ADM-201 dump PMP dumps pdf SSCP exam materials CBAP exam sample questions

如何破坏磁铁 – 译学馆
未登录,请登录后再发表信息
最新评论 (0)
播放视频

如何破坏磁铁

How to Destroy a Magnet (+ interactive periodic table)

这是一块钕磁铁-磁性很强
This is a neodymium magnet – it’s pretty darn strong.
而在火焰中加热后 它的磁性就消失了
And now, after heating it in a flame… it’s no longer magnetic.
到底发生了什么?
What just happened?
其实做一块磁铁
Well, to build a magnet,
你要做的是找一堆磁性原子
all you need to do is find a bunch of magnetic atoms.
那很简单 它们是拥有半填充电子层
That’s easy – they’re the ones with half-filled electron shells
而处于元素周期表中间的元素
in the middle of any of the major blocks of the periodic table
然后将它们
and then make a compound,
按照相同方向排列整合起来
where the magnetic fields of the atoms align in the same direction,
这称作铁磁性
this is Ferromagnetism,
根据铁命名 磁性极强
named after Iron, which is pretty darn magnetic.
然而 这很难实现
However, it’s not so easy –
有时那些原子会想要
sometimes the atoms actually want to
反向交替排列它们的磁场
align their magnetic fields in alternating directions –
这称为“反铁磁性”
this is called “anti-ferromagnetism,”
这意味着材料整体一点磁性都没有
and it means the bulk material won’t have a magnetic field at all.
或有时 原子排列(或反排列)的磁性趋势太弱
Or, sometimes the tendency of the atomic magnets to align (or anti-align)
不足以克服自身固有移动
is just too weak to overcome their intrinsic jiggling –
便产生了温度
that is, their temperature!
这种情况下即使物质自身所有原子都有磁性
In which case, even though all the individual atoms in the material are magnetic,
物质整体并没有磁性
the material as a whole isn’t.
然而在一个强外部磁场中
However, in a strong external magnetic field,
各原子将按照平行于磁场方向逐一排列
the atoms do tend to align with each other in the direction parallel to the field.
这叫做“顺磁性” 液氧就是一个极好的例子
This is called “para-magnetism,” and liquid oxygen is a great example –
它被一个磁铁所吸引
it’s attracted by a magnet,
虽然此前它并无磁性
though it doesn’t stay magnetized afterwards.
但我们回到问题
But let’s get back to the question –
你该如何毁灭一个磁铁?
how do you destroy a magnet?
一种材料只有温度足够低才能获得磁性
Well, a material can only be ferromagnetic if its temperature is low enough:
超过特定温度
above a certain point,
完美的排列原子磁场将被融化失控
the nicely ordered atomic magnetic fields “melt” into disorder,
就如同超过零摄氏度时冰的融化
just as ice crystals melt into water when heated past zero celsius.
因此 要毁灭磁铁
So to destroy a magnet,
你只需加热到它的“磁性熔点”以上
you just need to heat it up past its “magnetic melting point”,
也叫”居里温度”
called the “Curie Temperature” –
或许看不到所发生的变化
it probably won’t look like much is happening,
但一旦原子震荡到足够程度
but once the atoms are jiggling around enough,
它们得磁场方向便不会指向同一处
their magnetic fields will no longer all point in the same direction.
磁铁就此毁灭
Magnet destroyed!
正如不同的元素拥有不同的熔点
And just as different elements melt from solid to liquid at different temperatures,
铁磁性到顺磁性也有着不同的温度
they also melt from being ferromagnetic to paramagnetic at different temperatures,
这一切你都能在元素周期表中探索
which you can explore in this sweet interactive periodic table.
这一切亦将在元素周期表视频中展现
Which also plays all of the Periodic Table of Videos.
通过一个实验…
with an experiment…
本段一分钟化学由audible.com所提供
This episode of minute physics is supported by audible.com.
此次所有作品有声书的提供商
The leading provider of audiobooks across all types of literature
包括小说 非小说和期刊在内的
including fiction and nonfiction and periodicals
在元素周期表下探索研究科学与现实
to delve deeper into the stories and science behind the periodic table
以验证消逝的勺子
check out the disappearing spoon
真爱的谎言或是世界的历史
and other true tales of madness love and the history of the world from
通过元素周期表中元素探索一切 由山姆•肯赞助
from the periodic table of the elements by Sam keen.
老兄 这名称有点长
Man, that’s a long title.
你可以在audible.com/minutephysics
you can download this audiobook or another of your choice for free
网站免费选择下载这些有声书
at audible.com/minutephysics.
再次感谢以上所有让我有机会
Again, thanks to all above for making it possible for me
继续制作分钟化学和提供有声书的人
to keep producing minutephysics and for giving you a free audiobook
audible.com/minutephysics
at audible.com/minutephysics.

发表评论

译制信息
视频概述

分钟化学, 只用你知道磁铁是怎么诞生的, 你才能知道磁铁是怎么毁灭的!

听录译者

收集自网络

翻译译者

zohar

审核员

W

视频来源

https://www.youtube.com/watch?v=IlnZKSR73S0

相关推荐