| 单词 | alkene |
| 释义 | alkene noun[C] chemistryspecializeduk/ˈæl.kiːn/us/ˈæl.kiːn/anygasin agroupthatcontainscarbonandhydrogenatoms, with thecarbonatomsjoinedtogether in adoublebond: 烯烃，链烯（双链链接碳氢化合物）Ethene and propene are alkenes.乙烯和丙烯都是烯烃。 Chemicals, chemical compounds & gases
alkene| American Dictionaryalkene noun[C] us/ˈælˌkin/chemistry any of agroupofsubstancesthatcontainonly theelementscarbonandhydrogen, which areheldtogether by achemicalbondin which twoatomssharetwopairsofelectrons Examplesofalkenealkene The data indicated that at least onealkenewas present. From theCambridge English Corpus Paraffins are formed simultaneously with thealkeneseries but no acetylenic hydrocarbons have been detected. From theCambridge English Corpus All reactions proceed via an initial addition of the radical to alkenes, alkynes and aromatic species. From theCambridge English Corpus The relative proportions of alkenes were higher in this group (around 28 % versus 18 % of the total hydrocarbons). From theCambridge English Corpus The chemoselective ruthenium-catalysed olefin metathesis reaction was used to 'staple' together the twoalkenetethers to provide peptides that maintain helical structure, but with enhanced stability. From theCambridge English Corpus Methane, a series of about 20 different alkenes with single and conjugated double bonds have been detected. From theCambridge English Corpus The epoxides are prepared by oxidation with hydrogen peroxide of thealkene. From Wikipedia  This example is from Wikipedia and may be reused under a CC BY-SA license.The carbonyl group draws electrons away from thealkene, and thealkenegroup is, therefore, deactivated towards an electrophile, such as bromine or hydrochloric acid. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license.The carbon radical starts polymer chain formation with monomer for instance analkeneas in any ordinary radical polymerization. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license.In contrast, unactivated styrene reacts instead at thealkenealone via a linear polymerization reaction. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license.Dimethylamine addition opened the thiolactone ring with an exocyclicalkenegroup in 60 by elimination of the sulfide anion from the methyl group. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license.Hydroformylation, also known as oxo synthesis, is the reaction of analkenewith carbon monoxide and hydrogen. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license.The first reaction step involves 1,4-addition of the catalytic tertiary amine to the activatedalkeneto generate the zwitterionic aza-enolate. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license.This process is believed to occur through direct attack of the distal bond on the coordinatedalkene. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license.A related effect is thealkenecis effect. From Wikipedia This example is from Wikipedia and may be reused under a CC BY-SA license.These examples are from corpora and from sources on the web. Any opinions in the examples do not represent the opinion of the Cambridge Dictionary editors or of Cambridge University Press or its licensors. |
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