稀土元素对微生物的生物学作用研究进展

本文论述了稀土元素对微生物的生长、代谢产物的积累和关键酶的生物学效应研究进展。     

STUDY OF ADSORPTION OF RARE EARTH ELEMENTSBY FERRIC OXIDE GEL

Thereexistthreeformsofrareearthelements(REE)intheknownnaturalores:mineralcrystallineform,isomorphousreplacementformandexchangeableionicadsorptionform.Resently,however,anewkindofsecondaryoreofrareearthelementswidelydistributedintheoxidationzoneofthelargerbast--naesitedepositshasbeendiscoveredintheSouthwestofChinaandVietnam.Theneworelookslikeblackearthyefflorescence,andmainlyconsistsofamorphousFe--MnoxideandSt--Aloxide.Theformeraccountsfor74.14%(volumerate)andthelatter25.86%(volumerate).Ther…     

稀土元素对堆焊层组织与性能的影响

概述了稀土元素在焊接材料中的应用，并详细地讨论了稀土元素对堆焊层组织和性能的影响。稀土元素不但可以消除堆焊层中的有害杂质，净化堆焊层，细化堆焊层组织，改善堆焊焊缝韧性，减少堆焊层中的夹渣，而且可以改善焊接工艺性能，提高堆焊层的耐磨性和硬度以及其它性能，展望了稀土元素在堆焊焊条中的应用前景。     

Geochemistry of rare earth elements in groundwater from deep seated limestone aquifer in Renlou Coal Mine, Anhui Province, China

Rare earth element (REE) concentrations were measured by ICP-MS for groundwater collected from deep seated Taiyuan Fm limestone aquifer (from-400 to-530 m) in Renlou Coal Mine,northern Anhui Province,China.It can be concluded that the groundwater is warm (34.0-37.2 °C) Cl-Ca,Na type water with circum-neutral pH (7.35-8.28) and high total dissolved solids (TDS,1 746-2 849 mg/L).The groundwater exhibits heavy REEs enrichment relative to light REEs compared with Post Archean Average Shale (PAAS),as well as the...     

ICP—AES直接测定地质样品中微量稀土元素

研究了基体元素对15个稀土元素的干扰,优化了ICP的工作参数,采用Na2O2碱熔处理样品,加入三乙醇胺,EGTA络合干扰离子,计算机离峰背景校正消除基体元素干扰,ICP－AES法直接测定地质样品中15个微量稀土元素,方法的检出限为0．01－1．1μg.g^-1,精密度（RSD,n=8)为1．3％－5．6％,方法操作简便,快速,经对国家一级标准物质分析,结果与推荐值一致。     

煤矿酸性水中稀土元素的分布模式及影响因素

通过对山西省两个不同矿区的酸性矿井水、沉积物、围岩以及煤样中的稀土元素(REE)含量的测定,并结合吸附解吸实验和地球化学模拟软件(PHREEQC),研究了酸性矿井水中REE的分布模式及其主要的影响因素.研究表明:1)酸性矿井水中REE的含量很高,且呈典型的中稀土元素(MREE)富集模式分布;2)酸性水中的REE主要来源于围岩和黄铁矿的酸淋滤,而煤中REE的丰度相对较低;3)pH是影响酸性矿井水中REE含量及其分布模式最重要的因素;4)随着酸性矿井水pH的升高,Mn的氢氧化物沉淀对REE的含量影响最大,并且含铁沉积物优先吸附重稀土元素和中稀土元素;5)酸性矿井水中的REEs主要络合种类为REE(SO4)+(52.8%～79.4%),其次为REE(SO4)2-和REE3+.     

