国产欧美精品一区二区,中文字幕专区在线亚洲,国产精品美女网站在线观看,艾秋果冻传媒2021精品,在线免费一区二区,久久久久久青草大香综合精品,日韩美aaa特级毛片,欧美成人精品午夜免费影视

The quantum Hall electrical resistance technology is internationally recognized for the most up to date electrical resistance standard with the highest accuracy, but its metrological application is limited because of its quantization and non-continuous. Advanced electrical resistance comparison and metrology techniques are contrasted and analyzed by category, and feasible technical solutions are proposed for electrical resistance metrology with relative uncertainty of 10-8 in this paper. Furthermore, analysis conclusions are given to different technical solutions, which can provide important references for different metrology laboratories to establish high accuracy electrical resistance standard according to their own conditions. In the end, the domestic and overseas research tendency of quantum Hall electrical resistance is introduced, and especially, the development potential of graphene quantum Hall electrical resistances, which maybe could work at room temperature, is simply described. 