Electrochromic devices are a key technology to modulate optical and thermal energy for zero-energy buildings. With the sun as the heat source and deep space as the cold source, it would be beneficial to accomplish wideband regulation and control both solar and radiative heat simultaneously to obtain large heating and cooling performance. Here, a flexible ultra-wideband transparent conducting electrode (UWB-TCE) with low sheet resistance (R s = 22.4 ohm/sq) and high optical transmittance (T UV–vis = 85.63%, T near‑IR = 87.85%, and T mid‑IR = 84.87%) has been demonstrated to realize an electrochromic device that is capable of synergistic solar and radiative heat management. Enabled by the UWB-TCE, the metal-based electrochromic device can vary its emissivity between 0.12 and 0.94. The device can also switch between solar heating mode (high solar absorptivity and low thermal emissivity) and radiative cooling mode (low solar absorptivity and high thermal emissivity) by controlling the optimal electrodeposition morphology for surface plasmon resonance. The optimal solar absorptivity (α) and thermal emissivity (ε) of solar heating and radiative cooling mode are (α, ε) = (0.60, 0.20) and (0.33, 0.94), respectively. The UWB-TCE and dual-band solar and mid-IR electrochromic device can bring vast opportunities for applications in heat management, camouflage, display, and building energy efficiency.

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Composites have gained wide use in structural applications; however, they are sensitive to impact damage. The use of hybrid composites is an effective way to overcome this deficiency. The effects of various hybrid structures of interlayer and intralayer warp-knitted fabrics with carbon and glass fibers on the low-velocity impact behavior of composite laminates were studied. Drop-weight impact tests were conducted on two types of interlayer, sandwich and intralayer hybrid composite laminates, which were compared with homogenous composite laminates. During low-velocity impact tests, the time histories of impact forces and absorbed energy by laminate were recorded. The failure modes were analyzed using the micro-CT (computed tomography) and C-scan techniques. The results revealed that the hybrid structure played an important role in peak force and the absorbed energy, and that the hybrid interface had an influence on damage modes, whereas the intralayer hybrid composite laminate damage was affected by the impact location. The intralayer hybrid laminate with C:G = 1:1 exhibited better impact resistance compared to the other hybrid structures.

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Moisture diffusion behaviour of glass/epoxy composites coated with a polyurethane base paint and those without the paint were studied on immersion in water at 323 K. Neat resin castings of the epoxy resin system were also studied for comparison. The composite specimens with paint showed lower moisture absorption values than those of the unpainted specimens subjected to the same immersion conditions. The diffusion parameters obtained from the experiment conducted up to saturation limits agreed well with the data computed using moisture absorption programme (M8 gain) proposed by G. S. Springer. The mixture rule for moisture absorption was also verified for the weight fraction studied. Further, Fickian correlation was found to exist in all the cases.

The triaxial woven fabric is known for their light weight and isotropy of mechanical properties. However, researches that using it as reinforcement to form different structural composites were rarely mentioned. Here, we found that the effect of the triaxial woven fabric can be almost equivalent to the unidirectional fabric in flexural strength (99.18%) when it was added as a reinforcing material into the unidirectional fabric composites even though the weight of triaxial woven fabric has only a third of unidirectional fabric. Moreover, the effects and mechanisms are quite different when changing the position of the triaxial woven fabric in the composites. The damage modes of composites when triaxial woven fabric in different stacking sequences were summarized and the resin blocks model from triaxial woven fabric composites was presented in this paper.