Search Results (12,590)

In large-scale dam construction, the efficiency of concrete transport operations is fundamentally governed by the coordination between horizontal hauling and vertical hoisting capacities. Traditional experience-based scheduling approaches often fail to capture the stochastic, cyclic, and resource-coupled nature of these transport systems. This study developed a closed queuing network-based stochastic simulation framework to model dam concrete transportation as a finite-population cyclic service system. The process was abstracted into sequential service stages with stochastic service times, and a structured state-space representation combined with time-step simulation was constructed to describe dynamic resource occupation and task transitions under varying truck and cable crane configurations. Application to a real large-scale dam project revealed a characteristic multi-stage performance evolution pattern governed by capacity matching mechanisms. As the truck fleet size increased, system performance transitioned from a transport-limited regime to a capacity-coordination regime and ultimately to a hoisting-saturated regime in which further fleet expansion yielded diminishing returns. Sensitivity analysis demonstrated that hoisting capacity imposed an upper bound on system throughput, while adaptive fleet reconfiguration could restore operational equilibrium under constrained equipment availability. The results indicated that dam concrete transport should be treated as a dynamic capacity regulation problem rather than a static allocation task. The proposed framework provides an interpretable and quantitative decision-support tool for equipment configuration, bottleneck identification, and adaptive scheduling in large-scale hydraulic infrastructure projects. Full article

Visual–inertial odometry (VIO) often struggles with illumination variations, sparse visual features, and inertial drift in complex indoor settings, leading to scale uncertainties and accumulated errors. To address these issues, this paper proposes a new UWB–VIO initialization method combined with an enhanced Robust error-state Kalman filter (Robust ESKF) fusion technique for mobile robot localization. During initialization, common problems include scale drift and heading inconsistency. To solve these, a direction-consistent constrained initialization model is developed. By jointly optimizing the scale factor and yaw angle, this model ensures consistent alignment between the visual–inertial and ultra-wideband (UWB) coordinate frames. This approach removes the need for external calibration and independent coordinate transformation, which are typically required by traditional methods. In the fusion process, an improved residual-weighted robust filtering mechanism is employed to minimize the impact of abnormal UWB ranging data and noise interference. This mechanism adaptively suppresses outliers caused by UWB multipath reflections and non-line-of-sight (NLOS) propagation, thereby reducing VIO drift and improving the overall robustness and stability of the localization system. Experiments conducted in narrow-corridor environments, where both UWB and visual sensors are affected by interference, demonstrate that the proposed method significantly reduces trajectory drift and attitude jumps, resulting in better positioning accuracy and trajectory continuity. Compared to conventional UWB–VIO fusion algorithms, the proposed method enhances average localization accuracy by over 50% and maintains stable estimation even in severe multipath interference conditions, demonstrating high precision and strong robustness. Full article

Female reproductive aging is associated with a progressive decline in oocyte competence and reduced success in assisted reproductive technologies. While chromosomal abnormalities, mitochondrial dysfunction, and DNA damage have been extensively studied, these mechanisms do not fully explain developmental arrest in chromosomally euploid embryos or the variability in embryo competence. Human oocytes enter a transcriptionally quiescent state during meiotic maturation and rely almost entirely on the regulated translation of stored maternal messenger RNAs to support fertilization and early embryonic development until zygotic genome activation. In this context, translational fidelity becomes a critical determinant of proteome integrity and cellular function. Age-related alterations affecting ribosomal RNA integrity, transfer RNA modification, aminoacylation accuracy, and translational regulatory networks may impair the precision, timing, and coordination of protein synthesis. These defects can disrupt essential processes such as spindle assembly, cytoskeletal organization, and early cleavage dynamics, ultimately compromising embryo viability despite chromosomal normality. In addition, the follicular microenvironment, including redox balance, metabolic support, and signaling pathways, plays a crucial upstream role in maintaining translational integrity. This review integrates mechanistic evidence from molecular, cellular, and developmental studies to propose that progressive decline in translational fidelity represents a fundamental and previously underrecognized driver of reproductive aging. Understanding translational control as a central regulator of oocyte competence may provide new insights into unexplained IVF failure and support the development of novel biomarkers and therapeutic strategies aimed at preserving reproductive potential. Full article

