The writer first discovered the odd prime numbers symmetrical characteristics about natural numbers on the number axis, and denied the statement that prime numbers exist irregularly in natural numbers.

This paper gives a method of judging the hybridization form of central atomic orbital by number axis,its applications and laws.

On the basis of the national conditions and freight transport in China, the thought of improving both the axle load and the axle number to develop large freight cars in China is put forward; And the feasibility of the thought is expounded with the actual example of the 3-pivot point car with 6 axles.

Applying the program based on layer-elastic theory,changing the value of structure-layer parameter and wheelbase,the axle-number coefficient in the axle-load conversion formula for combined base asphalt pavement is calculated in this text under the two different conversion guidelines of pavement deflection and stress under semi-rigid base.

By use of program based on layer-elastic theory,with surface design deflection value and stress under semi-rigid base as conversion indexes under the conditions of different structure-layer and wheelbase parameters,the axle-number coefficient in the axle-load conversion formula for semi-rigid asphalt pavement is calculated.

Applying the program based on layer-elastic theory,changing the value of structure-layer parameter and wheelbase,the axle-number coefficient in the axle-load conversion formula for flexible-base asphalt pavement is calculated under the two different conversion guidelines of pavement deflection and stress under base.