【摘要】 纳米粒子布朗运动特性对Micro-/Nano-PIV的使用和与粒子相关的物理现象的研究有重要意义。观测了200nm荧光粒子的布朗运动,利用单粒子追踪(SPT)算法和自编程序处理图像,获得粒子的均方位移,计算了实验扩散系数Dexp为2.09×10-12m2/s。与Stokes-Einstein公式估计的理论扩散系数Dth相比,二者量阶一致,但实验扩散系数的数值偏小约5%。对相关的实验误差进行了分析。更多还原

【Abstract】 The Brownian motion of nano tracer has important effects on the measurement accuracy of Micro-/Nano-PIV and evaluating many other parameters of the liquids.In this paper,the author tracked the trajectories of 200nm particles.Using the single particle tracking(SPT) algorithm,an in-house image processing programe was compiled,with which the image series were processed.The experiment got a diffusion coefficent Dexp of about 2.09×10-12 m2/s.Compared with the theoretical value Dth estimated with the Stokes-Einstein equation,Dexp is of the same order of magnitude as Dth,the deviation is about 5%.Related error analysis on several possible causes was given in this paper.更多还原