Search Results (127)

Potassium bromide (KBr) thin films were deposited by resistive thermal evaporation at substrate temperatures ranging from 50 °C to 250 °C to systematically elucidate the temperature-dependent evolution of their physical properties. Structural, morphological, and optical characteristics were examined by X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Fourier transform infrared spectroscopy (FTIR). The results reveal a complex, non-monotonic response to temperature rather than a simple linear trend. As the substrate temperature increases, growth evolves from a mixed polycrystalline texture to a pronounced (200) preferred orientation. Morphological analysis shows that the film surface is smoothest at 150 °C, while the microstructure becomes densest at 200 °C. These structural variations directly modulate the optical constants: the refractive index attains its highest values in the 150–200 °C window, approaching that of bulk KBr. Cryogenic temperature (6 K) FTIR measurements further demonstrate that suppression of multi-phonon absorption markedly enhances the infrared transmittance of the films. Taken together, the data indicate that 150–200 °C constitutes an optimal process window for fabricating KBr films that combine superior crystallinity, low defect density, and high packing density. This study elucidates the temperature-driven structure–property coupling and offers valuable guidance for optimizing high-performance infrared and cryogenic optical components. Full article

Vegetation carbon sequestration (CS) is critical for mitigating climate change in urban agglomerations, yet its driving mechanisms remain poorly understood in rapidly urbanizing regions. This study introduces an integrated attribution and influence analysis framework, GWR-RF-SEM, to quantitatively assess the driving forces, mechanisms, and pathways of CS using multi-source remote sensing data at the county scale within the Yangtze River Delta Urban Agglomeration (YRDUA), China, from 2001 to 2020. Our results reveal an overall increase in CS across 70.14% districts in the YRDUA, with municipal districts exhibiting significantly lower CS compared to the outside districts. Photosynthesis and human activities emerged as the dominant drivers, collectively accounting for 73.1% of CS variation, significantly surpassing the influence of climate factors. Although most factors influenced urban vegetation CS either directly or indirectly, photosynthesis, afforestation, and urban green space structure were identified as the primary direct drivers of CS enhancement in both districts. Notably, we found significant spatial heterogeneity in CS drivers between municipal districts and the outside districts, highlighting the need for targeted strategies to enhance CS efficiency. These findings advance our understanding of urban vegetation CS mechanisms, providing essential support for the enhancement of nature-based solutions depending on ecosystem services under urbanization and climate change. Full article

This paper investigates the role of the digital economy in reducing carbon emissions, with a particular focus on the moderating and threshold effects of green finance. An analysis of data from 30 Chinese provinces shows that the digital economy significantly reduces carbon emission intensity by restructuring energy consumption and promoting green technological innovation. Green finance plays a crucial moderating role by alleviating financial barriers to digital transformation and supporting the implementation of emission-reducing technologies. The study reveals a nonlinear relationship, with green finance exhibiting a “strong initial, weak subsequent” threshold effect. At the same time, the digital economy’s impact on carbon reduction strengthens over time as technological development progresses. These findings contribute to understanding how digitalisation and green finance can work synergistically to drive sustainable low-carbon development. Full article

The interaction between cucurbit[8]uril (Q[8]) and the guest 1-methyl-4-(4-(1-methylpyridin-1-ium-4-yl)benzamido)pyridin-1-ium (PB²⁺) has been thoroughly investigated. Multiple techniques were employed, including ¹H NMR spectroscopy, mass spectrometry, isothermal titration calorimetry (ITC), UV–vis absorption spectrophotometry, and quantum chemistry calculations. The experimental results and calculation analysis have clearly shown that in aqueous solution, the host Q[8] preferentially encapsulates the phenylpyridinium salt moiety of the PB²⁺ guest within its hydrophobic cavity, forming a 1:2 inclusion complex. Full article

Objective: This study explores the material basis and biological functions of meridian interstitial channels in mini-pigs proximal to the stomach meridian by analyzing differential proteomics between interstitial channels and adjacent non-interstitial channel tissues. Methods: Liquid chromatography–mass spectrometry (LC-MS) under data-dependent acquisition mode was employed to analyze and identify the proteome of subcutaneous connective tissues along the stomach meridian and adjacent tissues. SWATH MS^ALL method and omicsbean online analysis platforms were used for protein quantification and differential proteomic analysis. Differential proteins were subjected to Gene Ontology annotation and KEGG pathway analysis to understand their functions and biological processes. Combining traditional Chinese meridian theory with modern meridian research, proteins most relevant to meridian functions were selected, and their expression levels were assessed using Western blotting. Results: GO annotation and KEGG pathway analysis revealed differences in molecular functions, biological processes, and metabolic pathways among differential proteins. Most downregulated proteins were enzyme functional proteins involved in amino acid metabolism (GOT1), adenosine nucleotide balance conversion (AK1), and calcium ion-binding processes (ANXA6). Most upregulated proteins were structural proteins in the extracellular matrix—collagen proteins (COL3A1, COL6A1, COL6A3, COL6A6, COL12A1, COL14A1) and proteoglycans (DCN, BGN, FMOD)—involved in influencing and regulating collagen fiber generation and arrangement. Intriguingly, almost all differential proteins were associated with gastrointestinal diseases, implying a pathological correlation of differential proteins in the stomach meridian interstitial channel. Conclusions: The stomach meridian interstitial channels in mini-pigs show 72 differentially expressed proteins compared to adjacent tissues. These differences include the upregulation of structural proteins and downregulation of functional proteins, potentially forming the molecular biological basis for the structural and functional specificity of meridians. Full article

