ca
ffeine
复数形式
caffeines
1
咖啡因, 茶碱
a substance present in coffee or tea that makes one's brain more active
Caffeine is a natural stimulant found in various beverages and foods, such as coffee, tea, energy drinks, and chocolate. It works by blocking the action of adenosine, a neurotransmitter that promotes relaxation and sleepiness. By doing so, caffeine increases alertness and reduces fatigue. Caffeine also stimulates the release of adrenaline, which can temporarily increase heart rate and blood pressure. Moderate consumption of caffeine is generally considered safe for most people and may even have some health benefits, such as improved mental alertness and enhanced exercise performance. However, excessive intake can lead to side effects like jitteriness, insomnia, headaches, and increased heart rate.
- The caffeine in her morning coffee helped her focus at work.
她早晨咖啡中的咖啡因帮助她在工作中集中注意力。
- He avoided caffeine after 3 PM to sleep better at night.
他避免在下午3点后摄入咖啡因，以便晚上睡得更好。
- Green tea has less caffeine than espresso but still gives energy.
绿茶比浓缩咖啡含有更少的咖啡因，但仍然能提供能量。
- Too much caffeine can make you feel jittery or anxious.
过多的咖啡因可能会让你感到紧张或焦虑。
- Decaf coffee has most of the caffeine removed.
无咖啡因咖啡大部分咖啡因已被去除。
同义词：