表面声波传感器及其应用

本文简要介绍多种表面声波传感器的结构、特点、应用及其研究进展概况。表面声波传感器依其波型分类,主要包括瑞利波、水平切变声板波、乐甫波和兰姆波传感器;其应用领域根据作用特点大致可分为物理传感器和化学、生物传感器,前者较易实现,后者特异性强,需要针对具体情况作更细致研究。由于表面声波的传播速度和相位对周围环境的参量变化极为敏感,因此有关传感器具有很高的灵敏度和广泛的应用领域。     

创新能力的培养与物理教学改革

本文阐述了创新能力的重要性及物理教学为培养具有创新能力的人才而进行改革的措施     

驻波演示仪的制作

每当讲到波动学的"驻波"这一节时,老师感觉难讲,学生也感觉难学.对于驻波在质点振动,相位变化,波形及能量的传播等方面与行波的区别,学生总爱犯糊涂.如果能结合教学演示仪,边讲边演示.学生对驻波这一特殊的波动形式就容易理解了.     

驻波演示仪的制作

本文分析介绍了横驻波演示仪和纵驻波演示仪的制作方法及其演示步骤。     

Performance of Non-Contact Linear Actuators Driven by Surface Acoustic Waves*

A new kind of non-contact linear actuator （motor） driven by surface acoustic waves （SAWs） is presented, in which the stators are made from SAW delay lines using 128° YX-LiNbO3 substrates. A fluid layer is introduced between the slider and the stator of the actuator, and the slider is a circular aluminum disk suspended on the surface of the liquid （water） layer. As the SAW is excited on the stator, the SAW is converted to a leaky wave in the interface of the stator and the liquid, and then propagates into the liquid. Owing to the nonlinear effect of wave propagation, acoustic streaming is generated, which pushes the slider to move. By the experiments, the relations between the slider velocity and the experimental parameters, such as the exciting voltage of the SAWs, the thickness and the kinematic viscosity of the liquid layer, are obtained.