Results 31 to 40 of about 13,725 (169)
ABSTRACT Early detection of thermal runaway (TR) is essential for lithium‐ion battery (LIB) safety, as unchecked TR risks catastrophic failures in energy storage systems. Gas‐based sensing offers a faster and more direct approach by detecting decomposition products at the molecular level.
Tianshui Liang +9 more
wiley +1 more source
ABSTRACT Regulating negative parameters of metacomposites is mainly limited by their unclear mechanisms, which affects their practical applications in new sensing, communication, electromagnetic (EM) protection and other fields. This work proposes a dual‐functional competitive design strategy based on the waste corncob‐derived carbon/polyaniline ...
Qiuyun Yang +4 more
wiley +1 more source
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
Major and trace-element zoning in metamorphic garnets and their metamorphic process implications [PDF]
This article introduces some of the modern techniques for analyzing compositional zonings/profiles in metamorphic garnet, emphasizing the significance of two-dimensional composition X-ray mapping for such investigations.
Chen, NS +4 more
core
ABSTRACT Introducing oxygen vacancies has emerged as an essential strategy to affect the sensing properties of nanomaterials. However, existing methods for manipulating oxygen require high cost, complex operation, and harsh conditions. Herein, a simple NH4+‐assisted heat treatment approach was designed to regulate the concentration of oxygen vacancies ...
Qiu‐Yue Zheng +10 more
wiley +1 more source
架空配电线路绝缘水平较低,因此雷电感应过电压引起的雷击跳闸率很高。为了分析配电线路感应雷过电压的特性,介绍了感应过电压的计算方法,使用二阶时域有限差分法(FDTD)计算感应过电压,以实际线路为例,分析了线路结构、雷电流参数、大地电导率及负载对感应过电压的影响。结果表明,线路高度的增加会使感应过电压增大;雷电参数对感应过电压计算结果影响较大;当大地电导率小于,其对感应过电压的影响不可忽略,计算分析时应予以考虑;需要对短时呈容性的设备做好防雷保护工作。
刘金亮, 杨彩梅, 林国华
doaj
Study on Corner-Fed Cavity-Backed Slot Dual-Polarized Antennas [PDF]
为了在2.4GHz频段WLAN中实现具有方向性辐射的MIMO技术,采用背腔环形缝隙结构辐射元,通过倒置正交微带线激励,设计具有一定方向性的正交双极化天线结构。为提高端口间的隔离度和辐射场的极化纯度,在馈线正对的另一侧共面加载尺寸完全一致的接地或不接地导体带条。在此基础上,采用角馈的方法以期进一步改善天线的性能,并对各种可能天线形态进行对比分析。具体内容如下。 (1)对于边馈情形(即馈线位置垂直平分矩形导体腔表面的直角边),可以发现,没有加载导体条时,较佳隔离度对应的频带要高于阻抗工作频带,且相隔距离较大。
谢昇
core
ABSTRACT Moist‐electric generators (MEGs) harness energy from ubiquitous ambient humidity, which has emerged as a promising way to collect energy irrespective of location and time. This study presents a high‐performance MEG employing a bilayer Janus nanofiber membrane: a hydrophilic layer (lithium chloride/citric acid/polyvinyl alcohol) for enhanced ...
Peng Chen +7 more
wiley +1 more source
针对现有雷电感应过电压数值计算模型工程适用性不强的问题,分析了雷电感应过电压产生的物理过程,基于时变电磁场理论提出了架空线路雷电回击入射场与感应场的电磁耦合关系,推导得出了架空线路雷电感应过电压时域波形的解析计算模型。计算分析了雷电流幅值、回击速度、雷电流波形对架空配电线路感应雷过电压时域波形的影响规律,结果表明:随着回击放电速度的增加,相同条件下感应过电压幅值有所降低且波头时间增加,当回击电流波前时间增加时,感应过电压幅值也显著降低 ...
汪进锋 +6 more
doaj
Design of constant voltage and constant current switching power supply [PDF]
随着电子科技日新月异的发展,每家每户使用的电器设备越来越多,而电器设备往往需要合适的电源来驱动。特别是带有锂电池的离线设备,比如吸尘器、电动车、手机、数码相机等需要高精度的恒压恒流的充电器,使之合理的充电曲线保证锂电池的充电安全和寿命。 开关电源因其小体积、低功耗、高可靠性、高效率等诸多优点受到广泛的关注。开关电源是通过PWM信号控制MOS器件开和关,使输入连续的直流电变成间断的脉冲,再通过电容电感储能滤波,将间断的脉冲滤成连续的直流电。从而可知,只要调节MOS器件的开 ...
林明威
core

