职称英语理工类考试考前每日一练(10)

　　职称英语理工类考试考前每日一练

　　The Tiniest Electric.Motor in the World

　　1.Scientists recently made public the tiniest electric motor ever built.You could stuff hundreds of them into the period at the end of this sentence.one day a similar engine might，power a tmy mechanical doctor that，would travel through your body to remove your disease.

　　2.The motor works by shuffling atoms between two molten metal droplets in a carbon nanotube.One droplet is eyen smaller than the other.When a small electric current is applied to the droplets，atoms slowly get out of the。larger droplet and join the smaller one.The small droplet growsbut never gets as big as the other dropletand eventually bumps into the large droplet.As they touch，the large droplet rapidly sops up the atoms it had previously lost.This quick shift in energy produces a power stroke.

　　3.The technique exploits the fact that surface tensionthe tendency of atoms or molecules to resist separating-becomes more important at small scales.Surface tension is the same thing that allows some insects to walk on water.

　　4.Although the amount of energy produced is small一20 microwattsit is quite impressive in relation to the tiny scale of the motor.The whole setup is less than 200 nanometers off a side，or hundreds of times smaller than the width of a human hair.If it could be scaled up to the size of an automobile engine，it would be l00 million times more powerful than a Toyota Camrys 225 horsepower V6 engine.

　　5.In l988，Professor Richard Muller and colleagues made the first operating micromotor，which was 100 microns across，or about the thickness of a human hair.In 2003，Zettls group created the first nanoscale motor.In 2006，they built a nanoeonveyor，which moves tiny particles along like cars in a factor。v.

　　6.Nanoteehnology engineers try to mimic nature。building things atombyatom.Among other things，nanomotors could be used in optical circuits to redirect light，a process called optical switchin9。Futurists envision a day when

　　nanomachines，powered by nanomotors，travel inside yur body to find disease and reFair damaged cells.

　　词汇：

　　shuffle v.来回运动 nanometer n.纳米，毫微米

　　molten adj.熔化的 micromotor n.微电机

　　droplet n.小滴 nanotube n.纳米管

　　Nanoconveyor n.纳米传送带 nanotechnology n.纳米技术

　　bump v.碰撞 mimic v.模仿

　　sop v.吸入 suoke n.行程，冲程

　　microwatt n.微瓦 nanomotor n.纳米发动机

　　nanomachine n.纳米机器

　　注释：

　　1.Power stroke：动力行程

　　2.at Small scales：在小等级上。这里指的是在纳米等级上。

　　3.it is quite impressive in relation to the tiny scale of the motor：与电动机的小等级相比，功率是相当可观了。In relation to是与相比。如：

　　The city is quite large in relation to its population.

　　4.Setup：装置。这里指nanomotor。

　　5.Ifit could be scaled up to the size of an automobile engine：如果纳米电动机能按比例放大到汽车发动机的尺寸。

　　scaleup to是把按比例放大到。

　　练习：

　　1.Paragraph 2_____

　　2.Paragraph 4_____

　　3.Paragraph 5_____

　　4.Paragraph 6_____

　　A.An introduction of a Toyotas 225 horsepower V6 engine.

　　B.A description of the nanomotor in terms of power and size.

　　C.Surface tension.

　　D.Previous inventions of nanoscale products.

　　E.The working principle of the nanomotor.

　　F.Possible fields of aplication in the future.

　　5.Doctors envision that the nanomotor would travel through human bodies to_____.

　　6.Surface tension means the tendency of atoms or molecules to_____.

　　7.Nanoconveyors could be used.to_____.

　　8.Applying a small electric current causes atoms to_____.

　　A.remove disease

　　B.resist separating

　　C.shuffle between two molten metal droplets

　　D.power nanomachines

　　E.Sop up molecules from the large droplet

　　F.transport nanoscale objects