钇基重稀土对NBC合金性能的影响

研究了钇基重稀土对NBC合金性能的影响。结果表明：NBC合金经过微量CU-3型稀土的微合金化处理后，其显微硬度、耐磨性和耐腐蚀性均有不同程度的提高，热膨胀系数有所下降；随着稀土加入量的增加，NBC合金的显微硬度逐渐提高，而其磨损量、平均腐蚀速率和热膨胀系数逐渐降低。     

Processing of Rare-Earth Elements from Loparite

Distribution of REEs and Th in extraction from chloride solutions with primary carboxylic acids C₇-C₉, 2-ethylhexanoic acid, and a crude mixture of higher branched carboxylic acids was studied. Thorium can be separated by extraction with carboxylic acids. The decay products were recommended to be precipitated after extraction of REEs. The radioactivity of loparite processing products considerably decreases with time.__________Translated from Radiokhimiya, Vol. 47, No. 1, 2005, pp. 77–79.Original Russian Text Copyright © 2005 by Lebedev, Rudenko.     

Influence of Rare-earth Elements on Mechanical Properties of Palladium

The influence of 0.1-0.6 at.-%RE additions (RE= La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Er, Yb) on themechanical properties of Pd was studied. All above RE additions increased not only the strengthproperties at ambient temperature but also the tensile strength, creep rupture time and activation en-ergy at high temperatures, simultaneously increased the elongation of Pd. In the range of dilute con-centration, the strength properties of Pd-RE alloy enhanced linearly with RE concentration. Whenthe strength properties of Pd-RE alloys were normalized at 0.1 at.-%RE, it was found that light REelements had stronger effect on the properties of Pd than heavy RE, whereas Eu, Yb, Ce had anoma-lous effect. In all Pd-RF alloys, Pd-Eu alloy had the highest strength properties, successively Pd-Yband Pd-Ce alloy. The effect mechanisms of RE in alloy, such as purifying impurities, increasingrecrystallization temperature, refining grain size. expanding crystal lattice, increasing dislocation den-sity and decreasing stacking fault energy, forming stable RE oxidation by internal oxidation, and soon, were observed. They were strengthening sensitive factors. The influence of the factors onstrength properties and elongation of Pd was discussed.     

掺杂不同微量元素对钼材性能的影响

采用粉末冶金工艺制备了纯钼和掺杂Ti,Zr,C的TZM和掺杂La2O3的ZHM钼合金.简述了工艺过程.给出了掺杂元素的成分范围和烧结温度范围,及对它们进行搭配优选,获得了一组最合适的工艺参数,使材料的性能最好.其TZM棒材经1 150℃,2 h退火后,抗拉强度和延伸率分别达到800 MPa和21%,ZHM棒经相同处理后分别达到650 MPa和27%.TZM完全适合制作轧制无缝钢管用的钼顶头,ZHM可以做高温发热炉隔热屏用材料.     

Classification of Raw Sources of Rare-Earth Elements in Kazakhstan

The characteristics of the mineral composition of ores and valuable set of components： The technology of processing depending on the type of mineralization, the nature of the impregnation of ore minerals and their composition have been considered. There have been given technological schemes for processing concrete objects. The analysis of fitness fields for industrial development （degree of scrutiny, the effectiveness of developed enrichment and hydrometallurgy technology） has been provided.     

Influence of Alloy Elements on Magnetic Properties of Fe-based Amorphous Alloys

1. IntroductionThe Fe-based amorphous alloy is a kind of important soft magnetic materials. Fe-St-B system amorphous alloys containing about 80 at. pci Fe havethe highest saturation magnetization induction. Thereseachers in the world pay a great attention to it.In order to enhance some magnetic properties to satisfy the demand of the different applications, the alloy compositions and the technological processes wereinvestigatedll~4]. In this article, the effect of alloy elements on the magne…     

稀土对上引连铸铜管坯质量影响的研究

通过上引连铸实验、力学性能检测和金相观察,研究了上引连铸中加入稀土添加剂对铜管坯机械性能的影响.研究结果表明,添加1#稀土的铜管坯抗拉强度平均提高6.03%,延伸率平均提高10.37%;添加2#稀土的铜管坯抗拉强度平均提高3.03%,延伸率平均提高12.94%.且实验结果确认了稀土在上引连铸生产铜管中的有利作用.     

