Search Results (1,521)

The growing demand for sustainable construction materials has led to significant advancements in ultra-high-performance concrete (UHPC), with a particular focus on geopolymer-based systems as an alternative to conventional cementitious binders. This review explores the latest developments in sustainable Ultra-High-Performance Geopolymer Concrete (UHPGPC) by analysing key material composition, mechanical, durability and microstructural properties. The incorporation of ground granulated blast furnace slag (GGBFS), silica fume (SF), and fly ash (FA) has demonstrated notable improvements in compressive strength, durability, and workability. Additionally, the use of activators such as sodium silicate and sodium hydroxide optimizes geopolymerization, resulting in a denser microstructure and enhanced mechanical performance. This review highlights the critical role of fibre reinforcement in UHPGPC, where steel fibres (SFs) and hybrid fibres significantly enhance compressive and tensile strength, as well as crack resistance. The inclusion of waste materials such as rice husk ash and recycled glass promotes sustainability by reducing CO₂ emissions while maintaining structural integrity. However, higher waste-glass content may adversely affect bonding due to its smooth surface texture. The findings highlight the potential of UHPGC as a high-performance, eco-friendly alternative to traditional cement-based UHPC. By integrating industrial by-products and alternative activation techniques, UHPGPC can contribute significantly to the global shift towards sustainable and low-carbon construction materials. Full article

Soil microbial carbon use efficiency (CUE) is a pivotal determinant of soil carbon sequestration, yet how forest quality gradients regulate CUE through the interplay of mineral-microbial interactions in subtropical conifer ecosystems remains poorly understood. To address this, we examined the CUE response and its drivers across a forest quality gradient (high-quality to poor-quality stands) in subtropical coniferous forests in China. Soil mineral composition (including soil texture and the contents of Fe₂O₃, CaO, and MgO), physicochemical properties, microbial community diversity, and CUE were quantified. The results showed that CUE decreased by 2.7%, from 0.533 in high-quality stands to 0.519 in low-quality stands. Concurrently, soil organic carbon (SOC), nutrient availability, and microbial diversity exhibited consistent declining trends along the forest quality gradient. The CUE showed a significant positive correlation with SOC (r > 0.90, p < 0.001). Structural equation modeling and random forest revealed that microbial diversity was the most dominant correlated factor of CUE (the total effects on CUE = 0.932), followed by SOC. However, soil minerals indirectly influenced CUE via SOC. These findings highlight microbial diversity as the dominant observed correlate of CUE across forest quality gradients. This study not only deepens the understanding of the microbial mechanisms underlying soil carbon dynamics in subtropical forests but also provides key scientific basis for ecological restoration of poor-quality forests and nature-based climate solutions. Full article

Phosphorus (P) accumulation in intensively agricultural soils represents a growing environmental concern due to its potential mobilization and contribution to eutrophication. This study investigated the mechanisms controlling P availability and redistribution in agricultural soils from the Elota–Piaxtla Irrigation District (northwestern Mexico) during cropping and non-cropping periods. Soil P fractions were determined using the Hedley sequential extraction method and related to soil physicochemical properties through a correlation analysis. During the cropping period, P in Fe/Al hydroxides dominated (45–67% of total P), indicating strong adsorption and fixation in fine-textured soils. In contrast, the non-cropping period showed a significant increase in organic P in humic substances (up to 55%), suggesting enhanced biological transformation and residue recycling. Labile P fractions decreased from 60% to 44% of total P between sampling periods, while moderately labile fractions increased, indicating seasonal redistribution of P pools. Statistical analysis revealed that P dynamics were primarily governed by mineralogical characteristics and organic matter transformations rather than by individual soil properties. The accumulation of moderately labile and organic P fractions during fallow periods highlights a latent environmental risk, particularly in irrigated systems prone to runoff and erosion. These findings emphasize the need for fraction-based nutrient management strategies that integrate both agronomic efficiency and environmental protection in intensive agricultural soil. Full article

