Fantasy/Sci-fi / Sci-fi/Fantasy Crossover

I think I read this in the mid naughties..

...two civilizations exploring out from their own world's through portals. One based on magic, the other on science. Inevitably bump into each other and have a fight. The dragons are like jets and firestrikes are called down on machine gun nests. The magic guys have teleportation crack troops I think. The portals go through to varying altitudes so sometimes when they are formed oceans crash through or there are tremendous winds as pressures stabilise. The first book ends with some protagonists from the tech side being dragged off to the magic world whilst I think the exploratory magic force gets stopped in it's tracks. There was a sense that the further they got away from there source world the less effective their gifts became.. So tech started malfunctioning and magic started getting weaker, I think.

It's been a long time since I read it but I got the impression it was the first book in a series and I'd love to reread it and read the rest if you can help me track it down.. Thanks in anticipation!