稀土贵金属材料研究进展

本文总结了贵金属材料应用中存在的关键问题,综述了近年来国内外稀土贵金属材料研究领域中的主要进展。从净化、细化和微合金化的角度,分析了稀土在贵金属中的作用机理。根据稀土在不同贵金属中的作用特性,讨论了在我国开展新型稀土贵金属材料研究,提高稀土附加值,满足工业增长需求的可行性和紧迫性。     

钢中微量稀土的测定

过去测定钢中稀土含量下限为0．005％(质量分数)．采用萃淋树脂分离，分光光度法测定碳钢及低合金钢中微量稀土，测定含量小于0．005％(质量分数)．本方法用pH=0．5的盐酸淋洗，使稀土与Fe(Ⅲ)离子分离，寻找对乙酰偶氮氯膦与稀土(Ⅲ)形成配合物的条件．     

固—液萃取分离测定球墨铸铁中的稀土元素

以切片石蜡为溶剂;铜试剂为萃取剂,用固－萃取技术分离测定球墨铸铁中微量稀土元素。     

Effects of rare earth elements on the microstructure and properties of magnesium alloy AZ91D

The effects of rare earth elements on the microstructure and properties of Magnesium alloy AZ91D alloy were studied.The different proportion of rare earth elements was added to the AZ91D and the tensile tests were carried out at different temperatures.The experimental results show that at room temperature or at 120℃ the AZ91D‘s decrease with the increasing amount of the rare earth elements.however,the ductility is improved.The influence of 0.14%Sb(mass fraction)on the AZ91D‘s strength is like that of rare earth elements(0.2%-0.4%)(mass fraction).Microstructure graphs demonstrate that appropriate amount of rare earth elements (0.1%-0.2%) can fine AZ91D‘s grain and improve its ductility.     

天冬氨酸与稀土元素酸式配合物的研究

本文从实验及数据处理等方面证实1-天冬氨酸与稀土元素形成酸式配合物,并用电位法测得15种稀土元素与1-天冬氨酸酸式配合物在离子强度0.1、温度30℃时的稳定常数及平衡常数。测定了酸式天冬氨酸与钇在四种有机溶剂中的稳定常数,可见其均比在水溶液中有明显提高。     

Effect of rare earth elements on the microstructure and property for magnesium alloy AM60B

The effects of rare earth elements on the microstructure and properties of magnesium alloy AM60B alloy were studied.Different proportions of rare earth elements were added to AM60B and the tensile tests were carried out under different temperatures.The experimental results show that at room temperature the tensile strength of AM60B can be improved with the addition of rare earth elements.The ductility of which at room or elevated temperature(120℃） can also be improved ,and the ductility is to some extent in proportion with the amount of rare earth elements.The ductility at 120℃ is better than that at room temperture,The microstructure graphs demonstrate that appropriate amount of rare earth elements (0.1%-0.2%,mass fraction)can fine AM60B‘s grain and improve its ductility.     

Rare earth elements in CO2-fluid inclusions in mantle lherzolite

Trace elements including REE (Rare Earth Elements) in fluid inclusions in lherzolite, olivine, orthopyroxene, and clinopy-roxene have been determined by heating-decrepitation and ICP-MS (Element Type Inductively Coupled Plasma-Mass Spectrometry)method. Normalized CO2 fluid/chondrite data show that mantle fluids are rich in REEs, especially LREEs (Light Rare Earth Ele-ments), several times or dozen times higher than mantle rocks and mantle mininerals. There are close relationships among the REEdata of olivine, orthopyroxene, clinopyroxene and lherzolite. Compared to the data of chemical dissolution method, it is believed thatREE data obtained from heating-decrepitation and ICP-MS technique are contributed by CO2 fluid inclusions. About 60% (massfraction) of tiny inclusions are observed not to be decrepitated above 1000℃, so REE data obtained are only contributed by decrepi-tated inclusions. Mantle fluids rich in LREE play an important role in mantle metasomatism, partial melting and mineralization.     

