The impact parameter dependence of the Pb + Pb K − MO spectrum

Molecular orbital X-rays are emitted during ion-atom collisions. The theoretical treatment, numerical results for the Pb + Pb system and a comparison with background radiation like NNB, SEB and γ-decay of Coulomb excited nuclei are presented.     

Rank-axiomatic characterizations of independence systems

Motivated by the rank-axiomatic definitions of a matroid and Woodall's characterization of independence systems [6] we provide an abstract framework for general independence systems in terms of their rank function.     

Eine Bemerkung zum Okaschen Prinzip auf streng pseudokonvexen Flächen

Ohne Zusammenfassung     

Semiclassical theory of nuclear rotation

The semiclassical theory of large amplitude collective motion developed previously by the author is applied to uniform nuclear rotation. In this way a sophisticated foundation of the self-consistent cranking model is given and its quantization is accomplished. The obtained quantization condition already contains the leading order correction to the self-consistent cranking model and also reveals the relation between the total angular momentum and the total signature. In the low frequency limit it yields the I(I + 1) law of a quantum rotor.     

A note on general relativistic dynamo mechanisms

Our previous investigation of a general relativistic primary dynamo mechanism based on the dragging of inertial frames, where we used the Cohen-Brill metric, is generalized to the case of the Kerr metric. It is shown that magnetic fields can be generated without the black hole being charged.     

Low spin structure of128Xe

The low spin structure of¹²⁸Xe has been studied by means of the (α,n) reaction using beam energies near the Coulomb barrier. An extended level scheme with spins I≤10? and many new spin and parity assignments could be established. The results point to the completeness of the reaction at low spins and excitation energies below 2.5 MeV.     

Synthese und Qualitätskontrolle 15N-markierter Stickoxide mit hoher 15N-Häufigkeit für umweltrelevante Tracer-Untersuchungen

Für die Untersuchung ausgewählter Probleme des Verhaltens und der Wirkung der Stickoxide NO _x (NO + NO₂) in Ökosystemen, z.B. die Aufnahme und Freisetzung von NOx durch das System “Boden-Pflanze”, bietet sich der Einsatz ¹⁵N-markierter Stickoxide an. Die dazu benötigten ¹⁵N-markierten Gasgemische hoher Reinheit werden aus eigens dafür synthetisiertem [¹⁵N]Stickstoffmonoxid oder [¹⁵N]Stickstoffdioxid mit hoher ¹⁵N-Häufigkeit hergestellt. Beide Synthesen gehen jeweils von der kostengünstig kommerziell erhältlichen [¹⁵N]Salpetersäure aus.

Im Falle des [¹⁵N]Stickstoffdioxids erfolgt die Herstellung über die Präparation von Bleinitrat und dessen thermische Zersetzung. Die Ausbeute liegt bei 70–75% bezogen auf eingesetzte [¹⁵N]Salpetersäure.

Die Herstellung von [¹⁵N]Stickstoffmonoxid erfolgt durch Reduktion von [¹⁵N]Salpetersäure mit Eisen-II-sulfat in stark saurer Lösung. Die Ausbeute beträgt 60–70%, bezogen auf eingesetzte Salpetersäure.

The application of ¹⁵N is very useful for the investigation of the behavior and the effect of the nitrogen oxides NO _x (nitric oxide + nitrogen dioxide) in ecosystems, e.g. the uptake and release of NO _x by the soil-plant system. The ¹⁵N labelled gas mixture needed for that purpose has to be prepared from synthesized highly enriched [¹⁵N]nitric oxide and [¹⁵N]nitrogen dioxide. These two syntheses both use the commercially available and reasonable [¹⁵N]nitric acid.

In the case of [¹⁵N]nitrogen dioxide the synthesis is carried out via [¹⁵N]lead nitrate and its decomposition with increasing temperature. The yield is 70–75% related to the [¹⁵N]nitric acid input. The preparation of [¹⁵N]nitric oxide is done by reduction of [¹⁵N]nitric acid by means of FeSO₄ in strong acid solution. The yield amounts to 60–70%.