The movability of coalbed water in deep coal reservoirs is a key factor restricting the effective output of coalbed methane. Based on the full investigation of results of previous researchers, combined with theoretical analyses and experimental test results, in order to clarify the evaluation method of the movability of coalbed water in deep coal reservoirs, this study discusses the progress of the research on the dynamic mechanism of the movability of coalbed water in deep coal reservoirs, analyzes the influencing factors and laws of the movability of coalbed water, and points out the development direction of future research. The results show that: A combination of methods is needed to characterize the water occurrence state and the water movability in coal reservoirs. Water vapor isothermal adsorption experiment can be used to clarify the water adsorption characteristics of nanoscale pores, and it is recommended to prioritize the use of nuclear magnetic resonance and mercury injection experiments to jointly characterize the movable water saturation and the full-scale pore structure, and then combine them with the core displacement experiment to verify the water movability in the coal reservoirs. The movability of coalbed water is affected by coal petrological characteristics, porosity and permeability characteristics, and mineral characteristics. Among them, the maximum vitrinite reflectance has a nonlinear effect on the movable water saturation by changing the coal rock pore structure, which first increases and then decreases. The movable water saturation increases significantly when the vitrinite volume fraction, ash yield, porosity, permeability and macropore (radius > 1 000 nm) volume fraction increase. While the inertinite volume fraction, fixed carbon yield, and micropore-mesopore (radius ＜ 1 000 nm) volume fraction increased to inhibit the movability of coalbed water. In the future, four research directions should be focused on, including the characterization of movable water, the main controlling factors and quantitative evaluation of water content, the simulation and mechanism analysis of water production, and the dynamic mechanism analysis of water migration in deep coal reservoirs.

Naturally occurring hydrogen（NOH） shows wide distribution and low exploitation costs, highlightens a strong energy potential. Current research lacks a unified and systematic standard for understanding the types of natural hydrogen. Starting from the formation mechanisms of natural hydrogen, this paper categorizes its types, discusses the formation mechanisms of natural hydrogen in China based on the tectonic background, and finally analyzes the hydrogen generation potential in China. The results show that a total of 9 types and 21 chemical processes can form natural hydrogen, including: Primordial deep hydrogen, hydrogen generation from iron-bearing minerals reactions, hydrogen generation from deep fluid evolution and degassing, hydrogen generation processes related to radioactive elements, hydrogen generation during metamorphism, hydrogen generation from rock mechanical fracturing, phosphine hydrolysis, water auto-electrochemical reactions, and the (potential) hydrogen generation mechanism in upper mantle-crust metasomatism. There are natural hydrogen formation mechanisms in three tectonic domains: Plate boundaries (divergent, convergent, and conservative), rift tectonic systems, and cratonic basements; Extensive plate convergence zones, rift basins, and cratonic basements provide the material basis for the formation of natural hydrogen in China; Currently, the discovered natural hydrogen is primarily associated with the serpentinization reaction of ultramafic-mafic rocks, and the hydrogen generation potential of other reaction processes still requires further study.

The development and evolution of the fault systems not only shaped the formation process and geological structure of the paleo-buried hills, but also profoundly influenced the hydrocarbon accumulation regularity within the buried hills. Focusing on the Paleozoic-Mesozoic buried hills in the Yidong area of the Bohai Bay basin, this study systematically characterizes the stratigraphic structure and tectonic patterns of the buried hills, and further investigates the differential development characteristics and spatiotemporal evolution of the fault systems. The formation processes and current structural configuration of the paleo-buried hills are clarified through balanced section restoration, further exploring the mechanisms of hydrocarbon migration, accumulation, and reservoir formation within the paleo-buried hills. The research results show that: The Meso-Paleozoic strata in the Yidong area can be divided into two major tectonic layers and four tectonic sub-layers. The stratigraphic structure of the hills is predominantly characterized by dual and multiple tectonic layers, though some remnants of single tectonic layers are still present. The formation of the Yidong paleo-buried hills underwent multiple phases of subsidence, uplift, and denudation from Mesozoic to Cenozoic, responding to the combined action of compression, extension and strike-slip movements associated with three sets of fault systems oriented NW, NNE-N, and NEE-E. The hydrocarbon reservoirs in paleo-buried hills are characterized by multiple oil-bearing layers, distribution along faults and separation by internal faults. The hydrocarbon accumulation rules are jointly determined by factors such as source-aligned faults, lateral hydrocarbon connection windows, and internal faults.

