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.

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.

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 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.