Therapeutic resistance remains a major obstacle to durable cancer control, with functional reprogramming of the DNA damage response (DDR) network playing a central role. The poly(ADP-ribose) polymerase (PARP) family, particularly PARP1 and PARP2, is crucial for maintaining genomic integrity. By exploiting synthetic lethality, PARP inhibitors (PARPi) selectively target tumors with homologous recombination deficiency (HRD) and are integral to precision therapy in ovarian, breast, and prostate cancers. However, over 40% of patients with BRCA1/2 alterations develop resistance, and patient eligibility remains limited by the low prevalence of HRD mutations. In this review, we summarize the molecular mechanisms of PARPi action, resistance pathways, and emerging combination strategies. PARPi resistance arises through HR restoration (e.g., BRCA1/2 reversion mutations), replication fork protection, RAD51-mediated strand invasion, and metabolic reprogramming. Combination therapies, integrating PARPi with histone deacetylase inhibitors, cyclin-dependent kinase inhibitors, immune checkpoint blockade, or radiation, enhance efficacy by converging on DNA repair pathways and the tumor immune microenvironment. A deeper understanding of coordinated DDR regulation and rationally designed combination regimens will be essential for overcoming PARPi resistance and advancing adaptive, precision-based therapeutic strategies. Full article

The development of lightweight materials with high and reversible hydrogen storage capacity remains a key materials design challenge. Here, we investigate pristine and Ti-decorated C₃B₂ quantum dots using DFT, DLPNO-CCSD(T), and statistical thermodynamics. Pristine C₃B₂ strongly chemisorbs H₂ (E_ads = −0.93 eV), while Ti decoration moderates the interaction to a reversible regime (E_ads = −0.39 eV) through a balanced Kubas-type mechanism. Structural analysis shows that the Ti center becomes saturated at approximately five H₂ molecules via Kubas-type coordination, while additional hydrogen molecules are stabilized in the vicinity of the Ti–C₃B₂ framework through cooperative interactions. Sequential adsorption shows that up to 20 H₂ molecules can be stored per Ti–C₃B₂ unit. Thermodynamic and kinetic analyses reveal moderate desorption temperatures (≈322–366 K) and ultrafast release times, ensuring efficient cycling. Under realistic operating conditions (30/3 atm; 298/373 K), Ti–C₃B₂ achieves a reversible capacity of 20.10 wt%, surpassing DOE targets. These results highlight Ti-decorated C₃B₂ quantum dots as a promising, design-tunable platform for next-generation solid-state hydrogen storage. Full article

The integration of intangible cultural heritage (ICH) and tourism development (TD) is regarded as a crucial national strategy for China’s sustainable development, as their synergistic relationship is considered pivotal for regional progress. A coupling coordination evaluation system was constructed. Kernel density estimation, entropy method, coupling coordination degree (CCD) and relative development degree (RDD) models, and a tobit model were employed to examine the spatiotemporal characteristics and influencing factors of ICH–TD integration in Sichuan Province. Key findings are as follows: (1) Sichuan is endowed with abundant ICH resources characterized by high heritage value and diverse typologies. However, the distribution is skewed toward traditional skills, exhibiting notable regional disparities. ICH demonstrates a “single-core, belt-shaped and multi-cluster” pattern, which is centered on Chengdu, extends along a north–south high-density belt, and forms several secondary high-density clusters. (2) Temporally, the CCD demonstrates a sustained upward trend, whereas the RDD transitions from ICH-lagged to TD-lagged. Spatially, the number of high coordinated cities increases annually, expanding radially from regional centers, while central-eastern regions consistently outperform the west. (3) Regarding influencing factors, comprehensive economic strength, distribution of industrial structure, overall level of urbanization, and transportation accessibility exert significant positive effects on the CCD, with comprehensive economic strength demonstrating the strongest influence. This study contributes to the theoretical understanding of ICH–TD synergy and provides policy-relevant guidance for integration. Full article

