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System-based approaches are critical for addressing the complex and interconnected nature of urban ecological development and restoration of ecosystem services. This study adopts a system perspective to investigate the spatiotemporal drivers of key ecosystem services, including carbon sequestration, water conservation, sediment reduction, pollution mitigation, and stormwater regulation, within the Yangtze River Delta Eco-Green Integrated Development Demonstration Area (YRDDA) from 2000 to 2020. We propose a novel framework for defining enhanced-efficiency ecosystem service management regions (EESMR) to guide targeted restoration. Our analysis revealed the complex interplay of 11, 9, 6, 6, and 10 driving factors for selected ecosystem services, highlighting the spatiotemporal heterogeneity of these drivers. By overlaying these key factors, we identified high-efficiency restoration priority areas for EESMR that ensure high returns on investment and the efficient restoration of ecosystem functions. This system-oriented approach provided critical spatial guidance for integrated ecological restoration, green development, and eco-planning. These findings offer valuable insights for policymakers and planners in the Yangtze River Delta and other rapidly urbanizing regions, supporting the formulation of effective land-use policies that balance environmental sustainability and urban growth. Full article

This paper describes the behavior of some epoxy, acrylic and polyurethane paints used in the protection of electrical equipment under the action of different degradation factors. The degradation factors chosen were temperature and UV radiation. The behavior of the paints under the action of these factors was interpreted by the variation of the tangent of the dielectric loss angle (tg Delta) as well as by FTIR and TG DSC analyses. Tg Delta was considered the reference dielectric characteristic because it best simulates the functionality of the material. The results presented in this paper lead to the conclusion that exposure to thermal cycles and UV radiation is necessary for each paint to give indications about their possibility of use in these conditions. At the same time, the evaluation of thermal stability, even if the exposure is at lower temperatures (than those at which we performed the tests) and/or for shorter periods, is very important for placing the paint in an insulation class. The tests that were the subject of this work provide us with the following information about the three types of paints analyzed: the highest resistance to thermal cycles is presented by S3, followed by S2 and then S1; thermal endurance tests place the polyurethane paint (S3) in insulation class E and the epoxy paint (S1) in insulation class B; and the tests to determine resistance to UV radiation qualify the best paint as acrylic (S2) and the worst as polyurethane (S3). Thus, it can be said that in applications where it is necessary for the protective film to withstand high temperatures, the use of S3 paint (polyurethane) is recommended, and in applications where the films are kept under the influence of UV radiation for a longer time, it is recommended to use coded paint S2 (acrylic). The results presented in this paper lead to the conclusion that the exposure to thermal cycles simulating the use in outdoor conditions and the resilience of paints under UV radiation conditions must be performed for each paint according to its specific use, and the dielectric characteristics must be carefully evaluated because they can reach values under the accepted limit—e.g., thermal stability evaluation—even if the exposure is at lower temperatures and/or for shorter periods. The conclusions of the experimental work must be generalized at different types of electrical insulating paints, and maybe a new standard is necessary to assess the paints’ behavior under usage conditions, with the paints needing to be treated separately from the classical polymeric insulation systems. Full article

Regional integration policies play a crucial role in promoting coordinated regional development. However, it remains unclear whether the polices simultaneously take into account urban–rural integration to achieve a dynamic balance between efficiency and equity. Based on socioeconomic data from 250 cities in China between 2003 and 2019, we used a staggered difference-in-difference method to investigate the impact of the strategy for the integrated development of the Yangtze River Delta (YD integrated development) on integrated urban–rural development. Our results indicate that the YD integrated development effectively promotes integrated urban–rural development and this conclusion holds after conducting various robustness tests and heterogeneity analyses. Additionally, the YD integrated development can facilitate integrated urban–rural development through the following three main pathways: promoting economic growth, improving road transport links, and advancing technological progress. This paper offers new insights for advancing integrated urban–rural development. The next step could involve the further exploration of the connections between external regional integration policies and internal rural reforms, which will contribute to expediting the establishment of an integrated urban–rural pattern. Full article

