Search Results (2,091)

The contents of biochemical components, such as theanine, tea polyphenols, water extract, and soluble sugar in Hakka stir-fried green tea (HSGT), serve as important indicators reflecting the intrinsic quality of tea leaves. In this study, 171 HSGT samples are collected, and their near-infrared spectroscopy (NIRS), together with the contents of the four indicators, are determined. The aim is to establish prediction models for these four indicators by extracting multiple features from the NIRS data. First, the NIRS data is preprocessed. Then, multiple features are extracted using competitive adaptive reweighted sampling (CARS), adaptive Fourier decomposition (AFD), fast Fourier transform (FFT), continuous wavelet transform (CWT), and band combination (BC). Finally, ridge regression (RR) and partial least squares regression (PLSR) models are constructed based on the NIRS features to predict the four indicators. Experimental results show that the model combining multiple features, namely CARS + AFD + BC, delivers the best overall performance. Specifically, the RR model based on multiple features provides the most accurate predictions for theanine, tea polyphenols, and soluble sugar, while the PLSR model performs better for water extract. This study provides a rapid and accurate method for detecting the substance content in HSGT. Full article

Long-term continuous cropping in cotton fields of Southern Xinjiang has limited crop productivity. To investigate how subsoiling depth regulates ecosystem-level water partitioning and thereby enhances water productivity mechanisms, a two-year field experiment was conducted in a mulched drip irrigation cotton field in Southern Xinjiang. Using a non-subsoiled field in the current season (CT) as the control, three subsoiling depths were established: subsoiling at 30 cm (ST1), 40 cm (ST2), and 50 cm (ST3). Changes in evapotranspiration partitioning and water use efficiency were analyzed. The results showed that subsoiling enhanced the utilization of deep soil water. Compared with CT, the ST2 and ST3 treatments significantly reduced soil water storage in the 0–60 cm layer during the flower opening to boll-setting stages, while soil water consumption increased by 26.4 mm and 28.8 mm, respectively. We demonstrate that subsoiling depth exerts a predominant control on the partitioning of evapotranspiration. Increasing subsoiling depth systematically shifted water loss from non-productive soil evaporation to productive plant transpiration, with the ST2 and ST3 treatments decreasing seasonal soil evaporation by 24.1% and 25.1%, respectively, and increasing plant transpiration by 21.9% and 22.8%, and lowering the Es/ET (where Es is soil evaporation and ET is evapotranspiration) ratio by 22.1% and 27.1%. However, this maximal physiological water-saving did not yield the optimal agronomic return. We established a non-linear relationship in which the ST2 treatment uniquely achieved the maximum seed cotton yield, WUE (water use efficiency), and IWUE (irrigation water use efficiency) (increasing by up to 34.4%, 17.2%, and 23.4%, respectively). This optimal depth better balances water resource allocation and reproductive growth. We conclude that under sandy loam soil conditions in typical mulched drip-irrigated cotton areas of Southern Xinjiang, implementing an optimal subsoiling depth (40 cm) can engineer a more resilient soil–plant–water continuum, providing a feasible pathway toward enhancing water and crop production sustainability. Full article

Sapium discolor is a valuable native species in southern China, valued for its rapid growth and vibrant foliage, and widely used in ecological restoration and landscaping. To identify superior propagation materials with fast growth and red leaves, regional open-pollinated progeny trials of 10 elite trees were established in Nanping, Sanming, and Zhangzhou (Fujian Province) in 2015. Growth (tree height and diameter) was monitored from 2015 to 2023, and leaf color (the proportion of red in leaf color) was assessed in 2024. The species showed early fast growth, with mean tree height and diameter at breast height (DBH) reaching 7.98 m and 9.99 cm at six years, then slowing. Family-level phenotypic variation was limited. ANOVA revealed highly significant differences among families for growth traits from 2016 onward and for leaf color in 2024. Broad-sense heritability was moderate for 2023 tree height (0.3839), DBH (0.1879), and 2024 leaf color (0.2102), with low narrow-sense heritability, indicating non-additive genetic effects. Clonal selection based on genotypic values achieved notable genetic gains, especially for growth. One superior clone combined improvements in height (13.1%), diameter (10.1%), and red coloration (8.3%). These results highlight the value of clonal selection and the need to consider genotype × environment interactions in breeding programs. Full article

