Search Results (2,676)

Warm-season precipitation over Sichuan, China, is jointly modulated by complex terrain, monsoon water vapor transport, and local convective activities, leading to significant spatiotemporal heterogeneity. However, radar observations over mountainous areas are frequently impaired by terrain blockage, beam shielding, and insufficient network coverage, which cause missing data and spatial discontinuity, thereby restricting the accurate monitoring of precipitation systems. To alleviate these problems, this study develops an Efficient Multi-Scale Attention (EMA) U-Net model integrated with Digital Elevation Model (DEM) information, termed EMA-U-Net-DEM, to retrieve radar composite reflectivity by utilizing multi-channel observations from the Fengyun-4A (FY-4A) Advanced Geostationary Radiation Imager (AGRI). In the experiments, FY-4A AGRI multi-spectral measurements were used as model inputs, while radar composite reflectivity products from the Severe Weather Automatic Nowcasting (SWAN) system were applied as reference labels. The modeling and validation were carried out using warm-season (June–August) datasets over Sichuan Province. The results indicate that the proposed EMA-U-Net-DEM exhibits better performance than the traditional U-Net and several typical attention-based benchmark models. Quantitatively, the model achieves a root mean square error (RMSE) of 6.728 dBZ, a mean absolute error (MAE) of 4.788 dBZ, a coefficient of determination $R^2$ of 0.656, a peak signal-to-noise ratio (PSNR) of 25.243 dB, and a structural similarity index measure (SSIM) of 0.793. Categorical verification further reveals that the model yields the highest critical success indices (CSI) of 0.850, 0.560, and 0.364 in the reflectivity ranges of 0–25 dBZ, 25–45 dBZ, and 45–70 dBZ, respectively, demonstrating its superior ability in characterizing weak precipitation backgrounds, moderate precipitation structures, and intense convective cores. The performance enhancements are mainly attributed to the strengthened multi-scale feature extraction by the EMA module and the effective topographic constraints introduced by DEM data. This study confirms that the fusion of FY-4A multi-spectral observations and topographic information can effectively improve radar composite reflectivity retrieval over complex terrain, providing a feasible solution for precipitation monitoring, quantitative precipitation estimation, and severe weather nowcasting in mountainous regions with limited radar coverage. Full article

Under ground-based observation geometry, infrared radiant-intensity sequences of space objects are jointly influenced by object micromotion, thermal radiation, time-varying viewing conditions, and atmospheric propagation. Existing simulation studies often prescribe the line of sight or simplify the coupling between viewing geometry and atmospheric attenuation, which limits long-duration ground-based sequence analysis. This study develops a physics-informed framework for generating atmosphere-attenuated infrared radiant-intensity sequences of space objects undergoing precession or tumbling. The framework reconstructs observation geometry from azimuth–elevation–range trajectories, updates facet normals through a unified micromotion attitude model, computes visible projected area and transient facet temperature, and incorporates MODTRAN-derived elevation-dependent atmospheric transmittance. Using this framework, we construct IRPeriodic, an eight-class simulated dataset for long-duration univariate time-series classification. We further propose LPD-Net, which integrates large-kernel residual feature extraction, prototype-guided dynamic temporal alignment, and differential periodic representation to capture long-range waveform morphology, sample-dependent temporal correspondence, and segment-level local variation. On IRPeriodic, LPD-Net achieves an accuracy of 0.8618 ± 0.0057, a macro-F1 of 0.8615 ± 0.0061, and a Matthews correlation coefficient of 0.8426 ± 0.0065, outperforming the evaluated neural-network and ROCKET-type baselines. Ablation and synthetic-noise sensitivity analyses indicate that the performance gain is mainly associated with long-context feature extraction, with additional improvements from dynamic alignment and differential periodic statistics. Auxiliary experiments on selected public UCR datasets suggest that the representation is also competitive for univariate time-series classification. These results demonstrate the effectiveness of LPD-Net on the proposed physics-informed benchmark for long-duration ground-based infrared radiant-intensity sequence classification. Full article