It is of great practical significance to utilize the agricultural carbon emission reduction effect of the policy of re-designation of counties as cities or city districts (RCCD) to achieve agricultural high-quality development. This paper uses panel data of 39 cities in the Yangtze River Delta region in China from 2010 to 2022, and adopts a staggered difference-in-difference model and a panel threshold model to identify the causal impact of the policy of RCCD on agricultural carbon emissions (ACE). We show that: (1) Overall, the policy of RCCD exerts a tangible dampening effect on ACE, with cities in the experimental group exhibiting a significant reduction of 0.069 in agricultural carbon emissions compared to the control group post-implementation of the policy. (2) A dual-threshold effect of environmental regulation emerges in the context of the policy of RCCD, wherein the impact on ACE varies depending on the level of environmental regulation. (3) The policy of RCCD exerts a notable inhibitory influence on urban ACE in cities with high urbanization levels, underdeveloped regions and central regions. (4) Agricultural green technology progress plays the mediating role in the relationship between the policy of RCCD and ACE. (5) The suppressive effect of the policy of RCCD on ACE is characterized by a delayed and enduring influence. Our study has both theoretical and practical implications for accelerating agricultural high-quality development. Full article

China has entered a period of high-quality development. As an important feature of high-quality development, green total factor productivity (GTFP) has attracted much attention. With the opening-up and economic globalization, the Yangtze River Delta, one of the strongest and most technological regions in China, has been attracting an increasing amount of foreign direct investment (FDI). This study investigates if FDI is conducive to GTFP under the constraints of specific resources and a specific environment, which has important practical significance for the utilization of FDI in the Yangtze River Delta and China. Through a literature review and sorting the current FDI in the Yangtze River Delta, the GTFP and its decomposition indicators of 27 cities from 2004 to 2019 are calculated based on their energy consumption and pollution. Using the fixed-effects model and threshold model of panel data, this study tests whether FDI promotes GTFP and whether a nonlinear impact of FDI on GTFP exists. It finds that (1) the GTFP of most cities in the Yangtze River Delta improved during the sample period, but their annual growth declined. Technology is the dominant factor affecting the growth of GTFP. (2) FDI in the Yangtze River Delta has increased, and the investment structure has improved, but the distribution among cities is uneven. (3) The scale and quality of FDI have a positive impact on GTFP, which supports the “Pollution Halo” hypothesis. Economics, education, networks, and trade openness can promote the growth of GTFP, while environmental regulation, government intervention, and industrialization have a negative impact. (4) The quality of FDI, economics, the industrial structure, the environmental regulation, and the internet are each a significant single threshold characteristic for the impact of FDI on GTFP. When one of these factors is lower than a certain threshold, FDI has less impact on GTFP. When one exceeds a certain threshold, FDI’s positive promotion effect on GTFP significantly improves. Based on the analysis, this study offers some suggestions. The government should improve the FDI selection mechanism based on realities, make appropriate environmental regulatory policies, strengthen the construction of networks, and improve the “Internet+” effect on productivity. Full article

Due to variations in chemical composition and production processes, homonymous austenitic stainless steels can differ significantly regarding their initial microstructure, metastability, and thus, their fatigue behavior. Microstructural investigations and fatigue tests have been performed in order to evaluate this aspect. Three different batches and production forms of nominally one type of steel AISI 347 were investigated under monotonic tensile tests and cyclic loading under total strain and stress control in low and high cycle fatigue regimes, respectively. The deformation induced α’-martensite formation was investigated globally by means of in situ magnetic measurements and locally using optical light microscopy of color etching of micrographs. The investigation showed that the chemical composition and the different production processes influence the material behavior. In fatigue tests, a higher metastability and thus a higher level of deformation induced α’-martensite pronounced cyclic hardening, resulting in significantly greater endurable stresses in total strain-controlled tests and an increase in fatigue life in stress-controlled tests. For applications of non-destructive-testing, detailed knowledge of a component’s metastability is required. In less metastable batches and for lower stress levels, α’-martensite primarily formed at the plasticization zone of a crack. Furthermore, the formation and nucleation points of α’-martensite were highly dependent on grain size and the presence of δ-ferrite. This study provides valuable insights into the different material behavior of three different batches with the same designation, i.e., AISI 347, due to different manufacturing processes and differences in the chemical composition, metastability, and microstructure. Full article

