3Kononov N K , Ignatov S M , Potapov V N , et al. A Digital System {or Producting X-Ray Images with a High Spatial Resolution. Instruments and Experimental Tech- niques. 2006, 49(5): 739-741.
5LEWISWJ , BENNETT LG L. The useof neutron radiography in the inspection of aircraft composite flight- cont rol surfaces [EB/ OL ] .
6Hillger W. Ultrasonic imaging of defects in sandwich composites from laboratory research to in-field inspec- tion. Proceedings of the 7th ECNDT, Copenhagen, 1998.