离子色谱法测定水样中氯离子的测量不确定度评定

分析了离子色谱法测定水样中氯离子不确定度的来源,包括标准系列配制引入的不确定度、标准系列浓度-峰面积拟合直线引入的不确定度、样品稀释引入的不确定度,计算了不确定度分量及合成不确定度,扩展不确定度为5.6%。     

石墨炉原子吸收法测定土壤中镉的测量不确定度评定

石墨炉原子吸收法测定土壤中镉的不确定度主要来源于称量样品、定容样品消解液、测定样品消解液中镉的质量浓度及测定土壤水分引入的不确定度。对各不确定度分量进行了计算,求得合成标准不确定度和扩展不确定度分别为0.0026、0.005mg/kg。镉测量不确定度的主要来源是测定样品消解液中镉质量浓度引入的不确定度。     

大气颗粒物中总碳含量的测量不确定度评定

分析了元素分析仪测定大气颗粒物中碳质组分的测量不确定度来源,对总碳含量的测量不确定度进行了评估。测定咖啡碱标准样品中的碳含量,称样量为1 500~2 500μg时,测定结果为(49.27±0.26)%;测定大气颗粒物样品中的总碳含量,样品面积为3.14 cm2时,测定结果为(106±3)μg/cm2。     

A quantitative method for dual‐pass electrostatic force microscopy phase measurements

Electrostatic force microscopy (EFM) has become a powerful tool for investigating charges on surfaces. The use of phase measurement in EFM is a direct and fast way to detect electrostatic force gradients, but only qualitatively. With the dual‐pass scheme, the phase signal at lifted height is often assumed to exclude any influences from the topography, but it does not. We report the collection of both topography and phase data by EFM on charged, micron‐sized metal wires. In order to quantify the electrostatic force, a cone model and finite element analysis are provided to integrate the force gradient from the phase signal. Copyright © 2007 John Wiley & Sons, Ltd.     

分光光度计测铁矿石中钛的测量不确定度评定

紫外-可见分光光度计在化学分析中应用较为广泛。对于借助其进行化学分析测量不确定度的评定，目前较多见于溶液测定。实际应用中，测试样品多为固体，涉及到称样、溶解、稀释、定容等步骤。此文试从随机效应和系统效应的角度考虑，对紫外-可见分光光度计应用ISO4691：1985铁矿石中钛含量的测定——二安替比林甲烷分光光度法对铁矿石中钛的测量过程中的不确定度来源进行了较为全面的分析，并最终给出评定结果。     

对在建标技术报告中正确贯彻《测量不确定度表示指南》的理解

针对计量人员在贯彻《测量不确定表示指南》,尤其是在撰写“建标技术报告”时遇到的一些体问题,进行了探讨。     

Advances in Acoustical Holography

The most recent branch of holography, acoustical holography employing acoustical radiation, presents a variety of new and highly interesting possible applications: Thus objects can be imaged in a turbid liquid medium (marine research); the technique can be used for non-destructive investigations of the internal structure of objects that are opaque to light (testing of materials) and is possibly also a potential tool for the three-dimensional imaging of biological structures (biomedical diagnosis).     

The assessment of compliance with legal limits. Part 2. How to consider both type I and type II errors when working in the concentration domain

Considering the uncertainty of measurement when assessing compliance with reference values given in compositional specifications and statutory limits is still a controversial matter. In theory, assessing compliance requires considering both type I (false positive) and type II (false negative) errors. The more the concentration of the analyte in the sample under investigation is close to the allowed concentration limit, the more critical it is to consider both types of errors. This paper describes how this could be done. The matter is discussed in the light of the most recent literature information.     

Ion association in calcium phosphate solutions at 37°C

Ion association in the system Ca(OH)₂–H₃PO₄–KCl–H₂O at 37°C has been studied potentiometrically over a range of pH from 3 to 9. The experimental conditions were optimized for the accurate determination of the association constants for the formation of the ion pairs CaH₂PO ₄ ⁺ , CaHPO₄ and CaPO ₄ ^– which were found to be 27.9±0.1, 591±2, and (1.35±0.02)×10⁶ L-mol^–1, respectively.