Search Results (8,463)

The thermal coal supply chain serves as core infrastructure for ensuring the safe and stable supply of electricity in China. Effective risk management and control of this supply chain are therefore critical to national energy security and socio-economic development. However, the thermal coal supply chain involves multiple complex risk dimensions, including cross-regional multi-entity coordination, a complex network structure, and a dynamic policy environment. Traditional risk analysis methods often fall short in depicting the concurrent events and dynamic propagation characteristics inherent to such a system. This necessitates systematically investigating the thermal coal supply chain within the Coal–Electricity Joint Venture (CEJV) operational framework, which primarily involves equity-based consolidation and long-term contractual coordination between coal producers and power generators, to comprehensively analyze its critical risk factors and transmission mechanisms. Initially, based on the integration of coal-fired power joint operation policy evolution and industry characteristics, 28 risk factors were identified across three dimensions: internal enterprise, external environment, and overall structure. These encompassed production fluctuation risks, thermal coal transport process risks, and insufficient supply chain flexibility. A dynamic behavior model for the thermal coal supply chain was constructed by analyzing the causal relationships among these risk factors, based on the operational processes of each link. Utilizing Petri net simulation technology enables a quantitative analysis of supply chain risks, facilitating the identification of bottleneck links and potential risk points. Through model simulation, 18 key risk factors were determined, providing a theoretical basis for optimizing supply chain resilience within CEJV enterprises. The limitations of traditional methods in dynamic process modeling and industrial applicability were addressed through a Petri net-based methodology, thereby establishing a novel analytical paradigm for risk management in complex energy supply chains. Full article

The shallow-water delta-front reservoir in Member II of the Oligocene Dongying Formation (Ed2), located in an oilfield within the Bohai Bay Basin, is a large-scale composite sedimentary system dominated by subaqueous distributary channels and mouth bars. Within this system, reservoir sand bodies exhibit significant thickness, complex internal architecture, poor injection–production correspondence during development, and an ambiguous understanding of remaining oil distribution. To enhance late-stage development efficiency, it is imperative to deepen the understanding of the genesis and evolution of the subaqueous distributary channel–mouth bar system, analyze the internal reservoir architecture, and clarify sand body connectivity relationships. Based on sedimentary physical modeling experiments, integrated with core, well logging, and seismic data, this study systematically reveals the architectural characteristics and spatial stacking patterns of the mouth bar reservoirs using Miall’s architectural element analysis method. The results indicate that the study area is dominated by sand-rich, shallow-water delta front deposits, which display a predominantly coarsening-upward character. The main reservoir units are mouth bar sand bodies (accounting for 30%), with a vertical stacking thickness ranging from 3 to 20 m, and they exhibit lobate distribution patterns in plan view. Sedimentary physical modeling reveals the formation mechanism and stacking patterns of these sand-rich, thick sand bodies. Upon entering the lake, the main distributary channel unloads its sediment, forming accretionary bodies. The main channel then bifurcates, and a new main channel forms in the subsequent unit, which transports sediment away and initiates a new phase of deposition. Multi-phase deposition ultimately builds large-scale lobate complexes composed of channel–mouth bar assemblages. These complexes exhibit internal architectural styles, including channel–channel splicing, channel–bar splicing, and bar–bar splicing. Reservoir architecture analysis demonstrates that an individual distributary channel governs the formation of an individual lobe, whereas multiple distributary channels control the development of composite lobes. These lobes are laterally spliced and vertically superimposed, exhibiting a multi-phase progradational stacking pattern. Dynamic production data analysis validates the reliability of this reservoir architecture classification. This research elucidates the genetic mechanisms of thick sand bodies in delta fronts and establishes a region-specific reservoir architecture model. This study clarifies the spatial distribution of mudstone interlayers and preferential flow pathways within the composite sand bodies. It provides a geological basis for optimizing injection–production strategies and targeting residual oil during the ultra-high water-cut stage. The findings offer critical guidance for the efficient development of shallow-water delta front reservoirs. Full article