Recent developments in particle physics require cost-effective pixel detectors capable of operating under increased energy and luminosity conditions foreseen in future collider experiments. In response, monolithic CMOS pixel sensors incorporating modern readout architectures have emerged, combining high-rate capability with substantial radiation tolerance. To optimize the performance of these sensors for application in tracking detectors, a comprehensive characterization has been done focusing on threshold and noise behavior as a function of front-end DAC tuning parameters. The effect of radiation damage has been investigated using high-intensity X-ray irradiation, followed by a detailed comparison of sensor performance before and after irradiation. The threshold distribution is observed to be uniform across the pixel matrix. Irradiation introduces a systematic shift in the threshold, with a larger impact at low-threshold configurations, while overall uniformity is preserved. In contrast, the noise remains largely stable across the parameter space. The correlation between threshold and noise is used to identify optimal operating regions, demonstrating that stable, efficient performance can be achieved across quite a wide range of configurations. These results confirm the robustness of the sensor under irradiation and its suitability for operation in radiation environments relevant to future high-energy physics experiments. Full article

Plateau environments are characterized by low temperatures, intensive radiation and drastic diurnal temperature fluctuations, all of which greatly suppress rooting and seedling establishment of tea chrysanthemum cuttings. To compare the regulatory effects of different rooting regulators on tea chrysanthemum cuttings under plateau cultivation conditions, this study conducted a 60-day plug-tray cultivation experiment from late July to late September with three biological replicates. All the cuttings, including the IBA-pre-treated control (CK), were uniformly pretreated with 500 mg·L⁻¹ indole-3-butyric acid (IBA). On this basis, four treatments, including 5-aminolevulinic acid hydrochloride (5-ALA, T1), γ-aminobutyric acid (GABA, T2), Bacillus amyloliquefaciens (T3) and Bacillus velezensis (T4), were applied to determine root morphology, seedling growth, physiological stress metabolism, photosynthetic capacity and rhizosphere substrate characteristics. The different rooting promoters exerted distinct regulatory effects on cutting performance. The GABA treatment significantly improved leaf gas exchange, seedling growth, antioxidant status and rhizosphere nutrient conditions, with net photosynthetic rate, stomatal conductance and transpiration rate improved by 316.34%, 92.31% and 168.00%, respectively, and significantly increased seedling vigor index, plant height and stem diameter by 21.74%, 60.85% and 46.08%, respectively. It also elevated the soluble sugar content and the ascorbate peroxidase (APX) activity, reduced malondialdehyde (MDA) and hydrogen peroxide (H₂O₂) accumulation, and optimized rhizosphere available nitrogen and phosphorus levels, as well as related enzyme activities. Nevertheless, the 5-ALA treatment exhibited unique advantages in improving rooting rate and seedling survival. Mantel tests confirmed that the seedling vigor index closely correlated with the root architecture, the total chlorophyll and the transpiration rate. A principal component analysis (PCA) and a cluster heatmap both identified GABA as the treatment with relatively balanced overall performance. A comprehensive D-value evaluation ranked the treatments as GABA > B. amyloliquefaciens > 5-ALA > B. velezensis > control. The treatment with 5-ALA mainly improved the antioxidant capacity, the B. amyloliquefaciens treatment favored root elongation and total nutrients, and the B. velezensis treatment only produced mild improvements. This study indicates that the different exogenous regulators target divergent growth and physiological processes, and the GABA treatment could coordinately boost root development, photosynthetic performance, antioxidant defense and rhizosphere nutrient cycling, thus presenting great application potential for tea chrysanthemum cutting propagation under plateau cultivation conditions. Full article

