periodicles期刊periodicadj.周期的；定期的；间歇的；完句的periodic epidemicity周期性流行periodic restriction周期制约periodic convergence周期收敛periodic undulations周期性起伏periodic performance周期性行为periodic disturbance周期干扰periodic gain region周期性增益区periodic lubrication周期润滑Periodic time window周期时间窗periodic coagulation间歇凝固