Part I
Professor: Okay. I know you all have a lot of questions about this lab assignment that's coming up so... I'm gonna take a little time this morning to discuss it. So, you know the assignment has to do with Spectroscopy, right? And your reading should help you get a good idea of what that's all about. But, let's talk about Spectroscopy a little now just to cover the basics. What is Spectroscopy?
Well, the simplest definition I can give you is that Spectroscopy is the study of the interaction between matter and light. Now, visible light consists of different colors or wavelengths, which together make up what's called spectrum, a band of colors, like you see in a rainbow.
And all substances, all forms of matter, can be distinguished according to what wavelength of light they absorb and which ones they reflect. It's like, um, well, every element has, what we call, its own spectral signature. If we can read that signature, we can identify the element. And that's exactly what spectroscopy does.
所有物质，所有形式的物质，都可以根据它们吸收的光的波长和反射的光的波长来区分。
1. spectroscopy |spekˈtrɒskəpi|
noun. the study of forming and looking at spectra using spectrometers , spectroscopes , etc. 光谱学
E.g.: infrared/laser spectroscopy
红外/激光光谱学
2. wavelength|ˈweɪvleŋθ|
noun. the distance between two similar points on a wave of energy, such as light or sound 波长
E.g.: Blue light has a shorter wavelength than red.
蓝光的波长比红光的短。
3. spectrum|ˈspektrəm|
noun. a band of coloured lights in order of their wavelengths , as seen in a rainbow and into which light may be separated 谱；光谱
E.g.: Red and violet are at opposite ends of the spectrum.
红色和紫色位于光谱的两端。
4. substance|ˈspektrəm|
noun. a type of solid, liquid or gas that has particular qualities 物质；物品；东西
E.g.: a chemical/radioactive, etc. substance
化学、放射性等物质
5. read|ri:d|
verb. to understand sth in a particular way 懂得；理解
E.g.: Silence must not always be read as consent.
不要总是将沉默理解为同意。
Part II
Now, Laser Spectroscopy, which is the focus of your assignment, works by measuring very precisely what parts of the spectrum are absorbed by different substances. And it has applications in a lot of different disciplines. And your assignment will be to choose a discipline that interests you, and devise an experiment. For example, I'm gonna talk about art. I'm interested in the art and to me it's interesting how spectroscopy is used to analyze art.
Let's say a museum curator comes to you with a problem. She's come across this painting that appears to be an original - let's say, a Rembrandt. And she wants to acquire it for her museum. But she's got a problem: she's not absolutely certain it's an original. So, what do you do? How do you determine whether the painting's authentic?
Okay. Think about the scientific process. You've got the question: Is the painting a Rembrandt? So first, you'll need to make a list of characteristics the painting would have to have to be a Rembrandt. Then you have to discover whether the painting in question has those characteristics.
激光光谱学，也是你们作业的重点，它通过非常精确地测量光谱的哪些部分可以被不同物质吸收来工作。
1. discipline|ˈdɪsəplɪn|
noun. an area of knowledge; a subject that people study or are taught, especially in a university 知识领域；（尤指大学的）学科，科目
E.g.:We're looking for people from a wide range of disciplines.
我们需要各个学科的人才。
2. devise |dɪˈvaɪz|
verb. to invent sth new or a new way of doing sth 发明；设计；想出
E.g.: A new system has been devised to control traffic in the city.
控制城市交通的新系统已经设计出来。
3. come across
to meet or find sb/sth by chance （偶然）遇见，碰见，发现
E.g.: She came across some old photographs in a drawer.
她在抽屉里偶然发现了一些旧照片。
4. Rembrandt|ˈrembrænt|
伦勃朗·哈尔曼松·范莱因是欧洲巴洛克绘画艺术的代表画家之一，也是17世纪荷兰黄金时代绘画的主要人物，被称为荷兰历史上最伟大的画家；在2004年票选最伟大的荷兰人当中，他排名第九，次于第八的安妮·法兰克。他所处的年代被称为荷兰黄金时代，荷兰的科学艺术与商贸成就达到顶峰。伦勃朗年少成名，惟半生潦倒。
E.g.: This painting is a typical Rembrandt.
这幅画是一幅典型的伦勃朗作品。
5. original |əˈrɪdʒənl|
noun. a document, work of art, etc. produced for the first time, from which copies are later made 原件；正本；原稿；原作
E.g.: This painting is a copy; the original is in Madrid.
这幅画是复制品，原画在马德里。
6. authentic |ɔ:ˈθentɪk|
adj. known to be real and genuine and not a copy 真正的；真品的；真迹的
E.g.: I don't know if the painting is authentic.
我不知道这幅画是不是真迹。
7. in question
that is being discussed 被提及的；讨论（或议论）中的
E.g.: On the day in question we were in Cardiff.
在所提及的那一天，我们在加的夫。
Part III
So first of all, you'll need to know the techniques Rembrandt used when he applied paint to canvas - his brushstrokes, how thickly he applied his paint. So you'd need to work with an art historian who has expert knowledge of Rembrandt's style. You'd have to know when he created his paintings, um... what pigments he used, in other words, what ingredients he used to make different colors of paint, ‘cause the ingredients used in paints and binding agents plus burnishes, finishes, what have you, have changed over time.
Since you're trying to verify if it's a Rembrandt, the ingredients in the pigment would need to have been used during Rembrandt's lifetime - in the 17th century. And that's where chemistry comes in. You've got to find out what's in those pigments, learn their composition, and that requires lab work - detective work really - in a word, Spectroscopy.
