There is a limit of 1000 in the "accumulated part of the preliminary work of the project" after the doctoral degree.

Postdoctoral (postdoctoral researcher/associate researcher/researcher, abbreviated as Postdoc) refers to those who engage in academic research in institutions of higher learning or research institutions after obtaining their doctoral degrees, usually working in postdoctoral mobile stations or postdoctoral research centers. It should be noted that "postdoctoral" is not a degree, but a doctoral degree winner who is allowed to enter the postdoctoral research mobile station to engage in scientific research.