Results 51 to 60 of about 22,626 (131)

Synthesizing Empirical Research on Learner Metacognition in Second Language Writing

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Despite considerable research interest in learner metacognition in second language (L2) writing, there is not yet a review that synthesizes the existing empirical findings and discusses their implications. To fill the void, this systematic review synthesized 39 empirical studies on learner metacognition in L2 writing and examined their salient
Chen Li, Icy Lee, Zhicheng Mao
wiley   +1 more source

直流滤波器差动保护误动作分析

open access: yesGaoya dianqi, 2012
笔者分析了宝安换流站差动保护误动作的情况。根据现场实际录波,考虑直流滤波器TA特性,讨论直流滤波器差动保护的特点、直流输电的特殊运行工况对直流滤波器差动保护的影响,并结合其特点提出相应3种反措,以提高差动保护的可靠性。这可以完善直流滤波器差动保护,从而增强高压直流安全稳定运行性能。
田庆
doaj  

Designing Integrated Policies for the Twin Transition: Challenges and Tradeoffs

open access: yesPolicy Studies Journal, EarlyView.
ABSTRACT Democratic governance faces the intertwined imperatives of managing the transformative risks and opportunities of digitalization, particularly stemming from artificial intelligence (AI), while achieving environmental sustainability within planetary boundaries.
Martino Maggetti
wiley   +1 more source

CTBA型手动弹簧机构

open access: yesGaoya dianqi, 1980
对CTA型与CTB型两种新型手动弹簧机构的研制工作作了介绍。给出了该机构的参数,详细介绍了动作原理、结构特点、输出力矩特性与断路器负载特性的配合计算以及有关试验结果。
doaj  

电抗器潜伏性故障特征及其耦合量分析综述

open access: yesGaoya dianqi, 2015
针对电抗器容量及电压等级提高所带来的潜伏性故障发生趋势增加,笔者分析了绝缘水平、温升、振动特征参量的检测技术特点及其局限性,阐述了振动信号可作为电抗器各类故障的体现方式及其与电抗器的绝缘、温升之间的耦合关系,提出基于振动法的电抗器潜伏性故障检测应解决的关键技术问题,尤其是大型电抗器阵列式振动传感器的应用及其振动传播特性对故障诊断与定位的作用。以潜伏性故障特征及其耦合关系的角度诊断故障类型与故障定位,对电抗器状态检修具有实际的工程应用价值。
林瑞聪   +4 more
doaj  

How Different Patterns of Policy Attention Drive Policy Diffusion: Evidence From China's River Chief System

open access: yesPolicy Studies Journal, Volume 54, Issue 3, August 2026.
ABSTRACT Despite extensive research on policy diffusion, the ways in which policy attention influences this process remain underexplored. This study addressed this gap by distinguishing between three types of policy attention—political speeches, policy issuance and field visits—and investigating their differential impacts when delivered by central and ...
Xiangning Chen, Yahua Wang
wiley   +1 more source

新型磁力操动机构EMFA的动态特性仿真研究

open access: yesGaoya dianqi, 2011
针对40.5kV新型磁力机构工作原理及其运动特点,进行了多场耦合的静态和动态特性仿真研究。首先,建立磁力操动机构的有限元模型,利用Maxwell软件对磁力机构的静态特性进行仿真;其次,根据电压平衡方程和达朗贝尔运动方程,在静态仿真基础上采用ADAMS和MATLAB建立40.5kV磁力机构SF6断路器运动模型,对磁力机构的动铁心、SF6断路器触头运动特性进行了仿真研究。最后,分析了磁力机构运动特性对SF6断路器性能的影响,为新型磁力机构在中压SF6断路器中应用提供了一定理论基础。
茹晶晶   +5 more
doaj  

适用于全周期结构的速度脉冲型地震动强度表征参数研究

open access: yesDizhen xuebao, 2019
鉴于传统的地震动强度表征参数(IM)不能有效地反映速度脉冲型地震动的破坏特征,需要研究能够在全周期段内表征速度脉冲型地震动强度的参数。本文首先从NGA-West2强震数据库中选取了236条速度脉冲记录,分析了42种地震动参数之间的相似性和相关性,初步给出了速度脉冲型地震动强度的表征参数;其次,利用单自由度体系动力时程分析方法,研究了不同延性μ条件下速度脉冲型地震动强度表征参数与最大非线性位移um之间的相关性系数随周期T的变化特征 ...
Xiaofen Zhao   +3 more
doaj   +1 more source

Microstructure Engineering Toward High Cost‐Effective Nd–Fe–B Sintered Magnets: A Review

open access: yesRare Metals, Volume 45, Issue 7, July 2026.
ABSTRACT Nd–Fe–B sintered magnets, critical for enhancing electromechanical conversion efficiency and operational stability in wind turbines and electric vehicle drives, are prized for their outstanding coercivity, high remanence, and superior maximum energy product.
Dongmin Zhang   +5 more
wiley   +1 more source

CT-3型弹簧操动机构

open access: yesGaoya dianqi, 1966
本文介绍了CT-3型弹簧操动机构的技术参数,结构、动作原理,控制线路,及其试验数据。这种机构不需要直流电源,可用交流电源或手动进行分、合闸操作,可节约电站投资,由于改造了合闸弹簧特性,它能够很好地与断路器反力特性相配合。
西安高压开关厂弹簧机构三结合小组
doaj  

Home - About - Disclaimer - Privacy