Magnetism
美音、自然拼读、分级阅读与词汇复习
Table of Contents Introduction.
导言表。
4 Magnetism and Magnets.
4 磁通与磁通.
5 Magnetic Field.
5磁场.
8 How Are Magnets Made?
8 磁铁是如何制造的?
10 Try This.
10 试试这个
12 Magnetism and Electricity.
12 磁力和电力。
13 Using Magnetism.
13 使用磁学.
16 Conclusion.
16 结论。
20 Glossary.
20 词汇表。
21 Introduction Look around your home and try to find a magnet.
21 导言 看看你的家 试着找到磁铁
A magnet is a metal object that sticks to other metals.
磁铁是粘住其他金属的金属物体.
You might have some magnets among your toys.
你的玩具里可能有磁铁
There are probably magnets on your refrigerator.
冰箱里可能有磁铁
But did you know that there may be hundreds of magnets in your home?
但你知道你家可能有上百个磁铁吗?
You cannot see most of them.
你看不到他们的大部分。
But they are inside your television, telephone, and stereo.
但它们在你的电视、电话和立体声里
They are inside electric motors that power your blender and hair dryer.
它们在电动马达内,为你的搅拌机和干发机提供动力。
Computers are full of magnets.
计算机充满了磁铁.
And all the electricity that runs these things comes from magnetism.
所有运行这些东西的电源都来自磁性。
Magnetism and Magnets Magnetism is an invisible force.
磁力和磁力是无形的力量.
A force is anything that pushes, pulls, or moves an object.
力是任何能推动,拉动或移动物体的东西.
Magnetism is a special force that only pulls on some metals, such as iron.
磁性是一股只从铁等一些金属上拉出的特殊力量.
A magnet will not push or pull plastic or tin.
磁铁不会推动或拉出塑料或锡。
Magnetism flows in one direction through a magnet, no matter what shape the magnet is.
磁铁通过磁铁向一个方向流动,无论磁铁是什么形状.
It flows in one end and out the other.
一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一一
The ends of a magnet are called magnetic poles.
磁铁的末端称为磁极.
Every magnet has a north and a south pole.
每块磁铁有北极和南极.
The force flows out the north pole and back in the south pole.
势力从北极流出后又回向南极.
You can use two magnets to feel magnetism flowing.
可以使用两个磁体来感受磁体流.
The north pole of one magnet will stick to the south pole of the other.
一个磁铁的北极会粘住另一个磁铁的南极.
Now, try to push the two north poles together.
现在,尝试把两个北极一起推.
It feels almost like trying to connect two hoses that are both spraying water.
感觉就像试图连接两个水管 两者都是喷水
The magnetic force pushes the north poles apart, because the magnetic forces are flowing against each other.
磁力将北极推开,因为磁力相向相向.
Two north poles will always repel each other.
二道北极常相击.
So will two south poles.
二相南极相会也.
The Earth’s iron core is magnetic.
地铁地心为磁.
The whole planet acts like a giant magnet.
整个星球就像个巨大的磁铁
If you dangle a magnet by a string, one pole will point north and the other will point south.
如果用一串来缠住磁铁,一个杆会指向北,另一个杆会指向南.
This is exactly how a compass works.
指南针就是这样工作的
This gave the north and south poles of a magnet their names.
这让北极和南极 磁铁的名字。
Magnetic Field The magnetic force flows out the north pole of the magnet.
磁场 磁力从磁铁的北极流出.
Then, it loops around outside the magnet and flows back in the south pole.
然后,它环绕在磁铁外,然后在南极回流.
Magnetism flows through space in lines of force.
磁体通过空间 以武力行。
The invisible shape formed by the lines of force around the magnet is called the magnetic field.
磁铁周围由力线所形成的无形外形被称作"磁场".
Do You Know?
你知道吗?
Earth’s north and south magnetic poles are not quite at the true North and South Poles.
地球的南北磁极并不完全位于真正的北极和南极。
The north magnetic pole is in northern Canada.
北磁极位于加拿大北部.
The south magnetic pole is in the Pacific Ocean south of Australia.
南磁极位于澳大利亚以南的太平洋.
Since Earth’s core moves around, the magnetic poles move, too.
由于地心运动,磁极也运动。
They can even flip completely around.
他们甚至可以完全翻转。
If this happened today, your compass needle would point south!
