Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2026•DOI: 10.1016/S1003-6326(26)67059-8
A multi-stage heat treatment (MSHT) strategy, comprising a high-temperature short-duration water quench (WQ) followed by low-temperature long-duration furnace cooling (FC), was applied to a near-alpha Ti-0.3Mo-0.8Ni-2Al-1.5Zr alloy to overcome the strength-ductility tradeoff. The WQ state produced lath nano-martensite alpha-prime, residual beta-prime, and equiaxed recrystallized alpha. Subsequent FC decomposition transformed alpha-prime/beta-prime into homogeneously dispersed nano-scale alpha+beta precipitates, while equiaxed alpha coarsened via grain boundary migration. The WQ condition exhibited an ultimate tensile strength (sigma_UTS) of 610 MPa and elongation to failure (epsilon_f) of 18.2%. The WQ+400FC condition achieved a peak sigma_UTS of 791.5 MPa with epsilon_f = 16.7%, yielding a strength-ductility product (sigma_UTS * epsilon_f) of 13.2 GPa*%, a 19% improvement over the WQ state. Texture analysis revealed a duplex texture in WQ: weak {0001}//Z0 and strong {0110}//Y0, inherited after FC. The 400FC sample showed the highest lattice strain inhomogeneity, with peak kernel average misorientation (KAM) of 1.5 degrees and grain orientation spread (GOS) of 0.96 degrees, correlating with the excellent sigma_UTS. Non-basal slip systems exhibited higher Schmid factor (SF) values after heat treatment, contributing to ductility. Burgers orientation relationship (BOR) reconstruction confirmed variant selection during beta to alpha-prime transformation, with only four predominant alpha-prime variants instead of the twelve theoretically possible.
Transactions of Nonferrous Metals Society of China (中国有色金属学报)•2026•DOI: 10.1016/S1003-6326(26)67064-1
The influence of thickness and annealing treatment on the microstructure and soft magnetic properties of Fe−Si−B−Cu−Nb alloy (Finemet) thin films prepared by magnetron sputtering was systematically investigated. As-deposited films are amorphous; coercivity decreases and saturation magnetization increases with thickness, stabilizing at 400 nm. Annealing at 773 K and 873 K precipitates nanocrystalline α-Fe within the amorphous matrix. Exchange coupling between nanocrystals and the amorphous matrix enhances soft magnetic properties. Rapid thermal processing (RTP) controls the heating rate to minimize grain size and optimize nanocrystal distribution, achieving low coercivity and high saturation magnetization without additional transition metals. The film annealed at 873 K for 30 min with a heating rate of 25 K/s exhibits a coercivity of 0.8 A/m and saturation magnetization of 1.45 T. Compared to the 773 K annealed film, the 873 K annealed film shows significantly lower coercivity due to smaller precipitated nanocrystals. RTP with controlled thermal gradient enables even smaller nanocrystals, further enhancing magnetic properties. These results demonstrate that RTP-treated Finemet films are promising for high-frequency, miniaturized, and integrated electronic devices.
Chinese Journal of Energetic Materials (含能材料)•2026•DOI: 10.11943/CJEM2026054
The solubility of β-octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (β-HMX) in dimethyl sulfoxide (DMSO)–methanol, DMSO–ethanol, and DMSO–n-propanol binary solvent mixtures was measured using a static method over the temperature range of 293.15–343.15 K at atmospheric pressure. The mole fraction of alcohol in the mixed solvent was varied from 0 to 1. The experimental solubility data were correlated with the Apelblat, Jouyban–Acree, and NRTL models. The Apelblat model provided the best fit, with an average relative deviation (ARD) below 5% and a root-mean-square deviation (RMSD) below 0.11%. Thermodynamic properties, including Gibbs free energy, enthalpy, and entropy of dissolution, were derived from the NRTL model. The dissolution process was endothermic, entropy-driven, and spontaneous in all three solvent systems. Solid-phase characterization by PXRD and DSC confirmed that no polymorphic transition of β-HMX occurred under the experimental conditions. Solvent composition stability tests showed that the maximum relative change in solubility due to composition fluctuation was less than 6.3%, corresponding to an equivalent temperature variation of 1.4–2.7 K. These data provide a foundation for optimizing anti-solvent crystallization processes for β-HMX.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/25120042
GaN-based vertical-cavity surface-emitting lasers (VCSELs) are constrained by the absence of p-type conductive epitaxial distributed Bragg reflectors (DBRs), forcing reliance on dielectric DBRs that impose high thermal resistance or complex substrate removal. This work demonstrates a room-temperature electrically injected GaN VCSEL incorporating a conductive nanoporous (NP) GaN DBR fabricated by electrochemical etching of alternating n-GaN layers with varying Si doping. The NP-GaN DBR exhibits low electrical resistance, enabling vertical current injection. Under pulsed operation, the device with a 10-μm aperture lases at 427.7 nm with a full width at half maximum (FWHM) of 0.8 nm. The threshold current is 26 mA, corresponding to a threshold current density of approximately 33 kA/cm². Polarization degree increases from 35% below threshold to 86% above threshold, confirming lasing. The turn-on voltage remains high, primarily due to p-side resistance. These results validate the potential of conductive NP-GaN DBRs for high-density two-dimensional VCSEL arrays, though further reduction of p-side resistance is required for continuous-wave operation.
