Abstract: To investigate the pore structure characteristics and multi-scale distribution of coal in the Chengzhuang mining area, coal samples from the Shanxi Formation were selected for analysis. High-pressure mercury intrusion (MIP), low-temperature nitrogen adsorption (LTNA), and scanning electron microscopy (SEM) were employed to comprehensively characterize pore types, pore size distribution, and pore-throat structure. The results indicate that the pore system in the study area is mainly composed of metamorphic pores and exogenous pores, with relatively poor connectivity. The MIP results show that the pore volume of both samples is dominated by transitional pores, followed by micropores, while mesopores and macropores account for relatively small proportions, suggesting that the pore system is primarily composed of small- to medium-scale pores. The LTNA results reveal that transitional pores contribute significantly to the pore volume, whereas micropores dominate the specific surface area. This indicates that pore volume is mainly controlled by transitional pores, while the specific surface area is primarily governed by micropores. Read More

Abstract: This study focuses on the Shanxi Formation coal-measure strata in the eastern Pingdingshan mining area and systematically investigates the mechanisms controlling the occurrence and enrichment of coal-measure gas under the coupling effects of sedimentary and tectonic processes. Based on integrated geological datasets, key sedimentary parameters (e.g., mudstone and sandstone ratios) and structural curvature attributes were quantitatively characterized to evaluate their influence on reservoir properties, gas preservation, and migration pathways. The results indicate pronounced spatial heterogeneity in both mudstone and sandstone distributions. Mudstone-dominated zones exhibit strong sealing capacity, favoring gas preservation, whereas sandstone-enriched intervals tend to enhance gas migration. High structural curvature zones are distributed in bands along fold belts and show a strong correlation with coal seam floor undulation. Moderate tectonic deformation promotes fracture development and improves reservoir permeability, while excessive deformation may degrade sealing conditions. The deformation responses of mudstone and sandstone layers are highly consistent, suggesting vertical coherence of tectonic processes. Overall, the coupling of sedimentary and tectonic factors is identified as the primary mechanism governing coal-measure gas enrichment. These findings provide a robust geological basis for favorable zone prediction and the efficient development of coal-measure gas resources. Read More

Abstract: Sequence stratigraphy not only provides an isochronous stratigraphic framework for basin analysis, but also offers an important integrated geological framework for sedimentary paleogeographic reconstruction and the exploration and development of sedimentary mineral resources. Over the past three decades, sequence stratigraphy has continued to develop in terms of theoretical systems, sequence architecture, integrated interpretation of multiple datasets, and applications in energy exploration. Significant progress has been made particularly in the controlling factors of sequence formation in continental basins, sequence-stratigraphic architecture of faulted, depressed, and foreland lacustrine basins, the distribution patterns of sand bodies, and research methods for sequence stratigraphy in continental lacustrine basins. Compared with marine basins, continental lacustrine basins are jointly controlled by tectonic activity, climatic change, lake-level fluctuation, proximal and multiple sediment supplies, and rapid changes in sedimentary facies; therefore, their sequence composition and stratigraphic stacking patterns are more complex. Future research on continental sequence stratigraphy should further focus on sequence architecture in different types of basins, standardization of research terminology and workflows, relationships between sequences and source-to-sink systems, relationships between sequences and shoreline-migration trajectories, stratigraphic stacking patterns and sedimentary responses, deep-water sequence stratigraphy, and numerical simulation of sequence architecture, so as to better serve the exploration and development of energy resources. Read More

Abstract: Oceanic Anoxic Events (OAEs) during the Cretaceous—designated OAE1, OAE2, and OAE3, with OAE1 further subdivided into OAE1a, OAE1b, OAE1c, and OAE1d—are widely attributed to volcanic activity from the Kerguelen, Ontong Java, and Caribbean Large Igneous Provinces (LIPs), which triggered at least two global OAEs. These events are characteristically marked by widespread deposition of organic‑rich black shales and positive carbon isotope excursions. By systematically reviewing the geochemical behavior of molybdenum (δ98Mo) and zinc (δ66Zn) isotopes, we find that δ98Mo primarily tracks the transition between locally euxinic and non‑euxinic conditions, whereas δ66Zn serves to distinguish different responses of local marine systems—including primary productivity, continental weathering, and sediment burial/decomposition. Nevertheless, the fractionation mechanisms governing these metal stable isotopes in the oceanic realm remain incompletely understood, and existing records focus predominantly on OAE2. Future research must therefore adopt a more comprehensive and systematic approach across all OAEs. Read More