The Zhijing-Ansai area is an important producing area of interlayered type shale oil in Chang 7 Member in Ordos basin. The sandstone reservoir is tight and poor in physical property, and there is still no specific reservoir classification and evaluation standards. In this study, lithological analysis, physical property testing, scanning electron microscopy, mercury injection experiment, nitrogen adsorption and other methods were used to analyze the petrological characteristics, physical characteristics and pore structure of Chang 7 sandstone reservoirs in Zhijing-Ansai area, and to establish classification and evaluation criteria. The results show that: 1) The mineral composition is mainly plagioclase. The rock types are mainly arkose and lithic feldspar sandstone. The porosity is 2%-17%, the permeability is 0.001×10-3-1.486×10-3  μm2, and the sandstone reservoir is tight. 2) Favorable reservoir diagenetic facies are feldspar dissolution diagenetic facies, chlorite film cementation diagenetic facies and authigenic clay mineral dissolution diagenetic facies. 3) The main pore types are primary pores, secondary pores, and microcracks. Reservoir pore throat structures can be classified into four categories. 4) Combined with the physical property and displacement pressure, the porosity of 2% and permeability of 0.01×10-3  μm2 are taken as the lower limits of effective reservoir properties in the study area. Ultimately, integrating reservoir characteristics and pore-throat classification criteria, a classification and evaluation standard for interbedded shale oil reservoirs in the Chang 7 Member of the study area was established, and the reservoirs were categorized into four types, with type I and type II identified as favorable reservoirs.

Fractures are crucial for improving the permeability of oil and gas reservoirs. Clarifying the distribution characteristics and development degree of reservoir fractures is of great research significance and application value for the scientific formulation of exploration and development plans for fractured oil and gas reservoirs, and for promoting the efficient development of oil and gas resources. This article systematically investigates the existing identification and prediction methods for oil and gas reservoir fractures, studies the research methods and progress of reservoir fractures, and analyzes the applicability of different reservoir fracture prediction methods. The research results indicate that seismic fracture prediction method, fractal method, curvature method, and production dynamic data prediction method can characterize the development degree of reservoir fractures in reservoir fracture identification methods, while numerical simulation of structural stress field and 3DMove simulation technology can quantitatively calculate fracture parameters. There are significant differences in the applicability of various reservoir fracture prediction methods, and it is necessary to conduct comprehensive reservoir fracture prediction research by combining the advantages of different methods to obtain more accurate fracture prediction results; The prediction results obtained by different reservoir fracture prediction methods have different accuracy and scale characteristics; Identifying and describing fracture characteristics at different scales based on different reservoir fracture recognition methods, and forming a multi method fusion prediction approach for reservoir fracture regions, well areas, and single wells, is an important research direction for future fracture studies.

Many deep wells in the Bozhong sag reveal oil and gas reservoirs in Mesozoic volcanic rocks, with most well sections having unsatisfactory production capacity and a few wells having higher production capacity. Reservoir heterogeneity is a core issue that restricts exploration. By means of casting thin sections, scanning electron microscopy, geophysics, and physical simulation experiments, the formation mechanism of Mesozoic volcanic rock reservoirs in the Bozhong sag was studied. The results indicate that the degree of development of structural fractures determines the differences in reservoir physical properties. Fractured reservoirs with a majority of structural fractures can break through the constraints of conventional volcanic edifices, lithology, and other primary factors, forming large-scale high-quality reservoirs. The development degree of structural fractures is influenced by the strike-slip activity during the Himalayan period and the pre-existing faults in the basement. The tensile faults formed by strike-slip during the Himalayan period mainly control the development of fractures in the reservoir section within 200 m of the top of the volcanic rock buried hill. The upward activation and connection of the pre-existing basement faults play an important role in controlling the development of fractures in the entire volcanic rock body. The physical simulation experiment shows that the single strike-slip shear zone has a narrow range of fractures, which are only concentrated near the fracture zone, but the right lateral left step strike-slip transition overlap area formed by the segmented growth of multiple strike-slip faults has large compressive torsional deformation and a wide range, which can form large-scale fractures; Under the background of forward compression, the strength of rock fracture is mainly limited to near fault zones, with a smaller scale. Based on this, this article proposes for the first time that the Himalayan period is a critical period for the development of structural fractures in volcanic rocks. The strike-slip overlay area of the Bozhong sag during the Himalayan period is a favorable zone for searching for large-scale fractured reservoirs.