China Foundry•2026•DOI: 10.1007/s41230-026-5163-9
In laser powder bed fusion (LPBF) additive manufacturing, surface depressions caused by melt pool instability can induce defects throughout the layer-by-layer printing process. To address the limited understanding of interlayer defect transmission mechanisms, synchrotron X-ray in situ imaging was used to systematically investigate the dynamic evolution of surface depressions during multi-pass printing by adjusting interlayer process parameters. Experimental results show that insufficient energy input in the first layer leads to balling and fracture of melt tracks. When the energy input in the second layer is increased, local overheating at the gap between melt tracks from the previous layer causes surface depressions. Reducing the energy input in the third layer hinders melt backflow, enlarging the depression region. Further lowering the energy input in the final layer leads to the formation of internal unfused defects. This study reveals the dynamic correlation between surface depressions and interlayer defect evolution, offering critical experimental evidence and theoretical guidance for closed-loop interlayer process control in laser additive manufacturing.
China Foundry (中国铸造 - 英文版)•2026•DOI: 10.1007/s41230-026-4124-6
In order to investigate the effect of die wall thickness on morphologies of defect band, a stepped mold with a wall thickness of 5 mm, 4 mm, 3 mm, 2 mm, and 1 mm was designed to carry out high pressure die casting experiments with AlSi10MgMn alloy. For castings with wall thickness of 2-4 mm, the ratio of the mean defect band width (w) and mean grain size (d) in the defect band (w/d) ranges 7-18, while it increases to 24.47 for the 5 mm-thick casting. This difference is related with the filling speed and the distribution of externally solidified crystals (ESCs). The mold flow analysis indicates that the filling speed decreases from 25.41 m·s-1 to 11.07 m·s-1 when wall thickness increases from 2 mm to 5 mm. Due to the decreasing filling speed along the wall thickness, ESCs gradually diffuse from the center to the defect band, which keep the shear strength in the defect band at a high-level during filling. Meanwhile, the shear strength generated during the filling also decreases as the shear rate drops. Finally, the defect bands in the 5 mm-thick region become widen and indistinct, and the porosity is as high as 5.25%.
Nano-Micro Letters•2026•DOI: 10.1007/s40820-025-01881-3
Sodium superionic conductor (NASICON)-type materials are promising cathodes for sodium-ion batteries due to their stable multi-channel frameworks and exceptional ionic conductivity. Among them, Na3V2(PO4)2F3 (NVPF) has attracted significant attention. However, the low electronic conductivity and phase impurities limit its sodium storage capability. Herein, we present a Fe and Mn dual-doped NVPF (FM-NVPF) cathode with improved phase purity, electronic conductivity, and electrochemical activities. Detailed ex-situ analyses and density functional theory calculations reveal that Fe and Mn dopants induce defect energy levels and modulate the electronic structure, resulting in a direct-to-indirect bandgap transition in NVPF, which in turn increases carrier concentration and lifetime, accelerates ionic/electronic transport, and improves structural stability. As a result, the FM-NVPF cathode delivers a high capacity of 126.6 mAh g⁻1 at 0.1 C (1 C = 128 mAh g⁻1) and outstanding high-rate capability of 67.6 mAh g⁻1 at 50 C, corresponding to 1.2 min per charge. Furthermore, Na ion full cells assembled with the FM-NVPF cathodes and hard carbon anodes exhibit a high energy density of about 175 Wh kg⁻1 cathode+anode mass and appealing cyclic stability. This work provides an efficient strategy for developing high-purity and high-performance NVPF cathode materials for advanced sodium-ion batteries.
