矿石中金的快速测定

研究了活性炭纤维滤布富集分离的条件和解脱方法,并利用微波溶样、液珠萃取比色法测定矿石中的金。该方法的测定范围为(0.5~xx)×10-6,相对标准偏差RSD为3.2%,可用于矿石中金的野外快速测定。     

Bandwidth correction for LED chromaticity

The spectral bandwidth formulae of Stearns and Stearns   are generalized for an arbitrary slit function. Correction coefficients are derived in terms of moments of the slit function. Application to model LED spectra measured with a compact, fiber‐coupled spectrometer having bandwidth of order 12 nm, and a nonlinear wavelength scale shows that accurate LED color measurements may be obtained with such an instrument. Fitting of the relatively broad slit function to line spectra for accurate wavelength calibration is also described. Such fitting, coupled consistently with the bandpass correction, improves the accuracy color measurements with a broad‐response spectrometer. © 2006 Wiley Periodicals, Inc. Col Res Appl, 31, 374–380, 2006; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20242     

NIST 0:45 reflectometer

The NIST 0:45 reflectometer measures the spectral reflectance factor at an influx angle of 0° and an efflux angle of 45° of colored, nonfluorescent specimens at room temperature, with widths ranging from 3 to 10 cm and heights from 3 to 20 cm and with an uncertainty of less than 0.5 in color difference units. Published in 2008 by John Wiley & Sons, Inc. Col Res Appl, 33, 94–99, 2008     

Uncertainty analysis for the NIST 0:45 Reflectometer

Sets of color tiles are available from the National Institute of Standards and Technology calibrated using the NIST 0:45 Reflectometer. The uncertainties associated with the measured values for the color tiles are an indispensable component of the calibration report that accompanies these tiles. A systematic, analytical approach developed previously was applied to the particular case of the reference instrument and color tile set, taking into account the operation and characteristics of the instrument and the spectral properties of the set. The primary sources of uncertainty were identified, and the resulting uncertainties in the color space values L*, a*, and b* were determined. In general, the uncertainties are lowest for those color tiles whose reflectance factors are nearly constant with wavelength. Published in 2008 by John Wiley & Sons, Inc. Col Res Appl, 33, 100–107, 2008     

BC—1型白平衡仪的原理与实践

ＢＣ－１型白平衡仪是一种光电积分式测色仪器，它通过颜色传感器获取屏幕的红，绿，蓝三条色信号，与预先存储在仪器中的标准信号值相比较通过ＬＥＤ条形显示器显示两者之偏差，用以直接指导彩电生产线的白平衡调整，仪器采用Ｉｎｔｅｌ１８０９８单片微机为系统核心，内藏信号发生器，仪器可任选红，绿，蓝作为基准色，具有基色亮度自动调整功能，该仪器的定标方法简单，快捷，可方便地存储８套基准白场标准数据，该仪器已可靠在应     

Chromatic luminance,colorimetric purity,and optimal aperture‐color stimuli

Chromatic luminance (i.e., luminance of a monochromatic color) is the source of all luminance, since achromatic luminance arises only from mixing colors and their chromatic luminances. The ratio of chromatic luminance to total luminance (i.e., chromatic plus achromatic luminance) is known as colorimetric purity, and its measurement has long been problematic for nonspectral hues. Colorimetric purity (p_c) is a luminance metric in contrast to excitation purity, which is a chromaticity‐diagram metric approximating saturation. The CIE definition of p_c contains a fallacy. CIE defines maximum (1.0) p_c for spectral stimuli as monochromatic (i.e., optimal) stimuli, and as the line between spectrum ends for nonspectrals. However, this line has <0.003 lm/W according to CIE colorimetric data and is therefore effectively invisible. It only represents the limit of theoretically attainable colors, and is of no practical use in color reproduction or color appearance. Required is a locus giving optimal rather than invisible nonspectral stimuli. The problem is partly semantic. CIE wisely adopted the term colorimetric purity, rather than the original spectral luminance purity, to permit an equivalent metric for spectrals and nonspectrals, but the parameter of equivalence was never clear. Since 1 p_c denotes optimal aperture‐color stimuli for spectrals, arguably 1 p_c should denote optimal stimuli consistently for all stimuli. The problem reduces to calculating optimal aperture‐color stimuli (“optimal” in energy efficiency in color‐matching) for nonspectrals, shown to comprise 442 + 613 nm in all CIE illuminants. This remedy merely requires redefinition of 1 p_c for nonspectrals as the line 442–613 nm, and gives meaningful p_c values over the hue cycle allowing new research of chromatic luminance relations with color appearance. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 469–476, 2007     

