Opto-Electronic Advances (光电进展)•2026•DOI: 10.29026/oea.2026.250269
Surface-enhanced Raman scattering (SERS) substrates face an intrinsic trade-off: the ultrasensitive hottest spots required for single-molecule detection amplify analyte signals by orders of magnitude, causing each molecule to be miscounted as hundreds during quantification. This study demonstrates a timeshare SERS platform that circumvents this contradiction by dynamically toggling between quantitative and sensitive modes on demand. The platform is constructed by transferring a monolayer gold nanosphere film onto an elastic hydrogel substrate. The hydrogel's volume change adjusts the inter-nanosphere distance, reversibly controlling the formation or extinction of SERS hottest spots without altering the spatial distribution of analyte molecules. In the absence of hottest spots, the platform exhibits strong quantification capability; when equipped with a substantial number of hottest spots, it achieves ultrahigh sensitivity. The authors demonstrate quantitative and ultrasensitive detection of various analyte molecules using the respective modes. This approach opens a route to designing SERS substrates that simultaneously offer high sensitivity and robust quantification, addressing a long-standing bottleneck in trace detection for analytical chemistry, environmental monitoring, food safety, and biomedical diagnostics.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/25070024
The introduction of high-k/metal gate (HK/MG) technology enables independent tuning of NMOS and PMOS threshold voltages, facilitating advanced nodes and improving overall chip performance. However, severe pattern loading effects during PMOS device fabrication pose challenges in dummy poly removal. This work reports the optimization of the photoresist etch back (PREB) process, providing a wider process window for subsequent AL CMP. By tuning the PR coating uniformity to 1.6% and applying four-zone electrostatic chuck (ESC) temperature control, the wafer-level uniformities of PR, SiN, and SiO2 were reduced to 6.3%, 2.3%, and 5.1%, respectively. An optimized over etch (OE) recipe with a high selectivity of PR : SiN : SiO2 ≈ 1 : 1 : 6 effectively balanced gate height loading between N- and PMOS regions. Furthermore, precise EB1 time tuning enabled defect removal, while advanced KLA inspection ensured early detection of critical failure modes. Collectively, these measures establish a robust and stable PREB process for advanced logic device fabrication.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2026•DOI: 10.1088/1674-4926/25070023
Prolonged exposure to n-butanol, a hazardous volatile organic compound (VOC), necessitates sensitive detection at low concentrations for environmental and health monitoring. This study presents a novel Eu/Ce-codoped MOF-ZnO gas sensor for n-butanol detection under ultraviolet (UV) activation at ambient temperature. A series of Eu/Ce-ZnO nanomaterials were synthesized via a simple co-precipitation route by varying the mass ratios of Eu and Ce incorporated into pristine ZnO derived from MOF precursors. Gas testing results revealed that introducing an appropriate amount of Eu and Ce enlarged the specific surface area and enriched the oxygen vacancy content compared to pristine MOF-ZnO. Upon UV irradiation, the 0.03 wt% Eu 0.04 wt% Ce-ZnO sensor achieved a superior response of 611 for 100 ppm n-butanol at room temperature, 15.28 times higher than that of pristine MOF-ZnO (40). Furthermore, the sensor presented rapid response/recovery times (15 s/28 s) and excellent selectivity. The doped rare earth elements Eu and Ce simultaneously suppress the recombination of photogenerated electron-hole pairs, greatly improving response, stability, and selectivity. These findings demonstrate the potential of Eu/Ce-codoped ZnO nanoparticles for efficient, cost-effective n-butanol detection, offering a promising avenue for highly sensitive, UV-enhanced gas sensors for ambient temperature VOC monitoring.
