Surface Technology (表面技术)•2026•DOI: 10.16490/j.cnki.issn.1001-3660.2026.09.009
Titanium alloys are extensively employed in aerospace, chemical, energy, and biomedical engineering owing to their high specific strength, low density, and excellent corrosion resistance. However, their inherently low surface hardness, poor wear resistance, and high friction coefficient restrict application under high-load, long-life conditions. Nitriding, a thermochemical treatment in which nitrogen atoms diffuse into the surface below the alloy transformation temperature to form a hard nitride layer, serves as an important means to upgrade surface performance. Its effect on fatigue behaviour is twofold: the nitrided layer introduces residual compressive stress and a hardness gradient that suppress crack initiation, while the brittle nitride film, grain coarsening, and interfacial stress concentration created during processing can act as fatigue crack nucleation sites and reduce fatigue life. This review systematically examines the effects of gas nitriding, plasma nitriding, hybrid nitriding, and several novel nitriding techniques on the fatigue response of representative titanium alloys. Conventional gas nitriding and high-temperature plasma nitriding produce a 2–10 µm surface compound layer of brittle TiN and Ti2N with hardness of 1,000–2,000 HV yet very low fracture toughness, which readily develops surface micro-cracks under cyclic loading and serves as the dominant fatigue crack origin. Beneath it, a 20–100 µm thick nitrogen diffusion zone exhibits graded hardness and high residual compression. Low-temperature, short-duration, or energy-controlled processes such as plasma nitriding, low-temperature plasma nitriding, and pulsed laser nitriding tend to form thin compound layers and deep diffusion layers, pushing crack sources to subsurface or internal defects and extending fatigue life. Hybrid treatments (nitriding followed by shot peening or heat treatment) further suppress surface crack initiation by removing the brittle layer, refining grains, and introducing high residual compressive stress, achieving significant fatigue strength improvement. The review clarifies the intrinsic relationship between nitrided layer architecture and fatigue performance, and reveals the micro-mechanisms of fatigue crack initiation and propagation, providing a theoretical basis for optimizing titanium alloy surface treatment processes.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01819-9
The electron localization is considered as a promising approach to optimize electromagnetic waves (EMW) dissipation. However, it is still difficult to realize well-controlled electron localization and elucidate the related EMW loss mechanisms for current researches. In this study, a novel two-dimensional MXene (Ti3C2Tx) nanosheet decorated with Ni nanoclusters (Ni-NC) system to construct an effective electron localization model based on electronic orbital structure is explored. Theoretical simulations and experimental results reveal that the metal–support interaction between Ni-NC and MXene disrupts symmetric electronic environments, leading to enhanced electron localization and dipole polarization. Additionally, Ni-NC generate a strong interfacial electric field, strengthening heterointerface interactions and promoting interfacial polarization. As a result, the optimized material achieves an exceptional reflection loss (RLmin) of −54 dB and a broad effective absorption bandwidth of 6.8 GHz. This study offers critical insights into the in-depth relationship between electron localization and EMW dissipation, providing a pathway for electron localization engineering in functional materials such as semiconductors, spintronics, and catalysis.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2026-41-03-07)
Conventional lignin-based carbons typically have sluggish ion transport and a limited number of active sites, which restrict their performance as electrodes in supercapacitors. A Moiré-like morphology was engineered by the in-situ deposition of lignin carbon onto DVD matrix onto lignin carbon for the fabrication of a photo-assisted supercapacitor (PASC). The Moiré-like structure modulates light propagation across different frequencies by dispersion effects, thereby increasing surface light absorption and improving the electrochemical performance of the PASC. Under illumination, the carbon has a specific capacitance of 253.5 F g−1 at 0.5 A g−1, corresponding to a 35.6% improvement over one without this grating surface (186.9 F g−1). A symmetrical capacitor using this material has an areal capacitance of 58.84 mF cm−2 and an energy density of 4.46 Wh kg−1 at a power density of 365.2 W kg−1, maintaining 85.2% of its initial capacitance after 5000 cycles, thus demonstrating excellent cycling stability. This work suggests a cost-effective strategy to simultaneously improve the light-harvesting ability and capacitive performance of PASCs.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25020034