Magnesium (Mg) alloy sheets usually suffer from severe mechanical anisotropy and a trade-off between strength and ductility. In this work, the effects of rolling temperature (200 °C and 400 °C) and rolling speed (50–1000 r/min) on the microstructure and mechanical properties of a Mg-1Sm (samarium, Sm) (wt.%) alloy were systematically investigated. Low-temperature rolling (200 °C) results in high dislocation density and a double-peak basal texture in Mg-1Sm alloy, causing very limited plasticity and a pronounced anisotropy with a lower yield strength along the rolling direction (RD) than along the transverse direction (TD). A significantly improved mechanical property (yield strength of ~196 MPa, elongation of 18.4% and near-isotropy) can be achieved in the Mg-1Sm alloy by optimizing the rolling conditions (400 °C, 500 r/min). The findings indicate that increasing the temperature is beneficial for activating non-basal slip and multiple twinning modes, thereby weakening and dispersing the basal texture, which can efficiently improve the anisotropic properties. Increasing the rolling speed can promote the recrystallization process, resulting in the enhancement of plasticity. Quantitative analyses reveal that the reduction in dislocation density and the suppression of Sm segregation at grain boundaries under high-temperature high-speed rolling are responsible for the improved ductility and reduced anisotropy. Full article

Mg–Y–Zn alloys have attracted considerable attention for lightweight structural applications; however, the influence of extrusion temperature on microstructural evolution and the underlying mechanisms governing strength–ductility synergy remains insufficiently understood. In this study, a novel YZG921 (Mg–9Y–1.8Zn–1.2Gd–0.5Zr–0.3Ca, wt.%) alloy was fabricated by hot extrusion at temperatures ranging from 480 to 520 °C. The microstructure, mechanical properties, and deformation behavior were systematically investigated using SEM, TEM, EBSD, in situ EBSD, and slip-trace analysis. The results show that extrusion temperature significantly affects the evolution of secondary phases, grain size, and texture intensity. At 500 °C, an 18R-LPSO phase was formed, accompanied by a more homogeneous distribution of secondary phases and the finest grain structure (~3.8 μm), whereas the average grain size remained close to 10 μm for the alloys extruded at 480 °C and 520 °C. Meanwhile, the maximum basal texture intensity decreased from 4.16 to 4.79 m.r.d. to 2.18–2.58 m.r.d. Mechanical testing revealed that the alloy extruded at 500 °C exhibited the optimum strength–ductility balance, with an ultimate tensile strength of 498.4 MPa and an elongation of 13.8%. In situ EBSD analysis showed that the fraction of low-angle grain boundaries increased from ~7% to 43% during tensile deformation, while the average KAM value increased from ~0.5° to 0.88°. Slip-trace analysis further demonstrated that plastic deformation was predominantly governed by basal slip, accounting for approximately 84.2% of the activated slip systems. The superior mechanical performance achieved at 500 °C is attributed to the synergistic effects of grain refinement, LPSO and second-phase strengthening, texture weakening, and sustained strain hardening. These findings provide insights into microstructure–property relationships and offer guidance for the optimization of thermomechanical processing parameters in Mg–Y–Zn alloys. Full article

In order to improve the poor wear resistance and adhesive wear of 7075 aluminum alloy under dry friction conditions, a nanosecond pulse laser was used to prepare surface micro-textures with different shapes, surface densities, and feature sizes. Subsequently, their friction and wear behavior, as well as the corresponding failure mechanisms, were systematically investigated. Circular, square, and hexagonal micro-pit textures were selected as the research objects. Combined with surface morphology characterization, ball-on-disk dry wear tests, reciprocating friction tests, and contact stress and wear model analyses, the effects of texture parameters on tribological performance were systematically revealed. The results indicate that laser microtexturing can reduce the coefficient of friction on the surface of 7075 aluminum alloy to a certain extent and improve its wear resistance, with the friction-reducing effect closely related to the texture shape, areal density, and feature size. Among these, hexagonal texturing exhibited the best friction-reducing effect, while circular texturing demonstrated superior formation quality and friction stability. Compared to other specimens, the T8 group with a 7.5% areal density and a feature size of 100 µm exhibited the lowest average coefficient of friction. During the friction process, the microstructures gradually fail due to plastic flow filling, wear debris accumulation, and edge collapse. The research findings provide a reference for the optimized design and engineering applications of surface microstructures on aluminum alloys. Full article

