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- 摘要：The mechanism of gallic acid （GA） scavenging hydroxyl radical （OH·） in weak acidic and weak alkaline aqueous environments of living organisms was investigated using the M06-2X functional method. The reaction between GA and OH· involves three pathways： 1） Hydrogen abstraction， addition， and single-electron transfer. Calculations show that for the hydrogen abstraction reaction， the optimal pathway under both weak acidic and weak alkaline aqueous environments is the abstraction of the hydroxyl hydrogen by OH·， which is significantly exothermic and barrierless. The suboptimal pathway is the abstraction of the hydrogen at the 10-position on the benzene ring by OH·， with energy barriers of 13.5 and 61.2 kJ/mol under weak acidic and weak alkaline aqueous environments， respectively， and the reactions are exothermic. 2） For the addition reaction， the optimal pathways under weak acidic and weak alkaline aqueous environments exhibit energy barriers of 23.8 and 46.0 kJ/mol， respectively， and are exothermic. 3） For the single-electron transfer reaction， the energy barrier is 5.0 kJ/mol under weak acidic aqueous environment， and the reaction is significantly exothermic； however， under weak alkaline aqueous environment， this pathway is thermodynamically and kinetically unfavorable. The results indicate that GA acts as an efficient OH· scavenger in both weak acidic and weak alkaline aqueous environments of living organisms， with superior antioxidant performance observed under weak acidic conditions.关键词：gallic acid;hydroxyl radical;density functional theory;self-consistent reaction field theory;transition state;electron transfer;free energy barrier0|0|0更新时间：2026-09-20
- 摘要：The co-culture of Aspergillus sp. TMw and A. flavus TM1， two endophytic fungi isolated from Gastrodia elata，was carried out using rice medium. The fermentation products were isolated and purified by chromatographic techniques，and their structures were identified by modern spectroscopic methods. A total of 11 known compounds were obtained，namely ditryptophenaline（1），cyclo-（N-methylphenylalanyltryptophenyl）（2），1，3，9-trimethyluric acid（3），kojic acid（4），methyl 5-（hydroxymethyl）furan-3-carboxylate（5），β-sitostenone（6），phomaligol A（7），phomapyrone C（8），bisphenol A（9），4-hydroxybenzaldehyde（10），and 4-（2-ethoxyethyl）phenol（11）. The cytotoxic activities of compounds 1-11 were evaluated using the CCK-8 method. The results showed that only compound 1 exhibited cytotoxicity against non-small cell lung cancer cell line H1975 with an IC50 value of （11.69±1.56） μmol/L, while other compounds exhibited weaker or no cytotoxic activity.关键词：endophytic fungi;Aspergillus;co-culture;secondary metabolites;cytotoxicity1|0|0更新时间：2026-09-20
- 摘要：The resonance modes in nanophotonic structures, such as plasmonic oscillations in metals and Mie resonances in semiconductors, govern their optical responses. Yet, directly linking these modes to perceptible colors at the single-particle level remains difficult. Here, we investigate gold nanoplates(Au NPs) as plasmonic resonators and silicon nanospheres (Si NSs) as dielectric resonators, and establish a systematic method to retrieve and visualize the colors associated with their resonant modes. Single-particle dark-field scattering spectroscopy was combined with a quantitative conversion framework based on the CIE 1931 color space. Au NPs were synthesized via wet-chemical anisotropic oxidation, and Si NSs by nanosecond laser ablation in liquid, enabling precise tuning of their resonances across the visible spectrum(454~769 nm).Scattering spectra of individual nanoparticles were acquired and converted to CIE tristimulus values and sRGB colors following ASTM E308 standards.Si NSs exhibit broad Mie resonances that produce a diverse color palette, whereas Au NPs support narrower plasmonic resonances that yield highly saturated colors.This work establishes a general framework linking nanoscale resonances to macroscale color perception, providing a guideline for designing nanostructures for applications in displays, imaging, and sensing.关键词：nanophotonics;structural color;plasmonic resonances;Mie resonances;dark-field scattering;colorimetry;gold nanoplates;silicon nanospheres3|2|0更新时间：2026-09-20
