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A fast-switching threshold memristor based on AlN/Ag/AlN stacked device for mental disorder electroencephalogram recognition
As artificial intelligence technology advances, volatile threshold switching (TS) devices gain increasing attention for neuromorphic applications; however, most conventional TS devices suffer from slow switching speeds, limiting their suitability for high-speed neuron circuits. This work introduces an additional thin Ag layer into the traditional Ag/AlN/n-Si structure, forming an Ag/AlN/Ag/AlN/n-Si configuration that accelerates filament formation and significantly improves threshold switching characteristics. The device achieves a steep turn-on slope of 0.1 V/decade and fast switching with 40 ns turn-on and 25 ns turn-off times, showing competitive performance with reported TS devices. Interestingly, this work demonstrates neuron activation and deactivation and enables a leaky integrate-and-fire model to construct an artificial neural network with ∼91% accuracy in mental disorder electroencephalogram recognition. These results highlight the device's potential for high-speed artificial neuron circuits and neuromorphic systems.
Evaluation of mdh, dld, tcfA, and folE gene markers for detection of enteric fever using real-time PCR
Recent progress on electric field control of magnetic tunnel junctions via strain-mediated magnetoelectric coupling
The rapid progress in information technologies has driven a strong demand for memory devices that combine large storage capacity, high-speed operation, and reduced energy consumption. Magnetic tunnel junctions (MTJs) possessing significant tunnel magnetoresistance effects have considerable applications in magnetic random-access memory (MRAM), read heads, and magnetic sensors. In current MTJ technologies, data writing is predominantly achieved via electric currents, a method that consumes substantial energy. Replacing it with electric-field-driven switching could greatly improve energy efficiency. Considerable attention has been directed toward integrating ferroelectric materials into the MTJ barriers and utilizing voltage-controlled magnetic anisotropy. However, these approaches often face challenges such as low operating temperatures, assistance of external magnetic fields, or volatile control of resistance states. Recent advancements in strain-mediated manipulation of magnetism via electric field in ferroelectric/ferromagnetic multiferroic heterostructures provide practical strategies for implementing manipulation of MTJs via electric field. In this perspective, we present a concise summary of the latest developments concerning the modulation of MTJ resistance states via electric fields composed of multiferroic heterostructures and ferroelectric Pb(Mg1/3Nb2/3)0.7Ti0.3O3. Progress on both in-plane and perpendicular magnetic anisotropic MTJs is summarized, and the discussion concludes with an outlook on potential developments. Furthermore, this work concludes by outlining prospective research avenues for the manipulation of MTJs in multiferroic heterostructures via electric field based on strain-mediated magnetoelectric coupling, a mechanism that is expected to remain pivotal for advancing fundamental understanding and realizing next-generation MRAM technologies.
Availability and spatial distribution of crop and forest biomass residues for biochar production in Kenya
Abstract Uptake of biochar for fuel briquetting and soil amendment is constrained in sub-Saharan Africa by inadequate knowledge of the quantity and distribution of feedstocks. This study assessed the quantities and spatial distribution of crop and forest residues available for biochar production in Kenya based on productivity data from 2021 and 2022. The residues were quantified using residue product ratios, surplus available factors and economically viable factors. Kenya produces (0.5–2.4) × 10 7 Mg y −1 of crop residues and (1.48–1.8) × 10 5 Mg y −1 of forest residues that are potentially available for biochar production. While crop and forest production are the core drivers of the availability of economically viable residues, residue to product ratios and surplus available factors are the primary drivers of residue densities. Crop residues were concentrated in counties located in western, central and southern Kenya. While all counties possess diverse types of residues, maize stalks were prevalent in all 47 counties. No county satisfied the combined requirements of high amounts of residues, high residue density and low supply uncertainties. Therefore, although Kenya has abundant and diverse residues that could produce economically viable biochar, locating production facilities will require a trade-off between counties with high residue densities, or those with supply uncertainty.
Viscoelastic effect on the wall pressure induced by tandem cavitation bubbles near a rigid boundary: A numerical study
High-speed liquid jets and pressure waves are key features in the near-wall collapse of cavitation bubbles, which generate strong hydrodynamic loadings on solid surfaces. However, previous studies mainly focus on cavitation bubbles in Newtonian fluids, while the viscoelastic effect of the liquid is not well understood. In this Letter, we perform numerical studies on the violent collapse of cavitation in a viscoelastic fluid near a solid boundary. Our simulation results reveal that at high Deborah numbers, the cavitation bubble dynamics are governed by both the inertia and fluid elasticity. In this regime, the bubble exhibits underdamped oscillations with high frequency and produces a premature jet, resulting in a synergistic effect on the wall pressure between the pressure pulse from the wave and the jet impact. The reason is due to the frequent mutual conversion between the elastic potential energy of the fluid and the kinetic energy of the cavitation bubbles. Furthermore, we observe that the amplitude of the wall pressure induced by cavitation bubbles is reduced by over 90% when considering the viscoelastic effect, while the interaction between cavitation bubbles can increase the amplitude of the wall pressure by up to 3.6-fold.
