Beiträge zur Methodik der chemischen Analyse der Uranpechblenden

Ohne Zusammenfassung     

Die quantitative Mikro-Mineralanalyse und ihre Ergebnisse

Ohne Zusammenfassung     

Eine Methode zur Analyse sehr kleiner Monazitmengen

Zusammenfassung An natürlichen Monaziten wurde eine Methode für die MikroGesamtanalyse dieser Mineralien entwickelt. Dieser Analysengang wurde sodann, an einem künstlichen Gemenge, welches ähnlich den natürlich vorkommenden Monaziten zusammengesetzt war und lediglich von den Nebenbestandteilen etwas größere Mengen enthielt, überprüft und für ausreichend genau befunden. Für Blei jedoch wurde eine Spezialmethode ausgearbeitet, da es nicht möglich war, innerhalb des beschriebenen Gesamtanalysenganges befriedigende Bleiwerte zu erhalten.Es ist uns eine angenehme Pflicht, dem Vorstand des Instituts, Herrn Professor Dr. A. Franke, für seine wirksame Förderung unserer Arbeit unseren wärmsten Dank auszusprechen.     

Surface reconstruction of chiral glassy oligomers under the action of volatile organic compounds (VOCs)

The response of chiral polymers to volatile organic compounds (VOCs) was studied by atomic force microscopy. It was found that under the influence of toluene vapour, the focal conic domains on the surface of chiral polymer undergo remarkable reconstruction that is at least partially reversible. This opens new ways for building VOC sensors and using surface reconstruction in creating new surface patterns for nanotechnology.     

The NN interaction in a quark model with quark-antiquark excitations

Quark-antiquark excitations inherent in the quark-gluon interaction have been incorporated into a quark model of the nucleon to study the effects of such excitations on the NN interaction within the framework of the resonating group method. The three-quark (3q) components of a single nucleon are augmented by ($\text{3}\text{q}\text{)(}\text{q}\text{q}$) excitations with the 24 possible spin, isospin, color combinations for the energetically lowest p-wave relative motion function. Quark exchange kernels are then calculated for the two-nucleon system described by these improved nucleon internal functions; and these exchange kernels are converted to phase-shift-equivalent effective NN potentials by the Wigner-transform WKB technique. The off-shell qq? pair-creation terms are derived from the one-gluon exchange diagrams in the Breit approximation in analogy with the derivation of the qq and qq? potentials. The parameters of the interaction are chosen to be consistent with the experimental Δ-N mass difference, the nucleon-vector-meson coupling constants, and the nucleon magnetic moments. Within these constraints, the predicted amplitudes of the ($\text{3}\text{q}\text{)(}\text{q}\text{q}$) components of the nucleon internal functions have been shown to be insensitive to the precise values of the model parameters. In particular, they pass the crucial test of being insensitive to very large changes in the magnitude of the confinement potential constant which is a necessary ingredient of the model. The qq? excitations lead to the following effects in the S-wave NN potentials: (i) The repulsive core heights of the simple 3q-3q model are greatly reduced but retain their strong essentially linear energy dependence, with numerical values very similar to those of the short-range phenomenological terms of the Paris potential. (ii) The effective potentials have acquired an attractive part in the 0.8-1.5 fm range. However, this attraction is too weak to bind the deuteron or fit the extreme low-energy S-wave phase shifts.