Nano-cemented carbide not only has high hardness, good wear resistance, but also has high strength and toughness, and has good comprehensive properties. Its application field is expanding constantly. It has been widely used in manufacturing micro-drills, precision tooling and difficult cutting fields. As the basic raw material of nano-cemented carbide production, nano tungsten carbide has been prepared and its properties for the production of nano-cemented carbide. It has a great influence and has almost become the bottleneck in the production of nano-cemented carbide. For this reason, many enterprises and research institutes in many countries have carried out a lot of research.

Among the two-dimensional transition metal sulfides, single-layer nano-tungsten disulfide is a typical sandwich layered structure. Because of its relatively weak van der Waals force between layers, it can also be peeled into single or few layers of nanosheets. It is considered to be another important two-dimensional nanosheet material besides graphene, which has unique physical, chemical and electrical properties.

Tungsten has the characteristics of high temperature resistance, high strength, high hardness and low thermal expansion coefficient. It is an irreplaceable key material in many fields, especially in the field of national defense, military industry and aerospace. However, its high density (too heavy) limits its application, so it is necessary to develop new lightweight materials with better comprehensive properties than tungsten.

The case of the girl in Yueqing, Zhejiang Province, who was killed by the drip and the wind, has aroused the attention of people from all walks of life. The occurrence of this case also reminded people of the Zhengzhou flight attendant’s car murder case three months ago. For a time, the voice of the question about the Drip Trip platform on the Internet was soaring. This also sounded the alarm of self-protection for the majority of female friends! We should still learn how to protect ourselves. Not only do we need to pay attention when we take a taxi, but we should also improve our vigilance at any time. After all, danger is everywhere, and it is impossible to prevent it! In order to be in distress, not only fear, Sun Tzu’s art of war tells us that it is necessary to have a plan to prepare for it! Below, mainly from three points to talk about how girls should defend themselves.