Rare earth elements in CO_2-fluid inclusions in mantle Iherzolite

Trace elements including REE (Rare Earth Elements) in fluid inclusions in Iherzolite, olivine, orthopyroxene, and clinopyroxene have been determined by heating-decrepitation and ICP-MS (Element Type Inductively Coupled Plasma-Mass Spectrometry) method. Normalized CO2 fluid/chondrite data show that mantle fluids are rich in REEs, especially LREEs (Light Rare Earth Elements), several times or dozen times higher than mantle rocks and mantle minerals. There are close relationships among the REE data of olivine, orthopyroxene, clinopyroxene and 1herzolite. Compared to the data of chemical dissolution method, it is believed that REE data obtained from heating-decrepitation and ICP-MS technique are contributed by CO2 fluid inclusions. About 60% (mass fraction) of tiny inclusions are observed not to be decrepitated above 1000℃, so REE data obtained are only contributed by decrepitated inclusions. Mantle fluids rich in LREE play an important role in mantle metasomatism, partial melting and mineralization.     

稀土元素钇和钬掺杂对铁酸铋磁性能的影响

铁酸铋是一种典型的单相多铁性材料,宏观上磁性很弱,为了改善其磁性能,用稀土元素钇和钬对其A位元素进行替代.采用水热法制备掺钇和掺钬的铁酸铋系列粉末样品,然后将这些粉末样品采用常规的固相反应法制备出陶瓷样品.以浓度12.5mol/L的氢氧化钾为矿化剂,反应温度为240℃,反应时间为24h时,得到了掺钇和掺钬的铁酸铋样品.X射线衍射结果显示,当掺杂量小于或等于0.05时,样品结构为纯相的三方铁酸铋结构,当掺杂量大于0.05时,出现了越来越多的杂相;通过振动样品磁强计测试样品的磁性能,发现所有样品都观察到了饱和的磁滞回线,说明掺钇和钬都能明显改善铁酸铋的磁性能;通过对比掺钇和掺钬所有样品的饱和磁化强度值,发现掺杂量相同时,掺钇样品的饱和磁化强度值都要比掺钬的大,而相同大小的钇离子没有磁性,钬离子有磁性,说明稀土离子本身的磁矩可能不是铁酸铋磁性增强的主要因素.     

稀土在镁合金中的应用

镁合金材料具有高的比强度、优异的阻尼减震、密度小等特性,是非常理想的轻质结构材料;但是,镁合金熔炼时极易燃烧,耐热性、耐腐蚀性差等问题严重制约了镁合金的开发和广泛应用．浅述了稀土在镁合金材料开发中的应用,通过分析金相图,研究了稀土-镁合金体系和多元Re—Mg合金体系的特点,讨论了稀土镁合金耐热性能的影响机理和稀土耐热镁合金的时效析出物。并对稀土阻燃镁合金研究现状进行了概括和总结．     

应用软测量技术实现稀土萃取分离过程的优化控制

为解决稀土萃取分离生产过程中元素组分含量难以在线检测的问题,提出了应用软测量技术实现稀土萃取分离过程监测点元素组分含量的在线估计和对萃取分离生产过程两端出口产品纯度进行优化控制的方法。将该方法应用于某公司HAB萃取分离提钇生产过程,实现了稀土萃取分离生产过程的优化控制和优化运行,保证了第1段产品氧化钆钇纯度≥99.5%,金属钇回收率提高了2%。     

可调极距式稀土电解槽电场的计算机模拟

建立了可调极距式稀土电解槽电场计算的三维数学模型，通过有限差分方法对电解槽的电场进行了计算机模拟，并对结果进行分析与讨论，为电解槽的设计及改造提供了理论依据．     

重轨钢中稀土与铌的交互作用规律的研究

Nb和RE元素对钢的性能均有重要影响.通过不同组分下对热轧后重轨钢中Nb的析出形态的透射电镜和扫描电镜的试样分析,讨论了稀土残留在重轨中对碳化铌的形状、大小及分布的影响.分析结果表明,稀土残留在钢中,使碳化铌尺寸减小,仍沿轧制方向分布,形状由矩形变为不规则形状.