Search Results (15,727)

To explore the effects of legume intercropping on soil nitrogen (N) and phosphorus (P) cycling processes in mulberry plantations during the winter fallow period, three treatments were set up: control (no intercropping, CK), single-legume intercropping (T1: Medicago polymorpha), and mixed-legume intercropping (T2: Medicago polymorpha + Astragalus sinicus). The variations in soil available nutrients, enzyme activities, microbial community structure, and functional gene abundances were investigated, with a focus on the influence of spatial heterogeneity (middle of inter-row as position A, and mulberry-adjacent as position B). Compared with CK, both T1 and T2 significantly altered soil microbial community composition and enhanced β-diversity (R² = 0.747, p < 0.001), and these effects were more pronounced at position A. For soil N cycling, T1 and T2 reduced available N content especially at position B; however, T2 significantly increased urease activity, while T1 decreased urease activity at position A. Both treatments elevated the abundances of N-cycling functional genes (e.g., glnA, ureC, nifD) and symbiotic nitrogen-fixing rhizobia, with T1 increasing Bradyrhizobium and T2 increasing Sinorhizobium. For soil P cycling, T1 and T2 enhanced phosphatase activity to promote organic P conversion; T1 strengthened the entire P metabolic chain by upregulating multiple P-related functional genes, while T2 specifically increased the abundance of the organic P transport gene ugpb. Structural equation modeling showed that soil microbial Shannon diversity promoted the relative abundances of N-cycling and P-cycling functional genes, and cascading pathways among nutrient-cycling genes and enzyme activities governed soil available N and P. The distinct effects of T1 and T2 highlight the importance of optimizing intercropping patterns, and spatial heterogeneity should be considered in agronomic effect evaluation. Leguminous green manure intercropping should be encouraged in mulberry plantations to boost soil nutrient-cycling processes driven by microorganisms. Full article

Cultivated grasslands provide an important strategy for reducing pressure on degraded natural grasslands and increasing high-quality forage supply. However, how stand-age-related variation affects belowground–aboveground coordination and forage production in cultivated Leymus chinensis remains unclear. Here, we compared a natural L. chinensis stand (NL) with 3-, 4-, and 5-year-old cultivated ‘Zhongke No. 1’ stands by integrating plant trait measurements, biomass assessment, nutrient analysis, forage quality evaluation, correlation analysis, and structural equation modeling. (1) Compared with NL, cultivated stands generally showed greater vegetative growth and aboveground biomass, lower fiber concentrations, and higher soluble sugar concentration and relative feed value. (2) Root and aboveground traits exhibited distinct stand-age-related patterns, with the 3Y stand showing greater root exploration traits, the 4Y stand achieving the highest aboveground biomass (4.61 t/hm²), and the 5Y stand exhibiting greater root thickening and ramet density. (3) Carbon, nitrogen, and phosphorus concentrations varied among stand ages, indicating shifts in nutrient status during stand development. (4) Correlation analysis and PLS-SEM revealed that root architecture, nutrient status, and aboveground morphology were closely associated with forage yield and quality variation. These findings highlight the importance of stand-age-dependent belowground–aboveground coordination for optimizing the management and utilization of cultivated L. chinensis grasslands. Full article

Production data transparency in smart manufacturing simultaneously enhances and impairs employee performance across organizational contexts. Existing research has not resolved this theoretical contradiction. Drawing on socio-technical systems theory, cognitive appraisal theory, and conservation of resources theory, this study develops a dual-pathway model. Data transparency influences adaptive performance through a bright empowerment pathway and a dark surveillance pathway mediated by EPM-induced strain. Procedural justice of data governance and digital self-efficacy operate as a perceived-institutional boundary condition and an individual-capability boundary condition, respectively. Latent moderated structural equations were applied to survey data from 412 employees in Chinese smart manufacturing enterprises. Results support both pathways and reveal a theoretically consequential asymmetry between these boundary conditions. Johnson–Neyman analysis indicates that institutional justice attenuates the strain pathway to non-significance within the observed distribution of responses. Conversely, digital self-efficacy requires near-ceiling levels to achieve the same pattern. This asymmetry indicates that continuous moderation produces sharply different practical outcomes across the observed data range. Institutional and individual remedies therefore address the visibility paradox on different practical scales. Governance adequacy represents a more attainable managerial lever than individual capability development. These findings advance socio-technical systems theory by detailing the asymmetric buffering capacities of different organizational resources. Full article

