http://www.kaganbinder.com/docs/14-ProtectingPatentsAcademic...
Maintaining “Novelty”: Timing is Everything
To be patentable, an invention must have novelty. Novelty is a requirement under the patent laws of virtually every country having such laws, although the scope of the novelty requirement varies from country to country. Once novelty is lost for an invention, patent rights for that invention are lost as well.

以下中英文对照的《中国专利法》第二十四条规定对你翻译发明专利请求书也许会有所帮助：
第二十四条 申请专利的发明创造在申请日以前六个月内，有下列情形之一的，不丧失新颖性：
　　 （一）在中国政府主办或者承认的国际展览会上首次展出的；
　　 （二）在规定的学术会议或者技术会议上首次发表的；
　　 （三）他人未经申请人同意而泄露其内容的。
Article 24. An invention-creation for which a patent is applied for does not lose its novelty where, within six months before the date of filing, one of the following events occurred:
(l) where it was first exhibited at an international exhibition sponsored or recognized by the Chinese Government;
(2) where it was first made public at a prescribed academic or technological meeting;
(3) where it was disc1osed by any person without the consent of the applicant.

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Note added at 2 hrs (2009-09-24 22:31:32 GMT)
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Sorry! I mean "Statement about the grace period of maintaining novelty".

It’s better to keep it as short as possible to fit it into the tiny box, e.g., Statement about Maintaining Novelty".

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Note added at 2 hrs (2009-09-24 22:40:05 GMT)
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专利请求书表格：
http://218.241.185.52/cn/UploadFile/200742010333160.pdf