共查询到20条相似文献,搜索用时 171 毫秒
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依据检定规程,移液器在检定过程中要测量其容量并判别其容量误差是否合格,文章主要叙述移液器在检定过程中容量误差测量的不确定度评定。 相似文献
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依据检定规程,移液器在检定过程中要测量其容量并判别其容量误差是否合格,文章主要叙述移液器在检定过程中容量误差测量的不确定度评定。 相似文献
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以JJG646-2006及ISO/TR 20461资料中移液器容积值计算公式作为测量模型进行不确定度评定,并对评定过程和结果进行分析、比较,以期了解进行移液器容积值测量时应重点关注的不确定度分量,可采取相应措施,提高测量准确度;同时了解我国现行检定规程与国际标准之间的相同点和不同之处。 相似文献
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通过分析移液器实际容量测量不确定度的评定,找出可以减小不确度的环节,使得十万分之一的机械天平,称量标称容量20μL移液器的10%容量检定点2μL,量取的检定介质的表观质量是可信的。 相似文献
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移液器主要用于环保、医药、食品卫生等科研部门,在生化分析及化验中做液体的取样或加液用,因此移液器的容量误差检定至关重要,同时有利于保证企事业、科研单位生产、检验、研究工作的顺利准确进行,有利于经济发展,具有重要社会意义及巨大经济效益,本文介绍了不同量程范围的移液器在建标报告中的不确定度评定。 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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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. 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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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)。 相似文献
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