“激光微纳制造”专题前言

<正>随着高端制造需求的日益增加,传统的制造手段已远远不能满足航空航天和电子制造等领域中精密零部件(如飞机发动机、惯性导航和半导体芯片等)的精细制造需求。因此,激光微纳制造技术应运而生,并始终矗立于基础科学前沿及制造领域尖端位置,成为国家战略新兴产业发展的重大关键技术之一,对我国的国防安全与国民经济建设起到了愈来愈重要的作用。     

基于双M-Z干涉仪的光纤周界防护系统

基于光纤双Mach-Zehnder干涉仪(MZI)结构对周界防护系统进行了设计研究。通过对两路经过不同延时的相同信号进行互相关运算,实现了对振动入侵点的定位。提出了一种分段数据处理方法,有效地提高了定位稳定性及准确性。测试结果表明,该双Mach-Zehnder干涉仪周界防护系统可以实时对振动点进行定位,在传感光纤长度为2km、采样率为2MHz时定位精度优于200m,能够长时间连续稳定工作。     

Al掺杂对正极材料LiNi0.33-xMn0.33Co0.33AlxO2结构和电化学性能的影响

以柠檬酸为螯合剂利用快速湿化学法合成了具有α-NaFeO₂型层状结构的LiNi_0.33-xMn_0.33Co_0.33Al_xO₂(x=0.00,0.01,0.02, 0.04)正极材料,并通过X-射线衍射、充放电测试、循环伏安和交流阻抗对材料的结构和电化学性能进行了系统研究。XRD结果表明此方法合成的材料具有很好的层状结构且阳离子的混排度随着Al³⁺含量的增加而下降。电化学测试表明,LiNi_0.31Mn_0.33Co_0.33Al_0.02O₂具有很好的电化学性能和和循环性能,1C放电倍率下首次放电比容量达到176.9 mAh·g^-1,且Al³⁺的掺杂能有效提高电荷在电极界面间转移并抑制了在高压循环过程中电荷转移阻抗的增加。     

浅谈榆林神华能源公司郭家湾煤矿“三网合一”

近年来,"数字矿山"概念的提出为煤炭工业的两化融合指出了具体实现途径。"数字矿山"其核心是在统一的时间坐标和空间框架下,以计算机及其网络为手段,将海量异质的矿山信息进行全面、高效、有序的管理和整合。作为"数字矿山"的基础平台和实现手段,计算机网络在"数字矿山"的建设中起着至关重要的作用。本文以"三网合一"在榆林神华郭家湾煤矿的现阶段具体应用为例,简要介绍了"三网合一"网络技术在矿区网络平台搭建中的建设以及应用。     

Tunable directional beaming assisted by asymmetrical SPP excitation in a subwavelength metallic double slit

We present a design for tunable directional beaming through a subwavelength metallic double slit surrounded by dielectric surface-relief gratings.On-axis and off-axis beaming can be switched by controlling the incident angle to asymmetrically excite surface plasmon polaritons(SPPs) that are subsequently coupled out to propagating beams by the two gratings on the left and the right sides of the double slit.Furthermore,the division of optical power into two off-axis beaming directions can be tuned smoothly by varying the incident angle while keeping the total power almost unchanged.The mechanism of this effect is analyzed theoretically and verified using rigorous numerical simulations.     

Femtosecond Bessel-beam-assisted high-aspect-ratio microgroove fabrication in fused silica

A simple and repeatable method to fabricate high-aspect-ratio(HAR) and high-quality microgrooves in silica is reported. The method consists of two steps:(1) formation of laser-modified regions by femtosecond Bessel beam irradiation, and(2) removing laser-modified regions through HF etching. Uniform, straight microgrooves can be fabricated and the highest aspect ratio that can be reached is ～52. The phenomenon is attributed to the uniform energy distribution in the long propagation distance, which leads to the long and uniform laser-modified regions and subsequent HF acid etching of laser-modified regions with high selectivity. This method will have potential applications in fabrication of HAR microgrooves in transparent materials.