Search Results (1,160)

Phosphorus (P) release from reservoir sediments critically influences water quality and ecosystem stability. This study analyzed surface sediments from four representative zones to investigate phosphorus fraction distribution, key influencing factors, and implications for water quality. Results showed that total phosphorus (TP) content in sediments from main and tributary inflow zones was significantly higher than in open-water and transition zones. Inorganic phosphorus (IP) was the dominant form, with iron-bound phosphorus (Fe-P) accounting for 33.2–42.0% of IP. A strong correlation existed between P release and the Fe/P molar ratio; notably, when the ratio approached 10, phosphorus desorption increased significantly, indicating a shift from sink to source. Sediments with grain sizes <0.01 mm had the highest P release rates, suggesting particle size, Fe content, and hydrodynamics jointly regulate P mobilization. Using the Diffusive Gradients in Thin Films (DGT) technique, phosphorus release in inflow zones exceeded 1 g/m² in all hydrological periods, contributing substantially to internal loading. Sediment-derived P primarily influenced bottom water, while surface water was more affected by external inputs. These findings highlight the spatial heterogeneity of P release and underscore the need for zone-specific management strategies in reservoir systems. Full article

This paper proposes a low-complexity signal detection method for orthogonal time frequency space (OTFS) communication systems, based on a separable convolutional neural network (SeCNN), termed SeCNN-OTFS. A novel SeparableBlock architecture is introduced, which integrates residual connections and a channel attention mechanism to enhance feature discrimination and training stability under high Doppler conditions. By decomposing standard convolutions into depthwise and pointwise operations, the model achieves a substantial reduction in computational complexity. To validate its effectiveness, simulations are conducted under a standard OTFS configuration with 64-QAM modulation, comparing the proposed SeCNN-OTFS with conventional CNN-based models and classical linear estimators, such as least squares (LS) and minimum mean square error (MMSE). The results show that SeCNN-OTFS consistently outperforms LS and MMSE, and when the signal-to-noise ratio (SNR) exceeds 12.5 dB, its bit error rate (BER) performance becomes nearly identical to that of 2D-CNN. Notably, SeCNN-OTFS requires only 19% of the parameters compared to 2D-CNN, making it highly suitable for resource-constrained environments such as satellite and IoT communication systems. For scenarios where higher accuracy is required and computational resources are sufficient, the CNN-OTFS model—with conventional convolutional layers replacing the separable convolutional layers—can be adopted as a more precise alternative. Full article

Selenium stress can adversely affect plants by inhibiting growth, impairing oxidative stress resistance, and inducing toxicity. In this experiment, we investigated the effect of exogenous 24-epibrassinolide (24-EBL; 2.0 mg/L), a brassinosteroid (BR), on alleviating selenium stress in peach trees by analyzing its impact on biomass, selenium accumulation, and the expression of selenium metabolism-related genes in peach seedlings. The results demonstrated that 24-EBL could effectively mitigate biomass loss in peach seedlings exposed to selenium stress. Compared to the Se treatment alone, the 24-EBL+Se treatment resulted in a significant 16.55% increase in root selenium content and a more pronounced 30.39% increase in selenium content in the aboveground parts. Regarding the subcellular distribution, the cell wall was the primary site of Se deposition, accounting for 42.3% and 49.8% in the root and aboveground parts, respectively, in the Se treatment. 24-EBL further enhanced Se distribution at this site, reaching 42.9% and 63.2% in root and aboveground parts, respectively, in the 24-EBL+Se treatment. The 24-EBL+Se treatment significantly increased the contents of different chemical forms of Se, including ethanol-soluble, water-soluble, and salt-soluble Se. The quantitative real-time PCR (qRT-PCR) results indicated that the Se treatment promoted the expression of organic Se assimilation genes (SATs, OAS-TL B, and OAS-TL C), and 24-EBL application further increased their expression. Meanwhile, the Se-only treatment up-regulated the organic Se metabolism gene CGS1. Consequently, we propose that 24-EBL alleviates Se stress in peach seedlings by enhancing Se uptake and assimilation, and by adjusting subcellular distribution and chemical forms. Full article

