Both high brightness and high efficiency of polymer light-emitting diodes can be obtained by electrical annealing after an appropriate thermal treatment. Light-emitting diodes made of poly @2-methoxy-5-~28-ethyl-hexyloxy!-1,4-phenylene vinylene# ~MEH-PPV! with an Al electrode were used for this study. Thermal annealing after Al deposition dramatically enhanced the luminous efficiency of electro...

Physikalisch-Technische Bundesanstalt, Abteilung Optik, Photometrie, Postfach 33 45, 38023 Braunschweig, Germany A trilateral intercomparison of photometric units between NIST (USA), NPL (UK), and PTB (Germany) has been conducted to update the knowledge of the relationship between the photometric units disseminated in the three countries. The luminous intensity unit (cd), the luminous responsiv...

We investigate the galaxy populations in seven X-ray selected, intermediateredshift groups (0.2 < z < 0.6). Overall, the galaxy populations in these systems are similar to those in clusters at the same redshift; they have large fractions of early-type galaxies (fe ∼ 70%) and small fractions of galaxies with significant star formation (f[OII] ∼ 30%). We do not observe a strong evolution in the g...

introduction: lasers, light emitting diodes (leds) and super luminous diodes (slds) are widely used to treat selected musculoskeletal, integumentary and neurological conditions. the mechanisms underlying the reported treatment effects of light therapy are unclear and the physiologic effect of light on a variety of tissues, particularly neurological, is mostly unknown. a few researchers have rep...

We present the first large-scale study of E+A galaxies that incorporates photometry in the ultraviolet (UV ) wavelengths. E+A galaxies are ‘post-starburst’ systems, with strong Balmer absorption lines indicating significant recent star formation, but without [OII] and Hα emission lines which are characteristic of ongoing star formation. The starburst that creates the E+A galaxy typically takes ...