Surface Technology (表面技术)•2026•DOI: 10.16490/j.cnki.issn.1001-3660.2026.11.003
Plasma arc cladding was employed to fabricate NiTi coatings with varying Ni contents (60, 63, 65, 67, and 70 wt.%) on TC4 titanium alloy to enhance surface wear resistance. Microstructural characterization via SEM, OM, and XRD revealed that coatings with 60–67 wt.% Ni were dense and defect-free, whereas the 70 wt.% Ni coating exhibited through-thickness cracks. All coatings exceeded 1.2 mm in thickness and comprised a NiTi toughening phase and Ti2Ni strengthening phase. Increased dilution ratio with higher Ni content reduced actual Ni in the coating, maximizing Ti2Ni fraction (78.6%) in the 67NiTi coating, which achieved a peak hardness of 677.41 HV0.2 (2.05 times that of the TC4 substrate). Tribological testing under 5–20 N loads showed that the average wear rate of all coatings decreased significantly, following a V-shaped trend with Ni content. The 67NiTi coating exhibited the lowest wear rate (2.74×10⁻⁴ mm³/(N·m)) at 20 N, a 65% improvement over the substrate, with wear mechanisms dominated by mild abrasive and adhesive wear. These findings demonstrate that optimized Ni content in plasma-clad NiTi coatings effectively mitigates the poor wear resistance of titanium alloys, offering a viable surface engineering solution for load-bearing applications.
Surface Technology (表面技术)•2026•DOI: 10.16490/j.cnki.issn.1001-3660.2026.12.007
The corrosion resistance of ASTM A182 F347 austenitic stainless steel was enhanced via a two-stage surface engineering protocol: plasma transferred arc deposition of Stellite 6 (STL6) followed by chemical vapor deposition of titanium nitride (TiN). Microstructural characterization confirmed a metallurgically bonded interface with elemental interdiffusion; the STL6 layer exhibited a graded structure from planar/equiaxed grains at the substrate to columnar dendrites and fine equiaxed grains at the surface, with minimal oxide content. Electrochemical testing in 3.5% NaCl solution revealed that the STL6/TiN composite coating reduced the corrosion current density to 0.37 μA/cm², the lowest among the three sample types (F347 substrate, F347-STL6, and F347-STL6-TiN). The composite coating also demonstrated the highest passivation potential (939 mV) and the largest impedance modulus |Z|, indicating superior passive film stability. Post-corrosion analysis showed that the F347 substrate suffered extensive deep pitting, while the STL6 coating exhibited intergranular corrosion with an oxide film. In contrast, the STL6/TiN composite coating displayed only sparse shallow pits. The improved performance is attributed to the formation of a dense Cr₂O₃ passive film on the STL6 layer and the additional barrier provided by the TiN topcoat. These findings offer a viable route for extending the service life of F347 stainless steel in aggressive environments.
Nano Research•2026•DOI: 10.26599/NR.2026.94908775
Flexible sensors have advanced rapidly to achieve skin-like multisensory capabilities, yet their performance is compromised by strain disturbances and multi-parameter interactions, impeding widespread deployment. Here, we report a flexible fibrous device with a patterned cellular structure enabling anti-strain interference, dual-parameter measurement, and static/dynamic detection. The patterned cellular fibrous structure achieves a heterogenous strain distribution that preserves sensing performance under 10% strain. The sensor integrates a piezoresistive component for low-frequency mechanical stimuli and a thermoelectric response to calibrate temperature-induced resistance changes. A hybrid piezoresistive/piezoelectric sensing platform was experimentally implemented for static pressure persistence and high-frequency acoustic excitation from 0 to 300 Hz. The hybrid tactile sensing achieved the highest material identification accuracy of 98.6%. This work provides valuable proposals to resolve practical constraints in flexible sensor applications, compelling advantages for broader wearable integration.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/25100021
This study addresses the integration bottlenecks of display driver integrated circuits (DDICs) arising from external NOR Flash and SRAM by developing an embedded resistive random-access memory (RRAM) on a 40 nm high-voltage CMOS logic platform. Systematic process optimizations in film sputtering and pre-deposition treatment reduce within-wafer resistance uniformity (RSU) of the oxygen-deficient layer (ODL) from 11% to 8% and inter-wafer process stability variation from 23% to below 6%. These improvements elevate the yield of 8 Mb RRAM embedded mass production products from 87% to 98.5%. The RRAM cell achieves a compact area of ~0.0625 mm²/Mb, a 4.8 ns read speed, read disturb immunity of 3 × 10⁸ cycles at 95 °C, 10³ write/erase endurance cycles for 1 Mb cells, and 12.5-year data retention at 125 °C. Post high-temperature operating life (HTOL) testing confirms a stable high/low resistance window. The work provides a reliability assurance framework for mass production of highly integrated, low-power embedded RRAM in display driver ICs.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/26030014