In recent decades, the urban population of Ecuador has grown, increasing the need for wastewater sanitation in cities. Wastewater treatment in this country generates sewage sludge (SS), which is mainly deposited on land near wastewater treatment plants or in sanitary landfills, generating significant environmental impacts. In view of this, composting or vermicomposting of SS can be suitable treatments for this waste, and the final materials obtained can be used as organic amendments. The objective of this study was to compare the agronomic and economic aspects of composting and vermicomposting using the same SS mixtures with different plant residues. For this purpose, the evolution of various physicochemical and biological parameters of both processes, the quality of the materials obtained, and the costs of their production were evaluated. The results revealed that all the amendments presented characteristics suitable for safe agricultural use. The vermicomposts had significantly lower levels of salts and higher levels of most macro- and micronutrients than the composts, thus increasing their economic value. However, the average production cost of composts was lower than that of vermicomposts, with faster stabilization of organic matter. All of this indicates that both techniques could be suitable for treating SS, but in order to choose the most appropriate technique for the study area, further studies with other waste mixtures and agricultural validation of the composts and vermicomposts obtained, as well as control of possible contaminants, would be required. Full article

The synergistic effects of climate change and human activities have profoundly influenced the spatiotemporal dynamics of vegetation in arid and semi-arid regions. In this study, MODIS NDVI data and an integrated methodological approach, including trend analysis, partial correlation, residual regression, and geographical detector modeling, were used to analyze the variations in NDVI in Gansu Province from 2000 to 2022. The results showed the following: (1) The growing-season NDVI in Gansu Province exhibited a significant increasing trend overall (0.0029 per year, p < 0.05). (2) Both the NDVI values and their increasing rates presented a spatial pattern of “higher in the southeast and lower in the northwest”; although low vegetation coverage dominated the entire province, 49.47% of the area showed an extremely significant increasing trend in NDVI (p < 0.01). (3) In the future, the area ratio of regions with improved NDVI to those with degraded NDVI in Gansu Province will be approximately 45.5%:54.5%. (4) The contribution rate of human activities to the spatiotemporal variations in NDVI was higher than that of climate change; however, the synergistic effect of the two factors was greater than their individual effects. (5) Precipitation and solar radiation were the two primary climatic factors affecting NDVI variations in Gansu Province, while human activities played a regulatory role in mediating climate–vegetation interactions. Therefore, we suggest implementing more proactive ecological management and restoration measures to mitigate the impacts of future climate change, particularly in regions where NDVI may degrade in the future. Full article

With the growing demand for refined security operations, Security Orchestration, Automation, and Response (SOAR) technologies have undergone rapid advancement. By leveraging intelligent orchestration capabilities in conjunction with core playbooks, SOAR facilitates both automated and semi-automated responses to security incidents. Nevertheless, the continuous evolution of network-attack techniques and the explosive growth of security alerts have rendered traditional static rule-based playbook matching and recommendation approaches increasingly inadequate in addressing the high frequency of alerts and the emergence of novel attack patterns. In this study, we propose an intelligent playbook recommendation algorithm for SOAR, developed under the paradigm of dynamic interest modeling. Specifically, the algorithm integrates a Transformer encoder, which captures long-term dynamic characteristics of alert signals in real time, with an LSTM network designed to extract short-term behavioral patterns. This hybrid architecture not only enables accurate playbook recommendations in high-volume alert scenarios, but also supports the reconstruction and optimization of playbooks, thereby offering valuable guidance for the mitigation of emerging threats. Experimental evaluations demonstrate that the proposed dynamic interest modeling-based algorithm exhibits high feasibility. It achieves improved performance in terms of both recommendation accuracy and efficiency, thus providing a robust technical foundation for enhancing the effectiveness of network security incident response and offering practical support for real-world security operations. Full article

Within the context of global climate change, the hydrological and sediment load dynamics in the Huai River Basin are expected to continue evolving due to intensified human activities and environmental changes. Effective river management requires a clear understanding of the magnitude, causes, and characteristics of these changes, coupled with insight into the dynamic response processes of the river channel. This study applied a suite of statistical methods, including the Mann–Kendall test, Sen’s slope estimator, Pettitt’s test, double mass curve, and morphological analysis, to examine trends in streamflow and sediment load at two hydrological stations in the mid-Huai River from 1982 to 2016, and to assess channel evolution between Wujiadu and Xiaoliuxiang. The results indicate that: (1) both hydrological stations exhibited no significant decrease in annual streamflow, but a significant reduction in sediment load, with a change point detected in 1991 at Wujiadu Station; (2) compared to 1982–1990, the mean streamflow and sediment load decreased by 23% and 50% during 1991–2016, with a significant shift in the streamflow-sediment relationship; (3) while temperature and evapotranspiration increased significantly, precipitation remained relatively stable, indicating that climate change had a minor effect on hydrological elements, and sediment load reduction was primarily driven by large-scale ecological restoration and engineering activities; and (4) differential channel adjustments were observed in response to reduced sediment supply and human activities, modulated by local boundary conditions. Erosion occurred in the WJD section, resulting in a transformation from a U-shape to a V-shape cross-section, whereas the XLX section remained stable with a local adverse gradient. This study reveals the complex mechanisms of hydro-sedimentary and channel evolution under human dominance, offering scientific support for the sustainable management of the Huai River basin and similar regulated rivers. Full article

