A Pokemon can only hold 1 item, if you were asking about it having the Power Bracer AND exp. share. If you were going to give the Power Bracer to Axew and give the exp. share to another Pokemon, Axew will gain boosted ev's and a smaller amount of exp, and the Pokemon with the exp share will obtain no ev's, but it will get a small amount of exp.
I hope this answers your question! -Jellohamster