Journal of Advanced Ceramics•2026•DOI: 10.26599/JAC.2026.9221338
Si3N4 fiber-reinforced ceramic composites are candidate materials for high-temperature wave-transparent applications, yet the relationships among composition, interfacial characteristics, and mechanical performance remain inadequately understood. This study designs three composites—Si3N4f/BN, Si3N4f/SiO2, and Si3N4f/SiO2–BN—and systematically investigates their performances. The reaction between BN precursors and silanol groups in the SiO2 matrix during fabrication of Si3N4f/SiO2–BN enhances chemical compatibility between fiber and matrix, promoting elemental interdiffusion and forming a thicker interfacial diffusion region. Consequently, the interfacial shear strength of Si3N4f/SiO2–BN is 1.86 and 2.35 times that of Si3N4f/BN and Si3N4f/SiO2, respectively. The stronger fiber-matrix bonding in Si3N4f/SiO2–BN suppresses fiber pull-out, whereas weaker bonding in the other two composites permits it. Si3N4f/BN primarily exhibits fiber bundle pull-out, whereas Si3N4f/SiO2 shows long single-fiber pull-out, indicating improved damage tolerance. In contrast, Si3N4f/SiO2–BN displays typical brittle fracture behavior with minimal fiber pull-out and degraded mechanical properties. Excessive interfacial bonding, together with thermal residual stress arising from thermal expansion mismatch between the Si3N4 fiber and the matrix, degrades flexural and compressive strengths. Moreover, this excessive bonding restricts interfacial debonding and fiber pull-out, leading to a brittle fracture mode. Despite differences in interfacial microstructure, all three composites exhibit good dielectric properties. The use of SiO2 and BN matrices effectively reduces both the dielectric constant and the dielectric loss tangent of Si3N4 fiber-reinforced ceramic composites. These findings provide valuable insights into the design of high-temperature wave-transparent composites operated in extreme environments.
Journal of Advanced Ceramics•2026•DOI: 10.26599/JAC.2026.9221334
Carbon fiber-reinforced ultrahigh-temperature ceramic composites (C/UHTCs) based on ZrC–SiC are limited by rapid ablation above 2500 °C under prolonged oxidizing exposure. This study reports C/ZrC–SiC–Cu3Si–Cu interpenetrating composites fabricated by infiltrating a Zr–Si–Cu ternary melt into carbon fiber-reinforced carbon aerogel (C/CA) preforms. The process yields a uniform metal-ceramic matrix via ceramization of the carbon aerogel and in situ precipitation of Cu-containing phases. During oxyacetylene ablation at a surface temperature of 2557–2600 °C for 1200 s, the composite exhibits mass and linear ablation rates of 0.0604 mg·cm−2·s−1 and 0.1808 μm·s−1, respectively, surpassing conventional C/ZrC–SiC and other reported ceramic and ceramic-metal matrix composites under similar conditions. The ablation resistance arises from transpiration cooling via continuous evaporation of dispersed Cu-containing phases, which maintains a surface temperature of approximately 2300 °C under a heat flux of 3.18 MW·m−2, combined with a protective Zr–Si–O glassy layer that inhibits oxygen diffusion and resists mechanical denudation. The composite also demonstrates a flexural strength of 194±7 MPa, a fracture toughness of 11.8±1.2 MPa·m1/2, and a work of fracture of 5315±1232 J·m−2, exceeding most reaction-melt-infiltration-derived C/ZrC–SiC. These properties are attributed to the highly reactive carbon aerogel matrix, a protective PyC interface, optimized interfacial debonding, crack deflection mechanisms, and compressive residual stresses. The combination of active-passive cooling and robust mechanical performance positions this composite as a candidate for structural applications in extreme thermal-mechanical environments.
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.
Chinese Journal of Energetic Materials (含能材料)•2026•DOI: 10.11943/CJEM2026036
To address the issue that resin matrices in carbon fiber reinforced polymer (CFRP) composites cannot participate in explosive energy release when used in warhead casings, an epoxy resin cured compound with both high mechanical properties and high energy-release characteristics was prepared by introducing more easily pyrolyzable polyether segments and fluoropolymer-coated nano-aluminum powder into a high-rigidity epoxy cured compound. The crosslinked network structure, mechanical properties, thermal decomposition characteristics, ignition and combustion characteristics, and energy-release performance were characterized using infrared spectroscopy, quasi-static mechanical testing, TG-DSC, laser ignition testing, and closed bomb testing. Results show that the cured compound has a well-formed crosslinked network, a tensile strength of 72.41 MPa, an initial thermal decomposition temperature of approximately 273 °C, a minimum ignition energy reduced to 1.77 J, a maximum pressure rise rate of 0.407 MPa·ms⁻¹, and a peak pressure increased to 5.935 MPa in closed bomb tests. The introduction of polyether segments and fluoropolymer-coated nano-aluminum enhances the energy release rate and total energy release, making the material a potential resin matrix for CFRP-based reactive structural materials.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/26020035
The discovery of robust ferroelectricity in scandium-doped aluminum nitride (Al1−xScxN) has sparked significant interest due to its compatibility with CMOS fabrication, making it a promising candidate for next-generation non-volatile memories and high-frequency devices. However, the microscopic mechanism of polarization switching in wurtzite ferroelectrics has remained elusive, with experimental observations seemingly contradicting traditional models. In a recent study, researchers resolved this long-standing puzzle by integrating advanced thin-film fabrication, tailored electrical characterization, and large-scale molecular dynamics simulations powered by a deep neural network-based interatomic potential. Their findings reveal that the broad 'transitional regions' observed in scanning transmission electron microscopy (STEM) are not a new nonpolar phase but a projection artifact arising from intrinsically three-dimensional zigzag domain walls. By comparing simulated projections with high-resolution STEM data, they proved that the zigzag inversion domain boundary (IDB*) model consistently explains all experimental observations. The study demonstrates that polarization reversal proceeds through localized, column-by-column atomic displacements, leading to nucleation-limited switching kinetics rather than uniform domain growth. Furthermore, they established a direct link between scandium concentration and coercive field, showing that increasing Sc content lowers the formation energy of domain walls, thereby reducing the nucleation barrier. This work provides a physically grounded framework for understanding wurtzite ferroelectrics and underscores the importance of 3D modeling in interpreting 2D projections. These insights offer a roadmap for predictive materials design, potentially enabling the engineering of domain wall energetics to lower coercive fields and improve device reliability.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2026•DOI: 10.1016/j.ijmst.2026.02.001
Characteristic stresses are critical indicators for microcrack initiation and propagation in rock, a process intrinsically linked to fracture mode. To investigate fracture mode evolution and its feasibility for estimating characteristic stresses, this study conducted uniaxial compression and cyclic loading-unloading tests on fine- and coarse-grained granite with acoustic emission (AE) monitoring. Cyclic target stresses were set within intervals determined by characteristic stresses. Analysis using the AE parameters AF-RA revealed that fracture mode evolution correlates with damage level, and shear microcrack propagation primarily governs macroscopic failure. A characteristic stress estimation method was developed by mapping key points on the shear crack proportion curve: crack closure stress (transition between fluctuating and stable segments), crack initiation stress (inflection point of curve rise), and crack damage stress (slope change point in ascending segment). Comparative analysis with the crack volumetric strain method validated the proposed method. The influences of fracture mode dividing line and statistical interval were discussed, with practical recommendations provided. Compared to conventional AE parameters, the fracture mode proportion exhibits lower sensitivity to AE parameter variations, enabling more reliable identification of characteristic stress points. Furthermore, it directly reflects microcrack evolution behavior, enhancing interpretability and providing a novel perspective for AE-based characteristic stress determination.
