Farbe und Fluoreszenz der Farbstoffe im kapillaranalytischen Bilde

Zusammenfassung Es wird die Farbe und die Lumineszenz von ca. 40 gut definierten Farbstoffen unter verschiedenen Versuchsverh?ltnissen (fest, in neutraler, saurer, alkalischer, alkoholischer L?sung und in kapillarisiertem Zustande) bestimmt. Die Farbe von Farbstoffen im Tages- und im filtrierten ultravioletten Lichte zeigt bedeutende Unterschiede bei Untersuchung in den genannten verschiedenen Zust?nden des Farbstoffes. Diese Lumineszenz- und Farbenunterschiede sind auf physikalisch-chemischer Grundlage deutbar. Die Trennung der Faser- und Flüssigkeitsfluoreszenz im Sinne der Gerngross's?hen Auffassung ist zu best?tigen. Diese Farben?nderungen stehen in keinem Zusammenhang mit der Metachromasie, so wie es Lehner annahm.     

Optimal management and inflation protection for defined contribution pension plans

Due to the increasing risk of inflation and diminishing pension benefits, insurance companies have started selling inflation-linked products. Selling such products the insurance company takes over some or all of the inflation risk from their customers. On the other side financial derivatives which are linked to inflation such as inflation linked bonds are traded on financial markets and appear to be of increasing popularity. The insurance company can use these products to hedge its own inflation risk. In this article we study how to optimally manage a pension fund taking positions in a money market account, a stock and an inflation linked bond, while financing investments through a continuous stochastic income stream such as the plan member’s contributions. We use the martingale method in order to compute an analytic expression for the optimal strategy and express it in terms of observable market variables.     

On combinatorial and affine automorphisms of polytopes

We disprove the longstanding conjecture that every combinatorial automorphism of the boundary complex of a convex polytope in euclidean spaceE ^d can be realised by an affine transformation ofE ^d .     

Growth and Characterization of BPO4 Single Crystals

Single crystals of BPO₄ were grown by chemical transport reactions with PCl₅ using a gradient from 1073 K to 973 K as well as with solvothermal syntheses in the temperature range between 413 K and 523 K using water, ethanol or 2‐propanol as polar protic solvents. The atomic arrangement of BPO₄ was reinvestigated by means of single crystal X‐ray diffraction data and confirmed the earlier findings with significantly smaller standard deviations. Thermogravimetric investigations of powdered samples which show no extra lines in X‐ray diffraction diagrams revealed weight decrements which are attributed to water losses. The presence of protonated borate and phosphate species in a number of X‐ray pure solvothermally grown BPO₄ samples is evidenced by infrared spectroscopy.     

Metal induced selectivity in phosphate ion binding in E9 DNase

Mass spectrometric and calorimetric data reveal that phosphate ion binding to the active site of colicin E9 DNase is delicately regulated by concomitant binding of specific transition metal ions.     

Nuclear reactions triggered by laser-accelerated relativistic electron jets

A relativistic electron beam, generated by relativistic self-focusing of an ultra-high-intensity laser pulse in a He gas jet, was targeted onto high-Z materials for conversion to high-energy bremsstrahlung. Nuclear reactions in the primary converter materials as well as in secondary and tertiary targets placed directly behind the converter were analyzed with time-resolved -spectroscopy. The electron-jet temperature of more than 35 MeV, matching the giant dipole resonances of heavy nuclei, enabled us to efficiently generate photo-induced nuclear reactions. The measured temperatures are significantly higher than suggested by ponderomotive scaling. We supplemented our earlier measurement of the (, n) reaction cross section of ¹²⁹I with a method solely based on nuclear reactions. The photo-induced transmutation yields were increased by two orders of magnitude compared to earlier experiments. Simulations with the Monte Carlo code MCNPX confirm the experimental results . PACS 52.38.Ph; 25.20.Lj     

Observation of laser-pulse shortening in nonlinear plasma waves

We have measured the temporal shortening of an ultraintense laser pulse interacting with an underdense plasma. When interacting with strongly nonlinear plasma waves, the laser pulse is shortened from 38 +/- 2 fs to the 10-14 fs level, with a 20% energy efficiency. The laser ponderomotive force excites a wakefield, which, along with relativistic self-phase modulation, broadens the laser spectrum and subsequently compresses the pulse. This mechanism is confirmed by 3D particle in cell simulations.