Results 11 to 20 of about 1,009,107 (167)

Making Interview Multilingualism Visible: Transnational Chinese Language Teacher Identity Construction

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT This study examines multilingual practices in research interviews, focusing on English lexical insertions in Chinese‐language research interviews with teachers of Chinese in Australian secondary schools, and treating these code‐switches as analytically meaningful rather than incidental.
Chengwen Yuan, Tianwei Zhang, Gary Bonar
wiley   +1 more source

局部放电脉冲的Wigner时频分布特性研究

open access: yesGaoya dianqi, 2008
为了提高时频分布的分析精度和有效性,笔者根据局部放电脉冲信号的非平稳特性,提出使用联合时频分布对其进行处理,从而分析脉冲信号的时频特性。针对目前在非平稳信号处理中广泛使用、属于Cohen类的Wigner-Ville分布(WVD),笔者以仿真脉冲为对象,分别研究了其原始WVD、平滑伪Wigner分布(SPWVD)以及重排平滑伪Wigner分布(RSPWVD)。分析结果表明:WVD能够对局部放电脉冲信号引发的短时变化具有高度的敏感性,更适合表征非平稳信号的时变信息;SPWVD能消除双线性函数引起的交叉干扰项,
袁鹏   +5 more
doaj  

Ultralight N‐Doped Interconnected Porous Carbon From Lignin: Synergistic Structural and Doping Engineering for High‐Performance Electromagnetic Wave Absorption

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT The development of lightweight, high‐attenuation, and broadband carbon‐based electromagnetic wave absorbers is hindered by the intrinsic trade‐off between impedance matching and dielectric dissipation. Herein, we report a facile and scalable synthesis of N‐doped lignin‐derived interconnected porous carbon (Nx‐LIPC) via hydrogen‐bond self ...
Bin‐Peng Zhang   +7 more
wiley   +1 more source

基于时频相似度的GIS多源局部放电信号分离方法

open access: yesGaoya dianqi, 2018
文中提出一种基于时频分析的GIS多源局部放电信号脉冲分离方法。首先,对记录的GIS局部放电脉冲波形序列进行S变换时频分析,以提取典型局部放电脉冲的时间—频率—幅值特征。然后,与由单一典型局部放电缺陷模型构造的时频数据库进行混合,基于时频相似度分析和仿射聚类方法对记录的脉冲群进行快速分类,最终实现多局部放电源脉冲群的分离。在局部放电源个数未知的情况下,文中方法可判断出局部放电源的个数和放电类型。且该方法可抑制随机干扰源的影响,并可分离典型的脉冲扰动波形。
高敬贝   +6 more
doaj  

Synergistic Modulation of Magnetic and Dielectric Properties via La‐V Co‐Substitution in Barium Hexaferrite for Advanced Millimeter‐Wave Absorption

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT The growing deployment of high‐frequency electronic systems has intensified the demand for high‐performance microwave absorption materials. In this work, we developed La‐V co‐substituted barium hexaferrites, Ba1‐xLaxFe11.9V0.1O19 (BLFVO), via a sol‐gel route.
Zhihui Yang   +7 more
wiley   +1 more source

闪光刺激前后脑电信号的时频多分辨分析

open access: yes四川大学学报. 自然科学版, 2010
目的:用基于傅立叶变换的时频多分辨分析方法,分别获取脑电信号的4种特征波来研究脑电信号在闪光刺激前后的功率变化.方法:自愿受试者10名,分别对闪光刺激前和闪光刺激后两种状态下的脑电信号进行时频多分辨分析.结果:采用此方法能获得闪光刺激前后脑电信号各成分的频域谱分布,以及功率、带宽等定量信息.结论:本文所采用的基于傅立叶变换的时频多分辨分析可方便用于脑电信号时、频域信息提取,易于获取各个选择频段的信息,特别适宜用于研究与刺激有关的高级神经系统的活动,为视觉生理和临床研究提供了新的方法.
刘玉红, 谢正祥
doaj  

A method of frequency adaptive detecting for synchronous phase and instantaneous symmetrical components(一种频率自适应的同步相位与对称分量检测方法)

open access: yesZhejiang Daxue xuebao. Lixue ban, 2012
电网不对称故障时,快速、准确地检测同步相位和对称分量是电力电子装置实现控制与保护的关键问题之一.分析了负序分量对传统三相锁相环检测性能的影响,设计了 一种频率自适应的同步相位与瞬时对称分量检测新方法.该方法利用瞬时对称分量理论在两相静止坐标系下实现对称分量的实时检测,利用广义二阶积分器实现90°相移,用测得的基波正序电压q轴分量作为锁相环的输入,用锁相环的输出角频率作为相移电路的谐振角频率,达到谐波抑制与频率自适应跟踪,是一个闭环的实时检测系统.分析了该方法的实现机理,给出了检测电路的实现框图 ...
CHENHai-rong(陈海荣)   +2 more
doaj   +1 more source

Enhancement of Corrosion and Wear Resistance in Polymeric Coatings via Ce(III)‐Functionalized Ternary ZnAlCe Layered Double Hydroxides Intercalated With EDTMP

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT The intricate corrosion environment necessitates the polymeric coating's adaptability to the surroundings. In this work, the integration of rare‐earth Ce(III) ions and ethylene diamine tetramethylene phosphonic acid (EDTMP) in a layered double hydroxide (LDH) material is developed to enhance the corrosion protection and anti‐wear properties of
Yangu Liu   +9 more
wiley   +1 more source

Boosting Thermoelectric Properties of BiSbSe3 Through Ag‐Induced Interstitial Occupancy and Multi‐Phase Microstructure

open access: yesRare Metals, Volume 45, Issue 6, June 2026.
ABSTRACT Te‐free BiSbSe3 is a promising medium‐temperature thermoelectric (TE) material owing to its cost‐effectiveness and intrinsically low lattice thermal conductivity. However, its comparatively low electrical conductivity has severely hindered the optimization of TE performance.
Xiaowei Shi   +10 more
wiley   +1 more source

断路器操作三维振动信号差异特征的研究

open access: yesGaoya dianqi, 2019
针对单轴传感器在断路器中应用的缺陷与不足,为了获取更多断路器分合闸时的状态信息,利用三维振动传感器同步采集断路器操作时振动信号,在时域、频域方面以及时频联合对X、Y、Z 3个方向的信号进行分析对比。在时域方面,运用X、Y、Z3个方向振动信号各个特征和能量的分布;在频域方面,运用快速傅立叶算法得出频谱分布图和功率谱图;在时频联合方面,运用小波包分解将三维传感器信号进行分解,并求出能量在各节点的分布和Wigner-Ville分布,说明三轴传感器放置方向对断路器测量信号故障诊断正确率的影响。实验分析结果表明 ...
丁巧林   +3 more
doaj  

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