食品中合成色素快速检测法研究及其应用

研究了食品中可能添加的非食用色素苏丹红,孔雀石绿,碱性橙Ⅱ号等的快速检测方法,并建立了同时测定饮料中人工合成色素柠檬黄,日落黄,胭脂红,苋菜红,亮蓝,靛蓝等多组分的方法,该方法与国标方法比较,检测结果相对误差小于5%,同时具有样品处理简单、快速、易操作的优点,适用于现场快速检测.     

碳材料在色素电化学传感中的研究进展

偶氮类色素因其着色力强、价格低廉等优点而作为食品添加剂并被广泛应用于食品行业之中.《中华人民共和国食品添加剂卫生使用标准(GB 2760)》明确指出各类食品中的色素严禁超范围和超剂量使用.电化学检测方法具有灵敏度高、检测速度快、操作简便的优点,因此构建性能优异的电化学传感器在偶氮类色素快速检测应用中具有重要意义.其中,基于碳纳米材料修饰的电化学传感器在色素检测中具有重要影响.本文从功能化石墨烯、金属有机框架、多孔碳等碳基纳米材料出发,总结了近年来碳基修饰的电化学传感器在偶氮类色素检测中应用的研究进展,分析对比了各种碳材料的结构性能、制备方法及应用,并对功能碳纳米材料及电化学传感器的发展进行了展望,为高灵敏的新型偶氮类色素电化学传感器的开发提供研究基础.     

偏最小二乘法-分光光度法同时检测6种合成色素的研究

基于多元校正曲线分辨技术,建立了立春红2R、日落黄、喹啉黄、碱性橙、酸性绿和直接绿B等6种合成色素的偏最小二乘法-分光光度法分析方法。研究了溶液p H值、吸光度加和性、计量模型主成分数及计量波段等主要因素的影响,实现了立春红2R等6种合成色素的偏最小二乘法-分光光度法同时分析,检测限分别为0.2、0.3、0.07、0.2、2.6、2.1μg/m L,测定相对标准偏差RSD小于3%;应用于样品分析,立春红2R等合成色素的加标回收率在98.2%~104.4%范围内。所建立的方法简单、快速,为分光光度法不经分离而直接测定立春红2R等合成色素提供一种新的途径。     

全自动固相萃取/超高效液相色谱串联质谱法检测食品中的9种合成色素

建立了超高效液相色谱串联质谱法检测食品中柠檬黄、苋菜红、胭脂红、日落黄、亮蓝、新红、靛蓝、诱惑红、赤鲜红9种合成色素的快速检测方法。采用反相-弱阴离子交换固相萃取小柱,在Labtech的Speline全自动固相萃取平台上实现对样品的连续、自动化处理过程,极大地提高了工作效率。净化液经Agilent XDB C18色谱柱,以甲醇和10mmol/L乙酸铵溶液为流动相梯度洗脱,6min内实现基线分离。采用电喷雾正离子模式（ESI＋）电离,多反应监测（MRM）模式定量检测。9种合成色素的质量浓度在10-500μg/L的范围内与其响应值呈线性关系,其检出限（3S/N）在0.009-0.044mg/kg之间。将该方法应用于食品中合成色素的测定,其回收率范围为88.8%-108.2%,相对标准偏差（n=6）均小于5%。该方法高效、快速、准确,可满足批量化检测的需求。     

光纤光谱仪的色素溶液浓度检测系统设计

设计了一种基于光纤光谱仪的溶液色素浓度检测系统.利用该系统对柠檬黄、日落黄、胭脂红与亮蓝四种人工合成色素的混合溶液以及每种色素的标准溶液进行吸光度检测,进而计算出混合色素溶液中各色素的质量浓度.实验结果表明,该系统测得混合色素溶液中各色素的质量浓度与理论值的相对误差分别为2%、3%、4%、2%,与北京普析通用仪器有限责任公司生产的TU-1901型双光束紫外可见分光光度计的测量结果具有很好的一致性,表明该系统同时具备结构紧凑与测量可靠的特点,在一定程度上可以代替分光光度计进行吸光度检测.     

7CDMA解相关多用户检测的快速处理方法摘要]针对CDMA多用户检测的解相关方法运算过程的复杂度较高、异步情况下难以实现等问题进行了研究,提出了一种解相关多用户检测的快速处理方法,从而便于实现及快速软件处理.仿真结果表明,该方法使运算复杂度大大降低,同时又使误码率较传统

针对CDMA多用户检测的解相关方法运算过程的复杂度较高、异步情况下难以实现等问题进行了研究,提出了一种解相关多用户检测的快速处理方法,从而便于实现及快速软件处理。仿真结果表明,该方法使运算复杂度大大降低,同时又使误码率较传统接收机和解相关接收机下降。     

广式腊味制品中总糖、食盐和亚硝酸盐检测方法的探究

建立一种简单、快速、高效的样品前处理方法,可同时应用于广式腊味制品中的总糖、食盐和亚硝酸盐等含量的测定。即以热水提取样品,加入亚铁氰化钾和乙酸锌沉淀蛋白后,其提取液可直接用于后续总糖、食盐和亚硝酸盐的检测。将本方法与国标总糖、食盐和亚硝酸盐的检测方法分别用于广式腊味制品,两者检测结果完全一致,与国标相比,本方法具有操作简单,检测快速、准确等优点,可高效地进行广式腊味制品的项目检测。     

合成色素快速分析仪的性能验证方法研究

目前对人工合成色素快速分析仪的计量性能控制主要采用标准试剂法进行比对溯源,该方案容易引入误差且工作量大。通过对分析仪稳定性(噪声、漂移)、波长和透射比等参数指标的试验分析,提出了可操作性的评价方法,实现对仪器本身的性能验证和质量控制,防止人工合成色素的超量或超范围使用。     

