the presence of students, ladies and teachers, everyone! i was prepared intervals of cloud today, in honor here entitled "technology and future" speech, i am very proud of both, but some unease. in recent years, we have seen our great motherland, the cause of the rapid development of technology, which allow me to a chinese i feel very proud. remember that long ago, cell phone use almost the only one, which is called, but a few years ago, cell phones has undergone great changes, not only look more beautiful, but also use more, you can use the phones to take pictures, meetings, internet, text messages, etc. a series of things that i their life more convenient, so i am more aware of the strength of the technology, but i am just a fledglings students, "technology" as the word also aware of the limited, i am unable to use some very difficult theory to elaborate technology xuanji, no right to work on their elders i can promise of the technology blueprint. but i am willing to use a student’s perspective to the imagine technology and the future.
from genetic engineering "is a live princes" dream, nano-technology "- not washing your clothing," promises; from artificial intelligence "will give you a cute robot dog" warm, transgenic technology "let people grow mouse ears" wonders. the new technology in the birth of a new technology that will let people wild with joy, because these new technologies is gradually improving our lives, let us learn more about ourselves. in the near term, china completed its first sars virus genome sequencing, sars is now the world’s largest recognized the dangers of the disease, but why not other countries completed first, and we just completed the countries? very si-mp-le, this illustrates that our country backward than others, worse than others, we look at the past, had just started a country’s reform and opening up to the current level of science and technology has lead a large country, our motherland experienced a number of ups and downs, how many difficulties and bumpy however, we still back all of the motherland, the motherland because we firmly believe that - not only technological change destiny, can change the future.
for our generation, the general feeling of the community is a strong sense of competition, learning a foot down. science knowledge is the focus of our attention, albert einstein, and stephen hawking, bill gates is the star we have in mind, computer science, physics and chemistry of modern dynamic is constantly affect us. we have to understand the importance of technology, know that the technology universal.
although technology to create a new life prospects soliciting thoughts, inspiring. however, the final analysis is that we rely on our common efforts to realize. , as the future construction of the backbone of our generation of young people shoulders the burden is not light, new opportunities are always accompanied risks and challenges, but we will not give up that easily, we use our youth to predecessors vowed: never live up to their predecessors of our hope.
looking back at the history of civilization, anderson is the history of mankind against the darkness of ignorance, is the scientific lit a fire in the raging human soul of hope; technology support civilization, science and technology to create the future, but the future is in our hands. let us become knowledge explorers, let us unknown roaming on the road, let me use our creativity to the world we live a better place.
参考翻译：
在场的学生们，女士们，老师，大家好！我准备间隔云今天，为了纪念在这里题为“科技与未来”的讲话，我感到非常自豪的两个，但有些不安。近年来，我们已经看到我们伟大的祖国，事业的迅速发展，技术，请允许我向中国我感到非常自豪。请记住，很久以前，手机应用几乎只有一个，这是所谓的，但在几年前，手机发生了很大变化，不仅看起来更漂亮，而且还更多地使用，您可以使用手机拍照，会议上，互联网，短信等一系列的事情，我的生活更方便，所以我更多地了解的力量，技术，但我只是一个幼鸟学生， “技术”作为也知道这个词的有限，我无法使用一些非常困难的理论阐述技术xuanji ，没有权利对他们的长辈的工作我可以保证的技术蓝图。但我愿意利用学生的观点，以创新技术和未来。
从基因工程“是一个生活王子”的梦想，纳米技术“不洗你的.衣服， ”承诺，从人工智能“会给你一个可爱的机器狗”热情，转基因技术“让人们增长鼠标耳朵”奇观。这项新技术的诞生，一种新技术，将让人们欣喜若狂，因为这些新技术正在逐步改善我们的生活，让我们更多地了解自己。在近期内，中国完成了其第一个sars病毒基因组测序， sars是目前世界上最大的承认危险的疾病，但我们为什么不把其他国家完成第一次，我们刚刚完成的国家？很简单，这说明我们的国家比其他国家落后，不如别人，我们回顾过去，刚刚开始了一个国家的改革开放和当前的科技水平已经导致一个大国，我们的祖国经历了一些的跌宕起伏，有多少困难和坎坷，但我们仍然回到所有的祖国，祖国，因为我们坚信， -不仅是技术变革的命运，可以改变未来。
我们这代人，一般感情的社会是一个强烈的竞争，学习一英尺下降。科学知识是我们关注的焦点，爱因斯坦，和斯蒂芬霍金，比尔盖茨是明星我们想到，计算机科学，物理学和化学的现代活力正在不断影响着我们。我们必须理解技术的重要性，知道该技术具有普遍性。
虽然技术创建一个新的生活前景征求思想，鼓舞人心的。然而，归根结底是要靠我们共同的努力，以实现。作为未来建设的骨干，我们这一代年轻人肩上的负担并不轻，新的机遇总是伴随的风险和挑战，但我们不会轻易放弃，我们用我们的青年前任誓言：决不辜负他们的前辈，我们的希望。
回首文明史上，安德森是人类历史上的黑暗的无知，是科学点燃了大火在肆虐人类灵魂的希望；技术支持文明，科学和技术，创造未来，但未来在我们的手中。让我们成为知识的探索者，让我们未知的道路上漫游，让我用我们的创造力，我们生活的世界变得更美好。
Good morning, my dear teacher and classmates, my name is ****, from***** I am here today to talk about the topic: ‘ Strong Spin-Orbit Splitting on Bi Surf-aces’. Before the topic ,I would like to introduce that ***** is located in Chinese economic and financial center of Shanghai, being one of the most prestigious universities in China and having two beautiful campuses. Welcome to visit our school.
