Growth of epitaxial graphene on the C-face of SiC has been investigated. Using a confinement controlled sublimation (CCS) method, we have achieved well controlled growth and been able to observe propagation of uniform monolayer graphene. Surface patterns uncover two important aspects of the growth, i.e. carbon diffusion and stoichiometric requirement. Moreover, a new "stepdown" growth mode has been discovered. Via this mode, monolayer graphene domains can have an area of hundreds of square micrometers, while, most importantly, step bunching is avoided and the initial uniformly stepped SiC surface is preserved. The stepdown growth provides a possible route towards uniform epitaxial graphene in wafer size without compromising the initial flat surface morphology of SiC. a) Electronic mail: xswu@pku.edu.cn 2

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Three‐dimensional (3D) six‐directional braided carbon/epoxy composites with different braiding angles were fabricated successfully. The effect of braiding angles and temperature on mechanical properties and failure mechanism were analyzed. The results show that the braiding angle and temperature both have a significant effect. As braiding angle increases, out‐of‐plane compression stress vs strain curve increases and the compression properties improve. At high temperatures, the stress vs strain curves are non‐linear up and the compression properties reduce. Besides, the out‐of‐plane performances of 3D six‐directional braided composite at room and high temperatures are more excellent than 3D four‐directional and five‐directional braided composites. Under out‐of‐plane compression, at room temperature, the materials appear 45° shear fracture; the phenomenon of fibers shear fracture and extraction is more distinct with larger braiding angle; the main failure is the fiber bundles expand outward and the matrix cracks. At high temperatures, the materials exhibit ±45° shear cracks; composites are compressed flat and expand along the transverse direction; the main failure is the matrix softening and exfoliation from the fiber bundles, the fiber/matrix interface debonds seriously.

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