外研版高中英语必修1 Module3 单元文化背景知识:Maglev Train

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单元文化背景知识:Maglev Train
磁悬浮列车
Q: What does maglev mean?
A: Maglev is short for magnetic levitation(漂浮), which means that these trains will
float over a guide way(导轨) using the basic principles of magnets to replace the old
steel wheel and track trains.
Q: What is guide way and how does it work?
A: The magnetized coil([电]线圈) running along the track, called a guide way, repels
the large magnets on the train's undercarriage (车盘), allowing the train to levitate(飘
浮) between 0.39 and 3.93 inches (1 to 10 cm) above the guide way. Once the train is
levitated, power is supplied to the coils within the guide way walls to create a unique
system of magnetic fields that pull and push the train along the guide way. The
electric current supplied to the coils in the guide way walls is constantly alternating to
change the polarity (极性) of the magnetized coils. This change in polarity causes the
magnetic field(磁场) in front of the train to pull the vehicle forward, while the
magnetic field behind the train adds more forward thrust (推力).
Q: How many components are there to a maglev train rail system?
A: The magnetic field created in this wire-and-battery experiment is the simple idea
behind a maglev train rail system. There are three components to this system:
Large electrical power source Metal coils lining a guide way or track large guidance
magnets attached to the underside of the train.
Q: What is the difference between a maglev train and a conventional (常规的,传统的)
train?
A: The big difference between a maglev train and a conventional train is that maglev
trains do not have an engine at least not the kind of engine used to pull typical train
cars along steel tracks. The engine for maglev trains is rather inconspicuous(不显眼
的,不引人注意的). Instead of using fossil fuels (矿物燃料), the magnetic field
created by the electrified coils in the guide way walls and the track combine to propel
(推进) the train.
Q: How fast can maglev trains travel?
A: Maglev trains float on a cushion of air (气垫), eliminating friction (摩擦). This
lack of friction and the trains' aerodynamic (空气动力学的) designs allow these trains
to reach unprecedented (空前的) ground transportation speeds of more than 500 kph.
In comparison, a Boeing-777 commercial airplane used for long-range flights can
reach a top speed of about 789 kph. Once manufacturers can prove that maglev trains
can transport passengers safely at such high speeds, maglev trains could become an
ideal alternative to airplanes. Developers say that they will likely link cities that are
up to 1,609 km apart. At 500 kph, you could travel from Paris to Rome in just over
two hours.