2Love A E H. Mathematical theory of elasticity[ M]. Now York:. Cambridge university press. 1934: 452.
3David A , Brown. Baffled ring directional transducers and arrays: United States of America, 6768702 [P].2004-07-24.
4Joln L, Butler, Alexander L, et al. A tri-model direction transducerl J ]. Acoustical Society of America, 2003, 115(2):658-665.
5Tetsuro Oishi, Boris Aronov, David A, et al. Broadband multimode baffled piezoelectric cylindrical shell transducers[J]. Acoustical Society of America, 2007, 121 (6) : 3465-3471.
6John L, Butler. Directional flextensional transducer:U- nited States of America. 4754441[P]. 1988-06-28.