麻豆传媒

Buried landmines are difficult to find, especially if they contain no metal parts. Now researchers at the Technical University of Darmstadt in Germany say a technique for looking inside the human body could help (Journal of Physics D, vol 35, p 939). In nuclear magnetic resonance, molecules placed in a powerful magnetic field emit a characteristic pattern of radio waves. With the operator at a safe distance, an NMR-based landmine detector could determine the substance鈥檚 chemical make-up and its position in the ground from the pattern of waves. The team says the technique could be particularly useful for identifying TNT, which is used in roughly half of all mines but is difficult to spot with other methods.