Browse Articles

Resilience of the gelatinous zooplankton species Oikopleura dioica to ocean alkalinity enhancement

Ocean alkalinity enhancement (OAE) through mineral dissolution is a promising marine carbon dioxide removal strategy because it increases the buffering capacity of seawater and thereby enhances passive storage of atmospheric CO 2 . However, the ecological consequences of OAE for zooplankton, particularly gelatinous species, remain poorly understood. Here, we assessed the response of a key gelatinous zooplankton species to OAE in a 53-day mesocosm experiment in a temperate Norwegian fjord . Oikopleura dioica is a globally distributed zooplankton member, known for its high secondary production capacity and key role in vertical carbon flux. O. dioica continuously produces mucous feeding structures (‘houses’), which efficiently retain submicron particles. Once discarded, these houses can sink rapidly and contribute to vertical carbon exports. To test the impacts of OAE on O. dioica abundances and their house production capacity, we exposed natural plankton communities to non-CO 2 -equilibrated OAE scenarios spanning a ΔTA range from 0–600 μmol kg -1 , using silicate-based (olivine) and calcium-based (slaked lime) minerals. Population dynamics of O. dioica were monitored alongside the plankton community, and targeted bottle incubations were used to quantify house production and feeding rates. We show that O. dioica abundances varied by an order of magnitude within and across treatments. No interaction between O. dioica abundance and alkalinity levels or mineral types could be detected. Instead, O. dioica abundance variations were primarily explained by prey availability (picoplankton). Additionally, house production and feeding rate experiments showed that O. dioica were unaffected by OAE across all treatments. These findings indicate that O. dioica, as a key gelatinous zooplankton member, is physiologically resilient to OAE within the tested range. Future studies should incorporate gelatinous zooplankton into OAE assessments and investigate higher alkalinity perturbations to evaluate potential ecosystem impacts and larvacean-mediated changes in carbon export during under OAE deployments above ΔTA 600 μmol kg -1 .

Luminescence mechanism of prismatic stacking faults in homoepitaxial AlN

A fundamental understanding of the correlation between the microstructure and luminescence properties is critical to advancing deep-ultraviolet optoelectronic applications of aluminum nitride (AlN). Here, we report the first observation and elucidation of hexagonal domain boundaries exhibiting green cathodoluminescence in homoepitaxial AlN. These boundaries consist of prismatic stacking faults (PSFs), which project as 4|8-membered ring chains on the (0001) plane and interconnect via deformed 8-membered rings forming stable 120° junctions. The negative formation energy of these PSF junctions confirms their thermodynamic stability. Atom probe tomography identifies oxygen at the boundary, consistent with a calculated segregation energy of −0.63 eV/atom for ON at PSFs. Partial density of states analysis further reveals that oxygen induces deep in-gap states exclusively within the PSF configuration. This work identifies the oxygen-decorated PSF as a defect-impurity complex responsible for the green cathodoluminescence, suggesting a promising pathway toward transforming defects into tailored optical emitters in wide-bandgap nitrides.

Strongly polarized metal telluride with slight metal precipitation enables excellent long-wave infrared transparent conductive properties

Long-wave infrared transparent conductive films (LITCFs) are crucial for next-generation infrared optoelectronic devices. However, the development of high-performance LITCFs is extremely challenging due to the simultaneous occurrence of charge carrier transport and carrier absorption. To address this problem, we propose a composite design strategy: a strongly polarized metal compound as the transparent matrix phase and a small amount of precipitated metal as the conductivity-enhancing phase. As a proof of concept, we fabricated WTe0.98 films, which possess coexisting WTe2 and a small amount of W phases. Compared with the conventional transparent conductive film ITO (1373.6 S/cm, 27.94%), WTe0.98 demonstrates not only a higher electrical conductivity (1992.0 S/cm) but also a significantly higher long-wave infrared (LWIR) transmittance (67.44%). We find that the high LWIR transmittance of WTe0.98 originates from the high optical dielectric constant of the WTe2 phase. This high dielectric constant is a result of the enhanced electronic polarizability from the strong p–d hybridized interlayer bonding. The high electrical conductivity of WTe0.98 stems from the high carrier concentration provided by the W phase. Therefore, this study solves the bottleneck problem of coordinating conductivity and LWIR transparency through the design of strongly polarized composite materials with a precipitated metal phase.

A model for hydrogel-based bioprinting

We adapt a constitutive model for the yielding of hydrogels in one-dimensional shear to the elongation-dominated flow in extrusion bioprinting, and develop a finite-element method for computing the morphology and structural evolution in the extrudate. Our numerical simulations capture the main features observed experimentally. In particular, the extrudate shows three regions corresponding to unyielded, yielded and degeled states of the bioink. We further develop theoretical estimations for key properties in each of the regions, which agree well with the numerical solutions.