Robotic computing systems play an important role in enabling intelligent robotic tasks through intelligent algorithms and supporting hardware. In recent years, the evolution of robotic algorithms indicates a roadmap from traditional robotics to hierarchical and end-to-end models. This algorithmic advancement poses a critical challenge in achieving balanced system-wide performance. Therefore, algorithm-hardware co-design has emerged as the primary methodology, which analyzes algorithm behaviors on hardware to identify common computational properties. These properties can motivate algorithm optimization to reduce computational complexity and hardware innovation from architecture to circuit for high performance and high energy efficiency. We then reviewed recent works on robotic and embodied AI algorithms and computing hardware to demonstrate this algorithm-hardware co-design methodology. In the end, we discuss future research opportunities by answering two questions: (1) how to adapt the computing platforms to the rapid evolution of embodied AI algorithms, and (2) how to transform the potential of emerging hardware innovations into end-to-end inference improvements.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.03.004
Gas content serves as a critical indicator for assessing the resource potential of deep coal mines and forecasting coal mine gas outburst risks. However, existing sampling technologies face challenges in maintaining the integrity of gas content within samples and are often constrained by estimation errors inherent in empirical formulas, which results in inaccurate gas content measurements. This study introduces a lightweight, in-situ pressure- and gas-preserved corer designed to collect coal samples under the pressure conditions at the sampling point, effectively preventing gas loss during transfer and significantly improving measurement accuracy. Additionally, a gas migration model for deep coal mines was developed to elucidate gas migration characteristics under pressure-preserved coring conditions. The model offers valuable insights for optimizing coring parameters, demonstrating that both minimizing the coring hole diameter and reducing the pressure difference between the coring-point pressure and the original pore pressure can effectively improve the precision of gas content measurements. Coring tests conducted at an experimental base validated the performance of the corer and its effectiveness in sample collection. Furthermore, successful horizontal coring tests conducted in an underground coal mine roadway demonstrated that the measured gas content using pressure-preserved coring was 34% higher than that obtained through open sampling methods.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.04.001
Pressure-preserved coring technologies are critical for deep-earth resource exploration but are constrained by the inability to achieve multidirectional coring, restricting exploration range while escalating costs and environmental impacts. We developed a multidirectional pressure-preserved coring system based on magnetic control for deep-earth environments up to 5000 m. The system integrates a magnetically controlled method and key pressure-preserved components to ensure precise self-triggering and self-sealing. It is supported by geometric control equations for optimizing structural stability. Their structure was verified and optimized through theoretical and numerical calculations to meet design objectives. To clarify the self-triggering mechanism in complex environments, a dynamic interference model was established, verifying stability during multidirectional coring. The prototype was fabricated, and functional tests confirmed that it met its design objectives. In a 300-meter-deep test inclined well, 10 coring operations were completed with a 100% pressure-preserved success rate, confirming the accuracy of the dynamic interference model analysis. Field trials in a 1970-meter-deep inclined petroleum well, representative of complex environments, demonstrated an in-situ pressure preservation efficiency of 92.18% at 22 MPa. This system innovatively expands the application scope of pressure-preserved coring, providing technical support for efficient and sustainable deep resources exploration and mining.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.08.015
