共查询到18条相似文献，搜索用时 812 毫秒
1.
采用《测量不确定度评定与表示指南》，以等离子体发射光谱法测定土壤中的稀土元素铈为例，对测定结果进行不确定度评定。分析了不确定度的重要来源，包括溶液制备过程中引入的不确定度、样品称量引入的不确定度、标准物质外标法测量不确定度及仪器重复测定的不确定度。提供了引入不确定度各参数的采集和计算方法，对各不确定度分量进行分析计算，最后合成标准不确定度，通过乘以95％概率下的扩展因子2，获得测量结果的扩展不确定度。 相似文献
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火焰原子吸收光谱法测定铜精矿中银含量的测量不确定度评定 总被引：2，自引：0，他引：2
采用《测量不确定度评定与表示指南》，以火焰原子吸收光谱法测定铜精矿中的银含量为例，对测量结果进行不确定度评定。分析了不确定度的重要来源，包括称样质量、标准工作溶液、工作曲线拟合、试液定容体积及测量重复性等引入的不确定度分量组成。对各不确定度分量进行分析计算，求得标准不确定度为1．56，扩展不确定度为3．12。 相似文献
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X射线荧光光谱法测定土壤样品中氯的不确定度评定 总被引：11，自引：7，他引：11
用实例对x射线荧光光谱法测定土壤样品中氯的不确定度进行了评定。测量结果的不确定度由仪器综合稳定性、制样、标准物质、回归工作曲线、重复测量等所引入的不确定度分量组成。在对各个不确定度分量进行量化的基础上，通过合成得到测量结果的标准不确定度，再乘以95％置信概率下的扩展因子2，得到测量结果的扩展不确定度。 相似文献
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通过对榴辉岩中金红石物相二氧化钛含量重复测定，建立数学模型，分析了测量过程的不确定度主要来源于样品制备的不确定度、标准物质引入的不确定度、曲线拟合中产生的不确定度．以及重复试验的不确定度。当二氧化钛平均含量为3．75％时，评定其扩展不确定度为0.16％。 相似文献
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氢醌滴定法测定金矿石中金的不确定度评定 总被引：5，自引：4，他引：5
以氢醌滴定法测定金矿石中贵金属金的实例进行不确定度评定。测量结果的不确定度由配制金标准母液、金标准工作液、氢醌滴定液浓度、称样质量、滴定样品所用氢醌溶液体积等所引入的不确定度分量组成。在对各个不确定度分量进行量化的基础上，通过合成得到测量结果的标准不确定度，再乘以95％置信概率下的扩展因子2，得到测量结果的扩展不确定度。 相似文献
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气相色谱法测定地下水中六六六结果的不确定度评定 总被引：7，自引：4，他引：3
依照《测量不确定度评定与表示》,对气相色谱法测定地下水中六六六(HCH)四种单体结果进行了不确定度评定。分析了测量过程中引入的不确定度来源,包括提取液体积的量取、样品提取溶液的定容体积、分析仪器的进样量、标准系列溶液的测量以及仪器重复测定等分量引入不确定度及其各参数的采集和计算方法,最后合成标准不确定度,通过乘以95%概率下的扩展因子2,获得测量结果的扩展不确定度。 相似文献
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大气颗粒物样品波长色散X射线荧光光谱法无机元素测量结果不确定度评估 总被引：4，自引：0，他引：4
分析了用X射线荧光光谱法（XRF）测定大气颗粒物样品（TSP）中Al、Na、Cl、Mg、Cu、zn、Ca、S、Fe、Mn、K、Pb、Cd、Ba等无机元素结果的不确定度来源，对石英滤膜颗粒物样品无机元素含量测量不确定度进行了评估。计算结果表明，XRF测定中无机元素薄膜标样示值误差和工作曲线拟合误差是测量结果不确定度的主要来源。对计算测量不确定度的公式合成法和蒙特卡洛（Monte Carlo）模拟法的结果进行了比较，两种计算方法所得的结果一致。 相似文献
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对采用伏尔哈特法测定银首饰中Ag质量分数的不确定度进行了评定。以某925银首饰为例,分析了影响该方法测定Ag质量分数不确定度的来源,对每个不确定度分量进行了量化,并应用Excel程序给出了扩展不确定度以及最终结果：wAg=（92.55±0.24）%,k=2,为有效地使用该方法测定银饰品中Ag的质量分数提供可靠的理论依据。 相似文献
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Roger Powell 《Contributions to Mineralogy and Petrology》1990,106(1):61-65
Fisher (1989) advocated using the Singular Value Decomposition (SVD) of the composition matrix of a set of minerals for the determination of reactions between the minerals, and therefore of the compatibility relationships between mineral assemblages. The advantage of using the SVD for this is that an independent set of reactions, the left nullspace of the composition matrix, can be determined for a rank-deficient composition matrix which is close to, or within error of, the observed matrix. The zero singular values in the SVD can be identified by propagating the measurement uncertainties through to the singular values, and saying that singular values are zero if they are within error of zero. Having obtained an independent set of reactions, the reactions in the independent set can be combined linearly to find the full set of reactions. Propagating the measurement uncertainties through to the left nullspace of the composition matrix, the uncertainties in the coefficients of the reactions in the independent set can be determined. From these uncertainties, the uncertainties in all of the reactions can be determined, allowing the identification of reactions which are degenerate within error. This is important because it allows the identification of ambiguities in the compatibility relationships between mineral assemblages. 相似文献
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Knut O. Ronold 《国际地质力学数值与分析法杂志》1990,14(4):279-296
