An investigation of short-lived isomers in the nuclei90,92Nb,99Mo,98,100,101Tc and101Ru

Short-lived isomers in the nuclei^90,92Nb,⁹⁹Mo,^98,100,101Tc and¹⁰¹Ru populated in photonuclear reactions were studied by pulsed beam techniques. Energy and half-life of theγ-rays deexciting the isomeric levels were measured by recording energy-time spectra. The delayedγ-rays andK X-rays were detected by means of an intrinsic Ge-detector of high resolution. From the measured intensity ratios internal conversion coefficients were determined. The multipolarities of the isomeric transitions could be deduced in most cases. A classification of the observed isomers has been tried on the basis of the obtained experimental results and most recent literature data.     

Eine optische Methode zur Bestimmung von Perchlorat

Ohne Zusammenfassung     

Positivity of cubic polynomials on intervals and positive spline interpolation

A criterion for the positivity of a cubic polynomial on a given interval is derived. By means of this result a necessary and sufficient condition is given under which cubicC ¹-spline interpolants are nonnegative. Further, since such interpolants are not uniquely determined, for selecting one of them the geometric curvature is minimized. The arising optimization problem is solved numerically via dualization.     

Elimination of 14β-hydroxy-12-mesyloxy-5β-steroids

Elimination of a 12α-methanesulfoxy group in 3β-acetoxy-14β-hydroxy-12α-mesyloxy-5β-androstane-17β-carboxylic-acid-14β-lactone under preventing Wagner-Meerwein rearrangements by steric fixation, is reported. Furthermore, the synthesis of this compound and the different elimination behaviors in the 12α- and the 12β-isomers are described.     

A systematic study of the shape of57Fe Mössbauer spectra in disordered ferromagnetic fcc Fe−Pt alloys

We investigate Fe–Pt alloys in the concentration range 24.9–33.9 at% Pt and determine the hyperfine parameters of Mössbauer spectra measured at about 20 K.