Bi Xiaotian acquired a new habit recently. Every time he opens his web browser, he checks the entry of paraxylene (PX) on Baidu Baike. As one of the participants in correcting the Baidu entry in early April, the 22-year-old chemical engineering major student from Tsinghua University is proud to be part of the team defending the purity of science. Guarding the truth is their responsibility.

　　近来，毕啸天养成了一个新习惯：只要打开浏览器就会在百度百科上查看PX词条。4月初，这名22岁的清华大学化工系学生加入“PX百度词条保卫战”。他表示，能够加入捍卫科学的队伍中，他感到很自豪。他们视捍卫真理为己任。

　　Wang Runjia was the first Tsinghua University student to correct PX entry. The 20-year-old sophomore student of chemical engineering turned on his laptop as usual on April 2. As he browsed the social network, a screenshot posted by a friend caught his attention. “It showed a modification of the PX entry on Baidu Baike, in which the toxicity of PX had been changed from ‘low’ to ‘high’,” he says.

　　清华大学化工系大二学生王润佳是该校首个参与修改PX词条的学生。4月2日，20岁的他像往常一样打开电脑。朋友在社交网站上发布的一张截图引起了他的注意。“截图中PX百度词条被篡改了，PX的毒性程度由‘低毒’变成了‘剧毒’。”他说。

　　After looking at the entry’s editing history in further detail, he found that the modification had been made several times. “The discussion of PX chemical plants has been ongoing for years. In class, we also learned related knowledge. Therefore I won’t let false information spread,” he says.

　　在进一步筛查此前的修改记录后，他发现该词条曾被多次篡改。“关于PX化工厂的讨论已持续多年。在课上，我们也学了一些相关知识。因此，我不会让错误信息传播开来，误导大众。”他说。

　　Out of professional spirit, he identified himself as a student of chemical engineering at Tsinghua University, correcting the mistakes and urging Baidu to prevent malicious tampering with sensitive entries.

　　出于专业精神，他以清华大学化工系学生的身份，对词条中的错误进行了修改，并且呼吁百度禁止对敏感词条的恶意篡改行为。

　　To his surprise, his act didn’t end the discussion. Instead, it was the beginning of an editing battle. Bi remembers that night well. He checked the entry once an hour just to ensure its correctness. In 120 hours, the entry was edited 36 times. “We took turns to safeguard the truth,” he says. “I’m glad to see that I’m not the only one doing so. Students from other departments and universities stood by our side, presenting scientific facts to the general public.”

　　令他颇感意外的是，他的举动并没有平息人们对于PX的争议。相反，一场“编辑战”才刚刚拉开序幕。毕晓天仍然清晰记得那个晚上：他每小时都会查看一下该词条，以此来确保词条内容的准确性。然而，在短短5天中，该词条一共被篡改了36次。“我们只好轮流来维护真理，”他说，“我很开心，因为我并不是一个人在战斗。还有一些其他院系、学校的同学支持我们，一起向大众传播科学真理。”

　　Qian Weizhong, an associate professor of chemistry at Tsinghua University, praised the students for being responsible citizens when interviewed by People’s Daily. “They are doing so not because of industrial interests, but out of their consciousness to popularize science,” he said. “Such activity informs the general public with scientific facts, facilitating rational communication.”

　　清华大学化学系副教授钱卫忠（音译）在接受《人民日报》采访时，称赞同学们是富有责任感的公民。“他们这么做并非出于商业目的，而是出于普及科学的意识，”他说，“这样的活动可以让大众了解科学真理，促进理性沟通。”

　　The students’ determination to protect the truth had a positive result. After locking the entry, Baidu Baike contacted Bi and asked him to write a introduction to PX. “For the entire afternoon on April 11, I worked on this task and sought professional assistance from my department.”

　　学生们捍卫真理的决心起到了积极作用。锁定该词条后，百度百科相关人员联系了毕啸天，希望他能够写一个关于PX的介绍。“4月11日的整个下午，我都在做这件事。为此，我还向系里寻求专业帮助。”

　　Now, the new entry on PX is a well-organized, objective reflection of reliable facts. “It’s a good opportunity for us,” Bi says. As many people don’t have enough knowledge to judge the truthfulness of online information, when false information is spread, experts must step in to deny rumors and convey the right information, he says.

　　现在，新的PX词条条理十分清晰，客观反映了可靠事实。“对我们来说，这是一个绝佳机会，”毕啸天说，“很多人缺乏相关知识来判断网上信息的真实性，当错误信息传播的时候，专家们就应该站出来阻止谣言的散播，揭露事实真相。”