Effects of the International Temperature Scale of 1990 (ITS-90) on CIE Documentary Standards for Radiometry,Photometry, and Colorimetry

The differences between ITS-90 and IPTS-68 above 1235 K are described. It is shown that none of the following CIE definitions or recommendations require revision because of the introduction of the ITS-90: International Lighting Vocabulary definitions; CIE Standard Illuminants A, D₆₅, other illuminants; and sources for realizing CIE Illuminants. The effect of the ITS-90 on previously calibrated sources for realizing CIE illuminants is negligibly small.²     

Evaluating the 1931 CIE color‐matching functions

The use of colorimetry within industry has grown extensively in the last few decades. Central to many of today's instruments is the CIE system, established in 1931. Many have questioned the validity of the assumptions made by Wright¹ and Guild,² some suggesting that the 1931 color‐matching functions are not the best representation of the human visual system's cone responses. A computational analysis was performed using metameric data to evaluate the CIE 1931 color‐matching functions as compared to with other responsivity functions. The underlying assumption was that an optimal set of responsivity functions would yield minimal color‐difference error between pairs of visually matched metamers. The difference of average color differences found in the six chosen sets of responsivity functions was small. The CIE 1931 2° color‐matching functions on average yielded the largest color difference, 4.56 ΔE. The best performance came from the CIE 1964 10° color‐matching functions, which yielded an average color difference of 4.02 ΔE. An optimization was then performed to derive a new set of color‐matching functions that were visually matched using metameric pairs of spectral data. If all pairs were to be optimized to globally minimize the average color difference, it is expected that this would produce an optimal set of responsivity functions. The optimum solution was to use a weighted combination of each set of responsivity functions. The optimized set, called the Shaw and Fairchild responsivity functions, was able to reduce the average color difference to 3.92 ΔE. In the final part of this study a computer‐based simulation of the color differences between the sets of responsivity functions was built. This simulation allowed a user to load a spectral radiance or a spectral reflectance data file and display the tristimulus match predicted by each of the seven sets of responsivity functions. © 2002 Wiley Periodicals, Inc. Col Res Appl, 27, 316–329, 2002; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.10077     

比色法测定巴西虫草菌丝体中虫草酸的含量

利用比色法简便、准确和快速地测定了巴西虫草菌丝体中虫草酸的含量.结果表明,虫草酸即D-甘露醇的最大特征吸收峰在412 nm处,质量浓度在10～50 mg/L范围内线性良好,它的线性回归方程为:Y=0.0102X-0.00029,R2=0.9989;仪器精密度良好,RSD为0.35%(n=6);样品显色后在180 min内基本没变化;平均回收率为100.30%,RSD为1.44%(n=5);干扰试验表明在葡萄糖、鼠李糖和果糖中,只有果糖对检测结果有较大影响.通过果糖的特征吸收峰和高效液相色谱法表明,巴西虫草菌丝体中没有果糖的存在,验证了比色法测定巴西虫草菌丝体中虫草酸含量的准确性;用该方法测定的巴西虫草菌丝体中虫草酸的质量分数为8.45%,RSD为0.34%(n=6).     

彩色亮度设计及其在颜色仿真中的应用

本文基于颜色仿真的要求,设计了彩色亮度计并编制了计算机程序进行颜色存储,可作为颜色标准和物体色的计算机存储,介绍了设计的思路,描述了系统硬件,软件以及为检测微弱信号,提高系统可靠性所采取的各种措施,改进了色度修正的方法并给出了相应公式。