土壤颜色由CIE向Munsell系统的定量转换

颜色是土壤重要形态特征之一,也为判断土壤理化特征、过程与功能的重要依据和指标。土壤颜色目前采用Munsell颜色系统表示,主要依靠将土壤样品与土壤Munsell比色卡比对而确定。该方法由于受个人视觉感官和判别环境等因素限制,导致土壤颜色判别结果存在主观性强,易出现偏差等问题。为此,寻求客观、定量、方便地表征土壤Munsell颜色的方法,对于今后有关土壤颜色应用的研究工作极为重要。该研究试图利用分光色度仪,结合Python计算机语言编程,采用邻近等明面插值等方法,提出了一套可操作的从CIE到Munsell颜色系统转换的方法,以实现土壤颜色从CIE到Munsell颜色系统的方便、快速、高精度转换,达到土壤颜色的客观、定量、标准化测定。由分光色度仪测得样品CIELAB颜色值,利用CIE和Munsell两大颜色系统的已有的转换模型和方法,由CIELAB值计算获得Munsell明度值V和色品坐标,以Python语言编制程序,实现样品的明度值和色品坐标的自动计算。进而采用邻近等明面数学插值法和色度变换图确定Munsell系统H和C值。以《中国标准土壤色卡》的419张色片和22个土壤与古土壤样品进行验证,结果表明利用本文方法色调（H）测定值与色片标准值相比较,仅有12张色片存在误差,验证准确率为97%。《中国标准土壤色卡》的明度值（V）、彩度值（C）测定值与标准值之间相关系数分别为0.987（p＜0.001）和0.976（p＜0.001）,测定结果与标准值之间存在极显著相关关系。土壤与古土壤样品测定值与目视判别色调差异较小,主要差别是明度和彩度,这可能与目视判读受个人主观、光学环境等因素影响所致。基于过去已有的由CIE到Munsell颜色系统转换方法,该研究利用Python计算机语言编程编写了程序代码,实现CIELAB值到Munsell明度V值和色品坐标的转换过程的自动计算,并提出一种基于邻近等明面新的插值方法,转换步骤简明,易实现,为土壤颜色的快速、定量获取提供途径。     

染色温度对叶绿素铜钠盐上染蚕丝织物的影响

研究了染色温度对叶绿素铜钠盐上染蚕丝织物的上染速率、染色织物颜色特征值及色牢度的影响。结果表明,在40—90℃染色温度范围内,当温度为70℃时,叶绿素铜钠盐上染蚕丝初期上染速率、平衡上染率均最大,染色蚕丝织物最为深绿;叶绿素铜钠盐染色蚕丝织物具有很好的耐洗和耐摩擦牢度（4级及以上）,但其耐日光色牢度较差（2—3级）;提高染色温度、延长染色时间对染色蚕丝织物的耐日光色牢度没有明显影响。叶绿素铜钠盐染色蚕丝织物适宜制作高档的居家服饰。     

纤维上染料的FT-Raman光谱法研究

本文采用近红外傅立叶变换拉曼光谱技术（NIR FT－Raman)对27种染色纤维样品进行了检验，同时得到了它们的本底纤维和染料的拉曼谱图，然后利用计算机谱图处理程序进行拉曼差谱处理，获得了染色纤维上染料的拉曼谱图，由此能够实现对纤维上染料的鉴定，根据染料分子的拉曼光谱的特征将24种染色纤维按局部结构特征分为7类，有助于同色纤维上染料的鉴别，该方法快速、简便，灵敏度高，不需从纤维上提取染料。     

苦瓜果实中盐酸小檗碱的提取工艺

以新鲜苦瓜为原料,用盐酸小檗碱为对照品,正交设计优化苦瓜中盐酸小檗碱提取条件,采用超声波和水浴提取法等2种工艺提取苦瓜中盐酸小檗碱,研究单因素对盐酸小檗碱提取率的影响,确定提取盐酸小檗碱的最佳条件.水浴提取苦瓜盐酸小檗碱以A2C1B1组合为最佳提取条件,提取率为5.1642mg/g.超声波提取苦瓜盐酸小檗碱以A3B2C2组合为最佳提取条件,提取率为6.3267mg/g.实验结果表明,超声波法提取效果优于水浴提取法.     

