利用复合换能器测量反射的二次谐波及介质的非线性参量

基金项目:

国家自然科学基金(19834040)和江苏省自然科学基金(BK99024)资助项目。

详细信息

The measurement of reflected second harmonics and nonlinearity parameter of media using a transducer with complex structure

The State Key Lab, of Modern Acoustics, Institute of Acoustics, Nanjing University Nanjing 210093

摘要: 计算了有限振幅声波在层状媒质中的传播和反射,研究了用二次谐波反射模式的非线性声参量测量方法,设计制作了用于反射法测量非线性声参量的复合结构超声换能器,利用该换能器及有限振幅插入取代法建立了脉冲反射式测量非线性声参量B/A的实验系统,对若干流体和生物样品进行了非线性声参量的测量,其结果与现有文献上的值吻合的很好。

Abstract: The sound transmission and reflection of finite amplitude acoustic wave in layered media is calculated in this article. The measurement of nonlinear parameter using the second-harmonic reflective model is studied and a new kind of complex ultrasound transducer is designed and fabricated for this purpose. With this transducer and the finite amplitude insert-substitution method an experimental system to measure the nonlinear parameter using reflective model is developed. The nonlinear parameter B/A values of some liquids and biological tissues are obtained and the results coincide well with the B/A values presented in the literatures.