成为其基本的技术目标,因此小型化、宽频或多频化、智能化等成为其天线选择和设计的主要内容。对此,微带结构天线是一种较佳的选择,它较易满足此类性能要求。 微带天线的出现将天线的加工成本大大降低,另外微带天线重量轻、体积小可以加工成各种形状,使微带天线在无线通信系统应用中具有优势。微带天线的带宽一般比较窄。怎样提高天线的带宽,同时保持或者降低天线的尺寸 ...
孟阳
core  

Engineering Geometric Active Sites in Cobalt Spinel Oxides for Energy and Environmental Catalysis

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Cobalt‐based spinel oxides (Co3O4 and derivatives) are among the most promising transition metal oxides for electrochemical energy conversion and environmental catalysis due to their abundant active sites, structural tunability, and robust redox flexibility.
Shenning Liu   +6 more
wiley   +1 more source

重新去极化对小脑颗粒神经元c-Jun 的影响

open access: yesZhongshan Daxue xuebao. Yixue kexue ban, 2002
【目的】观察重新去极化(redepolarizatio n, 25mmo l/ L K +)对原代培养的大鼠小脑颗粒神经元蛋白质c-Jun 的影 响, 对去极化挽救神经元过程中c-Jun 的作用及其调节机制进行初步探讨。【方法】用Western blotting 检测原代培养的大鼠小 脑颗粒神经元胞内c-Jun 总量及磷酸化水平;用逆转录-聚合酶链反应(rev erse tr anscription-polymerase chain reaction, RT-PCR) 检测编码基因c-jun ...
黄奕俊   +4 more
doaj  

均流电阻对直流接地极运行性能的影响分析

open access: yesDianci bileiqi, 2022
为了掌握加装均流电阻对直流接地极运行性能的影响,为均流电阻装置的应用及运维提供参考,以水平圆环接地极为对象,分析了接地极加装均流电阻后的电气性能和温升性能变化,以及均流电阻阻值偏移对接地极电流分布和跨步电压的影响。结果表明:加装均流电阻可以使电流在各环段上的分配更均衡,相应的各极环附近最大跨步电压和温升更均衡,从而减小接地极的最大跨步电压和最大温升。均流电阻阻值偏移量越大,极环电流和最大跨步电压的变化量越大;当各极环均流电阻阻值的偏移量不均衡时,极环电流和最大跨步电压的变化量会进一步增加 ...
童雪芳, 谭波, 李元杰
doaj  

Investigation of Improving Luminous Efficiency for GaN-Based Vertical-Structured Light Emitting Diodes [PDF]

open access: yes, 2014
宽禁带III-V族氮化物半导体材料具有优异的物理和化学特性,其合金材料的禁带宽度在0.7~6.2eV范围内连续可调,对应的波长覆盖了红外到远紫外光的范围且任意组分的合金均为直接带隙。因此已被广泛应用于制作高亮度发光器件、光电探测器以及高温、高频和大功率电子器件等,是近年来光电子材料领域研究的热门课题。尤其是基于大功率蓝紫光波段的发光二极管(LEDs)在推动全球固态照明的应用进程中担当着重要角色。半导体照明能够广泛应用的关键是提高氮化物LED芯片的发光效率 ...
李晓莹
core  

光纤耦合周期极化铌酸锂薄膜波导器件的研究

open access: yesChinese Journal of Lasers, 2023
冯新凯 Feng Xinkai   +3 more
semanticscholar   +1 more source

h‐BN/HfO2 Interface‐Enabled Optoelectronic Doping for Low‐Voltage, Reconfigurable MoTe2 Nanoelectronics

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT Engineering the semiconductor/dielectric interface is crucial for advancing two‐dimensional (2D) nanoelectronics, where device performance is predominantly governed by interfacial defects and dielectric coupling. Optoelectronic doping based on carrier trapping at the h‐BN/SiO2 interface has enabled non‐volatile and reversible carrier ...
Zhe Zhang   +6 more
wiley   +1 more source

Study of Fluoroethylene Carbonate (FEC) and Methylene Methanedisulfonate (MMDS) as Electrolyte Additives [PDF]

open access: yes, 2015
锂离子电池是近年来电化学能源领域的研究热点,锂离子电池电解液提供锂离子穿梭于正负极之间,是锂离子电池获得高电压、高比能量以及高比功率的重要前提条件,也对电池的其他性能(如高低温及其安全性能)等起着关键作用,因此研发功能电解液是开发高性能锂离子电池时需要考虑的重要课题。功能电解液主要包括基础电解液(基础溶剂及其电解质)与添加剂两种组分,添加剂由于其只要在基础电解液中进行少量的添加就能做为功能电解液进而有效改善锂离子电池电化学性能,且不需要改变锂离子电池的结构和工艺的特点,成为功能电解液研究的热点之一 ...
卞锋菊
core  

超表面太赫兹双频带线极化转换器设计及分析

open access: yesLaser & Optoelectronics Progress, 2023
潘 武 PAN Wu   +3 more
semanticscholar   +1 more source

Manipulating Terminal Bonds of Ti3C2Tx MXene for Highly Efficient Microwave Absorption and Photothermal Conversion

open access: yesRare Metals, Volume 45, Issue 4, April 2026.
ABSTRACT MXenes have been widely investigated as microwave absorption (MA) materials because of their unique properties. This study introduces a terminal bond manipulation strategy to enhance charge transfer and polarization in Ti3C2Tx, optimizing its MA performance.
Xiang Fang   +8 more
wiley   +1 more source

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