Nano-Micro Letters•2026•DOI: 10.1007/s40820-025-01996-7
The growing demand for personalized health care, smart wearables, and advanced environmental monitoring has spurred the development of multifunctional materials that combine flexibility, environmental adaptability, and diverse functionalities. However, conventional materials often failed to integrate these attributes simultaneously, hindering their applicability in next-generation technologies. Here, we present an organic–inorganic hybrid crystalline material with a unique sandwich-like architecture, in which a flexible organic crystal core is encased by reduced graphene oxide (rGO) and thermoplastic polyurethane (TPU). This strategic integration endows the material with fluorescence, cryogenic flexibility, and electrical conductivity, while also enabling dual sensing and actuation capabilities. The rGO layer facilitates real-time humidity (25–90% RH) and temperature (25–180 °C) sensing through environmental interactions, whereas the differential thermal expansion between TPU and the flexible crystal core drives efficient photothermal actuation at −150 °C for advanced thermal regulation. The hybrid material exhibits stable performance under extreme conditions, making it a promising candidate for biomedical monitoring, flexible electronics, and energy applications. This work establishes hybrid crystalline materials as versatile and scalable platforms for addressing complex technological demands, paving the way for their application in next-generation multifunctional devices.
Journal of Central South University•2026•DOI: 10.1007/s11771-026-6237-y
Intergrown ferromanganese ore resources are typical strategic mineral resources with huge reserves and abundant hematite, pyrolusite, and other valuable minerals, which is of great significance for its development and utilization. This paper adopts a combination of phase transformation and magnetic separation to explore the phase transformation mechanism of Fe minerals and Mn minerals during the roasting process. The analysis of the properties of the raw ore shows that the Fe-containing and Mn-containing minerals of the intergrown ferromanganese ore are hematite and pyrolusite, respectively. The optimal conditions for controlling the mineral phase were obtained, including roasting temperature of 600 ℃ for 30 min, and a grinding fineness of <0.074 mm accounting for 50%. Meanwhile, a Fe grade of 61.05% with a recovery of 80.77%, and a Mn grade of 61.60% with a recovery of 87.81% were acquired. The precise mineral phase transformation (MPT) could be realized via adjusting the roasting conditions. Hematite is transformed into magnetite, while pyrolusite is transformed into manganosite, and then they were effectively separated and concentrated via magnetic separation.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01834-w
Refractory wounds cause significant harm to the health of patients and the most common treatments in clinical practice are surgical debridement and wound dressings. However, certain challenges, including surgical difficulty, lengthy recovery times, and a high recurrence rate persist. Conductive hydrogel dressings with combined monitoring and therapeutic properties have strong advantages in promoting wound healing due to the stimulation of endogenous current on wounds and are the focus of recent advancements. Therefore, this review introduces the mechanism of conductive hydrogel used for wound monitoring and healing, the materials selection of conductive hydrogel dressings used for wound monitoring, focuses on the conductive hydrogel sensor to monitor the output categories of wound status signals, proving invaluable for non-invasive, real-time evaluation of wound condition to encourage wound healing. Notably, the research of artificial intelligence (AI) model based on sensor derived data to predict the wound healing state, AI makes use of this abundant data set to forecast and optimize the trajectory of tissue regeneration and assess the stage of wound healing. Finally, refractory wounds including pressure ulcers, diabetes ulcers and articular wounds, and the corresponding wound monitoring and healing process are discussed in detail. This manuscript supports the growth of clinically linked disciplines and offers motivation to researchers working in the multidisciplinary field of conductive hydrogel dressings.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01810-4