Abstract: The development and evolution of slopes can often destroy construction buildings, interrupt traffic, block rivers, and threaten the safety of people and animals. Therefore, it is of great practical significance to study their formation and development process and to take preventive measures. However, the surface structure often covers up some real structural appearance, so it can correctly identify the surface structure and distinguish it from the real structural deformation. It has great practical significance for geological mapping, regional structural research, analysis of hydrological engineering geological conditions, seismic geological survey and deposit exploration and mining. This paper first introduces the basic types of slope deformation and destruction and the mechanism mode of slope failure, and finally discusses the relationship between slope deformation and epinal structure. Read More

Abstract: As an important unconventional natural gas resource, the formation mechanism and genetic type of coalbed methane are of great significance to resource evaluation and development. This paper systematically analyzes the genetic types, formation mechanism and control factors of coalbed methane. Studies have shown that coalbed methane mainly includes two types: biogenic gas and thermogenic gas. Among them, biogenic gas is formed in a low-temperature and shallow-buried environment, while thermogenic gas is formed under higher temperature and pressure conditions. The generation of coalbed methane is not a single process, but a gradual transition from biogenic to thermogenic in the process of coalification, showing obvious continuous evolution characteristics. In addition, the formation and enrichment of coalbed methane are controlled by many factors, such as coal rock composition, coal metamorphic degree, temperature and pressure conditions and hydrodynamic force. The research in this paper is helpful to deepen the understanding of the genetic mechanism of coalbed methane and provide a theoretical basis for the development and utilization of coalbed methane resources. Read More

Abstract: This study focuses on the Luo River Basin in Henan Province, selecting six ecological evaluation factors—elevation, slope, land use, NDVI, aspect, and water buffer zone—to assess ecological sensitivity. The Analytic Hierarchy Process (AHP) and spatial autocorrelation analysis were employed to determine the weights and spatial distribution of each factor. Based on the GIS platform, comprehensive ecological sensitivity was classified into five levels, facilitating an integrated analysis of sensitivity distribution and spatial autocorrelation clustering patterns in the Luo River Basin from 1990 to 2020. The results indicate: ① According to single-factor evaluations, the weights of ecological sensitivity influence, in descending order, are NDVI, land use, elevation, slope, aspect, and water buffer zone. Among these, NDVI exerts the strongest impact on ecological sensitivity in the Luo River Basin, with a weight value of 0.345.② From 1990 to 2020 the eco-environmental sensitivity of the study area was predominantly extremely high, followed by low and high sensitivity. Extremely high and high sensitivity areas together accounted for 42.32% to 51.45% of the total regional area, exhibiting an increasing trend over time, with the proportion of extremely high sensitivity areas reaching up to 32.27%. moderate and low sensitivity areas displayed a declining trend, while very low sensitivity areas remained relatively stable at approximately 16%.③ The spatiotemporal variations in ecological sensitivity within the study area are pronounced. Overall, extremely high and high sensitivity areas are primarily concentrated in the mountainous and hilly regions of the western and central-southern parts, characterized by high elevations and steep slopes. Very low and low sensitivity areas are mainly distributed near urban clusters in the eastern and central valley regions of the Luo River Basin. The ecological sensitivity index in the basin  exhibits a zonal clustering pattern at the … Read More

Abstract: To ensure the safety and efficiency of solid potassium salt mine mining, this paper focuses on the research of stope structural parameters, including stope room span, roof safety thickness, and stope layout form. Based on the equilibrium arch theory and simply supported beam theory, the limit span of the stope room is analyzed and calculated, and the reasonable room span is determined by combining mining technology and safety requirements. Using the elastic mechanics thin plate theory and H. Tresca yield criterion, the safety thickness of the stope roof is calculated to ensure the overall stability of the stope during mining. Two stope layout schemes (uniform layout of rooms and pillars, interval large pillars with equal-width rooms) are designed, and the parameters of each scheme are calculated and compared from the aspects of pillar safety factor and recovery rate. The research results show that the reasonable room span of the carnallite ore layer is 8m, the safe thickness of the roof isolation layer should be more than 7.5m, and the interval large pillar layout scheme has higher recovery rate while ensuring safety, which can provide a theoretical basis and engineering reference for the design and construction of solid potassium salt mines. Read More