Aiming at the multifunctional requirements of the limited space in high-end vehicle side-door latches, a double single-loop RRUPRR mechanism driven by a single motor for both electric releasing and cinching is proposed based on the POC set. The kinematical equations of the RRURR mechanism possess 2 × 2 analytical solutions. In order to apply the current motion/force transmission performance index of the parallel mechanisms to the transmission performance analysis of the serial mechanisms, matching methods for chain-driving transference and the moving/fixed platform inversion are proposed. The solution of the performance index of a single-degree-of-freedom single-loop mechanism is equivalent to the solution of the input motion/force transmission performance index of a parallel mechanism. The overall motion/force transmission performance index of a single-loop mechanism is constructed, and the corresponding calculation procedure is defined. Chain-driving transference can be obtained through forward and inverse solutions of the RRURR mechanism. In response to the extremely high requirements for motion/force transmission performance of electric release mechanisms, the proposed overall motion/force transmission performance index is used to calculate for the input motion screw and corresponding transmission-force screw of the single-loop RRURR mechanism and obtain the overall motion/force transmission performance of the mechanism. The performance atlas of the mechanism shows that it has excellent motion/force transmission characteristics within the workspace. Using ADAMS simulation software, the driving torque required for electric releasing and cinching of a vehicle side-door latch mechanism with a single motor is analyzed. The overall motion/force transmission performance index of a single-loop mechanism can be applied to single-loop overconstrained mechanisms and non-overconstrained mechanisms. Full article

Quantum secret sharing (QSS) faces inherent limitations in scaling to multi-user networks due to excess noise introduced by highly asymmetric beam splitters (HABSs) in chain-structured topologies. To overcome this challenge, we propose an optical frequency comb-based continuous-variable QSS (OFC CV-QSS) scheme that establishes parallel frequency channels between users and the dealer via OFC-generated multi-wavelength carriers. By replacing the chain-structured links with dedicated frequency channels and integrating the Chinese remainder theorem (CRT) with a decentralized architecture, our design eliminates excess noise from all users using HABS while providing mathematical- and physical-layer security. Simulation results demonstrate that the scheme achieves a more than 50% improvement in maximum transmission distance compared to chain-based QSS, with significantly slower performance degradation as users scale to 20. Numerical simulations confirm the feasibility of this theoretical framework for multi-user quantum networks, offering dual-layer confidentiality without compromising key rates. Full article

High-speed trains have revolutionized modern transportation with their exceptional speeds, yet the essence of this technological breakthrough resides in the train’s wheels. These components are engineered to endure extreme mechanical stresses while ensuring high safety and reliability. In this paper, we selected the rim and web as representative components of the wheel and conducted a comprehensive and systematic study on their microstructure and mechanical properties. The wheels are typically produced through integral forging. To improve the mechanical performance of the wheel/rail contact surface (i.e., the tread), the rim is subjected to surface quenching or other heat treatments. This endows the rim with strength and hardness second only to the tread and lowers its ductility. This results in a more isotropic structure with improved fatigue resistance in low-cycle and high-cycle regimes under rotating bending. The web connects the wheel axle to the rim and retains the microstructure formed during the forging process. Its strength is lower than that of the rim, while its ductility is slightly better. The web satisfies current property standards, although the microstructure suggests further optimization may be achievable through heat treatment refinement. Full article

Ammonium (NH₄⁺) toxicity impairs plant growth, but nitrate (NO₃⁻) can mitigate this effect through unresolved mechanisms. Using leaf δ¹³C values (photosynthetic capacity) and a bidirectional ¹⁵N tracer (NH₄⁺ assimilation efficiency and source utilization), this study investigated these mechanisms in 35-day-old Orychophragmus violaceus plantlets grown in modified Murashige and Skoog media under varying NH₄⁺:NO₃⁻ ratios. ¹⁵N isotope fractionation during NH₄⁺ (same fixed 20 mM NH₄Cl) assimilation decreased with increasing NO₃⁻ supply (10, 20, and 40 mM NaNO₃). Under 20 mM NH₄⁺ (δ¹⁵N = −2.64‰) at two ¹⁵NO₃⁻-labels (δ¹⁵N-NO₃⁻ = 8.08‰, low ¹⁵N, L) and (δ¹⁵N-NO₃⁻ = 22.67‰, high ¹⁵N, H), increasing NO₃⁻ concentrations enhanced NO₃⁻ assimilation, alleviating acidic stress from NH₄⁺ and improving photosynthesis. Higher NO₃⁻ levels also increased NH₄⁺ utilization efficiency, reducing futile NH₄⁺ cycling and decreasing associated ¹⁵N fractionation during assimilation. Our results demonstrate that NO₃⁻ alleviates NH₄⁺ toxicity primarily by enhancing photosynthetic performance and optimizing NH₄⁺ utilization efficiency. Full article

