Journal of Advanced Ceramics•2026•DOI: 10.26599/JAC.2026.9221349
Polymer-derived SiC-based ceramic fibrous membranes are lightweight, thermally stable electromagnetic wave absorbers, but simultaneously achieving strong attenuation and good impedance matching remains difficult due to limited control over phase composition and dielectric behavior. This work prepares multiphase SiC-based fibrous membranes by electrospinning combined with polycarbosilane (PCS)-derived ceramic conversion. Phase evolution, fiber morphology, dielectric response, and electromagnetic wave absorption are regulated by tuning PCS content and pyrolysis temperature. Advanced characterization confirms a heterogeneous β-SiC/SiOxCy/carbon multiphase structure with good flexibility, providing abundant polarization centers, moderate conductive pathways, and multiple reflection sites, thereby balancing impedance matching and dielectric loss. The sample with 1.4 g PCS pyrolyzed at 1400 °C achieves a minimum reflection loss (RLmin) of −27.12 dB at 2.2 mm and a maximum effective absorption bandwidth (EAB) of 8.22 GHz at 2.7 mm, covering 9.78–18 GHz. Radar cross-section simulation verifies electromagnetic scattering suppression of the optimized fibrous ceramic coating. This study provides a strategy for tailoring phase composition and dielectric behavior in polymer-derived SiC-based fibrous membranes for broadband electromagnetic wave absorption.
Nano Research•2026•DOI: 10.26599/NR.2026.94908587
Aerogels are promising for thermal insulation due to their lightweight and low thermal conductivity, yet achieving high-temperature resistance (>1000 °C) alongside robust mechanical performance remains challenging. Here, we report a cactus-inspired spiral structure strategy via freezing-assisted direct ink writing (DIW). By controlling the rotation angle (θ) and printing spacing (x), we fabricate SiO2/ZrO2 aerogels with programmable macroscopic spiral architectures. The aerogel with θ = 40° and x = 1.3 mm exhibits excellent thermal insulation (30.2 mW·m−1·K−1) but limited compressive strength (159.3 kPa at 24.2% fracture strain). To enhance mechanical properties without compromising insulation, we propose an arctangent-topological DIW strategy using αn = arctan(1/n) to create four-fold rotational symmetry. At αn = 26.6° (n = 2), the aerogel achieves a thermal conductivity of 33.9 mW·m−1·K−1 and a compressive strength of 341.7 kPa at 24.6% fracture strain, representing a significant improvement. Finite element simulations (COMSOL Multiphysics) corroborate experimental results. Demonstrations on electronic chips and flame nozzles confirm effective thermal protection. This work provides a viable route to aerogels with integrated high-temperature stability and mechanical robustness.
Nano Research•2026•DOI: 10.26599/FRICT.2025.9441207
Wear debris particles critically influence frictional interfaces. Conventional understanding holds that debris accumulation causes severe wear. However, debris from metal friction pairs includes anti-wear metal oxides generated by tribochemical reactions, which can form a protective oxidation film to resist wear. Minimizing abrasive damage from accumulated debris and exploiting the anti-wear property of metal oxides are mutually exclusive. Here, a rational design of a bioinspired coupling surface (BCS) that manipulates nanoscale wear debris to resist further wear is reported. The BCS comprises surface textures that capture and temporarily store excess nanoscale wear debris, and a deposited self-cleaning coating that subsequently transfers part of the captured debris back into the sliding-contact interface, where it converts into a protective oxidation film. The coexistence of these two elements with contrasting properties in manipulating nanoscale wear debris considerably reduces wear under water lubrication, oil lubrication, and macroscale superlubricity. Specifically, the wear rate of steel is reduced by 50.4%, 51.2%, and 46.3% under these respective conditions. This strategy achieves the manipulation and utilization of wear debris for anti-wear purposes, promoting further investigation into the role of nanoscale wear debris and its utilization approaches.
Chinese Journal of Energetic Materials (含能材料)•2026•DOI: 10.11943/CJEM2026021
To elucidate the influence mechanism of particle size on the ignition and combustion behavior of Al-Li-Mg alloys, four alloy powders with median diameters of 9, 13, 16, and 24 μm were systematically investigated. Physicochemical properties were characterized by laser diffraction, scanning electron microscopy, X-ray diffraction, simultaneous thermal analysis, and oxygen bomb calorimetry. Ignition and combustion behaviors were assessed using a laser ignition test bench equipped with high-speed photography and fiber-optic spectrometry. Results show that with increasing particle size, ignition delay time first decreases sharply then stabilizes, dropping from 135 ms (9 μm) to 51 ms (13 μm), then to 15 ms (16 μm) and 18 ms (24 μm). Combustion intensity, indicated by maximum spectral intensity, decreases from 7300.4 (9 μm) to 1721.6 (24 μm). Combustion duration initially extends slightly then stabilizes, from 857 ms (9 μm) to 928 ms (13 μm) and approximately 920 ms for larger sizes. Notably, the 13 μm alloy achieves an optimal balance among ignition delay (51 ms), combustion duration (928 ms), and combustion intensity (6041.8). The study reveals a critical size effect: between 13 and 16 μm, ignition delay drops by 71% while combustion intensity decreases by 54%, indicating a transition from surface-diffusion-controlled to micro-explosion-dominated combustion. This mechanism arises from competition between heat conduction and elemental diffusion: larger particles restrict heat transfer, promoting Li and Mg surface enrichment and temperature gradients that induce micro-explosions, thereby shortening ignition delay but reducing combustion efficiency and intensity.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2026•DOI: 10.1016/j.ijmst.2026.01.001
In igneous-intruded coal seams, coal undergoes significant metamorphism, which critically alters its pore structure and oxygen consumption dynamics, thereby elevating its spontaneous combustion tendency. This study investigates the specific surface area, pore volume, structure complexity/connectivity, heterogeneity/local features of pore size distribution, and oxygen consumption dynamics of igneous metamorphic coal through N2/CO2 isothermal adsorption tests and low-temperature oxidation experiments, and elucidates the influence mechanisms of pore structure evolution on oxygen consumption dynamics during low-temperature oxidation. With increasing metamorphic degree, igneous metamorphic coal exhibits a more pronounced reduction in specific surface area during oxidation, while the increase in structure complexity due to coal-oxygen reactions is suppressed. Thermally metamorphic coal demonstrates accelerated oxygen consumption, with oxidation amplifying the difference in reaction rates compared to raw coal. Key mechanisms include oxidation-induced reduction in mesopore complexity and micropore volume, decreased dominance of small-pore-volume apertures, and increased heterogeneity, collectively leading to a lower half-oxygen-consuming temperature and steeper oxygen consumption curves. Simultaneously, increased pore volume/complexity and reduced uniformity/connectivity act synergistically to enhance oxygen consumption capacity, highlighting the coupling between pore structure evolution and oxidation behavior in igneous metamorphic coal. This study provides theoretical insights into the pore-oxygen coupling mechanisms governing coal spontaneous combustion in igneous intrusion areas.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/26020057
Integrated silicon photonics has emerged as a transformative technology for post-Moore computing, offering high bandwidth, ultralow latency, and low energy consumption that surpass traditional electronic architectures. As AI models grow in complexity, the demand for high-speed, energy-efficient computing has intensified research into photonic accelerators. Matrix multiply-accumulate (MAC) operations, central to deep learning and combinatorial optimization, are particularly amenable to photonic implementation because light enables parallel multiplication and accumulation with minimal data movement. However, practical deployment has been hindered by challenges in large-scale integration, electro-optical co-packaging, analog computation accuracy, and compatibility with mainstream AI models. Two recent Nature studies have achieved pivotal breakthroughs: a 64×64 photonic arithmetic computing engine (PACE) with over 16,000 monolithically integrated photonic components, and a universal photonic AI accelerator. PACE employs a 2.5D hybrid packaging approach, cointegrating a 65-nm silicon photonics PIC and a 28-nm CMOS EIC via flip-chip bonding, achieving a minimum bump pitch of 100 μm and parasitic capacitance of 40–60 fF. Its incoherent optical computing architecture eliminates cross-channel interference and enables high-precision calibration. These works validate photonic accelerators as competitive alternatives to electronic AI chips, marking a critical step toward commercialization.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2026•DOI: 10.1016/j.ijmst.2026.02.008
In deep hard rock mining, high confining pressure inhibits tensile failure, leading to low efficiency and severe tool wear in conventional mechanical rock breaking methods. To solve this problem, we propose a Controllable Free Surface Induced Tensile-Shear Collaborative Fracturing (CFS-TSCF) method. The method pre-forms an engineered controllable free surface (CFS) to reconfigure the local stress field, enabling a specialized device (FIPFD) to apply directional tensile-shear loads for low-energy breaking. A multi-scale approach integrating lab AE tests, DEM simulations, and field verification investigated the fracture mechanism and performance. Results revealed a predominantly tensile-driven (>50%) process. The CFS transforms the rock's triaxial compression into a specific stress path. This path, dominated by directional tension and constrained by lateral compression, guides the fracture along a low-energy channel. This also dictates the micro-mechanism's evolution from central quasi-tensile to peripheral tensile-shear failure. Field trials in hard rock (>200 MPa UCS) validated the method, demonstrating controllable, blocky spalling and achieving an average mining efficiency of 52.03 t/h. This research validates the CFS-TSCF method, offering a new technical paradigm for safe, efficient, continuous hard rock mining.
China Foundry•2026•DOI: 10.1007/s41230-026-5243-x
During the casting process, no-bake resin-bonded sand molds and cores rapidly heat up upon contact with high-temperature molten metal, causing dramatic changes in the resin binder system and a significant deterioration in mechanical properties, which subsequently leads to casting defects. To reveal the mechanism behind the evolution of high-temperature performance, the effects of resin content, base sand type, and particle size on the compressive strength of alkaline phenolic no-bake resin-bonded sand at temperatures ranging from 600 °C to 1,000 °C were investigated. The results show that the temperature range of 600-800 °C represents the primary stage of strength loss, corresponding to intense resin decomposition. Meanwhile, structural reorganization of the carbon skeleton above 900 °C can lead to a partial recovery of strength. This study provides key data and theoretical support for understanding the high-temperature mechanical behavior of resin-bonded sand and its relationship with casting defects.
China Foundry•2026•DOI: 10.1007/s41230-026-5146-x
Wire-arc directed energy deposition (WA-DED) has attracted considerable attention for the fabrication of magnesium (Mg) alloys due to its high efficiency, low cost, and rapid prototyping capability for complex components. However, the inherent rapid solidification and complex thermal cycling associated with WA-DED often result in coarse columnar grains and pronounced mechanical anisotropy, which severely limiting its application potential. In this study, a novel spiral oscillation (SO) strategy was implemented during WA-DED AZ31 Mg alloy to refine the microstructure, reduce mechanical anisotropy, and achieve a strength-ductility synergy. Specifically, the yield strength (YS), ultimate tensile strength (UTS), and elongation (EL) are increased by 9.7%, 38.1%, and 147%, respectively. These improvements by the SO strategy are primarily attributed to the promotion of columnar-to-equiaxed transformation (CET), a 74.2% reduction in maximum texture intensity, and a more uniform distribution of second-phase particles. Second-phase particles are primarily composed of Al8Mn5 and Al8Mn4Y. This study provides a novel strategy for microstructural control aimed at improving the performance of WA-DED AZ31 Mg alloy components.
Nano-Micro Letters•2026•DOI: 10.1007/s40820-025-02001-x
The development of gradient lubrication materials is critical for numerous biomedical applications, particularly in magnifying mechanical properties and service longevity. Herein, we present an innovative approach to fabricate biomimetic gradient lubrication hydrogel through the synergistic integration of three-dimensional (3D) printed metal–organic frameworks (MOFs) nanoparticle network hydrogel skeletons with bio-inspired lubrication design. Specifically, robust hydrogel skeletons were engineered through single or multi-material 3D printing, followed by the in situ growth of MOFs nanoparticles within this hydrogel network to create a reinforced, load-bearing architecture. Subsequently, biomimetic lubrication capability was enabled by mechanically coupling another lubricating hydrogel within 3D-printed MOFs nanoparticle network hydrogel skeleton. The superficial layer is highly lubricious to ensure low coefficient of friction (~ 0.1141) and wear resistance (40,000 cycles), while the deeper layer is stiffer to afford the obligatory mechanical support (fracture strength ~ 2.50 MPa). Furthermore, the gradient architecture stiffness of the hydrogel can be modulated by manipulating the spatial distribution of MOFs within the 3D-printed hydrogel skeleton. As a proof-of-concept, biomimetic gradient hydrogel meniscus structures with C- and O-shaped configurations were constructed by leveraging multi-material 3D printing, demonstrating exceptional lubrication performance. This innovative biomimetic design opens new avenues for creating implantable biomedical gradient lubricating materials with reinforced mechanical and lubrication performance.
Journal of Central South University•2026•DOI: 10.1007/s11771-026-6226-1
The sensorless control of surface-mounted permanent magnet synchronous motor (SPMSM) usually uses quadrature phase-locked loop (QPLL) to extract the phase information of the back electromotive force to realize the rotor angle estimation. However, the traditional QPLL has a convergence deviation of 180° when the motor is reversed, and the angle estimation error is obvious when the motor is accelerated and decelerated. To solve these problems, an enhanced QPLL (EQPLL) with polarity correction and high precision angle feedforward compensation is proposed. Firstly, the traditional phase discriminator is improved based on the two-phase stationary coordinate system, and the polarity correction function is designed by the error component of the improved phase discriminator to realize the non-convergent deviation angle estimation under the forward and reverse switching conditions of the motor. In addition, the error component of the improved phase discriminator is used as the feedforward compensation signal, and the enhanced generalized integrator is used to filter it, so as to realize the angle error compensation with low delay and low noise. Finally, the proposed scheme is verified by experiment on the motor platform, and compared with the existing scheme. The experimental results show that the proposed scheme can realize the polarity correction and angle error elimination, and at the same time, the noise mean square error is reduced by 24.33% compared with the existing angle feedforward compensation scheme.
Journal of Central South University•2026•DOI: 10.1007/s11771-026-6189-2
Plant roots serve as a natural reinforcement method with the potential to significantly enhance slope stability. In engineering practice, roots can function synergistically with geosynthetics, reducing the reliance on artificial materials. Based on a three-dimensional (3D) rotational failure mechanism, this study proposes a novel framework to evaluate the influence of plant roots on the stability of geosynthetic-reinforced slopes. By integrating the hydrological effects of transpiration and the mechanical composite action of root–soil interaction, the reinforcing capacity of uniform root systems is comprehensively assessed. The required dimensionless reinforcement strength at the limit failure state is derived using the functional balance equation. The validity of the proposed method is confirmed through comparisons with existing two-dimensional (2D) solutions for vegetated slopes and 3D solutions for non-vegetated reinforced slopes. Furthermore, various parameter plots are provided to facilitate design analysis. The results indicate that accounting for 3D spatial effects and plant root reinforcement significantly reduces the required reinforcement strength, thereby lowering construction costs and enhancing overall slope safety.
Nano-Micro Letters•2026•DOI: 10.1007/s40820-025-01949-0
TiNb2O7 represents an up-and-coming anode material for fast-charging lithium-ion batteries, but its practicalities are severely impeded by slow transfer rates of ionic and electronic especially at the low-temperature conditions. Herein, we introduce crystallographic engineering to enhance structure stability and promote Li+ diffusion kinetics of TiNb2O7 (TNO). The density functional theory computation reveals that Ti4+ is replaced by Sb5+ and Nb5+ in crystal lattices, which can reduce the Li+ diffusion impediment and improve electronic conductivity. Synchrotron radiation X-ray 3D nano-computed tomography and in situ X-ray diffraction measurement confirm the introduction of Sb/Nb alleviates volume expansion during lithiation and delithiation processes, contributing to enhancing structure stability. Extended X-ray absorption fine structure spectra results verify that crystallographic engineering also increases short Nb-O bond length in TNO-Sb/Nb. Accordingly, the TNO-Sb/Nb anode delivers an outstanding capacity retention rate of 89.8% at 10 C after 700 cycles and excellent rate performance (140.4 mAh g−1 at 20 C). Even at −30 °C, TNO-Sb/Nb anode delivers a capacity of 102.6 mAh g−1 with little capacity degeneration for 500 cycles. This work provides guidance for the design of fast-charging batteries at low-temperature condition.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01832-y
Silicon (Si) is a promising anode material for rechargeable batteries due to its high theoretical capacity and abundance, but its practical application is hindered by the continuous growth of porous solid-electrolyte interphase (SEI), leading to capacity fade. Herein, a LiF-Pie structured SEI is proposed, with LiF nanodomains encapsulated in the inner layer of the organic cross-linking silane matrix. A series of advanced techniques such as cryogenic electron microscopy, time-of-flight secondary ion mass spectrometry, and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry have provided detailed insights into the formation mechanism, nanostructure, and chemical composition of the interface. With such SEI, the capacity retention of LiCoO2||Si is significantly improved from 49.6% to 88.9% after 300 cycles at 100 mA g−1. These findings provide a desirable interfacial design principle with enhanced (electro) chemical and mechanical stability, which are crucial for sustaining Si anode functionality, thereby significantly advancing the reliability and practical application of Si-based anodes.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01828-8
The therapeutic efficacy of cuproptosis, ferroptosis, and apoptosis is hindered by inadequate intracellular copper and iron levels, hypoxia, and elevated glutathione (GSH) expression in tumor cells. Thermoelectric technology is an emerging frontier in medical therapy that aims to achieve efficient thermal and electrical transport characteristics within a narrow thermal range for biological systems. Here, we systematically constructed biodegradable Cu2MnS3-x-PEG/glucose oxidase (MCPG) with sulfur vacancies (SV) using photothermoelectric catalysis (PTEC), photothermal-enhanced enzyme catalysis, and starvation therapy. This triggers GSH consumption and disrupts intracellular redox homeostasis, leading to immunogenic cell death. Under 1064 nm laser irradiation, MCPG enriched with SV, owing to doping, generates a local temperature gradient that activates PTEC and produces toxic reactive oxygen species (ROS). Hydroxyl radicals and oxygen are generated through peroxide and catalase-like processes. Increased oxygen levels alleviate tumor hypoxia, whereas hydrogen peroxide production from glycometabolism provides sufficient ROS for a cascade catalytic reaction, establishing a self-reinforcing positive mechanism. Density functional theory calculations demonstrated that vacancy defects effectively enhanced enzyme catalytic activity. Multimodal imaging-guided synergistic therapy not only damages tumor cells, but also elicits an antitumor immune response to inhibit tumor metastasis. This study offers novel insights into the cuproptosis/ferroptosis/apoptosis pathways of Cu-based PTEC nanozymes.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01839-5
The emerging interfacial polarization strategy exhibits applicative potential in piezoelectric enhancement. However, there is an ongoing effort to address the inherent limitations arising from charge bridging phenomena and stochastic interface disorder that plague the improvement of piezoelectric performance. Here, we report a dual structure reinforced MXene/PVDF-TrFE piezoelectric composite, whose piezoelectricity is enhanced under the coupling effect of interfacial polarization and structural design. Synergistically, molecular dynamics simulations, density functional theory calculations and experimental validation revealed the details of interfacial interactions, which promotes the net spontaneous polarization of PVDF-TrFE from the 0.56 to 31.41 Debye. The oriented MXene distribution and porous structure not only tripled the piezoelectric response but also achieved an eightfold increase in sensitivity within the low-pressure region, along with demonstrating cyclic stability exceeding 20,000 cycles. The properties reinforcement originating from dual structure is elucidated through the finite element simulation and experimental validation. Attributed to the excellent piezoelectric response and deep learning algorithm, the sensor can effectively recognize the signals of artery pulse and finger flexion. Finally, a 3×3 sensor array is fabricated to monitor the pressure distribution wirelessly. This study provides an innovative methodology for reinforcing interfacial polarized piezoelectric materials and insight into structural designs.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01817-x
Organic–inorganic hybrid perovskite solar cells achieve remarkable efficiencies (> 26%) yet face stability challenges. Quasi-2D alternating-cation-interlayer perovskites offer enhanced stability through hydrophobic spacer cations but suffer from vertical phase segregation and buried interface defects. Herein, we introduce dicyanodiamide (DCD) to simultaneously address these dual limitations in GA(MA)nPbnI3n+1 perovskites. The guanidine group in DCD passivates undercoordinated Pb2+ and MA+ vacancies at the perovskite/TiO2 interface, while cyano groups eliminate oxygen vacancies in TiO2 via Ti4+–CN coordination, reducing interfacial trap density by 73% with respect to the control sample. In addition, DCD regulates crystallization kinetics, suppressing low-n-phase aggregation and promoting vertical alignment of high-n phases, which benefit for carrier transport. This dual-functional modification enhances charge transport and stabilizes energy-level alignment. The optimized devices achieve a record power conversion efficiency of 21.54% (vs. 19.05% control) and retain 94% initial efficiency after 1200 h, outperforming unmodified counterparts (84% retention). Combining defect passivation with phase homogenization, this work establishes a molecular bridge strategy to decouple stability-efficiency trade-offs in low-dimensional perovskites, providing a universal framework for interface engineering in high-performance optoelectronics.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01824-y