如果今天发生这种事 你的罗盘针会指向南方
Any iron or other magnets inside a magnetic field will be pulled toward the magnet.
磁场内的任何铁或其他磁体都会被拉向磁体。
Stronger magnets have more lines of force and larger magnetic fields.
更强力的磁铁具有更多的力线和更大的磁场.
To see a magnetic field, place a magnet on a piece of paper.
要看到磁场,就把磁铁放入一张纸上.
Sprinkle iron filings around the magnet.
在磁铁周围喷出铁片
The filings will gather along the lines of force in the shape of the magnetic field.
备案会按照力道以磁场外形来收集.
How Are Magnets Made?
磁铁怎么样?
The first magnets were made of a natural rock called lodestone.
最早的磁铁由一天然岩石所制成,被称作"地石".
People used pieces of lodestone in compasses.
人们在指南针中使用了地块.
But they did not know how they worked.
但他们不知道他们是如何工作的。
Every material is made of extremely tiny pieces called atoms.
每个材料都由极小的被称作原子的碎片所制成.
Most atoms spin.
大多数原子旋转。
This spinning creates a tiny, tiny force.
这种旋转产生出一股微小的力量.
In most things, like rocks or plastic, the atoms spin every which way.
在大多数事物中,如岩石或塑料,原子旋转的方式各有不同.
The tiny forces never add up.
微弱的力量从不增加。
But when something becomes magnetized, the atoms spin in the same direction.
但是当有东西变得磁化时,原子会向同一个方向旋转.
All the tiny forces add up to create a magnetic force.
所有微弱的力量加起来,形成磁力.
Eventually, people learned how to line up the atoms in some metals to create new magnets.
最终,人们学会了如何将一些金属中的原子排成一行来创造出新的磁铁.
Some things, such as iron, become magnetized more easily than others.
有些东西,如铁等,比起其他东西,变得更容易被磁化.
A piece of ordinary iron is placed inside a strong magnetic field.
一块普通铁被放入强磁场内.
The magnetic force makes the iron atoms line up and spin in the same direction.
磁力使铁原子排成一行并朝同方向旋转.
This makes a new magnet.
这让新的磁铁。
The more atoms that spin in the same direction, the stronger the magnet becomes.
向同方向旋转的原子越多,磁力就越强.
Sometimes if you drop a magnet, some of the atoms get knocked out of line, and the magnet gets weaker.
有时如果掉出磁铁,一些原子会被打出线外,而磁铁会变弱.
Make your own magnet!
做你自己的磁铁!
You will need a large iron nail, a strong magnet, and several paper clips.
你需要一个大铁钉 强力磁铁 还有几个纸夹
will start to line up the atoms in the nail.
将开始排出指甲中的原子
paper clips.
纸夹.
Does the nail pick up the clips?
钉子能拿起夹子吗?
How many can it pick up at once?
一时能取出多少.
Keep stroking the nail along the magnet to make the nail’s magnetic force stronger.
让钉子的磁力更强。
See if you can pick up all the paper clips at once.
看看能不能马上把剪报拿起来
Magnetism and Electricity Magnetism and electricity are very closely related.
磁学和电力磁学与电力密切相关.
Magnets can make electricity.
磁铁可以发电.
And electricity creates magnetic fields.
电能产生磁场。
This is because both magnetism and electricity affect the way atoms spin.
这是因为磁学和电力都影响着原子旋转的方式.
All the electricity you use comes from machines called generators.
你使用的所有电力都来自叫做发电机的机器.
Generators make electricity by spinning magnets around coils of wire.
发电机通过绕接线圈旋转磁铁来发电.
The magnetism creates an electric current in the wire.
磁性在电线中产生出一股电流.
The difficult part is getting the magnets spinning.
困难是磁铁在旋转
Power plants use running water, wind, or steam from burning fuel to turn the magnets.
发电厂使用自来水,风能,或从燃烧燃料中蒸汽来转动磁铁.
Electricity can create special magnets called electromagnets.
电力可以产生特殊的磁铁,称为电磁.
A wire is wrapped around a regular piece of iron.
铁丝网被固定的铁片包裹.
Then an electric current from a battery or outlet flows through the wire.
然后电池或出水口的电流通过电线流出.
The electric current makes a magnetic field.
电流产生磁场.
This magnetizes the iron.