你必须知道他的画是在什么时期创作的，嗯…他用的什么颜料，换句话说，他用什么成分来制作不同颜色的颜料，因为颜料、粘合剂以及抛光剂和饰面等等诸如此类中使用的成分随着时间的推移已经发生了变化。
1. apply |əˈplaɪ|
verb. to put or spread sth such as paint, cream, etc. onto a surface 涂；敷；施
E.g.: Apply the cream sparingly to your face and neck.
把乳霜薄薄地抹在脸和脖子上。
2. pigment |ˈpɪgmənt|
noun. a coloured powder that is mixed with a liquid to produce paint, etc. 颜料
E.g.: The Romans used natural pigments on their fabrics and walls.
古罗马人在织物和墙壁上使用天然颜料。
3. agent|ˈeɪdʒənt|
noun. a chemical or a substance that produces an effect or a change or is used for a particular purpose （化学）剂；作用剂
E.g.: binding/cleaning agent
粘合剂/去污剂
4. what have you
(informal) and other things of the same type 以及其他同样的东西；诸如此类
E.g.: So many things are unsafe these days—milk, cranberry sauce, what have you.
现如今很多食品都不安全——牛奶、蓝莓酱等等。
5. come in
to have a part in sth 在…中起作用；参与
E.g.: I understand the plan perfectly, but I can't see where I come in.
我完全了解这项计划，可是不明白我能起什么作用。
Part IV
So, how do we use Spectroscopy? Well, we put an infrared microscope - a spectroscope - on tiny tiny bits of paint. And using ultraviolet light we can see the spectral signature of each component part of the pigment. Then we compare these signatures with those of particular elements like zinc or lead, to determine what the pigment was made of.
So, you can see why this type of analysis requires a knowledge of the history of pigments, right? How and when they were made? Say we determined a pigment was made with zinc, for example. We know the spectral signature of zinc. And it matches that of the paint sample. We also know that zinc wasn't discovered until the 18th century. And since Rembrandt lived during the 17th century, we know he couldn't have painted it.
使用紫外线，我们可以看到颜料每个组成部分的光谱特征。然后我们将这些特征与锌或铅等特定元素的光谱特征进行比较，以确定颜料的成分。
1. infrared |ˌɪnfrəˈred|
adj. having or using electromagnetic waves which are longer than those of red light in the spectrum , and which cannot be seen 红外线的；使用红外线的
E.g.: searching with infrared scanners for weapons and artillery
用红外扫描仪搜索武器与大炮
2. ultraviolet |ˌʌltrəˈvaɪələt|
adj. of or using electromagnetic waves that are just shorter than those of violet light in the spectrum and that cannot be seen 紫外线的；利用紫外线的
E.g.: The sun's ultraviolet rays are responsible for both tanning and burning.
阳光中的紫外线是皮肤晒黑和灼伤的根源。
3. component |kəmˈpəʊnənt|
adj. The component parts of something are the parts that make it up. 组成的;构成的
E.g.: Polish workers will now be making component parts for Boeing 757s.
现在波音757飞机的组成部件将由波兰工人制造。
Part V
Now, Spectroscopy has a very distinct advantage over previous methods of analyzing our works, because it's not invasive. You don't have to remove big chips of paint to do your analysis, which is what other methods require. All you do is to train the microscope on tiny flecks of paint and analyze them.
Now a word or two about restoration: Sometimes original art works appear questionable or inauthentic because they've had so many restorers add touch-up layers to cover up damage, damage from the paint having deteriorated over time. Well, spectroscopy can reveal the composition of those touch-up layers too. So we can find out when they were applied. Then if we want to undo some bad restoration attempts, we can determine what kind of process we can use to remove them to dissolve the paint and uncover the original.
你不必摘掉大块颜料就可以进行分析，而通过摘掉大块颜料进行分析这是其他方法所必须的。
1. invasive |ɪnˈveɪsɪv|
adj. involving cutting into the body 切入的；开刀的
E.g.: Many people find the idea of any kind of invasive surgery unbearable.
很多人认为任何开刀手术都不堪忍受。
2. train ||treɪn|
verb. If you train something such as a gun, a camera, or a light on a person or thing, you aim it at them and keep it towards them. 把…对准(或瞄准)
E.g.: Police cameras had been specifically trained on that area.
警方摄像头已特别对准那一区域。
3. fleck|flek|
noun. a very small piece of sth 微粒；小片
E.g.: flecks of dust/foam/dandruff.
灰尘微粒；泡沫；头皮屑
4. restoration|ˌrestəˈreɪʃn|
noun. the work of repairing and cleaning an old building, a painting, etc. so that its condition is as good as it originally was 整修；修复
E.g.: The palace is closed for restoration.
王宫因整修而停止开放。
5. touch-up
noun. a quick improvement made to the appearance or condition of sth 润色；修饰；装点
E.g.: My lipstick needed a touch-up.
我的口红需要补一下。
6. deteriorate|dɪˈtɪəriəreɪt|
verb. to become worse 变坏；恶化；退化
E.g.: Her health deteriorated rapidly, and she died shortly afterwards.
她的健康状况急剧恶化，不久便去世了。
7. undo|ʌnˈdu:|
verb. to cancel the effect of sth 消除，取消，废止（某事的影响）
E.g.: It's not too late to try and undo some of the damage.
想办法补救部分损失还为时不晚。
8. dissolve|dɪˈzɒlv|
verb. to remove or destroy sth, especially by a chemical process; to be destroyed in this way （以化学手段）除去，分散；
E.g.: a new detergent that dissolves stains
新型去污洗涤剂
