Search Results (113)

Microbially induced carbonate precipitation (MICP) offers an eco-friendly approach to stabilize porous materials. This study evaluates its feasibility for protecting agricultural drainage ditch slopes through laboratory tests. Liquid experiments assessed calcium carbonate (CaCO₃) precipitation rates under varying bacteria–cementation solution ratios (BCR), cementation solution concentrations (1–2 mol/L), and urease inhibitor (NBPT) contents (0–0.3%). Soil experiments further analyzed the effects of solidified layer thickness (4 cm vs. 8 cm) and curing cycles on soil stabilization. The results showed that CaCO₃ precipitation peaked at a BCR of 4:5 and declined when NBPT exceeded 0.1%. Optimal parameters (0.1% NBPT, 1 mol/L cementation solution, BCR 4:5) were applied to soil tests, revealing that multi-cycle treatments enhanced soil water retention and CaCO₃ content (up to 7.6%) and reduced disintegration rates (by 70%) and permeability (by 83%). A 4 cm solidified layer achieved higher Ca²⁺ utilization, while an 8 cm layer matched or exceeded 4 cm performance with shorter curing. Calcite crystals dominated CaCO₃ formation. Crucially, reagent dosage should approximate four times the target layer’s requirement to ensure efficacy. These findings demonstrate that MICP, when optimized, effectively stabilizes ditch slopes using minimal reagents, providing a sustainable strategy for agricultural soil conservation. Full article

This study evaluates the effects of a compound microecological preparation named ATABG, which is composed of antimicrobial peptide ID13 and Saccharomyces boulardii, on Hu sheep’s growth performance, feed digestibility, and rumen parameters. A total of 40 three-month-old Hu sheep (21.65 ± 0.33 kg) were randomly assigned to two groups: the control group (Con), which received a basal diet, and the experimental group (ATABG), which received the same diet supplemented with 1 g/kg ATABG on a dry matter basis. After a 10-day pre-feeding period to adapt the animals to the experimental diet, dry matter intake and weight gain were recorded during the subsequent 63-day trial period. Body weight was measured on days 1, 21, 42, and 63 of the trial, and animals were slaughtered on day 63 to collect rumen fluid and tissue. Results indicated that ATABG supplementation significantly increased the apparent digestibility of crude protein, neutral detergent fiber, acid detergent fiber, and organic matter (p < 0.05). Rumen fluid analysis revealed increased microbial protein concentration and cellulase activity (p < 0.05) in the ATABG group. Microbiota analysis indicated that ATABG increased the relative abundance of Ruminococcus and Proteobacteria, elevated Firmicutes, and reduced Bacteroidota (p < 0.05). Correlation analysis showed Ruminococcus was positively associated with crude protein digestibility, while Quinella correlated with growth-related indices (r > 0.4, p < 0.05). In conclusion, ATABG supplementation improves protein digestibility and rumen microbial protein synthesis by enriching Ruminococcus and enhancing cellulase activity, potentially optimizing nitrogen utilization in Hu sheep. Full article

