丹-舍特曼（Dan Shechtman），以色列材料科学家，出生于特拉维夫，在以色列理工学院取得机械工程学士后，又接连取得材料科学硕士与博士学位。任以色列理工学院菲利普托比亚斯材料科学教授、美国能源部埃姆斯实验室（Ames Laboratory）助理、艾奥瓦州立大学材料科学教授。 1982年4月8日， Dan Shechtman 在快速冷却的铝锰合金中发现一种新形态的二十面体相（Icosahedral Phase）分子结构，开辟了研究准晶体的全新领域。 2011年， 为表彰其对准晶体的发现， Dan Shechtman 教授获颁诺贝尔化学奖。 除诺贝尔化学奖外， Dan Shechtman 教授 还获得过诸多奖项，如：1993年Weizmann Science Award、1998年Israel Prize in Physics、1999年Wolf Prize in Physics、2000年Gregori Aminoff Prize of the Royal Swedish Academy of Sciences、2002年EMET Prize in Chemistry、2008年European Materials Research Society (E-MRS) 25th Anniversary Award 。 在2013年7月举行的林道诺贝尔得主大会（ Lindau Nobel Laureate Meeting ）上， Dan Shechtman 教授 接受了Wiley的专访，谈到为何“准晶体”没有更早被发现，以及他在遭到同行反对时如何能依然坚持相信自己的研究。专访后还附有精选的 Dan Shechtman 教授 撰写的论文。 ---------------------------------------------------------------------------------------------------------------- --------------------- Wiley: In the mid-1980s, there were three ground-breaking discoveries in the chemistry of materials: fullerenes, high temperature super-conductors and your quasicrystals. The researchers of the first two received their Nobel Prize very quickly. But you had to wait 30 years. Did you think you might never get it? 在20世纪80年代中期，在材料化学领域有三个里程碑性的发现，分别是： 富勒烯 、高温超导体和您的准晶体。前两位发现者都很快获得了诺贝尔奖，但是您足足等了30年，您有没有想过自己可能永远拿不了诺贝尔奖了？ Dan Shechtman: I really do believe that anyone who gets the Nobel Prize deserves it. But that doesnt mean that whoever deserves a Nobel gets one. It never bothered me, personally. I always said: They have better candidates than me. I just put it out of my mind. So when it finally came, it was a total surprise. I was working on my computer, 11:15 in the morning. Thephone rings: Danny speaking, I said. Hello, this is the Royal Swedish Academy of Sciences. Please hold the line for a very important message. I said to myself, Oh oh. After the announcement they told me not to tell anyone else for half an hour, because at 11:45 they were going to announce it to the world. So I put down my work, left the computer,and just sat there at my desk staring at the floor in front of me, just staring, and thinking, whats going to happen now? I couldn't even imagine what actually happened next. I thought: OK, now there will be three or four invitations from here and there in the world, I will speak here and there; I totally underestimated the reality. Wiley: So it completely changed your life? 所以说这彻底改变了您的生活？ Dan Shechtman: Yes. I travel all over the world. I have endless invitations to many different places. I only accept a few, simply because – unlike an electron – I cannot be in two places at one time. And so ... but I really try... Lets put it this way: Im inspired to try to inspire young people. Wiley: I had the good fortune to attend your Master's class yesterday at the Lindau Nobel Laureate Meeting. It seemed to me that you enjoyed passing on your experience to the young people there. 我十分荣幸地参加了您在林道诺贝尔得主大会上的课程，您好像十分乐意将自己的经验传递给青年一代。 Dan Shechtman: Lindau is very special. There is no meeting like it anywhere in the world, where so many Nobel Laureates meet so many students over a longer period – a whole week. There is always lots of interaction. This is really unique. Yes, I enjoy it. I am a teacher. I like people to understand what I am talking about. This is why I always start with very simple questions like: What is order? What is rotation symmetry? I want people to understand what Im talking about. I feel like I'm on a mission to advance the education of the younger generation, and by doing this to promote peace in the world. We live in a world full of serious – even dire – problems. We have to work hard to calm this world down and start working on doing good things. Wiley: You have always been a dedicated teacher: You even invented a course at the Technion about entrepreneurship – I believe its called technological education? 