IVA元素掺杂的ZnO的电学和光学性质

基于密度泛函理论的总体能量平面波模守恒赝势方法,对掺杂Si、Ge、Sn的ZnO的电导率和光学性质进行了理论研究。结果表明,掺杂后晶格常数随着杂质原子序数的增大而增大。IVA族元素对Zn的替代可以提高ZnO的载流子浓度和电导率。ZnO∶Si的载流子浓度最大,ZnO∶Sn的电导率最大。IVA族元素对Zn的替代使得ZnO的吸收和反射都降低。此外,掺Sn的ZnO由于在可见光区吸收小和反射小,更适合用于制备高质量的透明导电氧化物。理论计算的结果与实验结果相一致。     

Precursor Influence on the Electrical Properties of Textured Bi-2212 Superconductors

Several synthetic methods, solid-state, sol-gel and polymer solution methods, have been used to prepare prereacted precursors, as well as a vitreous material obtained by melt quenching. The influence of the starting powder characteristics on the phase formation, microstructure, T _c and J _c of Bi-2212 textured rods prepared by directional crystallization from the melt has been analyzed. In all the cases, high transport critical current values (higher than 3000 A/cm² at 77 K) have been obtained, independently of the precursor type. Samples obtained by the polymer route show improved T _c values, associated to a lower oxygen content.     

Extraction Properties of Dibutylphosphoric Acid Zirconium Salt in Recovery of Transplutonium and Rare-Earth Elements from Nitric Acid Solution

The structures of dibutylphosphoric acid zirconium salt (Zr-DBP) and of the complexes formed in the organic phase in extraction of rare-earth elements with Zr-DBP were suggested on the basis of the extraction and IR data. The influence exerted by the acidity, Zr-DBP concentraiton, and degree of extractant saturation with the metal on the structure of the complexes was examined. The contributions of various extraction mechanisms for all the rare-earth elements and also for Am and Cm were revealed by mathematical simulation. Irrespective of the diluent, addition of TBP to Zr-DBP decreases the distribution factors of Ce, Eu, and Am but increases the extractant capacity for rare-earth elements by a value that considerably exceeds the extraction of the elements with TBP taken separately.     

氧化锌中的本征点缺陷对材料光电性能的影响

ZnO薄膜中的本征点缺陷对材料的电学、发光性能有着至关重要的影响.目前,对本征点缺陷的研究是ZnO领域的一大热点,也是实现ZnO基光电器件的关键技术之一.本文结合最新研究,扼要综述了本征点缺陷的电荷特性、对本征ZnO为n型的作用机理、对p型ZnO制备的影响及点缺陷对薄膜绿光发光的贡献.     

NaOH处理对石墨烯电学性能的影响

在CVD石墨烯的转移过程中无法避免会出现胶残留,导致了材料不必要的p型掺杂。研究表明,通常来自这种残余胶的p型掺杂影响了石墨烯的电学特性。本文发现NaOH溶液能够有效地去除这种PMMA(聚甲基丙烯酸甲酯(C5H8O2)x)中的含氧官能团,减少胶残留,并首次将其运用在CVD生长的石墨烯单层薄膜上。通过不同浓度NaOH溶液的选择,我们有效地解决了NaOH与SiO2/Si衬底反应的问题。处理结果显示,通过NaOH溶液浸泡石墨烯的载流子浓度变为原来的三分之一甚至更少,而且处理效果最明显的石墨烯样品的迁移率从880cm2/Vs升高到2260cm2/Vs。同时我们比较了水和NaOH处理效果的稳定性,结果显示用水处理的样品迁移率很快回到了处理前的数据,而用NaOH溶液处理的石墨烯薄膜迁移率最终稳定在原有迁移率的1.5倍。     