Greenhouse microclimates exhibit substantial spatial heterogeneity. Conventional evaluations based on average measurements cannot adequately describe the environmental conditions experienced by crops. This study developed a spatial frequency analysis method to quantify long-term temperature and relative humidity heterogeneity. This method was coupled with cucumber yield and downy mildew models to evaluate the biological consequences of environmental variability. Environmental conditions in four representative greenhouse structures were monitored using distributed sensor networks under different weather conditions. The proposed method successfully identified persistent environmental hotspots. The spatial distribution of environmental heterogeneity differed among greenhouse structures, whereas solar radiation primarily controlled its intensity. Long-season monitoring data indicate that the maximum spatial variations in temperature and relative humidity within the brick-wall solar greenhouse, the assembled greenhouse, the glass greenhouse, and the plastic multi-span greenhouse reach up to 10 °C and 46%, 8.5 °C and 46%, 12 °C and 50%, and 7 °C and 32%, respectively. The assembled solar greenhouse and plastic greenhouse exhibited higher environmental uniformity, while the brick-wall solar greenhouse and glass multi-span greenhouse showed pronounced spatial gradients. Environmental heterogeneity resulted in significant within-greenhouse differences in simulated cucumber yield, with the smallest variation occurring in the assembled solar greenhouse (5.3%) and the largest in the glass multi-span greenhouse (39.2%). Disease simulations further revealed clear spatial aggregation of cucumber downy mildew risk, with the southern region of the solar greenhouse exhibiting 17–67% higher cumulative infection risk than other positions. This study establishes an integrated framework linking greenhouse environmental heterogeneity with crop productivity and disease risk, providing a practical basis for spatially differentiated precision greenhouse management and greenhouse structural optimization. Full article

Background/Objectives: Pretreatment sarcopenia predicts adverse outcomes in head and neck squamous cell carcinoma (HNSCC). The conventional L3 skeletal muscle index (SMI) requires abdominal imaging, whereas the predictive value of the more accessible C3 muscle index for acute treatment-related complications remains uncertain. We compared pretreatment L3 SMI and the C3 index for identifying patients at risk of severe oral intake impairment, radiation interruption, and a longer treatment-to-discharge interval during definitive chemoradiotherapy. Methods: This retrospective single-center study included 55 patients with HNSCC treated with 80 mg/m² cisplatin every three weeks and 66 Gy intensity-modulated radiotherapy. Pretreatment computed tomography (CT) was analyzed using deep-learning-based automated segmentation. Firth-penalized logistic and multivariable linear regression were adjusted for age, sex, performance status, body mass index, and stage, with estimates standardized per 1-standard-deviation (SD) increase. Results: L3 SMI was associated with severe oral intake impairment (adjusted odds ratio per SD, 0.248; 95% CI, 0.053–0.891) and the treatment-to-discharge interval (adjusted β, −6.23 days; 95% CI, −11.89 to −0.58); the C3 index was not associated with any outcome. The standardized coefficients differed for oral intake impairment (p = 0.014) but not for other outcomes. Each binary outcome comprised only 10 events. Conclusions: L3 SMI was associated with nutritional vulnerability, whereas the fully automated C3 index was not; in an exploratory direct comparison, the two indices differed for severe oral intake impairment. These findings are hypothesis-generating and require confirmation in larger, multicenter cohorts. Full article

Amid the low-carbon transition, university teaching buildings feature high occupancy and energy use, making the synergistic enhancement of their daylighting and thermal environments crucial for “dual carbon” goals. However, traditional “north–south homogenization” designs in cold regions fail to address the spatial heterogeneity of solar radiation and climate resources, intensifying the trade-off between natural daylighting and Heating Energy Use Intensity (E_h) while restricting space performance optimization. Focusing on a typical cold-region teaching building, this study proposes a “parametric modeling–multi-objective optimization–machine learning” integrated framework. Targeting spatial daylight autonomy (sDA), useful daylight illuminance (UDI), and E_h, we compared the homogeneous baseline model with the Pareto-optimal solution set, demarcated key design parameter boundaries, and developed an ensemble-based rapid prediction model. Based on the parametric simulation analysis of this representative case building in a cold region, results indicate that: (1) Compared to the baseline, the overall optimal scheme reduced E_h by 17.43% while increasing UDI and sDA by 12.0% and 10.5%, respectively. (2) The Pareto set strictly converges toward a due-south orientation and a “deep-south, shallow-north” layout (depth ratio: 0.66–0.77); thermal configurations exhibit “enhanced northern insulation and southern heat gain,” confirming heterogeneous design matches cold climates better. (3) The four constructed machine learning models (MLP, LightGBM, XGBoost, and Random Forest) uniformly achieved test recall rates exceeding 99%, enabling highly precise, rapid classification of top-performing design scenarios during early-stage design. This study overcomes climate-matching blindness in traditional design, providing a multi-objective synergistic optimization path balancing low energy and high-quality daylighting with substantial engineering and theoretical value. Full article

