共查询到20条相似文献,搜索用时 125 毫秒
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包钢钢研所自己动手建设了一条三分组萃取南方稀土矿试验性生产线,经4月份连续10天的萃取试验:镧铈镨钕混合轻稀土、钐铕钆富集 相似文献
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采用程序升温分解、氧吸附和程序升温表面反应的方法,对稀土原料——氧化镧、富镧稀土、混合轻稀土、镨钕稀土和载于Al2O3载体上的氧化镧进行了热分解性能和催化氧化性能考察。考察结果表明,热分解从易到难的顺序是:镨钕稀土—混合轻稀土—富镧稀土—氧化镧;稀土原料的催化氧化性能从强到弱的顺序是:混合轻稀土—镨钕稀土—富镧稀土—氧化镧。试验发现,氧化镧被载于Al2O3上之后,其表面氧催化氧化H2的性能大大提高。 相似文献
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Synthesis, Characterization and Vulcanizing Properties of Rare Earth Complexes with 2-Mercaptobenthiazole 总被引:9,自引:1,他引:8
2 mercaptobenzothiazolewasfirstreportedbyHofmann[1 ] in 1 887.Ithasbeenusedasanacceleratorinthevulcanizationofrubberformanyyears .Todayitisstillbeingusedasamainacidicacceleratorinrubberindustry .Butithasdisadvantagesofvulcanizationreversionandeasyscorch[2 ] whe… 相似文献
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几种稀土氨基酸络合物合成及离解动力学研究 总被引:4,自引:2,他引:2
本文合成了稀土(RE=La,Pr)与甘氨酸(Gly),谷氨酸(Glu)四种络合物及镨与赖氨酸(Lys)的络合物。在模拟生理条件下,测定了络合物的离解动力学方程。实验表明,在pH=4时,络合物的离解呈现一级动力学规律,并且镨赖氨酸络合物离解迅速且离解程度较大,谷氨酸络合物离解速度亦较快,甘氨酸络合物则不发生离解。作为络合物中心离子的La和Pr对络合物的离解速度影响较小。稀土甘氨酸络合物较稳定,用于饲料添加剂是有利的 相似文献
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Two series of solid complexes of europium and terbium with biphenyl 4-carboxylic acid and phen were synthesized and characterized in this report. Their elemental analysis, molar conductivities and TG-DTA studies indicate that the complexes have the composition of Eu(phen)L3·1/2H2O, Eu0.5RE0.5(phen)L3·1/2H2O; Tb(phen)L3·H2O and Tb0.5RE0.5(Phen)L3·1/2H2O. (RE=Y3 , La3 and Gd3 ; L=biphenyl 4-carboxylic acid; phen=o-Phenanthroline). The studies of their IR, UV 1H NMR and molar conductivities demonstrate that biphenyl 4-carboylic acid is bounded with RE(Ⅲ) ion. Rare earth ions coordinate with two nitrogen atoms of phen molecules directly in these rare earth complexes. The fluorescence spectra and fluorescence lifetimes of the rare earth complexes show that the fluorescent intensity and lifetime of a series of europium complexes are longer than those of the series of terbium complexes as having the some ligands. There are better fluorescent intensity and lifetime of hetero-nuclear rare earth complexes than homo-nuclear rare earth complexes for europium complexes. The fluorescence emission intensity of Eu3 is raised by inert fluorescent rare earth ions (Y3 , Gd3 and La3 ), but in Tb3 hetero-nuclear rare earth complexes the intensity of Tb3 ions are quenched by the inert fluorescent rare earth ions. 相似文献
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The rare earth nitrate complexes with 2,2′:4′,4″:2″,2-quaterpyridine (L) were prepared in ethylacetate. These new complexes with the general formula [RE(NO3)3L]*H2O (RE = La, Pr, Eu, Tb, Er, Y) were characterized by elemental analysis, IR spectra, thermal analysis and molar conductance measurements. The luminescence properties of these complexes were also studied. 相似文献
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Eu(TTA)2(phen)(UAH) (UAH=undecylenic acid)with fine fluorescent property and active group was synthesized. The measurement and characterization of complexes were also carried out. A series of composites based silicon rubber were prepared by blending silicon rubber and Eu(TTA)2(phen)(UAH) rare earth complex with active groups. Next, the effect of vulcanizing time on the property of materials was mainly studied. The results show that the dispersed particle size of rare earth complexes decreases gradually in the vulcanizing process. 相似文献
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The extraction of RE(Ⅲ) (RE=La, Nd, Sm, Gd) in sulfuric acid medium using the mixture of HDEHP(H2B2) and HEH/EHP(H2L2) was investigated. The synergistic enhancement coefficient(R) was calculated for La (1.96), Nd(3.52), Sm(5.96), and Gd(5.71), respectively, at pH=2.0, and it was seen that the R increased with the increase of aqueous quilibrium pH. The configuration of the extracted complexes was considered to be RE(SOa)xH2x(HB2)3 with HDEHP, RE(SOa)xH2x(HL2)3 with HEH/EHP, and RE(HB2)2(HL2) with their mixture as the extractant with the slope method. The equilibrium constants and stability constants were calculated. A cation exchange mechanism was proposed as well. 相似文献
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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. 相似文献
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The enthalpies of solution in water of complexes of RE(NO3)3(RE = La - Nd, Sm- Lu, Y) with L-α-Histidine (His) were measured at 298.15 K. The standard enthalpies of formation of RE(His)^3 (aq) were calculated. The “tetrad effect” regularity was observed from the curve, which is the enthalpies of solution plotted against the atomic numbers of the elements in lanthanide series. 相似文献
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镧系元素高氯酸盐苯丁基亚砜配合物的合成与表征 总被引:7,自引:0,他引:7
本文以稀土高氯酸盐RE(ClO_4)_3nH_2O(RE=La~(3+)、Ce~(3+)、Pr~(3+)、Nd~(3-)、Sm~(3-)、Eu(3+),n=6~7)与苯丁基亚砜PBSO(C_6H_5C_4H_9)在无水乙醇体系中合成出六个新配合物,并对配合物进行了元素分析,稀土离子含量测定,配体PBSO含量测定ClO_4~-含量测定、IR谱、导电、TG-DTA分析及X-射线粉末衍射。确定了配合物的组成为[RE(BPSO)_7(ClO_4)](ClO_4)_2,配位数为8,电解质类型为1:2。 相似文献