As a phase change compound, vanadium dioxide (VO2) undergoes a transition from a high temperature tetragonal phase to a low temperature monoclinic phase at around 68 ° C. 

Nitrogen oxides (NOx) are important atmospheric pollutants that can cause environmental problems such as acid rain and photochemical smog, as well as direct damage to the human respiratory system. In addition, it also has an important contribution to the increasingly serious ash pollution in our country. Therefore, effective control of NOx emissions is a major strategic need in China.

Ceramic material is one of the most promising materials because of its excellent properties such as high temperature resistance, corrosion resistance and wear resistance. However, the brittleness of ceramic materials has been restricting its further development.

High specific gravity tungsten-based alloys are mainly composed of nickel, iron, cobalt, copper, chromium and other elements. The existing methods of preparing tungsten-based alloy materials are usually powder injection moulding, mainly using wax matrix system to make powder injection moulding.

Electric contacts are the core components of low-voltage electrical appliances. They take on the task of switching on and off the circuit in various control switches. They are widely used in military, aviation, aerospace and industrial control fields. The electrical properties of silver-based contact materials have a vital impact on the long life and high reliability of various electronic control systems.

Lactide is an important raw material for preparing high molecular weight polylactic acid. Its optical purity and chemical purity determine the quality of high molecular weight polylactic acid. At present, the two-step synthesis of lactide from lactic acid is widely used.

With the increasing shortage of global petroleum resources and the pressure of CO₂ emission reduction, diesel vehicles with good fuel economy and strong power are paid more and more attention. The trend of "diesel" of global automotive power has become increasingly evident. However, compared with gasoline vehicles equipped with three-way catalysts with relatively mature technology, the NO_x and PM in the exhaust of diesel vehicles using lean burn technology have become the bottleneck restricting their popularization and application.

Tungsten tailings are gangue minerals that remain after tungsten concentrate is selected from tungsten ore. The main mineral components include garnet, quartz and mica. For a long time, tungsten tailings, as a kind of solid waste, have been piled on the surface or backfilled into the mine. At present, there is no really efficient and large-scale way to utilize tungsten tailings.

Tungsten oxide inorganic semiconductor materials have been applied in photocatalysis, photochromism, gas sensitivity, electrochromism, and field emission due to their unique physical and chemical properties. Researchers can prepare tungsten oxide micro-nanomaterials with different sizes and morphologies, such as nanosheets, nanorods and hollow spheres.

At present, domestic aero-engine conduits are constrained by selected metal materials, overall design layout, hydraulic and pneumatic functions, and must be manufactured by welding at their joint joints. At present, the types of conduits used in aero-engine welded joints are numerous, and the shape of the conduits themselves. In order to ensure the strength of the weld, manual fusion welding is usually used to connect the joint with the main body of the pipe.