反射式电子书阅读器对比度的定义及测试分析

为了对反射式电子阅读器的显示质量进行合理测评,本文探讨了3种常用的D65光源、D50光源和A光源下不同对比度的定义:计量材料本身的光谱行为的对比度定义为反射率对比度Cρ;计量材料的反光行为和人眼的接收特性的对比度定义为反射率视觉对比度Cv;计量材料本身的光谱行为,同时计量光源和人眼的光谱光效特性的对比度定义为亮度对比度CL。通过测试实验选择的电子阅读器产品分析不同对比度之间的关联特性。实验结果表明,在常用光源下,CL和Cv线性相关,在表征该类阅读器的黑白对比度性能上具有等同的作用,考虑到CL进一步可用于衡量黑白对比度的绝对大小。     

火车票文字清晰度质量属性分析

火车票票面上文字具有足够的清晰度为最基本的要求。该文针对传统的纸质车票和新的背面涂有磁层的车票(分别称为纸票和磁票)正、背面上的文字清晰度属性指标进行了测试和分析。用文字中横、竖笔划线条的对比度、宽度和粗糙度三个主要指标表征组成文字基本单元的笔划清晰度属性;用对比度指标体现文字整体的清晰度性能。目前应用的纸票和磁票的平均实验结果表明,车票的正面文字中,纸票和磁票具有相当的笔划宽度和边缘粗糙度,但纸票的对比度高于磁票,因而具有较高的文字清晰度。磁票正面文字清晰度的提高需加大文字笔划的墨色暗度。车票的背面文字中,纸票白背景上的黑色文字笔划较磁票黑色背景上的白色文字笔划具有较高的对比度和较低的粗糙度,有利于纸票的文字清晰表现;但后者的笔划宽度大于前者。整体上,纸票背面的文字清晰度高于磁票;磁票背面文字清晰度的改善有待于其文字笔划对比度的提高和边缘粗糙度的降低。     

陶瓷原料质量评价方法研究

陶瓷原料质量受诸多因素影响,合适的原料是生产优质陶瓷产品的保证。本文通过一系列的应用研究,探讨了陶瓷原料的质量评价方法,以保证选取适当的陶瓷原料,为生产出高质量的陶瓷产品奠定基础。     

炼焦煤质量综合评价方法研究

依据炼焦企业的生产需求,基于层次分析法和两两比较法建立了炼焦煤质量评价体系,以及影响炼焦煤质量各影响因子的评分标准,并对云南煤业能源股份有限公司安宁分公司使用的炼焦煤进行了客观的评价。     

卫生洁具浆料质量评价方法的研究

本文在参考相关文献、结合工厂自身实际并借鉴其他公司先进做法的基础上,研究建立了一套系统的卫生洁具浆料质量评价方法,该评价方法涵盖了与浆料质量有关的大部分重要指标,并视其重要程度赋予不同的得分权重,最后以打分的方式评估出浆料质量的得分。经过长时间试运行,采用该评价方法得出的结果真实可靠,可科学客观的评价浆料质量的优劣,既可以用于企业自身纵向对比,也可用于不同企业间参照对比互找不足,为生产上改进浆料提供方向。     

混煤质量评价方法的研究与应用

建立在传统的单种煤基础上的配煤炼焦理论难以适应现代煤源状况,必须依据中国煤炭分类的原则和商品煤反射率分布图来确定炼焦煤的黏结性和结焦性,鉴别其混煤的程度,正确评价混煤的性质及其在炼焦配煤中的作用,通过小焦炉炼焦,制定合适的配煤方案。试验表明,合理利用混煤配煤炼焦,可以消除混煤对炼焦配煤的不利因素,生产出高质量的焦炭,满足高炉生产的要求。     

装配式房屋建筑施工质量风险评价方法研究

装配式房屋建筑施工过程存在风险隐患,需要一种装配式房屋建筑施工质量风险评价方法。搭建风险评估指标体系确定质量风险因素,计算确定评估指标权重,通过物元分析构建风险评估模型,以此实现装配式房屋建筑施工质量风险评价。结果表明：案例工程风险评估的综合特征值为2.1516,其施工质量为一般风险Ⅲ级别,检测的准确度可以达到90%。     

