1. Shen Z H, Yuan L, Zhang H C, et al. Laser ultrasound in solids[M], Beijing: Posts& Telecom Press, 2015:9–10.
2. Hassina K, Hakim D. The transducer vibratory profile effects on the detection of the transient ultrasonic field scattered by a rigid point reflector [J]. Ultrasonics, 2009, 50 (4).
3. Zhen H, Lin S Q. Ultrasonic testing [M], Beijing: China Labor and Social Security Publishing House, 2008:110–124.
4. Nie X, Guo Z F, He C Z. Parameters estimation of ultrasonic echo signal based on blind deconvolution and parameterized model [M]. Chinese Journal of Scientific Instrument, 2015, 36 (11):2611–2616.
5. Shi C L, Shi F F and Zhang B X. Analysis on defect classification by deep neural networks and wavelet packet transform [J]. ACTA ACU STICA, 2016, 41 (04): 499–506.