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In response to the precision machining of frictionless aluminum alloy cylinder with anodized oxide films, a composite spiral abrasive flow polishing method was proposed. A simulation model was established to analyze the collision between particles and the wall in polishing processes, and he influences of particle velocity in different directions on polishing were investigated. The processing mechanism of the composite spiral abrasive flow polishing was revealed. The simulation results show hat the composite spiral motion changes the trajectory of the abrasive particles, and the addition of rotational velocity enhances the effective stress of the abrasive. The effective plastic deformation of the wall increases with the spiral groove speed. Particle image velocimetry observation experimental results demonstrate that the composite spiral motion increases the rotational velocity of the abrasives and enhances the vorticity of the flow field. The experimental results show that the composite spiral abrasive flow polishing not only causes less damages to the aluminum alloy anodized film, and effectively improves the surface quality of the workpieces. [ABSTRACT FROM AUTHOR]

Swine enteric coronaviruses (SECs) cause significant economic losses to the pig industry in China. Although many commercialized vaccines against transmissible gastroenteritis virus (TGEV) and porcine epidemic diarrhea virus (PEDV) are available, viruses are still widespread. The recent emergence of porcine deltacoronavirus (PDCoV) and swine acute diarrhea syndrome coronavirus (SADS-CoV), for which no vaccines are available, increases the disease burden. In this review, we first introduced the genomic organization and epidemiology of SECs in China. Then, we discussed the current vaccine development and application in China, aiming to provide suggestions for better prevention and control of SECs in China and other countries. [ABSTRACT FROM AUTHOR]