a, Positive and negative magnetoresistance for reverse-biased ITO/MEHPPV(60 nm)/Al and forward-biased ITO/PVK(60 nm)/Al OLEDs.The insets show the chemical structures of MEHPPV and PVK. b ...

Scientists have created “soft” magnets that can flow and change shape, ... The solid magnet caused the positive and negative poles of the liquid magnets to follow the external magnetic ...

We tend to think of magnets as binary. Batteries have positive and negative ends. Compasses point north and south. And, until late last year, there were two kinds of magnetism: ferromagnetism and ...