Apparate

Ohne Zusammenfassung     

Influence of cobalt ions on the electrochemical properties of lamellar manganese oxides

Evaluation of Co-doping on the electrochemical properties of the sol-gel birnessite and the new lithiated manganese oxide Li_0.45MnO_2+δ is reported. For both compounds the synthesis of Co-doped materials via a solution technique is described. We demonstrate the interest of Co-doped structures with the selected content of 0.15 Co per mole of oxide as the optimum composition. In the case of Li_0.45Mn_1−yCo_yO_2+δ. prepared at 300 °C, a mixture of a lamellar phase and a cubic one is identified while the Co-doped birnessite appears as a single phase. A probable substitution of Mn by Co ions explains the better specific capacity of 185 mAh/g found and the excellent stability observed over 40 cycles in the voltage range 4.2−2.0 V. Paper presented at the 7th Euroconference on Ionics, Calcatoggio, Corsica, France, Oct. 1–7, 2000.     

Ein neues Reagens zum Nachweis geringer Mengen Wasserstoffsuperoxyds, speciell in Pflanzen

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Monitoring changes in the band structure of graphite following chemical reaction: An X-ray-induced photo-electron study of intercalation

Dramatic changes in the valence band of graphite, resulting from the insertion of bromine between the layers, are directly measurable using the ESCA technique.     

Zur Frage der Rothf?rbung der Carbols?ure

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On the origin of the integral representations in quantum optics

In Abelian subalgebras of observables it is shown that the integral representations of states in terms of coherent states result from the indistinguishability of the quanta of the harmonic oscillator under consideration. It is argued that these integral representations contain a quantum de Finetti theorem on Bose-Fock space.