中文摘要：

太阳总辐照在23和24太阳活动周的显著周期分别为35d和26d，进而推断太阳的准旋转周期在23和24太阳活动周也分别为35d和26d．太阳总辐照在24周极小期的值可能与蒙德极小期的值相近．在一个太阳旋转周到几个月的时间尺度上，太阳黑子是引起太阳总辐照变化的主要原因，但不是唯一的原因；在几天到一个太阳旋转周的时间尺度上，太阳总辐照的变化与MgII特征指数是不相关的．

英文摘要：

The significant periods of total solar irradiance are 35 days and 26 days in solar cycle 23 and 24, respectively. It is inferred that the solar quasi-rotation periods are 35 days and 26 days in solar cycle 23 and 24, respectively. The value of total solar irradiance in solar cycle 24 minimum should be close to the value of Maunder minimum. On short time scales, sunspots should be the main reason to cause variations of total solar irradiance on the scale of one solar rotation cycle to several months, but not the unique one, and the variations of total solar irradiance are not related with the Mg II index on the scale of a few days to one solar rotation cycle.