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.
參考翻譯：
在場的學生們，女士們，老師，大家好！我準備間隔雲今天，為了紀念在這裏題為“科技與未來”的講話，我感到非常自豪的兩個，但有些不安。近年來，我們已經看到我們偉大的祖國，事業的迅速發展，技術，請允許我向中國我感到非常自豪。請記住，很久以前，手機應用幾乎只有一個，這是所謂的，但在幾年前，手機發生了很大變化，不僅看起來更漂亮，而且還更多地使用，您可以使用手機拍照，會議上，互聯網，短信等一系列的事情，我的生活更方便，所以我更多地瞭解的力量，技術，但我只是一個幼鳥學生， “技術”作為也知道這個詞的有限，我無法使用一些非常困難的理論闡述技術xuanji ，沒有權利對他們的長輩的工作我可以保證的技術藍圖。但我願意利用學生的觀點，以創新技術和未來。
從基因工程“是一個生活王子”的夢想，納米技術“不洗你的.衣服， ”承諾，從人工智能“會給你一個可愛的機器狗”熱情，轉基因技術“讓人們增長鼠標耳朵”奇觀。這項新技術的誕生，一種新技術，將讓人們欣喜若狂，因為這些新技術正在逐步改善我們的生活，讓我們更多地瞭解自己。在近期內，中國完成了其第一個sars病毒基因組測序， sars是目前世界上最大的承認危險的疾病，但我們為什麼不把其他國家完成第一次，我們剛剛完成的國家？很簡單，這説明我們的國家比其他國家落後，不如別人，我們回顧過去，剛剛開始了一個國家的改革開放和當前的科技水平已經導致一個大國，我們的祖國經歷了一些的跌宕起伏，有多少困難和坎坷，但我們仍然回到所有的祖國，祖國，因為我們堅信， -不僅是技術變革的命運，可以改變未來。
我們這代人，一般感情的社會是一個強烈的競爭，學習一英尺下降。科學知識是我們關注的焦點，愛因斯坦，和斯蒂芬霍金，比爾蓋茨是明星我們想到，計算機科學，物理學和化學的現代活力正在不斷影響着我們。我們必須理解技術的重要性，知道該技術具有普遍性。
雖然技術創建一個新的生活前景徵求思想，鼓舞人心的。然而，歸根結底是要靠我們共同的努力，以實現。作為未來建設的骨幹，我們這一代年輕人肩上的負擔並不輕，新的機遇總是伴隨的風險和挑戰，但我們不會輕易放棄，我們用我們的青年前任誓言：決不辜負他們的前輩，我們的希望。
回首文明史上，安德森是人類歷史上的黑暗的無知，是科學點燃了大火在肆虐人類靈魂的希望；技術支持文明，科學和技術，創造未來，但未來在我們的手中。讓我們成為知識的探索者，讓我們未知的道路上漫遊，讓我用我們的創造力，我們生活的世界變得更美好。
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!
關於科學的英語演講稿 [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.
學識谷