The stability of the electrolyte is very important for the development of high-performance all-solid-state lithium batteries. To improve the stability of electrolyte performance, it is essential to first understand the causes of its deterioration. Physically speaking, the degradation of electrolyte performance is mainly due to interface degradation. PAN-PVDF-HFP-LiClO₄-Li₆.₄La₃Zr₁.₄Ta₀.₆O₁₂ (LLZTO) gel polymer electrolyte was prepared by the UV curing method and assembled into a solid-state battery. The electrochemical properties of solid-state batteries were tested at −20 °C, 30 °C, and 60 °C. The test results show that the gel polymer electrolyte exhibits good electrochemical performance in this temperature range. (The ionic conductivities of the gel polymer electrolyte at −20 °C and 60 °C were 3.95 × 10⁻⁴ S·cm⁻¹ and 5.04 × 10⁻⁴ S·cm⁻¹, respectively.) At a current density of 0.2 C, the battery exhibited high initial specific discharge capacities of 122 mAh g⁻¹ and 151.6 mAh g⁻¹ at −20 °C and 60 °C. The gel polymer electrolyte before and after working at different temperatures was characterized, and the ion transport was analyzed to explore the physical reasons for the degradation of the gel polymer electrolyte membrane interface. Therefore, this work provides a certain theoretical basis for improving the stability of solid-state lithium-ion batteries. Full article

Electrochemical advanced oxidation processes based on peroxymonosulfate (PMS-EAOPs) have shown great promise for eliminating organic pollutants from water. However, earlier research primarily concentrated on pollutant degradation at the cathode, with little attention given to the anode’s role in PMS-EAOPs. In this work, we developed a PMS-EAOP system using nitrogen-doped carbon nanotubes (N-CNTs) as the electrocatalyst and examined the degradation of pollutants (acetamiprid (ATP) and sulfamethoxazole (SMX)) at both the cathode and anode. Our findings indicate that SMX was rapidly degraded at both electrodes, while ATP was effectively broken down only at the cathode, demonstrating the selective nature of PMS-EAOP. At a voltage of −2 V and 2.5 mM PMS, the pseudo-first-order rate constant (k_obs) for ATP at the cathode reached 0.122 min⁻¹, with over 92% removal within 30 min. In contrast, the anode exhibited high selectivity, removing ~75% of SMX (k_obs = 0.041 min⁻¹) while less than 20% of ATP was degraded. Analysis of reactive oxygen species showed that hydroxyl and sulfate radicals were produced and contributed to pollutant degradation at the cathode. In contrast, selective oxidation occurred at the anode, likely driven by direct electrolysis-induced nonradical oxidation responsible for the selective degradation. Phosphates and bicarbonates significantly inhibited the degradation of pollutants in the PMS-EAOP process (31.7–76.4%). In contrast, chloride ions exhibited an electrode-dependent effect, with the anode being less susceptible to interference from common water anions. Overall, this study highlights that while PMS-EAOP can selectively remove contaminants, the influence of water matrix components must be taken into account when treating real wastewater. Full article

The durability of coral concrete in marine tidal zones is a critical concern due to the coupling effects of impact loads and aggressive ion erosion. This study investigates the dynamic mechanical degradation of Sisal Fiber-Reinforced Coral Aggregate Concrete (SFCAC) under a semi-submerged environment, focusing on the interplay between fiber bridging and corrosion evolution. Split Hopkinson Pressure Bar (SHPB) tests were conducted on specimens with varying fiber dosages (0–6 kg/m³) and erosion durations (0–120 days). Quantitative results indicate that while the addition of sisal fibers had a limited effect on increasing the peak impact-compression strength, it significantly modified the failure characteristics. The dynamic compressive strength exhibited a non-linear trend, peaking at 30 days due to pore filling. However, after 120 days, the strength of the Plain Coral Concrete (SF0) deteriorated to 70.84 MPa, while the 6 kg/m³ fiber-reinforced group (SF6) maintained a higher residual strength of 77.63 MPa. Crucially, although the 6 kg/m³ specimens still suffered crushing failure under high strain rates, the fibers effectively mitigated catastrophic shattering by holding the fragments together, exhibiting superior post-peak energy absorption compared to the pulverized plain matrix. Microscopic analysis (SEM) revealed that although the hydrophilic nature of sisal fibers accelerated ion transport (leading to Friedel’s salt and gypsum formation), their physical bridging effect counteracted the corrosion-induced brittleness. Collectively, these findings provide a theoretical basis for the durability design of SFCAC structures in severe marine splash zones and offer new insights into utilizing sustainable, locally sourced materials for island engineering. Full article