Nitrate is the most prevalent inorganic pollutant in aquatic environments, posing a significant threat to human health and the ecological environment, especially in lakes and groundwater, which are located in the high agricultural activity intensity areas. In order to reveal the sources of nitrogen pollution in lakes and groundwater, this study of the transformation mechanism of nitrogen in the interaction zone between lakes and groundwater has become an important foundation for pollution prevention and control. The coupling effect between the biogeochemical processes of nitrate and iron has been pointed out to be widely present in various water environments in recent years. However, the impact of iron minerals on nitrate reduction in the lake–groundwater interaction zone of a high-salinity environment still remains uncertain. Based on the sediment and water chemistry characteristics of the Chagan Lake–groundwater interaction zone in northeastern China (groundwater TDS: 420~530 mg/L, Na⁺: 180~200 mg/L, and Cl⁻: 15~20 mg/L and lake water TDS: 470~500 mg/L, Na⁺: 210~240 mg/L, and Cl⁻: 71.40~87.09 mg/L), this study simulated relative oxidizing open system conditions and relative reducing closed conditions to investigate hematite and siderite effects on nitrate reduction and microbial behavior. The results indicated that both hematite and siderite promoted nitrate reduction in the closed system, whereas only siderite promoted nitrate reduction in the open system. Microbial community analysis indicated that iron minerals significantly promoted functional bacterial proliferation and restructured community composition by serving as electron donors/acceptors. In closed systems, hematite addition preferentially enriched Geobacter (denitrification, +15% abundance) and Burkholderiales (DNRA, +12% abundance), while in open systems, siderite addition fostered a distinct iron-carbon coupled metabolic network through Sphingomonas enrichment (+48% abundance), which secretes organic acids to enhance iron dissolution. These microbial shifts accelerated Fe(II)/Fe(III) cycling rates by 37% and achieved efficient nitrogen removal via combined denitrification and DNRA pathways. Notably, the open system with siderite amendment demonstrated the highest nitrate removal efficiency (80.6%). This study reveals that iron minerals play a critical role in regulating microbial metabolic pathways within salinized lake–groundwater interfaces, thereby influencing nitrogen biogeochemical cycling through microbially mediated iron redox processes. Full article

The effects of opening size and braiding angle on the tensile behavior of 3D five-way braided composites were systematically studied, and the mechanical properties, failure modes, and fracture characteristics of the composites were comprehensively analyzed. Initially, a static tensile test was conducted. The results demonstrated that both the tensile strength and tensile modulus of the three-dimensional (3D) braided composites decreased as the braiding angle increased. The sensitivity of the tensile modulus to the aperture size increased significantly as the aperture increased. For specimens with varying braiding angles, smaller apertures were more effective in withstanding higher stress concentrations around the opening, with minimal impact on the tensile strength. In comparison to the laminate composites, the 3D braided composites, regardless of braiding angle, retained higher tensile strength after hole formation at the same aperture size. The fracture of the samples was observed and captured using an optical microscope. It was observed that the failure mode of the 3D braided composites progressively transitioned from fiber fractures to interface debonding with an increase in the braiding angle. After hole formation, stress concentration at the aperture edge caused crack propagation along the braiding direction. Larger apertures resulted in more severe cracks, ultimately leading to specimen failure. Full article

Background/Objectives: Congenital bicuspid aortic valve (BAV) signifies the most frequent category of congenital cardiovascular anomaly globally, occurring in approximately 0.5–2% of the general population worldwide. BAV is a major cause of thoracic aortopathy, encompassing aortic stenosis, aortic root dilation with regurgitation, aortic dissection, and aortic aneurysms, consequently leading to substantial late-onset morbidity and mortality. Accumulating evidence convincingly demonstrates the strong genetic basis underpinning BAV, though the inheritable reasons responsible for BAV in most patients remain largely obscure. Methods: A genome-wide genotyping with 400 polymorphic genetic markers followed by linkage analysis, haplotype assay, and sequencing analysis of candidate genes was conducted in a 4-generation BAV kindred of 47 individuals. Biochemical assays were performed to evaluate the functional effect of the identified mutation on TBX20. Results: A novel BAV-causative locus was mapped to chromosome 7p14. A sequencing assay of the genes within the mapped chromosomal region (locus) unveiled that only the c.656T>G (p.Ile219Arg) variation of TBX20 was in co-segregation with BAV in the entire pedigree. The missense mutation was not uncovered in 322 healthy persons employed as control individuals. Functional deciphers revealed that the mutation significantly decreased the transcriptional activation of the representative target gene ANP and the binding ability to the ANP promoter and impaired the intranuclear distribution of TBX20. Conclusions: This investigation maps a new genetic locus (chromosome 7p14) linked to BAV and uncovers TBX20 as a novel causative gene for familial BAV, adding more insight into the mechanisms underlying BAV and providing a molecular target for the individualized management of BAV. Full article

