英语科技论文常用句型结构
2.6.1 表达不同功能的常用句型
1）定义
定义是对一事物的本质特征或一个概念的内涵与外延的确切简要的说明，常见的表达方式和句型有：
The term macromolecule(means … 、sinnifies ... is considered to be … 、is taken to be … 、refers to …)
(In this article、In this paper、In this essay、In this context、In computer science、For this purpose) network (will be taken to mean … 、will be used in the 、will be considered to be …、will refer to … 、will be used in…)
为了说明上述表达方式的用法，现举例如下：
Paradigm refers to models of inquiry that guides scientific work.
在对某些事物进行定义时，还可使用以下固定形式。
(the words to be defined) is a kind of (class) which (distinguishing features)
从以上例子中可以看出，一般定义的组成部分是：概念+属性+种差，例如：
A solar cell（概念）is a device（属性）which converts the energy of sunlight into electric energy（种差）。
2）分类
在科技论文中，作者有时需要对描述、说明的对象按其性质、大小、作用等分成若干种类，然后依次阐述。常见的表达分类的句型有：
(break down 、divide 、subdivide 、be classified)+ … （总体）+into/as …（部分）
具体用法举例如下：
· Classification breaks down the general topic into its related parts in a logical way.
· This classification system divided carbides into two distinct categories.
· Substances can/may be classified as gases, liquids and solids.
The models (fall into、can be divided into、may be classified into、are of) two(major 、general(groups、classes、categories)、broad)
There are two(major、general(groups、classes of … 、categories)、broad)
Two(major、general (groups、classes、categories)、broad)
There are two (major 、general (groups、classes、categories)、broad) of…
3）比例关系
常见表达比例关系的句型有：
· Most objects are big in proportion to the size of an atom but small in proportion to the size of the sun.
·The ration between students of science to students of engineering is 3:2.
· There is a relationship between the cross-sectional area of a rope and its strength. Its strength is directly proportional to its cross-sectional area.
· Pressure is inversely proportional to volume.
· Air and fuel are mixed in a proportion of 15 to 1.
· Three colours: red, green and blue will, if they are mixed together in the right proportion, give us white light.
· Ion the final printed version, graphs and diagrams are usually reduced in scale by a factor of two or three.
· The model is made to scale.
· As the demand for power increases, the supply is proportionally increased.
· A good coolant is formed by mixing water and soluble oil in a ratio of 10:1 to 20:1.
· The acceleration of a body is directly proportional to the force acting on it.
· Intensity of an electric field is relative to current.
· The density of air varies directly as the pressure, with temperature being constant.
· The electric current varies directly with the voltage.
· The resultant modulated wave has the same frequency as the carrier, but the carrier wave amplitude varies in direct relation to the modulating wave.
4）用途和功能
常见表达用途和功能的句型有：
· Definitions as given here apply only to the subject treated in this standard.
· To some extent these methods are only applicable to long series of production.
· Although both the planer and the shaper are adapted to the machining of flat surfaces, they differ widely in construction and in method of operation.
· While these methods are correct, they are not adaptable to the viscous flow problem.
· Orbital and planetary cutting machines are particularly useful for cutting off tubular work.
· The binary scale is perfectly used for the “off-on” pulses of electricity.
· This two-body approximation holds for the motion of planets about the sun.
· These motors are fit for machines requiring constant-torque and adjustable speed.
· Filmcrotrons can fit into smaller, flatter places.
