材料期刊网

PRODUCTION OF HIGHLY GRAPHITIZED MULTIWALlED CARBON ANOTUBES

X.L.Zhao1) , T.L.Guo2) , M.Ohkohchi3) , T.Okazaki3) , S.Iijima and Y.Ando3) 1) Japan Science and Technology Corporation , Department of Physics , Meijo University , Shiogamaguchi1 501 , Tempaku ku , Nagoya 468 8502 , Japan 2) Scientific Research Department , Shenyang University , Wanghuanan Street21 , Dadong District , Shenyang 110044 , China 3) Department of Physics , Meijo University , Shiogamaguchi 1 501 , Tempaku ku , Nagoya 468 8502 , Japan$

金属学报(英文版)

Multiwalled carbon nanotubes ( MWNTs) were prepared by DCarc dischargein hydrogen gas, and werethermally purified byinfrared radiation in air. The morphology of pristineand purified MWNTs was observed by scanning electron microscope ( SEM) , and the crys tallinestructureand perfection wereinvestigated by high resolution transmission electron mi croscope( HRTEM) and Raman spectrometer. Itcameto the conclusion thatthese MWNTs possessed a high degreeof graphitization and very narrow centralchannel(about1 0 nm indiameter) , giving risetotheappearanceof breathing modesfor MWNTs.

关键词: multiwalled carbon nanotubes , null , null , null , null

580m3高炉开炉实践

王少红 , 刘志勇

金属世界 doi:10.3969/j.issn.1000-6826.2009.01.005

本文主要介绍了承德建龙炼铁厂580m3高炉开炉前的准备工作、开炉方案的确定以及开炉生产实践等.本次开炉采用了热风点火、全焦开炉等当前新方法,通过制订合理的烘炉和开炉方案,高炉开炉取得圆满成功,生产水平快速提高.

关键词: 高炉 , 开炉 , 烘炉 , 效果

M3Gd(PO4)3:Tm3+(M=Mg,Ca,Sr,Ba)真空紫外发光特性

李鑫 , 何大伟 , 卢鹏志 , 王永生

稀有金属材料与工程

研究了M3Gd(PO4)3:Tm3+(M=Sr,Ba,Ca,Mg)样品的结构特性、发光特性.M3Gd(PO4)3:Tm3+属于立方晶系.基质掺入铥离子后其结构没有明显变化.M3Gd(PO4)3:Tm3+在166 nm和210 nm附近有强烈的吸收峰.位于166 nm附近的强烈吸收峰归因于基质的强烈吸收,210 nm附近的吸收峰则归因于Gd3+的8S7/2-6GJ的能级跃迁.在166 nm真空紫外光激发下,样品在453 nm及363 nm处有较强的发射峰,发射主峰位于453 nm.随着样品中阳离子的变化,M3Gd(PO4)3:Tm3+的激发峰发生强烈变化,从而导致其发射光谱有了较大变化.

关键词: 发光特性 , VUV , 蓝色发射 , 激发光谱

ON THE M_7C_3 IN Cr27 CAST IRON

LI Yuqing WANG Cirong GU Zhaofeng Research Institute of Daye Steel Works , Huangshi , China Senior Engineer , Research Institute of Daye Steel Works , Huangshi 435001 , China

金属学报(英文版)

Determination of(Fe,Cr)_7C_3 in Cr27 cast iron results about 30 v.-%.Minor Si and Mn are present.Sectional area of the M_7C_3 grains is 1—50μm~2.Combining matrix analysis of elec- tron diffraction pattern with calculated angle between plane traces,{011}twins and also {013}twins producing local environment for Ru_7B_3 are observed in the orthorhombic M_7C_3. A crystallographic model for M_7C_3 is proposed.