To date, limited research has systematically explored the interconnections between perceived teacher support, self-concept, engagement, and academic achievement specifically regarding the reading domain. Most previous studies have been conducted in Western cultures, making it difficult to extrapolate the findings to Eastern cultures, such as China. Therefore, this study investigated the relationship between perceived teacher support, reading self-concept, reading engagement, and reading literacy in a Chinese educational context. A structural equation modeling analysis was conducted using 12,058 Chinese students from the Programme for International Student Assessment 2018 data. The results revealed that perceived teacher support did not directly affect students’ reading literacy. However, it could indirectly affect reading literacy through the independent mediation effects of reading self-concept and reading engagement as well as their chain mediation effect. Hence, the results suggest that perceived teacher support can increase students’ sense of reading self-concept, resulting in greater reading engagement, which may lead to improved reading achievement. Full article

The quantitative measurement of TCC at tourist cities involves considerable methodological complexities. Conventional evaluation methods based on fixed numerical criteria are frequently insufficient since tourism systems are characterized by unclear information, gradual shifts, and subjective experiences. To address these methodological constraints, this study develops and implements a hybrid FAHP-weighted Fuzzy Comprehensive Evaluation (FCE) framework to estimate TCC. The framework incorporates four critical indicators, visitor density, waste generation, infrastructure load, visitor perception, reflecting the physical, environmental, infrastructural, and socio-cultural dimensions of tourism development. These indicators are assessed using a structured analytical procedure integrating fuzzification, expert-derived weighting through the fuzzy analytic hierarchy process, fuzzy comprehensive evaluation, and centroid defuzzification. This study presents a hybrid SEM–FAHP–FCE framework, which is a multi-method integrated decision model that combines SEM (structural equation modeling) for visitor perception and behavioral drivers, FAHP (fuzzy analytic hierarchy process) for expert-based indicator weighting and FCE (fuzzy comprehensive evaluation) for final carrying capacity assessment under uncertainty. This combined methodology offers a more adaptive and empirically grounded assessment of TCC by synthesizing quantitative conditions with qualitative stakeholder perceptions within a unified evaluative model. The framework is validated through empirical application to Vrindavan, Uttar Pradesh, one of India’s most visited destinations, across eight study sites and two seasonal conditions (normal and festival-peak). Primary data collection comprises 300 visitor count observation units and field data, i.e., visitor count, waste generation and infrastructure details. The defuzzified FAHP–FCE results for each site (W = 3.94, 3.33, 2.44, 1.95, 3.66, 1.87, 1.86 and 2.71) reveal that major pilgrimage nodes exhibit scores approaching the upper bound of the evaluation scale, indicating that tourism pressure has significantly exceeded carrying capacity during peak periods. This study establishes proof-of-concept for the FAHP–FCE framework as a standardized, replicable instrument for evidence-based TCC governance at tourism cities. Full article

Artificial intelligence is increasingly adopted by tourism organisations, yet its relationships with creativity, innovation, and organisational growth intention remain insufficiently understood across national contexts. This study examined relationships among current organisational AI use, intention to use or expand the use of AI, perceived usefulness of AI for tourism service development, creativity at workplace, organisational innovation, and organisational growth intention in Lithuania, Poland, and Sweden. Survey responses, provided by 436 representatives of tourism organisations, were analysed using structural equation modelling, bias-corrected bootstrapping, and exploratory multi-group comparisons. Current organisational AI use was positively associated with creativity at workplace in the pooled model, but the association was modest and was not robust in country-specific bootstrap analyses. Perceived usefulness of AI for tourism service development showed a more robust positive association with organisational innovation, while creativity at workplace was strongly associated with organisational innovation and organisational innovation was positively associated with organisational growth intention. Intention to use or expand the use of AI was positively associated with organisational growth intention in the hypothesised structural model, but this relationship was specification-dependent and did not remain statistically significant after controlling for main activity group and number of employees. Significant indirect associations were also identified, and country-specific analyses indicated heterogeneity in selected relationships. The findings support distinguishing the three AI-related dimensions and suggest that creativity-supportive and innovation-management practices remain important alongside AI-related practices. Full article

