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本文对高纯铽和氧化铽中稀土杂质的测定方法进行了研究。由于ICP—MS方法灵敏度高,它常用于包括稀土在内的超微量元素的分析。当以ICP—MS法测定高纯铽中的稀土元素时,由于基体干扰,被测元素的离子强度降低20~80%,而巳由于~(159)Tb~(16)O的影响,~(175)Lu不能测定。 本文作者曾对铽中稀土杂质分析的HPLC/ICP—AES方法做过报道,在此方法中,铽和稀土杂质用HPLC柱分离,随后以ICP-AEE法进行测定。本文对ICP—MS法与HPLC的联用技术进行了论述。稀土杂质的检出限为0.nppm。 相似文献
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铈含量对NiAl-28Cr-5.5Mo-0.5Hf共晶合金氧化性能的影响 总被引:2,自引:2,他引:0
研究了不同稀土元素Ce含量对NiAl-28Cr-5.5Mo-0.5Hf合金在1100℃空气中的氧化行为的影响.结果表明:适量稀土元素Ce的添加显著地提高了基体合金的抗高温氧化性能,而过量添加稀土元素则会恶化基体合金的高温氧化性能.X射线结构与SEM分析表明:基体合金表而氧化膜主要由α-Al2O3构成,并含有少量的Cr2O3和HfO2,而当稀土元素添加量达到0.5%(质量分数),氧化膜中出现富稀土Ce的氧化物.采用EDAX分析研究了合金表面氧化产物的微观组织及成分,并从合金相组成探讨了稀土元素Ce提高基体NiAl-28Cr-5.5Mo-0.5Hf合金的抗高温氧化性能的机制. 相似文献
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稀土元素在纯铜中的分布及对铸态组织的影响 总被引:9,自引:0,他引:9
研究了不同稀土加入量在纯铜中的分布情况 ,分析了稀土元素在纯铜中的存在状态 ,观察了稀土元素对纯铜铸态组织的影响。研究发现 ,在晶界上 ,稀土的存在形式为以稀土化合物为基形成固溶体 ;稀土元素可以细化铸态组织的晶粒。 相似文献
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白石溪锰矿床位于江南造山带西南段,上扬子陆块的南东缘.矿床主要赋存在南华系下统大塘坡组第一段的炭质砂页岩中.含锰岩系Ca O+Mg O值表明在成因上与海相碎屑沉积有关;n(Si O2)/n(Al2O3)值表明锰矿床的形成与热水活动和生物活动有关.微量元素Sr/Ba值表明锰矿床沉积环境为滞留浅海环境,n(V)/n(V+Ni)比值进一步表明其形成环境为还原环境,Co/Zn-(Cu+Co+Ni)相关性图显示其形成过程受到了热液活动的影响.区内含锰岩系形成过程中轻、重稀土元素分异明显,呈现富集轻稀土元素的特征.北美页岩标准化稀土元素配分图上曲线呈近水平分布,具有弱的正Eu异常和弱的正Ce异常,反映还原的沉积环境.δCe值和La/Yb-ΣREE图解进一步确认了其沉积环境为受热水影响的大陆边缘区.因此白石溪锰矿床系在大陆边缘还原环境沉积并受热水活动影响形成的矿床. 相似文献
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通过微弧氧化技术一步合成了CaTi4(PO4)6生物陶瓷膜,并研究了电解液浓度对微弧氧化膜生长过程的影响.结果表明,在同一电解液浓度下,微弧氧化膜层质量的增加与时间呈线性关系.随着电解液浓度的增加,膜层的增重速度加快,形成时间缩短,击穿电压降低,且陶瓷膜表面Ca元素含量增加,P元素含量基本不变;但当电解液浓度增大到一定程度后再继续增加时,陶瓷膜表面的Ca、P元素含量逐渐降低. 相似文献
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《中国稀土学报(英文版)》2019,37(5):520-527
In order to achieve deeper understanding of rare earth elements(REEs) behaviors during phosphate rock processing with H_3PO_4. The solubility of REEs in Ca(H_2PO_4)_2-H_3PO_4 solutions with various concentrations of Ca(H_2PO_4)_2 at different temperatures were tested. The results demonstrate that REEs solubility decreases sharply with the increasing concentration of Ca(H_2PO_4)_2. Equations between [REE~(3+)] and [H~+],[H~+] and [Ca~(2+)] in Ca(H_2PO_4)_2-H_3PO_4 solutions were built based on the precipitation-dissolution equilibrium of rare earth phosphates and the ionization equilibrium of H_3PO_4. According to the equations, the decreasing mechanism of REEs solubility caused by elevated concentration of Ca(H_2PO_4)_2 was determined. The mechanism can be illustrated as that the elevated concentration of [H_2 PO_4~-] decreases the concentration of hydrogen ion by retarding the ionization process of H_3PO_4 and directly promotes the precipitation of rare earth phosphates. Furthermore, it can be easy deduced that similar effect would be caused by the other cation impurities(Fe~(3+), Al~(3+), etc.) on REEs solubility based on the mechanism. In addition, superimposed reduction effect on REEs solubility caused by the elevated concentration of Ca(H_2PO_4)_2 and the elevated temperature is found. This superimposed effect leads to a super low solubility of REEs in Ca(H_2PO_4)_2-H_3PO_4 solution. On the basis of the experimental study, outlooks and suggestions for further development of REEs recovery method are given. 相似文献