- 摘要：Blue-green-gray spaces are principal components of urban underlying surfaces， and optimizing their landscape patterns can significantly mitigate urban thermal risks. However， studies on the impacts of blue-green-gray space landscape patterns on land surface temperature （LST） across multiple grid scales in urban agglomerations remain limited. Therefore， this study selected the Pearl River Delta urban agglomeration as the study area and used land cover data and MODIS LST data for 2022 to investigate how landscape patterns of blue-green-gray spaces affect summer daytime LST across multiple grid scales （i.e.， 1， 2， and 3 km） by combining the XGBoost model， SHAP method， and accumulated local effects （ALE） method. Results show that gray space landscape patterns are the primary drivers of LST variation across all scales， whereas the influence of blue and green spaces increases with grid size. In addition， the ALE results indicate that increasing the proportion， patch density， and aggregation of blue and green spaces， reducing the proportion， patch density and aggregation of gray spaces， and reasonably regulating the largest patch size and shape complexity of various spaces can effectively reduce LST. However， the optimal landscape configuration must be determined according to specific spatial scales. The findings provide a scientific basis for optimizing urban landscape patterns and support the sustainable development of urban agglomerations.关键词：blue-green-gray space;landscape pattern;land surface temperature;the Pearl River Delta urban agglomeration;grid scale1|0|0更新时间：2026-09-20
- 摘要：An autonomous intelligent navigation algorithm for automatic guided vehicles（AGV） based on an improved deep deterministic policy gradient（DDPG） is proposed.First，an adaptive exploration strategy based on environmental risk is introduced，which includes predicting the trajectories of dynamic obstacles. Next， a multi-objective weighted reward function is designed to guide the AGV to reach its destination as quickly as possible while avoiding obstacles and staying within boundaries.Then，experiences are extracted using a dual-factor approach based on risk coefficients and experience freshness，which shortens the training cycle and improves training quality. Finally，action rehearsal during runtime further reduces the risk of collisions and boundary violations. To validate the algorithm's performance，simulation experiments were conducted under different numbers，sizes，and speeds of obstacles.The results showed that the AGV navigation algorithm based on the improved DDPG achieved an average success rate of 94.8%， an average timeout rate below 3%，and an average collision rate below 2.3%. Moreover，both the training cycles and navigation time were shorter than those of comparison algorithms， showing clear advantages.关键词：deep reinforcement learning;DDPG;AGV;intelligent navigation7|4|0更新时间：2026-09-20
- 摘要：The default urban morphology parameters in the WRF （weather research and forecasting） model are spatially homogenized and cannot adequately characterize the spatial heterogeneity of real urban underlying surfaces. To investigate the impacts of localized urban morphology parameters on thermodynamic environment simulations using different urban canopy schemes in the WRF model， this study takes the megacity of Guangzhou as a case study and conducts sensitivity experiments. The simulation performances of the single-layer urban canopy （UCM） and the multi-layer building effect parameterization （BEP） schemes for near-surface meteorological elements under the default and localized parameters settings are compared. The results show that： 1） The optimization effects of the localized urban morphology parameters differ significantly between the two schemes. The most notable improvements are found in 2 m temperature for the UCM scheme and in 10 m wind speed for the BEP scheme， with bias reduction rates reaching 90.1% and 49.8%， respectively. More than 71% of stations exhibit improved performance in 2 m temperature simulations， and over 93% show enhanced capability in 10 m wind speed simulations. 2） The localized urban morphology parameters lead to increases in simulated surface skin temperature in both schemes， with a more pronounced rise in the central urban area. Specifically， the BEP scheme demonstrates a greater temperature rise due to narrowed street canyons and enhanced heat trapping. The impact of these parameters on surface skin temperature is greater than that on 2 m temperature. 3） Due to increased surface roughness induced by larger standard deviations of building height， the 10 m wind speeds in both schemes decrease by more than 0.8 m/s. These parameters cause the planetary boundary layer height to increase by 60-90 m in the UCM scheme， while it decreases by 10-30 m in the BEP scheme. These differences are closely related to changes in 2 m temperature and vertical turbulent momentum exchange. This study clarifies the response characteristics of different urban canopy schemes to urban morphology parameters， refines the localized application of these parameters in the WRF model，and provides technical support for high-resolution urban climate simulations.关键词：urban canopy scheme;urban morphological parameter;thermodynamic environment;WRF model;Guangzhou4|0|0更新时间：2026-09-19