Journal of Central South University•2026•DOI: 10.1007/s11771-026-6238-x
In deep underground engineering, rock brittleness is closely associated with rockburst and feasibility of hydraulic fracturing. The loading rate plays a crucial role in determining the severity of rockburst and cuttability. By conducting uniaxial compression tests and single-cycle loading-unloading experiments, the brittle evolution of four types of granite under different loading rates was investigated. During the uniaxial compression process, acoustic emission parameters were used to characterize the crack evolution patterns. Additionally, the macroscopic failure process of the specimens and the post-failure rock fragments were recorded with a high-speed camera, providing multi-scale validation. This study proposes a quantitative brittleness index based on rock fracture energy, and its validity is verified by analyzing the rock failure process and the macroscopic characteristics of rock fragments. This work contributes to advancing research on rock brittleness indices considering the coupling between energy evolution and kinematic mechanisms. The research results indicate that as the loading rate increases from 0.1 mm/min to 5 mm/min, the quantitative evaluation index (Bs) for brittleness increases from 0.17 to 0.28, while the qualitative evaluation indices MF (projectile mass ratio) and l (average lumpiness) increase from 0.3261 to 0.4184 and from 32.96 mm to 38.12 mm, respectively. With increasing loading rates, the brittleness of the rock increases significantly. A series of qualitative and quantitative results, including fractal characteristics and acoustic emission parameters, reveal the crack evolution patterns of granite under different loading rates and confirm the rationality of the brittleness index. This study provides theoretical guidance for practical deep underground engineering applications.
Nano-Micro Letters•2026•DOI: 10.1007/s40820-025-02002-w
The rapid proliferation of microelectronics, coupled with the advent of the internet of things (IoT) era, has created an urgent demand for miniaturized, integrable, and reliable on-chip energy storage systems. All-solid-state thin-film microbatteries (TFMBs), distinguished by their intrinsic safety, compact design, and compatibility with microfabrication techniques, have emerged as promising candidates to power next-generation IoT devices. Nevertheless, in contrast to the well-established development of conventional lithium-ion batteries, the advancement of TFMBs remains at an early stage, facing persistent challenges in materials innovation, interface optimization, and scalable manufacturing. This review critically examines the pivotal role of vapor deposition technologies, including magnetron sputtering, pulsed laser deposition, thermal/electron-beam evaporation, chemical vapor deposition, and atomic layer deposition, in the fabrication and performance modulation of TFMBs. We systematically summarize recent progress in thin-film electrodes and solid-state electrolytes, with particular emphasis on how deposition parameters dictate crystallinity, lattice orientation, and ionic transport in functional layers. Furthermore, we highlight strategies for solid–solid interface engineering, three-dimensional structural design, and multifunctional integration to enhance capacity retention, cycling stability, and interfacial compatibility. Looking ahead, TFMBs are expected to evolve toward multifunctional platforms, exhibiting mechanical flexibility, optical transparency, and hybrid energy-harvesting compatibility, thereby meeting the heterogeneous energy requirements of future IoT ecosystems. Overall, this review provides a comprehensive perspective on vapor-phase-enabled TFMB technologies, delivering both theoretical insights and technological guidelines for the scalable realization of high-performance microscale power sources.
Journal of Central South University•2026•DOI: 10.1007/s11771-025-6108-y
With increasing mining depth in metal mines, the stability of roadway support structures is significantly affected by the complex surrounding rock. This study performs biaxial compression and bolt pull-out experiments on anchorage body specimens with different structural plane dip angles to explore failure mechanisms of anchorage structures and evolutionary law of bolt anchorage force. Results show the dip angle notably impacts the bearing capacity and failure modes of anchorage specimens. Their peak stress exhibits a V-shaped trend: decreasing from 54.80 MPa to 19.65 MPa as dip angles increase from 0° to 45°, with failure mode transitioning from tensile to shear; at 60°, it becomes a tensile-dominated mixed mode. Bolt anchoring significantly enhances bearing capacity (most remarkably by 153.22% at 45°) and changes failure from brittle to ductile. Pull-out tests reveal two failure modes: slip at the bolt-rock interface and bolt fracture. At 45°, bolt fracture occurs under a 14.55 kN peak pull-out load, matching the bolt's yield strength. This failure mechanism involves two key factors: structural plane sliding that shears the bolt, and mechanical interlocking that restricts pull-out, substantially increasing anchorage force. These findings provide insights for stability assessment and support design of roadway structures in complex geological environments.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-025-3153-3
Mg–Zn–Mn alloys have the advantages of low cost, excellent mechanical properties, and high corrosion resistance. To clarify the phase equilibria of Mg–Zn–Mn alloy in the Mg-rich corners, the present work experimentally investigated the phase equilibria in the Mg-rich corner at 300–400°C with equilibrated alloy method using electron probe micro analyzer (EPMA), X-ray diffractometer (XRD), transmission electron microscopy (TEM), and differential scanning calorimeter (DSC). Mn atoms were found to dissolve into MgZn2 to form a ternary solid-solution type compound, in which Mn content can be up to 15.1at% at 400°C. Three-phase equilibrium of α-Mg + MgZn2 + α-Mn and liquid + α-Mg + MgZn2 were confirmed at 400°C. Subsequently, thermodynamic modeling of the Mg–Zn–Mn system was carried out using the CALPHAD method based on the experimental data of this work and literature data. The calculated invariant reaction Liquid + α-Mn → α-Mg + MgZn2 at 430°C shows good agreement with the DSC results. In addition, the results of solidification path calculations explain the microstructure in the as-cast and annealed alloys well. The agreement between the calculated results and experimental data proves the self-consistency of the thermodynamic database, which can provide guidance for the compositional design of Mg–Zn–Mn alloys.
