Thermal emission is ubiquitous in nature and essential for applications including thermal management, thermophotovoltaics, infrared camouflage, and multispectral sensing. Realizing tunable control over the spectral, polarization, and angular characteristics of thermal emission is crucial for multifunctional and adaptive thermal photonic systems. Here, we propose a VO2-based grating metasurface emitter that enables polarization-selective, switchable emission bandwidths and directional control in the long-wave infrared (LWIR) region. In the metallic state of VO2, the emitter exhibits a broadband, wide-angle emission for both transverse electric (TE) and transverse magnetic (TM) polarizations. Upon transition to the insulating state, the emitter demonstrates a nearperfect, highly directional narrowband emission with a quality factor of 619 for TM polarization, whereas it remains low-emission (epsilon approximate to 0.06) for TE polarization. Besides, the electromagnetic field and power dissipation analyses reveal the underlying physical mechanisms. Specifically, the broadband high emission originates from the intrinsic loss of metallic VO2 together with the excitation of Fabry-Perot cavity modes and surface plasmonlike hybrid modes, while narrowband emission arises from the magnetic polariton excitation in the insulating state. Furthermore, we investigate the influence of structural parameters on the performance of the emitter. The results show that the wavelength corresponding to the narrowband emission in the insulating state can be effectively tuned, while the broadband emission in the metallic state remains essentially unchanged. This work demonstrates a multifunctional grating metasurface emitter, providing a promising platform for tunable thermal radiation, infrared camouflage, and multispectral detection.

Abstract Designing active surfaces to control interfacial reaction dynamics is crucial for advanced water treatment. Herein, we report ultrathin porous CuS-CuPt nanosheets (CuS-CuPt UPNSs) whose limited thickness and high-density pore network create a highly efficient solid–liquid interface for the photo-Fenton degradation of dyes. The porous surface morphology, confirmed by FEM simulations to generate localized electric field hotspots, works in synergy with bimetallic sites to accelerate the production of hydroxyl radicals (•OH) at the catalyst–water interface. This interfacial activity leads to rapid and complete pollutant degradation with sustained catalytic recyclability. Our findings highlight the importance of nanoscale surface engineering in manipulating interfacial charge transfer and radical generation pathways for environmental purification.

Outdoor electrical houses face significant challenges of thermal accumulation under high-temperature conditions, which can lead to equipment failure and threaten grid stability. To address this issue, this study introduces a dual-mode passive thermal management strategy using a phase change-radiative cooling coupled material (PCM-RC) applied to building envelopes. The material combines a shape-stabilized phase change material (PCM) base with high latent heat (106.32 kJ/kg) and a radiative cooling (RC) overlay featuring high solar reflectance (91 %) and strong mid-infrared emissivity (93 %). A silane coupling agent enhances interfacial adhesion between the two functional layers. The RC layer minimizes solar heat gain through high reflectivity and continuous radiative heat dissipation, while the PCM layer provides transient thermal storage through latent heat absorption, thereby delaying indoor temperature rise and attenuating heat flux penetration. Experimental tests under ambient temperatures above 40 degrees C show that the PCM-RC coating remarkably reduces roof and wall surface temperatures by up to 19.9 degrees C and 17.3 degrees C, respectively, compared to conventional enclosures, maintaining indoor electrical equipment within a safe operational temperature range. This work demonstrates a feasible and efficient approach to passive thermal management for electrical infrastructure, with strong potential for application in practical engineering fields involving rigorous thermal regulation and temperature control.

The effect of graphene defects introduced by ion bombardment on interfacial thermal conductance (ITC) at the 3C-SiC/graphene/w-AlN heterointerface is systematically investigated by molecular dynamics simulations. Firstly, the regulation mechanism of graphene morphology is deeply analyzed by simulating ion bombardment. It reveals the coexistence of quantitative and topological defects, and their types and proportions exhibit distinct energy- and dose-dependent stage characteristics. In addition, there is a high degree of spatial correlation between topological defects and vacancy defects. These results are markedly different from artificially introduced graphene defects. Furthermore, with increasing bombardment doses, the ITC shows an upward trend that is rapid first, then gradual, and finally rapid again. This phenomenon stems from the differences in defect characteristics under different bombardment doses. Besides, the maximum ITC increases by approximately one-fold compared to the defect-free intrinsic interface. The enhancement mechanism lies in that ion bombardment enhances the phonon density of states of graphene and SiC in the frequency ranges of 0-8 THz and 0-15 THz, respectively, optimizes interfacial phonon coupling, increases interfacial phonon transmission in the 0-15 THz range, and ultimately significantly increases ITC. This work provides theoretical basis and significant practical guidance for optimizing thermal management of GaN semiconductor chips.