Janus XGeN3 (X = Cr, Mn, Fe) monolayer with large out-of-plane magnetic anisotropy and high Curie temperature

Two-dimensional magnetic materials have garnered extensive attention for their exceptional properties and diverse applications, yet their low Curie temperature (Tc) and in-plane magnetic anisotropy severely hinder practical deployment. Herein, via first-principles calculations, we predict Janus XGeN3 (X = Cr, Mn, Fe) monolayers as promising candidates for next-generation spintronics. We systematically verify their stabilities from dynamic, mechanical, and thermodynamic perspectives. Notably, CrGeN3 and FeGeN3 exhibit robust ferromagnetic coupling with Tc of 304 and 317 K, while MnGeN3 shows antiferromagnetic behavior. All three monolayers possess the large out-of-plane magnetic anisotropy energies as 19.16 μeV/Cr, 46.13 μeV/Mn, and 70.16 μeV/Fe. Furthermore, MnGeN3 and FeGeN3 have band gaps of 0.18 and 0.14 eV, respectively, while CrGeN3 exhibits half-metallic properties. These theoretical predictions of Janus XGeN3 monolayers with high Tc and out-of-plane magnetic anisotropy highlight their great potential for spintronic devices and nanoscale sensors.

Sorting nanoparticles by their optical absorption

This work demonstrates the continuous-flow separation of ≈50 nm metal nanoparticles by their optical properties using counter-propagating laser beams. Metal nanoparticles are widely used, particularly in biotechnology, where their optical properties depend on size, shape, and chemistry. Heterogeneous mixtures are common, and greater homogeneity improves product performance and expands applications. We characterize the motion of gold and silver nanoparticles in solution under intense blue and green laser irradiation, imaging them via light scattering. When mixed and illuminated, 58 nm silver nanoparticles are primarily pushed by the blue laser, while 47 nm gold nanoparticles respond to the green laser. Continuous flow mitigates bulk temperature rise. This approach offers a potentially practical and efficient method for separating nanoparticles with desirable optical properties from less valuable byproducts, addressing a key challenge in nanoparticle synthesis.

High-performance solar-blind UV photodetector based on Ti3C2Tx MXene/α-Ga2O3 heterojunction

The integration of two-dimensional MXenes with ultrawide bandgap semiconductors presents a novel pathway for high-performance optoelectronics. However, the coupling of Ti3C2Tx with the corundum metastable α-phase of gallium oxide (α-Ga2O3) with wider bandgap than conventional β-phase remains largely unexplored. In this work, we demonstrate a high-sensitivity solar-blind ultraviolet photodetector based on a Ti3C2Tx MXene/α-Ga2O3 heterojunction, fabricated via mist chemical vapor deposition (mist-CVD) and spray-coating techniques. The resulting device exhibits superior optoelectronic performance, achieving a remarkably high photoresponsivity of 31.1 mA/W and an ultralow dark current of 0.41 pA under 254 nm illumination. This enhanced performance is attributed to the formation of high-quality Schottky junction at the MXene and α-Ga2O3 interface, where a work function difference creates a built-in electric field that facilitates efficient carrier separations. Notably, the responsivity of this architecture surpasses that of state-of-the-art α-Ga2O3-based photodetectors, establishing the Ti3C2Tx/α-Ga2O3 heterostructure as a promising candidate for next-generation, low-power deep-UV sensing applications.

Valence equivalence guided high-throughput search for stable monolayer MA2Z4 and M2A2Z4

The chemical vapor deposition synthesis of two-dimensional (2D) materials without bulk counterparts, such as MoSi2N4, has opened new avenues for materials design. MoSi2N4 can be viewed as MoS2 in which the S atoms are replaced by SiN2 groups, as both S and the SiN2 group have a −2 valence state. Inspired by this principle, we propose a valence equivalence strategy for designing 2D materials without bulk counterparts. Specifically, we substitute the chalcogenide (X) layers in conventional 2H-MX2 (M = V, Nb, Ta, Cr, Mo, and W), 1T-MX2 (M = Ti, Zr, Hf, and Sn), and α-MX (M = Ga and In) monolayers with AZ2 (A = C, Si, and Ge; Z = N, P, and As) groups. Using high-throughput first-principles calculations, we screened 108 candidate monolayer structures (2H-MA2Z4, 1T-MA2Z4, and α-M2A2Z4), of which 82 are dynamically stable. This result confirms the effectiveness of our design principle. The stable materials exhibit diverse electronic properties, including metals, semimetals, and semiconductors with bandgaps ranging from 0.06 to 3.08 eV. Notably, VSi2As4 and VGe2As4 emerge as promising intrinsic magnetic semiconductors, while the wide-bandgap Ga2Si2N4 shows great potential for efficient photocatalytic overall water splitting. These properties make them potential candidates for applications in spintronics, optoelectronics, and photocatalysis. This work provides a database of predicted novel 2D materials and establishes a general design strategy for future materials discovery.