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通过对包头市路尘中14种稀土元素(rare earth elements,REEs)含量的测定分析以及小型人工降雨冲刷模拟,对稀土元素在路尘中的赋存特征及在其降雨径流中的流失特征进行了分析和探讨。结果表明,(1)路尘中的稀土元素随降雨过程发生迁移并在径流产生"流失浓缩"效应,浓缩强度随雨强增加而增强;相同雨强下,水泥下垫面的聚集效应高于沥青混凝土下垫面。(2)径流中水相稀土元素含量随降雨时间下降。(3)径流流失过程中,固相颗粒态中稀土元素的配分模式与路尘样品基本一致,呈现轻稀土富集的特征,轻重稀土之间的分馏程度较高;而水相中稀土元素的配分模式与原始路尘样品中有一定差异,轻重稀土之间的分馏程度降低。 相似文献
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Content and distribution patterns of rare earth dements (REEs) in the suspended particulate material (SPM) of Daliao River system were investigated and compared with those in the fiver and sea sediments, loess, and soils of China. Twenty-seven samples of SPM were taken in Daliao River system and digested with various acids followed by ICP-MS analysis for REEs and ICP-OES analysis for Al, Fe, Mn, Ti, Mg, Ca, Na, and K, to measure the total concentrations of these elements. Results indicated that the spatial change in the content of REEs was great, with the coefficient of variance (CV) from 84% to 105%, while the contents of REEs were significantly correlated with each other. Chondrite-normalized patterns of REEs were characterized by higher enrichment of light REEs than heavy REEs, and a depletion of Eu in the SPM was generally found. The positive anomaly of Eu in the SPM of Xi River was due to anthropogenic source in Shenyang City. Furthermore, chondfite- and upper continent crust-normalized patterns of REEs in the SPM of Daliao River system, sediments of Yangtze River and Yellow River, sediments of Yellow Sea, East Sea, South Sea of China, and loess and soil of China, were very similar to one another. These demonstrated that the weathering and sedimentary processes resulted in constant REE distribution not only in the typical sedimentary rocks, but also in the modem riverine particle, sea sediments, loess, and soils. 相似文献
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Inductivelycoupledplasmamassspectrometry(ICP MS)isapowerfultechniquefortracemulti ele mentandisotopicanalysis[1,2 ] .Thistechniquecom binesthecharacteristicsoftheICPforatomizingandionizinginjectedmaterialwiththesensitivityofMS .Ithasbeensatisfactorilyappliedtotheanalysisofvari oussamplesinthefieldsofgeological,environmental ,industrial ,food ,medicalandnuclearsciences .How ever,highlevelsofmatrixelementcancausematrixeffectssuchasCa ,Mg ,K ,NaandCl .Severallitera tures[3~ 5] reportedthee… 相似文献
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Increasinguseofrareearthelements(REEs)inindustryandagricultureinChinahasresultedinresidueandaccumulationinriverandintertidalzone ,henceitwouldcausewaterpollution ,whatarethegeochemistrycharacteristicsofREEsinvariouswaterbod ies ,itisanurgentproblemtobeso… 相似文献
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采用湿法磷酸工艺的返回酸浸出磷矿中伴生稀土与磷,稀土与磷以磷酸二氢盐的形式进入溶液。考察温度、浓度、时间、液固比等因素对稀土与磷浸出的影响。结果表明,适宜的浸出条件为:返回酸浓度25%、温度65℃、液固比10∶1、浸出时间8h,在此条件下,稀土浸出率可达90.4%,磷浸出率达98.7%。 相似文献
