Simply flanking the piezoelectric layer with thin concentric layers of metal would not work because metals tend to have a low viscosity.
仅仅在两侧安放压电层和薄薄的同心金属层是起不了多大作用的，因为金属的粘度很低。
2
The method of decomposition and machinability evaluation used for multi-layer and concentric holes of complex box-shaped parts is discussed and it has been applied to CAPP-NC system.
针对复杂箱体多层同轴孔的分解和加工性判断进行了研究，并应用于CAPP - NC系统中。
3
The dryer shaft is welded with several sets of multi-layer non-concentric seamless tubes, each of which is comprised of multiple seamless tubes having different sizes bent in Archimede's spiral.