Study on the effects of hydrological connectivity on the dispersal and driving factors of macroinvertebrate communities
Shear-driven off-plane detachment of water drops from superhydrophobic surfaces
Shear-driven drop motion is a common phenomenon with critical implications for applications such as aircraft anti-icing, where efficient drop detachment is essential to reduce water retention, limit freezing, and suppress subsequent ice accumulation. While tangential air shear is typically associated with in-plane drop motion, it has not been considered effective for inducing detachment. Here, combining experiments, simulations, and theoretical analysis, we demonstrate that off-plane drop detachment can occur under specific conditions determined by surface wettability, drop radius, and wind speed. Notably, we identify a distinct scaling regime for the critical wind speed required for detachment as a function of drop radius, determined by the balance between lift and restoring force. Our findings advance the fundamental understanding of drop–airflow interactions and offer inspiring design strategies for efficient drop removal.
Application of LSTM-CNN in skiing action recognition under artificial intelligence technology
High-resolution broadband characterization of resonance dispersion in an optical microresonator
Accurate knowledge of the uneven free spectral range of an optical microresonator, which provides direct insight into group velocity dispersion, is essential for understanding and controlling Kerr frequency comb dynamics. In this work, we present a simple and highly precise method for measuring the free spectral range over a 5 THz bandwidth in silicon nitride microresonators, leveraging a wavemeter with 0.4 MHz resolution. Our fully fibered plug-and-play experimental setup enables accurate extraction of resonance frequencies. By carefully analyzing the spectral position of each resonance, we measure both second- and third-order free spectral range expansion coefficients. This approach offers a robust and accessible tool for dispersion characterization in integrated photonic circuits, paving the way for next generation of Kerr comb sources and quantum photonic technologies.
Single-cell transcriptomics reveal heat shock protein dysregulation in severe SARS-CoV-2–associated pediatric encephalopathy
Flexible dual-heterojunction device design for high-performance photodetection and energy harvesting in self-powered visible light communication
Self-powered visible light communication (VLC) is attracting growing interest for its high-speed transmission, low power consumption, and sustainability. However, conventional optoelectronic converters struggle to combine efficient energy harvesting with high-performance photodetection. Herein, we propose a textured-Si-based dual-heterojunction device featuring self-supporting and flexible characteristics, capable of achieving high performance in both photodetection and energy harvesting for VLC applications. The designed device exhibits, at zero bias, a responsivity of 0.339 A W−1, a specific detectivity of 1.58 × 1013 Jones, and a response time of 20 ns under 467 nm illumination, alongside an energy conversion efficiency of 22.64% under white light-emitting diode irradiation. The underlying physical mechanisms for the excellent performances have been thoroughly investigated, revealing why the conventional photodetectors and solar cells cannot achieve these goals. This work demonstrates that the synergy between geometry and junction engineering enables strong absorption and efficient charge extraction, offering a theoretical design guideline for preparing high-performance self-powered VLC devices.
Deep learning-based labor relations prediction system with multi-source data fusion and early warning mechanisms
Temperature imaging of chips with high spatiotemporal resolution using diamond nitrogen-vacancy centers
The operating temperature of a chip is a critical factor determining its operational efficiency and service life. In industrial control environments, temperature imaging of a chip plays a vital role in detecting localized heat accumulation and heat dissipation system failures. Although many advanced techniques have been proposed, achieving high spatiotemporal resolution temperature imaging on the chip still presents significant challenges. In this study, we proposed a temperature imaging method based on ensemble diamond nitrogen-vacancy (NV) centers and applied it to the temperature imaging of interdigital electrodes. This method achieved temperature imaging of the chip surface with a spatial resolution of 863 nm and a temporal resolution of up to 2.05 s, capturing the changes in thermal distribution with different applied voltages. The results indicate that NV centers can overcome the limitations of traditional temperature measurement methods in terms of spatiotemporal resolution, offering a promising measurement solution for chip temperature detection.