水环境质量评价方法浅析

对指数评价法、灰色评价法、模糊评价法、层次分析法等几种常见的水环境质量评价方法进行了综述介绍,评述了各自的优缺点,并介绍了各种评价方法的改进情况。     

我国配合煤质量与评价方法研究

选取了国内１４家焦化厂的生产配煤，在实验室条件下，研究了各配煤对所得焦炭质量的影响并提出了质量评价模型。     

桥梁维修加固后质量评价方法研究

因为桥梁时间长了可能老化、设计结构不能满足现在的交通运行,受到环境因素的影响,要求在使用一段时间后对其进行维护稳定,但是维护固定的质量没有一定的标准要求。在此主要介绍几种常用的维护桥梁的方法,使用的方法包括层次分析法、贴近度法、模糊评价法,构建相关体系,对维护后的成功进行评估,结合具体工程实例对维护固定进行指导。     

A shift of the perceptual attributes of color due to the manifestation of the simultaneous contrast effect on a display

This research shows the effect of simultaneous contrast on a design solution that generates it, and it also shows how its manifestation affects the shift of perception attributes of the observer's color. In the conducted research, 55 subjects had to harmonize the primary stimuli from the reproduction obtained with the help of digital printing technology, with the primary stimuli presented on two computer screens. As a visual harmonization technique, simultaneous binocular harmonization was used. The primary stimuli were made achromatic, with a 50% Raster Tone value (RTV), and are surrounded by achromatic secondary stimuli whose values increase in steps from 10% RTV up to 100% RTV. A shift in the perceptual attributes of color has been shown with the help of the CIEDE2000 system. Using ANOVA with repeated-measures and Fisher's post hoc analysis, statistically significant differences were found between the perceived means of shift in the ΔC₀₀ chroma and ΔL₀₀ lightness on defined samples on both computer screens, while in the case of the ΔH₀₀ hue, no statistically significant differences were observed. The research also determined colorimetric differences in the ΔE₀₀ color difference. Moreover, the student's t test was used to determine that the effect is stronger when manifested on the Lenovo computer than on the Asus computer screen (P < .05).     

Complexity of the color appearance of objects with nonuniform illumination

An inversion relationship is clarified between lightness and brightness, and also between chroma and colorfulness under nonuniform illumination with different illuminance levels (high and low) within the same visual field. Brightness (or colorfulness) of object color with low lightness (or chroma) under high illuminance level is perceived higher than that of another object color with high lightness (or chroma) under low illuminance level. Two color images are given for showing the inversion phenomena on brightness–lightness and colorfulness–chroma between object colors under different illuminance levels. These color images are useful for making researchers on color understand the differences in concept between brightness and lightness, and also between colorfulness and chroma. In particular, the concept of colorfulness is important, but difficult to understand. © 2007 Wiley Periodicals, Inc. Col Res Appl, 32, 372–377, 2007     

纤维过滤板质量评价方法的探索

以蚓激酶料液和纯化水为实验介质,探索了过滤板质量的评价指标及检测方法,为建立有效的过滤板质量评价体系奠定了基础.蚓激酶料液实验表明,滤速与过滤板的除杂能力密切相关,滤板滤速越慢,除杂能力越强.0.05 MPa的纯化水实验表明,纤维过滤板滤速受到诸多自身因素影响,滤板重量越大,灰分值越高,紧度越大,滤速越慢,除杂能力也越强.操作压力也是一个影响过滤板滤速及除杂效果的重要参数,操作压力越高,滤液浊度也越大,滤板除杂效率越差,同时纯化水实验结果表明操作压力与过滤板滤速存在近线性关系.     

Visual comfort as a function of lightness difference between text and background: A cross‐age study using an LCD and a tablet computer

Two experiments were performed to investigate the effects of text‐background lightness difference on visual comfort. A panel of 21 young and 20 older observers in Taiwan participated in Experiment I, using an LCD TV (with a display luminance of 551.8 cd/m²) as the presentation media. The results show that on a light background, visual comfort increases as the lightness difference gets larger and larger. On a dark background, however, the highest visual comfort value can be obtained when there is a moderate lightness difference. There seems to be little effect of age on visual comfort using the LCD TV with regard to the lightness difference. In Experiment II, 20 young and 20 older Taiwanese observers participated, using a tablet computer (with a display luminance of 397.3 cd/m²). According to the results, the larger text‐background lightness difference, the higher visual comfort value for older observers. For young observers, however, the highest visual comfort value can be obtained when there is a moderate, rather than extremely high, lightness difference. These findings can help provide useful guidelines for graphic user interface design in modern e‐reading devices. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 125–134, 2015     

