Search Results (1,018)

To address single-row feeding and embryo-orientation requirements in rice-seed preprocessing, a two-stage cooperative vibratory conveying and orientation device was developed for one tested batch of the long-grain hybrid indica cultivar ‘Y Liangyou 900’. The circular module fluidizes bulk seeds and forms a single-row stream, and the linear module uses stepped V-shaped grooves for passive posture correction. For 50 individually identified seeds, repeated camera measurements gave a longitudinal embryo-end center-of-mass offset of 0.285 ± 0.040 mm (mean ± sample SD; range 0.215–0.344 mm; CV 14.1%). Five tipping trials per seed at 200 V, 100 Hz, a 6 mm step, and a 9° chute showed a positive but overlapping relationship between Δd and tipping probability; threshold screening placed the effective stabilizing moment M_save,eff on the order of 10⁻⁷ N·m. At 100 Hz, PCB M352C68 accelerometer measurements with five 10 s repeats per voltage gave amplitude equivalents of 0.100, 0.137, and 0.176 mm at 160, 180, and 200 V, corresponding to peak accelerations of 4.03, 5.52, and 7.09 g. Five paired physical-simulation calibration tests gave mean absolute relative errors of 0.89% for angle of repose and 0.43% for bulk density. Across 11 conveying conditions, DEM and bench throughputs ranged from 180–208 and 176–204 grains/min, respectively, with a mean absolute percentage error of 1.98%. Orthogonal testing selected a 6 mm step height, 9° chute inclination, 200 V linear-vibrator setpoint, and 100 Hz vibration frequency; ten independent 200-seed verification runs (2000 seeds total) gave mean forward-retention and reverse-correction rates of 92.4% and 88.1%. The archived verification records preserve aggregate means but not the complete run-level values required for dispersion estimates. Integrated optimization selected a conveyor-belt speed of 31.5 mm/s, a 200 V setpoint, and a 5.30 mm transfer drop height; validation means were 91.2% orientation success and 14.5% seed-flow-uniformity CV. In an unreplicated condition-level robustness screen, lower performance values were descriptively observed at high moisture and under dusty or broken-glume conditions. Because each condition was evaluated only once, these observations do not constitute statistical evidence of robustness or factor effects. The findings therefore remain specific to the tested cultivar, conditions, and short-run protocol. Full article

The present study examined the factor structure, measurement invariance across sex and language, concurrent and discriminant validity and achievement-related criterion validity of the eight-item mathematics self-concept scale from TIMSS 2023 in a sample of 4463 eighth-grade students in Hong Kong. Cronbach’s alpha was high (α = 0.86) and a confirmatory factor model accounting for wording-related method variance fit the data substantially better than a strictly unidimensional model. Equivalence testing revealed that the mathematics self-concept scale achieved strict measurement invariance across both sex and language groups. Correlations provided strong concurrent/convergent evidence with liking mathematics (r = 0.59) and moderate evidence with valuing mathematics (r = 0.36), discriminant evidence through a small association with science self-concept (r = 0.20), and achievement-related criterion evidence through a positive association with mathematics achievement (B = 10.65) using a multilevel modeling approach. Findings support the mathematics self-concept scale’s practical utility for describing students’ perceived mathematical competence and for making cross-group comparisons while cautioning against overreliance on a strict unidimensional structure that ignores negative wording effects. Implications, limitations and future directions of the present study are discussed. Full article

Research on the coupling coordination relationship between land–use carbon emissions (LUCE) and ecosystem service value (ESV) is vital for achieving China’s “dual carbon” goals and advancing ecological civilization. Applying the carbon emission coefficient method, equivalent factor method, coupling coordination degree model, and Geographically and Temporally Weighted Regression (GTWR) model, this study examined spatiotemporal patterns of land–use changes, carbon emissions per unit area (ACE), and ecosystem service value per unit area (AESV) across China (excluding Xizang, Hong Kong, Macao, and Taiwan) from 2000 to 2020, along with their coupling relationship and driving forces. Results showed that grassland, forest, and cropland accounted for more than 70% of China’s land area, with a total land–use conversion area of 1.42 × 106 km². ACE increased while AESV generally decreased, both displaying strong spatial heterogeneity and agglomeration. The average Dagum Gini coefficients were approximately 0.70 for ACE and 0.58 for AESV. Coupling coordination degree mostly fluctuated around 0.20, rising initially and then falling, with distinct spatial variations in coordinated development types. Population density, Normalized Difference Vegetation Index (NDVI), and average elevation were negatively correlated with the synergistic effect between LUCE and ESV, whereas GDP density, annual precipitation, and average slope showed positive correlations. These findings provided theoretical support for formulating scientific land–use policies, optimizing carbon emission management, and implementing effective ecological protection measures. Full article

