国产精品亚洲YOURPORN,日韩欧美一区二区三区不学,欧美大鸡巴性爱网站,91精品视频成人网

  • <noscript id="4bm7e"><optgroup id="4bm7e"><div id="4bm7e"></div></optgroup></noscript>
    <i id="4bm7e"></i>
    1. 今天是
      今日新發(fā)布通知公告0條 | 上傳規(guī)范

      物理學(xué)院“博約學(xué)術(shù)論壇”系列報(bào)告第18期

      發(fā)布日期:2012-05-08

      物理學(xué)院“博約學(xué)術(shù)論壇”系列報(bào)告第18期        (2012年第7期)
       

      題  目:Structure and dynamical properties in glass formation in CuZr metallic alloys
      報(bào)告人:李茂枝 教授
      單  位:中國(guó)人民大學(xué)物理系
      時(shí)  間:2012年5月11日(星期五)上午10:00
      地  點(diǎn):中心教學(xué)樓701 

      摘  要:
      Describing the structure of amorphous materials such as metallic glasses and understanding the glass formation have been longstanding challenges in materials science. Despite enormous efforts and progress that have been made during the past several decades, a rational glass transition mechanism of real alloy systems is still absent. In this talk, I will talk about a distinct medium-range arrangement motif and an icosahedral two-phase structure observed in ZrCu binary metallic glasses. We find that the glass structure is a heterogeneous mixture of interpenetrating 13-atom icosahedral clusters connected in a string-like fashion forming a solid-like backbone network within a liquid-like matrix. A significant self-aggregation effect of icosahedral short-range order (ISRO) in high temperature ZrCu liquids is also discovered, which is highly consistent with that observed in atomic models of corresponding glass system. It is found that the development of ISRO upon cooling is driving the system into dynamical arrest. Moreover, the aggregation of ISRO remarkably enhances this effect and provides a positive feedback for the development of ISRO in the system. Due to its intrinsic non-space-filling character, the self-aggregation of ISRO results in a string-like network, expanding the slowing effects to a large portion of the system. When the network percolates, dynamics in the whole system is arrested, leading to a glass transition.

      簡(jiǎn)  歷:

      2001年于中科院物理研究所獲得博士學(xué)位;
      2001年至2007年在美國(guó)Ames國(guó)家實(shí)驗(yàn)室做博士后和助理研究員;
      2007年10月回國(guó)在中國(guó)人民大學(xué)任教。

      先后從事包括表面生長(zhǎng)動(dòng)力學(xué)中表面納米結(jié)構(gòu)的形成和穩(wěn)定性、微觀原子擴(kuò)散對(duì)表面形貌的形成機(jī)制、量子尺寸效應(yīng)對(duì)表面納米結(jié)構(gòu)形貌和穩(wěn)定性的影響、非晶合金等體系中過(guò)冷液態(tài)和玻璃態(tài)的微觀結(jié)構(gòu)、動(dòng)力學(xué)性質(zhì)和力學(xué)性質(zhì)以及玻璃轉(zhuǎn)變機(jī)制等的理論和計(jì)算機(jī)模擬研究。

      邀請(qǐng)人:姚裕貴  教授 

      聯(lián)系方式:物理學(xué)院辦公室(68913163)
      網(wǎng)    址: http://physics.bit.edu.cn/