Both the kind and amount of {HEAD ~ the cross} linking {TAIL ~ substance} added and the energy input of the subsequent irradiation then control the hardness of the material of the second region 
linking
Both the kind and amount of { HEAD ~ the cross } linking { TAIL ~ substance } added and the energy input of the subsequent irradiation then control the hardness of the material of the second region
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH