Syntheses,characterization, and luminescence of two lanthanide complexes [Ln2（acetate）6（HeO）4]·4H2O （Ln=Tb（1）, Sm（2））

Two dinuclear compounds [Ln2（acetate）6（H2O）4]-4H2O （Ln=Tb（1）, Sm（2）） were obtained by the hydrothermal reaction of Ln2O3 with malonic acid at 150 ℃. Both compounds were characterized by elemental analyses, infrared spectra, and single crystal X-ray diffraction. The results showed that complexes 1 and 2 were isomorphous and crystallize in triclinic space group P 1. The coordination geometry around Ln（Ⅲ） ions in the complexes 1 and 2 was a distorted tricapped trigonal prism with a nine coordination. In the crystal, the molecular organization was further stabilized by well-defined weak hydrogen bonding interactions between the neutral dinuclear molecular units that led to the formation of a three-dimensional network. The fluorescence properties of the two complexes 1 and 2 in organic solvents were also studied. The results show that the ligand acetate favored energy transfer to the emitting energy level of Tb（Ⅲ） in complex 1. Some factors that influence the fluorescent intensity were also discussed in the article.     

Mg~（2＋）,Ca~（2＋）,Ba~（2＋）离子部分取代对SrAl_2O_4：Eu~（2＋）,Dy~（3＋）晶体结构和发光性能的影响

采用高温固相反应法制备了Sr0.9M0.1Al2O4：Eu2＋,Dy3＋（M=Mg,Ca,Ba）长余辉发光材料,并对其晶体结构、光谱性质、余辉特性进行了分析.X射线衍射测试结果表明,Mg2＋,Ca2＋,Ba2＋离子部分取代SrAl2O4基质中的Sr后,基质晶体结构并没有发生改变.光谱测试结果表明,Mg2＋,Ca2＋,Ba2＋取代后发光材料的激发光谱都是一个从250~450 nm范围内的宽激发带,在266nm,320nm,360nm,416 nm处各有一个激发峰.发射光谱中Mg2＋和Ba2＋的取代使波长出现蓝移,而Ca2＋的取代使波长出现红移.余辉测试结果表明,Ca2＋取代后的余辉时间长于Mg2＋和Ba2＋的取代.     

ABSTRACTS——From Journal of Iron and Steel Research （in Chinese）2005, 17（1）-2005, 17（2）

Conception and Application of Technological Control Theoryfor Continuous Rolling ZHANG Jin zhi(Xinye Hi Tech GroupCoLtd,Beijing 100081,China) Abstract:Theseparation of mechanical and electrical system fromlog is ticsystemisthecharacteristicoftechnological…     

ABSTRACTS—— From Journal of Iron and Steel Research （in Chinese） 2006, 18（1）-2006, 18（2）

Application of Controlled Cooling Technology to Improvement of Steel Quality YUAN Guo, WANG Zhao-dong, WANG Guo-dong, LIU Xiang-hua (The State Key Laboratory of Rolling and Automation, Northeastern University, Shenyang 110004, Liaoning, China) Abstract:The application of accelerated cooling technology (ACC) and direct quenching (DQ) to the plate production was reviewed. The ultra fast cooling (UFC) system in which the cooling rate can be over 300 ℃/s for hot strip was desc…     

HPBI对镧（Ⅲ）,铈（Ⅲ）,铕（Ⅲ）,钍（Ⅳ）,铀（Ⅵ）的溶剂萃取行为

本工作研究了HPBI~a(以氯仿为稀释剂)对La(Ⅲ)、Ce(Ⅲ)、Eu(Ⅲ)、Th(Ⅳ)、U(Ⅵ)的萃取行为。探讨了萃取机理和几种萃取类型。计算了每种体系的萃取常数。该体系已用于从U(Ⅵ)中分离Th(Ⅳ)及从La(Ⅲ)、Ce(Ⅲ)、Eu(Ⅲ)中分离Th(Ⅳ)。比较了HPBI、HPMBP~b、HTTA的萃取常数,结果表明HPBI萃取上述几种金属要优于HPMBP和HTTA     

