97 resultados para TERBIUM


Relevância:

20.00% 20.00%

Publicador:

Resumo:

A process for in situ synthesis of terbium complex with salicylic acid by a two-step sol-gel method in silica matrix has been proposed. The luminescence properties of the silica gels codoped with terbium and salicylic acid have also been discussed with respect to that of the gel doped with terbium and that of pure terbium complex with salicylic acid.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Electroluminescent devices with PVK film doped with monohexadecyl phthalate terbium and PBD were fabricated. The device structure of glass substrate/ITO/PPV/PVK:Tb(MHP)(3):PBD/Alq(3)/Al was employed. The emissive layer was formed by a spin-casting technique. The EL cells exhibited characteristic emission of terbium ions with a maximum luminance of 74 cd/m(2) at 18 V. (C) 1998 Elsevier Science S.A. All rights reserved.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Terbium(III) stearoylanthranilate has been prepared as a high property Z-type Langmuir-Blodgett (LB) film on various substrates by a vertical transfer process. The UV-visible absorption spectra and the low angle X-ray diffraction peaks have been collected in order to investigate the molecular arrangement and aggregation in the LB films. The average molecular orientation in multilayer stacking was determined by Attenuated Total Reflection Spectroscopy. The influence of the chemical environment of terbium within the LB films on the luminescence properties has been discussed. (C) 1997 Elsevier Science S.A.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Ternary complexes of terbium with ortho (and pam) aminobenzoic acid and 1,10-phenanthroline were introduced into silica gel by the sol-gel method. The luminescence behavior of the solid-state samples was studied during the sol-gel aging process by means of emission. excitation spectra, lifetimes and quantum efficiencies.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The differences between the solvent extraction of Tb(III) and Tb(IV) periodate complexes with quaternary amine were studied carefully for the first time. The effects of extractant concentration, phase ratio, the pH value of stock solution, salting-out agent, extractant form, diluent, and extraction time were comprehensively investigated. Under optimal conditions the separation factor between Tb(IV) and Tb(III) periodate complexes is over 5.5.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