A probabilistic model for stability analysis of a deepwater gravity-based platform foundation is defined, based on theory for wave loading in conjunction with conventional slip surface considerations. The model accounts for uncertainties in loading as well as in soil properties, and model uncertainties are also considered. The model is updated through in-service measurements of some of the governing variables, and measurement uncertainties are included. The practical application of the model is illustrated by presentation of calculations for a typical foundation. Probability calculations are performed by first-order reliability methods. 相似文献
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N.A. Renzetti 《Tectonophysics》1986,130(1-4):61-76
Low cost, portable receivers using signals from satellites of the Global Positioning System (GPS) will enable precision geodetic observations to be made on a large scale. A number of important geophysical questions relating to plate-motion kinematics and dynamics can be addressed with this measurement capability. We describe a plan to design and validate a GPS-based geodetic system, and to demonstrate its capability in California, Mexico and the Caribbean region. The Caribbean program is a prototype for a number of regional geodetic networks to be globally distributed.
In 1985, efforts will be concentrated on understanding and minimizing error sources. Two dominant sources of error are uncertainties in the orbit ephemeris of the GPS satellites, and uncertainties in the correction for signal delay due to variable tropospheric water vapor. Orbit ephemeris uncertainties can be minimized by performing simultaneous satellite observations with GPS receivers at known (fiducial) points. Water vapor corrections can be made by performing simultaneous line-of-sight measurements of integrated water vapor content with ground-based water vapor radiometers. Specific experiments to validate both concepts are outlined.
Caribbean measurements will begin in late 1985 or early 1986. Key areas of measurement are the northern strike-slip boundary, and the western convergent boundary. Specific measurement plans in both regions are described. 相似文献
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基于涡度相关技术估算植被/大气间净CO2交换量中的不确定性 总被引：7，自引：0，他引：7
近年来，涡度相关技术的进步使陆地生态系统CO2通量的长期和连续观测成为可能。目前，涡度相关技术是全球通量观测网络（FLUXNET）测定植被/大气间CO2通量的主要技术手段，但绝大部分CO2通量观测站点都处于非典型的理想条件下，不能完全满足涡度相关技术的基本假设条件，从而导致基于涡度相关技术估算植被/大气间净生态系统CO2交换量的不确定性。系统介绍了涡度相关技术的基本假设，基本理论公式和误差的类型与特征等理论问题，重点阐述了通量测定中仪器本身的物理限制、二维和三维的气流运动、数据处理的方法和夜间通量的低估等不确定性的主要来源，并据此对通量观测研究中需要优先考虑的问题提出一些建议。研究认为数据质量控制与分析以及误差评价是不同通量站点间的结果比较和全球尺度综合分析的过程中需重点考虑的问题。 相似文献
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在分析地质标准物质标准值不确定度来源的基础上,提出了在多个实验室协作研制地质标准物质时,协作单位除提供重现性检测数据外,还应分别提供各项目检测数据的合成不确定度。分析方法或实验室之间的平均值的合成不确定度按不等精度方法处理。标准物质标准值的不确定度由分析方法、检测实验室、样品均匀性和样品稳定性的不确定度合成后乘以扩展不确定度置信水平下的包含因子而得。 相似文献
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Damage identification using inverse analysis in coupled thermo‐hydro‐mechanical problems applied to masonry dams 
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下载免费PDF全文 In this paper, we propose a method to detect the damage and estimate the degree of damage by means of a multifield‐based inverse analysis. The fields being considered are displacement, temperature, and water pressure. Furthermore, the uncertainties due to the size of the damage, the errors in the measurement data, and the errors in the model parameters are also investigated. The uncertainty due to the measurements is quantified by assuming different sources of noise in the measurements. The inverse problem is solved repeatedly by a sampling process. The uncertainties in the inverse solutions can be quantified by their probability distributions. This method can be applied to identify damages in masonry dams using coupled nonlinear thermo‐hydro‐mechanical problems. 相似文献