Aqueous zinc-ion batteries are promising candidates as stationary storage systems for power-grid applications due to their high safety and low cost. The practical implementation of Zn-ion batteries currently still faces formidable challenges because of Zn dendrite growth, hydrogen evolution, and inadequate environmental adaptability. Herein, to address these challenges, a strategy of regulation of water molecules coordination in electrolyte is proposed via developing a cross-linked hydrophilic hydrogel polymer electrolyte. Within this system, the continuous hydrogen bond among H2O molecules is disrupted and the isolated H2O molecules are strongly bound with a polymeric matrix comprised of polyacrylamide, carboxymethyl cellulose, and ethylene glycol, which can restrain the activity of H2O molecules, thus effectively alleviating Zn dendrite growth and hydrogen evolution and enhancing the anti-freezing ability. With this electrolyte, the Zn||Cu cell presents a high coulombic efficiency of 99.4% over 900 cycles and Zn||Zn symmetric cell exhibits high cycling stability, maintaining plating/stripping for over 1,700 h. Moreover, the assembled Zn||PANI device also demonstrates outstanding electrochemical performance over a wide-temperature range, including a long cycling life over 14,120 cycles at room temperature and an ultralong cycling surpassing 30,000 cycles even at −40 °C. This showcases the manipulation of water coordination chemistry for advanced, highly adaptable batteries.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01791-4
Conductive hydrogels have garnered widespread attention as a versatile class of flexible electronics. Despite considerable advancements, current methodologies struggle to reconcile the fundamental trade-off between high conductivity and effective absorption-dominated electromagnetic interference (EMI) shielding, as dictated by classical impedance matching theory. This study addresses these limitations by introducing a novel synthesis of aramid nanofiber/MXene-reinforced polyelectrolyte hydrogels. Leveraging the unique properties of polyelectrolytes, this innovative approach enhances ionic conductivity and exploits the hydration effect of hydrophilic polar groups to induce the formation of intermediate water. This critical innovation facilitates polarization relaxation and rearrangement in response to electromagnetic fields, thereby significantly enhancing the EMI shielding effectiveness of hydrogels. The electromagnetic wave attenuation capacity of these hydrogels was thoroughly evaluated across both X-band and terahertz band frequencies, with further investigation into the impact of varying water content states—hydrated, dried, and frozen—on their electromagnetic properties. Moreover, the hydrogels exhibited promising capabilities beyond mere EMI shielding; they also served effectively as strain sensors for monitoring human motions, indicating their potential applicability in wearable electronics. This work provides a new approach to designing multifunctional hydrogels, advancing the integration of flexible, multifunctional materials in modern electronics, with potential applications in both EMI shielding and wearable technology.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01767-4
Manganese-based chalcogenides have significant potential as anodes for sodium-ion batteries (SIBs) due to their high theoretical specific capacity, abundant natural reserves, and environmental friendliness. However, their application is hindered by poor cycling stability, resulting from severe volume changes during cycling and slow reaction kinetics due to their complex crystal structure. Here, an efficient and straightforward strategy was employed to in-situ encapsulate single-phase porous nanocubic MnS0.5Se0.5 into carbon nanofibers using electrospinning and the hard template method, thus forming a necklace-like porous MnS0.5Se0.5-carbon nanofiber composite (MnS0.5Se0.5@N-CNF). The introduction of Se significantly impacts both the composition and microstructure of MnS0.5Se0.5, including lattice distortion that generates additional defects, optimization of chemical bonds, and a nano-spatially confined design. In situ/ex-situ characterization and density functional theory calculations verified that this MnS0.5Se0.5@N-CNF alleviates the volume expansion and facilitates the transfer of Na+/electron. As expected, MnS0.5Se0.5@N-CNF anode demonstrates excellent sodium storage performance, characterized by high initial Coulombic efficiency (90.8%), high-rate capability (370.5 mAh g−1 at 10 A g−1) and long durability (over 5000 cycles at 5 A g−1). The MnS0.5Se0.5@N-CNF //NVP@C full cell, assembled with MnS0.5Se0.5@N-CNF as anode and Na3V2(PO4)3@C as cathode, exhibits a high energy density of 254 Wh kg−1 can be provided. This work presents a novel strategy to optimize the design of anode materials through structural engineering and Se substitution, while also elucidating the underlying reaction mechanisms.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01758-5
Photothermoelectric (PTE) photodetectors with self-powered and uncooled advantages have attracted much interest due to the wide application prospects in the military and civilian fields. However, traditional PTE photodetectors lack of mechanical flexibility and cannot operate independently without the test instrument. Herein, we present a flexible PTE photodetector capable of dual-mode output, combining electrical and optical signal generation for enhanced functionality. Using solution processing, high-quality MXene thin films are assembled on asymmetric electrodes as the photosensitive layer. The geometrically asymmetric electrode design significantly enhances the responsivity, achieving 0.33 mA W−1 under infrared illumination, twice that of the symmetrical configuration. This improvement stems from optimized photothermal conversion and an expanded temperature gradient. The PTE device maintains stable performance after 300 bending cycles, demonstrating excellent flexibility. A new energy conversion pathway has been established by coupling the photothermal conversion of MXene with thermochromic composite materials, leading to a real-time visualization of invisible infrared radiation. Leveraging this functionality, we demonstrate the first human–machine collaborative infrared imaging system, wherein the dual-mode photodetector arrays synchronously generate human-readable pattern and machine-readable pattern. Our study not only provides a new solution for functional integration of flexible photodetectors, but also sets a new benchmark for human–machine collaborative optoelectronics.