The investigation of the effect of processing parameters on forming quality has been one of the highlight researches in spinning. The thickness distribution is an important criterion to evaluate the forming quality. Spinning force affects the processing and equipment design greatly. Combining with the FEA simulation and orthogonal test method, taking the maximum reduction ratio in thickness of workpiece and the maximum spinning force as the evaluation criterion, the esequence of the main forming parameters, such as the feed rate and roundness radius of roller, and the relative height of workpiece were analyzed based on an orthogonal scheme of three-factor and three-level. Both FEA simulation and experiment results show that, during the pentagonal section hollow-part spinning, the influence sequence on the maximum reduction ratio in thickness is relative height of workpiece, feed rate and roundness radius of roller; the influence sequence on the maximum spinning force is relative height of workpiece, roundness radius of roller and feed rate.

SUMMARY:We examined the ability of scleractinian corals with different polyp sizes to remove picoeukaryotes by predation and the effect of coral exudates on picoeukaryote growth. Experiments were conducted by adding picoeukaryotes to Stylophora pistillata (SP) and Montipora stellata (MS). Within six hours the picoeukaryote concentration in the SP and MS tanks was significantly lower than the control without corals. SP showed higher overall activity than MS, and the particle removal activity of MS decreased in light conditions. Picoeukaryotes exposed to SP exudates grew significantly denser than those exposed to MS exudates or those in water without coral exudates. Dissolved organic carbon concentrations in the SP tanks were also significantly higher. We concluded that the picoeukaryote removal rates were higher in S. pistillata than in M. stellata, and coral exudates can reciprocally enhance picoeukaryote growth.Keywords: scleractinian corals, Stylophora pistillata, Montipora stellata, picoeukaryotes, grazing, coral exudates. RESUMEN: EfEcto dEl tamaño dE pólipo y dE los Exudados dE coralEs sobrE la dinámica dE picoEucariotas En un ambiEntE controlado. -Hemos estudiado la capacidad de corales escleractinios con diferentes tamaños de pólipo de depredar picoplancton eucariótico, y también el efecto de los exudados de los corales sobre el crecimiento de picoplancton eucariótico. Los experimentos se realizaron añadiendo picoplancton eucariótico a Stylophora pistillata (SP) y Montipora stellata (MS). Después de 6 horas, las concentraciones de picoplancton eucariótico en los tanques de SP y MS fueron significativamente reducidas, en comparación con las del tanque control sin coral. SP mostró en general una actividad depredadora algo más grande que MS, y éste redujo su actividad en condiciones de luz. Los picoeucariotas expuestos a exudados de SP llegaron a concentraciones más altas que cuando fueron expuestos a exudados de MS o a agua sin corales. La concentración de carbono orgánico disuelto en los tanques de SP también fué significativamente más alta. Se concluye que las tasas de depredación sobre los picoeukaryotes fueron más altas con S. pistillata que con M. stellata, y que los exudados del coral pueden recíprocamente mejorar el crecimiento de picoplancton eucariótico.

The dynamic analysis and structural parameters optimization approach based on ADAMS for a parallel platform is presented in this paper. Firstly the parameterized modeling of the parallel platform is performed, which is composed of up and down platform, two linear motors and one support beam. And then the impact of the parameters on the performance of the platform is studied. After that the parallel platform is optimized via the optimization module of the ADAMS. Eventually the conclusions are obtained, which provide the guidance for the mechanical and control design of the parallel platform.

A novel PM arc guideway motor (PMAGM) is developed due to the drawback of the conventional motor reciprocating within certain angle. The PMAGM can directly drive load to make reciprocating motion within a limited angle with advantages of simplification, reliability, high efficiency, etc.. Aiming at the permanent magnet (PM) magnetization and solenoid coil electrifying modes, the PM deflection angle is parameterized and the influence on electromagnetic force has been analyzed between different magnetization and electrifying modes. Results show that electromagnetic force in Y direction magnetized along the external field force lines at proposal 1 is 51.23% higher than that of vertical magnetization, and the electromagnetic resultant force increases by 45.91%. As the angle of the PM deflection within 3o, the electromagnetic force in X direction points to the right, which is not good for PM slidable assembly swing. Based on comprehensive analysis of the advantages and disadvantages of several electrifying modes, the electricity combination under full swing angle is optimized.