The combination of passive radiative cooling and fine-tuned control of the solar spectrum represents a key infrared physical approach for achieving zero-energy thermal control in buildings. This paper describes a transparent photonic ultrathin-film structure that can be fabricated on a large scale; by synergistically regulating the transmission characteristics of the solar spectrum and the infrared radiative heat transfer process, it achieves highly efficient passive thermal control. This structure exhibits excellent multispectral modulation properties: it maintains high transmittance in the visible light band to ensure light transmission, achieves high reflectance in the near-infrared solar spectrum to suppress solar heat radiation input, and possesses high emissivity in the long-wave infrared atmospheric window band. This optical functional system is constructed based on a dielectric/metal/dielectric/metal/dielectric multilayer stack structure. Using glass as the substrate and a functional layer of polydimethylsiloxane (PDMS) with high infrared emissivity on the surface, it forms a transparent heat-insulating cooling window (THCW) photonic device. Optical test results indicate that the device has an average visible light transmittance of 0.6, an average reflectance of 0.92 in the near-infrared solar spectrum, and a long-wave infrared emissivity as high as 0.938. Building thermal environment simulation results show that under the tropical climate conditions of New Delhi, this structure can reduce building air conditioning energy consumption by 72.39 kWh/m2; in the Zhengzhou region, it can achieve a maximum indoor temperature reduction of 16 K.

The ability to efficiently and flexibly manipulate near-field radiative heat transfer (NFRHT) is of great scientific importance and offers promising applications in thermal management technologies. This study explores NFRHT between two multilayer black phosphorus (BP)/Calcite (CaCO3) heterostructures and elucidate the underlying regulatory mechanisms. We find that hybridization between surface plasmon polaritons (SPPs) in BP and hyperbolic phonon polaritons (HPPs) in CaCO3 enhances the heat flux in BP/ CaCO3 heterostructures by factors of 1.8 and 3.7, relative to BP sheets and CaCO3 films, respectively. Moreover, increasing the number of periods in the multilayer heterostructures further enhances the NFRHT. We further demonstrate that tuning the electron density in BP enables effective modulation of the heat flux, achieving a maximum modulation ratio of 6.8. In addition, we combine twistronics to introduce a twist angle into the system, offering a novel approach for efficient NFRHT manipulation. By jointly tailoring the twist angle of multilayer heterostructures and electron density of BP to modulate the hybridization between SPPs and HPPs, we achieve a modulation ratio of approximately 11.2. This work serves as a promising reference for the design of thermal management devices employing anisotropic two-dimensional materials.

With the rapid development of multi-band infrared detection, traditional static camouflage struggles to achieve coordinated concealment and thermal management across visible, laser, and infrared bands. To overcome the limitations of single-band regulation and costly lithography, this study proposes a lithography-free seven-layer film structure (Cr/ZnS/VO2/Ge/MgF2/Ge/ZnSe), optimized via Finite-Difference Time-Domain (FDTD). Leveraging the metal-insulator transition (MIT) of VO2 near 68 degrees C, the structure enables dynamic emissivity control: in the insulating state, average emissivity drops to 0.233 in the mid-wave infrared (MWIR, 3-5 & micro;m) and 0.172 in the long-wave infrared (LWIR, 8-14 & micro;m), suppressing infrared signatures; in the metallic state, emissivity rises to 0.754 in the non-atmospheric window (NAW, 5-8 & micro;m) for efficient radiative cooling. By tuning the top ZnSe layer thickness, visible multicolor camouflage is achieved while maintaining low reflectivity at key laser wavelengths (1.06, 1.55, 10.6 & micro;m). The design remains robust up to 60 degrees incidence and demonstrates effective thermal management across a broad temperature range, significantly reducing target-background temperature differences. This fabrication-friendly and lithography-free structure offers a scalable and practical solution for multispectral camouflage and adaptive thermal regulation.

