Results 21 to 30 of about 1,353,308 (172)
ABSTRACT The development of high‐performance and stable electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) plays a critical role in advancing clean energy technologies, including metal‐air batteries and hydrogen production through overall water splitting.
Chen‐Yu Cai +4 more
wiley +1 more source
极性反转是直流输电设备的一种特殊工作状态。笔者以三层电介质复合绝缘结构为研究对象,采用场路耦合方法,建立了介质极性反转的数学模型,分析了极性反转时各层电介质中的电场分布、电流特性,以及热生成率随时间变化的关系,最后还分析了不同介质交界面上电荷极性反转的特点。研究结果可为直流输电设备绝缘结构设计提供参考。
张启民, 张良县, 陈模生
doaj
ABSTRACT In conventional piezoceramics, the coordinated change between the dielectric constant (εr) and the piezoelectric charge constant (d33) usually limits the piezoelectric voltage constant g33 (g33 = d33/εr), a critical figure of merit for piezoelectric sensors.
Xiaoying Feng +7 more
wiley +1 more source
为深入理解氦气氛围电介质材料对介质阻挡放电(dielectric barrier discharge,DBD)的电气特性影响,建立单介质覆盖高压电极的1-D流体模型,通过有限元分析法进行数值模拟,采用频率10.0 k Hz、幅值2.0 kV的正弦交流激励,研究了亚稳态氦原子数密度、电子密度、电场强度的时空变化特性,以及介质材料、放电间隙和介质厚度对介质阻挡放电特性的影响。仿真结果表明:随着介电常数增加,电子密度和氦离子数密度均增大,同时介质表面累积的电荷密度增加,放电强度增强,碰撞功率损失变大 ...
李平, 徐俊生, 陈兆权, 许桂敏
doaj
ABSTRACT Emerging as attractive alternatives for sustainable, low‐cost, and high‐performance electromagnetic interference (EMI) shielding, biomass‐derived carbon is nonetheless constrained by a limited repertoire of shielding mechanisms. Herein, a straightforward method was employed to synthesize self‐supporting Co nanoparticles embedded in porous N ...
Yingjie Xu +6 more
wiley +1 more source
重点研究了铁电铁磁复合材料甚高频段的介电响应.研究发现铁性双复介质在外场作用下,微观感应电场与磁场之间存在明显的耦合作用,该作用可体现在介电频谱之中.实验中调节复合材料的磁性能,保持其他特性完全相同.随磁导率升高,材料频谱中介电共振峰有明显的宽化现象,介电响应由共振型向弛豫型转变.提出了一套共振参数,用以描述介质介电响应过程的特性,定义了共振度和对称度来定量表征介电响应类型,定量判断其倾向于共振型或弛豫型的程度.共振度和对称度越高,表明介质频谱曲线的共振型特性越明显,反之,表明弛豫型特征越明显 ...
白洋 +4 more
doaj
ABSTRACT To break electromagnetic wave absorption (EMA) tech's single‐attenuation bottleneck, enhancing multi‐wave absorption synergy in composites is key for microstructure design. This study uses mesoporous hollow carbon spheres to make metal nanospheres with cobalt, iron, and nickel nanoparticles, then encapsulates them via electrospinning into a ...
Wei‐Lian Zhang +10 more
wiley +1 more source
ABSTRACT This study developed a FeSiAl@LMPGP composite material to address the demand for low‐frequency electromagnetic absorption. Through controllable heat treatment, FeSiAl particles and PbO nanoparticles self‐assembled into a high‐density Mott–Schottky heterointerface structure, which exhibited a significant built‐in electric field (BIEF) effect ...
Yuqi Wang +5 more
wiley +1 more source
采用筛网电极和聚对苯二甲酸乙二醇脂(PET)薄膜作为阻挡介质的介质阻挡放电(DBD)结构在空气中产生大气压辉光放电(APGD)。通过测量空气中APGD的电气特性和发光强度空间的分布特性,比较了它们与丝状DBD的区别: 通过研究APGD的放电特性,分析了空气中APGD的放电机理。实验结果与分析表明,采用该电极结构可以在空气中产生APGD,空气中APGD的放电特性与丝状DBD具有明显的区别,筛网电极起到了在气隙击穿前产生电晕放电对驻极体阻挡介质充电的作用。
方志, 王辉, 邱毓昌
doaj
ABSTRACT The development of high‐performance electromagnetic protection materials integrating broadband absorption and effective shielding capabilities is hindered by challenges in simultaneously optimizing multiple electromagnetic properties through conventional material designs.
Changlong Du +9 more
wiley +1 more source

