时间:2019-02-15 作者:英语课 分类:英语时差8,16


英语课

 Ever wonder how they determine how many calories are in food? Yael and Don explain it in this Moment of Science.   Y: All right, Don. What are you doing?


D: I'm using a bomb calorimeter to figure out how many calories are in my lunch. See, I put my sandwich in this sealed container, which I'm going to submerge in water, and then I'm going to burn my sandwich and figure out how much the temperature of the water has changed, because a calorie is defined as the amount of energy it takes to heat up a kilogram of water one degree centigrade--and then--Y: Whoa, Don, two things: First of all, you won't be able to eat your lunch once you burned it.
D: Oh, good point.
Y: Second, no one uses the bomb calorimeter anymore to measure the calorie content of food.
D: They don't?
Y: Nope. Today most of the nutritional 1 information you find on food labels is generated indirectly 2, using what's known as the Atwater system. So basically, calories are calculated by adding up the calories provided by each of the food's energy- containing nutrients 3.
D: Oh, like proteins and fats?
Y: And carbohydrates 4 and alcohol. According to the Atwater system, there are on average four calories in each gram of protein, nine in each gram of fat, seven in each gram of alcohol, and four in each gram of carbohydrates.
D: Oh, I've seen that conversion 5 scale on the label on my potato chips.
Y: Also, because some carbs contain fiber 6 that your body can't break down, their total is adjusted accordingly before figuring out calories. Atwater already figured all that out using your beloved bomb calorimeter, so now you don't have to.
D: Darn. I sure do love burning things!   

adj.营养的,滋养的
  • A diet lacking in nutritional value will not keep a person healthy.缺乏营养价值的饮食不能维持人的健康。
  • The labels on food products give a lot of information about their nutritional content.食品上的标签提供很多关于营养成分的信息。
adv.间接地,不直接了当地
  • I heard the news indirectly.这消息我是间接听来的。
  • They were approached indirectly through an intermediary.通过一位中间人,他们进行了间接接触。
n.(食品或化学品)营养物,营养品( nutrient的名词复数 )
  • a lack of essential nutrients 基本营养的缺乏
  • Nutrients are absorbed into the bloodstream. 营养素被吸收进血液。 来自《简明英汉词典》
n.碳水化合物,糖类( carbohydrate的名词复数 );淀粉质或糖类食物
  • The plant uses the carbohydrates to make cellulose. 植物用碳水化合物制造纤维素。 来自《简明英汉词典》
  • All carbohydrates originate from plants. 所有的碳水化合物均来自植物。 来自辞典例句
n.转化,转换,转变
  • He underwent quite a conversion.他彻底变了。
  • Waste conversion is a part of the production process.废物处理是生产过程的一个组成部分。
n.纤维,纤维质
  • The basic structural unit of yarn is the fiber.纤维是纱的基本结构单元。
  • The material must be free of fiber clumps.这种材料必须无纤维块。
学英语单词
acetylphosphoric acid
approbated
arteriola efferens
assembler loader package
babusar pass
basivolsella
beef stroganoffs
biosphere reserve
black teals
blandished
board bridge
breanna
calcium pyrophosphate
chemical insecticide
clear panel key
colouring book
computer forensics
cool-summer damage due to impotency
Cuproartinite
customs compound
customs supervision
decaudates
direct current source
documents-against-payment bill
DTRTT
electric resistance wire
enthalpy-entropy chart
excess mean portfolio return
firmware support
food-purchasing
four-address code
friction pressure
ghiaour
greys
Hawkins Point
hedonic price method
high-tempreature strain gauge
hovde
hyperpipecolatemia
intraploidy
job-lot production
kellwood
Keota
Koh Sla, Stung
lightly deformed crystal
lindeberg's condition
liquefaction temperature
Lloyd's anchors and chains proved
Loxwood
lymphonoduli aggregati
Madipelesa
magnaliums
mark sth up
megawatt (mw)
micromechanically
momentum cutoff
muhs
myristicic acid
nonutilized
obituarial
OGRL
Omlet
on-line cipher
orbiculately
ortho-nitraniline
Os Draconis
philosoph
piratesses
possessive pronoun
pritchie
pseudoprognathism
pulpitless
Q clearance
R. M. S.
rauca
reattend
remote sensing for atmospheric pollution
residual current operated protective device
Rhododendron mainlingense
sassen
sea language
see ... do
self-redemptions
simple HISAM data base
Skave
steam water interface
steering gear tube cam
stratum compactum of integument
stress bolt
suicide bombing
synchronization
tatouay
Thai Ridgebacks
thorotrast
turite
type of machine
varnish-treated tape
vigna angulariss
wage tax
wheeler and dealer
worm-gears