Results 1 to 10 of about 7,869 (117)
ABSTRACT The composition and structural characteristics of metacomposites are crucial for tuning their negative electromagnetic parameters; however, the lack of a clear structure–property relationship severely limits their application in dielectric and magnetic fields.
Chunyuan Deng +9 more
wiley +1 more source
传统交流温升试验电源系统采用电网直接供电,因此只能进行50 Hz温升试验,而无法实施60 Hz温升试验,同时,由于其自动化程度较低,在电网电压波动以及负载随温度变化的情况下,只能通过现场手动调节调压器实现电流的稳定控制,且缺乏有效的远程监控手段,不利于系统运行的综合管理。为解决上述问题,笔者结合温升试验的工艺要求以及试验室的具体试验条件,采用发电机作为温升试验电源,通过调节变频器的输出频率改变拖动电动机的转速,实现了试品对不同试验频率的需求;采用可编程控制器设计了一套温升试验自动控制系统 ...
贾一凡 +6 more
doaj
接地体短路温升是校核接地材料短路耐受性能的重要指标,但目前的短路温升计算方法主要在无散流、无传热的空气环境中进行,校核结果未能充分反映接地导体在土壤中的温升特性。笔者采用电磁-温度耦合有限元计算方法模拟短路电流作用下接地导体的散流及地中温升过程。研究发现接地体轴向地中短路温升分布具有两端高中间低的特点,且由于土壤发热与本体发热共同作用,接地体两端温升显著高于空气环境短路温升。同时,土壤电阻率增大及趋肤效应会进一步加剧端部温升。随后结合侵蚀算法模拟了接地导体的过热失效 ...
吴泳聪, 阮江军
doaj
ABSTRACT Light‐activated gas sensors hold significant potential in environmental monitoring and smart Internet of Things (IoT) owing to their advantage in room temperature operation. Nevertheless, due to a narrow light absorption range, high photocarrier recombination rate, and weak redox activity of the sensing material, the performance enhancement of
Jinyong Hu +5 more
wiley +1 more source
采用4种不同纵磁触头结构的126kV单断口真空断路器温升性能对比研究
为进一步提升126 kV单断口真空断路器额定通流能力,文中针对4种采用不同纵磁触头结构的126 kV真空断路器的温升特性通过仿真进行了对比研究。4种纵磁触头分别为2/3、3/4匝线圈型、马蹄铁型和开槽马蹄铁型纵磁触头。有限元仿真结果表明在通流3 150 A时4种触头的热态交流电阻分别为30.2、36.9、24.0、16.3μΩ。4种断路器整机的温度分布采用有限体积法计算得到,温升仿真模型由通流2 500 A下的实验结果验证。结果表明,仿真模型在灭弧室周围的5个测温点内计算误差小于10 ...
马朝阳 +6 more
doaj
Read the free Plain Language Summary for this article on the Journal blog. Abstract Soil organic nitrogen (SON) transformation is critical for global nutrient cycling and ecosystem productivity, yet how its responsiveness to climate change differs across diverse land use types remains poorly resolved.
Xinyi Yang +10 more
wiley +1 more source
This study used camera trap data from 6 years between 2016 and 2021 and generalized linear mixed models to explore the factors that influence the spatial density distribution of lynx and its prey populations in warm and cold seasons in Inner Mongolia Hanma National Nature Reserve, China.
Wentao Zhang +11 more
wiley +1 more source
基于NEX-GDDP-CMIP6的不同温升情景下中国气候要素变化
目的全球温升对气候系统具有持续性影响,深入理解不同温升情景下气候要素的变化趋势及其空间分布特征,有助于为制定差异化的气候适应策略提供科学依据。方法基于NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP-CMIP6)高分辨率数据,评估全球温升1.5~5.0 ℃情景下中国气候要素的变化,重点分析6个关键气候变量的变化趋势及空间分布。结果中国陆地增温速率高于全球平均水平,且相对增幅随全球温升呈加剧趋势。当全球温升1.5 ℃时 ...
温姗姗, 汪辰钰, 翟建青, 周彪
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ABSTRACT Near‐infrared (NIR) phosphors with broadband and efficient emission are pivotal for the performance of NIR phosphor‐converted light emitting diodes (pc‐LEDs). In this study, the double perovskite phosphor La2MgTiO6:Cr3+ phosphor with broadband emission in the range of 650–950 nm was prepared.
Xu Qian +7 more
wiley +1 more source
ABSTRACT Improving catalytic activity for volatile organic compounds (VOCs) oxidation and enhancing water‐tolerance stability remain challenging in practical applications. Herein, a composite catalyst integrating Pt/CoOx‐NiOx mesoporous nanorods (MNRs) with a phenyltriethoxysilane (PhTES)‐modified surface was fabricated via a facile route for toluene ...
Jiaqin He +13 more
wiley +1 more source

