Physical and chemical properties of gold

Gold is a precious metal and was one of the first metals discovered and exploited by people. It has been around for more than 6,000 years. It is an important raw material for making jewelry and currency, so it is known as the “king of me.......

Abnormal noise analysis of DF_7 locomotive gearbox


Field experience Exceptional noise analysis of DF7 locomotive gearbox Cui Yuqin, Jie Sidong (Beijing Erqi Locomotive Works, Beijing's main reason for analysis, and proposed corresponding improvement measures DF7 locomotive gearbox with starter gearbox, auxiliary gearbox static Pressure.......