4.It's a mean of geotechnical investigation, including borehole surveying, costeaning, trenching exploration, test pitting, hole exploration, geophysical exploration and penetration sounding.
6.Modified larch tannin was prepared by grafting copolymerization and sulfoalkylation, and successfully used as retanning agent, possessing good water solubility and enhanced penetration rate.
7.The pattern of fracture by impact penetration test and tensile fatigue test of thermite welding with stereoscan was observed,and the component of defect with energy spectrum was analyed.