The modulation of thermal radiation is essential for advanced photonic applications, offering a novel perspective for information carriers. However, current carriers are limited to a few discrete radiation states at isolated time points and cannot capture the entire dynamic process along the full temporal axis, resulting in substantial information loss. Here, we propose and experimentally validate a novel spatiotemporal modulation strategy that dynamically tailors emissivity across the entire temporal domain, where gentle and uniform modulation of atomic configurations enables the creation of entirely novel permittivity libraries. To realize flexible thermal radiation tailoring, we utilize an Ag-In3SbTe2 (IST) interface atomic rearrangement metamaterial (ARM). As a dynamic optical control platform, ARM exhibits continuous spectral modulation with remarkably high amplitudes (64.74% in the 3- to 5-μm band and 73.94% in the 8- to 14-μm band), together with rich variations across the temporal domain to realize tailored infrared emissivity and infrared information encryption. This work establishes a unified framework for continuous, atomic-scale spatiotemporal control of thermal radiation, opening new pathways for spectral modulation and photonic information regulation in the time domain.

The weak van der Waals (vdW) bonding at the interface between two-dimensional (2D) layered materials and bulk substrates causes high thermal resistance, impeding heat dissipation in 2D electronics. Although prior studies have indicated that interfacial thermal conductance (ITC) varies with the number of 2D layers, the reported trends remain inconsistent. Using graphene/GaN as a prototype, we systematically examine how interfacial and interlayer interactions govern layer-dependent ITC by atomic simulations. Results show that the ITC increases with the number of graphene layers N and asymptotically converges. Spectral analysis reveals that approximately 95% of ITC is contributed by the out-of-plane phonons, and the increase in ITC with N is due to the emergence of additional ZA mode branches. Strengthening interfacial coupling reduces the dependence of ITC on N, as the accompanying rise in graphene interlayer thermal resistance partly offsets the ITC gain from added layers. Furthermore, the ITC exhibits a non-monotonic dependence on interlayer coupling-initially increasing and then declining-with a peak occurring when the interlayer binding energy approaches that of the interface. Finally, we highlight the crucial role of substrate surface phonon modes, which contribute 1.5-2 MWm- 2K- 1 for graphene/GaN ITC by creating additional thermal transport channels. This work clarifies the fundamental mechanisms in 2D/3D vdW interfacial thermal transport and offers design guidance for thermal management of 2D devices via engineering of interface and interlayer interactions.

Passive daytime radiative cooling (PDRC) films can dissipate heat without any energy input, providing a sustainable pathway for high efficiency thermal management. However, despite recent advances in scalable PDRC fabrication, achieving a fully dry, solvent-free for flexible PDRC films with stable outdoor cooling performance remains insufficiently explored. Herein, we demonstrate a solvent-free method to produce ceramic-polymer composite films inspired by dry-process electrodes. A wide variety of ceramic nano-powders including magnesium oxide (MgO), silicon oxide (SiO2), barium sulfate (BaSO4), titanium oxide (TiO2), and aluminum oxide (Al2O3) were fabricated to flexible films, using polytetrafluoroethylene as a binder. Following the incorporation of hollow SiO2 and polyvinylidene fluoride microsphere, the obtained films achieve sub-ambient daytime radiative cooling capacity, with a high solar reflectance of 95.15% and high atmospheric window emissivity of 96.75%. Under direct sunlight (peak solar irradiance >800 W m(-2)), a temperature reduction of approximately 6 degrees C was observed below the ambient temperature. Simulation results show that applying these materials to passenger vehicle energy-saving curtains can significantly reduce energy consumption and carbon emissions. Taking Brasilia City as an example, it could reduce annual cooling energy use by about 13%, demonstrating substantial potential for energy conservation and emission reduction.

