Hole - Similar to a positive charge, this is caused by the absence of a valence electron.

空穴-和正电荷类似，是由缺少价电子引起的。

youdao

Natural sand adsorbed viruses increasing with the presence of metal cations, their contents and valence, but this positive role was not clear to modified sand adsorption viruses.

金属阳离子可促进天然砂吸附病毒，并随其浓度和价态的增加而增加，但对修饰砂作用不明显。

youdao

This awareness of themselves on a larger map than the miseries of the slum allowed them to knowingly present themselves as actors with a positive valence, not merely poor hopeless individuals living in utter misery.

FORBES: The Global City And The Global Slum