A Terahertz or THz wave usually refers to an electromagnetic wave with a frequency between 0.1 THz and 10 THz, between the microwave and the infrared. The terahertz time-domain spectroscopy system is a coherent detection technology that can simultaneously obtain the amplitude information and phase information of the terahertz pulse. By performing Fourier transform on the time waveform, the optical parameters such as absorption coefficient and refractive index of the sample can be directly obtained.

In the textile industry, azo dyes are an important raw material and a large class of organic substances that cause increasing environmental risks. These azo dyes are potentially toxic and difficult to biochemically handle. Therefore, it is of great environmental significance to take active and effective measures to treat and control azo dyes.

Tungsten-based high specific gravity alloys are widely used in the defense industry and aerospace for their high performance, high strength, high toughness, strong absorbing ability, good electrical and thermal conductivity, high corrosion resistance and good ductility.  And civil industry, is a very important dual-use material for both military and civilian.

Flotation separation of Scheelite from calcium gangue minerals is a difficult and hot topic in the field of mineral processing. In the actual production of scheelite, most of them adopt the Petrov method of fatty acid collector roughing at room temperature - concentrating and adding a large amount of sodium silicate to warm and concentrate to realize the flotation separation of Scheelite from calcium gangue minerals such as fluorite and calcite, and obtain qualified Scheelite Concentrate products.

As a typical transition metal oxide functional material, tungsten trioxide has been extensively studied by researchers in lithium ion batteries, electrochromic, photochromic, photoluminescence and sensors due to its rich chemical valence. In addition, WO₃ is an important n-type semiconductor photocatalyst, and shows high catalytic activity in the field of photocatalytic degradation of pollutants in water.

Vanadium dioxide (VO₂) is a well-known phase change material with superparamagnetism, non-linear current/voltage properties and reversible infrared light response characteristics. In order to reduce the reversible phase transition temperature of vanadium, tungsten doping is usually needed to improve its structure. With phase transition, the electrical conductivity, infrared transmittance, resistivity and reflectivity of tungsten-doped M-phase VO₂ will change abruptly, which makes tungsten-doped VO₂ have wide application prospects in intelligent temperature-controlled films, thermistor materials, photoelectric switch materials, infrared detection materials and other fields.

Tungsten carbide is a compound composed of tungsten and carbon. Its hardness is similar to that of diamond. It has good hardness and stable properties. It is not only used in cemented carbide, but also as wear-resistant and corrosion-resistant materials for iron-based or nickel-based alloys.

Tungsten is one of the widely used electrode materials. However, due to the low emission efficiency of pure metal tungsten electrode, and Recrystallization at high temperature to form equiaxed grain structure, the tungsten wire sags and breaks. Therefore, tungsten electrode can be widely used in various kinds of small and medium vacuum electronic devices, but it can not meet the requirements of high power microwave devices with high current density and long life.

Electrical contact materials play an important role in instruments and electrical switches. With the development of high-voltage power transmission and transformation to large capacity and ultra-high voltage, the improvement of automation level and sensitivity of low-voltage power distribution system and control system, as well as the renewal of electronic industrial products, have put forward new requirements for electrical contact materials.

Cemented carbide is a kind of alloy material which is made by powder metallurgy process, with high hardness and refractory metal carbide powder (WC, TiC, TaC, NbC, etc.) as the main phase and transition metal cobalt, nickel as the binder phase. With high hardness, high strength, high toughness, wear resistance, high temperature resistance and small expansion coefficient, it is widely used in cutting, drilling, mining, tool forming and wear-resistant parts and other fields.