综合水质指数法对滴水湖水质的评价

正确认识和评价滴水湖水质的变化特征是进行水环境管理的前提。通过监测2006-2009年滴水湖水体溶解氧(DO)、高锰酸盐指数(CODMn)、五日生化需氧量(BOD5)、氨氮(NH3-N)以及总磷(TP)等5种主要污染因子的月度变化,利用综合水质污染指数法进行了比较评价。结果表明2006-2009年间滴水湖湖区整体水质已达到地表水IV类水标准(GB 3838—2002),水质状况有明显好转;有机污染物和总磷是滴水湖水体主要污染因子。     

Considerations on the calibration of color displays assuming constant channel chromaticity

To calibrate a CRT color monitor, several assumptions are often made about its performance, one of the most accepted being constanel channel chromaticity. However, when the measurements are taken in a extended field of CRT screen, where it is assumed that only one primary phosphor is excited, the relative spectral radiance of the other primary phosphors that are contained in that field also contributes, if the background luminance is not zero. This contribution is greater at low levels of RGB channel stimulation and would invalidate the results obtained with calibration methods based on the hypothesis of constancy of chromaticity coordinates of RGB channels. We have studied this effect on the calibration of the CRT color monitor and, as a result, we propose a calibration that takes this effect into account. to evaluate the accuracy of the method, we have calculated color differences between the chromaticity that we wanted to reproduce and the one displayed with the CIELUV color-difference formula, and the color tolerances with the line element of MacAdam ellipses.     

Effects of surrounding brightness on visual search for safety colors

The present article reports the investigation of the effects of surrounding brightness on a visual search for three safety colors: red, orange, and yellow. Images of visual stimuli consisting of an array of colored circles placed on a large visual field (a visual angle of 40°) were displayed on an 80‐in. screen with a DLP projector. Experiment I examined the search efficiency under three levels of background luminance that were equivalent to the three target luminances. The results showed that the search efficiency for the orange target decreased as the number of distractors increased, under each of the background luminance levels, whereas the efficiency scarcely decreased for the red and yellow targets. Although a reduction in background luminance increased the search efficiency for the orange target, it is suggested that the effect of background luminance is smaller than the effect of the target color in search efficiency. Experiment II examined the search efficiency under three conditions of low levels of incident illuminance, which were matched with a linear regression to the luminance of color chips of safety colors measured twilight conditions. The results showed that the search efficiency for the orange target decreased as the number of distractors increased under each of the different illuminance conditions, whereas the efficiency scarcely decreased for red and yellow targets. Furthermore, as illuminance decreased, the search time for the orange target was more greatly impacted than for red or yellow. These results imply that the recognition of orange tends to be influenced by the surrounding brightness. © 2005 Wiley Periodicals, Inc. Col Res Appl, 30, 400–409, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/col.20152     

高盐度水质中微量镍的检测方法探讨

在火焰原子吸收分析的原子化过程中形成的固体颗粒对光的散射以及基体分子对光的吸收统称为背景吸收,它叠加在待测原子真实吸收之上产生正干扰,待测试液和标准试液物理性质的差异又会产生物理干扰,这两种干扰往往同时存在,给分析带来很大的误差。现讨论利用标准加人法消除物理干扰的功能和双谱线扣背景法扣除背景干扰的原理,可以同时将两种干扰消除,本方法很适用于无扣除背景干扰功能的普通火焰原子吸收分光光度计对于高盐度水质中微量元素的检测。     

色差法确定化学反应终点的研究

建立用色差法确定化学反应终点的分析方法,探索色度学在化学分析中的应用。应用色度学理论,利用色差计测定反应终点前后的颜色变化(色差ΔE),作ΔE—Vol曲线,Δ1E/ΔVol1—Vol曲线及Δ2E/ΔVol2—Vol曲线,用内插法计算求得反应终点的滴定液消耗的体积数。用该法测定的滴定液体积数与常规方法结果相符合。该方法消除了由于人眼对颜色的敏感程度不同而造成的对反应终点的判断偏差。实验结果客观,准确,若结合该方法制造出自动色差滴定仪,则使化学分析方法更客观,更准确,更方便。