Results 1 to 10 of about 13,996 (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  

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  

Root exudates mediate microorganisms to improve rhizosphere nutrient availability and crop productivity under straw mulching and slow‐release nitrogen fertilizer

open access: yesFunctional Ecology, EarlyView.
Read the free Plain Language Summary for this article on the Journal blog. Abstract Root exudates play a key role as signals and nutrients in mediating plant–microbe communication. However, critical knowledge gaps remain regarding how root exudates mediate soil–microbe–plant interactions to regulate crop yield under long‐term straw mulching combined ...
Jiajie Song   +7 more
wiley   +1 more source

Rapid construction of insect–plant interaction networks via multiplexed long‐fragment DNA metabarcoding and NGS

open access: yesMethods in Ecology and Evolution, EarlyView.
Abstract Molecular identification of insect food webs can accurately reveal complex trophic interactions and serve as a foundation for understanding ecosystem functioning and advancing biodiversity conservation. This process typically involves DNA library construction, high‐throughput sequencing and subsequent steps, including data assembly, annotation,
Xiao‐man Zhang   +9 more
wiley   +1 more source

Calibration of the species threat abatement and restoration metric's threat abatement component in a Costa Rican landscape

open access: yesConservation Biology, EarlyView.
Abstract Achieving global conservation policy goals requires the ability to set and measure progress toward science‐based targets for biodiversity. The species threat abatement and restoration (STAR) metric was developed to enable actors to set science‐based targets for species.
Louise Mair   +17 more
wiley   +1 more source

试验回路布置对变电站地网冲击特性测试的影响

open access: yesDianci bileiqi, 2020
开展地网冲击特性测试需搭建冲击放电回路,试验回路布置的差异会对地网冲击特性测试产生较大影响。在分析现有接地装置冲击试验系统构成的基础上,搭建试验回路对110 kV变电站地网进行了现场试验,研究了注流点对地网冲击特性的影响,并通过仿真计算研究了回流点对地网冲击特性的影响。试验结果表明,试验回路中注流点、回流点的选择会明显影响地网电位分布和电流的大小。在雷电冲击下地网高电位区域会集中在注流点附近,远离注流点的区域地网电位分布较均匀,注流点附近区域的地网散流变化大,远离注流点区域的地网散流较平均。仿真结果表明,
黄佳瑞   +4 more
doaj  

A more‐than‐human political ecology of Indonesian songbird trade

open access: yesConservation Biology, EarlyView.
Abstract Since its inception, conservation science has considered wildlife trade a problem. In focusing on conservation outcomes, conservationists almost completely ignore the welfare of traded animals and plants and the harms they endure. We developed a political ecology approach that incorporates the interconnectedness of people with animals and ...
Sicily Fiennes   +9 more
wiley   +1 more source

Home - About - Disclaimer - Privacy