纯度要求 meaning in Chinese

purify requirement

Building construction - expression of users ' requirements - air purity requirements
建筑物建造.第2部分:用户要求的表达.空气纯度要求
Purified water should be used where there are technical requirements for greater chemical purity
如果有更高的化学纯度要求，应使用纯化水。
This paper is mainly concerned about how to purify the industrial products of the antioxidant d and bht , how to determine their purities , determining their purities and the purities need to be more than 99 % . in order to attain this objective , the recrystalizing method is used to purify antioxidant d and antioxidant bht . the methods of high performance liquid chromatography ( hplc ) is used to determine the chemical composition of the antioxidant d and bht , it is qualitative analysis
本论文是以防老剂d与bht工业品为主要原料制备防老剂d与bht标准物质，首先进行了防老剂d与bht的提纯和熔点的测定试验，并通过实验确定了防老剂d与bht重结晶提纯工艺；然后设计区域熔融装置，拟定操作规程和技术条件，通过用区域熔融法提纯重结晶后的防老剂d和bht产品满足标准物质的纯度要求。