No abstract available

[en] Using spectroscopic data of the Nd(III)-nicotinic acid N-oxide (nic NO) system in methanol as example data, the requirements of the ISO Guide to the Expression of Uncertainty to the evaluation of spectroscopic data are demonstrated. The cause-and-effect diagram approach suggested by EURACHEM is shown and applied to the evaluation of single-component spectra and thermodynamic data of the Nd(III)-nic NO system using computer-intensive statistical methods like the threshold bootstrap in combination with target factor analysis (FA)

[en] This paper evaluates a new inferior vena caval filter delivery system for the percutaneous transvenous interruption of the inferior vena cava. Design of the filter is described. Experimental methods are given and results are analyzed

[en] Three Tb³⁺ doped mixed strontium – rare earths borate phosphors of general formula Sr₃RE₂(BO₃)₄:Tb³⁺ (RE = Y, La or Gd) of 25–40 nm particle size were obtained by the Pechini sol–gel method, using citric acid and ethylene glycol as gel-forming agents. The structures of prepared materials were confirmed and characterized using X-ray powder diffraction and transmission electron microscopy. Photoluminescence properties, such as emission and excitation spectra and luminescence lifetimes of the phosphors, were measured. Excitation of the phosphors using different wavelengths in the UV range is possible. Lifetimes measured for the phosphors ranged from 2.2 to 2.7 ms. All of the Tb³⁺-doped phosphors show excellent luminescent properties, with a bright emission of green light under UV excitation. The color coordinates of emitted light on CIE1931 chromaticity diagram are close to those of National Television Standards Committee (NTSC) standard of green. - Graphical abstract: Display Omitted - Highlights: • Mixed strontium-rare earths borate Tb³⁺-doped nanoluminophors were obtained for the first time. • Optimal conditions for the synthesis of Sr₃RE₂(BO₃)₄:Tb³⁺ were found. • Photoluminescence properties of well-emitting products are discussed. • The color CIE coordinates of the nanosized (40 nm) particles were determined

[en] Luminescence intensities and lifetimes of trivalent lanthanide ions and their complexes in solution have been reviewed and discussed. Energy transfer processes in the systems containing lanthanide(III) ions and the inner-sphere complexation of the europium(III) ion have been examined. (author). 77 refs, 6 figs, 4 tabs

[en] Luminescence lifetime and intensity measurements of lanthanide(III) ions, Ln³⁺ (Eu, Gd and Tb), in non-aqueous solutions containing azide ions (N₃^-) have been performed to study the quenching effect of N₃^- using time-resolved laser-induced luminescence spectroscopy and conventional luminescence spectroscopy. The luminescence Stern-Volmer quenching constants K_sv^PHI and azide non-radiative decay constants k_N3 of the excited Eu(III) ion in the presence of N₃^- were measured in N,N-dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N-methylformamide (NMF), formamide (FA) and methanol (MeOH). The obtained quenching effect of the Ln³⁺ luminescence by azide in the non-aqueous solvents shows the order: Gd>Eu>Tb, which does not obey the energy gap law, ΔE, between the emitting and the ground state of the Ln³⁺ ion (Gd>Tb>Eu). The anomaly in the quenching pattern observed in the case of Eu³⁺ can be attributed to its partial reduction to Eu²⁺, additionally to the energy transfer from excited state of Eu³⁺ to N₃^-. The values of quenching rate constants k_N3measured for Eu³⁺ in various solutions depend on the acceptor number (AN) of the solvents used

[en] The complexes of all lanthanides (excluding Pm) with thenoyltrifluoroacetone (TTA) of a general formula Ln(TTA)₃nH₂O have been prepared. The results of elemental analysis and of titration with K. Fischer reagent show a different degree of hydration from La to Lu. The dehydration process, its reversibility and the thermal behaviour of these compounds have been studied. The different degree of hydration of the complexes determines their different behaviour in the course of thermogravimetric analysis and dehydration-hydration experiments. The solubility of hydrated complexes was determined in carbon tetrachloride and benzene, that of dehydrated complexes in carbon tetrachloride and hexane respectively. In the case of the solubility of hydrated complexes in CCl₄ the points appear to lie on a parabola with a minimum at Gd. The solubility of dehydrated complexes in CCl₄ increases more or less monotonicly with Z. The I.R. spectra of the solid compounds in the 3000-3800 cm^-1 range show that the hydrogen bonding is present in these complexes. (author)

[en] Short communication

No abstract available

[en] The results of investigation related to physico-chemical properties, synthesis and structure of polyoxometalates and their lanthanide(III) complexes are briefly reviewed. Useful techniques for verification of polyoxometalate compositions and the determination of components are compared. Complexation of metal ions, especially of lanthanide(III) ions, with polyoxometalates using absorption (in the UV-visible and near infrared region) and luminescence spectroscopy methods are presented. Absorption hypersensitive transitions of certain lanthanide(III) ions and laser-induced europium(III) ion luminescence spectroscopy are shown to be useful in complexation investigations. The significance of some polyoxometalate complexes as potential magnetic resonance imaging agents and in biological as antiviral agents are discussed. (author)