Dual substitution induces room-temperature ferromagnetism and negative thermal expansion in BiFeO₃

Using a dual-cation substitution approach, researchers at Science Tokyo introduced ferromagnetism into bismuth ferrite, a ...
EDN

Using the substitution theorem to derive Thevenin resistance values with SPICE

Thevenin and Norton equivalent circuits [1-3] are a valuable analytical tool for circuit designers and researchers. How to obtain the Thevenin resistance and Norton conductance of a network with ...