Search Results (3,260)

The physicochemical properties of starch in high-quality hybrid indica rice (HQR) varieties that have received the National High-Quality Rice Gold Award are not well characterized. Ten HQR and two ordinary-quality indica rice (OQR) varieties were selected for this study. All varieties were identically cultivated under late-season conditions in southern China and were subsequently analyzed for differences in taste-related attributes, amylopectin fine structure, and functional properties. Compared with OQR varieties, HQR varieties exhibited a distinct starch profile: lower amylose (16.6–20.2%) but higher amylopectin content (62.6–65.0%), a greater proportion of small and medium starch granules, and a higher ratio of A and B1 chains in amylopectin (with few exceptions). Functionally, HQR varieties showed significantly (p < 0.05) higher gel consistency, solubility, and swelling power, along with higher breakdown but lower setback. They also generally exhibited higher crystallinity and gelatinization enthalpy, alongside a softer texture. Notably, the functional properties showed strong correlations (p < 0.05) with most taste-related attributes and amylopectin fine structures across all varieties. These findings provide critical guidance for future breeding programs aimed at improving the quality of indica rice and developing new elite HQR varieties. Full article

The herbal tea industry has experienced substantial growth, particularly regarding green tea (Camellia sinensis). In the manufacturing of filter tea, fine herbal dust is generated as a residual by-product during grinding and sieving and is typically discarded as waste. This study aims to explore the application of ultrasound-assisted extraction (UAE) for secondary valorisation of green tea herbal dust by investigating the effects of various parameters on extraction efficiency. Antiradical activity of UAE extracts was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, and the total phenolic content (TPC) was measured using Folin–Ciocalteu’s assay. Furthermore, selected phenolics were quantified by HPLC and qualitatively characterised by liquid chromatography coupled with electrospray ionisation and quadrupole time-of-flight tandem mass spectrometry (LC-ESI-QToF-MS/MS). The results demonstrate that UAE parameters have a pronounced influence on the antioxidant activity, TPC, and individual polyphenolic profile of green tea herbal dust extracts. Ethanol–water mixtures at a ratio of around 40–60%, as well as moderate impulse regimes (around 60%) and extraction times (around 10 min), were the most suitable for extracting green tea polyphenols. Epigallocatechin gallate was the predominant phenolic component in most extracts, alongside epicatechin, epigallocatechin, catechin, and gallic acid. The findings highlight the UAE technique as a robust, green, and scalable method for valorising green tea by-products, thereby facilitating the development of high-value natural extracts for applications in the food, pharmaceutical, and cosmetic industries. Full article

From an environmental perspective, the use of clam shells contributes positively to marine waste management and promotes more sustainable construction practices. This study aims to analyze the influence of clam shell-derived filler on the mechanical properties of cementitious mortars, evaluating its effect as a function of dosage and particle fineness, in order to determine its potential as a sustainable additive in construction applications. The shells were ground for 0.5, 1.0, and 1.5 h and incorporated at percentages ranging from 0.5% to 5.0% by mass of cement. Slump (reduced Abram’s cone) was performed in the fresh state for each specimen mixture, while flexural strength, and compressive strength tests were performed at 7, 14, and 28 days of curing. Microstructural characterization was also performed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) analysis. In addition, particle size distribution parameters were determined to quantify the effect of grinding time on particle refinement and its relationship with mechanical performance. A multifactor ANOVA was conducted to evaluate the statistical significance of grinding time and filler dosage on compressive strength. The results showed that the combination of 0.5 h of grinding and 1.0% filler provided the best mechanical performance for both flexural and compressive strength, with values of 7.27 MPa and 26.16 MPa, respectively. Dosages higher than 2.0% tended to decrease strength, which is associated with saturation of non-cementing particles. EDX analysis showed adequate calcium distribution without generating chemical segregation. The results showed that the combination of 0.5 h of grinding and 1.0% filler provided the best mechanical performance for both flexural and compressive strength, with values of 7.27 MPa and 26.16 MPa, respectively. Dosages higher than 2.0% tended to decrease strength, which is associated with saturation effects and increased specific surface area. The statistical analysis confirmed that both grinding time and filler dosage significantly influence compressive strength, highlighting the importance of optimizing particle size distribution and filler content to achieve improved mechanical performance. Full article