色度分析仪的原理与在彩扩中的应用

色度分析仪的原理与在彩扩中的应用胡耀民，陈晓白（北京轻工业学院北京１０００３７）为了获得一张颜色逼真，色彩还原性好的照片，在扩印中色彩校正是非常关键的一步．只有经过正确的校色才能制出色彩还原好的彩色照片．手工校色非常繁琐，费时费力，效率很低．色度分析...     

黄连不同提取物的红外光谱研究

中药提取物是传统中药融合现代制药技术的新型产品,具有广泛的国际市场。建立快速、有效的分析方法有助于中药提取物的实时质量监控。文章利用傅里叶变换红外光谱技术(FT-IR)对黄连药材、水提物和醇提物作了研究。结果表明：黄连药材及其提取物有着各自稳定的光谱特征,谱图中位于1 505 cm-1的芳环骨架振动峰是判断盐酸小檗碱在不同黄连样品中含量高低的主要依据,而相应的二阶导数谱图可以大大提高原始谱图的分辨率。黄连药材经过提取,以小檗碱为代表的主要活性成分得到有效富集,两种提取物中小檗碱的含量明显增高;黄连醇提物中小檗碱的含量又明显高于其水提物。FTIR能够简便、快速地提供中药提取物中主要化学成分的定性与半定量信息,从而为后续的化学成分分析和中药提取分离工艺的改进提供有效参考。     

等色染料离子对浮选光度法研究-四溴荧光素*罗丹明6G体系

本文研究了四溴荧光素（ＴＢＦ）、罗丹明６Ｇ（Ｒ６Ｇ）等色染料离子对浮选光度法测定锗、铂和铁的方法。首先将被测金属离子形成的［ＭｅＬｎ（Ｒ６Ｇ）ｍ］（Ｌ：配位体,ｍ、ｎ为整数）有机溶剂浮选物,用碱解析并反萃于水相。而后加入与罗丹明６Ｇ等色的四溴荧光素溶液继续浮选,将形成的等色染料离子对Ｒ６ＧＴＢＦ浮选物溶解于丙酮。于５３０ｎｍ处测定吸光度值。由于２ｍ个染料同时吸收同一波长的光,而提高了方法灵敏度。测定Ｇｅ、Ｐｔ和Ｆｅ的摩尔吸光系数均在１０５Ｌｍｏｌ－１ｃｍ－１以上     

涂料颜色配方预测的人工神经网络模型实验研究

人工神经网络技术近年来在颜色空间变换或色域映射的研究中显示了特有的效果。人工神经网络用于粉末涂料配方的预测,其特点是用BP算法神经网络建立粉末涂料反射样品的标准色度参数与配方浓度参数之间的映射关系。通过对典型颜色样本训练和预测,结果表明基于多隐层BP网的模型可以实现粉末涂料样品的配方浓度空间与标准三刺激值颜色空间的相互映射,即用BP网络实现粉末涂料的配方预测。     

一种色度自适应投影标记点的选取方法

近年来,对物体的颜色显现力、光源光谱功率分布和自身表面反射光谱三者的定量关系方面的研究备受大家关注。在三维扫描测量领域,由于颜色特征具有反映物体材料和纹理等丰富信息的优势,提出了一种主要由彩色相机、投点光源和PC机组成的色度自适应投点仪结构,其中数字微镜(DMD)作为投点光源的核心元件用于调制R,G,B 三个LED光源的光谱功率分布。然而主动式标记点的颜色显现力因受未知反射光谱投影接受面的影响,其颜色特征往往难以识别和区分。为了提高投影标记点与不同反射光谱的投影接收面作为背景的分辨力,描述了一种色度自适应投影标记点的选取方法。在高维线性反射光谱建模的基础上,用光谱响应的方法对彩色投点仪设备特征化,以解决三通道彩色相机设备特征化精度低的问题。并通过样本训练为高维线性反射光谱的求解提供条件约束。继而,在CIE1931色度坐标空间下,选取与投影接收面背景色度坐标欧氏矩最大的色度坐标点。根据投点仪设备特征化结果,推导其LED最优设定值。最后,采用24孟塞尔色卡作为被投影对象,主动标记点与色块的色差作为其颜色显现力的评价参数,通过与激光二极管投点仪做对比性实验。实验结果表明对各不同色度的投点接受面,提出的色度自适应投影标记点的选取方法均有较好表现。     

