材料期刊网

INVESTIGATION OF PHYSICO METALLURGICAL PHENOMENA FOR THE CC FORMING OF WCP/Fe C COMPOSITES

B.Z. Li1) , Y.P. Song1) , K.U. Kainer2) , H. Zhang3) , J.P.Xie1) and R.Xiang4) 1) Department of Materials Engineering , Luoyang Institute of Technology , Luoyang 471039 , China2) Institute of Material Science and Technology , TU Clausthal , D 38678 Clausthal Zellerfeld , Germany 3) Institute of Mechanicaland Electrical Engineering , Zengzhou University , Zengzhou 450052 , China 4) Luoyang Steeland Iron Group Corp , Luoyang 471023 , China

金属学报(英文版)

Theinvestigation of physicometallurgicalphenomena forthe CC formingof WCP/ Fe Ccom posites wasperformed. Resultsshow that underthe patentcondition, WCP/ Fe Ccomposite surfacelayerof16 20 m m heavycross sectioncan beacquiredintheoutsideofa hollow cylin der. The surface of CTC particlescould be partially dissolved by Fe containing melt. Thefineshortstick like WCcrystallitesarein situseparated neartothesurfaceof CTC particles.Far from the CTC particles,someseparated, finetungsten carbidecrystallitesand Fe, W,Mo and Cretc. containing web composite carbides, are distributed on the matrix of WCP/ Fe Ccomposite. Fe Calloy matrix of the hollow composite cylinder is alloyed in differenthigh levels.

关键词: physicometallurgical phenomena , null , null

Pressure effects on spectra of tunable laser crystal GSGG : Cr3+ IV: Pressure-induced shifts of R-1 line, R-2 line, and U band at 300 K

Communications in Theoretical Physics

By means of both a theory for pressure-induced shifts (PS) of energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction (EPI), the 'pure electronic' PS and the PS due to EPI of R-1 line, R-2 line, and U band of GSGG:Cr3+ at 300 K have been calculated, respectively. The calculated results are in good agreement with all the experimental data. Their physical origins have also been explained. It is found that the mixing-of degree \t(2)(2)(T-3(1))e(4)T(2)> and \t(2)(3) 2E> base-wavefunctions in the wavefunctions of R-1 level of GSGG:Cr3+ at 300 K is remarkable under normal pressure, and the mixing-degree rapidly decreases with increasing pressure. The change of the mixing-degree with pressure plays a key role not only for the 'pure electronic' PS of R-1 line and R-2 line but also the PS of R-1 line and R-2 line due to EPI. The pressure-dependent behaviors of the 'pure electronic' PS of R-1 line (or R-2 line) and the PS Of R-1 line (or R-2 line) due to EPI are quite different. It is the combined effect of them that gives rise to the total PS of R-1 line (or R-2 line). In the range of about 15 kbar similar to 45 kbar, the mergence and/or order-reversal between t(2)(2)(T-3(1))e(4)T(2) levels and t(2)(32)T(1) levels take place, which cause the fluctuation of the rate of PS for t(2)(2)(T-3(1))e(4)T(2) (or t(2)(3) T-2(1)) with pressure. At 300 K, both the temperature-dependent contribution to R-1 line (or R-2 line or U band) from EPI and the temperature-independent one are important.

关键词: high-pressure effect;spin-orbit interaction;electron-phonon;interaction;d orbital;coupling between t(2)(2)(3T(1))e(4)T(2) and;t(2)(32)E;tunable laser crystal;theoretical calculations;temperature-dependence;thermal broadenings;garnet crystals;cr3+ ions;r-line;cr-3+;luminescence;ruby;spectroscopy

O2在U和U-Nb合金表面吸附的XPS研究

伏晓国 , 刘柯钊 , 汪小琳 , 柏朝茂 , 赵正平 , 蒋春丽

金属学报

采用X射线光电子能谱(XPS)分析研究了298 K时O2在金属U和U Nb合金清洁表面的原位吸附过程,作为对照还研究了在纯Nb表面的吸附.吸附各阶段XPS图谱的变化揭示了O2在U,Nb和U-Nb合金表面的吸附将导致UO2,NbO和Nb2O5等多种产物形成定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45 L和40 L(1 L=L33x10-4Pa.s),而O2在金属Nb上的饱和吸附量仅约为10 L.

