The law states that blood flow is proportional to the fourth power of the vessel's internal radius.

定律显示，血流与血管内半径的四次方成正比。

We explain the size-flow relationship through a law, and that law states that blood flow is proportional to the fourth power of the vessel's internal radius.

我们通过一个定律来解释大小-流量关系，这个定律表明血液流量与血管内径的四次方成正比。