Abstract: Rock burst is a typical dynamic disaster in coal mining, and its occurrence is closely related to the distribution of mining-induced stress. Taking the N2107 working face of Yuwu Coal Mine as the research object, this paper systematically studies the stress distribution and evolution law of the gob-side coal body during the retreat mining process by comprehensively applying theoretical analysis, in-situ stress monitoring, microseismic data inversion, and FLAC3D numerical simulation. The results show that under the influence of mining activities, the gob-side coal body can be divided into three typical zones: the decompression zone, the stress concentration zone, and the original stress zone. The peak of the stress concentration zone is located approximately 150 m from the gob-side of the working face, and the range of the decompression zone is about 35 m. The microseismic b-value inversion results are consistent with the conclusions of stress monitoring and numerical simulation, verifying the reliability of the stress zoning. Based on the characteristics of stress evolution, rock burst prevention measures are proposed, including implementing pressure-relief boreholes in the stress concentration zone, optimizing support parameters in the decompression zone, and combining real-time microseismic b-value monitoring for risk early warning. This study provides theoretical basis and technical support for safe and efficient mining in deep coal mines. Read More

Abstract: Coalbed methane (CBM) bioengineering has emerged as a promising approach for enhancing methane recovery from low-permeability and marginal coal reservoirs. This study systematically reviews the mechanisms of biogenic methane generation, recent advances in key bioengineering technologies, and the associated engineering challenges. Biogenic methane production in coal seams is driven by a multi-stage anaerobic metabolic network involving hydrolytic, fermentative, and methanogenic microorganisms, in which syntrophic interactions play a critical role in maintaining system stability and efficiency. Recent technological developments have focused on microbial stimulation and bioaugmentation strategies, aiming to enhance methane generation through nutrient regulation and functional microbial consortia. In addition, coupling biological processes with reservoir stimulation techniques, such as hydraulic fracturing and gas injection, has been explored to improve treatment efficiency and expand the effective reaction zone. Advances in monitoring and numerical simulation have further contributed to the understanding and optimization of subsurface biogeochemical processes. Despite these progress, field-scale application remains constrained by reservoir heterogeneity, slow microbial kinetics, and limited process controllability. Moreover, challenges related to microbial stability, substrate conversion efficiency, and environmental risks continue to hinder large-scale deployment. Overall, future research should focus on improving mechanistic understanding, enhancing process control, and integrating multidisciplinary approaches to advance CBM bioengineering toward practical and sustainable applications. Read More

Abstract: Understanding how sowing density influences spontaneous plant communities over time is critical for optimizing vegetation management in urban park greenspaces. This study investigated the temporal responses of spontaneous plant community diversity to varying sowing densities of cultivated herbs in Hangzhou, China. A semi-controlled field experiment was conducted using three sowing densities (20, 100, and 200 plants m⁻²), and spontaneous plant communities were monitored monthly from December to May. Diversity was assessed using the Shannon–Wiener index, Pielou’s evenness index, and Margalef’s richness index, and the data were analyzed with linear mixed-effects models. Spontaneous plant diversity exhibited clear seasonal dynamics, with diversity indices increasing from winter to spring and peaking in March–April. The effects of sowing density were strongly time-dependent. Differences among density treatments were relatively small during the initial stages but became more pronounced during the spring growth period. Specifically, medium and high densities were associated with lower diversity and species richness during the peak period. In contrast, evenness was primarily influenced by temporal variation rather than sowing density. Community composition varied among treatments, mainly through shifts in species abundance rather than species turnover. These findings indicate that sowing density can serve as a practical tool for regulating spontaneous plant diversity and highlight March–April as a key period for management interventions in park greenspaces. Read More