Artificial intelligence (AI) has become a strategic resource for enhancing supply chain resilience in environments characterized by growing uncertainty and complexity. Building on the resource-based view (RBV) and organizational information processing theory (OIPT), this study examines how AI assimilation as a firm-level strategic capability improves supply–demand visibility and strengthens supply chain risk management (SCRM). Using survey data collected from 129 manufacturing firms in China, the proposed research framework is tested through structural equation modeling. The results show that AI assimilation significantly enhances both supply–demand visibility and SCRM, with visibility playing a partial mediating role in translating AI-enabled capabilities into more effective risk control. These findings indicate that AI contributes to resilience not merely through technological deployment but through its integration into organizational processes that support information processing and coordination. From a managerial perspective, the study suggests that firms should approach AI as an ongoing strategic capability development process rather than a one-time technological investment. By embedding AI into core supply chain functions such as production planning, inventory management, and demand forecasting, firms can improve visibility, anticipate disruptions, and shift toward more proactive and resilient risk management practices. This study advances the literature by integrating RBV and OIPT to explain the strategic mechanisms through which AI assimilation enhances visibility in SCRM, providing empirical evidence from a manufacturing context. Full article

Against the backdrop of coordinated advancement in new urbanization and rural revitalization strategies, the integration of urban and rural areas serves as a core approach to dismantling the urban–rural dichotomy and driving high-quality regional development. The enabling effects of its policy implementation on regional sustainable development have garnered significant attention. As pivotal conduits where urban and rural elements converge, peri-urban fringe zones have emerged as the primary arena for policy implementation and impact realization. Using panel data from 268 prefecture-level and above cities in China from 2015 to 2024 as the sample, this study treats the establishment of urban–rural integration pilot zones as a quasi-natural experiment. Employing a multi-period Difference-in-Differences model, instrumental variables method, and spatial econometric model, it systematically investigates the impact effects, operational mechanisms, heterogeneous characteristics, and spatial spillover effects of urban–rural integration policies on regional sustainable development. Findings reveal that urban–rural integration policies significantly promote regional sustainable development. This conclusion remains robust after endogeneity treatment and stability tests, with policies demonstrating stronger enabling effects on ecological sustainability than on economic and social sustainability, forming a development pattern characterized by “ecological priority and multidimensional coordination”. Policies achieve synergistic enhancement of regional economic, ecological, and social sustainability through three pathways: optimizing urban–rural factor allocation, establishing ecological co-governance systems, and advancing equitable public services. Policy effects exhibit significant heterogeneity: the stronger the urban baseline conditions, the more pronounced the policy’s enabling effect, while excessive population concentration exerts a marginal negative impact on ecological sustainability. Urban–rural integration policies generate a significant positive spatial spillover effect, accounting for 38.9% of the total effect. This spillover gradually diminishes with increasing distance within a 120 km radius, with geographic distance and administrative barriers serving as core constraints. This study provides empirical insights and practical pathways for optimizing urban–rural integration policy design and advancing regional sustainable development. Full article