Dissolved organic matter (DOM) exerts a significant influence on the environmental behavior of heavy metals in water. This study investigated the spatial distribution characteristics of DOM in the upper reaches of the Yangtze River and its vertical (0–10 m) binding behavior with heavy metals. The results indicated that humic acid-like substances dominated the DOM composition in the river water, exhibiting spatial variability horizontally, with a higher proportion of protein-like components observed at the depth of 8 m. The DOM showed complexation affinity (LogK) values were 4.71–6.38 for Cu²⁺ and 4.27–6.26 for Hg²⁺, with the protein-like component C3 exhibiting higher LogK values when binding with Cu²⁺ or Hg²⁺ compared to humic-like components. The LogK_Cu and LogK_Hg varied distinctly with water depth, and at 8 m depth, humus-like component C1 exhibited stronger binding affinity for Hg²⁺, whereas protein-like component C3 showed greater affinity for Cu²⁺. The 2D-FTIR-COS analysis revealed that, in the DOM-Cu complexes, DOM from surface water preferentially bound to O-H groups of carbohydrates, phenols, and carboxylic acids, while deep water DOM favored C=O groups in amides; for DOM–Hg complexes, the active binding sites varied distinctly with depth. This study provides novel insights into the migration and transformation mechanisms of heavy metals in rivers. Full article

Alfalfa (Medicago sativa) is a perennial forage crop with significant economic and ecological significance. If alfalfa can be planted in saline-alkali land, it will not only improve the utilization rate of marginal land and alleviate the competition between forage and cereal crops for arable land but will also increase the yield of high-quality domestic forage. In this study, we conducted transcriptomic analysis on the saline-alkali-tolerant alfalfa cultivar NQ-1 and compared its metabolite accumulation levels with saline-alkali-sensitive cultivars. The results showed that under saline-alkali stress, the photosynthesis and some secondary metabolic pathways in NQ-1 were activated, such as α-Linolenic acid metabolism, Phenylpropanoid and Flavonoid biosynthesis, and Photosynthesis-related pathways, providing substances and energy for enhancing NQ-1 stress tolerance. Furthermore, some specific flavonoids were detected that may contribute to the saline-alkali tolerance of NQ-1. In addition, transcription factors that may regulate flavonoid biosynthesis in NQ-1 under saline-alkali stress were also identified. This study deepens the understanding of the resistance mechanism of saline-alkali-tolerant cultivars of alfalfa and provides valuable information for molecular design breeding strategies for stress-resistant alfalfa. Full article

Assessing the nutritional quality of silage maize (Zea mays L.) hinges largely on its oil content, a complex quantitative trait influenced by multiple genes. Mining candidate genes within oil content-related quantitative trait loci (QTLs) can provide genetic resources and a theoretical foundation for cultivating high-oil silage maize varieties. This study employed 274 doubled haploid (DH) lines derived from the parental lines BY4944 and DNF34-2 to perform main gene plus polygene mixed genetic analysis and complex interval mapping (CIM), with the goal of pinpointing oil content-related QTLs and genes distributed across the Z. mays L. genome. Leveraging 5400 single nucleotide polymorphism (SNPs), a high-resolution silage maize genetic linkage map covering 3864.51 cM was constructed with an average interval between markers of 0.74 cM. Analysis of the map revealed 13 oil content-related QTLs. The most significant large-effect QTL (qOIL-1-1), located on chromosome 1 within the region spanning 240.93 Mb to 256.57 Mb, exhibited a logarithm of odds (LOD) score of 3.34 and explained 5.06% of oil content-related phenotypic variation. Within these QTLs, 617 genes were annotated. Through transcriptome analysis combined with quantitative real-time polymerase chain reaction (RT-qPCR), five candidate genes potentially associated with oil content were predicted and subsequently validated within these genetic loci. This research underscores the potential of identifying candidate genes to enhance breeding efforts aimed at augmenting oil content, thereby advancing animal husbandry practices. Full article

