The purity of a metal is relative to impurities. Broadly speaking, impurities include chemical impurities (elements) and physical impurities (crystal defects). Physical impurities mainly refer to dislocations and vacancies, while chemical impurities refer to atoms from outside the matrix that are incorporated in the form of substitution or interstitial.

The G value is the solar gain value (shading coefficient). It is a measure of the total solar energy transmittance. The southern region requires a lower G value, the better, and the northern region requires a higher G value, the better.

Platinum, also known as platinum, is more expensive than gold and is often used because of its many excellent properties. Platinum has a melting point as high as 1774°C and is chemically stable. It does not undergo chemical changes after burning in the air and does not absorb moisture. Most chemical reagents have no corrosive effect on it.

Chemical vapor deposition is a thermochemical reaction process, which is a gaseous chemical reaction carried out at a specific temperature and on the surface of a specially treated substrate (including cemented carbide and tool steel). CVD technology is often classified by reaction type or pressure, including low-pressure CVD (LPCVD), atmospheric pressure CVD (APCVD), plasma-enhanced CVD (PECVD), and Hot-Filament cVD and Laser Induced CVD.

The reduction method of metal oxides and salts is one of the most widely used powder preparation methods. Solid carbon can be used to reduce iron powder and tungsten powder, and hydrogen or decomposed ammonia can be used to produce tungsten, molybdenum, iron, copper, cobalt, nickel and other powders; natural gas and coal gas can be converted to produce iron powder, etc., and metals such as sodium, calcium, and magnesium can be used as reducing agents to produce tantalum, niobium, titanium, zirconium, thorium, uranium and other rare metal powders.