This paper investigates the critical role of government policies in promoting green development through enterprise-level green innovation (GI). We specifically examine the impact of environmental subsidies (ES) on heavily polluting enterprises and analyze how government environmental enforcement (EE) moderates this relationship. Furthermore, we explore how these effects vary across different ES characteristics and allocation patterns. Using data from heavy-polluting enterprises listed on China’s A-share market from 2012 to 2021, our analysis reveals several key findings. First, ES has unexpectedly hindered GI in heavily polluting enterprises. This negative effect stems from both ES characteristics and allocation patterns. Specifically, advance subsidies, targeted subsidies, and pollution prevention subsidies prove ineffective. The adverse impact of ES on GI is particularly pronounced in state-owned enterprises, companies lacking environmental protection investments, and firms engaging in earnings management practices. However, our findings indicate that strong environmental enforcement (EE) can effectively mitigate these ES-related issues. Under strict EE, ES demonstrates a positive effect on GI and addresses problems associated with both ES design characteristics and allocation patterns. These results offer valuable insights for government policymakers, particularly in developing countries undergoing green transition, to design and implement more effective environmental policies. Full article

The guide vane mixed-flow pump is a crucial component in medium-to-low-head pumping stations. The guide vanes are mostly fixed in traditional designs. The efficiency of these pumps under off-design operating conditions tends to be low, leading to higher energy consumption. This study explores the design of an adjustable guide vane for the conventional guide vane of a mixed-flow pump at a certain pumping station. Through numerical simulations and two sets of three-factor, five-level orthogonal experiments, we investigate the impact of flow rate, guide vane angle, and impeller angle on efficiency. Through numerical simulation, we identify the optimal relationships between an impeller angle of ±2° and 0° and guide vane angles of ±6°, ±3°, and 0°, focusing on the entropy production rate (EPR) as a key performance metric. The results demonstrate that adjustable guide vanes significantly improve the performance of mixed-flow pumps under off-design conditions. Efficiency increases by up to 17.71% at high flow rates, and by up to 5.48% at low flow rates. Energy consumption is notably reduced. As the flow rate and impeller blade angle vary, the adjustable guide vane rotates to match with the impeller, enhancing flow adaptation, expanding the high-efficiency operating range, and reducing overall energy consumption. Full article

In this paper, we propose a zoom auxiliary imaging lens based on the four-component mechanical zoom method for a modulation transfer function (MTF) test system. The auxiliary imaging lenses of the current MTF test system typically use fixed-focus optical systems, which are unable to meet the test scenarios of fast and batch measurement and measure lenses with an extensive focal length range. Compared with the fixed-focus auxiliary imaging lens, the zoom auxiliary imaging lens can simultaneously satisfy the measurement of wide-angle and telephoto miniature lenses without losing measurement accuracy. The entrance pupil distance of the zoom lens is greater than that of traditional lenses, and it is constant for each focal length of the zoom lens. The zoom lens uses an intermediate real image surface to obtain the perfect image quality and lower the diameter of the rear group. Additionally, the zoom lens dynamically adjusts magnification to optimize image size and align with the detector’s pixel resolution, thereby preventing undersampling and enhancing measurement precision. The optical design is optimized for stability, delivering high resolution and minimal aberrations across the zoom range. The image quality of the zoom lens is nearly at the diffraction limit at each focal length, which significantly reduces the impact of the auxiliary lens on MTF test results, enhancing both flexibility and accuracy. This design is particularly well suited for testing miniature lenses in optoelectronic technology applications. Full article

