【作者】 朱拓；

【导师】 倪晓武；

【作者基本信息】 南京理工大学 ， 光学工程， 2005， 博士

【摘要】 根据甲醇溶液的紫外吸收光谱和紫外光激励的荧光光谱实验研究结果，得到了甲醇溶液能较好吸收波长短于260nm的紫外光，且随着溶液浓度变化其吸收光谱和荧光光谱的变化规律，进而对甲醇分子吸收和发射光谱的机理进行了讨论和分析。 对乙醇溶液的吸收光谱和荧光光谱，以及与甲醇溶液的光谱对比研究结果表明：两者的最长吸收波长差为15nm左右，荧光中心波长差为33nm左右，推算得到了甲醇分子和乙醇分子产生荧光主跃迁的能级差，从而为准确区分甲醇和乙醇提供了实验依据；进而根据分子结构理论合理地解释了两种溶液的光谱特性存在差异的原因；并由此提出了用最长吸收波长和荧光光谱中心位置的光谱特性有效区分甲醇和乙醇分子的方法。 针对乙醇物质的应用产品——白酒，我们选择地产的洋河大曲原酒进行了光谱学的研究，进而对不同地区的代表性白酒的三个品牌的浓香型商品酒进行了比较式光谱学研究，得到了几种具有典型应用价值的结果，为酒的陈化年代的估计和不同品牌酒的识别给出了一种有效的方法。 我们还研究了正丙醇、异丙醇的紫外吸收光谱及荧光光谱，并进行了分析和比较。研究结果表明使用紫外吸收和荧光光谱能容易地鉴别正丙醇与异丙醇，同时对二者光谱的差异原因进行了解释。进而对四种醇类物质的光谱进行了对比研究。 在光子密度波成像理论的光子密度波扩散方程求解与模拟计算方面，我们根据试验模型的要求，得到了在复光源照射下，无限长、半无限长矩形空间及立方体边界条件下的格林函数，应用这些格林函数求解了相应条件下光子传输方程扩散近似的形式解，并分别演算出了三种模型下，与入射面相对应的出射面处的光子通量和多散射介质中吸收系数改变量之间的关系表达式，从理论上解决了更加复合实际情况的光子传输方程扩散近似的求解问题。针对光子密度波的模拟计算问题，我们在已经得到的三种直角坐标下解析解的基础上，提出了一种快速计算光通量的算法，并编制了对应的计算程序。进而考察了三种求解模型光通量及其相对偏差随不同参数的变化，给出了不同解析模型的特点，并分析了不同参数对光子密度的影响。 本文的研究结果为醇类物质的识别及白酒不同品牌和年代的鉴别提供了一种新的有效的测定方法，其结果对量子化学计算也有参考价值。光子密度波成像技术的研究结果为同类研究提供了理论基础，所提算法实现的程序及模拟计算结果也为今后的反演计算和实验研究奠定了基础。更多还原

【Abstract】 The absorption and fluorescent spectra of four monohydric alcohol fully dissolved in water, and its characteristic are fully studied in theory and experiment. The solution of diffusion equation and numerical value simulation on photon density wave theory are also systematically studied in this paper.From the experimental outcomes of the UV-light absorption spectra and the fluorescent spectra of methanol, we find that methanol molecules can absorb the exciting light with a wavelength less than 260nm, and the fluorescent intensity has a regularity change with the concentration change of methanol. Thus the absorbing-emitting mechanism of methanol molecule is discussed and analysized.The UV-light absorption spectra and the fluorescent spectra of ethanol are studied, which are especially compared to the methanol solution. Based on the obtained results, a difference of 15nm in longest absorption wavelengths and a difference of 33nm in center fluorescent wavelength can be used precisely to distinct methanol and ethanol. The spectra difference of two solutions can be explained reasonably on the structural theory of molecule. Furthermore, a new method to distinguish methanol and ethanol is put forward by the spectra characteristics in longest absorption wavelengths and center fluorescent wavelength.Yanghe original alcohol with typical flavor of Jiangsu was chosen in the study of its spectroscopy, just because alcohol is the most quantitive production and ethanol be applied to foodstuff industry. Three brands of stronger fragrant flavor alcohol which come from different regions were compared in study of spectroscopy. Many useful results were obtained that can be used to tell the age of the alcoholic and wine and identify the different brands.The UV-light absorption spectra and the fluorescent spectra of propanol and isopropanol are also compared in study. According to the results of our researches, propanol and isopropanol could be clearly distinguished by absorption spectra and fluorescent spectra. In this paper, the reasons of difference spectra of two liquids are also explained. Moreover, the fluorescent spectra of the four kinds of different alcohol were compared and the results were discussed. The solution of diffusion equation and the numerical value simulation on photon density wave theory are studied. We consider the general situation in which a amplitude of the point light source may be modulated at frequency Ω. The solutions of diffusion equation in infinite, semi-infinite and finite cube space with photon density wave were researched based on the need of experimental model. The analytic solution of Green-function is occurred under the boundary conditions, and the relationship betweenthe flux J_n and absorption factor △μ_a was worked out by calculation. By use of three更多还原