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通过石墨炉原子吸收法测定胶囊中的铬含量,建立数学模型,分析评定不确定度的来源和影响程度,实验中样品称量、微波消解、回归曲线和重复性测试对合成相对不确定度的贡献比较大,计算合成标准不确定度为0.045 mg/kg,扩展不确定度为0.11 mg/kg. 相似文献
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对用氢化物发生-冷原子吸收法测定出口欧盟玩具表面涂层中可迁移汞含量进行研究。建立不确定度评定程序和方法,并依据EN71-3:1994+A1:2000+AC:2002《欧洲玩具安全标准第三部份特定元素的迁移》建立数学模型。确定影响可迁移汞含量的主要因素,归纳测定过程中不确定度的主要来源。对各不确定度分量进行量化,经合成得到相对标准不确定度,从而求得扩展不确定度。当可迁移汞含量为165 mg/kg时,相对不确定度为4.0%,扩展不确定度为13 mg/kg(k=2)。 相似文献
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建立了原子吸收光谱法测量奶粉中锌含量的不确定度评定方案,合理地赋予被测量值的分散性。本文根据JJF1059-1999技术规范要求,以AAS法测定婴儿奶粉中锌含量为例,全面分析了测量过程中引起不确定度的各种因素,并评估各不确定度的分量,计算得到合成标准不确定度和计算扩展不确定度,以不确定度的形式报告测量结果。本例的相对标准不确定度为5.4%,扩展不确定度为0.42mg/100g,测量结果为(3.90±0.42)mg/100g。评定方案适用于AAS法测定食品中锌、铁等金属离子含量的不确定度评估。 相似文献
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采用火焰原子吸收光谱法测定化妆品中镉的含量,并评估其测量结果的不确定度。评定过程为按照测定步骤建立数学模型、识别不确定度来源、量化各不确定度分量及合成标准不确定度,最终得到扩展不确定度。经计算,火焰原子吸收光谱法测定化妆品中的镉含量为17.75 mg/kg,扩展不确定度为0.54 mg/kg(包含因子k=2),其中由标准曲线拟合引入的不确定度分量为该不确定度的主要来源。为此可采取提高标准曲线线性、增加被测溶液平行测定次数等措施降低不确定度,提高分析结果的准确度。 相似文献
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对石墨炉原子吸收法测定药用明胶胶囊壳中铬含量进行了不确定度评价。通过建立数学模型,分析了不确定度的来源,对影响实验结果的各个不确定度进行了计算评定分析。当药用明胶胶囊壳中铬的含量为0.326 mg/kg时,扩展不确定度为0.013 mg/kg(k=2)。 相似文献
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乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。 相似文献
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D. G. Gordeev L. F. Gudarenko M. V. Zhernokletov V. G. Kudel’kin M. A. Mochalov 《Combustion, Explosion, and Shock Waves》2008,44(2):177-189
A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation
of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from
the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO2) of density 0.08 g/cm3.
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Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008. 相似文献
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Jorge Marcelo Romero Soledad Bustillo Hugo Enrique Ramirez Maisuls Nelly Lidia Jorge Manuel Eduardo Gómez Vara Eduardo Alberto Castro Alicia H. Jubert 《International journal of molecular sciences》2007,8(7):688-694
A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out. 相似文献
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A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%. 相似文献
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塔设备改造选型的分析 总被引:2,自引:0,他引:2
就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后,着重介绍一种新型塔板(导向梯形浮阀塔板)和一种新型填料(波环填料——乾隆帕克)。 相似文献