Fibrous calcite veins are of great interest to geologists because of their special characteristics and formation mechanisms, which are important indicators of the organic matter enrichment and paleoenvironmental evolution recovery. Based on lithological, geochemical, and C-O isotope data of the large number of fibrous calcite veins found in Upper Member of the Bayingebi Formation in the Yin’e basin, this paper discusses the differences in the formation mechanisms of different types of fibrous veins and their connection with hydrothermal activities. In the Yin’e basin, there are mainly syntaxial and antiaxial fibrous veins. Antiaxial veins are mainly developed in dolomite, with a middle line in the vein. Fibrous features are mainly found at the edge of the antiaxial vein, which show multi-phase growth characteristics. The syntaxial veins are mainly developed in the oil shale, with larger vein widths, obvious fibrous symmetry, and fewer growth phases. Elemental geochemical results show that the fibrous calcite veins in the study area have been affected by hydrothermal activity to different degrees, with an average δ13C of about 9.06‰ and δ18O of about -7.09‰ for syntaxial veins and average δ13C of about 2.24‰ and δ18O of about -10.62‰ for antiaxial veins. The syntaxial veins developed under moderate hydrothermal activity, and the anomalously high pressures required were derived from the dewatering of clay minerals. While the antiaxial veins mainly developed under intense hydrothermal activity, and the anomalously high pressures required were derived from deep hydrothermal activity. All results show a close relationship between the formation of different types of fibrous calcite veins and the intensity of hydrothermal activity.

Resistivity of basalts is commonly lower than 50 Ω·m in the deep part of oil and gas bearing basins represented by the Paleogene basalts in the Liaohe depression. The low resistance characteristics may lead to multiple interpretations of lithology identification and fluid property analysis in reservoir logging interpretation. Through the combination of drilling core description, thin section analysis, scanning electron microscope, mineral X-ray diffraction analysis, and resistivity logging data of 25 wells, the mineralogical characteristics and conductive mechanism of low resistivity basalts are summarized, and the petroleum geological  significance of low resistivity basalt is discussed. The research shows thatprimary minerals in basalt, including plagioclase, olivine and pyroxene, are high resistivity non-conductive minerals, while a small amount of accessory minerals, such as magnetite and other conductive secondary minerals formed by burial diagenesis, are the key internal factors causing low resistivity of basalts. According to different conductive mechanisms, there are three main types of conductive minerals including metal minerals, zeolites, and clay minerals.  The resistivity of basalts is mainly determined by magnetite and saponite due to their strong conductivity. The low resistivity of basalt in the deep part of basin indicates that it has undergone a certain degree of alteration. Intercrystalline microporosity and microfractures formed by clay mineralization and the matrix dissolution porosity formed by superimposed dissolution are beneficial to the improvement of pore connectivity and reservoir permeability in basaltic reservoirs. 