Nano-Micro Letters•2026•DOI: 10.1007/s40820-025-01997-6
Single-atom catalysts (SACs) have demonstrated excellent performance in heterogeneous catalytic reactions owing to their maximized atomic efficiency, distinctive geometric, and electronic configurations. However, the efficacy of SACs remains limited for certain reactions requiring simultaneous activation of multiple reactants over metallic active sites. Herein, we report an atomically dispersed Pt1Ru1 dual-atom pair site anchored on nanodiamond@graphene (ND@G) for CO oxidation. The Pt1Ru1 dual-atom catalyst shows an exceptional turnover frequency (TOF) of 17.6 × 10−2 s−1 at significantly lower temperature (30 °C), achieving a tenfold increase in TOF compared to single-atom Pt1/ND@G catalyst (1.5 × 10−2 s−1) and surpassing to previously reported Pt-based catalysts under similar conditions. Moreover, the catalyst demonstrates excellent stability, maintaining its activity for 40 h at 80 °C without significant deactivation. The superior catalytic performance of Pt-Ru dual-atom catalysts is attributed to the synergistic effect between Pt and Ru atoms with enhanced metallicity for improving simultaneous adsorption and activation of CO and O2, and the tuning of conventional competitive reactant adsorption into a non-competitive pathway over dual-atom pair sites. The present work manifests the advantages of dual-atom pair sites in heterogeneous catalysis and paves the way for precise design of catalysts at the atomic scale.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01788-z
Although three-dimensional metal halide perovskites are promising candidates for direct X-ray detection, the ion migration of perovskites seriously affects the detector stability. Herein, face-/edge-shared 3D heterometallic glycinate hybrid perovskitoid Pb2CuGly2X4 (Gly = -O2C-CH2-NH2; X = Cl, Br) single crystals (SCs), in which the adjacent lead halide layers are linked by large-sized Cu(Gly)2 pillars, are synthesized in water. The Cu(Gly)2 pillars in combination with face-/edge-shared inorganic skeleton are found able to synergistically suppress the ion migration, delivering a high ion migration activation energy (Ea) of 1.06 eV. The Pb2CuGly2Cl4 SC X-ray detector displays extremely low dark current drift of 1.20 × 10–9 nA mm−1 s−1 V−1 under high electric field (120 V mm−1) and continuous X-ray irradiation (2.86 Gy), and a high sensitivity of 9,250 μC Gy−1 cm−2 is also achieved. More excitingly, the Pb2CuGly2Cl4 nanocrystal can be easily dispersed in water and directly blade-coated on thin-film transistor (TFT) array substrate, and the obtained Pb2CuGly2Cl4-based TFT array detector offers an X-ray imaging capability with spatial resolution of 2.2 lp mm−1.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01730-3
Amplification-free, highly sensitive, and specific nucleic acid detection is crucial for health monitoring and diagnosis. The type III CRISPR-Cas10 system, which provides viral immunity through CRISPR-associated protein effectors, enables a new amplification-free nucleic acid diagnostic tool. In this study, we develop a CRISPR-graphene field-effect transistors (GFETs) biosensor by combining the type III CRISPR-Cas10 system with GFETs for direct nucleic acid detection. This biosensor exploits the target RNA-activated continuous ssDNA cleavage activity of the dCsm3 CRISPR-Cas10 effector and the high charge density of a hairpin DNA reporter on the GFET channel to achieve label-free, amplification-free, highly sensitive, and specific RNA detection. The CRISPR-GFET biosensor exhibits excellent performance in detecting medium-length RNAs and miRNAs, with detection limits at the aM level and a broad linear range of 10−15 to 10−11 M for RNAs and 10−15 to 10−9 M for miRNAs. It shows high sensitivity in throat swabs and serum samples, distinguishing between healthy individuals (N=5) and breast cancer patients (N=6) without the need for extraction, purification, or amplification. This platform mitigates risks associated with nucleic acid amplification and cross-contamination, making it a versatile and scalable diagnostic tool for molecular diagnostics in human health.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01697-1
The transition to renewable energy sources has elevated the importance of SIBs (SIBs) as cost-effective alternatives to lithium-ion batteries (LIBs) for large-scale energy storage. This review examines the mechanisms of gas generation in SIBs, identifying sources from cathode materials, anode materials, and electrolytes, which pose safety risks like swelling, leakage, and explosions. Gases such as CO2, H2, and O2 primarily arise from the instability of cathode materials, side reactions between electrode and electrolyte, and electrolyte decomposition under high temperatures or voltages. Enhanced mitigation strategies, encompassing electrolyte design, buffer layer construction, and electrode material optimization, are deliberated upon. Accordingly, subsequent research endeavors should prioritize long-term high-precision gas detection to bolster the safety and performance of SIBs, thereby fortifying their commercial viability and furnishing dependable solutions for large-scale energy storage and electric vehicles.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-025-01680-w