To address the issue of reduced target detection accuracy due to interfering targets and clutter reference cells in complex traffic scenarios, we propose the ADVI-CFAR (Adaptive Discriminant Variation Index Constant False Alarm Rate) detection algorithm. Considering that the non-uniformity of the background environment leads to significant variations in signal power magnitude, we introduce a background power transition point to evaluate the uniformity of the background environment within the reference window. Moreover, in complex background environments, clutter distributions often exhibit skewness rather than a Gaussian distribution. We incorporate the higher-order statistical skewness of the clutter to calculate the background power threshold index, thereby improving the accuracy of background power estimation. Then, based on the transition points and clutter power index, the background environment is classified, and an appropriate detection threshold calculation method is chosen for target detection. We conduct a simulation analysis in uniform, non-uniform, and clutter edge environments, and the results show that the identification accuracy exceeds 95% for all three background environments. At a detection probability of 50%, the performance loss is 0.08 dB in uniform environments and 0.36 dB in multi-target environments. When the false alarm probability is set to ${10}^{-4}$, the ADVI-CFAR algorithm significantly suppresses false alarms, with the false alarm peak occurring at ${10}^{-3.52}$. Real data from urban traffic scenarios validate the method, showing that it achieves a high detection accuracy for target detection in real traffic scenarios and effectively meets the radar target detection requirements in practical traffic environments. Full article

In this study, we proposed a fast and accurate PatchMixer-based framework (Patch-TS). After the data were processed, which included missing values and normalization, the environmental factors were selected via the Pearson correlation coefficient method. Then, the newly developed sap flow prediction model was trained. The resulting data demonstrated that the coefficient of determination (R²), mean squared error (MSE), and mean absolute error (MAE) are 0.921, 0.00824, and 0.0497, respectively. The R² of Patch-TS further improved to 0.929 after 7 factors were extracted via the Pearson correlation method. Furthermore, we comparatively analyse the mitigating effects of RevIn (Reversible Instance Normalization) and Dish-TS on data drift. In addition to the predictive performance of the models under different prediction windows, Patch-TS outperforms the other models. The results demonstrate that the model developed in this paper is an effective tool for accurately predicting sap flow, which is a valuable contribution to the practical management of trees and forests. Full article

The tracking accuracy of the traditional Strong Tracking Unscented Kalman Filter algorithm (ST-UKF) decreases when the motion state of the traffic target changes significantly. A multidimensional adaptive factor-based strong tracking UKF (MAST-UKF) algorithm is proposed. The method introduces multidimensional attenuation factors in the prediction and updating process of filtering, and realizes the strong tracking filtering of vehicle targets by adjusting the uncertainty of state noise covariance and observation noise covariance and dynamically updating the multidimensional attenuation factors by adaptively adjusting the threshold based on the observation residuals and the state estimation error. Target tracking simulations are performed under system model uncertainty, and the tracking errors of MAST-UKF are reduced by 32.67%, 28.54%, and 23.17% compared to UKF, ST-UKF, and AST-UKF, respectively. The real vehicle experiments show that MAST-UKF reduces the distance error by 18.29% and speed error by 15.25% compared to AST-UKF. The results demonstrate that the MAST-UKF algorithm is able to adaptively adjust the noise covariance and effectively cope with the inaccuracy of the state noise and observation noise, thus realizing the accurate tracking of the target under complex conditions. Full article

Gummy stem blight (GSB) is a pervasive disease that causes considerable economic losses in cucurbit crops and poses a significant threat to pumpkin production. However, the molecular interaction mechanisms between pumpkin and the pathogen remain largely unexplored. In our previous research, we isolated and identified Stagonosporopsis cucurbitacearum (Sc) as the primary causative agent of pumpkin stem blight in Northeast China. Through whole-genome analysis, we identified several pathogenic genes associated with Sc infection in pumpkins. In this study, we performed a comprehensive comparative transcriptomic and metabolomic analysis of unvaccinated and Sc-inoculated pumpkins. We observed distinct differences in gene expression profiles, with these genes being significantly enriched in pathways related to plant–pathogen interactions, phytohormone signal transduction, and metabolic processes, including phenylpropanoid biosynthesis. Joint analysis revealed that the phenylpropanoid biosynthesis pathway was activated in Sc-infected pumpkins. Notably, two metabolites involved in the phenylpropanoid and flavonoid biosynthesis pathways, p-coumaric acid and quercetin, exhibited significant upregulation, suggesting their potential roles in conferring resistance to GSB. These findings enhance our understanding of the molecular mechanisms underlying the defense response against GSB infection in pumpkins and may provide valuable insights for developing strategies to control GSB disease. Full article