这个磁化了铁.
But the iron only stays magnetized as long as the electricity is on.
但只要开通了电,铁就会一直磁化
Using Magnetism The earliest use of magnetism was the compass.
使用磁学 磁学最早的使用是罗盘.
A small, freely moving magnetic needle pointed to Earth’s magnetic north pole.
一个能自由移动的小磁针指向地磁北极.
This helped guide travelers and explorers.
这有助于引导旅行者和探险者.
Modern travelers still use compasses.
现代出行者仍然使用指南针.
Electricity comes from spinning magnets inside generators.
电力来自发电机内部的旋转磁铁.
And electric motors work like generators in reverse.
而电动马达的功用就像发电机在倒转.
They use electric current to spin magnets.
他们用电流旋转磁铁.
The magnets are attached to fans, cutting blades, or wheels.
磁铁被附着在风扇上,被切割出叶片,或者被取出轮子.
This is how fans, blenders, and remote-control cars work.
粉丝、搅拌机和遥控车就是这样工作的。
Magnets can also encode information, or store it in a special code.
磁铁还可以将信息编码,或者存储在特殊代码中.
Cassette tapes, videotapes, computer disks, and credit cards all use strips of tiny magnets.
磁带、录像带、电脑磁盘和信用卡都使用小磁铁条。
The magnets are the size of grains of powder.
磁石是粉末粒的大小.
There can be millions of magnets on one tape, disk, or credit card.
一盘磁带,磁盘,或信用卡上可以有上百万个磁铁.
Each tiny magnet points in its own direction.
每个微小的磁铁都指向自己的方向.
The different positions of the magnets create a code.
磁铁的不同位置创造了一个代码.
Tape players, VCRs, and computers sense the tiny magnetic fields and read the code.
磁带播放器,VCR,和计算机能感知到微小的磁场并读取代码.
Putting a credit card, tape, or disk near a powerful magnet can mess up or erase the code.
在有威力的磁铁附近放出信用卡,磁带,或磁盘,可能会弄乱或抹去密码.
Some high-speed trains run on electromagnets.
一些高速列车运行在电磁铁上.
The trains have powerful electromagnets on the bottom.
列车底部有强大的电磁铁.
The track also has powerful electromagnets.
赛道还拥有强大的电磁.
The two electromagnets face each other so that they repel each other.
两个电磁相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相会相
The magnetic force is so strong that it lifts the train off the track.
磁力很强,使列车脱轨.
The train floats above the track.
列车在轨道上方浮动.
It actually flies as it travels.
飞行时会飞起
This makes a fast, smooth ride.
这让车跑得很快 顺畅
Special machines called MRIs can look inside a person’s body.
特殊机器称为MRI,可以查看一个人的身体。
The person lies inside a tube cut right down the center of a very powerful magnet.
这个人躺在一个被切开的管子里 紧接着一个非常强大的磁铁的中心
The lines of force flow through the person’s body.
武力线贯穿个人的身体。
The magnetism is so strong that it causes the atoms in the body to spin in the same direction.
磁性极强,会使体内的原子向同方向旋转.
Special sensitive instruments can tell how fast the atoms spin.
特殊的敏感仪器可以分辨出原子旋转的速度有多快.
Computers figure out what kind of atoms they are based on how they spin.
计算机会根据它们是如何旋转的来判断它们是什么原子.
This gives doctors an idea of what is going on inside a person’s body.
这让医生们了解到一个人的身体里发生了什么。
Doctors can find atoms that are not supposed to be there.
医生可以找到不该存在的原子.
They can see cancer and other diseases.
他们可以看到癌症和其他疾病。
MRIs give doctors a look inside the body without having to cut the body open.
核磁共振让医生检查身体内部,而不必切开身体。
Conclusion While magnets may seem simple, there is no end to their uses.
结论 虽然磁铁看起来可能很简单,但其用途并没有停止。
Every time you watch a tape, turn on the air conditioner, or even turn on a light, you are using magnets.
每次看磁带,打开空调,甚至打开灯光,你都会使用磁铁。
Someday you may ride on a high-speed train or use an MRI.
某天你可能会乘坐高速列车或使用核磁共振.
Playing with magnets can be lots of fun.
玩磁铁会很有趣
The magnetism you play with is the same force that has made modern life possible.
你所玩的磁力 和现代生活一样