Alpine meadow degradation is a serious challenge for animal husbandry and ecosystem safety in the Qilian Mountain area, northwest China. Although some restoration methods have been used, fertilization practices still rely heavily on chemical fertilizers. As a type of green and effective fertilizer, microbial fertilizer was put into a degraded alpine meadow in this study, and six fertilization treatments, including no fertilization (CK), diammonium phosphate (600 kg∙ha⁻¹) (DP), microbial fertilizer (75 kg·ha⁻¹) (MF), diammonium phosphate (600 kg∙ha⁻¹) with microbial fertilizer (75 kg·ha⁻¹) (DPMF1), diammonium phosphate (450 kg∙ha⁻¹) with microbial fertilizer (75 kg·ha⁻¹) (DPMF2), and diammonium phosphate (300 kg∙ha⁻¹) with microbial fertilizer (75 kg·ha⁻¹) (DPMF3), were conducted on a moderately degraded alpine meadow using field plot experimental methods to evaluate the effects of reduced chemical fertilizer combined with microbial fertilizer on the vegetation and soil characteristics of degraded alpine meadow in 2023 and 2024. The results indicated that DP showed the highest biomass production in the two study years, but there was no significant difference between DPMF2 and DP in 2024. The dominance of originally fine forage Kobresia humilis and Medicago ruthenica showed the highest values for the DPMF3 treatment in 2023 and for the DPMF2 treatment in 2024. The vegetation Shannon–Wiener diversity and richness indices of DPMF1, DPMF2 and DPMF3 were significantly higher than those of CK. However, community diversity decreased in the second year of fertilization. DPMF2 treatment significantly increased the contents of soil organic matter, available nitrogen and available phosphorus in 2024. Grey correlation analysis indicated that 450 kg·ha⁻¹ of diammonium phosphate combined with 75 kg·ha⁻¹ of microbial fertilizer was the most suitable regime for moderately degraded alpine meadow restoration in the study area. Full article

Concentrated natural rubber skim latex is a sustainable, value-added product derived from natural rubber latex processing, offering high rubber content, fine particle size, and shorter polymer chains compared to pure latex, making it suitable for diverse industrial applications. This study employed an environmentally friendly ultrafiltration method using composite membranes composed of polyvinylidene fluoride (PVDF), titanium dioxide (TiO₂), and polyvinylpyrrolidone (PVP) to concentrate skim latex without hazardous chemicals. The process generated two fractions: concentrated skim latex and skim serum. Membrane performance and fouling behavior were evaluated using FESEM-EDX and FTIR. Post-filtration analysis revealed significant latex particle deposition on the membrane surface, with elemental mapping confirming the presence of organic and inorganic residues. FTIR spectra indicated interaction between latex components and membrane functional groups, though the membrane’s structural integrity remained intact. Sodium dodecyl sulfate (SDS) was assessed as a cleaning agent and demonstrated the effective partial restoration of membrane performance, as confirmed by flux recovery (PVDF-PVP-TiO₂ membrane recovered to a slightly higher flux of 7.35 L/m²h). These results highlight the membrane’s durability, fouling characteristics, and cleaning potential, supporting its reusability in latex processing. This study contributes to the development of sustainable separation technologies in the rubber industry, promoting circular economy and zero-discharge practices. Full article

This study investigates the influence of the physical and chemical characteristics of three polycarboxylate ether (PCE) superplasticizers—differing in main-chain length, side-chain density, and dispersing-to-stabilizing polymer ratio (75:25, 50:50, and 25:75)—on the dispersion of calcined clays with varying metakaolinite contents (30.04–74.91 wt%) in synthetic cement pore solution (SCPS). Clays were characterized by XRF, XRD, TGA, FTIR, BET, Blaine fineness, and particle size distribution; PCEs were characterized by FTIR, ¹H NMR, GPC, and zeta potential. Dispersion was assessed via mini-slump tests for water demand, PCE dosage to achieve 260 ± 5 mm spread, and slump retention over 120 min, quantified by a normalized spread retention index (SR₁₂₀). Results revealed that clays with a higher metakaolinite content (58.45–74.91 wt%) and Blaine fineness (up to 13.116 m²/g) required two times higher PCE dosages and exhibited greater water demand due to enhanced surface reactivity and Ca²⁺/carboxylate affinity. Slump retention depended on PCE–clay compatibility: at a low metakaolinite content (30.04 wt%), all PCEs yielded SR₁₂₀ ≈ 1; at higher contents, dispersing-rich PCEs (e.g., 75:25 ratio) sustained superior retention (SR₁₂₀ > 1 in intermediate cases), while stabilizing-rich variants showed rapid loss. Zeta potential values remained close to zero due to the high ionic strength of the SCPS, indicating that electrostatic interactions play only a secondary role in the dispersion process, while steric effects govern the performance of the investigated PCEs. Overall, optimal PCE selection requires matching polymer architecture to clay reactivity for effective dispersion and fluidity retention in sustainable calcined clay systems. Full article

