Search Results (10,105)

The identification of the multifunctional combination of production–living–ecological spaces (PLES) in urban agglomerations, particularly in urban cores and peri–urban areas, is a critical issue in the urbanization process. This study, using the Hohhot–Baotou–Ordos–Yulin (HBOY) urban agglomeration, a key node in China’s “Two Horizontals and Three Verticals” urbanization strategy, proposes a hexagonal grid–based PLES quantification framework using POI data. A three–level POI classification system was developed, with functional element weights determined via the Analytic Hierarchy Process and public perception surveys. The framework quantifies PLES within hexagonal grids and analyzes its patterns and functional coupling mechanisms using spatial overlay, Average Nearest Neighbor Index (ANNI), kernel density analysis, and spatial autocorrelation analysis. The following results were obtained. (1) PLES classification accuracy reached 90.83%, confirming the reliability of the method. (2) The HBOY urban agglomeration exhibits a dominant production space (40.84%), balanced living and ecological spaces (29.37% and 29.36%, respectively), and a severe shortage of mixed spaces (0.43%). (3) Production and living spaces show significant clustering ( ≤ 0.581), mixed spaces follow ( = 0.660), and ecological spaces are relatively evenly distributed (= 0.870). (4) The spatial distribution patterns show that production and living spaces exhibit “core concentration with peripheral dispersion”, ecological spaces show “block concentration with point–like distribution”, and mixed spaces show “point–like dispersion”. (5) Production and living spaces exhibit strong spatial autocorrelation ( > 0.7) and the highest spatial correlation (= 0.692), while the spatial correlation with ecological spaces is weakest ( = 0.150). The proposed PLES identification framework, with its efficiency and dynamic updating potential, provides an innovative approach to urban spatial governance under the global Sustainable Development Goals. The findings offer integrated decision–making support for spatial diagnosis and functional regulation in the ecologically vulnerable areas of northwest China’s new urbanization. Full article

To cut a clod of soil containing the roots of trees in nurseries, a semi-circular vibrating blade digging machine with diameters up to 1.2 m is increasingly used. The heart of the machine is the mechanical oscillator that produces an excitation torque supplied to the blade together with the cutting torque of the soil. The advantage of the vibrating blade is a reduction in the cutting torque up to 70%. This advantage led to the present study of the extension to blades of even 1.8 m for the digging of very large trees. To build an oscillator suitable for all blade sizes (from 0.6 to 1.8 m), it was necessary to equip it with nonlinear (quadratic) springs, since with traditional linear springs, it would not be versatile. The design and simulation of its operation required the development of a new mathematical model. Therefore, an approximate solution of the differential equation of the forced vibration with quadratic springs and dry friction between the blade and soil was developed, aimed at calculating the maximum blade displacement and the phase lag. These quantities, together with the cutting time, had to satisfy certain values to ensure the maximum reduction in the cutting torque (−70%). After the construction of the oscillator, it was coupled with all the blades (0.6, 0.9, 1.2, and 1.8 m) for experimental tests. For all diameters, the oscillator was able to optimally vibrate the blades, preventing the springs from reaching the end of the stroke when cutting the soil. Measuring the maximum blade displacement compared with the calculated one provided a good accuracy of the mathematical modeling, resulting in a mean error of 5.6% and a maximum error of 7.2%. Full article

Spike structures appear in several phenomena, whereas spike trains (STs) are of particular importance, since they can carry temporal encoding of information. Regarding the STs of the biological neuron type, several models have already been proposed. While existing models effectively simulate spike generation, they fail to capture the dynamics of high-frequency spontaneous membrane potential fluctuations observed during relaxation intervals between consecutive spikes, dismissing them as random noise. This is eventually an important drawback because it has been shown that, in real data, these spontaneous fluctuations are not random noise. In this work, we suggest an ST production mechanism based on the appropriate coupling of two specific intermittent maps, which are nonlinear first-order difference equations. One of these maps presents small variation in low amplitude values and, at some point, bursts to high values, whereas the other presents the inverse behavior, i.e., from small variation in high values, bursts to low values. The suggested mechanism proves to be able to generate the above-mentioned spontaneous membrane fluctuations possessing the associated dynamical properties observed in real data. Moreover, it is shown to produce spikes that present spike threshold, sharp peak and the hyperpolarization phenomenon, which are key morphological characteristics of biological spikes. Furthermore, the inter-spike interval distribution is shown to be a power law, in agreement with published results for ST data produced by real biological neurons. The use of the suggested mechanism for the production of other types of STs, as well as possible applications, are discussed. Full article

