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1.
江涛  章伟光  申俊英 《稀土》2000,21(3):39-41
于空气中一步合成出二乙基二硫代氨基甲酸稀土 (镧、钕、铕和混合稀土 )共四种配合物 ,产率达 90 %以上 ,本文首次报道了该系列稀土配合物促进橡胶硫化性能和应用于胶鞋大底生产的配方试验 ,结果表明 ,除混合稀土配合物外 ,镧、钕、铕配合物均具有对橡胶硫化促进作用。选择镧配合物在胶鞋大底生产上试用 ,生产的胶鞋物理机械性能均达国家一级品标准。  相似文献   

2.
Rare Earth Elements-Doped LiCoO2 Cathode Material for Lithium-Ion Batteries   总被引:1,自引:0,他引:1  
Thedevelopmentoflithium ionbatteriesreliesonthesuccessfuldevelopmentoflithiumintercalationandde intercalationcompounds ,whichareusedasthecathodeandanodeactivematerials .Forthecathode ,LiCoO2 ,LiNiO2 andLiMn2 O4 areselectedasthecan didate .Amongthematerials ,thelayeredtransitionmetaloxideofLiCoO2 isregardedasthemostattrac tivecathodematerialforcommerciallithium ionbat terybecauseofitshighspecificcapacity ,highoperat ingcellvoltageandexcellentrechargeability .Recent ly ,moreextensivestudies…  相似文献   

3.
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   

4.
The cathode material plays an important role inthe performance of lithium ion batteries. Commerciallithium cells use lithium cobalt oxide cathodes and thehigh cost of this material has prompted the design andsynthesis of alternate insertion hosts. Among these al ternatives, spinel LiMn2O4 has been found to bepromising in terms of specific energy, non toxicity,and low cost[1~3]. It is thought that lithium man ganese oxides will be used in lithium ion batteries forel…  相似文献   

5.
The optimum amount of rare earth elements (RE) for treating glass fiber surface and its effect on the tensile properties of glass fiber reinforced polytetrafluoroethylene (GF/PTFE) composites were investigated. The tensile properties of GF/PTFE composites with different surface treatment conditions were measured. The fracture surface morphologies were observed and analyzed by SEM. The results indicate that rare earth elements can effectively promote the interfacial adhesion between the glass fiber and PTFE, owing to the effects of rare earth elements on the compatibility. The tensile properties of GF/PTFE composites can be improved considerably when the content of RE in surface modifier is 0.2%-0.4%,and the optimum performance of GF/PTFE composites is obtained at 0.3 % RE content.  相似文献   

6.
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   

7.
刘睦清  高忆慈 《稀土》2006,27(5):15-19
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   

8.
合成了六种稀土苯氧乙酸的二元、三元配合物,其通式为RE(POA)3、RE(POA)3Phen、RE(POA)2hq(RE=L a、Y;HPOA=苯氧乙酸;Phen=邻菲罗啉;Hhq=8-羟基喹啉)。研究了配合物在不同溶剂中的溶解性及摩尔导电性,用IR、UV、DTA等方法研究配合物的结构特点,并对L a(POA)3对植物铅、镉污染的影响做了初步的探讨。  相似文献   

9.
Themetalcomplexesofhydrazideshaveattractedconsiderableinterestowingtotheirantifungalandantibacterialactivities[1 ,2 ] .Theycanalsobeusedasanalyticalreagents[3 ]andextractingagentsformetalsalts[4 ] .Manycomplexesofhydrazideshavebeensynthesizedandcharacterized[5]…  相似文献   

