Nanjing has already lost its factories.

* The article discusses the economic development of various cities in China, particularly focusing on the South-North economic divide.

* Northern Chinese cities like Beijing and Tianjin are among the world's top 10 research cities, while southern Chinese cities like Guangzhou and Shenzhen have seen rapid growth and development.

* The article suggests that political factors and industry policies may have contributed to the disparity between northern and southern China.

* Some argue that the definition of a "big factory" should be based on factors such as size, technology level, and job creation rather than simply being associated with state-owned enterprises.

* Southern Chinese cities like Nanjing have seen economic growth in recent years due to the development of emerging industries such as electronics.