The development of industrial applications in lighting and flat color display screens based on a xenon plasma discharge, which generates VUV radiation within an energy range of approximately 8.5 to 7 eV (145 and 180 nm), has induced a revival of interest in VUV-excited phosphors and in VUV spectroscopy using synchrotron radiation facilities. Both applications need very efficient and stable phosphors under ionizing conditions. In addition, mercury-free fluorescent lamps require, phosphors with...| www.sciencedirect.com
There is considerable variation in the ratio of palisade to spongy mesophyll, e.g., some leaves of some species may appear to have all palisade mesophyll and others all spongy mesophyll. In addition, this ratio may vary in the same tree depending upon whether the leaves are exposed to the sunny conditions of the top of the canopy or the darker conditions of the middle and lower parts of the canopy.| The William & Lynda Steere Herbarium