【摘要】 本文对X射线选择BLLac天体（XBLs）的完备样品进行了较细致的研究，讨论了该样品各观测量的分布、最新发现的几例X射线和ROSAT选择的BLLac天体的Hubble关系及BLLac天体的红移起源问题．更多还原

【Abstract】 The distribution of multiwavelength observation data and effective spectral indices are shown for a complete sample of X-ray selected BL Lac objects (XBLs), and some newly discovered XBLs are added to the Hubble diagram of the complete sample. The results show that their optical emission mechanism is mainly nonthermal, Doppler enhancement (beaming effect) is weak for XBLs, and their redshifts are originally cosmological.更多还原