Hydrothermal alteration provides critical information for both the exploration and scientific research of hydrothermal uranium deposits. The Xiangshan uranium ore field, the largest volcanic-hosted uranium deposit in China, is characterized by different alterations, including hematitization, illitization, sericitization, chloritization, carbonation and silicification. However, the mineralogical and geochemical characteristics of hydrothermal alterations and their relationships with uranium mineralization remain unclear. In this study, we conducted detailed petrography, TIMA mapping, μ-XRF analyses, mass balance calculations and thermodynamic modeling on the hematitized and illitized porphyritic lava from the Zoujiashan deposit in the Xiangshan ore field. During hematitization, hematite and albite are produced, while quartz, K-feldspar, chlorite, sericite and biotite are consumed, consistent with the increase in Na₂O, Al₂O₃, Fe₂O₃-T, U, As, Pb, Cu, Sc, V, Zr, Y, Hf and Th and the loss of K₂O, MgO, Li, Zn, Ni and Ba. The production of hydrothermal hematite, illite and sericite indicates that the ore fluids are acidic and oxidized. Such physiochemical conditions are favorable for uranium transport as UO₂Cl₂(aq), UO₂SO₄(aq) and UO₂OH⁺. Geological processes such as fluid–rock interactions, fluid mixing and fluid boiling could cause fO₂(g) decrease, pH increase and temperature decrease and therefore result in the decrease in uranium solubility and mineralization. Full article

Architectural color painting is one of the cultural heritages of the Tibetan people. To address the issues of “loss” and “variation” in architectural color paintings during the renovation of traditional Tibetan timber dwellings in Yunnan, it is essential to organize and categorize the forms and cultural content of ethnic minority timber architectural paintings. This approach will help supplement foundational research on the subject. This study, based on linguistic research findings, focuses on the Diqing South Locus Dialect Region as the research area, conducting field investigations in over 30 settlements (involving more than 80 dwellings). This study analyzes patterns, colors, and forms across various architectural elements to develop a detailed atlas of decorative painting patterns. A combined analysis of historical documentation reveals three primary folk causes behind the architectural color paintings of Tibetan timber buildings in Yunnan: (1) primitive worship under animism; (2) decorative norms guided by religious beliefs; and (3) cultural fusion resulting from ethnic heritage. This will help people understand the cultural essence behind architectural paintings, avoiding the cognitive limitation of knowing only their form but not their meaning. This paper aims to raise awareness of the cultural heritage of regional timber buildings, providing a basis for typological accumulation and model references for the protection and transmission of regional timber architectural color paintings. Full article

The rural population aging poses a great challenge to China’s agricultural production, which is dominated by small farmers. Based on the panel data of 30 provinces or cities (except Tibet) in China from 2005 to 2020, the DEA-Malmquist index is employed to measure the agricultural total factor productivity (ATFP) in each province (city), and then the mediation effect model is used to reveal the mechanism by which the rural population aging affects the ATFP through farmland transfer, agricultural social services, and agricultural machinery. The results show that the rural population aging has made a significant contribution to the ATFP, and farmland transfer, agricultural socialized services and agricultural machinery have a intermediary effect on the increase of the ATFP. Further decomposition of ATFP reveals that the rural population aging can significantly contribute to the scale efficiency and technical progress rate through farmland transfer, agricultural socialization services and agricultural machinery, but does not have a significant effect on pure technical efficiency. In order to promote the high-quality and high-efficiency development of agriculture in the context of population aging, it is necessary to optimize the market environment for farmland transfer, improve the agricultural socialized service system, and continue to strengthen agricultural science and technology innovation. Full article

The 2015 Tianjin Port chemical explosion highlighted the severe environmental and structural impacts of industrial disasters. This study presents an Adaptive Weighted Coherence Ratio technique, a novel approach for assessing such damage using synthetic aperture radar (SAR) data. Our method overcomes limitations in traditional techniques by incorporating temporal and spatial weighting factors—such as distance from the explosion epicenter, pre- and post-event intervals, and coherence quality—into a robust framework for precise damage classification. This approach effectively captures extreme damage scenarios, including crater formation in inner blast zones, which are challenging for conventional coherence scaling. Through a detailed analysis of the Tianjin explosion, we reveal asymmetric damage patterns influenced by high-rise buildings and demonstrate the method’s applicability to other industrial disasters, such as the 2020 Beirut explosion. Additionally, we introduce a technique for estimating crater dimensions from coherence profiles, enhancing assessment in severely damaged areas. To support structural analysis, we model air pollutant dispersal using HYSPLIT simulations. This integrated approach advances SAR-based damage assessment techniques, providing rapid reliable classifications applicable to various industrial explosions, aiding disaster response and recovery planning. Full article