10.
Effect of Rare Earth on Microstructure of γ-TiAl Intermetallics   总被引:3,自引:0,他引:3  
The rare earth (RE) elements (Ce, La) were added to binary Ti-47% Al alloys (atomic fraction) by Induction Skull Melting. The element Ce of 1.0 atomic percent was added individually, and La of 0.2 atomic percent was added individually. This article studied the influences of rare earth metal (Ce, La) on microstructure of as-cast TiA1 based alloy by XRD, SEM, EMPA and TEM measurement methodology. The results show that most of rare earth-rich phases (AlCe, Al-La) are uniformly distributed in grain boundary in the shape of discontinuous network, and some particles of rare earthrich phases within the grains are mainly ellipsoids. In addition, rare earth element can obviously refine the grain size and the lamellar thickness of as-cast TiAl based alloy samples. The grain size of Ti-47Al-1.0Ce-0.2La alloy reaches about 30~80μm, and the lameUar thickness of its γ phase and α2 phase are less than 200 and 20nm, respectively.  相似文献   

11.
摘 要:对显色剂2,4-二氯-6-溴偶氮氟膦与稀土元素在微波催化下的显色反应进行了研究。在硝酸及少量吡啶介质中,于40℃的微波水浴中加热催化8 min,试剂与各稀土发生显色反应,形成稳定的蓝色配合物。典型稀土元素La、Ce与显色剂的配合比均为1︰3,各稀土配合物的最大吸收波长位于632~636 nm,表观摩尔吸光系数相近,ε为 0.89~1.15×105 L?mol-1?cm-1。以634 nm作为测定波长,改变混合稀土的配分进行试验,结果表明,La、Ce、Y的比例对稀土总量测定的影响不显著。加入四元混合掩蔽剂,采用本方法对岩石等实际样品中稀土总量进行测定,相对标准偏差(RSD, n=5)为2.0%~2.4%,回收率为 93%~98%。  相似文献   

12.
The effects of rare earth(RE)on the structure,acidity,and catalytic performance of HZSM-5 zeolite were investigated.A series of RE/HZSM-5 catalysts,containing 7.54% RE(RE=La,Ce,Pr,Nd,Sm,Eu or Gd),were prepared by the impregnation of the ZSM-5 type zeolites(Si/Al=64:1)with the corresponding RE nitrate aqueous solutions.The catalysts were characterized by means of FT-IR,UV-Vis,NH3-TPD,and IR spectroscopy of adsorbed pyridine.The catalytic performances of the RE/HZSM-5 for the catalytic cracking of mixed butane to light olefins were also measured with a fixed bed microreactor.The results revealed that the addition of light rare earth metal on the HZSM-5 catalyst greatly enhanced the selectivity to olefins,especially to propylene,thus increasing the total yield of olefins in the catalytic cracking of butane.Among the RE-modified HZSM-5 samples,Ce/HZSM-5 gave the highest yield of total olefins,and Nd/HZSM-5 gave the highest yield of propene at a reaction temperature of 600℃.The presence of rare earth metal on the HZSM-5 sample,not only modified the acidic properties of HZSM-5 including the amount of acid sites and acid type,that is,the ratio of L/B(Lewis acid/Brnsted acid),but also altered the basic properties of it,which in turn promoted the catalytic performance of HZSM-5 for the catalytic cracking of butane.  相似文献   

13.
Thelanthanidecomplexesoforganiclig andsasfluorescentmaterialshavereceivedex tensiveattention .Theuseoffluorescentorgano lanthanidecomplexesrequirehighfluo rescenceintensityandlowcostcomplexes .Inrecentyears ,thefluorescenceenhancementofTb(Ⅲ )orEu(Ⅲ )complexe…  相似文献   

14.
王文  林美娟  章文贡 《稀有金属》2004,28(5):825-828
选择了几种功能不同的Pr,Eu,Gd,Th,Dy,Ho和Er的三异丙氧基化合物与苯乙烯本体聚合获得稀土掺杂聚苯乙烯,采用ESEM,DMTA,冲击强度测试研究了不同稀土对聚合物力学性能的影响,结果表明不同稀土引入聚苯乙烯中均能使韧性得以提高,它们的力学性能与稀土的原子序数、原子半径大小有关。  相似文献   