The area law obeyed by the thermodynamic entropy of black holes is one of the fundamental results relating gravity to statistical mechanics. In this work, we provide a derivation of the area law for the quantum relative entropy of the Schwarzschild black hole for an arbitrary Schwarzschild radius. The quantum relative entropy between the metric of the manifold and the metric induced by the geometry and the matter field has been proposed in G. Bianconi as the action for entropic quantum gravity leading to modified Einstein equations. The quantum relative entropy generalizes Araki’s entropy and treats the metrics between zero-forms, one-forms, and two-forms as quantum operators. Although the Schwarzschild metric is not an exact solution of the modified Einstein equations of the entropic quantum gravity, it is an approximate solution valid in the low-coupling, small-curvature limit. Here, we show that the quantum relative entropy associated to the Schwarzschild metric obeys the area law for a large Schwarzschild radius. We provide a full statistical mechanics interpretation of the results. Full article

Ecosystem water use efficiency (WUE) is a key indicator of the coupling between carbon and water cycles. With the increasing frequency of extreme climate events, WUE may also show trends of extremization. Understanding the dominant drivers behind extreme WUE variations is crucial for assessing the impact of climate variability on WUE. We investigate the main drivers and regional sensitivity of extreme WUE variations across seven geographical regions in China. The results reveal that extreme WUE variations are collectively influenced by gross primary productivity (GPP) and evapotranspiration (ET) (43.72%). GPP controls extreme WUE variations in 36.00% of the areas, while ET controls 20.17%. Furthermore, as the climate shifts from arid to humid regions, the area where GPP dominates extreme WUE variations increases, while the area dominated by ET decreases, suggesting a relationship with precipitation. Ridge regression analysis shows that vapor pressure deficit (VPD) is the primary driver of interannual WUE variation in China, with an average relative contribution of 38.64% and an absolute contribution of 0.025 gC·m⁻²·mm⁻¹·a⁻¹. We studied the changes in WUE and its driving mechanisms during extreme disaster events, providing a perspective focused on extreme conditions. In the future, these results may help regulate the carbon–water cycle in different regions, such as by guiding vegetation planting and land use planning based on the spatial characteristics of the dominant factors influencing extreme WUE variations to improve vegetation WUE. Full article

Obesity is commonly associated with metabolic diseases including type 2 diabetes, hypertension, and dyslipidemia. Moreover, individuals with obesity are at increased risk of cardiovascular disease. However, a subgroup of individuals within the obese population presents without concurrent metabolic disorders. Even though this group has a stable metabolic status and does not exhibit overt metabolic disease, this status may be transient; these individuals may have subclinical metabolic derangements. To investigate the latter hypothesis, an analysis of the proteome signature was conducted. Plasma samples from 27 subjects with obesity but without an associated metabolic disorder (obesity only (OBO)) and 15 lean healthy control (LHC) subjects were examined. Fasting samples were subjected to Olink proteomics analysis targeting 184 proteins enriched in cardiometabolic and inflammation pathways. Our results distinctly delineated two groups with distinct plasma protein expression profiles. Specifically, a total of 24 proteins were differentially expressed in individuals with obesity compared to LHC. Among these, 13 proteins were downregulated, whereas 11 proteins were upregulated. The pathways that were upregulated in the OBO group were related to chemoattractant activity, growth factor activity, G protein-coupled receptor binding, chemokine activity, and cytokine activity, whereas the pathways that were downregulated include regulation of T cell differentiation, leukocyte differentiation, reproductive system development, inflammatory response, neutrophil, lymphocyte, monocyte and leukocyte chemotaxis, and neutrophil migration. The study identifies several pathways that are altered in individuals with obesity compared to healthy control subjects. These findings provide valuable insights into the underlying mechanisms, potentially paving the way for the identification of therapeutic targets aimed at improving metabolic health in individuals with obesity. Full article

