Advanced Materials Research Vol. 421

Abstract: The calculated aerodynamic power by using formulas in references is always much less than practical one. The reason was found through analyzing the transformation of mechanical energy output by the motor to heat energy of the whole system and motion energy of the air newly getting in based on the relations of moment equilibrium. New formula of aerodynamic power and equation of air following flow ratio were deduced for closed chamber and holed chamber geotechnical centrifuges. The aerodynamic powers of one constructed closed chamber geotechnical centrifuge and one constructed holed chamber geotechnical centrifuge were computed by using different formulas and the results were compared with each other as well as the practical values, respectively. The comparisons show that the new formulas are much more accurate than previous ones in references.

Abstract: To investigate the effect of high magnetic fields on the solidification behavior of binary eutectic system, solidification and quenching experiments of Al-11.8 wt.%Si and Ag-10 wt.%Cu alloys were carried out with and without an 8.8 T high magnetic field. It was found that the application of the high magnetic field could increase the concentration of Si in the primary Al and Cu in the primary Ag at their eutectic temperatures, but could not obviously affect the Si concentration in the primary Al at room temperature. The above increase can be attributed to the weakness of the solute diffusion at the liquid-solid interface during solidification caused by the high magnetic field.

Abstract: The domestic electric forklift market is big. After meeting certain conditions, the direct-drive equipment can improve many shortcomings of ordinary electric forklift to offer new opportunities of innovative design for electric forklift. The innovation design of electric forklift based on Direct-drive Equipment is mainly in three areas: appearance innovations design, functional structure innovation design and technical innovation design, which can be applied to all electric forklifts based on direct-drive equipment and has broad market prospects.

Abstract: The noise of the rubber bearing is closely related to its vibration characteristics, thereby, the study of the natural vibrations is of an important significance for the safety of the warships. Based on the finite element method, this paper analyzes the effect of the structural parameters and material properties on the natural vibrations of the rubber bearings, the numerical results show that in the low frequencies its vibration modes mainly present the shear deformations in its center of the rubber strip. The influences of the variations in the thickness of the built-in steel bars on the natural frequencies are larger than that in the width, and the variations of rubber materials’ mechanical properties on the natural frequencies are remarkable. Thus, increasing the elastic modulus of rubber material will effectively enlarge the value of the natural frequencies, as well as improve their intensive distribution.

Abstract: Mirror symmetry is a most common phenomenon in static structure of mechanical products, and plays an important role in realizing the function of mechanical systems, improving their performance, and meeting their design restrictions. On the basis of analyzing plentiful instances, the existences of mirror symmetry were studied. By taking the independence property of symmetry components, the type of symmetry benchmark and the number of symmetry benchmark as standards, the concept system of mirror symmetry in static structure of mechanical products was established, and can provides a theoretical basis for the further comprehensive research on the application laws of mirror symmetry in mechanical systems.

Abstract: A newly developed coal flotation collector EDO and its flotation characteristics for three Shanxi different coals were introduced in this paper. EDO was an emulsion composed by diesel oil, water and independent development surfactant PGS. Compared flotation experiments show that, at the same dosage, EDO gives 2~5% combustile material recovery promotion than typical collector with only a slightly ash content increment, but saving over 70% diesel oil, and improves the floatation speed. EDO could promote the dispersion of diesel oil in the slurry, so that the efficiency of floatation was improved. The flotation results showed that the EDO had the characteristics of excellent performance, high selectivity and good stability.