Browse Articles

Extended multi-temperature model for electron–phonon coupling and ultrafast thermal transport in graphene

Ultrafast thermal transport in low-dimensional materials challenges traditional diffusive models due to reduced scattering, strong electron–phonon coupling, and pronounced non-equilibrium effects. To address these complexities, we extend the macroscopic multi-temperature model by incorporating non-diffusive and non-local phenomena, treating electrons, optical phonons, and acoustic phonons as coupled but thermally distinct subsystems. We benchmark this enhanced framework against the multi-temperature Boltzmann transport equation, enabling detailed resolution of branch-dependent energy relaxation and identifying bottlenecks in thermalization. This approach provides a more accurate and comprehensive description of heat flow in emerging materials, offering novel insights into phonon dynamics and electron–phonon interactions. These theoretical advances pave the way for the improved design and optimization of next-generation nanoelectronic and photothermal devices.

Author Correction: Machine learning analysis of CO2 and methane adsorption in tight reservoir rocks

Acid‐ and Nucleophile‐Gated Photoisomerization of Phosphaindirubin

Abstract Nature uses protonation and microenvironmental effects to modulate photoisomerization, as seen in rhodopsins and GFP. Inspired by this, we report phosphaindirubin (PI), a visible‐light responsive photoswitch bearing a stereogenic phosphorus center that exhibits reversible Z / E isomerization controlled by light, acid, and nucleophiles. While structurally related to photoinert isoindigo, phosphaindirubin undergoes efficient Z → E isomerization in low‐polarity solvents but remains inert in polar media unless protonated. Acid gating alters the excited‐state landscape, enabling switching under light irradiation in acetonitrile. Strikingly, the thermal back‐isomerization of PI is accelerated by nucleophiles, including pyridine and iodide, offering an underexplored mechanism for catalyzing double bond rotation. This triple‐responsiveness to light, acid, and nucleophile enables reversible, fatigue‐resistant cycling between Z ‐ and E ‐forms. These findings introduce a new design principle for photoswitches based on dynamic, multi‐stimuli gating of excited‐state and ground‐state reactivity.

Spinel CuGa2O4-based memristor enabling synaptic plasticity and associative learning for next-generation memory devices

As conventional memory technologies face limitations in scalability, volatility, and energy efficiency, resistive random-access memory (RRAM) has emerged as a promising candidate for next-generation memory and neuromorphic computing. Among various oxide materials, copper oxide (CuO) has been studied for RRAM applications due to its simple binary structure, ease of synthesis, and inherent defect-mediated switching behavior. However, despite these advantages, CuO-based devices often suffer from limited endurance and poor retention. To overcome these drawbacks, we explore CuGa2O4, a complex spinel oxide, as a more stable and tunable alternative. The multinary composition and the spinel structure of CuGa2O4 offer enhanced control over defect chemistry and switching dynamics, leading to improved reliability and multifunctionality. The device demonstrates analog switching characteristics, including transition from short to long-term plasticity under repeated stimulation, mimicking biological synapses. Furthermore, associative learning behavior, reminiscent of the Pavlovian conditioning model, is observed, demonstrating the device's potential in neuromorphic systems.

An integrated approach to unravel the deep-shallow aquifer connectivity in the Eastern Sahara

Abstract The ambitious agricultural development projects in Egypt and the associated horizontal expansion into the core desert lands and desert fringe zones around the Nile Valley primarily depend on water availability. This study investigates the vertical recharge from the deep Nubian Aquifer System (NAS) toward the shallow aquifers, including the Carbonate and Quaternary aquifers in southern Egypt. While this connectivity has been studied locally through case studies, the present study integrates stable isotope data from all previous studies, together with analyses from vastly distributed new groundwater samples, remote sensing, and geophysical methods to better understand groundwater dynamics and aquifer connectivity over a regional domain. Findings show that: (1) the depths to the basement surface range from 350 to 4700 m below the land surface, (2) the major structural trends are E-W, NW–SE, NE-SW, ENE, NNW, and WNW trends, (3) the contribution ratios from the deep NAS to the overlying aquifers range between 10 and 98% as estimated using isotope mass balance calculations, and (4) the intersection of NW, ENE, and NE structural trends, which show similar trends between surface faults and deep faults, indicating vertical continuity, plays a major role in aquifer connectivity along the western desert fringes of the Nile River, particularly south of latitude 26°30′N. These findings indicate that the relatively thin sedimentary cover overlying the NAS south of latitude 26°30′N facilitates the upwelling of the NAS groundwater along with the intersection of the NW, ENE, and NE fault systems. Given the consensus of high hydraulic heads of the NAS compared to the overlying aquifers, the study suggests that a large-scale vertical upwelling at the deduced intersecting structural trends throughout the entire Limestone Plateau is worthy of further investigation. Such vertical upwelling could bring significant groundwater resources to shallow levels, as long as the NAS maintains its higher heads, and thus supports desert greening projects in Egypt. The findings also highlight the necessity of examining similar mechanisms in other desert environments with multiple aquifer systems.