Abstract: Coal biomethanation, as a green and low-carbon energy conversion technology, has shown significant application potential in coalbed methane (CBM) development. This paper systematically reviews the mechanisms and research progress of microbial coal biodegradation for methane production. The key processes, including hydrolysis, fermentation, hydrogen-producing acetogenesis, and methanogenesis, as well as their synergistic microbial interactions, are analyzed in detail. The characteristics of microbial community structures in coal seams are summarized, revealing that methane generation generally follows a metabolic pattern of “bacterial primary degradation coupled with archaeal terminal methanogenesis,” with hydrogenotrophic methanogens dominating in most basins. Furthermore, the progress of mixed microbial cultures combining indigenous and exogenous microorganisms for enhancing coal biogasification is reviewed. It is indicated that multi-source microbial consortia exhibit significant functional complementarity; however, their performance is influenced by factors such as community structure, environmental conditions, and interspecies interactions. Finally, current limitations in degradation mechanisms, functional microbial identification, and system stability are discussed, and future research directions are proposed, emphasizing the need for deeper mechanistic insights and microbial regulation strategies to promote the engineering application of coal biomethanation. Read More

Abstract: This study uses iron recovered from excess sludge to enhance an anammox system. Results show that sludge‑derived iron significantly improves nitrogen removal efficiency, optimizes extracellular polymeric substances (EPS) composition, and increases heme c content to strengthen microbial activity. Microbial analysis reveals that iron selectively enriches anammox functional bacteria. The reactor with K1 carrier performs best. This approach realizes sludge resource utilization and enhances anammox process, achieving waste treatment by waste. Read More

Abstract: As a crucial energy resource, coal plays a pivotal role in the global energy mix. This is particularly evident in China. Endowed with abundant reserves, the country relies on coal as its primary energy source. However, traditional extraction methods are fraught with challenges, including resource depletion, environmental degradation, and significant safety hazards. Consequently, the advancement of intelligent mining technologies is of paramount importance. These innovations enhance resource utilization efficiency, mitigate environmental impacts, and safeguard the well-being of miners. Intelligent coal mining leverages modern information systems, automation, and artificial intelligence to achieve a fully automated, informatized, and smart extraction process. In this context, "intelligence" denotes a comprehensive system capability. It encompasses the real-time, precise perception of data objects, alongside rapid and accurate decision-making support. Furthermore, it involves efficient execution coordination and the autonomous ability to analyze, judge, and act upon external stimuli, coupled with the capacity for independent learning and process optimization. Recent years have witnessed remarkable technological breakthroughs in this domain. These advancements are primarily driven by the integration of big data, artificial intelligence, the Internet of Things (IoT), advanced sensor technologies, and 5G+ networks. By systematically aggregating mine production data, big data and AI have substantially elevated the sophistication of production management. Concurrently, IoT and sensor technologies facilitate the real-time monitoring of mine environments and equipment operational status, thereby ensuring absolute data accuracy and immediacy. Read More

Abstract: To address the problem of surface collapse and sinkhole disasters induced by fully mechanized top-coal caving mining of extra-thick coal seams beneath thick unconsolidated layers, the F6204 working face of Buliangou Coal Mine was selected as the engineering background. Field investigation, theoretical analysis, and numerical simulation were employed to investigate the evolution characteristics of overburden failure and the formation mechanism of surface sinkholes. The results indicate that the overburden structure of the F6204 working face is mainly composed of a “loess layer–conglomerate–basalt” assemblage, in which the basalt stratum acts as the primary key stratum. After coal extraction, a distinct “three-zone” overburden structure is formed. With the increase in mining thickness, the stability of the beam-arch structure in the overburden gradually decreases. Once the basalt primary key stratum fractures, surface collapse and sinkhole disasters are likely to occur. When the coal seam thickness exceeds 15 m, surface deformation gradually transforms from continuous subsidence to discontinuous stepped collapse. Based on these findings, a control technology combining high-level key stratum presplitting and separation-layer grouting is proposed, which can effectively mitigate surface sinkhole hazards. The research results can provide a reference for the safe and efficient mining of extra-thick coal seams under similar geological conditions. Read More