电介质储能材料被誉为“现代工业的血液”, 具有介电常数高、损耗低、功率密度大、充/放电速度快、可靠性好等优点, 是各类脉冲电力电子系统元器件的关键部件, 受到了科学界广泛的关注。但其储能密度低、效率差的缺点也极大地限制了多领域的应用。如何显著提高电介质材料的储能性能成为近年来功能陶瓷研究的热点之一。本工作对比了无机电介质储能材料的性能优势, 概述了电介质材料储能原理和储能特性的主要参数, 分析了线性电介质、弛豫铁电体、反铁电体等多种无机材料体系的组分设计思路和储能特性, 涵盖了陶瓷、膜及多层陶瓷电容器等多种材料形式, 并从材料组成、结构、制备工艺等多方面讨论了性能调控方法与增强机制, 最后分析了无机电介质储能材料所面临的机遇和挑战, 展望了其在未来的发展趋势。

In this study, carbon black (CB) powder-loaded polyurethane (PU) composites (CB–PU composites) were prepared by melt mixing method with different volume percentages (45, 50, 55, 58 and 61 vol.%) of CB in the PU matrix. The prepared CB–PU composites had been further studied for surface morphology using the field-emission scanning electron microscopy (FESEM) technique. Dielectric properties in terms of real permittivity (𝜀′) and imaginary permittivity (𝜀′′) of the fabricated composites were computed using an Agilent E8364B vector network analyzer in the frequency range of 8–12 GHz (X-band). Dielectric loss factor of the prepared CB–PU composites was computed in terms of the dielectric loss tangent (tan δe = 𝜀′′/𝜀′). Microwave absorbing properties were appraised in terms of the reflection loss (RL) which in turn was calculated for varying thicknesses of the prepared composites from the measured real and imaginary permittivity data. The minimum RL was observed as −20.10 dB for the absorber with a thickness of 2.2 mm and the bandwidth achieved was 1.92 GHz for RL ≤−10 dB. Based on the above results these CB–PU composites have potential use as effective microwave absorbers in 8–12-GHz (X-band) frequency range.In this study, carbon black (CB) powder-loaded polyurethane (PU) composites (CB–PU composites) were prepared by melt mixing method with different volume percentages (45, 50, 55, 58 and 61 vol.%) of CB in the PU matrix. The prepared CB–PU composites had been further studied for surface morphology using the field-emission scanning electron microscopy (FESEM) technique. Dielectric properties in terms of real permittivity (𝜀′) and imaginary permittivity (𝜀′′) of the fabricated composites were computed using an Agilent E8364B vector network analyzer in the frequency range of 8–12 GHz (X-band). Dielectric loss factor of the prepared CB–PU composites was computed in terms of the dielectric loss tangent (tan δe = 𝜀′′/𝜀′). Microwave absorbing properties were appraised in terms of the reflection loss (RL) which in turn was calculated for varying thicknesses of the prepared composites from the measured real and imaginary permittivity data. The minimum RL was observed as −20.10 dB for the absorber with a thickness of 2.2 mm and the bandwidth achieved was 1.92 GHz for RL ≤−10 dB. Based on the above results these CB–PU composites have potential use as effective microwave absorbers in 8–12-GHz (X-band) frequency range.

针对金属表面等离激元光镊热损耗问题, 设计了一种硅基双纳米柱加纳米环的光镊结构.通过有限元仿真在1 064 nm入射光场下计算了三种不同硅基纳米结构(硅基纳米球、纳米柱、纳米环)的场增强效果.利用硅基纳米结构光学共振机理, 设计了一种电场增强倍数达到7.39倍的硅基双纳米柱光镊结构.在此基础上, 增加纳米环使光镊结构的环中心与双纳米柱间隙产生光学共振耦合现象, 得到的电场增强倍数高达11.9倍, 形成了稳定的光学势阱.最后采用麦克斯韦应力张量法对硅基光镊中不同直径的聚苯乙烯小球进行了捕获分析, 并在x、y、z方向上计算分析了直径为25 nm的聚苯乙烯小球在不同位置的捕获力、捕获势能以及捕获刚度.设计的硅基纳米双圆柱加纳米环的光镊结构能够对聚苯乙烯小球起到良好的捕获效果.

处于等离子体环境中的航天器的介质材料受到带电粒子的作用，表面将产生电位。对背面接地的介质材料，上表面将与接地背面形成电势差。当电势差达到一定阈值时将产生放电，表面充电电位对充放电效应影响至关重要。综合考虑等离子体中粒子的质量、温度及密度，介质材料的二次电子效应，体电流泄漏以及介质材料的运行速度等因素，基于气体动理论，利用粒子的麦克斯韦速度分布函数理论推导得出等离子体环境中背面接地介质材料表面充电电位一般表达式。讨论了地球同步轨道环境下，表面电位与等离子体环境及材料表面电阻等各个参数的关系，总结出等离子环境背面接地介质材料表面充电规律，为航天器介质材料静电防护设计提供一定的理论基础。

作为超材料的重要组成部分, 介质层是影响超材料响应特性的关键因素.固定超材料的尺寸和表层金属图形, 通过理论推导和仿真模拟详细分析了在太赫兹波段下介质层的介电常数和厚度两个参数对超材料响应特性的控制规律, 并首次确定了响应频率与介电常数的关系方程.结果表明, 在其他参数不变的情况下, 超材料的响应频率主要取决于介质层的介电常数的实部大小, 而其吸收率则主要取决于介质层的厚度.据此, 提出一种设计超材料的新方法: 首先将设计要求的响应频率代入频率方程计算出相应介质层的介电常数, 由此挑选合适的介质材料; 然后固定介电常数、调节介质层厚度, 获得在特定频率具有特定吸收率的超材料.