Birds have remarkable flight capabilities due to their adaptive wing morphology. However, studying live birds is time-consuming and laborious, and obtaining information about the complete wingbeat cycle is difficult. To address this issue and provide a complete dataset, we recorded comprehensive motion capture wing trajectory data from five free-flying pigeons (Columba livia). Five key motion parameters are used to quantitatively characterize wing kinematics: flapping, sweeping, twisting, folding and bending. In addition, the forelimb skeleton is mapped using an open-chain three-bar mechanism model. By systematically evaluating the relationship of joint degrees of freedom (DOFs), we configured the model as a 3-DOF shoulder, 1-DOF elbow and 2-DOF wrist. Based on the correlation analysis between wingbeat kinematics and joint movement, we found that the strongly correlated shoulder and wrist roll within the stroke plane cause wing flap and bending. There is also a strong correlation between shoulder, elbow and wrist yaw out of the stroke plane, which causes wing sweep and fold. By simplifying the wing morphing, we developed three flapping wing robots, each with different DOFs inside and outside the stroke plane. This study provides insight into the design of flapping wing robots capable of mimicking the 3D wing motion of pigeons. Full article

The Mississippi Delta region has worse population health outcomes, including higher overall cardiovascular and infant mortality rates. Water quality has yet to be considered as a factor in these health disparities. The objective of this paper is to determine overall differences in basic water quality indicators, electrolytes of cardiovascular importance, trace elements, heavy metals, and radioactive ions of groundwater in delta and non-delta counties in states along the Mississippi River. Data were sourced from the major-ions dataset of the U.S. Geological Survey. We used the Wilcoxon rank sum test to determine the difference in water quality parameters. Overall, delta counties had lower total dissolved solids (TDS) (47 and 384 mg/L, p-value < 0.001), calcium (7 and 58 mg/L; p-value < 0.001), magnesium (2 and 22 mg/L; p-value < 0.001), and potassium (1.57 and 1.80 mg/L; p-value < 0.001) and higher sodium (38 mg/L and 22 mg/L; p-value < 0.001) compared to non-delta counties. Overall, there were no statistical differences in trace elements, heavy metals, and radioactive ions across delta versus non-delta counties. These results underscore the need for further epidemiological studies to understand if worse health outcomes in delta counties could be partially explained by these parameters. Full article

As Sustainable Development Goals (SDGs) gain traction in Chinese society, fostering sustainable entrepreneurship among university students has emerged as a key priority for universities and governments. Methods for increasing students’ sustainable entrepreneurship skills and knowledge for the creation of sustainable startups have attracted substantial attention. This study constructs a moderated mediation model based on entrepreneurial cognition theory to investigate the mediating roles of opportunity identification and attitude in the relationship between sustainable entrepreneurship education and sustainable entrepreneurial intention among university students, in addition to the moderating effect of empathy. The study surveyed 307 students from universities in the Yangtze River Delta region and employed hierarchical regression analysis to test the hypotheses. The results indicate that sustainable entrepreneurship education enhances students’ sustainable entrepreneurial intention by fostering their opportunity identification and attitude, and this enhancement effect is stronger when their level of empathy is higher. These findings enrich entrepreneurial cognition and empathy theories within the context of sustainable entrepreneurship and offer valuable insights for universities and policymakers in developing strategies to support sustainable entrepreneurship among university students. Full article