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01649-9
Practical Zn metal batteries have been hindered by several challenges, including Zn dendrite growth, undesirable side reactions, and unstable electrode/electrolyte interface. These issues are particularly more serious in low-concentration electrolytes. Herein, we design a Zn salt-mediated electrolyte with in situ ring-opening polymerization of the small molecule organic solvent. The Zn(TFSI)2 salt catalyzes the ring-opening polymerization of (1,3-dioxolane (DOL)), generating oxidation-resistant and non-combustible long-chain polymer (poly(1,3-dioxolane) (pDOL)). The pDOL reduces the active H2O molecules in electrolyte and assists in forming stable organic–inorganic gradient solid electrolyte interphase with rich organic constituents, ZnO and ZnF2. The introduction of pDOL endows the electrolyte with several advantages: excellent Zn dendrite inhibition, improved corrosion resistance, widened electrochemical window (2.6 V), and enhanced low-temperature performance (freezing point = −34.9 °C). Zn plating/stripping in pDOL-enhanced electrolyte lasts for 4200 cycles at 99.02% Coulomb efficiency and maintains a lifetime of 8200 h. Moreover, Zn metal anodes deliver stable cycling for 2500 h with a high Zn utilization of 60%. A Zn//VO2 pouch cell assembled with lean electrolyte (electrolyte/capacity (E/C = 41 mL (Ah)−1) also demonstrates a capacity retention ratio of 92% after 600 cycles. These results highlight the promising application prospects of practical Zn metal batteries enabled by the Zn(TFSI)2-mediated electrolyte engineering.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2025-6-3)
The typical method for preparing the porous carbon used in supercapacitors (SCs) is time-consuming and energy-intensive. We report a fast and efficient route to synthesize and tailor the structure of porous carbon by a Joule heating technique (JHT) using phenolic resin and precursors. During the JHT process, the time and energy needed are both significantly reduced because the precursor is heated to the target temperature at a rate of 1100 K/s, so the porous carbon is formed with the release of small molecules and the etching of the substrate by K2CO3. JHT has a higher energy efficiency than traditional carbonization methods in a tube furnace and allows for precise control of the pyrolysis process, thus achieving better control of the material's structure and properties. Samples obtained by JHT contain abundant pores and a large specific surface area (1652.7 m2/g), which give an excellent specific capacitance of 476.0 F/g and rate capability (75.1% capacitance retention at 64.0 A/g in an aqueous alkaline electrolyte). Furthermore, in electrolytes of 17.0 mol/kg NaClO4 (water-in-salt) and 1.0 mol/L TEABF4/AN, the symmetric SCs have a maximum energy density of 33.3 and 50.8 Wh/kg at power densities of 220.4 and 376.4 W/kg, respectively. The cells also have good long-term stability, with a nearly 100% Coulombic efficiency, and a capacitance retention of 93.1% in a water-in-salt electrolyte after 10000 cycles, and 88.9% in an organic electrolyte after 8000 cycles. This study shows that JHT has the potential to serve as an ultra-fast method to prepare porous carbons for energy storage.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2025-4-2)
Smart batteries play a key role in upgrading energy storage systems. However, they require a well-balanced integration of material structure, functional properties, and electrochemical performance, and their development is limited by conventional material systems in terms of energy density, response time, and functional integration. Carbon materials have emerged as a key solution for overcoming these problems due to their structural adjustability and multifunctional compatibility. Strategies for improving their electrochemical performance by changing the pore structure and interlayer spacing, as well as chemical functionalization, and composite design are analyzed, and their impact on improving the specific capacity and cycling stability of batteries is demonstrated. The unique advantages of carbon materials in realizing smart functions such as power supply, real-time monitoring and energy management in smart batteries are also discussed. Based on current progress in related fields, the prospects for the use of carbon materials in smart batteries are evaluated.
