It means attaching one thing to another. Gardeners sometimes 'graft' part of one plant onto another to get the two to grow together as one plant. In this case, people are applying modern research techniques/findings to ancient philosophy.

grafting means making something out of nothing. Or simply working on to make something out of nothing. -.- this was harder to explain then i thought. You are trying to form modern research into Confucian philosophy. sorry for the bad explanation ^^