Betula luminifera H. Winkler, a fast-growing broad-leaved tree species native to China’s subtropical regions, possesses significant ecological and economic value. The species’ adaptability and ornamental characteristics make it a crucial component of forest ecosystems. However, the impacts of global climate change on its geographical distribution are not well understood, necessitating research to predict its potential distribution shifts under future climate scenarios. Our aims were to forecast the impact of climate change on the potential suitable distribution of B. luminifera across China using the MaxEnt model, which is recognized for its high predictive accuracy and low sample data requirement. Geographical coordinate data of B. luminifera distribution points were collected from various databases and verified for redundancy. Nineteen bioclimatic variables were selected and screened for correlation to avoid overfitting in the model. The MaxEnt model was optimized using the ENMeval package, and the model accuracy was evaluated using the Akaike Information Criterion Correction (delta.AICc), Training Omission Rate (OR10), and Area Under the Curve (AUC). The potential distribution of B. luminifera was predicted under current and future climate scenarios based on the Shared Socio-economic Pathways (SSPs). The optimized MaxEnt model demonstrated high predictive accuracy with an AUC value of 0.9. The dominant environmental variables influencing the distribution of B. luminifera were annual precipitation, minimum temperature of the coldest month, and standard deviation of temperature seasonality. The potential suitable habitat area and its geographical location were predicted to change significantly under different future climate scenarios, with complex dynamics of habitat expansion and contraction. The distribution centroid of B. luminifera was also predicted to migrate, indicating a response to changing climatic conditions. Our findings underscore the importance of model optimization in enhancing predictive accuracy and provide valuable insights for the development of conservation strategies and forest management plans to address the challenges posed by climate change. Full article

This article primarily focuses on examining the existence and uniqueness analysis of boundary fractional difference equations in a class of Riemann–Liouville operators. To this end, we firstly recall the general solution of the homogeneous fractional operator problem. Then, the Green function to the corresponding fractional boundary value problems will be reconstructed, and homogeneous boundary conditions are used to find the unknown constants. Next, the existence of solutions will be studied depending on the fixed-point theorems on the constructed Green’s function. The uniqueness of the problem is also derived via Lipschitz constant conditions. Full article

Alterations to intestinal microbiota are assumed to occur in the pathogenesis of inflammatory bowel disease (IBD). This study aims to analyze the association of fecal microbiota composition, body composition, and lipid characteristics in patients with Crohn’s disease (CD). In our cross-sectional study, patients with CD were enrolled and blood and fecal samples were collected. Clinical and endoscopic disease activity and body composition were assessed and laboratory tests were made. Fecal bacterial composition was analyzed using the shotgun method. Microbiota alterations based on obesity, lipid parameters, and disease characteristics were analyzed. In this study, 27 patients with CD were analyzed, of which 37.0% were obese based on visceral fat area (VFA). Beta diversities were higher in non-obese patients (p < 0.001), but relative abundances did not differ. C. innocuum had a higher abundance at a high cholesterol level than Bacillota (p = 0.001, p = 0.0034). Adlercreutzia, B. longum, and Blautia alterations were correlated with triglyceride levels. Higher Clostridia (p = 0.009) and B. schinkii (p = 0.032) and lower Lactobacillus (p = 0.035) were connected to high VFA. Disease activity was coupled with dysbiotic elements. Microbiota alterations in obesity highlight the importance of gut microbiota in diseases with a similar inflammatory background and project therapeutic options. Full article