An accurate assessment of sidewalk conditions is critical for ensuring compliance with the Americans with Disabilities Act (ADA), particularly to safeguard mobility for wheelchair users. This paper presents a novel 3D reconstruction framework based on neural radiance field (NeRF), which utilize a monocular video input from consumer-grade cameras to generate high-fidelity 3D models of sidewalk environments. The framework enables automatic extraction of ADA-relevant geometric features, including the running slope, the cross slope, and vertical displacements, facilitating an efficient and scalable compliance assessment process. A comparative study is conducted across three surveying methods—manual measurements, LiDAR scanning, and the proposed NeRF-based approach—evaluated on four sidewalks and one curb ramp. Each method was assessed based on accuracy, cost, time, level of automation, and scalability. The NeRF-based approach achieved high agreement with LiDAR-derived ground truth, delivering an F1 score of 96.52%, a precision of 96.74%, and a recall of 96.34% for ADA compliance classification. These results underscore the potential of NeRF to serve as a cost-effective, automated alternative to traditional and LiDAR-based methods, with sufficient precision for widespread deployment in municipal sidewalk audits. Full article

The Pacific Decadal Oscillation (PDO), as the dominant mode of decadal sea surface temperature variability in the North Pacific, exhibits both interannual and decadal fluctuations that significantly influence global climate. The complexity associated with PDO changes poses challenges for accurate predictions. This study develops a BiLSTM-WOA-MMD (BWM) model, which integrates a bidirectional long short-term memory network with a whale optimization algorithm (WOA) and multiple modal decomposition (MMD), to forecast PDO at both interannual and decadal time scales. The model successfully predicts monthly/annual average PDO index of up to 15 months/5 years in advance, achieving a correlation coefficient of 0.56/0.55. By utilizing the WOA to effectively optimize hyperparameters, the model enhances the PDO prediction skill compared to existing deep learning PDO prediction models, improving the correlation coefficient from 0.47 to 0.68 at a 6-month lead time. The combination of MMD and WOA further minimizes prediction errors and extends the forecasting effective time to 15 months by capturing essential modes. The BWM model can be employed for future PDO prediction and the predicted PDO will remain in its cool phase in the next year both using the PDO index from NECI and derived from near-time satellite data. This proposed model offers an effective way to advance the prediction skill of climate variability on multiple time scales by utilizing all kinds of data available including satellite data, and provides a large-scale background to monitor marine heatwaves. Full article

The substantial volume of data acquired through remote-detection acoustic logging poses a remarkable challenge because of the limited real-time upload speed of the cable, which severely impedes its further application. To address this issue, a two-stage data compression method that was implemented at the acquisition node was proposed in this study. This approach includes a field programmable gate array (FPGA)-based hardware system and a two-stage downhole data compression algorithm combining wavelet transform and adaptive differential pulse-code modulation paired with ground decompression software. Finally, the proposed compression method was evaluated using actual logging data. The test results revealed that the overall compression rate of the two-stage compression method was 25.1%. The reconstructed waveforms highly retained the overall shape of the original waveforms, and the severe relative distortion of individual data points did not affect the extraction of the sliding longitudinal, sliding transverse and reflected waveforms. The FPGA compressed 2048 16-bit waveforms in approximately 100 μs with low resource utilization and workload. It considerably outperformed DSP-based pre-transmission compression. Herein, the data compression method at the acquisition node helped in reducing the workload on the master control node and increasing the effective speed of the cable transmission up to 400%, thereby enhancing the remote-detection acoustic logging. Full article

With the increasing complexity of ecological and environmental problems, eco-anxiety is increasingly recognized as an essential problem in China. Despite its prevalence, there is a lack of valid measurements in China. The purpose of the present study was to expand the Hogg Eco-anxiety Scale (HEAS) under the Chinese context and evaluate the psychometric attributes of the expanded scale. Specifically, a qualitative study was conducted in Study 1 (n = 17) to expand the HEAS in the Chinese context. Exploratory factor analysis in Study 2 (n = 297) and confirmatory factor analysis in Study 3 (n = 374) were conducted to validate the scale. The climate change anxiety scale and pro-environmental behavior scale were used to assess criterion-related validity in Study 4 (n = 305). Results indicated that a new eco-anxiety scale (i.e., EAS-20) including 20 items attributed to four dimension (somatic symptoms, affective symptoms, rumination, and behavioral symptoms) was developed. It showed satisfactory psychometric properties, including high internal consistency (α = 0.97) and a four-factor structure explaining 84.36% of the variance. The criterion-related validity was acceptable (0.25 ≤ r ≤ 0.37). The article concludes that the 20-item Eco-Anxiety Scale (EAS-20) has good psychometric properties and can be applied to measure eco-anxiety in the Chinese adult population. Full article

