2020年经济学人 司法鉴定(1)

Since the first use of fingerprints¹ to identify and convict a murderer, in 1892,

自从1892年首次使用指纹来识别并定罪谋杀犯以来，

detectives the world over have come to rely heavily on print evidence to build their cases against suspects.

世界各地的侦探都开始严重依赖指纹证据来建立针对嫌疑人的案件。

One limit on the value of fingerprints, though, is that it is hard to work out how old they are.

然而，指纹价值的一个限制是很难计算出它们的年代。

This is a particular problem when a crime is committed somewhere

当犯罪发生在犯罪嫌疑人经常且正当出入的场所，如工作地时，

that a suspect frequently and legitimately² visits, such as a place of work.

这个问题就特别的突出。

In this case exactly when a print was made might be crucial to establishing guilt³ or innocence⁴.

在这种情况下，准确的指纹时间可能是确定有罪或无罪的关键。

But it is information that science has, until now,been unable to provide with any accuracy.

但是直到现在，科学还不能提供任何准确的信息。

As they write in Analytical⁵ Chemistry, Paige Hinners and Young Jin Lee of Iowa State University

正如他们在《As they write in Analytical Chemistry》所写的那样，爱荷华州立大学的

believe they can remedy this state of affairs. They knew from work conducted by other laboratories

Paige Hinners和Young Jin Lee认为他们可以改变这种状况。他们从其他实验的工作中了解到

that the triglyceride oils contained in fingerprints change by oxidation over the course of time.

指纹中所含的甘油三脂油会随着时间的推移而氧化。

That provides an obvious way to date prints.

这为推算指纹时间提供了一种明显的方法。

The problem is that the techniques which have been applied⁶ to analyse these oils are able to distinguish age only crudely.

问题是用来分析这些油的技术只能粗略地分辨出年代。

In practice, they can determine whether or not a print is over a week old, but nothing else.

在实践中，他们可以确定一个指纹是否已经超过一周了，但除此之外别无其他。

Dr Hinners and Dr Lee wondered if higher precision could be obtained by thinking a bit more about oxidation.

Hinners博士和Lee博士想知道更高的精确度是否可以通过更多地考虑氧化来获得。

Oxygen molecules⁷ in the air come in two varieties. Most have a pair of atoms but some, known as ozone⁸, have three.

空气中的氧分子有两种，大多数都有一对原子，但也有一些被称为臭氧的有三个原子。

Though far rarer than diatomic oxygen, ozone is more reactive and also reacts in ways different from those of its two-atomed cousin.

尽管臭氧比双原子氧更加稀有，但它的反应性更强，而且反应方式也与双原子氧不同。

The two researchers therefore decided⁹ to focus their attentions on ozonolysis, as triatomic oxidation is known.

因此，这两位研究人员决定将他们的研究重点放在臭氧（即三原子氧化）的分解上。

Triglycerides, as their name suggests, are three-tailed molecules.

甘油三脂，顾名思义，是三尾分子。

Each tail is a chain of carbon atoms, with hydrogen atoms bonded¹⁰ to the carbons.

每条尾巴都是一个碳原子链，氢原子连着碳原子。

1 fingerprints   

n.指纹( fingerprint的名词复数 )v.指纹( fingerprint的第三人称单数 )

参考例句：

• Everyone's fingerprints are unique. 每个人的指纹都是独一无二的。
• They wore gloves so as not to leave any fingerprints behind (them). 他们戴着手套，以免留下指纹。 来自《简明英汉词典》

2 legitimately   

ad.合法地；正当地，合理地

参考例句：

• The radio is legitimately owned by the company. 该电台为这家公司所合法拥有。
• She looked for nothing save what might come legitimately and without the appearance of special favour. 她要的并不是男人们的额外恩赐，而是合法正当地得到的工作。 来自英汉文学 - 嘉莉妹妹

3 guilt   

n.犯罪；内疚；过失，罪责

参考例句：

• She tried to cover up her guilt by lying.她企图用谎言掩饰自己的罪行。
• Don't lay a guilt trip on your child about schoolwork.别因为功课责备孩子而使他觉得很内疚。

4 innocence   

n.无罪；天真；无害

参考例句：

• There was a touching air of innocence about the boy.这个男孩有一种令人感动的天真神情。
• The accused man proved his innocence of the crime.被告人经证实无罪。

5 analytical   

adj.分析的；用分析法的

参考例句：

• I have an analytical approach to every survey.对每项调查我都采用分析方法。
• As a result,analytical data obtained by analysts were often in disagreement.结果各个分析家所得的分析数据常常不一致。

6 applied   

adj.应用的；v.应用，适用

参考例句：

• She plans to take a course in applied linguistics.她打算学习应用语言学课程。
• This cream is best applied to the face at night.这种乳霜最好晚上擦脸用。

7 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。

8 ozone   

n.臭氧，新鲜空气

参考例句：

• The ozone layer is a protective layer around the planet Earth.臭氧层是地球的保护层。
• The capacity of ozone can adjust according of requirement.臭氧的产量可根据需要或调节。

9 decided   

adj.决定了的，坚决的；明显的，明确的

参考例句：

• This gave them a decided advantage over their opponents.这使他们比对手具有明显的优势。
• There is a decided difference between British and Chinese way of greeting.英国人和中国人打招呼的方式有很明显的区别。

10 bonded   

n.有担保的，保税的，粘合的

参考例句：

• The whisky was taken to bonded warehouses at Port Dundee.威士忌酒已送到邓迪港的保稅仓库。
• This adhesive must be applied to both surfaces which are to be bonded together.要粘接的两个面都必须涂上这种黏合剂。