中文摘要：

文章研究了162个射电源，其中包括了47个BL Lacs，21个galaxies，94个平谱射电类星体（FSRQs），这些源是通过Michigan大学的26m的射电望远镜观测的。大多数源都包含了3个波段的观测数据：4．8GHz，8GHz和14．5GHz。文中计算了3个子类的平均的流量密度，并且得到了相应的谱指数（αwei），αBL=0．08±0．28，αGAL=-0．91±0．32，αFSRQ=-0．14±0．4。同时也讨论了这些源的射电性质，其中包含了谱指数，流量密度和红移之间的关系，流量密度和谱指数之间的关系。

英文摘要：

In this paper, 162 radio sources, including 47 BL Lacs, 21 galaxies and 94 fiat spectral radio quasars （FSRQs） are studied. All sources were extracted from the University of Michigan Radio Astronomy Observatory （UMRAO） database observed by the 26-meter Michigan Radio Telescope. Most of the sources were observed at three bands： 4.8GHz, 8GHz and 14.5GHz. The average flux densities of the three subclasses are calculated and the weighted average spectral index （αwei）, αBE = 0.08 ± 0.28, αGAL = - 0.91 ± 0.32, αFSRQ =- 0.14 ±0.4 are obtained . Some radio properties are discussed in this paper, including the spectral index, the relation between the flux and the redshift, the relation between the flux and the spectral index.