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动词在科技英语(EST)中的应用

摘要：为了从根本上弄清动词在科技英语(EST)中的应用,笔者试图根据M•A•K Halliday(韩礼德,英国语言学家)的系统功能语法分析动词在EST语篇中的使用情况。依照系统功能学派的观点,代写英语论文语言是社会活动的产物,语言在社会活动中具有多种功能。Hallidy把诸多功能归纳为三个元功能:概念、人际和语篇。动词在语篇中的应用主要归属于语言的概念功能,表达人们的各种经历和情感。概念功能在语义系统中的主要实现手段是及物性和语态。

关键词：动词 科技英语 社会活动

1　及物性中过程的选择及其功能　　
及物性是实现概念功能的语义手段,其作用是把人们的所作所为按语义功能划分为若干种过程。Halliday把过程归纳为六种:物质过程(表示做某事),心理过程,关系过程(反映事物间的关系),行为过程,言语过程(通过讲话实现交际)和存在过程。体现过程的语法手段是动词,主要是谓语动词。在EST语篇中,科技工作者主要选择物质过程和关系过程,表达对科学的理解,描述科学发现,论证自然界中诸事间的关系。选择这两个过程主要同EST语体和交际目的以及两个过程本身的语义功能有关。EST是用于实现科学活动的语言,它要求准确、客观、严谨。由于语篇的交际功能不同,科技工作者往往会在物质和关系过程之间作出有意义的选择,或交替使用两种关系,各自实现一定的语义功能。例如:在自动挤奶机器人一文中奶桶连接策略部分谈到:“…Themilking cups are attached to a rack which is con-nected to a two link passive arm,which can bemoved easily. The connection strategy startswhen the passive arm is in a parked position withthe arm retracted completely……”(参考译文:挤奶桶固定到与两连杆被动臂相连的架子上,这样能运动自如。当被动臂处于驻留位置,完全缩回的状态时连接策略就开始了。)

2　语态的选择及其功能　　
在EST语态选择中被动语态多于主动语态这是EST的重要特点之一。动词be+ed形式的动态化是物质过程的被动式,表示某动作的活动情况。例如:https://www.51lunwen.org/wordings/Through the discussion on the ad-vantages and disadvantages of inertial navigationsystem (INS) and global positioning system(GPS) fro aircraft,and the application of Kal-man filtering method in the integrated positio-ning system,GPS/INS integrated navigation sys-tem,a data fusion method based on neural net-work is proposed.(参考译文:文章讨论了飞机惯性导航系统与全球卫星导航系统的利与弊以及卡尔曼滤波方法在组合定位中的应用情况,进而提出了基于神经网络数据融合方法的GPS/INS组合导航系统。)
被动语态的使用场合包括:(1)在EST中并不关心行为主体,有时也很难指出行为主体,动作的执行者经常是泛指的。例如:Gears must beproperly lubricated.(2)为了突出动作对象,用客体作主语便于表达思想。例如:Heat and lightare given off in some chemical reactions.(3)便于句子结构安排。例如:Madame Curie is one ofthe world’s greatest women scientists and willalways be remembered as the discoverer of ra-dium。受到谓语动词表达上的限制,此句并列谓语前后分别用主动态和被动态。又例如:Thethree factors are interdependent for each influ-ences and is influenced by the actions and reac-tions of the others.句中each同时是influence动作的执行者和接受者。

3　避免重复使用　　
正如英语中的名词一样,在一个段落中动词也不会重复出现,而是由另外相关动词取而代之,以避免单调机械的重复。下面一段描述是关于加工非球面透镜用的磁流变技术的利与弊。
One advantage of this technology is that itoffersa way to produce highprecision aspheres inmoderate volume. A planoconvex lens with aspherical surfacefocusesincoming rays, all ofwhich are parallel to the optical axis (collimatedlight).In the figure,there is no place along theoptical axis where all the raysconvergeto a per-fect point focus. The spherical shape of the lenssurfacecausesthis focus error,which is termedspherical aberration. In contrast a planoconvexlens can be designed with and aspheric surfacethat theoretically focuses all in coming light raysparallel to the optical axis to a single point.
In most lens systems, designers must usemultiple surfaces to overcome spherical aberra-tion. Added elementstranslate intomore com-plex alignment and mounting, greater weightand,sometimes,higher cost. Aspheric lenses canprovidethe optical designer with a powerful op-tion that often attains performance,packaging orcost goals that might be difficult or impossibleusing spherical surfaces alone.
Why,then are aspheres not used more ex-tensively in optical designs? The problem lieswith the traditional methods used for optics fab-rication. To produce spherical parts, the lensblanks are polished between convex and concaveparts of the intended radius of curvature using anabrasive slurry.
The semirandom movement of a convexspherical surface against a concave spherical sur-face tends to pro本论文由英语论文网提供整理，提供论文代写，英语论文代写，代写论文，代写英语论文，代写留学生论文，代写英文论文，留学生论文代写相关核心关键词搜索。