高性能不锈钢（2）

通过考察铁——铬——镍三元体系及考虑其它合金元素所带来的改变,可以从冶金学角度充分理解高性能不锈钢。三元体系有效地描述了两个主要的相：奥氏体和铁素体,它区分出三种结构类型。主要的添加元素是钼、氮和碳以及稳定化铁素体不锈钢中的钛和铌,这些元素以及铬引入了通常不希望存在的二次相。了解发生这种情况的条件及主要相和二次相的影响对于成功使用高性能不锈钢是必要的。     

不锈钢概论（2）

1．2不锈钢的分类 不锈钢的牌号,成分、性能各异,常用的分类方法主要是按钢的主要化学成分（特征元素）和组织结构以及二者相结合的方法来进行分类。     

LaCo_（13）基及R_2（Fe_（1－x）Co_x）_（17－y）Al_y化

ＬａＣｏ_（１３）基及Ｒ_２（Ｆｅ_（１－ｘ）Ｃｏ_ｘ）_（１７－ｙ）Ａｌ_ｙ化合物的结构及磁性ＴｈｅＳｔｒｕｃｔｕｒｅａｎｄＭａｇｎｅｔｉｃＰｒｏｐｅｒｔｉｅｓｏｆＬａＣｏ_（１３）－ＢａｓｅｄＳｙｓｔｅｍｓａｎｄＲ_２（Ｆｅ_（１－ｘ）Ｃｏ_ｘ）_（１７－...     

熔盐法合成LiMn_（1/3）Ni_（1/3）Co_（1/3）O_2及AA电池的电化学性能

以KCl为熔盐,采用熔盐法合成了锂离子电池正极材料LiMn1/3Ni1/3Co1/3O2,扫描电子显微镜（SEM）显示此方法制备产物具有较好的晶形,颗粒较均匀.XRD表征结果显示产物为层状结构,充放电测试结果显示出材料在3.6 V平台附近有较大的可逆容量.在900℃时保温8 h时合成的LiMn1/3Ni1/3Co1/3O2具有较好的电化学性能,制作成AA电池,在2.75～4.2 V之间进行充放电测试,在1 C倍率下放电,LiMn1/3Ni1/3Co1/3O2的初始放电容量可达132.9 mAh/g,循环50多次后容量仍为124.6 mAh/g,容量保持率为93.75﹪.     

Magnetic Properties and Molecular Field Analysis of （ Ce, Nd） 2 （Fe, Si, Mn） 17 Compounds

The temperature-dependent magnetization of the ( Ce, Nd) 2 (Fe, Si, Mn) 17 intermetallic compounds were measured and analyzed by molecular field theory (MFr). The relationship between Tc and the intrasublattice coupling interactions was discussed. The two-sublattice MFT model can well describe the temperature dependence of the magnetization for all the compounds investigated. Ce ion in (Ce, Nd)2Fel7 compounds does not simply dilute the magnetic structure, but is likely present in a mixed-valence state. The substitution of Si for Fe strongly raises Tc and the mean Fe moment remains unchanged for Ce2(Si, Fe)17 compounds, and the 3d exchange coupling constant JFF increases linearly. Mn decreases Tc of Nd2(Mn, Fe)17 compound by reducing JFF。     

Synthesis kinetics and thermophysical properties of La_2（Zr_（0.7）Ce_（0.3））_2O_7 ceramic for thermal barrier coatings

La2(Zr0.7Ce0.3)2O7 (LZ7C3) ceramic was synthesized by solid state reaction with La2O3, ZrO2 and CeO2 as starting materials. The synthesis kinetics, phase structure, mass loss and microstructure were studied by thermo gravimetric-different thermal analyzer (TG-DTA), X-ray difference (XRD) and scanning electron microscopy (SEM). The thermal conductivity and thermal expansion coefficient were measured by laser-flash method and pushing-rod method, respectively. XRD results showed that LZ7C3 was a mixture of La2Zr2O7 (LZ, pyro- chlore) and La2Ce2O7 (LC, fluorite). The lowest synthesis temperature and time of LZ7C3 were 1400 oC and 5 h. There were no peaks of La2O3 when the powder granularity was about 0.82 μm in the synthesis process. The atom ratio La:Zr:Ce of prepared LZ7C3 powder was very close to 10:7:3 which was the theory value of LZ7C3. The thermal conductivity of LZ7C3 decreased gradually with the temperature increased up to 1200 oC, and was located within 0.79 to 1.02 W/(m·K), which was almost 50% lower than that of LZ, whereas its thermal expansion coefficient was larger and the value was 11.6×10-6 K-1.     