Free-wake vortex-ring models are the simplest way of describing a uniformly loaded actuator disc consistently with the Euler equations, i.e., including the radial velocity that accompanies slipstream contraction or expansion. This paper examines the numerical behavior of this model class using an independent open-source FORTRAN 90/95 implementation and a 1:1 Python (v3.12) replica, for the propeller case ($c_T=1$) and the Betz case ($c_T=-8/9$). Three results are reported. First, the two convergence measures in common use—the residual of the wake (sheet) equations and the deviation of the power coefficient $c_P$ from momentum theory—are shown not to be equivalent: the latter has a discretization floor and is not monotone, so it is unsuitable as a stopping criterion, and accuracy figures obtained with it are sometimes misleading. Second, the discrete Kelvin–Helmholtz saw-tooth mode is stabilized by a damping factor proportional to $\sqrt{z}$, which reaches the residual floor within a few hundred instead of ${10}^4$ iterations; the remaining $c_P$ fluctuation band reflects the unresolved disc-edge region and is removed by node collocation with a spacing-proportional vortex kernel, which converges to a unique fixed point with machine-level residuals and $c_P-(-16/27)=+4.7\times {10}^{-5}$. Third, the converged solutions show a bounded edge strength with fitted exponent $a=0.00\pm 0.04$ in $\gamma \propto s^a$, differing from both the $s^{-1/2}$ spiral and the constant-$\gamma$ proposals in the literature; it is explained why single-valued, regularized sheet discretizations cannot decide this question. Full article

During drilling circulation, the wellbore temperature field changes in response to drilling-fluid rheology, borehole geometry, drillstring eccentricity, and cuttings concentration. Conventional wellbore temperature models use fixed heat-transfer parameters and therefore cannot accurately represent real-time heat-transfer conditions. To address this limitation, a transient temperature model was developed. Bottomhole annular-fluid temperatures generated by OLGA were used as synthetic observations for MHE calibration. An MHE-based calibration method was developed to estimate the equivalent heat-transfer correction factor. The temperature model was first benchmarked against the Kabir analytical model and the commercial simulator OLGA. The estimated correction factor was then used by the mechanistic model to update the wellbore temperature field. The results showed that, under different initial values of the correction factor and assumed measurement-noise standard deviations, the equivalent heat-transfer correction factor converged to a steady-state value of approximately 0.941. Additional sensitivity tests showed generally stable calibration performance under moderate parameter settings, whereas stronger observation noise reduced calibration stability and accuracy. Under varying operating conditions, the calibrated bottomhole temperature yielded a mean absolute error of 0.033–0.332 °C, representing a reduction of 45.97–98.73% relative to the corresponding uncalibrated results. When the observation delay was extended to 2400 s (d = 8), the MAE was still reduced by 26.50–68.20% across different operating stages. These numerical results show that the proposed method can use bottomhole temperature observations to dynamically compensate for equivalent heat-transfer model mismatch under the investigated simulation conditions. The method reduces model-prediction errors and improves bottomhole temperature prediction under the tested varying operating conditions. The proposed method has potential applications in wellbore temperature prediction and high-temperature risk assessment for deep-well drilling. Full article