The advancement of clean electricity is positioning electrochemical reactors at the forefront of future electrosynthesis technologies. Solid-state electrolyte (SSE) reactors emerge for their distinctive configurations and ability to produce high-purity fuels and chemicals efficiently without additional purification steps. This marks a substantial development in electrochemical synthesis. In this perspective, we critically examine cutting-edge innovations in SSE devices with particular emphasis on the architectural introduction of core cell components, novel electrochemical cell configurations, and assembly methodologies. The use of SSE reactors is presently undergoing a pivotal transition from fundamental laboratory investigations to large-scale engineering implementations, demonstrating remarkable progress in multiple domains: (1) sustainable synthesis of high-value organic acids (formic and acetic acids), (2) production of critical oxidizers hydrogen peroxide (H2O2) and liquid fuels (ethanol), (3) ammonia (NH3) production, (4) carbon capture technologies, (5) lithium recovery and recycling, and (6) tandem or coupling strategies for high-value-added products. Importantly, the transformative potential in environmental remediation, particularly for airborne pollutant sequestration and advanced wastewater purification, is addressed. Additionally, the innovative architectural blueprints for next-generation SSE stack are presented, aiming to establish a comprehensive framework to guide the transition from laboratory-scale innovation to industrial-scale deployment of SSE devices in the foreseeable future.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01822-0
In photocatalytic water treatment processes, the particulate photocatalysts are typically immobilized on membrane, through either chemical/physical loading onto the surface or directly embedding in the membrane matrix. However, these immobilization strategies inevitably compromise the interfacial mass diffusion and cause activity decline relative to the suspended catalyst. Here, we propose a binder-free surface immobilization strategy for fabrication of high-activity photocatalytic membrane. Through a simple dimethylformamide (DMF) treatment, the nanofibers of polyvinylidene fluoride membrane were softened and stretched, creating enlarged micropores to efficiently capture the photocatalyst. Subsequently, the nanofibers underwent shrinking during DMF evaporation, thus firmly strapping the photocatalyst microparticles on the membrane surface. This surface self-bounded photocatalytic membrane, with firmly bounded yet highly exposed photocatalyst, exhibited 4.2-fold higher efficiency in hydrogen peroxide (H2O2) photosynthesis than the matrix-embedded control, due to improved O2 accessibility and H2O2 diffusion. It even outperformed the suspension photocatalytic system attributed to alleviated H2O2 decomposition at the hydrophobic surface. When adopted for UV-based water treatment, the photocatalytic system exhibited tenfold faster micropollutants photodegradation than the catalyst-free control and demonstrated superior robustness for treating contaminated tap water, lake water and secondary wastewater effluent. This immobilization strategy can also be extended to the fabrication of other photocatalytic membranes with diverse catalyst types and membrane substrate. Overall, our work opens a facile avenue for fabrication of high-performance photocatalytic membranes, which may benefit advanced oxidation water purification application and beyond.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01797-y
Solid-state batteries are widely recognized as the next-generation energy storage devices with high specific energy, high safety, and high environmental adaptability. However, the research and development of solid-state batteries are resource-intensive and time-consuming due to their complex chemical environment, rendering performance prediction arduous and delaying large-scale industrialization. Artificial intelligence serves as an accelerator for solid-state battery development by enabling efficient material screening and performance prediction. This review will systematically examine how the latest progress in using machine learning (ML) algorithms can be used to mine extensive material databases and accelerate the discovery of high-performance cathode, anode, and electrolyte materials suitable for solid-state batteries. Furthermore, the use of ML technology to accurately estimate and predict key performance indicators in the solid-state battery management system will be discussed, among which are state of charge, state of health, remaining useful life, and battery capacity. Finally, we will summarize the main challenges encountered in the current research, such as data quality issues and poor code portability, and propose possible solutions and development paths. These will provide clear guidance for future research and technological reiteration.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01757-6
Bimodal pressure sensors capable of simultaneously detecting static and dynamic forces are essential to medical detection and bio-robotics. However, conventional pressure sensors typically integrate multiple operating mechanisms to achieve bimodal detection, leading to complex device architectures and challenges in signal decoupling. In this work, we address these limitations by leveraging the unique piezotronic effect of Y-ion-doped ZnO to develop a bimodal piezotronic sensor (BPS) with a simplified structure and enhanced sensitivity. Through a combination of finite element simulations and experimental validation, we demonstrate that the BPS can effectively monitor both dynamic and static forces, achieving an on/off ratio of 1029, a gauge factor of 23,439 and a static force response duration of up to 600 s, significantly outperforming the performance of conventional piezoelectric sensors. As a proof-of-concept, the BPS demonstrates the continuous monitoring of Achilles tendon behavior under mixed dynamic and static loading conditions. Aided by deep learning algorithms, the system achieves 96% accuracy in identifying Achilles tendon movement patterns, thus enabling warnings for dangerous movements. This work provides a viable strategy for bimodal force monitoring, highlighting its potential in wearable electronics.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01724-1
Soft electronics, which are designed to function under mechanical deformation (such as bending, stretching, and folding), have become essential in applications like wearable electronics, artificial skin, and brain-machine interfaces. Crystalline silicon is one of the most mature and reliable materials for high-performance electronics; however, its intrinsic brittleness and rigidity pose challenges for integrating it into soft electronics. Recent research has focused on overcoming these limitations by utilizing structural design techniques to impart flexibility and stretchability to Si-based materials, such as transforming them into thin nanomembranes or nanowires. This review summarizes key strategies in geometry engineering for integrating crystalline silicon into soft electronics, from the use of hard silicon islands to creating out-of-plane foldable silicon nanofilms on flexible substrates, and ultimately to shaping silicon nanowires using vapor–liquid–solid or in-plane solid–liquid–solid techniques. We explore the latest developments in Si-based soft electronic devices, with applications in sensors, nanoprobes, robotics, and brain-machine interfaces. Finally, the paper discusses the current challenges in the field and outlines future research directions to enable the widespread adoption of silicon-based flexible electronics.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01680-w
Proton exchange membrane (PEM) water electrolysis presents considerable advantages in green hydrogen production. Nevertheless, oxygen evolution reaction (OER) catalysts in PEM water electrolysis currently encounter several pressing challenges, including high noble metal loading, low mass activity, and inadequate durability, which impede their practical application and commercialization. Here we report a self-constructed layered catalyst for acidic OER by directly using an Ir–Ta-based metallic glass as the matrix, featuring a nanoporous IrO2 surface formed in situ on the amorphous IrTaOx nanostructure during OER. This distinctive architecture significantly enhances the accessibility and utilization of Ir, achieving a high mass activity of 1.06 A mgIr−1 at a 300 mV overpotential, 13.6 and 31.2 times greater than commercial Ir/C and IrO2, respectively. The catalyst also exhibits superb stability under industrial-relevant current densities in acid, indicating its potential for practical uses. Our analyses reveal that the coordinated nature of the surface-active Ir species is effectively modulated through electronic interaction between Ir and Ta, preventing them from rapidly evolving into high valence states and suppressing the lattice oxygen participation. Furthermore, the underlying IrTaOx dynamically replenishes the depletion of surface-active sites through inward crystallization and selective dissolution, thereby ensuring the catalyst’s long-term durability.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01674-8
Gate-all-around field-effect transistors (GAA-FETs) represent the leading-edge channel architecture for constructing state-of-the-art high-performance FETs. Despite the advantages offered by the GAA configuration, its application to catalytic silicon nanowire (SiNW) channels, known for facile low-temperature fabrication and high yield, has faced challenges primarily due to issues with precise positioning and alignment. In exploring this promising avenue, we employed an in-plane solid–liquid-solid (IPSLS) growth technique to batch-fabricate orderly arrays of ultrathin SiNWs, with diameters of DNW = 22.4 ± 2.4 nm and interwire spacing of 90 nm. An in situ channel-releasing technique has been developed to well preserve the geometry integrity of suspended SiNW arrays. By optimizing the source/drain contacts, high-performance GAA-FET devices have been successfully fabricated, based on these catalytic SiNW channels for the first time, yielding a high on/off current ratio of 10^7 and a steep subthreshold swing of 66 mV dec−1, closing the performance gap between the catalytic SiNW-FETs and state-of-the-art GAA-FETs fabricated by using advanced top-down EBL and EUV lithography. These results indicate that catalytic IPSLS SiNWs can also serve as the ideal 1D channels for scalable fabrication of high-performance GAA-FETs, well suited for monolithic 3D integrations.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01675-7
The morphological distribution of absorbent in composites is equally important with absorbents for the overall electromagnetic properties, but it is often ignored. Herein, a comprehensive consideration including electromagnetic component regulation, layered arrangement structure, and gradient concentration distribution was used to optimize impedance matching and enhance electromagnetic loss. On the microscale, the incorporation of magnetic Ni nanoparticles into MXene nanosheets (Ni@MXene) endows suitable intrinsic permittivity and permeability. On the macroscale, the layered arrangement of Ni@MXene increases the effective interaction area with electromagnetic waves, inducing multiple reflection/scattering effects. On this basis, according to the analysis of absorption, reflection, and transmission (A–R–T) power coefficients of layered composites, the gradient concentration distribution was constructed to realize the impedance matching at low-concentration surface layer, electromagnetic loss at middle concentration interlayer and microwave reflection at high-concentration bottom layer. Consequently, the layered gradient composite (LG5-10–15) achieves complete absorption coverage of X-band at thickness of 2.00–2.20 mm with RLmin of −68.67 dB at 9.85 GHz in 2.05 mm, which is 199.0%, 12.6%, and 50.6% higher than non-layered, layered and layered descending gradient composites, respectively. Therefore, this work confirms the importance of layered gradient structure in improving absorption performance and broadens the design of high-performance microwave absorption materials.