Proton exchange membrane (PEM) water electrolysis presents considerable advantages in green hydrogen production. Nevertheless, oxygen evolution reaction (OER) catalysts in PEM water electrolysis currently encounter several pressing challenges, including high noble metal loading, low mass activity, and inadequate durability, which impede their practical application and commercialization. Here we report a self-constructed layered catalyst for acidic OER by directly using an Ir–Ta-based metallic glass as the matrix, featuring a nanoporous IrO2 surface formed in situ on the amorphous IrTaOx nanostructure during OER. This distinctive architecture significantly enhances the accessibility and utilization of Ir, achieving a high mass activity of 1.06 A mgIr−1 at a 300 mV overpotential, 13.6 and 31.2 times greater than commercial Ir/C and IrO2, respectively. The catalyst also exhibits superb stability under industrial-relevant current densities in acid, indicating its potential for practical uses. Our analyses reveal that the coordinated nature of the surface-active Ir species is effectively modulated through electronic interaction between Ir and Ta, preventing them from rapidly evolving into high valence states and suppressing the lattice oxygen participation. Furthermore, the underlying IrTaOx dynamically replenishes the depletion of surface-active sites through inward crystallization and selective dissolution, thereby ensuring the catalyst’s long-term durability.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25030011
The optical soliton characteristics of GaSb-based ~2 μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications, infrared countermeasures, and gas environment monitoring. In the research of two-section integrated optical chips, more attention is paid to their passive mode-locked characteristics. The ability of its structure to generate stable soliton transmission has not yet been studied, which will limit its further application in high-performance near-mid infrared optoelectronic technology. In this paper, we design and prepare a GaSb-based ~2 μm wavelength two-section integrated semiconductor laser chip structure, and test and analyze its related properties of soliton, including power−injection current−voltage (P−I−V), temperature and mode-locked characteristics. Experimental results show that the chip can achieve stable mode-locked operation at nearly ~2 μm wavelength and present the working characteristics of near optical soliton states and multi-peak optical soliton states. By comparing and analyzing the measured optical pulse sequence curve with the numerical fitting based on the pure fourth order soliton approximation solution, it is confirmed that the two-section integrated optical chip structure can generate stable transmission of multi-peak optical soliton. This provides a research direction for developing near-mid infrared mode-locked integrated optical chips with high-performance property of optical soliton.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-05-10)
The hydrogen evolution reaction (HER) is a promising way to produce hydrogen, and the use of non-precious metals with an excellent electrochemical performance is vital for this. Carbon-based transition metal catalysts have high activity and stability, which are important in reducing the cost of hydrogen production and promoting the development of the hydrogen production industry. However, there is a lack of discussion regarding the effect of carbon components on the performance of these electrocatalysts. This review of the literature discusses the choice of the carbon components in these catalysts and their impact on catalytic performance, including electronic structure control by heteroatom doping, morphology adjustment, and the influence of self-supporting materials. It not only analyzes the progress in HER, but also provides guidance for synthesizing high-performance carbon-based transition metal catalysts.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-02-11)
Mesophase-pitch-based carbon fibers (MPCFs) were prepared using industrial equipment with a constant extrusion rate of pitch while controlling the spinning temperature. The influence of spinning temperature on their microstructures, mechanical properties and thermal conductivities was investigated. SEM images of the fractured surface of MPCFs show that the graphite layers have a radiating structure at all spinning temperatures, but change from the fine-and-folded to the large-and-flat morphology when increasing the spinning temperature from 309 to 320 °C. At the same time the thermal conductivity and tensile strength of the MPCFs respectively increase from 704 W·m−1·K−1 and 2.16 GPa at 309 °C to 1 078 W·m−1·K−1 and 3.23 GPa at 320 °C. The lower viscosity and the weaker die-swell effect of mesophase pitch at the outlets of the spinnerets at the higher spinning temperature contribute to the improved orientation of mesophase pitch molecules in the pitch fibers, which improves the crystallite size and orientation of the MPCFs.
