SSS 2011-02-17
时间：2018-12-24 作者：英语课 分类：Scientific American(二)月
This is Scientific American’s 60-Second Science. I’m Cynthia Graber. This will just take a minute.
Usually, we trust common sense to solve problems. Is a runny mixture too thick? Add some fluid. That’ll make it runnier. Except when the fluid makes it thicker. Scientists now think they know why.
The flow of a runny mixture, technically 1 a suspension, is generally controlled by the size, shape and amount of the solid particles. The researchers started out with tiny hydrophilic glass beads 2 in an organic solvent 3. Then they added just one percent weight of water. And like when you add water to sand and it clumps 4 together, the mix turned into almost a gel. Microscopic 5 analysis showed that a few beads stick tightly to each water drop.
Then the scientists made the glass beads hydrophobic. But the addition of water still made the mixture firmer. Turns out that in this case the beads form loose rings around the water droplets 6, as this formation minimizes each beads contact with water. The research was published in the journal Science.
The scientists say this effect could be used to keep solids from separating out of liquids, or to fine-tune the viscosity 7 of a liquid in engineering. Because sometimes, to make a mixture thicker, just add water.
Thanks for the minute. For Scientific American’s 60-Second Science, I’m Cynthia Graber.
- Technically it is the most advanced equipment ever.从技术上说，这是最先进的设备。
- The tomato is technically a fruit,although it is eaten as a vegetable.严格地说，西红柿是一种水果，尽管它是当作蔬菜吃的。
- a necklace of wooden beads 一条木珠项链
- Beads of perspiration stood out on his forehead. 他的前额上挂着汗珠。
- Gasoline is a solvent liquid which removes grease spots.汽油是一种能去掉油污的有溶解力的液体。
- A bankrupt company is not solvent.一个破产的公司是没有偿还债务的能力的。
- These plants quickly form dense clumps. 这些植物很快形成了浓密的树丛。 来自《简明英汉词典》
- The bulbs were over. All that remained of them were clumps of brown leaves. 这些鳞茎死了，剩下的只是一丛丛的黃叶子。 来自《简明英汉词典》
- It's impossible to read his microscopic handwriting.不可能看清他那极小的书写字迹。
- A plant's lungs are the microscopic pores in its leaves.植物的肺就是其叶片上微细的气孔。