平果铝厂赤泥堆场堆存能力估计

平果铝厂赤泥堆场堆存能力估计田跃（贵阳铝镁设计研究院５５０００１）１概述平果氧化铝厂赤泥为拜尔法赤泥，堆存采用引进的德国技术。拜尔法赤泥在天然状态下的固结能力比烧结法赤泥差（主要是因水作用），采用我国以往低浓度输送至堆场的拜尔法赤泥，在堆场不能形成自...     

一种新型红外测温传感器的原理与应用

MLX90614系列芯片是一组通用的红外测温芯片。它具有精度高、体积小、输出接口多、使用方便等特点，在多种精密设备装置中都有广泛的应用。文中以MLX90614AA为例介绍其原理及应用方法。     

桂林高新区:漓东科技城,现代国际版高新技术产业园区

<正>广西桂林高新区,伴随着风风雨雨迎来了成立20周年喜庆日子。20年来,一批批企业在这里由小到大、由弱变强,展翅飞翔。为谋求高新技术产业更大快速发展,桂林高新区人经过科学筹划和反复论证,在漓东老城区与华     

基于Maxwell软件的齿轮测速传感器的磁路分析

齿轮测速传感器在工业测量和自动控制中有着广泛而重要的应用,其中尤其以磁敏类传感器应用最为广泛.对比于光电类齿轮测速传感器,磁敏测速传感器抗震动,不怕油污,特别适合在恶劣条件的工业现场使用.齿轮的形状和大小强烈的影响传感器检测到的磁通的分布,进而影响到信号的检测,因此测速齿轮可以设计成不同与传动齿轮的非标准齿轮,使得检测信号最大.有限元模拟软件Maxwell在磁场模拟中有着广泛的应用,其界面简单,使用方便,模拟真实.本论文以Maxwell为基础对测速传感器的磁路进行分析,以磁敏感芯片为中心,分析了齿轮的尺寸和形状,永磁磁铁和齿轮之间的气隙,以及永磁磁铁的磁感应强度的大小,分析的结论对实际传感器的设计有较好的指导意义.     

利用微波测量土水系统环保传感器研究

土水系统的复介电常数受土水系统物理化学性质的影响,通过测量土水系统的复介电常数就可以准确的评估地质环境的变化.本文对测土水系统复介电常数的微波环保传感器做了进一步研究,并且描绘了复介电常数的测量.     

Luminescent properties of Eu~（3＋） doped Gd_2WO_6 and Gd_2（WO_4）_3 nanophosphors prepared via co-precipitation method

Eu3+ doped Gd2WO6 and Gd2(WO4)3 nanophosphors with different concentrations were prepared via a co-precipitation method. The structure and morphology of the nanocrystal samples were characterized by using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM), respectively. The emission spectra and excitation spectra of samples were measured. J-O parameters and quantum efficiencies of Eu3+ 5D0 energy level were calculated, and the concentration quenching of Eu3+ luminescence in different matrixes were studied. The results indicated that effective Eu3+:5D0-7F2 red luminescence could be achieved while excited by 395 nm near-UV light and 465 nm blue light in Gd2WO6 host, which was similar to the familiar Gd2(WO4)3:Eu. Therefore, the Gd2WO6:Eu red phosphors might have a potential application for white LED.     

Influences of post-annealing and internal stress on magnetoresistance properties of Ni80Fe20 films

Ni80 Fe20 films with thickness about 54 nm were deposited on K9 glass and thermally oxidized silicon substrates at ambient temperature by electron beam evaporation with deposition rate about 1.8 nm/min. The as-deposited films were annealed at 350, 450 and 570 ℃ respectively for 1 h. After annealing at 570 ℃, the anisotropic magnetoresistance ratio(RAM) of the films is greatly improved. It increases to 3%- 3.5% nearly about three times of that of the as-deposited films. The grain size increases with the annealing temperature and the [111] crystal orientation is obviously enhanced after annealing at temperature above 450 ℃. The internal stress in the films deposited on K9 glass is compressive and the resistance measurement shows that RM∥ is larger than RM⊥ in these films. However, in the films deposited at the same conditions but on oxidized silicon substrates, the internal stress is tensile and RM⊥ is larger than RM∥. The differences of RM∥ and RM⊥ in two series of specimens are discussed.     

赤泥堆存的力学特性

从赤泥的产生入手分析赤泥堆存的力学特性。指出不同铝矿及不同生产方式产出的赤泥的化学成分不同，粒级不同，力学特性会有很大差异，认为赤泥堆场应根据各氧化铝厂的具体情况确定设计方案。     

大体积混凝土温度裂缝防治的研究

大体积混凝土开裂的问题是建筑施工中一个普遍性的技术问题。裂缝一旦形成,特别是基础贯穿裂缝出现在重要的结构部位,危害极大,它会降低结构的耐久性,削弱构件的承载力,同时可能会危害到建筑物的安全使用。本文分析大体积混凝土裂缝的产生原因,然后通过实际案例提出具体的防裂措施。     

Composition-dependent optical transitions and 2.0 μm emission properties of Ho~(3+) in xGeO_2-(80-x)TeO_2-9.5ZnF_2-10NaF-0.5Ho_2O_3 glasses

Ho3+ doped glasses with various compositions xGeO2-(80-x)TeO2-9.5ZnF2-10NaF-0.5Ho2O3(x=0,10,20,30,40,50,60,70 and80) were prepared by a melt-quenching technique.The composition-dependent optical transition properties of Ho3+ were investigated in theframework of Judd-Ofelt theory.The emission cross sections for 5I7→5I8 transition of Ho3+ in these glasses were calculated according toMcCumber theory,and their compositional dependence was discussed.A simple method was proposed in calculating the emission cross ...