Thermal transport in ultra-drawn polyethylene films

Mechanical stretching is an effective strategy for enhancing in-plane heat transport in polymers, yet the atomistic mechanisms governing thermal conductivity evolution under high draw ratios remain unclear. Here, thermal property measurements are combined with molecular dynamics (MD) simulations to elucidate the stretching-induced structural and heat transport evolution of polyethylene under different draw ratios. Experiments show a monotonic increase in in-plane thermal conductivity and thermal diffusivity with increasing draw ratio, providing macroscopic benchmarks. MD simulations reproduce the full deformation sequence from amorphous chain alignment to strain-induced crystallization and cavitation. Analysis based on an orientation order parameter reveals a direct correlation between tensile strain and crystallinity. In addition to crystalline domains, highly oriented interlamellar regions contribute substantially to the overall thermal conductivity. These results establish a mechanistic link between chain dynamics, phase evolution, and stretch-enhanced thermal transport in polymers.

Evolution mechanism of pore structures in sandstone under coupled effect of hygrothermal cycles and Na2SO4 solution

NiCo alloys with optimized electronic structure for ultralow overpotential alkaline hydrogen evolution

Modulating the electronic structure of alloy catalysts is a pivotal strategy for enhancing their intrinsic hydrogen evolution reaction (HER) performance. This work demonstrates that incorporating cobalt into nickel can effectively modulate the electronic structure of nickel while leveraging the excellent lattice matching between Ni and Co to maintain alloy structural integrity, thereby simultaneously enhancing intrinsic HER activity and endowing the catalyst with superior structural stability. The optimized Co1Ni1/C catalyst exhibits an ultralow overpotential of 21.2 mV at 10 mA cm−2, which not only surpasses that of most reported NiCo alloys but also approaches the level of NiMo alloys, while effectively avoiding the common metal leaching issues associated with NiMo alloys. Systematic characterization using X-ray photoelectron spectroscopy and electron paramagnetic resonance proved that cobalt doping induces electron transfer from Ni to Co, raising the d-band center of Ni and increasing unpaired electron density. These electronic reconfigurations strengthen water adsorption at nickel active sites, thereby accelerating the water dissociation kinetics. The catalyst also exhibits superior stability with minimal performance decay during prolonged operation. The catalyst also demonstrates excellent stability with minimal performance degradation during prolonged operation, outperforming conventional NiMo alloys.

An interpretable Convex Stacking with Guarded Calibration ensemble approach for predicting rock fragmentation in mine blasting

Step-guided etching toward aligned MoS2 nanoribbons

Fabricating aligned arrays of hexagonal transition metal dichalcogenide nanoribbons is essential for high-density integrated devices but remains challenging due to the intrinsic lattice symmetry, which typically favors multi-directional orientations. Here, we report a step-guided anisotropic etching strategy that exploits the reconstructed steps of annealed c-sapphire substrates to overcome this symmetry constraint, yielding unidirectional MoS2 nanoribbon arrays. This process achieves precise orientation control while preserving the high crystallinity of the parent film. Crucially, angle-resolved spectroscopic investigations reveal a striking decoupling between the linear and nonlinear optical responses in these one-dimensional nanostructures. While polarized Raman spectroscopy confirms a strain-free lattice with isotropic phonon response, second harmonic generation measurements uncover an anisotropy governed by the one-dimensional confinement and strong depolarization field effects. Our findings not only establish a top-down pathway for orientation-controlled nanomanufacturing but also highlight the potential of geometric engineering in tailoring nonlinear light–matter interactions, enabling polarization-sensitive functionalities.

