By means of researching the meshing impact in the engagement of standard chain respectively with the spur toothed sprocket and the involute toothed sprocket,it has been discovered through analysis that by adopting the involute tooth for the sprocket could reduce the normal impact velocity in the engaging instant of chain and s.

On the basis of meshing impact dynamics model in gear transmission established in document [1], and by means of theoretical analysis and compiling corresponding analytical program, the impact force of meshing and the variation status of impact speed in the transmission of involute spur gears were calculated.

The characteristics of meshing impact is improved by using meshing analysis procedure in FORTRAN language so that such gears will have low-noise performance.

It is found that the chain/sprocket meshing impact is reduced and the transverse vibration of chain is decreased by applying the new sprocket.

Owing to the modified error in principle, the manufacturing error and the variation of the load,there still exists the mesh impact in the transmission of modified spur gear.

The main results are as followings: the active reserve is positively related to the probability and magnitude of the output shock,the relative risk aversion coefficient,the subjective discount rate of the representative agent and relative price of international reserves,while negatively related to eco.

The qualities of coal and pressures of the gas have influence on the shock wave of coal and gas outburst propagation law.