Ground penetrating radar (GPR) is widely used for subsurface object detection, but manual interpretation of hyperbolic features in B-scan images remains inefficient and error-prone. In addition, traditional forward modeling methods suffer from low computational efficiency and strong dependence on field measurements. To address these challenges, we propose an unsupervised data augmentation framework that utilizes CycleGAN-based model to generate diverse synthetic B-scan images by simulating varying geological parameters and scanning configurations. This approach achieves GPR data forward modeling and enhances the scenario coverage of training data. We then apply the EfficientDet architecture, which incorporates a bidirectional feature pyramid network (BiFPN) for multi-scale feature fusion, to enhance the detection capability of hyperbolic signatures in B-scan images under challenging conditions such as partial occlusions and background noise. The proposed method achieves a mean average precision (mAP) of 0.579 on synthetic datasets, outperforming YOLOv3 and RetinaNet by 16.0% and 23.5%, respectively, while maintaining robust multi-object detection in complex field conditions. Full article

Lung cancer is the leading cause of cancer-related deaths worldwide. Non-small cell lung cancer (NSCLC) is the major subtype, accounting for more than 85% of all lung cancer cases. Recent advances in precision oncology have allowed NSCLC patients bearing specific oncogenic epidermal growth factor receptor (EGFR) mutations to respond well to EGFR tyrosine kinase inhibitors (TKIs). Due to the high EGFR mutation frequency (up to more than 50%) observed particularly in Asian NSCLC patients, EGFR-TKIs have produced unprecedented clinical responses. Depending on their binding interactions with EGFRs, EGFR-TKIs are classified as reversible (first-generation: gefitinib and erlotinib) or irreversible inhibitors (second-generation: afatinib and dacomitinib; third-generation: osimertinib). While the discovery of osimertinib represents a breakthrough in the treatment of NSCLC, most patients eventually relapse and develop drug resistance. Novel strategies to overcome osimertinib resistance are urgently needed. In Asian countries, the concomitant use of Western medicine and traditional Chinese medicine (TCM) is very common. Ganoderma lucidum (Lingzhi) and Coriolus versicolor (Yunzhi) are popular TCMs that are widely consumed by cancer patients to enhance anticancer efficacy and alleviate the side effects associated with cancer therapy. The bioactive polysaccharides and triterpenes in these medicinal mushrooms are believed to contribute to their anticancer and immunomodulating effects. This review presents the latest update on the beneficial combination of Lingzhi/Yunzhi and EGFR-TKIs to overcome drug resistance. The effects of Lingzhi/Yunzhi on various oncogenic signaling pathways and anticancer immunity, as well as their potential to overcome EGFR-TKI resistance, are highlighted. The potential risk of herb–drug interactions could become critical when cancer patients take Lingzhi/Yunzhi as adjuvants during cancer therapy. The involvement of drug transporters and cytochrome P450 enzymes in these herb–drug interactions is summarized. Finally, we also discuss the opportunities and future prospects regarding the combined use of Lingzhi/Yunzhi and EGFR-TKIs in cancer patients. Full article

This study examines fatigue crack growth behavior in induction-hardened S38C axle steel with a gradient microstructure. High-frequency three-point bending fatigue tests were conducted to evaluate crack growth rates (da/dN) across three depth-defined regions: a hardened layer, a heterogeneous transition zone, and a normalized core. Depth-resolved da/dN–ΔK relationships were established, and Paris Law parameters were extracted. The surface-hardened layer exhibited the lowest crack growth rates and flattest Paris slope, while the transition zone showed notable scatter due to microstructural heterogeneity and residual stress effects. These findings provide experimental insight into the fatigue performance of gradient-structured axle steels and offer guidance for fatigue life prediction and inspection planning. Full article

This study aimed to clarify the effects of jujube–cotton intercropping on cotton yield and photosynthetic characteristics, providing a theoretical basis for its application in the oasis irrigation areas of southern Xinjiang and offering practical recommendations to local farmers for increasing economic benefits. The effects were investigated from 2020 to 2023 using Zhongmian 619 cotton and juvenile jujube trees. Changes in leaf area index (LAI), transpiration rate (Tr), stomatal conductance (Gs), net photosynthetic rate (Pn), intercellular CO₂ concentration (Ci), yield, and economic benefits were evaluated over the years. The results showed that (1) a positive correlation was observed between LAI and the photosynthetic characteristics of cotton. Compared to monoculture cotton, intercropped cotton exhibited lower Pn, Gs, and Tr, and at the peak boll stage, monoculture cotton had significantly higher photosynthetic characteristics, indicating that intercropping affected cotton photosynthesis. (2) From 2020 to 2023, the land equivalent ratio (LER) of jujube–cotton intercropping remained above 1, with overall yield and economic benefit surpassing those of monoculture cotton and jujube, particularly in 2023 when the yield increased by 55.35%. (3) A significant positive correlation was found between cotton yield and LAI. In conclusion, jujube–cotton intercropping enhances photosynthesis, improving yield, economic benefits, and land use efficiency. Full article