Much and though study has been done in the advantage of comparativeness and backwardness in social and economic development by scholars at home and abroad, however, less has been done in the disadvantage of backwardness, which requires further exploration.

There also exist the technological disadvantages as the late comer.

Research situation and development trends of flash butt welding;

On existing researching circumstance and development trend of ecologic concrete;

Characteristics and development trend of heavy oil high pressure hydrocracking technologies;