共查询到15条相似文献,搜索用时 525 毫秒
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对废水中的磷用钼蓝分光光度法进行了测量,对测量过程的不确定度进行了分析,找出了影响不确定度的因素,对不确定度进行评估,给出不确定度,以如实反映测量的置信度和准确度,提出了在检测过程中应采取一些技术改进措施。 相似文献
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通过对分光光度法测定茶叶中游离氨基酸总量的测量过程进行分析,根据《测量不确定度评定与表示》(JJF 1059.1-2012)中有关规定,识别检测过程的不确定度来源,并推导出不确定度计算公式,得出各种因素对检测结果的影响程度,发现标准曲线拟合对不确定度的影响最大,这为提高测量数据的质量提供了依据。 相似文献
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文章分析了ACQ木材防腐剂中DDAC活性成分测量不确定度的来源,并对测定过程中产生的不确定度分量进行了评估,结果表明样品重复测定的准确度是影响DDAC测量不确定度的主要因素,DDAC扩展不确定度为0.059%。 相似文献
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以某化工企业矩形堰为例,对超声波流量计测定废水中流量的不确定度进行了评定。分析认为,测量结果的不确定度可能来自于仪器设备的分辨率和重复性测量过程。最终计算得出,此次使用超声波流量计对废水流量测量的扩展不确定度为1.07 m^3/h。其中流速测量不确定度分量的贡献较大,在测试过程中应多增加流速测试的次数。 相似文献
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依据《煤的工业分析方法》(GB/T 212-2008)对某烟煤的挥发分进行了测定,并分析了测量过程中不确定度的来源:煤样的两次称量、水分的测定、重复性等,在此基础上对各不确定度分量进行了评定,并计算得到了合成不确定度和扩展不确定度,最后提出了在测定过程中减小不确定度的有效途径. 相似文献
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建立电感耦合等离子体质谱法(ICP-MS)测定明胶空心胶囊中铬含量的不确定度评定方法,探讨影响铬含量测定的不确定度分量。通过测定过程,建立数学模型,对测量过程中的不确定度分量进行了评估。结果表明:ICP-MS法测定明胶空心胶囊铬含量为1.07 mg/kg,其扩展不确定度为0.058 mg/kg,测量结果表示为(1.07±0.058)mg/kg,k=2。建立了明胶空心胶囊铬含量的测量不确定度评定方法,分析产生不确定度的主要来源,为测定明胶空心胶囊铬含量方法的准确性提供可靠的理论依据,并为不确定度评定提供参考。 相似文献
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依据GB/T 9846-2004《胶合板》标准,对胶合板胶合强度测试过程进行研究,分析了胶合强度测量过程主要不确定度的来源并对其进行评定。介绍了胶合强度测量不确定度的评定方法和步骤,对各不确定度分量进行量化,得到了胶合强度的合成不确定度和扩展不确定度。 相似文献
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Uncertainty in eddy covariance measurements and its application to physiological models 总被引:1,自引:0,他引:1
Flux data are noisy, and this uncertainty is largely due to random measurement error. Knowledge of uncertainty is essential for the statistical evaluation of modeled and measured fluxes, for comparison of parameters derived by fitting models to measured fluxes and in formal data-assimilation efforts. We used the difference between simultaneous measurements from two towers located less than 1 km apart to quantify the distributional characteristics of the measurement error in fluxes of carbon dioxide (CO2) and sensible and latent heat (H and LE, respectively). Flux measurement error more closely follows a double exponential than a normal distribution. The CO2 flux uncertainty is negatively correlated with mean wind speed, whereas uncertainty in H and LE is positively correlated with net radiation flux. Measurements from a single tower made 24 h apart under similar environmental conditions can also be used to characterize flux uncertainty. Uncertainty calculated by this method is somewhat higher than that derived from the two-tower approach. We demonstrate the use of flux uncertainty in maximum likelihood parameter estimates for simple physiological models of daytime net carbon exchange. We show that inferred model parameters are highly correlated, and that hypothesis testing is therefore possible only when the joint distribution of the model parameters is taken into account. 相似文献
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《林业研究》2021,32(5)
Models of above-ground tree biomass have been widely used to estimate forest biomass using national forest inventory data.However,many sources of uncertainty affect above-ground biomass estimation and are challenging to assess.In this study,the uncertainties associated with the measurement error in independent variables(diameter at breast height,tree height),residual variability,variances of the parameter estimates,and the sampling variability of national inventory data are estimated for five above-ground biomass models.The results show sampling variability is the most significant source of uncertainty.The measurement error and residual variability have negligible effects on forests above-ground biomass estimations.Thus,a reduction in the uncertainty of the sampling variability has the greatest potential to decrease the overall uncertainty.The power model containing only the diameter at breast height has the smallest uncertainty.The findings of this study provide suggestions to achieve a trade-off between accuracy and cost for above-ground biomass estimation using field work. 相似文献
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按《JJF1059-1999测量不确定度评定与表示》规定的方式,依据往复式内燃机输出功率的测量方法,对影响内燃机输出功率测量结果不确定度的因素及其累积效应逐一进行分量评定、计算合成标准不确定度、评定扩展不确定,旨在提高内燃机输出功率测量结果的质量. 相似文献