Helical trilayer graphene (HTG) with equal twist angles in the same rotational sense has been predicted to reconstruct into triangular domains with opposite Chern numbers, giving rise to topological boundary modes. This work reviews the direct imaging of the supermoiré landscape in HTG using a scanning single-electron transistor (SET) probe that maps local inverse compressibility dμ/dn. The device comprises an HTG stack encapsulated in hexagonal boron nitride (hBN) with a graphite back gate for electrostatic doping. Linecuts of dμ/dn reveal uniform, weakly dispersive incompressible peaks at moiré filling factors ν = ±1 for a twist angle θ ≈ 1.45°, corresponding to a moiré wavelength λM ≈ 10 nm. These peaks indicate that within individual domains the lattice relaxes into a well-ordered moiré pattern. At larger length scales, the interference between multiple moiré patterns produces a supermoiré modulation with period λSM ≈ 380 nm, forming a mosaic of two inequivalent domain types due to local C2z symmetry breaking. The ratio of experimental to theoretical area Aexp/Ath and the strain parameter ε = 1 − cosθ are extracted, providing quantitative metrics for lattice relaxation. The findings establish SET as a powerful tool for characterizing relaxation and topological order in twisted multilayers, with implications for moiré-based quantum devices.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/26020003
Single-photon sources are indispensable for scalable quantum information technologies, including quantum communication, key distribution, computing, and sensing. Optically active point defects in solid-state materials, known as color centers, are promising candidates for next-generation single-photon emitters (SPEs) due to their atom-like properties, enabling high efficiency, purity, and indistinguishability, while their solid-state nature facilitates integration into scalable quantum photonic devices. Among these, color centers in wide-bandgap semiconductors are particularly attractive for their stable operation at room temperature or higher and wide spectral tunability. Their compatibility with mature semiconductor technology allows direct integration into practical optoelectronic systems. Recent progress has realized defect-based SPEs in diamond, silicon carbide (SiC), silicon nitride (Si3N4), gallium nitride (GaN), aluminum nitride (AlN), hexagonal boron nitride (h-BN), zinc oxide (ZnO), and beta-phase gallium oxide (β-Ga2O3). This mini-review summarizes recent advances in SPEs based on wide-bandgap semiconductors, highlighting their potential for integrated quantum photonic circuits. Key platforms include diamond, hosting nitrogen-vacancy (NV) centers and group-IV impurity-based defects (SiV, GeV, SnV, PbV) with narrow emission lines and nanosecond lifetimes; Si3N4, where native defects in nitrogen-rich films exhibit linearly polarized emission at 567–670 nm with saturated room-temperature single-photon intensity of 5×10^5 cps; and h-BN, with an ultrawide bandgap of ~6 eV, enabling ultrabright, polarized single-photon emission at room temperature, with carbon-related defects (VBCN−) identified as visible quantum emitters. Challenges remain in structural identification and spectral uniformity, but controlled synthesis and strain engineering offer pathways to scalable quantum photonics.
Journal of Central South University•2026•DOI: 10.1007/s11771-026-6266-6
To reduce the subjectivity of conventional instability criteria in deep rock engineering, this study develops an energy-driven criterion grounded in cusp catastrophe theory and embeds it within an improved nonlinear Hoek-Brown (H-B) strength-reduction framework. We derive an explicit algebraic transformation that maps a quartic energy potential to the standard cusp form and introduce the mutation eigenvalue Δ as a physically interpretable measure of proximity to the vanishing of the energy barrier. Building on this, failure staging is diagnosed in practice by the concurrence of a slope mutation in displacement-reduction-factor curves, a threshold jump of total plastic strain-energy increment typically exceeding threefold between adjacent reduction steps, and video-confirmed crack through-connection. Integrating Δ with the nonlinear reduction scheme yields reproducible integral safety factors. Two representative cavern layouts (Model A/B) are validated by scaled physical model tests and companion simulations: global failure occurs at the overload safety factor K=2.33 for Model A and K=2.73 for Model B, with relative deviations from tests (2.4P0 and 2.9P0) of 1.3% and −5.9%, respectively, coinciding with the energy-jump threshold and the multi-evidence diagnosis. Compared with the equivalent Mohr-Coulomb parameter approach, the improved nonlinear scheme produces smaller (more conservative) safety factors by 5.7% and 2.5%, while better matching the observed destabilization process. The framework clarifies the role of Δ as an energy-based instability indicator and offers a practical, verifiable criterion for cavern stability assessment.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01820-2
