Binary Lead Fluoride Pb3F8

The binary lead fluoride Pb₃F₈ was synthesized by the reaction of anhydrous HF with Pb₃O₄ or by the reaction of BrF₃ with PbF₂. The compound was characterized by single-crystal and powder X-ray diffraction, IR, Raman, and solid-state MAS ¹⁹F NMR spectroscopy, as well as thermogravimetric analysis, XP and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Solid-state quantum-chemical calculations are provided for the vibrational analyses and band assignments. The electronic band structure offers an inside view of the mixed valence compound.     

Estimating non-linear functions of the spectral density,using a data-taper

Letf() be the spectral density of a Gaussian stationary process. Consider periodogram-based estimators of integrals of certain non-linear functions off(), like , where () is a bounded function of bounded variation, possibly depending on the sample sizeT. Then it is known that, under mild conditions on , a central limit theorem holds for these statisticsH _T if the non-tapered periodogramI _T() is used. In particular, Taniguchi (1980,J. Appl. Probab.,17, 73–83) gave a consistent and asymptotic normal estimator of , choosing to be a suitable transform of a given function . In this work we shall generalize this result to statisticsH _T where a taper-modified periodogram is used. We apply our result to the use of data-tapers in nonparametric peak-insensitive spectrum estimation. This was introduced in von Sachs (1994,J. Time Ser. Anal.,15, 429–452) where the performance of this estimator was shown to be substantially improved by using a taper.This work has been supported by the Deutsche Forschungsgemeinschaft.     

Measurement of spin-transfer observables in p p-->Lambda Lambda at 1.637 GeV/c

Spin-transfer observables for p p-->Lambda Lambda have been measured using a transversely polarized frozen-spin target and a beam momentum of 1.637 GeV/c. Current models of the reaction near threshold are in good agreement with existing measurements performed with unpolarized particles in the initial state but produce conflicting predictions for the spin-transfer observables Dnn and Knn (the normal-to-normal depolarization and polarization transfer), which are measurable only with polarized target or beam. Measurements of Dnn and Knn presented here are found to be in disagreement with predictions from these models.     

Ungleichungen für Umfang,Flächeninhalt und Trägheitsmoment konvexer Kurven

Ohne Zusammenfassung Vorgelegt von G. Hajós     

Spacetimeb-boundaries

It is shown that Schmidt'sb-boundary for a spacetime can be analyzed using a submanifold of the tangent bundle, rather than the principal bundle or the bundle of orthogonal frames.