(点击右边三个点，可调整速度，电脑上可下载)

听力参考原文 ↓↓↓

[00:00.04]The Mona Lisa is the famous Leonardo da Vinci painting

[00:05.92]of a woman with a mysterious smile.

[00:10.68]This week, the painting gave up a secret.

[00:15.92]Scientists used X-rays to examine the chemical structure

[00:22.36]of an extremely small part of the more than 500-year-old painting.

[00:30.64]The researchers discovered a technique Leonardo used in the work.

[00:37.84]A team in France and Britain discovered an oil paint

[00:42.36]used for the Mona Lisa was a special, new chemical mixture.

[00:49.24]The research was published Wednesday

[00:52.28]in the Journal of the American Chemical Society.

[00:56.96]It suggests that the Italian artist

[01:00.32]may have been in an experimental mood

[01:04.08]when he set to work on the painting early in the 16th century.

[01:10.68]"He was someone who loved to experiment,

[01:13.56]and each of his paintings

[01:15.60]is completely different technically," said Victor Gonzalez.

[01:21.52]He is the study's lead writer

[01:24.28]and a chemist at France's top research organization,

[01:29.60]the National Center for Scientific Research (CNRS).

[01:34.72]Gonzalez has studied the chemical makeup of several works

[01:39.40]by Leonardo, Rembrandt and other artists.

[01:45.16]"In this case, it's interesting to see

[01:48.16]that indeed there is a specific technique

[01:52.04]for the ground layer of Mona Lisa,"

[01:55.80]he said in an interview with The Associated Press.

[02:01.52]Specifically, the researchers found a rare compound,

[02:07.00]plumbonacrite, in Leonardo's first layer of paint.

[02:13.00]The discovery, Gonzalez said, confirmed that da Vinci

[02:18.16]most likely used lead oxide to thicken and help dry his paint.

[02:26.56]Carmen Bambach, a specialist in Italian art

[02:30.56]at New York's Metropolitan Museum of Art,

[02:34.32]called the research "very exciting."

[02:38.12]Bambach, who was not involved in the study,

[02:41.96]said it shows "Leonardo's spirit of passionate

[02:46.60]and constant experimentation as a painter,"

[02:50.72]she wrote in an email.

[02:53.56]The speck of paint in the imaging study

[02:56.96]is about the thickness of a human hair.

[03:01.20]It lies in the top right area of the painting.

[03:06.24]The scientists looked into its atomic structure

[03:10.96]using X-rays in a synchrotron.

[03:15.24]The machine moves particles at close to the speed of light,

[03:20.60]permitting researchers to look deeper into the paint structure.

[03:26.64]"Plumbonacrite is really a fingerprint of his recipe," Gonzalez said.

[03:33.28]"It's the first time we can actually chemically confirm it."

[03:39.68]Dutch artist Rembrandt may have used a similar mixture

[03:44.40]when he was painting in the 17th century.

[03:49.00]Gonzalez and other researchers

[03:52.16]have found plumbonacrite in his work, too.

[03:56.36]"It tells us also that those recipes

[03:59.72]were passed on for centuries," Gonzalez said.

[04:04.08]"It was a very good recipe."

[04:07.88]Leonardo is thought to have melted lead oxide powder,

[04:13.08]which has an orange color, in linseed or walnut oil

[04:18.96]to make it thicker and dry faster.

[04:23.28]"What you will obtain is an oil

[04:26.04]that has a very nice golden color," Gonzalez said.

[04:30.68]"It flows more like honey."

[04:34.76]But the Mona Lisa — said by the Louvre

[04:38.44]to be a portrait of Lisa Gherardini,

[04:41.96]the wife of a Florentine silk merchant

[04:45.52]— and additional works by Leonardo

[04:48.56]still have other secrets to tell.

[04:52.28]"There are plenty, plenty more things to discover," Gonzalez said.

[04:57.88]"What we are saying is just a little brick more in the knowledge."

[05:04.08]I'm Caty Weaver.

______________________

Words in This Story

passionate - adj. showing, expressing strong emotion

constant - adj. happening all the time or very often

recipe - n. a way of doing something that will produce a particular result

powder - n. very fine, dry substance

obtain - v. to gain or get something usually by effort