亚洲午夜精品福利在线视频_国产一区二区三区在线观看福利_精品久久久久久久国产性色av_韩国伦理电影哪里看_三级黄色片成人_日韩欧美精品三级_中文字幕久久第一页久久_欧美黑人巨大xxxxxx视频

Scale inhibitor: it can disperse insoluble inorganic salt in water, prevent or interfere with the precipitation and scaling of insoluble inorganic salt on metal surface, and maintain good heat transfe...

PH regulator, also known as pH regulator, acidity regulator or pH control agent, is a kind of food additive used to adjust or maintain pH value (acid or alkali). Acidity regulator can be organic or in...

A reducing agent is a substance that loses electrons in an oxidation-reduction reaction. Generally speaking, the reactant with higher valence of a substance is a reducing agent. Reducing agent itself ...

According to its chemical composition, flocculants can be divided into inorganic flocculants and organic flocculants. Inorganic flocculants include inorganic coagulant and inorganic polymer flocculant...