- 摘要：Reconstituted specimens with fine-particle contents of 10%， 30%， and 50% were prepared. Saturated consolidated undrained dynamic triaxial tests were then conducted after 1，10，50，and 100 drying-wetting cycles. The evolution of accumulated plastic strain， stress-strain hysteresis behavior， and resilient modulus was analyzed under different confining-pressure conditions. The results show that the dynamic response of the soil exhibits pronounced stage-dependent and non-monotonic characteristics under long-term drying-wetting cycles. For specimens with 10% and 30% fine-particle contents， the accumulated plastic strain increases from 1 to 10 cycles， decreases at 50 cycles， and increases again at 100 cycles. For specimens with 50% fine-particle content， relatively large deformation is observed after 10 drying-wetting cycles， whereas the accumulated plastic strain gradually decreases after 50~100 cycles. Both the area of the stress-strain hysteresis loops and the resilient modulus show stage-dependent variations associated with the drying-wetting history， indicating that structural disturbance， particle rearrangement， and subsequent re-stabilization jointly govern the evolution of the soil’s dynamic properties.关键词：granite residual soil;drying-wetting cycles;accumulated plastic strain;resilient modulus14|11|0更新时间：2026-09-19
- 摘要：Naturalistic driving data from the Tengchong-Longling Expressway in Yunnan Province are used，and an analytical framework involving driver characteristics，vehicle operation，road environment， and abnormal driving behaviors is constructed. A causation analysis dataset is developed based on vehicle motion data，road environment data，driver information，and risk levels obtained through fuzzy comprehensive evaluation. Structural equation modeling is applied to examine the linear influence paths，and fuzzy-set qualitative comparative analysis is used to identify configurations leading to high-risk and non-high-risk abnormal driving behaviors. The results show that driver characteristics have a negative effect on abnormal driving behaviors，while vehicle operation and road environment have positive effects. High-risk abnormal driving behaviors are mainly induced by three configurations：low-skill and high-risk-taking type， environmental-pressure type，and operation-environment coupling type，whereas non-high-risk behaviors are characterized by a robust defensive configuration.关键词：traffic safety;mountainous expressway;abnormal driving behavior;structural equation model;fuzzy-set qualitative analysis26|8|0更新时间：2026-09-18
- 摘要：This paper first investigates the spectra of the product
- 摘要：The study was to investigate the aromatic derivatives and evaluate their antimicrobila activity from the endophytic fungus，Fusarium solani PGS19，isolated from the mangrove plant Bruguiera gymnorrhiza in the Nansha Wetland Nature Reserve. Firstly，the ethyl acetate extract of F. solani PGS19 was isolated and purified using various chromatographic techniques，including silica gel column chromatography，reversed-phase ODS medium-pressure preparation，semi-preparative high-performance liquid chromatography（HPLC），and thin-layer chromatography（TLC）. Then，the structures of the purified compounds were elucidated by modern spectroscopic methods. Finally，the antimicrobial activities of all isolated compounds were evaluated in vitro using broth microdilution method. Sixteen compounds were obtained from F. solani PGS19 and identified as 2-acetonyl-3-methyl-7-methoxynaphthazarin（1），3-methyletherfusarubin（2），solaniol（3），anhydrofusarubin（4），anhydrojavanicin（5），3-demethoxylfusarnaphthoquinone B（6），（2S，3S，4S）-8-dehydroxy-8-methoxyldihydronaphthalenone（7），dihydronaphthalenone（8），nepetoidin F（9），7-hydroxy-2，5-dimethyl-4H-1-benzopyran-4-one（10），methyl ferulate（11），p-hydroxyphenylacetic acid methylester（12），p-hydroxybenzaldehyde（13），4-hydroxyacetophenone（14），acetovanillone（15），and 3，4-dimethoxyacetophenone（16）. Among them，compound 9 was isolated from an endophytic fungus for the first time，expanding its biological source. Antibacterial activity assays indicated that compound 6 exhibited weak inhibitory effects against MRSA and Staphylococcus aureus，with MIC values of 100 µg/mL for both，while the remaining compounds showed no significant activity at the tested concentrations. This study further enriches the chemical diversity of secondary metabolites from mangrove endophytic F. solani.关键词：endophytic fungus;Fusarium solani;aromatic derivatives;antimicrobial activity78|79|0更新时间：2026-07-13