China Foundry•2025•DOI: 10.1007/s41230-025-4072-7
Ceramic cores fabricated by stereolithography exhibit great potential in casting turbine blades. Previous research on ceramic core molding was primarily conducted using vertical printing techniques, which not only resulted in lengthy molding durations but also compromised the mechanical strength. In this work, silica (SiO2) ceramic cores, with fine complex geometric shapes, were fabricated using 65vol.% ceramic slurry by digital light processing (DLP) with different printing angles. Printing angles significantly impact the surface accuracy, shrinkage, printing efficiency of green bodies, as well as the microstructure and mechanical properties of sintered ceramic core samples. As the printing angle in the green body increases, the bonding area decreases, surface roughness on the XY plane worsens, shrinkage in the Z direction becomes more pronounced, and the printing efficiency declines. Similarly, an increase in the printing angle in the sintered body leads to a reduction in bending strength. At a printing angle of 30°, the printing time is reduced to half of that at 90°, which improves the molding efficiency. Meanwhile, the obtained bulk density of 1.71 g·cm-3, open porosity of 24%, and flexural strength of 10.6±1 MPa can meet the requirements of sintered ceramic cores. Therefore, designing and optimizing the printing angles can achieve the balance between shrinkage, printing efficiency, and flexural strength.
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/s40820-025-01794-1
Zinc-ion hybrid supercapacitors (ZHSs) are promising energy storage systems integrating high energy density and high-power density, whereas they are plagued by the poor electrochemical stability and inferior kinetics of zinc anodes. Herein, we report an electrolyte additive-assembled interconnecting molecules–zinc anode interface, realizing highly stable and fast-kinetics zinc anodes for ZHSs. The sulfobutyl groups-grafted β-cyclodextrin (SC) supramolecules as a trace additive in ZnSO4 electrolytes not only adsorb on zinc anodes but also self-assemble into an interconnecting molecule interface benefiting from the mutual attraction between the electron-rich sulfobutyl group and the electron-poor cavity of the adjacent SC supramolecule. The interconnecting molecules–zinc anode interface provides abundant anion-trapping cavities and zincophilic groups to enhance Zn2+ transference number and homogenize Zn2+ deposition sites, and meanwhile, it accelerates the desolvation of hydrated Zn2+ to improve zinc deposition kinetics and inhibit active water molecules from inducing parasitic reactions at the zinc deposition interface, making zinc anodes present superior reversibility with 99.7% Coulombic efficiency, ~30 times increase in operation lifetime and an outstanding cumulative capacity at large current densities. ZHSs with 20,000-cycle life and optimized rate capability are thereby achieved. This work provides an inspiring strategy for designing zinc anode interfaces to promote the development of ZHSs.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01750-z
With the rapid development of electronic detective techniques, there is an urgent need for broadband (from microwave to infrared) stealth of aerospace equipment. However, achieving effective broadband stealth primarily relies on the composite of multi-layer coatings of different materials, while realizing broadband stealth with a single material remains a significant challenge. Herein, we reported a highly compact MXene film with aligned nanosheets through a continuous centrifugal spraying strategy. The film exhibits an exceptional electromagnetic interference shielding effectiveness of 45 dB in gigahertz band (8.2–40 GHz) and 59 dB in terahertz band (0.2–1.6 THz) at a thickness of 2.25 μm, owing to the high conductivity (1.03 × 10^6 S m−1). Moreover, exceptionally high specific shielding effectiveness of 1.545 × 10^6 dB cm2 g−1 has been demonstrated by the film, which is the highest value reported for shielding films. Additionally, the film exhibits an ultra-low infrared emissivity of 0.1 in the wide-range infrared band (2.5–16.0 μm), indicating its excellent infrared stealth performance for day-/nighttime outdoor environments. Moreover, the film demonstrates efficient electrothermal performance, including a high saturated temperature (over 120 °C at 1.0 V), a high heating rate (4.4 °C s−1 at 1.0 V), and a stable and uniform heating distribution. Therefore, this work provides a promising strategy for protecting equipment from multispectral electromagnetic interference and inhibiting infrared detection.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01707-2
Harnessing solar energy to enhance the rechargeable zinc–air batteries (RZABs) performance is a promising avenue toward sustainable energy storage and conversion. Simultaneously enhancing light-absorption capacity and carrier separation efficiency in nanomaterials, as well as improving electrical conductivity and configuration for electrocatalysis, presents a formidable challenge due to inherent trade-offs and interdependencies. Here, we have developed a Janus dual-atom catalyst (JDAC) with bifunctional centers for efficient charge separation and electrocatalytic performance through a bipolar doping strategy. The in situ X-ray absorption near-edge structure and Raman spectroscopy analyses demonstrated that the Ni and Fe centers in JDAC not only function as effective sites for oxygen evolution reaction and oxygen reduction reaction, respectively, but also serve as efficient hole and electron enrichment sites, effectively suppressing photoelectron recombination while enhancing photocurrent generation. As a result, the assembled JDAC-based light-assisted RZABs exhibited extraordinary stability at large current densities. This work delivers pivotal insight to design Janus dual-atom catalysts that efficiently convert solar energy into electric and chemical energy.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01695-3
Ammonia and nitric acid, versatile industrial feedstocks, and burgeoning clean energy vectors hold immense promise for sustainable development. However, Haber–Bosch and Ostwald processes, which generates carbon dioxide as massive by-product, contribute to greenhouse effects and pose environmental challenges. Thus, the pursuit of nitrogen fixation through carbon–neutral pathways under benign conditions is a frontier of scientific topics, with the harnessing of solar energy emerging as an enticing and viable option. This review delves into the refinement strategies for scale-up mild photocatalytic nitrogen fixation, fields ripe with potential for innovation. The narrative is centered on enhancing the intrinsic capabilities of catalysts to surmount current efficiency barriers. Key focus areas include the in-depth exploration of fundamental mechanisms underpinning photocatalytic procedures, rational element selection, and functional planning, state-of-the-art experimental protocols for understanding photo-fixation processes, valid photocatalytic activity evaluation, and the rational design of catalysts. Furthermore, the review offers a suite of forward-looking recommendations aimed at propelling the advancement of mild nitrogen photo-fixation. It scrutinizes the existing challenges and prospects within this burgeoning domain, aspiring to equip researchers with insightful perspectives that can catalyze the evolution of cutting-edge nitrogen fixation methodologies and steer the development of next-generation photocatalytic systems.
