摘要
利用转移矩阵方法研究了声波在短程关联边耦合一维二元合金链中的传播特性。结果表明:在边耦合原子与主链原子总是相同或总是不相同的情况下,如果主链上原子是随机的,则系统不存在共振透射态;如果主链上原子是随机的,但都是以二聚体的形式出现,则系统存在多个共振透射频率。在边耦合原子总是与主链原子相同时,有4个共振频率。并且,若一种原子的刚度系数与质量比值ηa保持不变,其中两个共振透射频率不随另一种原子的刚度系数与质量比值ηb的变化而变化,其余两个共振透射频率随ηb的增大而增大。在边耦合原子与主链原子总是不相同时,若ηb较小,该链有3个共振频率。并且,当ηb增大到ηa的两倍时,最低的共振频率分裂为两个共振频率,其余两个共振频率都随ηb的增大而增大。
The transport properties of acoustic waves in a side-coupled one-dimensional binary chain with short-range correlations are studied by using the transfer matrix method. The results show that the res- onant tunneling state is absent in the system whether the side coupled atom is always the same as the corresponding atom in the main chain or not, in which the atoms of main chain randomly appear. There are many resonant tunneling states when the atoms in the main chain are random dimers. Four resonant tunneling states appear in the side-coupled chain, in which the side-coupled atoms are always the same as the corresponding atoms in the main chain. When the ratio ria of the stiffness and the density of one kind of the atoms is constant, two resonant frequencies do not change with the ratio rib of the stiffness and the density of the other kind of the atoms, and the other two resonant frequencies increase with the increas- ing ηb. When the ratio is smaller, three resonant tunneling states appear in the chain, where the side- coupled atoms are always not the same as the corresponding atoms of the main chain. Moreover, the lowest resonant frequency will split into two frequencies when the ratio ηb is double of the first ratio ηa. And the two other resonant frequencies increase with the increasing ηb.
出处
《南京航空航天大学学报》
EI
CAS
CSCD
北大核心
2013年第6期813-818,共6页
Journal of Nanjing University of Aeronautics & Astronautics
基金
国家自然科学基金(11175086
51175245)资助项目
江苏省自然科学基金(BK2010073)资助项目
南京航空航天大学基本科研业务费专项科研基金(NZ2012308)资助项目
关键词
无序结构
弹性波
共振透射
disordered structures
acoustic waves
resonant tunneling states
作者简介
通信作者：胡冬生，男，副教授，1968年出生，E-mail：dongshenghu@nuaa．edu．cn。
