偶极子模型在颗粒链中的使用范围

Limits for Validity of Dipole Approximation in a Chain of Particles

针对偶极子近似模型认为球体内是均匀电场的条件 ,利用电场唯一性定理 ,设定球体边界不受周围偶极子影响的最低限制值 ,提出了统一的条件 ;分别讨论了在纵向和横向电场中 ,两个球体和无限多球体的颗粒链使用偶极子模型时 ,不同的球体间距与不同介电常数的使用要求 ,超出此范围 ,偶极子模型不再有效。

The Limits for validity of the dipole approximation in a chain of particles,two particles and infinite particles,are presented through the electric field analysis Because of the uniqueness theorem,the inside electric field experienced by a sphere is still uniform if the electric field(the disturbance field)at the surface of this sphere,due to all spheres outside the sphere,is zero It is clear that the dipole approximation is acceptable when the disturbance field at the surface of this sphere is small enough to be negligible According to the influence of the other spheres on the surface electric field of one sphere,the same standard is presented for a chain of particles in longitudinal and transverse field We calculate the different composed values of dielectric coefficients,which decided the limits,with the difference in distance between two adjacent spheres These results are consistent with some previous studies