Thermal transport in individual atomic junctions and chains is of great fundamental interest because of the distinctive quantum effects expected to arise in them. By using novel, custom-fabricated, picowatt-resolution calorimetric scanning probes, we measured the thermal conductance of gold and platinum metallic wires down to single-atom junctions. Our work reveals that the thermal conductance of gold single-atom junctions is quantized at room temperature and shows that the Wiedemann-Franz law relating thermal and electrical conductance is satisfied even in single-atom contacts. Furthermore, we quantitatively explain our experimental results within the Landauer framework for quantum thermal transport. The experimental techniques reported here will enable thermal transport studies in atomic and molecular chains, which will be key to investigating numerous fundamental issues that thus far have remained experimentally inaccessible.
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http://dx.doi.org/10.1126/science.aam6622 | DOI Listing |
J Hazard Mater
January 2025
Key Laboratory of Coastal Urban Resilient Infrastructures (Ministry of Education), College of Civil and Transportation Engineering, Shenzhen University, Shenzhen 518060, China; Beijing Key Laboratory of Indoor Air Quality Evaluation and Control, Department of Building Science, Tsinghua University, Beijing 100084, China; State Key Laboratory of Intelligent Geotechnics and Tunnelling, Shenzhen University, Shenzhen 518060, China; State Key Laboratory of Subtropical Building and Urban Science, Shenzhen 518060, China; Key Laboratory of Eco Planning & Green Building (Tsinghua University), Ministry of Education, Beijing 100084, China. Electronic address:
The primary challenges impeding the extensive application of adsorption for indoor air purification have been low efficiency and effective capacity. To fill the research gap, we developed carbonaceous net-like adsorption films featuring multi-scale porous structures for efficient indoor formaldehyde removal. By optimizing the interfacial mass transfer and internal diffusion, we designed macro- to mesoscale meshes on the film surface and micro- to nano-scale pores within the materials, which were achieved by direct-ink-writing (DIW) printing and sacrificial template methods, respectively.
View Article and Find Full Text PDFNanoscale
January 2025
Laboratory for Multiscale Mechanics and Medical Science, SV LAB, School of Aerospace, Xi'an Jiaotong University, Xi'an 710049, China.
Based on the molecular dynamics (AIMD), the temperature and velocity statistics of diatomic semiconductors were proposed to be classified by atomic species. The phase differences resulting from lattice vibrations of different atoms indicated the presence of anharmonicity at finite atomic temperatures. To further explore the electronic properties, the effect of temperature on electrostatic potential field vibrations in semiconductors was studied, and the concept of electrostatic potential oscillation (EPO) at finite atomic temperature was introduced.
View Article and Find Full Text PDFComput Methods Biomech Biomed Engin
January 2025
Department of Clinical Surgery, Cty Clin Emergency Hosp, Sibiu, Romania.
This study examines heat transfer and nanofluid-enhanced blood flow behaviour in stenotic arteries under inflammatory conditions, addressing critical challenges in cardiovascular health. The blood, treated as a Newtonian fluid, is augmented with gold nanoparticles to improve thermal conductivity and support drug delivery applications. A hybrid methodology combining finite element method (FEM) for numerical modelling and artificial neural networks (ANN) for stability prediction provides a robust analytical framework.
View Article and Find Full Text PDFAdv Sci (Weinh)
January 2025
Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong SAR, Hong Kong.
Lead-free halide double perovskites provide a promising solution for the long-standing issues of lead-containing halide perovskites, i.e., the toxicity of Pb and the low stability under ambient conditions and high-intensity illumination.
View Article and Find Full Text PDFACS Appl Mater Interfaces
January 2025
School of Chemistry and Materials Science, Jiangsu Key Laboratory of New Energy Devices & Interface Science, Nanjing University of Information Science & Technology, Ning-Liu Road 219, Nanjing 210026, China.
Radiative cooling, a passive cooling technology, functions by reflecting the majority of solar radiation (within the solar spectrum of 0.3-2.5 μm) and emitting thermal radiation (within the atmospheric windows of 8-13 μm and 16-20 μm).
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