Diamond demonstrates significant application potential in electronic devices owing to its excellent properties, yet its practical application is often limited by interface challenges in precisely controlling its interfacial electronic properties. This study demonstrates that surface termination engineering serves as a potential strategy for effectively modulating the electron affinity (EA) of diamond, thereby tuning the band offsets and Schottky barrier heights (SBHs) at its interfaces. By constructing 24 distinct diamond termination models, the EA of diamond can be tuned from -3.95 to 2.71 eV, governed by the combined effects of surface dipole moment and gap states. Furthermore, the terminated diamond forms a charge-blocking layer at the heterojunction interface, thereby largely preserving the original band positions. Consequently, a linear modulation of the band offset from 0.58 to 4.34 eV is accomplished by integrating beta-Ga2 O3 with 12 different diamond terminations. For metal/diamond contacts, an SBH adjustment from -0.78 to 2.14 eV is achieved at Pt/diamond interfaces by employing different terminations. Notably, the introduction of surface-state-free terminations effectively suppresses metal-induced gap states, thereby achieving significant Fermi-level depinning. This work elucidates the underlying mechanism of termination-induced EA tuning and establishes a paradigm for quantitative band offset and SBH control, providing critical guidance for the rational design of high-performance diamond-based devices. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.
Abstract Enhancing the durability of bituminous pavements requires effective antiaging additives for bitumen. However, the unclear differences in microstructure and performance enhancement among various additives hinder their optimization and application. This study evaluates the effects of four antiaging additives on bitumen performance and aging resistance: antioxidant (AO), ultraviolet absorber (UVA), their combination (UVA+AO), and a novel zinc oxide/expanded vermiculite composite (ZnO/EV). Results show that unlike UVA and AO, which undergo structural changes in bitumen, ZnO/EV maintains structural stability and demonstrates superior ultraviolet absorption (about 20% higher than UVA) and thermal stability. These superior intrinsic properties translate into enhanced performance for ZnO/EV modified bitumen. ZnO/EV significantly increases bitumen stiffness and elastic response in the unaged state, improving resistance to permanent deformation while maintaining excellent low-temperature flexibility. Critically, ZnO/EV provides consistently superior short- and long-term aging resistance across all tested conditions, markedly reducing aging-induced changes (e.g., softening point increment, viscosity aging index). In contrast, the common additives show limitations: UVA can impair short-term aging resistance, AO provides only moderate improvement, and the UVA+AO compound fails to synergize effectively, underperforming ZnO/EV. This study conclusively demonstrates that ZnO/EV significantly outperforms conventional antiaging additives in both enhancing bitumen’s key performance properties and providing robust, multicondition aging resistance, highlighting its strong potential for durable pavement applications.
Efficient thermal management is paramount for enhancing the power density and operational longevity of proton exchange membrane fuel cells. This study systematically investigates twelve feasible coupled coolant–reactant flow-direction configurations within the same three-stage segmented cooling-channel geometry featuring straight, wavy, and tapered sections. We propose a robust data-driven framework that integrates high-fidelity physical modeling, Bayesian surrogate modeling, and multi-objective genetic algorithms to decouple complex thermo-fluid mechanisms. Case 12 is identified as the best-performing flow-direction topology, reducing the average temperature uniformity index by 45.7% relative to Case 8 based on ten Latin-hypercube-sampled coolant velocity–temperature difference combinations under identical geometric and operating conditions. The subsequent optimization determines a synergistic operating window with a velocity of 1.989 m/s and a temperature difference of 6.109 K, yielding an additional 14.53% enhancement in thermal uniformity while sustaining a high current density. The thermo-hydraulic synergistic mechanism involves reshaping the thermal boundary layer via induced secondary Dean vortices and spatial acceleration while successfully avoiding diminishing returns. This work provides a systematic design framework for coordinated flow-orientation and operating-parameter optimization in proton exchange membrane fuel cell thermal management systems.
Background Al-based radiators are core components of offshore generator sets, and their anticorrosion performance directly affects the safe and stable operation and service life. Methods A novel chitosan (CTS) derivative (CTS-ZIM) was synthesized through an amidation reaction by using a zwitterionic imidazole compound as a modifying monomer. Significant findings CTS-ZIM shows a significantly enhanced inhibition performance, achieving an inhibition efficiency of 97.1% at a low concentration of 1000 mg L–1 for Al fin in a 1.0 M HCl solution. Weight loss method, electrochemical method, and physical characterizations demonstrate that the inhibitor effectively suppressed the corrosion process through adsorption on the steel surface. The introduction of the zwitterionic imidazole compound into CTS provides abundant ionic structures, unsaturated bonds (CO, CC, CN), Schiff base moieties, imidazole rings, and heteroatoms (N, O). These changes enhance its adsorption on metal surfaces, favoring the formation of a protective layer. Moreover, density functional theory calculations indicate that the introduction of zwitterionic imidazole can enhance the adsorption strength and electron-donating ability of the inhibitor. It is believed that this work can provide sufficient guidance for the precise design of efficient corrosion inhibitors.
Let Fℓ be the fan graph obtained by joining a vertex with a path on ℓ−1 vertices. Yu, Li and Peng [Discrete Math. 346 (2023)] conjectured that if the number of edges of G is m and the spectral radius λ(G)>k−1+4m−k2+12, then G contains a F2k+1 and F2k+2, unless G=Kk∨(mk−k−12)K1. The case k≥3 of the above conjecture has been confirmed by Li, Zhao and Zou [J. Graph theory 110 (2025)]. Zhang and Wang [Discrete Math. 347 (2024)], Yu, Li and Peng [Discrete Math. 348 (2025)], Gao and Li [Discrete Math. 349 (2026)] confirmed the case k=2. However, the extremal graphs for the case k=2 only exist when m is odd. The case with m even has not been determined. In this paper, we characterize the extremal graph for F6 and even m≥3000.
