基于声学超晶格铌酸锂的新型体声波器件(英文)

设计了一种集成的声学器件 .它的基本结构是由下列 3部分组成的 ,即换能器部分、声学开关部分和声传播介质部分 ,但其材料均来源于铌酸锂晶体 .其中换能器与声开关部分是由声学超晶格铌酸锂构成的 ,而声的传播介质则是单畴铌酸锂 .着重研究了声开关部分所外加的直流偏压对在该器件中传播的声波的影响 .结果显示 :声开关部分对声波的反射率受到这一外加偏压大小的影响 ,外加偏压越大 ,则反射率越强 ;声子带隙也受到外加偏压的影响 ,外加偏压越大 ,则声子带隙将会增宽 .同时我们还发现了声开关的反射谱分布决定于铌酸锂超晶格的周期大小 ,且超晶格周期数的减小也会增宽声子带隙 .该器件在设计上有两大优点 :一是实现了声学开关器件的集成化 。

Simultaneous Exact Controllability of Wave Sound Propagations in Multilayer Media

In this work we study one problem of mathematical interest for their applications in several topics in Applied Science. We study simultaneous controllability of a pair of systems which model the evolution of sound in a compressible flow considered as a transmission problem. We show the well posed of the problem. Furthermore provided appropriate conditions in the geometry of the domain are valid and suitable assumptions on the fluid, is possible to conduce the pair of systems to the equilibrium in a simultaneous way using only one control.