Dutch Delft University of Technology and the University of Antwerp, Belgium announced on the 30th,The researchers found,Dutch painter Vincent Van Gogh oil painting
"grass", under the possession of a female portrait, that is, "picture-in-picture".
    "Grass" with green paint and painted blue,These paints under the possession of a piece of brown and red portrait of women."Grass" by Van Gogh created in 1887,is
 collected by the Le Mule Museum of Art Library now.Researchers previously knew that another hidden below a oil painting,but do not know the specific details of this piece
of "picture-in-picture,"
   For a clear reproduction of this "picture-in-picture",Researchers using a new technology in measuring the color of chemical substances,In particular the elements
antimony and mercury.This new technology based on "stimulate synchrotron radiation x-ray fluorescence spectroscopy," Than the existing x-ray photography has
improved, has been used for other "picture-in-picture" was found.
    With regard to the significance of this discovery, researchers say, will help art historians a better understanding of the evolution of the works of Van Gogh.
    Art history sector in general believes that, due to insufficient funds to buy oil painting materials, Van Gogh made in a number of paintings on canvas oil painting again.
His works may be as many as one-third of the "picture-in-picture".
    Dutch Van Gogh Museum announced in August 2007. Art historians found that Van Gogh works, "canyon" to hide another piece of work "of wild plants."In
October 2005, the Netherlands art historian Aokejiewei Er Jisi of Van Gogh in Paris,underside a landscape oil painting . He found an early self-portraits.