随着地铁逐渐成为缓解城市交通压力的首选方式,地铁隧道施工中的安全问题也得到了重视,因此对隧道内人员进行实时定位具有重大意义。超宽带(Ultral Wide Band,UWB)技术可以实现高精度的测距定位功能,被广泛应用在室内定位等场合,但是目前的UWB定位技术普遍存在非视距(Non-Line of Sight,NLOS)干扰、动态跟踪定位性能差、定位基站覆盖不够合理等一系列问题,而且目前针对隧道中
Hexagonal-plate BaFe12O19 nano-particles were prepared by combining the co-precipitation and molten-salt method. The effects of molten-salt NaCl on the products
Studies of nanoindentation were performed on nc-Si:H films to evaluate the effects of the fabrication processes on their mechani-cal properties. It is observed