7Liu ZQ,Lu WeiMA.Structures noise reduction of ultrasonic signals using rtificial neural network adaptive filtering Ultrasonics[J].Proc of 8th APCNDT Shoanghai,1997,(1):5-6.
8Si Ik M G.Sizeing like defects by ultrasonic means.Research Techniques in Non-destructive Testimg[M].London:Academlc Press,1977:3-4.
9Mauric Silk.BS 7706-1993 Guide to Calibration and Setting-up of the Ultrasonic Time of Flight Diffraction(TOFD)Techinque For Defect Detection[M].London:Academic Press,1993:46.
