论文英文摘要中语态和时态的用法

1、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 pare the qua

2、lity 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 examinatio

3、n 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 pointspoor or not visualized).Statistical parisons were made using nonparametric tests. Results:S

4、even 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 rating2.42 pointsSE=0.12)than on the transportable scanner(average rating3.10 pointsSE=0.12(p=0.001).Depiction of the cerebellummidbrainand supratentorial gray? white matter was better on the fixed scanner(p 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 _来说，撰写英