Near-field radiative heat transfer (NFRHT) is promising for nanoscale thermal management. In practical devices, the surrounding environment is a critical factor affecting their NFRHT. However, the influence of the environmental refractive index on near-field heat flux remains insufficiently explored. Here, we theoretically investigate the NFRHT between hexagonal boron nitride (hBN) films under varying dielectric environments. For z-aligned hBN films, the dielectric environment enhances NFRHT in ultrathin films, while a moderate environmental refractive index becomes more favorable as the film thickness increases. For x-aligned films, the influence of the dielectric environment changes from suppression in ultrathin films to enhancement in thicker films, with a moderate dielectric environment producing the most favorable heat-transfer response. Specifically, the enhancement in z-aligned films results from the excitation of volume-confined hyperbolic polaritons, whereas the variations in x-aligned films are governed by the excitation and suppression of both surface-confined and volume-confined hyperbolic polaritons. This work reveals the underlying mechanism of dielectric-mediated polariton excitation, offering a theoretical foundation for designing tunable near-field thermal radiative devices.

The continuous advancement of microelectronic devices has driven a sharp rise in localized heat flux densities, leading to an increasingly high risk of chip thermal failure. To address the chip thermal failure, this paper proposes a structural optimization strategy for microchannel heat sinks based on coupled control of inlet and outlet opening widths for the central hotspot region. This heat sink consists of multiple parallel microchannels, and the central hotspot is covered by a pin-fin region with a size of 2 mm × 2 mm. Findings indicate that this strategy significantly reduces hotspot temperatures while improving both thermal uniformity and local Nusselt number distribution in the radiator. The results reveal that when the inlet opening width is reduced to 1000 μm and the outlet opening width is enlarged to 4000 μm, compared with the baseline structure whose inlet and outlet opening widths are both set to 2500 μm at the Reynolds number is 250, the peak temperature of the heat sink is lowered by 8.58 K, the local Nusselt number is increased by 46%, and the performance evaluation criterion reaches a value of 1.19. In this study, a simple and effective structure is designed, which can effectively lower the hotspot temperature of the model and enhance thermal performance, thereby providing an important basis for effective thermal management of microelectronic devices under elevated heat flux density.

With the rapid advances in infrared detection, the development of infrared stealth devices has become increasingly urgent. In this paper, we propose a spectrally selective device consisting of a single-layer grating and two thin-film layers, which simultaneously achieves dual-band infrared stealth and enables temperature-adaptive radiative heat dissipation. Under transverse magnetic (TM) polarization, the device exhibits low average emissivities of 0.17 in the mid-wave infrared (MWIR, 3-5 & micro;m) band and 0.16 in the long-wave infrared (LWIR, 8-14 & micro;m) band. Under transverse electric (TE) polarization, the corresponding values are 0.17 and 0.15, respectively, indicating effective suppression of infrared signatures. In contrast, in the 5-8 & micro;m non-atmospheric window, the average emissivity reaches 0.82 under TM polarization and 0.61 under TE polarization, enabling efficient radiative heat dissipation. By evaluating the temperature dependence of the signal reduction rate and the radiation intensity, we demonstrate that the device suppresses infrared signatures over a wide temperature range while offering temperature-adaptive radiative heat dissipation, thereby achieving effective infrared camouflage. The simulation-based design offers a favorable balance between structural complexity and infrared stealth performance, providing a feasible and promising approach for the advancement of infrared stealth technologies.

Solar energy has attracted widespread scholarly attention due to its capacity to cut carbon emissions and advance the energy transition. Direct absorption solar collector (DASC), which is a critical part of the photothermal conversion utilization, would be improved by utilizing nanoparticles (NPs). Most existing studies on core–shell structures for DASC focus on single-core–shell configurations, while investigations of multicore–shell structures for DASC remain limited. In this work, a multicore–shell structure is proposed to systematically compare the photothermal conversion efficiency of single-core versus multiple-core Au@SiO2 nanoparticles. Considering the localized surface plasmon resonance (LSPR) of metallic particles of Au and the thermal stability of silicon, single-Au@SiO2 and multiple-Au@SiO2 are analyzed via COMSOL Multiphysics based on the finite element method (FEM). The findings exhibit that the photothermal conversion efficiency (ηabs) of multiple-Au@SiO2 approaches 90

