Do you want to ask the author when to write two units? In the process of writing and publishing a paper, the author only needs to write two units when changing his work unit.

The method of marking the author's unit is generally to write 123 or abc in the upper right corner. When the first author of sci has two units, the writing method is to mark 1, 2 or A, B in the upper right corner of the first author, such as Wang Moumou 12 or Wang Moumou ab, where 1 or A represents one unit and 2 or B represents another unit.