From the perspective of “dynamic supply–demand coordination,” this study evaluates the development level of China’s economic “dual circulation” across 30 provinces during 2001–2020. Employing Kernel density estimation, natural breakpoint method, and exploratory spatial–temporal data analysis (ESTDA), we provide a comprehensive examination of the spatiotemporal evolution and developmental dynamics of China’s “dual circulation” economy. Furthermore, a nested matrix linking the quantile response types of driving factors with spatiotemporal transition types is constructed to uncover the mechanisms underlying these transitions, in order to form a unified understanding of the significance of China’s implementation of the economic “dual circulation” strategy against the background of high-quality development and lay a solid theoretical foundation for the empirical measurement of China’s economic “double circulation”. The results reveal the following: (1) Despite the “dual circulation” development level of Chinese provinces steadily improving over time, a marked east-to-west gradient of regional imbalance remains; (2) The spatial correlation of the “dual circulation” development level across provinces is significant, with changing trends influenced by neighboring provinces, showing both “concentration” and “differentiation” characteristics; (3) The spatial agglomeration trend of China’s “dual circulation” economy continues to strengthen, with distinct characteristics of “high rigidity + low mobility.” The low mobility of provinces locked in low-level spatial patterns will become a key limiting factor for their overall transition; (4) The quantile response types of the driving factors for the “dual circulation” development level in each province exhibit nest ability with their spatiotemporal transition types. The driving and constraining patterns of various driving factors coexist and interact. Full article

As a form of living cultural heritage, local residential landscapes manifest the essence of long-term, resilient human–land interactions. The Wuling Corridor, a vital ethnic and cultural passage connecting the Central Plains with Southwest China in Chinese history, serves as a crucial region for the mixed residence and cultural exchange of Tujia, Miao, Dong, Han, and other ethnic groups. Within this region, Ganlan stands as both the most representative vernacular architectural heritage and a residential form that is still extensively used, constituting a continuous and unique residential landscape. The spatial distribution patterns of Ganlan are the physical witness of the history of ethnic groups adapting to the complex topographic and cultural conditions. Current research focuses on the case description of single Ganlan forms, failing to systematically investigate the spatial formation mechanisms of Ganlan as a residential landscape from a geographical continuum perspective. Therefore, this study establishes a geographical database encompassing 9425 Ganlan samples from the Wuling Corridor. It integrates the geographic information system (GIS) with clustering algorithms to systematically identify the distribution patterns of Ganlan within specific geographic–cultural units and their coupling relationships with natural environments. It conducts quantitative analysis on the key driving factors concerning the emergence and evolution of Ganlan in the study area; the findings reveal the following: (1) Ganlan buildings exhibit a spatially aggregated distribution pattern along major water systems, demonstrating characteristics of multi-ethnic sharing and spatial interweaving. (2) Their distribution is constrained by natural geographical factors and influenced by the transmission pathways of construction techniques during ancient ethnic migrations to the southwest China. (3) Within multi-ethnic settlement structures, inter-ethnic cultural interactions (particularly with Central Plains culture) serve as a key driving force for the typological evolution of Ganlan. (4) The evolutionary lineage of “full-Ganlan,” “semi-Ganlan,” and “courtyard-style Ganlan” systematically demonstrates the dynamic adaptive capacity of local residential systems. Additionally, by integrating massive Ganlan heritage data with multiple spatial analysis methods, the study serves as a typical case study illuminating the adaptive strategies and resilience mechanisms of Ganlan as a local residential landscape formed in response to the environmental conditions and social changes. Also, it provides a scientific basis for the holistic conservation of architectural heritages shared by multiple ethnic groups and the integrated development of local cultural tourism industries. Full article