Driven by the dual imperatives of global economic green transformation and the advancement of digital technologies, achieving synergistic enhancement through digitalization and greenization to promote sustainable development has become a focal point for both academia and practical fields. This study, utilizing a sample of Chinese A-share listed companies from 2010 to 2023, aims to explore the transformative potential of digital–green synergy (DGS) for enhancing enterprise sustainable development within the realm of production efficiency improvement. Employing a coupling coordination model based on the entropy-weighted TOPSIS method, the research measures the DGS levels of enterprises. Grounded in strategic synergy theory, the resource-based view, and dynamic capability theory, this study thoroughly investigates the direct impacts of DGS on corporate TFP, intermediary mechanisms, moderating effects, and heterogeneous roles. The research findings robustly demonstrate that DGS can significantly improve enterprise TFP through optimizing resource allocation, reducing cost stickiness, and enhancing operational efficiency, thereby facilitating the dynamic reorganization of production factors and the creation of sustainable value. Furthermore, external factors, such as financing constraints and environmental regulation, alongside internal organizational factors like executive characteristics, are shown to exert significant moderating effects on the effectiveness of DGS. In summary, this research not only highlights the crucial role of DGS in enhancing production efficiency as a driver for high-quality corporate development and the pursuit of sustainable goals but also provides important theoretical guidance for policymakers to incentivize digital and green transformation. It also offers practical insights for enterprise managers to strategically formulate synergistic development strategies, enhance economic benefits, and achieve long-term sustainable performance. Beyond these practical implications, this study further enriches the theoretical landscape by first extending strategic synergy theory to firm-level digital–green synergy in emerging markets; second by enhancing sustainability research by adopting a broader “environment-society” framework; methodologically innovating by developing a novel “goal-strategy-input-technology” synergy measurement framework; and finally, deepening the theoretical understanding of DGS-TFP relationships through mechanism and moderator exploration. Full article

Abandoned production and monitoring wells in depleted oil and gas fields can readily serve as primary leakage pathways for stored CO₂. The temperature, pressure conditions around the wellbore bottom, and CO₂ concentration influence the phase behavior of CO₂ during leakage. This study establishes a 3D wellbore–reservoir coupled model using CO₂ injection data from 1 December 2009, in the DAS area, eastern Cranfield oilfield, Mississippi, USA, to analyze the dynamic evolution of CO₂ leakage along wellbores. Simulations are conducted using the collaboration of ECO2M and ECO2N v2.0 modules. The study examines leakage regimes under varying distances from the injection well and different reservoir temperatures. The results indicate that CO₂ phase changes occur primarily in wells near the injection point or under high-pressure and high CO₂ saturation conditions, usually with a short leakage period due to ice formation at the wellhead. In areas with low CO₂ saturation, prolonged leakage periods lead to significant pressure drops at the bottom, as well as the temperature as a result of the Joule–Thomson effect. Lower reservoir temperatures facilitate smoother and more gradual leakage. These findings provide a theoretical foundation for ensuring the safe implementation of CCUS projects and offer insights into the mechanical explanation of CO₂ geyser phenomena. Full article

The frequent occurrence of disasters has brought significant challenges to increasingly complex urban systems. Resilient city planning and construction has emerged as a new paradigm for dealing with the growing risks. Infrastructure systems like transportation, lifelines, flood control, and drainage are essential to the operation of a city during disasters. It is necessary to measure how risks affect these systems’ resilience at different spatial scales. This paper develops an infrastructure risk and resilience evaluation index system in city and urban areas based on resilience characteristics. Then, a comprehensive infrastructure resilience evaluation is established based on the risk–resilience coupling mechanism. The overall characteristics of comprehensive infrastructure resilience are then identified. The resilience transmission level and the causes of resilience effects are analyzed based on the principle of resilience scale. Additionally, infrastructure resilience enhancement strategies under different risk scenarios are proposed. In the empirical study of Zhengzhou City, comprehensive infrastructure resilience shows significant clustering in the city area. It is high in the central city and low in the periphery. Specifically, it is relatively high in the southern and northwestern parts of the airport economy zone (AEZ) and low in the center. The leading driving factors in urban areas are risk factors like flood and drought, hazardous materials, infectious diseases, and epidemics, while resilience factors include transportation networks, sponge city construction, municipal pipe networks, and fire protection. This study proposes a “risk-resilience” coupling framework to evaluate and analyze multi-hazard risks and the multi-system resilience of urban infrastructure across multi-level spatial scales. It provides an empirical resilience evaluation framework and enhancement strategies, complementing existing individual dimensional risk or resilience studies. The findings could offer visualized spatial results to support the decision-making in Zhengzhou’s resilient city planning outline and infrastructure special planning and provide references for resilience assessment and planning in similar cities. Full article

Camouflaged Object Detection (COD) aims to identify objects that are intentionally concealed within their surroundings through appearance, texture, or pattern adaptations. Despite recent advances, extreme object–background similarity causes existing methods struggle with accurately capturing discriminative features and effectively modeling multiscale patterns while preserving fine details. To address these challenges, we propose Iterative Refinement Fusion Network (IRFNet), a novel framework that mimics human visual cognition through progressive feature enhancement and iterative optimization. Our approach incorporates the following: (1) a Hierarchical Feature Enhancement Module (HFEM) coupled with a dynamic channel-spatial attention mechanism, which enriches multiscale feature representations through bilateral and trilateral fusion pathways; and (2) a Context-guided Iterative Optimization Framework (CIOF) that combines transformer-based global context modeling with iterative refinement through dual-branch supervision. Extensive experiments on three challenging benchmark datasets (CAMO, COD10K, and NC4K) demonstrate that IRFNet consistently outperforms fourteen state-of-the-art methods, achieving improvements of 0.9–13.7% across key metrics. Comprehensive ablation studies validate the effectiveness of each proposed component and demonstrate how our iterative refinement strategy enables progressive improvement in detection accuracy. Full article

