参加美国声学学会第97届会议(50周年庆祝纪念)纪要

美国声学学会成立于1929年,也是国际上同学科学会中创建最早的。今年6月11—15日在美国麻省剑桥的麻省理工学院召开的第97届声学学会会议,同时纪念该学会成立50周年,因此规模很大,参加代表千余人,其中不少来自其他国家,提出学术报告有七百多篇。1954年6月该学会曾在纽约召开过25周年纪念会,可是这次比当年无论从报告论文的篇数(那次是五百多篇)还是从报告的具体内容来看,都反映出这门学科正在蓬勃发展。     

声学与物理教育及科学研究

声学这门学科的核心问题是研究机械波和它的辐射,它和电磁波以及其它波动有不少共同之处,它在物理学的发展中曾起过很好的作用.远在麦克斯韦建立电磁场理论之前,声波就常被用来模拟光波和电磁波的性质,这当然是科学史上的事.光学上理想的单频相干光只是在激光出现以后才算获得,     

Water Surface Wave in a Trough with Periodical Topographical Bottom under Vertical Vibration

We investigate the water surface waves in a vertically vibrated long rectangular trough with several identical Plexiglas rectangles lined periodically on the bottom. The band structure is computed theoretically by the method of transfer matrix. Some interesting phenomena, such as the localized wave, especially the solitary-like wave inside the band gap . are observed in the experiments.     

Real-Time Measurements and Modelling on Dynamic Behaviour of SonoVue Bubbles Based on Light Scattering Technology

The dynamic behaviour of SonoVue microbubbles, a new generation ultrasound contrast agent, is investigated in real time with light scattering method. Highly diluted SonoVue microbubbles are injected into a diluted gel made of xanthan gum and water. The responses of individual SonoVue bubbles to driven ultrasound pulses are measured. Both linear and nonlinear bubble oscillations are observed and the results suggest that SonoVue microbubbles can generate strong nonlinear responses. By fitting the experimental data of individual bubble responses with Sarkar＇s model, the shell coating parameter of the bubbles and dilatational viscosity is estimated to be 7.0 nm-s-Pa.