比色测温双波长的选择及滤波片最小带宽的计算

介绍了近红外CCD比色测温的基本原理,详细讨论了滤波片最小带宽的选择以及比色双波长的选择方法,并通过Matlab仿真计算确定了在给定温度范围内的最佳比色波长组合.     

非制冷红外焦平面阵列比色测温双波长的选择

非制冷红外焦平面阵列的工作波长一般为8～14 μm.通过添加特定波长的滤波片,可使非制冷红外焦平面阵列获得该波长的辐出度,从而利用比色测温的方法完成对工业产品在工业中低温范围内的精确测量.介绍了非制冷红外焦平面阵列比色测温的基本原理,详细讨论了在8～14 μm波长范围内选择最佳比色双波长组合的理论依据,用MATLAB仿真计算确定了工业中低温范围最佳双波长组合的选择原则.最后模拟(8.8 μm,10.6 μm)双波长组合的T- R(T)图像,模拟结果满足测温精度要求.     

比色测温理论中带宽对测量误差影响的研究

基于比色测温原理,论述了比色测温理论中的滤光片带宽,得出滤光片带宽对测温精度的影响很大,并不能简单的将峰值透过率波长代替整个带宽。然后通过考虑滤光片的带宽导出合理的比色测温算法,并通过实验证实此算法大大减小了测温误差。     

倍波长法测温技术的研究

研制出一种新型红外比色测温仪，其主要特点是工作波长λ2=2λ1， 即倍波长关系，与一般比色测温仪相比较，可以减小1%的测量误差，从而提高准确度1%，测温范围600～3000℃，研究了比辐射率问题，利用黑体探头校正比辐射率，可应用于冶金工业中。     

比色测温法的最优波段及测温精度的研究

目前火炮膛温测试存在测试难度大、精准度低和条件恶劣等问题。针对此类问题,本文设计了基于比色测温的火炮膛温测试系统。论证了波长的选择和标定误差是影响比色测温精度的两大重要因素,并通过分析波长与采集电压之间的灵敏度关系,得出最优波段为0960μm和1000μm,提高了比色测温法的测温精度。分别使用最小二乘法和遗传算法(GA)对实验数据进行拟合,对系统进行测试验证。结果表明:选择最优波长能够提高测温精度,遗传算法在精度上对比最小二乘法有明显提高,整体测量误差小于4 ‰。     

辐射测温仪的误差分析及设计考虑(二)

本文导出计算亮度温度计及比色温度计可能达到的最小可鉴别温差的公式、与此对应的带宽公式及灵敏度公式,并根据这些公式讨论设计辐射测温仪时应如何选取波长及带宽的问题。对比色法最佳工作波长的选取进行了讨论,并对典型样机的数据进行了分析比较。     

基于小波分析的比色测温波段选择

基于辐射测温原理,介绍了比色测温理论,为提高钢水的测温精度,对比色测温波长进行了最佳选择。搭建实验平台,获得了不同温度下的熔融金属辐射亮度曲线,通过小波去噪方法获得信噪比较高的亮度曲线,利用Matlab软件作出了波长选择的GUI界面。当滤波片中心波长选择为λ1=580nm,λ2=590nm时,测量误差满足了测量精度要求。     

比色测温理论中误差修正函数的研究

介绍了比色测温理论中的K值来源,通过实验对不同波长组合的K值进行分析,得出它随温度的变化而变化的规律,然后通过插值函数和最小二乘法对K值进行修正以减小比色测温误差,并对两种方法进行比较,得出:用插值函数进行修正在某段会出现较大误差,而利用最小二乘法对K值进行修正则能获得较好效果.     