Nano-Micro Letters•2025•DOI: 10.1038/sino-451789
Chinese laboratories and battery manufacturers are compressing the all-solid-state battery (ASSB) timeline, with sulfide electrolyte production scaling to pilot tons and cell prototypes targeting 450–500 Wh/kg. This report dissects the empirical state of sulfide solid electrolytes—specifically argyrodite Li6PS5Cl—against high-nickel cathodes (NMC811, NMC9055), focusing on interfacial resistance kinetics, dry-coating process yields, and the operational hazards of H2S generation. CATL, BYD (FinDreams), and Gotion pilot lines reveal a persistent trade-off: energy density gains versus cycle life degradation, with current data showing >80% capacity retention after 1,000 cycles at 0.5C only under optimized stack pressure and temperature. Concurrently, sodium-ion batteries (NIBs) emerge as a pragmatic complement, with layered oxide cathodes achieving $42/kWh at cell level—versus $75/kWh for LFP—and retaining 80% discharge capacity at -30°C. The report benchmarks technical parameters across solid-state, liquid Li-ion, and Na-ion chemistries, concluding that sulfide-based ASSBs will enter niche markets (e.g., aviation, high-end EVs) by 2027, while Na-ion dominates stationary storage and low-cost mobility. CAPEX per annual metric ton for sulfide electrolyte production remains prohibitive at $1.2M–$1.8M, with Western refiners lagging Chinese cost structures by 40–60%.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01662-y
The use of microneedles (MNs) has been established as an effective transdermal drug delivery strategy that has been extensively deployed for treating various diseases, including skin diseases. MNs can surpass the constraints of conventional drug delivery methods by their superior safety and efficacy through precise targeting, while simultaneously enabling painless delivery. Currently, MNs are increasingly used as carriers for drug delivery, with the loading of insoluble drugs to improve their treatment efficiency or combining with bioactive substances for the construction of an efficient drug delivery system to maximize the effects of bioactive substances. The methods used for preparation MNs are diverse, enabling them to meet the requirements of most applications. The emergence of MNs has addressed the shortcomings associated with insoluble drugs, expanded the applications of bioactive substances, and improved their use in clinical practice. This review summarizes current information on the application of MNs in a variety of skin diseases, such as psoriasis, vitiligo, alopecia, hypertrophic scarring, atopic dermatitis, melanoma, acne, and skin infections. The current clinical applications and future opportunities for MNs in the treatment of skin diseases are also discussed. Despite substantial progress in the clinical application of MNs as delivery vectors, issues such as low drug loading and poor mechanical strength during MNs preparation remain the main challenges. Therefore, clinical implementation of MNs-based therapies remains limited, highlighting key opportunities for future research.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01639-3
Carbon-based perovskite solar cells (C-PSCs) exhibit notable stability and durability. However, the power conversion efficiency (PCE) is significantly hindered by energy level mismatches, which result in interfacial charge transport barriers at the electrode-related interfaces. Herein, we report a back electrode that utilizes atomically dispersed metallic cobalt (Co) in carbon nanosheets (Co1/CN) to adjust the interfacial energy levels. The electrons in the d-orbitals of Co atoms disrupt the electronic symmetry of the carbon nanosheets (CN), inducing a redistribution of the electronic density of states that leads to a downward shift in the Fermi level and a significantly reduced interfacial energy barrier. As a result, the C-PSCs using Co1/CN as back electrodes achieve a notable PCE of 22.61% with exceptional long-term stability, maintaining 94.4% of their initial efficiency after 1000 h of continuous illumination without encapsulation. This work provides a promising universal method to regulate the energy level of carbon electrodes for C-PSCs and paves the way for more efficient, stable, and scalable solar technologies toward commercialization.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2026-41-03-13)
Four-directional dual-matrix C/C composites were fabricated from PAN-based carbon fibers using a combined approach of soft-hard hybrid weaving preform molding, chemical vapor infiltration (CVI) of pyrolytic carbon (PyC), high pressure impregnation and carbonization of pitch-derived carbon. The ablation resistance of the composites was evaluated by testing in a dual-pulse solid rocket motor, and their ablation behavior was investigated. The carbon rods formed by twisting and carbonizing fiber bundles, exhibited a hexagonal cross-section, surrounded by a dense PyC “wall” structure formed during the CVI process. The linear ablation rates of the composites after pulse I and pulse II were 0.068 mm/s and 0.113 mm/s, respectively. A cellular-like PyC layer and nanowire structures were deposited on the surface of the throat convergent section during the post-combustion cooling phase, while cracks and delamination occurred on and within the divergent section. The ablation of C/C composites under these conditions was a complex multi-mechanism process, including ultra-high temperatures, high-speed gas scouring, oxygen-containing thermochemical ablation, and thermal shock. This work elucidates the ablation behaviors of C/C composites under dual-pulse conditions and provides technical guidance and a theoretical basis for designing and fabricating C/C composites for extreme ablation environments.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2026-41-03-11)
A MgO/biochar composite (MBC) with a wide range of pore sizes was prepared by a MgCl2-NaOH co-impregnation method using lavender stalks as the biochar source, which can effectively remove Pb(II) and Cd(II) from wastewater. The co-impregnation treatment resulted in a specific surface area of the MBC that was approximately 54 times greater than that of the biochar derived from untreated stalks. The ion-exchange capacity of MBC was increased by the incorporation of MgO nanoparticles, which increased the alkali metal ion (Mg2+) content. These specific structures and compositions gave the MBC a high adsorption capacity for Pb(II) and Cd(II). The adsorption data followed a quasi second-order kinetic model. For Cd(II) and Pb(II), the maximum adsorption capacities of MBC-700 (treated at 700 ℃ for 2 h) reached 520 mg/g and 808 mg/g, respectively. The primary adsorption mechanisms were ion exchange, precipitation, electrostatic attraction and surface complexation. Furthermore, metallic lead was recovered by using the reducing properties of the biochar at high temperatures. This study provides a reference for developing inexpensive and efficient heavy metal adsorbents and the low-carbonization utilization of biomass waste.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-06-13)
The effect of functionalized graphene on the growth and development of Vicia faba L. was investigated by analyzing its impact on the composition and diversity of the microbial community in rhizosphere peat soil. Seedlings of V. faba planted in this peat soil were treated with either distilled water (CK) or 25 mg·L−1 (G25) of functionalized graphene solution. Results showed that the height and root length of V. faba seedlings in the G25 group were significantly larger than those in CK group. The microbial community was analyzed by amplifying and sequencing the 16S rRNA gene V3–V4 region of bacteria and internal transcribed spacer region of fungi in rhizosphere soil using Illumina MiSeq technology. Alpha and beta diversity analysis indicated that functionalized graphene increased the richness and diversity of bacteria and fungi in the V. faba rhizosphere peat soil. The abundances of three nitrogen cycling-related bacteria, Hydrogenophaga, Sphingomonas and Nitrosomonadaceae, were also altered after treatment with the functionalized graphene. The relative abundance of Basilicum, related to soil phosphorus solubilization, decreased in the fungal community, while the relative abundance of Clonostachys and Dimorphospora, which exhibited strong biological control over numerous fungal plant pathogens, nematodes and insects, increased in the soil after functionalized graphene treatment. Redundancy analysis revealed that the potential of hydrogen (pH), organic matter, and total phosphorus contributed the most to the changes in bacterial and fungal community composition in the rhizosphere soil. Overall, our findings suggested that the addition of functionalized graphene altered the relative abundances of nitrogen and phosphorus cycling-related microorganisms in peat soil, promoting changes in the physicochemical properties of the soil and ultimately leading to the improved growth of V. faba plants.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-05-11)
The use of three-dimensional (3D) electrodes in water treatment is competitive because of their high catalytic efficiency, low energy consumption and promising development. The use of particle electrodes is a key research focus in this technology. They are usually in the form of particles that fill the space between the cathode and anode, and the selection of materials used is important. Carbon-based materials are widely used because of their large specific surface area, good adsorption performance, high chemical stability and low cost. The principles of 3D electrode technology are introduced and recent research on its use for degrading organic pollutants using carbon-based particle electrodes is summarized. The classification of particle electrodes is introduced and the challenges for the future development of carbon-based particle electrodes in wastewater treatment are discussed.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-05-03)
Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity, making them suitable for high-performance applications. N-doping has been widely investigated because of its similar atom radius to carbon, high electronegativity as well as many different configurations. We summarize the preparation methods and properties of N-doped carbon materials, and discuss their possible use in sodium ion storage. The relationships between N content/configuration and crystallinity, electronic conductivity, wettability, chemical reactivity as well as sodium ion storage performance are discussed.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-03-03)
Graphene is widely used in photodetection because of its high carrier mobility and wide spectral absorption range. However, its high dark current caused by its low light absorption severely limits its performance. Molybdenum dihalide (MoX2, X=S, Se and Te) has a high absorption coefficient, which can compensate for the high dark current in graphene-based photodetectors and result in outstanding photoelectronic properties of those based on a graphene/MoX2 van der Waals heterostructure (vdWH). In this review, we firstly review working principles, performance indicators, and structures of photodetectors. After that, the significance of graphene/MoX2 vdWH photodetectors is highlighted from the fundamental perspective. Preparation methodologies and performance enhancement strategies of graphene/MoX2 vdWH photodetectors are correspondingly summarized. In the end, we highlight the current challenges and future directions of the graphene/MoX2 vdWH photodetectors. This review will guide the design of high-performance vdWH photodetectors.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-02-10)
Efficient electrocatalysts with a low cost, high activity and good durability play a crucial role in the use of direct formic acid fuel cells. Pd nanoparticles supported on N-doped hollow carbon nanospheres (NHCNs) embedded in an assembly of N-doped graphene (NG) with a three-dimensional (3D) porous structure by a simple and economical method were investigated as direct formic acid fuel cell catalysts. Because of the unique porous configuration of interconnected layers doped with nitrogen atoms, the Pd/NHCN@NG catalyst with Pd nanoparticles has a large catalytic active surface area, superior electrocatalytic activity, a high steady-state current density, and a strong resistance to CO poisoning, far surpassing those of conventional Pd/C, Pd/NG, and Pd/NHCN catalysts for formic acid electrooxidation. When the HCN/GO mass ratio was 1∶1, the Pd/NHCN@NG catalyst had an outstanding performance in the catalytic oxidation of formic acid, with an activity 4.21 times that of Pd/C. This work indicates a way to produce superior carbon-based support materials for electrocatalysts, which will be beneficial for the development of fuel cells.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2025•DOI: 10.1016/S1003-6326(25)67014-2
