材料期刊网

EFFECT OF ANNEALING ON THE ELECTRODE PERFORMANCES OF ZrTi(MnVCoNi)_2 HYDROGEN STORAGE ALLOY

X.G , Yang , Q.A. Zhang , K. Y Shu , YL. Du , YQ. Lei and Q.D. Wang (Department of Materials Science and Engineering , Zhejiang University , Hangzhou 310027 , China )W.K. Zhang(Department of Applied Chemistry , Zhejiang University of Technology , Hangzhou 3100l4 , China )G.L. Lu(Central Lab , Zhejiang University , Hangzhou 310028 , China)

金属学报(英文版)

The annealing treatment was found to improve the cyclic stability but to degmde discharpe capacity, activation and high-rate discharpeability for the Ti-substituted AB2type alloy electrode. A larper polarization was found in the annealed alloy because of its poor discharpe kinetics resulted hem the structural homogeneity. At larae discharpe cumnts, the hydmpen dchsion in the bulk of the alloy was mpaofed as the mte-determining step. Based on the P ressure-composition isotherm measurement, we concluded that the decrease in discharpeability of the annealed alloy is owing to the low and flat pressure plateau, as well as the large hysteresis, but the hydrgen stomge density almost remains unchangeable after annealing.

关键词: AB_2 , null , null , null , null , null

Studies of the spin-Hamiltonian parameters and defect structures for the trigonal Mo3+ centers in Y3Al5O12 and Lu3Al5O12 crystals

Radiation Effects and Defects in Solids

The complete diagonalization (of energy matrix) method (CDM) and the perturbation theory method (PTM) are applied to calculate the spin-Hamiltonian (SH) parameters (electron paramagnetic resonance g factors g(//), g(perpendicular to) and zero-field splitting D) of the trigonal Mo3+ centers in Y3Al5O12 and Lu3Al5O12 crystals. Both methods are based on the cluster approach in which the covalence effect due to the admixture between the d orbitals of central d(n) ion and p orbitals of ligands is considered. The g factors calculated by both methods are close to each other and agree with the experimental values. However, the calculated zero-field splittings D from PTM for both crystals are about 84% those from CDM. The reasons that the CDM is preferable to the PTM in the calculations of SH parameters are discussed. The angular distortions of Mo3+ centers in both garnet crystals are predicted.

关键词: defect structure;electron paramagnetic resonance;crystal and ligand;fields;Mo3+;garnets;superposition model analysis;atomic screening constants;magnetic-resonance;scf functions;jahn-teller;ions;field;spectra;sites;cr3+

LaB6功能陶瓷材料的研究现状

郑树起 , 闵光辉 , 于化顺 , 韩建德 , 王维倜 , 张树玉

材料导报

综述了目前国内外LaB6功能陶瓷材料的研究概况及应用,综合了制备LaB6粉末、多晶、单晶的各种工艺.

关键词: LaB6 , 功能陶瓷 , 制备工艺

氯化钾镀锌二问问一——为何镀液中氯化钾达近400g/L?

袁诗璞

电镀与涂饰

氯化钾镀锌液配方中,氯化钾的含量通常是200～ 250 g/L,但在生产维护时分析镀槽中的氯化钾有时高达近400 g/L.认为以EDTA滴定法及硝酸银滴定法分别测总锌与总氯,然后从总氯中减去氯化锌所占氯的量而计算出氯化锌含量的常规化验方法有一定的局限性,尤其不适用于大生产已久的镀液.介绍了控制氯化钾含量的方法:先调整pH,接着通过赫尔槽试验分析并调整锌离子浓度,然后分析并调整光亮剂及硼酸,最后通过试验确定氯化钾补加量.

关键词: 镀锌 , 氯化钾 , 分析 , 调整 , 赫尔槽试验

Terahertz spectroscopy of central and soft phonon modes in LuFe(2)O(4)

Applied Physics a-Materials Science & Processing

The terahertz dielectric response of LuFe(2)O(4) is investigated by terahertz time-domain spectroscopy over a temperature range of 6-290 K. It is revealed that besides the central mode associated with the charge-ordered state, a soft TO(1) mode at below similar to 240 K is identified indicating the existence of displacing ferroelectricity, in addition to the charge-ordering-induced ferroelectricity at below 320 K. The anomaly of the soft mode at similar to 180 K reflects the magnetoelectric correlation between the soft TO(1) mode and the spin/charge fluctuations revealed recently. Finally, the magnetic property at below similar to 240 K is discussed.

