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Spin–orbit torque (SOT) can provide efficient electrical manipulation of magnetism via applying electrical current to breaking the symmetry of damping-like torque. In the heterojunction of heavy and ferromagnetic metal, Dzyaloshinskii–Moriya interaction (DMI) is one of the key ingredients for stabilizing chiral spin structures, like chiral domain walls. Meanwhile, materials with larger charge-spin conversion rates are also highly expected for the efficient SOT. In this paper, spin–orbit torque magnetic switching is observed in the perpendicularly magnetized Pt/Co/Bi2Se3 and shows relatively high efficiency with low critical switching current density of about 5 × 105 A cm−2. The SOT efficiency and DMI in perpendicularly magnetized Pt/Co/Bi2Se3 were quantitatively investigated by electrical detection of the effective spin Hall field. The DMI constant is about 2.6 mJ m−2, and the effective spin Hall angle of Pt/Co/Bi2Se3 is about 0.14. The work also demonstrates that the Bi2Se3 layer takes the main responsibility for SOT, and the Pt/Co interface is the main source of DMI in Pt/Co/Bi2Se3 structures, which makes it possible to achieve independent optimization of DMI and SOT in the Pt/Co/Bi2Se3 structure at room temperature for the advanced application of spintronic devices. [ABSTRACT FROM AUTHOR]

Spin–orbit torque (SOT) can provide efficient electrical manipulation of magnetism via applying electrical current to breaking the symmetry of damping-like torque. In the heterojunction of heavy and ferromagnetic metal, Dzyaloshinskii–Moriya interaction (DMI) is one of the key ingredients for stabilizing chiral spin structures, like chiral domain walls. Meanwhile, materials with larger charge-spin conversion rates are also highly expected for the efficient SOT. In this paper, spin–orbit torque magnetic switching is observed in the perpendicularly magnetized Pt/Co/Bi2Se3 and shows relatively high efficiency with low critical switching current density of about 5 × 105 A cm−2. The SOT efficiency and DMI in perpendicularly magnetized Pt/Co/Bi2Se3 were quantitatively investigated by electrical detection of the effective spin Hall field. The DMI constant is about 2.6 mJ m−2, and the effective spin Hall angle of Pt/Co/Bi2Se3 is about 0.14. The work also demonstrates that the Bi2Se3 layer takes the main responsibility for SOT, and the Pt/Co interface is the main source of DMI in Pt/Co/Bi2Se3 structures, which makes it possible to achieve independent optimization of DMI and SOT in the Pt/Co/Bi2Se3 structure at room temperature for the advanced application of spintronic devices. [ABSTRACT FROM AUTHOR]

Elucidating the correlation between coordination structures and catalytic performances of single-atom active sites is imperative for the precise design of highly efficient catalysts; however, the feasible regulation of coordination environments in single-atom catalysts presents a formidable challenge. Herein, we fabricate single-atom Ru-based catalysts with Ru–F4 and Ru–O4 configurations (named Ru–F4 SAs/PA and Ru–O4 SAs/PA, respectively), demonstrating that fine-tuning of the coordination structure of Ru sites can significantly enhance performances for CO2 hydrogenation to methane under mild conditions in a photo-thermal synergistic catalytic process. Comparative studies reveal that Ru–F4 SAs/PA outperformed Ru–O4 SAs/PA counterparts, giving superior CO2 methanation performances with a CH4 production rate of 47.4 mmol gcat−1 h−1 and CH4 selectivity of 93.8% at 200 °C in the presence of light irradiation (200–1100 nm, 1.9 W cm−2) under atmospheric pressure. Theoretical investigations unravel that the transition from Ru–O4 to Ru–F4 coordination environments optimizes the electronic states, thereby enhancing the adsorption of reactants and intermediates. Moreover, the optimized electronic structure promotes the production and transformation of key intermediate species, lowers the energy barrier for CO2 conversion, and thus elevates the catalytic activity. This comprehensive study not only clarifies the relationship between the coordination structures of active sites and catalytic performance at the atomic-level but also offers a novel paradigm for the design of efficient CO2 conversion catalysts. [ABSTRACT FROM AUTHOR]

