Abstract: A high strength cast magnesium alloy, relating to the technical field of magnesium alloy material preparation. The composition and mass percentage of cast magnesium alloy are: Zn 7.0%, Al 3.0%˜5.0%, Mn 0.3%˜0.5%, RE 0.5%˜1%, the total amount of unavoidable impurities is less than or equal to 0.04%, and the allowance is Mg, wherein the RE includes La and Ce, La and Ce account for 35% and 65% of the total amount of RE, respectively. Among them, Mn, La and Ce are added in the form of Mg-5 wt. % Mn, Mg-30 wt. % La and Mg-30 wt. % Ce intermediate alloys respectively. Then it is prepared through battering, melting, melt purification, pouring and heat treatment. By adding RE, the alloy melt can be purified, and the corrosion resistance and casting performance of the alloy can be increased. The tensile strength of the alloy is 300 MPa˜314 MPa, the elongation is 7%-13%, and the light rare earth content is low, the raw material and processing cost is low, and it is easy to realize mass production.

Abstract: A well constrained transverse variable height-velocity curve constructing method for seismic wave velocity field construction involves the steps of: a) calculating interval velocity of each stratum by a sonic logging curve, and calculating the conversion horizon velocity of each horizon; b) drawing a circle to collect well points; c) calculating the characteristic parameter values of the height-velocity curve by the interval velocity and the conversion interval velocity of each well; d) calculating the characteristic parameter values by Kriging interpolation.

Abstract: A well constrained horizontal variable height-velocity curve constructing method for seismic wave velocity field construction involves the steps of: a) calculating horizon velocity of each horizon by a sonic logging curve, and calculating the conversion horizon velocity of each horizon; b) drawing a circle to collect well points; c) calculating the characteristic parameter values of the height-velocity curve by the horizon velocity and the conversion horizon velocity of each well; d) calculating the characteristic parameter values by Kriging interpolation.