Catalysts CuCe?OH and CuCe?CO₃ were prepared by hydrothermal method using KOH and K₂CO₃ as precipitating agents. The catalyst was characterized by XRD, BET, H₂?TPR and TG?DTA, and its CO catalytic oxidation performance was evaluated by a fixed bed reactor. The results show that the type of precipitator not only has a great influence on the texture properties of the catalyst, but also determines whether the CuCe catalyst without heterocrystalline phase can be successfully prepared. The specific surface areas of CuCe?OH and CuCe?CO₃ catalysts were 96.5 m²/g and 17.3 m²/g, respectively. Under the evaluation conditions of 60 000 mL/（g·h）, CO volume fraction of 0.6%, O₂ volume fraction of 1.5%, Ar volume fraction of 97.9%, CuCe?OH catalyst showed good catalytic activity, and CO conversion reached 99.0% at 140 ℃.

The finite element model of the bolt flange washer was established, and the fastening experiment of the DN500 bolt flange connection system was carried out to verify the rationality of the finite element model. By controlling the width of the nut washer and the medium pressure of the pipeline, the effect of adding the nut washer on the stress distribution on the washer and bolt was compared and analyzed. It was found that adding a reasonable sized nut washer can not only increase the contact area between the nut and the flange surface and increase the compressive stress on the gasket, but also in the case of high bolt pre?tightening load and medium pressure. Prevent the bending deformation of the bolts and the pressure failure of the washers, increase the service life of the bolts, and improve the overall sealing performance of the bolt flange connection system.

In order to study the sealing performance of bolted flange connection system under high temperature condition, the thermal?structural coupling analysis of bolted flange connection system under 400.00 ℃ was carried out by Ansys?Workbench. The results show that the temperature decreases gradually from the inside of the flange wall to the outside, the maximum stress appears on the contact surface between the nut and flange, and the maximum strain appears on the gasket. Evaluated the sealing performance of gaskets at room temperature and 400.00 ℃; at the same time, aiming at the easy sealing failure of gaskets in the connection system under high temperature, established gasket strength failure of bayesian networks, based on a series of methods such as expert evaluation to calculate the prior probability, used Bayesian network reverse reasoning to calculate the posterior probability of the root node and sort them to find out the main factors leading to the invalid gasket, so as to enhance the reliability in the process of using gasket.

In recent years, with the increasing demand for natural gas, more and more attention was paid to the transmission efficiency of gas transmission pipeline. Because the main loss of gas pipeline was the friction resistance, therefore reducing the resistance became the focus of the study. To explore the Vshaped riblets in transmission gas pipeline of drag reduction application, FLUENT was used to simulate two different geometric size of Vshaped riblets. The pipeline drag reduction of bionic riblets could approximate switch into flat gas transmission for numerical simulation. The results of the study showed that: compared with the smooth gas transmission pipeline, Vshaped riblet gas transmission pipeline of the turbulent boundary layer of velocity profile in the logarithmic layer was different| in the same gas velocity inlet, Vshaped riblet at the top of the shear stress was greater than the bottom of the riblet, also riblet on the bottom of the near wall local turbulent kinetic energy was small| the riblet height and spacing size of both 0.90 mm Vshaped riblet pipeline had more drag reduction effect than the size of both 0.51 mm Vshaped riblet pipeline.

The steel pipe was eroded easily in the acid alkali chemical environment and damp environment. In order to improve the durability and bearing capacity of the structure, the GFRP-concrete-PVC tube new type composite column was put forward on the basis of the research of steel tubular concrete column and GFRP tube concrete column. The GFRP-concrete-PVC tube column was designed to analyze the composite column axis pressure performance and the ANSYS for GFRP-concrete-PVC tube column was used to analyze the assembly axial compression column numerically.  The results showed that the bigger was the concrete strength, the bigger was ultimate bearing capacity of GFRP-concrete-PVC tube composite column, but the smaller was the increasing-rate of bearing capacity. With the increase of concrete strength, the constraints ferrule effect of GFRP outer tube to core concrete was reduced. The composite column constraint ability was the largest when concrete strength was C30, the ferrule constraint factor was 2.31.