共查询到20条相似文献,搜索用时 45 毫秒
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一、数理统计检验方法
按照GB/T15000.1~15000.5—1994《标准样品工作导则》的要求,在标准样品的研制过程中,需要对标准样品的均匀性数据和多家实验室协作定值数据进行相关的数理统计检验,以判断样品是否均匀、定值数据是否为正态分布、定值数据是否需要剔除、定值数据是否为等精度测量等,最后计算出标准样品的标准值和不确定度。 相似文献
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研制了2,3,4-三氯苯甲醚标准物质,介绍了其制备与定值方法。将制备的2,3,4-三氯苯甲醚标准物质分装成500瓶样品,随机抽取其中11瓶做均匀性检验,经F检验和t检验,结果表明在95%置信范围内样品均匀性良好。按短期与长期稳定性分别进行稳定性检验,结果表明在常温20℃下,2,3,4-三氯苯甲醚的稳定期不少于12月。采用液相色谱法和差示扫描量热法2种不同原理的方法对2,3,4-三氯苯甲醚标准物质纯度定值及不确定度评定,并采用液相色谱标准添加的方法确认了2,3,4-三氯苯甲醚标准物质中的主要杂质2,3,6-三氯苯甲醚。定值结果为99.56%± 0.40%(k=2)。 相似文献
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《现代测量与实验室管理》2021,(2)
X射线荧光光谱法测定铂首饰中铂,现有的国家铂标准物质中只含有Pt、Pd,而实际铂首饰样品的主成分是Pt,时常伴有Cu、Pd、Ag、Au。本文开展了铂首饰中铂、铜、钯、金、银化学成份标准样品的研制,主要内容包括制备标准物质候选物;对标准物质候选物进行均匀性检验;采用多家有资质的实验室协作定值的方式对标准样品进行定值;并对标准样品定值结果的不确定度进行评定。用所建标准样品制作回归曲线,对实际样品进行检测,检测结果与ICP法进行比较,最大标准偏差为:0.11%,符合实际检测工作要求。方法适用于铂质量分数为95.5~99.9%的铂首饰的测定。 相似文献
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《中国测试》2016,(8):48-52
建立甲醇中氯苯溶液标准物质的研制及不确定度评定方法。使用气相色谱(GC)和液相色谱(HPLC)两种不同方法精确测定氯苯主成分含量,电感耦合等离子体质谱仪(ICP-MS)和卡尔·费休水分仪(KF)测定无机杂质和水分含量,并最终通过质量平衡法对氯苯纯度进行准确定值。采用重量-容量法制备特性量值为10.0μg/m L的甲醇中氯苯溶液标准物质,其主要用于污染物中氯苯的成分分析、环境评价以及相应分析方法的确认等,制备的标准物质均匀性和稳定性良好,定值结果的相对扩展不确定度为U=3%(k=2),有效期限24个月,通过与同类国家标准样品甲醇中氯苯GSB 07-1220——2000量值比对,验证制备方法定值结果的准确性。 相似文献
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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. 相似文献
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Liebert A Wabnitz H Grosenick D Möller M Macdonald R Rinneberg H 《Applied optics》2003,42(28):5785-5792
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. 相似文献
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O'Brien RS 《Radiation protection dosimetry》2003,105(1-4):95-100
Australia has several uranium mines and a large number of mineral sand mines, with associated processing facilities. Exposures resulting from these mining and processing operations usually involve intakes of mixtures of radionuclides. This work describes the development of a suite of first order, linear compartment models, based on the ICRP Publication 66 respiratory tract model, and an analytical solution to the decay equations, for assessing the consequences of such intakes. The computer programs based on these models directly compute excretion, organ retention and organ and whole-body doses for intakes of either single radionuclides or any mixture of radionuclides belonging to the same radioactive decay chain. The intake can be via inhalation, ingestion or injection, and can be acute, chronic or of limited duration. The starting concentration and degree of secular (dis)equilibrium can be specified for each radionuclide. No assumptions need to be made about the relative magnitudes of the radioactive half-lives of the different nuclides. 相似文献
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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. 相似文献
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本文根据多年的实践检定经验 ,参照JJF1 0 59- 1 999《测量不确定度评定与表示》以及《测量不确定度表达 1 0讲》 ,对卧式金属罐容量的测量结果不确定度进行了评定。 相似文献
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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。 相似文献