trace metal impurities的用法和樣例：
例句
- Introduction of metal impurity into TiO_2 to improve the photocatalytic activity of TiO_2 has been studied widely.
在二氧化鈦中引入金屬雜質(zhì)以提高二氧化鈦的光催化活性受到人們的廣泛研究。 - Advanced manufacturing processes are applied and the content of metal impurity is rigorously controlled.The oxidant is reduced to the minimum extent in each manufacturing process.
采用先進(jìn)制程并嚴格控制金屬雜質(zhì)的含量，并在每一制程中將氧化物降至最低程度。