Digital transformation has reshaped work processes across the tourism industry, increasing the need to understand how employees perceive organizational digital systems and how these perceptions are associated with workplace behaviors. This study examined the relationships among perceived digital system support (PDSS), psychological empowerment, and voice behavior among tourism employees from an organizational behavior perspective grounded in the Technology Acceptance Model. Data were collected through an online survey of employees working in travel agencies, airlines, hotels, and foodservice organizations in South Korea, and 314 valid responses were analyzed using structural equation modeling. The results indicated that PDSS was positively associated with psychological empowerment, and psychological empowerment was positively associated with voice behavior. By contrast, the direct relationship between PDSS and voice behavior was not statistically significant, whereas the indirect association via psychological empowerment was significant, indicating a pattern consistent with full mediation. These findings suggest that employees’ positive perceptions of organizational digital systems show an indirect association with constructive voice behavior via psychological empowerment, particularly competence, self-determination, and impact. The study extends the application of the Technology Acceptance Model from technology acceptance to employee organizational behavior in digital work environments and highlights the importance of fostering psychologically empowering workplaces during digital transformation. Full article

Pedestrian-induced vibration is a critical serviceability concern for flexible structures such as footbridges and long-span floors. Existing human–structure interaction models commonly rely on single-degree-of-freedom simplifications and time-domain simulations, making them less suitable for frequency-domain analysis. This paper proposes a spectral analysis model for crowd-structure interaction vibration under unrestricted pedestrian traffic. The structure was formulated as a multi-degree-of-freedom modal system, whereas each pedestrian is represented by an independent spring–mass–damper system. To address the time-varying nature of moving crowds, a piecewise stationary assumption was introduced: the continuous walking path was discretized into fixed position groups, within each of which a time-invariant coupled equation of motion was established. The response spectra obtained for different position groups were combined using residence-time weighting, thereby allowing nonuniform walking speeds to be considered. The corresponding frequency response function was derived using the state–space method, and the structural acceleration power spectral density and root mean square responses were obtained by incorporating an unrestricted crowd walking load spectral model. Comparisons with field measurements from two footbridges demonstrated reasonable agreement. The resulting framework offers an efficient frequency-domain approach for vibration serviceability assessment under unrestricted pedestrian traffic. Full article

With the continuous advancement of deep and ultra-deep well drilling technologies, formations with complex pressure windows are becoming increasingly common. During casing running operations, it is necessary to ensure both leak prevention in loss-prone formations and pressure stabilization in high-pressure formations, demanding increasingly higher accuracy in wellbore pressure calculation. This study establishes a wellbore pressure calculation model for managed pressure casing (MPC) running in deep wells, specifically addressing the scenario where a multi-density gradient drilling fluid column exists in the annulus after tripping out. The model’s novelty lies in integrating transient surge pressure calculation with a dynamic fluid column structure model that tracks the displacement of multi-density drilling fluid layers during casing running. The governing equations based on one-dimensional unsteady flow theory are solved using the method of characteristics with adaptive time stepping and a grid independence study confirming the discretization scheme. Quantitative analysis reveals that casing running speed is the dominant factor affecting surge pressure; when the speed increases from 0.5 m/s to 1.5 m/s, the surge pressure increases from approximately 1.2 MPa to 3.5 MPa at a 2000 m depth. Drilling fluid properties also significantly influence surge pressure: increasing the density from 2.0 g/cm³ to 2.22 g/cm³ results in a surge pressure increase of approximately 0.6 MPa; increasing the yield value from 2.85 Pa to 15 Pa leads to an increase of about 1.1 MPa; the surge pressure shows a clear increasing trend with both the consistency coefficient and flow behavior index. Casing running depth affects the buffering effect of the bottomhole flow channel; when the casing is run to 7000 m, the surge pressure is approximately 0.5 MPa higher than at 2000 m. Taking a typical deep well (8578 m) with a negative pressure window of −0.008 g/cm³ as an example, three casing running speed plans were designed and evaluated. Plan 1 was selected with running speeds ranging from 0.16 m/s in the upper section to 0.115 m/s in the lower section, maintaining the equivalent circulating density (ECD) within the safe density window throughout the entire operation. Field application of this plan proceeded smoothly without any occurrences of lost circulation or overflow. This provides a practical basis for MPC running technology in deep wells with narrow or negative pressure windows. Full article