The dynamics and plant composition of toxic weeds in alpine meadows are strongly influenced by management practices such as livestock grazing. Here, the effect of grazing management on vegetation and soil characteristics within an alpine meadow ecosystem was assessed over a 5-year period. The experimental grazing treatments comprised no grazing (control), light grazing (5 sheep/ha), moderate grazing (10 sheep/ha), and heavy grazing (15 sheep/ha). The characteristics of both edible grass and toxic weeds, along with the soil’s physicochemical and biological properties, were evaluated. Under heavy grazing, the biomass of toxic weeds increased by 15.0%, while the biomass of edible species decreased by 57.0% compared to the control. The findings indicated that after 5 years, the plant composition changed significantly, with edible species such as Taraxacum mongolicum and Tibetia himalaica decreasing and disappearing under moderate and heavy grazing treatments. Conversely, toxic weeds like Stellera chamaejasme and Euphorbia micractina emerged under moderate or heavy grazing. Additionally, the richness of toxic weeds increased from 6.3 under the control to 14.2 under heavy grazing. Regarding soil properties, the levels of soil glucosidase, amylase, and cellulose decreased by 39.0%, 53.0%, and 40.0%, respectively. The amount of available potassium initially decreased and then increased under heavy grazing. The results demonstrated that the quality of the vegetation cover and a soil’s properties directly depend on land management. Overall, light to moderate grazing kept the soil in a better chemical and biological state and kept the biomass of palatable plants at a desirable level, which also controlled the abundance and biomass of toxic weeds. Enhancing soil nutrient conditions, such as by adding nitrate fertilizers, can be effective in restoring grasslands that have been severely degraded by grazing. Full article

As climate change continues to alter species distributions, Pinus bungeana, an endangered conifer of significant ecological and ornamental value, faces heightened vulnerability, underscoring the critical need to understand and predict its future habitat shifts. Here, we used 83 effective geographic distribution records, along with climate, topography, soil, and drought indices, to simulate the potential distribution of suitable ecological niches for P. bungeana under current conditions and across three future time periods (2040–2060, 2060–2080, and 2080–2100) under two shared socioeconomic pathways: SSP126 (low emissions) and SSP585 (high emissions), using the maximum entropy (MaxEnt) model. The results show that the area under the receiver operating characteristic curve (AUC) for all simulations exceeded 0.973, indicating high predictive accuracy. Soil moisture, the minimum temperature of the coldest month, temperature seasonality, isothermality, the precipitation of the wettest quarter, and altitude were identified as key environmental factors limiting the distribution of P. bungeana, with soil moisture and the minimum temperature of the coldest month being the most important factors. Under the current climatic conditions, the potentially suitable ecological niches for P. bungeana were primarily located in Shaanxi Province, southern Shanxi Province, southeastern Gansu Province, northeastern Sichuan Province, Henan Province, and northwestern Hubei Province, covering approximately 75.59 × 10⁴ km². However, under the future climate scenarios, highly suitable areas were projected to contract, with the rate of decline varying significantly between scenarios. Despite this, the total area of potentially suitable ecological niches was predicted to expand in the future periods. Additionally, a pronounced eastward shift in P. bungeana’s distribution was projected, especially under the high-emission SSP585 scenario. These findings provide insights into the potential impacts of climate change on the distribution of P. bungeana, and they offer valuable guidance for its conservation strategies and habitat management in the context of climate change. Full article

With the rapid advancement of intelligent unmanned aerial vehicle (UAV) technology, UAV swarm technology is being increasingly applied with autonomous control, intelligent collaboration, and flexible deployment. It exhibits tremendous potential in emergency rescue, environmental monitoring, wireless communication and other areas. UAV swarms require stable communication links to perform tasks such as formation control, route planning, and data acquisition. To improve the high-speed, secure communication capability and environmental adaptability of UAV swarms, this paper proposes the use of optical communication technology, which offers advantages such as rapid deployment, resistance to electromagnetic interference, and strong confidentiality, to help maintain communication links under special conditions such as emergency scenarios, strong electromagnetic interference, and communication impedance. UAVs are characterized by their high maneuverability and low payload capacity, making it difficult for traditional laser communication to maintain the communication link under such dynamic conditions. This paper proposes an optical communication scheme with a specific divergence angle, ensuring transmission distance and covering a certain communication range. The research results demonstrate that the proposed optical communication platform can maintain a transmission rate of 100 Mbps within a specified angle. We propose that the future direction of UAV optical communication development lies in more efficient transmission and reception technologies, smarter coding and modulation techniques, and enhanced environmental adaptability. Finally, we constructed two scenarios for UAV swarms, including air-to-ground and air-to-air, and assessed the application potential of swarm optical communication technologies in these two scenarios. Full article