- 摘要：To solve the limitations of traditional adenosine content determination methods, such as complex sample preparation and time-consuming operations, in this study, Fourier transform infrared (FTIR) spectroscopy combined with chemometric methods was employed to establish a rapid detection model for adenosine content in Cordyceps sinensis. A rapid, efficient, and non-destructive quantitative method was proposed based on FTIR spectroscopy integrated with Simpson's integration rule. Spectral data were collected from 77 samples of C. sinensis. Through statistical analysis, 1 365 significant data points were screened from 1 868 original data points, determining five critical wavenumber regions (399.19-833.29, 1 033.36-1 380.46, 1 710.13-1 790.89, 1 870.56-3 020.78, and 3 980.46-3 999.71 cm-1). Four types of spectral characteristic variables—peak area (A), full width at half maximum (FWHM), area-to-height (H) ratio (A/H), and mean absorbance of the spectral band (MBA). A total of 62 samples (80%) were allocated as the training-validation set for 5-fold cross-validation to establish Multiple Linear Regression (MLR) and Partial Least Squares Regression (PLSR) models; the remaining 15 samples (20%) served as an independent test set for model generalization validation. FTIR characteristic analysis revealed that the principal absorption peaks of C. sinensis were located at 3 289.17 cm-1 (O—H stretching), 2 928.53 cm-1 (asymmetric C—H stretching), and 1 652.72 cm-1 (amide I band). Modeling results demonstrated that the A/H ratio feature exhibited optimal performance on the calibration set (MLR: R²=0.941±0.029), but suffered from severe overfitting (ΔR²=0.225); the PLSR-MBA combined model achieved the best cross-validation performance (R²=0.807±0.031, RMSE=0.189±0.005) with minimal overfitting (ΔR²=0.078). Independent test set validation further confirmed the superior predictive accuracy and robustness of the PLSR-MBA model (R²=0.886, RMSE=0.107), significantly outperforming the MLR-A/H model (R²=0.845, RMSE=0.169). The PLSR-MBA combined model achieves an optimal balance among fitting accuracy, generalization capability, and overfitting resistance, and is recommended as the preferred method for rapid quantitative analysis of adenosine content in C. sinensis. This study provides important theoretical basis and practical guidance for feature extraction and modeling strategy selection in spectral quantitative analysis of traditional Chinese medicines.关键词：chemometric methods;Cordyceps sinensis;adenosine;infrared spectroscopy;Simpson's rule;partial least squares regression;multiple linear regression44|85|0更新时间：2026-07-13
- 摘要：Dysregulation of manganese ion （Mn2+） homeostasis is closely associated with various diseases. However， the existing detection methods rely on expensive instruments and involve cumbersome operations， making it difficult to meet the demands for rapid and convenient analysis. In this study， a highly sensitive and selective colorimetric biosensor was constructed based on the cascade signal amplification principle of Mn2+-specific DNAzyme （Mn5V） and G-quadruplex/hemin DNAzyme for the detection of Mn2+ in complex biological matrices. The sensor employs a "hairpin-locked" substrate probe design. In the presence of Mn2+， Mn5V is activated and specifically cleaves the substrate strand， releasing a DNA fragment that folds into a G-quadruplex structure. The G-quadruplex then binds with hemin to form a complex with peroxidase-like activity， which catalyzes the TMB-H2O2 colorimetric reaction， enabling visual signal output. Our results demonstrated that the sensor exhibits excellent analytical performance for Mn2+， showing a good linear relationship in the range of 7.0×10-8 to 1.0×10-5 mol/L with a detection limit as low as 1.69×10-9 mol/L. The sensor also showed strong anti-interference ability against common coexisting metal ions. When applied to spiked recovery experiments in MCF-7 and A549 cell lysates， the recovery rates ranged from 98.00% to 101.00% with relative standard deviations below 4.3%， verifying its accuracy and reliability in complex biological samples. The cascade signal amplification colorimetric sensor constructed in this study provides a novel and efficient analytical tool for environmental monitoring and mechanistic research on the diseases related with manganese metabolism disorders.关键词：Mn2+;Mn5V;DNAzyme;colorimetric assay52|77|0更新时间：2026-07-13