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.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.06.010
Coral reef limestone (CRL) constitutes a distinctive marine carbonate formation with complex mechanical properties. This study investigates the multiscale damage and fracture mechanisms of CRL through integrated experimental testing, digital core technology, and theoretical modelling. Two CRL types with contrasting mesostructures were characterized across three scales. Macroscopically, CRL-I and CRL-II exhibited mean compressive strengths of 8.46 and 5.17 MPa, respectively. Mesoscopically, CRL-I featured small-scale highly interconnected pores, whilst CRL-II developed larger stratified pores with diminished connectivity. Microscopically, both CRL matrices demonstrated remarkable similarity in mineral composition and mechanical properties. A novel voxel average-based digital core scaling methodology was developed to facilitate numerical simulation of cross-scale damage processes, revealing network-progressive failure in CRL-I versus directional-brittle failure in CRL-II. Furthermore, a damage statistical constitutive model based on digital core technology and mesoscopic homogenisation theory established quantitative relationships between microelement strength distribution and macroscopic mechanical behavior. These findings illuminate the fundamental mechanisms through which mesoscopic structure governs the macroscopic mechanical properties of CRL.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.12.016
Natural gas hydrate in Class I reservoirs holds significant commercial potential, as demonstrated by production trials in the South China Sea. However, experimental studies have focused largely on Class III systems, with Class I/II reservoirs remaining underrepresented due to the difficulties in simulating the geothermal gradient and interlayer interactions. This study investigates depressurization performance across all three classes using a novel 360° rotatable reactor with segmented temperature control, enabling precise simulation of reservoir conditions. Results reveal: (i) Class I shows two-stage gas production, with 50% from early free gas enabling rapid depressurization, followed by dissociated gas dominance. They achieve 38.4%–78.3% higher cumulative production and superior gas-to-water ratios due to efficient energy use. (ii) The free gas layer in Class I accelerates pressure and heat transfer. Class II’s water layer provides sensible heat but causes water blocking, impairing heat flow. Class III exhibits rapid initial dissociation but a quick decline without fluid support. (iii) Low temperature, low hydrate saturation, and high production pressure collectively reduce efficiency by increasing flow resistance, limiting gas supply, and reducing dissociation drive. Over-depressurization risks hydrate reformation and ice blockage. This work bridges experimental gaps for Class I/II reservoirs, offering key insights for optimizing recovery.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01275-x
Under the paradigm of Industry 5.0, intelligent manufacturing transcends mere efficiency enhancement by emphasizing human-machine collaboration, where human expertise plays a central role in assembly processes. Despite advancements in intelligent and digital technologies, assembly process design still heavily relies on manual knowledge reuse, and inefficiencies and inconsistent quality in process documentation are caused. To address the aforementioned issues, this paper proposes a knowledge push method of complex product assembly process design based on distillation model-based dynamically enhanced graph and Bayesian network. First, an initial knowledge graph is constructed using a BERT-BiLSTM-CRF model trained with integrated human expertise and a fine-tuned large language model. Then, a confidence-based dynamic weighted fusion strategy is employed to achieve dynamic incremental construction of the knowledge graph with low resource consumption. Subsequently, a Bayesian network model is constructed based on the relationships between assembly components, assembly features, and operations. Bayesian network reasoning is used to push assembly process knowledge under different design requirements. Finally, the feasibility of the Bayesian network construction method and the effectiveness of Bayesian network reasoning are verified through a specific example, significantly improving the utilization of assembly process knowledge and the efficiency of assembly process design.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01336-1
Autonomous driving technology is constantly developing to a higher level of complex scenes, and there is a growing demand for the utilization of end-to-end data-driven control. However, the end-to-end path tracking process often encounters challenges in learning efficiency and generalization. To address this issue, this paper designs a deep deterministic policy gradient (DDPG)-based reinforcement learning strategy that integrates imitation learning and feedforward exploration in the path following process. In imitation learning, the path tracking control data generated by the model predictive control (MPC) method is used to train an end-to-end steering control model of a deep neural network. Another feedforward exploration behavior is predicted by road curvature and vehicle speed, and adds it and imitation learning to the DDPG reinforcement learning to obtain decision-making experience and action prediction behavior of the path tracking process. In the reinforcement learning process, imitation learning is used to update the pre-training parameters of the actor network, and a feedforward steering technique with random noise is adopted for strategy exploration. In the reward function, a hierarchical progressive reward form and a constrained objective reward function referring to MPC are designed, and the actor-critic network architecture is determined. Finally, the path tracking performance of the designed method is verified by comparing various training results, simulations, and HIL tests. The results show that the designed method can effectively utilize pre-training and feedforward prior experience to obtain optimal path tracking performance of an autonomous vehicle, and has better generalization ability than other methods. This study provides an efficient control scheme for improving the end-to-end control performance of autonomous vehicles.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01597-w
