美国科学60秒 SSS 2015-04-16
时间：2018-12-24 作者：英语课 分类：2015年Scientific American(四)月
英语课
This is Scientific American 60 Second Science. I'm Christofer Tagiya. Got a minute?
Ever run along white sand and it hardens up almost like concrete under your feet? But pick up that same sand and it drizzles 1 through your fingers.So that's the essence of why granular materials are interesting. Yale physicist 2 Abe Clark. Sometimes they can behave like solids. Another times like fluids.Understanding the transitions between liquid and solid. That's really nontrivial.
Grains of sand and otherwise are Clarks's specialty 3. He and his collegues recently investigated how a bucket of beeds responds when another objects falls into it. It's analogous 4 to dropping a stone on sand and then observing how the stone's force transfers to the grains.
The top grain is contacted by an intruder, and then it tells a friend and it tells a friend and so forth 5 and it moves along a little chain. So what this looks like is basically a little lightning bolts of force shoot off the intruder. But the faster that impact gets, think me*** or missiles track, the more extensive that chain like network between the grains becomes, meaning the grains behave more like a solid, which in some cases make the intruding 6 projectiles 7 bounce right off.
The finding is in the journal Physical Review Letters.
The work was funded in part by the Defence Threat Reduction Agency, part of the DOD. So of course some of the obligations are military. Grainulor materials might be the perfect thing to thwart 8 a missile attact, for example. And on a smaller scale... Well if I was gonna go build sandbags for the military, I would tell them to use rubber pellets to fill their sanbands with instead of sand. Because he says rubber beeds would create a stronger longer-lasting repellent force against bullets.
But remember, Abe and his collegues are physics. I've seen a couple of crazy blogs or something saying, you know, scientists are building b***b***, sorts of, you know, something like that. So no. We are definitely not doing something like that. Afterall, that would be a task for engineers.
Thanks for the minute, for Scientific American 60 Second Science. I'm Christofer Tagiya.
1 drizzles
蒙蒙细雨，毛毛雨( drizzle的名词复数 )
- "Grain lain" day-bringing gentle drizzles-was not far off. “谷雨”节一天近一天了。 来自汉英文学 - 春蚕
- It drizzles sometimes, moistening the thirsty fields lightly and selflessly. 它大多是毛毛细雨，轻柔而又无私地滋润着干涸的大地。
2 physicist
n.物理学家，研究物理学的人
- He is a physicist of the first rank.他是一流的物理学家。
- The successful physicist never puts on airs.这位卓有成就的物理学家从不摆架子。
3 specialty
n.(speciality)特性，特质；专业，专长
- Shell carvings are a specialty of the town.贝雕是该城的特产。
- His specialty is English literature.他的专业是英国文学。
4 analogous
adj.相似的；类似的
- The two situations are roughly analogous.两种情況大致相似。
- The company is in a position closely analogous to that of its main rival.该公司与主要竞争对手的处境极为相似。
5 forth
adv.向前；向外，往外
- The wind moved the trees gently back and forth.风吹得树轻轻地来回摇晃。
- He gave forth a series of works in rapid succession.他很快连续发表了一系列的作品。
6 intruding
v.侵入，侵扰，打扰( intrude的现在分词)；把…强加于
- Does he find his new celebrity intruding on his private life? 他是否感觉到他最近的成名侵扰了他的私生活？
- After a few hours of fierce fighting,we saw the intruding bandits off. 经过几小时的激烈战斗，我们赶走了入侵的匪徒。 来自《简明英汉词典》
7 projectiles
n.抛射体( projectile的名词复数 )；（炮弹、子弹等）射弹，（火箭等）自动推进的武器
- These differences are connected with the strong absorption of the composite projectiles. 这些差别与复杂的入射粒子的强烈吸收有关。 来自辞典例句
- Projectiles became more important because cannons could now fire balls over hundreds or yards. 抛射体变得更加重要，因为人们已能用大炮把炮弹射到几百码的距离之外。 来自辞典例句