More and more researchers are studying the heat transfer performance of aeronautical materials at high temperatures. In this paper, we use a quartz lamp to irradiate fused quartz ceramic materials, and the sample surface temperature and heat flux distribution were obtained at a heating power of 45~150 kW. Furthermore, the heat transfer properties of the material were analyzed using a finite element method and the effect of surface heat flow on the internal temperature field was investigated. The results show that the fiber skeleton structure has a significant effect on the thermal insulation performance of fiber-reinforced fused quartz ceramics and the longitudinal heat transfer along the rod fiber skeleton is slower. As time passes, the surface temperature distribution tends to stability and reaches an equilibrium state. The surface temperature of fused quartz ceramic increases with the increase in the radiant heat flux of the quartz lamp array. When the input power is 5 kW, the maximum surface temperature of the sample can reach 1153 °C. However, the non-uniformity of the sample surface temperature also increases, reaching a maximum uncertainty of 12.28%. The research in this paper provides important theoretical guidance for the heat insulation design of ultra-high acoustic velocity aircraft.

Thermoelectric performance enhancement in a liquid-like material Cu2Se by introducing CB4 nanopowders based on the hydrothermal method and hot-pressing technique.

Creating antidot lattices in graphene nanoribbons (GNRs) can significantly modify the electronic transport features and may open up an avenue to many practical applications. We here study the effects of antidot lattices on two-terminal transport in GNRs with zigzag edges (ZGNRs), based on the tight-binding method in combination with Green’s function formalism. The antidots in this work are set to be hexagonal structure. For the case of two antidots arranging in ZGNRs, many conductance resonances are found and they become denser and shaper with the increasing of the separation between antidots. However, no any effective transport gap is observed around Fermi energy. For the case of multi-antidots structure, each resonance shows a (m-1)-splitting, where m is the number of antidots. The analysis on local density of states (LDOS) indicates that all of resonances are related to the quasi-standing waves in ZGNRs. To obtain an effective and stable transport gap, we suggest keeping a dense array of such antidots in ZGNRs. The computed results show that the transport gap decreases very rapidly as the separation between antidots increases. These results might guide the design of the future graphene-based devices.

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