关键词: cast iron , null , null , null , null

Ab initio study of polymorphism in layered ternary carbide M(4)AlC(3) (M = V, Nb and Ta)

Scripta Materialia

The mechanical and thermodynamic stabilities of M(4)AlC(3) (M = V, Nb and Ta) and Ti(4)AlN(3) polymorphs were investigated by means of the first-principles pseudopotential total energy method. All compounds satisfied the Born criteria for mechanical stability, but had different thermodynamic stabilities. Only Ta(4)AlC(3) showed a possible polymorphic phase transformation driven by thermodynamic competition. The present theoretical results support the polymorphism of Ta(4)AlC(3) in experimental synthesis and explain the underlying thermodynamic mechanism. Polymorphism was excluded from V(4)AlC(3), Nb(4)AlC(3) and Ti(4)AlN(3). (C) 2008 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

关键词: carbides;phase stability;density functional calculation;thermodynamic;phase thin-films;mechanical-properties;1st-principles;ti3sic2;ta4alc3;transformation;deformation;stability;ti3gec2;growth

2500 m3高炉效能优化综合技术应用

储滨 , 唐培华 , 肖阳

钢铁

介绍了宝钢股份不锈钢分公司2500 m3高炉所采用的多焦种配焦技术、改进现场操作技术、应用低硅冶炼技术、实施低燃料比等效能优化综合技术，高炉各项技术指标取得了长足的进步，年利用系数达到2385 t/（m3·d），燃料比达到48583 kg/t,综合指标跃居国内同类型高炉前列， 高炉的生产和管理实现了高产、优质、低耗。

关键词: 炼铁;利用系数;燃料比;低硅冶炼;专家系统

2500 m3高炉效能优化综合技术应用

储滨 , 唐培华 , 肖阳

钢铁

介绍了宝钢股份不锈钢分公司2 500 m3高炉所采用的多焦种配焦技术、改进现场操作技术、应用低硅冶炼技术、实施低燃料比等效能优化综合技术,高炉各项技术指标取得了长足的进步,年利用系数达到2.385 t/(m3·d),燃料比达到485.83 kg/t,综合指标跃居国内同类型高炉前列,高炉的生产和管理实现了高产、优质、低耗.

关键词: 炼铁 , 利用系数 , 燃料比 , 低硅冶炼 , 专家系统

2000m3高炉设计与生产实践

焦英占 , 王学伶 , 李进友

钢铁

邯钢2000 m3高炉是在引进德国二手设备的基础之上建造而成的.该高炉原有效容积1 858 m3,改进后高炉有效容积2000 m3.采用了槽下过筛,焦丁与烧结矿混装入炉,无料钟炉顶,软水闭路循环和薄壁炉衬的长寿炉体,双预热热风炉,底滤法水冲渣,富氧大喷吹,高炉煤气燃气轮机鼓风机,比绍夫煤气清洗系统,高炉煤气炉顶余压发电,计算机自动控制等先进技术.投产近4年来,各项指标均达到和超过了设计水平.

关键词: 高炉 , 二手设备 , 设计 , 生产

Relationship between degeneration of M7C3 and precipitation of M23C6 in a cobalt base superalloy

Materials Science and Technology

The relationship between degeneration of the primary M7C3 carbide and precipitation of the secondary M23C6 carbide has been investigated in a cobalt base superalloy after 100 h aging at 850 degrees C. The results indicated that the primary M7C3 carbide could not transform in situ into the secondary M23C6 carbide. The M23C6 formed by a direct reaction between chromium and carbon atoms. The dissolution of M7C3 provided the precipitation of M23C6 with essential carbon, which acted as a carbon reservoir. Near M7C3, the chromium content is a controlling factor of M23C6 precipitation while away from it, the carbon content dominated the reaction. The precipitate free zone around M7C3 is attributed to chromium depletion which is inherited from the as cast condition. MST/4174

关键词:

2.7～3 μm稀土激光晶体研究进展

陈家康 , 孙敦陆 , 张会丽 , 窦仁勤 , 罗建乔 , 刘文鹏 , 张庆礼 , 殷绍唐

人工晶体学报

本文介绍了以稀土Er3+和Ho3+为激活离子,YAG,YAP,YLF,YSGG,GSGG为基质的2～7～3μm激光晶体的特点和应用背景,展示了其中一些晶体的吸收和荧光光谱,讨论了这些晶体的能级结构、光谱和激光特性及器件研究进展,并认为提高效率和激光输出功率以及获得新的特征波长是今后2～7～3 μm激光晶体的主要发展方向.

关键词: 激光晶体 , 基质 , 激活离子 , LD泵浦