Radiotherapy (RT) is one of the most widely used methods to treat cancer in clinic. Its main principle is to inhibit the proliferation of cancer by using high intensity ionizing radiation (X-ray or gamma-ray) with very strong penetrating force.

Nitrogen oxides (NO_x) are toxic and harmful gases that cause environmental problems such as acid rain and photochemical smog and pose a great threat to human beings. It is very important for human health to study high performance gas sensitive materials and devices for accurate detection and monitoring of nitrogen oxides.

Pearlescent pigments consist of metal oxide coated mica. Because of their excellent chemical corrosion resistance and high temperature resistance, pearlescent pigments have been widely used in building decoration, ink, automotive paint, textile printing and other fields. So far, the mature pearlescent pigments are titanium oxide (titanium dioxide) / tin oxide (SnO₂) / iron oxide (Fe₂O₃) - mica pearlescent pigments.

Heteropoly acids with Keggin structure generally refer to inorganic compounds expressed in the following general chemical formulas. They are one of the most active catalysts used in acid catalytic reactions and redox reactions. It has good catalytic properties for the hydration and esterification of olefins, etherification of epoxides, alkylation of olefins and aldehydes, epoxidation of olefins and alkyl aromatization, etc. It has wide applications in petrochemical industry.