Developing innovative resource utilization strategies to achieve sustainable recycling of waste-to-fuel is highly desirable, yet the design of cost-effective bifunctional catalysts with dual high-efficiency remains unexplored. While the Fenton-like reaction relies on enhancing peroxymonosulfate (PMS) adsorption and accelerating interfacial electron transfer to improve kinetic rates, CO2 reduction is constrained by sluggish kinetics and competing hydrogen evolution reaction. Herein, we construct a bifunctional catalyst (NiFe-BNC) featuring dual-atomic active sites by introducing boron atoms into a biomass-derived chitosan substrate rich in functional groups, which optimizes atomic coordination environments. In situ experiments and density functional theory calculations reveal that B-atom modulation facilitates carbon substrate defect enrichment, while the charge-tuning effect between metal sites and "boron electron bridge" optimizes PMS adsorption configurations. This synergistic effect facilitates the interfacial electron transfer and enhances the CO2 adsorption capacity of NiFe-BNC by 6 times that of NiFe-NC. The obtained NiFe-BNC exhibits significantly enhanced catalytic activity and selectivity, realizing 99% efficient degradation of volatile organic pollutants in the flowing phase within 2 h and stable mineralization exceeding 60%, while achieving a large current density of 1000 mA cm−2 and CO Faraday efficiency of 98% in the flow electrolytic cell. This work innovatively paves a new way for the rational design of cost-effective functional catalysts to achieve carbon cycle utilization.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01781-6
Designing high-performance electrocatalysts is one of the key challenges in the development of microbial electrochemical hydrogen production. Transition metal-based (TM-based) electrocatalysts are introduced as an astonishing alternative for future catalysts by addressing several disadvantages, like the high cost and low performance of noble metal and metal-free electrocatalysts, respectively. In this critical review, a comprehensive analysis of the major development of all families of TM-based catalysts from the beginning development of microbial electrolysis cells in the last 15 years is presented. Importantly, pivotal design parameters such as selecting efficient synthesis methods based on the type of material, main criteria during each synthesizing method, and the pros and cons of various procedures are highlighted and compared. Moreover, procedures for tuning and tailoring the structures, advanced strategies to promote active sites, and the potential for implementing novel unexplored TM-based hybrid structures suggested. Furthermore, consideration for large-scale application of TM-based catalysts for future mass production, including life cycle assessment, cost assessment, economic analysis, and recently pilot-scale studies were highlighted. Of great importance, the potential of utilizing artificial intelligence and advanced computational methods such as active learning, microkinetic modeling, and physics-informed machine learning in designing high-performance electrodes in successful practices was elucidated. Finally, a conceptual framework for future studies and remaining challenges on different aspects of TM-based electrocatalysts in microbial electrolysis cells is proposed.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01805-1
Titanium dioxide (TiO2) has been an important protective ingredient in mineral-based sunscreens since the 1990s. However, traditional TiO2 nanoparticle formulations have seen little improvement over the past decades and continue to face persistent challenges related to light transmission, biosafety, and visual appearance. Here, we report the discovery of two-dimensional (2D) TiO2, characterized by a micro-sized lateral dimension (~1.6 μm) and atomic-scale thickness, which fundamentally resolves these long-standing issues. The 2D structure enables exceptional light management, achieving 80% visible light transparency—rendering it nearly invisible on the skin—while maintaining UV-blocking performance comparable to unmodified rutile TiO2 nanoparticles. Its larger lateral size results in a two-orders-of-magnitude reduction in skin penetration (0.96 w/w%), significantly enhancing biosafety. Moreover, the unique layered architecture inherently suppresses the generation of reactive oxygen species (ROS) under sunlight exposure, reducing the ROS generation rate by 50-fold compared to traditional TiO2 nanoparticles. Through precise metal element modulation, we further developed the first customizable sunscreen material capable of tuning UV protection ranges and automatically matching diverse skin tones. The 2D TiO2 offers a potentially transformative approach to modern sunscreen formulation, combining superior UV protection, enhanced safety and a natural appearance.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01746-9
Diamond, an ultrawide-bandgap semiconductor material, is promising for solar-blind ultraviolet photodetectors in extreme environments. However, when exposed to high-temperature conditions, diamond photodetector surfaces are unavoidably terminated with oxygen, leading to low photoresponsivity. To address this limitation, single-crystalline diamond nanowires (DNWs) embedded with platinum (Pt) nanoparticles were developed using Pt film deposition followed by chemical vapor deposition (CVD) homoepitaxial growth. During the CVD, Pt nanoparticles (approximately 20 nm in diameter) undergo dewetting and become uniformly embedded within the single-crystalline DNWs. Photodetectors fabricated with these Pt nanoparticles-embedded DNWs achieve a responsivity of 68.5 A W−1 under 220 nm illumination at room temperature, representing an improvement of approximately 2000 times compared to oxygen-terminated bulk diamond devices. Notably, the responsivity further increases with temperature, reaching an exceptional value of 3098.7 A W−1 at 275 °C. This outstanding performance is attributed to the synergistic effects of the one-dimensional nanowire structure, deep-level defects, the localized surface plasmon resonance effects induced by embedded Pt nanoparticles, and localized Schottky junctions at the Pt/diamond interface, which enhance optical absorption, carrier generation, and separation efficiency. These results highlight the significant potential of Pt nanoparticles-embedded DNWs for advanced deep ultraviolet detection in harsh environments, including aerospace, industrial monitoring, and other applications.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01634-8