15.
Teapolysacchridecomplex ,oneofthebasicmacromoleculesintea ,hasmanyphar maceuticaleffectsandiseasytodissolveinteainfusion[1] .Zhongetal .[2 ] discoveredthatthereisaREbindingpolysaccharideinleavesofteaplant (CamelliaSinensisLO .Kuntze) .Inthispaper ,thestudyontheco…  相似文献   

16.
Different rare earth(RE=La, Ce, Pr, Nd, Sm, Y) and Cu modified nickel catalysts for hydrogen production from methane decomposition were synthesized by a sol-gel process and method. The catalysts were characterized or analyzed through Brumauer-Emmett-Teller(BET), X-ray diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM) techniques. And the hydrogen production performance was also evaluated by a fixed-bed and micro-reaction technique with CH4→C+H2 as a probe reaction. The results showed that rare earth modification had played a great role for nickel catalysts, for example, smaller nickel particles, good thermal stability, high activity, etc. La was the best additive among rare earth modification. The SEM of rare earth modified catalysts showed ordered flower-like structure and rare earth modification made the nickel particles move to the surface of catalysts. In addition, the SEM of nano-carbons was also changed by rare earth modification with long, narrow nano-carbon fibers or tubes obtained. Solid carbon formation was prevented by rare earth modification.  相似文献   

17.
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   

18.
王衍鹏  龚琦  李斌 《冶金分析》2011,31(2):20-27
考察了La、Ce和Yb等基体元素对稀土杂质元素测定的光谱干扰。在杂质元素谱线窗口内,La、Ce和Yb所产生的干扰线总数量比文献报导的少,且当基体元素浓度增大时,在杂质元素谱线窗口内出现一些未曾报道过的谱线。经多元光谱拟合(MSF)法校正,基体元素的光谱干扰得到有效消除,杂质元素的检出限明显降低,但仍达不到没有La、Ce和Yb时的水平。当测定质量浓度为0100 μg/mL杂质元素时允许质量浓度为1 000~2 000 μg/mL基体元素存在,当被测的杂质浓度进一步降低时允许基体元素的最高浓度也随之降低。建立MSF模型时,应使建模溶液中杂质元素浓度是这些元素检出限的100倍,基体元素浓度接近实际样品中基体的存在量,MSF建模数据与样品测定数据还须在同一实验条件下完成。  相似文献   

19.
Effects of rare earth (RE) additions on microstructure and mechanical properties of the wrought AZ31 magnesium alloy were investigated. The results show that, by adding 0.3%, 0.6% and 1.0% RE elements, the as-cast microstructure can be refined, and the as-cast alloys‘ elongation and tensile strength can be improved. After extrusion, the alloy with 0.3 % and 0.6% RE additions obtain a finer microstructure and the best mechanical properties, but the alloy with 1.0% RE addition has the coarse A1-RE compound particles in grain boundaries which decreased elongation and tensile properties. Usually, Rare earth (RE) elements were used to improve the creep properties of aluminium-containing magnesium pressure die cast alloys at elevated temperatures. In this paper, it is also found that the high temperature strength of extruded materials can be increased by RE elements additions.  相似文献   

20.
Ca2RE8(SiO4)6O2 (RE=Y, Gd, La) is a kind of ternary rare-earth-metal silicate with the oxyapatite structure, which was used as host materials for the luminescence of various rare earth and mercury-like ions. Ca2Gd8(SiO4)6O2:Er3 phosphors were prepared through the sol-gel process. X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence spectra were used to characterize the resulting phosphors. The results of XRD indicate that the phosphors crystallized completely at 1000 ℃. SEM study reveals that the average grain size is 400~1000 nm. In Ca2Gd8(SiO4)6O2:Er3 phosphors, the Er3 shows its characteristic green emission at 528 nm (2H11/2-4I15/2) and 548 nm(4S3/2-4I15/2) upon excitation into 382 nm, with an optimum doping concentration of 5% (mole fraction) of Gd3 in the host lattices.  相似文献   

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