听翻轴 Kaijor
这是一个很显然的难题 Obviously is quite a problem.
你如何制作重水 How do you make D2O?
因为氘在水会被稀释7000倍 Because normally the deuterium in the water is diluted by
这对化学家来说是很棒的稀释剂 a factor of seven thousand(这句话可能有点问题), which for chemist is really pretty dilute.
制取重水的最佳方法是电解法 The best way of making D2O is by a process called electrolysis.
当你将电流通入水中制取氢气时 When you pass a current through the water to make hydrogen
这个制取过程第一次被大规模采用是在挪威 the process was first carried out on the large scale in Norway.
在二战前 Just before the second world war in Norway,
挪威这个山脉连绵的国家 which is a very mountainous country,
挪威人利用河流流成瀑布的水能发电 they have a lot of cheap electricity from hydro power
获取了极其廉价的电 rivers going over waterfalls.
他们因此而获得电 并且创造了经济意义 So they have electricity and it makes economic sense
他们通过电解水来制取氢气 to generate hydrogen to make them for making ammonia
进而制取氨气和化肥 and fertilizers by electrolyzing water.
如果你电解水 你会发现水的电解速度 And if you electrolyze water you find that the H2O
要比重水的电解速度稍微快一点 react a little bit faster than the D2O.
如果你继续电解更多的水 So if you go on electrolyzing more and more of water and
并且保持水的余量不变 然后在电解的几个步骤中 keeping what's left and then doing several stages of
你会渐渐发现 electrolysis you can gradually concentrate
最终得到越来越多的纯粹的重水 more and more of the D2O to eventually
这个电解方法是在 it's nearly pure. This process was carried out
挪威中部的一个非常偏远的发电站进行的 in a fairly remote power station in central Norway
如今 在核科学发展的早期重水主要被用于 in an regional telemark now one of the main uses of D2O
制作核反应堆 in the early stages of nuclear science was for making nuclear reactors
在二战期间 nuclear piles and during the Second World War
英国和美国都被德国震慑 the British and the Americans were terrified that Germany
德国当时占领了挪威 从而获取了重水 who occupied Norway in those at that time might get hold of the D2O
并开始研究核能 and start nuclear research and in one of the best raids
在二战期间的一次最佳袭击 of the whole Second World War six Norwegians
6个挪威人摧毁了一个重水装置 attacked the power station destroyed the heavy-water apparatus
然后撤退了 这次袭击之所以如此成功 and retreated and the reason it was so successful is that
是因为无人伤亡 nobody was injured and nobody was killed.
所以他们潜入了那个地方 引爆了发电站 So they got into the place blew it up
然后无人员伤亡撤离了 and escaped without anybody being injured. And in fact
实际上 德军的将军对此事进行调查 the German General that investigated thought it was one of them
将军认为他们中有一个他没见过的出色的军人做的 as magnificent military feet he'd ever seen.
另外一个版本就是说 德国人入侵挪威 There's another story that before the Germans invaded Norway
是为了让重水供应到嘎纳 that the supply of heavy water to Cannes.
只有几加仑被走私到英国 这说明了重水在当时是弥足珍贵 A few gallons was smuggled out to the UK and it was so valuable
据说这些重水被运到美国之前 It is said that it was put under King George the six bed overnight
一直放在乔治六世的床底下过夜以确保安全 so it should be safe before it was then transported to America
真的吗 Is that true?
这只是一个传说 Well, this is the the legend and the story is that when it was flown to
据说重水是用无暖气的飞机运到美国的 America in an unheated plane
重水已经结冰了 the water froze. So when the people took it off
据说当人们把重水拿出来时 容器是空的 重水附在了容器上面 it sounded as if the cans were empty and they got really wear it
当你加热重水时 重水融化了 but then it warmed up and melted.
重水的应用非常广泛 D2O has a number of applications, but it's real use is in a technique all
但是只有应用在核磁共振才能使它真正发挥作用 nuclear magnetic resonance.