The U-hosting strata of sandstone-type uranium deposits in the Kelulun sag are the Lower Cretaceous Damoguaihe and Yimin Formations. However, systematic studies on their sediment provenance remain limited. This study integrates petrology, zircon U-Pb dating and sandstone geochemistry to constrain the sediment sources of the U-hosting strata and to support further uranium exploration in this area. Petrological observation shows that the gravel and debris components of Yimin and Damoguaihe Formations in the western part of Kelulun sag are mainly granitic, with minor volcanic contributions. Proximity to the Tarbagete uplift corresponds to increased gravel content, coarser grain size, and poorer sorting and rounding of granitic clasts. Some fine conglomerates consist of quartz, feldspar and other minerals derived directly from weathered granite, showing near-source rapid accumulation. In contrast, drilling cores from the eastern sag show gravel assemblages dominated by volcanic rock fragments, with granite gravel being rare. Zircon U-Pb dating results show that detrital zircon ages in the eastern part are mainly concentrated in three age groups of 170-154 Ma, 180-177 Ma and 269-244 Ma. These age peaks correlate well with Early-Middle Jurassic granites and Middle-Late Jurassic volcanic rocks surrounding the sag. Detrital zircon ages in the western part of the sag is mainly concentrated in 257-236 Ma, closely matching the ages of widespread Permian and Triassic magmatic rocks in the Tarbagete uplift, indicating that detrital sediments in the west were mainly derived from this uplift area. Major and trace element geochemistry of sandstones shows low compositional maturity, consistent with rapid accumulation, and points to felsic source rocks. The comprehensive analysis shows that uranium-bearing Permian and Triassic granites in the northwestern provenance area are the main sediment source and a key uranium source for the U-hosting strata and associated mineralization in the western Kelulun sag. In contrast, sediments in the eastern sag were mainly derived from Jurassic volcanic rocks and granites in  Hanwula uplift along the eastern margin.

The Sankuanggou Fe-Cu deposit is an important skarn deposit in the northern Great Hinggan Range. This study investigates the genesis of garnet and its implications for the mineralization process using LA-ICP-MS U-Pb chronology, as well as the major and trace element analyses of garnet conducted by electron probe microanalysis (EPMA) and LA-ICP-MS. The U-Pb dating of garnet yields a weighted mean 206Pb/238U age of (177.1±0.6) Ma, implying that  Sankuanggou skarn Fe-Cu despoit formed during the Early Jurassic in a paleo-Pacific subduction environment. Garnets are predominantly andradite, with minor grossular and uvarovite components. Trace element geochemistry shows depletion in large-ion lithophile elements (such as Rb, Ba and Sr), and enrichment in high field strength elements (such as Th, U, Nb and Ce). Chondrite-normalized rare earth element (REE) patterns are strongly right-inclined, characterized by enrichment in light REEs, depletion in heavy REEs, and positive Eu and Ce anomalies. These features provide insights into the fluid conditions during the early mineralization stage, suggesting that the garnet formed in an acidic and weakly oxidized environment.

Suitability analysis is conducive to the reasonable layout of rural production, living, and ecological space, and is of great significance for coordinating rural land planning in the implementation of rural revitalization strategy in China. On this basis, landscape ecological risk assessment further supports the sustainable and high-quality development of rural areas. From the perspective of production-living-ecology spatial framework, this study establishes a hierarchical evaluation index system for spatial suitability and constructs a landscape ecological risk assessment model at the village scale. The results of the case study in Zhaojiayu Village, Jizhou District, Tianjin, indicate that the most suitable highly suitable areas for ecological space are mainly concentrated in the eastern and southeastern parts of the village. For production space, the most and highly suitable areas are predominantly located in the northern part of the village, while low-suitability and unsuitable areas are mainly found in the south. Living space is primarily composed of most, high, and moderately suitable areas, distributed in the northern region. The landscape ecological risk, ecological space exhibits low risk, with woodland and shrub areas showing the lowest levels. Living space presents a moderate level of risk, while production space demonstrates high risk—particularly in areas designated for tourism production, where the risk is highest. Based on these findings, targeted spatial adjustments and improvements are proposed to support the development of ecological civilization in the village.