For elevators, appropriate speed control is pivotal for ensuring the safety and comfort of passengers and optimizing energy efficiency, system stability, and service life. Therefore, the design and implementation of effective speed control strategies are crucial for the operation and management of modern elevator systems. In response to this issue, this paper establishes a dynamic model of an elevator through mechanism analysis. Then, a novel fractional-order sliding mode control strategy with the assistance of a fixed-time adaptive sliding mode observer is proposed. The designed observer can effectively monitor and counteract external perturbations, thereby enhancing the stability and precision of the control system. The fractional-order sliding mode controller can realize a fixed-time convergence property, which is rigorously proven in the sense of Lyapunov. Finally, the effectiveness and superiority of the control scheme are validated by simulations compared with benchmark controllers. Full article

Plant-based meat analogs (PBMAs) are promising sustainable food sources. However, their high moisture and protein contents make them prone to microbial deterioration, limiting their shelf life and sensory appeal. This study explored enhancing PBMAs’ shelf life using nanoemulsions of Litsea cubeba and cinnamon essential oils, emulsified with chitosan and Tween 80. The composite nanoemulsion, produced through high-pressure homogenization, exhibited a droplet size of 4.99 ± 0.03 nm, a polydispersity index (PDI) of 0.221 ± 0.008, and a zeta potential of 95.13 ± 2.67 mV, indicating remarkable stability (p < 0.05). Applied to PBMAs stored at 4 °C, it significantly improved color and pH balance and reduced thiobarbituric acid reactive substances and cooking loss. Most notably, it inhibited the growth of Escherichia coli and Staphylococcus aureus, curbing spoilage and protein oxidation, thereby extending the products’ shelf life and preserving sensory quality. As shown above, the encapsulation of LCEO/CEO in nanoemulsions effectively inhibits spoilage and deterioration in PBMAs, improving flavor and quality more than direct addition. Future studies should explore using various essential oils and emulsifiers, as well as alternative encapsulation techniques like microcapsules and nanoparticles, to further prevent PBMA deterioration. Full article

Due to the complexity of the actual geotechnical environment, the backfill compaction design theory and calculation method are not reflected in the current specification. Therefore, in order to investigate the effect of the hydraulic compactor on the foundation structure during the treatment of the backfill of an independent foundation under a column, the Menard formula was modified. At the same time, relying on an independent foundation project under a column in Jinan, the dynamic model of compactor tamping backfilling soil was established. The applicability of the calculation formula is verified by simulating the single-point multiple tamping on the backfill directly above the foundation tie beam, and the influence law of two factors, the thickness of the backfill and the tamping energy, on the force of the foundation tie beam is elucidated. The results show that after reaching the optimum number of tamping, the cumulative soil settlement and the effective reinforcement depth of tamping show a stable trend, and their simulation results are in good agreement with the analytical solution, which provides a supplement to the relevant safety standards. At this critical point, the force on the tie beams peaked and showed up and down fluctuations under the subsequent ramming action. The tamping action of the compactor has a significant effect on the structural forces within the effective reinforcement range, and there is a negative correlation between the magnitude of the structural forces and the thickness of the backfill. According to the numerical calculation results to choose the best construction programme, the on-site monitoring shows that under 42 KJ tamping energy and 1.5 m single backfilling thickness, the tie beam reinforcement stress reaches 18.5~55.5% of the specification warning value, which meets the safety standard. The research results of this paper can provide important guidance for the hydraulic tamping treatment of an independent foundation backfill project. Full article