基于无线网络的矿井燃爆监测及预警系统模型研究

目前,中小型煤矿一般没有完善的瓦斯监测报警系统,大型煤矿的报警系统投资巨大、且难随掘进及时增加监测点。文章提出基于无线网络的矿井燃爆监测及预警系统,由无线监测节点、监控计算机、报警器组成;成本低,组网简单,可动态增加、调整监测点,移动式报警器由人员携带,自动链入监测网,实时接收检测数据和报警信息;大大提高监测的全面性、报警的实时性和到位率,最大限度地避免爆炸事故的发生。     

In-phase mode selection of 18-core photonic crystal fiber based on Talbot resonator

An effective mode selection is important for the multi-core photonic crystal fiber（PCF）to obtain good output.Talbot cavity is popular to lock the in-phase mode,but few satisfactory experimental results have been reported.In this paper,a dual-Talbot cavity with reflected mirrors on each side of PCF is designed to lock the in-phase mode.The design gains the advantage of in-phase mode against out-of-phase mode.What＇s more,it can weaken the influence brought by the imperfect end facet of the fiber.The corresponding theoretical analyses and the experiment are taken.The experimental results suggest that the dual-Talbot cavity improves the capacity of mode selection.