New Carbon Materials (新型炭材料)•2025•DOI: 10.1016/S1872-5805(NCM2024-39-02-09)
It is imperative to design suitable anode materials for both lithium-ion (LIBs) and sodium-ion batteries (SIBs) with a high-rate performance and ultralong cycling life. We fabricated a MoO2/MoS2 heterostructure that was then homogeneously distributed in N,S-doped carbon nanofibers (MoO2/MoS2@NSC) by electrospinning and sulfurization. The one-dimensional carbon fiber skeleton serves as a conductive frame to decrease the diffusion pathway of Li+/Na+, while the N/S doping creates abundant active sites and significantly improves the ion diffusion kinetics. Moreover, the deposition of MoS2 nanosheets on the MoO2 bulk phase produces an interface that enables fast Li+/Na+ transport, which is crucial for achieving high efficiency energy storage. Consequently, as the anode for LIBs, MoO2/MoS2@NSC gives an excellent cycling stability of 640 mAh g−1 for 2000 cycles under 5.0 A g−1 with an ultralow average capacity drop of 0.002% per cycle and an exceptional rate capability of 614 mAh g−1 at 10.0 A g−1. In SIBs, it also produces a significantly better electrochemical performance (reversible capacity of 242 mAh g−1 under 2.0 A g−1 for 2000 cycles and 261 mAh g−1 under 5.0 A g−1). This work shows how introducing a novel interface in the anode can produce rapid Li+/Na+ storage kinetics and a long cycling performance.
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25020033
To optimize turn on velocity of the SiC LIMS, we proposed a new structure for the LIMS that incorporates an optimized n+ layer and a multi-light triggered electrode design for the anode. The chip size is 5.5 mm × 5.5 mm in dimension. The experiment results indicate that the saturation laser energy required to trigger the prepared SiC LIMS has been decreased from 1.8 mJ to 40 μJ, with the forward blocking voltage of the prepared SiC LIMSs capable of withstanding over 7000 V. The leakage current is about 0.3 μA at room temperature, and the output current density achieves 4.25 kA/cm2 (with di/dt larger than 20 kA/μs).
Journal of Semiconductors (半导体学报 - 中国科学院半导体研究所)•2025•DOI: 10.1088/1674-4926/25030011
The optical soliton characteristics of GaSb-based ~2 μm wavelength integrated optical chips have broad application prospects in optoelectronic fields such as optical communications, infrared countermeasures, and gas environment monitoring. In the research of two-section integrated optical chips, more attention is paid to their passive mode-locked characteristics. The ability of its structure to generate stable soliton transmission has not yet been studied, which will limit its further application in high-performance near-mid infrared optoelectronic technology. In this paper, we design and prepare a GaSb-based ~2 μm wavelength two-section integrated semiconductor laser chip structure, and test and analyze its related properties of soliton, including power−injection current−voltage (P−I−V), temperature and mode-locked characteristics. Experimental results show that the chip can achieve stable mode-locked operation at nearly ~2 μm wavelength and present the working characteristics of near optical soliton states and multi-peak optical soliton states. By comparing and analyzing the measured optical pulse sequence curve with the numerical fitting based on the pure fourth order soliton approximation solution, it is confirmed that the two-section integrated optical chip structure can generate stable transmission of multi-peak optical soliton. This provides a research direction for developing near-mid infrared mode-locked integrated optical chips with high-performance property of optical soliton.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.05.008
In cold-region environments, where complex stresses and mining disturbances occur, rock masses are frequently segmented into discontinuous bodies by fractured structural planes, leading to anisotropic physical and mechanical properties. To explore the evolution of microcracks, degradation characteristics, and failure modes of fractured rocks in cold regions under the influence of freeze–thaw cycles, integrating laboratory experiments with the damage mechanics of freeze–thaw cycles. A numerical model for freeze–thaw cycle damage in rocks with various fracture dip angles was developed. The study revealed that the freeze–thaw expansion force generated during the pore water–ice phase transition is the primary driving factor behind freeze–thaw cycle damage. The initiation and propagation of microcracks and micropores, the detachment of matrix particles, and the loosening of clay mineral structures result in the transformation of the rock from a dense to a porous state, causing significant degradation in macroscopic mechanical properties. As freeze–thaw cycles increase, both the uniaxial compressive strength and the deformation modulus of the rock decrease significantly, with the failure mode gradually shifting from brittle instability to brittle-plastic or plastic failure. The findings of this study offer a practical approach to uncovering the mechanical response mechanisms between freeze–thaw damage in fractured rocks and structural planes.
