Underhill Patrick T, Doyle Patrick S
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2007 Jul;76(1 Pt 1):011805. doi: 10.1103/PhysRevE.76.011805. Epub 2007 Jul 19.
We investigate DNA stretching during electrophoresis when the mobility abruptly changes. This is a simplified geometry that produces a nonhomogeneous strain rate over the scale of a single molecule. An effective Weissenberg number (Wi) and Deborah number were identified, and the degree of stretching was examined as a function of these two parameters. The system does not undergo a coil-stretch transition. The finite extensibility of the chains only affects the response if the chain is stretched to a significant fraction of the contour length. The wormlike chain shows a characteristic approach to full extension of Wi(-1/2).
我们研究了电泳过程中迁移率突然变化时的DNA拉伸情况。这是一种简化的几何结构，在单个分子尺度上产生了非均匀应变率。确定了一个有效魏森贝格数（Wi）和德博拉数，并研究了拉伸程度作为这两个参数的函数。该系统不会经历卷曲-拉伸转变。只有当链被拉伸到轮廓长度的很大一部分时，链的有限可伸展性才会影响响应。蠕虫状链呈现出一种特征性的接近Wi(-1/2)完全伸展的方式。