我们在视频中 We have shown it on our video about T
你们可以以此来分析分子 how you can use it to analyze molecules
核磁共振对氢原子十分敏感 and nuclear magnetic resonance is very sensitive to hydrogen atoms.
如果你想研究一些在水中溶解的分子 So if you want to study some sort of molecules dissolved in water
如果你利用氢原子在普通水中溶解 if you use ordinary water the hydrogen atoms in the water
你会发现反应很快 have such a strong signal
那你根本研究不了溶解的分子 that you can't study the dissolved molecules at all.
因此 你应该用重水代替普通水 这样反应速率就会比较慢 So instead you use D2O which do not respond to the same
你还会获得很好的光谱图 frequencies as the hydrogen and so you get a nice spectrum.
我觉得正在收看本节目的观众有两个问题 I think people watching will have two questions.
重水的味道怎么样 what does heavy water tastes like?
如果我喝了重水会发生什么 and what will happen to me if I think it
虽然我从未喝过 well I've never tasted D2O?
我猜重水的味道应该和普通水的味道差不多 I suspect that it will taste really quite similar to H2O.
虽然它的味道很难预测 Though it's difficult to predict,
因为有的时候 一些东西尝起来味道的差别很很大 because sometimes things taste quite different.
水确实没有什么味道 But water doesn't really taste anyway.
你通常会品尝盐水 或者其他东西溶解在水里 You usually tastes what's dissolved in the water salts or whatever
我需要强调一点 重水是有毒的 There is a strong body of opinion that D2O is quite poisonous
之所以有毒性 是因为在你的身体里面 and the reason why it's poisoners is because in your body
有各种各样的含有氢原子的分子 you have all sorts of molecules that have hydrogen bonded
有一部分分子还有氧原子 particularly to oxygen and the these bones break as part of the
随着你身体内发生的各种化学反应 对使你的骨骼破裂 various chemical processes in your body
氘和氧结合的反应 deuterium oxygen bonds are slightly stronger
比氢氧结合的反应更加强烈 所以 than hydrogen oxygen bombs. And therefore,
如果你的身体由于氘氢结合而开始发生变化 if you start changing your body for the the chemicals in your body
骨骼的破裂会变得更缓慢 from hydrogen to deuterium these bones will break more slowly and so various
从而导致你体内的各种生理反应也慢下来 processes in your body are likely to slow right down.
如果这些反应慢下来 就有可能完全停止 If they slow down they may completely stopped.
有人告诉我 Well I was always told
我可以制作一个有重水的空腔来杀人 that you could kill someone by making a cavity with D2O.
其原理就是 Because what it does is there a difference between the way that
氢原子和你体内的氘发生反应 hydrogen reacts and you deuterium reacts in the body.
氘就会取代你体内的氢原子 So it can replace hydrogen in the body and obvious everywhere
只要有水的地方就会有显著的反应 to know the water and it's in all the end times that
并且会在你能想到的身体部位一直反应直至结束 you think that are in your body.
但是我曾经见过有人的体内 But I have since read that apparently need to replace about
有50%的水被重水取代 fifty percent of the water in your body and
说实话 用重水杀人是有点不切实际的 to actually kill you with D2O which is kind of impractical,
所以目前还没有过重水夺取人命的事情发生 so where would be murder is don't try out one to on work.（听不出来）
我要澄清一个谣言 我从来都没有证实过 There is a rumor which I've never been able to verify that
美国芝加哥附近的氩实验室 the argon lab in the United States just outside Chicago
有过一次用狗来做实验 at one time had to do to rate a dog
这只狗是用重水养大的 which had been brought up and fed on D2O
但是我觉得这就是一个逗逼在无中生有 but I think this is probably just a nerb named it never happened
我还有一个建议 There's also a suggestion that
如果你用重水而不是普通水来稀释威士忌 if you dilute your whiskey with D2O rather than H2O
当你喝多了 你不会那么容易醉 that you might not get so dizzy when you drink too much
但是你可能会狗带 but you might be dead.
所以这可不是什么适合人类尝试好东西 So it's not something that one should try
毕竟 它也是很贵的 and anyway it's far too expensive