Against the backdrop of global warming and intensified anthropogenic activities, groundwater reserves are rapidly depleting and facing unprecedented threats to their long-term sustainability. Consequently, investigating groundwater reserves is of critical importance for ensuring water security and promoting sustainable development. This study takes the Heilongjiang (Amur) River Basin as the research area. Groundwater storage was estimated using data from the Gravity Recovery and Climate Experiment (GRACE) satellite and the Global Land Data Assimilation System (GLDAS) covering the period from 2002 to 2024. A combination of Random Forest (RF), SHapley Additive exPlanation (SHAP) models, and Pearson partial correlation coefficients was employed to analyze the spatiotemporal evolution characteristics, driving mechanisms, and spatial linear correlations of the primary influencing factors. The results indicate that the basin’s groundwater storage anomaly (GWSA) exhibits an overall declining trend. GWSA is influenced by multiple factors, including climatic and anthropogenic drivers, with temperature (TEM) and precipitation (PRE) identified as the primary controlling variables. Spatiotemporal analysis reveals significant spatial heterogeneity in the relationship between GWSA evolution and its primary drivers. This study adopts a “retrieval–attribution–spatial analysis” framework to provide a scientific basis for enhancing regional groundwater security and supporting sustainable development goals. Full article

This study systematically investigates the velocity characteristics and coupling mechanisms of tunnel flow fields under the interactions of natural wind, traffic wind, mechanical ventilation, and structural factors (such as transverse passages and relative positions between vehicles and fans). Using CFD simulations combined with turbulence model analyses, the flow behaviors under different coupling scenarios are explored. The results show that: (1) Under natural wind conditions, transverse passages act as key pressure boundaries, reshaping the longitudinal wind speed distribution into a segmented structure of “disturbance zones (near passages) and stable zones (mid-regions)”, with disturbances near passages showing “amplitude enhancement and range contraction” as natural wind speed increases. (2) The coupling of natural wind and traffic wind (induced by moving vehicles) generates complex turbulent structures; vehicle motion forms typical flow patterns including stagnation zones, high-speed bypass flows, and wake vortices, while natural wind modulates the wake structure through momentum exchange, affecting pollutant dispersion. (3) When natural wind, traffic wind, and mechanical ventilation are coupled, the flow field is dominated by momentum superposition and competition; adjusting fan output can regulate coupling ranges and turbulence intensity, balancing energy efficiency and safety. (4) The relative positions of vehicles and fans significantly affect flow stability: forward positioning leads to synergistic momentum superposition with high stability, while reverse positioning induces strong turbulence, compressing jet effectiveness and increasing energy dissipation. This study reveals the intrinsic laws of tunnel flow field evolution under multi-factor coupling, providing theoretical support for optimizing tunnel ventilation system design and dynamic operation strategies. Full article

The continuous evolution of SARS-CoV-2 and its variants poses persistent challenges to global public health. As a sublineage of the XDV.1 variant, NB.1.8.1 has rapidly emerged as a dominant strain worldwide, triggering a new wave of infections. Representing a product of viral adaptation, this variant has acquired several critical amino acid mutations—including A435S and T478I—which enhance its transmissibility and immune evasion capabilities compared to the ancestral XDV.1 lineage. This review systematically summarizes the genomic characteristics, epidemiological features, and immune escape potential of NB.1.8.1. It emphasizes that sustained genomic surveillance and serological assessments are crucial for informing public health response strategies, guiding vaccine development, and optimizing containment measures. Full article

The shell liner is a core component of Semi-Autogenous Grinding (SAG) mills, suffering severe wear from ore impact and friction, and its shape directly affects grinding efficiency and maintenance costs. In this study, the Finnie wear model in EDEM2022 software was improved to predict the wear morphology evolution of shell liners. A Python-based coupled simulation of the Discrete Element Method (DEM, EDEM) and Finite Element Method (FEM, ABAQUS) was established to analyze liner wear mechanisms, stress states, and mill service performance (wear resistance, grinding efficiency, and stress distribution). The simulated wear profile showed high consistency with laser three-dimensional scanning (LTDS) results, confirming the improved Finnie-DEM model’s effectiveness in reproducing liner wear evolution. Shearing in crushing/grinding zones was the main wear cause, with additional contributions from relative sliding among ore, grinding balls, and liners in grinding/discharge zones. DEM-FEM coupling revealed two circumferential instantaneous wear extremes (Max^a > Max^b) and two lifter wear rate peaks (M^a > M^b). In the grinding zone, liner stress distribution matched wear distribution, with maximum instantaneous stress at characteristic points A and B—stress at A reflects liner impact degree, while stress at B indicates mill ore-crushing capacity. Optimizing flat liner shape adjusted wear rate peaks (M^a, M^b), improving overall liner wear. This optimization significantly affected stresses at A/B and ore normal collision but had little impact on mill energy efficiency. Full article