Multi-physical field regulation of spin reorientation phase transition in YFe0.7Mn0.3O3 single crystal

This study systematically investigates the regulation of the spin reorientation behavior in YFe0.7Mn0.3O3 (YFMO) single crystal under electric, magnetic, and hydrostatic pressure fields. X-ray photoelectron spectroscopy analysis reveals a characteristic mixed-valence state dominated by Fe2+ along with a high concentration of oxygen vacancies. Magnetic measurements indicate that an electric field of 10 kV/cm does not alter the c axis magnetization, regardless of the field direction. The magnetic response shows clear anisotropy. A high field (>23 kOe) along the a axis induces the Γ2 (Fx) phase, while along the c axis it drives a reversible transition between the Γ1 (Cz) and Γ4 (Fz) phases. Hydrostatic pressure further exhibits versatile regulatory capabilities. It not only shifts the Γ4→Γ1 transition temperature along the c axis but also induces an emergent Γ3 (Fy) phase along the b axis. Consequently, the phase transition pathway expands from a simple Γ4→Γ1 sequence to a complex process involving mixed Γ3 phases. This work elucidates the anisotropic response of YFMO to external fields and reveals the potential of pressure for regulating spin order, providing valuable insights for developing room-temperature spintronic devices.

Optimization of sporulation of Trametes sanguinea ZHSJ and untargeted metabolomics of spores, mycelium and fruiting body

X-ray diffraction study of mixed-phase BiFeO3: Structural modulation via proton injection

Incorporating hydrogen into transition metal oxides with intricate structures offers significant potential for discovering exotic phenomena and functionalities by facilitating interactions between hydrogen ions and structural phases. Mixed-phase (MC + R′/T′ phases) BiFeO3 (BFO) has attracted considerable attention due to its numerous physical property discoveries, making it a promising candidate for modulation through hydrogen insertion. This study systematically investigates the structural evolution of BFO films under three distinct hydrogen injection methods: noble metal-catalyzed injection, ionic liquid gating, and hydrogen reduction. Comprehensive XRD analysis reveals that varying proton pathways and injection intensities induce characteristic structural modifications. X-ray absorption spectroscopy and x-ray photon spectroscopy results provide a more in-depth examination of the variations in valence states and oxygen ions migration induced by protonation in BFO films. Furthermore, the magnetism of the mixed-phase BFO increases, and the spontaneous polarization domains are enhanced, during the migration of protons and oxygen ions. This work provides valuable insights into hydrogen-associated electronic phase transitions within the mixed-phase BFO, advancing its potential applications in next-generation electronic devices.

Integrated site selection framework for origin-based cold storage using GIS-MCDM and improved Harris Hawks optimization

AlScN as an electron blocking layer in blue light emitting diodes: A first look

Electron blocking layers (EBLs) are instrumental in visible light emitters based on nitride semiconductor heterostructures. AlScN (a) can be lattice-matched to GaN, (b) can be grown at GaN compatible conditions, and (c) offers favorable band offsets required for EBLs, but has not been used in light emitting devices to date. In this work, we test if lattice-matched AlScN can be integrated as an EBL layer in a blue light emitting diode (LED) pn junction heterostructure. We find that blue LED operation with peak electroluminescence (EL) at ∼460 nm can indeed be realized with an AlScN EBL. In the LED with the AlScN EBL, we observe low reverse leakage current density, and ∼6 nm lower full-width at half maximum of the EL peak compared to a control sample. Though the turn-on voltage of the AlScN EBL containing blue LED is high, this demonstration proves its feasibility and provides guidance for improved performance in the future.

