undulance
1. Ektexine surface veins of Chinese and Russian seahuckthorn are approximate to smoothness, and those of Mongolian seabuckthorn have cockle undulance.
外壁表面纹饰中国沙棘和俄罗斯沙棘近于平滑,蒙古沙棘有皱波状;
2. The Design of Intelligent High Frequency and Precision Function Undulance Signal Generator
智能高频精密函数波形发生器的设计