材料期刊网

Algorithm Design and Application of Laminar Cooling Feedback Control in Hot Strip Mill

LIU En-yang , ZHANG Dian-hua , SUN Jie , PENG Liang-gui , GAO Bai-hong , SU Li-tao

钢铁研究学报(英文版)

Abstract： Feedback control is one of the most important ways to improve coiling temperature control precision during laminar cooling process. Laminar cooling equipments of a hot strip mill and structure of the control system were introduced. Feedback control algorithm based on PI controller and that based on Smith predictor were designed and tested in a hot strip mill respectively. Practical application shows that the feedback control system based on PI controller plays a limited role in improving coiling temperature control precision. The feedback control system based on Smith predictor runs stable and reliable. When the measured coiling temperature deviates from the target value, it can be adjusted to the required range quickly and steadily by Smith predictor feedback control, which improves the coiling temperature control precision greatly, and qualities of hot rolled strips are improved significantly.

关键词: Key words: hot strip mill , laminar cooling , feedback control , Smith predictor , PI controller

Crystal structure and photoluminescence of Tb3+ doped Y3GaO6

Journal of Alloys and Compounds

A solid solution with formula (Y1-xTbx)(3)GaO6 (x = 0-0.5) was prepared by solid-state reaction method. Powder X-ray diffraction (XRD) shows that Y3GaO6 is isostructural to Gd3GaO6 (Cmc2(1)), and the lattice parameters are a = 8.8364(1) angstrom, b = 11.0899(1) angstrom and c = 5.3937(1) angstrom. Atomic parameters were derived by Rietveld refinement of the XRD pattern. Photoluminescence (PL) spectra show a strong green emission of 543 nm from the D-5(4) -> F-7(5) transition of Th3+ at room and liquid nitrogen temperature. There is a wide saturation range of the PL intensity for the Th3+ content from x = 0.04-0.20, and a long life time about 1200 mu s for the green 543 nm emission at room temperature. (c) 2006 Elsevier B.V. All rights reserved.

关键词: Y3GaO6;crystal structure;Tb3+ doped;photoluminescence;luminescence properties;dependence;y3al5o12;phosphor;ions;ce3+;tb-3;uv

A systematic study on crystal structure and magnetic properties of Ln(3)GaO(6) (Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er)

Journal of Solid State Chemistry

The crystal structures of a series of compounds with the composition Ln(3)GaO(6)(Ln = Nd, Sm, Eu, Gd, Tb, Dy, Ho and Er) synthesized by solid-state reaction at 1400degreesC are investigated. X-ray diffraction shows that Ln3GaO6 has a non-centro symmetric orthorhombic structure (space group Cmc2(1)). Lattice parameters a, b, c and cell volume and the average distances between Ln(l)-O, Ln(2)-O of these compounds decrease with the decreasing of the radii of trivalent Ln ions, which accord with the expected lanthanide contraction behavior. There are two sites of seven-fold coordination for Ln atoms with oxygens, and Ga atoms are in oxygen tetrahedra which are distorted and elongated along the a-axis. Magnetization measurements indicate that the susceptibility X changes with temperature in Curie-type manner. (C) 2004 Elsevier Inc. All rights reserved.

关键词: Ln(3)GaO(6);crystal structure;Rietveld refinement;X-ray diffraction;garnets

Optical spectra of Ln(3+)(Nd3+, Sm3+, Dy3+, Ho3+, Er3+)-doped Y3GaO6

Journal of Luminescence

Ln(3+) (Ln = Nd, Sm, Eu, Gd, Dy, Ho, Er)-doped Y3GaO6 compounds were prepared by solid-state reaction, and their optical spectra such as absorption, photoluminescence, excitation and time-resolved spectra have been measured for Ln Nd, Sm, Dy, Ho, Er. X-ray powder diffraction shows that the lattice parameters of the compounds (Y(0.96)Ln(0.04))(3)GaO6 decrease with the decrease of the radii of trivalent Ln(3+) ions, indicating that Ln(3+) ions have substituted for y(3+) ions in the lattice. Optical spectra show that there are obvious absorptions at ultraviolet to visible region. The strong emissions in visible and infra-red region show that Y3GaO6 is a suitable host for rare-earth-doped laser crystal and phosphor materials. (C) 2004 Elsevier B.V. All rights reserved.

关键词: crystal-field;absorption-spectra;luminescence;y3ga5o12;glasses;garnet;y2o3;ions;laf3;tb3

Optical properties of (Y1-xTmx)(3)GaO6 and subsolidus phase relation of Y2O3-Ga2O3-Tm2O3

Journal of Solid State Chemistry

A serial of samples in Y2O3-Ga2O3-Tm2O3 pseudo-ternary system are prepared by solid-state chemical reaction method. The range of solid solution in (Y1-xTmx)(3)GaO6 is 0 < x < 0.384. Powder X-ray diffraction shows that the compounds crystallize in Gd3GaO6 (Cmc2(1))-type structure. The solid solubilities of Y3+xGa5-xO12 (x = 0-0.77) and Tm3+xGa5-xO12 (x = 0-0.62) are 37.5-47.11 at% Y2O3, and 37.5-45.26 at% Tm2O3, respectively. PL spectra of Tm-doped Y3GaO6 show that there is a sharp blue emission at similar to 456 nm from the D-1(2) -> F-3(4) transition at room temperatures with two lifetimes (similar to 5 and similar to 15 mu s) and a narrow saturation range of PL intensity for the Tm3+ content from x = 0.005 to 0.03. The sharp emission and long lifetime of (Y1-xTmx)(3)GaO6 indicate that Y3GaO6 is a potential phosphor and laser crystal host material. (c) 2005 Elsevier Inc. All rights reserved.

