But, of course, we want to go all the way to distance, so we take the second derivative and we have this equation for force here.

当然我们最后想要的是距离,所以我们取二阶微,分就有这个式子。

麻省理工公开课 - 化学原理课程节选

You want that shield up so that it pretty well meets your helmet, so it's going to be at a certain distance but it will also go down to where it needs to go down here.

盾牌上缘能与头盔配合保护上身,所以盾牌和身体是要有一定距离的,而盾牌的下缘用来保护下半身

耶鲁公开课 - 古希腊历史简介课程节选

These details aren't important, it is described in your book, but the thing that is important to know is that diffusion occurs fast over short distances, but because of the physics of diffusion it occurs slowly over longer distances.

这些具体细节无关轻重,书上都有,重点是你要明白,距离越短扩散越快,由于扩散现象的物理特性,距离越长扩散越慢

耶鲁公开课 - 生物医学工程探索课程节选