To enable non-destructive quantitative characterization of constituent content in C/C–SiC ceramic-matrix composites, this study develops a physics-guided framework based on multispectral photon-counting X-ray detection. In practical photon-counting measurements, multispectral attenuation features are jointly distorted by detector-response non-idealities, including charge sharing, K-escape, and finite energy resolution, as well as by beam-hardening effects from the polychromatic X-ray source. To address this coupled problem, a Geant4 11.2-based detector-response model was incorporated into a unified correction workflow together with beam-hardening compensation, so that physically consistent multispectral attenuation vectors could be recovered for subsequent constituent inversion rather than merely for spectrum restoration. On this basis, a fine-grained theoretical database covering different SiC mass fractions was established, and quantitative constituent inversion was achieved by matching the corrected attenuation features to the database. Experimental results show that the proposed framework effectively suppresses thickness-dependent bias in attenuation measurements and yields an average relative error below 3% for pure aluminum. For C/C–SiC composites, the SiC mass fraction can be quantified with an accuracy better than 3 wt%. These results demonstrate that the proposed method provides a practical non-destructive route for constituent-content characterization in heterogeneous ceramic-matrix composites and is valuable for manufacturing quality control and in-service assessment. Full article

The efficient recovery of coalbed methane (CBM) is critically constrained by the inherent low permeability of coal reservoirs, a challenge predominantly attributed to mineral blockages within the pore-fracture structure. In this study, the deashing efficacy of several acid solutions (HCl, HNO₃, HF, and CH₃COOH) on bituminous coals from the Yushuwan (YSW) and Jiangna (JN) mines was initially assessed to determine the optimal acidizing system. Subsequently, the multi-scale evolution of pore-fracture structures and the fractal characteristics of coal samples treated with the optimized acids were systematically investigated. A multi-analytical approach, integrating scanning electron microscopy (SEM), X-ray diffraction (XRD) with microcrystalline peak-fitting, and low-temperature nitrogen gas adsorption (LT-N₂GA), was employed to quantitatively elucidate the underlying transformation mechanisms. The experimental results indicate that HCl and HNO₃ emerged as the most effective agents for the YSW and JN coals, respectively. Optimized acidification achieved significant reductions in ash content (specifically, an ash removal efficiency of 83.99% for HCl-treated YSW coal) through the selective dissolution of carbonate and clay minerals, thereby facilitating the exposure of the organic matrix and the induction of extensive dissolution pits and secondary fractures. Although the dissolution-induced collapse of mineral-supported fine pores led to a reduction in both total pore volume and BET specific surface area, the average pore diameter undergoes a substantial increase (e.g., nearly doubling from 9.0068 nm to 16.5126 nm for the JN coal). Furthermore, the reduction in Frenkel–Halsey–Hill (FHH) fractal dimensions (D₁ and D₂) indicates a decrease in pore-surface complexity and structural heterogeneity. These findings reveal that optimized acidification induces significant alterations in pore structure and mineral composition. The treatment facilitates the conversion of isolated pores into interconnected networks, accompanied by an increase in pore volume and a shift in pore size distribution toward larger dimensions. This research elucidates the mechanisms of mineral dissolution and pore expansion, providing a fundamental characterization of the microstructural evolution of coal in response to acid treatment. Full article

