The environmental contamination caused by tetracycline hydrochloride (TC) has aroused widespread concern, photocatalytic degradation of TC has become an effective method. CeO₂ was prepared by coprecipitation method, and solvothermal synthesis of CeO₂@UiO-66 composite catalysts. The prepared catalysts were characterized by FT-IR, XRD, SEM and EDS respectively, and the effects of the amount of CeO₂, catalyst mass concentration and H₂O₂ mass fraction on the photocatalytic degradation of TC were also investigated. The results showed that CeO₂@UiO?66 was successfully synthesized. When the amount of CeO₂ substance is 25 mmol, the mass concentration of TC solution is 20 mg/L, the mass concentration of catalyst is 0.2 g/L, and the mass fraction of H₂O₂ is 2%, CeO₂@UiO?66 photocatalytic effect is the best, and the TC degradation rate reaches over 98% when irradiated by UV lamp for 70 min. The free radical trapping experiments showed that holes and ·OH were the main contributors in the photocatalytic process. In addition, after six cycles, the degradation rate of TC composite photocatalyst can still maintain above 85%, which indicates its good stability.

In order to determine the reasonable shape of the patching plate for the corrosion defects in the bottom of crude oil storage tank, this paper used finite element analysis to calculate the changes of the stress value in the corrosion defects after repairing different patching plate shapes, and then investigated the stress distribution and the safety factor value of the patching plate, and finally gave the best shape of the patching plate for the bottom of 20 000 m³ crude oil storage tank in Liaohe oil field. The results show that the best shape of the patching plate is a round patching plate. After repairing the corrosion defect, the stress value in the corrosion defect only decreases with the increase of the radius of the patching plate after the repair of the corrosion defect, and does not change with the change of the depth and radius of the defect. With the increase of the radius of the patch plate, the cost and safety of the patch plate will also increase, the specific size of the patch plate should be developed in accordance with the actual situation of the project. The results of the study can give theoretical guidance to the tank bottom repair from a scientific point of view.