Effect of rare earth doping on thermo-physical properties of lanthanum zirconate ceramic for thermal barrier coatings

The effect of rare earth doping on thermo-physical properties of lanthanum zirconate was investigated. Oxide powders of various compositions La2Zr2O7 were synthesized by coprecipitation-calcination method. High-temperature dilatometer, DSC, and laser thermal diffusivity methods were used to analyze thermal expansion coefficient （TEC）, specific heat, and thermal diffusivity. The results showed that CeO2 doped pyrochlores La2（Zr1.8Ce0.2）2O7 and La1.7（DyNd）0.15（Zr0.8Ce0.2）2O7 had higher TEC than La2Zr2O7 and La1.7Dy0.3Zr2O7. La2（Zr1.8Ce0.2）2O7, La1.7Dy0.3Zr2O7, and La1.7（DyNd）0.15（Zr0.8Ce0.2）2O7 had lower thermal conductivity than undoped La2Zr2O7. The Dy2O3, Nd2O3, and CeO2 codoped composition showed the lowest thermal conductivity and the highest TEC. Thermo-physical results also indicated that TEC of rare earth oxide doped La2Zr2O7 ceramic was slightly higher than that of conventional ZrO2-8Wt.% Y2O3 （8YSZ）, and its thermal conductivity was lower than that of 8YSZ.     

稀土氧化物复合ZrO2陶瓷的制备及应用研究进展

稀土氧化物可作为稳定剂、烧结助剂、掺杂改性剂加入到ZrO₂陶瓷材料中,能极大地提高和改善陶瓷材料的强度、韧性,降低其烧结温度,减少生产成本.文中简要综述了稀土氧化物ZrO₂陶瓷材料的制备及应用研究状况,包括Y₂O₃复合ZrO₂陶瓷粉体、富铈稀土氧化物复合ZrO₂陶瓷粉末、Nd₂O₃复合ZrO₂陶瓷材料、Pr₂O₃\Pr₆O₁₁复合ZrO₂陶瓷、La₂O₃复合ZrO₂陶瓷、Yb₂O₃复合ZrO₂陶瓷、Sm₂O₃复合ZrO₂陶瓷材料及氧化锆中掺杂多种稀土氧化物陶瓷粉体的制备和应用,分析讨论了一些需要解决的问题,并展望了稀土复合ZrO₂陶瓷制备技术及未来研究发展趋势.      

等离子喷涂双相复合结构顶层热障涂层的研究

热障涂层 (TBCs) 是燃气轮机等设备的高温部件上不可缺少的防护技术。 La2Zr2O7 是最具潜力的顶层材料, 但其韧性差等问题限制了其应用。 本研究采用双相复合陶瓷技术对 La2Zr2O7 进行改性, 以 LaPO4 与 La2Zr2O7 的 双相复合材料为热障涂层顶层材料。 采用机械混合和喷雾造粒技术制备双相陶瓷材料, 利用等离子喷涂的方法制 备双相陶瓷顶层。 通过热循环和冲蚀实验检测双相复合涂层的性能。 利用 X 射线衍射仪 (XRD) 检测涂层的相结构, 利用扫描电镜(SEM)检测涂层的表面和剖面形貌。结果表明, 双相复合结构涂层表面微细裂纹增多, 粗大裂纹减少, 裂纹会产生曲折和分叉。 LaPO4 的加入提高了双相陶瓷材料的韧性和断裂强度, 和单相 La2Zr2O7 涂层相比, 双相 陶瓷涂层在冲蚀过程中失重较少。     

等离子喷涂Sm2Zr2O7热障涂层的高温时效行为以及有序-无序相变

烧绿石结构的稀土锆酸盐材料是新型热障涂层的潜在候选材料之一,能进一步提升涡轮发动机使用寿命和可靠性。通过大气等离子体喷涂技术制备了Sm2Zr2O7热障涂层,并对其显微结构和相组成进行表征。Sm2Zr2O7涂层表现出阴离子无序和阳离子有序的萤石相结构特征。经过高温热处理后,涂层结构的向有序方向转变。当热处理温度超过1200℃时,涂层转变为有序的烧绿石结构。热处理温度升高造成涂层中微裂纹的愈合,导致Sm2Zr2O7涂层典型的片层结构特征消失。     

稀土配合物[REL3(4-picNO)H2O]的合成与表征

合成了2,3-二氯异丁酸根和4-甲基吡啶氮氧化物稀土三元配合物(RE=La、Ce、Pr、Nd、Sm、Eu).通过元素分析、红外、紫外、荧光、X射线粉末衍射、XPS、热分析以及摩尔电导等分析手段,确定了配合物的组成为[REL3(4-picNO)H2O](L= CH3C2H2Cl2COO -),并对它们的性质进行了讨论.     

