基于干涉原理和数字图像处理技术的动态浓度监/检测方法研究

【作者】 袁博宇；

【导师】 吴晓娟；

【作者基本信息】 山东大学 ， 信号与信息处理， 2007， 硕士

【摘要】 溶液浓度变化的检测和测量是化学，生物学，材料学等领域十分关注的研究课题。在生物领域，可以利用测量细胞体内的浓度分布及其变化来分析活体细胞；在晶体生长过程中，晶体表面浓度分布变化的监测是制备高质量晶体的关键技术之一。在电化学领域，当电极发生阳极溶解、阴极沉积等电极过程时，电极／溶液界面溶液浓度发生改变，分析这种随电极反应过程的溶液浓度动态变化和溶液扩散层厚度变化对阐明电极反应机理有重要的意义。本文结合数字全息干涉技术和数字图像处理方法测量了电化学反应中电极／溶液界面处溶液的浓度变化分布。由于在全息干涉测量中引入载波条纹，所以能够方便地应用傅里叶分析方法分析计算干涉条纹的动态变化。通过对全息干涉图像序列的分析计算得到了电极反应过程中溶液浓度变化所引起的物光相位变化，并把相位差分布用来描述浓度变化分布。重建的相位差分布图像比较直观地再现了电极反应过程中电极／溶液界面处溶液的浓度变化，扩散层厚度等信息，从而为动态半定量分析和检测浓度变化提供了一种新的方法。另外，本文还利用该方法定量测量了单溶质溶液的浓度变化。根据溶液浓度和折射率的对应关系，由相位差分布得到了单一溶质溶液的浓度变化分布，从而实现了对单一溶质溶液浓度变化二维分布的定量测量。为了实现浓度分布变化的实时观测，本文提出用TI公司生产的视频处理芯片DM642处理干涉条纹视频图像的设想。结合光学干涉测量系统，由DM642完成图像信号的分析，处理等过程，并通过液晶显示器显示测量结果以实现对浓度变化的实时监／检测。本文以金属电极的模拟腐蚀过程为研究对象，致力于开发新的观测方法和新的测量平台。目前该方法已实现了浓度分布变化的实时定性观测，单一溶质溶液浓度变化的定量测量。在其它学科如生物、医学等研究领域将会有一定的应用价值。更多还原

【Abstract】 Concentration measurement has wide applications in Chemistry, Biology, Material and other domains. In Biology, concentration distribution of a cell is measured to analyze the live cell. During the process of crystal growing, the surveillance of concentration change at the surface of crystal is one of the main techniques to make high quantity crystal. In electrochemistry, the concentration of the solution near the electrode/solution changes during electrochemical reaction processes such as anode dissolution and cathode deposition. It is important to analyze those concentration changes for illustrate the mechanism of the electrochemical reaction processes.Digital holographic interferometry was used to measure concentration change distribution of the solution at the interface of electrode/solution during electrochemical reactions in this thesis. With the introduction of carrier fringes in digital holographic interferometry, Fourier analysis method was used to analyze interference patterns and calculate their dynamic changes conveniently. The phase difference of object wave front, which was caused by the change of the solution’s concentration during the electrochemical reaction, was calculated from interference patterns to reflect the concentration change distribution. The reconstructed phase images, which were distribution of the phase difference of object wave front, reflected the changes such as concentration distribution, diffusion layer, etc. It provided a new method to detect and analyze dynamic concentration changes. Moreover, this concentration measurement system could obtain the quantitative concentration changes of single solute solution. It based on the relationship between the concentration and refractive index of the solution. It was the first time that the dynamic change distribution of the single solute solution’s concentration was measured quantitatively.For the real-time measurement of concentration changes, DM642 would be used to process the video signals of interferometry fringes. Combined with the optical interferometry system, DM642 could be applied to analyze and process the digital holograms. The results which were calculated from the images might be shown on the LCD screen in real-time. We applied ourselves to study the metal electrode’s corrosion processes and develop new method and system of concentration measurement in our work. This system could detect the concentration changes in real time and measure the single solute solution’s concentration quantitatively. It could be applied in other domains such as biology and medicine.更多还原