分光光度法测定水中氨氮含量结果不确定度评定

文章按照国家标准HJ535—2009水质氨氮的测定,采用分光光度法测定水中氨氮含量,试验根据JJF1059.1-2012《测量不确定度评定与表示》,分析了各种测量不确定度的来源,考虑到了各种输入量的影响,在规定的测量条件下,经过计算给出测量不确定度,对分光光度法测定氨氮的测量重复性、测量线性及结果进行不确定度评定。同时测定了国家水质氨氮的质控样(BW0598)标准值及扩展不确定度为:9.92±0.50μg/m L,k=2。与本实验室测定结果为:μg/30.10m L,相吻合。     

The making of scientific butter: injecting scientific reasoning into agriculture

Both Danish and English agriculture underwent fundamental restructuring during the second half of the 19th century, and in both cases the dairy sector made great advances. However, the two agricultural industries differed in aims and strategies, and crucially in the extent to which new technologies and scientific methods were implemented. Economic historical analysis is insufficient to explain why the Danish and English dairy industries developed in different ways, and how Danish butter achieved success in the competitive English market. However, with a focus on the role of science and a scientific understanding of the development of these two dairy industries, all becomes clear.     

茶叶冰淇淋的新配方

通过对冰淇淋的配方中茶叶的加入量、稳定剂的选用,研究制得的产品组织细腻、风味独特,具有很好的市场发展前景。