- 摘要：SrTiO₃/LaAlO₃/SrTiO₃ （substrate） sandwich heterostructures were grown on SrTiO₃ （001） substrates by pulsed laser deposition. Atomic-scale structural characterization reveals gradient La diffusion near the n-type interface （SrTiO₃ substrate/LaAlO₃）， accompanied by partial reduction of Ti⁴⁺ to Ti³⁺， yielding a carrier concentration of approximately 4.98×10¹³ cm⁻². Ferroelectric-like displacement polarization vector analysis demonstrates that both interfaces exhibit a tail-to-head configuration： The SrTiO₃ polarization points toward the interface， while the LaAlO₃ polarization points away from the interface， with the LaAlO₃ polarization intensity being significantly stronger than that of SrTiO₃. At the n-type interface， the net negative bound charge generated by the tail-to-head ferroelectric-like polarization partially counteracts the electron accumulation driven by the polar discontinuity， resulting in an experimental carrier concentration approximately one order of magnitude lower than the theoretical value predicted by the polar catastrophe model. At the p-type interface， the net negative bound charge arising from the LaAlO₃ ferroelectric-like polarization acts synergistically with the hole requirement of the p-type polar discontinuity to drive two-dimensional hole gas formation. This study reveals the modulation mechanism of ferroelectric-like displacement polarization distributions induced by lattice distortions within the film on the dual-interface conduction behavior.关键词：SrTiO₃/LaAlO₃/SrTiO₃ heterostructure;two-dimensional electron gas;two-dimensional hole gas;polar catastrophe;ferroelectric-like displacement polarization18|53|0更新时间：2026-07-13
- 摘要：A minimal sediment model with diffusion is proposed. Firstly， the existence of Turing-Hopf bifurcation for the model is investigated； Secondly， the normal form of model at the Turing-Hopf bifurcation point is derived； Finally， the dynamics of model are analyzed by means of numerical results. The research indicates that near the Turing-Hopf bifurcation point， the model exhibits rich spatiotemporal dynamics， including the spatially homogeneous periodic solutions， spatially inhomogeneous periodic solutions and spatially inhomogeneous steady-state solutions.关键词：minimal sediment model;Turing-Hopf bifurcation;normal form;spatiotemporal dynamics83|78|0更新时间：2026-07-13
- 摘要：Melicope pteleifolia is a traditional medicinal herb in China and a vital raw material for renowned Chinese patent medicines such as Guangdong herbal tea and Sanjiu Weitai Granules. In the present study， M. pteleifolia seedlings were employed as experimental materials， and various types of microbial inoculants were foliar-sprayed to investigate the variations in seedling growth and development as well as rhizosphere soil microbial communities. The results demonstrated that microbial inoculant treatments significantly enhanced the plant height， the stem diameter， the seedling vigor index， and the number of leaf nodes of M. pteleifolia seedlings， among which the treatment with photosynthetic bacterial inoculant （T2） exhibited the most remarkable effect. Soil microbial analysis revealed that the application of compound EM inoculants （T1）， photosynthetic bacterial inoculant （T2）， or their combined application （T4） could all increase the number of soil operational taxonomic units （OTUs）， whereas other microbial inoculants resulted in a reduction in OTU abundance. It was observed that Proteobacteria was the dominant phylum in the rhizosphere soil of M. pteleifolia seedlings， and the application of all microbial inoculants elevated the relative abundance of Acidobacteriota in the rhizosphere soil. α diversity analysis indicated that the diversity of soil microbial communities was higher under T1， T2， and T4 treatments， and this diversity was positively correlated with seedling growth indices. In conclusion， T1， T2， and T4 can serve as suitable microbial fertilizer application schemes for M. pteleifolia at the seedling stage， among which Acidobacteriota and Bacteroidota may play pivotal roles in regulating rhizosphere microbial communities and improving soil fertility. This study provides a theoretical foundation for optimizing the cultivation techniques of M. pteleifolia.关键词：Melicope pteleifolia;microbial inoculants;rhizosphere microorganism;seedling stage34|74|0更新时间：2026-07-13