The Yidun island arc was formed in response to the Late Triassic westward subduction of the Ganzi–Litang oceanic plate, a branch of the Paleo-Tethys Ocean. The Zhongdian arc, located in the south of the Yidun island arc, has relatively large number of porphyry (skarn) type Cu–Mo ± Au polymetallic deposits, the largest of which is the Pulang Cu (–Mo–Au) deposit with proven Cu reserves of 5.11 Mt, Au reserves of 113 t, and 0.17 Mt of molybdenum. However, the relationship between mineralization and the potassic alteration zone, phyllic zone, and propylitic zone of the Pulang porphyry deposit is still controversial and needs further study. Titanite (CaTiSiO₅) is a common accessory mineral in acidic, intermediate, and alkaline igneous rocks. It is widely developed in various types of metamorphic rocks, hydrothermally altered rocks, and a few sedimentary rocks. It is a dominant Mo-bearing phase in igneous rocks and contains abundant rare earth elements and high-field-strength elements. As an effective geochronometer, thermobarometer, oxybarometer, and metallogenic potential indicator mineral, titanite is ideal to reveal the magmatic–hydrothermal evolution and the mechanism of metal enrichment and precipitation. In this paper, major and trace element contents of the titanite grains from different alteration zones were obtained using electron probe microanalysis (EPMA) and laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to define the changes in physicochemical conditions and the behavior of these elements during the process of hydrothermal alteration at Pulang. Titanite in the potassic alteration zone is usually shaped like an envelope. It occurs discretely or is enclosed by feldspar, with lower contents of CaO, Al, Sr, Zr and Hf; a low Nb/Ta ratio; high ∑REE + Y, U, Th, Ta, Nb, and Ga content; and high FeO/Al₂O₃ and LREE/HREE ratios. This is consistent with the characteristics of magmatic titanite from fresh quartz monzonite porphyry in Pulang and other porphyry Cu deposits. Titanite in the potassium silicate alteration zone has more negative Eu anomaly and a higher U content and Th/U ratio, indicating that the oxygen fugacity decreased during the transformation to phyllic alteration and propylitic alteration in Pulang. High oxygen fugacity is favorable for the enrichment of copper, gold, and other metallogenic elements. Therefore, the enrichment of copper is more closely related to the potassium silicate alteration. The molybdenum content of titanite in the potassium silicate alteration zone is 10²–10⁴ times that of the phyllic alteration zone and propylitic alteration zone, while the copper content is indistinctive, indicating that molybdenum was dissolved into the fluid or deposited in the form of sulfide before the medium- to low-temperature hydrothermal alteration, which may lead to the further separation and deposition of copper and molybdenum. Full article

Equine follicle-stimulating hormone receptor (eFSHR) contains four extracellular N-linked glycosylation sites, which play important roles in agonist-induced signal transduction. Glycosylation regulates G protein-coupled receptor mechanisms by influencing folding, ligand binding, signaling, trafficking, and internalization. Here, we examined whether the glycosylated sites in eFSHR are necessary for cyclic adenosine monophosphate (cAMP) signal transduction and the phosphate extracellular signal-regulated kinase 1/2 (pERK1/2) response. We constructed mutants (N191Q, N199Q, N268Q, and N293Q) of the four N-linked glycosylation sites in eFSHR using site-directed mutagenesis. In wild-type (wt) eFSHR, the cAMP response gradually increased dose-dependently, displaying a strong response at the EC₅₀ and Rmax. Two mutants (N191Q and N199Q) considerably decreased the cAMP response. Both EC₅₀ values were approximately 0.46- and 0.44-fold compared to that of the eFSHR-wt, whereas Rmax levels were 0.29- and 0.45-fold compared to eFSHR-wt because of high-ligand treatment. Specifically, the EC₅₀ and Rmax values in the N268Q mutant were increased 1.23- and 1.46-fold, respectively, by eFSHR-wt. pERK1/2 activity in eFSHR-wt cells was rapid, peaked within 5 min, consistently sustained until 15 min, and then sharply decreased. pERK1/2 activity in the N191Q mutant showed a pattern similar to that of the wild type, despite impaired cAMP responsiveness. The N199Q mutant showed low pERK1/2 activity at 5 and 15 min. Interestingly, pERK1/2 activity in the N268Q and N298Q mutants was similar to that of eFSHR-wt at 5 min, but neither mutant showed any signaling at 15 min, despite displaying high cAMP responsiveness. Overall, eFSHR N-linked glycosylation sites can signal to pERK1/2 via PKA and the other signals, dependent on G protein coupling and β-arrestin-dependent recruitment. Our results provide strong evidence for a new paradigm in which cAMP signaling is not activated, yet pERK1/2 cascade remains strongly induced. Full article

