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Thermochromic window develops as a competitive solution for carbon emissions due to comprehensive advantages of its passivity and effective utilization of energy. How to further enhance the solar modulation ($${\triangle T}_{{{{{{{\rm{sol}}}}}}}}$$ △ T sol ) of thermochromic windows while ensuring high luminous transmittance ($${T}_{{{{{{{\rm{lum}}}}}}}}$$ T lum ) becomes the latest challenge to touch the limit of energy efficiency. Here, we show a smart window combining mechanochromism with thermochromism by self-rolling of vanadium dioxide (VO2) nanomembranes to enhance multi-level solar modulation. The mechanochromism is introduced by the temperature-controlled regulation of curvature of rolled-up smart window, which benefits from effective strain adjustment in VO2 nanomembranes upon the phase transition. Under geometry design and optimization, the rolled-up smart window with high $${\triangle T}_{{{{\rm{sol}}}}}$$ △ T sol and $${T}_{{{{{{\rm{lum}}}}}}}$$ T lum is achieved for the modulation of indoor temperature self-adapted to seasons and climate. Furthermore, such rolled-up smart window enables high infrared reflectance after triggered phase transition and acts as a smart lens protective cover for strong radiation. This work supports the feasibility of self-rolling technology in smart windows and lens protection, which promises broad interest and practical applications of self-adapting devices and systems for smart building, intelligent sensors and actuators with the perspective of energy efficiency.

In this paper, two kinds of pumice particles with different diameters and water absorption rates are employed to substitute the corresponding size of river sands by volume fraction, and their effects on the hydration characteristics and persistent shrinkage of Ultra-High Performance Concrete (UHPC) are investigated. The obtained experimental results show that adopting a low dosage of 0.6–1.25 mm saturated pumice as the internal curing agent in UHPC can effectively retract the persistent shrinkage deformation of concrete without a decrease of strength. Heat flow calorimetry results demonstrate that the additional water has a retarding effect and promotes the hydration process. X-ray Diffraction (XRD) and Differential Thermal Gravimetry (DTG) are utilized to quantify the Ca(OH)2 content in the hardened paste, which can confirm that the external moisture could accelerate the early cement hydration and secondary hydration of active mineral admixtures. The Ca/Si ratio of C–S–H calculated by the Energy Dispersive Spectrometer (EDS) reveals that the incorporation of wet pumice can transform the composition and structure of hydration products in its effective area.

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For many types of fuel cells (FCs), the electrochemical oxygen reduction reaction (ORR) is the bottleneck reaction. At present, a major challenge to the industrialization of these devices is attributed to the high price and inferior stability of the common platinum group metal (PGM) catalysts. To address this issue, a zeolitic imidazolate framework (ZIF-8) derived tungsten (W) single-atom electrocatalyst has been synthesized and evaluated for the ORR. It was found that the prepared catalyst (W–N–C) possesses a W single-atom catalysis center coordinated in a nitrogen-rich carbon matrix with a half-wave potential (E 1/2) of 0.86 V and a negligible current decay over a long-term durability test, which surpass those of many reported nonprecious metals and even commercial Pt/C catalysts.

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