建立了砂轮的球基渐开螺旋面方程和分度球面螺旋线方程,给出螺旋运动参数、螺旋线导程.The mechanism of grinding internal gear of spherical worm emery - wheel is researched.正圆锥螺旋面是正圆柱螺旋面被同轴正圆锥面截得.The ortho cone helicoid was used interrsect intercept by the ortho con...
The five small arthropod were still very serious pest, especially aphid, scale and whitefly.其中,五小害虫的危害仍然非常严重, 尤其是蚜虫 、 蚧壳虫和粉虱.The outermost layer of cuticle of an arthropod exoskeleton, composed mostly of wax.主要为水生的节肢动物,通...
One , restricted those who contract is emulative, influence collective contracts duly income.限制了承包的竞争性, 影响集体应有的承包收入.Finally, the feasibility of the model is tested through the emulative result and a successful case.仿真结果和...
In 1742 he suffered a fatal attack of smallpox.1742年,他染上了致命的天花.He gave money to the World Health Organisation to help defeat smallpox.他向世界卫生组织提供资金以帮助消灭天花。He gave money to the World Health Organisation to help defeat smal...