关键词: 合金 , null , null

O2在U和U-Nb合金表面吸附的XPS研究

伏晓国 , 刘柯钊 , 汪小琳 , 柏朝茂 , 赵正平 , 蒋春丽

金属学报 doi:10.3321/j.issn:0412-1961.2001.06.004

采用X射线光电子能谱(XPS)分析研究了298 K时O2在金属U和U Nb合金清洁表面的原位吸附过程,作为对照还研究了在纯Nb表面的吸附.吸附各阶段XPS图谱的变化揭示了O2在U,Nb和U-Nb合金表面的吸附将导致UO2,NbO和Nb2O5等多种产物形成定量分析表明,O2在U和U-Nb合金表面的饱和吸附量大约分别为45 L和40 L(1 L=L33x10-4Pa@s),而O2在金属Nb上的饱和吸附量仅约为10 L.

关键词: O2 , U , U-Nb合金 , 表面吸附 , X射线光电子谱

Al-Mg-Si合金中U1和U2相的原子成键与性能

高英俊 , 陈华宁 , 韦娜 , 文春丽 , 黄创高

中国有色金属学报

应用EET理论和改进的TFD理论对Al-Mg-Si合金时效过程中析出的U1与U2相的原子成键和结合能进行计算.结果表明:两相晶胞中最强键和次强键都是Al-Si键,其键络比基体Al晶胞中的最强键络都强得多;两析出相晶胞中都以较强的Al-Si键构成主要键络骨架结构,起到增强基体键络强度、强化合金的作用.由于析出相U1比析出相U2具有更强的Al-Si键络结构,且结合能较大,因此,相对U2相来说,U1相更稳定.计算结果还表明:(001)Al//(110)U1相界面处电荷保持连续且连续性较好,界面应变能较低,界面较稳定;界面(001)Al// (010)U2处的面电荷密度偏离连续条件,因此在此界面处,应力较大,界面原子键匹配较差,界面储能(应变能)较高,容易成为新相形核、长大和裂纹萌生的地方.

关键词: Al-Mg-Si合金 , U1和U2相 , 原子成键 , 力学性能

H2O分子在α-U(001)表面的吸附和解离

李赣 , 余慧龙 , 银陈

稀有金属材料与工程

采用广义梯度密度泛函理论研究了H2O分子在α-U(001)表面上的吸附、扩散和解离.结果表明,H2O分子在a-U(001)表面的最稳定构型为平行于表面的顶位吸附结构,吸附能为0.58 eV.吸附作用主要源于H2O分子1b1轨道与表面U原子6d轨道的空间交叠,同时伴有弱的H2O 3aα1-U 6d轨道交叠.近邻顶位间H2O分子的扩散能垒为0.20～0.23 cV,预示H2O分子易于在a-U(001)表面发生扩散迁移.OH+H解离吸附较分子吸附在能量上高1.24～1.39 eV,解离能垒为0.56～0.62 eV,预示一定热激活条件下,吸附H2O分子趋向解离形成OH基团和H原子.

关键词: 密度泛函理论 , α-U(001)表面 , H2O分子 , 吸附

CO在U2N3+xOy薄膜表面反应特性研究

罗丽珠 , 陆雷 , 刘柯钊 , 赵东海

无机材料学报 doi:10.15541/jim20130641

采用磁控溅射沉积方法在Si基底表面制备U2N3+xOy薄膜，采用X光电子能谱(XPS)分析技术观测CO气氛环境下 U2N3+xOy薄膜表面腐蚀行为，以期获得 U2N3+xOy薄膜在 CO 环境下的表面腐蚀机理。结果表明：超高真空条件下， CO在U2N3+xOy薄膜表面表现为氧化特性；CO在薄膜表面吸附解离生成的C以无定形碳形式聚集在薄膜表面，深度剖析过程中并未观察到C向U2N3+xOy薄膜内部扩散；而解离生成的氧在薄膜内扩散并发生氧化反应，生成高价氧化物或铀氮氧化物和氮。氧化反应生成的氮向薄膜内部扩散，并在次表面反应生成富氮中间产物。随着CO暴露反应进程的推进，富氮层逐渐向薄膜内部迁移，这是导致U4f谱卫星峰变化的主要原因。

