periodic law周期律,门捷列夫定律periodicadj.周期的；定期的；间歇的；完句的periodic hydrarthrosis of knee策尔尼氏病periodic acid oxidation method高碘酸氧化法periodic differential equation周期微分方程periodicboundary value problem周期边值问题Periodic ELINT Analysis Report定期电子情报分析报告periodic acid-Schiff reagent高碘酸-希夫试剂, PAS试剂periodic pulse metering method周期脉冲度量法periodic acid-Schiff's stainperiodic temperature variation周期性温度变化periodic side-band switching周期性边带转换