A measurement of polarization in π−p→ K°Λ° at 5 GeV/c

We have measured the Λ° polarization in π^?p→ K°Λ° at 5 GeV/c, using a data sample of 3709 events. The polarization is positive for small t, passes through zero near t = ?0.3 (GeV/c)², and becomes large and negative at larger t, consistent with a value of ?1.0 for t between ?0.7 and ?1.6(GeV/c)².     

Identification of a nonlinear circuit

The identification of a differential equation underlying a measured time series is a prerequisite for numerous types of applications. In the validation of a proposed parameterized model one often faces the dilemma that it is hard to decide whether possible discrepancies between the measured time series and the simulated model output are caused by an inappropriate model or by wrongly specified parameters in a correct type of model. We propose a combination of parametric modelling based on Bock's multiple shooting algorithm and nonparametric modelling based on optimal transformations as a strategy to test proposed models and if rejected suggest and test new ones. We exemplify this strategy on an experimental time series from a nonlinear chaotically oscillating circuit where we finally obtain an extremely accurate reconstruction of the observed attractor.     

Synthesis and characterization of some derivatives of lupinine and aminolupinine. Collision induced dissociation mass spectrometry studies of protonated molecules

Some ester, amide and thioether derivatives of lupinine, aminolupinine and bromolupinine were synthesized and characterized in order to search biologically active compounds. The protonated molecules were studied by tandem mass spectrometry using collision induced dissociation (CID) technique in order to find out how different structural features and functional groups in different quinolizidine derivatives influence fragmentation behavior. Some theoretical calculations were also made to clarify the conformations of neutral and protonated molecules, to reveal the fragmentation routes and the product ions obtained. The functional groups clearly directed the fragmentations although the typical fragments for lupinine were still observed in all the cases. Theoretical calculations were in agreement with observed fragmentations and greatly helped interpretation of the CID spectra.     

Nickel(II) Phosphane- and N-heterocyclic Carbene Complexes with Tridentate,Dianionic [S,N,O]2– Ligands

Square-planar dinuclear nickel(II) complexes containing [S,N,O]^2– ligands formed by condensation of acetyl acetone or benzoyl acetone with cysteamine were prepared. These dimeric nickel(II) compounds undergo bridge-cleavage reactions with the cage phosphine PTA (PTA = 1,3,5-triaza-7-phosphaadamantane) or in situ generated N-heterocyclic carbenes. The resulting diamagnetic, square planar Ni^II complexes were characterized by spectroscopic methods and X-ray diffraction.