Inspired by the vectorial lattice Boltzmann method for linear elastodynamics (Boolakee et al., 2025), we construct a total-Lagrangian vectorial lattice Boltzmann formulation for two-dimensional finite-strain hyperelastic dynamics. The governing equations are first written as a conservative first-order system for the material velocity and the full deformation gradient. This representation separates the kinematic part of the dynamics from the constitutive closure: the first Piola–Kirchhoff stress is evaluated locally from the current deformation gradient and enters the lattice only through nonlinear flux moments. A D2Q4 stencil with six-component vector populations is then used to match the state and the two material-coordinate fluxes. The formulation includes a second-order population initialization, trapezoidally centered body forcing, displacement reconstruction by velocity quadrature, and half-way reconstructions for velocity Dirichlet and Neumann traction boundaries on grid-aligned domains. The resulting method preserves the local collide-stream structure of standard lattice Boltzmann schemes while adapting the vectorial first-order strategy from linear elastodynamics to hyperelastic finite-strain dynamics.
This study uses density functional theory (DFT) to investigate the selective hydrogenation of acetylene (C2H2) on palladium-based catalysts with core@shell (M13@Pd42) and Crown-Jewel (CJ-M43Pd12) structures. The influence of Cu, Ag, and Au dopants are evaluated to guide the design of highly efficient Pd-based catalysts for converting acetylene to ethylene (C2H4). The calculation reveals that the Crown-Jewel structured Cu43Pd12 (CJ-Cu43Pd12) catalyst exhibits superior activity and selectivity for ethylene production compared to the core@shell structured Cu13@Pd42 and the pure Pd55 catalysts. Electronic structure analysis reveals that the Cu-Pd interaction and electron transfer from Cu to Pd enhance performance in the CJ-Cu43Pd12 catalyst. The findings highlight the significance of geometrical and electronic considerations in the design of catalytic systems for acetylene hydrogenation. These results establish an atomistic theoretical framework for Pd-efficient acetylene semihydrogenation catalysts, demonstrating that the Crown-Jewel geometry can integrate Pd-site isolation and Cu to Pd electronic modulation to balance C2H2 activation, C2H4 desorption, and Pd atom utilization efficiency.
Urban water systems (UWSs) are critical infrastructure that support public health and economic development, yet their life cycle environmental burdens remain poorly understood at the national scale. This study developed a system-scale life cycle assessment (LCA) to quantify environmental impacts and examine structural disparities across water companies. Using operational data from 17 major water companies in England and Wales for 2022–2023, the life cycle impacts of water abstraction, treatment, distribution, wastewater treatment and sludge management were assessed across multiple environmental impact categories. Results showed that electricity consumption and infrastructure construction—particularly sewer networks—dominated environmental burdens across several impact categories, including global warming, fossil resource scarcity, ecotoxicity, human toxicity and terrestrial acidification. Freshwater eutrophication and stratospheric ozone depletion were mainly driven by phosphorus discharges and nitrous oxide emissions from wastewater treatment processes. In contrast, sludge treatment generated environmental benefits through energy recovery and nutrient recycling. Substantial disparities were observed among companies, driven by differences in infrastructure intensity, operational characteristics and service scale, with patterns consistent with scale efficiencies in larger companies under the adopted inventory assumptions. These findings provide transferable insights into the environmental drivers of urban water systems and highlight opportunities for decarbonization and infrastructure optimization in the water sector.
Communication across languages is increasingly mediated by artificial intelligence (AI). This creates opportunities for people with different language backgrounds to communicate in their respective native languages. AI-mediated communication can therefore reduce cognitive effort, disfluency, and social stigma associated with speaking a non-native language. At the same time, non-native language use influences cognitive, emotional, and social processes that go beyond the accurate transmission of meaning. By affecting these processes and introducing new cues, AI-mediated communication could also have unintended effects on communication effectiveness and social evaluations between interlocutors. We examine the conditions under which these effects may help or hinder cross-linguistic interactions and identify directions for research on the psychology of cross-linguistic communication as AI language tools become prevalent.
Thermal management in micro- and nano-scale solids can depart strongly from classical Fourier diffusion on length scales of less than 1μm where phonon-mediated transport exhibits wave-like, finite-speed propagation. Although the Maxwell–Cattaneo–Vernotte (MCV) equation captures this non-Fourier behaviour, existing studies almost universally assume temperature-independent material properties. This is a severe limitation because appreciable thermal gradients render the heat capacity and thermal conductivity strongly spatially and temporally varying, especially at low temperatures, introducing non-linear coupling that fundamentally alters transport dynamics. Here, we extend the MCV framework to incorporate fully temperature-dependent heat capacity and thermal conductivity, and apply it to homogeneous and patterned silicon–germanium systems. In homogeneous bars, the temperature-dependent coefficients jointly govern the phase, amplitude, and damping of thermal waves, yielding quantitatively distinct propagation in the 100–200 K and 200–300 K regimes. In hierarchical metamaterials with asymmetric graded periodicity, the interplay between geometric asymmetry and temperature-dependent properties produces a pronounced transient directional thermal asymmetry: mirror-image configurations exhibit markedly different transient temperatures during heating and cooling. The resulting asymmetric peaks at approximately 160 K in the 100–200 K range are nearly three times larger than at 200–300 K and persist for less than 4 ns. This asymmetry vanishes under isothermal non-Fourier conditions, proving that transient rectification requires both finite heat-flux relaxation and temperature-varying material properties. These findings provide design principles for pulsed thermal management and transient thermal diodes, and identify Si/Ge heterostructures as experimentally accessible platforms for probing non-linear non-Fourier heat transfer.
