摘要：Magnesium (Mg) is a promising alternative to lithium (Li) as an anode material in solid-state batteries due to its abundance and high theoretical volumetric capacity. However, the sluggish Mg-ion conduction in the lattice of solid-state electrolytes (SSEs) is one of the key challenges that hamper the development of Mg-ion solid-state batteries. Though various Mg-ion SSEs have been reported in recent years, key insights are hard to be derived from a single literature report. Besides, the structure-performance relationships of Mg-ion SSEs need to be further unraveled to provide a more precise design guideline for SSEs. In this viewpoint article, we analyze the structural characteristics of the Mg-based SSEs with high ionic conductivity reported in the last four decades based upon data mining - we provide big-data-derived insights into the challenges and opportunities in developing next-generation Mg-ion SSEs. © 2024 Chinese Chemical Society. All rights reserved.

摘要：针对传统钢轨检测技术的效率低下、精度不足、安全隐患等问题,提出了基于曲率滤波和改进高斯混合模型（GMM）的钢轨表面缺陷检测方法。首先,提出了基于垂直投影的区域定位算法和灰度对比算法,克服现场工况复杂、轨面反射不均、信道噪声干扰的难题;考虑到图像信号受强工况噪声干扰,研究了具有隐式计算和曲面保持特性的曲率滤波法进行图像去噪;建立了基于马尔科夫随机场（MRF）的高斯混合模型完成表面缺陷的精确快速分割。最后,设计了＂区域定位-灰度均衡化-滤波-分割＂的实验流程,实验结果验证了算法的有效性,检测性能达到了精确度92.0%,相比其他方法更加精确、快速,具有更好的鲁棒性。

摘要：大功率轨道牵引传动系统的开关频率较低,而调速范围较宽,导致了载波比变化范围大,需要设计混合脉宽调制策略以满足要求.本文分析了一种低开关频率下SVPWM和特定谐波消除PWM(Selective Harmonic Eliminate PWM,SHEPWM)混合脉宽调制方法,即在低频阶段采用异步调制的SVPWM,在高频阶段采用不同载波比的SHEPWM,最后转入方波工况.研究了它们之间的切换条件,实现了异步调制的SVPWM、不同载波比的SHEPWM和方波之间的平滑切换.仿真和实验结果证实了本文的混合调制方法具有较好的谐波特性和SVPWM,以及不同载波比SHEPWM间切换方法的正确性,减小了电流冲击.

摘要：This paper firstly reviews the recent development in power system protection and control, with special attention paid to the wide-area and integrated protection, in order to look into future development of integration of protection and control for smart grids. This paper mainly reports on the development of integrated wide area protection and control for power systems. The concept of integrated wide area protection and control is introduced, in which a hierarchical protection and control system provides the protection and control of wide area or regional power substations/ plants and their associated power network. The system is mainly divided into three levels, the local, the substation/plant and the wide area/regional protection and control. The integrated functions at each level are described in details with an aim to develop an optimal coordination mechanism between the levels. One of the core elements in the system is the synchronised wide area communication network between the substations and the protection and control system, in which latest communication technology is employed. Another important player in the system is the wide area synchronized protection and control information platform, which not only enables the fusion three line of defence for power system protection and control, but also provides a perfect tool for the application of cloud computing to substations and power networks.

摘要：提出了一种航天器高压直接配电设计方案,将100 V母线电压输送到负载端进行一次变换后直接使用,对系统拓扑、过流保护设计、高压安全控制、系统接地等技术进行了研究。相比于两级式配电方案,直接配电方案减少了一级变换环节,更能发挥高压传输的优势,提高系统的能源使用效率;由于高压DC/DC的大量使用,为规范选型、提高供配电系统性能,对不同拓扑结构DC/DC进行比较研究,给出了不同拓扑结构DC/DC适用的条件。经实际系统评估,航天器在轨运行良好,采用100 V直接配电方案后,系统整体变换效率提高了8.1%。

摘要：15-kV SiC IGBT的设计与优化图3给出了15-kVN沟道4H-SiC IGBT的半单元截面图。4H-SiC n^＋衬底上生长有外延层。厚3μm、1×10^19cm^-3掺杂的P＋发射极层是第一个外延层。其后是n型底部缓冲层（场塞）,厚5μm,掺杂浓度1×10^17cm^-3,可以防止场击穿,同时实现了较好的性能折中。