Coal and gangue identification method based on the intensity image of lidar and DenseNet.

Coal and gangue (rock) identification is the essential process in a coal preparation plant. In an actual coal preparation plant, the existing classification methods have many disadvantages in safety and identification rate. We utilized the echo intensity image (EII) of lidar for coal and gangue identification for the first time, to the best of our knowledge, and achieved outstanding recognition results with a convolutional neural network.

Double-end-pumped Nd:YVO4 slab laser at 1064 nm.

We demonstrate a high-power laser diode stacks double-end-pumped Nd:YVO4 1064 nm slab laser with a folded stable-unstable hybrid resonator. An output power of 220 W was obtained at the pump power of 490 W with optical conversion efficiency of 44.9%.