基于数值模拟的栓塞修复过程中AE信号分析

为探讨木质部栓塞修复过程监测到大量AE信号现象的原因,基于Rayleigh -Plesset方程建立描述栓塞修复过程中空化泡的运动方程,并用数值模拟方法得到空化泡运动方程的解,对AE信号进行动力学分析.结果表明:当木质部液水势升高时,空化泡会塌缩为半径较小的气泡.但经过一次塌缩并不会使栓塞修复.在压强升高的情况下,气泡会经多次塌缩直到形成稳定的微小气泡,栓塞才会完全修复.在气泡多次塌缩的过程中,气泡半径减小,但是并不是单调减小而是以减幅振动的方式减小,从而形成振源,成为AE信号的来源之一.

Analysis of AE Signals from Embolism Repairing Process Based on Numerical Simulation

A bubble motion equation of embolism repair was established based on the Rayleigh-Plesset equation in order to discuss the reason that a lot of AE signals were detected from embolism repairing process,and the solution to the bubble motion equation was worked out to analyze the dynamics of AE.Results show that the bubbles contract and get smaller when xylem water potential rises.However,the embolisms cannot be repaired by only contracting once.When the pressure rises,the bubbles will continue to contract until they become tiny stable ones.And then the embolisms can be repaired.In the process of repeated bubble contraction,the radius of bubbles does not decrease monotonically but by the way of convergent oscillation,and this is one of the sources of AE signals.