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.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2025-6-2)
Because of their excellent low-temperature (−15 to −40 °C) tolerance, sodium-ion batteries are emerging as a complement to lithium-ion batteries for use in extremely cold environments (e.g. high-latitude areas). Hard carbon has a high low-voltage sodium storage capacity and a good initial efficiency, making it one of the most promising anode materials for sodium-ion batteries. It has a complex structure, featuring closed pores, nano graphitic domains, and surface functional groups. The sodium storage sites in hard carbon are reviewed as are the widely accepted sodium storage mechanisms. The main factors contributing to the degradation of the good low-temperature performance in hard carbon anodes are considered, including sodium dendrite formation, low ion diffusion rates, and surface-side reactions. Finally, strategies to increase the low-temperature sodium storage performance of hard carbon anodes are summarized, including bulk structure design, and improvements in interfaces and cut-off voltage. Guidance is provided for improving the low-temperature performance of hard carbon anodes to accelerate the development of these batteries.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-03-09)
Metal chloride-intercalated graphite with excellent conductivity and a large interlayer spacing is highly desired for use in sodium ion batteries. However, halogen vapor is usually indispensable in initiating the intercalation process, which makes equipment design and experiments challenging. In this work, SO2Cl2 was used as a chlorine generator to intensify the intercalation of BiCl3 into graphite (BiCl3-GICs), which avoided the potential risks, such as Cl2 leakage, in traditional methods. The operational efficiency in the experiment was also improved. After the reaction of SO2Cl2, BiCl3, and graphite at 200 °C for 20 h, the synthesized BiCl3-GICs had a large interlayer spacing (1.26 nm) and a high amount of BiCl3 intercalation (42%), which gave SIBs a high specific capacity of 213 mAh g−1 at 1 A g−1 and an excellent rate performance (170 mAh g−1 at 5 A g−1). In-situ Raman spectra revealed that the electronic interaction between graphite and intercalated BiCl3 is weakened during the first discharge, which is favorable for sodium storage. This work broadly enables the increased intercalation of other metal chloride-intercalated graphites, offering possibilities for developing advanced energy storage devices.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25010024
In this work, we design and fabricate AlGaN/GaN-based Schottky barrier diodes (SBDs) on a silicon substrate with a trenched n+-GaN cap layer. With the developed physical models, we find that the n+-GaN cap layer provides more electrons into the AlGaN/GaN channel, which is further confirmed experimentally. When compared with the reference device, this increases the two-dimensional electron gas (2DEG) density by two times and leads to a reduced specific ON-resistance (Ron,sp) of ~2.4 mΩ·cm2. We also adopt the trenched n+-GaN structure such that partial of the n+-GaN is removed by using dry etching process to eliminate the surface electrical conduction when the device is set in the off-state. To suppress the surface defects that are caused by the dry etching process, we also deposit Si3N4 layer prior to the deposition of field plate (FP), and we obtain a reduced leakage current of ~8 × 10−5 A·cm−2 and breakdown voltage (BV) of 876 V. The Baliga’s figure of merit (BFOM) for the proposed structure is increased to ~319 MW·cm−2. Our investigations also find that the pre-deposited Si3N4 layer helps suppress the electron capture and transport processes, which enables the reduced dynamic Ron,sp.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25010026
AlGaN-based LEDs with peak wavelength below 240 nm (far-UVC) pose no significant harm to human health, thus highlighting their broader application potential. While, there is a significant Schottky barrier between the n-electrode and Al-rich n-AlGaN, adversely impeding electron injection and resulting in considerable heat generation. Here, we fabricate V-based electrodes of V/Al/Ti/Au on n-AlGaN with Al content over 80% and investigate the relationship between the metal diffusion and contact properties during the high-temperature annealing process. Experiments reveal that decreasing V thickness in the electrode promotes the diffusion of Al towards the surface of n-AlGaN, which facilitates the formation of VN and thus the increase of local electron concentration, resulting in lower specific contact resistivity. Then, increasing the Al thickness inhibits the diffusion of Au to the n-AlGaN surface, suppressing the rise of Schottky barrier. Experimentally, an optimized n-electrode of V(10 nm)/Al(240 nm)/Ti(40 nm)/Au(50 nm) on n-Al0.81Ga0.19N is obtained, realizing an optimal specific contact resistivity of 7.30 × 10−4 Ω·cm2. Based on the optimal n-electrode preparation scheme for Al-rich n-AlGaN, the work voltage of a far-UVC LED with peak wavelength of 233.5 nm is effectively reduced.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2025•DOI: 10.1016/S1003-6326(25)67034-8
A new technology was proposed to produce ammonium paratungstate (APT) from ammonium metatungstate (AMT) solution by adding (NH4)2CO3 or NH4HCO3 in order to reduce energy consumption and subsequent ammonia recovery burden in crystallization step. Specifically, the effects of ammonium source dosage, temperature, reaction time and stirring speed on crystallization yield, crystalline phase and morphology of APT products were systematically investigated. The results showed that crystallization yields under optional conditions with (NH4)2CO3 and NH4HCO3 as ammonium sources could reach 85.4% and 86.9% with particle size (D50) of 358.8 μm and 441.3 μm, respectively. The crystallization mechanism could be identified as H2W12O40^6- first transforming to H2W12O42^6- and finally to H2W12O42^10-, resulting in the APT precipitation by H2W12O42^10- combining with NH4^+. (NH4)6[H6W12O42]·10H2O played as an intermediate in the crystallization, which could also react with ammonium sources to form APT crystals. Compared to NH3·H2O as an ammonium resource, the corresponding maximum crystallization yields under the same optimal conditions were in order of NH4HCO3>(NH4)2CO3>NH3·H2O, while different ammonium sources affect the morphology of crystallization product.