During the drilling process of 10,000 m deep wells, loss zones face complex environments with ultra-high temperatures and pressures. Traditional bridging plugging materials exhibit insufficient temperature resistance and tend to carbonize under downhole high-temperature conditions, leading to recurrent loss. To address the technical challenges of drilling fluid loss in ultra-high-temperature formations of 10,000 m deep wells, experimental research was conducted to evaluate the properties of plugging materials resistant to 240 °C. Rigid particles, elastic particles, flaky materials, and fiber materials resistant to 240 °C were optimized. An experimental evaluation method for ultra-high-temperature dense pressure-bearing loss prevention and plugging formulations was established. The ultra-high-temperature while-drilling leak prevention formulation was optimized through sand disk plugging experiments. Millimeter-scale fracture plugging simulation experiments optimized ultra-high-temperature stop-drilling plugging formulations for different fracture apertures, achieving a bearing capacity of 15 MPa within 1–5 mm fracture apertures. Through the synergistic effects of various loss prevention materials, a reinforced force chain network structure forming a dense pressure-bearing plugging layer was achieved under 240 °C high-temperature conditions. This research provides material and system support for the solving drilling fluid loss challenges in high-temperature formations of 10,000 m ultra-deep wells. Full article

This study introduces a novel control device, the nonlinear air-spring absorber (ASA), aimed at improving the collapse resistance of transmission tower-line systems subjected to severe wind loads. Initially, a detailed finite element (FE) model is developed for a representative transmission tower-line system, grounded in an actual engineering project, and the wind load applied to the system is obtained. Then, the working principle and design method of the ASA are introduced, and the device is embedded into the FE model. The Inter-Segment Displacement Ratio (ISDR) is employed as a collapse indicator to systematically evaluate, via fragility analysis, the effectiveness of the ASA. The effectiveness of the ASA at improving the collapse resistance of the tower-line system under different wind attack angles is systematically studied through a fragility analysis. The results show that the device effectively suppresses the structural wind-induced vibration and significantly improves the system’s collapse resistance. In particular, the vibration suppression effect is most pronounced along the transmission line (90° wind attack angle), with the critical collapse wind speed increasing by up to 23%. This study provides a practical and feasible technical approach for addressing the problem of wind-induced collapse control. Full article

Reliable joining of multi-layer aluminum foil current collectors is crucial for enhancing the performance and safety of high-capacity lithium-ion batteries. However, laser welding of such thin-thick aluminum combinations is often hindered by porosity, cracks and unstable weld-pool behavior. In this study, a ring-mode fiber laser combined with sinusoidal oscillation and linearly gradient power modulation was employed to achieve high-quality lap welding between 80 layers of 1060 aluminum foil (1 mm in total thickness) and a 1.5 mm thick aluminum plate. Welding experiments and thermo-mechanical simulations were conducted to investigate the effects of welding speed (15–45 mm/s) and central-power modulation parameters (−2, 0, +2, +4) on weld morphology, defect formation, and mechanical properties. The results indicate that increasing the welding speed can effectively suppress cracks and improve the shear strength from 249.8 N to 403.9 N, but it also leads to an increase in porosity from 5.78% to 12.26% and deterioration of the weld reinforcement. Higher central-power modulation (+2, +4) transformed the weld-pool geometry from an ω shape to U shape, effectively suppressing fusion-line cracks but leading to increased porosity (up to 8.41%) and deteriorated surface morphology. Overall, a low welding speed of 15 mm/s combined with an optimized power modulation strategy achieves effective crack suppression while maintaining controlled porosity, resulting in a welded joint with superior comprehensive performance. This research provides a robust process solution for high-quality laser welding of multi-layer aluminum foil current collectors in power battery manufacturing. Full article

