Qianju Cheng

High dynamic range (HDR) imaging has received sustained interest for its ability to capture a wider scene radiance range than conventional imaging by fusing multi-exposure images. However, increasing the number of exposures aggravates ghosting artifacts during fusion, prompting modern devices to use only one or two shots. This leads to the fact that a single exposure is unable to simultaneously preserve details in both dark and bright regions, and even dual-exposure settings are insufficient to capture the full scene radiance. Under limited exposure conditions, distinct challenges arise for both physics-driven and data-driven models, with the former struggling to model unobserved irradiance distributions and the latter having difficulty capturing diverse exposure variations, leading to unrealistic brightness artifacts in highlights and shadows. To address this problem, we propose a mixed causal–acausal assisted compensation model that integrates physics-driven and data-driven modules to generate interpolated and extrapolated pseudo-exposure images for recovering missing brightness information. The proposed model decomposes pseudo-exposure image generation into a hybrid representation consisting of a causal part reflecting radiance variation and an acausal part capturing the residual scene structure. The causal representation is derived by estimating the physics-driven intensity mapping function from adjacent exposure images while the acausal one is obtained through a data-driven attention-augmented hybrid network. Both theoretical analysis and experimental results demonstrate that the pseudo-exposure images perform well in both objective and subjective evaluations. In addition, it is validated that incorporating interpolated or extrapolated images into raw images can indeed mitigate brightness artifacts in dual-exposure fusion as well as in single-exposure enhancement.

Solid–liquid phase-change materials (PCMs) have attracted considerable attention in heat energy storage due to their appropriate phase-transition temperatures and high thermal storage density. The primary issues that need to be addressed in the wide application of traditional PCMs are easy leakage during solid–liquid phase transitions, low thermal conductivity, and poor energy conversion function. The heat transfer properties of PCMs can be improved by compounding with carbon materials. Carbon nanotubes (CNTs) are widely used in PCMs for heat storage because of their high thermal conductivity, strong electrical conductivity, and high chemical stability. This study investigates the thermal properties of 1-octadecanol (OD) modified with different diameters and amounts of CNTs using the melt blending method and the ultrasonic dispersion method. The aim is to enhance thermal conductivity while minimizing latent heat loss. The physical phase, microstructure, phase-change temperature, phase-transition enthalpy, thermal stability, and thermal conductivity of the OD/CNTs CPCMs were systematically studied using XRD, FTIR, SEM, DSC, and Hot Disk. Moreover, the heat charging and releasing performance of the OD/CNTs CPCMs was investigated through heat charging and releasing experiments, and the relationship among the composition–structure–performance of the CPCMs was established.

Multiform NiO nanowalls with a high specific surface area were constructed in situ on carbon foam (CF) to construct NiO@CF/OD composite phase change materials (CPCMs). The synthesis mechanism, microstructures, thermal management capability, and photothermal conversion of NiO@CF/OD CPCMs were systematically studied. Additionally, the collaborative enhancement effects of CF and multiform NiO nanowalls on the thermal properties of OD PCMs were also investigated. NiO@CF not only maintains the porous 3D network structure of CF, but also effectively prevents the aggregation of NiO nanosheets. The chemical structures of NiO@CF/OD CPCMs were analyzed using XRD and FTIR spectroscopy. When combined with CF and NiO nanosheets, OD has high compatibility with NiO@CF. The thermal conductivity of NiO@CF/OD-L CPCMs was 1.12 W/m·K, which is 366.7% higher than that of OD. The improvement in thermal conductivity of CPCMs was theoretically analyzed according to the Debye model. NiO@CF/OD-L CPCMs have a photothermal conversion efficiency up to 77.6%. This article provided a theoretical basis for the optimal design and performance prediction of thermal storage materials and systems.