Atomic Energy Science and Technology (原子能科学技术)•2025•DOI: 10.7538/yzk.2025.youxian.0449
The single-event susceptibility of three silicon carbide (SiC) metal-oxide-semiconductor field-effect transistor (MOSFET) power devices structures (planar, trench and double trench) is researched by the technology computer-aided design (TCAD) simulation. Comparative analysis of the heavy-ion irradiation effects on three device structures reveals distinct susceptibility characteristics. The gate oxide region is identified as the most sensitive position in planar devices, while trench and double-trench structures exhibit no localized sensitive regions. Furthermore, the single-event susceptibility demonstrates strong depth dependence across all three structures, with enhanced vulnerability observed at greater ion penetration depths.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.01.008
To evaluate the accuracy of rockburst tendency classification in coal-bearing sandstone strata, this study conducted uniaxial compression loading and unloading tests on sandstone samples with four distinct grain sizes. The tests involved loading the samples to 60%, 70%, and 80% of their uniaxial compressive strength, followed by unloading and reloading until failure. Key parameters such as the elastic energy index and linear elasticity criteria were derived from these tests. Additionally, rock fragments were collected to calculate their initial ejection kinetic energy, serving as a measure of rockburst tendency. The classification of rockburst tendency was conducted using grading methods based on burst energy index (WET), pre-peak stored elastic energy (PES) and experimental observations. Multi-class classification and regression analyses were applied to machine learning models using experimental data to predict rockburst tendency levels. A comparative analysis of models from two libraries revealed that the Random Forest model achieved the highest accuracy in classification, while the AdaBoost Regressor model excelled in regression predictions. This study highlights that on a laboratory scale, integrating ejection kinetic energy with the unloading ratio, failure load, WET and PES through machine learning offers a highly accurate and reliable approach for determining rockburst tendency levels.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2025•DOI: 10.1016/S1003-6326(25)66948-2
The age-hardening response, mechanical, and corrosion-resistant properties of AA7085 alloys with and without the addition of 0.3 wt.% scandium (Sc) were compared. Using advanced techniques such as aberration-corrected transmission electron microscopy and first-principles calculations, the underlying micromechanisms of Sc microalloying were revealed. Results show that the increase in strength of the AA7085-Sc alloy is mainly attributed to the decreased Al grain size and increased number density of both Al3Sc@Al3(Sc,Zr) core−shell nanoparticles and Sc-containing ηp and GP−ηp nanoprecipitates. Strong strain fields and evident electron transfer from Zr to the neighboring matrix Al atoms exist at the Al3Sc@Al3(Sc,Zr)/Al interface. The Sc doping in GP−ηp and ηp suppresses the GP−ηp → ηp transformation. Modified corrosion resistance of the AA7085-Sc alloy compared with AA7085 alloy is associated with the fine grain boundary precipitates of η phases and narrow precipitation free zone. The reasons of property changes of AA7085 alloy after Sc microalloying are explored based on the multiscale microstructural characterization.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.04.004
Dynamic stress adjustment in deep-buried high geostress hard rock tunnels frequently triggers catastrophic failures such as rockbursts and collapses. While a comprehensive understanding of this process is critical for evaluating surrounding rock stability, its dynamic evolution is often overlooked in engineering practice. This study systematically summarizes a novel classification framework for stress adjustment types—stabilizing (two-zoned), shallow failure (three-zoned), and deep failure (four-zoned)—characterized by distinct stress adjustment stages. A dynamic interpretation technology system is developed based on microseismic monitoring, integrating key microseismic parameters (energy index EI, apparent stress ra, microseismic activity S), seismic source parameter space clustering, and microseismic paths. This approach enables precise identification of evolutionary stages, stress adjustment types, and failure precursors, thereby elucidating the intrinsic linkage between geomechanical processes (stress redistribution) and failure risks. The study establishes criteria and procedures for identifying stress adjustment types and their associated failure risks, which were successfully applied in the Grand Canyon Tunnel of the E-han Highway to detect 50 instances of disaster risks. The findings offer invaluable insights into understanding the evolution process of stress adjustment and pinpointing the disaster risks linked to hard rock in comparable high geostress tunnels.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25050012
High-precision analog-to-digital converters (ADCs) are fundamental components in modern electronic systems, bridging the physical analog world and digital intelligence. They find ubiquitous applications across diverse domains, ranging from the Internet of Things (IoT) to embodied artificial intelligence systems. Achieving high precision necessitates various circuit techniques including high-performance amplifiers and advanced calibration schemes. Furthermore, the evolution of ADC architectures has gradually elevated the significance of peripheral circuitry co-design in optimizing system-level performance metrics. In ISSCC 2025, several techniques are proposed to address these challenges. Amplifiers are typically the main bottleneck in the performance and efficiency of high-precision ADCs. The open-loop charge-transfer amplifier is a promising candidate for its good efficiency. However, conventional ones suffer from poor power supply rejection ratio (PSRR) and common-mode rejection, leading to signal-to-noise ratio (SNR) and robustness challenges. To overcome these problems, Huang et al. proposed a floating charge transfer topology, where the transistors are powered by a floating capacitor. As input and output currents of the capacitor are forced to be equal, supply noise will be forced to circulate within the amplifier. The post-layout simulation shows that the gain variation is limited to ±2.7% over process-voltage-temperature (PVT) variations without any trimming. Fabrication-induced variations, such as inter-stage gain errors and capacitor mismatches, can degrade ADC performance. Researches presented several improvements in dynamic element matching (DEM) and calibration techniques this year to address these challenges. Zhao et al. implemented a 120 dB SNDR 189 dB Schreier FoMs noise-shaping (NS) successive approximation register (SAR) ADC with hybrid mismatch shaping and system-level chopping. The 8b capacitor digital-to-analog converter (CDAC) is segmented into 3 most significant bits (MSBs) with 8 equal capacitors and 5 binary-weighted least significant bits (LSBs). Data weighted averaging (DWA) and mismatch error shaping (MES) are applied to the MSBs and LSBs respectively, increasing the quantizer resolution effectively. System-level chopping is adopted to eliminate the offset, 1/f noise, and the VCM induced CDAC nonlinearity simultaneously. In Ref. [4], Gao et al. extended the MES to multi-stage applications and presented a 93.3 dB-SNDR 180.4 dB-FoMs calibration-free NS pipelined-SAR ADC with cross-stage gain-mismatch-error-shaping technique. An extra capacitor CFB is added in the 1st-stage CDAC to serve as the mismatch reference of the 2nd-stage CDAC and residue amplifier. By involving CFB in the MES procedure of the 1st stage, both the capacitor mismatch of two stages and the gain error can be shaped and eliminated. This work further solved the MES saturation problem by pre-comparison during sampling. Sampling noise is a critical problem for discrete-time (DT) ADCs. Wang et al. proposed a single-amplification-based kT/C noise cancellation technique, and implemented a 92.5dB-SNDR 184.8dB-FoMs incremental NS pipeline ADC with a dither-based background gain error calibration scheme. In the design, single amplifier is used for the multi-cycle kT/C noise-cancelled conversion. This is enabled by moving the noise-cancellation amplifier out of the noise-shaping loop and utilizing dual CNC in a ping-pong fashion. By injecting dither in both sampling and residue amplification phases, the calibration engine can expand the kT/C noise-limited SNR beyond 100 dB with only 0.8 pF sampling capacitance. Another technique to solve the gain error problem is proposed in Ref. [6]. Chen et al. exploited the metastability and proposed a fast and robust background calibration technique in a 79.4dB-SNDR 176.3dB-FoMs pipelined-SAR ADC. This work adopts an improved version of the opportunistic PN-injection-based calibration. By monitoring the probability of metastability and adjusting the comparator delay, the