It uses oxygen with a purity of 93.5%-99.2% and combustible gas (such as acetylene) to produce a flame of extremely high temperature, thereby melting the metal. The metallurgical process cannot do without oxygen. In order to strengthen the production of nitric acid and sulfuric acid, oxygen is also required. Instead of using air, a mixture of oxygen and water vapor is blown into the coal gasifier to obtain coal gas with high calorific value.

Oxygen is a colorless and odorless gas, and the most common elementary form of oxygen. Melting point is -218.4°C, boiling point is -183°C. It is not easily soluble in water, and about 30mL of oxygen can be dissolved in 1L of water. Oxygen in the air accounts for about 21%. Liquid oxygen is sky blue. Solid oxygen is blue crystals.

Common tetra-group lead, ferrocene, MMT (methylcyclopentadiene trikarbonyl manganese) or CMT is common, because metal deposits can occur in the inside of the launching machine, resulting in a cylinder wear, spark plug ignition Poor problems such as poisoning, oxygen sensors and ternary catalysts, have been prohibited or constrained. The addition of tetra-element and ferrocene added is known as national standards, and the manganese-based anti-explosive agent is strictly constrained (the detection limit is less than 0.018 g / L). Simple in the market is mainly manganese antnel, and there is a small amount of Dikin anterior explosion.

There are two isomers of 2,4-toluene diisocyanate and 2,6-toluene diisocyanate (TDI). According to the content of the two isomers, there are three standard products in the industry: (1) TDI-65 contains 2,4-TDI65%, 2,6-TDI35%; (2) TDI-80 contains 2,4- TDI80%, 2,6-TDI20%, more common; (3) TDI-100 contains 2,4-TDI100%. Carbon dioxide occurs with water effect. Easy to work with compounds containing active hydrogen atoms. Linear polyurethane or polyurethane resin with diol effect.

Miscible with ether, diethylene glycol, acetone, carbon tetrachloride, benzene, chlorobenzene, kerosene and olive oil. It can react with hydroxyl-containing compounds, water, amines and compounds with active hydrogen atoms to generate carbamate, urea, semicarbazide, etc. Toluene is nitrated with mixed acid to obtain 2,4- and 2,6-dinitrotoluene, and then hydrogenated and reduced in the presence of nickel catalyst to obtain 2,4- and 2,6-diaminotoluene, which is then reacted with light in chlorobenzene solution. produced by gas reaction. It is mainly used as a raw material for the production of polyurethane resins for the production of polyurethane foams, coatings, rubbers, adhesives, sealants, etc. It can also be used as rubber vulcanizing agent, protein cross-linking agent, etc. Contains foam; polyurethane coatings; polyurethane rubber; polyimide fibers and adhesives, etc. are also used.

When the temperature drops to 2.18K, the properties of liquid helium will change suddenly, the viscosity is very small, and it becomes a super fluid that can flow upwards along the wall of the container. The thermal conductivity is 800 times that of copper. It becomes a thermal conductor with excellent thermal conductivity. Its specific heat capacity, surface tension, and compressibility are all abnormal. This abnormal liquid is called liquid helium II, and the normal liquid helium is called liquid helium I.

Can gradually decompose, moist and high temperatures can accelerate decomposition. Can be decomposed by ethanol and silver ion.White crystalline powder.

The solubility in water was 549 g / L at 20 ° C. Relative density 2.400 (deposit density: 0.7).

Addition with hydrogen chloride generates 2-chloropropionic acid. Used in the preparation of acrylic resins and other organic synthesis. It is made by oxidation of acrolein or hydrolysis of acrylonitrile, or made by carbon monoxide, acetylene and water under the action of nickel catalyst.

Only a small part of ammonia molecules react with water to form ammonia monohydrate, which is a weak base that only exists in ammonia.

Industrial ammonia is an aqueous solution containing 25% to 28% ammonia. Only a small part of ammonia molecules react with water to form ammonia monohydrate, which is a weak base that only exists in ammonia.

From the perspective of physics, the methods to eliminate foam mainly include placing baffles or filters, mechanical stirring, static electricity, freezing, heating, steam, radiation, high-speed centrifugation, pressure and decompression, high-frequency vibration, instantaneous discharge and ultrasonic (acoustic) Liquid control), etc., these methods promote the gas permeation rate at both ends of the liquid film and the drainage of the bubble film to varying degrees, so that the stability factor of the foam is smaller than the attenuation factor, and the number of foams is gradually reduced. However, the common shortcomings of these methods are that the use is highly restricted by environmental factors, the defoaming rate is not high, etc., and the advantages are environmental protection and high recycling rate.