The influence of double continuous cold rolling followed by annealing on the texture evolution and mechanical properties of a commercial low-carbon ferritic steel was investigated. Ultrathin sheets (final thickness 0.22 mm) were produced through a two-stage cold rolling process with intermediate and final annealing at 690 °C for 35 s, followed by light temper rolling at 100 °C for 20 s. Texture evolution was characterized using Electron Backscatter Diffraction (EBSD) with Orientation Imaging Microscopy (OIM), producing pole figures and orientation distribution functions (ODFs). Mechanical properties were evaluated through Vickers microhardness and ultimate tensile strength measurements obtained from three independent locations per sample. Quantitative ODF analysis (φ₂ = 45°) revealed that γ-fiber ({111}//ND) intensity increased after each cold reduction stage and decreased after annealing due to recrystallization. The α-fiber (110/RD) and cube components (001//RD) showed a slight increase after annealing. The final ultrathin sheet exhibited moderate γ-fiber intensity (≈3 M.R.D), low Vickers microhardness (100–150 HV), and tensile strength (400–450 MPa). These results demonstrate controlled evolution of texture and microstructure during double cold rolling and annealing, providing a basis for future studies on forming-related behavior without directly assessing formability. Full article

Polyurethane synthetic leather is a widely used covering material in automotive interiors, and its surface coating characteristics directly determine the occupant experience. However, the underlying mechanisms by which these characteristics influence visuo-tactile perception in the context of new energy vehicles (NEVs) require further investigation. In this study, a composite experimental matrix was constructed by combining surface textures with distinct roughness gradients and representative colors extracted via data mining within the HSV color space. Targeting these two surface coating characteristics—color and texture—systematic evaluations were conducted across three independent perception stages: purely visual, purely tactile, and combined visuo-tactile. Eye-tracking metrics, specifically pupil diameter and total fixation duration, were extracted and cross-analyzed alongside multidimensional subjective evaluations. The results indicate that surface texture exerts a significant main effect on both perceived tactile softness and pleasantness, whereas the impact of color variation is remarkably weak. Furthermore, highly complex surface textures lead to prolonged fixation durations, reflecting increased exploratory interest and the high perceptual salience of intricate details rather than mere cognitive workload. Moreover, significant differences in pupil diameter were observed across texture conditions, potentially reflecting the combined influence of low-level image properties and higher-order texture perception. Concurrently, an interference effect of visual features on tactile perception was observed; specifically, the introduction of visual cues (encompassing color and texture) significantly diminished the pleasantness experienced during tactile interaction. These findings elucidate the intrinsic connections between surface coating characteristics and users’ visuo-tactile perception, offering important theoretical guidance and practical implications for optimizing the surface design of automotive polyurethane synthetic leather and enhancing the overall occupant experience. Full article

To address the demand for lightweight, high-performance Al-Si-Mg alloys in aerospace and automotive industries, this work proposes a novel synergistic strengthening strategy by combining rare-earth Y microalloying and in situ synthesized ZrB₂ nanoparticles to construct a hybrid reinforcement architecture. The effects of Y-ZrB₂ additions on the microstructure, crystallographic orientation evolution, and mechanical properties of Al-Si-Mg alloys were systematically investigated via XRD, SEM, EBSD, and tensile/hardness tests. Results show that compared with the base alloy and single-modified alloys, the co-addition of Y and ZrB₂ simultaneously enhances mechanical properties and optimizes grain structure. The optimal comprehensive performance is achieved at 0.3 wt.% Y + 2 wt.% ZrB₂ after T6 heat treatment, with ultimate tensile strength of 332.87 MPa, yield strength of 271.35 MPa, elongation of 16.24%, and Vickers hardness of 153.9 HV. Phase analysis and SEM-EDS confirm a synergistic coupling relationship between Y-rich phases and ZrB₂ nanoparticles. EBSD characterization reveals that Y-ZrB₂ modification has negligible effect on the morphology and crystallographic orientation stability of primary α-Al grains, but effectively regulates the lattice rotation, texture redistribution, and growth behavior of eutectic Si. At the optimal composition, the fraction of high-angle grain boundaries (HAGBs) reaches a maximum of 34.3%. Furthermore, the synergistic effect significantly increases the geometrically necessary dislocation (GND) density and reduces the Schmid factor of the dominant {111}⟨110⟩ slip system, thus enhancing dislocation strengthening and plastic deformation resistance. This work clarifies the intrinsic strength-ductility synergy mechanism of Y-ZrB₂ co-modified Al-Si-Mg alloys, paving a new pathway for the development of advanced lightweight aluminum alloys. Full article

