【作者】 王金环；

【导师】 郭颖； 李宝军；

【作者基本信息】 中国地质大学（北京） ， 宝石学， 2010， 硕士

【摘要】 本论文从光源的角度入手,阐述了光源对翡翠绿色评价的影响,首先计算了光源(D65、A)的显色指数、总结了三种不同照明光源下翡翠样品颜色指数特点,分析了照明体引起的两翡翠样品同色异谱的原因。为了研究绿色翡翠样品各颜色参数之间的关系,采用了数学分析方法中的方差和聚类分析。本论文采用PR715分光辐射计测得了光源D65和A的光谱功率分布,按照国标GB／T 5702-2003中光源显色指数的计算步骤,计算了这两种光源的显色指数,分别为80.02和92.39,分析计算结果发现,D65和A光源的光谱功率分布与其对应的标准照明体光谱功率分布的差异是这两种光源显色指数小于100的主要原因。采用color i5分光光度计测得了277颗绿色弧面翡翠样品在三种光源照明下(D65、CWF和A)的颜色指数,数据分析表明,D65光源下翡翠样品颜色的明度L*值最高；a*值从大到小的排序为D65光源、A光源、CWF光源,所以从绿色方向的饱和度来看,D65光源能最好的表现翡翠的绿色。挑选了三类在D65光源下颜色差异各异的翡翠样品进行照明体同色异谱分析,发现它们的同色异谱指数主要与光源的光谱功率分布和翡翠样品的反射率曲线有关,光源的光谱功率分布直接决定了样品可以吸收或反射哪些波长的光,两翡翠样品的反射率曲线相似程度越大,即曲线的交点越多,改变光源后颜色变化越小。双因素方差分析结果表明光源和翡翠样品自身两种因素对实际观察到的翡翠颜色影响都很大,单因素方差分析结果显示光源的变化对翡翠样品明度值的影响最小,对翡翠样品其它颜色指数的影响都很大。挑选了颜色相似且为较纯正绿色的16颗翡翠样品,对其颜色变量和同色异谱指数进行了变量聚类,发现明度L*与同色异谱指数大小的关系最紧密,其次为b*值、a*值,为计算一般显色指数用的权重系数提供了依据。更多还原

【Abstract】 From perspective of light to explain how light sources affect the evaluation of green jade. It calculates (D65、A) two lights’color rending indexs. It tests and summarys the jades’color parameters characteristics on the condition of three different lights(D65、CWF、A).It explains the phenomenon of metamerism caused by light changes. In order to study the relationship between color parameters and the color difference, mathematical analysis of variance and cluster analysis are used.In this thesis, two light sources’(D65、A) spectral power distribution are measured by PR715 spectral radiometer. In accordance with GB/T 5702-2003, it calculates the D65 and A light sources’color rendering index, respectively,80.02,92.39. The different spectrum power distribution between D65、A and the standard lightings’is the main reason why D65’s and A’s color rending index less than 100.It measures 277 jades’color parameters in three light sources (D65、CWF、A) by spectrophotometer. In D65, jades appear the highest L*.The sorting of a* from small to large is D65、A、CWF. Therefore, in order to make the green jades show perfect color, the selecting light order will be D65、A、CWF.In D65, it selects three groups of jades, every group’s jades have tiny color difference. It found that their metamerism index are mainly related with light sources’spectral power distribution and their reflect curves. The light source determines which part of the spectral that jade can absorb or reflect. The similar of the two jades’s reflectant curve, the less color change when changing light sources.Two factor variance analysis shows that both the light source and the jade itself have great impact on the color of jade. Single factor analysis of variance shows that changing light has less impact on the L* of jade, while, it has great impact on the other color parameters.It picks up some Jades with similar green color, their color variables and their metamerism indexs are clustered, shows that L* has the biggest effect on two jades’metamerism, followed by b*, a*, which provides some basis for general calculation of metamerism indexs.更多还原