Fiber–particle-reinforced silica aerogels are widely applied in thermal insulation. Knowing their effective thermal conductivity (ETC) and radiative characteristics under high temperatures is necessary to improve their performance. This article first analyzes the radiation characteristics of silica aerogels doped with opacifier particles and reinforced fibers, and then a universal model is established to predict the ETC. Furthermore, the impacts of different parameters of opacifier particles and reinforced fibers on the thermal insulation performance of silica aerogels are investigated. The results indicate that SiC exhibits comparatively strong absorption characteristics, making it a good alternative for opacifiers to improve thermal insulation performance under high temperatures. For the given type and volume fraction of opacifier particles, there exists an optimal diameter and volume fraction to achieve the best insulation performance of silica aerogel under a certain temperature. Considering that SiO₂ fibers exhibit a limited extinction capability and higher conductive thermal conductivity under high temperatures, for fiber–particle-reinforced silica aerogels, it is beneficial for their insulation performance to reduce the fiber volume fraction when the required mechanical properties are satisfied.

To solve the thermal management problem in the three-dimensional integrated circuit (3D-IC) with high integration and multi-layer, this paper establishes a 3D-IC interlayer microchannel model with various embedded TSV micro-pin fins to explore the temperature distribution of chips and flow velocity distribution inside the microchannel. The sense amplifier and half adder are selected as the heat source of the memory and processor in the calculation model, and the power densities of the circuit modules are 885 kW/m² and 1.832 MW/m² combined with the layout size, respectively. Meanwhile, the effects of the shape and arrangement of TSV micro-pin fins on the flow and heat transfer characteristics are investigated. The result shows that the 1.2:1 diamond micro-pin fin microchannel with staggered arrangement has the best overall flow and heat transfer performance. Compared with the basic circular micro-pin fin with the in-line arrangement, the average Nusselt number of this microchannel is improved by 3.20-3.37 times, and the maximum temperature of chips is controlled at 325.92-312.43 K for Re=628-1819.