共查询到20条相似文献,搜索用时 62 毫秒
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采用金相法测量了某镀镍铜线的镀镍层厚度,从试验重复性、金相试样镶嵌的垂直度以及光学显微镜标尺的校准等方面对影响镀层厚度测量结果的不确定度进行了分析和阐述,并对各不确定度分量进行了计算和合成,最终给出了镀镍层厚度测量的不确定度报告。结果表明:该镀镍铜线的镀镍层厚度为16.57μm,扩展不确定度U=1.68μm,包含因子k=2。 相似文献
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主要介绍了不确定度的定义和来源,并以塑料薄膜拉伸强度测定的不确定度分析为例,考虑了试验机的重复性,拉力测试不确定度、厚度测试不确定度和宽度测试不确定度的影响,系统介绍了实验室不确定度的分析和计算方法。 相似文献
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《理化检验(物理分册)》2015,(9)
根据JJF 1059-2012和GB/T 6462-2005,采用光学显微镜和金相图像分析软件对活塞硬质阳极氧化层厚度进行观察和测量,从试验重复性、试样镶嵌的垂直度以及光学显微镜校准对活塞硬质阳极氧化层厚度测量结果不确定度的影响进行了分析和阐述,并对每个不确定度分量进行了评定、计算和合成,最终给出了扩展不确定度及测量结果的不确定度报告。结果表明:活塞硬质阳极氧化层的厚度为10.13μm,扩展不确定度U=1.24μm,包含因子k=2。 相似文献
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董吉华 《现代测量与实验室管理》2008,16(3)
对电线电缆绝缘厚度的测量进行了测量不确定度评定。通过对测量不确定度有主要影响的3个分量即读数的分散性、仪器的最大允许示值误差和环境温度影响的不确定度评定得出了标准不确定度依次为:0.00234mm、0.00231mm、0.00032mm;合成标准不确定度为0.0033mm。 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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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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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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