中国岫岩玉的致色机理及色度学研究

通过岫岩玉的成分、过渡金属离子的价态及配位状态来研究岫岩玉的致色机理。电感耦合等离子原子发射光谱(ICP-AES)结果显示样品中除了铁和锰,几乎没有其他过渡金属元素。电子顺磁共振谱(EPR)则揭示了位于八面体晶格上的Mn2+和位于四面体和八面体晶格上的Fe3+,而吸收光谱(OAS)则证实了Fe2+和Fe3+的共同存在。分析结果表明Fe2+对岫玉的绿色起主要作用而岫玉的黄色则是由Fe2+和Fe3+的共同作用决定的。此外通过漫反射光谱(DRS)计算出岫玉的色度坐标,对比发现人眼感觉颜色类似的样品其实色度坐标有很大差异。因此可以通过色度坐标来定量区分岫玉颜色的差异,这具有一定的学术价值和经济价值。     

Investigation of natural dyes and ancient textiles from korea using TOF-SIMS

The identification of the colorants used on ancient textiles provides a historical pathway to the understanding of the processes associated with one of the oldest of chemical technologies, namely textile dyeing. In this paper, time-of-flight secondary ion mass spectrometry (TOF-SIMS) was used to detect dyes on textiles avoiding the time-consuming and destructive extraction procedures necessary for the spectrophotometric and chromatographic methods previously used. The plant dyes investigated belong to a variety of chemical groups, which include curcumin, crocin, carthamin, purpurin, alizarin, brazilin, shikonin, and indigo. Reference textile samples were prepared with dye extracts of plants and were characterized by TOF-SIMS. TOF-SIMS spectra for the dyed textiles showed element ions from metallic mordants, specific fragment ions, and molecular ions from organic dyes. Remnant dyes on excavated textiles have also been identified using TOF-SIMS. The ancient textile sample showed the presence of indigo clearly, although the fiber itself had degraded badly. From the results, it was concluded that most of plant dyes can be identified with TOF-SIMS and it is a very promising technique for the archaeology field.     

Polyester Fabric’s Fluorescent Dyeing in Supercritical Carbon Dioxide and its Fluorescence Imaging

As one of the most important coumarin-like dyes, disperse fluorescent Yellow 82 exhibits exceptionally large two-photon effects. Here, it was firstly introduced into the supercritical CO₂ dyeing polyester fabrics in this work. Results of the present work showed that the dyeing parameters such as the dyeing time, pressure and temperature had remarkable influences on the color strength of fabrics. The optimized dyeing condition in supercritical CO₂ dyeing has been proposed that the dyeing time was 60 min; the pressure was 25 MPa and the temperature was 120 °C. As a result, acceptable products were obtained with the wash and rub fastness rating at 5 or 4–5. The polyester fabrics dyed with fluorescent dyes can be satisfied for the requirement of manufacturing warning clothing. Importantly, the confocal microscopy imaging technology was successfully introduced into textile fields to observe the distribution and fluorescence intensity of disperse fluorescent Yellow 82 on polyester fabrics. As far as we know, this is the first report about supercritical CO₂ dyeing polyester fabrics based on disperse fluorescent dyes. It will be very helpful for the further design of new fluorescent functional dyes suitable for supercritical CO₂ dyeing technique.     