光栅棱镜内调制比色测温仪研究

探讨了在内调制光电管的基础上使用光栅棱镜作为前端分色设备进行比色测温的方法,结果表明：与使用光纤分束作为前端分色设备的方法相比,其设备简单,并具有工作波长及其带宽选择灵活的优点,安全可以达到实用化的要求。     

用三片截止型玻璃滤光片实现比色测温

截止型玻璃滤光片具有光谱透射特性好，性能稳定，工作波长容易选择等特点。本文介绍了一种巧妙利用三片截止型玻璃滤光片实现比色辐射测温的方法。用该方法测温，具有灵敏度高，抗干扰能力强等特点     

Iridium‐Complex‐Modified Upconversion Nanophosphors for Effective LRET Detection of Cyanide Anions in Pure Water

Because of the extreme toxicity of cyanide anions, a great deal of effort has been invested in developing probes that use colorimetric and fluorometric methods to detect them. To date, most of the current optical probes require the use of organic solvents or a mixture of organic solvents and water. Upconversion nanophosphors (UCNPs) can serve as excellent emitters as a result of their sharp emission peaks and simple control of the emission wavelength. Here, the fabrication of hybrid material composed of iridium complex and UCNPs to detect cyanide anions selectively in pure water is described. In addition to the colorimetric detection, the upconversion luminescence emission can serve as a detection signal based on an effective luminescent resonance energy transfer (LRET) process within the hybrid nanoparticles.     

大气与环境影响分析的红外比色测温方法

传统的比色测温法通常利用可见光和近红外波段,对距离较近的高温目标具有较高的测量精度,而对距离较远的中低温目标无法精确测量。针对传统比色方法适用局限性,提出考虑大气和环境影响的红外比色测温方法,建立基于中波红外相机的比色测温实验系统。首先使用标准黑体进行中波红外相机和比色系统单波段定标;然后推导加入环境辐射参数的比色测量模型,进而建立新的目标辐射亮度比值与目标温度间的函数关系;最后,进行了实验室内自制灰体目标温度测量实验,验证了提出方法的可行性。实验表明:在实验温度范围内,温度绝对误差和相对误差分别小于4 ℃和6.7%,目标辐射亮度测量精度高于10%,考虑大气与环境影响的比色测温方法可实现中低温目标温度精确测量。     

准积分法构建视觉可感知三维色域的研究

为了更全面地评价显示器的色重显性能,用准积分法构建了人类视觉可感知三维色域.该算法用CIE标准色度观察者观察、混配等能单色辐射测得的CIE 1931 XYZ色度系统光谱三刺激值,按某一波长间隔求累加和,来近似实现未知函数表达式的多重积分运算.构建的色域囊括了人眼能识别的全部颜色,是宽色域、高动态范围显示设备的目标色域.还用三棱锥体积求和算法计算出该色域体积,验证了算法的可行性.进而由实测的LCD电视显示器数据,用同样方法计算其三维色域,并与视觉可感知三维色域进行定量比较.这些工作表明,本算法可为定量评价显示器的三维色域提供理论依据和可行算法,用这种方法给出的显示设备三维色域覆盖率可克服通常在二维色度图计算色域覆盖率的局限性.     

低端数码相机的颜色特性化——基于多项式模型法

近年来随着数字技术以及彩色数字图像输入输出设备的不断发展和广泛使用,颜色在不同的设备之间精确的传递或再现成为该领域的重要课题。文章以彩色数码相机特性化为研究内容,采用多项式转换方法,研究了多项式回归模型不同系数矩阵、不同训练样本对数码相机特性化精度的影响,得出了系数矩阵为20×3多项式模型时误差较小（2.095ΔE＊ab）的结论,达到了实用水平。     

A Combinatorial Approach for Colorimetric Differentiation of Organic Solvents Based on Conjugated Polymer‐Embedded Electrospun Fibers

A combinatorial approach for the colorimetric differentiation of organic solvents is developed. A polydiacetylene (PDA)‐embedded electrospun fiber mat, prepared with aminobutyric acid‐derived diacetylene monomer PCDA‐ABA 1, displays colorimetric stability when exposed to common organic solvents. In contrast, a fiber mat prepared with the aniline‐derived diacetylene PCDA‐AN 2 undergoes a solvent‐sensitive color transition. Arrays of PDA‐embedded microfibers are constructed by electrospinning poly(ethylene oxide) solutions containing various ratios of two diacetylene monomers. Unique color patterns are developed when the conjugated polymer‐embedded electrospun fiber arrays are exposed to common organic solvents in a manner which enables direct colorimetric differentiation of the tested solvents.     

