But once in awhile, one of these plus twos comes in almost on axis, and it gets whipped around by the Coulombic repulsive forces.

但是偶尔一个带两个正电荷的粒子,以接近于轴的位置进入，会快速的移动到周围,由于库仑斥力的作用。

麻省理工公开课 - 固态化学导论课程节选

We talked about this a little bit in section last week, when you eat vegetables or meat, you're eating a lot of DNA but that doesn't enter the cells of your body because of the barrier properties of cell membranes.

这个我们上周讨论会讲过一些,我们在吃蔬菜或者肉类时,摄入了大量DNA,它们之所以不会进入你的体细胞,就是由于细胞膜的这种屏障作用

耶鲁公开课 - 生物医学工程探索课程节选