By discussing the interaction among land resource, population, economy and technology in detail, this paper suggests that it is advisable to adopt high-density development in order to build future ecological city in China.

Then,from existing development density,regional carrying capacity,potential development capacity,this article analyzs method of state space,relative carrying capacity of resources and environment and the evaluating method of the regional development potential applied in .

The analysis indicates that molding time of resin can\'t reduce with the enlargement of density of holes in foam core,on the contrary,if the density of each row holes is same and big enough,the decrease of row of holes will reduce the molding time of resin because of decrement of interference of resins from different directions.