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第1段
1 .Listen to part of a lecture in a biology class.
听一堂生物课的部分内容。
2 .P: What we're gonna talk about today has to do with animal coloration, how certain animal species produce their colors. What's the most common way this happens?
教授：我们今天要讲的内容与动物的体色有关，也就是某些动物物种是如何产生它们的颜色的。最常见的产生颜色的方式是什么呢？
3 .S: Usually color is created by a pigment in the animal's surface, the pigment reflects some colors of light and absorbs others. Like, if something's yellow, it's because the pigment reflects yellow wavelengths of visible light and absorbs the rest?
学生：通常颜色是由动物体表的色素产生的，这种色素反射某些颜色的光并吸收其他颜色的光。比如说，如果某个东西是黄色的，那是因为这种色素反射了可见光中的黄色波长的光，并吸收了其余的光，对吗？
4 .P: Right. And a pigment is composed of chemicals. This chemical based type of coloration is quite common. So, for example, if we see a bird that appears yellow, it's often because its feathers contain a yellow pigment, but not always.
教授：对的。而且色素是由化学物质组成的。这种基于化学物质的颜色形成方式相当常见。所以，比如说，如果我们看到一只看起来是黄色的鸟，通常是因为它的羽毛中含有黄色的色素，但也并不总是这样。
5 .Coloration can also occur through structure. What do I mean by that? On an animal surface, its skin or feathers or shell, there could be arrays of tiny structures that change the direction of light waves. Certain wavelengths of light pass between the structures. Other wavelengths are redirected. The redirected light waves result in intense color perceived by the viewer.
颜色也可以通过结构来产生。我这么说是什么意思呢？在动物的体表，比如它的皮肤、羽毛或外壳上，可能会有一些微小结构的排列，这些结构会改变光波的方向。某些波长的光会在这些结构之间穿过。其他波长的光则会被改变方向。被改变方向的光波就会让观察者看到鲜明的颜色。
6 .These structures I'm talking about are extremely tiny, so small they're measured in nanometers. Hence the term nanostructures. Nanostructures sometimes result in shifting colors. We have an example of these kinds of nanostructures in the feathers of a bird called Lawes's Parotia.
我所说的这些结构极其微小，小到要用纳米来度量它们。因此就有了“纳米结构”这个术语。纳米结构有时会导致颜色的变化。我们可以在一种叫做劳氏六线风鸟（Lawes's Parotia）的鸟的羽毛上看到这类纳米结构的例子。
7 .In Lawes's Parotia, the male bird's breast feathers are covered in nanostructures that create orange yellow reflections, but a part of each structure can also reflect blue light from a different angle. So, by slightly moving its feathers, the male can change its breast color from orange yellow to blue green.
在劳氏六线风鸟身上，雄鸟胸部的羽毛上覆盖着纳米结构，这些结构能产生橙黄色的反光，但每个结构的一部分也能从不同角度反射蓝光。所以，通过轻微地移动它的羽毛，雄鸟就能把它胸部的颜色从橙黄色变成蓝绿色。
8 .S: Does it use that for camouflage to hide in some kind of blue, green vegetation?
学生：它是用这种颜色变化来伪装自己，以便隐藏在某种蓝绿色的植被中吗？
9 .P: No, some animal species use color to hide, but color that's created structurally tends to be quite vivid, so the goal here isn't to avoid notice.
教授：不是的，有些动物物种会利用颜色来隐藏自己，但通过结构产生的颜色往往相当鲜艳，所以在这里它的目的不是为了不被注意到。
10 .S: Oh, so like if a potential mate is nearby?
学生：哦，那么是比如当潜在的配偶在附近的时候这样做吗？
11 .P: Exactly. The bird shifts its feathers to get the other birds' attention. Let me give you a sense of how tiny these nanostructures are. A human hair is at least 50,000 nanometers wide. A nanostructure, by contrast, may be only a few 100 nanometers wide.
教授：完全正确。这只鸟移动它的羽毛是为了引起其他鸟的注意。让我来给你们讲讲这些纳米结构到底有多小。一根人类的头发至少有5万纳米宽。相比之下，一个纳米结构可能只有几百纳米宽。
12 .S: Wow. So to see the structures on this bird's feather, we'd need what? An electron microscope?