With accelerating urbanization and climate change, outdoor thermal comfort (OTC) in high-intensity urban blocks presents a critical challenge. While existing studies have established the general correlation between morphology and microclimate, most remain descriptive and lack a systematic framework to quantitatively integrate the non-linear coupled effects between multi-dimensional morphological variables and green infrastructure. To address this, this study proposes an automated performance-based design (PBD) framework for urban morphology optimization in Shenzhen. Unlike traditional simulation-based analysis, this framework serves as a generative tool for urban renewal planning. It integrates a multi-dimensional design element system with a genetic algorithm (GA) workflow. Analysis across four urban typologies demonstrated that the Full Enclosure layout is the most effective strategy for mitigating thermal stress, achieving a final optimized UTCI of 37.15 °C. Crucially, this study reveals a non-linear synergistic mechanism: the high street aspect ratios (H/W) of enclosed forms act as a “radiation shelter”, which amplifies the cooling efficiency of green infrastructure (contributing an additional 1.79 °C reduction). This research establishes a significant, strong negative correlation between UTCI and the combined factors of building density and green shading coverage. The results provide quantifiable guidelines for retrofitting existing high-density districts, suggesting that maximizing structural shading is prioritized over ventilation in ultra-high-density, low-wind climates. Full article

During the diesel engine start-up phase, low rotational speed and coolant temperature result in poor fuel atomization and prolonged ignition delay. This impedes the in-cylinder combustion process and directly impacts the engine’s emission performance. As the first combustion cycle during the starting process, the initial starting cycle significantly influences subsequent combustion cycles and overall starting performance. This paper proposes a target-torque-based control strategy for fuel injection quantity during the starting process. It optimally determines the target acceleration curve for the starting process, thereby calculating the optimal fuel injection quantity for the initial starting cycle. Based on this, a combustion system simulation model of the diesel engine was established using the 3D CFD software AVL FIRE v2010. The simulation investigated the impact of first injection speed on the combustion process and performance of the first firing cycle under different ambient temperatures: normal temperature (20 °C), low temperature (5 °C), and cold start (−10 °C). The results indicate that the optimal first cycle injection quantities under normal, low, and cold start conditions are 17.3 mg, 18.5 mg, and 20.4 mg, respectively. The impact of first injection speed on the first firing cycle combustion process primarily manifests in the mixture formation rate and time, and higher speeds do not necessarily yield better results. The optimal first injection speeds at normal temperature (20 °C), low temperature (5 °C), and cold start (−10 °C) were 220 r/min, 240 r/min, and 220 r/min, respectively. Corresponding indicated thermal efficiencies were 30.74%, 28.67%, and 28.7%, with relatively low emissions of pollutants such as CO, NOx, and HC. Full article

This work investigates the corrosion behavior of 18%Ni high-strength steel (00Ni18Co-8Mo5TiAl, solution-treated at 820 °C for 3 h and aged at 480 °C for 3 h) in NaCl solutions with 1%, 3.5%, and 6% chloride ions, as well as chloride ions’ effect on passive film properties. The corrosion process was systematically studied via chemical immersion tests (GB/T 17897-1999, 144 h, solution-to-sample contact area ratio 20:1) and electrochemical methods, including EIS (frequency range: 100 kHz–0.01 Hz) and Tafel polarization curves (scan rate: 10 mV/min). Passive film evolution was analyzed via Mott–Schottky curves (fixed frequency: 1000 Hz, scanning potential: −1 V to 1 V vs. SCE). Microstructural observations show the steel exhibits pitting corrosion in chloride environments, with corrosion products transforming from loose outer α-FeOOH/γ-FeOOH to dense inner Fe₃O₄/β-FeOOH. These dense products inhibit anodic reactions. Electrochemical results reveal polarization resistance decreases and corrosion current density rises with increasing chloride concentration. Mott–Schottky curves indicate that flat band potential increases from −0.2177 V to −0.1258 V with rising chloride concentration, increasing point defects in the passive film and weakening its self-healing ability. Full article

