Experts have revealed a new type of paper that can be erased¹ and rewritten without the need for ink.

研究人员成功研制出一种可重复书写的新型纸张，且书写打印时无需油墨。

They say that even in early prototype form, it can be rewritten 20 times without affecting the resolution.

研究者称，即使是初期版本，这种纸也能反复擦写20次，而且可保有较高的清晰度。

It works by using ultraviolet light to photobleach a dye in the paper, except the portions that constitute the text on the paper.

再写纸的原理是：利用紫外光漂白某些染料，使之呈现出无色状态，而只有文字或图像可在纸上显示出来。

The new rewritable paper can be erased and written on more than 20 times with no significant loss in contrast or resolution.

这种新的再写纸能反复擦写20次多，且不会影响对比度或清晰度。

Chemists at the University of California,Riverside say their rewritable paper is based on the color switching property of commercial chemicals called redox dyes.

加利福利亚大学河滨分校（University of California, Riverside）的化学家们表示，再写纸利用了氧化还原染料的颜色转换特性。

The dye forms the imaging layer of the paper.

这种染料能形成纸的成像层。

'This rewritable paper does not require additional inks for printing, making it both economically and environmentally viable,' said Yadong Yin, a professor of chemistry, whose lab led the research, which is published today in Nature Communications.

殷亚东是加利福利亚大学的化学教授，他带领团队进行再写纸的研究，其研究报告已发表于《自然通讯》（Nature Communications）杂志。他说：“再写纸在打印时无需添墨，使其在经济和环保两个方面都切实可行。”

'It represents an attractive alternative to regular paper in meeting the increasing global needs for sustainability and environmental conservation.'

“再写纸可以作为普通纸张之外另一种富有吸引力的选择，它能够满足全球可持续发展和环境保护的需求。

Heating at 115 Cc an speed up the reaction so that the erasing² process is often completed in less than 10 minutes.

这种纸加热至115摄氏度时，其化学反应速率会加快，因此在不到10分钟的时间内便可消除字迹。

'The printed letters remain legible with high resolution at ambient conditions for more than three days – long enough for practical applications such as reading newspapers,' Yin said.

殷教授表示：“印在纸上的文字可以在清晰度很高的情况下保持三天以上，对于读报这样的实际应用而言已经绰绰有余。”

'Better still, our rewritable paper is simple to make, has low production cost, low toxicity³ and low energy consumption.'

“更妙的是，这种再写纸制造简单，且生产成本低、毒性低、能耗低。”

His lab is currently working on a paper version of the rewritable paper.

他的团队目前正在改进纸质版的再写纸。

'Even for this kind of paper, heating to115 Cposes no problem,' Yin said.

殷教授说：“这种纸加热至115摄氏度也不会有问题。”

'In conventional laser printers, paper is already heated to200 Cin order to get toner particles to bond to the paper surface.'

“在使用传统的激光打印机时，为了让调色剂粒子粘附到纸张表面，纸张需要加热至200摄氏度。”

His lab also is working on increasing the cycling number (the number of times the rewritable paper can be printed and erased), with a target of 100, to reduce overall cost.

他的团队也在致力研究如何增加再写纸的循环数，即纸张重复打印和擦除的次数。他们希望再写纸可重复使用100次，这样便能降低生产总成本。

His research team is exploring ways to extend the legibility of the printed texts or images for more than three days to expand their potential uses.

同时，他们还想方设法提高三天后纸张上的文字和图像的识别度，以扩大这种纸的潜在用途。

'One way is to develop new photocatalyst nanoparticles that become highly reductive when irradiated by ultraviolet light,' Yin said.

殷教授介绍：“其中一种方法是研制新的光催化剂纳米颗粒，让它在被紫外光照射时能高度还原。”

'We are exploring, too, the possibility of multi-color printing.

“同样，我们也在探索多色印刷的可能性。

'The design principle can be extended to various commercial redox dyes to produce rewritable paper capable of showing prints of different colors.

“同样的设计原理可扩展至其他各类氧化还原染料，然后有望制造出能够彩印的纸张。

All these efforts will help increase the practical applications of the technology.'

这些付出都将有助于提高该技术的实际应用。”