🎁 MP3音檔 (按右鍵可下載聽)：
http://online1.tingclass.net/voaspe/2016/20161204sa_tech.mp3
🎁 中英文稿：
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.
老黃狗(來自電影《老黃狗》)嗅覺非常的靈敏。一般而言，狗具有優越的嗅覺。它們可以發現屍體、毒品、炸藥——甚至癌症。但是狗狗們並不僅僅擁有強大的嗅覺器官。另外一個原因就是它們還具有神奇的“化學探測器”?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.
“結果表明，幾乎每個品種的狗吸氣的頻率都是5赫茲。即一秒鐘5次。”Matthew Staymates是美國國家標準與技術研究院的機械工程師和流體動力學家。他表示，嗅是有兩個過程。“吸氣和呼氣?”吸氣，呼氣，吸氣，呼氣。第二部分，呼氣才是關鍵。
"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.
“當狗狗在地上嗅賴嗅去的時候，在它呼氣的時候，每個皮孔都會噴出紊流空氣。就像我們呼氣的時候，我們的鼻孔就會有氣流噴出。但是狗狗是附身嗅地面，呼出的空氣流會反沖會自己的呼吸器官。在流體動力學領域，如果我們呼出空氣流是朝一個方向，最後，也會吸入這個空氣流。”所以，狗狗在製造一種壓力差，可以使鼻子嗅出新的氣味。
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.
Staymates和同事們利用拉布拉多獵犬鼻子的3維模型研究了效果並用以檢測流體動力學設備。受到狗嗅覺的啟發，他們在商業蒸汽探測器上也安裝了“嗅覺”裝置。結果發現，與通常的方法——僅持續的吸入氣流相比，這種嗅覺設備在識別炸藥氣味上更加卓越。該研究結果發表在《科學報告》雜誌上。
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.
Staymates表示，希望下一代的感測器可以認真考慮嗅覺裝置。有的納米感測器可以進行精微檢測。但有一點被人們所忽視：“如何獲得分子探測器?這樣你就可以擁有世界上最先進的探測裝置，或許裝置不太實用，但是前提是你得擁有裝置材料。”只添加一個嗅覺裝置，就可以讓那些感應器更加的靈敏。
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