Based on years of input from the four geodetic techniques(SLR, GPS, VLBI and DORIS),the strategies of the combination were studied in SHAO to generate a new glo
We compiled the radio, optical and X-ray data of blazars from the Sloan Digital Sky Survey database, and presented the distribution of luminosities and broadban
We present different mass ratio distributions of massive black hole(MBH)binaries due to different mechanisms involved in binary evolution. A binary system of MB