Laser-induced electro-response (LIER), as a new method that complements conventional rock physics testing techniques, is expected to address issues such as unclear mechanisms, model deficiency, inconsistent evaluation parameters, and difficulty in separating multiple coupling factors in shale anisotropy evaluation, and establish a more complete and reliable shale physical property evaluation system. A testing strategy for out-of-plane anisotropy (OPA) was proposed for characterising anisotropy by LIER, where near-infrared (NIR) continuous laser (CL) and nanosecond pulsed laser (PL) were used to irradiate the surface of oblique cut shale, and the transverse LIER of the surface was measured. A LIER detection model is constructed from the laser-thermal effect, residual transverse polarization electric field and thermionic emission transport mechanism, which is strongly relying on laser power, bias voltage, and inclination angle of the measurement direction relative to the bedding plane of shale. For OPA test on the slice of oblique cut shale under CL irradiation, the relationship between the product of LIER simulation parameters and the tilting angle can be described by a cubic function and an impulse function with a maximum value at the threshold angle. In addition, the thermal accumulation and transient thermal effects are induced in the shale under a high-energy short laser pulse irradiation, and the simulation results indicate that there is an exponential relationship between the product of parameters in the LIER model and the tilt angle. Thus, for OPA test under CL and PL irradiations, it is recommended to use the product of parameters as an evaluation index for shale anisotropy. Furthermore, to solve the problem of multiple influencing factors entangled in the exponential term of the LIER model, the tangential LIER measurement was performed on the side of cylindrical shale core, where the provided LIER model effectively presented the anisotropy of tight shale plug, especially the effects of bias voltage and laser power on LIER were relatively separated as independent variables. Finally, the LIER at the end of laser drilling is presented well using the optimized model under a focused ns NIR PL irradiation, indicating that LIER is expected to be a real-time means for characterizing shale anisotropy during laser drilling processes. These results show that the present work is fundamental for the precise evaluation and effective development of anisotropic shale reservoirs, and will drive the advances of LIER in the exploration for shale oil and gas.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01273-z
As a crucial component of intelligent chassis systems, air suspension significantly enhances driver comfort and vehicle stability. To further improve the adaptability of commercial vehicles to complex and variable road conditions, this paper proposes a linear motor active suspension with quasi-zero stiffness (QZS) air spring system. Firstly, a dynamic model of the linear motor active suspension with QZS air spring system is established. Secondly, considering the random uncertainties in the linear motor parameters due to manufacturing and environmental factors, a dynamic model and state equations incorporating these uncertainties are constructed using the polynomial chaos expansion (PCE) method. Then, based on H2 robust control theory and the Kalman filter, a state feedback control law is derived, accounting for the random parameter uncertainties. Finally, simulation and hardware-in-the-loop (HIL) experimental results demonstrate that the PCE-H2 robust controller not only provides better performance in terms of vehicle ride comfort compared to general H2 robust controller but also exhibits higher robustness to the effects of random uncertain parameters, resulting in more stable control performance.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01217-7
The high-temperature oxidation resistance of AISI 321 stainless steel used in solar thermal power heat exchangers determines its service life. In this study, aluminizing and subsequent laser shock peening (LSP) treatments were employed to improve the high-temperature oxidation resistance of AISI 321 stainless steel at 620 °C. These two treatments decreased the oxidation rate of AISI 321 steel. Specifically, the optimal oxidation resistance was observed in aluminized steel before oxidation for 144 h owing to the increased entropy of the LSP-treated specimen. After 144 h, LSP-treated steel achieved the best oxidation resistance because of the formation of a protective α-Al2O3 film. Moreover, the large amount of subgrain boundaries formed on the aluminized layer of the LSP-treated samples could act as short-circuit paths for the outward diffusion of Al, facilitating the rapid nucleation of α-Al2O3. Meanwhile, the aluminized layer could isolate the contact between the oxidation environment and matrix, thereby decreasing the oxidation rate. Furthermore, the minimum oxidation parabolic constant was calculated for LSP-treated steel (6.45787 × 10−14), which was 69.18% and 36.36% that of aluminized and 321 steel, respectively, during the entire oxidation process. Therefore, the combination of aluminizing and LSP treatments can improve the high-temperature oxidation resistance of 321 stainless steel, providing a new idea for its surface treatment to achieve a long service life at high temperatures.
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.