利用视频显微系统及开源软件追踪分析布朗运动

Tracking and Analyzing Brownian Motion with Video Microscopy System and Open Source Program

布朗运动理论与实验的结合,有效证实了分子热运动的存在,并可用于布朗粒子扩散系数、尺寸和阿伏伽德罗常数的确定。利用普通显微镜与智能手机实现了布朗运动显微视频的拍摄,用开源的粒子追踪程序追踪布朗颗粒的运动,使得粒子尺寸等物理量的确定非常简便;另外,也为追踪程序创建了用户友好的界面以方便操作。涉及的理论、实验及程序较适合大学生学习,可锻炼他们的动手能力和统计计算能力,并全面理解布朗运动的概念和随机过程。

The kinetic molecular theory of Brownian motion,coupled with experimental confirmation,offered the proof of existence of molecules and enabled the early determination of Brownian particle size,diffusion coefficient and Avogadro＇s constant.Here,a sequence of images converted from videos of Brownian motion,was run through a widely used open source image processing package,which permits more convenient measurement of physical quantities.Additionally,we established an graphical user interface for the program for easy operation.This study provides students with the opportunity to conduct experiment and statistical calculations,which engages students in fuller conceptual realization of the random nature of particle dynamics.