Rapid urbanization in the Huaihe River Basin has reshaped land use and intensified the tension between ecological protection and food security. A key gap is that most basin-scale ecosystem service value (ESV) assessments describe changes in land-cover composition but do not identify how landscape configuration–ESV associations vary across space. Using land use remote sensing images from 2000 to 2020, we quantitatively characterized the spatiotemporal evolution of land use via transfer matrices and landscape pattern indices. By integrating the equivalent value factor method, contribution analysis, spatial correlation analysis, and the geographically weighted regression (GWR) model, we examined the spatiotemporal dynamics and driving mechanisms of ecosystem service value (ESV). Key findings are as follows: (1) From 2000 to 2020, cropland area steadily decreased, while construction and forest land expanded markedly, with a synthetic land-use dynamic degree reaching 9.66%. (2) ESV first rose then fell, showing an overall decline. Forest land (18.882 billion CNY) and water areas (20.331 billion CNY) were the primary contributors. The ESV response to land use change manifested as a trade-off between short-term gains and long-term degradation. (3) Landscape patterns exhibited significant spatial heterogeneity, and ESV correlated strongly with patch number (NP) and landscape shape index (LSI). Class area (CA) emerged as the dominant factor, with CA of forest land, cropland, and water areas exerting the most pronounced effects. Based on the differential driving effects of landscape patterns and identified land use change hotspots, we propose enhancing ecosystem service values and mitigating conflicts between ecological conservation and food security through differentiated ecological engineering and ecological compensation strategies. Full article

The co-evolution of urban–rural spatial transformation and ecosystem services represents a key scientific issue for high-quality basin development and metropolitan ecological governance. As a core growth pole in the lower Yellow River Basin, the Jinan Metropolitan Area (JMA) faces the overlapping pressures of rapid urbanization and ecological constraints, making it an appropriate case for exploring the interactions between the urban–rural gradient and ecosystem service value (ESV). Based on multisource spatiotemporal datasets for 2000–2024, this study deploys a modified equivalent-factor method, a multidimensional urban–rural gradient model, and a geographic detector to investigate ESV dynamics, the evolution of the urban–rural gradient, and their coupling relationship at a 1 km × 1 km grid scale. The results show that: (1) Total ESV in the JMA increased slightly from 2000 to 2024, with pronounced spatial heterogeneity. High-ESV areas were distributed in the southern mountainous region and along the Yellow River, whereas low-ESV areas were mainly distributed across the northern plains and urban built-up areas. Forestland and water bodies provided the primary foundation for regional ESV stability. (2) Inner-suburban areas expanded rapidly and became the dominant urban–rural transition zone, while rural areas continued to contract. Urban areas exhibited both polarization and sprawl along transportation corridors. (3) The coupling coordination between ESV and the urban–rural gradient exhibited a “high-periphery, low-middle” spatial pattern and declined slightly over time. Land-use change, population density and normalized difference vegetation index (NDVI) serve as core driving factors, with nonlinear threshold effects; pairwise factor interactions exert stronger explanatory power than individual factors. This study advances the analytical framework for examining ESV in basin-metropolitan areas and provides a reference for integrated urban–rural development and ecological protection in similar regions. Full article

Expected stock returns reflect cash distributions, fundamental growth, and market valuation, yet these sources are often examined separately. This study develops a Theoretical Rate of Return (TRR) framework that organizes them within a common multiplicative representation. The theoretical foundation is a one-period ex post decomposition of realized total shareholder return into dividend yield, internal growth, and valuation adjustment. Its empirical implementation instead uses Growth and Value characteristics observable at portfolio formation as predictive proxies; these variables are neither individually novel nor treated as exact equivalents of subsequently realized components. Using quarterly Chinese A-share data, the study evaluates the joint Growth–Value return relation through within-quarter sequential double sorting, log-linear ordinary least squares, interaction and centered quadratic specifications, and threshold regression. The full-sample results indicate that Growth generally provides the stronger first-order relation, whereas the standalone Value coefficient is less consistent across horizons. The interaction term is not robust to multiple-testing adjustment, while evidence of curvature is confined to selected specifications and horizons; threshold evidence is likewise limited and requires cautious interpretation. Quarter-by-quarter cross-sectional regressions and a purged four-period out-of-sample design further show that the quadratic model is not systematically more stable or predictively superior to the parsimonious linear benchmark. Supplementary evidence from Hong Kong and the United States indicates that the relative importance of Growth and Value varies across market environments. The contribution is therefore not a new pricing factor or econometric method. Rather, TRR provides a common economic organization for established characteristics and a disciplined framework for distinguishing full-sample functional-form evidence from temporal stability and out-of-sample predictability. Full article