To address the frequent occurrence of rainstorms and the increasing risk of rockfall and landslide geological disasters in recent years, and to further improve the research system for collapse-landslide catastrophes in igneous rock areas of Northeast China, this paper systematically summarizes the disaster types and their hazard-causing mechanisms of rockfalls and landslides in igneous rock slopes of the Changbai Mountains, based on the 1 240 km field investigation along the Jilin section of National Highway G331. The results indicate that the development characteristics of igneous rock slope collapse-landslide hazards in Northeast China are closely related to volcanic eruption cycles and intrusion patterns. These can be classified into five types: soft-under-hard stratigraphic collapses caused by a single eruption cycle, unconformity-type stratigraphic collapses induced by late-stage eruptions, alternating soft-hard stratigraphic collapses resulting from rhythmic eruptions, differential-weathering stratigraphic collapses associated with quiescent eruptions, and intrusive-weathering stratigraphic collapses produced by localized magma intrusions. 

Karst collapse is a common dynamic geological hazard in karst development areas, characterized by high suddenness and concealment, posing severe threats to site stability and engineering safety. To accurately identify the primary triggering factors of karst collapse in the study area, this paper constructs both a deep neural network (DNN) model and a traditional analytic hierarchy process (AHP) model based on regional geological conditions to evaluate and predict collapse susceptibility, followed by comparative validation of their accuracy. The results demonstrate that the DNN model outperforms the AHP model in both predictive accuracy and reliability, achieving an overall evaluation accuracy of 87.9%, significantly higher than the 66.7% attained by the AHP model. The DNN model exhibits distinct advantages in assessing karst collapse susceptibility and can provide a scientific basis for disaster prevention and planning in karst regions.

In high seismic intensity reservoir areas, the seismic performance of high filled artificial peninsula with soil-rock mixtures on deep overburden is a key issue that needs to be considered in engineering design and construction. The seismic response of such structures is complex, not only affected by seismic waves, but also by the interaction between the overburden and the filling body. This paper takes the construction project of the Xiangbiling residential settlement in the Baihetan hydropower station reservoir area as the research background. Based on the geotechnical investigation results of the engineering site and structure design documents, a three-dimensional finite element refined model of the artificial peninsula-foundation-upper structure system is conducted using the finite element software MIDAS GTS/NX. According to field and laboratory test data, the physical and mechanical properties and constitutive model parameters of various geotechnical materials and filling materials are determined. Based on the seismic safety evaluation results of the site, the trigonometric series method is used to synthesize the artificial seismic waves with a 50 years exceedance probability of 10% for the engineering site. Through elastic-plastic dynamic time history analysis, the dynamic interaction mechanism, seismic response, and permanent deformation characteristics of the artificial peninsula-foundation-upper structure system are studied. The research results indicate that under the action of fortification earthquakes, the peak acceleration distributions along the transvers, longitudinal, and vertical directions at the central axis of the artificial peninsula generally shows a trend of first decreasing and then increasing with elevation, and their maximum acceleration amplification coefficients are 1.43, 1.81 and 1.67, respectively; The peak relative displacement along the transvers, longitudinal, and vertical directions at the central axes of the artificial peninsula reveals a non-linear increasing relationship with elevation, and the displacement in the transvers direction exhibits a clear whiplash effect; The maximum permanent deformation of the top platform along the transvers and longitudinal directions are 12.2 and 1.7 cm, respectively, which are much smaller than the limit given in the specifications; The maximum settlement of the top platform is 7.6 cm, and the corresponding seismic settlement rate is 0.25%, which is much smaller than the limit given in the specifications.

