Vanadium oxides include V2O3, V3O5, V4O7, V5O9, V6O13, VO2 and V2O5, in which the atom ratio of oxygen to vanadium varies from 1.5 to 2.5. Among them, VO2 presents a reversible first-order metal-insulator transition (MIT) at a critical temperature (Tc). Intensive investigations have been made on the preparation of VO2 and its properties. It is generally believed that VO2 is a monoclinic structure (M), and presents semiconductive and relatively infrared transparent below Tc, whereas it transforms into tetragonal structure (R), and presents metallic and infrared reflection above Tc. These features make the VO2 suitable for the applications in intelligent energy windows coating, optical switching devices, optical data storage medium, electrodes for electrochromics, lithium batteries and supercapacitors, etc. Nevertheless, the high critical transition temperature of VO2 material (about 68 °C) limits its application.

Molybdenum carbide (Mo2C) and tungsten carbide (WC) have attracted attention for nearly four decades, due to their noble metal-like behavior in heterogeneous catalysis. These materials are catalytically active in reactions such as hydrocarbon hydrogenolysis and isomerization, ammonia synthesis, methanation, methane reforming and water–gas shift. Existing strategies for preparing high surface area carbides frequently produce non-stoichiometric surfaces, containing either residual oxygen or excess carbon which can block the active surface. Thus, an effective method that can remove the surface carbon is necessary.

Tungsten heater is used in vacuum coating furnace, which is widely used to coat the surface of bottle lid. With the development of bottles and lids, beauty is not the only target now, fashion, anti-artificial, different are all the targets with the times going.

Ammonium paratungstate (APT), is a prevalent starting material in the production of tungsten oxides, catalysts, tungsten alloys, electrochromic materials and so on. It is produced by crystallization from purified ammonium tungstate solutions in batch and continuous processes. Commonly, repeated crystallization is used as a method of improving the quality of the product.

Chitosan (Chit) is a non-toxic derivative of chitin, namely the β-(1,4)- linked polysaccharide of D-glucosamine. Application of chitosan coatings on substrates by the dip coating technique was proved to be highly effective in corrosion prevention by producing thin layers with controlled characteristics. The transparency of chitosan coatings also constitutes an advantage as it does not change the appearance of the underlying substrate.

Thermal decomposition of ammonium paratungstate (APT) in air has been investigated previously. The thermal decomposition of ammonium paratungstate (APT) in hydrogen (H2) now has been studied to investigate the decomposition process.

Low grade tungsten concentrate has such characteristics as a high content of calcium and impurities, and a low content of WO3. But it has a lower price than standard tungsten concentrate.

Ammonium paratungstate (APT), is an important starting material in tungsten industry. Through reduction of APT, produces most of the tungsten products, including tungsten trioxide, tungsten bronze, etc.

Tungsten alloy application in military industry is mainly for aerospace, weapon and nuclear industry. Tungsten alloy (WHA) is heavy metal with main content of tungsten 90~97%, and other elements, such as copper, nickel, iron, manganese, and molybdenum.

It seems that there is no correction between tungsten heater and alcohol bottle, however, they are related together by the vacuum coating furnace, which can make the bottles with colorful surface.