Uncertainty evaluation of the spectral UV irradiance evaluated by using the UVSPEC radiative transfer model

The radiative transfer models allow calculating the spectral UV irradiance from some set of measured input quantities linked with the surface reflectivity, the solar zenith angle, the ozone column and the characteristics of clouds and aerosols. The spectral irradiance yielded by a model is influenced by errors in the measurement of the input quantities. In this paper, the influences of these errors are characterized and compared with other systematic effects through an uncertainty analysis. We evaluated the uncertainty of the spectral UV irradiance rendered by the UVSPEC model, under cloudless sky conditions. In order to express the uncertainty of the output quantities (the global, direct and diffuse irradiances) in terms of the standard uncertainties of the input quantities, we used a Monte Carlo-based uncertainty propagation technique. We found that the uncertainty of the irradiance in the UV-B part of the spectrum was strongly influenced by the uncertainty attributed to the ozone column datum. Moreover, the uncertainities associated with the aerosol parameters accounted for most of the UV-A global irradiance uncertainty; the latter increased from about 4% under low aerosol conditions, up to about 14% in case of polluted air. We conclude that the UV irradiance evaluation through radiative transfer models requires paying special attention to the assessment of the aerosols properties.     

ToF-SIMS study on the cleaning methods of Au surface and their effects on the reproducibility of self-assembled monolayers

The production of reproducible self-assembled monolayers (SAMs) is essential to many nano(bio)technology applications. To check the effects of different cleaning methods on a reproducible SAMs formation, the cleaning methods were varied and then used for preparing each SAM. The reproducibility of each SAM was examined by ToF-SIMS analysis along with principal component analysis (PCA). Using what we found to be a superior method of cleaning gold surfaces, alkanethiol SAMs with different terminal groups such as 1-dodecanethiol (DDT), 11-mercaptoundecanoic acid (MUA), 11-mercapto-1-undecanol (MUD) were reproduced. Our statistical results show that reproducible alkanethiol SAMs on a well-cleaned gold surface can be produced within only a few standard deviation percentages obtained from point-to-point and sample-to-sample spectra.     

盐岩样品中钙的分析不确定度评定

对EDTA容量法测定盐岩样品中Ca2+含量的分析过程,详细地分析了引入的不确定度来源:分析结果的不确定度由标准溶液配制及EDTA溶液的标定、样品的制备及样品的分析过程、样品均匀性及检验重复性等分量引入的不确定度组成,求得测量结果的标准不确定度和扩展不确定度分别为0.70%和1.40%。     

乌兰拜兴矿区铁矿石中TFe含量分析的不确定度评定

用K2Cr2O7容量法测定铁精粉中TFe含量,详细分析了不确定度的来源,对各分量所引入的标准不确定度和相对标准不确定度进行了评定,求得测量结果的合成相对标准不确定度和相对扩展不确定度分别为0.19%和0.38%。     

ICP-MS测定油墨中总铬的测量不确定度评定

通过对油墨中总铬含量的不确定度评定分析,找出引起不确定度产生的主要因素,评定确认由最小二乘法拟合校准曲线是影响结果的最主要因素,使用标准物质（标准储备液）及稀释过程引入的不确定度也应引起重视,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,此方法对类似的ICP-MS法测定样品中待测元素含量有借鉴和参考作用.     

矿石中金的分析不确定度评定

针对原子吸收光谱法测定金矿石中金的实验过程,详细地分析了引入的不确定度来源。测定结果的不确定度由标准配制、样品制备、曲线拟合、样品均匀性及检验重复性4个部分引入的不确定度分量组成,样品制备过程中考虑了活性炭吸附率的影响,求得测量结果的标准不确定度和扩展不确定度分别为0.043μg/g和0.09μg/g。     

EDTA法测定水中总硬度测量不确定度的评定与表示

通过检测水中总硬度的含量,论述水中总硬度测定结果的测量不确定度的来源及评定方法,当k=2,水中总硬度含量测定结果的扩展不确定度为（209.0±0.7）mg/L。     

氢化物发生-原子荧光光谱法测定啤酒中砷的不确定度评估

对氢化物发生-原子荧光法测定啤酒中总砷含量的不确定度进行了评定。分析了方法中不确定度的来源,测量结果的不确定度由样品制备、校准曲线、重复性试验、平行试验等所引入的不确定度分量组成。评定结果表明,校准曲线是影响该方法不确定度的主要因素。     

火焰原子吸收光谱法测定车间空气中钠及化合物的不确定度评定

对火焰原子吸收光谱法测定工作场所空气中钠及化合物含量的测定过程分析,合理选择评定方法,简化了测试过程中的不确定分量,计算出其相对合成不确定度和相对扩展不确定度,达到了对其测量不确定度合理评定的目的。     

ICP-AES分析茶叶中Mg和K含量的不确定度评定

对用电感耦合等离子体-原子发射光谱法(ICP-AES)测定茶叶中的金属元素Mg、K含量的不确定度来源进行分析和计算.其分析方法的标准不确定度主要来源包括物质称量、线性回归拟合、溶液稀释等过程,并依据不确定度的评定方法计算各不确定度分量,结果表示茶叶中Mg、K的含量依次为1773、16666mg/kg,标准不确定度依次为...     

