Abstract-The time synchronization in the virtual radio system is determined as one of thorny technical problems. Especially in TT&C (Telemetry、Tracking and Command) system, it requires incredible precision with time. A novel method for time synchronization by high-precision in a unified virtual radio model specially designed is derived based on AD/DA cache and software cache in the present study. The unified virtual radio model with distributed frame is designed for most applications of virtual radio. And on this basis, the time synchronization strategy is detailed on time synchronization strategy from two designs of daughter card and front-end computer software. Finally, it is also discussed preliminary that time delay of demodulation for this model have an effect on radio system (TT&C).

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Using semi automatic manual flux cored welding methods, selection of Φ 2.8 (V-100Mo) cored wire for overlaying welding in 36 (Q235B) steel substrate with different welding processes for multi-layer welding experiment. The deposited metal microstructure and mechanical properties of welding rod are analyzed. The hardness and bending strength of deposited metal are investigated. The results show that the hardness of the deposited layers depends on the microstructure. After welding, bending strength improved significantly by using heat preservation and slow cold. Finally the reasonable welding process which has high hardness and good bending performance is determined.

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