JCQ depurant-muffler is adopted on 49ZQ engine using small rare-earth element balls as catalyst and took the method of quadrature frequency band optimization to opetmize the configuration parameters.

用于492Q发动机的JCQ净消声器采用稀土小球为，用正交频带加权优法优选消声器结构参数，取得良好的消声、净性。

OFDM (Orthogonal Frequency Division Multiplexing) is a method that can combat multipaths, fully use the frequency band and has high data rate, and has a promising future in UWA communication.

摘要正交频分复用(OFDM)技术具有抗多径、频带利用充分、传输数据率高的优，声通信中具有重要的发展前景。