During the laser cladding process, the distribution of the temperature field directly influences the morphology, microstructure, and residual stress state of the cladding layer. However, the process involves transient characteristics of rapid heating and cooling, making it challenging to study temperature field variations directly through experimental methods. Therefore, numerical simulation has become a crucial tool for gaining a deeper understanding of the laser cladding mechanism, providing theoretical basis and guidance for optimizing process parameters. This study systematically integrates COMSOL Multiphysics coupling simulation with Jmatpro material thermal property data to perform simulations of temperature field evolution, melt pool flow behavior, and Marangoni effects during laser cladding of nickel-based alloy (IN718) onto an EA4T steel substrate. It highlights the influence patterns of different process parameters (e.g., laser power, scanning speed) on the temperature gradient and flow characteristics of the molten pool, providing an in-depth theoretical basis for understanding the formation mechanism of the molten pool and microstructure control. Full article

In this study, thermogravimetric analysis (TGA) was coupled with Fourier-transform infrared (FTIR) spectroscopy to systematically investigate the pyrolysis characteristics and mechanisms of cement fiberboard across varying heating rates. Experimental findings demonstrated that the thermal degradation process occurs in four distinct phases. Overlapping decomposition peaks in DTG curves were successfully resolved using a double-Gaussian deconvolution algorithm. A comprehensive kinetic analysis was conducted by integrating model-free iso-conversional methods (Flynn–Wall–Ozawa and Kissinger–Akahira–Sunose analysis) with a model-fitting technique (Coats–Redfern approximation) to determine the activation energies for each degradation stage. A subsequent FTIR spectroscopic analysis revealed that the evolution of gaseous products follows the sequence CO₂ > H₂O > CH₄. The CO₂ release was found to originate from multiple pathways, including the decomposition of organic components and high-temperature inorganic reactions. Notably, while the heating rate had a negligible impact on product speciation, it exhibited a statistically significant influence on CO₂ emission intensities. Finally, mechanistic interpretations integrating Arrhenius parameters with time-resolved infrared spectral features were proposed for each thermal decomposition stage. Full article

Investigating ecological irrigation risks associated with mine water utilization is of great significance for alleviating water resource shortages in arid mining regions of western China, thereby supporting efficient coal extraction and coordinated ecological development. In this study, a representative mining area in Xinjiang was investigated to reveal the evolution patterns of mine water quality under arid geo-environmental conditions in western China and to systematically assess environmental risks induced by ecological irrigation. Surface water, groundwater, and mine water samples were collected to study ion ratio coefficients, hydrochemical characteristics, and evolution processes. Based on this, a multi-index analysis was employed to evaluate ecological irrigation risks and establish corresponding risk control measures. The results show that the total dissolved solids (TDS) of mine water in the study area are all greater than 1000 mg/L. The evolution of mine water quality is mainly controlled by water–rock interaction and is affected by evaporation and concentration. The main ions Na⁺, Cl⁻, Ca²⁺, and SO₄²⁻ originate from the dissolution of halite, gypsum, and anorthite. If the mine water is directly used for irrigation without treatment, the soluble sodium content, sodium adsorption ratio, salinity hazard, and magnesium adsorption ratio will exceed the limits, leading to the accumulation of Na⁺ in the soil, affecting plant photosynthesis, and posing potential threats to the groundwater environment. Given the evolution process of mine water quality and the potential risks of direct use for irrigation, measures can be taken across three aspects: nanofiltration combined with reverse osmosis desalination, adoption of drip irrigation and intermittent irrigation technologies, and selection of drought-tolerant vegetation. These measures can reduce the salt content of mine water, decrease the salt accumulation in the soil layer, and lower the risk of groundwater pollution, thus reducing the environmental risks of ecological irrigation with mine water. The research will provide an important theoretical basis for the scientific utilization and management of mine water resources in arid areas by revealing the evolution law of mine water quality in arid areas and clarifying its ecological irrigation environmental risks. Full article