The advancement of materials has played a pivotal role in the advancement of human civilization, and the emergence of artificial intelligence (AI)-empowered materials science heralds a new era with substantial potential to tackle the escalating challenges related to energy, environment, and biomedical concerns in a sustainable manner. The exploration and development of sustainable materials are poised to assume a critical role in attaining technologically advanced solutions that are environmentally friendly, energy-efficient, and conducive to human well-being. This review provides a comprehensive overview of the current scholarly progress in artificial intelligence-powered materials science and its cutting-edge applications. We anticipate that AI technology will be extensively utilized in material research and development, thereby expediting the growth and implementation of novel materials. AI will serve as a catalyst for materials innovation, and in turn, advancements in materials innovation will further enhance the capabilities of AI and AI-powered materials science. Through the synergistic collaboration between AI and materials science, we stand to realize a future propelled by advanced AI-powered materials.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-05-12)
Silicon anodes are promising for use in lithium-ion batteries. However, their practical application is severely limited by their large volume expansion leading to irreversible material fracture and electrical disconnects. This study proposes a new top-down strategy for preparing microsize porous silicon and introduces polyacrylonitrile (PAN) for a nitrogen-doped carbon coating, which is designed to maintain the internal pore volume and lower the expansion of the anode during lithiation and delithiation. We then explore the effect of temperature on the evolution of the structure of PAN and the electrochemical behavior of the composite electrode. After treatment at 400 °C, the PAN coating retains a high nitrogen content of 11.35 at%, confirming the presence of C―N and C―O bonds that improve the ionic-electronic transport properties. This treatment not only results in a more intact carbon layer structure, but also introduces carbon defects, and produces a material that has remarkable stable cycling even at high rates. When cycled at 4 A g−1, the anode had a specific capacity of 857.6 mAh g−1 even after 200 cycles, demonstrating great potential for high-capacity energy storage applications.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-04-04)
A transformation of naphthalene-based coalescenced mesophase pitch (NMP) to mesophase microbeads was achieved by heating a mixture of NMP and fullerene (C60). This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100% anisotropic bulk mesophase, but rather a reverse transformation. The effects of C60 loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron microscopies. The physical changes in the NMP induced by C60 were characterized by thermogravimetric analysis, Fourier transform infrared spectroscopy, X-ray diffractometry and Raman spectroscopy. The results show that the coalesced NMP can be converted to a spherical type at 300–320 °C with the addition of 5% C60, and the size of the mesophase microbeads increases with increasing temperature. Furthermore, a model is established to explain the unique induction effect of C60 in the transformation process. This work makes the morphological transformation of MP controllable, and provides a new idea for the understanding and research of mesophase pitch.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-04-07)
A toughener that can effectively improve the interlaminar toughness in carbon fiber composites is crucial for various applications. We investigated, the toughening effects of phenolphthalein-based cardo poly (ether sulfone) (PES-C) on E51/ DETDA epoxy and its carbon fiber composites (CFCs). Scanning electron microscopy showed that the phase structures of PES-C/epoxy blends change from island (of dispersed phase) structures to bi-continuous structures (of the matrix) as the PES-C content increased, which is associated with reaction-induced phase separation. After adding 15 phr PES-C, the glass transition temperature (Tg) of the blends increased by 51.5 °C, and the flexural strength, impact strength and fracture toughness of the blends were improved by 41.1%, 186.2% and 42.7%, respectively. These improvements could be attributed to the phase separation structure of the PES-C/epoxy system. A PES-C film was used to improve the mode-II fracture toughness (GIIC) of CFCs. The GIIC value of the 7 μm PES-C film toughened laminate was improved by 80.3% compared to that of the control laminate. The increase in GIIC was attributed to cohesive failure and plastic deformation in the interleaving region.
