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计算机模拟取样确定出口吨袋装氟石干粉取样的合理样本容量
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作者 阮毅 陈因聪 《检验检疫学刊》 1995年第4期28-31,共4页
计算机模拟取样确定出口吨袋装氟石干粉取样的合理样本容量阮毅,陈因聪(浙江商检局)取样是检验工作的关键步骤。通常袋装氟石取样是依照标准或规程以百分比法操作,而不根据总体的品质波动来决定样本容量,从而可能造成取样量过大,... 计算机模拟取样确定出口吨袋装氟石干粉取样的合理样本容量阮毅,陈因聪(浙江商检局)取样是检验工作的关键步骤。通常袋装氟石取样是依照标准或规程以百分比法操作,而不根据总体的品质波动来决定样本容量,从而可能造成取样量过大,或品质严重不匀之商品所取样品代表性... 展开更多
关键词 计算机模拟 样本容量 正态分布 合理样本 取样计算 品质波动 样品标准偏差 频率分布直方图 错判概率 氟石
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Determination of impurity elements in MnZn ferrites by inductively coupled plasma mass spectrometry 被引量:3
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作者 张萍 符靓 +1 位作者 马俊才 唐有根 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第1期37-42,共6页
An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+H... An inductively coupled plasma mass spectrometry(ICP-MS) method was developed for the determination of Na, Mg, Al,K, Ca, Ti, Cr, Co, Ni, Cu, Ga, As, Mo, Ag, Cd and Pb in MnZn ferrites. The sample was digested by HNO3+HCl with microwave digestion followed by dilution with ultrapure water, then the above 16 impurity elements in the solution were analyzed directly by ICP-MS. The impurity elements were introduced by the helium gas or hydrogen gas into the octopole reaction system(ORS) to eliminate the polyatomic interferences caused by the high salty matrixes. The matrix effect was minimized through matrix matching,and Be, Y and Rh were used as internal standard elements. The working parameters of the instrument were optimized. The results show that the method has good precision and high accuracy. The detection limits for the investigated elements are in the range of0.9-37.5 ng/L, the relative standard deviation of each element is within 1.1%-4.8%, and the recovery of each element is 90%-108%. 展开更多
关键词 inductively coupled plasma mass spectrometry(ICP-MS) MnZn ferrites octopole reaction system(ORS) impurity elements
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Spectrophotometric Error Due to Uncertainty in Reading the Signal
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作者 Mavroudis A. Demertzis Anastasios I. Palios Alexandru V. Calin Cristina-Ioana M. Vijdeluc George A.Chrysafis 《Journal of Chemistry and Chemical Engineering》 2012年第7期585-590,共6页
Based upon the standard deviations for the intercept and the slope of a linear regression line, as well as by differentiating both Beer's law and a linear relationship between transmittance and concentration at high ... Based upon the standard deviations for the intercept and the slope of a linear regression line, as well as by differentiating both Beer's law and a linear relationship between transmittance and concentration at high transmission, it is proved that the relative spectrophotometric error of a measurement becomes greater as the sample concentration only decreases. Further, it is demonstrated that the present knowledge with regard to the error in absorption spectrophotometry is necessary to be reexamined. The total scale of transmittance can literally be used for measurements, unfolding workable dynamic ranges about two orders of magnitude lower than usually and thus absorption spectrophotometry can efficiently compete with other methods of analysis with respect to detection limits. 展开更多
关键词 Spectrophotometric error transmittance uncertainty sensitive spectrophotometry transmittance noise.
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