Particle detection properties of charge coupled devices

A detailed quantitative analysis of particle events observed in Charge Coupled Devices (CCDs) requires the knowledge of particle detection properties of the employed CCDs such as the detection threshold for energy deposition, efficiency for different kinds of radiation and the relation between the signal and the deposited energy inside the sensitive volume. For this purpose the CCD-chip was described by a simple geometrical model containing the effective thicknesses of the p-n semiconductor junctions dj and a covering dead layer d_T above them as parameters. The corresponding geometrical quantities were experimentally estimated to be 1.3 μm and 0.9 μm respectively by using different kinds of radiation.     

A detector telescope with charge coupled devices for particle dosimetry in space

A telescopic device with charge coupled devices (CCDs) for particle dosimetry in space has been developed. Data on ionization events of energetic particles passing the CCDs are processed in an image analyzing system of a PC. As ‘Charged Particle Telescope’ (CHAPAT), the equipment was flown on the russian space station MIR during the EUROMIR mission in 1995. The response of the CCDs to various charged particles and methods for the discrimination of heavy particles in CCDs are discussed. First results of a correlation of temporal particles fluxes to the actual orbital parameters of MIR clearly identify passages through the South Atlantic Anomaly (SAA).     

New tetrahydroanthraquinones from the genus Cortinarius

Austrocortirubin and austrocortilutein the first hydroxylated tetrahydro-anthraquinones from Basidiomycetes, have been isolated from an Australian toadstool belonging to the subgenus Dermocybe of Cortinarius.     

1,1-Dithiooxalsäurederivate als Liganden in Übergangsmetallkomplexen: Struktur von O-Methyl-1,1-dithiooxalato-bis(triphenylphosphin)kupfer(I) und -silber(I)

1,1-Dithiooxalic Acid Derivatives as Ligands in Transition Metal Complexes: Structure of O-Methyl-1,1-dithiooxalato-bis(triphenylphosphine)copper(I) and silver(I) Despite O-Alkyl-1,1-dithiooxalates are also tetradentate thioligands their tendency towards the formation of multi-nuclear bridged chelates as found for the basic 1,1-dithiooxalate does practically not exist because of derivatisation. The reaction with triphenylposphinemetal(I)-halogenides yields defined mono-nuclear mixed ligand complexes: O-Methyl-1,1-dithiooxalato-bis(triphenylphosphine)copper(I) ( 2 ) and silver(I) ( 1 ). X-ray analysis shows that both complexes ( 1 and 2 ) are isostructural and crystallize in the monoclinic space group P2₁/n: (Ph₃P)₂Ag(S₂C₂O₂Me) ( 1 ) with a = 12.794(1), b = 21.314(4), c = 13.560(1) Å, β = 97.983(6)°, and (Ph₃P)₂Cu(S₂C₂O₂Me) ( 2 ) with a = 12.622(1), b = 21.196(2), c = 13.426(1) Å, β = 96.533(7)°. These complexes are the first authentic examples of exclusively end-on coordinated thiooxalate.     

The Suitability and Usage of 18O and Chloride as Natural Tracers for Bank Filtrate at the Middle River Elbe

Abstract

Flow times and infiltration behaviour are very important for water extraction from riverbank filtration. Both the chloride content and the isotopic composition of oxygen (δ¹⁸O) were found to be suitable indicators for the conditions encountered in the middle course of the River Elbe near Torgau. The ranges for Elbe water were measured to be 20–43 mg Cl/l (1995-97) and -11 to -8.5‰ δ¹⁸O (1993-97). Both methods permitted flow-time spectra at two adjacent sampling profiles incorporating river and production wells to be obtained, indicating the preferred flow paths and the vertical extension of the riverbank filtrate plume in the aquifer. However, since the differences between the mean values for river water and regional groundwater were too small the percentage of river water abstracted from production wells could not be calculated.     

Stable Isotope Geochemistry of Antarctic Salt Efflorescences

Salt efflorescences consisting of gypsum sampled mainly in the Schirmacher Oasis have been analyzed for the isotopic composition of the water of crystallization and of the sulphate-sulphur. For comparison, a few samples from other Antarctic locations (Guettard Range, Prince Charles Mts., Insel Mts.) were included in the study. The isotopic variations of the water of crystallization of secondary gypsum and the calculated isotopic composition of the mother solution reflect the local climatic conditions during the precipitation of the efflorescences. It is therefore possible to obtain qualitative information about the climatic conditions prevailing in the studied region.