Word · Frequency #22623
caffeine
咖啡因；咖啡碱
核心释义
a bitter alkaloid found in coffee and tea that is responsible for their stimulating effects
- 1.
一种生物碱,C8H10N4O2,天然存在于茶树和咖啡树中,对中枢神经系统有轻度刺激作用。
An alkaloid, C8H10N4O2, found naturally in tea and coffee plants, which acts as a mild stimulant on the central nervous system.
一种生物碱,C8H10N4O2,天然存在于茶树和咖啡树中,对中枢神经系统有轻度刺激作用。；咖啡因；咖啡碱；[化] 咖啡因; 咖啡碱
用法In use
Drinking coffee late at night keeps me awake because of the caffeine.
用法提示：caffeine 为不可数名词，指咖啡因，在句中作 because of 的宾语。
If you are sensitive to caffeine, try switching to decaffeinated tea.
用法提示：caffeine 在条件从句中作介词 to 的宾语，表示咖啡因这种物质。
The label says this energy drink contains about eighty milligrams of caffeine per can.
用法提示：caffeine 为不可数名词，在从句中作 contains 的宾语，表示所含的咖啡因量。
caffeine + be found in + [food/drink]
用于说明咖啡因的来源，常用于科普或日常说明。
Caffeine is found in coffee and tea.
咖啡因存在于咖啡和茶中。
caffeine + be responsible for + [effect]
用于解释因果关系，句型较正式。
相关词与表达Connections
搭配Collocations
- caffeine content
- 咖啡因含量
- The label lists the caffeine content of the drink.标签上列出了这种饮料的咖啡因含量。
- caffeine intake
- 咖啡因摄入量
- Doctors recommend limiting your caffeine intake in the afternoon.医生建议你在下午限制咖啡因的摄入。
- caffeine withdrawal
- 咖啡因戒断
- Her headache was caused by caffeine withdrawal after she quit coffee.她戒掉咖啡后，头痛是由咖啡因戒断引起的。
- caffeine sensitivity
- 咖啡因敏感性
- His caffeine sensitivity means he cannot drink soda after dinner.他对咖啡因敏感，所以晚饭后不能喝汽水。
- caffeine buzz
学习提示Learner notes
记忆技巧Memory Tip
读音近似“咖啡因”，咖啡中让人提神的成分就是 caffeine——记住“咖啡因”三个字即可。
语境与语域Context & Register
语域：neutral 常见场景：everyday conversation、scientific writing、food and drink labels 该词通常为中性用法，日常对话、科普文章和产品说明中都比较常见，无明显的正式或非正式倾向。
语法说明Grammar Note
通常作不可数名词；表示不同种类时可用复数形式 caffeines。
发音与拼写Pronunciation & Spelling
Caffeine /ˈkæfiːn/ has no common exact rhyme because its stressed vowel is /æ/ and the following syllable is /fiːn/. Codeine (/ˈkoʊdiːn/) and protein (/ˈproʊtiːn/) share the final /iːn/ sound and a similar -eine/-ein spelling, but their stressed vowel is /oʊ/, so they do not rhyme. Warning: vein (/veɪn/) has the -ein spelling but is pronounced /veɪn/, not /iːn/; ceiling (/ˈsiːlɪŋ/) and receive (/rɪˈsiːv/) show the -ei- spelling pronounced /iː/ but with different endings.
用法优先级Usage priority
Dictionary facts from ECDICT, WIKTIONARY.