...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Non-Crystalline Solids: A Journal Devoted to Oxide, Halide, Chalcogenide and Metallic Glasses, Amorphous Semiconductors, Non-Crystalline Films, Glass-Ceramics and Glassy Composites >Predicting glass properties from structure data and intermolecular forces
【24h】

Predicting glass properties from structure data and intermolecular forces

机译：根据结构数据和分子间力预测玻璃性能

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Beside energy, entropy is a basic property determining the relative stability of different states of matter. For glass both properties cannot be determined by measuring energy exchange with the surroundings. However, given interaction potentials, both energy and entropy can be determined from molecular distributions. The entropy function S = S(E) is related to structure by partial derivative S-2/partial derivativeE(2) = - <(DeltaE)(2)> (-1), where <(DeltaE)(2)> are the spatial energy fluctuations, expressible in terms of low order molecular distributions. The functional dependence on E implies certain constraints kept fixed while the energy E is varied. Such constraints are controllable by external forces when the system is in internal equilibrium, or can be explicitly introduced in computer experiments, but are only assumed to exist in the case of glass, practically preventing it from changing with time, although the glass phase is unstable in principle. Integration of the differential equation for S(E) is performed with the aid of a modeling of the radial distribution g(r) in form of a parametrized analytic function, g(r) = g(r; L, D), where L is a lattice characterizing the dominant local configurations of atoms and D is a 'structural diffusion' parameter specifying the degree of spatial decay of coherence between local structures. The modeling provides a representation of structure by a point in the low dimensional parameter space {L, D}. This space includes also the ordered state (L) equivalent to (L, 0), for which S = S(L) = 0, as follows from the third law of thermodynamics. Thus integration can be performed along a (virtual) path connecting (L, D) to (L, 0). The method is illustrated by evaluating the entropy of a model metal in the liquid and glass state. (C) 2001 Elsevier Science B.V. All rights reserved. [References: 21]
机译：除了能量之外，熵是确定物质不同状态的相对稳定性的基本属性。对于玻璃，无法通过测量与周围环境的能量交换来确定这两个属性。但是，在给定相互作用势的情况下，能量和熵都可以从分子分布中确定。熵函数S = S（E）通过偏导数S-2 /偏导数E（2）=-<（DeltaE）（2）>（-1）与结构相关，其中<（DeltaE）（2）>为空间能量波动，可以用低阶分子分布表示。对E的功能依赖性意味着在改变能量E时，某些约束保持固定。当系统处于内部平衡状态时，此类约束可由外力控制，或可以在计算机实验中明确引入，但仅假定存在于玻璃中，尽管玻璃相不稳定，但实际上可防止其随时间变化。原则上。利用参数化分析函数形式的径向分布g（r）建模g（r）= g（r; L，D）对S（E）的微分方程进行积分是一个表征原子主要局部构型的晶格，D是一个“结构扩散”参数，指定局部结构之间相干性的空间衰减程度。建模通过低维参数空间{L，D}中的一点来表示结构。该空间还包括等效于（L，0）的有序状态（L），对于该状态，S = S（L）= 0，这是根据热力学第三定律得出的。因此，可以沿着将（L，D）连接到（L，0）的（虚拟）路径执行集成。通过评估液态和玻璃态的模型金属的熵来说明该方法。 （C）2001 Elsevier Science B.V.保留所有权利。 [参考：21]

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号