Int. Journal of Mining Science and Technology (采矿与安全工程)•2025•DOI: 10.1016/j.ijmst.2025.09.013
As underground mining advances to greater depths, cemented paste backfill (CPB) is increasingly subjected to complex thermo-mechanical loading conditions, including multiaxial stress states and elevated temperatures. This study investigates the coupled effects of field-representative vertical self-weight and horizontal rockwall closure stresses, along with in-situ temperatures, on the mechanical behavior and pore water pressure (PWP) evolution of CPB. Experiments were conducted using a novel apparatus capable of controlling multiaxial stress and temperature during curing, replicating in-situ stress paths and thermal profiles typical of deep mine environments. Results show that multiaxial stress enhances CPB strength and stiffness by promoting denser particle packing, reducing porosity, and increasing frictional resistance. Elevated temperatures independently accelerate early-age cement hydration, further improving bond strength and stiffness. When combined, multiaxial stress and elevated temperature produce a synergistic enhancement in unconfined compressive strength (UCS) and elastic modulus, as confirmed by two-way ANOVA and synergy index analysis. PWP responses were also highly sensitive to thermo-mechanical conditions. The evolution of positive and negative PWP was governed by the interplay of thermal expansion, hydration-induced desaturation, and mechanical compaction. Multiaxial stress amplified early positive PWP and delayed its dissipation, whereas elevated temperature accelerated hydration and reduced pore pressure, leading to enhanced suction at later ages. A transient “stress-induced resaturation” effect was observed under late-stage excessive horizontal stress but was mitigated by elevated temperatures. These findings provide critical insights into the coupled mechanical and hydraulic behavior of CPB under realistic field conditions and offer guidance for optimizing backfill design, binder content, and barricade stability in deep mining applications.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6050-z
The aerodynamic performance of a high-speed train deteriorates sharply under crosswind, severely affecting its operational safety. This paper adopted a three-car high-speed train as the benchmark and established leeward side (LWS) airbag-train models. Based on the three-dimensional steady SST k-ω two-equation turbulence model, this study investigated the aerodynamic characteristics of trains under crosswind at three different airbag’s installation positions. The results show that the airbags installed on the LWS change the surface pressure distribution on the LWS of the train body, lowering the lateral force coefficient and overturning moment coefficient, and the aerodynamic performance of the train under crosswinds is enhanced. The airbag structure located at the top of the LWS (Model III) shows the most significant improvement in crosswind performance that the lateral force coefficient is reduced by 16.71%, and the lift coefficient is increased by 17.95%, which collectively led to a decrease in the train’s overturning moment coefficient by 23.65%. The research findings provide a reference for improving the anti-overturning performance of the next generation high-speed trains under crosswind.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01328-1
During the grinding train operation process, the grinding force between the grinding wheel and the rail is critical in ensuring the grinding quality and efficiency. The coupling vibration among the frame, the grinding wheels, and the wheelsets will seriously affect the stability of the grinding force. In this paper, the coupled mechanical model of the grinding wheel/rail is established based on the contact mechanics theory, which is embedded as a sub-model into the dynamic model of the multi-rigid buggy. The interaction among the frame, the grinding wheels and the wheelsets is analysed by setting the convex irregularity on the rail. The grinding effect is evaluated in combination with the subway’s long wave corrugation grinding conditions. The results show that when the grinding buggy passes the convex irregularity, the vibration excited by the wheelset system has a significant impact on the dynamic behavior of the grinding wheels. The vibration of the grinding wheel is mainly transmitted between the grinding wheel and the frame, less affecting the wheelset. For the long wave corrugation of the subway, the grinding effect of the grinding wheel has a certain correlation with the phase angle of the wheelset through the corrugation. The research results provide an important reference for the setting of the grinding pattern.
