With the continuous development of science, technology and productivity, power electronic equipment plays an increasingly important role in our lives and work. Among them, the BTW69 thyristor, a key power electronic device, has a wide...

1. Lubrication The hydrophilic group in the superplasticizer has solid polarity, so the adsorption film of the water-reducing representative externally of the concrete particles can form a stable solvated water film with water molecules. This water...