关键词: Tm3+ -doped Y3GaO6;Y2O3-Ga2O3-Tm2O3 system;(Y1-xTmx)(3)Ga5O12 solid;solution;luminescence;crystal-structure;luminescence;phosphor;cations;ions;tb3

不同温度下碳源对AOA-SBR工艺PAO与GAO竞争释磷的影响

张兰河 , 李德生 , 王旭明 , 张海丰

硅酸盐通报

为了提高生物除磷效率,研究采用AOA-SBR工艺进行了长期连续除磷实验,考察不同温度下碳源(乙酸钠、丙酸钠、葡萄糖)对PAO与GAO竞争的影响.结果表明:当温度由10℃升高至25℃时,利用丙酸钠作为碳源时,污泥含磷量与含糖量分别从7.2％和5.1％升高至7.9％和6.3％,PHA转化量升高了23.1 mg/L,厌氧释磷量从105.9 mg/L升高至149.9 mg/L,VSS/MLSS由71％降低至65％;利用乙酸钠作为碳源时,污泥含磷量与含糖量分别从6.9％和5.3％升高至7.6％和6.7％,PHA转化量升高了23.9 mg/L,厌氧释磷量从73.8 mg/L升高至108.8 mg/L,VSS/MLSS由73％降低至71％;利用葡萄糖作为碳源时,污泥含磷量与含糖量分别从5.8％和6.3％升高至6.6％和8.8％,PHA转化量升高了33.2 mg/L,厌氧释磷量从37.4 mg/L升高至43.2 mg/L,VSS/MLSS由80％升高至88％.当温度升高至30℃时,3个反应器均出现厌氧末期PHA浓度下降和糖原浓度升高,厌氧释磷量减少,污泥含磷量均下降,污泥含糖量上升,VSS/MLSS均很高.与葡萄糖相比,采用乙酸钠和丙酸钠作为碳源,有利于PAO生长繁殖,PAO为优势菌种,抑制GAO增殖.同时,低温更有利于PAO的生长繁殖.

关键词: 温度 , 碳源 , SBR , PAO与GAO

Preface to Special Issue on Photocatalysis for celebrating the 20th anniversary of Professor Jimmy C. Yu’s return to Hong Kong and leading photocatalytic research there

催化学报 doi:10.1016/S1872-2067(15)61006-3

关键词:

光谱和电化学方法研究黄芩素与核酸相互作用的机理

郭蒙 , 王淑敏 , 王佳丽 , 李丹 , 高庆宇 , 李丽敏

应用化学 doi:10.3724/SP.J.1095.2014.30232

在pH=3.22的NaAc-HAc溶液中,应用循环伏安法、方波伏安法、荧光光谱法、紫外可见光谱法和黏度法研究了黄芩素(BAI)与鲱鱼精子DNA(fsDNA)之间的相互作用,发现二者通过沟槽作用形成一电活性较高的复合物,fsDNA为BAI提供了一个低极性的疏水环境导致BAI的峰电流显著增强,增强的峰电流与fsDNA在7.0×10-8 ～7.0×10-6 g/mL浓度范围内呈正比,由此建立了一种测定核酸的新方法,检测限达到4.1×10-8 g/mL.

关键词: 黄芩素 , 核酸 , 电化学 , 沟槽作用

Improved Nonlinear Equation Method for Numerical Prediction of Jominy EndQuench Curves

SONG Yuepeng , LIU Guoquan , LIU Shengxin , LIU Jiantao , FENG Chengming

钢铁研究学报(英文版)

Without considering the effects of alloying interaction on the Jominy endquench curves, the prediction results obtained by YU Baihai′s nonlinear equation method for multialloying steels were different from those experimental ones reported in literature. Some alloying elements have marked influence on Jominy endquench curves of steels. An improved mathematical model for simulating the Jominy endquench curves is proposed by introducing a parameter named alloying interactions equivalent (Le). With the improved model, the Jominy endquench curves of steels so obtained agree very well with the experimental ones.

关键词: Jominy endquench curve;nonlinear equation method;alloying interaction parameter;computer simulation

Mg单原子替位掺杂β-Ga2O3的电子结构和光学性质计算研究

宋庆功 , 徐霆耀 , 杨宝宝 , 郭艳蕊 , 陈逸飞

材料导报 doi:10.11896/j.issn.1005-023X.2015.18.027

宽禁带半导体β-Ga2O3因其出色的物理化学性能而备受关注,通过掺杂改善β-Ga2O3性能一直是研究的热点.采用基于密度泛函理论的第一性原理方法,利用广义梯度近似加U对Mg单原子掺杂β-Ga2O3体系的晶体结构、电子结构和光学性质等进行了研究和分析.总能量和结合能的对比显示:单原子替位掺杂β-Ga2O3时,Mg优先替代八面体位的Ga原子形成Mg-Gao体系.电子结构显示,Mg-Gao体系变为间接半导体,带隙变窄为4.672eV;其自旋极化率为100％,呈现半金属特性.作为光学材料,Mg-Gao体系可在紫外、深紫外区域工作,并且折射率、反射率和吸收率有所降低,透射率明显提高.

关键词: Mg掺杂β-Ga2O3 , 第一性原理 , 晶体结构 , 电子结构 , 光学性质