Strong-Superstrong Transition in Glass Transition of Metallic Glass

Dynamic fragility of bulk metallic glass （BMG） of Zr64Cu16Ni10Al10 alloy is studied by three-point beam bending methods. The fragility parameter mfor Zr64Cu16Ni10Al10 BMG is calculated to be 24.5 at high temperature, which means that the liquid is a ＂strong＂ liquid, while to be 13.4 at low temperature which means that the liquid is a ＂super-strong＂ liquid. The dynamical behavior of Zr64Cu16Ni10Al10 BMG in the supercooled region undergoes a strong to super-strong transition. To our knowledge, it is the first time that a strong-to-superstrong transition is found in the metallic glass. Using small angle x-ray scattering experiments, we find that this transition is assumed to be related to a phase separation process in supercooled liquid.     

A Topological Glass

We propose and study a model with glassy behavior. The state space of the model is given by all triangulations of a sphere with n nodes, half of which are red and half are blue. Red nodes want to have 5 neighbors while blue ones want 7. Energies of nodes with other numbers of neighbors are supposed to be positive. The dynamics is that of flipping the diagonal of two adjacent triangles, with a temperature dependent probability. We show that this system has an approach to a steady state which is exponentially slow, and show that the stationary state is unordered. We also study the local energy landscape and show that it has the hierarchical structure known from spin glasses. Finally, we show that the evolution can be described as that of a rarefied gas with spontaneous generation of particles and annihilating collisions.     

钕玻璃片状放大器玻璃腔的概念设计

针对片状放大器片腔的洁净度问题,提出一种钕玻璃片状放大器玻璃腔的设计方案.选用滤紫外石英玻璃作为主框架的材料,对玻璃腔的结构和密封方案进行设计,并利用玻璃腔外表面镀金属材料的方式进行遮光.采用神光Ⅱ升级主放和100片状放大器进行不同腔体的洁净度对比试验,结果表明玻璃腔的洁净度较不锈钢腔提高了近70%.运用光学高级系统分析程序对玻璃腔进行光线追迹,其钕玻璃泵浦比例提高了8.84%.该方案不仅能减少腔内气溶胶的产生,还能提高钕玻璃泵浦比例.     

微小非球面玻璃透镜超精密模压成型数值模拟

利用非线性有限元软件MSC.Marc,建立了微小非球面玻璃透镜超精密模压的有限元模型,并进行了微小非球面玻璃透镜模压数值模拟分析.通过对比模拟出的不同加工参量下的成型透镜和模具的残余应力分布结果,得出最优的超精密模压成型的模压速率和模压温度范围,并解释了模压速率和模压温度影响微小非球面玻璃透镜成型质量的原因.模拟可以对实际的大批量生产微小非球面玻璃透镜提供有力的帮助.     

微小非球面玻璃透镜超精密模压成型数值模拟

利用非线性有限元软件MSC.Marc,建立了微小非球面玻璃透镜超精密模压的有限元模型,并进行了微小非球面玻璃透镜模压数值模拟分析.通过对比模拟出的不同加工参量下的成型透镜和模具的残余应力分布结果,得出最优的超精密模压成型的模压速率和模压温度范围,并解释了模压速率和模压温度影响微小非球面玻璃透镜成型质量的原因.模拟可以对实际的大批量生产微小非球面玻璃透镜提供有力的帮助.     

Magnetoelectric Coupling Induced Electric Dipole Glass State in Heisenberg Spin Glass

Multiferroic behavior in an isotropic Heisenberg spin glass with Gaussian random fields, incorporated by magneto-electric coupling derived from the Landau symmetry argument, are investigated. Electric dipole glass transitions at finite temperature, due to coupling, are demonstrated by Monte Carlo simulation. This electric dipole glass state is solely ascribed to the coupling term with chiral symmetry of the magnetization, while the term associated with the spatial derivative of the squared magnetization has no contribution.     

Glass fiber image converter

The principle of operation of a glass-fiber image converter is outlined. Calculations are made indicating that a Perot-Fabry interferometer used with the image converter and an electro-optical amplifier gives an increased relative aperture, compared with the usual setup which consists of the interferometer with a diaphragm and a photomultiplier. Some results obtained with an experimental image-converter sample and the technique of manufacturing such converters are described.The authors express their gratitude to the laboratory assistant R.P. Rebezovaya, who helped in sorting and arranging the fibers.     

A Modified Glass Formation Criterion for Various Glass Forming Liquids with Higher Reliability

A modified indicator of the glass forming ability （GFA） from the previous 7 = Tx/（Tl ＋ Tg） for various glass forming liquids is proposed based on a conceptual approach which combines more acceptable physical metallurgy views in terms of the time-temperature-transformation diagrams. It is found that the glass forming ability for glass forming liquids is closely associated mainly with two factors, i.e. （2Tx - Tg） and Tl （wherein Tx is the onset crystallization temperature, Tg the glass transition temperature, and Tl the liquidus temperature）, and could be predicated by a unified parameter γm defined as （2Tx - Tg）/Tl. This approach is confirmed and validated by experimental data in various glass forming systems including oxide glasses, cryoprotectants and metallic glasses, which all shows a higher reliability when their glass forming ability is predicted by the modified parameter.     

