Extinction limits and flame bifurcation of lean premixed dimethyl ether-air flames are investigated numerically using the counterflow flame with a reduced chemistry. Emphasis is paid to the combined effect of radiation and flame stretch on the extinction and flammability limits. A method based on the reaction front is presented to predict the Markstein length. The predicted positive Markstein l...

about 35 samples were collected from lower and upper parts of the proposed frasnianamennian boundary in three sections of upper devonian marine sediments of the kerman province. the biostratigraphical and geochemical studies indicate that about 45% extinction of brachiopods probably caused by the frasnian-famennian bioevents, which is slightly higher than thr rate of devonian-carboniferous exti...

Metasurfaces have shown an unprecedented ability to modulate electromagnetic waves at subwavelength scales, especially polarized optical metasurfaces, applied for imaging, navigation and detection. In this work, a kind of efficient all-dielectric diatomic metasurface polarization phase changing, consisting pair GaAs nanopillar nanocube, is proposed. By adjusting the unit cell structural paramet...