科学家发现梵高名画色泽变暗 呼吁“防晒”

Scientists have published an editorial in the journal Analytical Chemistry, explaining why the bright yellows in some of Vincent van Gogh's paintings have turned brown - a complex chemical reaction is behind the deterioration of the works.
Sunlight can penetrate only a few micrometers into the paint, but over this short distance, the researchers found it could trigger a hitherto unknown chemical reaction turning chrome yellow into brown pigments, altering the original composition.
Scientists suggest shielding the affected paintings as much as possible from UV and sunlight.
Van Gogh started to paint in these bright colors after leaving his native Holland for France where he became friends with artists. The chrome yellow allowed van Gogh to achieve the intensity of, for example, his series of Sunflowers paintings.
科学家们日前在科学杂志《分析化学》撰文分析了为什么梵高一些画作里鲜艳黄色越来越暗淡：一系列复杂的化学反应损害了画作。
研究人员发现，日光的照射只能影响到图画表面的几微米。但在这短短的距离内，日光会产生一种先前无人知道的化学作用，使图画中的铬黄变成暗棕，原有的化学成分被改变。
科学家们建议设立屏障遮挡紫外线和阳光来保护这些名画。
梵高在他早年离开家乡荷兰赴法时，认识了一些艺术家，自此开始较多地使用明亮色彩作画。而铬黄更赋予梵高画作强烈的冲击感，比如《向日葵》系列。