This paper presents a simple vapour deposition method for onestep synthesis of SiC//SiO 2 core-shell heterostructured nanowires. The phases, structures and morphologies of the synthesized core-shell heterostructures are systemically studied by field emission scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, and high-resolution transmission electron microscopy. The results show that these heterostructures consist of a single crystalline SiC core of 20$30 nm diameter covered by a uniform layer, about 15 nm thickness of amorphous SiO 2 . Such heterostructures were grown based on the vapour-solid mechanism and the deposition way has an important influence on their morphology. A unique optical property has also been found in their photoluminescence spectra that have blue shift relative to the bulk SiC.

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Internal flow field ablation is an important issue in thermal protection materials for rocket engines and hypersonic vehicles. In this paper, a new multiphase flow ablation test system, with an Al2O3 particle delivery device based on an oxygen-kerosene liquid rocket engine, is designed and manufactured. A general variable-precision modular system simulation method is proposed to analyze the dynamic characteristics of the system. In addition, a unique internal flow field ablation test was performed on the 4D C/C composite simulating the working conditions of the SRM. The results show that the system can provide a wide temperature range (756~3565 K) and pressure range (0.2~4.2 MPa). The multi-disciplinary dynamic variable-precision system simulation method is helpful for more accurate design and test analysis, and the maximum error is less than 5%. The ablation tests show that the line ablation rate of the C/C composite nozzle at 3380 K and 1 MPa is 0.053 mm/s, verifying the combined effect of thermochemical and mechanical ablation. The ablation environment is controllable, which provides an effective way for the ablation test of thermal protection materials. In addition, the variable-precision dynamic simulation method has important reference value for the system design related to liquid rocket engine.