So its been a while since I studied maxwells equations, anyway: So From my ignorant perspective, trying to derive conceptual meaning from these, I can see that the time dependant study there is some conductivity x the partial differential of the magnetic vector potential plus the cross product of mu*B which is H minus SOMETHING? equals the electron current density. I don't really remember what the magnetic vector potential is (well, that is to say, I remember not really understanding it when I tried learning about it in the first place), or the last term....or what the cross product of H is. I'm at a similar loss regarding the Frequeny Domain study. To be honest all I really remember about the cross product is that it is perpendicular to the two vectors being multiplied. If any one can offer a more indepth explanation of these formulas in English, I mean some maths is fine, but for a layman, that'd be great. Cheers!!