Spring-bead chain definition

As discussed in Chapter 3, each bead of the Rouse chain, under ceaseless collisions with fast moving small molecules and/or microstructural segments, is undergoing Brownian motion. At the same time the bead at Rn is affected by both the tensile forces on the nth and (n — l)th bonds. According to the same definition used in Eqs. (6.4) and (6.5), the total force asserted on the nth bead by the springs is expressed as... 

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