The solidification and splash phenomena of Ni during plasma spray deposition were simulated by VOF model. The Navier?Stokes equations are solved in combination with the volume?of?fluid technique to track the free surface of the particles. In addition, the heat transfer including phase change is modeled using the enthalpy method. The coating formation process of nickel droplets at high speed was simulated by setting three different experimental conditions. The formation mechanism of nickel coating was analyzed deeply. During the spraying process of different speeds, the diffusion coefficient of higher droplet speed is greater than that of slower speed and there will be splash. In the case of different substrate temperatures, the higher the substrate temperature, the farther the molten particle tiling distance is. In addition, the diameter of the molten droplet is changed. Under the same other simulation conditions, the larger the particle diameter, the larger the spread distance, but it is not linearly related, and the larger the particle, the greater the thickness of the solidified sheet.

The stringent environmental management of petrochemical industries requires high⁃efficient waste disposals and wastewater treatment. Value⁃added and all⁃component resource technologies were insufficient for petrochemical wastes. Moreover, the advanced treatment of petrochemical wastewaters was lack of highly active and low cost catalysts. Based on the compositions of petrochemical wastes and ozonation catalysts, the present overview proposed that petrochemical wastewaters were treated using petrochemical wastes derived catalysts. Petrochemical wastes and wastewaters management might be synchronously improved by employing a "wastes⁃treat⁃wastes" strategy.

Because the risk factors for oil and gas transmission pipeline have complexity and fuzziness, and the factor weights are difficult to distribute. Therefore the entropy weight method was used to determine the factor weights, and the fuzzy comprehensive was used to evaluate the risk. First of all, the basic principle of entropy weight method and steps of fuzzy comprehensive evaluation method were briefly described. Then a section of oil conveying pipeline in Beijing area as an example, the risk evaluation index system was established and the factors weights were determined by using the entropy weight method. Finally, the risk level was determined by using the fuzzy comprehensive evaluation method, and the result was consistent with the judgment made by field experts. And according to the evaluation results, the corresponding prevention measures were proposed, so as to verify the feasibility of the method.