经典英语美文:指纹探测新技术问世

New Fingerprint Technology Developed

Los Alamos National Laboratory scientists are using a new technique to see fingerprints on surfaces that typically make them invisible.

The method uses a technology called mini-X-ray fluorescence to detect chemical elements in fingerprints without altering them, said Christopher Worley, a scientist on the project.

"The conventional methods are meant to bring out fingerprint patterns with regular light and they have to treat those with powder, which alters them," Worley said. "With this you don"t have to alter it or treat it at all. We can determine the elements in a fingerprint and get a pattern at the same time."

The technology focuses a tight beam of X-rays on surfaces with fingerprints and creates a computer picture out of those scans.

The equipment costs about $175,000.

For big labs, the method could be a great way to bring out prints that can"t be seen any other way, said Vahid Majidi, another lab scientist.

"The technique fills a unique niche," Majidi said. "These are prints that would otherwise be useless. If you have prints on a dark surface, for example, they really don"t develop well using normal techniques. If you have prints from an adolescent or child, the chemicals in the fingertips are different and don"t stick around long enough for traditional methods."

The new method might also be able to tell if the person that left them handled certain types of bomb-making materials, said George Havrilla, another lab scientist.

"This is a new approach to fingerprint visualization," Havrilla said. "We"re lifting prints, but instead of looking at the finger"s natural oils and organic residues we"re looking at elemental features left behind."

The technology for scanning the prints is widely available. What"s new is the method the lab has created to see them which includes computer software and ways of manipulating the machinery, Worley said.

But the technique isn"t for everyone.

"We"ve already had some negative comments on it," Havrilla said with a laugh. "One reviewer told us it"s just not practical. But the goal of our work was to demonstrate that it was feasible to see these things."

美国洛斯阿拉莫斯国家实验室的科学家们采用了一种新技术，可以观察到原本很难在物体表面上看见的指纹。

参与该科研项目的科学家克里斯托弗·沃尔利说，该方法使用了一种“微X射线束荧光技术”，可以探测到指纹携带的化学成分，却不会改变指纹的保存状态。

沃尔利说：“传统的方法是通过常规光线使指纹显示出来，而且要借助粉末等物质，这会改变指纹保存状况。有了这种新方法，你根本用不着改变或处理指纹了，我们可以测定指纹所含的化学成分，同时获取指纹图案。”

这项技术将一束密集的X光对准留有指纹的物体表面，并根据扫描结果创建出计算机图像。

这套设备造价17.5万美元。

该实验室的另一位科学家瓦希德·马吉德表示，对那些大实验室来说，这是获取用其他方法看不到的印迹的最好方法。

马吉德说：“这项技术填补了一项空缺。如果没有这项技术，某些印迹就会变得毫无意义。比如说，如果是深色表面上的指纹，普通技术确实无法精确地探测到它们;如果是青少年或小孩的指纹，他们的指尖留下的化学成分(和成人)是不同的，而且这些指纹附着在物体表面的时间并不久，因此不适宜使用传统的分析方法。”

该实验室的另一位科学家乔治·豪夫里洛表示，这种新技术也许还能检测出指纹所有者是否触摸过某些类型的'炸弹制造材料。

豪夫里洛说：“这是清晰显示指纹的一种新途径。我们查找印迹时不再只观察手指分泌的油脂和残留有机物，而是专注于其背后隐藏的特殊化学成分。”

沃尔利指出，扫描印迹的技术目前已被广泛采用。该实验室发明的这种新型指纹探测法的创新之处在于它包含了计算机软件技术和机器操作方法。

但是这一技术也并非众人皆宜。

豪夫里洛笑着说：“我们已经收到了一些负面评论。一位批评者对我们说它压根不实用。但我们工作的目标是证明这种技术是切实可行的。”

Vocabulary:

fluorescence: the emission of electromagnetic radiation, especially of visible light, stimulated in a substance by the absorption of incident radiation and persisting only as long as the stimulating radiation is continued(荧光，尤指可见光等电磁辐射的散光)

niche: a special area of demand for a product or service(适当的位置，产品或服务所需的特殊领域)

stick around: 逗留

residue: the remainder of something after removal of parts or a part(残留物)