Über die Formengruppe

Ohne Zusammenfassung     

Droplet traffic at a simple junction at low capillary numbers

We report that, when a train of confined droplets flowing through a channel reaches a junction, the droplets either are alternately distributed between the different outlets or all collect into the shortest one. We argue that this behavior is due to the hydrodynamic feedback of droplets in the different outlets on the selection process occurring at the junction. A "mean field" model, yielding semiquantitative results, offers a first guide to predict droplet traffic in branched networks.     

Photofission of heavy nuclei at energies up to 4 GeV

Total photofission cross sections for 238U, 235U, 233U, 237Np, 232Th, and natPb have been measured simultaneously, using tagged photons in the energy range Egamma=0.17-3.84 GeV. This was the first experiment performed using the Photon Tagging Facility in Hall B at Jefferson Lab. Our results show that the photofission cross section for 238U relative to that for 237Np is about 80% over the entire energy range, implying the presence of important processes which compete with fission. If we assume that for 237Np the photofission probability is equal to unity, we observe a significant shadowing effect, starting below 1.5 GeV.     

Der Multiplikator von Thetareihen höheren Grades zu quadratischen Formen ungerader Ordnung

Ohne Zusammenfassung     

Singular unitary representations and indefinite harmonic theory

Square-integrable harmonic spaces are defined and studied in a homogeneous indefinite metric setting. In the process, Dolbeault cohomologies are unitarized, and singlar unitary representations are obtained and studied.     

Thermodynamic properties of iron—selenium alloys

Selenium vapor pressures of iron-selenium alloys were determined by an isopiestic method between 700 and 1 200 K and 50 to 60 at%Se, and activities and partial molar enthalpies of selenium were calculated. ByGibbs-Duhem integration activities of iron, and integralGibbs energies were obtained. A theoretical model was successfully applied to interprete the thermodynamic properties of the hexagonal -phase with NiAs-structure. Assuming a random distribution of iron vacancies in every transition metal layer of the lattice excellent agreement with experimental data was found. The energy of interaction betwen iron vacancies was calculated to be 147.0 kJ/g-atom.

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Thermodynamische Eigenschaften von Eisen—Selen—Legierungen

Zusammenfassung Die Selendampfdrücke von Eisen-Selen-Legierungen wurden mit Hilfe einer isopiestischen Methode zwischen 700 und 1 200 K und zwischen 50 und 60 At%Se bestimmt. Daraus wurden die Aktivitäten und die partiellen molaren Enthalpien von Selen berechnet, und über eineGibbs-Duhem-Integration wurden die Eisen-Aktivitäten und die integralenGibbs'schen Energien erhalten. Ein theoretisches Modell wurde erfolgreich angewendet, um die thermodynamischen Eigenschaften in der hexagonalen NiAs-Phase zu interpretieren. Unter der Annahme einer statistischen Verteilung von Eisen-Leerstellen über sämtliche Übergangsmetall-Schichten wurde eine ausgezeichnete Übereinstimmung mit den experimentell gefundenen Daten festgestellt. Die Wechsel-wirkungsenergie zwischen diesen Leerstellen wurde zu 147,0 kJ/g-atom ermittelt.

     

Photoströme und Ladungsträgerbeweglichkeiten in Pyreneinkristallen

Zeitschrift für Physik A Hadrons and nuclei - Transient space-charge-limited photocurrents measured with the method ofKepler andLeBanc and steady-state photocurrents were observed in pure...