On Sep.14, Prof. Hailan ZHANG did a wonderful report in Room 218, Dezhao Building as one of the successive colorful academic activities held by Ultrasonic physics and testing lab.

The report Prof. ZHANG delivered was titled: "The influence of bubbles on the resonance frequency of liquid-filled resonator". First, he mentioned some practical problems encountered in measuring the acoustic characteristics of the rock by resonance spectroscopy method and predicting gas content in the strata and hydrocarbon filled-in. Then he took the influence of bubbles on the resonance frequency of liquid-filled resonator for example and analyzed it through the coupling vibration method and perturbation method. After that, Prof. Zhang further stated the relationship between coupling state of medium and resonance frequency and the limitations of perturbation method in dealing with this kind of problems. At the end of the report, Prof. Zhang introduced the application of symbolic computation in matlab. He pointed out it can simplify the treatment process and improve the computation efficiency.

After the report, Prof. WANG Xiuming made a summary to Prof. ZHANG's report. He highly praised the report and said the simplification of the complex problems would be of great help to discover the nature of problems.

Prof. ZHANG Hailan

Prof. Wang Xiuming