The n-type semiconductor SnO2 with a wide band gap (3.6 eV) is massively used in gas-sensitive materials, but pure SnO2 still suffers from a high operating temperature, low response, and tardy responding speed. To solve these problems, we prepared small-sized pure SnO2 using hydrothermal and freeze-drying methods (SnO2-FD) and compared it with SnO2 prepared using a normal drying method (SnO2-AD). The sensor of SnO2-FD had an ultra-high sensitivity to NO2 at 100 °C with excellent selectivity and humidity stability. The outstanding gas sensing properties are attributed to the modulation of energy band structure and the increased carrier concentration, making it more accessible for electron exchange with NO2. The excellent gas sensing properties of SnO2-FD indicate its tremendous potential as a NO2 sensor. [ABSTRACT FROM AUTHOR]

Aero-space aluminum alloys, as vital materials in aerospace engineering, find extensive application in various aerospace components. However, prolonged usage often leads to the emergence of fatigue natural cracks, posing significant safety risks. Therefore, research on accurate quantitative detection techniques for the cracks in aerospace-aluminum alloys is of vital importance. Firstly, based on the three-points bending experimental model, this paper prepared the fatigue natural crack specimen, and the depth of the natural crack is calibrated. Then, given the complexity of geometric characteristics inherent in natural cracks, the pulsed eddy current signal under the different natural crack depth is acquired and analyzed using an experimental study. Finally, to better exhibit the non-linearity between PEC signal and crack depth, a GA-based BPNN algorithm is proposed. The Latin Hypercube method is considered to optimize the population distribution in the genetic algorithm. The results indicate that the characterization accuracy reaches 2.19% for the natural crack. [ABSTRACT FROM AUTHOR]

This research focuses on the under-studied phenomenon of maritime borders by providing a civilian perspective on how fishers live, negotiate, contest, and transcend state borders and surveillance at sea. It explores the everyday transboundary practices of Chinese fishers in the geopolitically sensitive South China Sea (SCS), examining their cross-border tactics to sustain fishing livelihoods and the mechanisms underpinning these tactics. Based on long-term, continuous ethnographic investigations, we unravel four tactics employed by Chinese fishers to elude the constraints of territorial borders: contract production, trans-territorial production, paying for the sea, and the appropriation of marine physicality. These transboundary strategies are supported by three mechanisms, including common fisher identity, historical transnational networks, and regional development structures. This research shows the agency and creativity of fishers in challenging and punctuating maritime territoriality in the context of increasing militarisation and securitisation of borderlands. It illustrates how the distinct materiality, mobility, and temporality of the ocean can be weaponised by fishers to undermine state-bordering processes. By exposing the extensive, dynamic, and complex civilian interactions and collaborations in the region, we demonstrate that the SCS is more than a geopolitical space but at the same time a social site of cooperation and solidarity. In doing so, this research contributes to studies of maritime borders and civilian geopolitical subjectivity by illuminating the flexibility of fishers in exercising powers on borders at sea. It also advances the existing SCS area studies by 'peopling' the political geography of the region. [ABSTRACT FROM AUTHOR]

Aerogel-based composites, renowned for their three-dimensional (3D) network architecture, are gaining increasing attention as lightweight electromagnetic (EM) wave absorbers. However, attaining high reflection loss, broad effective absorption bandwidth (EAB), and ultrathin thickness concurrently presents a formidable challenge, owing to the stringent demands for precise structural regulation and incorporation of magnetic/dielectric multicomponents with synergistic loss mechanisms within the 3D networks. In this study, we successfully synthesized a 3D hierarchical porous Fe 3 O 4 /MoS 2 /rGO/Ti 3 C 2 T x MXene (FMGM) composite aerogel via directional freezing and subsequent heat treatment processes. Owing to their ingenious structure and multicomponent design, the FMGM aerogels, featured with abundant heterogeneous interface structure and magnetic/dielectric synergism, show exceptional impedance matching characteristics and diverse EM wave absorption mechanisms. After optimization, the prepared ultralight (6.4 mg cm -3 ) FMGM-2 aerogel exhibits outstanding EM wave absorption performance, achieving a minimal reflection loss of -66.92 dB at a thickness of 3.61 mm and an EAB of 6.08 GHz corresponding to the thickness of 2.3 mm, outperforming most of the previously reported aerogel-based absorbing materials. This research presents an effective strategy for fabricating lightweight, ultrathin, highly efficient, and broad band EM wave absorption materials.