In order to clarify the strength deterioration characteristics and microscopic mechanism of  Qinghai-Xizang Plateau moraines during freeze-thaw cycles, laboratory tests (standard triaxial, scanning electron microscopy and nuclear magnetic resonance tests) and numerical regression methods were used to study the moraines under different initial conditions (water content and freeze-thaw cycles). A quantitative relationship between macroscopic strength parameters and freeze-thaw action was established through regression analysis. The research results show that: 1) The stress-strain curve of the moraines after the freeze-thaw cycle exhibited a strain softening trend, with both elastic modulus and shear strength showing a downward trend, in the early freeze-thaw cycle (0-5 times) damage by about 16.60% and 10.33% respectively, strength degradation is most obvious, and later in the freeze-thaw cycle (10-20 times) a slight fluctuations and steady state. Freezing and thawing cycles and cohesion of negative exponent, internal friction angle with the increase of freeze-thaw cycles was fluctuated, extends the applicable under the ice moraine soil freezing and thawing cycle of Mohr coulomb strength criterion, and established the shear strength, elastic modulus and multi-parameter coupling mathematical model of freeze-thaw cycles. 2) SEM images showed that with the increase of freeze-thaw cycles, the arrangement of moraine particles changed from dense and ordered to loose and disordered.And the pore characteristic structure changes. 3) NMR results demonstrated evolution characteristics in the internal pore structure of moraines under the freeze-thaw cycle. With deepening freeze-thaw cycles, large, medium pore proportion increased to 59.55%（N=20） micro, small pore proportion reduced to 40.45%（N=20）. The small and small pores gradually expanded and merged under the action of frost heave force generated during the water-ice phase transition. Large and medium pores were formed, and the characteristic evolution process of pore structure was basically completed in the late freeze-thaw period (10-20 times).

Aim to reveal the intrinsic mechanism of percolation in geotechnical granular media, geotechnical granular media samples were prepared by adjusting the ratio of clay and coarse sand, and their permeability coefficients were measured. With the help of image analysis methods, the distribution parameters of coarse sand in experimental sample images and randomly simulated images were statistically analyzed. Based on this, the percolation law and intrinsic mechanism of geotechnical granular media were analyzed. The results showed that as the mass fraction of coarse sand increased, the number of connected clusters of coarse sand showed a pattern of first increasing and then decreasing. The maximum connected cluster area, average connected cluster area, fractal dimension of coarse sand distribution, and permeability coefficient of experimental samples all showed a monotonic increase. The 30.0% mass fraction of coarse sand is the turning point of the change in the number of connected clusters. When the mass fraction of coarse sand is around 60.0%, the growth rate of the number of connected clusters, the maximum connected cluster area, and the average connected cluster area drops sharply or increases sharply. At the same time, the permeability coefficient of the soil particle media also quickly crosses two orders of magnitude, and percolation occurs. The occurrence of percolation in soil particle media is closely related to the changes in the morphology of connected clusters caused by changes in the proportion of coarse sand. When the mass fraction of coarse sand is below 30.0%, the coarse sand particles are dispersed in an “isolated island” shape in the clay particles. When the mass fraction of coarse sand exceeds 30.0%, the coarse sand begins to connect with each other, and the number of connected clusters decreases, but still appears in a “patchy” shape with poor connectivity. After the mass fraction of coarse sand reaches 60.0%, the probability of coarse sand connecting to each other as a single connected cluster approaches 1.0, and a high permeability channel that runs through the entire seepage path is formed, triggering percolation.

The groundwater exploitable quantity is an important basis for the development, use and management of water resources, and is subject to constraints imposed by the ecological environment and geological conditions. Taking the Puyang irrigation area of the Sanjiang plain as an example, this paper determined the lower limit of the ecological water depth for groundwater development and utilization, aiming to mitigate risks such as the prevention of wetland vegetation degradation, land subsidence, quaternary aquifer dredging, and the disconnection between groundwater and surface water. Based on this, a numerical simulation model of the irrigation area is constructed using MODFLOW to simulate and evaluate the groundwater exploitable quantity. The lower limit of ecological water depth in the irrigation area is between 2.27 and 9.84 m; Based on groundwater numerical simulations, the annual average recharge amount of the irrigation area during the study period (2013-2017) was 25 515.9×104 m3, the discharge volume was 26 194.1×104 m3, and the change of storage volume was -678.3×104 m3, indicating a negative equilibrium, but the burial depth of groundwater level had not yet reached the lower threshold, suggesting that the groundwater still has potential for exploitation. Furthermore, a long-term prediction model was established and calibrated based on the control criteria of ensuring a balance between recharge and discharge and the threshold of the lower limit of the buried depth of the ecological groundwater level, combined with the meteorological and hydrological conditions during the study period. The maximum recoverable groundwater in the irrigation area was determined to be 29 343.2×104 m3/a.

