Yangshao era: refers to the Yangshao cultural period. Yangshao culture is an important Neolithic culture in the middle reaches of the Yellow River. Yu 192 1 was found in Yangshao Village, Mianchi County, Sanmenxia City, Henan Province. Yangshao culture lasted about 5000 to 3000 BC, distributed in the middle reaches of the Yellow River from today's Gansu to Henan. At present, thousands of Yangshao cultural sites have been discovered in China, with the largest number of 2040 in Shaanxi Province, accounting for 40% of the total number of Yangshao cultural sites in China, and it is the center of Yangshao culture.
Longshan period: refers to the Longshan cultural period. Longshan culture generally refers to a cultural relic in the middle and lower reaches of the Yellow River in China in the late Neolithic period. Bronze culture was named after its first discovery in Longshan Town (now Zhangqiu), Licheng, Shandong Province, about 4350-3950 years ago. Distributed in Shandong, Henan, Shanxi, Shaanxi and other provinces in the middle and lower reaches of the Yellow River. In Dawenkou culture, the fast-wheel pottery-making technology was widely used in this period. The polished black pottery is more in quantity and better in quality. It is made by firing vessels as thin as eggshells and its surface is as bright as paint, which is the peak period in the history of pottery making in China.
Door-door politics: refers to the rule of the gentry and imperial power in the Eastern Jin Dynasty, which is a kind of abnormal condition of imperial power politics under certain conditions. During the hundred years of the Eastern Jin Dynasty, there were only a few gentry who once lived in the center of power. Among them, Yingchuan Jade was slaughtered by Huan Wen; After the defeat of Huan Xuan, Huan's family died; Taiyuan Wang was called, and its two branches were also destroyed in the political struggle. Only Wang Langxie and Xie Chenjun did not suffer a concentrated and devastating blow in the long and complicated conflict. Therefore, Wang and Xie family figures became tools to serve the new dynasty, and received special attention, which enabled the family development to continue for a long time. As for the last years of the Southern Dynasties. Later generations called it a five-generation family, so Wang and Xie were its representatives. This situation was caused by the political situation in the Eastern Jin Dynasty, not that Wang and Xie had the highest family status among the gentry since the Wei and Jin Dynasties. Gentry is a special name for the landlord class in Wei, Jin, Southern and Northern Dynasties. Aristocratic landlords in the Eastern Han Dynasty were their predecessors, based on the manor economy, learning classics all the time, and were senior officials of the times. "Know yourself and know yourself, and your followers are all over the world." The sign of the formation of the gate valve system is the implementation of the nine-product system.