metastability can be better controlled, leading to fast and robust calibration without affecting ADC’s normal conversion. In addition, the offset is cancelled by equalizing the likelihood of the second-stage MSB resolving to 1 or 0. ADCs are not standalone blocks—their peripheral circuits, together with the ADC core, have a significant impact on system-level performance. ISSCC 2025 showcased some pioneering co-design architecture that optimize ADC cores alongside peripheral circuits including input buffers and filters. In Ref. [8], Luan et al. focused on the input stage and proposed a gain-embedded bootstrapped sampler. The sampler is a PMOS transistor whose gate and drain are connected to the feedback signal through two CDACs. The input signal connects to the source, making the transistor work as a Gm cell. Since the sampler only draws a small current that relates to the residue signal, the driving requirements are relaxed. In addition, this structure also features lower sampling noise, good linearity and weaker kickback. In Ref. [9], Ye et al. proposed a continuous-time correlated level shifting (CLS) technique that realized a rail-to-rail high-linearity input buffer. An extra CLS capacitor and level shift phase are added compared to conventional CLS. After sampling the coarse version of input, the two CLS capacitors are connected in series at the output of the amplifier one by one. Therefore, the output swing can be extended and the equivalent open-loop gain can be boosted at the end of the second level shift phase, leading to a rail-to-rail linear operation. In Ref. [6], Chen et al. also put efforts into the innovation of the input buffer and proposed a split coarse-fine input-buffer-sampling scheme. The input buffer is split into a low-power push−pull source follower as the coarse buffer and a high-power cascoded one as the fine buffer. During sampling, the coarse buffer first charges its loading capacitor CS,C to a value close to the input signal, and then, the input directly connects to CS,C, resulting in a small differential voltage to the fine buffer. Finally, a coarse ADC quantizes and [truncated]
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.07.003
The tensile strength of rocks under real-time high-temperatures is essential for enhanced geothermal system development. However, the complex occurrence and deep burial of hot dry rocks limit the quantity and quality of standard samples for mechanical testing. This paper compared the tensile strengths obtained from Brazilian splitting tests on standard samples (with a diameter of 50 mm and a thickness of 25 mm) and micro-tensile samples (with a diameter of 50 mm and a thickness of 25 mm) of two types of granites. A power-law size effect model was established between the two sets of data, validating the reliability of the testing method. Then, miniature Brazilian splitting under real-time high-temperature, combined with X-ray diffraction (XRD) revealed temperature-dependent strength variations and microstructural damage mechanisms. The results show that: (1) The comparison error between the tensile strength obtained by the fitting model and that of the measured standard samples was less than 6%. (2) In real-time high-temperature conditions, tensile strength of granite exhibited non-monotonic behavior, increasing below 300 °C before decreasing, with sharp declines at 400–500 °C and 600–700 °C. (3) Thermal damage stems from the differences in the high-temperature behavior of minerals, including dehydration, phase transformation, and differential expansion.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.08.011
To study the relationships between rock mass crack propagation and damage and confining pressure under blast impact loading during straight-hole cut blasting, tests were performed under different confining pressures. Then, the characteristics of rock mass crack development were analyzed, and the pressure resistance values of core samples before and after blasting were compared to study the trends of rock mass damage. Moreover, a three-dimensional numerical simulation model was established by LS-DYNA to analyze the stress wave propagation, cavity shape and crack propagation characteristics under different confining pressures. The propagation of rock blasting cracks is negatively correlated with the confining pressure. The greater the confining pressure, the shorter the crack development time. Additionally, the crack width is reduced from 0.4–1.7 to 0.04–1.4 mm, and the length is shortened from 280 to 120 mm. A comparison of the compressive strength revealed that blasting reduces the compressive strength of the rock mass. The greater the distance from the explosion source, the lower the degree of strength attenuation. An increase in the confining pressure can inhibit strength attenuation. Numerical simulations revealed that under the same confining pressure, the stress first peaks at the bottom of the blast hole. The greater the confining pressure, the longer the stress peak duration, the smaller the cavity volume, and the shorter the crack propagation length and depth. Under a confining pressure of 4 MPa, the longest crack was only 154.5 mm in length and 102 mm in depth. The research results provide a scientific basis for controlling rock damage and optimizing design in the excavation of deep rock roadways by blasting.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.09.004
The safe and efficient development of geothermal energy is a key driver of the energy revolution and environmental governance in this century. To understand the effect of water driving pressure on drilling safety and hydraulic fracturing efficiency during the development of geothermal energy under varying reservoir temperatures, dynamic compression tests were conducted on granite samples subjected to thermal treatment (25, 100, 200, 300, 400 and 600 °C) and subsequent forced water absorption (0, 4, 8, 12 MPa) using a split Hopkinson pressure bar system. The results indicate that a higher water driving pressure exacerbates the deterioration of dynamic compressive strength with increasing temperature, while it enhances the rate dependence of dynamic compressive strength, except at 600 °C. The dynamic increase factor (DIF) of dynamic compressive strength vs. strain rate is determined by both temperature and water driving pressure. A prediction model for the deterioration of dynamic compressive strength considering reservoir temperature and water driving pressure is proposed for geothermal reservoirs. While the splitting failure of samples remains unchanged, crack density increases with increasing temperature and water driving pressure, exhibiting multiscale failure cracks parallel to the loading direction. The structure effective strength model, the wing-crack propagation model, the effect of pore water pressure on dynamic stress intensity factor, and the dynamic response of forced absorbed water can collectively reveal the response mechanisms of dynamic strength. Based on the experimental findings, implications for safe and productive geothermal energy development are discussed, with particular attention to the effect of drilling fluid leakage on wellbore stability and the impact of residual fracturing fluid after backflow on repeated fracturing. This study has important reference value for understanding dynamic wellbore stability under drilling disturbance loads and for the design of repeated dynamic hydraulic fracturing schemes in geothermal energy development.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.09.013
As underground mining advances to greater depths, cemented paste backfill (CPB) is increasingly subjected to complex thermo-mechanical loading conditions, including multiaxial stress states and elevated temperatures. This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses, along with in-situ temperatures, on the mechanical behavior and pore water pressure (PWP) evolution of CPB. Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing, replicating in-situ stress paths and thermal profiles typical of deep mine environments. Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing, reducing porosity, and increasing frictional resistance. Elevated temperatures independently accelerate early-age cement hydration, further improving bond strength and stiffness. When combined, multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength (UCS) and elastic modulus, as confirmed by two-way ANOVA and synergy index analysis. PWP responses were also highly sensitive to thermo-mechanical conditions. The evolution of positive and negative PWP was governed by the interplay of thermal expansion, hydration-induced desaturation, and mechanical compaction. Multiaxial stress amplified early positive PWP and delayed its dissipation, whereas elevated temperature accelerated hydration and reduced pore pressure, leading to enhanced suction at later ages. A transient “stress-induced resaturation” effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures. These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design, binder content, and barricade stability in deep mining applications.
