Co@CNT/CN nanocomposites were obtained by a simple one-pot co?precipitation method using dicyandiamide, glucose and cobalt nitrate as raw materials. The effect of carbon nanotubes (CNTs) on the catalytic activity of Co was investigated by X-ray diffraction (XRD) and electrochemical tests. The results show that Co@CNT/CN can be obtained only at the calcination temperature of 850 ℃. And after electrochemical performance test, it was found that the electrocatalytic activity of Co@CNT/CN material with carbon nanotubes was significantly higher than that of other samples, mainly because carbon nanotubes have special conductivity, but also can promote the separation of Co elemental, reduce the agglomeration phenomenon, so as to obtain higher electrocatalytic activity.

The parameters of PID controller determine the stability and speed of tension control system, so it is important to study the parameter tuning optimization of classical PID controller in winding tension control. The PID tension controller based on the modified whale algorithm is designed by combining PID and modified whale optimization algorithm with winding tension control as an entry point. The improved whale algorithm (L?WOA) is combined with PID in order to improve its convergence speed and convergence accuracy when rectifying the PID parameters. A mathematical model and a dynamic torque balance equation are developed to analyze the effect of wire speed and web diameter on web tension. The parameters are optimized using the modified whale algorithm and various other algorithms, respectively, and the results show that the PID controller optimized by the improved whale algorithm proposed in this paper has the advantages of rapid response, more steady output, sturdy anti?interference ability and better robustness when the PID controller is controlled.