The effects of adding a novel Al−3Ti−4.35La master alloy and Nd and heat treatment on the microstructure and mechanical properties of Al−7Si alloy were investigated. The results showed that the secondary dendrite arm spacing of α-Al in the as-cast Al−7Si alloy was refined from 18.3 to 11.9 μm after modification with 0.2 wt.% Al−Ti−La and 0.03 wt.% Nd, and the length of eutectic Si was reduced from 8.6 to 5.0 μm. After heat treatment at 535 °C for 3 h followed by 165 °C for 3 h, the morphology of the eutectic Si became more rounded, and the size decreased. The microhardness, ultimate tensile strength, and elongation were HV 66.1, 184.9 MPa, and 24.4%, respectively, which increased by 24.2%, 11.6%, and 194.0% compared to the as-cast state. The addition of Al−3Ti−4.35La master alloy and Nd can reduce the nucleation temperature of eutectic Si in Al−7Si, thereby suppressing its growth. Notably, the Ti2(Al,Si)20(La,Nd) phase formed in the Al−7Si alloy after the addition of Al−Ti−La and Nd adhered to or coexisted near the eutectic Si particles, inhibiting their growth.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2025•DOI: 10.1016/S1003-6326(25)67015-4
6061 Al/Cu layered composites were fabricated by accumulative roll bonding (ARB). The microstructural evolution was examined using scanning electron microscopy, electron backscatter diffraction, and transmission electron microscopy. After seven ARB cycles, the tensile strength increased to 416 MPa, whereas the elongation decreased to 6.7%. The strength enhancement is mainly attributed to work hardening and grain refinement. No brittle intermetallic compounds (IMCs) were detected at the interface, and interfacial bonding improved with additional ARB cycles. The small hardness difference between Al and Cu promoted uniform plastic deformation across layers, enhancing interfacial cohesion. However, strain localization due to different work hardening responses of Al and Cu led to pronounced shear band formation after seven ARB cycles, reducing the plasticity.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2025•DOI: 10.1016/S1003-6326(25)66982-2
To exploit the combined strengthening effects of nanotwins and carbon nanotubes (CNTs) in Cu matrix composites, the nanotwins with a width ranging from 3 to 30 nm were incorporated into the CNTs-reinforced Cu matrix composites using cryogenic rolling and optimizing the initial particle size of the raw Cu powders. The formation of nanotwins in the Cu matrix composite reinforced by only 0.2 wt.% CNTs is accompanied by the increased dislocation density and refined Cu grain size, resulting in much better strength−ductility synergy than the referenced composite without significant nanotwins formation. The analysis of strengthening and toughening mechanisms demonstrates that the strength increment mainly derives from grain refinement strengthening, dislocation strengthening, and nanotwin strengthening. The strength increment from the contribution of the nanotwins accounts for 19.9% of the overall strength increment for the composite. Meanwhile, the retention of good tensile ductility can be reasonably explained by the increased dislocation accommodation ability due to the formed nanotwins and the decreased induced dislocation proliferation.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2025•DOI: 10.1016/S1003-6326(25)66983-4
The dependence of interface structure and mechanical properties on the modulation layer thickness of VN/TiN−Ni nano-multilayered films deposited on Si substrates using a reactive magnetron sputtering technique was systematically investigated. The films were characterized using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, and nanoindentation. The results show that the TiN−Ni layer grows epitaxially on the VN layer, forming a coherent interface between the two sublayers. When the deposition time ratio of the two sublayers (TTiN−Ni꞉TVN) is 10꞉12, the films exhibit remarkable mechanical properties, with hardness, elastic modulus, and fracture toughness values of 25.9 GPa, 317 GPa, and 1.88 MPa·m1/2, respectively. Meanwhile, fracture toughness is improved by approximately 50% compared to the VN monolithic film. This enhancement is attributed to the coherent interface between the sublayers and the phase separation in the TiN−Ni layer.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.01.005
The combination of ultrasonic and acid fracturing fluid can strengthen the modification effect on the micropore structure of the coal matrix, thereby enhancing the efficiency of the acid fracturing process. In this research, acetic acid was utilized to formulate acid fracturing fluids with varying concentrations, and the evolutionary traits of both the acid fracturing fluids and ultrasonic waves in relation to coal samples were investigated. The functional group structure, mineral composition, micropore structure and surface morphology of coal samples were characterized by FTIR, XRD, N2 adsorption at low temperature and SEM-EDS. The results showed that aromatics (I) and branching parameters (CH2/CH3) were reduced by 81.58% and 88.67%, respectively, after 9% acetic acid treatment. Acetic acid can dissolve carbonates and clay minerals in coal, create new pores, and increase porosity, pore volume and pore fractal dimension. After modification by 7% acetic acid, the pore volume increased by 5.7 times. SEM observation shows that the diameter of coal surface holes increases, EDS scanning shows that the content of mineral elements in coal decreases, the connectivity of coal holes increases, and the holes expand. The findings of this research offer theoretical direction for optimizing ultrasonic-enhanced acid fracturing fluid modification.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.01.002
Under submerged conditions, compared with traditional self-excited oscillating pulsed waterjets (SOPWs), annular fluid-enhanced self-excited oscillating pulsed waterjets (AFESOPWs) exhibit a higher surge pressure through self-priming. However, their pressure frequency and cavitation characteristics remain unclear, resulting in an inability to fully utilize resonance and cavitation erosion to break coal and rock. In this study, high-frequency pressure testing, high-speed photography, and large eddy simulation (LES) are used to investigate the distribution of the pressure frequency band, evolution law of the cavitation cloud, and its regulation mechanism of a continuous waterjet, SOPW, and AFESOPW. The results indicated that the excitation of the plunger pump, shearing layer vortex, and bubble collapse corresponded to the three high-amplitude frequency bands of the waterjet pressure. AFESOPWs have an additional self-priming frequency that can produce a larger amplitude under a synergistic effect with the second high-amplitude frequency band. A better cavitation effect was produced after self-priming the annulus fluid, and the shedding frequency of the cavitation clouds of the three types of waterjets was linearly related to the cavitation number. The peak pressure of the waterjet and cavitation erosion effect can be improved by modulating the waterjet pressure oscillation frequency and cavitation shedding frequency.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25020033
To optimize turn on velocity of the SiC LIMS, we proposed a new structure for the LIMS that incorporates an optimized n+ layer and a multi-light triggered electrode design for the anode. The chip size is 5.5 mm × 5.5 mm in dimension. The experiment results indicate that the saturation laser energy required to trigger the prepared SiC LIMS has been decreased from 1.8 mJ to 40 μJ, with the forward blocking voltage of the prepared SiC LIMSs capable of withstanding over 7000 V. The leakage current is about 0.3 μA at room temperature, and the output current density achieves 4.25 kA/cm2 (with di/dt larger than 20 kA/μs).
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25030031
Quantum key distribution (QKD) achieves information-theoretic security based on quantum mechanics principles, where single-photon detectors (SPDs) serve as critical components. This study focuses on the sinusoidal gated SPDs widely used in high-speed QKD systems. We investigate the mechanisms underlying the rising-edge jitter in detection signals, identifying contributions from factors such as the temporal width of injected optical pulses, avalanche generation processes, avalanche signal extraction, and pulse discrimination. To address the issue of excessive jitter-induced bit errors, we propose a retiming scheme that utilizes coincidence signals synchronized with the sinusoidal gating signal. This approach effectively suppresses detection signal jitter and reduces the after-pulse probability of the detector. Experimental validation using a high-precision time-to-digital converter (TDC) demonstrates a significant reduction in the rising-edge jitter distribution after applying the suppression scheme. The proposed method features clear principles and straightforward engineering implementation, avoiding direct interference with the detector's operational processes. The designed high-speed sinusoidal gated InGaAs/InP SPD operates at 1.25 GHz, achieving a remarkable reduction in after-pulse probability from 10.7% (without jitter suppression) to 0.72%, thereby enhancing the overall performance of QKD systems.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.07.001
Renewable energy storage technologies are critical for transitioning to sustainable energy systems, with salt caverns playing a significant role in large-scale solutions. In water-soluble mining of low-grade salt formations, insoluble impurities and interlayers detach during salt dissolution and accumulate as sediment at the cavern base, thereby reducing the storage capacity and economic viability of salt cavern gas storage (SCGS). This study investigates sediment formation mechanisms, void distribution, and voidage in the Huai’an low-grade salt mine, introducing a novel self-developed physical simulation device for two butted-well horizontal (TWH) caverns that replicates compressed air injection and brine discharge. Experiments comparing “one injection and one discharge” and “two injections and one discharge” modes revealed that (1) compressed air effectively displaces brine from sediment voids, (2) a 0.5 MPa injection pressure corresponds to a 10.3 MPa operational lower limit in practice, aligning with field data, and (3) sediment voidage is approximately 46%, validated via air-brine interface theory. The “two injections and one discharge” mode outperformed in both discharge volume and rate. Additionally, a mathematical model for brine displacement via compressed air was established. These results provide foundational insights for optimizing compressed air energy storage (CAES) in low-grade salt mines, advancing their role in renewable energy integration.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.09.012
Biotite content critically influences rock mechanical behavior and threatens underground engineering stability. Uniaxial compression tests with acoustic emission (AE) monitoring were conducted on granite pegmatite samples having varying biotite content. Peak frequency distribution analysis, rise angle-average frequency (RA-AF) analysis, multifractal theory, and a dynamic multifractal algorithm were applied to explore the relationship between damage evolution and AE characteristics. Results indicate that increased biotite content reduces uniaxial compressive strength and elastic modulus, enhances plastic deformation, and increases the proportion of shear cracks. The segmented evolution of the dynamic multifractal parameter Dam is biotite-dependent. Oscillations during the elastic phase signify localized shear crack initiation and propagation; their attenuation in the plastic phase reflects frictional closure along biotite cleavage planes, promoting elastic energy storage and delaying release. AE-based damage models and time-varying signals characterize rock damage progression. Stress concentrations around biotite minerals foster localized shear band formation, leading to concentrated shear failure at lower damage levels. Higher biotite content accelerates crack propagation, while smooth cleavage planes lower the fracture energy threshold, reducing strength and stiffness. These findings enhance understanding of biotite-influenced progressive rock damage and underpin stability monitoring and early-warning systems for underground engineering.
China Foundry•2025•DOI: 10.1007/s41230-025-5161-3
With the increase in power of the industrial gas turbine and thrust-weight ratio of aeroengine, the conventional strengthening method of adding refractory elements into superalloys has become difficult to meet the demands for the higher mechanical properties. A novel Ni-based superalloy was designed with enhanced strength and hardness based on the graphene nanosheets (GNs) synergistic in-situ nano-carbides strengthening in the present work. Nano-carbides were induced by in-situ reaction of the GNs with alloy powders during additive manufacturing. The microstructure and thermophysical properties of different alloys with 0.1wt.% GNs and without GNs were investigated by SEM, EBSD, TEM, differential scanning calorimetry (DSC), and small angle neutron scattering (SANS). Residual GNs were also detected by SANS and DSC. The nano-carbides are uniformly distributed in the matrix and combine with residual GNs to refine the cellular structure. Compared with the original alloy (ASE100), the hardness of the alloy with 0.1wt.% GNs (ASE100-0.1GN) is increased by 31 HV (from 315 HV to 346 HV), and the yield tensile strength is increased by 86 MPa (from 756 MPa to 842 MPa). The GNs react with alloy melt in the molten pools to generate nano-carbides under the Marangoni effect during manufacturing process. The dispersion nano-carbides are distributed at both grain boundaries and within grains, effectively hindering the movement of dislocation and enhancing the strength of alloy.