Effects of ultrasonic energy on dyeing of polyamide (microfibre)/Lycra blends

Although ultrasonic energy is widely used cleaning and degreasing of parts and assemblies in automotive and other industries, the use of ultrasonic energy in an industrial scale for textile washing is very new. This is due to the complexity of controlling the combination of chemical and mechanical effects, whereas with degreasing of machine parts only the mechanical effects is applied. The use of ultrasonic energy in dyeing PA/Lycra fabrics with reactive dyes has been studied spectrophotometrically in this work. PA/Lycra (85/15) blends have been dyed using conventional and ultrasonic dyeing techniques with three reactive dyes containing different chromophore and reactive groups. The dyeing carried out conventionally and by the use of ultrasonic techniques. The results were compared in terms of percentage exhaustion; total dye transferred to the washing bath after dyeing and the fastness properties.     

Ecofriendly laccase–hydrogen peroxide/ultrasound-assisted bleaching of linen fabrics and its influence on dyeing efficiency

This study evaluates the bleaching efficiency of enzymatically scoured linen fabrics using a combined laccase–hydrogen peroxide bleaching process with and without ultrasonic energy, with the goal of obtaining fabrics with high whiteness levels, well preserved tensile strength and higher dye uptake. The effect of the laccase enzyme and the combined laccase–hydrogen peroxide bleaching process with and without ultrasound has been investigated with regard to whiteness value, tensile strength, dyeing efficiency and dyeing kinetics using both reactive and cationic dyes. The bleached linen fabrics were characterized using X-ray diffraction and by measuring tensile strength and lightness. The dyeing efficiency and kinetics were characterized by measuring dye uptake and colour fastness. The results indicated that ultrasound was an effective technique in the combined laccase–hydrogen peroxide bleaching process of linen fabrics. The whiteness values expressed as lightness of linen fabrics is enhanced by using ultrasonic energy. The measured colour strength values were found to be slightly better for combined laccase–hydrogen peroxide/ultrasound-assisted bleached fabrics than for combined laccase–hydrogen peroxide for both reactive and cationic dyes. The fastness properties of the fabrics dyed with reactive dye were better than those obtained when using cationic dye. The time/dye uptake isotherms were also enhanced when using combined laccase–hydrogen peroxide/ultrasound-assisted bleached fabric, which confirms the efficiency of ultrasound in the combined oxidative bleaching process. The dyeing rate constant, half-time of dyeing and dyeing efficiency have been calculated and discussed.     

Physicochemical characterization of thermally aged Egyptian linen dyed with organic natural dyestuffs

A number of organic natural dyestuffs used in dyeing in ancient times, i.e. indigo, madder, turmeric, henna, cochineal, saffron and safflower, have been used to colour Egyptian fabrics based on linen. Their physicochemical properties have been evaluated on thermally aged linen samples. The aged dyed linen samples were thoroughly examined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and tensile strength and elongation measurements. It was found that, in the molecular level, dyes interact mainly with the cellulose compounds of the aged linen while in the macroscopic level tensile and elongation parameters are altered. Tensile strength is positively related to the dye treatment while elongation depends specifically on the type of the dye used. Results converge that the dyed textiles did indeed play a role as protecting agents affecting strength and reducing thermal deterioration.     

Ultrasonic dyeing of cellulose nanofibers

Textile dyeing assisted by ultrasonic energy has attained a greater interest in recent years. We report ultrasonic dyeing of nanofibers for the very first time. We chose cellulose nanofibers and dyed with two reactive dyes, CI reactive black 5 and CI reactive red 195. The cellulose nanofibers were prepared by electrospinning of cellulose acetate (CA) followed by deacetylation. The FTIR results confirmed complete conversion of CA into cellulose nanofibers. Dyeing parameters optimized were dyeing temperature, dyeing time and dye concentrations for each class of the dye used. Results revealed that the ultrasonic dyeing produced higher color yield (K/S values) than the conventional dyeing. The color fastness test results depicted good dye fixation. SEM analysis evidenced that ultrasonic energy during dyeing do not affect surface morphology of nanofibers. The results conclude successful dyeing of cellulose nanofibers using ultrasonic energy with better color yield and color fastness results than conventional dyeing.     

