溶胶-凝胶法合成ZnGa_2O_4∶Eu及其光学性能

以柠檬酸为络合剂,通过溶胶-凝胶法合成了铕为激活剂的ZnGa2O4∶Eu荧光粉。讨论了煅烧温度、保温时间和激活剂的浓度对该荧光粉发光性能的影响。利用X-射线衍射、荧光分光光度计等手段对ZnGa2O4∶Eu荧光粉的相组成和发光性能进行了检测。实验结果表明,以Zn(CH3COO)2.2H2O和Ga2O3为原料,通过溶胶-凝胶法,在950～1000℃煅烧4h可合成出ZnGa2O4荧光体。当n(Zn)∶n(Ga)为1∶4时,所得成品的最强发射峰位于613nm处,为Eu3 特征5D0→7F2跃迁,其对应于红色光谱。Eu3 离子在ZnGa2O4晶体中占据的位置为非反演对称中心。     

黄色荧光粉Sr3SiO5:Eu2+相转变机理简

高温固相法合成Sr3 SiO5：Eu2＋过程中,杂质相Sr2 SiO4：Eu2＋的存在会不同程度影响Sr3 SiO5：Eu2＋的光致发光性能及余辉性能。本文通过压片烧结和燃烧法两种方法制备Sr3 SiO5：Eu2＋,结合热重-差热分析和X射线衍射分析,研究了Sr3 SiO5：Eu2＋在合成过程中的相变化规律以及动力学过程。研究表明：原料与坩埚的接触处形成的界面以及原料在升温过程经过Sr2 SiO4：Eu2＋的合成温度区间是导致杂质相产生的主要原因。在升温过程中,当温度经过1200℃左右的温度区间时,由于原料与坩埚接触处可以看作是两组不同物质的分界面,Sr2 SiO4：Eu2＋的合成首先在该分界面处合成,而更多的原料需要扩散通过生成物层才能进一步反应;但随着温度的升高,原料随后进入Sr3 SiO5：Eu2＋的合成过程,从而导致了Sr2 SiO4：Eu2＋杂质相的生成。     

稀土铕配合物在荧光防伪油墨中的应用

以铕离子(Eu3+)为中心,以苯甲酰丙酮(BZA)、苯甲酸(BA)、邻菲咯啉(Phen)为配体,在无水乙醇中合成了三元配合物Eu(BZA)3Phen与Eu(BA)3Phen.配合物的紫外可见光谱与红外光谱分析表明配体与铕离子发生配位,合成了三元配合物.研究配合物的荧光性能,发现Eu(BZA)3Phen的相对荧光强度大于Eu(BA)3Phen.将荧光强度高的Eu(BZA)3Phen作为荧光剂制备了荧光防伪油墨.荧光防伪油墨的荧光性能显示,油墨与配合物Eu(BZA)3Phen发射波长相同,均为612,nm.荧光防伪油墨在可见光下无色,在紫外灯下呈现红色,可用于防伪包装印刷.     

Synthesis and Luminescent Properties of Eu~(3 )-Doped Na_(24)P_2W_(22)O_(83)

TheheteropolytungstateisoneofthemostchallengingprojectsininorganicchemistryduetoitsaPPlicationonsolidstatechemistly,catalysis,biochemistry,separationandanalysis,etcl-4.Inthispaper,thepreparationmethodandluminescencepropertiesofEu' -dopedNanPZW22O83wereinvestigated.Therelationshipbetweentheluminescentpropertiesandcrystalstructurewasdiscussed.ExperimentalThesampleswerepreparedbysolidstatereactionfrommixturesofN'PZO7'10HZO,WOe,NaZWO"ZHzOandEuZO3.Thestoichiometricalmixtureswerecalcined…     

人尿中IgG的时间分辨荧光免疫分析法──以铕标记链亲和素作为标记物

利用铕标记链亲和素作为标记物，建立了固相抗体竞争性的人尿中ＩｇＧ的时间分辨荧光免疫分析法，标准曲线范围０．６２５～４０．０ｍｇ／Ｌ．检测范围宽，可以用于检测人尿中的ＩｇＧ含量，不用对样品进行稀释，能满足临床检测需要．     