China Foundry•2025•DOI: 10.1007/s41230-025-5001-5
Ceramic cores are important in the fabrication of superalloy hollow blades, which are increasingly characterized by intricate internal cavity channels. This complexity poses significant challenges to traditional manufacturing processes. The vat photopolymerization 3D printing technology provides a new choice for ceramic cores with complex structures. However, the lamellar structure of the vat photopolymerization 3D printed ceramic cores leads to the anisotropy. Meanwhile, the low strength and high shrinkage of ceramic cores restrict their industrial application. In this study, using Al2O3 powder as the main material, the effects of zircon content on the sintering shrinkage, open porosity, flexural strength, and other properties of Al2O3-based ceramic cores were studied to address the aforementioned issues. The influencing mechanism of zircon distribution on sintering shrinkage was analyzed, and the strengthening mechanism of mullite on ceramic cores was discussed from both thermodynamics and dynamics aspects. Through the comprehensive evaluation of ceramic core properties, the Al2O3-based ceramic core with 15vol.% zircon exhibites the optimal performance. Compared with the core samples without zirconium addition, the flexural strength of the Al2O3-based ceramic core with 15vol.% zircon increases from 14.80 MPa to 61.54 MPa at 25 °C, an increase of 315.8%; and from 4.91 MPa to 11.59 MPa at 1,500 °C, an increase of 136.0%. The shrinkage in the Z-axis is reduced by 21%, which better weakens the anisotropy of the shrinkage of 3D printed Al2O3-based ceramic cores. ZrO2 phase and mullite phase are formed by zircon, which improve the comprehensive properties of Al2O3-based ceramic cores. The successful 3D printing of high-performance Al2O3-based ceramic cores via vat photopolymerization has promoted its industrial application for fabricating ceramic cores with complex structures.
China Foundry•2025•DOI: 10.1007/s41230-025-5003-3
The performance of an aero-engine is closely related to the cooling ability of the hollow turbine blades. Ceramic core is an important component in the production of hollow turbine blades with a complex structure. As the pace of updating and iteration in turbine blade design continues to accelerate, the internal cavity structures of turbine blades have become increasingly complex. Traditional hot injection process is difficult to meet the production requirements of ceramic cores with complex structures. 3D printing technology can manufacture ceramic cores without the need for moulds, significantly shortening the production cycle and providing a new technology for the production of ceramic cores with complex structures. To meet the technical requirements of the investment casting process, ceramic cores must possess adequate mechanical strength and appropriate porosity. In this work, the ceramic slurry with polysilazane (PSZ) precursor was successfully prepared, and the Al2O3-based ceramic cores with high performance were fabricated using 3D printing technology. The regulation mechanism of polysilazane on the performance of ceramic cores was investigated. The results show that with the increase of PSZ content, the flexural strength of ceramic cores firstly increases and then decreases. When the content of PSZ is 5%, the flexural strength at 25 °C and 1,500 °C are 31.5 MPa and 13.1 MPa, respectively, and the porosity is 36.7%. This work is expected to advance the research and practical application of high-performance ceramic cores fabricated via 3D printing.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01303-w
Lead zirconate titanate (PbZrxTi1-xO3, PZT) ferroelectric films possess remarkable characteristics such as high residual polarization, high dielectric constant, and high piezoelectric coefficient and have great application prospects in modern electronics, communications, medical care, and military fields. At present, the microstructure changes of PZT ferroelectric thin films have a significant impact on their electrical properties. Therefore, this work summarizes the influences of geometric structure (thickness, porosity), composition structure (Zr/Ti ratio, doping), and grain structure (grain size, grain boundaries, orientation) on the electrical properties of PZT ferroelectric thin films. The results show that the changes in thickness and porosity have a significant impact on the electrical properties of PZT ferroelectric films. Especially, the actual application scenarios and preparation processes determine the required geometric dimensions and structures of PZT ferroelectric films. The Zr/Ti ratio and doping mainly affect the electrical properties by influencing the phase composition of PZT ferroelectric films. The changes in grain size, boundary structure, and orientation dependence mainly have a certain degree of influence on the domain response and domain switching behavior of PZT ferroelectric thin films. In conclusion, different structures have different influence effects on the dielectric, ferroelectric, and piezoelectric properties of PZT ferroelectric films. The way the tiny structure affects how PZT thin films work was shown, helping to guide the design of ferroelectric thin film devices. In order to further study and apply piezoelectric ceramic devices, it is crucial to have an in-depth understanding of the relationship between the structure and performance of piezoelectric ceramic devices.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01355-y
This paper proposes virtual impedance adaptation of the lower-limb exoskeleton for human performance augmentation (LEHPA) based on deep reinforcement learning (VIADRL) to mitigate reliance on model accuracy and address the ever-changing human-exoskeleton interaction (HEI) dynamics. The classical sensitivity amplification control strategy is expanded to the virtual impedance control strategy with more learnable virtual impedance parameters. The adjustment of these virtual impedance parameters is formalized as finding the optimal policy for a Markov Decision Process and can then be effectively resolved using deep reinforcement learning algorithms. To ensure safe and efficient policy training, a multibody simulation environment is established to facilitate the training process, supplemented by the innovative hybrid inverse-forward dynamics simulation approach for executing the simulation. For comparison purposes, the SADRL strategy is introduced as a benchmark. A novel control performance evaluation method based on the HEI forces at the back, thighs, and shanks is proposed to quantitatively evaluate the performance of our proposed VIADRL strategy. The VIADRL controller is systematically compared with the SADRL controller at five selected walking speeds. The lumped ratio of HEI forces under the SADRL strategy relative to those under the SADRL strategy is as low as 0.81 in simulation and approximately 0.89 on the LEHPA prototype. The overall reduction of HEI forces demonstrates the superiority of the VIADRL strategy in comparison to the SADRL strategy.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01292-w
Distributed drive electric vehicles (DDEVs) endow the ability to improve vehicle stability performance through direct yaw-moment control (DYC). However, the nonlinear characteristics pose a great challenge to vehicle dynamics control. For this purpose, this paper studies the DYC through the Takagi-Sugeno (T-S) fuzzy-based model predictive control to deal with the nonlinear challenge. First, a T-S fuzzy-based vehicle dynamics model is established to describe the time-varying tire cornering stiffness and vehicle speeds, and thus the uncertain parameters can be represented by the norm-bounded uncertainties. Then, a robust model predictive control (MPC) is developed to guarantee vehicle handling stability. A feasible solution can be obtained through a set of linear matrix inequalities (LMIs). Finally, the tests are conducted by the Carsim/Simulink joint platform to verify the proposed method. The comparative results show that the proposed strategy can effectively guarantee the vehicle’s lateral stability while handling the nonlinear challenge.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01217-7
The high-temperature oxidation resistance of AISI 321 stainless steel used in solar thermal power heat exchangers determines its service life. In this study, aluminizing and subsequent laser shock peening (LSP) treatments were employed to improve the high-temperature oxidation resistance of AISI 321 stainless steel at 620 °C. These two treatments decreased the oxidation rate of AISI 321 steel. Specifically, the optimal oxidation resistance was observed in aluminized steel before oxidation for 144 h owing to the increased entropy of the LSP-treated specimen. After 144 h, LSP-treated steel achieved the best oxidation resistance because of the formation of a protective α-Al2O3 film. Moreover, the large amount of subgrain boundaries formed on the aluminized layer of the LSP-treated samples could act as short-circuit paths for the outward diffusion of Al, facilitating the rapid nucleation of α-Al2O3. Meanwhile, the aluminized layer could isolate the contact between the oxidation environment and matrix, thereby decreasing the oxidation rate. Furthermore, the minimum oxidation parabolic constant was calculated for LSP-treated steel (6.45787 × 10−14), which was 69.18% and 36.36% that of aluminized and 321 steel, respectively, during the entire oxidation process. Therefore, the combination of aluminizing and LSP treatments can improve the high-temperature oxidation resistance of 321 stainless steel, providing a new idea for its surface treatment to achieve a long service life at high temperatures.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6145-6
The increasing aerodynamic noise caused by high-speed maglev trains (HSMTs) contributes substantially to environmental pollution and passenger discomfort. Numerical studies were performed to examine the effect of air blowing/sucking modes, positions and velocities on the flow field change and their potentials in mitigating the aerodynamic noise produced by HSMTs. The results indicate that the aerodynamic noise can be effectively mitigated by implementing air-blowing in the transition region between the streamlined tail nose and constant cross-sectional body (Scheme 1) and the wake vortex shedding area near the tail nose (Scheme 3) at speeds below 0.3U (train speed), as well as in the side edge area (Scheme 2) at various speeds (0.1U−0.5U), primarily due to the suppression in wake vortices. The optimal noise reduction value of 1.53 dB(A) is achieved when blowing in Scheme 1 at a speed of 0.1U, while the efficacy of the air-sucking mode is inferior with a smaller noise reduction value less than 0.84 dB(A). Additionally, simultaneous reductions in aerodynamic noise and drag can be achieved when sucking in Scheme 2 at speeds below 0.2U and blowing in Scheme 3 at speeds below 0.3U. These findings offer valuable insights for the application of active flow control technology in the design of low-resistance and low-noise HSMTs.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6136-7
The increase in aerodynamic drag brings high energy consumption, which is a critical issue in the development of high-speed trains. Inspired by the excellent hydrodynamic characteristics of fish movement in nature, a two-dimensional numerical simulation method based on spring-smoothing model and adaptive mesh technology was utilized to explore the effects of different fishtail structures and two flexible motion modes (Eel mode and Lunate-tail mode) on the wake of high-speed trains, and to assess their potential for aerodynamic drag reduction. Results indicate that the biomimetic fishtail successfully suppresses the alternating shedding of vortices in the wake, and induces the aerodynamic drag fluctuation period to align with the fishtail oscillation period. The fishtail length, oscillation mode, and frequency have a significant impact on the wake flow and aerodynamic drag of the train. Among these, a 1850 mm Eel fishtail with parameters of λ=1 and T=8 s achieves the optimal drag reduction effect, with drag reduction rates of 39.12% and 26.00% for the tail car and the entire train, respectively. These findings provide a theoretical basis for the design of new low-resistance railway trains, promoting the sustainable development of rail transit towards goals of high-speed and energy-efficient.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6127-8