The proliferation of wearable biodevices has boosted the development of soft, innovative, and multifunctional materials for human health monitoring. The integration of wearable sensors with intelligent systems is an overwhelming tendency, providing powerful tools for remote health monitoring and personal health management. Among many candidates, two-dimensional (2D) materials stand out due to several exotic mechanical, electrical, optical, and chemical properties that can be efficiently integrated into atomic-thin films. While previous reviews on 2D materials for biodevices primarily focus on conventional configurations and materials like graphene, the rapid development of new 2D materials with exotic properties has opened up novel applications, particularly in smart interaction and integrated functionalities. This review aims to consolidate recent progress, highlight the unique advantages of 2D materials, and guide future research by discussing existing challenges and opportunities in applying 2D materials for smart wearable biodevices. We begin with an in-depth analysis of the advantages, sensing mechanisms, and potential applications of 2D materials in wearable biodevice fabrication. Following this, we systematically discuss state-of-the-art biodevices based on 2D materials for monitoring various physiological signals within the human body. Special attention is given to showcasing the integration of multi-functionality in 2D smart devices, mainly including self-power supply, integrated diagnosis/treatment, and human–machine interaction. Finally, the review concludes with a concise summary of existing challenges and prospective solutions concerning the utilization of 2D materials for advanced biodevices.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01295-7
The accessory gearbox is a vital component of aviation engines, and its power loss, flow characteristics, and temperature distribution significantly influence engine performance, particularly under high-temperature and high-speed conditions. However, research on the thermal and flow characteristics of entire transmission systems remains limited. This study presents a mathematical model designed to evaluate power loss and heat generation within the transmission system of an accessory gearbox. The Moving Particle Semi-Implicit (MPS) method, a Lagrangian numerical technique for fluid dynamics, was utilized to calculate the flow field of the gearbox and determine the surface convective heat transfer coefficient under stable flow conditions. Subsequently, a three-dimensional finite element thermal network method was employed to calculate the gearbox temperature distribution. This method captures detailed temperature fields of key components while estimating other components using lumped parameters, effectively balancing accuracy and efficiency in temperature field calculations. The results indicate that rotational speed has a greater impact on total power loss than the oil inlet temperature. The bevel gears, which are responsible for power input, along with the input shaft bearings, are the primary contributors to power loss, collectively accounting for nearly 50% of the total power loss. This research introduces a predictive method for examining the thermal and flow characteristics of aviation transmission systems, facilitating rapid forecasting of the flow field, temperature distribution, and power consumption.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01314-7
As space equipment become larger in size and more flexible, generalized mechanisms are being widely used in space-deployable structures. Dynamic modeling of large-scale generalized space-deployable mechanisms is challenging owing to the coupling between the deformation of flexible links and rigid body motion. This study develops a dynamic modeling method for generalized mechanisms using the local frame of the SE(3) Lie group. The model represents both rigid and flexible links within a unified Lie group setting. The expressions for the velocities of rigid links and deformation of flexible links are derived using the Lie algebra framework. The nonuniqueness of the degrees of freedom of generalized kinematic pairs is considered, and the velocity fields of kinematic pairs in different situations are expressed. The equations of motion are derived using Hamilton’s principle. Because the velocities are expressed in the local frame, the mass matrix in the equation is constant, which yields a compact and unified expression for the dynamic equation. A Lie group generalized-α time integration method is adopted to ensure numerical stability and efficiency in simulating multibody systems with large rotations and deformations. Two numerical examples are studied to demonstrate a formulation that reflects the motion responses under varying configurations and loading conditions. This study broadens the application of the local frame of the Lie group formulation in space mechanisms and provides a new concept for dynamic modeling of generalized mechanisms.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6100-6
In this study, AZ31 Mg alloy sheets were processed by a severe plastic deformation (SPD) technique called forging-bending repeated deformation (FBRD). The effect on the microstructure and microhardness of AZ31 Mg alloy through FBRD was investigated with increasing temperature treatment and a 90° cross route. The results reveal that the effective strain increases with the number of passes. The flow uniformity is effectively enhanced due to alterations in shear deformation direction. After four passes of deformation, the average grain size is refined by 79.3% compared to the initial specimen. The grain refinement mechanism predominantly originates from the synergistic effects of discontinuous dynamic recrystallization (DDRX), continuous dynamic recrystallization (CDRX), and twinning-induced recrystallization (TDRX). The formation of {1012} extension twins (ET) significantly contributes to coarse grain subdivision and plastic deformation coordinated. Furthermore, pyramidal <c+a> slip activation effectively enhances the plasticity of Mg alloys. By post four-pass processing, the alloy exhibits a microhardness of 81.9HV, primarily governed by fine grain strengthening and dislocation strengthening mechanisms.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6087-z
