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On the basis of Tianyou Liu start-up pressure calculation model, the restart pressure model was divided into three parts. Considering the pressure drop caused by elevation difference along the pipeline, friction pressure drop was solved by pipe regional discretization and Houska thixotropic model was used in the pressure drop caused by thixotropic factor. A new calculation method of waxy crude oil pipeline restart pressure was set up and Qin-Jing Pipeline data were substituted into corresponding analog computation. Calculation results are in conformity with the actual situation and the new calculation method is more widely applicable.

In this study, three kinds of natural clay minerals (kaolin clay, montmorillonite and diatomaceous earth) were used to treat the raw water containing humic acid (HA) by adsorption/sedimentation. The results indicated that natural kaolin clay had no obvious effect on removing HA in water. Using chitosan to modify montmorillonite and diatomaceous earth, the removal effect of the modified diatomaceous earth for HA was better than modified montmorillonite, and the optimal ratio between chitosan and diatomaceous earth was 1:30. Compared with natural diatomaceous earth, the modified clay had better adsorption property for HA at the same dosage. Using modified diatomaceous earth, the maximal removing rates for TOC and turbidity could respectively reach 85.9% and 64.6% with 60 mg/L dosage and 50 min.

Algae and bacteria blooms in eutrophication in summer have made the quality of landscape water degradation. Treatment efficiency of potassium monopersulfate compound, a new kind of oxidation reagent, on killing algae and bacteria has been valued and the effect of influence factors, such as dosage, contact time and temperature are also discussed. The results indicated that potassium monopersulfate is appropriate for killing algae and bacteria in landscape water, dosage and contact time are the major influence factors. The contact time should be longer than 20min and the algicidal rate is higher when the temperature is above 20°C.

As heating transportation technology is widely used in waxy crude pipelines, elements that affect flow safety in pipeline transportation are uncertain and have wave property, thus impacting safety margin variation of the heater. This text proposes an assessment method for direct-heater performance of waxy crude pipeline station and establishes the risk assessment model for heater techniques based on waxy crude flow safety, to technically support safe and efficient waxy crude transportation.

In allusion to environmental pollution brought about by wastewater irrigation, EM technology was introduced to study the feasibility of EM application in wastewater irrigation. The results show that EC, NO3--N and TN value of EM treatment in shallow groundwater are all less than those of WW treatment as a whole. In all samples, 59.3% NO3--N values are in the alert status, and when irrigation amount reaches 360mm, treatment WW has caused shallow groundwater pollution. TN concentration in treatment WW-3 on June 27 and July 9 is more than 110 mg/L. It suggests that NO3--N can easily penetrate into shallow groundwater with wastewater irrigation and there is insurance of groundwater pollution in the long-term wastewater irrigation. It also indicates that application of wastewater treated by EM reused for irrigation is feasible. TP values are all very low and suggest the pollution of P does not happen.

A new soil-rock mechanics method—parallel cellular element method is introduced. In this method the integer analysis of structure is changed into a series of part analysis by using the idea of Cellular Automata. It may have a good future in soil-rock mechanics. The basic principle is introduced; the computing steps and results are presented. Based on the numerical results, the feasibility, advantages of cellular element method are discussed.

With a small cross section, a light deadweight and a convenient replaceable tendon, externally prestressed bridges have many special traits compared with other bridges. With a practical case, this paper analyzes the design of externally prestressed steel box girder bridges, which contains the bridge span, beam construction, externally prestressed layout, substructure and construction programs. Through economic, social analysis, discusses the prospects for the application of external prestressing structure .

The externally pre-stressed steel-box girder bridge is a novel structure, it has the advantage of lightness, less height and fast construction speed. The structure has a very bright application prospect in the future. Seismic effect of this kind of bridge was analyzed with the finite element method in combination of engineering practices. The dynamic characteristics, dynamic response under the action of E1 and E2 was calculated. The results of first five natural frequencies, mode of vibration, internal force and deflection under the action of seismic were listed and discussed. The results show that the externally pre-stressed steel-box girder bridge has a good seismic performance.

The combined three-section crossbeam is an important component in the heavy gantry CNC milling-lathing machine tool and the dynamic characteristics are key precision factors for the machine tool. Three sections of the combined crossbeam are bolted by large industrial bolts and the influence of bolted joints should be evaluated in the dynamic analysis of the combined crossbeam. The dynamic characteristics of the combined three-section crossbeam were extracted by the modal experiment. The FEM of the monolithic crossbeam was modeled to analyze the dynamic characteristic parameters. The comparison of the analysis result and experimental result were shown. The experimental result matched well with the FEM of the monolithic crossbeam without bolted joints. As a result, the influence of the bolted joints could be ignorable in dynamic characteristic for the combined three-section crossbeam.

To verify the existing sports bicycle frames design and to achieve the fast and accurate self-design of frames, a simulation model of the frames is established during three development processes. First, the modal and static tests were designed for the study of a particular sports bicycle frame. Second, the initial simulation model of the frame was developed with Pro/Engineer and ANSYS Workbench software, and the simulation model was used to conduct the modal and static analysis on the frame. Finally, based on the comparison of the analysis and test result, the parameters of the simulation model were modified. The results show that the simulation model is consistent with the test result and it can be used for the optimal design of sports bicycle frame.