关键词: CO , U2N3+xOy , 表面腐蚀 , 氧化

Investigation of the spin-Hamiltonian parameters for the trigonal U(5+) center in CaF(2) crystal

Spectrochimica Acta Part a-Molecular and Biomolecular Spectroscopy

The spin-Hamiltonian parameters (g factor g(parallel to),g(perpendicular to) and hyperfine structure constants A(parallel to),A(perpendicular to)) of the trigonal U(5+) center in CaF(2) crystal have been calculated from the complete diagonalization (of energy matrix) method (CDM) for 5f(1) ions in trigonal crystal field and under an external magnetic field. In the calculation, the crystal-field parameters are estimated from the superposition model. From the calculations, these spin-Hamiltonian parameters are reasonably explained, and the defect model (i.e., the trigonal U(5+) center is attributed to U(5+) substituting for Ca(2+) in CaF(2) with six F(-) ions replaced by O(2-) and the other two F(-) sites vacant because of charge compensation) given in the previous paper is confirmed. The results are discussed. (C) 2010 Elsevier B.V. All rights reserved.

关键词: Electron paramagnetic resonance (EPR);Defect model;Crystal- and;ligand-field theory;U(5+);CaF(2);superposition-model analysis;spectroscopy;field;uranium;ions

PU(U)A/SiO2杂化水分散液及成膜性能研究

宋春梅 , 喻志刚 , 袁荞龙 , 王得宁

材料科学与工艺 doi:10.3969/j.issn.1005-0299.2005.04.003

用异佛尔酮二异氰酸酯(IPDI)、聚酯二元醇、二羟甲基丙酸(DMPA)、乙二胺、二乙醇胺、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、甲基丙烯酸羟乙酯(HEMA)通过原位聚合方法合成了聚氨酯(脲)/聚丙烯酸酯水分散液,并且通过溶胶-凝胶方法合成了聚氨酯(脲)/聚丙烯酸酯/硅溶胶(PU(U)A/SiO2)杂化水分散液.杂化水分散液在pH值为7～11时的贮存稳定性大于1年;经高温、冻融试验后,无絮凝或沉淀出现,与PU(U)A水分散液相同.杂化膜的摆杆硬度、粘附力、耐吸水性、耐溶剂性比无硅溶胶的膜性能好.PU(U)A/SiO2杂化水分散稀溶液成膜后的透射电镜(TEM)结果表明,粒径为8～10nm的硅溶胶(SiO2)包覆在粒径 为50～200nm的PU(U)A粒子外围.ART-FTIR分析结果表明,杂化膜表面富含Si-O-Si官能团.AFM结果表明,与PU(U)A膜相比,杂化膜的硬区相畴尺寸变小.

关键词: 聚氨酯(脲)/聚丙烯酸酯 , 硅溶胶 , 杂化材料 , 水性涂料 , 膜性能

INVESTIGATION OF THE ANION DISTORTION PARAMETER-U FOR CHROMIUM DOPED ZNGA2O4 SPINEL

Solid State Communications

The EPR parameters (D, g parallel-to and g perpendicular-to) for chromium doped MgAl2O4 and ZnAl2O4 spinels have been calculated from the crystal-field theory relative to the structural parameters of these crystals by using the parameters obtained from the optical spectra. The results show reasonable agreement with the experimental findings, suggesting that the calculated method is suitable. Based on this method, we estimate approximately the anion distribution parameter u of ZnGa2O4 spinel from the EPR and optical spectra of ZnGa2O4:Cr3+ crystal. Considering that there may be more or less some relaxations of ligands due to the substitution of impurity Cr3+ for Ga3+ ions in ZnGa2O4 crystal, which are difficult to know, the reliability of the estimated parameter u(almost-equal-to 0.381 +/- 0.001) should be checked by other methods.

关键词: