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Abstract:The three-dimensional compression scramjet inlet has been investigated by using surface oil dot visualization and numerical simulation. The research has revealed the details of the internal flow pattern, which included the structure of the shock waves, the spillage, the spatial vortical structures, and the boundary layer separations etc.. These features determined the performance of the inlet, which gave the mass flow capture ratio of 0.86, total pressure recovery of 0.41. The results showed that the arrangement of the shocks is critical for such kind of inlet. More researches have been carried out to investigate the effect of the cowl shape, and the results showed the flow field would be changed little for the cowls with different shapes but the same internal contraction ratios.

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In the current study, the external morphology and microstructure of the compound eyes of the scarab beetle Anomala corpulenta Motschulsky (Coleoptera: Rutelinae) were examined, and the regulatory mechanisms of light absorption were preliminarily identified. According to observations using electron microscopy and optical microscopes, the thickness of cornea of the compound eye was >50 μm, which is thicker than found in most insect species (<10 μm) and likely to provide protection to the eye when the insect is moving through the soil. The compound eyes of A. corpulenta are superposition eyes with a 'clear-zone', which is characterized by the migration of secondary iris and membrane pigment granules upon light/dark adaptation, the migration of basement membrane pigment particles from the proximal to distal ends of the eye, and the migration of secondary iris pigment granules into the clear-zone under light adaptation, which prevents light from being received during daytime. By contrast, the screening pigment granules were collectively clustered in distal interommatidial spaces around the cone and there was a basement membrane distribution of pigment granules in the proximal part of the eye, which would enable the eye to react to weak light levels.