Analyse von biologischem Material

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Die spektrophotometrische Bestimmung von Niob und Tantal mit 1-(2-Pyridylazo)-resorcin empfehlen

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Die gravimetrische Bestimmung von Gallium als Phosphat

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Nuclear structure studies of the neutron deficientN=50 nucleus96Pd

The neutron deficient nucleus⁹⁶Pd, four proton holes below the doubly magic¹⁰⁰Sn, has been studied in the reaction⁶⁴Zn (³⁶Ar, 2p 2n). Innγ andγγ coincidences levels up to 7 MeV excitation energy were established, and a new neutron core-excited isomer with T_1/2=35(4)ns and g=0.83 (5) was identified. A detailed shell model study yields excellent agreement for states within the π(p_1/2,g_9/2) configuration space but fails to reproduce the isomerism andg-factor for the core-excited state.     

Transient processes in photogalvanic cells: Part III. The alternating current photogalvanic cell

An alternating current photogalvanic cell, having a symmetrical electrode configuration, is described. It uses the Ru(bipy)₃²⁺/Fe³⁺ system. The light beam alternately illuminates the two electrodes, yielding almost rectangular current/time and voltage/time responses. The main advantage of this type of a cell is a very stable power output. Unlike other cells, mass transport from one electrode to the other is not necessary, eliminating the disadvantage of slow diffusion processes. A computer simulation of this behaviour is presented. The long-term characteristics depend on the Fe³⁺/Fe²⁺ concentration ratio.     

Study of pyrolytic carbon films for non-emitting grid applications

Pyrolytic carbon films were prepared on a hot substrate inside UHV system back-filled with 6 × 10⁻⁵ Torr of CH₄. The resulting films showed two different chemical states of carbon; carbides formed on W and Ta substrates and graphitic carbon layers were yound on ?. Ir substrate. Alter BaO deposition, the carbides showed a work function too low to be useful as grids. On the other hand, the work function of pyrolytic carbon films were high both before and after Ba or BaO coverage. Study of the degradation mechanisms of carbon films, formed by e-bean techniques, however, showed that they also reacted rapidly with W and T₂ resulting in a carbide formation. Thus it suggested that in the application of pyrolytic graphite grids, contact with carbide-forming metals should be avoided. Interaction of the pyrolytic carbon with BaO also resulted in the removal of carbon. However, this “leeching” phenomenon projects a life for pyrolytic graphite grids much longer than actually observed in the tube tests. The diffusion of Ba and BaO through pyrolytic carbon layer was evident in this workm but its precise relation to life failure rate is not yet understood.     

Chiral homoenolate equivalents. I. Asymmetric synthesis of β-substituted aldehydes via metalated chiral allylamines

Metalated chiral allylamines of type 2 (M = Li, K) are used as chiral homoenolate equivalents and allow after alkylation and acidic hydrolysis asymmetric CC bond formations to β-substituted aldehydes in enantiomeric excesses up to 67%.     

Ein Ger?t zur Schnellbestimmung sch?dlicher Beimengungen in Luft

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