So if we want to talk about the volume of that, we just talk about the surface area, which is 4 pi r squared, and we multiply that by the thickness d r.

如果我们要讨论它的体积，我们要用的是表面面积，也就是４πｒ的平方，乘以厚度ｄｒ

麻省理工公开课 - 化学原理课程节选

But as an object gets smaller, the ratio between its surface area and its volume rises.

ECONOMIST: Small wonders

Self-seeding may explain why large tumors tend to grow (in percentage terms) more slowly than small tumors: It could be that growth is a function of surface area rather than volume.

FORBES: Magazine Article

The result, they claim in a paper that will appear this month in the Journal of Physical Chemistry, is a nanofibre material with an extremely high ratio of surface-area to volume.

ECONOMIST: Space-age soot