Bronchopulmonary dysplasia (BPD) remains one of the leading chronic respiratory complications of extreme prematurity despite major advances in neonatal intensive care. Current diagnostic definitions are primarily based on respiratory support requirements and provide limited information on the biological heterogeneity and longitudinal evolution of lung injury. Lung ultrasound (LUS) is progressively reshaping the clinical approach to BPD by enabling radiation-free, bedside, and repeatable assessment of peripheral lung abnormalities throughout the neonatal course. This narrative review examines the current role of LUS in BPD, integrating its pathophysiological basis with the available evidence and distinguishing explicitly between its diagnostic, prognostic, monitoring, and treatment-guiding applications, which are supported by markedly different levels of evidence. We discuss how LUS findings reflect the major components of BPD pathophysiology, compare LUS with conventional imaging modalities, and summarize the scanning protocols, semiquantitative scoring systems, examination schedules, and patient populations that have been evaluated to date. We also review the emerging contribution of artificial intelligence to automated image analysis, standardized image acquisition, and personalized risk prediction. Most of the available evidence is prognostic rather than diagnostic: early LUS scores predict BPD subsequently defined at 36 weeks’ postmenstrual age, whereas LUS has not been validated as a diagnostic test for established BPD, and reported cutoffs remain study- and protocol-specific rather than universally applicable. Randomized evidence is confined to LUS-guided surfactant administration, where the demonstrated benefits concern the timing of treatment and the need for invasive ventilation; no trial has yet shown that LUS-guided management reduces the incidence of BPD. Current evidence supports LUS as a complementary imaging modality that extends beyond the assessment of acute neonatal respiratory disease and enables longitudinal bedside monitoring of peripheral lung aeration. Although further multicenter prospective studies are required to harmonize protocols and validate LUS-guided management strategies, the integration of standardized LUS assessment with emerging artificial intelligence technologies has the potential to establish LUS as a key component of precision respiratory care for infants at risk of BPD. Full article

Nonlinear biological systems exhibit complex interactions, uncertain parameters, and strong treatment-dependent dynamics, making mathematical modeling and control essential for designing reliable therapeutic intervention strategies. This study proposes a multi-input adaptive smooth sliding mode control (AMIS-SMC) framework for regulating combined radiotherapy and chemotherapy in a nonlinear tumor–immune dynamical system described by ordinary differential equations. The proposed controller integrates a hyperbolic tangent smoothing mechanism with adaptive parameter-estimation laws to compensate for uncertainty in tumor and healthy-cell growth dynamics. In this way, the method explicitly links biological-system modeling, feedback control, treatment-dose management, and parameter adaptation within a single mathematically analyzable framework. Fundamental closed-loop properties are established analytically, including positivity and boundedness of all biological state variables, asymptotic convergence of the sliding surfaces, and explicit upper bounds on the administered radiation and chemotherapeutic drug dosages. Lyapunov-based stability analysis is used to guarantee boundedness of the closed-loop signals and convergence of the sliding manifold. Numerical simulations based on a brain-tumor case study demonstrate that the proposed AMIS-SMC algorithm achieves rapid tumor suppression while administering substantially lower treatment intensities than conventional and integral SMC approaches. Under nominal conditions, the proposed controller reduces cumulative radiation and chemotherapy dosages while maintaining effective tumor mitigation. Under mismatched parameter conditions, AMIS-SMC consistently drives the tumor-cell population toward the desired equilibrium across all tested scenarios, whereas conventional and integral SMC show limited adaptability. Statistical analysis using Mann–Whitney U and Fisher’s tests further indicates that AMIS-SMC provides an effective mathematical-control and treatment-management strategy for tumor suppression in a simplified nonlinear tumor–immune biological system under parameter uncertainty. Full article