Chinese Journal of Mechanical Engineering•2025•DOI: 10.1186/s10033-025-01355-y
This paper proposes virtual impedance adaptation of the lower-limb exoskeleton for human performance augmentation (LEHPA) based on deep reinforcement learning (VIADRL) to mitigate reliance on model accuracy and address the ever-changing human-exoskeleton interaction (HEI) dynamics. The classical sensitivity amplification control strategy is expanded to the virtual impedance control strategy with more learnable virtual impedance parameters. The adjustment of these virtual impedance parameters is formalized as finding the optimal policy for a Markov Decision Process and can then be effectively resolved using deep reinforcement learning algorithms. To ensure safe and efficient policy training, a multibody simulation environment is established to facilitate the training process, supplemented by the innovative hybrid inverse-forward dynamics simulation approach for executing the simulation. For comparison purposes, the SADRL strategy is introduced as a benchmark. A novel control performance evaluation method based on the HEI forces at the back, thighs, and shanks is proposed to quantitatively evaluate the performance of our proposed VIADRL strategy. The VIADRL controller is systematically compared with the SADRL controller at five selected walking speeds. The lumped ratio of HEI forces under the SADRL strategy relative to those under the SADRL strategy is as low as 0.81 in simulation and approximately 0.89 on the LEHPA prototype. The overall reduction of HEI forces demonstrates the superiority of the VIADRL strategy in comparison to the SADRL strategy.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6137-6
Aerodynamic drag is the dominant factor contributing to energy consumption as the operational speed of high-speed trains increases, necessitating effective aerodynamic optimization strategies. This study investigates the aerodynamic characteristics of the bogie region under two bogie fairing configurations: baseline bogie fairing (BBF) and full bogie fairing (FBF). Both stationary and rotating wheelset conditions are considered. Wind tunnel experiments were conducted on a full-scale bogie model equipped with a wheelset drive system to simulate wheelset rotation. Additionally, numerical simulations were employed to analyze flow structures. Results indicate that the FBF configuration promotes a more uniform front-to-rear pressure distribution in the bogie region. The rotation of the wheelset notably affects the airflow near the wheels and extends its influence throughout the entire bogie region. Specifically, wheelset rotation reduces drag by 6.38% in the BBF configuration but increases drag by 3.5% in the FBF configuration. Further analysis reveals that, in the FBF configuration, aerodynamic drag primarily originates from the wheelsets. The rotating wheelset increases the aerodynamic drag by 18.8% for the rear wheelset, which is attributed to the shift in the pressure curve on the wheelset in the rotating direction. Therefore, the impact of wheelset rotation on aerodynamic characteristics should not be overlooked.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-6045-9
The study aims to investigate the carbonated water erosion mechanism of lining concrete in tunnels traversing karst environment and enhance its resistance. In this study, dynamic carbonated water erosion was simulated to assess erosion depth, microstructure, phase migrations, and pore structure in various tunnel lining cement-based materials. Additionally, Ca2+ leaching was analyzed, and impact of Ca/Si molar ratio in hydration products on erosion resistance was discussed by thermodynamic calculations. The results indicate that carbonated water erosion caused rough and porous surface on specimens, with reduced portlandite and CaCO3 content, increased porosity, and an enlargement of pore size. The thermodynamic calculations indicate that the erosion is spontaneous, driven by physical dissolution and chemical reactions dominated by Gibbs free energy. And the erosion reactions proceed more spontaneously and extensively when Ca/Si molar ratio in hydration products was higher. Therefore, cement-based materials with higher portlandite content exhibit weaker erosion resistance. Model-building concrete, with C-S-H gel and portlandite as primary hydration products, has greater erosion susceptibility than shotcrete with ettringite as main hydration product. Moreover, adding silicon-rich mineral admixtures can enhance the erosion resistance. This research offers theory and tech insights to boost cement-based material resistance against carbonated water erosion in karst tunnel engineering.
Journal of Central South University•2025•DOI: 10.1007/s11771-025-5900-z
A high-speed train travelling from the open air into a narrow tunnel will cause the “sonic boom” at tunnel exit. When the maglev train’s speed reaches 600 km/h, the train-tunnel aerodynamic effect is intensified, so a new mitigation method is urgently expected to be explored. This study proposed a novel asymptotic linear method (ALM) for micro-pressure wave (MPW) mitigation to achieve a constant gradient of initial compression waves (ICWs), via a study with various open ratios on hoods. The properties of ICWs and MPWs under various open ratios of hoods were analyzed. The results show that as the open ratio increases, the MPW amplitude at the tunnel exit initially decreases before rising. At the open ratio of 2.28%, the slope of the ICW curve is linearly coincident with a supposed straight line in the ALM, which further reduces the MPW amplitude by 26.9% at 20 m and 20.0% at 50 m from the exit, as compared to the unvented hood. Therefore, the proposed method effectively mitigates MPW and quickly determines the upper limit of alleviation for the MPW amplitude at a fixed train-tunnel operation condition. All achievements provide a new potential measure for the adaptive design of tunnel hoods.