Near-field radiative heat transfer (NFRHT) has opened application prospects in areas such as thermal management and energy conversion. In this work, we investigate the NFRHT in a three-body system formed by α-MoO3 films under different rotational conditions. It is demonstrated that individually rotating the emitter, the repeater, or the receiver leads to modulation factors of 1.457, 2.875, and 5.193, respectively. This modulation comes from the rotation-dependent anisotropic transmission-channel matching in different α-MoO3 layers. It is found that the rotation mainly affects the heat transmission coefficient within the Band I and Band II hyperbolic bands of α-MoO3, while almost unchanged within the Band III hyperbolic band. Moreover, the simultaneous rotation of the emitter and repeater is investigated to further clarify the two-angle modulation behavior of the three-body system. These findings clarify the influence of rotation on anisotropic transmission-channel matching and provide guidance for nanoscale thermal management and heat-flow modulation.

Transparent heat reflective window (THRW) can effectively reflect near-infrared (NIR) radiation while maintaining high visible light (VIS) transmittance, thereby significantly reducing building energy consumption. Traditional THRW often uses dielectric/metal/dielectric (D/M/D) structures to regulate the transmission and reflection characteristics of solar spectra. In this study, a THRW consisting of three dielectric materials, Al2O3, TiO2 and ZnS, and Ag metal was designed. By utilizing the difference in refractive index of different materials and combining particle swarm optimization (PSO) algorithm to optimize the thickness of each layer, an average NIR reflectance of 94.7% and a VIS transmittance of 83.2% were achieved. The sample prepared based on electron beam evaporation technology showed a VIS transmittance of 75% and a NIR reflectance of 90% in the experiment, further verifying the effectiveness of the design. This study provides new solutions for improving building energy efficiency, reducing energy consumption, and enhancing indoor thermal comfort, especially in hot weather conditions, showing promising application prospects.

Surface nanostructuring provides an effective route to enhance absorption and photoelectric conversion efficiency in crystalline silicon (c-Si) solar cells. Particularly, optimized surface targeting upright solar cells can not only enhance absorption performance but also significantly expand their application scenarios. This study presents an ultra-thin c-Si solar cell with a trapezoidal nanostructure. Without relying on additional materials, the absorption performance under large-angle (30 degrees-60 degrees) installation conditions is improved solely through geometric optimization. Simulation results indicate that the cell exhibits an average absorption exceeding 80% across the 350-1125 nm wavelength range and an effective absorption above 90% for the AM1.5 G solar spectrum. Performance comparisons with other structures confirm that the superiority of this design stems from its enlarged light-receiving area and optimized light-trapping path. Analysis of the electric field distribution indicates that the absorption enhancement stems from localized field amplification driven by multi-path light reflection and scattering. Electrical output calculations further confirm the superior performance of the proposed cell, which outperforms all compared structures, achieving a Voc of 0.635 V, an FF of 83.4%, and a PCE of 20.9%. This work makes a meaningful contribution to the development of high-efficiency ultra-thin c-Si solar cells under large-angle installation conditions.

The protective structure of maize husks often leads to the underestimation of pesticide residues in kernels, where limited pesticide residue data pose significant challenges for effective risk management. This large-scale investigation evaluated residue levels and dietary risks of 60 representative pesticides in maize kernels from China's three major maize production regions (358 field samples). Samples were analyzed using a QuEChERS-based pretreatment method combined with ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Sixteen pesticides were detected, with pyraclostrobin, tebuconazole, carbendazim, triadimefon, chlorpyrifos, and fludioxonil being the most frequently detected (detection rate >= 5 %), with concentrations ranging from 1.0 to 175.9 mu g/kg. Pesticide residues in maize kernels primarily originate from soil, stalks, and husks. Co-occurrence analysis revealed that 21.3 % of samples contained at least one pesticide, with up to six residues detected in a single sample. Overall, multiple pesticide co-occurrence was low, and correlations between different pesticides were weak. Probabilistic dietary risk assessment indicated that, at the 97.5th percentile exposure level, risk quotient (RQ) values ranged from 2.7 x 10- 7 to 2.9 x 10-4, which were well below safety thresholds. However, pyraclostrobin, thiamethoxam, and atrazine exceeded China's maximum residue limits (MRLs) in two samples each. These findings highlight the need for continued monitoring and targeted control strategies to reduce potential dietary risks associated with pesticide residues in maize.