Of course, MASW has some shortcomings, such as the restrictions of horizontal resolution and the two-dimensional forward.
当然MASW还有一些不足，如横向分辨率的限制，还不能实现二维正演等，需做进一步的研究。
2
Four-dimensional point groups are deduced by generating normal three-dimensional point groups with certain restrictions which are unique for modulated structures.