红宝石的色度学研究

根据色度学原理,利用USB2000+光纤光谱仪,量化红宝石颜色的主波长或补色波长、色调角以及颜色描述的分析可知:色调角h*ab在(0°,18°),补色波长λc为490～ 496 nm时,红宝石色调为红色;色调角hab*在(342°,360°),补色波长λc为497～509 nm时,红宝石色调为粉红色;色调角h*ab在(324°,342°),补色波长λc为509 ～ 542nm时,红宝石色调为紫红色;色调角h*ab在(306°,324°),补色波长λc为542～ 570 nm时,红宝石色调为紫色.因此,利用光纤光谱仪、适当的照明方式及光谱采集方法,应用色度学原理,可以客观、定量地描述红宝石的颜色,可作为评价红宝石颜色的适用技术.     

南宋官窑青瓷釉呈色机理研究

本文将南宋官窑青瓷釉的颜色分釉色色调（颜色种类）与釉色饱和度（颜色鲜艳程度）两方面进行研究，釉色色调与主波长位置对应，釉色饱和度与刺激纯度对应，用穆斯堡尔谱分析，配以反射光谱测定，ＣＩＥ色品图．及配位场理论分析研究南宋官窑青瓷釉的釉色色调，并试验烧成温度和釉层厚度对釉色饱和度的影响。主要结论如下：（１）南宋官窑青瓷釉的颜色主要受六配位Ｆｅ（２＋）离子的ｄｄ跃迁与Ｆｅ（３＋）离子的荷移光谱控制，前者的吸收带位置在１０００ｎｍ左右近红外区，后者在２３０ｎｍ左右紫外区，两者共同决定南宋官窑釉在可见光区的吸收光谱。（２）实验表明，控制南宋官窑青瓷釉色色调，关键是控制／Ｆｅ（３＋）比值。／Ｆｅ（３＋）比值增大，主波长位置移向短波方向，反之则移向长波方向。（３）实验表明，烧成温度提高和釉层厚度增大都使南宋官窑青瓷釉色饱和度增大。     

基于CIE 1976 L* a* b*色空间的翡翠绿色明度的质量评价

通过翡翠绿色明度与彩度、明度与色差等关系的研究,确定明度对颜色质量评价的作用.三维均匀色空CIE 1976 L* a* b*中,当翡翠绿色的明度较低即L*<19.52时,明度与彩度呈正相关;当19.5260时,明度则与彩度呈负相关.通过CIE DELAB、DECMC、CIE DE2000三个色差公式的计算,证明DL*是决定DE的直接因素, DC*次之,而DH*对色差几乎无贡献.得出结论,翡翠绿色的质量评价应以明度为首要因素,这是最直观且最符合色知觉效果的,而后依次为彩度与色调角两个标准.     

CIE1976 L*a*b*均匀色空间下照度对锰铝榴石颜色的评价

通过照度实验,基于CIE1976L*a*b*均匀色空间研究照度对锰铝榴石颜色评价的影响.照度增加,锰铝榴石黄色的明度L*显著增加,且自身明度较低的锰铝榴石黄色明度更易受照度变化的影响.△a*平均为17.30,△b*平均为36.83,明显大于△a*的均值,表明照度对锰铝榴石黄色调的影响更大;当照度较低时,彩度C*与照度呈正相关,当照度超过227.73 lx后,C*将不再增大或与照度呈负相关;色调角h0随照度增加而增大,平均色调角增量△h0=11.59,增幅较明度和彩度小.同时验证Stevens效应、Hunt效应、Helmholtz-Kohlrausch效应、Bezold-Brücke色相偏移理论在锰铝榴石颜色观察上的体现.此外,当明度差值DL* ＞15时,DL*与色差DE2000呈正相关且相关性最大,说明明度对色差具有最大贡献.得出结论,照度影响锰铝榴石的明度、彩度、色相,间接影响色差,其中对明度影响最直观,故在质量评价时应严格控制照度标准.     

绿色翡翠颜色计算机分级技术的可行性研究-基于HSL颜色空间模型

翡翠颜色是翡翠质量和价值评估的重要环节之一.近年来有许多的学者针对翡翠颜色评价进行了各种研究,并且在学术方面取得了一定的成果,然而这些成果在市场上并没有得到广泛的运用与推广.笔者希望通过此次的研究找到一种简单快捷的翡翠颜色分级方法.本研究拟运用色度学HSL颜色空间模型对绿色翡翠的图像颜色进行色调、饱和度、明度的描述,并基于理论基础之上进行实践证明,即通过一系列针对绿色翡翠颜色数据的分析归类,最终得到各种绿色翡翠各自的HSL数值范围及阈值,并进行计算机编程.然后将通过计算机程序分级的绿色翡翠再运用肉眼感官和Gemdialogue色卡进行分级验证.最后证明基于HSL颜色空间模型对绿色翡翠颜色计算机分级技术的研究是具有可行性的.     