学生：哇。那么要看到这只鸟羽毛上的这些结构，我们需要什么呢？一台电子显微镜吗？
13 .P: We could use electron microscopes, but they're not ideal for biological samples. To be viewed under an electron microscope, the feather would need to go into a vacuum chamber. To withstand the vacuum, the feather would need to be specially treated first, with a coating of gold or another metal. A much less involved option is actually a scanning probe microscope. With scanning microscopy, a probe is moved across the surface to trace the features, and that's how the image is created.
教授：我们可以用电子显微镜，但它们对于生物样本来说并不是理想的选择。要在电子显微镜下观察，羽毛需要被放入一个真空室。为了能承受真空环境，羽毛首先需要进行特殊处理，涂上一层金或其他金属。实际上，一个复杂程度低得多的选择是扫描探针显微镜。使用扫描显微镜时，一个探针会在表面移动以描绘出这些特征，图像就是这样生成的。
14 .S: I've heard of nanostructures before, in engineering classes, these nanostructures on the feathers, aren't they similar to materials already being engineered?
学生：我以前在工程课上听说过纳米结构，这些鸟羽毛上的纳米结构，和已经被设计出来的材料不是很相似吗？
15 .P: Absolutely. And there's new research on creating color changing surfaces for textiles or surface coatings for automobiles. Structures like those on Lawes's Parotia have inspired these ideas, and there are other color producing nanostructures we might imitate. Take the swallowtail butterfly. The swallowtail butterfly's wings have nanostructures that are shaped like tiny bowls. The center of each bowl reflects only yellow light, while the sides of the bowl reflect only blue. The scale is so small that human eyes can't resolve the color separately. We see only green nano structures like this could be used as a security feature for credit cards. A unique colored mark on the card formed by nanostructures would make unauthorized duplication much more difficult.
教授：完全正确。而且现在有关于为纺织品创造变色表面或者为汽车创造表面涂层的新研究。像劳氏六线风鸟身上的那种结构就启发了这些想法，而且还有其他我们可以模仿的产生颜色的纳米结构。以燕尾蝶为例。燕尾蝶的翅膀上有形状像小碗一样的纳米结构。每个小碗的中心只反射黄光，而碗的边缘只反射蓝光。这个尺度太小了，以至于人眼无法分别分辨出这些颜色。我们只能看到绿色。像这样的纳米结构可以用作信用卡的安全特征。由纳米结构在信用卡上形成的独特彩色标记会让未经授权的复制变得困难得多。
16 .S: And this mark, like the butterfly, it would look like one color, but under a microscope, you'd see it's actually too?
学生：而且这个标记，就像蝴蝶一样，它看起来是一种颜色，但在显微镜下，你也会看到它实际上？
17 .P: You wouldn't need a microscope. A special filter could be used to filter out one color and confirm the card's authenticity.
教授：你不需要显微镜。可以用一个特殊的滤光器来过滤掉一种颜色并确认信用卡的真实性。
18 .S: How do engineers create these structures?
学生：工程师们是如何创造出这些结构的呢？
19 .P: It's a challenge. Traditionally, manufacturing has meant building something with tools. But imagine creating tools small enough to work on nanostructures, not easy, so researchers have had to come up with new approaches like coaxing particles into forming nanostructures on their own, using magnetism, for example. There are also cell culture techniques, some cells that form nanostructures can actually be grown in a lab.
教授：这是一个挑战。传统上，制造意味着用工具来制造东西。但是想象一下制造出足够小的工具来处理纳米结构，这可不容易，所以研究人员不得不想出新的方法，比如哄诱粒子自己形成纳米结构，例如利用磁力。还有细胞培养技术，实际上一些能形成纳米结构的细胞可以在实验室里培养出来。
20 .S: So researcher’s kind of get nanostructures to build themselves?
学生：所以研究人员有点像是让纳米结构自己形成吗？
21 .P: Exactly. Nanostructure technology is exciting because it's an area where many different fields intersect, not just biology and engineering, chemistry, material science, physics, they're all relevant. If you're someone who likes to collaborate, nanotechnology presents some great opportunities.
教授：完全正确。纳米结构技术令人兴奋，因为它是一个许多不同领域交叉的领域，不仅仅是生物学和工程学，化学、材料科学、物理学，它们都与之相关。如果你是一个喜欢合作的人，纳米技术提供了一些很好的机会。