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.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.03.010
The energy-focusing blast is an innovative and ingenious method to achieve directional fracturing. Understanding its energy regulation mechanism is critical to enhancing its practical effectiveness. This study investigates the energy regulation mechanism and explores the medium-filling effects within the energy-focusing blast by employing theoretical analysis, numerical simulations, and model tests. The findings by theoretical and numerical analysis first reveal that two stages of the fracturing and tensile stage govern the directionally crack propagation, in which the explosion energy in the non-energy-focusing direction is suppressed, compressing the borehole wall, while redirected energy produces tensile stress in the energy-focusing direction, driving the formation of directional cracks. The choice of filling medium significantly affects directional cracking due to its impact on energy distribution and regulation, and key properties such as wave impedance and compressibility of the filling medium are critical. Experimental comparisons using air, sand, and water as filling media further disclose the distinct effects of the medium on energy regulation and directional crack growth of the energy-focusing blast. The maximum shaped-energy coefficients for air, sand, and water are 1.30, 4.41, and 6.12 in the energy-focusing direction, respectively. Meanwhile, the stress attenuation rate of air, sand, and water increases in that order. The higher wave impedance and lower compressibility of water support efficient and uniform energy propagation, which subtly enhances the tensile actions in the focusing direction and intensifies the overall stress impact of the energy-focusing blast. In addition, the stresses in the non-energy-focusing directions decrease as the angle from the energy-focusing direction increases, while the stresses are relatively uniform for both air and water but noticeably uneven for sand; meanwhile, the fractal dimensions of blasting cracks in the case of air, water, and sand are 1.076, 1.068, and 1.112, respectively. Sand as a filling medium leads to increased crack irregularities due to its granularity and heterogeneity. The water medium strikes an optimal balance by promoting the blasting energy transition and optimizing the energy distribution, maintaining the least flatness of the directional crack during energy-focusing blasts.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.07.010
Geological storage and utilization of CO2 involve complex interactions among Thermo-hydro-mechanical-chemical (THMC) coupling processes, which significantly affect storage integrity and efficiency. To address the challenges in accurately simulating these coupled phenomena, this paper systematically reviews recent advances in the mathematical modeling and numerical solution of THMC coupling in CO2 geological storage. The study focuses on the derivation and structure of governing and constitutive equations, the classification and comparative performance of fully coupled, iteratively coupled, and explicitly coupled solution methods, and the modeling of dynamic changes in porosity, permeability, and fracture evolution induced by multi-field interactions. Furthermore, the paper evaluates the capabilities, application scenarios, and limitations of major simulation platforms, including TOUGH, CMG-GEM, and COMSOL. By establishing a comparative framework integrating model formulations and solver strategies, this work clarifies the strengths and gaps of current approaches and contributes to the development of robust, scalable, and mechanism-oriented numerical models for long-term prediction of CO2 behavior in geological formations.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.08.007
Fracability evaluation is critical for efficiently extracting deep shale gas using hydraulic fracturing to avoid blind drilling and fracking. However, existing fracability indices often fail to systematically consider the mechanical behavior of rocks at high temperatures and high pressures (HTHP), coupled with geostress distributions and heterogeneous reservoir characteristics. This critical omission limits their effectiveness in accurately identifying the optimal fracability sweet spots within deep reservoirs. In this work, a fracability evaluation model was proposed based on the combined weighting method, integrating the improved brittleness index, rock strength, geostresses and natural weakness characteristics. A fracability grading evaluation was carried out to determine the potential fracture characteristics corresponding to shales with different fracability levels. Additionally, the fracability index was used for field validation and applications. Results show that rock brittleness and fracability are not equivalent for deep reservoirs. The fracability index is closely related to the pay zones and actual gas production, with a correlation as high as 84%, implying that the proposed method has practical significance in both experimental and field applications. The above findings can provide theoretical guidance for the selection of fracturing candidates and the optimal design of fracturing in deep resource development.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.08.002
