科学美国人60秒 SSS 红外线为解冻提供了一种更酷的方法_在线英语听力室

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This is Scientific American's 60-second Science, I'm Adam Levy¹.

Water molecules² can arrange themselves to form much larger structures. Take intricate snowflakes, which form all by themselves in the right conditions. Well, now researchers have created some delicate water structures of their own, in the form of microscopic³ ice mazes⁴, with a little help from light.

The team took some sugar water, and kept it at a temperature where ice crystals and water can happily coexist. They then exposed the H2O to infrared⁵ light at a particular frequency that is absorbed much more easily by the ice crystals than it is by the water.

"We thought that something interesting would happen when you illuminate⁶ ice which absorb more than water. Because once the ice is melting, then it becomes liquid water and then it absorbs less, so you have kind of a negative feedback situation. And we did not know what will happen with this."

Physicist⁷ Ido Braslavsky from the Hebrew University in Jerusalem, Israel. The heating caused by the light melted tiny holes into the crystals. These holes sometimes joined up to form channels, and the researchers watched as a labyrinth-like pattern gradually formed over the course of an hour.

"At some point we suddenly saw a whole spectrum⁸ of patterns that appear. There were holes that opened and closed, there were channels that were appearing. And all together we realized that we had found a new phenomenon that was not observed before." The researchers have published their findings in the journal Science Advances.

And cool as all this may sound, there may also be some icy applications for this technique. Defrosting may make you think of microwave ovens, but heating ice with microwaves has some drawbacks. "The microwave actually warms the water but not the ice. So here we have a system in which we warm the ice even more than we warm the water."

And because the shorter wavelength⁹ infrared light warms the ice more than the water, the technique could come in handy for carefully unfreezing delicate biological samples that have been kept on ice. Which would be a good thing to see. And to have thaw¹⁰.

Thanks for listening for Scientific American — 60-Second Science. I'm Adam Levy.

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收听单词发音

1 levy
n.征收税或其他款项，征收额
参考例句：
They levy a tax on him.他们向他征税。 A direct food levy was imposed by the local government.地方政府征收了食品税。

2 molecules
分子( molecule的名词复数 )
参考例句：
The structure of molecules can be seen under an electron microscope. 分子的结构可在电子显微镜下观察到。 Inside the reactor the large molecules are cracked into smaller molecules. 在反应堆里，大分子裂变为小分子。

3 microscopic
adj.微小的，细微的，极小的，显微的
参考例句：
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。

4 mazes
迷宫( maze的名词复数 )；纷繁复杂的规则；复杂难懂的细节；迷宫图
参考例句：
The mazes of the dance were ecstatic. 跳舞那种错综曲折，叫人快乐得如登九天。 For two hours did this singlehearted and simpleminded girl toil through the mazes of the forest. 这位心地单纯的傻姑娘在林间曲径中艰难地走了两个来小时。

5 infrared
adj./n.红外线(的)
参考例句：
Infrared is widely used in industry and medical science.红外线广泛应用于工业和医学科学。 Infrared radiation has wavelengths longer than those of visible light.红外辐射的波长比可见光的波长长。

6 illuminate
vt.照亮，照明；用灯光装饰；说明，阐释
参考例句：
Dreams kindle a flame to illuminate our dark roads.梦想点燃火炬照亮我们黑暗的道路。 They use games and drawings to illuminate their subject.他们用游戏和图画来阐明他们的主题。

7 physicist
n.物理学家，研究物理学的人
参考例句：
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。

8 spectrum
n.谱，光谱，频谱；范围，幅度，系列
参考例句：
This is a kind of atomic spectrum.这是一种原子光谱。 We have known much of the constitution of the solar spectrum.关于太阳光谱的构成，我们已了解不少。

9 wavelength
n.波长
参考例句：
The authorities were unable to jam this wavelength.当局无法干扰这一波长。 Radio One has broadcast on this wavelength for years.广播1台已经用这个波长广播多年了。

10 thaw
v.（使）融化，（使）变得友善；n.融化，缓和
参考例句：
The snow is beginning to thaw.雪已开始融化。 The spring thaw caused heavy flooding.春天解冻引起了洪水泛滥。

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科学美国人60秒 SSS 红外线为解冻提供了一种更酷的方法