Against the backdrop of a gradual shift in the focus of cultural heritage (CH) conservation and utilization toward the integrated system formed by CH and its surrounding environment as well as regional systems, research on the coordinated protection of nature and culture to promote regional high-quality development has become a new trend. However, systematic summaries of the spatial–temporal distribution of CH in cross-regional typical geomorphic units at the river basin scale and their correlation with the natural environment remain insufficient. This study takes 387 Cultural Relics Protection Units in the Three Gorges of the Yangtze River (the Three Gorges region) as the research objects, utilizing GIS spatial analysis technology to examine the impact of the natural environment on CH across different periods and types. The theory of time-depth is introduced to reveal the layering mechanisms and underlying cultural logics. Coupled with the Minimum Cumulative Resistance (MCR) model, this study constructs a cultural corridor network and proposes spatial planning strategies. The findings are as follows: (1) The absolute core area for the distribution of CH across all periods remains the gentle slope zone near the river, characterized by elevations below 500 m, slopes within 25°, and distances from water systems within 1 km. However, the adaptive scope exhibits a diachronic evolution from core accumulation to peripheral expansion. (2) Different types of CH exhibited distinct natural adaptation strategies and vertical accumulation. Settlement Sites in the Before Qin Dynasty Period formed the foundational layer of survival rationality, while Ordinary Tombs in the Qin–Yuan Dynasty Period reinforced sedentism. Ancient Architecture in the Ming–Qing Dynasty Period underwent a transformation from “adapting to nature” to “reconstructing nature” as a product of environmental construction. Modern and Contemporary Significant Historical Sites and Representative Buildings in the After Qing Dynasty Period are characterized by a ruptured insertion on steep slopes, inscribing revolutionary memory onto space. The main stream of the Yangtze River serves as the core area of continuous deposition, while the extremely steep slopes form a distinctive stratigraphic accumulation of precipitous terrain. (3) Based on these distribution patterns, the study further proposes a spatial framework for CH called “One Corridor, Three Wings.” This framework uses the main stream of the Yangtze River as the spatial–temporal axis, linking the four core overlapping nodes of Fengjie, Wushan, Badong, and Xiling, supplemented by three secondary cultural clusters of the red heritage sites in southern Badong, the ancient town along the Daning River in Wushan, and the fortress sites in the Xiling–Yiling area. This research not only reveals the evolutionary path of CH in the Three Gorges region, but also provides a scientific basis for the systematic conservation and differentiated utilization of regional CH. Furthermore, it serves as a planning foundation and strategic reference for planning the Yangtze River National Cultural Park, as well as for the integrated preservation and utilization of river basin CH and linear CH with the aim of coordinated natural and cultural conservation. Full article

The deep integration of the digital and real economies is a critical force reshaping the global economic landscape. At the same time, new high-quality productive forces that are distinguished by their high level of efficiency, quality, and technology mark a new phase in productivity evolution. Understanding the spatial interplay between these two phenomena is crucial for coordinated development. This study empirically investigates their bidirectional relationship and spatial spillover effects. With panel data from 30 provinces in China (2011–2022), we use the Generalized Spatial Three-Stage Least Squares (GS3SLS) approach to estimate a spatial simultaneous equations model. The results reveal a significant bidirectional positive correlation, with the promotional effect of digital–real integration on new quality productive forces being slightly stronger. However, we also identify significantly negative spatial spillover effects between them. These findings underscore the necessity of strengthening their interactive development, fostering interregional cooperation, and optimizing source allocation to alleviate adverse spillovers. This study systematically examines their spatial dynamics and proposes policy recommendations to foster the coordinated advancement of both digital–real integration and New Quality Productive Forces. Full article

The rapid proliferation of electric vehicles (EVs) has introduced significant challenges to the efficient operation of hydrogen-containing integrated energy systems (H-IESs). To cope with these challenges, this paper develops a bi-level optimal scheduling strategy for H-IESs that simultaneously incorporates a ladder-type carbon emission trading mechanism, demand response, and the operational characteristics of EVs. A demand response model is formulated by considering the coupling characteristics of electric and thermal loads. Price-based incentive signals are further designed to coordinate the interactions between the H-IES operator and EV users, enabling flexible resources to actively participate in system scheduling. In the proposed bi-level framework, the upper-level problem aims to minimize the total operating cost of the H-IES, while the lower-level problem seeks to reduce the charging cost of EV users. The resulting bi-level optimization problem is reformulated and solved using the Karush–Kuhn–Tucker (KKT) conditions. Case study results demonstrate that, compared with the single-level benchmark, the proposed bi-level strategy reduces the total operating cost by 34.79% and lowers the EV charging cost by 4.50%. Full article

The coupling of electricity, heat, and hydrogen subsystems together with carbon capture technologies introduces complex operational interactions in modern multi-energy systems. Existing game-based scheduling studies mainly focus on electricity–heat or electricity–heat–gas coupling, often neglecting hydrogen blending, carbon capture integration, and strategic coordination among heterogeneous stakeholders. To address these gaps, this study develops a game-theoretic hierarchical optimization framework for electricity–heat–hydrogen integrated energy systems incorporating carbon capture. Compared with conventional multi-energy game models, the proposed framework integrates hydrogen blending and carbon capture into a unified electricity–heat–hydrogen–carbon coupling structure, enabling coordinated low-carbon operation. A Stackelberg leader–follower structure is adopted, where the upper-level operator determines electricity and heat prices, and lower-level participants optimize generation dispatch and demand response accordingly. The bi-level model is transformed into an equivalent single-level formulation using Karush–Kuhn–Tucker conditions and solved through a hybrid particle swarm optimization–mathematical programming approach. Simulation results based on an extended IEEE 30-bus system demonstrate improved coordination, enhanced scheduling flexibility, and reduced operating costs and carbon emissions. Compared with centralized optimization, the proposed framework enables the integrated energy operator and energy supplier to achieve revenues of 3.18 × 10⁵ CNY and 3.95 × 10⁵ CNY, respectively, while reducing the load aggregator’s cost by 41.71%, confirming its effectiveness for coordinated low-carbon IES scheduling. Full article

