来自《耶鲁大学开放课程：生物医学工程探索 第18集 第18集》
-
the ones below it are going to move a little slower than that,再下面的更慢一些 -
slower than that, slower than that, slower than that再下面一层较其上层再慢一些 -
until the ones at the very bottom don't move at all直到其底部 完全不移动 -
because they're experiencing friction from the bottom plate.那是由于其受到底板摩擦力的作用 -
If I could look microscopically at what happens如果微观地看 -
when I shear this top plate over the bottom plate当我对这一"三明治"结构的 -
within the layer of fluid between,顶板施以剪切力时所发生的情况 -
I've created a velocity gradient就是我构建了一个速度梯度 -
where the fluid is moving very fast最接近顶板的那层液体 -
near the top plate, slower in the middle,速度最快 中间的要慢一些 -
and not at all at the surface of the bottom plate.靠近底板的那层液体则纹丝不动 -
And by doing this I can measure the force that's required这样一来 我就能计算