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Cellulose aerogels were prepared by combining the NaOH/thiourea/H 2 O solvent system and the freeze-drying technology. Hydrophobic aerogels were obtained with the cold plasma modification technology. The results showed that cellulose aerogel had good heat insulation performance, while the main factors affecting thermal conductivity were density and porosity. Thermal conductivity decreased with the decrease of density and the increase of porosity. It could be as low as 0.029 W/(m K). Cellulose aerogel adsorbed moisture easily. The moisture adsorption had a significant influence on the heat insulation performance of aerogel. After conducting hydrophobic modification using CCl 4 as plasma, cellulose aerogel was changed from hydrophilic to hydrophobic and water contact angle was as high as 102 . Hydrophobic modification did not affect the heat insulation performance of aerogel. This work provided a foundation for the possibility of applying cellulose aerogels in the insulating material field.

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Braided carbon/carbon composites are widely used in the aerospace field due to their superior performance. However, because braided carbon/carbon composite materials have anisotropy characteristics, the distribution of screw loads in the fastener connection structure will differ from that of metal. In view of the particularity of the braided carbon/carbon composite fasteners’ connection, this paper obtains the theoretical results of the load distribution of screw teeth through the homogenization of stiffness and establishes a finite element model for comparative verification. The trend of finite element results is the same as that of theoretical calculation results which can provide guidance for the engineering design of carbon/carbon composite fastener.

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