Modeling and analysis of stochastic quantum magnetohydrodynamics equations with energy estimates

A bilayer structure laterally excited bulk acoustic resonator with enhanced heat dissipation and acoustic properties

The poor heat dissipation of the laterally excited bulk acoustic resonator (XBAR) based on a single-layer piezoelectric film prevents it from sustaining operation under high-power conditions. Consequently, it is critical to improve the heat dissipation and enhance the power handling capability of the device. To address the limitation of poor heat dissipation, this study proposes a bilayer XBAR consisting of a piezoelectric layer and a thermally conductive layer (Si, SiC, or diamond), which possesses excellent acoustic properties and heat dissipation performance. The finite element simulation results indicate that the bilayer XBAR has higher operating frequencies and excellent electromechanical coupling coefficients. The bilayer structures feature lower thermal resistance and more uniform heat distribution. A maximum device temperature rise of only 2.8 °C was obtained with a diamond thermally conductive layer at an input power of 26 dBm and the temperature reduction efficiency reached 85%. More importantly, the maximum temperature rise is only 19.3 °C at an input power of 30 dBm. The approach of using the bilayer structure provides a solution for designing XBARs with high-power handling capability.

A unified low-carbon cybersecurity framework integrating energy-efficient intrusion detection, lightweight cryptography, and carbon-aware scheduling for edge–cloud architectures

Abstract The rapid expansion of edge–cloud computing infrastructures has intensified both cybersecurity demands and the associated energy consumption and carbon footprint of intrusion detection systems (IDS). This paper presents GreenShield, a unified low-carbon cybersecurity framework that integrates energy-efficient deep learning-based intrusion detection with knowledge distillation and dynamic quantization, ASCON lightweight cryptography, hierarchical federated learning with gradient compression, and a carbon-aware scheduling engine across distributed edge–fog–cloud architectures. GreenShield employs a threat-adaptive quantization mechanism that scales model precision (4–32 bit) based on real-time threat levels and a carbon-conscious scheduling controller that dynamically aligns security workload execution with renewable energy availability forecasts. Extensive experiments on the UNSW-NB15 and CIC-IDS2017 datasets demonstrate that GreenShield achieves 98.73% detection accuracy with 67.4% energy reduction compared to conventional deep learning-based IDS, while reducing operational carbon emissions by up to 97.6% (equivalent to approximately 2.8 kg CO 2 -eq per hour savings in a typical edge deployment). The hierarchical federated learning architecture reduces communication overhead by 58.2% through Top-k gradient sparsification, and the dynamic quantization mechanism achieves 71.3% inference energy reduction during low-threat periods. These results establish GreenShield as a viable, scalable solution for sustainable cybersecurity that supports carbon-conscious security workflows in next-generation edge–cloud computing environments.

Upper bounds on charging power and tangible advantage in quantum batteries

A quantum battery is expected to outperform its classical counterpart due to quantum effects. Usually, in a quantum battery made of N cells, quantum advantage is demonstrated through super-extensive scaling of the upper bound to the charging power with N. In this work, we show that potential quantum advantage as measured by the power bounds need not translate to tangible advantage in practice. We demonstrate this by considering an all-to-all coupled spin-chain model of a quantum battery with 2-local interactions. It exhibits super-extensive charging when analyzed using the upper bound derived from the uncertainty principle. Unlike the previously studied models, the contribution to this apparent quantum advantage is twofold—arising from both the battery and the charger. The model is also experimentally friendly, as it does not require global couplings and yet generates genuine multipartite entanglement. However, we demonstrate that the potential quantum advantage in this scenario is not tangible by employing a tighter upper bound on power. Additionally, we show that even this tighter bound can fail in a range of physical situations and indicate a quantum enhancement that is intangible in practice. Hence, we argue that actual power transferred must be evaluated along with proper characterization of the resources before claiming quantum advantage.

DeepSentRec: a deep learning-based sentiment-aware product recommendation system

Dielectric spectroscopy and electrochemical modulation of polymorphic Ag+ migration in PVP-coated AgI nanoparticles

Polyvinylpyrrolidone (PVP)-coated silver iodide nanoparticles (12.3–15.6 nm) were synthesized to investigate Ag+ transport relevant to halide solid electrolytes for all-solid-state batteries. Broadband dielectric spectroscopy and electrochemical modulation reveal a strongly suppressed α → β/γ-phase transition (hysteresis ≈ 110 °C) due to surface energy and PVP coordination. In the β/γ regime, two relaxations correspond to interstitial Ag+ hopping and electrode polarization. In the α-phase, two distinct processes emerge: a low-frequency fragile relaxation (Pα1) following the Vogel–Fulcher–Tammann law, attributed to glassy surface dynamics, and a high-frequency Arrhenius process (Pα2) representing local hopping within the crystalline core. The activation energy of Pα2 increases with decreasing size but decreases with electrochemically enriched Ag+ content that enhances α-phase conductivity. These results establish a spatially layered model of Ag+ migration, under nanoscale confinement and suggest a viable strategy for designing high-performance halide solid-state electrolytes.

Decoding garden design language via semantic segmentation for social aesthetic interaction