Fiberhome Engineer

The protagonist Lin Zhiyuan, a top military engineer and military history enthusiast from 2025, accidentally traveled back to Shanghai in 1937 on the eve of the Songhu Battle. He doesn't have a system that can change his fate, nor can he conjure weapons out of thin air, but he has the next 80 years of material science, mechanical principles, and tactical ideas in his mind. How will he use the knowledge that transcends the times to "sharpen the war blade" for the soldiers who fought bloody battles in the context of absolute weakness, and write a legend of the Anti-Japanese War belonging to technicians in the gaps in history?