What are the characteristics of official learning in Wei and Jin Dynasties compared with that in Han Dynasty?

Great changes have taken place in the official schools in Wei and Jin Dynasties due to the turmoil of the current situation, and the academic system of official schools is also varied and difficult to unify. The five lakes countries, the Northern and Southern Dynasties, went their own way, guided by the situation, and the academic system was not necessarily. But generally speaking, compared with the Han Dynasty, the establishment and changes of the official school system in Wei, Jin, Southern and Northern Dynasties have the following aspects: First, the dual-track system of the central government school was gradually formed and established. As far as its authenticity is concerned, there was only one official school in the Han Dynasty, with mixed students, both children of officials and children of civilians. It is not a special school for nobles or civilians. Cao Wei rebuilt imperial academy in the former site of the Eastern Han Dynasty in Luoyang, generally following the Han system, and did not distinguish between scholars and ordinary people. Later, due to the further strengthening of the imperial clan political system, aristocratic men occupied a unique position in politics, economy and culture. Moreover, most aristocratic men had handed down family history and had a high cultural starting point, so they were unwilling to go to imperial academy with the children of the common people. They also demanded to expand their cultural advantages in the current official school system and further expand the patent of imperial clan to the patent in the official school system.