关键词: system lufe2o4;charge;polarization

放电等离子烧结制备亚微米LaB6块体材料

金帅 , 刘丹敏 , 周身林 , 张久兴

稀有金属 doi:10.3969/j.issn.0258-7076.2008.05.018

采用氢直流电弧等离子体法,以稀土镧块为原料,制备出了平均粒度为20 nm的La纳米粉末.以L丑纳米粉和B纳米粉为原料,采用放电等离子烧结(SPS)技术制备出了LaB6亚微米晶块体材料.通过系统研究各烧结参数对材料结构和性能的影响,得到了最佳的烧结工艺.获得了相对密度高达99.3%的致密烧结体,其维氏硬度达到14.1 GPa.采用XRD,SEM和TEM对材料的相组成和微观组织进行了测试分析.结果表明.SPS烧结LaB6块体的晶粒细小,平均晶粒尺寸为150nm,整体结构均匀致密.实验表明,SPS技术可以实现LaB6细晶块体材料的快速烧结.

关键词: LaB6 , 热阴极材料 , 放电等离子烧结

钼酸盐系列缓蚀剂在含5g/L Cl^-溶液中对Q235钢的缓蚀研究

沈素峰

腐蚀学报（英文）

  通过电化学阻抗谱(EIS)，研究了钼酸盐系缓蚀剂在含g">5g/L Cl^-溶液中对Q235钢的缓蚀性能，结果表明：由钼酸盐为主盐与硅酸盐、磷酸盐、有机胺A复配而成的缓蚀剂，可以达到低成本、高缓蚀率的效果.并通过失重法实验对此配方进行了验证，复配缓蚀剂的缓蚀率接近88.4%，明显高于单组分缓蚀剂.

关键词: 钼酸盐 , inhibitor , compound inhibitors

钼酸盐系列缓蚀剂在含5g/L Cl-溶液中对Q235钢的缓蚀作用

沈素峰

腐蚀学报（英文） doi:10.3969/j.issn.1002-6495.2009.02.034

通过电化学阻抗谱(EIS),研究了钼酸盐系缓蚀剂在含5g/L Cl-溶液中对Q235钢的缓蚀性能,结果表明:由钼酸盐为主盐与硅酸盐、磷酸盐、有机胺A复配而成的缓蚀剂,可以达到低成本、高缓蚀率的效果.并通过失重法实验对此配方进行了验证,复配缓蚀剂的缓蚀率接近88.4%,明显高于单组分缓蚀剂.

关键词: 钼酸盐 , 缓蚀 , 复配缓蚀刺

La2O3-B4C系反应合成LaB6粉末

郑树起 , 闵光辉 , 邹增大 , 王效志 , 韩建德

金属学报

系统研究了利用La2O3和B4C粉制备LaB6粉末的反应合成工艺.La2O3-B4C系反应热力学分析表明反应产物的气体分压对LaB6的形成有重要影响,减小气体分压可以明显降低LaB6的合成温度,结合DTA测定结果,确定了LaB6粉末的合成温度.利用X射线衍射分析了不同温度和保温时间条件下所生成粉末的相组成,并分别用扫描电镜和化学分析方法分析了所生成LaB6粉末的颗粒尺寸、形貌及纯度.实验结果表明,La2O3-B4C系制备LaB6粉末的优化工艺是真空度133 Pa,1673 K保温2.5 h,所合成的LaB6粉末颗粒比较规整,大多呈近似圆球形,平均直径3μm,纯度达98.2%.

关键词: La2O3 , null , null , null , null

La2O3-B4C系反应合成LaB6粉末

郑树起 , 闵光辉 , 邹增大 , 王效志 , 韩建德

金属学报 doi:10.3321/j.issn:0412-1961.2001.04.018

系统研究了利用La2O3和B4C粉制备LaB6粉末的反应合成工艺.La2O3-B4C系反应热力学分析表明反应产物的气体分压对LaB6的形成有重要影响,减小气体分压可以明显降低LaB6的合成温度,结合DTA测定结果,确定了LaB6粉末的合成温度.利用X射线衍射分析了不同温度和保温时间条件下所生成粉末的相组成,并分别用扫描电镜和化学分析方法分析了所生成LaB6粉末的颗粒尺寸、形貌及纯度.实验结果表明,La2O3-B4C系制备LaB6粉末的优化工艺是真空度133 Pa,1673 K保温2.5 h,所合成的LaB6粉末颗粒比较规整,大多呈近似圆球形,平均直径3μm,纯度达98.2%.

关键词: La2O3 , B4C , 反应 , 合成 , LaB6