In the 21st century, energy and environmental pollution have become a worldwide problem. The development and application of new energy sources is imminent. Lithium-ion batteries have advantages such as high operating voltage and high specific energy, and have been applied to portable electronic products such as laptops, mobile phones and digital cameras. In recent years, the rapid development of full electric vehicles and hybrid electric vehicles has provided a huge market prospect and high-speed development for lithium-ion batteries. It also poses new challenges for performance improvement and cost reduction of lithium-ion batteries.

At present, China's major cities are booming in the construction of rail transit projects. Due to the great advantages, the shield tunneling method has been widely used in the construction of rail transit tunnels.

Tungsten disulfide (WS2) is a hard\dry lubricant with characteristics similar to graphite. It has excellent high temperature resistance and extreme pressure resistance. It has good attach to metal surfaces and low thermal conductivity. WS2 was first applied to the lubrication of key parts of the Mariner project’s spacecraft. What’s more, it was used to prepare high temperature resistant grease and engine oil.

Tungsten disulfide (WS2) is a hard\dry lubricant with characteristics similar to graphite. It has excellent high temperature resistance and extreme pressure resistance. It has good attach to metal surfaces and low thermal conductivity. WS2 was first applied to the lubrication of key parts of the Mariner project’s spacecraft. What’s more, it was used to prepare high temperature resistant grease and engine oil.

The fifth-generation jet fighter is the most advanced generation of fighters in the world. It is fully maneuvered with low detectability technology and has high maneuverability, advanced avionics system, highly integrated computer network, excellent battlefield situational awareness and information fusion capabilities.The fifth-generation fighters currently in service are only the US F-22, F-35, Russia's T-57 and China's Chengdu J-20.

Photoelectrochemical cells (PEC) decompose water to produce hydrogen to convert solar energy into chemical energy. It is considered to be a feasible solution to replace the current fossil fuel based energy. Semiconductor material is an important research direction in this field.

3D printing technology is also known as additive manufacturing. The use of this technology to manufacture metal parts is somewhat the same as the traditional powder metallurgy. They both use powder material such as ceramic powders and metal powders. The difference is that the material powder is not joined by sintering, but is formed by using a special adhesive to "print" the cross section of the part onto the material powder.

When an aircraft is flying, its balance will affect the controllability, performance and safety of the aircraft. It is important to maintain a stable center of gravity for optimal control and compliance with flight safety standards. It is important to distribute the weight to allow the aircraft to be balance after considering the weight of onboard equipment, passengers and fuel. In order to achieve this process, it is necessary to temporarily or permanently install the counterweight.

The single crystal blade is a cast blade with only one oriented crystal grain, which eliminates the lateral grain boundary sensitive to voids and cracks, so that all grain boundaries are parallel to the stress axis direction, thereby improving the performance of the alloy. In the past 60 years, single crystal turbine blades have been critical to the development of jet engines and have been an important technology for the development of the aircraft industry.

Tungsten disulfide (WS2) is a silver-gray lubricant powder, with an extreme low friction (COF: 0.03) and excellent thermal stability and pressure resistance. When coated on a substrate, it forms a 0.5 micron thick layer of WS2 coating, which reduces the friction and increases thermal stability and pressure resistance of it. Here are   four coating methods to apply WS2 powder: