当粒子撞击到屏幕的时候就记录一次。

They count where these particles hit the screen.

youdao

这一碰撞可发生在两个相斥的粒子之间，并不要求接触下产生的撞击。

The collision can occur between two charged particles; it need not involve direct physical contact.

youdao

这一碰撞可发生在两个相斥的粒子之间，并不要求接触下产生的撞击。

The collision can occur between two charged particles; it need not involve direct physical contact.

youdao