1. The ions of Ca and K condition general luminescence, and are therefore necessary to the conduction of the impulse. 2. In van't Hoff's solution from which Mg is omitted, Beroe shows hyperirritability with respect to luminescence. This is the result of the action of Ca and K ions unantagonized by Mg. 3. The luminescent material spread on filter paper does not show luminescence in sea water, Na...

Vibrio fischeri ES114, an isolate from the Euprymna scolopes light organ, produces little bioluminescence in culture but is ∼1,000-fold brighter when colonizing the host. Cell-density-dependent regulation alone cannot explain this phenomenon, because cells within colonies on solid medium are much dimmer than symbiotic cells despite their similar cell densities. To better understand this low lum...

The defect structure of CdTe substrates has often been investigated with luminescence techniques. In particular, a luminescence band normally referred as the 1.40 eV band, has been associated with recombination processes involving defects but its nature seems to be complex. Myers et al.’ in their photoluminescence study of CdTe wafers concluded that a significant part of the 1.40 eV band is dir...

The up-conversion luminescence of Zn1−xMgxS:Mn 2+ nanoparticles fabricated by an inorganic precipitation method is studied by using a near-infrared femtosecond laser. The up-converted luminescence is blueshifted when increasing the Mg composition because of weaker crystal field effect. Comparing with thin films, the luminescence of Zn1−xMgxS:Mn 2+ nanoparticles shifts several nanometers to the ...

By combining a high frequency modulation system for measurement of fluorescence with a phosphoroscope type apparatus for measurement of luminescence, recordings of fluorescence and luminescence induction kinetics under identical conditions were obtained. Both measuring sys­ tems tolerated the application of saturating pulses of white light for rapid, transient elimination of photochemical quenc...

Thiol-capped CdTe nanocrystals with cubic zinc blende structure are synthesized in aqueous solution. Their steady-state and time-resolved luminescence characteristics are studied at room and liquid nitrogen temperatures. A strong exciton luminescence peak at 2.3 eV dominates the emission spectrum of CdTe nanocrystals at room temperature, whereas the trap band centered at 2.0 eV undergoes substa...

Optical properties of Er doped Si=SiO2 superlattices and SiO=SiO2 superlattices are compared. In the case of Si=SiO2 superlattices with Si layers thicknesses between 2 and 19 nm polycrystalline like Si layers are observed after annealing. The samples show a very weak defect related red room temperature luminescence. No significant enhancement of the Er luminescence could be shown. The SiO=SiO2 ...

the mixed metal nanocomposite mgo∙al2o3∙zno has been prepared by coprecipitation method. the product was characterized by xrd. the average particle size was found to be 34.89 nm from xrd data. sem and sem-eds were studied for evaluating surface morphology and elemental composition. the ftir spectrum of prepared mixed metal nanocomposites mgo∙al2o3∙zno and mgo∙al2o3∙zno-curcumin were studied. th...