At present, doctoral graduation is basically linked to papers, especially sci papers. Generally, schools only dare to ask about the number of papers and never dare to divide them. Otherwise, it is the only paper for the Ministry of Education, but the doctoral tutor can supplement the materials. For example, the Chinese Academy of Sciences has a doctoral supervisor who requires students to publish two papers and one if> 1 0 in the1area. However, for most training units, the zoning requirement is still unrealistic. Let's just say that the research direction is different. There are only three top journals in many fields, such as iron and steel metallurgy and nonferrous metallurgy. There are many similar examples in the second district, so the third district must be recognized.