Clay's solid-fluid phase transition, a key cause of geohazards like landslides and debris flows, remains notoriously difficult to model due to its coupled frictional yielding and strain-rate-dependent fluidization. Its complexity poses a substantial challenge to constitutive modeling. For the first time, this study proposes a novel critical-state hydrodynamic model (CSHM), which efficiently captures clay's nonlinear solid-fluid phase transition by integrating quasi-static and viscous stress components in a unified framework. The quasi-static stress is described by a critical-state-based elastoplastic model, representing the solid-like behavior. In contrast, the viscous stress is described using a novel hydrodynamics-based rheological model that captures the fluid-like behavior by introducing a state variable termed “clay temperature”. The quasi-static component captures key aspects including nonlinear elasticity, stress dilatancy, and critical state, whereas the proposed viscous component describes shear-heating or shear-cooling rheology. Subsequently, extensive element simulations are employed to evaluate the new CSHM. Finally, validation against experimental data demonstrates that the CSHM accurately captures the clay's solid-to-fluid phase transition. The analyses reveal that: (i) While sand undergoes a shear-induced heating phase transition and is well described by the existing kinetic theory, clay exhibits shear-cooling, which our novel model accurately captures. (ii) Clay's phase transition is characterized by two transitional points (critical-state point and viscous-stress-dominant point) and three different regimes (solid-like, transitional, and fluid-like). (iii) Unlike the traditional HB model, a 2D model describing stress in the fluid-like state, the CSHM is a 3D full-range phase transition model that captures evolution from initial to critical state, and eventually fluid-like state. • Proposes critical-state hydrodynamic model for clay's solid-fluid phase transition. • CSHM integrates critical-state elastoplasticity (solid) and hydronhamics (fluid). • Proposes novel hydrodynamic model with ‘clay temperature’ for viscous stress. • Seamlessly bridges solid and fluid states via critical-state and clay temperature. • Comparison with experimental results confirm the model's accuracy.

Temperature variations may cause solid–liquid phase transition and damage evolution, which requires more refined modelling. In this study, a solid–liquid thermo-mechanical phase field model based on thermodynamically approach is established. A novel predictive equation of temperature-dependent critical strain energy density is firstly derived by combining force-heat equivalent principle and effective heat capacity method. The critical strain energy density of typical brittle materials with narrow phase transition interval (e.g., ice and Al 2 O 3 ) can be successfully captured by the proposed formulation. A simple but effective degradation function associated with phase transition variable is embedded in the phase field model to describe the mechanical degradation within phase transition and avoids the undesirable damage that occurs in liquid-state domain. The established multi-physical framework is implemented through finite element method. In numerical simulations, the phase transition part is verified through the two-phase Stefan’s melting issue preliminarily. Then, the thermo-mechanical module is studied through the shrinkage cracking of a 1D bar. The insensitivity of length scale and fracture toughness degradation under the assumption of small transition interval is proved. The proposed model is subsequently applied to thermal cracking in additive manufacturing and electrothermal de-icing, with its effectiveness and accuracy demonstrated by comparing with experimental results and empirical criterion

Near-term projection of precipitation over the southern Tibetan Plateau constrained by the Interdecadal Pacific Oscillation

Wideband tunable terahertz metamaterial absorber based on vanadium dioxide (VO2) for terahertz sensing and communication

Lithium-rich manganese oxides (LRMOs) show great promise as high capacity, cost effective cathodes for next-generation Li-ion batteries, Nevertheless, they still confront issues such as voltage decline, capacity loss, and structural instability. Recent breakthroughs in in situ / operando characterization methods have emerged as highly effective means for uncovering the dynamic changes in structure and electrochemical activity of these materials. This review delves into advanced methodologies enabling the real time observation of phase alterations, oxygen redox interactions, and the migration of transition metals (TMs) throughout the battery's charge/discharge cycles. By combining various characterization tools, researchers can reveal crucial connections between defect formation, redox mechanisms, and the stability of the battery's structure, enabling the development of novel approaches to suppress performance degradation. The study illustrates that mechanistic insights into phase transitions and failure modes, gained through advanced characterization, are instrumental in improving LRMOs. Prioritizing multiscale in situ methodologies coupled with machine learning for data interpretation will be crucial for rapidly developing viable LRMOs. These advancements in real time analysis hold promise for addressing current limitations and fast tracking the market introduction of high-energy-density materials for future energy storage.

