Optical absorption and fluorescence properties of Er3+ in sodium borate glass

Spectroscopic properties of Er³⁺ ions in sodium borate glass have been studied. The indirect and direct optical band gaps (E_opt) and energy level parameters (RacahE ¹, E² and E³), spin-orbit (ξ_4f) and configurational interaction (α)) are evaluated. Spectral intensities for various absorption bands of Er₃₊ doped sodium borate glass are calculated. Using Judd-Ofelt intensity parametersΩ ₂, Ω₄, Ω₆, radiative transition probabilities (A), branching ratios (β) and integrated absorption cross sections (Σ) are reported for certain transitions. The radiative lifetimes (τ_R) for different excited states are estimated. From the fluorescence spectra, the emission cross section (σ_P) for the transition,⁴I_13/2 → ⁴I_15/2 is reported.     

On the reinitialization procedure in a narrow‐band locally refined level set method for interfacial flows

A local level set algorithm for simulating interfacial flows described by the two‐dimensional incompressible Navier–Stokes equations is presented. The governing equations are solved using a finite‐difference discretization on a Cartesian grid and a second‐order approximate projection method. The level set transport and reinitialization equations are solved in a narrow band around the interface using an adaptive refined grid, which is reconstructed every time step and refined using a simple uniform cell‐splitting operation within the band. Instabilities at the border of the narrow band are avoided by smoothing the level set function in the outer part of the band. The influence of different PDE‐based reinitialization strategies on the accuracy of the results is investigated. The ability of the proposed method to accurately compute interfacial flows is discussed using different tests, namely the advection of a circle of fluid in two different time‐reversed vortex flows, the advection of Zalesak's rotating disk, the propagation of small‐amplitude gravity and capillary waves at the interface between two superposed viscous fluids in deep water, and a classical test of Rayleigh–Taylor instability with and without surface tension effects. The interface location error and area loss for some of the results obtained are compared with those of a recent particle level set method. Copyright © 2005 John Wiley & Sons, Ltd.     

电解加工中最小间隙检测方法

针对现有间隙检测方法存在精度低,且仅能测量平均间隙的缺点,提出一种测量最小间隙的简单方法———低电压湿对刀方法,介绍了湿对刀方法测最小加工间隙的原理,并进行了试验验证,试验结果表明:测量精度可达2μm。     

Measurement methods for LCoS displays

Abstract— Two measurement methods to characterize uniformity and the absolute cell gap of LCoS images will be reviewed. These are simple to use in a production environment and have allowed major improvements in manufacture to be achieved. For the purpose of this paper, the liquid‐crystal mode used is the 45° normally black mode.     

随机早期诊断(RED)队列管理算法的改进研究

本文总结了近十年来RED队列管理机制的各种改进研究思路，并对限制高带度流量进行了仿真以证实其对丢包性能的影响，最后分析了根据总的丢包量度大小来估计某流量的到达率的不合理性，从而我们很有必要利用仿真工具来验证比分析的正确性，并对RED加以修正使其拥塞控制的性能更好。     

Effects of Deposition Temperature on the Properties of Fluorinated Amorphous Carbon Films

Fluorinated amorphous carbon films (a-C:F) were prepared at different temperatures using a microwave electron cyclotron resonance chemical vapor deposition (ECR-CVD) reactor with CHF3 and C2H2 as source gases. Films were annealed at 500℃ in vacuum ambience inorder to investigate the relationship of their thermal stability, optical and electrical propertieswith deposition temperature. Results indicate that the films deposited at high temperature have a less CFx bonding and a more cross-linking structure thus a better thermal stability. They also have a lower bandgap, higher dielectric constant and higher leakage current.     

适合铝丝键合后热老化要求的金导体浆料

研究了一种适合铝丝键合后热老化要求的金导体浆料，性能达到使用要求。在金浆中添加了少量合金元素，并选用混合型粘结剂。对金导体铝丝焊后热老化失效机理以及添加合金元素的作用，进行了讨论     

叶轮式分级机的环隙对分级性能的影响

有关环隙对叶轮式超细分级机性能的影响研究尚未有公开发表的资料,本文在这方面做了一些初步的实验研究。实验研究发现：环隙对分级性能的影响很大,把环隙作为调控参数很有前途。     

中板轧机支承辊轴承使用技术的改进

本文通过对中板轧机支承辊轴承烧坏的原因分析，介绍了轴承的技术改进，以及改进后的使用情况。     

气体开关触发间隙与过压间隙击穿特性研究

为研究快脉冲直线变压器驱动源（FLTD）多间隙气体开关的触发击穿特性,针对一种环形电极两间隙等效实验开关,开展不同触发电压、工作系数和电极材料下的击穿特性实验,对比两个间隙的击穿延时和抖动,分析间隙击穿特性的主要影响因素和作用机制。实验结果表明：触发间隙击穿延时主要受触发电压影响,而工作系数是过压间隙击穿延时的主要影响因素;开关抖动主要来自于触发间隙,触发间隙抖动随触发电压的增大明显减小,过压间隙抖动基本不随触发电压和工作系数变化且维持在较低值;石墨电极开关的击穿延时和抖动明显小于不锈钢、黄铜和钨铜电极开关,具有良好的触发击穿性能。通过分析指出,是否有预电离可能是两个间隙击穿特性差异的主要原因。