- 摘要：Let
- 摘要：A systematic investigation is conducted on the inverse problem of radiative coefficient reconstruction for a class of degenerate parabolic equations defined on semi-unbounded domains. The study begins by introducing an exact artificial boundary condition，which effectively reduces the original problem on the semi-unbounded region to an equivalent formulation on a bounded domain. Within the optimal control framework，the inverse problem is reformulated as a minimization problem. A priori estimates for the direct problem are derived，and the existence of a minimizer for the control functional is established，along with the necessary conditions satisfied by the extremum. The uniqueness and stability of the minimizer are demonstrated through an analysis based on these necessary conditions. Finally，based on the necessary optimality conditions，a gradient-based optimization algorithm was designed，and numerical examples were presented to demonstrate its effectiveness.关键词：Semi-unbounded degenerate parabolic equation;radiative coefficient inversion;artificial boundary;optimal control;well-posedness26|29|0更新时间：2026-07-13
- 摘要：The Zoige Basin， located on the northeastern Qinghai-Tibet Plateau， is a geomorphic unit highly sensitive to climate change. Widespread continuous aeolian deposits in this region provide valuable insights into regional surface processes and climate changes. This study investigated the loess-paleosol sequence at Kesheng Village （KSC） on the second terrace of the Yellow River in the Maqu Valley. Based on geochemical elemental analysis， micromorphological observation， and optically stimulated luminescence （OSL） dating， we reconstructed the chemical weathering history of the profile and revealed the phased climatic evolution since 13.2 ka. The results indicate that： 1） Stable aeolian dust accumulation commenced on the second terrace of the Yellow River at around 13.2 ka， forming a continuous and complete loess-paleosol sequence. From bottom to top， this sequence comprises loess L1（13.2~8.5 ka）， paleosol S0（8.5~3.0 ka）， loess L0（3.0~1.2 ka）， and modern soil MS （1.2 ka to present）. 2） The KSC profile is generally in the initial stage of chemical weathering （mean CIA=59.8）. Although the paleosol exhibits higher weathering intensity than the loess units， it remains within the initial weathering stage. The weathering intensity follows the order： paleosol S0 （mean CIA=62.3）
- 摘要：In 2023， Tainan experienced a severe dengue fever epidemic， the spread of which was influenced by complex environmental factors. This study analyzes the spatiotemporal patterns of dengue fever transmission in Tainan and identifies the key meteorological drivers， aiming to provide a scientific basis for local surveillance and evidence-based prevention. Monthly dengue case data and meteorological records for Tainan from January to December 2023 were analyzed using a standard deviational ellipse analysis， Moran’s I， correlation analysis， multicollinearity diagnostics， and a Bayesian spatiotemporal model. The findings reveal a clear temporal pattern of “increase-peak-decline” in case numbers for the full year of 2023. Spatially， the epidemic evolved through four stages：sporadic occurrence， random distribution， clustering， and eventual dissipation. The relative risks of meteorological factors followed the order： number of rainy days
- 摘要：An aerial image detection algorithm named MA-YOLOv11 is proposed based on YOLOv11. First，the SE-C3k2 module is designed to preserv the features of small branches while achieving lightweight. Second，the multi-scale shared convolution module replaces the SPPF module. Then，a novel HMA-Net network structure is constructed by incorporating the MAFPN architecture，adding a small target detection head P2，and reducing redundant paths. This enhances the interaction between shallow detail information and high-level semantic information，thereby improving the detection accuracy for small targets. Finally，a multi-scale attention detection head is employed to effectively handle scenes with leaf occlusion. Experimental results show that compared to the baseline model，the improved MA-YOLOv11 model increases of 4.2% in precision，4.1% in recall，and 5.2% in the mAP50 metric，validating the effectiveness of this method for treeencroachment detection.关键词：tree invasion;YOLOv11;spatial channel reconstruction convolution41|110|0更新时间：2026-06-26
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