Int. Journal of Minerals, Metallurgy and Materials (矿物冶金与材料学报)•2025•DOI: 10.1007/s12613-025-3269-5
Low-concentration coal mine methane (LC-CMM), which is predominantly composed of methane, serves as a clean and low-carbon energy resource with significant potential for utilization. Utilizing LC-CMM as fuel for solid oxide fuel cells (SOFCs) represents an efficient and promising strategy for its effective utilization. However, direct application in Ni-based anodes induces carbon deposition, which severely degrades cell performance. Herein, a medium-entropy oxide Sr2FeNi0.1Cr0.3Mn0.3Mo0.3O6−δ (SFNCMM) was developed as an anode internal reforming catalyst. Following reduction treatment, FeNi3 nano-alloy particles precipitate on the surface of the material, thereby significantly enhancing its catalytic activity for LC-CMM reforming process. The catalyst achieved a methane conversion rate of 53.3%, demonstrating excellent catalytic performance. Electrochemical evaluations revealed that SFNCMM-Gd0.1Ce0.9O2−δ (GDC) with a weight ratio of 7:3 exhibited superior electrochemical performance when employed as the anodic catalytic layer. With H2 and LC-CMM as fuels, the single cell achieved maximum power densities of 1467.32 and 1116.97 mW·cm−2 at 800°C, respectively, with corresponding polarization impedances of 0.17 and 1.35 Ω·cm2. Furthermore, the single cell maintained stable operation for over 100 h under LC-CMM fueling without significant carbon deposition, confirming its robust resistance to carbon formation. These results underscore the potential of medium-entropy oxides as highly effective catalytic layers for mitigating carbon deposition in SOFCs.
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/s40820-024-01577-0
Harvesting the immense and renewable osmotic energy with reverse electrodialysis (RED) technology shows great promise in dealing with the ever-growing energy crisis. One key challenge is to improve the output power density with improved trade-off between membrane permeability and selectivity. Herein, polyelectrolyte hydrogels (channel width, 2.2 nm) with inherent high ion conductivity have been demonstrated to enable excellent selective ion transfer when confined in cylindrical anodized aluminum pore with lateral size even up to the submillimeter scale (radius, 0.1 mm). The membrane permeability of the anti-swelling hydrogel can also be further increased with cellulose nanofibers. With real seawater and river water, the output power density of a three-chamber cell on behalf of repeat unit of RED system can reach up to 8.99 W m−2 (per unit total membrane area), much better than state-of-the-art membranes. This work provides a new strategy for the preparation of polyelectrolyte hydrogel-based ion-selective membranes, owning broad application prospects in the fields of osmotic energy collection, electrodialysis, flow battery and so on.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01546-7
Sodium-ion batteries hold great promise as next-generation energy storage systems. However, the high instability of the electrode/electrolyte interphase during cycling has seriously hindered the development of SIBs. In particular, an unstable cathode–electrolyte interphase (CEI) leads to successive electrolyte side reactions, transition metal leaching and rapid capacity decay, which tends to be exacerbated under high-voltage conditions. Therefore, constructing dense and stable CEIs are crucial for high-performance SIBs. This work reports localized high-concentration electrolyte by incorporating a highly oxidation-resistant sulfolane solvent with non-solvent diluent 1H, 1H, 5H-octafluoropentyl-1, 1, 2, 2-tetrafluoroethyl ether, which exhibited excellent oxidative stability and was able to form thin, dense and homogeneous CEI. The excellent CEI enabled the O3-type layered oxide cathode NaNi1/3Mn1/3Fe1/3O2 (NaNMF) to achieve stable cycling, with a capacity retention of 79.48% after 300 cycles at 1 C and 81.15% after 400 cycles at 2 C with a high charging voltage of 4.2 V. In addition, its nonflammable nature enhances the safety of SIBs. This work provides a viable pathway for the application of sulfolane-based electrolytes on SIBs and the design of next-generation high-voltage electrolytes.
Nano-Micro Letters•2025•DOI: 10.1007/s40820-024-01538-7
Gas quenching and vacuum quenching process are widely applied to accelerate solvent volatilization to induce nucleation of perovskites in blade-coating method. In this work, we found these two pre-crystallization processes lead to different order of crystallization dynamics within the perovskite thin film, resulting in the differences of additive distribution. We then tailor-designed an additive molecule named 1,3-bis(4-methoxyphenyl)thiourea to obtain films with fewer defects and holes at the buried interface, and prepared perovskite solar cells with a certified efficiency of 23.75%. Furthermore, this work also demonstrates an efficiency of 20.18% for the large-area perovskite solar module (PSM) with an aperture area of 60.84 cm2. The PSM possesses remarkable continuous operation stability for maximum power point tracking of T90 > 1000 h in ambient air.