Anomalous diffusion in branched elliptical structure  

作　　者：Kheder Suleiman 张雪岚 王二辉 刘圣娜 郑连存 Kheder Suleiman;Xuelan Zhang;Erhui Wang;Shengna Liu;Liancun Zheng(School of Energy and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China;School of Mathematics and Physics,University of Science and Technology Beijing,Beijing 100083,China)

机构地区：[1]School of Energy and Environmental Engineering,University of Science and Technology Beijing,Beijing 100083,China [2]School of Mathematics and Physics,University of Science and Technology Beijing,Beijing 100083,China

出　　处：《Chinese Physics B》2023年第1期137-144,共8页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant Nos.11772046 and 81870345)。

摘　　要：Diffusion in narrow curved channels with dead-ends as in extracellular space in the biological tissues,e.g.,brain,tumors,muscles,etc.is a geometrically induced complex diffusion and is relevant to different kinds of biological,physical,and chemical systems.In this paper,we study the effects of geometry and confinement on the diffusion process in an elliptical comb-like structure and analyze its statistical properties.The ellipse domain whose boundary has the polar equationρ(θ)=b/√1−e^(2)cos^(2)θ with 0<e<1,θ∈[0,2π],and b as a constant,can be obtained through stretched radius r such that Υ=rρ(θ)with r∈[0,1].We suppose that,for fixed radius r=R,an elliptical motion takes place and is interspersed with a radial motion inward and outward of the ellipse.The probability distribution function(PDF)in the structure and the marginal PDF and mean square displacement(MSD)along the backbone are obtained numerically.The results show that a transient sub-diffusion behavior dominates the process for a time followed by a saturating state.The sub-diffusion regime and saturation threshold are affected by the length of the elliptical channel lateral branch and its curvature.

关 键 词：anomalous diffusion Fokker–Planck equation branched elliptical structure 

分 类 号：O29[理学—应用数学]