TC2 titanium alloy (Ti-4Al-1.5Mn, wt.%) is a near-α titanium alloy with promising aerospace and biomedical applications, but its limited room temperature ductility and strong texture sensitivity hinder the fabrication of high-performance sheets. In this study, the effects of hot rolling at 830 °C and 930 °C on the microstructure, macro-texture, mechanical properties, and fracture behavior of TC2 alloy were investigated. Compared with the 830 °C rolled sample, the 930 °C rolled sample exhibited finer primary α grains, a higher volume fraction of fine and dispersed secondary α_s phase, and more uniform Mn distribution, while both samples retained an α + β phase constitution. Texture and ODF (orientation distribution function) analyses revealed that increasing the rolling temperature reduced the maximum intensity of the (0001) pole figure from 6.68 to 5.23 m.r.d. (multiples of a random distribution) and increased that of the (10-10) pole figure to 9.62 m.r.d., indicating weakened basal texture, enhanced prismatic texture, and more dispersed orientation distribution. Consequently, although the tensile strength slightly decreased to approximately 730 MPa, the elongation increased from approximately 24% to 28%. The finer and denser dimples observed after 930 °C rolling further confirmed improved plastic deformation coordination. Full article

Ready-to-eat sea cucumbers (RSC) cannot be preserved at room temperature due to autolysis, which is closely related to the instability of collagen resulting from the disruption of hydrogen bonds. To investigate the protective effect of N-(3-Dimethylaminopropyl)-N′-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) cross-linking against disruption of hydrogen bonds and its role in stabilizing RSC quality at room temperature, this study designed comparative experiments involving EDC/NHS cross-linking treatments with varying sequences of hydrogen bonds disruption. The results indicated that EDC/NHS positively affects the stabilization of the collagen structure in RSC. The various quality parameters of both groups of RSC that underwent cross-linking treatment before and after hydrogen bonds disruption were significantly better than those of the control group, which only experienced the breaking of hydrogen bonds. Notably, the Eb group, which underwent EDC/NHS cross-linking treatment prior to the disruption of the hydrogen bonds network, yielded even more favorable results. Preliminary analyses of textural properties and moisture content suggested that EDC/NHS helps delay the deterioration of RSC quality. The levels of soluble components and carbonyl groups indicated that prior cross-linking treatment is more effective in mitigating collagen degradation and oxidation. Differential scanning calorimetry revealed that the reduction in ΔH for the Eb group was only 2.4%. Furthermore, fluorescence spectroscopy, Fourier transform infrared spectroscopy, and circular dichroism spectroscopy, examined from the perspectives of secondary and tertiary structures respectively, indicated that the cross-linking mechanism of EDC/NHS involves the formation of a more robust network of amide bonds, thereby preventing the disruption of hydrogen bonds and enhancing collagen stability, enabling it to better resist the cleavage of hydrogen bonds due to urea. The scanning electron microscope and Van Gieson’s staining techniques offer a clearer illustration of this point from a microscopic perspective. Moreover, molecular docking simulations have indicated the cross-linking mechanism of EDC/NHS at the atomic level, thereby establishing a scientific foundation for the potential application and development of EDC/NHS in room-temperature storage technologies for RSC. Full article

Microbial dolostones of the Sinian Qigebulake Formation in the Kepin area, northwestern Tarim Basin, represent an important target for deep to ultra-deep hydrocarbon exploration. Based on integrated analyses of outcrop sections, drilling cores, thin sections, scanning electron microscopy (SEM), and petrophysical data, this study systematically investigates the lithofacies characteristics, reservoir space types, and controlling factors of microbial dolostone reservoirs. (1) Five major lithofacies types were identified, including stromatolitic dolostone, clotted dolostone, foamy laminated dolostone, granular dolostone, and crystalline dolostone. These lithofacies mainly developed in an inner-ramp depositional setting and vertically formed a shallowing-upward sedimentary succession from tidal flat to microbial mound and shoal facies. Reservoir spaces are dominated by secondary dissolution pores, including framework dissolution pores, intergranular and intragranular dissolution pores, vugs, fractures, and karst cavities. The reservoirs are characterized by medium porosity, low permeability, and strong heterogeneity. (2) Sedimentary facies, microbial dolomitization, and karstification jointly controlled the development of relatively favorable reservoir intervals. Early microbial-induced dolomitization enhanced the rigidity of microbial frameworks and facilitated the preservation of primary pores, whereas meteoric karstification associated with the terminal Sinian Keping Movement significantly improved reservoir quality through large-scale dissolution enlargement and fracture-cavity development. SEM observations reveal abundant microbial mineralization textures, including cauliflower-shaped, dumbbell-shaped, and spheroidal dolomite morphologies associated with EPS remnants, providing direct evidence for microbial mediation during dolomite precipitation. (3) Reservoir intervals with relatively favorable physical properties are mainly distributed in the middle-upper microbial mound intervals and upper karst-modified zones of the Qigebulake Formation, forming a favorable source–reservoir–seal assemblage with the overlying Yuertusi Formation black shales. This study provides new insights into the formation and preservation mechanisms of deep microbial dolostone reservoirs and offers important implications for ultra-deep hydrocarbon exploration in the Tarim Basin. Full article

