英文摘要中语态和时态用法

英文摘要中语态和时态用法
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:Thepurposeofthisstudywastodeterminewhetheraninhospitaltransportable CTscannercanprovidediagnosticbrainimagesandtocomparethequalityoftheseimagesw iththosefromaconvertionalfixed?platformCTscanner.
SubjectsandMethods:Twentysevenpatientswithknownorsuspectedintracranialpathol ogyunderwentimagingonatransportablescannerandafixed?platformscannerwithin1hr ofeachother.ImagesfromeachCTexaminationwereevaluatedindependentlybytwoneur oradiologistswhowereunawareofpatienthistory.Conspicuousnessofintracranialpathol ogyandnormalanatomywereratedona5?pointscale(1point’’’’optimal;5points’’’’pooror notvisualized).Statisticalcomparisonsweremadeusingnonparametrictests.
Results:SevenCTscanswereinterpretedasshowingnormalfindingsand20scansrevealedi ntracranialpathologyonbothCTscanners.Imagequalitywashigheronthefixedscanner(av eragerating’’’’2.42points’’’’SE=0.12)thanonthetransportablescanner(averagerating’’’’3.10points’’’’SE=0.12(p=0.001).Depictionofthecerebellum’’’’midbrain’’’’andsupratent orialgray?whitematterwasbetteronthefixedscanner(p＜0.05
＝.However’’’’wefoundnosignificantdifferencesindetectionofintracranialpathologybe tweenscanners.Bothradiologistsfoundimagesfrombothscannerstobediagnosticinall27 patients.
Conclusion:ImagesofthebrainonthetransportableCTscannerwerelessclearthanthoseo nafixedscanner.However’’’’imagesfromthetransportableCTscannerwerediagnosticin2 7consecutivepatients.TheimplicationsofthisfindingareimportantfortheprovisionofCTs ervicesforcriticallyillpatientswhocannotbetransportedtotheradiologydepartment.
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：①用词简练、准确；②时态为过去时；③不用第一人称，多用被动语态；
④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，才能提高英文写作水平，从而写出高质量的英文摘要。