1-1科技英语知识简介课件.pptVIP

化学化工专业英语Specialty English for Chemistry and Chemical Engineering;课程概况;第一章 科技英语知识简介Introduction to English for Science and Technology ;科技英语力求平易、客观和精确，避免行文晦涩、表露感情、刻意修辞等。行文时陈述句多，感叹句、疑问句少。例如： Since 1940 the chemical industry has grown at a remarkable rate, although this has slowed significantly in recent years. The lions share of this growth has been in the organic chemicals sector due to the development and growth of the petrochemicals area since 1950. The explosive growth in petrochemicals in the 1960s and 1970s was largely due to the enormous increase in demand for synthetic polymers such as polyethylene, polypropylene, nylon, polyesters and epoxy resins. ;科技论文作者在说明事理、提出设想、探讨问题和推导公式时，常常涉及到各种前提、条件和场合。为了避免武断，表示谦虚或保持谨慎的态度，经常使用虚拟语气，使口吻变得委婉。例如： If a pound of sand were broken up and turned into atomic energy, there would be enough power to supply the whole of Europe for a few years. 如果一磅沙子裂变，放出（所有）原子能，那将够整个欧洲用几年。 在说明注意事项时，则常常使用祈使句。例如： Be careful not to mix the liquids. 注意！不要把这几种液体混起来。 ;使用should或祈使句，使句式显得简捷明了。在实验或操作说明，以及在假设和计算中常常使用命令句这种形式： 让水冷却10分钟，然后再测量温度。 Allow the water to cool for ten minutes and then take the temperature. 计算炉子产生的热量。 Calculate the amount of heat which the furnace produces． 假设X等于每分钟的碳转化率 Let X equal the carbon conversions per minute.;另外，科技英语的表达方式较为程式化。科技文章往往由标题、摘要、关键词、正文、参考文献等部分构成（视具体情况，可以有其中的几种或全部）。 正文一般又分为引言、论述与结论三个部分。 在引言部分说明文章的主题和有关背景等。 在论述部分对文章主题按一定次序展开叙述和讨论。 如果是介绍实验成果的文章，则首先介绍实验仪器与设备、实验参数、实验过程和实验结果，然后展开讨论。 在结论部分则根据前面的讨论与推理，作出总结或提出建议。 ;2 时态方面;(一般过去时);3 词汇方面;此外，在科技英语中，还大量使用逻辑语法词：;4 句式方面;（1）长句 On the basis of the present study carried out under well-controlled conditions, it cannot be concluded that organically grown onions, carrots, and potatoes generally have higher contents of health-promoting secondary metabolites(植物代谢产物)in comparison with the conventionally cultivated ones. Polyphenols(多酚) have one or more phenol units in their chemical structure and are a group of secondary plant metabolites(植物代谢产物), frequently speculated to have positiv