原子荧光光度计锑元素检出限的测量不确定度评定

本文根据国家计量技术规范JJF1059-1999《测量不确定度评定与表示》、国家计量检定规程JJG 393-2009《原子荧光光度计检定规程》并结合实际工作经验,对原子荧光光度计砷元素检出限的不确定度进行评定。     

荧光分光光度计检出极限校准结果的不确定度评定

依据JJF 1059-1999《测量不确定度评定与表示》及JJG537-2006《荧光分光光度计》检定规程评定了荧光分光光度计检出限测量结果的不确定度。建立了评定检出限测量结果不确定度的数学模型,分析了各不确定度分量,并计算了合成不确定度和测量结果的扩展不确定度。     

原子荧光光度计检出限测量值的不确定评定

本文依据JJG 939-2009《原子荧光光度计检定规程》,对原子荧光光度计检出限的不确定度评定进行分析。     

原子荧光光度计测量砷元素检出限测量不确定度分析与评定

原子荧光光度计测定砷、锑、硒、汞等元素具有灵敏度高、检出限低、精密度高等优点,在国家标准规范方法中应用较多,文章主要依据JJG 939—2009 《原子荧光光度计检定规程》对测定砷元素检出限建立数学模型、分析不确定来源、评定不确定度分量、最终合成得到原子荧光光度计测量砷元素检出限标准不确定度UAs=0.016 ng(k=2),对于检定和校准原子荧光光度计工作有着重要参考和指导意义。     

原子荧光光度计砷元素检出限的测量不确定度评定

<正>一、概述1.测量依据JJF1059.1-2012《测量不确定度评定与表示》;JJG939-2009《原子荧光光度计检定规程》。2.环境条件温度为15℃~30℃,且相对稳定,相对湿度不大于80%。3.测量标准砷溶液标准物质(Urel=0.1%,k=2)。4.被测对象原子荧光光度计测砷元素的检出限。规程技术指标要求原子荧光光度计测砷检出限不得大于0.4ng。5.测量过程将仪器各参数调至最佳工作状态,用硼氢化钠     

原子荧光光度计法测锑检出限测量结果的不确定度评定

文章介绍了原子荧光光度计法测锑检出限的不确定度评定并给出结果.     

液相色谱-原子荧光联用仪最小检测量不确定度评定

本文根据JJG 1151-2018《液相色谱-原子荧光联用仪检定规程》和JJF 1059. 1-2012《测量不确定度的评定与表示》,分析了各不确定度分量,建立了评定最小检测量不确定度的测量模型,评定了液相色谱-原子荧光联用仪最小检测量的不确定度。     

紫外可见分光光度计波长示值误差测量结果不确定度评定

本文介绍了紫外可见分光光度计的工作原理，并依据JJG178-2007《紫外、可见、近红外分光光度计》和JJF1059-2012《测量不确定度评定与表示》，对紫外可见分光光度计波长示值误差测量结果不确定度进行了评定。     

示波极谱仪镉元素检出限的测量不确定度评定

不确定度是一个合理表征测量结果的分散性参数,测量结果的可用性在很大程度上取决于其不确定度的大小。本文根据JJG748-2007《示波极谱仪检定规程》和JJF1059.1-2012《测量不确定度评定与表示》对示波极谱仪镉元素检出限测量不确定度进行了评定。     

紫外、可见分光光度计波长示值误差测量结果的不确定度评定

本文依据JJG178-2007《紫外、可见、近红外分光光度计》检定规程对紫外、可见分光光度计波长示值误差测量结果的不确定度评定,主要对紫外、可见分光光度计波长示值误差测量结果的不确定度进行分析。     

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)。