SSS 2010-03-24
时间：2018-12-24 作者：英语课 分类：Scientific American(三)月
Here are two seemingly unrelated facts. One: from the late 1940s through 1963, we tested atomic bombs in the atmosphere. Two: wine lovers are sometimes duped into spending exorbitant 1 amounts for fake vintage bottles that weren’t from the year they were supposedly grown.
But Graham Jones at Australia’s University of Adelaide thought he could use bomb information against counterfeit 2 wines. Carbon dating works by comparing the amount of carbon 14, which is a less common and less stable form of carbon, to the more abundant carbon 12.
For thousands of years, the ratio between the two has been the same. But those two decades of atomic bomb tests increased the C-14 in the atmosphere. And as growing grapes absorb carbon dioxide, they take in trace amounts of the heavier carbon isotope—which eventually show up in the wine.
The research team checked C-14 levels in 20 Australian red wines with vintages from 1958 to 1997. They compared the wine’s C-14 to C-14 in atmospheric 3 samples from the same years. And found a direct match—C-14 levels could give away the vintage year for each wine. So beware wine scammers. Because even at the atomic level, in vino veritas.
- More competition should help to drive down exorbitant phone charges.更多的竞争有助于降低目前畸高的电话收费。
- The price of food here is exorbitant. 这儿的食物价格太高。
- It is a crime to counterfeit money.伪造货币是犯罪行为。
- The painting looked old but was a recent counterfeit.这幅画看上去年代久远，实际是最近的一幅赝品。
- Sea surface temperatures and atmospheric circulation are strongly coupled.海洋表面温度与大气环流是密切相关的。
- Clouds return radiant energy to the surface primarily via the atmospheric window.云主要通过大气窗区向地表辐射能量。