We use wavelet transform to analyze the daily relative sunspot number series over solar cycles 10-23. The characteristics of some of the periods shorter than ~ 6
Using the 13.7 m radio telescope at Delingha, the millimeter-wave radioobservatory of Purple Mountain Observatory, we made mapping observations in12CO J = 1 - 0
We report on time-resolved spectroscopic observations of the SU Ursae Majorisdwarf nova, YZ Cnc for over 11 h on two nights during its 2002 January superoutburs