高阶科技|第81集：自测版纯净原声

hey 这位同学你好呀! 上节课的内容都听溜了么？一定记得复习和学习新内容同等重要~ 今天我们来听的是科技新闻，时长 2 分 28 秒。主题我先不告诉你，仍然尝试努力听懂大意。来，集中精力，模拟考场，预备，开始！

像上节课一样听写知识点�

1

ol_________ g_________

嗅觉装置

2

in the world of fluid d__________s

在流体动力学领域

3

吸气 + 呼气

ins_________, ex_________

4

Labrador re_________

拉布拉多寻回犬

5

One of the things that's been o_________,

但有一点被人们所忽视：

[知识点讲解]

1

olfactory gear 

嗅觉装置

�⊹ 味觉怎么说?

⊹ 我的嗅觉不灵了

It seems my olfactory sense is a bit muddled.

⊹ 日语窗户怎么读?

⊹ 刺激我的嗅觉和味觉

And I am trying to stimulate

My olfactory and gustatory senses

to try to recreate it. 

2

in the world of fluid dynamics

在流体动力学领域

3

吸气 + 呼气

Inspiration, expiration

Inhale, exhale, inhale, exhale...

4

Labrador retriever

拉布拉多寻回犬

⊹ 我来拿回我的东西 :) �

I came to retrieve my property.

5

One of the things

that's been overlooked,

但有一点被人们所忽视：

[听力文稿及翻译]

Dogs Teach Bomb-Sniffing Machines New Tricks

狗狗传授新技能

Old Yeller was a great smeller. Dogs in general have superior smelling abilities. They detect dead bodies, illegal drugs and explosives—even cancer. But dogs don't just have great olfactory gear. Another reason they're amazing chemical detectors? [sniffing sound] … is the sniff.

老黄狗(来自电影《老黄狗》)嗅觉非常的灵敏。一般而言，狗具有优越的嗅觉。它们可以发现尸体、毒品、炸药——甚至癌症。但是狗狗们并不仅仅拥有强大的嗅觉器官。另外一个原因就是它们还具有神奇的“化学探测器”?那就是嗅。

"And it turns out almost every breed of dog does this at 5 Hz. Five times a second." Matthew Staymates, a mechanical engineer and fluid dynamicist at the National Institute of Standards and Technology. Sniffing, he says, is really a two-part process. “Inspiration, expiration, right? Inhale, exhale, inhale, exhale." That second part, the exhale, is key.

“结果表明，几乎每个品种的狗吸气的频率都是5赫兹。即一秒钟5次。”M S 是美国国家标准与技术研究院的机械工程师和流体动力学家。他表示，嗅是有两个过程。“吸气和呼气?”吸气，呼气，吸气，呼气。第二部分，呼气才是关键。

"So when the dog is actively sampling or sniffing on the ground, there is a turbulent air jet that exits each nostril during the exhale phase. Just like when you and I exhale there's an air jet that comes out of our nostrils. But the dog is down on the ground and those air jets are vectored down and toward its rear. And in the world of fluid dynamics, if I pulse an air jet in one direction I basically pull air with it." So the dog is creating a pressure differential that effectively pulls new scents toward its nose.

“当狗狗在地上嗅赖嗅去的时候，在它呼气的时候，每个皮孔都会喷出紊流空气。就像我们呼气的时候，我们的鼻孔就会有气流喷出。但是狗狗是附身嗅地面，呼出的空气流会反冲会自己的呼吸器官。在流体动力学领域，如果我们呼出空气流是朝一个方向，最后，也会吸入这个空气流。”所以，狗狗在制造一种压力差，可以使鼻子嗅出新的气味。

Staymates and his colleagues discovered that effect using a 3-D–printed model of a Labrador retriever's nose, which they tested with fluid dynamics equipment. They then outfitted a commercial vapor detector with sniffing nostrils, inspired by the dog nose. And they found that the actively sniffing detector was 16 times better at picking up the scent of explosives, compared to just continuously drawing in air—the usual method. The results are in the journal Scientific Reports.

S 和同事们利用拉布拉多猎犬鼻子的3D模型研究了效果，并用以检测流体动力学设备。受到狗嗅觉的启发，他们在商业蒸汽探测器上也安装了“嗅觉”装置。结果发现，与通常的方法——仅持续的吸入气流相比，这种嗅觉设备在识别炸药气味上更加卓越。该研究结果发表在《科学报告》杂志上。

Staymates says he hopes next-generation sensors take sniffing seriously. "There's nanosensors out there that can detect very, very small amounts of materials. One of the things that's been overlooked: is how do you get the molecules of interest to the detector? So you can have the most sophisticated detector in the world, but unless you can get material to it, it's not very useful." Adding a sniffer though…could be just the thing to make those detectors more dogged.

S 表示，希望下一代的传感器可以认真考虑嗅觉装置。有的纳米传感器可以进行精微检测。但有一点被人们所忽视：“如何获得分子探测器?这样你就可以拥有世界上最先进的探测装置，或许装置不太实用，但是前提是你得拥有装置材料。”只添加一个嗅觉装置，就可以让那些感应器更加的灵敏。

[课程制作] 00

[听力源头] scientificamerican.com

[背景音乐] River by Enya