英文摘要时态

看期刊吧，我最近投了一个is全部都给改成了was

论文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:The purpose of this study was to determine whether an in hospital transportable CT scanner can provide diagnostic brain images and to compare the quality of these images with those from a convertional fixed? platform CT scanner.

Subjects and Methods:Twenty seven patients with known or suspected intracranial pathology underwent imaging on a transportable scanner and a fixed? platform scanner within 1hr of each other.Images from each CT examination were evaluated independently by two neuroradiologists who were unaware of patient history.Conspicuousness of intracranial pathology and normal anatomy were rated on a 5? point scale (1 point 'optimal;5 points'poor or not visualized).Statistical comparisons were made using nonparametric tests.

Results:Seven CT scans were interpreted as showing normal findings and 20 scans revealed intracranial pathology on both CT scanners.Image quality was higher on the fixed scanner(average rating'2.42 points'SE=0.12)than on the transportable scanner(average rating'3.10 points'SE=0.12(p=0.001).Depiction of the cerebellum'midbrain'and supratentorial gray? white matter was better on the fixed scanner(p<0.05=.However'we found no significant differences in detection of intracranial pathology between scanners.Both radiologists found images from both scanners to bediagnostic in all 27 patients.

Conclusion:Images of the brain on the transportable CT scanner were less clear than those on a fixed scanner.However'images from the transportable CT scanner were diagnostic in 27 consecutivepatients.The implications of this finding are important for the provision of CT services for critically ill patients who cannot be transported to the radiology department.

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。

论文摘要英文翻译时态，英文摘要时态的运用也以简练为佳，常用一般现在时、一般过去时，少用现在完成时、过去完成时，进行时态和其他复合时态基本不用。

一般现在时。

用于说明研究目的、叙述研究内容、描述结果、得出结论、提出建议或讨论等。

分别举例如下：This study(investigation) is (conducted, undertaken) to…The anatomy of secondary xylem(次生木质部) in stem of Davidia involucrata (珙桐) and Camptotheca acuminata (喜树) is compared. The result shows(reveals)…，It is found that…The conclusions are…The author suggests….涉及到公认事实、自然规律、永恒真理等，当然也要用一般现在时。

一般过去时。

用于叙述过去某一时刻(时段)的发现、某一研究过程(实验、观察、调查、医疗等过程)。

例如：The heat pulse technique was applied to study the stemstaflow (树干液流) of two main deciduous broadleaved tree species in July and August,1996.需要指出的'是，用一般过去时描述的发现、现象，往往是尚不能确认为自然规律、永恒真理的，而只是当时如何如何;所描述的研究过程也明显带有过去时间的痕迹。

现在完成时和过去完成时。

完成时少用，但不是不用而过去完成时可用来表示过去某一时间以前已经完成的事情，或在一个过去事情完成之前就已完成的另一过去行为。

例如：Concrete has been studied for many years. Man has not yet learned to store the solar energy.?