基于图像处理的包装印刷缺陷检测方法

目的为了提高包装印刷品缺陷检测的准确度和适用性,基于图像处理设计一种包装印刷缺陷检测方法。方法采用几个关键步骤包括图像配准、配准区域自动选取、缺陷检测等,并根据包装印刷品图像特征选择配准区域,同时给出一种快速图像配准算法,利用改进差影匹配算法实现缺陷检测;基于DSP和FPGA设计控制系统硬件平台,主要包括控制单元、图像采集与处理单元、成像单元等,并进行实验研究。结果所述方法能够准确识别出细微的刀丝、拉条类缺陷。结论该方法具有较高的可靠性、通用性,可实现包装印刷品缺陷的快速检测。     

法医DNA快速检验研究进展

法医DNA快速检验技术是目前研究的热点,主要应用于个体识别和亲子鉴定领域。该文分别从快速提取,快速扩增,快速设备,微流控芯片,全自动DNA分型检测设备方面对现有DNA快速检验的技术方法,实验原理进行充分说明和举例论证,同时对该行业在快速检验方法的选择问题上提出明确的建议——采用强抑制力的缓冲体系,高效酶并结合快速扩增程序实现快速PCR检测技术,同时提出芯片化DNA检测的实现方式,指出国产的便携式全自动快速检测仪器是未来发展的主要方向。     

Estimation of Parameters of Universal Distribution of Moments of Failure of Products

A method is proposed for estimating the parameters of a mixture of exponential and Weibull distributions for which the accuracy of preliminary estimates obtained by graphical analysis is refined in accordance with the criterion of maximum likelihood. The efficiency of the proposed method is supported by the results of statistical modeling.     

Evaluation of optical properties of highly scattering media by moments of distributions of times of flight of photons

A novel method for the determination of the optical properties of tissue from time-domain measurements is presented. The data analysis is based on the evaluation of the first moment and the second centralized moment, i.e., the mean time of flight and the variance of the measured distribution of times of flight (DTOF) of photons injected by short (picosecond) laser pulses. Analytical expressions are derived for calculation of absorption and of reduced scattering coefficients from these moments by application of diffusion theory for infinite and semi-infinite homogeneous media. The proposed method was tested on experimental data obtained with phantoms, and results for absorption and reduced scattering coefficients obtained by the proposed method are compared with those obtained by fitting of the same data with analytical solutions of the diffusion equation. Furthermore, the accuracy of the moment analysis was investigated for a range of integration limits of the DTOF. The moment analysis may serve as a comparatively fast method for evaluating optical properties with sufficient accuracy and can be used, e.g., for on-line monitoring of optical properties of biological tissue.     

Analysis of the rate of propagation of the wave of change of boiling modes

An approximate analytical expression is derived for the velocity of the front of the wave of change of boiling modes on a rod and on a plate. The impact of the Thomson effect and of the heater orientation in the gravity field is included. Adequate agreement is demonstrated between the derived relations and experimental data.     

Estimation of potentialities of methods of summation of direct measurement errors

Conventional methods for summation of direct measurement errors are considered. Conditions under which these methods provide consistent results are stated. It is proposed to utilize for characteristic of the total error, its interval estimator or the half-sum of the value obtained by adding up its arithmetic and geometric random errors.Translated from Izmeritel'naya Tekhnika, No. 4, pp. 10–12, April, 1995.     

空压机轴承箱蜗壳温度探头油封改造

由于空压机进气侧轴承箱蜗壳温度探头密封效果不好,使空压机及其后续管道受到油污染。后将温度探头的O形圈密封改为骨架油封,杜绝了轴承箱漏油问题。文章简介空压机的结构和技术参数,详细介绍了骨架油封的制作和优点。     

Characteristics of mechanical properties of materials in studies of conditions of attainment of marginal states

It is shown that conditions of attainment of marginal states in the material of structural components are formulated on the basis of analysis of force and deformation criteria of formation and development of destruction. The parameters of these criteria are data on types of structural materials, standard and special characteristics of their mechanical properties, structural forms of considered elements of the equipment, and their operating stress loading. In this case, the construction of a system of state equations for describing interrelation of current damage, external actions, and responses to them is based on the concept of calculating variations in properties of materials at all stages of the design life cycle.     

Determination of parameters of microstructural inhomogeneity of deformation of metals by the method of modeling

The article suggests a method of evaluating the microstructural inhomogeneity of deformation of metals by modeling. The method includes the measurement of deformations of metal according to meshes of a dividing grid with small base and the calculation of the distribution parameters of microdeformations in model representation. It is shown that the modeling method makes it possible objectively to evaluate the microinhomogeneity of deformation of metals independently of the chosen mesh size of the dividing grid. New structural characteristics are introduced: the base and wave of variation expressing the degree of crumbling or amalgamation of metal grains by inhomogeneity of deformation.Translated from Problemy Prochnosti, No. 7, pp. 40–44, July, 1991.     

水三相点复现的不确定度评定

水三相点是开尔文热力学温度的唯一基准点，也是ITS-90国际温标重要的定义固定点。因此，水三相点不确定度分析对整个温标的建立、温度量值传递起着至关重要的作用。近3年来，中国计量科学研究院研制出一系列高质量的水三相点容器，加强了水三相点的研究，为不确定度的分析提供了更为可靠的实验依据。同时，不确定度的分析也是客观评价新研制容器性能的一个重要指标。因此，根据实验结果对新研制容器所复现的水三相点进行了不确定度评定。评定结果表明，其扩展不确定度为0．16mK(k=2．69，P=0．99)。