A novel fluorescent sensor for Al~(3+) and Zn~(2+) based on a new europium complex with a 1,10-phenanthroline ligand

A new europium complex Eu(tta)₃Li(la)based on 1,10-phenanthroline derivative(Li=(2-(3,5-dimethoxyphenyl)-1 H-imidazo[4,5-f][1,10]phenanthroline),tta=2-thenoyItrifluoroacetone)was designed and synthesized.Its structure was characterized by¹H and¹³C NMR,elemental analysis,UV-vis,fluorescence spectra and single crystal X-ray diffraction.The crystal of the complex la belongs to monoclinic system with the space group P2_1/n.The europium complex la in the solid and in the solution displays the typical emission of Eu(III)ion centered at 612 nm as a result of the electric dipole transition(⁵D₀-?⁷F₂).It exhibits high quantum yield(20.42%),long lifetime(0.29 ms)and good CIE color coordinate(0.67,0.33)in solid.In addition,the complex shows high sensitivity and selectivity towards Al³⁺and Zn²⁺in methanol solution which can be attributed to the Al³⁺/Zn²⁺cation instead of Eu³⁺in the complex la.The LODs for Al³⁺and Zn²⁺were calculated to be 5.880×10^-7and 7.678×10^-8mol/L,respectively.Besides,the additions of Al³⁺and Zn²⁺express remarkable color changes from red to bright blue and ivory that can be clearly observed by the naked eye respectively.     

Mixing and Simplex Search for Optimal Illumination in Machine Vision

Mixed-color illumination affects the quality of images in industrial vision system and it is important to optimize color and intensity for image acquisition. This study used simplex search to find the optimal illumination in a short amount of time. A typical color mixer synthesized various color of lights by changing the inputs of RGB power LEDs and passing the lights through an optical system. The image quality under mixed-color illumination was calculated according to the sharpness. For the purpose of optimal illumination using simplex search, a probe network was organized with N + 1probing points for N inputs. The shape of the probe network, simplex, was varied through procedures of extension, contraction, and shrinkage. The inputs of the color mixer were changed until the size of the simplex became smaller than a threshold. The simplex search was tested for commercial semiconductor patterns, and was useful for finding the optimal illumination.     

Affective matches of fabric and lighting chromaticity

This study investigates the impact of lighting colors on subjective judgments of fabric: in particular, whether the influence of lighting varies depending on fabric types and color combinations. We conducted two visual assessments. In Study 1 (N = 44), eight illuminants and six types of fabric were presented as cloth stimuli. Derived from the literature review, four sets of adjectives (humble-luxurious, cool-warm, old-new, and not preferred-preferred) were used as metrics. In Study 2 (N = 41), five sets of fabric color combination swatches were assessed under lighting conditions that were identical to those of Study 1. Three bipolar scales (ordinary-characterful, classic-modern, and soft-rigid), were employed from factor analysis along with three unipolar scales (luxurious, preferred, harmonious with lighting). The results showed that hue characteristics of lighting and cloth types influenced participants' perceptions of the fabric. Overall, white lighting with 4000 K was the most preferred and luxurious lighting across various types of clothes, while a pinkish white with 4700 K (duv = −0.0127) was the best matched in every color combination. In addition, there were interaction effects between lighting colors, clothes types, and fabric color combinations with regard to each of the perceptual qualities. This study provides empirical evidence for optimally match lighting colors with fabric in the presentation of fabric goods.     

Estimation of illuminant chromaticity based on highlight detection for face images with varying illumination

Illuminant chromaticity estimation is required in the fields of the tracking and recognition of human faces, compensation and detection of skin color, image reproduction, and color constancy. This article proposes a simple and effective method to estimate the illuminant chromaticity using highlights from the face region. We first select the candidate points through the detection of highlights around the leftmost pixel of the rg chromaticity space from the facial images under various illuminant conditions and then estimate the illuminant chromaticity by averaging the chromaticities of the candidate points. To enhance the illuminant chromaticity estimation accuracy, we propose a more elaborate estimation method, which effectively readjusts the candidate points of the highlight regions according to the conditions derived from two ethnic and three illuminant groups. The experiment results show that our proposed method reliably estimates the illuminant chromaticity under various color temperatures and illuminant directions. © 2012 Wiley Periodicals, Inc. Col Res Appl, 39, 188–199, 2014     

Ce对玻璃光谱曲线及色度指标的影响

用CeO2及TiO2混合着色可以生产金黄色的玻璃,铈的用量及玻璃配合料氧化还原性都容易造成玻璃光学指标及色度指标的改变,使玻璃产生较大的色差。通过改变玻璃中铈的用量和氧化还原剂用量熔制玻璃样片,然后用CARY500分光光度计对玻璃样片进行光度及色度指标分析。结果表明:着色剂的用量、配合料的氧化还原性、萤石的添加量对玻璃的光学指标及色度指标都有较大影响。     

双通道PWM的冷暖白光LED混色模型研究

LED光色度的动态调节是实现智能照明的基础, 采用冷暖白光LED和双通道脉冲宽度调制(PWM)法,基于1931CIE标准建立混合光源模型,推导出混合光源色坐标、相关色温 、最大亮度、显色指数与双通道调制脉冲 占空比比值的关系式。采用暖白光(色温3282 K)和冷白光(色温12930K)两种白光LED进行 混色实验, 通过微控制器输出PWM信号控制LED驱动电源,改变冷色光和暖色光的比重,得到的混合 光源色坐 标、最大亮度、相关色温及显色指数值与理论计算值吻合很好,证明了理论模型的正确性。 理论和实验结 果还表明,混合光源在双通道调制脉冲占空比比值为1的附近可得到低色温、高显色性和大 光通量的混合白光。     

数显便携式测色仪设计

为了使牙齿健康美容领域中牙齿的配色更加精确,设计出一款以色度学原理为基础,应用白平衡调节手段,采用集成数字化电路及掌上结构设计的牙齿测色仪器。设备以正白光高亮LED为光源、mega128单片机为核心,采用TCS230可编程颜色传感器采集颜色信号,通过C语言编程来实现颜色数据的采集、显示以及存储。通过比色卡对比实验,分析了几种影响测量精确度的因素。仪器具有测量精度高、稳定度好、功耗低、便于携带等优点,具有广泛的应用前景及市场空间。     

实时单幅图片高光去除算法

单幅图片的高光去除是一个非常具有挑战性的课题。综述以往多数方法,一般需要进行图像分割等预处理,或者要求用户进行交互输入。采用的方法是从高光图片的颜色统计规律出发,发现了最大漫反射色度局部平滑这一特性;然后估计镜面反射像素最大漫反射色度,由基于线性模型对最大色度的值进行扩散传播,从图像中的漫反射像素传播到镜面反射像素;最后求出图像中每个像素的漫反射分量。与传统方法相比较,这种高光去除的方法效果较好,而且非常简单,适合并行,可以满足实时应用需要。