The understanding of the structure−activity relationship can help us design desired functional materials. SiO 2 shell is widely used as a physicochemical inert layer to protect materials from corrosion or oxidization. But, in electromagnetic (EM) absorption studies, silica shell, supposed to be EM transparent, has been found to significantly influence the EM absorption performance. Here, we studied the microstructure, EM parameters, and electronic structure of silica shell coated SiC/Co (SiC/Co@SiO 2 ) nanowires to figure out the nature of silica shell influencing on their EM absorption. Xray absorption near-edge structures on Co L 3,2 -edge and O K-edge analysis confirm that silica links with Co by Si−O−Co bonds. Electron transfer takes place between silica and Co, which leads to formation of gradient ε field within silica and more incident EM wave entering into the absorbers. Generating significant interfacial polarization, the silica shell improves the EM absorption performance. The present research offers a novel insight on the functional role of silica shell.

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To make the missile safely separate from the internal weapons bay, a wedge flow control device is mounted on the front of the bay to control the variation of flow during the separation. The numerical simulations of missile separation without and with wedge flow control device under different sizes are carried out. The flow fields of different separation processes are obtained and discussed; the aerodynamic parameters and trajectory parameters of missile of different cases are illustrated and compared. Results show that, the wedge flow control device can accelerate the missile separation and has the effect of regulating the angular motion of missile. The influence of the wedge height is stronger than that of its length on the center of gravity motion and angular motion of missile.

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