TY - Journal of Yangtze River Scientific Research Institute A1 - WANG Jin-chao, WANG Chuan-ying, TANG Xin-jian T1 - A Method for Determining Empty Area Profile Based on Borehole Ultrasonic Scanning Technique Y1 - 2018-03-01 JF - Journal of Yangtze River Scientific Research Institute JO - Journal of Yangtze River Scientific Research Institute SP - 104 EP - 109 VL - 35 IS - 3 UR - http://ckyyb.crsri.cn N1 - 10.11988/ckyyb.20171086 ER -