美国科学60秒 SSS 2013-01-15
时间：2018-12-24 作者：英语课 分类：Scientific American(一)月
How do you to find 1 kilogram? Easy. It's the exact mass of medal cylinder 1 called the international prototype kilogram. IPK, for short. Kept in controlled conditions in France. But the standard kilogram has gained weight since its creation in 1875. To trim and end its many replicas 3 down to size, we need to clean them. The report is in the journal M*. When scientists analyzed 4 the surface of an IPK replica 2, they found it carries tens of additional macro-grams. These changes are due to contaminates built up in the kilograms despite their careful storage of the glass. The additional mass as equal to just a grain of sand, but the kilogram is such an essential unit that tiny changes to different replicas are important. To remove the contaminates, we need to standard and reproducible cleaning method. Researchers exposed one kilogram measure to ozone 5 and ultraviolet light which would remove the cover base contamination without damage the medal. But to permanently 6 standardize 7 the kilogram we will need to find terms of fundamental coincidence, not a lump of medal in a jar.
- What's the volume of this cylinder?这个圆筒的体积有多少？
- The cylinder is getting too much gas and not enough air.汽缸里汽油太多而空气不足。
- The original conservatory has been rebuilt in replica.温室已按原样重建。
- The young artist made a replica of the famous painting.这位年轻的画家临摹了这幅著名的作品。
- His hobby is building replicas of cars. 他的爱好是制作汽车的复制品。 来自《简明英汉词典》
- The replicas are made by using a thin film of fusible alloy on a stiffening platen. 复制是用附着在加强托板上的可熔合金薄膜实现的。 来自辞典例句
- The doctors analyzed the blood sample for anemia. 医生们分析了贫血的血样。 来自《简明英汉词典》
- The young man did not analyze the process of his captivation and enrapturement, for love to him was a mystery and could not be analyzed. 这年轻人没有分析自己蛊惑著迷的过程，因为对他来说，爱是个不可分析的迷。 来自《简明英汉词典》
- The ozone layer is a protective layer around the planet Earth.臭氧层是地球的保护层。
- The capacity of ozone can adjust according of requirement.臭氧的产量可根据需要或调节。
- The accident left him permanently scarred.那次事故给他留下了永久的伤疤。
- The ship is now permanently moored on the Thames in London.该船现在永久地停泊在伦敦泰晤士河边。
- We will extend and standardize legal services and provide effective legal aid.拓展和规范法律服务，积极开展法律援助。
- There is a drive both to standardise components and to reduce the number of models on offer.正在为实现零部件标准化和减少推出的型号数量而努力。