文档介绍：专业英语
English for Special Purpose
Lecturer:Mr. Lü Hongming
Tel:0515-3127908
Email: lhmyg@
概述
第一篇专业英语基础
第1章绪论
1. 课程教学目的
培养学生对专业语言的理解能力和应用能力;让学生承担专业阅读必需的基本技能和知识,使学生能够以英语为工具获取专业科技知识及其他与专业有关的信息。
2. 专业英语的起源
最初出现于20世纪50年代。
3. 专业英语的教学特点
语言教学密切结合专业知识,教材大都来源于相关的专业文献。
4. 专业英语的学习方法
专业英语阅读与普通英语的快速阅读的方法也所不同,专业英语阅读要把准理解放在首位,在准确理解的基础上提高阅读速度。和其他的英语能力—祥,专业英语阅读能力,需要通过长期的实践才能获得,不可能一蹴而就,多读多练是提高专业英语阅读能力的最有效的方法。
专业英语的基本特点
为了了解专业英语的特点,我们先阅读下面一段关于许用应力的课文。
Despite the tests described in Chapters 1l and 12,materials may still fail in service,sometimes with disastrous results (. when the failure occurs in ,ships,etc.). To try to avoid such disastrous occurring,the designer avoids using materials continuously at their maximum allowable stress. This is done by employing a factor of safety.
Unfortunately,increasing the strength of ponent in the interests of safety not only increases the initial material costs,but also the operating costs. For example,the stronger and heavier the structure members of an aircraft,the fewer passengers it can carry and the more fuel it a balance has to be maintained between safety,initial cost and operating designer is constantly striving to improve the former whilst reducing the latter.
Allowable working stress is taken as a proportion of the yield or proof stress;that is,ponent is only stressed within its elastic range when in example, consider the screwed fastening shown in Fig. . When the nut is tightened normally the bolt is stretched slightly and,providing it is stressed within its elastic range,it will behave like a very powerful spring and will pull the joint faces together very firmly.
The stress in the bolt is made up of two elements. Firstly, the stress imparted by the initial tightening of the bolt; secondly,the stress imparted by the load on the fastening in sum of these stress must not be allowed to approach,let alone exceed,the yield stress for t