In this study, the effect of Cu2+ on the cassiterite and calcite flotation using octanohydroxamic acid (OHA) as collector was investigated through flotation tests, solution reaction tests and calculation, zeta potential measurements, XPS analysis and residual reagent concentration measurements. Results indicated that Cu2+ played an activation role on cassiterite flotation but a depression role on calcite flotation. The copper cations were adsorbed on the cassiterite surface by forming a Cu―O bond, and the pre-adsorbed copper cations and the OHA-Cu complexes promoted the adsorption of OHA on the cassiterite surface. Thus, cassiterite flotation was activated. The dissolved HCO3− in the calcite pulp underwent a double hydrolysis reaction with copper cations (Cu2+, CuOH+, Cu2(OH)2 2+ and Cu3(OH)4 2+) to form CuCO3. Some copper cations were adsorbed on the calcite surface as well, but some adsorbed Cu2+ on the calcite surface was desorbed by bonding with OHA, and most of OHA was consumed by Cu2+, basic copper carbonate and copper hydroxide. The residual OHA in the pulp was not sufficient for flotation, so calcite flotation was depressed. Finally, a model of the reaction mechanism of Cu2+ and OHA on the cassiterite and calcite surfaces was established.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6100-6
In this study, AZ31 Mg alloy sheets were processed by a severe plastic deformation (SPD) technique called forging-bending repeated deformation (FBRD). The effect on the microstructure and microhardness of AZ31 Mg alloy through FBRD was investigated with increasing temperature treatment and a 90° cross route. The results reveal that the effective strain increases with the number of passes. The flow uniformity is effectively enhanced due to alterations in shear deformation direction. After four passes of deformation, the average grain size is refined by 79.3% compared to the initial specimen. The grain refinement mechanism predominantly originates from the synergistic effects of discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), and twinning-induced recrystallization (TDRX). The formation of {1012} extension twins (ET) significantly contributes to coarse grain subdivision and plastic deformation coordinated. Furthermore, pyramidal <c+a> slip activation effectively enhances the plasticity of Mg alloys. By post four-pass processing, the alloy exhibits a microhardness of 81.9HV, primarily governed by fine grain strengthening and dislocation strengthening mechanisms.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6095-z
In this paper, the multi cross-rolling and cryogenic treatment were adopted to process the AZ31 Mg alloy to study the influence of passes and cryogenic treatment on cross-rolled AZ31 Mg alloy. The tensile properties and hardness were tested. The microstructure was characterized using electron backscatter diffraction (EBSD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM) in order to elucidate the influencing mechanism. The results indicate that the treatment method can significantly improve the mechanical properties of AZ31 Mg alloy. The 3-pass sample processed by cryogenic treatment shows the highest strength (351 MPa) and has the highest hardness (76.1HV) and best hardness uniformity (standard deviation=0.9HV). The 2-pass sample has the highest ductility among all the samples but poor hardness evenness. The strengthening mechanism of 3-pass sample can be attributed to the fine grains, bimodal structure, high dislocation density, and precipitation strengthening. Due to repeated heat preservation of 4-pass and 5-pass, their comprehensive performances decrease.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6040-1
During underground excavation, the surrounding rock mass is subjected to complex cyclic stress, significantly impacting its long-term stability, especially under varying water content conditions where this effect is amplified. However, research on the mechanical response mechanisms of surrounding rock mass under such conditions remains inadequate. This study utilized acoustic emission (AE) and resistivity testing to monitor rock fracture changes, revealing the rock’s damage state and characterizing the damage evolution process during uniaxial cyclic loading and unloading. First, a damage variable equation was established based on AE and resistivity parameters, leading to the derivation of a corresponding damage constitutive equation. Uniaxial cyclic loading and unloading tests were then conducted on sandstone samples with varying water contents, continuously monitoring AE signals and resistivity, along with computed tomography scans before and after failure. The predictions from the damage constitutive equation were compared with experimental results. This comparison shows that the proposed damage variable equation effectively characterizes the damage evolution of sandstone during loading and unloading, and that the constitutive equation closely fits the experimental data. This study provides a theoretical basis for monitoring and assessing the responses of surrounding rock mass during underground excavation.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-3086-2
The converter steelmaking process represents a pivotal aspect of steel metallurgical production, with the characteristics of the flame at the furnace mouth serving as an indirect indicator of the internal smelting stage. Effectively identifying and predicting the smelting stage poses a significant challenge within industrial production. Traditional image-based methodologies, which rely on a single static flame image as input, demonstrate low recognition accuracy and inadequately extract the dynamic changes in smelting stage. To address this issue, the present study introduces an innovative recognition model that preprocesses flame video sequences from the furnace mouth and then employs a convolutional recurrent neural network (CRNN) to extract spatiotemporal features and derive recognition outputs. Additionally, we adopt feature layer visualization techniques to verify the model’s effectiveness and further enhance model performance by integrating the Bayesian optimization algorithm. The results indicate that the ResNet18 with convolutional block attention module (CBAM) in the convolutional layer demonstrates superior image feature extraction capabilities, achieving an accuracy of 90.70% and an area under the curve of 98.05%. The constructed Bayesian optimization-CRNN (BO-CRNN) model exhibits a significant improvement in comprehensive performance, with an accuracy of 97.01% and an area under the curve of 99.85%. Furthermore, statistics on the model’s average recognition time, computational complexity, and parameter quantity (Average recognition time: 5.49 ms, floating-point operations per second: 18260.21 M (1 M = 1 × 106), parameters: 11.58 M) demonstrate superior performance. Through extensive repeated experiments on real-world datasets, the proposed CRNN model is capable of rapidly and accurately identifying smelting stages, offering a novel approach for converter smelting endpoint control.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-025-3114-x
Digital modeling and autonomous control of the die forging process are significant challenges in realizing high-quality intelligent forging of components. Using the die forging of AA2014 aluminum alloy as a case study, a machine-learning-assisted method for digital modeling of the forging force and autonomous control in response to forging parameter disturbances was proposed. First, finite element simulations of the forging processes were conducted under varying friction factors, die temperatures, billet temperatures, and forging velocities, and the sample data, including process parameters and forging force under different forging strokes, were gathered. Prediction models for the forging force were established using the support vector regression algorithm. The prediction error of Ff, that is, the forging force required to fill the die cavity fully, was as low as 4.1%. To further improve the prediction accuracy of the model for the actual Ff, two rounds of iterative forging experiments were conducted using the Bayesian optimization algorithm, and the prediction error of Ff in the forging experiments was reduced from 6.0% to 1.5%. Finally, the prediction model of Ff combined with a genetic algorithm was used to establish an autonomous optimization strategy for the forging velocity at each stage of the forging stroke, when the billet and die temperatures were disturbed, which realized the autonomous control in response to disturbances. In cases of −20 or −40°C reductions in the die and billet temperatures, forging experiments conducted with the autonomous optimization strategy maintained the measured Ff around the target value of 180 t, with the relative error ranging from −1.3% to +3.1%. This work provides a reference for the study of digital modeling and autonomous optimization control of quality factors in the forging process.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-3043-0
Tensile deformation and microvoid formation of quenched and tempered SA508 Gr.3 steel were studied using an in-situ digital image correlation technique and in-situ electron backscatter diffraction (EBSD) measurements. The quenched steel with a mixture of upper bainite and granular bainite exhibited a high ultimate tensile strength (UTS) of ~795 MPa and an elongation of ~25%. After tempering, long-rod carbides and accumulated carbide particles were formed at the interface of bainite–ferrite subunits and prior austenite grain boundaries (PAGBs), respectively. The UTS of the tempered steel decreased to ~607 MPa, whereas the total elongation increased to 33.0% with a local strain of 191.0% at the necked area. In-situ EBSD results showed that strain localization in the bainite–ferrite produced lattice rotation and dislocation pileup, thus leading to stress concentration at the discontinuities (e.g., martensite–austenite islands and carbides). Consequently, the decohesion of PAGBs dotted with martensite–austenite islands was the dominant microvoid initiation mechanism in the quenched steel, whereas microvoids primarily initiated through the fracturing of long-rod carbides and the decohesion of PAGBs with carbides aggregation in the tempered steel. The fracture surfaces for both the quenched and tempered specimens featured dimples, indicating the ductile failure mechanism caused by microvoid coalescence.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-025-3112-z
The hook formation mechanism in continuously cast slabs of ultra-low carbon steel was analyzed in detail through numerical calculations and experimental observations using optical microscopy, and its distribution characteristics were determined. Numerical simulations confirmed that the freezing–overflow mechanism is the primary cause of hook formation. They also revealed that the freezing event occurs unpredictably, while the overflow event takes place during the positive strip time. The average pitch of oscillation marks (OMs) on the slab surface was 8.693 mm, while the theoretical pitch was 8.889 mm, with a difference of approximately 2%. This discrepancy primarily results from varying degrees of overflow, which affects the morphology of the OMs and the positions of their deepest points. Notably, this result further confirmed that the freezing and overflow in the meniscus were indeed caused by the periodic oscillation of the mold. Higher superheat hindered hook formation, leading to a negative correlation between the hook depth distribution around the slab and the temperature distribution within the mold. Therefore, the depth of the corner hook was greater than that of other positions, which was caused by the intensified cooling effect of the corner. Moreover, key factors influencing hook development were analyzed, providing insights into transient fluid flow and heat transfer characteristics within the mold. Transient fluid flow and heat transfer contributed to the randomness and tendency of hook formation. This randomness was reflected in the varying angles of the hooks, whereas the tendency was evident in the negative correlation between superheat and hook length. Based on the randomness and tendency of hook formation and its profile characteristics, a new method for controlling hook depth based on “sine law” is proposed.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-3045-y
