According to the characteristics of Unmanned Aerial Vehicle(UAV) data link synchronization technique,the paper analyses how the different offsets affect the demodulation,realizes the combined synchronization of frequency domain and that of time domain separately by using pilot and cyclic prefix,and proposes the plan of time-frequency two-stage combined synchronization.

The corrosion survey for the complex unit during the turnaround finds out the minor corrosion in the primary distillation tower (metallurgy: Q235-B) with a coupon corrosion rate of 0.

The paper taking Guangzhou ethylene project as an example, introduce the production feature, weak area, and organizing production principle and measure of ethylene complex unit.