The segment(s) and optionally the element, are preferably in an annulararray to form a ring, necklace and the like and may be of the same or different configurations.
所述段和任选的单元件优选以环形排列以构成戒指、 项链等，并可具有相同或不同的结构。
2
The results show that the annulararray in different combination and excitation condition has radiation characteristics of monopole, dipole and quadrupole of acoustic logging.