Color Glass Condensate and glasma

In this talk, I review the Color Glass Condensate theory of gluon saturation, and its application to the early stages of heavy ion collisions.     

硅酸铅玻璃光敏性研究

采用四倍频的Nd∶YAG脉冲激光 (波长 2 6 6nm ,脉宽 10ns)对氧化铅摩尔分数在 0 3至 0 5的硅酸铅玻璃体样品进行照射 ,并对照射前后样品的折射率及紫外可见吸收光谱进行了测量。研究发现不同能量密度的2 6 6nm激光照射硅酸铅玻璃体样品 ,会使样品的紫外可见吸收光谱产生不同的变化 :当 2 6 6nm激光能量密度较高时 (15 0mJ/cm2 ) ,样品在可见区域的吸收系数明显增大 ,样品表面会产生褐色斑点 ;而当 2 6 6nm激光能量密度较低时 (5 0mJ/cm2 ) ,尽管累计剂量较大 ,样品表面无斑点产生 ,吸收系数稍有增加 ,而折射率下降明显 ,最大Δn =- 0 .2 5± 0 .0 4。对氧化铅摩尔分数为 0 4 3的硅酸铅玻璃用不同能量密度的 2 6 6nm激光进行照射 ,发现当激光能量密度大于某一阈值时 ,样品在可见区域的吸收系数突然增大 ,这可能是由于硅酸铅玻璃吸收 2 6 6nm激光能量导致局部温度升高而引起玻璃结构改变所致。     

SiO2水玻璃微球辐射增强扩散研究

激光惯性约束聚变使用的玻璃微球经中子辐照后,产生辐射增强扩散效应,Ar在玻璃微球中的扩散性能显著改善,获得了常规加热加压扩散方式无法得到的扩散效果。而带电离子辐照玻璃微球后Ar的扩散性能却没有明显改善。研究了中子和其它带电粒子辐射增强扩散效应的差异。After being radiated by neutron, the glass microspheres, which used in ICF research, have greatly increased the ability of Ar diffusion in it because of the radiation-enhanced diffusion. Such results cannot be achieved by means of thermal diffusion. But after being radiated by charged particles, the ability of Ar diffusion in glass has not increased very much. The differences of the radiation-enhanced diffusion caused by neutron and ions are presented.     

玻璃模具的化学处理

本文介绍了如何解决光学玻璃模具易破碎的问题。作者对某些牌号的玻璃,根据不同的用途,不同的性质进行了多次试验,研究出了增加光学玻璃模具强度的新工艺,从而使玻璃模具的力学性能成倍的提高。     

Glass models on Bethe lattices

We consider lattice glass models in which each site can be occupied by at most one particle, and any particle may have at most occupied nearest neighbors. Using the cavity method for locally tree-like lattices, we derive the phase diagram, with a particular focus on the vitreous phase and the highest packing limit. We also study the energy landscape via the configurational entropy, and discuss different equilibrium glassy phases. Finally, we show that a kinetic freezing, depending on the particular dynamical rules chosen for the model, can prevent the equilibrium glass transitions.Received: 23 July 2003, Published online: 19 February 2004PACS: 64.70.Pf Glass transitions - 64.60.Cn Order-disorder and statistical mechanics of model systems - 75.10.Nr Spin-glass and other random models     

Glass sealing technology for displays

A key element in the manufacture of virtually any kind of electronic display is the sealing glass and its relationship to other components in the device. This paper discusses sealing glasses, their properties, and their applications.     

利用胶体系统研究玻璃态

玻璃态是一种无序结构的固体,组成单元可以是原子、分子、高分子、胶体粒子等等。尽管玻璃态材料在生活中很常见,有广泛的工业应用,但相关理论,尤其是液体到玻璃态转变的理论是物理学中争议最多的领域之一。溶液中的胶体粒子可以形成晶体、液体、玻璃等各种态。在光学显微镜下可以直接看到三维内部单个微米胶体粒子,通过图像处理还可以得到粒子的布朗运动轨迹,从而得到玻璃化转变过程中的微观动力学信息,这是原子分子玻璃系统中难以测量的。文章介绍了胶体作为模型系统对玻璃态的研究,主要包括传统的过冷液体到玻璃态的转变,另外还涉及气相、凝胶、多晶等其他无序或半无序态与玻璃态之间的过渡或转变。     

K9玻璃薄膜对离子交换磷酸盐玻璃波导表面保护的优化研究

采用镀K9玻璃薄膜方法来解决离子交换掺铒磷酸盐玻璃波导表面的侵蚀问题,对K9玻璃薄膜的厚度进行了优化研究。测量分析了样品的荧光光谱和荧光寿命,采用光学显微镜和棱镜耦合技术对不同K9玻璃薄膜厚度下制备波导的表面形貌和导光特性进行了表征和测试。结果表明,与掺铒磷酸盐玻璃原材料相比,镀K9玻璃薄膜后荧光光谱保持不变,荧光寿命稍有下降(约0.2 ms);K9玻璃薄膜的厚度在60~80 nm的范围内保护效果最佳。为下一步制备掺铒有源玻璃光波导器件奠定了良好的实验基础。