Die sowjetische Politik im hohen Norden

Available from Bibliothek des Instituts fuer Weltwirtschaft, ZBW, Duesternbrook Weg 120, D-24105 Kiel C 155323 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Die sowjetische Politik im hohen Norden

SIGLEUuStB Koeln(38)-890106080 / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman

Visual resolution with retinal implants estimated from recordings in cat visual cortex

We investigated cortical responses to electrical stimulation of the retina using epi- and sub-retinal electrodes of 20-100 microm diameter. Temporal and spatial resolutions were assessed by recordings from the visual cortex with arrays of microelectrodes and optical imaging. The estimated resolutions were approximately 40 ms and approximately 1 degrees of visual angle. This temporal resolution of 25 frames per second and spatial resolution of about 0.8 cm at about 1m and correspondingly 8 cm at 10 m distance seems sufficient for useful object recognition and visuo-motor behavior in many in- and out-door situations of daily life

Status of the rising project at relativistic energies

The RISING project was designed to perform high-resolution gamma-ray spectroscopy with radioactive beams at GSI. Unstable beams were produced by fragmentation of relativistic heavy ion projectiles provided by the SIS synchrotron. The fragment separator FRS was used to select and to focus the exotic fragments at about 100A MeV energy on a secondary target. Various charged particle detectors enabled an event-by-event tracking of the incoming radioactive projectiles and the reaction products, thus allowing for a selection of the nuclei of interest and their velocity vector reconstruction. The gamma-ray detection system consisting of the EUROBALL Cluster Ge detectors and the large volume HECTOR BaF2 detectors measured prompt gamma-radiation from nuclei excited in the secondary target. Despite the huge Doppler shift due to the high recoil velocity (beta approximate to 40%), RISING achieved a gamma-energy resolution below 2%. The paper reviews the present status of the RISING project