They are characterized by ruggedness, light weight, high sensitivity, low acousticimpedance, easy conformability to complex surface, low cost and large bandwidth.
它具有耐磨、量轻、灵敏度高、声学阻抗低、容易固定在复杂的表面、价格便宜，频带宽等特点。
2
Negative coefficients occur where there is a decrease in acousticimpedance across the reflecting interface.
当反射界面上下两侧的声波组抗降低时，反射系数就会出现负值。
3
A special nomograph designed for calculating the normal specific acousticimpedance is proposed.