科技英语写作（3）

SECTION IV

从句 SUB-CLAUSES

I. 状语从句 adverbial clause

1. 特殊状语从句的翻译
(1) not…until
该机器直到接收到信号后才工作。
The machine will `not` work `until` it receives a signal.
(2) before
Something further must be done to the amplified signals `before` they can be sent to the transmitting antenna.
The body will move on for some distance `before` it stops.  该物体将继续向前运动一段距离后才停下来。
The values of most things must be converted from decimal to binary before computations can begin.
(3) since   
Great changes have taken place here `since` he left.
I haven’t heard from him `since` he lived in Beijing.
> Since + 静态动词的过去式   ----表达此动词状态已经结束
It is three years `since` he was in the army.
It is a long time `since` I studied English.
(4)while�           
> 表示让步和对比concession, contrast
`While` this concept is used chiefly in electricity, the same terms are applicable to magnetism.  虽然这个概念主要用在电学中，但同样的一些术语也可用于磁学之中。
水是液体而冰则是固体。
At this time the kinetic energy approaches infinity, `while` the potential energy approaches the minimum.

II 同位语从句 appositive clause

常见句型：
1. There is evidence that…
2. There is no doubt that…
3. There is every possibility that…
4. There is (no) guarantee that…

There is evidence that this equation holds. 有证据表明这个式子是成立的。
There is no doubt that there is no solution to that equation.  毫无疑问，那个方程无解。
There is every possibility that satisfactory results will be obtained.  完全有可能取得理想的结果。

Ⅲ. 名词性从句Nominal clause

What从句的特殊句型：

(1) what is + called/ named/ termed/ described as/ known as/ referred to as/ spoken of as

我们都熟悉人们所说的电流。
We are all familiar with `what is called` the electric current.
我们所说的机器人只不过是一种特殊的电子设备。
`What is called` a robot is no more than a special kind of electronic equipment.
过去人们通常所说的留声机(phonograph)现在称为唱机了。
`What used to be called `a phonograph is now called a record player.
在1947年后期，他们发现了后来人们所说的“晶体管”效应。
Late in 1947, they discovered `what was later` to be named the “transistor” effect.

(2)in what follows=in what is to follow
下面，我们用f来表示频率。
`In what follows`, we use f to represent frequency.

(3) What it is [they are]         …现在这个样子
    what it was [they were]      …过去[原来]那个样子

这些工厂与原来大不一样了。
These factories are quite different from `what they were`.
月球表面，物体的重力仅为在地球上的六分之一。
On the surface of the Moon, the gravitational force on a body is only 1/6 `what it is` on Earth.

IV. 关系从句Relative clause

Ⅰ . 关系词Connectives

1. 关系代词  Relative pronoun
that\ which\ who( whom)\ whose\ as\ 
but ＝that\ which + not \ who

2. 关系副词Relative adverbs

(数学表达式，方程，等式)place, extent, degree, point, case, situation ··· + where

when 
wherein  = in which
whereby = by which
whereon = on which
whence   = from which (comes)

可以使用小型计算机的场合似乎是无止境的。
The places `where` small computers can be used appear endless.
我们必须懂得这里使用该电路的原因。
We must understand the reason `why` this circuit is used here.

Ⅱ. “介词＋which”引导的关系分句

1. “ of which” 在从句中充当状语
consist of\ be composed of\ be made of\ be made up of\ be constructed of ;
be + {capable of\ descriptive of\ representative of\ characteristic of\ symptomatic of}
 
构成水的两种元素是氧和氢。
The two elements `of which water` is made are the oxygen and hydrogen.
这是该晶体管所能给出的最大放大量。
This is the maximum amount of amplification `of which the transistor is capable`.

2. “ of which” 在从句中充当定语
我们能够找到几个条件，其中只有两个是必要条件。
We can find a few conditions `only two of which are necessary`.

其每一点的 Y 坐标均为零的曲线就是 X 轴。
The curve `the Y-coordinate of every point on which is zero` is just the x-axis.

3. 其他介词 + which
这取决于电流流动的容易程度。
This depends on the `ease` `with` which a current flows.
这是能量守恒定律适用的一个过程。
This is a process `to` which conservation of energy law `applies`.
铁是我们最熟悉的金属之一。
Iron is one of the metals `with` which we are most `familiar`.
必须确定人眼最敏感的波长。
It is necessary to determine the wave length `to` which the eye is most `sensitive`.