To scientifically evaluate the response of groundwater system to ecological water conveyance projects in the Xiliaohe plain, this study employed FEFLOW to construct a groundwater flow numerical model. The model simulated the dynamic changes in the unconfined aquifer under three water delivery scenarios with annual operation durations of 70, 80, and 90 days. Considering the uncertainties in specific yield, hydraulic conductivity, and river infiltration recharge intensity of the unconfined aquifer, a Gaussian process regression (GPR) surrogate model combined with the Monte Carlo method was employed to quantify the influence of parameter uncertainty on groundwater storage variations. The results indicate that ecological water conveyance significantly raised the groundwater levels in the Xar Moron-Laoha River confluence zone and the distribution area of confined aquifer, with increases of 0-3 m and 3-5 m, respectively, and the influence range of up to 5 500 m on both sides of the river. The estimated groundwater storage variations under the three scenarios were 3.04×108-5.83×108，3.48×108-6.55×108，and 3.87×108-7.22×108 m3, respectively, with exceedance probabilities of 46.1%, 44.1%, and 45.0%, all below 50%, suggesting that deterministic approaches overestimate actual recharge quantity.

To evaluate the effectiveness of zeolite as a filling medium for permeable reactive barriers (PRB) in remediating NH4+ contaminated groundwater and the applicability of in-situ regeneration processes. Achieve the sustainable use of zeolites in removing NH4+ contamination from groundwater. This study combines the adsorption and ion exchange functions of zeolite with in-situ chlorination regeneration technology, based on the mechanism of NH4+ breakpoint chlorination removal, it was carried out through batch adsorption and ion exchange experiments, dynamic simulation tests, combined with mechanism analysis. The results indicate that when the zeolite dosage is 40 g/L, the initial pH is 7, and the adsorption time is 180 min, the removal efficiency is 92.47%, and the maximum adsorption capacity is 6.22 mg/g. Dynamic simulation experiments show that the chloride regeneration technology can remove 99% of the NH4+ adsorbed on zeolite, and there is almost no NH4+left in the regenerant. The NH4+ on the surface of the zeolite is first replaced by Na+ and then oxidized into N2. Both natural zeolite and modified zeolite adsorption columns showed good dynamic removal of NH4+, and the proposed in-situ zeolite regeneration process proved to be stable during continuous cycle tests, making it suitable for the treatment of NH4+ contaminated groundwater.

In the audio-frequency magnetotelluric (AMT) forward modeling, the conventional finite element method (FEM) is inherently constrained by the trade-off between computational accuracy and efficiency. To address this issue, this study proposes an adaptive finite element method  based on super convergent patch recovery (SPR). This method utilizes a posteriori error estimation to dynamically identify elements that require refinement, enabling robust local mesh optimization, and directly employs the high-accuracy recovered gradient values obtained from the SPR computation for auxiliary field calculation, thereby substantially enhancing the overall forward modeling precision. A series of systematic numerical experiments were conducted to comprehensively validate the algorithm’s accuracy and computational efficiency. First, comparative accuracy results with conventional FEM in horizontally layered media demonstrate that the  root mean square relative error is reduced to just 1.02% after five iterations, fully confirming its high precision. Second, in forward modeling of a composite high- and low-resistivity model, the apparent resistivity values progressively approach the true model resistivity as the iteration proceeds, verifying the algorithm's robust convergence behavior. Finally, simulations of complex geoelectrical structures confirm the algorithm’s strong adaptability to heterogeneous geological models models. The results conclusively show that the SPR-based posteriori error estimation method effectively identifies elements for refinement and significantly improves the accuracy of auxiliary field calculation, thus substantially elevating the accuracy of AMT forward modeling.