Solid-state electrolytes (SSEs) have attracted much attention due to their high safety and cycling stability for lithium-ion batteries. However, the high interface impedance between the electrode and the solid-state electrolyte hinders their practical application. In this work, the solid-liquid hybrid electrolyte S-Li1.3Al0.3Ti1.7(PO4)3-LE05(S-LATP-LE05) (LATP: Li1.5Al0.5Ti1.5 (PO4)3) sheet is prepared by dropping liquid electrolyte (LE) with appropriate FeF2 into spark plasma sintering S-LATP (solid-liquid hybrid electrolyte), which shows high-density and high-ionic-conductivity (5.78×10−4 S/cm). When the amount of FeF2 is 0.5 wt% , the interfacial properties between the anode and electrolyte are improved, and the S-LATP is well protected by LiF-rich (solid electrolyte interface) (SEI) interface in cycling process. The Li|S-LATP-LE05|Li symmetric battery and full battery show better electrochemical performance and stability relatively. The overpotential of the Li|S-LATP-LE05|Li symmetric battery is smaller and shows more stable electrochemical performance after cycling for 350 h, revealing good compatibility with a lithium metal anode and can inhibit the growth of lithium dendrites effectively. The Li|S-LATP-LE05|LiFePO4 full battery delivers a specific discharge capacity of 160 mA·h/g at 0.2C for 50 cycles. The corresponding coulombic efficiency is about 99.9% and displays better rate performance compared with the battery without FeF2 LE.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-025-3177-8
Lead-free vacancy-ordered double perovskites have emerged as promising materials for optoelectronic applications due to their environmentally friendly characteristics and exceptional properties. However, conventional synthesis methods often depend on toxic reagents and stringent conditions, limiting their large-scale synthesis and practical application. In this work, an environmentally friendly synthesis route was proposed for preparing vacancy-ordered double perovskites Cs2SnX6 (X = Cl, Br, and I) with high crystallinity under low-temperature and ambient-pressure conditions. This method utilizes ion liquid (i.e., 1-butyl-3-methylimidazolium chloride ([Bmim]Cl), 1-butyl-3-methylimidazolium bromide ([Bmim]Br) and 1-butyl-3-methylimidazolium iodide ([Bmim]I)) in combination with saturated aqueous solutions of ammonium halides as solvents, replacing traditional hydrogen halide acid or polar organic solvents. Experimental and characterization results demonstrate that the Cs2SnX6 (X = Cl, Br, and I) possess high crystallinity, well-defined morphology, and improved thermal stability. These improvements are attributed to the hydrogen bonding interactions between ionic liquids and the perovskite precursors. Additionally, the halogen-rich environment provided by ionic liquids and ammonium halide salts facilitates defect passivation. Furthermore, this method is applicable to the synthesis of doped perovskite crystals, demonstrated by the successful synthesis of Bi-doped Cs2SnCl6 crystals with a photoluminescence quantum efficiency of 12.73%. This study presents a novel strategy for synthesizing high-quality vacancy-ordered double perovskites and their doping or alloyed compounds.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-024-3081-7
Copper–nickel tailings (CNTs), consisting of more than 80wt% magnesium-bearing silicate minerals, show great potential for CO2 mineral sequestration. The dissolution kinetics of CNTs in HCl solution was investigated through a leaching experiment and kinetic modeling, and the effects of reaction time, HCl concentration, solid-to-liquid ratio, and reaction temperature on the leaching rate of magnesium were comprehensively studied. Results show that the suitable leaching conditions for magnesium in CNTs are 2 M HCl, a solid-to-liquid ratio of 50 g·L−1, and 90°C, at which the maximum leaching rate of magnesium is as high as 83.88%. A modified shrinking core model can well describe the leaching kinetics of magnesium. The dissolution of magnesium was dominated by a combination of chemical reaction and product layer diffusion, with a calculated apparent activation energy of 77.51 kJ·mol−1. This study demonstrates the feasibility of using CNTs as a media for CO2 mineral sequestration.
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/s12613-024-3029-y
The underhand cut-and-fill mining method is widely employed in underground mines, especially when the quality of surrounding rock mass or ore body is inferior or subjected to high stresses. Such a method typically requires the construction of sill mats with cemented backfill to provide operators with safe artificial roofs. Accurate estimation of the minimum required strength of the sill mat is crucial to minimize binder consumption and ensure its stability upon base exposure. Over the years, only a few publications were devoted to determining the minimum required cohesion (cmin) of sill mats. None of them considered rock wall closure to be associated with the creep of surrounding rock mass. Moreover, the effect of rock wall closure associated with rock creep on the cmin of the sill mat remains unknown. Thus, a series of numerical simulations was performed to fill this gap. The influence of rock creep on the cmin of base-exposed sill mat was investigated for the first time. The numerical results indicate that Mitchell’s models could be suitable for sill mats subjected to negligible wall closure. However, this scenario is rare, especially when mine depth is large. In general, the cmin of sill mats increases as mine depth increases. Neglecting rock creep would significantly underestimate the cmin of sill mats. When mine depth is large and the rock mass exhibits severe creep, cemented backfill with ductile behavior (i.e., with low stiffness but enough strength) should be considered to reduce binder consumption and prevent crushing failure. In all cases, promptly filling the mined-out stope below the sill mat can improve its stability and reduce its cmin value.