英文摘要中语态和时态的用法

1、英文摘要中语态和时态的用法 英文摘要的字数大多数期刊规定不超过250个词，内容应与中文摘要对应。医学论文中，一般少用第一人称和主动语态，多用第三人称和被动语态，用以体现叙述客观事实。所用时态需与事情发生时间一致，叙述基本规律时可用现在时，叙述研究对象、方法和结果时，用过去时。举例如下。Objective:ThepurposeofthisstudywastodeterminewhetheraninhospitaltransportableCTscannercanprovidediagnosticbrainimagesandtocomparethequalityoftheseimageswitht

2、hosefromaconvertionalfixed?platformCTscanner. SubjectsandMethods:Twentysevenpatientswithknownorsuspectedintracranialpathologyunderwentimagingonatransportablescannerandafixed?platformscannerwithin1hrofeachother.ImagesfromeachCTexaminationwereevaluatedindependentlybytwoneuroradiologistswhowereunawareo

3、fpatienthistory.Conspicuousnessofintracranialpathologyandnormalanatomywereratedona5?pointscale(1pointoptimal;5pointspoorornotvisualized).Statisticalcomparisonsweremadeusingnonparametrictests. Results:SevenCTscanswereinterpretedasshowingnormalfindingsand20scansrevealedintracranialpathologyonbothCTsca

4、nners.Imagequalitywashigheronthefixedscanner(averagerating2.42pointsSE=0.12)thanonthetransportablescanner(averagerating3.10pointsSE=0.12(p=0.001).Depictionofthecerebellummidbrainandsupratentorialgray?whitematterwasbetteronthefixedscanner(p0.05.Howeverwefoundnosignificantdifferencesindetectionofintra

5、cranialpathologybetweenscanners.Bothradiologistsfoundimagesfrombothscannerstobediagnosticinall27patients. Conclusion:ImagesofthebrainonthetransportableCTscannerwerelessclearthanthoseonafixedscanner.HoweverimagesfromthetransportableCTscannerwerediagnosticin27consecutivepatients.TheimplicationsofthisfindingareimportantfortheprovisionofCTservicesforcriticallyillpatientswhocannotbetransportedtotheradiologydepartment. 上面是AJR(美国放射学杂志)中一段完整的英文摘要，从中可以看出其特点：用词简练、准确；时态为过去时；不用第一人称，多用被动语态；方法和结果中强调统计方法及数据。对母语非英语的作者来说，撰写英文摘要的质量好坏直接与作者的英文水平有关，在这方面，只有多阅读英文文献，才能提高英文