The measurement of apparent dielectric permittivity (ε_s) by low-frequency capacitance sensors and its conversion to the volumetric water content of soil (θ) through a factory calibration is a valuable tool in precision irrigation. Under certain soil conditions, however, ε_s readings are substantially affected by the bulk soil electrical conductivity (EC_b) variability, which is omitted in default calibration, leading to inaccurate θ estimations. This poses a challenge to the reliability of the capacitance sensors that require soil-specific calibrations, considering the EC_b impact to ensure the accuracy in θ measurements. In this work, a multivariate calibration equation (multivariate) incorporating both ε_s and EC_b for the determination of θ by the capacitance WET sensor (Delta-T Devices Ltd., Cambridge, UK) is examined. The experiments were conducted in the laboratory using the WET sensor, which measured θ, ε_s, and EC_b simultaneously over a range of soil types with a predetermined actual volumetric water content value (θ_m) ranging from θ = 0 to saturation, which were obtained by wetting the soils with four water solutions of different electrical conductivities (EC_i). The multivariate model’s performance was evaluated against the univariate CAL and the manufacturer’s (Manuf) calibration methods with the Root Mean Square Error (RMSE). According to the results, the multivariate model provided the most accurate θ estimations, (RMSE ≤ 0.022 m³m⁻³) compared to CAL (RMSE ≤ 0.027 m³m⁻³) and Manuf (RMSE ≤ 0.042 m³m⁻³), across all the examined soils. This study validates the effects of EC_b on θ for the WET and recommends the multivariate approach for improving the capacitance sensors’ accuracy in soil moisture measurements. Full article

The Mississippi River Delta Front (MRDF) is a subaqueous apron of rapidly deposited and weakly consolidated sediment extending from the subaerial portions of the Birdsfoot Delta of the Mississippi River, long characterized by mass-wasting sediment transport. Four (4) depositional environments dominate regionally (an undisturbed topset apron, mudflow gully, mudflow lobe, and prodelta), centering around mudflow distribution initiated by a variety of factors (hurricanes, storms, and fluid pressure). To better understand the spatiotemporal scales of the events as well as the controlling processes, eight cores (5.8–8.0 m long) taken offshore from the South Pass (SP) and the Southwest Pass (SWP) were analyzed for gamma density, grain size, sediment fabric (X-radiography), and geochronology (²¹⁰Pb/¹³⁷Cs radionuclides). Previous work has focused on the deposition of individual passes and has been restricted to <3 m core penetration, limiting its geochronologic completeness. Building on other recent studies, within the mudflow gully and lobe cores, the homogeneous stepped profiles of ²¹⁰Pb activities and the corresponding decreased gamma density indicate the presence of gravity-driven mass failures. ²¹⁰Pb/¹³⁷Cs indicates that gully sedimentary sediment accumulation since 1953 is greater than 580 cm (sediment accumulation rate [SAR] of 12.8 cm/y) in the southwest pass site, and a lower SAR of the South Pass gully sites (2.6 cm/y). This study shows that (1) recent dated mudflow deposits are identifiable in both the SWP and SP; (2) SWP mudflows have return periods of 10.7 y, six times more frequent than at the SP (66.7 y); (3) ²¹⁰Pb inventories display higher levels in the SWP area, with the highest focusing factors in proximal/gully sedimentation, and (4) submarine landslides in both study areas remain important for sediment transport despite the differences in sediment delivery and discharge source proximity. Full article

Rapidly capturing the spatial distribution of soil salinity plays important roles in saline soils’ management. Existing studies mostly focus on the macroscopic distribution of soil-salinity changes, lacking effective methods to detect the structure of micro-regional areas of soil-salinity anomalies. To overcome this problem, this study proposes a 3D Soil-Salinity Anomaly Structure Extraction (3D-SSAS) methodology to discover soil-salinity anomalies and step forward in revealing the irregular 3D structure of soil-anomaly salinity areas from limited sampling points. We first interpolate the sampling points to soil voxels using 3D EBK. A novel concept, the Local Anomaly Index (LAI), is developed to identify the candidate soil-salinity anomalies with the greatest amplitude of change. By performing differential calculations on the LAI sequence to determine the threshold, the anomaly candidates are selected. Finally, we adopt 3D DBSCAN to construct anomalous candidates as a 3D soil-salinity anomaly structure. The experimental results from the Yellow River Delta data set show that 3D-SSAS can effectively identify the 3D structure of salinity-anomaly areas, which are highly correlated with the geographical distribution mechanism of soil salinity. This study provides a novel method for soil science, which is conducive to further research on the complex variation process of soil salinity’s spatial distribution. Full article