Electronic structure and related properties of metallic glasses: Linear muffin-tin orbital approach

We describe various aspects of electronic structure calculation for amorphous metals using the linear muffin-tin orbital (LMTO) scheme. We discuss calculations of the magnetic properties within the framework of multiple scattering formalism assuming collinear magnetic structure and using the linear muffin-tin orbital Green’s function method. Results for the effective exchange coupling parameters and local magnetic moments for amorphous Fe and Co are discussed with special emphasis on the dependence of these quantities on the local and global features of the structure. A method of calculating the electronic transport properties in transition metal glasses, based on the LMTO-recursion method and the Kubo-Greenwood formula, is presented. The practical limitations of the method and the ways to overcome them are briefly discussed. This article is based on a presentation made in the “Structure and Properties of Bulk Amorphous Alloys” Symposium as part of the 1997 Annual Meeting of TMS at Orlando, Florida, February 10–11, 1997, under the auspices of the TMS-EMPMD/SMD Alloy Phases and MDMD Solidification Committees, the ASM-MSD Thermodynamics and Phase Equilibria, and Atomic Transport Committees, and sponsorship by the Lawrence Livermore National Laboratory and the Los Alamos National Laboratory.     

用首次积分降阶Lagrange方程的统一方法

通过定义对状态的变换,导出对Ｌａｇｒａｎｇｅ方程的变换．新方程以某个非循环坐标为自变量,时间变量成为“广义坐标”,并保持了Ｌａｇｒａｎｇｅ方程的形式．由此得到能同时利用原方程全部首次积分（循环积分和能量积分）降阶Ｌａｇｒａｎｇｅ方程的统一方法．示例说明了新方法的应用     

单点校准线性测量系统不确定度的蒙特卡洛法评定模型构建与应用

线性测量系统是化学分析、物理测试领域最普遍的测量系统,按其线性关系的构建和拟合方式,可分为单点校准、双点校准、多点校准(线性拟合)及标准加入法。其中,单点校准常用于色谱分析、滴定分析等分析方法及气体分析、碳硫分析等测量项目。实验引入2个随机效应修正因子或相对随机误差表征各种条件变异及系统波动对校准用标准物质和实际样品测量重复性的影响,提出了蒙特卡洛法(MCM)评定单点校准线性测量系统不确定度的数学模型与方法,并基于惰性气体熔融-热导法测定TC4钛合金中氢含量的示例,系统阐释了MCM的具体评定流程与应用。在实验测量条件下(标准物质重复4次,实际样品重复7次),平均测量结果为w(H)=(20±3)μg/g,k=2,该扩展不确定度评定结果与采用"不确定度传播律"得到被测量估计值测量不确定度的方法(GUM法)相一致。实验所给出的方法和示例可直接应用于气体分析(惰气熔融-红外吸收法/热导法)、碳硫分析(高频感应燃烧红外吸收法)与色谱分析、滴定分析等单点校准线性测量系统的不确定度的评定,一定程度上解决了MCM应用于化学分析领域的模型构建与仪器校准引入不确定度的量值导入等关键问题,有望推动MCM在单...