In order to promote the high-quality utilization of solid waste—steel slag—this study prepared ground steel slag powder with specific surface areas of 400 m²/kg, 500 m²/kg and 600 m²/kg respectively. Different fineness levels of steel slag powder were used to replace cement to prepare ultra-high performance concrete (UHPC), with replacement rates of 20%, 30% and 40% respectively. The effects of fineness and dosage of steel slag powder on the workability, mechanical properties and microstructure of UHPC were further investigated. The results show that the incorporation of steel slag powder can significantly reduce the yield stress and plastic viscosity of UHPC, thereby increasing its fluidity, but also decreasing its thixotropy. The tensile properties of UHPC mixed with steel slag powder were all superior to those of the reference group. The compressive strength of UHPC prepared by using steel slag powder with a specific surface area of 400 m²/kg or 600 m²/kg instead of 20% cement was higher than that of the reference group. The compressive strength of UHPC mixed with 600 m²/kg specific surface area steel slag powder was generally stronger at the same dosage. At the same fineness, the mechanical properties of UHPC decreased gradually with the increase in steel slag powder content. The recommended dosage for the steel slag powder with a specific surface area of 400 m²/kg is 20%, which results in the best comprehensive properties in UHPC. At this time, compared with the reference group, the compressive strength increased by 3.35%, and the tensile strength increased by 20.73%. Moreover, adequate fineness of the steel slag powder can be achieved without excessive grinding energy, which contributes to sustainability. Full article

This study investigates the origin and Nb–Ta enrichment mechanisms of the Middle Triassic Nare Alkaline Rocks in Gerze, central Tibet, using petrological, geochemical, and geochronological data. U–Pb zircon dating constrains the trachyte formation to the Middle Triassic, identifying NaOI as the oldest known seamount fragment in the zone and providing a key age for the early Meso-Tethyan Ocean. Whole-rock geochemistry data show the basalts possess typical OIB signatures, derived from a depleted mantle source modified by a mantle plume. The trachyte originated via a multi-stage process: Middle Triassic basaltic magmas underplated to form a deep-seated magma chamber, underwent high-pressure fractional crystallization, and the resulting crystal mush was later reheated and partially melted by subsequent magmas to generate trachytic melt. This model is supported by Hf isotopes and mineral chemistry. The rocks formed in a mature, thick-lithosphere intra-oceanic plate setting. Niobium occurs primarily as ilmenorutile with high Nb₂O₅ content, but its low modal abundance and very fine grain size imply low beneficiation recovery and limited current economic potential. However, the NaOI formed in an intra-oceanic island setting and hosts an early-stage Nb–Ta metallogenic system linked to alkaline magma differentiation, highlighting their potential for rare-metal exploration. Full article

Against the backdrop of dual-carbon goals and resource constraints, the high-value utilization of recycled fine aggregates (RFAs) remains limited, leading to inconsistent engineering performance and insufficient durability. Enzyme-induced carbonate precipitation (EICP) represents a promising low-carbon cementation method, yet its deposition uniformity and cementation efficiency are influenced by the pore structure of granular media and associated mass transfer pathways. This study employs a two-stage experimental design to investigate the synergistic effects of particle size distribution characteristics, represented primarily by d₅₀, and fiber addition on EICP-cemented RFA. Phase I (fiber-free; d₅₀ = 0.67–1.14 mm) results indicate that, across the tested gradation schemes, the CaCO₃ content generally decreased from 9.49% to 7.72% as the representative d₅₀ increased, while the dry density changed only slightly (1.637–1.617 g/cm³). However, the unconfined compressive strength (UCS) decreased from 1000 kPa to 541 kPa (45.9% reduction), indicating that strength is primarily governed by the connectivity of the cementation network rather than solely by the degree of densification. In Phase II, glass fiber (GF), polypropylene fiber (PPF), and jute fiber (JF) were incorporated into the ERFA4 gradation scheme selected for fiber modification. All three systems exhibited a unimodal optimum pattern: the peak CaCO₃ contents reached 10.71% (GF 0.5%), 10.11% (PPF 0.7%), and 11.46% (JF 0.7%), corresponding to peak UCS values of 1917, 1874, and 2450 kPa, respectively. Microscopic analysis suggested that fiber bridging coupled with CaCO₃ deposition may contribute to the formation of a “fiber-CaCO₃-particle” stress-transfer network, which is consistent with the observed enhancements in load-bearing capacity, ductility, and post-peak stability. Full article