The presence of multiple waves will cause serious distortion of seismic data imaging, increase the interference of the target layer, and thus have an adverse impact on the accurate interpretation of geological data and the development planning of oil and gas reservoirs. Although the parabolic Radon transform based on L1/2 norm constraint shows excellent results in multiple suppression, the traditional fast iterative shrinkage-thresholding algorithm (FISTA) is difficult to meet the requirements in terms of computational efficiency when facing large-scale seismic data. To this end, this paper proposes an improved greed-fast iterative shrinkage-thresholding algorithm (G-FISTA). This algorithm achieves a significant improvement in the inversion calculation efficiency by optimizing the iterative steps and combining convergence conditions with a restart mechanism. The numerical test results show that compared with  FISTA, the convergence speed of G-FISTA is significantly improved, and it shows good multiple suppression effects in both synthetic data and actual seismic data. Compared with the traditional algorithm that iterates ten times to reach the optimal solution, G-FISTA  only needs four iterations, nearly doubling the iteration efficiency.

Traveltime tomography is a key technique in seismology and seismic exploration. However, traditional traveltime tomography methods face numerous challenges, such as inaccuracies in imaging results due to spatial resolution, numerical errors, and data matching after model discretization, as well as limitations in the efficiency of multi-source simulations. To overcome these limitations, this study employs physics-informed neural networks (PINNs) to solve the eikonal equation for simulating seismic traveltimes and implementing traveltime tomography. This PINN-based tomography approach is named PINNtomo. PINNtomo integrates physical constraints (the eikonal equation) and data constraints (travel times) into the loss function, enabling rapid and accurate traveltime field simulation and velocity modeling without relying on an initial model. This paper investigates the impact of multiplicative and additive traveltime T factorization on the accuracy and efficiency of PINNtomo. The results demonstrate that as the model size increases, the additive factorization method not only significantly improves imaging efficiency (the reduction in computation time for additive PINNtomo increases from 92 s to 3 486 s compared to multiplicative PINNtomo), but also enhances accuracy and optimizes computational performance.

 

In alpine and high-altitude areas, the engineering geological background is complex, geological disasters occur frequently, and the ecological environment is fractured. To explore the applicability of the advanced geological prediction system in the alpine and high-altitude geological environment, this paper, based on a certain tunnel section in alpine and high-altitude area, analyzes the signal characteristics of unfavorable geological bodies in the tunnel based on different combined modes of advanced geological prediction, and further verifies the accuracy of the advanced geological prediction system in alpine and high-altitude areas by combining with the on-site excavation situation. The results show that conventional single advanced geological prediction detection methods are prone to unstable and messy signal ripples and insignificant geological radar signal characteristics in alpine and high-altitude areas, which interfere with the correct prediction of unfavorable geological bodies in tunnels. The use of multiple geophysical combination signals with different sensitivities can make up for the geological radar signal characteristics of 21-30 m and improve the prediction accuracy of unfavorable geological bodies in alpine and high-altitude tunnels.

Using deep learning technology to carry out image recognition of tight sandstone reservoir thin section can effectively improve the accuracy and efficiency of compositional identification, which is the development trend of mineral identification. However, factors such as the difficulty of thin section image acquisition, the high cost of annotation and privacy protection, result in a scarcity of tight sandstone thin section image samples, which cannot meet the training requirements of deep learning image recognition models. In order to increase the number of samples and improve the training effect of the deep learning model, this paper takes the Linxing block in Ordos basin as the target area and proposes a tight sandstone image augmentation method by combining the respective advantages of oversampling data method and data deformation method. Firstly, the style generative adversarial network is improved to generate high-resolution tight sandstone images and enhance data diversity. Secondly, we use data deformation methods to achieve data augmentation with labeled images, thereby reducing annotation costs and expanding the data scale. Finally, the Blend Mask algorithm is trained using augmented data to accurately identify and precisely segment sandstone particles. The experimental results show that compared with the similar contrast algorithms, this proposed method has an IS (inception score) value with a maximum of 2.43 and an FID (Fréchet inception distance) value with a minimum of 22.71. Meanwhile, the recognition accuracy after adding the generated images is 92.7%. It indicates that the method proposed in this paper has significant advantages in terms of the quality of generated images and the improvement of the training effect of the deep learning model.