Disconnections, long recognized as the key mediators of grain boundary (GB) kinetics in polycrystalline materials, have traditionally been understood to nucleate through thermal or mechanical activation. In this work, using atomistic simulations, we reveal a distinct nucleation mechanism driven exclusively by solute interstitial segregation across multiple substitutional binary alloy systems (e.g., Al-Ni, Al-Fe). This process exhibits zero-nucleation energy barriers, contrasting sharply with the nucleation mechanisms in pure systems. We identify states which are activated through segregation induced GB phase transitions: (i) isolated disconnections or phase junctions that promote GB migration and disappear with continuous segregation, and (ii) composite disconnections that are formed via two oppositely oriented isolated disconnections. The disconnections are mechanically robust, suppressing shear-coupled migration and instead resulting in GB amorphization and pure sliding under applied shear loading. The long-range stress fields associated with these composite disconnections further attract solute atoms and assist the nucleation of precipitates. These disconnections, absent in pure materials, follow unique nucleation pathways as confirmed through dichromatic pattern analysis and persist across different alloy chemistries and crystal structures. Our findings demonstrate that solute interstitial segregation provides a powerful and previously unrecognized pathway for barrier-free disconnection formation, thereby fundamentally extending current understanding of GB kinetics in alloy systems.

Agent-based analysis of electricity contract switching considering multi-dimensional consumer satisfaction and social influence

Phase transitions at high and low densities for a rotating QCD matter from holography

Temperature-dependent changes in gas chromatographic separation metrics for trihexyl(tetradecyl)phosphonium-based ionic liquid stationary phases and comparison to conventional polysiloxane stationary phases.

We present an extensive investigation on the properties of Eu 3+ optical emissions associated with deformation of ZnO host applying an external hydrostatic pressure, combining in situ synchrotron X-ray diffraction and photoluminescence spectroscopy with first-principles calculations. A pressure-induced phase transition from the hexagonal wurtzite to the cubic rocksalt structure near 10 GPa is accompanied by complete quenching of the 5 D 0 → 7 F J emissions near the threshold, followed by a partial but reproducible recovery at higher pressures, likely associated with the emergence of structural disorder. Concurrently, as the crystal field strength increases, the Stark components of the emissions exhibit a systematic redshift (∼0.40 ± 0.02meV/GPa) and pressure-induced broadening (∼0.55 ± 0.02 meV/GPa). The first-principles calculations support the observed pressure-induced shifts in the Eu-4f states and emphasize the influence of lattice symmetry on their electronic environment. These findings establish hydrostatic pressure as a powerful tool for tuning rare-earth optical emissions through symmetry-driven and local-environment modifications, laying the foundation for pressure-engineered photonic functionalities and luminescent devices. • Pressure-driven wurtzite-to-rocksalt transition modulates Eu 3+ luminescence in ZnO. • The structural transition initiates at ∼5.8 GPa, with cubic dominance above 10GPa. • Redshift and Stark splitting due to enhanced lattice symmetry and crystal field. • DFT reveals symmetry-dependent reshaping of electronic states under compression. • Lattice symmetry control governs RE optical activity under extreme conditions.