This study examined the interaction between spatial frequencies and emotion processing using tachistoscopic presentations of emotional faces, in a patient with right capsulo–thalamic damage and a matched control group (N = 3). Emotional (happy, angry and sad) and neutral faces were presented in one of two ways: broadband emotional images and hybrid faces, which were created by superimposing emotional Low Spatial Frequencies (LSFs) to the High Spatial Frequencies (HSFs) of the same identity with a neutral expression, resulting in a subliminal presentation of the emotional content. According to LeDoux’s dual-route model, which suggests a cortical–conscious emotional analysis and subcortical–unconscious emotional processing, we expected healthy participants to show different variations in friendliness ratings compared with the case study patient. In particular, we hypothesized that while healthy participants should show friendliness ratings varying consistently with the facial expressions for both unfiltered (conscious) and filtered (unconscious) stimuli, reflecting the efficiency of both routes, the patient should show a selective deficit in the unfiltered condition due to the disruption of the thalamo–cortical connections. The results showed that healthy controls evaluated emotions consistently across both conditions. Notably, there were no significant differences between the case study patient and the control group for hybrid faces, suggesting that the “hidden” LSF successfully activated the intact subcortical route. However, significant differences emerged for unfiltered stimuli: the case study patient was able to distinguish between positive and negative valence, but she failed to discriminate between negative emotions. This finding suggests that the fine-grained differentiation of negative emotions requires an intact cortical analysis, mediated by the internal capsule. Full article

The microstructure and mechanical behavior during 100 °C warm rolling of the high-Zn-content Al₈₀Zn₁₄Li₂Mg₂Cu₂ alloy were investigated. The alloy plate was warm-rolled to reductions of 40%, 60%, and 80%. Hardness and tensile strength decreased continuously with increased rolling up to 60%, demonstrating work softening, followed by a slight increase at 80% reduction, indicating work hardening. Systematic characterization revealed that this non-monotonic mechanical response arises from a competition between particle-stimulated nucleation (PSN)-assisted recrystallization and dislocation-driven hardening. The multi-scale intermetallic particles in this alloy play a dual role: coarse Al₅CuLi₃ particles generate high-strain particle deformation zones (PDZs) that serve as potent PSN sites, while fine nano particles pin the recrystallized grain boundaries and restrict their growth. The unusually low PSN activation temperature is attributed to the synergistic effects of the high PDZ storage energy and the progressive subgrain rotation mechanism within the PDZ. The ability to control PSN via micro- and nano-scale intermetallics presents a viable pathway for achieving grain refinement in Al-based alloys and enhancing the machinability of high-Zn-content Al alloys. Full article

Exemplar-based image translation generates an output image by transferring appearance from a reference exemplar to a content image. Existing works only consider the local correspondences between two modalities, and ignore the global distributions in each modality, struggling to obtain fine-grained details with efficient computation. In this paper, we propose OTFormer, a multi-scale Optimal Transport transformer for exemplarbased image translation. We formulate cross-modal alignment as a multi-scale optimal transport problem, which progressively provides a globally coherent matching. In addition, we design a lightweight multi-scale fusion block to extract and fuse features efficiently. Experiments on CelebA-HQ and DeepFashion demonstrate that OTFormer improves both image fidelity and style adherence, while reducing model parameters by 62% and achieving faster inference compared with strong baselines. These results highlight OTguided global alignment as an effective and deployable solution for high-fidelity exemplarbased image translation. Full article

With the continuous emergence of exam question types, accurate classification of knowledge points is crucial for intelligent exam analysis. Existing methods focus on text or text–image fusion but largely ignore spatial layout. To address this limitation, we propose a heterogeneous layout-aware cross-modal framework for knowledge point classification. The architecture begins with an encoding module where independent text and layout encoders extract semantic content and spatial configurations, respectively. We then design a layout-aware enhancing module consisting of two parallel cross-modal blocks, namely a Layout-Aware Text-Enhancing block and a Context-Aware Layout-Enhancing block. This module supports the bidirectional fusion of text and layout features and generates a comprehensive representation that integrates both semantic and spatial information. Furthermore, a dynamic router with top-k expert selection is introduced to dynamically adapt to question-specific knowledge distributions and focus on core knowledge points for precise classification. Experimental results demonstrate that our method effectively integrates text and layout information, significantly enhancing performance on the proposed QType-EDU dataset. The approach achieves 91.56% accuracy for coarse-grained classification and 80.58% for fine-grained classification, with an overall F1-score of 91.39%, surpassing all baseline models. Full article