您一直是个师者，您甚至在以色列理工开了一门讲授企业家精神的课，好像是叫 technological education ？ Dan Shechtman: Yes. I will have been teaching it for 27 years now. Year after year after year. By now I have about 10,000 graduates who are well-known engineers or scientists in Israel. So over the past 25 years Israel has become a start-up nation, and Im proud to have contributed to this. Wiley: How did you happen to make your way into science? 是什么样的契机让您投身科学事业？ Dan Shechtman: Purely accidentally. When I was young, I wanted to become an engineer, because I loved the book, The Mystery Island, by Jules Verne. I'll let you in on a secret: I have this book with me right now. I'm reading it again, after 50 years without touching it. I brought it here with me, to recall it to my mind. In this book, the five characters are stranded on an island together and have to make everything themselves that they need to survive. The leader is an engineer. They all obey him and admire him because he can do anything. So I wanted to be like him. And indeed, after my military service, I went to the Technion and studied mechanical engineering. But then, in 1966,there was a big recession in Israel and I couldnt find a job. So I said to myself, I will do my Master's degree and in two years I will find a job. But during those two years I fell in love with science and decided to go for a Ph.D. And this is why I am here today. Wiley: In the beginning it was very hard for you to convince other people of your ideas about quasicrystals. Was there ever a moment, when you wanted to go to your lab boss and say: Yeah, you're right, the crystals aret wins. There are no quasicrystals. 开始的时候，您很难说服别人相信准晶体的存在，您有没有过那么一刻想放弃，想走到实验室跟头儿说：是的，你对了，晶体胜利，世界上没有准晶体这个东西。 Dan Shechtman: Never. You don't know me. I am almost never affected by what other people think. I repeated my experiments. I was an expert in electron microscopy, and I knew that my experiments were correct. I said to the others: If you want to prove me wrong, repeat my experiments. Show me what is wrong in my experiments. Don't tell me it can't be true just because of what you read in your books. And everybody who repeated my experiments said: “Danny, fantastic”. And all these people who were lined up against me – Linus Paulingas the spearhead – were simply wrong. It's a pity: Pauling was really, in fact,the greatest chemist of the 20th century, definitely the greatest in the United States. He was a great scientist. He fought me for ten years, from 1984 to 1994– until he died. And he made himself a laughing stock, because after a few years everyone knew he was wrong. The journals finally started rejecting his papers and sending them back to him. He disgraced himself. A sad story. Wiley: Why weren't quasicrystals discovered before 1982? 为什么1982年以前没人发现准晶体的存在呢？ Dan Shechtman: That's a very good question. Is it because they are so rare?– No, there are hundreds of them. Is it because they're made up of esoteric materials? – No, they are made of iron and copper and aluminum and magnesium –materials we use by the ton, every year, all around the world. Is it because they aren't stable? – Many are not stable, true, but what does notstable mean anyway? – It means that if you heat them to 400 °C they will transform into something that is periodic. At room temperature, though, they are stable. Wiley: So what was the reason? 