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Flos Sophorae and Fructus Sophorae are two kinds of traditional Chinese medicines. In this work, the two kinds of traditional Chi-nese medicines collected from eleven areas of Dezhou, were analyzed by inductively couple plasma-mass spectrometry (ICP-MS) to compare the content and distribution of 14 kinds of rare earth elements (REEs). The method was verified by analyzing GBW07605 certified reference material. The results showed that ICP-MS is an accurate, sensitive and reliable technique for determining REEs in traditional Chinese medi-cine. There were big differences in contents for REEs in Flos Sophorae and Fructus Sophorae from different areas. The contents of total REEs in Flos Sophorae samples from different areas ranged from 1.0785 to 2.2659 g/g, while those in Fructus Sophorae from 0.6826 to 1.0527 g/g. The contents of total REEs in Flos Sophorae samples from different areas were obviously higher than those in Fructus Sophorae of the same area and there was big difference between various Flos Sophorae samples. Interestingly, the higher the content of total REEs in Flos Sophorae samples, the lower the content of total REEs in Fructus Sophorae samples of the same area. The plots of normalized element con-centration versus atomic number showed some characteristic distribution trends. The distribution trend of light REEs (La-Gd) was relatively flat except a positive Eu anomaly, however, that was steep and discrepant for heavy REEs (Tb-Lu). The results could provide a valuable ref-erence for understanding the relationship between the curative mechanism, pharmacology characteristics and their geological condition for the two traditional Chinese medicines investigated. 相似文献
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The subcellular locations of Ca(2+)-ATPases in the membranes of cauliflower (Brassica oleracea L.) inflorescences were investigated. After continuous sucrose gradient centrifugation a 111-kD calmodulin (CaM)-stimulated and caM-binding Ca(2+)-ATPase (BCA1; P. Askerlund [1996] Plant Physiol 110: 913-922; S. Malmstr?m, P. Askerlund, M.G. Plamgren [1997] FEBS Lett 400: 324-328) comigrated with vacuolar membrane markers, whereas a 116-kD caM-binding Ca(2+)-ATPase co-migrated with a marker for the plasma membrane. The 116 kD Ca(2+)-ATPase was enriched in plasma membranes obtained by aqueous two-phase partitioning, which is in agreement with a plasma membrane location of this Ca(2+)-ATPase. Countercurrent distribution of a low-density intracellular membrane fraction in an aqueous two-phase system resulted in the separation of the endoplasmic reticulum and vacuolar membranes. The 111-kD Ca(2+)-ATPase co-migrated with a vacuolar membrane marker after countercurrent distribution but not with markers for the endoplasmic reticulum. A vacuolar membrane location of the 111-kD Ca(2+)-AtPase was further supported by experiments with isolated vacuoles from cauliflower: (a) Immunoblotting with an antibody against the 111-kD Ca(2+)-ATPase showed that it was associated with the vacuoles, and (b) ATP-dependent Ca2+ uptake by the intact vacuoles was found to be CaM stimulated and partly protonophore insensitive. 相似文献
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Rareearthelements (REEs)werewidelyappliedtotracingthesourcesofmaterialsandtostudyingtheirevolutionprocessesinmanyfieldsofearthscienceinconsiderationoftheirsimilarityandsystematicdiffer enceinchemicalproperties .Furthermore ,lanthanidesarebothimportantprod… 相似文献