Detection of Hydrogen Peroxide in River Water via a Microplate Luminescence Assay with Time-Resolved (“Gated”) Detection

Hydrogen peroxide (HP) in river water was determined using the highly luminescent Eu³⁺-tetracycline hydrogen peroxide (EuTc-HP) complex. A 15-fold increase in luminescence intensity of Eu³⁺-tetracycline (EuTc) is observed at 616nm after formation of EuTc-HP. In order to eliminate interferences by other fluorescent substances that exist in river water, a time-resolved scheme is employed: EuTc-HP has a main decay time of 61µs, while background fluorescence decays within a few ns. Thus, by performing measurements after a delay time of typically 30µs, the signal becomes highly specific for EuTc-HP. Under optimized conditions (pH 7 in MOPS buffer), the calibration curve for the determination of HP was linear over the range of 2 to 160µmolL^–1. The limit of detection is 1.1µmolL^–1 HP. An average recovery of 99.5% was obtained for measurements of river water samples spiked with HP. The relative standard deviation of less than 2% indicates the high accuracy and precision of the method.     

Chemiluminescence in the reduction of XeO3 by europium(II)

Chemiluminescence has been observed in the reduction of perchloric aqueous solutions of XeO₃ with Eu²⁺ ions, Fast (several seconds) consumption of Eu^II occurs when the ratio of the initial concentrations of the reactants (Eu²⁺]₀ : [XeO₃]₀ < 6; however, the chemiluminescence remains sufficiently bright and prolonged (up to –10 min after nearly complete oxidation of Eu^II to Eu^III). The assumption was made that intermediates in the reduction of XeO₃ participate in the chemiluminescent stages of the process.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2909–2911, December, 1996.     

铕与PMBP配合物晶体结构和电子结构的研究

本文测定了 Eu(PMBP) 3 · 2 H2 O的晶体结构 ,该晶体属于单斜晶系 ,空间群 P2 1 / n,a=14 .982 1(1) ,b=14 .75 18(8) ,c=2 4 .4 979(9) ,β=10 1.5 2°,Z=4 ,V=5 30 2 .2 3 ,M=10 0 1.9,Dc=1.2 5 4 g/ cm3 ,μ=12 .315 cm-1 。 Eu与 PMBP及水中的 8个氧原子形成四方反棱柱配位多面体 ,根据选用的模型计算其电子结构 ,分子能量 ,净电荷分布和 Mulliken键级 ,进而讨论了配合物的结构和化学键的特征。实　验　部　分按 Eu(Cl O4) 3 · 2 H2 O中 Eu( )与 HPMBP摩尔比 1∶ 3反应 ,得到配合物固体。置于水与无水乙醇中 ,数周后…     

Differential pulse polarographic determination of europium in the presence of humic substances

Humic substances (HS) and other substance of similar nature (“building blocks” of HS, such as salicylates or phthalates) influence strongly a polarographic behaviour of europium at a mercury drop electrode. An addition of these substances into the supporting electrolyte causes an enhancement of the differential pulse polarographic (DPP) peak of Eu and an anodic shift of the maximum peak potential. It was deduced from the dependence of the peak height on the pulse time and from other experimental dependencies that an adsorption of the Eu-HS (salicylate, phthalate) complexes on the working electrode is the main mechanism responsible for the peak enhancement. Because no peak distortion or splitting were observed, the DPP determination of Eu can be realised readily in the presence of HS, e.g. in environmental samples. The sensitivity of the measurements increased in the presence of HS, whereas the limit of detection (LOD) decreased (LODs were 255 and 140 nmol/l in the absence and in the presence of HS, respectively). However, the calibration dependencies were non-linear in the presence of HS. It was found that the non-linear calibration dependencies may be approximated by the Langmuir-type equation. Special procedures, such as a method of (at least) two standard additions and numerical iterative calculations, are necessary for an evaluation of measurements.