There are three states of matter: gas, liquid and solid.
物质有三种状态：气体，液体与固体。
There are three main laws of mechanics, or three laws of  newton.
力学有三大定律，即牛顿三定律。
3. 宾语译为主语：
Semiconductors have a lesser conducting capacity than metals.
半导体的导电性能比金属差。 （英语为动宾结构）
A car battery has a voltage of 6 or 12 volts.
汽车电瓶的电压为6伏或12 伏。
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
4. 表语译为主语
Wood is not as dense as water and therefore it floats.
木材的密度比水小,因而能浮在水面上。
A transistor radio is a less complicated structure than a TV.
晶体管收音机的结构不象电视那样复杂。
(二) 转换为汉语谓语
1. 主语译为谓语：若主语为动名词时，往往可译为谓语。
The statement of the conservation and transformation of energy is as follows.
能量守恒与能量转换可表述如下。
The expression of the relation between pressure, volume and temperature is as follows.
压力、体积与温度的关系可表述如下。
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
2. 定语译为谓语
The two machines have the same efficiency.
这两台机器的效率相同。
Solids have a shape independent of the container.
固体的形状与容器无关。
3.表语译为谓语
This explanation is against the natural laws.
这种解释违反自然定律。
The axle is out of true.
轴部位不正常了。
We realize that potential energy is different form kinetic energy
我们知道，势能不同于动能。
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
(三) 转换成宾语
1.被动语态的句子若无“by”导出的逻辑主语,主语往往可译为宾语。
A great force was needed to separate the two hemispheres.
分开这两个半球，需要很大的力。
If there is a hydroelectric plant at the waterfall, the energy of 
the falling water is used to drive the turbines.
假如瀑布附近有一水电站,那么就利用流下的水的能量驱动涡轮机。
Work is done, when a object is lifted.
当举起一个物体时就作了功。
2.若被动语态句子有by (for)引导的逻辑主语,则可译成主谓宾结构。
Two systems of units are commonly used by the scientists.
科学家们通常使用两种单位制。
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
(四) 转换为定语
1.状语译为定语:位于句首的某些地点状语有时可译为主语的定语。
Throughout the world ,coal consumption is growing rapidly.
全世界的煤炭消耗量正在迅速增长。
In any machine the work accomplished never exceeds the amount of work expended in working the machine.
任何机器所完成的功永远还会超过开动机器所消耗的功。
2. 主语译为定语：
Aluminum has poorer conductivity than copper.
铝的导电性比铜差。
A large steam engine may have as much power capacity as 100000 horses.
大型蒸汽机的功率可达100000马力。
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
3. 若形容词译为名词作主语，则原主语可译为定语。
Steel is much stronger than wood.
钢的强度比木材大得多。
This gas turbine is only about 30 per cent efficient.
这种燃汽轮机的效率只有30%左右。
The atmosphere of Mars is not so dense as that of the earth.
火星的大气密度不及地球的大。
4. 若动词译为名词作主语，原主语则译为定语。
Steel weighs about eight times as much as water.
钢的重量大约 是水的8倍。
Power means the speed, or rate of doing work.
功率的意思是作功的速度或速率。
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
二、改变句子的类型
    英语和汉语都把句子划分成简单句、并列复合句和主从复合句三种类型，但在翻译时，译句的句子类型却不一定要与英语原句的
类型完全相同。为了使译文符合汉语习惯，常常需要将英语句子改译成另一种类型的汉语译句。
 (一) 定语从句译成状语从句：有些定语从句具有明显的状语意义，说明主语的时间、条件、原因、目的、结果、让步等，对于这种包
含状语意义的定语从句，往往可译为状语从句。
Heat energy that is not so obvious as kinetic energy exists in 
many things.
热能虽然不像动能那样明显，但它却存在于许多物体之中。（让步状语）
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
The door of which you lost the key cannot be opened.
因你把开门的钥匙丢了，所以这个门打不开。(译为原因状语)
We have to oil the moving parts of machine, the friction of 
which may be greatly reduced.
为显著减少摩擦，我们必须给机器运动部件加油。(译为目的状语)
(二) 定语从句译成并列分句：
The cable are composed of thousands of wires, made of high-tensile steel, which are galvanized to resist corrosion.
钢缆由成千根高强度钢拉制的钢丝所组成，这些钢丝经过电镀，以防生锈。（译为与主句并列的单独句子）
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
小结定语从句的三种译法：
(1) 译为定语， (2) 译为单独句子， (3) 译为状语
The electric power which is consumed in an electrical circuit is measured in watts or kilowatts.
电路中消耗的电力是以瓦或千瓦计量的。(译为定语)
The cable are composed of thousands of wires, made of high-tensile steel, which are galvanized to resist corrosion.
钢缆由成千根高强度钢拉制的钢丝所组成，这些钢丝经过电镀，以防生锈。（译为单独句子）
We have to oil the moving parts of machine, the friction of which may be greatly reduced.
为显著减少摩擦，我们必须给机器运动部件加油。(译为目的状语)
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
(三) 从句译为主句：
1. When 引导的时间状语从句,有时译为主句,以符合汉语规范。
Hardly had he got to the station when the train left.
他刚到车站，火车就开了。(比较：当火车开动时，他刚到车站。)
Scarcely had the circuit been closed when the current started to flow.
电路刚一闭合,电流就开始流动。(当电流开始流动时,电路刚闭合)
2. 由before引导的时间状语从句，翻译时有时需作主从对换处理。
The cooling water must be supplied before the machine start operation.       
必须先提供冷却水，才能开动机器。
It will be five years before we meet. 
五年后，我们才能再见面。（比较：我们再见面前，需要五年。） 
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
(四) 简单句译成复合句
Steel is widely used in engineering, for its properties are most suitable for construction purposes. (简单并列句)
钢广泛用于工程中,因其性能极适合用于建筑. (译为因果关系复合句)
The line ab, representing the direction of the forces, is called the line of action.（现在分词短语作定语的简单句）
线段ab称为作用线，它代表力的作用方向。（译为并列复合句）
When we “oil” a machine, it turns easily, and it does not get hot either. (简单并列句)
我们给机器“加油”, 它就转动自如,因而不再发热. (译为因果关系复合句)
 
