Der Einbau von Radiokohlenstoff in Tabakmosaikvirus verschiedenen “Alters”

Zusammenfassung Tabakblätter wurden wenige Tage nach der Infektion mit Mosaikvirus zur photosynthetischen Aufnahme radioaktiven Kohlenstoffs veranlaßt. Das Virus wurde sodann isoliert und die Abhängigkeit der spezifischen Radioaktivität des Virus von dem seit der Infektion verflossenen Zeitraum (Alter des Virus) geprüft. Es ergibt sich, daß in dem untersuchten Bereich sowohl die sperifische Radioaktivität des Virus als auch die Gesamtradioaktivität des Virus weit höher ist, als wenn die Photosynthese mit dem virusgesättigten Blatt erfolgt. Dieses Ergebnis ist auch für die praktische Darstellung des markierten Virus bedeutungsvoll.Herrn Prof. Dr.A. Franke zum 80. Geburtstag gewidmet.     

Oxidation of alcohols by electrochemically regenerated nickel oxide hydroxide. Selective oxidation of hydroxysteroids

Primary alcohols, α,ω-diols and secondary alcohols are easily transformed into carboxylic acids, dicarboxylic acids or ketones, respectively, by heterogeneous oxidation with nickel oxide hydroxide electrochemically regenerated at a nickel hydroxyde electrode. The results are discussed in comparison to those of the nickel peroxide and chromic acid oxidation. The oxidation rate decreases with increasing steric hindrance of the alcohol, thus allowing the selective oxidation of the 3-position in hydroxysteroids.     

Functional bosonization of interacting fermions in arbitrary dimensions

We bosonize the long-wavelength excitations of interacting fermions in arbitrary dimension by directly applying a suitable Hubbard-Stratonowich transformation to the Grassmannian generating functional of the fermionic correlation functions. With this technique we derive a surprisingly simple expression for the singleparticle Greens-function, which is valid for arbitrary interaction strength and can describe Fermi- as well as Luttinger liquids. Our approach sheds further light on the relation between bosonization and the random-phase approximation, and enables us to study screening in a nonperturbative way.     

Hot electron relaxation in one-dimensional models: exact polaron dynamics versus relaxation in the presence of a Fermi sea

We present the exact solution for the time evolution of the electron and phonon momentum distribution for a one-dimensional polaron model with alinear electronic energy dispersion. The electron momentum distribution is shown to obey aMarkovian quantum kinetic equation. Numerical results for the polaron model are compared to the corresponding exact results, when the negative momentum states are filled in the initial state. The presence of this Fermi sea modifies the dynamics except in the short time regime. The different, long time dynamics might show up in comparison of hot electron relaxation of undoped and doped semiconductors.     

Resonant electron transfer andL-shell excitation at 3.6 MeV/u Smq+→Xe collisions

Resonance energies and widths of four resonances in the reaction²⁵Mg(p,γ)²⁶Al were measured with the high resolution proton beam of the new 500 kV accelerator IONAS. The previously given large width of the 389 keV resonance, Γ= 460±70 eV. (1), used in the interpretation of stellar²⁶A1 production was shown to be incorrect and probably caused by target oxidation effects and insufficient energy resolution of the beam. The new value is Γ<4 eV.