Results 21 to 30 of about 8,001 (171)

Research of laser and solar hybrid powered system for Active optical-electronic current transformer [PDF]

open access: yes, 2011
随着电力工业的不断发展,电网电压等级的不断提高,对电压、电流的测量要求也在不断提高。传统的电磁式互感器无法满足迅速发展的数字化电网电压的测试要求。目前电子式(光电式)互感器已成为电网中高电压、高电流测量新的研究热点,有源式光电电流互感器是新型互感器研究的典型代表,而高压端的供能是有源式光电电流互感器的关键部件之一。目前研究的主要有线圈从母线上取能、高压电容分压式供能、激光供能、蓄电池供能、超声电源供能等供能方法。 本文在光电互感器基本原理理论研究的基础上,对上述各种供能方法进行分析研究,结合激光供能 ...
孙存淼
core  

Learning Styles, Engagement and Anxiety in AI‐Mediated Writing: A Multimodal Feedback Study

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Artificial intelligence (AI) tools now permeate English academic writing. However, evidence on how feedback modalities align with student differences and with psychological mechanisms remains limited. Prior work often reduced learning styles to simple matches with delivery modes and treated learning engagement and writing anxiety as peripheral.
Yi Ren   +3 more
wiley   +1 more source

Optical Fiber Voltage Sensor with New Fiber Component and Optical Path Design [PDF]

open access: yes, 2008
光学电压互感器(OVT)是一种新型的电力互感器,它克服了传统电压互感器(VT)的许多缺点,在未来的电力系统中有着广阔的应用前景,光学电压互感器经过几十年的发展,已经形成了一套相关的理论,但是依然存在有待发展和完善的问题,本文的主要研究对象为光学电压互感器的核心部分即传感头,以后均称为光学电压传感器(OVS)。本文首先介绍了偏振光在晶体与双折射光纤中传输的基本理论,并在这个基础上分析了两种不同结构的光学电压传感器:一种是创新的运用高双折射光子晶体光纤制作的四分之一波片的透射式光学电压传感器 ...
徐俊娇
core  

Perceptions and Acceptance of Generative Artificial Intelligence Influencing Chinese EFL Learners’ Engagement in Informal Digital Learning of English: Mediating Roles of Self‐Efficacy and Motivation

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Generative artificial intelligence (GenAI) has emerged as a powerful tool in the Informal Digital Learning of English (IDLE) environment, offering personalized, interactive, and innovative language learning experiences that may enhance learning engagement.
Jin Liu, Meilu Liu, Yuan Yao, Dechao Li
wiley   +1 more source

二次电流为1A的高压电流互感器

open access: yesGaoya dianqi, 1996
一、前言 我国的电力系统一直采用二次电流为5A的电流互感器,和5A的测量、保护用仪表以及继电器。但从近几年引进工程中的成套配电装置来看,采用二次电流为1A的电流互感器越来越多。如南京扬子石化公司从日本引进的低压聚乙烯装置和聚丙烯装置变电所,6kV及380V电流互感器几乎都是二次电流为1A的。南京化学工业公司年产5万吨已内酰胺装置引进设备中的奥地利产电流互感器全为1A的。 目前世界上许多国家在电流互感器技术标准中明确规定出额定二次电流为1A及5A。如西德国家标准中规定1A的电流互感器为标准型互感器 ...
李和, 李天泰, 常修平
doaj  

Study and Design on Circuitry System of Fiber Optical Electronic Current Transformer [PDF]

open access: yes, 2010
近几年对数字化变电站新技术的研究及应用成为热点,数字化变电站已在国内电力系统试点应用并取得一定经验。电力系统中传统的大电流传感器通常采用电磁互感技术,其具有反应速度慢、容易饱和、在高压下容易被击穿等缺点,正在被新型的电子式电流互感器所取代。电子式电流互感器具有反应速度快、采集精度高、耐高压、智能化、网络化等诸多优点,在国外的电力系统中已经获得了广泛应用,实现了电力系统的一次设备智能化、二次设备网络化、运行管理系统自动化、设备间相互可操作等功能,提高了电力系统的测量精度 ...
李钧均
core  

Promoting Foreign Language Enjoyment Through Displaying Affiliation in Collaborative Digital Multimodal Composing in Hong Kong ESL Classrooms: Insights From Translanguaging and Transpositioning Perspectives

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Studies on classroom interactions suggest that displaying affiliation through linguistic and multimodal resources could promote positive emotions like enjoyment, thereby enhancing engagement and enthusiasm in second/foreign language learning.
Karen C. K. Choi, Kevin W. H. Tai
wiley   +1 more source

测定TPY级电流互感器暂态误差的新方法

open access: yesGaoya dianqi, 1999
随着电力系统对保护用电流互感器暂态特性要求的不断提高,电流互感器暂态误差测试已被许多电力系统用户及电流互感器生产厂家所重视.为了促进TPY级保护用电流互感器的发展和不断完善,对TPY级保护用电流互感器的暂态误差测试进行了研究和探讨,并提出了一套新方法.利用它先后为多家互感器生产厂家的多种型号的TPY级电流互感器进行了暂态误差测试,试验十分成功.
薛晔, 徐俊华
doaj  

一种利用顶点位形描述的任意正交折线线圈阻抗解析建模新方法 [PDF]

open access: yes, 2018
本文利用顶点位形描述方法,建立了任意正交折线线圈阻抗的封闭模型.首先,利用二阶矢量位公式对一个线形矩形线圈的电磁场分布进行描述,并推导了该矩形线圈的标量势表达式,其包含有一个利用矩形四个顶点的位置因子和角形因子进行描述的积分项;其次,证明了角形因子的两个重要性质,并利用该性质将矩形线圈的标量势表达式推广到任意正交折线线圈的情况;最后,建立了任意正交折线线圈阻抗的解析表达式,并以矩形螺线线圈为例进行了阻抗计算,并将计算结果与实验测量值进行了对比.结果表明,计算值与测量值之间有较好的吻合度 ...
何天府   +3 more
core  

The Impact of AI‐Assisted L2 Learning on Learners’ Emotions: A Meta‐Analysis

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT The scope of research on AI‐assisted second/foreign language (L2/FL) learning has expanded beyond learning outcomes to focus on learners’ emotional experiences. Despite their proliferation, existing empirical findings are inconsistent, and few studies have systematically synthesized the impacts of AI‐assisted L2 learning on learners’ emotional
Jiaqi Jing   +4 more
wiley   +1 more source

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