Advanced manufacturing and cutting machinery often operate under variable material properties and uncertain load conditions, making real-time process optimization difficult when high-fidelity simulations and physical experiments are costly. To address this problem, this study proposes a physics-guided surrogate-assisted reinforcement learning framework for multi-objective speed regulation of coal–rock cutting machinery. The haulage speed and drum rotational speed are jointly optimized to balance production rate, cutting specific energy consumption, current load, vibration impact, and speed-regulation stability. First, an EDEM–RecurDyn–Simulink co-simulation model was established to obtain cutting current and vibration response data under different coal–rock structures and speed combinations. Similar-material cutting experiments were conducted to validate the vibration response, with root mean square (RMS) relative errors of 3.38%, 4.21%, 5.75%, and 5.03% under full-coal, single-gangue-layer, double-gangue-layer, and full-rock conditions, respectively. Based on these data, an improved physics-informed neural network (PINN) surrogate model was developed by embedding an equivalent coal–rock difficulty factor, a speed-matching factor, a semi-empirical current prior, and a vibration residual calibration mechanism. The surrogate model achieved R² values of 0.9623 and 0.9147 for cutting current and vibration kurtosis, respectively. It was then integrated into a Soft Actor–Critic (SAC) control environment to learn continuous dual-variable speed-regulation policies. Across five independent SAC training seeds, the improved SAC achieved an average theoretical productivity of 207.8033 ± 6.5641 t·h⁻¹ and a cutting specific energy consumption of 0.3387 ± 0.0114 kW·h·t⁻¹. Compared with the fixed-speed, empirical speed-regulation, and conventional SAC strategies, the proposed method increased the average theoretical productivity by 2.65%, 5.01%, and 1.77%, respectively, while reducing the corresponding specific cutting energy consumption by 1.37%, 4.05%, and 2.22%. These results demonstrate that the proposed framework provides an efficient intelligent optimization method for condition-aware speed regulation in complex industrial cutting processes. Full article

Environmental, social, and governance (ESG) quality cannot be directly observed because substantial disagreement across rating providers contaminates the observed ESG scores with measurement error. This paper addresses this problem by modelling the true ESG state as a latent, vector-valued Itô diffusion defined on a filtered probability space whose information set is progressively enlarged by FinTech signals. We establish the well-posedness of the latent ESG process, prove the existence of an equivalent martingale measure under an explicit exponential-moment condition, and solve an ESG-constrained portfolio problem under a wealth-scaled sustainability constraint through a Hamilton–Jacobi–Bellman verification theorem. Computationally, raw sustainability information is extracted from SEC Form 10-K filings using a FinBERT transformer architecture and incorporated into a linear Gaussian state-space model, where the latent ESG state is recovered via Kalman filtering. Theoretical results are then linked to asset pricing, portfolio allocation, and systemic risk networks through a common filtered ESG factor. Using an unbalanced panel of 1086 U.S. listed firms over 2011–2023 and ESG information from MSCI, Refinitiv, and Sustainalytics, we document substantial provider disagreement and show that the observed ESG ratings contain significant transitory measurement noise. The filtered ESG state exhibits higher reliability, lower noise, and greater persistence than individual provider scores. In asset pricing tests, the latent ESG state predicts future excess returns, whereas a composite provider-based ESG measure does not; a one-standard-deviation increase in the latent ESG state is associated with approximately 0.35 percentage points higher monthly excess returns (about 4.3% annualised). When both measures are included simultaneously, only the filtered ESG state retains explanatory power. Out-of-sample portfolio tests show that a latent ESG strategy achieves a Sharpe ratio of 0.72, significantly exceeding both an unconstrained benchmark (0.59) and a composite ESG screen strategy (0.55). At the network level, ESG-adjusted weighting attenuates systemic fragility by reducing the spectral abscissa from 0.34 to 0.21, with the mitigating effect remaining significant under permutation-based placebo tests. Overall, the evidence supports the central hypothesis that ESG measurement error attenuates the observed pricing effects and that FinTech-enabled filtering recovers economically meaningful sustainability information relevant for asset pricing, portfolio construction, and systemic risk assessment. Full article