Cardiomyocyte-derived TGFB3 attenuates cardiac fibrosis and preserves cardiac function in heart failure

A melting mode of frozen sessile droplets with unmelted ice layer deposited at the bottom

Water-repellent properties of superhydrophobic surfaces make them promising for anti-icing and deicing applications. Through experimental visualization of frozen sessile droplets undergoing melting on superhydrophobic surfaces, we identify a melting mode with the unmelted ice layer deposited at the bottom of the melting droplet, even though the density of ice is lower than that of water. In the deposited mode of the melting process, the time required for the frozen droplet to melt completely is much shorter than that in the floating mode. Force analysis shows that the melted fluid flows along the gas–liquid interface toward the top of the melting droplet, thereby exerting force and then suppressing the upward movement of the unmelted ice layer. Moreover, the flow within the liquid film formed between the unmelted ice layer and the heating wall is dominated by the viscous force, which has a lubrication effect and maintains the deposition of the unmelted ice layer. High heating temperature, large contact angle, and low particle concentration are helpful for the occurrence of the deposited mode.

The effect of punishment on cooperation in a multilevel public goods game: compositional data analysis

Abstract When addressing collective challenges, cooperation is essential both within and across subgroups. In multilevel social dilemmas, cooperation can occur at two levels: local cooperation (within one’s subgroup) and global cooperation (across subgroups). While punishment has been shown to foster local cooperation in standard, non-multilevel public goods games, its role in promoting global cooperation remains unclear. To examine cooperative behavior at both levels, the present study involves 120 participants and employs a multilevel public goods game with punishment. Participants decided how to allocate endowments among self, local, and global accounts. We tested (i) whether punishment promotes local and/or global cooperation, (ii) whether individuals punish in-group or out-group members more, and (iii) what behaviors are punished. Using compositional data analysis suitable for examining allocation ratios among multiple targets, we found that punishment promoted both local and global cooperation by primarily targeting non-cooperators. Importantly, punishment behavior toward in-group and out-group members did not differ. These findings suggest that punishment can facilitate cooperation beyond subgroup boundaries and provide a potential mechanism for sustaining collective action across groups.

Ethane Chlorination Toward Vinyl Chloride Synthesis: Mechanistic and Catalytic Perspectives

ABSTRACT Ethane chlorination has emerged as a promising alternative to conventional ethylene‐ and acetylene‐based routes for the production of vinyl chloride monomer (VCM). Unlike conventional catalytic processes, this approach relies on chlorine radical‐mediated activation to convert ethane into 1,2‐dichloroethane, followed by thermal cracking to VCM. However, this route remains in its early stages, hindered by the complexity of gas‐phase radical chemistry and catalyst deactivation under chlorination conditions. This review provides a critical assessment of the mechanistic foundations of ethane chlorination, highlighting the interplay between radical‐mediated and surface‐catalyzed pathways. Particular attention is given to advances in rare‐earth oxychloride catalysts, which have shown the ability to stabilize key intermediates. We also discuss major deactivation mechanisms, including phase transformation and surface hydroxylation, that limit catalyst lifetime. Furthermore, we highlight the feasibility of ethane chlorination as a low‐carbon VCM production route under future decarbonized energy scenarios. Finally, key directions in catalyst design, mechanistic understanding, and process integration are outlined to advance ethane chlorination from laboratory‐scale innovation to industrial reality.

Erratum: “Modeling realistic multi-layer devices for superconducting quantum electronic circuits” [Appl. Phys. Lett. <b>126</b> , 142601 (2025)]

The stress hyperglycemia ratio as a novel risk marker for postoperative delirium after cardiac valve surgery