Enhancing the carrying capacity of the ecological environment serves as a pivotal pathway to achieving sustainable development and also constitutes a concrete response to the UN SDGs. Based on a provincial panel dataset covering 30 Chinese provinces spanning 2011–2023, the present work examines how digital finance shapes EECC and explores the corresponding transmission mechanisms. Findings from the empirical analysis confirm that digital finance exerts a significant positive effect in boosting ecological environmental carrying capacity. Heterogeneity tests further show that this catalytic influence is most salient in eastern China, while it lacks statistical significance or even turns negative in the central and western areas. Meanwhile, the catalytic function of digital finance becomes more distinct in highly urbanized areas. Mechanism analysis verifies that digital finance assumes a partial mediating function by cutting down energy consumption intensity and boosting human capital accumulation. Further analysis reveals that as digital finance matures, the above impact exhibits increasing marginal returns. Our spatial spillover assessment further indicates that digital finance contributes to stronger EECC within host provinces, while also facilitating coordinated improvements in this key indicator across neighboring jurisdictions. Accordingly, we propose that economies speed up the building of digital-related infrastructure, expand the outreach of digital finance, and properly steer the orderly movement of population, thus facilitating the eco-friendly sustainable advancement of the natural environment. Full article

Based on panel data from 14 prefectures in Xinjiang from 2004 to 2022, this study employs the Super-SBM model and panel threshold regression to assess how urbanization and industrial growth influence industrial water resource utilization efficiency (IWRUE). Xinjiang exhibits a distinct “high-north–low-south” spatial pattern: Urumqi and other northern regions show continuous improvement and Tacheng maintains long-term superiority, while southern areas such as Kizilsu and Hotan remain persistently low. Although IWRUE increases overall, regional trajectories diverge considerably. Two significant thresholds are identified—industrial output value and urbanization rate. Below these thresholds, water consumption strongly suppresses IWRUE, industrial employment exerts a negative effect, and investment plays a positive role. Once the thresholds are exceeded, the negative effect of water consumption weakens, industrial employment turns positive, and investment becomes insignificant. Policy implications suggest that regions below the thresholds should strengthen investment in water-saving technologies and productive capital, whereas regions beyond the thresholds should focus on enhancing labor quality, promoting green innovation and improving refined management to stabilize IWRUE and foster coordinated regional development. Full article

This study develops and optimizes a hybrid plant that couples a recompression sCO₂ Brayton cycle to a central-tower particle receiver with a bottoming Organic Rankine Cycle (ORC), including environmental and exergy balances. The two scenarios revealed Pareto points that raised the exergy efficiency to 0.65 in winter and reduced the fuel flow to 15 kg/s. Scenario number two achieves an overall thermal efficiency of 0.50 with total daily emissions of 2520 t CO₂ and 2850 kg NO_x, enabling nearly constant net power. Exergy destruction is concentrated in the high-temperature recuperator (HTR) and ORC turbines (27% each) and the ORC condenser (25%). Compared to a non-optimized baseline, the best solutions increased the ORC and Brayton efficiencies by 6.8–12.66% and 33.4–33.5%, respectively; cut gas-turbine power by 34% and ORC power to 10%; and lowered daily CO₂ and NO_x emissions by 52%. The gains stem from the coordinated adjustments of key levers: lower gas-turbine inlet temperature (about 10%), reduced Brayton mass flow (23%), and tuned ORC turbine inlet pressure. Full article