In the context of the global green development wave and the rapid iteration of digital technology, digital empowerment has become the core driving force for high-end manufacturing enterprises to achieve green transformation. At present, China’s manufacturing industry is facing the dual pressures of tightening resource and environmental constraints and industrial upgrading. How to break the bottleneck of green development through digital technology innovation has become a key issue to be solved urgently. Based on the techno-economic paradigm, green development theory and value creation theory, this study constructs a theoretical analysis framework for the green development of a digital-enabling manufacturing industry and deeply analyzes the mechanisms of digital technology (such as big data, Internet of Things, artificial intelligence, etc.) in optimizing energy allocation, improving production efficiency and reducing environmental emissions. By selecting 303 manufacturing enterprises of different scales in China as samples, the structural equation model is used for empirical tests. The results show that (1) digital empowerment has a significant positive impact on the green value performance of manufacturing enterprises, and (2) green development plays an intermediary role between digital empowerment and the green value performance of enterprises; that is, digital technology indirectly promotes green development by improving energy conservation and emission reduction, green innovation and green upgrading of enterprises. The research reveals the internal logic of digitally enabling the green development of Chinese manufacturing enterprises and provides a theoretical basis and implementation path for enterprises to formulate the innovation mechanism of digital–green development. Full article

This paper presents a mathematical model to investigate how waves and currents interact with a flexible perforated floating membrane in finite water depth within the framework of linear wave theory. The perforated flexible membrane is modeled based on Darcy’s law and the one-dimensional string equation. The complex dispersion relation in the presence of current velocity is derived from the Green’s function technique using a fundamental source potential solution. The dispersion curve is analyzed by comparing the phase and group velocities for different water depths. Further, a physical model associated with the effect of current on a moored finite floating perforated flexible membrane integrated with a vertical wall is formulated. Then, the theoretical solution of a physical boundary value problem near a vertical rigid wall is obtained using the matching technique and the roots of the dispersion relation derived from the Green’s function technique. Numerical simulations are provided to verify the convergence of the series solution and the accuracy of the obtained analytical findings are evaluated against previously published analytical and experimental datasets. Further, several numerical results on the membrane deflection, hydrodynamic coefficients, and horizontal force on the wall for various structural parameters, mooring stiffness, and current velocities are analyzed. It is observed that the present analysis with this perforated membrane breakwater will be helpful to coastal and marine engineers to understand the influence of current velocity. Full article

Historic university campuses increasingly face simultaneous demands for functional renewal and heritage conservation amid rapid urbanization. However, the relationship between campus landscape perceptions and students’ built heritage conservation intention, together with the psychological pathways underlying this relationship, remains insufficiently understood. This cross-sectional study examines the association between Campus Landscape and Built Heritage Conservation Intention, focusing on the mediating roles of Place Identity and Place Dependence. Using a multidimensional place-attachment framework, the proposed model was tested with structural equation modeling (SEM) based on 569 student questionnaires collected at the Jungong Road Campus of the University of Shanghai for Science and Technology (formerly Hujiang University), which contains the Hujiang University modern architectural complex, designated as a major historical and cultural site protected at the national level in China. Campus Landscape was positively associated with Built Heritage Conservation Intention. Place Identity showed a significant positive indirect association, whereas the indirect association through Place Dependence was not statistically significant. In subgroup analyses, the estimated indirect association through Place Dependence was positive among undergraduates and negative among postgraduates, but it was not statistically significant in either subgroup and should therefore be interpreted as exploratory. These findings highlight the significant indirect association through Place Identity and offer illustrative implications for campus landscape planning that is attentive to place identity and for the conservation of historic campuses in active use. Full article