The corrosion degradation of organic coatings in tropical marine atmospheric environments results in substantial economic losses across various industries. The complexity of a dynamic environment, combined with high costs, extended experimental periods, and limited data, places a limit on the comprehension of this process. This study addresses this challenge by investigating the corrosion degradation of damaged organic coatings in a tropical marine environment using an atmospheric corrosion monitoring sensor and a random forest (RF) model. For damage simulation, a polyurethane coating applied to a Fe/graphite corrosion sensor was intentionally scratched and exposed to the marine atmosphere for over one year. Pearson correlation analysis was performed for the collection and filtering of environmental and corrosion current data. According to the RF model, the following specific conditions contributed to accelerated degradation: relative humidity (RH) above 80% and temperatures below 22.5°C, with the risk increasing significantly when RH exceeded 90%. High RH and temperature exhibited a cumulative effect on coating degradation. A high risk of corrosion occurred in the nighttime. The RF model was also used to predict the coating degradation process using environmental data as input parameters, with the accuracy showing improvement when the duration of influential environmental ranges was considered.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-3035-0
Electrochemical metallurgy at low temperature (<473 K) shows promise for the extraction and refinement of metals and alloys in a green and sustainable manner. However, the kinetics of the electrodeposition process is generally slow at low temperature, resulting in large overpotential and low current efficiency. Thus, the application of external physical fields has emerged as an effective strategy for improving the mass and charge transfer processes during electrochemical reactions. This review highlights the challenges associated with low-temperature electrochemical processes and briefly discusses recent achievements in optimizing electrodeposition processes through the use of external physical fields. The regulating effects on the optimization of the electrodeposition process and the strategies for selecting various external physical fields, including magnetic, supergravity, and ultrasonic fields are summarized from the perspectives of equipment and mechanisms. Finally, advanced methods for in-situ characterization of external physical field-assisted electrodeposition processes are reviewed to gain a deeper understanding of metallic electrodeposition. An in-depth exploration of the mechanism by which external physical fields affect the electrode process is essential for enhancing the efficiency of metal extraction at low temperatures.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-2962-0
The wave-absorbing materials are kinds of special electromagnetic functional materials and have been widely used in electromagnetic pollution control and military fields. In-situ integrated hierarchical structure construction is thought as a promising route to improve the microwave absorption performance of the materials. In the present work, layer-structured Co-metal-organic frameworks (Co-MOFs) precursors were grown in-situ on the surface of carbon fibers with the hydrothermal method. After annealed at 500°C under Ar atmosphere, a novel multiscale hierarchical composite (Co@C/CF) was obtained with the support of carbon fibers, keeping the flower-like structure. Scanning electron microscope, transmission electron microscope, X-ray diffraction, Raman, and X-ray photoelectron spectroscopy were performed to analyze the microstructure and composition of the hierarchical structure, and the microwave absorption performance of the Co@C/CF composites were investigated. The results showed that the growth of the flower-like structure on the surface of carbon fiber was closely related to the metal-to-ligand ratio. The optimized Co@C/CF flower-like composites achieved the best reflection loss of −55.7 dB in the low frequency band of 6–8 GHz at the thickness of 2.8 mm, with the corresponding effective absorption bandwidth (EAB) of 2.1 GHz. The EAB of 3.24 GHz was achieved in the high frequency range of 12–16 GHz when the thickness was 1.5 mm. The excellent microwave absorption performance was ascribed to the introduction of magnetic components and the construction of the unique structure. The flower-like structure not only balanced the impedance of the fibers themselves, but also extended the propagation path of the microwave and then increased the multiple reflection losses. This work provides a convenient method for the design and development of wave-absorbing composites with in-situ integrated structure.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01613-z
Organic additives with multiple functional groups have shown great promise in improving the performance and stability of perovskite solar cells. The functional groups can passivate undercoordinated ions to reduce nonradiative recombination losses. However, how these groups synergistically affect the enhancement beyond passivation is still unclear. Specifically, isomeric molecules with different substitution patterns or molecular shapes remain elusive in designing new organic additives. Here, we report two isomeric carbazolyl bisphosphonate additives, 2,7-CzBP and 3,6-CzBP. The isomerism effect on passivation and charge transport process was studied. The two molecules have similar passivation effects through multiple interactions, e.g., P=O···Pb, P=O···H–N and N–H···I. 2,7-CzBP can further bridge the perovskite crystallites to facilitates charge transport. Power conversion efficiencies (PCEs) of 25.88% and 21.04% were achieved for 0.09 cm2 devices and 14 cm2 modules after 2,7-CzBP treatment, respectively. The devices exhibited enhanced operational stability maintaining 95% of initial PCE after 1000 h of continuous maximum power point tracking. This study of isomerism effect hints at the importance of tuning substitution positions and molecular shapes for organic additives, which paves the way for innovation of next-generation multifunctional aromatic additives.
China Foundry•2025•DOI: 10.1007/s41230-025-3157-7
In this work, the influences of surface layer slurry at different temperatures (10 °C, 14 °C, 18 °C, 22 °C) on wax patterns deformation, shrinkage, slurry coating characteristics, and the surface quality of the casting were investigated by using a single factor variable method. The surface morphologies of the shell molds produced by different temperatures of the surface (first) layer slurries were observed via electron microscopy. Furthermore, the microscopic composition of these shell molds was obtained by EDS, and the osmotic effect of the slurry on the wax patterns at different temperatures was also assessed by the PZ-200 Contact Angle detector. The forming reasons for the surface cracks and holes of thick and large ZTC4 titanium alloy by investment casting were analyzed. The experimental results show that the surface of the shell molds prepared by the surface layer slurry with a low temperature exhibits noticeable damage, which is mainly due to the poor coating performance and the serious expansion and contraction of wax pattern at low temperatures. The second layer shell material (SiO2, Al2O3) immerses into the crack area of the surface layer, contacts and reacts with the molten titanium to form surface cracks and holes in the castings. With the increase of the temperature of surface layer slurry, the damage to the shell surface tends to weaken, and the composition of the shell molds’ surface becomes more uniform with less impurities. The results show that the surface layer slurry at 22 °C is evenly coated on the surface of the wax patterns with appropriate thickness, and there is no surface shell mold rupture caused by sliding slurry after sand leaching. The surface layer slurry temperature is consistent with the wax pattern temperature and the workshop temperature, so there is no damage of the surface layer shell caused by expansion and contraction. Therefore, the shell mold prepared by the surface layer slurry at this temperature has good integrity, isolating the contact between the low inert shell material and the titanium liquid effectively, and the ZTC4 titanium alloy cylinder casting prepared by this shell mold is smooth, without cracks and holes.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01592-1
Micrometer-sized silicon oxide (SiO) anodes encounter challenges in large-scale applications due to significant volume expansion during the alloy/de-alloy process. Herein, an innovative deep eutectic electrolyte derived from succinonitrile is introduced to enhance the cycling stability of SiO anodes. Density functional theory calculations validate a robust ion–dipole interaction between lithium ions (Li+) and succinonitrile (SN). The cosolvent fluoroethylene carbonate (FEC) optimizes the Li+ solvation structure in the SN-based electrolyte with its weakly solvating ability. Molecular dynamics simulations investigate the regulating mechanism of ion–dipole and cation–anion interaction. The unique Li+ solvation structure, enriched with FEC and TFSI−, facilitates the formation of an inorganic–organic composite solid electrolyte interphase on SiO anodes. Micro-CT further detects the inhibiting effect on the SiO volume expansion. As a result, the SiO|LiCoO2 full cells exhibit excellent electrochemical performance in deep eutectic-based electrolytes. This work presents an effective strategy for extending the cycle life of SiO anodes by designing a new SN-based deep eutectic electrolyte.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01580-5
The ability to unlock the interplay between the activity and stability of oxygen reduction reaction (ORR) represents an important endeavor toward creating robust ORR catalysts for efficient fuel cells. Herein, we report an effective strategy to concurrent enhance the activity and stability of ORR catalysts via constructing atomically dispersed Fe–Mn dual-metal sites on N-doped carbon (denoted (FeMn-DA)–N–C) for both anion-exchange membrane fuel cells (AEMFC) and proton exchange membrane fuel cells (PEMFC). The (FeMn-DA)–N–C catalysts possess ample dual-metal atoms consisting of adjacent Fe-N4 and Mn-N4 sites on the carbon surface, yielded via a facile doping-adsorption-pyrolysis route. The introduction of Mn carries several advantageous attributes: increasing the number of active sites, effectively anchoring Fe due to effective electron transfer to Mn (revealed by X-ray absorption spectroscopy and density-functional theory (DFT), thus preventing the aggregation of Fe), and effectively circumventing the occurrence of Fenton reaction, thus reducing the consumption of Fe. The (FeMn-DA)–N–C catalysts showcase half-wave potentials of 0.92 and 0.82 V in 0.1 M KOH and 0.1 M HClO4, respectively, as well as outstanding stability. As manifested by DFT calculations, the introduction of Mn affects the electronic structure of Fe, down-shifts the d-band Fe active center, accelerates the desorption of OH groups, and creates higher limiting potentials. The AEMFC and PEMFC with (FeMn-DA)–N–C as the cathode catalyst display high power densities of 1060 and 746 mW cm−2, respectively, underscoring their promising potential for practical applications. Our study highlights the robustness of designing Fe-containing dual-atom ORR catalysts to promote both activity and stability for energy conversion and storage materials and devices.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01538-7
Gas quenching and vacuum quenching process are widely applied to accelerate solvent volatilization to induce nucleation of perovskites in blade-coating method. In this work, we found these two pre-crystallization processes lead to different order of crystallization dynamics within the perovskite thin film, resulting in the differences of additive distribution. We then tailor-designed an additive molecule named 1,3-bis(4-methoxyphenyl)thiourea to obtain films with fewer defects and holes at the buried interface, and prepared perovskite solar cells with a certified efficiency of 23.75%. Furthermore, this work also demonstrates an efficiency of 20.18% for the large-area perovskite solar module (PSM) with an aperture area of 60.84 cm2. The PSM possesses remarkable continuous operation stability for maximum power point tracking of T90 > 1000 h in ambient air.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2024•DOI: 10.1088/1674-4926/24120026
All-perovskite tandem solar cells (ATSCs) have the potential to surpass the Shockley−Queisser efficiency limit of conventional single-junction devices. However, the performance and stability of mixed tin–lead (Sn–Pb) perovskite solar cells (PSCs), which are crucial components of ATSCs, are much lower than those of lead-based perovskites. The primary challenges include the high crystallization rate of perovskite materials and the susceptibility of Sn2+ oxidation, which leads to rough morphology and unfavorable p-type self-doping. To address these issues, we introduced ethylhydrazine oxalate (EDO) at the perovskite interface, which effectively inhibits the oxidation of Sn2+ and simultaneously enhances the crystallinity of the perovskite. Consequently, the EDO-modified mixed tin−lead PSCs reached a power conversion efficiency (PCE) of 21.96% with high reproducibility. We further achieved a 27.58% efficient ATSCs by using EDO as interfacial passivator in the Sn−Pb PSCs.