White Peroxidase‐Mimicking Nanozymes: Colorimetric Pesticide Assay without Interferences of O2 and Color

Given the promising prospect of peroxidase‐like nanozymes in colorimetric assay, it is interesting and significant to eliminate their oxidase‐like activities and color interference for nanozyme‐based colorimetric assay. Here, the enzyme‐mimicking activity of GeO₂ nanomaterials is discovered. GeO₂ nanozymes exclusively possess peroxidase‐like activity without oxidase‐like characteristics, freeing the corresponding assay system from O₂ interference. Moreover, GeO₂ nanozymes are white, thereby eliminating the color interference of the nanozymes themselves in nanozymes‐based colorimetric assay. Interestingly, compared with other metal oxides, GeO₂ nanozymes are easily decomposed by thiocholine, acetylcholinesterase (AChE)‐catalyzed hydrolysate, which triggers an ultrasensitive and anti‐interference organophosphate pesticides assay process based on the irreversible inhibition of AChE. The proposed strategy about finding nanozymes with single activity without interference color will open avenues for improving the performance of colorimetric analysis systems based on nanozymes.     

A Colorimetric Hydrocarbon Sensor Employing a Swelling‐Induced Mechanochromic Polydiacetylene

Exceptional challenges have confronted the rational design of colorimetric sensors for saturated aliphatic hydrocarbons (SAHCs). The main reasons for this difficulty are the extremely nonpolar nature of these targets and their lack of functional groups that can interact with probes. By taking advantage of a mechanochromic conjugated polydiacetylene (PDA) and the hydrocarbon‐induced swelling properties of polydimethylsiloxane (PDMS), a sensor film that enables simple, colorimetric differentiation between a variety of C5 to C14 aliphatic hydrocarbons is fabricated. The unprecedented PDA–PDMS composite sensor undergoes a blue‐to‐red colorimetric transition on a timescale that is dependent on the chain length of the hydrocarbon target. In addition, the development of the red color is directly proportional to the swelling ratio of the film. This straightforward approach enables naked‐eye differentiation between n‐pentane and n‐heptane. The versatility of the sensor system is demonstrated by using it for the colorimetric determination of kerosene in adulterated diesel oil. Finally, the observation that a PDA microcrystal in the film undergoes significant expansion and tearing in concert with a blue‐to‐red colorimetric transition during the swelling process provides direct evidence for the mechanism for the mechanochromic behavior of the PDA.     

Specific Colorimetric Detection of Proteins Using Bidentate Aptamer‐Conjugated Polydiacetylene (PDA) Liposomes

The development of a bidentate aptamer‐functionalized polydiacetylene (PDA) liposome sensor that is capable of specific colorimetric detection of proteins, directly in complex mixtures (e.g., serum), at sub‐micromolar concentrations within 15 min, is reported. In comparison to sensors fabricated with a single aptamer reagent, the conjugation of bidentate aptamer pairs that recognize two distinct exosites of the target protein (thrombin) to the liposome results in significant enhancements of the sensitivity and the specificity. To elucidate the mechanism behind this enhancement, experimental evidence is presented that suggests that the liposomic aggregation triggered by specific, multi‐site binding to the target protein is responsible for the improved colorimetric response. Since the colorimetric protein sensor does not require any power or instrumentation, it offers a promising approach towards molecular diagnostics at point‐of‐care (POC), especially in low‐resource settings.     

Fractal capacity dimension of three-dimensional histogram from color images

To contribute to the important task of characterizing the complex multidimensional structure of natural images, a fractal characterization is proposed for the colorimetric organization of natural color images. This is realized from their three-dimensional RGB color histogram, by applying a box-counting procedure to assess the dimensionality of its support. Regular scaling emerges, almost linear over the whole range of accessible scales, and with non-integer slope in log-log allowing the definition of a capacity dimension for the histogram. This manifests a fractal colorimetric organization with a self-similar structure of the color palette typically composing natural images. Such a fractal characterization complements other previously known fractal properties of natural images, some reported recently in their colorimetric organization, and others reported more classically in their spatial organization. Such fractal multiscale features uncovered in natural images provide helpful clues relevant to image modeling, processing and visual perception.