Now I will use the following four parts to introduce my topic: Firstly, The
Background of Rashba Effect , secondly, Surf-ace Geometric Structure of Bismuth, then ,Surf-ace States on Low-index Surf-aces of Bismuth, finally, we will have the Conclusion.
Rashba effect is a momentum-dependent splitting of spin bands in two-dimensional condensed matter systems similar to the splitting of particles and anti-particles in the Dirac Hamiltonian. The splitting is a combined effect of atomic spin-orbit coupling and asymmetry of the potential in the direction perpendicular to the two-dimensional plane. The possible use of this effect is for spintronics applications, spin-filter devices and quantum computing.
Bi is a striking example of the possible difference between surf-ace and bulk material properties. Most importantly, the surf-aces are much better metals than the bulk due to the existence of electronic surf-ace states crossing the Fermi level. Here the Bi surf-aces were simulated by a 22 layer film embedded in vacuum., being confirmed by
angleresolved photoemission (ARPES) investigations and first-principles calculations.
Here we explain the Bi(111) surf-ace in figure shows surf-ace states of Bi(111) calculated without and with spin-orbit splitting included. The shaded areas show the projection of the bulk bands obtained without and with SOC and their
superposition. In the case without SOC, a parabolic surf-ace state is located around Γ in the non-relativistic energy gap. This surf-ace state band gives rise to a hexagonal electron-like Fermi surf-ace element. When the SOC term is included in the
calculation it results in a spin-splitting of the surf-ace state in all directions and leaves it degenerate only at Γ and at M. Very close to Γ the relativistic surf-ace state bands are degenerate with bulk states and show less clear surf-ace character.
A comparison to the experimental dispersion can therefore immediately reveal if the spin–orbit splitting picture is correct. Such a comparison is shown in Fig. 5. The figure shows the calculated and measured electronic structure in the vicinity of two high symmetry points on surf-aces of Bi(111), which is in good agreenment. We can see that the intensity of both surf-ace states strongly decreases close to Γ. This is most likely due to the overlap with the projected bulk band structure. The surf-ace states are no longer genuine surf-ace states but surf-ace resonances, which penetrate much more deeply into the crystal and give a lower photoemission intensity. Having inversion symmetry, this calculation yields two spin-degenerate bands near the Fermi energy
that do not cross at Γ.
In this picture, we can also see that both calculations of Bi(110) and Bi(100) surf-aces show the very steep dispersion of the bands close to the symmetry point which is characteristic for the strong SOC.
In conclusion, strong Spin-Orbit Splitting on Bi Surf-aces is studied by first-principles calculations.
The SOC term leads to a strong and anisotropic splitting of the surf-ace-state bands that profoundly modifies the dispersion of the surf-ace states and the surf-ace FS.
Thank you for listening!
关于科学的英语演讲稿 [篇3]
the presence of students, ladies and teachers, everyone! i was prepared intervals of cloud today, in honor here entitled "technology and future" speech, i am very proud of both, but some unease. in recent years, we have seen our great motherland, the cause of the rapid development of technology, which allow me to a chinese i feel very proud. remember that long ago, cell phone use almost the only one, which is called, but a few years ago, cell phones has undergone great changes, not only look more beautiful, but also use more, you can use the phones to take pictures, meetings, internet, text messages, etc. a series of things that i their life more convenient, so i am more aware of the strength of the technology, but i am just a fledglings students, "technology" as the word also aware of the limited, i am unable to use some very difficult theory to elaborate technology xuanji, no right to work on their elders i can promise of the technology blueprint. but i am willing to use a student’s perspective to the imagine technology and the future.
from genetic engineering "is a live princes" dream, nano-technology "- not washing your clothing," promises; from artificial intelligence "will give you a cute robot dog" warm, transgenic technology "let people grow mouse ears" wonders. the new technology in the birth of a new technology that will let people wild with joy, because these new technologies is gradually improving our lives, let us learn more about ourselves. in the near term, china completed its first sars virus genome sequencing, sars is now the world’s largest recognized the dangers of the disease, but why not other countries completed first, and we just completed the countries? very si-mp-le, this illustrates that our country backward than others, worse than others, we look at the past, had just started a country’s reform and opening up to the current level of science and technology has lead a large country, our motherland experienced a number of ups and downs, how many difficulties and bumpy however, we still back all of the motherland, the motherland because we firmly believe that - not only technological change destiny, can change the future.
for our generation, the general feeling of the community is a strong sense of competition, learning a foot down. science knowledge is the focus of our attention, albert einstein, and stephen hawking, bill gates is the star we have in mind, computer science, physics and chemistry of modern dynamic is constantly affect us. we have to understand the importance of technology, know that the technology universal.
although technology to create a new life prospects soliciting thoughts, inspiring. however, the final analysis is that we rely on our common efforts to realize. , as the future construction of the backbone of our generation of young people shoulders the burden is not light, new opportunities are always accompanied risks and challenges, but we will not give up that easily, we use our youth to predecessors vowed: never live up to their predecessors of our hope.
looking back at the history of civilization, anderson is the history of mankind against the darkness of ignorance, is the scientific lit a fire in the raging human soul of hope; technology support civilization, science and technology to create the future, but the future is in our hands. let us become knowledge explorers, let us unknown roaming on the road, let me use our creativity to the world we live a better place.
学识谷
