3 resultados para RARE EARTHS COMPLEXES

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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We demonstrate a multicore multidopant fiber which, when pumped with a single pump source around ∼800 nm , emits a more than one octave-spanning fluorescence spectrum ranging from 925 to 2300 nm . The fiber preform is manufactured from granulated oxides and the individual cores are doped with five different rare earths, i.e., Nd3+ , Yb3+ , Er3+ , Ho3+ , and Tm3+ .

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In 2014, the Dispute Settlement Body (DSB) of the World Trade Organization (WTO) adopted seven panel reports and six Appellate Body rulings. Two of the cases relate to anti-dumping measures. Three cases, comprising five complaints, are of particular interest and these are summarized and discussed below. China – Rare Earths further refines the relationship between protocols of accession and the general provisions of WTO agreements, in particular the exceptions of Article XX GATT. Recourse to that provision is no longer excluded but depends on a careful case-by-case analysis. While China failed to comply with the conditions for export restrictions, the case reiterates the problem of insufficiently developed disciplines on export restrictions on strategic minerals and other commodities in WTO law. EC – Seals Products is a landmark case for two reasons. Firstly, it limits the application of the Agreement on Technical Barriers to Trade (TBT Agreement) resulting henceforth in a narrow reading of technical regulations. Normative rules prescribing conditions for importation are to be dealt with under the rules of the General Agreement on Tariffs and Trade (GATT) instead. Secondly, the ruling permits recourse to public morals in justifying import restrictions essentially on the basis of process and production methods (PPMs). Meanwhile, the more detailed implications for extraterritorial application of such rules and for the concept of PPMs remain open as these key issues were not raised by the parties to the case. Peru – Agricultural Products adds to the interpretation of the Agreement on Agriculture (AoA), but most importantly, it confirms the existing segregation of WTO law and the law of free trade agreements. The case is of particular importance for Switzerland in its relations with the European Union (EU). The case raises, but does not fully answer, the question whether in a bilateral agreement, Switzerland or the EU can, as a matter of WTO law, lawfully waive their right of lodging complaints against each other under WTO law within the scope of their bilateral agreement, for example the Agreement on Agriculture where such a clause exists.

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The explorative coordination chemistry of the bridging ligand TTF-PPB is presented. Its strong binding ability to Co(II) and then to Ni(II) or Cu(II) in the presence of hexafluoroacetylacetonate (hfac(-)), forming new mono-and dinuclear complexes 1-3, is described. X-ray crystallographic studies have been conducted in the case of the free ligand TTF-PPB as well as its complexes [Co(TTF-PPB)(hfac)(2)] (1) and [Co(hfac)(2)(mu-TTF-PPB)Ni(hfac)(2)] (2). Each metal ion is bonded to two bidentate hfac-anions through their oxygen atoms and two nitrogen atoms of the PPB moiety with a distorted octahedral coordination geometry. Specifically, nitrogen donor atoms of TTF-PPB adopt a cis-coordination but not in the equatorial plane, which is quite rare. Electronic absorption, photoinduced intraligand charge transfer ((1)ILCT), and electrochemical behaviour of 1-3 have been investigated. UV-Vis spectroscopy shows very strong bands in the UV region consistent with ligand centred pi-pi* transitions and an intense broad band in the visible region corresponding to a spin-allowed pi-pi* (1)ILCT transition. Upon coordination, the (1)ILCT band is bathochromically shifted by 3100, 6100 and 5900 cm(-1) on going from 1 to 3. The electrochemical studies reveal that all of them undergo two reversible oxidation and one reversible reduction processes, ascribed to the successive oxidations of the TTF moiety and the reduction of the PPB unit, respectively.