Color assessment of granitic rocks and implications for their ornamental utilization

The purpose of this study is to evaluate the factors affecting the assessment of granite color, such as grain size and texture, and to propose a methodology for this task which would reduce the margin of error associated with this procedure. For this purpose, an evaluation was carried out on the color of several granites with different textures used in the dimensional stone industry to highlight the importance of the sample area, the number of measurements per sample and the aperture of the equipment. A colorimeter was used to measure the granite color according to the CIE‐L*a*b* and CIE‐L*C*_abh_ab systems, in both large slabs and small samples selected in a processing plant of ornamental granites. Granite color characteristics from large slabs had to be obtained with at least 60 shots due to the variation between different slabs. Therefore, several samples are needed for granite characterization. The color of gray granites does not vary significantly. Nevertheless, the more weathered granites show significant differences which are more evident in the b*‐parameter, or the yellow–blue component, which allow the use of the colorimeter for quality control. By doing so significant differences among the rock pieces used in a single building can be avoided. There were no significant differences found in the color parameters from distinct apertures. However, due to the heterogeneity of the granite the color is evaluated better with larger apertures. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2012     

陶瓷颜料的颜色分析

从颜色科学的基本理论出发 ,以CIE标准色度学系统为基础 ,通过对陶瓷颜料的颜色进行定量描述及分析 ,为陶瓷颜料的颜色调配提供可靠而实用的理论依据。     

Color discrimination results from a CRT device: Influence of luminance

In this article, we report new color discrimination ellipsoids calculated from two normal observers, using a CRT device and five values of luminance at each of the five centers recommended by the CIE in 1978 (Col Res Appl 1978;3:149–151). Our main goal was to test the weighting function for lightness adopted by the CIE94 color‐difference model (CIE Publication 116, 1995). Although some of the experimental conditions employed here (CRT monitor, small size of the visual field, and controlled exposure time) did not fit those recommended by this model, our results support the weighting function for lightness proposed by CIE94. The only robust trends observed in the ellipsoids obtained were a confirmation of Weber's law and a decrease in the area of the x, y chromaticity ellipses, when the luminance of each reference stimulus increased towards the one of the surround. © 1999 John Wiley & Sons, Inc. Col Res Appl, 24, 38–44, 1999     

Improvement of CMC upon CIEDE2000 for a new experimental dataset

This communication reports additional analyses of the dataset presented in the article “A preliminary comparison of CIE color differences to textile color acceptability using average observers” by Mangine, Jakes, and Noel © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 239–241, 2006     

Enhanced photoluminescence of SiO2 coated CaTiO3:Dy3+,Li+ nanophosphors for white light emitting diodes

Systematic analysis of SiO₂@CaTiO₃:Dy³⁺_{(3 mol %)}:Li⁺_{(0.25–1 mol %)} core shell nanoparticles (C–S NPs) were carried out. CaTiO₃:Dy³⁺ _{(3 mol %)}, Li⁺ _{(0.25–1 mol %)} NPs were prepared using low temperature solution combustion method. C–S structured samples were synthesized using SiO₂ in equal weight quantities. All samples were characterised by powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) in order to study and compare its structural properties. Photoluminescence (PL) properties of uncoated and SiO₂ coated samples were studied in detail and optimum luminescence behaviour was investigated. Higher luminescence intensity is observed for codoped CaTiO₃:Dy³⁺_{(3 mol %)}:Li⁺_{(0.5 mol %)} sample. Further enhancement was observed in SiO₂@CaTiO₃:Dy³⁺:Li⁺ structured nanoparticles. Emission spectra of SiO₂@CaTiO₃:Dy³⁺_{(3 mol %)}:Li ⁺_{(0.25–1.0 mol %)} C–S nanophosphors exhibit white emission dominated by ⁴F_9/2 → ⁶H_13/2 (570 nm) transition of Dy³⁺ ions under. All the results suggested that the present material provides a platform for fabricating new functional materials which can be applied in the field of wLEDs and solid state display applications.     

色度学理论的建立及在钛白粉颜色测量中的应用

介绍了CIE标准色度学系统的建立及理解,给出了钛白粉颜色测量中各指标的计算公式。     

Quantitative representation of floral colors

Human and insect pollinator perceived floral colors of 81 species of angiosperms (flowering plants) from Trivandrum (Kerala, India) was represented using the CIE 1976 L*a*b* color space and color hexagon, respectively. The floral color difference among human perceived red, yellow, and blue‐hued flowers and that of each flower from its respective pure hue was calculated using the CIE ΔE 2000 formula. Human perceived floral color difference values were consistently higher than 3.5, indicating the uniqueness of floral colors. Flowers perceived red and yellow by humans were dominant and of comparable proportions. Insect pollinators perceive most of the flowers as blue‐green. Quantitative representation of human and pollinator perceived floral colors would be invaluable to understand the information broadcasted by flowers. It can form the basis of flower grading in the floriculture industry and underpin objectivity in evolving the framework for national pollinator strategies.