Slope stability in vegetated hillslopes depends on groundwater, geometry, external loading, soil properties, and root reinforcement. This study evaluated a low-plasticity clayey silt (CL–ML) from Loja, Ecuador, under bare soil, Eucalyptus, Pine, Vetiver, and Kikuyu covers. Direct shear tests on root-containing specimens provided equivalent Mohr–Coulomb parameters for limit-equilibrium and PLAXIS 2D strength-reduction analyses considering three slope geometries and three loading conditions: elevated groundwater, groundwater plus an 8 kN m⁻² surcharge, and groundwater, surcharge, and pseudo-static loading. The resulting 90 factor-of-safety values were assessed using scenario-based factorial ANOVA and MANOVA. Geometry and loading explained 41.4% and 35.0% of total variance, respectively, whereas numerical method explained 1.1%. Limit-equilibrium factors of safety were 5.4% higher on average than PLAXIS 2D values. The vegetation-cover main effect was small and marginal (η² = 1.5%, p = 0.051), while significant cover–loading and cover–method interactions indicated a scenario- and method-dependent response. Under pseudo-static loading, Vetiver and Kikuyu showed the highest PLAXIS 2D factors of safety, whereas LEM results remained narrowly grouped, precluding a general ranking of vegetation effectiveness. These findings support scenario-specific evaluation of equivalent root reinforcement in slope-stabilization design. Full article

Background/Objectives: Acute lymphoblastic leukemia (ALL) treatment is effective but involves the use of cardiotoxic anthracyclines. Data on three-dimensional (3D) strain echocardiography utility in the monitoring of acute and early-onset cardiotoxicity in children with ALL are scarce. The aim was to assess the left ventricular function in 3D strain echocardiography in children with ALL treated with anthracyclines in reference to a healthy cohort and to assess risk factors of possible subclinical cardiotoxicity. Methods: For this study, medical records from between May 2023 and December 2024 were retrospectively analyzed, and the echocardiographic data were reassessed. The study group consisted of children diagnosed and treated for ALL for at least 6 months with the use of daunorubicin and doxorubicin (or only with daunorubicin) who underwent routine cardiological evaluation with 3D echocardiography in >6 months and <2 years from the beginning of treatment. The echocardiographic records were reassessed offline to analyze the left ventricle 3D global longitudinal (GLS 3D), circumferential (GCS 3D) and radial (GRS 3D) strain. The results were compared with the results of 24 apparently healthy peers matched by sex and age. A set of models was developed to test literature-based subclinical cardiotoxicity determinants in relation to the obtained 3D strain values. Results: The study group consisted of 42 children (22 males and 20 females) aged 2–17 years (mean 7.7 ± 4.1 years) treated for ALL. The median time from the first anthracycline dose was 0.59 (IQR1 = 0.5; IQR3 = 0.96) years with a cumulative equivalent anthracycline dose of 158.2 ± 78.0 (min. 48.0–max. 451.8) mg/m². Statistically significant differences between study and control groups were observed in terms of LVEF 3D (53.9 ± 4.4% vs. 59.1 ± 5.8%, p < 0.001), GLS 3D (−21.8 ± 4.2% vs. −25.2 ± 3.6%, p < 0.001), GCS 3D (−22.3 ± 3.8% vs. −27.3 ± 4.7%, p < 0.001) and GRS 3D (37.1 ± 5.0% vs. 44.6 ± 5.7%, p < 0.001). None of the previously described cardiotoxicity risk factors—age at the diagnosis, sex, age at treatment initiation, body surface area (BSA) at treatment initiation, time since treatment initiation, ALL subtype, total anthracycline dose and doxorubicin treatment—were statistically significant in the GLS or GCS models. Conclusions: GLS 3D, GCS 3D and GRS 3D of the left ventricle may be sensitive indicators of myocardial dysfunction in children with ALL treated with anthracyclines. The relation of the previously described cardiotoxicity risk factors to the 3D strain values and myocardial dysfunction is inconclusive; further studies are warranted. Full article

