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Based on the classical Mayer-arc model, this paper establishes the equivalent circuit of traction network for AC25kV electric railway from the essence of contact loss discharge. The voltage waves of contact loss arc at different moments are obtained by MATLAB/simulink. Through the analysis, it can be confirmed that the EMI (electromagnetic interference) with broad band and high amplitude will appear at the moment the contact loss between pantograph and catenary happens. Finally, relevant measures are given to avoid the probability event of contact loss.

Based on the transmission line theory, this paper applies the mode theory to predict the MTL(multi-conductor transmission line) crosstalk by selecting voltage as the research object, thus establish the model of estimating MTL crosstalk in inhomogeneous medium. Then make numerical calculation in MATLAB for the estimate model established in this paper, and also compare the calculated values with the simulated values in EMC studio. The compared results show that the calculated results of this model is highly consistent with the practical simulated values, verifying the correctness and feasibility of mode theory in MTL crosstalk prediction.

The paper establishes signal correlation processing mathematical model according to Ordinary differential equations with boundary value, which is introduced into the analysis on basketball virtual simulation sliding technique, and it designs the signal autocorrelation computer processing system. In order to verify the reliability and practicality of the system in the basketball technology analysis, this paper extracts the temperature signal using the FLUENT software, it obtains the isotherm diagram and temperature distribution cloud picture, verifies the effectiveness of the system. Finally, it verifies the practicality system in basketball technology analysis, taking analysis of back gliding speed rhythm of basketball as an example, and it gets the basketball shuffle rhythm control 3D signal response curves, which provides technical reference for basketball players.

Convert Inhomogeneous media space into infinite homogeneous medium space with method of image charges, obtain the relations between Inhomogeneous media wire bound charge and free charge rely on electromagnetic theory and deduced analytical the model of parasitic capacitance per unit length of Inhomogeneous dielectric wire in insulation in automotive cable harness. Taking a car harness for example, analytical formulas and Ansys Q3D Extractor software were used to calculation and analysis harness unit length parameter matrix. Among them, the algorithm of Ansys Q3D Extractor software to calculate the parasitic of automotive cable harness is two-dimensional static finite element method, numerical methods belong.

Coolant for gundrill under MQL is impermissible to be high pressure, large quantity, or direct emission on the interface. These restricts would be seriously unfavorable to lubrication. Experiments reveal that poor lubricating always appear on the hole periphery with dark burns on the hole wall. A prospective solution is to regulate the pressure distribution by modifying the dub-off structure. Its derivation is detailed in this paper. Its validity is demonstrated by practical experiments.

Customers’ individual and rapid product customization demands for 2K-V series reducers are taken as the study background. The rapid modeling method of the product skeleton and the parametric design method of the product level are studied. Products’ assembly models and templates of products’ skeleton models for series products are created on the basis of analyzing the structure similarity. Through changing parameters’ values of the skeleton template the product’s assembly model can be updated automatically and this template is rapidly transformed to the product instance so as to realize the rapid variant design. The above method not only is effective to 2K-V series reducers but also has reference value to others series products’ design.

The design load plays an important role in research on structural analysis of surface warship. The methods for the design loads have been proposed by many famous classification societies rules. In this paper the methods of the design loads from the native existing classification societies rules and foreign rules were studied, and based on these rules, the design loads of a warship were obtained. Meanwhile, segment model self propulsion tests of this ship were performed in heading waves in the seakeeping tank to confirm the design values. Comparisons of calculation of classification societies rules with experimental data were also conducted and results were summarized in this paper. It is concluded that the evaluation methods from the rules don’t take full account of the importance of slamming，the slamming moments from rules are fewer and wave moments are too large while those from BV rules give relatively conservative design values for the surface warship.

To understand the thermal distribution in a complex structure and high quality linkage casting, a mathematical model of temperature and stress field was established. Numerical simulation techniques was applied by using Procast software in the temperature and stress fields of solidification process, and the foundry defect such as old lap, misrun, shrinkage and dispersed shrinkage was predicted. The stress distribution and deformation in cooling process of casting were analyzed. The simulation results can supply a scientific foundation for foundry technology.

Nanocomposite tool materials are very important in engineering field for their advantage in mechanical properties and have a good foreground in the coming years. However, there are lots of puzzles in the materials design theory. So in this paper, a new nanocomposite tool materials design method is proposed based on the interface debonding theory. The wild phase content can be fixed by calculating the debonding interface rate and the strength requirement of the tool materials. Therefore, an experiment is carried out to fabricate WC based nanocomposite tool materials under the guider of the interface debonding theory. Results show that the experimental data is in accordance well with the calculation and the model is proved to be correct.

Wear behavior of WC based nanocomposite cutting tool when high speed cutting ductile cast iron was investigated. Orthogonal cutting tests were carried out on a CA6140 lathe using three speeds, namely, 100, 215 and 287m min-1. The WC based nanocomposite tool is found to be superior to cemented carbide tools (YG8). The tool life is prolonged 60% as compared to cemented carbide, as the width of the wear land (VB), which was monitored at selected time intervals. Meanwhile, the topography of worn surfaces was scanned by a profilemeter. Wear characterization of the rake face and the flank surfaces as well as of the collected chips was conducted using a scanning electron microscopy (SEM). Results showed that distinctive traces of single abrasive tool wear event were found on the rake face of the tool, additionally, the adhesion wear is the main wear mechanism in the flank face of the tool. However, the extent of improvement in tool life depends strongly on the cutting conditions, with the greatest benefits being seen at higher cutting speeds and feed rates.