sphere of instability

• 不稳定区

sphere of instability的用法和样例：

例句

1. The excitation frequencies of all simple and combinational instability regions shifted because of the mode variations with increasing ply-angle of the composite plates.
   随复材板叠层数目增加，各单频与混频不稳定区之激发频率往高频处偏移，且各不稳定区激发频率之间距亦增加。