那么原因是？ Dan Shechtman: Electron microscopy. Electron microscopy was needed to discover quasicrystals, because they are very small. The traditional crystallographers wanted x-ray diffraction data. It took us three years to grow quasicrystals that were large enough to see with an electron microscope – and I didnt do that: friends of mine in France and Japan did it. Once we had the selarger quasicrystals, the battle was won. Wiley: But the initial discovery was only possible with electron microscopy? 但是最开始的发现只能通过电子显微镜来看？ Dan Shechtman: Yes. And just being an electron microscopist was not enough:you had to be an expert in electron microscopy. And this is what I'm asking students now: Do you want to succeed in science or just be up on it? If you want to succeed in science, you have to have broad knowledge, true, but you also have to develop a very high peak of expertise. Find something interesting. Bite it. Bite into it like a Rottweiler dog. Don't let go. Don't let go until you know what it is. Listen to other people, but if they talk nonsense, shut yourears. You have to be stubborn, not in a negative but in a positive sense.Persistent. That's it. Wiley: I see you are wearing a tie with a quasi-periodic array? 您戴了一个有准周期性数组图案的领结？ Dan Shechtman: My University, the Technion, had this tie made for me for my birthday, before I got my Nobel Prize. After the Nobel Prize, the demand for them got so intense that the Technion had to make 5,000 more. Now they will probably have to come out with a third edition because they are running out of them again. Wiley : A very nice idea. Thank you very much for the interview. 这主意很棒，非常感谢您接受我们的采访。 Dan Shechtman 教授 论文精选 Low Temperature Superplastic Deformation of Mg–Bi–Si Alloy, S. Remennik, A. Katsman, D. Shechtman, TMS 2012 141st Annual Meeting and Exhibition, Supplemental Proceedings, Volume 2, Materials Properties, Characterization, and Modeling , The Minerals, Metals Materials Society (TMS), John Wiley Sons Ltd., Hoboken, USA, 2012 , 465–470. ISBN: 978-1-118-29609-7 Guest Editorial: Prologue , Daniel Shechtman, Israel J. Chem. 2011 , 51 , 1143–1143. DOI: 10.1002/ijch.201100122 Twin Quintuplet Surfaces in CVD Diamond , Dan Shechtman, J. Mater. Sci. 2006 , 41 , 7720–7724. DOI: 10.1007/s10853-006-0705-4 Metallic Phase with Long-Range Orientational Order And No Translational Symmetry , Dan Shechtman, I. Blech, D. Gratias, Phys. Rev. Let. 1984 , 53 (20) . 1951–1953. DOI: 10.1103/PhysRevLett.53.1951
“修改安培定义”的一些新思考 现有安培定义的两类缺陷： （1）目前SI安培定义里“无限长”、“圆横截面积可忽略”分别是在现实世界中难以实现的无穷大和无穷小。这样的定义，显著增大了安培定义在现实世界中实现、进行标准单位校准的困难性。 （2）电流方向相同时导线间的相互吸引力 F A ，和电流方向相反时的排斥力 F R ，是否严格相等，即 F A = F R 是否严格成立? 有没有高精度的物理实验对此进行过检验? 1822年安培的实验结论不用怀疑，但是其精度到底达到怎样的水平? 一些新的思考： （1）电子、质子的电荷是否随参照系变化，还需要一些高精度的实验确认。 但是，在低运动速度、弱磁场、弱引力场等情况下面，变化应该是很小的。 因此，目前： （2）指定两平行导线的金属材料、长度和直径，并指定两平行导线之间的电流方向相反（同一电流的来回），仍然采用当前的安培定义的其它要求，是一种比较折中的方案。至少其可校准行得到明显的改善。 我们可以不破坏指定的“定义设备”，而获得可行的“安培”校准。这比 标准质量（千克器） 是个进步。 在“用基本物理常数重新定义基本单位”的过程中，谁能保证这些基本物理常数的稳定？比如它们随引力场强度和方向等可能出现的改变？ 谁能保证静电场和静止的引力场是相互独立的？ 谁能保证空间的弯曲仅受质量的影响（而不受静电场的影响）？ 谁做过这方面的精确实验？ 一些稳妥的可能性： 利用两个基本物理量的比值，可能比过比利用单个基本物理量更 稳定：这两个基本物理量可能随外界条件发生相同的变化。 相关链接： 中国科学院 “ 科学智慧火花 ” ：《SI基本单位中安培定义的两种可能缺陷》，投稿时间：2012-04-12： http://idea.cas.cn/viewdoc.action?docid=4681 科学网 › 群组 › 物理综合《 平行导线间磁力大小，与电流方向的关系》，2012-04-23： http://bbs.sciencenet.cn/thread-552690-1-1.html 修改安培定义，2012-10-10： http://blog.sciencenet.cn/home.php?mod=spaceuid=107667do=blogid=731819 Unit of electric current (ampere), SI brochure, Section 2.1.1.4 ttp://www.bipm.org/en/si/si_brochure/chapter2/2-1/ampere.html
标签: 材料
