Accelerated urbanization places extraordinary demands on sewer networks; thus optimization research to improve the design of these systems has practical significance. In this article, a subsystem nonlinear programming model is developed to optimize pumping station layout and sewage pipe network design. The subsystem model is expanded into a large-scale complex nonlinear programming system model to find the minimum total annual cost of the pumping station and network of all pipe segments. A comparative analysis is conducted using the sewage network in Taizhou City, China, as an example. The proposed method demonstrated that significant cost savings could have been realized if the studied system had been optimized using the techniques described in this article. Therefore, the method has practical value for optimizing urban sewage projects and provides a reference for theoretical research on optimization of urban drainage pumping station layouts.

Considering the intertwining of information technology and engineering specialty courses, research on the application of the "Five-in-one" teaching mode based on building information modeling (BIM) in the teaching of engineering specialty courses is practical and significant. This article comprehensively analyzes the research status of the teaching mode of engineering courses in China and the integration of BIM in the teaching of specialized courses. On the basis of the personnel cultivating programs for various engineering majors in combination with the three-dimensional information model, BIM, this study proposed the "Five-in-one" teaching mode covering aspects of scenario creation, new knowledge exploration, knowledge application, thinking training, and teamwork. This teaching mode is adaptable to the reform of engineering classroom teaching and it complements professional talent training goals. The "Five-in-one" teaching mode guides students to learn to choose and develop actively, enabling them to become the core of the classroom. The academic performances of students are studied using variance and covariance analysis models, forming a complete set of analysis results. This study uses the teaching practice of the BIM-based "Five-in-one" teaching mode in the engineering courses of an application-oriented university in Guangxi as an example. The results obtained show that this method achieved good results. The students' mastery of basic knowledge, basic skills, and basic thinking methods of the subject improved significantly. Thus, theoretical references for the practice and research of the teaching mode of professional courses for application-oriented universities at home and abroad have been provided.

In this study, a secondary subsystem mathematical model is established under the condition that the layout of the sewage collection branch, trunk, and main pipe network projects is fixed. The sewage collection branch and trunk pipe network projects are treated as the research objective by taking the minimum annual cost of the sewage collection pipe network projects as the objective function, the longitudinal slope of the pipe section and the economic flow rate of the pipe section as constraints, and the diameter of the pipe section as the decision variable. A first-level subsystem mathematical model is established by taking the sewage collection branch, trunk, and main pipe network project as the research object. A large system mathematical model is established in the same manner. This model can be solved using the large system secondary decomposition–dynamic programming aggregation method, and the optimal diameter for each pipe section can be obtained. A regional sewage collection pipe network project in Taizhou city was considered as an example for comparative analysis before and after optimization, and the results verified that the optimization method proposed in this study can solve this complex large system optimization problem.

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Expanding tube separation device is a commonly used linear separation device, whose energy resource is a shielded mild detonation cord (SMDC). In this research, the SMDC is a mild detonation cord sheathed in flat polyethylene. Two experiments were achieved to discuss the energy output efficiency of the SMDC. In the first experiment, the SMDC was inserted into 1060 aluminum cylinder directly. While in the other experiment, the SMDC was insert into aluminum cylinder after contained within a flat steel tube. The velocity and displacement of the characteristic points on the outer surface of the aluminum cylinder during explosion were measured by photonic Doppler velocimetry (PDV). The simulation results with Ls-dyna fluid-solid coupling algorithm correspond well with the experimental results. According to the simulation analysis, the distribution of total energy of explosives were obtained. The plastic strain energy of the aluminum cylinder corresponds to the ability of the SMDC to do external work. The result shows that, 39.3% of the total energy in the explosive is output to aluminum cylinder with SMDC acting on it directly, while the energy output efficiency turns to 20.8% after passing through the flat tube.