摘要 根据洛伦兹电子论和朗伯-比尔定律，当溶液浓度不是很高，且作用于溶液的光场频率为常数时，溶液的浓度与其折射率之间近似地呈线性关系。因此，原则上可通过测定折射率来确定溶液的浓度。本文以罗丹明B溶液为例，基于光学折射定律来测定不同浓度下的溶液折射率，并利用最小二乘法系统分析实验所得数据，从而确定了折射率随溶液浓度的变化关系以及该变化关系对溶剂（如超纯水和无水乙醇）的依赖性。研究结果表明，在超纯水和无水乙醇两种溶剂中，当溶液浓度较低时，溶液的浓度与折射率的关系均呈现线性关系，但在相同浓度下，以水为溶剂的溶液折射率要小于以无水乙醇为溶剂的溶液。对于某给定浓度的罗丹明B水溶液，通过测定其折射率，并根据已确定的折射率与浓度的线性关系计算得到的溶液浓度的理论值与给定浓度的实际值误差小于4%。该研究结果将为废水污染程度的测定提供一种简便有效的方法。90050

毕业论文关键词：折射率；溶液浓度；罗丹明B；废水；最小二乘法。 

Abstract According to Lorentz's theory of electrons and Lambert-Beer's law, when the solution concentration is not very high and the frequency of the field acting on the solution is constant, the relationship between solution concentration and its refractive index approximately obeys linear。 Therefore, solution concentration can be determined by measuring the refractive index of the solution in principle。 In this thesis, Rhodamine-B solution is used as an example, and refractive indexes of the solution at different concentrations have been measured based on the optical refraction law。 The experimental data have been systematically analyzed using the least square method, and finally the relationship between the refractive index and the solution concentration as well as the dependence of the relationship on solvent (such as water and ethanol) has been determined。 Our results show that the relationship between the concentration and the refractive index of the solution is linear in the solvent of either water or ethanol when the concentration of the solution is low。 However, at the same solution concentration, the refractive index is lower in the solvent of water than that in ethanol。 For a given concentration of rhodamine-B aqueous solution, the error between the actual value and the theoretical value of the solution concentration calculated from the determined linear relationship is less than 4%。 The results of this study will provide a simple and effective method for the determination of pollution level of waste water。

Key words: refractive index; solution concentration; rhodamine-B; waste water; least square method。

目录

摘要 2

目录 4

第一章 绪论 5

1。1 课题研究背景和研究意义 5

1。2 溶液浓度与其折射率关系的理论模型 5

1。3液体折射率的测量方法 7

1。3。1 最小偏向角法 7

1。3。2 掠入射法 9

1。3。3 波动光学法 9

1。3。4 光纤传感法 10

1。4 本论文的研究内容 12

第二章 利用折射定律测量液体折射率 13

2。1实验设备及实验过程 13

2。1。1实验仪器及实验药品 13

2。1。2实验测量装置