China Foundry•2025•DOI: 10.1007/s41230-025-4199-6
An Al2O3/Al-Cu-Mn composite was fabricated using a combination of ball milling and liquid-solid reaction, with a nominal composition of Al-4Cu-0.5Mn-2.8γ-Al2O3. The composite contains reinforcement particles, including nano-sized θ’ and T(Al20Cu2Mn3) particles after T6 heat treatment, as well as in-situ synthesized nano-sized γ-Al2O3 particles. Tensile tests of the Al-4Cu-0.5Mn-2.8γ-Al2O3 composite and the Al-4Cu-0.5Mn base alloy after T6 treatment were carried out at room temperature and elevated temperatures (200 °C, 300 °C, and 400 °C). Compared with the base alloy, the yield strength of the Al-4Cu-0.5Mn-2.8γ-Al2O3 composite after T6 treatment increases significantly from 187 MPa to 263 MPa at room temperature. Simultaneously, at elevated temperatures, the yield strength is also enhanced, with a yield strength of 52 MPa at 400 °C for this composite. The in-situ fabricated γ-Al2O3 particles, mainly distributed along the grain boundaries, are supposed to play the main strengthening role, especially at high temperatures. This work acts as a reference for designing composites for high-temperature applications.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-3066-6
The rapid growth of semiconductor, photovoltaic, and other emerging industries has led to a sharp increase in the demand for high-purity quartz in China, particularly 4N5-grade (99.995% pure SiO2). However, heavy reliance on imported high-purity quartz poses a significant risk to the security of key national strategic industries. To address this challenge, China is focusing on identifying domestic sources of high-purity quartz and developing efficient evaluation methods. This study investigates the inclusion content in three types of quartz: pegmatite, vein quartz, and white granite. A grading system based on the transmittance of quartz grains was established by analyzing the number of inclusions. Five quartz ore samples from different regions were purified, and the resulting concentrates were analyzed using inductively coupled plasma mass spectrometry (ICP-MS). The relationships among the inclusion content of raw quartz, impurity composition of purified quartz, and quality of sintered fused quartz products were examined. The findings demonstrate that quartz with fewer inclusions results in lower impurity levels after purification, higher SiO2 purity, and more translucent glass, as confirmed by firing tests. Herein, this study establishes a clear connection between quartz inclusions and the overall quality of high-purity quartz. The proposed approach enables the rapid assessment of quartz deposit quality by identifying inclusions, offering a practical and efficient method for locating high-quality quartz resources.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01257-z
The existing research on the path following of the autonomous electric vehicle (AEV) mainly focuses on the path planning and the kinematic control. However, the dynamic control with the state observation and the communication delay is usually ignored, so the path following performance of the AEV cannot be ensured. This article studies the observer-based path following control strategy for the AEV with the communication delay via a robust explicit model predictive control approach. Firstly, a projected interval unscented Kalman filter is proposed to observe the vehicle sideslip angle and yaw rate. The observer considers the state constraints during the observation process, and the robustness of the observer is also considered. Secondly, an explicit model predictive control is designed to reduce the computational complexity. Thirdly, considering the efficiency of the information transmission, the influence of the communication delay is considered when designing the observer-based path following control strategy. Finally, the numerical simulation and the hardware-in-the-loop test are conducted to examine the effectiveness and practicability of the proposed strategy.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6059-3
Microseismic (MS) source location plays an important role in MS monitoring. This paper proposes a MS source location method based on particle swarm optimization (PSO) and multi-sensor arrays, where a free weight joints the P-wave first arrival data. This method adaptively adjusts the preference for “superior” arrays and leverages “inferior” arrays to escape local optima, thereby improving the location accuracy. The effectiveness and stability of this method were validated through synthetic tests, pencil-lead break (PLB) experiments, and mining engineering applications. Specifically, for synthetic tests with 1 µs Gaussian noise and 100 µs large noise in rock samples, the location error of the multi-sensor arrays jointed location method is only 0.30 cm, which improves location accuracy by 97.51% compared to that using a single sensor array. The average location error of PLB events on three surfaces of a rock sample is reduced by 48.95%, 26.40%, and 55.84%, respectively. For mine blast event tests, the average location error of the dual sensor arrays jointed method is 62.74 m, 54.32% and 14.29% lower than that using only sensor arrays 1 and 2, respectively. In summary, the proposed multi-sensor arrays jointed location method demonstrates good noise resistance, stability, and accuracy, providing a compelling new solution for MS location in relevant mining scenarios.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01315-6
Short-arc machining is a novel electrical discharge machining method that utilizes high-energy arc discharge as the energy carrier. Due to its low cost and high processing efficiency, it has been widely applied in the efficient processing of superalloys. To address the challenges of efficient and high-precision processing of superalloys, a processing method combining short-arc machining with precision milling is employed. Advanced material characterization techniques such as electron backscatter diffraction (EBSD) are utilized to analyze the physical properties of the recast layer and surface crystal characteristics. High-temperature low-cycle fatigue life tests are conducted to investigate the correlation between fatigue life and typical surface integrity parameters (surface roughness, residual stress), as well as crystallographic parameters (grain size, grain orientation spread, geometrically necessary dislocations). Processing parameter optimization is achieved with fatigue life as the target. The results indicate that at high temperatures during short-arc machining, the surface material underwent recrystallisation to form a recast layer with a grain size reduction of 85.5% and a heat affected layer depth of over 400 μm. The trends in fatigue life are consistent with changes in residual stress, grain orientation spread and geometrically necessary dislocations. Selecting a larger axial depth of cut and lower feed per tooth is advantageous for achieving a higher fatigue life. The proposed research provides an instruction for high efficient precision machining of superalloys.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01206-w
Predictive cruise control (PCC) is an intelligence-assisted control technology that can significantly improve the overall performance of a vehicle by using road and traffic information in advance. With the continuous development of cloud control platforms (CCPs) and telematics boxes (T-boxes), cloud-based predictive cruise control (CPCC) systems are considered an effective solution to the problems of map update difficulties and insufficient computing power on the vehicle side. In this study, a vehicle-cloud hierarchical control architecture for PCC is designed based on a CCP and T-box. This architecture utilizes waypoint structures for hierarchical and dynamic cooperative inter-triggering, enabling rolling optimization of the system and commanding parsing at the vehicle end. This approach significantly improves the anti-interference capability and resolution efficiency of the system. On the CCP side, a predictive fuel-saving speed-planning (PFSP) algorithm that considers the throttle input, speed variations, and time efficiency based on the waypoint structure is proposed. It features a forward optimization search without requiring weight adjustments, demonstrating robust applicability to various road conditions and vehicles equipped with constant cruise (CC) system. On the vehicle-side T-box, based on the reference control sequence with the global navigation satellite system position, the recommended speed is analyzed and controlled using the acute angle principle. Through analyzing the differences of the PFSP algorithm compared to dynamic programming (DP) and Model predictive control (MPC) algorithms under uphill and downhill conditions, the results show that the PFSP achieves good energy-saving performance compared to CC without exhibiting significant speed fluctuations, demonstrating strong adaptability to the CC system. Finally, by building an experimental platform and running field tests over a total of 2000 km, we verified the effectiveness and stability of the CPCC system and proved the fuel-saving performance of the proposed PFSP algorithm. The results showed that the CPCC system equipped with the PFSP algorithm achieved an average fuel-saving rate of 2.05%–4.39% compared to CC.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01312-9
The intricate relationship between origami and mechanism underscores the fertile ground for innovation, which is particularly evident in the construction theory of thick-panel origami. Despite its potential, thick panel origami remains relatively unexplored in the context of single-loop metamorphic mechanisms. Drawing inspiration from thick-panel origami, particularly Miura origami, this study proposes a pioneering single-loop 6R multiple metamorphic mechanism. Through rigorous mathematical modeling (including the construction and resolution of the D-H closed-loop equation) and leveraging advanced analytical tools such as the screw theory and Lie theory, this study meticulously elucidates the planar, spherical, and Bennett motion branches of the mechanism. Furthermore, it delineates all the three bifurcation points between the motion branches, thereby providing a comprehensive understanding of the kinematic behavior of the mechanism. A metamorphic network can be constructed by applying several single-loop mechanisms to a symmetrical layout. Owing to its metamorphic properties, this network can act as a structural backbone for deployable antennas, aerospace shelters, and morphing wing units, thereby enabling a single mechanism to achieve multiple folding configurations. This paper not only introduces innovative metamorphic mechanisms but also suggests a promising method for uncovering and designing metamorphic mechanisms by developing new mechanisms from thick-panel origami.