翻译的基本方法 – 改变句子结构 Skills of Translation –transform sentence structure
(五)复合句译成简单句
The material we choose must also obey Hooke’s law. (定语从句)
所选材料必须符合虎克定律。
Factories everywhere are demanding for the new instruments with which it is possible to perform many experiments.
各地的工厂都需要这种新仪器，用它能作许多试验。
By means of an engine steam is changed into energy of moving machinery, and then, by the aid of a generator, into electrical energy, which is transmitted over wires and, at some distant point is changed into light, or heat, or energy of
moving machines.
利用发动机把蒸汽能变成运转机器的机械能，然后再用发电机变成电能，电能通过电线输送出去，在某一远处转换成光、热或运转机
器的能量。
 
机械工程专业英语文献阅读之六  The Strength of Mechanical Elements 2
It is with the last three categories that we shall be mostly concerned. This means that the designer will usually have only published values of yield strength, ultimate strength, and percentage elongation. With this meager information the engineer is expected to design against static and dynamic loads, biaxial and triaxial stress states, high and low temperatures, 
and large and small parts! The data usually available for design have been obtained from the simple tension test, where the load was applied gradually and the strain given time to develop. Yet these same data must be used in designing parts with complicated dynamic loads applied thousands of times per minute.  No wonder machine parts sometimes fail.
 
机械工程专业英语文献阅读之六  Words Learning
publish  出版,公布,发表
We can find the values of yield strength and ultimate strength for many kinds of material in a published material hand book.
我们可以从出版的材料手册中查到许多材料的屈服强度和极限强度的数据。
expect  期待,预期,盼望  
We expect that the percentage elongation of the new material will reach the needed goal.
我们期待着新材料的延伸率能达到要求的指标。
available可得到的,可达到的,可利用的,有效的
Biaxial and triaxial drawings are available by Solidworks.
用 Solidworks 软件可作出二维和三维图。