Interaction between Tb 3 and Fibrinolytic Principle from Agkistrodon Acutus Venom

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Luminescence enhancement of the Tb(III) ion with the thenoyltrifluoroacetonate ligand acting as an efficient sensitizer

The synthesis, structural investigation, and photophysical properties of the complex [Tb(TTA)₂(NO₃)(TPPO)₂] are reported. Unlike the analog tris-diketonate complex [Tb(TTA)₃(TPPO)₂], the new complex presents abnormally high luminescence intensity centered on the terbium ion. Our results clearly suggest a higher energy transfer efficiency from the TTA antenna ligand to the Tb(III) ion in the bis-diketonate complex compared with that in the tris-diketonate complex. A mechanism involving the increasing of triplet state energy when one TTA ligand is replaced by the NO₃^? group in the first coordination sphere is suggested and experimentally investigated to explain the anomalous luminescence properties of the new complex [Tb(TTA)₂(NO₃)(TPPO)₂].     

铽配合物荧光研究及在光波转换材料中的应用

选择荧光效应强的稀土铽(Tb)元素并以N,N,N-三(2-甲基苯并咪唑)胺(NTB)作为第一配体,在乙醇溶液体系中通过荧光强度试验选择了十六烷基三甲基溴化铵(CTMAB)为表面活性剂,邻菲啰啉(phen)为协配体,并同时探索了各组分配比对配合物体系荧光强度的影响,得出Tb,NTB,CTMAB与phen的最佳物质的量之比为1∶2∶0.5∶6。将制得的荧光性能良好的配合物体系与PVC粉掺杂,获得了可将紫外光转换为可见光的薄膜。     

Growth and scintillation properties of Tb doped LiGdF4/LiF eutectic scintillator

Tb-doped LiGdF₄-LiF eutectics were grown at various growth rate and their directionally solidified eutectic (DSE) system has been investigated. Well aligned fiber like eutectic structure with around 1.7 μm in diameter and 1200 μm in maximum length was obtained the growth speed of 0.15 mm/min. The sample showed optical transparency like bundle optical fibers and around 40% of transmittance at 1.5 mm thick was achieved in 380–630 nm range. The expected 380–630 nm emission exited by UV and α-ray, and 270–330 nm excitation of Tb^{3+ 8}S -⁶P transition have been observed. The weak emission of Gd³⁺ 4f-4f transition at 310 nm was also observed under alpha-ray excitation. The Observed excitation bands peaking at around 275 nm and 310 nm correspond respectively to the ⁸S^7/2- ⁶I_7/2 and ⁸S_7/2-⁶P_J absorption bands of Gd³⁺.     

Determination of total phenols in tea infusions,tomato and apple juice by terbium sensitized fluorescence method as an alternative approach to the Folin–Ciocalteu spectrophotometric method

A fast screening of total phenols in tea infusions, tomato and apple juice samples using terbium sensitized fluorescence is described. The proposed method is based on the fluorescence sensitization of terbium (Tb³⁺) by complexation with flavonols (quercein as a reference standard) (at pH 7.0), which fluoresces intensely with an emission maximum at 545 nm when excited at 310 nm. Quercetin and terbium cations (at pH 7.0) form a stable complex and the resulted emission at 545 nm can be used for the determination of the total phenols concentration expressed in terms of “quercetin equivalent”. Based on the obtained results, a sensitive, simple and rapid spectrofluorimetric method was developed for the determination of total phenols. In the optimum conditions, the calibration graph was linear from 0.01 to 2 μg mL⁻¹, with the limit of detection of 0.002 μg mL⁻¹. The relative standard deviation values were in the range of 0.75–2.3%. The total concentrations of quercetin equivalent in five tested samples were found in the range of 6.6–27.9 μg mL⁻¹ and the results compare favorably with those obtained by spectrophotometric method (r = 0.999).     