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/s11771-025-6077-1
With the continuous expansion of deep underground engineering and the growing demand for safety monitoring, microseismic monitoring has become a core method for early warning of rock mass fracture and engineering stability assessment. To address problems in existing methods, such as low data processing efficiency and poor phase recognition accuracy under low signal-to-noise ratio (SNR) conditions in complex geological environments, this study proposes an intelligent phase picking model based on ResUNet. The model integrates the residual learning mechanism of ResNet with the multi-scale feature extraction capability of UNet, effectively mitigating the vanishing gradient problem in deep networks. It also achieves cross-layer fusion of shallow detail features and deep semantic features through skip connections in the encoder-decoder structure. Compared with traditional short-time average/long-time average (STA/LTA) algorithms and advanced neural network models such as PhaseNet and EQTransformer, ResUNet shows superior performance in picking P- and S-wave phases. The model was trained on 400000 labeled microseismic signals from the Stanford earthquake dataset (STEAD) and was successfully applied to the Shizhuyuan polymetallic mine in Hunan Province, China. The results demonstrate that ResUNet achieves high picking accuracy and robustness in complex geological conditions, offering reliable technical support for early warning of disasters such as rockburst in deep underground engineering.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6043-y
The phase transformation of galena in H2SO4 −Fe2(SO4)3 system under oxygen pressure was investigated. Results indicated that the critical conditions for the phase transformation of galena into lead jarosite (Pb-J) were 130 ℃, 30 g/L H2SO4, 15 g/L Fe3+, and an oxygen partial pressure of 0.4 MPa. Furthermore, increased Fe3+ concentration and oxygen partial pressure did not enhance jarosite formation. Conversely, lowering the temperature and increasing the H2SO4 concentration facilitated PbSO4 formation and inhibited its further conversion to Pb-J. Additionally, the effects of potassium sulfate, sodium sulfate, and high concentrations of zinc sulfate on the phase transformation of galena were examined through leaching tests, XRD, SEM-EDS, and FT-IR analyses. All three sulfates inhibited the conversion of galena to Pb-J. Among these, potassium sulfate prevented Pb-J formation and converted it more thoroughly into potassium jarosite. However, high concentrations of zinc sulfate facilitated the crystallization of both PbSO4 and Pb-J, which altered the morphology of the product. Zinc ions coprecipitated with Pb-J, thereby integrating into the product.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-2977-6
Large-scale underground projects need accurate in-situ stress information, and the acoustic emission (AE) Kaiser effect method currently offers lower costs and streamlined procedures. In this method, the accuracy and speed of Kaiser point identification are important. Thus, this study aims to integrate chaos theory and machine learning for accurately and quickly identifying Kaiser points. An intelligent model of the identification of AE partitioned areas was established by phase space reconstruction (PSR), genetic algorithm (GA), and support vector machine (SVM). Then, the plots of model classification results were made to identify Kaiser points. We refer to this method of identifying Kaiser points as the partitioning plot method based on PSR–GA–SVM (PPPGS). The PSR–GA–SVM model demonstrated outstanding performance, which achieved a 94.37% accuracy rate on the test set, with other evaluation metrics also indicating exceptional performance. The PPPGS identified Kaiser points similar to the tangent-intersection method with greater accuracy. Furthermore, in the feature importance score of the classification model, the fractal dimension extracted by PSR ranked second after accumulated AE count, which confirmed its importance and reliability as a classification feature. The PPPGS was applied to in-situ stress measurement at a phosphate mine in Guizhou Weng’an, China, to validate its practicability, where it demonstrated good performance.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-2945-1
At present, the emerging solid-phase friction-based additive manufacturing technology, including friction rolling additive manufacturing (FRAM), can only manufacture simple single-pass components. In this study, multi-layer multi-pass FRAM-deposited aluminum alloy samples were successfully prepared using a non-shoulder tool head. The material flow behavior and microstructure of the overlapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum alloys. The results showed that a mechanical interlocking structure was formed between the adjacent layers and the adjacent passes in the overlapped center area. Repeated friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone, which made the recrystallization degree in the left and right edge zones of the overlapped zone the highest, followed by the overlapped center zone and the non-overlapped zone. The tensile strength of the overlapped zone exceeded 90% of that of the single-pass deposition sample. It is proved that although there are uneven grooves on the surface of the overlapping area during multi-layer and multi-pass deposition, they can be filled by the flow of materials during the deposition of the next layer, thus ensuring the dense microstructure and excellent mechanical properties of the overlapping area. The multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.
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.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2024•DOI: 10.1016/j.ijmst.2024.12.011
As mining activities expand deeper, deep high-temperature formations seriously threaten the future safe exploitation, while deep geothermal energy has great potential for development. Combining the formation cooling and geothermal mining in mines to establish a thermos-hydraulic coupling numerical model for fractured formation. The study investigates the formation heat transfer behaviour, heat recovery performance and thermal economic benefits influenced during the life cycle. The results show that the accumulation of cold energy during the cold storage phase induces a decline in formation temperature. The heat recovery phase is determined by the extent of the initial cold domain, which contracts inward from the edge and decelerates the heat recovery rate gradually. With groundwater velocity increases, the thermal regulation efficiency gradually increases, the production temperature decreases, while the effective radius and thermal power increase first and then decrease. The injected volume and temperature significantly affect, with higher injection temperatures slowing thermal recovery, and the thermal regulation efficiency is more sensitive to changes in formation permeability and thermal conductivity. The heat extraction performance is positively correlated with all factors. The levelized cost of electricity is estimated at 0.1203 $/(kW h) during the cold storage. During the heat recovery, annual profit is primarily driven by cooling benefits.