M$$\vphantom{0}^2$$DGAT: Multi-view multi-scale dynamic graph attention network(GAT) based prediction of Parkinson’s disease(PD) progression using whole-blood RNA sequencing data
Theory of electric reactance emerging from spin Hall effect
The spin Hall effect in a heavy metal intercorrelates an AC electric current to the magnetization dynamics in an adjacent ferromagnet, which manifests as an electric reactance in the system's current–voltage response. We present a comprehensive theoretical analysis for this emergent reactance contribution in the frequency regime relevant to transport measurements up to a few GHz. Our analysis reveals that the reactance becomes inductor-like at low frequency below the ferromagnetic resonance. Crucially, we find that the sign of the reactance is directly governed by the spin transfer mechanism at the interface, which depends on the competition between its damping-like and field-like components parametrized by the spin mixing conductance. This characteristic behavior in the reactance offers a powerful transport observable in distinguishing the interfacial spin transfer processes in spintronic materials.
Low-voltage U-shaped RF MEMS shunt switch integration for K-band phased array beam steering
Reduction of carbon impurities in GaN grown by MOCVD using an NH3-plasma source
In this work, we demonstrate GaN epitaxial growth by plasma-enhanced metalorganic chemical vapor deposition (MOCVD) using trimethylgallium [TMGa, Ga(CH3)3] and ammonia (NH3). Impacts of TMGa, NH3 molar flow rates, and plasma power on surface morphologies and carbon residual impurity concentrations in GaN epitaxial layer have been clarified. GaN surfaces showed step and terrace structures under a wide range of TMGa and NH3 molar flow rates. The residual carbon atomic concentrations in GaN epitaxial layers are found to be remarkably reduced by using NH3-plasma. The electrical characteristics of AlGaN/GaN-based high electron mobility transistor structure exhibits a lower sheet resistance when NH3-plasma is applied. This is mostly owing to the reduction in carbon residual impurities, which act as electron traps. The plasma MOCVD enables reduction in NH3 consumption or increase in GaN growth rate by 50%, which leads to enhancement of manufacturing productivity.
Log-transformed variance from individual growth curves as a potential indicator of resilience in Nile tilapia Oreochromis niloticus
Abstract The ability of the animal to cope with environmental changes may be measured by log-transformed variance of deviations from expected weights (LnVar). We calculate LnVar by fitting the expected individual growth curve based on longitudinal weights (LnVar ind ) of Nile tilapia that were grown in either an aerated or a non-aerated freshwater pond. We estimated genetic parameters for LnVar ind in Nile tilapia, the genetic correlation between LnVar ind and growth and the genetic correlation for LnVar ind between aerated and non-aerated pond. The heritability estimate for LnVar ind (0.28) in the non-aerated pond was higher than in aerated pond (0.06). In the aerated pond, genetic correlations of LnVar ind were − 0.44 ± 0.23 with daily growth coefficient (DGC) and − 0.45 ± 0.24 with harvest weight (W 5 ). In the non-aerated pond, genetic correlations with DGC and W 5 were − 0.68 ± 0.12 and − 0.52 ± 0.17, respectively. These values suggest that selection for fish with high growth rate will reduce LnVar ind . However, genetic correlation of LnVar ind between aerated and non-aerated pond was 0.50, suggesting that genetic improvement in the aerated environment will reduce LnVar ind in the non-aerated environment. Therefore, incorporating records from relatives in non-aerated pond is beneficial for breeding programs targeting this environment.
Cycle-dependent evolution of critical heat flux in pool boiling in water on copper driven by oxidation-induced surface modification
Boiling heat transfer enables extremely high heat fluxes at small temperature differences, but the underlying mechanisms remain difficult to resolve due to the dynamic interplay of microscale interfacial processes and macroscopic heat transfer. In this work, synchronized optical–thermal measurements of pool boiling on mechanically ground-and-polished copper surfaces were conducted to directly correlate near-wall temperature transients with boiling regime transitions. Embedded micro-thermocouples captured repeatable near-wall temperature transients associated with boiling regime transitions, while synchronized video recording confirmed regime transitions from natural convection to nucleate and film boiling. Critical heat flux (CHF) values of 105.1–132.0 W/cm2 were measured at transition wall superheats of 25.3–31.4 °C for all three tested samples. The largest performance change occurred after the first boiling cycle, with wall superheat and CHF increasing significantly, whereas subsequent cycles produced smaller shifts. On cooling, film-to-nucleate collapse occurred at wall superheats around 4–17 °C higher than in the forward transition, confirming a pronounced hysteresis effect. Scanning electron microscopy analysis revealed substantial roughening after three boiling cycles, while energy-dispersive x-ray spectroscopy showed the oxygen-to-copper x-ray intensity ratio nearly doubled (0.08–0.17), indicating oxide layer growth. These surface modifications (conditioning) explain the observed performance evolution: roughening enhanced CHF, while oxidation introduced thermal resistance, elevating wall superheat. Taken together, these results demonstrate that boiling hysteresis and cycle-dependent CHF evolution are governed by coupled morphological and chemical transformations of the surface. The integrated optical, thermal, and microstructural approach provides direct evidence linking interfacial dynamics to surface conditioning in pool boiling.