Background/Objectives: Scenario-specific anticipatory anxiety among anesthesia professionals is poorly characterized. We describe scenario ratings, career incidents, and associated factors. Methods: This cross-sectional survey (20 June–6 July 2026) included a self-selected convenience sample of 400 anesthesia professionals in Bursa, Türkiye. Participants rated 12 scenarios and reported incidents, post-event impact, burnout, and institutional preparedness. Multivariable regression examined the preliminary mean index. Results: An internal split-sample stability assessment—not independent validation—showed inadequate confirmatory fit; the 12-item mean was therefore treated as a preliminary descriptive index, not a validated scale. Ratings were highest for pediatric complications (7.01), medication errors (6.45), and malignant hyperthermia (6.15). Difficult airway was selected most often in a separate, non-equivalent incident item (95.8%); selections indicate citation salience, not prevalence. All respondents reported a participant-defined career incident. The invitation denominator was unknown; self-selection may have inflated the observed 100% incident-reporting proportion. Only 7.8% reported past-year simulation training. The exploratory model explained 10.9% of the index variance. Higher values were associated, after adjustment, with female sex (β = 0.55, 95% CI 0.15–0.96), faculty (β = 1.58, 95% CI 0.50–2.66) and specialist roles (β = 1.36, 95% CI 0.82–1.90) relative to technicians, and with a higher study-specific burnout rating (β = 0.20/point, 95% CI 0.09–0.31). Reporting ≥6 vs. <6 incidents was associated with a modestly lower value (β = −0.64, 95% CI −1.20 to −0.09), without a monotonic trend. Conclusions: The findings are hypothesis-generating. Selection, reverse causation, measurement error, untested cross-role measurement invariance, common method covariance, multiplicity, and unexplained variance limit interpretation. Multisite studies using validated measures are required before application. Full article

Grape stems (GSs), a key by-product of winemaking, are a rich source of bioactive polyphenols and have potential applications in functional foods, antioxidant additives, and cosmetics. In this study, the production of polyphenol-rich extracts from GS using an ultrasound-assisted, acid-catalyzed organosolv process was explored, using isopropanol as solvent. Sulfuric acid served as an effective catalyst for breaking down lignocellulosic material, and the process conditions were optimized using response surface methodology to maximize efficiency. Following an initial single-factor analysis, sulfuric acid and isopropanol concentrations were selected as the main variables. The optimal conditions—54% isopropanol and 1% sulfuric acid—yielded the highest polyphenol content (50.9 ± 4.4 mg caffeic acid equivalents per gram of dry mass). Further analysis using liquid chromatography–mass spectrometry revealed that acid catalysis significantly altered the polyphenolic composition of the extracts. These changes enhanced antioxidant potency, as expressed by the radical scavenging activity but not by the reducing power, while the exact nature of the newly formed compounds was unclear. Overall, the results provide useful insights into modifying the polyphenolic profile of grape stems to obtain extracts with improved antioxidant capacity, supporting more sustainable and value-added uses of winemaking by-products within biorefinery systems. Full article

The traditional spring wheat–sunflower relay intercropping system in the Hetao Irrigation District of Inner Mongolia is constrained by restrictions on sowing time, relatively low resource use efficiency, and suboptimal strip configurations. Based on the winter-seeding technique for spring wheat, this study established an annual double-cropping system of winter-seeded spring wheat relay intercropped with sunflower. The objectives were to evaluate crop photosynthetic performance, grain yield, resource use efficiency, and economic benefits under different strip configurations and to identify a suitable strip arrangement. A two-year fixed-site field experiment was conducted from 2023 to 2025. Four winter-seeded spring wheat/sunflower relay-intercropping treatments (W9S2, W9S4, W18S2, and W18S4) were compared with sole-cropped winter-seeded spring wheat and sole-cropped sunflower. Relay intercropping increased leaf area index, SPAD values, and the net photosynthetic rate of both crops at key growth stages and also improved grain yield and resource use efficiency. Among the strip configurations, W18S2 showed the best overall performance. Its two-year average grain yields of wheat and sunflower were 13.2% and 32.2% higher, respectively, than those of the corresponding sole-cropping treatments. The land equivalent ratio and nitrogen uptake equivalent ratio of all relay-intercropping treatments were greater than 1, with the highest values observed under W18S2. In addition, W18S2 had higher light use efficiency, water use efficiency, and nitrogen partial factor productivity than the sole-cropping treatments and the other relay-intercropping configurations. The two-year average net profit of W18S2 was 46.8% and 8.0% higher than that of sole-cropped wheat and sole-cropped sunflower, respectively. Overall, the superior performance of W18S2 was associated with a more favorable canopy structure and photosynthetic performance, greater dry matter accumulation, and coordinated improvements in grain yield, resource use efficiency, and economic benefits. These findings provide a reference for the high-yield and resource-efficient cultivation of winter-seeded spring wheat relay intercropped with sunflower in the Hetao Irrigation District. Full article