The geological tectonic zone is closely related to outburst. Taking the outburst coal bodies in tectonic zones as the research object, combined with DIC and AE monitoring technologies and discrete element simulation, the mechanical response, crack evolution and energy characteristics of coal bodies under different loading rates (impact disturbances) were studied. The results show that both the uniaxial compressive strength and elastic modulus are positively correlated with the loading rate, with a maximum increase in compressive strength of 25.15%. The uniaxial compressive strength is more sensitive to impact disturbances. The failure modes of coal bodies can be divided into the ''slip-crack synchronization (S & C) type'' and the ''crack-first-then-slip (C & S) type''. The slip in tectonic zones is more severe at high loading rates. At low loading rates, shear cracks dominate (60.01%), while the proportion of tensile cracks increases significantly (70.52%) at high loading rates. Additionally, the rate of axial crack growth decreases as the loading rate increases. The peak values of total energy and dissipated energy increase significantly with the loading rate, and the peak energy of the C & S type is greater than that of the S & C type. Energy is preferentially released through the slip of tectonic zones and the propagation of radial cracks.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6065-5
Arching and cracking of joints between slabs have become a problem in China Railway Track System (CRTS) II slab track. The slab track is susceptible to complex temperature variations as a longitudinal continuous structure. Based on measured data, a thermal-mechanical coupling model of the track was established. The deformation characteristics and interfacial damage behavior of joints under typical temperature fields were studied. The findings indicate that the annual extreme temperature range of the slab track, fluctuates from −1.4 to 49.8 ℃. The annual temperature gradient within the vertical depth range of 0 to 0.2 m of the track varies between −16.19 ℃/m and 30.15 ℃/m. The vertical deformation of joints is significantly influenced by high temperatures, with a maximum measured deformation of 0.828 mm. The joint seams are primarily affected by low temperatures, which lead to a separation of 0.9 to 1.0 mm. Conversely, interlayer damage of joints is predominantly influenced by elevated temperatures. In summer, the maximum ratio of interface damage area in the joint can reach up to 95%, with the maximum debonding area ratio can be as high as 84%. The research results can provide help for joint damage regularity and deformation control of CRTS II slab track.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-025-3100-3
Sn-based solder is a widely used interconnection material in the field of electronic packaging; however, the performance requirements for these solders are becoming increasingly demanding owing to the rapid development in this area. In recent years, the addition of micro/nanoreinforcement phases to Sn-based solders has provided a solution to improve the intrinsic properties of the solders. This paper reviews the progress in Sn-based micro/nanoreinforced composite solders over the past decade. The types of reinforcement particles, preparation methods of the composite solders, and strengthening effects on the microstructure, wettability, melting point, mechanical properties, and corrosion resistance under different particle-addition levels are discussed and summarized. The mechanisms of performance enhancement are summarized based on material-strengthening effects such as grain refinement and second-phase dispersion strengthening. In addition, we discuss the current shortcomings of such composite solders and possible future improvements, thereby establishing a theoretical foundation for the future development of Sn-based solders.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01259-x
The study of capture mechanisms with high capture adaptability is the key to improving the efficiency of autonomous underwater vehicle (AUV) retrieval and release. This study aims to develop a capture mechanism for the launch and recovery of AUV and elucidate its kinematic characteristics. Initially, based on the principles of deployment and retraction for AUV capture movements, a design scheme for a novel foldable and deployable capture mechanism is proposed. Subsequently, a detailed analysis of the Degrees of Freedom (DoFs) for enveloping and grasping movements is conducted according to screw theory. Additionally, the structural design of the actuation units for the capture mechanism is thoroughly discussed. Motion screw topology diagram is utilized to construct the kinematic model. On this basis, kinematic simulation verification of the capture mechanism is performed. The theoretical analysis revealed that the DoF for enveloping and grasping movements are 6 and 2, respectively. By appropriately configuring the actuation mechanism, enveloping and grasping movements can be achieved with a single actuation. The displacement and velocity curves of the capture mechanism were smooth, with no interference occurring. Vibration test results validate the reliability of the capture mechanism. The research work provides a valuable reference for the development of novel capture equipment for AUVs.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6060-x
To enhance the recuperation rate of the mine and comply with the stipulations of green mining technology, it is vital to expeditiously recuperate the coal pillar resources in the final stage, thus preventing the considerable squandering of resources. The coal pillar resource of the main roadway and its branch roadway constitutes a significant recovery subject. Its coal pillar shape is regular and possesses a considerable strike distance, facilitating the arrangement of the coal pillar recovery working face (CPRWF) for mining operations. However, for the remaining coal pillars with a thick and hard roof (THF) and multiple tectonic zones, CPRWF encounters challenges in selecting an appropriate layout, managing excessive roof pressure, and predicting mining stress. Aiming at the roadway coal pillar group with THF and multi-structural areas in specific projects, a method of constructing multi-stage CPRWF by one side gob-side entry driving (GSED) and one side roadway reusing is proposed. Through theoretical calculation of roof fracture and numerical simulation verification, combined with field engineering experience and economic analysis, the width of the narrow coal pillar (NCP) in the GSED is determined to be 10 m and the length of the CPRWF is 65 m. Concurrently, the potential safety hazard that the