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出厂水泥不同抽样方法误差比较研究
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作者 张大康 《水泥工程》 CAS 2009年第3期56-58,共3页
目前水泥厂对出厂水泥采用的是一种近乎没有限制的"随意"抽样方法,与国家标准采用随机抽样的规定不符。原因主要是随机抽样在水泥厂实际操作中难以实行。应用蒙特卡罗方法模拟了随机抽样、系统抽样、分层抽样、近似系统抽样... 目前水泥厂对出厂水泥采用的是一种近乎没有限制的"随意"抽样方法,与国家标准采用随机抽样的规定不符。原因主要是随机抽样在水泥厂实际操作中难以实行。应用蒙特卡罗方法模拟了随机抽样、系统抽样、分层抽样、近似系统抽样和分层任意抽样的抽样误差,旨在寻找一种抽样误差不大于随机抽样,而又易于实施的抽样方法。结果表明,五种抽样方法的抽样误差接近。据此,从易于操作的角度提出以近似系统抽样的方法代替随机抽样。 展开更多
关键词 出厂水泥 抽样方法 抽样误差 蒙特卡罗模拟
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Radiocarbon Concentration Measurements in Tree Leaves near SOCOCIM (Rufisque, Senegal), A Cement Factory
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作者 Maurice Ndeye Hans-Arno Synal Matar Séne 《Open Journal of Air Pollution》 2022年第1期1-12,共12页
Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO<sub>2</sub> due to anthropogenic activities. A total of 20 samples of several types of tree leaves, were anal... Radiocarbon content in biogenic samples is widely used to study the variation of atmospheric CO<sub>2</sub> due to anthropogenic activities. A total of 20 samples of several types of tree leaves, were analyzed for this study. Sampling was carried out at the end of the rainy season in 2017 from the surrounding of the SOCOCIM cement factory in Rufisque town. Rufisque is located on the peninsula of Cape Verde, 25 km east of Dakar, where it is the 《south gate》 of the agglomeration. Reference samples of five different species were collected during the same period (2017) from a clean zone. The <sup>14</sup>C method was used for the determination of Δ<sup>14</sup>C values. The data show that the <sup>14</sup>C concentration in the studied sites was significantly lower than the clean area, due to the release of anthropogenic CO<sub>2</sub>. To estimate the Suess effect, the fossil fuel fraction was determined based on equations of mass balance for CO<sub>2</sub> concentration, stable isotopic composition of carbon, and <sup>14</sup>C concentration. The results show that selected locations are affected differently according to their distance from the factory and the wind direction. 展开更多
关键词 Radiocarbon Concentration Fossil Fuel Fraction Tree leaves cement factory
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