As rapid population aging coincides with intensifying urban heat island (UHI) effects, ensuring the outdoor thermal comfort of the elderly in hot–humid regions has become a critical challenge. This study investigates the influence of residential spatial morphology and wind environment on elderly thermal comfort in Fuzhou, China, by integrating PHOENICS and RayMan numerical simulations with a multivariate statistical framework. The Physiological Equivalent Temperature (PET) was calculated across three metabolic intensities (sedentary, walking, and exercising), while the LMG algorithm was used in R to identify the driving mechanisms. Residential layouts are stratified into High-Performance (Group A) and High-Risk (Group B) categories based on their thermal risk. In Group A, the microclimate is convective-dominant wind speed and air changes per hour are the primary determinants of thermal comfort. Conversely, Group B exhibits a radiation-dominant mechanism, with the sky view factor acting as the primary driver of heat stress in confined environments. Furthermore, metabolic intensity emerges as a decisive factor, as physical exercise frequently pushes PET beyond the 37.1 °C threshold even in high-performance layouts. Accordingly, this study proposes differentiated strategies: prioritizing ventilation-led optimization for Group A and radiation-shielding interventions for Group B, while advocating for supplementary active cooling in high-intensity activity zones to safeguard the geriatric population during peak summer heat. Full article

Greenhouses in subtropical and tropical regions must be designed as agricultural engineering systems adapted to local climates, rather than simply replicating the “insulation” models of temperate areas. Under extreme climatic conditions such as persistent high temperatures, intense solar radiation, high humidity, heavy rainfall, and frequent extreme winds, greenhouses transform from enclosed insulation layers into selective climate filters, mitigating crop stress while maintaining close contact with the outdoor environment. This paper summarizes how these climate drivers are reshaping the use, structure, and control concepts of greenhouses, emphasizing that the performance of warm-zone greenhouses depends primarily on heat dissipation, humidity management, and biohazard control, rather than heating and insulation. In this review, we analyze the climatic boundary conditions that define warm-climate conservation cultivation, including long-term overheating risk, high UV radiation, vapor pressure deficit, and suppressed condensation tendency, as well as storm-induced uplift and dynamic loads. These constraints necessitate unique structural forms: tall, lightweight, well-ventilated building types with large roof and side openings, roof geometries that facilitate rainwater runoff, sophisticated drainage systems, and corrosion-resistant materials suitable for humid and coastal environments. Because insect netting significantly reduces ventilation, pest control and temperature regulation become co-design issues, requiring oversized vents, optimized airflow paths, and hybrid roof–mesh structures. Ventilation is considered the primary climate-control mechanism, supplemented by passive cooling measures such as shading and radiation/optical management (e.g., diffuse films and near-infrared-selective films). Active evaporative cooling is considered a conditional measure due to humidity limitations and disease risks. This paper also integrates the impacts on specific crops (fruits and vegetables, leafy greens, and orchids). It highlights emerging trends: typhoon-resistant and adaptive geometries, computational fluid dynamics (CFD)-based design, and sensor-rich IoT/digital twin control frameworks. These principles collectively establish a coherent design framework for achieving resilient, resource-efficient greenhouse production in warm climates. Full article

Coastal warm fog poses a serious threat to the safety and efficiency of port shipping. However, its artificial dispersal and the effect evaluation of the dispersal remain a worldwide challenge. This paper conducted a field experiment of artificial fog dispersal using an unmanned aerial vehicle (UAV) to spray a new hygroscopic catalyst in Jinshan District, Shanghai, China. A traversing window method was proposed to quantitatively evaluate the dispersal effect of the catalyst on coastal warm fog using the RHI detection mode of a visibility lidar. The experimental results show that the operation period was a typical coastal radiation fog process with a stable meteorological background field. The near-surface wind was weak and the wind direction was constant southeast. The new composite hygroscopic catalyst had a certain effect on coastal warm fog dispersal, and its effect was closely related to the background fog concentration. The operation effect became prominent when the background fog concentration decreased. The maximum visibility improvement reached 456 m, and the peak effect appeared 2–3 min after the end of spraying. The best location for dispersal effect was observed below the operation position and in the downwind direction. The traversing window method proposed in this paper effectively reduces the contingency and spatial representativeness limitations of single-point evaluation. It can locate the optimal area of fog dispersal effect and quantify its intensity. This study provides technical support for the operational application of artificial fog dispersal in coastal area. Full article

