Results showed that nitrite formation appeared mainly in the initial stage of fermentation, and nitrite disappeared gradually with the decrease of pH value.

结果发现，亚硝酸盐的出现期主要集中在发酵前期，随发酵液酸度的增加亚硝酸盐逐渐消失。

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Since the beginning of the industrial era, the pH of surface waters has decreased slightly but significantly from 8.2 to 8.1, and it continues to decrease.

自从工业时代开始以来，海洋表层水的pH就已经缓慢地下降，但是值得注意的是已经从8.2下降到8.1，而且还在继续下降。

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