Formation of cristobalite in lead borosilicate glass at 700° C is completely prevented by addition of 5-10 vol% alumina. Thermal expansion results show that, in contrast to the sample without a sufficient amount of alumina, the thermal expansion coefficient of the cristobalite-free sample remains relatively unchanged with sintering time at the temperature investigated, and is close to those theoretically calculated.
An ultra-thin compact frequency selective surface with dual passband, which can be independently tuned, has been designed. It produces two passbands at 8.2 and 11.4 GHz with transmission zeros on both sides of the passband to improve frequency selectivity. The electromagnetic coupling structure makes the overall structure ultra-thin, and the singleended short resonator reduces the unit size. Simulation was performed to demonstrate the effectiveness of the design.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.