We report on electric field measurements recorded onboard the China Seismo-Electromagnetic Satellite (CSES). In this study, we emphasize the whistler and transmitter very low frequency (VLF) radiations recorded in the frequency range between 1.8 kHz and 25 kHz. The electric field detector (EFD) instrument onboard the CSES works as a double probe instrument and allows access to the three electric components of VLF waves. Three frequencies were selected, two related to whistler hiss (i.e., 2.5 kHz channel) and chorus (i.e., 5 kHz channel) radiations and one to the NAA ground-based transmitter signal (i.e., 24 kHz). We investigate the corresponding power spectral density variations, from which we derive the Stokes intensity I and normalized q linear polarization components. This leads us to study their statistical fluctuations and to emphasize the behaviors of natural whistler hiss and chorus radiations and man-made transmitter emissions. The Stokes intensities of the natural whistler and NAA transmitter radiations are estimated, respectively, to be about 1 mV² m⁻² Hz⁻¹ and 0.05 mV² m⁻² Hz⁻¹. The correlation coefficients of the Stokes intensity polarizations are in the order of 98% powerfully coupled, contrary to the Stokes normalized linear polarizations, which are found to be relatively paired, i.e., less than 60%. The signal-to-noise ratio is estimated considering three intensity levels (i.e., high, medium, low). This analysis leads us to characterize the Stokes normalized linear components of VLF radio waves and to show different behaviors of the polarization when considering the Northern and Southern Hemispheres. The regions of enhanced whistler Stokes intensities of whistler hiss and chorus emissions are confined to the sub-auroral regions in both hemispheres, particularly at geomagnetically ranges linked to the NAA transmitter station and its conjugate region in the Southern Hemisphere. In this investigation, we point out the Stokes polarization parameters, which are essential for the characterization of whistler VLF radio waves, particularly when considering the CSES mission objectives and commitments. Full article

Microplastics (MPs), defined as plastic particles smaller than 5 mm in diameter, are an emerging class of environmental contaminants of global concern. As the “Water Tower of Asia” and a critical global ecological barrier, the environmental condition of the Qinghai–Tibet Plateau has a direct influence on the ecological security of major river systems and the well-being of populations downstream. MPs have now been detected across multiple environmental compartments on the plateau, including soils, water bodies, and glaciers. Given the fragility and ecological uniqueness of the region, systematic investigation of plastic pollution here is essential for safeguarding its ecological security. Based on current research, existing data on MP pollution across the Qinghai–Tibet Plateau are reviewed and synthesized. Evidence suggests that the abundance of MP varies significantly across different environmental media in various regions and is influenced by multiple factors. Two major potential sources are identified: local anthropogenic activities and transboundary inputs via atmospheric transport and other pathways. The unique environmental conditions of the region, such as intense ultraviolet radiation, large day–night temperature variation, and frequent high-wind events, provide a distinctive setting for the migration, dispersion, transformation, and degradation of MPs across environmental matrices. Understanding the distribution, sources, and migration patterns of microplastics on the Qinghai–Tibet Plateau will help facilitate sustainable environmental management, ecosystem conservation, and pollution control in these fragile high-altitude regions. Full article

Relativistic interaction of ultra-intense laser pulses with cluster targets is of particular interest for high-energy-density physics, compact X-ray source development, and laboratory astrophysics. Understanding the dynamics of such plasmas requires precise control of their parameters, in particular temperature, on subpicosecond timescales. In this study, X-ray spectral methods were used to diagnose the laser plasma of krypton cluster targets, created at laser pulse intensities of the order of 10²⁰–10²¹ W/cm². The use of a time-dependent detailed radiation-collisional kinetic model made it possible to describe the results of the observed X-ray spectra in the femtosecond laser plasma of a cluster target. We present a method for diagnosing the non-stationary plasma of high-atomic-number (krypton) clusters using resonance spectral lines 1s²2s²2p⁵3s ¹P₁–1s²2s²2p^{6 1}S₀ and 1s²2s²2p⁵3s ³P₁–1s²2s²2p^{6 1}S₀ of the Ne-like Kr XXVII ion, allowing one to determine the plasma temperature at the moment of “plasma channel” formation. In the experiment, this temperature was shown to be 55 ± 5 eV. The same spectroscopic approach can be extended to other cluster species (for example, Ar, Xe) for non-stationary plasma diagnostics in the relativistic regime. Full article