Dietary emulsifiers, common in processed and ultra-processed foods, improve food texture and shelf life but may affect gut health by interacting with the microbiota and intestinal barrier. While emulsifiers have long been considered safe, growing evidence links their presence in ultra-processed foods to chronic disease risk. This review aims to evaluate the current understanding of the factors and mechanisms underlying individual differences in intestinal mucosal susceptibility to dietary emulsifiers. A search of PubMed and Embase through February 2026 identified eight relevant studies. Overall, the available evidence indicates a heterogeneous and highly individualized host response to dietary emulsifiers. These differences appear to be strongly influenced by the gut microbiota and its functional properties, while animal studies further suggest that host factors such as sex-related differences in microbial composition may also contribute to variability in response. Importantly, not all emulsifiers have the same effects, underscoring compound-specific impacts on gut physiology. The findings demonstrate that sensitivity to dietary emulsifiers varies substantially between individuals, challenging the long-standing assumption that these additives are universally safe. Given the multifactorial nature of this susceptibility, particularly the role of the gut microbiota, future research should adopt an integrative approach that combines microbial profiling with host genetics, immune responses, and early-life exposures. Such efforts will be essential to identify at-risk individuals and to inform more personalized dietary recommendations aimed at preserving intestinal health and reducing disease risk. Importantly, there is a clear need for larger, well-powered studies that can validate and expand upon these initial observations. Full article

Pretwinning followed by annealing was employed to modify the microstructure and texture of an AZ31 wrought magnesium alloy. A precompression step was applied to an as-rolled plate to introduce dense extension twin bands, after which annealing at 300 °C for 5, 15, and 60 min was conducted. The resulting microstructures were analyzed in terms of grain size, recrystallization behavior, and texture evolution. Mechanical properties were evaluated using uniaxial compression tests along the rolling, transverse, and normal directions to quantify changes in mechanical anisotropy. The results show that this thermomechanical treatment effectively reduces yield strength anisotropy through twin-assisted recrystallization and texture randomization. The mechanical response is interpreted based on microstructural changes and the activation of twining and slip systems. Full article

The complex geometries feasible with Laser Powder Bed Fusion (PBF-LB/M) lead to varying sizes of scanned cross sections within the layers and hence differing cooling rates. Since PBF-LB/M results in intragranular cell structures, which cause relatively high strengths in the austenitic steel AISI 316L, the influence of changes in the specimen size on the cell structure was investigated. The results obtained from the geometries realized in this work showed no significant influence of the specimen size on the cell sizes. To analyze the relation between the cell structure and the mechanical properties, cyclic indentation tests (CIT) were performed accordingly, revealing no clear influence of the specimen size on the mechanical properties and no correlation between the cell size and the mechanical properties. Additionally, the impact of the cell size on the well-known anisotropy in mechanical properties of AISI 316L produced via PBF-LB/M was investigated. While the cell size was observed to be independent of the specimen orientation on the build plate, the orientation between the direction of loading and the building direction reveals a slight influence on the mechanical properties obtained from CIT. In comparison to the properties determined using CIT, a stronger influence of the orientation between the load and the building direction was observed in tensile tests, which was not caused by the intragranular cells. It was concluded that the anisotropy in the tensile properties is mainly affected by the texture, the elongated grains, and the layer orientation. Full article