Accurate measurement of semantic similarity between geographic terms is a fundamental challenge in geographic information science, directly influencing tasks such as knowledge retrieval, ontology-based reasoning, and semantic search in geographic information systems (GIS). Traditional ontology-based approaches primarily rely on a narrow set of features (e.g., semantic distance or depth), which inadequately capture the multidimensional and context-dependent nature of geographic semantics. To address this limitation, this study proposes an ontology-driven semantic similarity model that integrates a backpropagation (BP) neural network with multiple ontological features—hierarchical depth, node distance, concept density, and relational overlap. The BP network serves as a nonlinear optimization mechanism that adaptively learns the contributions of each feature through cross-validation, balancing interpretability and precision. Experimental evaluations on the Geo-Terminology Relatedness Dataset (GTRD) demonstrate that the proposed model outperforms traditional baselines, including the Thesaurus–Lexical Relatedness Measure (TLRM), Word2Vec, and SBERT (Sentence-BERT), with Spearman correlation improvements of 4.2%, 74.8% and 80.1%, respectively. Additionally, comparisons with Linear Regression and Random Forest models, as well as bootstrap analysis and error analysis, confirm the robustness and generalization of the BP-based approach. These results confirm that coupling structured ontological knowledge with data-driven learning enhances robustness and generalization in semantic similarity computation, providing a unified framework for geographic knowledge reasoning, terminology harmonization, and ontology-based information retrieval. Full article

In this study, a pectin polysaccharide named DESP was extracted using a deep eutectic solvent (DES) from sweet potato residue (SPR) and the extract was optimized through response surface methodology (RSM). The DESP, based on choline chloride–urea (ChCl-Ur), was characterized for yield, molecular weight (Mw), and monosaccharide composition. Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), ¹H-nuclearmagnetic resonance (¹H-NMR), and scanning electron microscopy (SEM) were used to analyze the structure. Optimal extraction conditions for DESP were ChCl-Ur in a molar ratio of 1:2, water content of 75 wt.%, extraction time of 125.7 min, extraction temperature of 83.2 °C, and a liquid-to-solid ratio of 37.0 mL·g⁻¹. The optimized extraction yield was 5.6% ± 0.09%, which was 2.4 times higher than that of hot-water-extracted sweet potato pectin (HWSP, 2.32%). The monosaccharide analysis revealed that galacturonic acid (GalA) was the most abundant saccharide, followed by glucose (Glc), galactose (Gal), arabinose (Ara), and rhamnose (Rha). The Mw of DESP was 20.90 kDa, which was lower than that of HWSP and HASP. In addition, DESP exhibited certain anti-inflammatory activity. Full article

Limpets are marine gastropod molluscs well adapted to intertidal rocky environments, yet their taxonomic resolution remains challenging due to extensive morphological convergence and the presence of cryptic species. In this study, we applied an integrative taxonomic framework combining multi-locus DNA barcoding and fine-scale morphological characterization to clarify species boundaries within three families of limpets—Nacellidae, Lottiidae, and Siphonariidae. A total of 132 individuals collected from six coastal sites in Shenzhen and adjacent areas of southern China were analyzed using four markers Cytochrome c oxidase subunit I (COI), 16S ribosomal RNA (16S rRNA), Cytochrome b (Cytb) and 28S ribosomal RNA (28S rRNA), together with scanning electron microscopy (SEM) observations of radular morphology. Molecular analyses identified nine distinct species across five genera. Kimura two-parameter distance analyses revealed clear barcode gaps in 16S rRNA, Cytb, and 28S rRNA genes, particularly among Cellana and Nipponacmea, whereas COI exhibited stronger discriminatory power within Siphonaria. Moreover, our study provides newly 16S, 28S references for Nipponacmea formosa and Cytb references for Nipponacmea formosa, Lottia luchuana, Siphonaria atra, Siphonaria sirius, Siphonaria sp. and Siphonaria sirius, enriching the public references and explaining the lack of corresponding records in previous BLAST searches. In addition, we identified misannotated COI references in NCBI which were labelled as Nipponacema schrenckii but belong to Cellana toreuma, highlighting inconsistencies in existing reference data rather than issues with our samples. SEM-based radular features displayed consistent interspecific variation that corroborated molecularly defined clades, offering comprehensive search of the NCBI reliable morphological evidence for species delimitation. Collectively, our findings highlight the value of integrating lineage-specific molecular markers with detailed morphological analyses to resolve taxonomic ambiguities in morphologically conservative marine gastropods. Furthermore, this approach strengthens molecular reference resources essential for future biodiversity and evolutionary research on intertidal limpets. Full article