There are no discrete molecules of the title compound, catena-poly[{triaquaterbium-tris-beta-(p-nitro-benzoato)-O,O':O;O:O,O';O:O'-aqua(p-nitroben-zoato-O,O')terbium}-bis-mu-(p-nitrobenzoato-O:O') hydrate], [Tb2(C7H4NO4)6(H2O)5], in the crystal structure.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Homogeneous DNA hybridization assay based on the luminescence resonance energy transfer (LRET) from a new luminescence terbium chelate, N,N,N-1,N-1-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-phenylpyridine]tetrakis(acetic acid) (BPTA)-Tb3+ (lambda(ex) = 325 nm and lambda(em) = 545 nm) to an organic dye, Cy3 (A,. = 548 nm and A,. = 565 nm), has been developed. In the system, two DNA probes whose sequences are complementary to the two different consecutive sequences of a target DNA are used; one of the probes is labeled with the Tb3+ chelate at the T-end, and the other is with Cy3 at the 5'-end. Labeling of the Tb3+ chelate is accomplished via the linkage of a biotin-labeled DNA probe with the Tb3+ chelate-labeled streptavidin. Strong sensitized emission of Cy3 was observed upon excitation of the Tb3+ chelate at 325 run, when the two probe DNAs were hybridized with the target DNA. The sensitivity of the assay was very high compared with those of the previous homogeneous-format assays using the conventional organic dyes; the detection limit of the present assay is about 30 pM of the target DNA strand.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A new nonadentate ligand, N, N, N-1, N-1-[2,6-bis(3'-aminomethyl-1 1'-pyrazolyl)-4-phenylpyridine]tetrakis(acetic acid) (BPTA) for a Tb3+ fluorescent complex was synthesized. The Tb3+ complex is strongly fluorescent, having a large fluorescence quantum yield of 1.00 and very long fluorescence lifetime of 2.681 ms in 0.05 M berate buffer of pH 9.1. Streptavidin (SA) was labeled with SPTA by using its succinimidyl monoester, and the BPTA-Tb3+-labeled SA was used in sandwich-type time-resolved fluoroimmunoassay (TR-FIA) of alpha -fetoprotein (AFP) and carcinoembryonic antigen (CEA) in human sera. The Tb3+-labeled SA was also used in competitive type TR-FIA of bensulfuron- methyl (BSM) in water. The detection limits of these assays are 42 pg/mL for AFP, 70 pg/mL for CEA, and 0.4 ng/mL for BSM. In addition, a new simultaneous measurement method for AFP and CEA in a human serum sample was developed by using 4,4'-bis(1 " ,1 " ,1 " ,2 " ,2 " ,3 " ,3 " -heptafluoro-4 " ,6 " -hexanedion-6 " -yl)chlorosulfo-o-terphenyl ((BHHCT)-Eu3+-labeled anti-AFP antibody, biotinylated anti-CEA antibody, and BPTA-Tb3+-labeled SA. The concentrations of AFP and CEA in 39 human serum samples were determined, and the results were compared with those of the independently determined AFP and CEA by TR-FIA with a single-label method. A good correlation was obtained with the correlation coefficients of 0.991 for AFP and 0.994 for CEA.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A sensitive homogenous time-resolved fluoroimmunoassay (TR-FIA) method for bensulfuron-methyl (BSM) based on fluorescence resonance energy transfer (FRET) from a Tb3+ fluorescent chelate with N,N,N',N'-[2,6-bis(3'-aminomethyl-1'-pyrazoly)-4-phenylpyridine] tetrakis(acetic acid) (BPTA-Tb3+) to organic dye, Cy3 or Cy3.5 has been developed. New method combined the use of BPTA-Tb3+ labeled streptavidin, Cy3 or Cy3.5 labeled anti-BSM monoclonal antibody and biotinylated BSM-BSA conjugate (BSA is bovine serum albumin) for competitive-type immunoassay. After BPTA-Tb3+ labeled streptavidin was reacted with a competitive immune reaction solution containing biotinylated BSM-BSA, BSM sample and Cy3 or Cy3.5 labeled anti-BSM monoclonal antibody, the sensitized and long-lived emission of Cy3 or Cy3.5 derived from FRET was measured, and thus the concentration of BSM in sample was calculated. The present method has the advantages of rapidity, simplicity and high sensitivity since the B/F (bound reagent/free reagent) separation steps and the solid-phase carrier are not necessary. The method gives the detection limit of 2.10 ng ml(-1). The coefficient variations of the method are less than 1.5% and the recoveries are in the range of 95-105% for BSM water sample measurement. (C) 2001 Elsevier Science B.V. All rights reserved.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Terbium-doped zinc oxide nanoparticles have been prepared by hydrolyzing zinc acetate and terbium acetate. Nanoparticle-matrix-facilitated photoluminescence which is related to Tb3+ ions has been observed for ZnO:Tb nanoparticles. The dependence of emission intensity on doping concentration of Tb3+ ions has been investigated. An energy transfer from excited states of ZnO hosts to dopants is disclosed by the fact that the emission intensity of Tb3+ centers increases with increasing Tb content at the expense of emission from defect states in ZnO matrix.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

有机电致发光器件(organiclight-emittingdiodes,OLEDs)由于具有全色、低压直流驱动、视角广、高效率、发光颜色丰富等优点,在平板大面积显示领域具有广阔的应用前景,已引起广泛的重视.至目前为止,各式各样多层结构的器件、新的电致发光功能材料在深入研究,各种发光颜色甚至全色器件都已经相继报道.探索新材料,优化器件结构是目前电致发光研究的主要课题.该文主要包括以下几方面工作:(1)稀土配合物真空蒸镀所成膜的形态结构;(2)稀土配合物中第二配体的引入对稀土配合物电致发光性能的影响;(3)稀土配合物溶解性的改善;(4)铝配合物与聚合物PVK基激复合物对电致发光器件性能的影响及基激复合物的证实;(5)高效吡唑啉生物的合成及其电致发光器件的设计.通过深入系统的研究,取得了创新性的结果.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The reactions of sodium p-sulfonatocalix[4]arene (Na5L) and terbium/europium(III) chloride in the presence of pyrazine-N,N'-dioxide (PNNO) in aqueous solutions gave the crystalline complexes 1 and 2. Both structures contain molecular capsules of p-sulfonatocalix[4] arene with PNNO as guest molecules in the cavity of the calix[4]arenes. The molecular capsules are connected through sodium and terbium (or europium) centers forming a three-dimensional framework.