Ultrasound energy to accelerate dye uptake and dye–fiber interaction of reactive dye on knitted cotton fabric at low temperatures

Acoustic cavitation formed due to propagation of ultrasound wave inside a dye bath was successfully used to dye cotton fabric with a reactive dye at lower temperatures. The energy input to the system during sonication was 0.7 W/cm². This was within the energy range that contributes towards forming cavitation during ultra-sonication. The influence of ultrasound treatment on dye particle size and fiber morphology is discussed. Particle size analysis of the dye bath revealed ultra-sonication energy was capable of de-agglomeration of hydrolyzed dye molecules during dyeing. SEM micrograph and AFM topographical image of the fiber surface revealed fiber morphology remains unchanged after the sonication. The study was extended in understanding the contribution of ultrasound method of dyeing towards achieving good color strength on the fabric, compared to the normal heating method of dyeing. Study showed color strength obtained using ultra sound method of dyeing is higher compared to normal heating dyeing. Ultrasound energy was able to achieve the good color strength on cotton fabric at very low temperature such as 30 °C, which was approximately 230% more than the color strength achieved in normal heating method of dyeing. This indicates that energy input to the system using ultrasound was capable of acting as an effective alternative method of dyeing knitted cotton fabrics with reactive dye.     

Degradation and toxicity reduction of textile dyestuff by ultrasound

Degradability of four textile dyes was investigated in deionized water solutions during 520 kHz ultrasonic irradiation. It was found that for all dyes, the rate of color decay was first order in the visible absorption of the dye, and related to the type of functional groups that characterized the chromophore in the dye molecules. The destruction of aromatic/olefinic carbons in azo dyes was slower than that of color--to be attributed to the priority of hydroxyl radical attack on the N=N bonds, and to the formation of numerous oxidation intermediates of organic character during the course of dye degradation. Toxicity analysis of the dye solutions prior to sonolysis revealed that "reactive" dyes were non-toxic, but "basic" ones were toxic at the test concentrations employed in the study. Significant degrees of toxicity reduction were accomplished along with color and aromatic carbon degradation.     

古代丝织品及古建彩画蓝色染料的微量及无损分析

染料分析是研究织物颜色老化变色的基础,同时对于了解我国印染工艺的发展有非常重要的作用。通过薄层色谱和拉曼光谱方法,对六个唐代丝绸样品的蓝色染料和故宫建福宫建筑彩画的蓝色物进行了分析,并对两种方法在文物上的适用性进行了比较。结果表明这些呈色物质均为靛蓝,靛蓝不仅作为染料被古人使用,也被当作颜料用于彩绘壁画,使用范围非常广范。两种分析的方法各有利弊,拉曼光谱是无损分析,薄层色谱需要样品量少,但可获得更多的信息。     

Fourier‐transform surface‐enhanced Raman spectroscopy (FT‐SERS) applied to the identification of natural dyes in textile fibers: an extractionless approach to the analysis

In the present study, an application of a silver colloid substrate in order to obtain Fourier‐transform surface‐enhanced Raman (FT‐SER) spectra of natural historical dyes is presented. In detail, we collected a spectral database from solutions of pure dyes and then we carried out extractionless both hydrolysis and non‐hydrolysis FT‐SERS analyses on wool fibers previously dyed in our laboratory and on ancient textiles. The term ‘extractionless’ refers to a method of SERS analysis applied directly on the fiber, thus avoiding the extraction of dyes from textile samples. The combination of a low‐energy source of radiation, as in the FT‐Raman technique, with SER spectroscopy can bring the important advantage of reducing the fluorescence typical of ancient samples and organic dyes. In some historical textile samples, for which SER spectra by use of visible excitation could not be obtained, the FT‐SER spectrum of an iron‐gall dye was recorded without hydrolysis, while, with an HF hydrolysis pre‐treatment on ancient fibers, madder, lac dye and brazilwood were clearly recognized. Copyright © 2014 John Wiley & Sons, Ltd.