Background: Angrogenetic alopecia (AGA) is one of the most prevalent hair loss disorders worldwide. The hair follicle stem cell (HFSC) is closely related to the formation of hair follicle (HF) structure and HF self-renewal. The activation of HFSC in AGA is critical for hair growth. Pilose antler has been reported to have hair growth-promoting activity, but the mechanism of action on AGA and HFSC has not been reported. Methods: We previously extracted an active component from the pilose antler known as PAEs. In this study, we conducted experiments using AGA mice and HFSC. The effects of PAEs on hair growth in AGA mice were firstly detected, and then the mechanisms of PAEs for AGA were predicted by integrating network pharmacology and de novo transcriptomics data of pilose antler. Finally, biological experiments were used to validate the molecular mechanism of PAEs in treating AGA both in vivo and in vitro . Results: It was found that PAEs promoted hair regrowth by accelerating the activation of anagen, delaying the anagen-catagen transition. It also alleviated the morphological changes, such as hair shortening, thinning, miniaturization, and HF number reduction, and regulated the hair regeneration process of four subtypes of hair. We further found that PAEs could promote the proliferation of HFSC, outer root sheath (ORS) cells, and hair bulb cells in AGA mice. We then integrated network pharmacology and pilose antler transcriptomics data to predict that the mechanism of PAEs treatment in AGA mice is closely related to the PI3K-AKT/Wnt-β-Catenin pathways. Subsequently, it was also verified that PAEs could activate both pathways in the skin of AGA mice. In addition, we found that PAEs perhaps increased the number of blood vessels around dermal papilla (DP) in experiments in vivo . Meanwhile, the PAEs stimulated the HFSC proliferation in vitro and activated the AKT and Wnt pathways. However, the proliferative activity of HFSC was inhibited after blocking the Wnt pathway and AKT activity. Conclusion: This study suggests that the hair growth-promoting effect of PAEs in AGA mice may be closely related to the stimulation of the AKT and Wnt pathways, which in turn activates the proliferation of HFSC., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, He, Liu, Sun, Ma, Sun and Wang.)

Bimetallic alloy nanoparticles have garnered substantial attention for diverse catalytic applications owing to their abundant active sites and tunable electronic structures, whereas the synthesis of ultrafine alloy nanoparticles with atomic-level homogeneity for bulk-state immiscible couples remains a formidable challenge. Herein, we present the synthesis of Ru x Co 1- x solid-solution alloy nanoparticles (ca. 2 nm) across the entire composition range, for highly efficient, durable, and selective CO 2 hydrogenation to CH 4 under mild conditions. Notably, Ru 0.88 Co 0.12 /TiO 2 and Ru 0.74 Co 0.26 /TiO 2 catalysts, with 12 and 26 atom % of Ru being substituted by Co, exhibit enhanced catalytic activity compared with the monometallic Ru/TiO 2 counterparts both in dark and under light irradiation. The comprehensive experimental investigations and density functional theory calculations unveil that the electronic state of Ru is subtly modulated owing to the intimate interaction between Ru and Co in the alloy nanoparticles, and this effect results in the decline in the CO 2 conversion energy barrier, thus ultimately culminating in an elevated catalytic performance relative to monometallic Ru and Co catalysts. In the photopromoted thermocatalytic process, the photoinduced charge carriers and localized photothermal effect play a pivotal role in facilitating the chemical reaction process, which accounts for the further boosted CO 2 methanation performance.