We examined the relationships between self-directed learning skills, university belonging, and student engagement in open online and distance learning environments within the framework of Self-Determination Theory. The research was conducted using a correlational survey model. Data were collected from 696 university students enrolled at a large-scale open, online and distance learning institution in Türkiye. We used three instruments measuring self-directed learning skills, university belonging, and student engagement. The data were analyzed using partial least squares structural equation modeling. The findings indicate that university belonging significantly and positively predicts all dimensions of student engagement. While self-control skills, learning skills, and sustaining the desire to learn significantly explain university belonging, metacognitive awareness and ability to identify sources were found to have no significant effect. Furthermore, it was found that university belonging acts as a significant mechanism in the relationships between self-control skills, learning skills, and sustaining the desire to learn, and student engagement. In this open and distance learning context, student engagement was not explained by individual learning skills alone. University belonging may therefore be one mechanism that partly accounts for the association between self-directed learning and academic participation. The study contributes by testing self-directed learning at the level of its dimensions, by identifying university belonging as a mechanism that partly accounts for its association with engagement, and by situating this model in a large-scale open and distance learning setting. Full article

The rapid expansion of electric vehicle (EV) charging infrastructure has increased the importance of improving the user experience alongside expanding charging availability. While previous studies have primarily examined EV adoption from technological, economic, and infrastructural perspectives, limited research has investigated how Human Factors characteristics of charging systems influence users’ continuance intention. This study extends the Theory of Planned Behavior (TPB) by integrating Human Factors constructs as antecedents of behavioral beliefs associated with continuance intention toward public EV charging stations in the Philippines. A quantitative cross-sectional survey was conducted among 286 EV users in the National Capital Region, and the proposed model was evaluated using Partial Least Squares Structural Equation Modeling (PLS-SEM). Interface usability significantly influenced both attitude and perceived behavioral control, while participatory ergonomics significantly influenced subjective norm. Physical ergonomics, cognitive ergonomics, and accessibility did not significantly predict their proposed behavioral beliefs. Among the TPB constructs, perceived behavioral control and attitude significantly predicted continuance intention, whereas subjective norm was not significant. Furthermore, interface usability exhibited significant indirect effects on continuance intention through both perceived behavioral control and attitude. The findings demonstrate that Human Factors characteristics contribute selectively to the behavioral mechanisms underlying continued charging-station use, with perceived behavioral control emerging as an important pathway linking the charging experience with continuance intention. The study extends TPB by positioning Human Factors as antecedents of behavioral beliefs in a post-adoption context and highlights the importance of usable, understandable, and manageable charging interactions in supporting continued engagement with public EV charging infrastructure. Full article

Shale gas reservoirs are characterized by low permeability, nanoscale pore structures, and complex fracture networks. Multistage fractured horizontal wells are an important technology for commercial shale gas development. However, many shale gas productivity models primarily emphasize gas transport within the reservoir and fracture system, while pressure variations caused by frictional losses along the horizontal wellbore are often simplified or treated separately. To address this issue, this study develops a fully coupled multiscale dual-porosity numerical model that integrates the shale matrix, hydraulic fractures, and horizontal wellbore within a unified simulation framework. The model incorporates key physical mechanisms governing shale gas transport, including Knudsen diffusion, Langmuir adsorption–desorption, stress sensitivity, and non-Darcy flow in fractures. Meanwhile, the Darcy–Weisbach equation is introduced to describe wellbore frictional pressure losses. The reliability of the proposed model is validated through history matching with field production data from the Changning shale gas reservoir. The results demonstrate that neglecting wellbore friction losses leads to a 30–50% overestimation of horizontal well productivity, indicating that wellbore friction has a significant impact on fracture flow distribution and productivity prediction. Furthermore, an exponent factor r is introduced to characterize and evaluate non-uniform fracture placement patterns. The results show that toe-dense fracture placement can increase cumulative gas production by approximately 37.8% compared with uniform fracture placement when r = 1.10, which yields the highest cumulative gas production among the tested cases. However, the additional production benefit becomes substantially smaller after the initial increase and remains relatively stable as r further increases. This study improves the understanding of friction-induced heel-to-toe effects and provides an effective numerical approach for productivity prediction and fracture placement design in shale gas horizontal wells. Full article