Isolation piles are critical for mitigating excavation-induced tunnel displacements, yet two unresolved challenges persist in tunnel engineering: (1) controversies regarding the influence of key parameters (e.g., pile head depth, pile length, and pile-to-pit distance) on their performance, and (2) insufficient understanding of the effects on both horizontal and vertical displacement control of tunnel. These challenges stem from the current research focus on isolated displacement components or simplified scenarios, which fails to address the complex interactions between key parameters and the deformation mechanisms. To address these gaps, this study proposes a hybrid validation framework integrating a three-dimensional finite element model (HS-Small constitutive model) with field monitoring data. A concept of “control efficiency” is introduced to quantify the effectiveness of isolation piles, complemented by a parametric sensitivity analysis framework. By synergizing the mirror image method and statistical theory, the research reveals a dual-path control mechanism involving displacement blocking and tunnel geometric reconfiguration. The findings advance the state of the art by resolving controversies over critical parameters and establishing a unified theoretical framework for coupled displacement control, providing actionable insights for optimizing isolation pile design in engineering practice. Full article

We herein demonstrate the utility of gelatin methacryloyl (GelMA)/poly(ethylene glycol) diacrylate (PEGDA)–cerium oxide (CeO₂) hydrogel inks for manufacturing hydrogel scaffolds with antimicrobial efficacy by vat photopolymerization. For uniform blending with GelMA/PEGDA hydrogels, CeO₂ nanoparticles with a round shape were synthesized by the precipitation method coupled with calculation at 600 °C. In addition, they had highly crystalline phases and the desired chemical structures (oxidation states of Ce³⁺ and Ce⁴⁺) required for outstanding antimicrobial efficacy. A range of GelMA/PEGDA-CeO₂ hydrogel scaffolds with different CeO₂ contents (0% w/v, 0.1% w/v, 0.5% w/v, 1% w/v, and 5% w/v with respect to distilled water content) were manufactured. The photopolymerization behavior, mechanical properties, and biological properties (swelling and biodegradation behaviors) of hydrogel scaffolds were characterized to optimize the CeO₂ content. GelMA/PEGDA-CeO₂ hydrogel scaffolds produced with the highest CeO₂ content (5% w/v) showed reasonable mechanical properties (compressive strength = 0.56 ± 0.09 MPa and compressive modulus = 0.19 ± 0.03 MPa), a high swelling ratio (1063.3 ± 10.9%), and the desired biodegradation rate (remaining weight after 28 days = 39.6 ± 2.3%). Furthermore, they showed outstanding antimicrobial efficacy (the number of colony-forming units = 76 ± 44.6 (×10³)). In addition, macroporous GelMA/PEGDA-CeO₂ hydrogel scaffolds with tightly controlled porous structures could be manufactured by vat photopolymerization. Full article

The conflict between socio-economic development and ecological protection is prominent, as the practice framework for territorial spatial planning and the rational layout and function coordination of production–life–ecological (PLE) spaces are crucial for achieving regional sustainable development. However, the dynamic evolution of PLE structure and function, as well as the driving mechanisms for the sustainable development of PLE, are still understudied. Therefore, this study takes the Ji-shaped bend Energy-Rich Area (ERA) of the Yellow River basin as a case study, classifies the PLE spaces based on land use data, and develops a PLE function indicator system consistent with the regional characteristics of an ERA. This paper characterizes PLE from both structure and function perspectives and explores the coupling and coordinated degree (CCD) among PLE functions and their driving factors. The results show the following: (1) From 2000 to 2020, the area of living space increased by 35.86%, while areas of production and ecological space decreased by 2.10% and 0.08%, respectively. (2) The PLE function increased, with the production function performing better in the typical ERA and the ecological function performing well in the atypical ERA. (3) From 2000 to 2020, the CCD of the PLE function increased by 24.85%, with atypical ERA demonstrating a higher CCD than typical ERA. (4) Factors in production function had the most significant impact on the CCD of PLE function, followed by living drivers. These results provide valuable insights and guidance for regulating PLE and promoting sustainable development. Full article