Abstract The stress hyperglycemia ratio (SHR) has been demonstrated to be associated with numerous adverse outcomes; however, its relationship with postoperative delirium (POD) in patients undergoing cardiac valve surgery remains unclear. This study aimed to investigate the association between SHR and POD in this surgical population. This retrospective study analyzed the data from 1830 adult patients who underwent cardiac valve surgery from the Medical Information Mart for Intensive Care IV (MIMIC-IV, version 3.1) database. Primary outcome was the incidence of POD within 7 postoperative days. Secondary outcomes included lengths of stay in the intensive care unit (ICU) and hospital, as well as 28-day and 90-day mortality. Multivariable logistic regression identified SHR as an independent risk factor for POD (odds ratio [OR] 1.47, 95% confidence interval [CI] 1.03–2.11, P  = 0.034). Using the optimal SHR cutoff, patients were stratified into high-SHR (≥ 1.164) and low-SHR (&lt; 1.164) groups. Those with high SHR had a significantly elevated risk of POD compared to the low-SHR group (OR 1.55, 95% CI 1.18–2.03, P  = 0.002). Sensitivity analyses confirmed the robustness of these findings. After 1:1 propensity score matching based on key confounders, the high-SHR group also exhibited prolonged ICU stay and higher 28-day and 90-day mortality. No significant interactions were detected in any of the predefined subgroup analyses. These findings suggest that SHR is an important risk factor for POD following cardiac valve surgery and demonstrates considerable potential as a novel risk marker for POD in this surgical population.

Interpretation of ferroelectric behavior in AlScN films with TiN and Ta bottom electrodes

Ferroelectric properties of 50-nm-thick Al0.88Sc0.12N films with different bottom electrodes (BEs) of TiN and Ta were characterized. Capacitance–voltage (C–V) curves of the capacitors indicate sharp switching with the Ta BE, whereas partial polarization can be obtained with the TiN BE. By analyzing the electric field distribution of the partial polarization obtained from positive-up negative-down measurements, two kinds of coercive field (Ec) with Lorentzian distributions can be extracted: one high Ec with AlScN domains and another low Ec with defect-incorporated domains. The distribution of the inverted nucleus becomes narrower with the Ta BE and appears to correlate with the degree of c-axis orientation evaluated by rocking-curve x-ray diffraction. The defect-incorporated domains were found to shift their mean Ec to a higher electric field by switching cycles, resulting in the fatigue effect. The present interpretation provides insight into understanding the ferroelectric behavior of AlScN films.

Multi-objective optimization design of oil spray cooling system for hairpin motor based on particle swarm optimization-backpropagation-non-dominated sorting genetic algorithm III

Giant room-temperature nonvolatile magnon on–off modulation ratio in a multiferroic Pt/Bi1.05La0.05FeO3/Pt sandwiched structure

We experimentally demonstrated magnon transmission in a vertical geometry consisting of multiferroic Bi1.05La0.05FeO3 (BLFO) and heavy-metal Pt layers. Notably, a giant nonvolatile on–off modulation ratio of ∼120% under zero-field operation, together with high magnon drag efficiency (∼3.51 × 10−3 V A−1), was observed in a vertical Pt/BLFO/Pt device at room temperature. The magnon-mediated drag effect in the nonlocal Pt/BLFO/Pt symmetrical layers was investigated via the magnetic field, angle, and current density dependence. The intrinsic giant on–off modulation of the magnon signal, along withnonvolatile transport under zero-field operation and polarization-controlled Néel vectors of multiferroics, moves a possible step toward the practical utilization of multiferroic vertical magnon devices. This work may contribute to magnonic transport with high-speed, miniaturization and ultralow energy consumption.

Validation and application of a standardized quantitative PCR assay for the assessment of antimicrobial resistance genes in surface water

Abstract Antimicrobial resistance can be an indicator of anthropogenic contamination in surface waters and is a potential public health threat. Methodological standardization for characterization of antimicrobial resistance in the environment is lacking. Quantitative PCR (qPCR) is used for rapid assessment of antibiotic resistance genes (ARGs) from environmental sources, including surface water. Here we describe the validation and application of a qPCR assay for 47 bacterial gene targets intended for surface water samples. The qPCR assay displayed excellent sensitivity (97.66%) and specificity (98.71%) for detecting ARGs when compared to whole genome sequencing of bacterial isolates. The qPCR assay was able to detect up to 6/8 (75.0%) of ARGs spiked into sterile water at varying concentrations and four sample ultrafiltration volumes. Nineteen different ARGs were detected across six samples sites at three national parks in Alaska using ultrafiltered surface water samples. The number of unique ARGs detected was higher at sites within parks with greater visitation. The relative abundance of ARGs/16S from Exit Creek in Kenai Fjords National Park, downstream from a visitor center was greater than all other sampled sites. We have demonstrated a robust qPCR assay for monitoring ARGs in surface waters, including those that are minimally human impacted.