掺杂La对钼丝组织和性能的影响

用粉末冶金工艺先制取掺杂稀土La的钼坯,再经旋锻、拉拔制成掺杂钼丝.通过力学性能实验和SEM观测,对掺杂钼丝与纯钼丝的性能和组织结构进行对比分析.结果表明,由于稀土元素La与Mo中的氧结合形成细小弥散分布的La2O3质点,强化了显微组织,使其再结晶温度较纯钼丝提高500℃左右,室温脆性显著改善,高温加工性能和室温弯折性能大幅提高.所研制的掺杂钼丝是制造高温加热元件和耐高温结构元件理想的材料.     

孪晶对Cu的力学和电学性能影响的研究进展

金属Cu中孪晶的作用已受到广泛关注.介绍了孪晶的分类及晶体学结构,综述了孪晶对Cu强度、塑性、加工硬化、应变速率敏感性、变形机制和电阻率(或电导率)等方面的影响规律及内在机理,讨论了孪晶Cu研究的不足之处及需要加强的方面,并指出通过适当的工艺技术,在晶粒中引入高密度的孪晶同时获得高强度、高塑性和良好电导性能,将是未来发...     

杂质分布对多晶硅薄膜电性能的影响

报道了多晶硅薄膜的制备方法及光生截流子在多晶硅晶界区域的收集、复合情况，并采用剖面分析方法研究了杂质的分布对多晶硅薄膜太阳电池电性能的影响。     

多孔硅的制备及其吸杂处理对电学性能的影响

多孔硅吸杂是减少晶体硅中杂质和缺陷,提高太阳能电池转换效率的有效方法。采用电化学腐蚀方法在单晶硅片上制备多孔硅,通过观察多孔硅的形貌、结构及单晶硅片的电阻率变化,研究不同电流密度制备的多孔硅对吸杂效果的影响,并从多孔硅的结构出发探究多孔硅吸杂的机理。结果表明,随电流密度增加,孔隙率明显增加,多孔硅在电流密度为100mA/cm2时,孔隙率最大;电流密度越大,多孔硅伴随所产生的弹性机械应力增加,晶格常数相应增加,这两个因素都有利于缺陷和金属杂质在多孔硅层-基底界面处迁移和富集,导致单晶硅吸杂后电阻率增大。     

Influence of Point Defects on the Electrical Conductivity and Dielectric Properties of Langasite

The temperature-dependent electrical conductivity and dielectric permittivity and room-temperature optical absorption spectra of La₃Ga₅SiO₁₄ (langasite) crystals grown under different conditions are measured. The resistivity and peak-loss temperature t _tanδ of the crystals are shown to be determined by the concentration of oxygen vacancies, which originate from changes in melt composition during crystal growth. The t _tanδ of langasite is shown for the first time to be anisotropic (measurements on Z- and X-cuts). The properties of the crystals are suitable for the fabrication of stable piezoelectric elements capable of operating above 600°C.     

Extraction of Rare-Earth Elements from Nitric Acid Solutions with Ethylenediphosphine Dioxides

Extraction of microamounts of Y, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu from HNO₃ aqueous solutions with ethylenediphosphine dioxides in organic diluents was studied. The effect of the dioxide structure on its extractive power and selectivity was considered. The stoichiometry of extractable solvates was determined.     

晶界电性能对ZnO压敏陶瓷性能的影响

研究了传统烧结与热压烧结对ZnO压敏陶瓷显微结构和电性能的影响.采用扫描电镜观察(SEM)、电流-电压测试(I-V)、电容-偏压测试(C-V)以及阻抗谱等分析方法或测试手段研究了陶瓷的显微结构、电性能.结果表明,热压烧结增大了ZnO压敏陶瓷的烧结密度,提高了电性能.晶界特性参数测试结果表明,热压烧结还可以增强晶界特性.