Results 11 to 20 of about 14,445 (117)

不同注水方式下断层动力学响应数值模拟研究

open access: yesDizhen xuebao, 2021
工业开采注水能导致现存断层活化,从而诱发大量的破坏型地震。因此,研究注水作用下断层的动力学响应对探索诱发地震的力学机理具有重要的意义。本文基于孔弹性弹簧-滑块模型,采用多孔介质弹性耦合数值模拟,计算分析了三类典型注水方式(上升型、迅速上升/下降型和间歇型)对断层稳定性的影响。研究结果表明:随着流体的不断注入,断层内部流体压力会经过缓慢上升、迅速上升和稳定上升三个阶段。针对于不同的注水方式,这三个阶段并不完全相同,体现形式存在差异;在注水方式相同的条件下,储层的渗透率越小,井口附近流体压力越大 ...
Aiyu Zhu   +5 more
doaj   +1 more source

雷电冲击电压下气制变压器油中流注放电发展机理研究

open access: yesGaoya dianqi, 2023
为深入研究气制变压器油在雷电冲击电压下的流注放电发展机理,文中通过搭建冲击电压放电实验平台,在流注起始电压阶段至加速电压阶段,对气制油中流注尖端电离过程和热效应引起的流注传播相关特征参量变化进行观测,以明确流注尖端电离过程和热效应在流注各个发展阶段的具体作用。研究结果表明,在流注起始阶段,流注的物理本质为局部气液相变化形成的低密度气体通道。在流注传播和击穿阶段,流注的物理本质为流注头部高场强导致的光电离过程,并在液体直接电离过程中导致气液相界面的持续产生 ...
陆怡冰   +4 more
doaj  

温度对棒—板间隙正流注电晕放电特性的影响研究

open access: yesGaoya dianqi, 2022
目前国内外温度对棒板间隙流注电晕放电特性影响的研究仍不完善。文中基于低温环境流注放电试验平台,利用光电倍增管、ICCD、CCD等弱光检测设备对低温下棒—板间隙的正流注传播特性进行了试验研究和理论分析。研究结果表明,温度降低对棒—板间隙正流注放电具有抑制作用,体现在发光强度和分叉程度随温度降低而减小;在流注电晕存在的电压区间内,外加电压增大,流注电晕电流脉冲峰值呈先增后减的规律;相同电极下,温度下降,流注电晕电流脉冲峰值并不是绝对的增加或减小;相同温度下,电极头部曲率半径增大,平均流注电晕电流脉冲峰值增大;
邬登金   +5 more
doaj  

一字型接地体冲击散流机理研究

open access: yesDianci bileiqi, 2023
为了研究接地体在遭受雷电流时的暂态散流规律,以一字型接地体为例进行了现场的冲击注流试验,选择不同幅值的冲击电流注入5 m长度铜覆扁钢的端部和中心,以及不同幅值的冲击电流注入5 m长度不锈钢包钢圆钢的端部,以总结一字型接地体在遭受冲击电流注入时的冲击散流规律。试验推理出土壤火花放电效应在一字型接地体散流时明显存在,并且接地体在散流时呈现出明显的端部效应,当端部注流时,首端和末端的散流比例高于中间导体约5%~15%,端部注流时的冲击电阻值比中心注流时大15%~25 ...
李伟   +7 more
doaj  

Twelve Years Revisited: Translanguaging as Relational Pedagogy for Sustaining Language Learning Motivation

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT This study examines how foreign language teachers’ beliefs about the medium of instruction and translanguaging evolve over time by revisiting three in‐service teachers twelve years after their initial interviews. Using a qualitative longitudinal design, the study traces how translanguaging was initially framed as pedagogically deficient but ...
Danping Wang
wiley   +1 more source

一种低谐波和零电流关断换流器运行特性的研究

open access: yesGaoya dianqi, 2023
为了解决高压大功率换流器谐波含量高、功率因数低和零电流关断(zero current switching,ZCS)问题,文中以7电平电流重注入换流器(seven level current reinjection current source converter,SLCR-CSC)为对象,研究其电流控制特性。通过分析多绕组变压器磁化电流合成原理,构建了重注入变压器电流合成数学模型,给出电流重注入变压器和功率器件的选型依据,以及重注入电流通路控制原理。MATLAB ...
赵建阳, 张福民
doaj  

The Academic Literacy of International Postgraduate Students in Australia: A Cause for Concern?

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT This article discusses the academic literacy challenges faced by international postgraduate students at a South Australian university and evaluates the effectiveness of existing institutional support mechanisms. Drawing on survey data, the study highlights significant difficulties in academic reading, writing, and spoken communication, with ...
Werner Botha   +6 more
wiley   +1 more source

Comparing the Effects of Collaborative and Independent Writing on EFL Learners’ Individual Writing Performance: An Intervention Study

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Collaborative writing has attracted increasing attention in English as a Foreign Language (EFL) instruction due to its potential to enhance learners’ writing competence. However, few studies have examined the comparative effects of collaborative versus independent writing on EFL learners’ individual performance, especially in higher‐order ...
Ting Huang, Chenze Wu, Wenkang Zhang
wiley   +1 more source

Assessing Argument Quality in L2 Argumentative Writing: Integrating Argument Elements and Intellectual Standards

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Many existing rubrics for L2 argumentative writing prioritize form‐based linguistic accuracy and complexity while insufficiently addressing substantive argumentative rigor and effectiveness. This limitation is further complicated by cross‐cultural variation in rhetorical conventions and educational practices, which challenge the direct ...
Zihan Xu, Peiyun Liu
wiley   +1 more source

AI foundation models in plant biology

open access: yesNew Phytologist, EarlyView.
Foundation models decode genomes, engineer proteins, phenotype crops, and drive AI agents across plant biology. This figure was created in BioRender (BioRender.com/xcmmkel). Summary Rapid technological progress has enabled plant biologists to accumulate unprecedented volumes of multi‐scale, multi‐modal data, yet this abundance of data has intensified ...
Haopeng Yu
wiley   +1 more source

Home - About - Disclaimer - Privacy