roof will fall asymmetrically and THF is difficult to break during CPRWF mining after GSED is analyzed and verified. Then, a control method involving the pre-cutting of the roof in the reused roadway before mining is proposed. This method has been shown to facilitate the complete collapse of THF, reduce the degree of mine pressure, and facilitate the symmetrical breaking of the roof. Accordingly, a roof-cutting scheme based on a directional drilling rig, bidirectional shaped polyvinyl chloride (PVC) pipe, and emulsion explosive was devised, and the pre-splitting of 8.2 m THF was accomplished. Field observations indicate that directional cracks are evident in the roof, the coal wall is flat during CPRWF mining, and the overall level of mining pressure is within the control range. Therefore, the combined application of GSED and roof-cutting technology for coal pillar recovery has been successfully implemented, thereby providing new insights and engineering references for the construction and pressure relief mining of CPRWF.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-3084-4
The effect of cryogenic treatment (CT) and relaxation annealing on the average nearest neighboring distance of atom (dm), thermodynamic stability, soft magnetic properties, microhardness (Hv), and corrosion resistance of as-spun (Fe0.5Co0.5)75B21Nb4 metallic glasses (MGs) is studied. On the premise of maintaining a fully amorphous phase, appropriate CT and relaxation annealing are conducive to achieving the synergistic effect of increasing saturation magnetization (Ms) and reducing coercivity (Hc). Shallow CT at 213 K optimally enhances the soft magnetic properties of MGs. Given its low activation energy of nucleation and increased activation energy of growth, appropriate CT is beneficial for achieving uniform annealed nanocrystals in amorphous phases. The correlation between free volumes (FVs) and potential energy suggests that the variation in Hc depends on the expansion and contraction behavior of amorphous phases after different CT processes. The fitting formulas of Hc–dm and Ms–Hv correlations demonstrate that soft magnetic parameters have a solid linear relationship with the contents of FVs and degree of dense random packing. Moreover, pitting resistance is improved by appropriate CT and relaxation annealing. This improvement is characterized by the promotion of the stability of the Nb-rich passive film formed during electrochemical corrosion in 3.5wt% NaCl solution.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-025-3115-9
In order to avoid poor machinability caused by excessive hardness under high-silicon conditions in the traditional free-cutting graphited steel, it is important to develop a suitable silicon-saving, aluminum-containing free-cutting steel. This study investigated the microstructure and graphite precipitation behavior of Fe–0.58C–1.0Al (wt%) steels with varying silicon contents (0.55wt%–2.67wt%) after tempering at different temperatures (680°C, 715°C). The tempering structure and the precipitation behavior of graphite and Fe3C in Fe–0.58C–1.0Al steels were systematically studied by optical microscopy (OM), field emission scanning electron microscopy (FESEM), and electron microprobe analyzer (EPMA). The results showed that, at both tempering temperatures, the microstructure of 0.55wt% Si steel is ferrite + granular Fe3C, and the microstructures of 1.38wt%–2.67wt% Si steels are ferrite + petaloid graphite + granular Fe3C. With increasing Si content from 1.38wt% to 2.67wt% at constant tempering temperature, the number density of graphite particles increases, though their average size decreases. Meanwhile, the number density and average size of Fe3C in experimental steels continuously decrease with the increase of Si content. For 0.55wt% Si steel without graphite precipitation, increasing tempering temperature promotes the accumulation and growth of Fe3C. For 1.38wt%–2.67wt% Si steels with graphite precipitation, higher tempering temperature promotes graphite particles growth while accelerating the decomposition and refinement of Fe3C. Furthermore, compared with the experimental steels containing 0.55wt% Si, 1.38wt% Si, and 2.67wt% Si, the 1.89wt% Si steel exhibits significantly lower hardness. Especially, when tempered at 715°C, Fe–0.58C–1.0Al steel with 1.89wt% Si exhibits enhanced graphitization behavior and reduced hardness, which is nearly HV 20 lower than previously reported Fe–0.55C–2.33Si steel.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-2930-8
Carbon materials are widely recognized as highly promising electrode materials for various energy storage system applications. Coal tar residues (CTR), as a type of carbon-rich solid waste with high value-added utilization, are crucially important for the development of a more sustainable world. In this study, we employed a straightforward direct carbonization method within the temperature range of 700–1000°C to convert the worthless solid waste CTR into economically valuable carbon materials as anodes for potassium-ion batteries (PIBs). The effect of carbonization temperature on the microstructure and the potassium ions storage properties of CTR-derived carbons (CTRCs) were systematically explored by structural and morphological characterization, alongside electrochemical performances assessment. Based on the co-regulation between the turbine layers, crystal structure, pore structure, functional groups, and electrical conductivity of CTR-derived carbon carbonized at 900°C (CTRC-900H), the electrode material with high reversible capacity of 265.6 mAh·g−1 at 50 mA·g−1, a desirable cycling stability with 93.8% capacity retention even after 100 cycles, and the remarkable rate performance for PIBs were obtained. Furthermore, cyclic voltammetry (CV) at different scan rates and galvanostatic intermittent titration technique (GITT) have been employed to explore the potassium ions storage mechanism and electrochemical kinetics of CTRCs. Results indicate that the electrode behavior is predominantly governed by surface-induced capacitive processes, particularly under high current densities, with the potassium storage mechanism characterized by an “adsorption–weak intercalation” mechanism. This work highlights the potential of CTR-based carbon as a promising electrode material category suitable for high-performance PIBs electrodes, while also provides valuable insights into the new avenues for the high value-added utilization of CTR.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01591-2
