Thermal sensors based on ytterbium-erbium doped nano-glassceramics
Lead-fluoride nano-glassceramics doped with ytterbium and erbium have been developed and synthesized. The influence of heating on the green up-conversion luminescence of erbium has been experimentally investigated. Nano-glassceramics are promising candidates for temperature sensors.
SiO2–PbF2–CdF2 glasses and glass ceramics
Abstract Lead–Cadmium fluorosilicate stable glasses were prepared and the vitreous domain region determined in the composition diagram. Characteristic temperatures were obtained from thermal analysis and the structural studies performed illustrate clearly the role played by lead atoms in the glasses crystallization behavior and the glass-forming ability of cadmium atoms. The occurrence of either a cubic lead fluoride or a lead–cadmium fluoride solid solution in crystallizing samples was found to be dependent on Er3+ doping. The optically active ions were found to concentrate in the crystalline phase and in fact play the role of nucleating agent as suggested from X-ray diffraction and EXAFS measurements.
Effects of signaling topic structure on text recall
Two experiments studied effects of signaling devices (headings, overviews, and summaries) on text memory. In Experiment 1, subjects read a text with or without signals, then recalled the topics of the text. Signaling produced better memory for the topics and their organization. In Experiment 2, subjects recalled the content of the text they read, and recalls were scored for the number of accurately recalled ideas. Signals produced recalls that were better organized by text topics. Signals also influenced the distribution of recall of ideas: Subjects remembered more topics but recalled less about each accessed topic if the text they read contained signals than if it did not