Tb(Ⅲ)Transport in Dispersion Supported Liquid Membrane System with D2EHPA as Carrier in Kerosene

The transport of Tb(Ⅲ)in dispersion supported liquid membrane(DSLM)with polyvinylidene fluoride membrane(PVDF)as the support and dispersion solution including HCI solution as the stripping solution and di(2-ethylhexyl)phosphoric acid(D2EHPA)dissolved in kerosene as the membrane solution,has been studied.The effects of pH value,initial concentration of Tb(Ⅲ)and different ionic strength in the feed phase,volume ratio of membrane solution to stripping solution,concentration of HCl solution,concentration of carrier,different stripping agents in the dispersion phase on the transport of Tb(Ⅲ)have also been investigated,respectively.As a result,the optimum transport conditions of Tb(Ⅲ)were obtained,i.e.,the concentration of HCI solution was 4.0 mol/L,the concentration of D2EHPA was 0.16 mol/L,the volume ratio of membrane solution to stripping solution was 30:30 in the dispersion phase and pH value was 4.5 in the feed phase.Ionic strength had no obvious effect on the transport of Tb(Ⅲ).Under the optimum conditions,the transport percentage of Tb(Ⅲ)was up to 96.1% in a transport time of35 min when the initial concentration of Tb(Ⅲ)was 1.0×10-4 mol/L.The diffusion coefficient of Tb(Ⅲ)in the membrane and the thickness of diffusion layer between feed phase and membrane phase were obtained and the values were 1.82×10-8 m2/s and 5.61 μm,respectively.The calculated results were in good agreement with the literature data.     

Usefulness of terbium-sensitised luminescence detection for the chemometric classification of wines by their content in phenolic compounds

A method for wine classification based on the phenolic compound content, wine variety and geographical area is described. The method involves the use of the results obtained from the analysis of fifteen samples of Italian and Spanish wines from different geographical origins [Sicilia (Italy) and Córdoba (Spain)] using liquid chromatography (LC) with photometric and fluorimetric detection, in which eighteen phenolics were determined: gallic acid, protocatechuic acid, p-hydroxybenzoic acid, salicylic acid, vanillic acid, caffeic acid, syringic acid, catechin, vanillin, p-coumaric acid, syringaldehyde, epicatechin, ferulic acid, rutin, trans- and cis-resveratrol, quercetin and kaempferol. Photometric measurements were performed selecting four wavelengths (256, 280, 320 and 365 nm), using a diode-array detection system. The fluorimetric detection was achieved by measuring the sensitised luminescence provided by the chelates formed between each analyte and terbium (III). All samples were commercial wines bought in local markets and analysed immediately after they were opened. The pattern data matrix was constructed by the concentration of each analyte present in wine, which was determined by the most adequate method, namely LC-photometric or LC-fluorimetric method. This data matrix was subjected to different algorithms in order to classify and characterise the wine samples adequately. Supervised (LDA) and un-supervised (FA) pattern recognition methods were used. The wine pattern generation with LC separation and dual detection approach to determine eighteen phenolic compounds and the chemometric treatment provide an appropriate way with recognition and prediction rates. The values obtained for these rates were 100% when fluorimetric detection was used. These results can be considered satisfactory, which proves the usefulness of the selected variables.     

SiC Nanorods Grown on Electrospun Nanofibers Using Tb as Catalyst: Fabrication, Characterization, and Photoluminescence Properties

Well-crystallized β-SiC nanorods grown on electrospun nanofibers were synthesized by carbothermal reduction of Tb doped SiO₂ (SiO₂:Tb) nanofibers at 1,250 °C. The as-synthesized SiC nanorods were 100–300 nm in diameter and 2–3 μm in length. Scanning electron microscopy (SEM) results suggested that the growth of the SiC nanorods should be governed by vapor-liquid-solid (VLS) mechanism with Tb metal as catalyst. Tb(NO₃)₃ particles on the surface of the electrospun nanofibers were decomposed at 500 °C and later reduced to the formation of Tb nanoclusters at 1,200 °C, and finally the formation of a Si–C–Tb ally droplet will stimulate the VLS growth at 1,250 °C. Microstructure of the nanorod was further investigated by transmission electron microscopy (TEM). It was found that SiC <111> is the preferred initial growth direction. The liquid droplet was identified to be Si₈₆Tb₁₄, which acted as effective catalyst. Strong green emissions were observed from the SiC nanorod samples. Four characteristic photoluminescence (PL) peaks of Tb ions were also identified.     

无污染,快速液膜法分离稀土的系统研究——钆和铽,镝的分离

本文对乳液型液膜分离钆和铽、镝进行了实验室研究。本研究是本所进行系统性分离稀土元素的一部分。通过实验考察了内、外水相ＨＣｌ浓度、载体浓度以及乳水经等诸因素对分离的影响，实验结果表明，通过优化实验条件和液膜配方，简单价廉的煤油－Ｐ２０４－ＨＣｌ液膜体系可有效分离和铽、镝、从而为此系统研究中（Ｓｍ－Ｅｒ）组的进一步分组奠定了基础。