ICP-AES测定人发中铁的不确定度分析

通过ICP-AES测定人发中铁的不确定度的评定实践,分析了该方法测定过程中的不确定度来源,建立了数学模型,并计算了各标准不确定度分量、合成标准不确定度、扩展不确定度等。     

电感耦合等离子体-原子发射光谱法测定塑料中的铅的不确定度评价

对电感耦合等离子体-原子发射光谱法测定塑料中的铅含量的不确定度进行了评定.建立了该方法的定量数学模型并推导出不确定度计算公式,找出了该检测过程中的不确定度来源,并且计算了公式中各个变量的不确定度,最后计算出了检测结果的合成标准不确定度和扩展不确定度.     

确定度评定在化妆品中砷含量ICP-AES测定中的应用

通过对电感耦合等离子体发射光谱(ICP-AES)测定化妆品中As含量的不确定度的评定实践,建立了该分析过程的相应数学模型,对数学模型中各个参数进行不确定度来源分析,分别对A类不确定度(由测量的结果统计分布计算的不确定度)或B类不确定度(基于经验或其他信息的概率分布估计的不确定度)进行评定。按照国际通用方法对各不确定度分量合成和扩展,得到ICP-AES法测定化妆品中As含量的不确定度评定。研究结果表明：标准溶液的配制、标准曲线拟合线性方程及样品溶液的定容是不确定度的主要来源,该不确定度评定所用方法同样适用于以线性回归标准曲线法获得测定结果不确定度的评估。     

ICP-MS测量溶液中痕量Sm的不确定度评定

为了更合理、科学地表示测量结果 ,本文按照 GUM和国家质量技术监督局颁布的计量技术规范 ,对电感耦合等离子体 -质谱 (ICP- MS)测量溶液中痕量 Sm的不确定度进行了评定 ,提供了计算过程所需各参数的采集和计算方法 ,评定了各标准不确定度分量、合成标准不确定度、自由度和扩展不确定度。此方法还可为类似仪器测量结果不确定度的评定提供参考。     

基于PCA的土壤Cd含量高光谱反演模型对比研究

土壤重金属污染对人类健康造成了极大的威胁,如何快速摸清土壤污染情况尤为重要.高光谱遥感具备光谱分辨率高,快速无损等优势,使其在土壤组分反演方面具有巨大的潜力.针对高光谱信息冗余及光谱变换对土壤镉(Cd)含量估算的影响进行分析,并利用变换前后的高光谱数据对比研究了不同高光谱模型对土壤Cd含量反演的性能.首先利用等离子体质...     

石墨炉原子吸收光谱法测定山药中镉含量的不确定度评定

建立有效的数学模型,全面分析了微波消解石墨炉原子吸收光谱法测定山药中镉不确定度的主要来源,并系统地评定各因素的不确定度。结果表明,对于山药中镉含量为25.12μg/kg的样品,扩展不确定度为3.47μg/kg(k=2),最终测量结果表示为25.12±3.47μg/kg。影响最终不确定度的主要有标准溶液配制、测量重复性及样品回收率3个分量,而称重和消解液的定容过程对结果影响较小。通过对测量的不确定度评定,为有效地控制山药中镉含量的检测提供可靠的理论依据。     

ICP-AES测定塑料中的镉的不确定度评定

分析了ICP-AES法测定塑料中的镉的检测过程,建立了该方法的定量数学模型并推导出不确定度计算公式,找出了该检测过程中的不确定度来源,并且计算了公式中各个变量的不确定度,最后计算出了检测结果的合成标准不确定度和扩展不确定度.     

Emerging trends in numerical simulations of combustion systems

Numerical simulations have played a vital role in the design of modern combustion systems. Over the last two decades, the focus of research has been on the development of the large eddy simulation (LES) approach, which leveraged the vast increase in computing power to dramatically improve predictive accuracy. Even with the anticipated increase in supercomputing capabilities, the use of LES in design is limited by its high computational cost. Moreover, to aid decision making, such LES computations have to be augmented to estimate underlying uncertainties in simulation components. At the same time, other changes are happening across industries that build or use combustion devices. While efficiency and emissions reduction are still the primary design objectives, reducing cost of operation by optimizing maintenance and repair is becoming an important segment of the enterprise. This latter quest is aided by the digitization of combustors, which allows collection and storage of operational data from a host of sensors over a fleet of devices. Moreover, several levels of computing including low-power hardware present on board the combustion systems are becoming available. Such large data sets create unique opportunities for design and maintenance if appropriate numerical tools are made available. As LES revolutionized computing-guided design by leveraging supercomputing, a new generation of numerical approaches is needed to utilize this vast amount of data and the varied nature of computing hardware. In this article, a review of emerging computational approaches for this heterogeneous data-driven environment is provided. A case is made that new but unconventional opportunities for physics-based combustion modeling exist in this realm.     

迈克尔逊风场探测干涉仪探测温度不确定度分析

根据迈克尔逊风场探测干涉仪探测原理,所探测的温度不确定度是由装置调制度不确定度和发射线的表观调制度不确定度所决定的.通过它们之间的定量关系,求出了对应于一定温度不确定度的调制度不确定度的允许范围,并进行了模拟计算.最后针对影响因素提出了提高温度不确定度的方法, 明显提高了温度测试准确度.     

ICP-MS测定三七中铬、砷、汞、镉和铅的测量不确定度的评估

合理评估ICP-MS测定三七中铬、砷、汞、镉、铅的测量不确定度,对测试方法的每一步骤进行不确定度的分析评估.