A modified gambler's ruin model of polyethylene chains in the amorphous region

被引:5
作者
Duan, ZH [1 ]
Howard, LN [1 ]
机构
[1] FLORIDA STATE UNIV,DEPT MATH,TALLAHASSEE,FL 32306
关键词
semicrystalline polymers; random walk; difference equations;
D O I
10.1073/pnas.93.19.10007
中图分类号
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号
07 ; 0710 ; 09 ;
摘要
Polyethylene chains in the amorphous region between two crystalline lamellae M unit apart are modeled as random walks with one-step memory on a cubic lattice between two absorbing boundaries. These walks avoid the two preceding steps, though they are not true self-avoiding walks. Systems of difference equations are introduced to calculate the statistics of the restricted random walks, They yield that the fraction of loops is (2M - 2)/(2M + 1), the fraction of ties 3/(2M + 1), the average length of loops 2M - 0.5, the average length of ties 2/3M(2) + 2/3M - 4/3, the average length of walks equals 3M - 3, the variance of the loop length 16/15M(3) + O(M(2)), the variance of the tie length 28/45M(4) + O(M(3)), and the variance of the walk length 2M(3) + O(M(2)).
引用
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页码:10007 / 10011
页数:5
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