In this paper,the factors,such as fragments initial velocity,the mass and shape of a single fragment,the blasting height,impact angle and terminal velocity of the projectile and so on,which affect the lethality of premade fragments were analyzed,and the conditions,which make the lethal area largest,were calculated,and the theoretic gist for optimum design of the projectile were provided.

To meet the requirements of penetrating,which induces a larger impact angle and a smaller terminal angle of attack,the terminal attitude control should be added to laser-guided bombs guidance.

I call those stories which happen in the corners as“the corner stories.

Through calculation of the mini vlaue of the complementary angle of front angle α,conclusion is made that the impact of complementary angle of front angle on the carding effect is an important factor to the figuration of new clothing in addition to the factors such as performance of the processed fiber,carding process,and production condition.

Research about the tooth pitch and hook angle having an effect on the noise of idling circular saw blade;

It also discusses the problems such as striping away the protector, changing the shape of the vice flushing hole, altering the degree of the hook angle and the arrangement of the cutting prongs.