“cracking”的概念、定义、翻译、参考文献-科学参考

cracking

Chemistry

The process of breaking down chemical compounds by heat. The term is applied particularly to the cracking of hydrocarbons in the kerosine fraction obtained from petroleum refining to give smaller hydrocarbon molecules and alkenes. It is an important process, both as a source of branched-chain hydrocarbons suitable for gasoline (for motor fuel) and as a source of ethene and other alkenes. Catalytic cracking is a similar process in which a catalyst is used to lower the temperature required and to modify the products obtained.

Chemical Engineering

A process in which high molecular weight hydrocarbons are broken down into lower molecular weight products by the effect of high temperature in the presence of an alumina-silica catalyst. The process is used to produce gases such as methane, ethane, propylene, and propane that are the subsequent raw materials used for the manufacture of a wide range of products including of plastics, detergents, textiles, and agricultural chemicals. Thermal cracking uses high temperatures and pressures to break the molecular bonds to form smaller molecules. Catalytic cracking uses a catalyst to assist in the breakdown of the molecules. In a fluidized bed catalytic cracker, the catalyst is present as a bed of very fine particles which is agitated by the vaporized hydrocarbons as they pass up through the bed.

Computer

1. Gaining, or attempting to gain, unauthorized access to computers with malicious intent. Distinguished from hacking, which may be benevolent or neutral.
2. Obtaining plaintext passwords or encryption keys, usually from information protected by irreversible encryption.

Geology and Earth Sciences

Breaking down or decomposition of large, more complex molecules, particularly hydrocarbons, into small simple molecules, usually by heating. The process can occur naturally, resulting in older deposits containing lighter crude oil than those of younger fields. Commercially, cracking is carried out in oil refineries.

单词	cracking
释义	cracking Chemistry The process of breaking down chemical compounds by heat. The term is applied particularly to the cracking of hydrocarbons in the kerosine fraction obtained from petroleum refining to give smaller hydrocarbon molecules and alkenes. It is an important process, both as a source of branched-chain hydrocarbons suitable for gasoline (for motor fuel) and as a source of ethene and other alkenes. Catalytic cracking is a similar process in which a catalyst is used to lower the temperature required and to modify the products obtained. Chemical Engineering A process in which high molecular weight hydrocarbons are broken down into lower molecular weight products by the effect of high temperature in the presence of an alumina-silica catalyst. The process is used to produce gases such as methane, ethane, propylene, and propane that are the subsequent raw materials used for the manufacture of a wide range of products including of plastics, detergents, textiles, and agricultural chemicals. Thermal cracking uses high temperatures and pressures to break the molecular bonds to form smaller molecules. Catalytic cracking uses a catalyst to assist in the breakdown of the molecules. In a fluidized bed catalytic cracker, the catalyst is present as a bed of very fine particles which is agitated by the vaporized hydrocarbons as they pass up through the bed. Computer 1. Gaining, or attempting to gain, unauthorized access to computers with malicious intent. Distinguished from hacking, which may be benevolent or neutral. 2. Obtaining plaintext passwords or encryption keys, usually from information protected by irreversible encryption. Geology and Earth Sciences Breaking down or decomposition of large, more complex molecules, particularly hydrocarbons, into small simple molecules, usually by heating. The process can occur naturally, resulting in older deposits containing lighter crude oil than those of younger fields. Commercially, cracking is carried out in oil refineries.
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