DSAM lifetimes of the ground state band in48Cr

Lifetimes have been determined in the ground state band in⁴⁸Cr and found in agreement with Shell Model calculations.     

Unusual isospin-breaking and isospin-mixing effects in the A=35 mirror nuclei

Excited states have been studied in 35Ar following the 16O(24Mg,1alpha1n)35Ar fusion-evaporation reaction at 60 MeV using the Ge-detector array GASP. A comparison with the mirror nucleus 35Cl shows two remarkable features: (i) A surprisingly large energy difference for the 13/2(-) states, in which the hitherto overlooked electromagnetic spin-orbit term is shown to play a major role, and (ii) a very different decay pattern for the 7/2(-) states, which provides direct evidence of isospin mixing.     

First identification of excited states in the T_z\! = \!1/2 nucleus 93 Pd

The first experimental information about excited states in the N = Z + 1 nucleus ⁹³Pd is presented. The experiment was performed using a 205 MeV ⁵⁸Ni beam from the Vivitron accelerator at IReS, Strasbourg, impinging on a bismuth-backed ⁴⁰Ca target. Gamma-rays, neutrons and charged particles emitted in the reactions were detected using the Ge detector array Euroball, the Neutron Wall liquid-scintillator array and the Euclides Si charged-particle detector system. The experimental level scheme is compared with the results of new shell model calculations which predict a coupling scheme with aligned neutron-proton pairs to greatly influence the level structure of nuclei at low excitation energies.Received: 28 October 2003, Revised: 4 December 2003, Published online: 26 January 2004PACS: 21.10.Hw Spin, parity, and isobaric spin - 23.20.Lv transitions and level energies - 27.60. + j - 21.60.Cs Shell model     

Reaction mechanism studies using the CN/ER spin distribution

To study basic properties of the fusion reaction dynamics for heavy compound systems the partial-wave distribution can be employed as an alternative to the classically used fusion/fission excitation functions. A variety of reactions leading to compound nuclei (CN) in the Pb region can be used to investigate features like the fusion-fission competition, the role of deformation in the fusion of heavy systems and a possible effect of the Z = 82 shell on the enhancement of evaporation residue (ER) production.Received: 5 November 2002, Revised: 26 March 2003, Published online: 9 March 2004PACS: 24.75. + i General properties of fission - 25.70.Gh Compound nucleus - 25.70.Jj Fusion and fusion-fission reactions     

Resonant scattering of ions on charged dust particles

Resonant scattering ("scattering through waves") of ions on dust particles in plasmas is considered in the framework of the kinetic theory which consistently takes into account ion-dust collisions and dust charge fluctuations. Resonance with low frequency dusty plasma modes can enhance the ion-dust scattering cross section and the ion drag force on dust particles.     

Highly efficient C-H insertion reactions of hydrogen peroxide catalyzed by homogeneous and heterogeneous methyltrioxorhenium systems in ionic liquids

A convenient and efficient C-H insertion reaction of environment friendly H₂O₂ into representative hydrocarbon derivatives by homogeneous methyltrioxorhenium (MTO), heterogeneous poly(4-vinylpyridine)/methyltrioxorhenium (PVP/MTO) and microencapsulated polystyrene/methyltrioxorhenium (PS/MTO) systems in ionic liquids, is described. In some cases a higher activity was observed if compared with the same reaction in molecular solvents. The heterogeneous catalysts are stable systems under the reaction conditions and can be recycled for more transformations.     

Alcohols and aluminium alkoxides in the presence of raney nickel as alkylating agents. 1. Alkylation of indoles and pyrroles

Indole and 3-methylindole are completely converted by alcohols into N-alkyl or N-isoalkyl derivatives in the presence of aluminium alkoxides and Raney Nickel; 2-methylindole gives lower yields. Pyrroles suffer N- and C-alkylation but the initially formed N-alkylpyrroles are reduced into N-alkylpyrrolidines in the reaction mixtures. The occurrence of these N-alkylations is at variance with the C-alkylation of indoles and pyrroles which takes place by means of alcohols and sodium alkoxides. This suggests that the reaction occurs between the substrate and the reagent both coordinated by aluminium.     

Conduction in fully ionized binary alloys and the problem of Jupiter's magnetic field

The resistivity of metallic hydrogen and H⁺-He⁺⁺ alloys is calculated. The ionic structure is described with charged-hard-spheres correlation functions. Some recent models of Jupiter's deep interior are used to evaluate its conductivity with reference to the problems of the origin of the jovian magnetic field and convective core.     

Synthesis of 2-amino-3-methoxypyrazinc

A new synthesis of 2-amiuo-3-methoxypyrazine, an intermediate in the synthesis of sulfalene, via 2-carbamido-3-hydroxy pyrazine and subsequent Hofmann rearrangement of 2-carhamido-3-methoxypyrazine, is described.