The Global Precipitation Measurement (GPM) core satellite’s Dual-frequency Precipitation Radar (DPR) provides new insights into detecting solid-to-liquid phase transition heights of precipitation particles. However, significant anomalies can be found in the “binMixedPhaseTop” parameter within its official Level 2 data products during shallow convective precipitation events. Statistical analysis of the Yangtze and Huai River Basins from 2014 to 2023 reveals that the anomaly rate for shallow convective precipitation is 64.94%, far exceeding those for convective (0.61%) and stratiform (0.48%) precipitation. Further investigation demonstrates that the warm-rain process characteristic of shallow convective systems lacks a distinct solid-to-liquid phase transition layer, leading to algorithmic misinterpretations. An improved identification algorithm for “binMixedPhaseTop” is proposed to address this problem. It incorporates additional checks to ensure that the phase-transition height is only identified when a melting layer is present, thereby preventing misjudgments and redundant computations. The enhanced version is validated against 10-year observations from South China (2014–2023), demonstrating 91% anomaly suppression through extreme deviation truncation. This study highlights the need for algorithm refinement to accurately detect phase-change heights in different precipitation types, thereby enhancing the reliability of the “binMixedPhaseTop” product for convective precipitation detection. 星载双频降水测量雷达GPM DPR能够探测降水相变层顶高度.然而, 其Level 2数据 (V07A) 中的“binMixedPhaseTop”物理量在浅对流降水中表现异常.在2014年—2023年夏季GPM DPR探测江淮流域降水数据中, "binMixedPhaseTop"在浅对流降水中的异常率高达64.94%, 显著高于其在对流降水 (0.61%) 和层状降水 (0.48%) 中的异常率.本文认为浅对流降水的暖雨过程缺乏固态到液态的清晰相变层, 导致GPM DPR现有算法出现误判.为此, 本文提出一种改进的“binMixedPhaseTop”识别算法, 即通过增加相变层存在性验证, 有效避免了无相变层时的误判及冗余计算.验证结果表明改进算法有效降低了GPM DPR探测浅对流降水相变高度的识别异常率.

Antiferroelectric/ferroelectric phase transitions in Pb(Hf1-Ti )O3 ceramics with low Ti content

A multi-layer dynamic model of information propagation considering individual three-phase linear modulated behaviors

Influence of surface magnetism on phase transitions in thin ferromagnetic films with antidot lattice: Monte Carlo simulation

Preparation and properties of short blade sodium ion batteries with Mg/Ti Co-Doped P2-type cathode materials

Raman spectral weight redistribution driven by spin–lattice coupling in Sm2Ir2O7

Combination of electronic structure regulation and controllable phase transition engineering for urea-assisted energy-saving hydrogen production.

Multi-walled carbon nanotubes (MWCNTs) and graphene nanoplatelets (GNPs) were embedded into poly(vinylidene fluoride) (PVDF) electrospun fibers with varying mass fractions (0–4 wt%). In addition, the hybrid combinations at 1.5 wt.% GNP/MWCNT/PVDF were fabricated to evaluate potential synergistic effects. The electrospun fiber mats were thermally post-treated at 145°C for 3 and 6 h to assess the influence of annealing on the microstructure, crystalline phase composition, and functional performance. The morphological, structural, mechanical, and piezoelectric properties were examined in relation to both the distinct geometries of the fillers and the thermal annealing. The combination of annealing and nanofiller-induced nucleation significantly improved the crystallinity of the fibers. The tensile strength increased up to 11.1 MPa for 0.5 wt.% MWCNT/PVDF and 15.7 MPa for 1.5 wt.% GNP/PVDF after 6 h of annealing. Structural analysis revealed a pronounced α→β phase transition in the 1.5 wt. % hybrid compositions, reaching a β/α ratio up to 7.8 substantially greater than the transitions observed for mono-filler systems: 4.7 for 1.5 wt.% GNP/PVDF and 3.0 for 1.5 wt.% MWCNT/PVDF. The effect of the high β-phase content was further confirmed at the nanoscale by piezoresponse force microscopy (PFM), which showed a consistent piezoelectric response through the fibers: a coercive voltage of approximately ± 40 V, which decreased to ± 20 V, ascribed to the dispersed nanofillers within the fiber. These results demonstrate that combining hybrid carbon fillers with controlled annealing enables tunable crystalline structures and enhanced electromechanical performance in electrospun PVDF nanofibers. • hybrid GNP/MWCNT fillers drive synergetically β-phase nucleation mechanisms. • The interfacial interaction between PVDF and carbon fillers was quantified using Piezoresponse Force Microscopy (PFM) measurements. • PFM confirmed a consistent piezoelectric response with coercive voltage decreasing from ± 40 V to ± 20 V due to dispersed nanofillers • Hybrid fillers and annealing tailor PVDF crystallinity and functional performance.

Heterogeneity-dominated discrete phase transitions in multistable systems: A unified bistable chain framework

Infrared brightness temperature–based indicators for identifying thunderstorm clouds: Insights from FY-4A satellite observations