Well I know you can link your Steam account to Uplay but I think that's only for games purchased on Steam (Most Uplay titles on Steam require Uplay anyways) which I would assume add that to your Uplay library (but still may have to launch through Steam not entirely sure of this.) However, I don't think the process adds any Uplay purchased titles to your Steam account. I believe the only way to add your Uplay purchased games on Steam is to add them to your library as a Non-Steam game. This will not show the game as in your library on the Steam store page (nor can you purchase any DLC for the game from the Steam store) but it can be launched from your Steam client in this way.

tl;dr Yes, but only as a manually added non-steam game.