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Every year, about 10 million tons of paper winds up in American landfills and incinerators, which is not only wasteful but adds CO2 to the atmosphere. Recycling helps, but even that material has to be repulped and paper-ized before you can use it to print out that recipe you’ll never make. But what if you could wipe the page clean and use it again?
在美國，每年有約1000萬噸的紙被丟進了垃圾堆或傾倒在焚化爐中，這不僅造成了大量的紙張浪費，還增加了大氣中二氧化碳的含量。把紙張回收是個辦法，但必須通過再次成漿和紙化之后才能重新變成打印紙——目前還沒有這樣的方法。但是，如果現在你只需把紙張擦拭干凈就可繼續使用，這會怎么樣？
Light amplification by stimulated emission of radiation to the rescue. A new study shows that laser light can erase the toner from a piece of printed paper. The approach appears in the Proceedings of the Royal Society A.
激光派上了用場。一項新的研究表明，激光可以清除打印紙上的墨粉。該方法刊登在《英國皇家學會》上。
Taking a page from the art-restoration handbook, scientists sampled a variety of light sources to see if any could be used to strip the ink from laser-printed documents without damaging or discoloring the paper. UV and infrared were too harsh. But a bright green laser applied in 4 nanosecond pulses vaporizes the print, leaving paper that looks as good as new.
科學家從一本藝術修復手冊上取下了一張紙，然后嘗試了多種光源，看看是否可以去除激光打印紙上的油墨同時不損壞紙張或讓紙張褪色。紫外線和紅外線太強烈了。但一道4納秒脈沖的明亮的綠色激光將紙張上的油墨成功氣化，得到了嶄新如初的一張紙。
Such unprinters will probably run about 30,000 bucks, so they probably won’t catch on for home use. But people in the recycling world might find that the green laser fits the bill—for making paper that’s really green.
這種裝置（我們可以稱之為unprinter）大概3萬塊美元左右，所以如今還不適合家庭使用。但回收行業的人可能會覺得這種裝置物有所值——可以實現真正的綠色造紙。
注：本文譯文屬可可英語原創，未經允許，請勿轉載。