Inspired by the remarkable electromagnetic response capabilities of the complex morphologies and subtle microstructures evolved by natural organisms, this paper delves into the research advancements and future application potential of bionic microwave-absorbing materials (BMAMs). It outlines the significance of achieving high-performance microwave-absorbing materials through ingenious microstructural design and judicious composition selection, while emphasizing the innovative strategies offered by bionic manufacturing. Furthermore, this work meticulously analyzes how inspiration can be drawn from the intricate structures of marine organisms, plants, animals, and non-metallic minerals in nature to devise and develop BMAMs with superior electromagnetic wave absorption properties. Additionally, the paper provides an in-depth exploration of the theoretical underpinnings of BMAMs, particularly the latest breakthroughs in broadband absorption. By incorporating advanced methodologies such as simulation modeling and bionic gradient design, we unravel the scientific principles governing the microwave absorption mechanisms of BMAMs, thereby furnishing a solid theoretical foundation for understanding and optimizing their performance. Ultimately, this review aims to offer valuable insights and inspiration to researchers in related fields, fostering the collective advancement of research on BMAMs.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01566-3
Rehabilitation training is believed to be an effectual strategy that can reduce the risk of dysfunction caused by spasticity. However, achieving visualization rehabilitation training for patients remains clinically challenging. Herein, we propose visual rehabilitation training system including iontronic meta-fabrics with skin-friendly and large matrix features, as well as high-resolution image modules for distribution of human muscle tension. Attributed to the dynamic connection and dissociation of the meta-fabric, the fabric exhibits outstanding tactile sensing properties, such as wide tactile sensing range (0~300 kPa) and high-resolution tactile perception (50 Pa or 0.058%). Meanwhile, thanks to the differential capillary effect, the meta-fabric exhibits a "hitting three birds with one stone" property (dryness wearing experience, long working time and cooling sensing). Based on this, the fabrics can be integrated with garments and advanced data analysis systems to manufacture a series of large matrix structure (40×40, 1600 sensing units) training devices. Significantly, the tunability of piezo-ionic dynamics of the meta-fabric and the programmability of high-resolution imaging modules allow this visualization training strategy extendable to various common disease monitoring. Therefore, we believe that our study overcomes the constraint of standard spasticity rehabilitation training devices in terms of visual display and paves the way for future smart healthcare.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01573-4
Global interest in lithium–sulfur batteries as one of the most promising energy storage technologies has been sparked by their low sulfur cathode cost, high gravimetric, volumetric energy densities, abundant resources, and environmental friendliness. However, their practical application is significantly impeded by several serious issues that arise at the cathode–electrolyte interface, such as interface structure degradation including the uneven deposition of Li2S, unstable cathode–electrolyte interphase (CEI) layer and intermediate polysulfide shuttle effect. Thus, an optimized cathode–electrolyte interface along with optimized electrodes is required for overall improvement. Herein, we comprehensively outline the challenges and corresponding strategies, including electrolyte optimization to create a dense CEI layer, regulating the Li2S deposition pattern, and inhibiting the shuttle effect with regard to the solid–liquid–solid pathway, the transformation from solid–liquid–solid to solid–solid pathway, and solid–solid pathway at the cathode–electrolyte interface. In order to spur more perceptive research and hasten the widespread use of lithium–sulfur batteries, viewpoints on designing a stable interface with a deep comprehension are also put forth.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01495-1
Rechargeable magnesium batteries (RMBs) have been considered a promising “post lithium-ion battery” system to meet the rapidly increasing demand of the emerging electric vehicle and grid energy storage market. However, the sluggish diffusion kinetics of bivalent Mg2+ in the host material, related to the strong Coulomb effect between Mg2+ and host anion lattices, hinders their further development toward practical applications. Defect engineering, regarded as an effective strategy to break through the slow migration puzzle, has been validated in various cathode materials for RMBs. In this review, we first thoroughly understand the intrinsic mechanism of Mg2+ diffusion in cathode materials, from which the key factors affecting ion diffusion are further presented. Then, the positive effects of purposely introduced defects, including vacancy and doping, and the corresponding strategies for introducing various defects are discussed. The applications of defect engineering in cathode materials for RMBs with advanced electrochemical properties are also summarized. Finally, the existing challenges and future perspectives of defect engineering in cathode materials for the overall high-performance RMBs are described.