Synthesis and Electrical Conductivities of Sm2O3-CeO2 Systems

Solidoxidefuelcell(SOFC)hasattracteda greatattentionasapromisingtechniqueforelectrical powergeneration[1].Thecurrentstate of the art SOFCsusesyttriastabilizedzirconia(YSZ)electro lyte,operatesat800～1000℃duetothelowoxy genionicconductivityoftheYSZelect…     

镁基六铝酸镧热障涂层材料的制备及表征

以氢氧化铝、氧化镧和氧化镁为原料,采用二步固相高温烧结法合成了镁基六铝酸镧(LaMgAl11O19)热障涂层材料,分别利用X射线衍射、扫描电子显微镜、差示扫描量热法、差示热膨胀法和激光脉冲法对材料的物相组成、微观结构、热容、热膨胀系数、热扩散系数和导热系数进行了表征。结果表明,LaMgAl11O19以六方相为主晶相,呈板状结构,在RT~1200℃温度范围内,随着温度的升高,材料的热容逐渐增大,热扩散系数和热导率降低,材料的导热系数优于目前普遍使用的6%~8%氧化钇部分稳定的氧化锆。     

Interaction of Yttrium,Lanthanum, and Samarium Oxides at 1600°C

Phase equilibria and structural transformations in the La2O3–Y2O3–Sm2O3 system at 1600°C were studied by X-ray diffraction and petrography over the entire composition range. Solid solutions based on the hexagonal (A) modification of La2O3, cubic (C) modification of Y2O3, and monoclinic (B) modification of La2O3 (Sm2O3) were found to form in the system. The starting materials were La2O3, Sm2O3, and Y2O3 (99.99 %) powders. The samples were prepared from nitrate solutions with subsequent evaporation and decomposition at 800ºC for 2 h. The samples were subjected to heat treatment in three stages: at 1100°C (for 2464 h), at 1500°C (for 50 h), and then at 1600°C (for 10 h) in furnaces with Fechral (H23U5T) and Superkanthal (MoSi2) heating elements, respectively. The isothermal section of the La2O3–Y2O3–Sm2O3 phase diagram at 1600°C is characterized by three single-phase (A-La2O3, B-La2O3 (Sm2O3), C-Y2O3) and two-phase (A + B, B + C) regions. The ordered phase of perovskite-type was not found at 1600°C in this system. An infinite series of solid solutions based on the monoclinic modification of B-La2O3 (Sm2O3), which occupies the largest area of the isothermal section, forms in the system. Yttrium oxide stabilizes the total mutual solubility of lanthanum and samarium oxides. The lattice parameters of the B phase decrease, the lattice volume increases with the addition of a heavier ion, and the lattice of solid solutions based on the B modification of rare earth metal oxides becomes more densely packed with higher yttrium oxide. The lattice parameters of the B phase lattice vary from a = 1.3988 nm, b = 0.3774 nm, and c = 0.8427 nm in the single-phase sample containing 15 mol.% Y2O3–42.5 mol.% La2O3– 42.5 mol.% Sm2O3 to a = 1.3806 nm, b = 0.3709 nm, and c = 0.8312 nm in the two-phase sample containing 45 mol.% Y2O3–27.5 mol.% La2O3–27.5 mol.% Sm2O3.     

镧热还原氧化钐烧结堆料对金属钐收率的影响研究

进行了镧热还原氧化钐时，烧结堆料对金属钐收率影响的研究。采用化学分析法和热重法得到的坩埚不同部位物料的金属钐收率，静水称量法测定镧渣的孔隙率，证实了镧热还原氧化钐过程在坩埚底部存在烧结堆料现象。根据试验结果分析了烧结堆料的原因，并进行了优化试验，提高了金属钐的收率。