摘要：Shear strain energy is a pivotal physical quantity in the occurrence of earthquakes and rockbursts during deep mining operations.This research is focused on understanding the changes in shear strain energy in the context of retreating longwall mining,which is essential for the optimized design and mitigation of rockbursts and seismic events.Through the application of innovative analytical models,this study expands its analytical range to include the variations in shear strain energy caused by fault coseismic slip.An integrated methodology is utilized,taking into account the changes in coseismic and fault friction parameters as well as enhancements in mining-induced stress and existing background stresses.Our numerical investigation highlights the significance of mining location and fault characteristics as key determinants of shear strain energy modifications.The analysis demonstrates significant spatial variability in shear strain energy,especially noting that fault slip near the mining face greatly increases the likelihood of rockburst.This finding emphasizes the need to integrate fault coseismic slip dynamics into the triggering factors of rock(coal)bursts,thus broadening the theoretical foundation for addressing geological hazards in deep mining operations.The results are further corroborated by observa-tional data from the vicinity of the F16 fault zone,introducing the concept of mining-induced fault coseismic slip as an essential element in the theoretical framework for understanding rockburst triggers.

摘要：Microstructural heterogeneity of low-permeability sandstone roofs of deep unmineable coal seams due to diagenesis signifi-cantly affects rock mechanical behavior,greatly impacting the sealing potential of in situ CO2 sequestration and the structural stability of the geological formation.However,little is known about how the microstructure of different mineral groups influences the multiscale mechanical behavior of deep sandstone.This study proposes a new method for quantitatively char-acterizing the multiscale mechanical properties of low-permeability sandstone and shows the mechanisms responsible for mechanical failure at the micro-,meso-,and macroscale.Triaxial compression tests and targeted nanoindentation tests were conducted to assess the micro-and macroscale mechanical properties of different types of sandstone.The micro-and macro-scale experiments were coupled with numerical simulations of compression using a unified cohesive model based on Voronoi polygons to clarify the multiscale mechanical behavior.The results indicate that quartz,the primary mineral component of the sandstones examined,exhibits the strongest micromechanical properties,followed by feldspar,calcite,and clay minerals.Compared to polycrystalline quartz,monocrystalline quartz has a more stable microstructure and is mechanically stronger.The macro-mechanical properties of tight sandstone samples are weakened by increased microstructural inhomogeneity and larger grain size.This leads to a higher likelihood of splitting damage,characterized by a high degree of discrete and weak stress sensitivity.The major conclusion is that the positive rhythm lithofacies of medium-grained sandstone to siltstone are the most favorable for efficient CO2 sequestration in deep unmineable coal seams.

摘要：The mainstream method for extracting shale gas involves hydraulic fracturing to create fracture networks.However,as extraction depth increases,notable issues such as rapid production decline,low recovery rates,high water consumption,and resource waste become apparent.Identifying new and efficient auxiliary rock-breaking technologies is crucial for overcoming these challenges.The laser,successfully utilized in industrial production,medical treatment,and technological research,offers unique features such as good directionality,coherence,and high energy density,providing novel possibili-ties for addressing the limitations of existing deep reservoir transformation.This research focuses on a novel laser-assisted rock-breaking technology,with shale featuring different bedding angles as the subject of investigation.The investigation methodically explored how shale responded to thermal fracture at high temperatures when exposed to laser irradiation with different spot diameter.It investigates the spatiotemporal evolution characteristics of the shale temperature field under laser irradiation,the propagation features of cracks on shale surface,and the physicochemical fracture mechanisms.The research yields the following results:(1)The region of thermal influence of the irradiation surface can be divided into three regions based on the change of rise curve of temperature in the shale surface.(2)Based on the scanning electron microscopy(SEM)testing,combined with the macroscopic and microscopic morphological characteristics of shale fracture surfaces,it reveals significantly distinct zoning characteristics in the roughness of the rock sample's fracture surfaces after laser irradiation.(3)The thermal fracturing process of shale under laser irradiation involves chemical reactions of constituent minerals and stress generated by the thermal expansion of shale oil in the reservoir.(4)The damage and fracture of shale under the irradiation of laser show significant bedding effect,and there are three modes of rock sample failure:Pattern T(thermal failure),Pattern T-B(thermal and bedding synergistic failure),and Pattern B(bedding failure).The research findings presented in this article serve as a foundation and reference for the theory and technology of laser-assisted shale gas extraction.

摘要：Accurate prediction of coal and gas outburst(CGO)hazards is paramount in gas disaster prevention and control.This paper endeavors to overcome the constraints posed by traditional prediction indexes when dealing with CGO incidents under low gas pressure conditions.In pursuit of this objective,we have studied and established a mechanical model of the working face under abnormal stress and the excitation energy conditions of CGO,and proposed a method for predicting the risk of CGO under abnormal stress.On site application verification shows that when a strong outburst hazard level prediction is issued,there is a high possibility of outburst disasters occurring.In one of the three locations where we predicted strong outburst hazards,a small outburst occurred,and the accuracy of the prediction was higher than the traditional drilling cuttings index S and drilling cuttings gas desorption index q.Finally,we discuss the mechanism of CGO under the action of stress anoma-lies.Based on the analysis of stress distribution changes and energy accumulation characteristics of coal under abnormal stress,this article believes that the increase in outburst risk caused by high stress abnormal gradient is mainly due to two reasons:(1)The high stress abnormal gradient leads to an increase in the plastic zone of the coal seam.After the working face advances,it indirectly leads to an increase in the gas expansion energy that can be released from the coal seam before reaching a new stress equilibrium.(2)Abnormal stress leads to increased peak stress of coal body in front of working face.When coal body in elastic area transforms to plastic area,its failure speed is accelerated,which induces accelerated gas desorption and aggravates the risk of outburst.

摘要：Tight glutenite reservoirs are known for strong heterogeneity,complex wettability,and challenging development.Gas-Assisted Gravity Drainage(GAGD)technology has the potential to significantly improve recovery efficiency in glutenite reservoir.However,there is currently limited research on GAGD processes specifically designed for glutenite reservoirs,and there is a lack of relevant dimensionless numbers for predicting recovery efficiency.In this study,we developed a theoreti-cal model based on the characteristics of glutenite reservoirs and used phase-field method to track the oil-gas interface for numerical simulations of dynamic GAGD processes.To explore the factors influencing gas-driven recovery,we simulated the effects of strong heterogeneity and dynamic wettability on the construction process under gravity assistance.Additionally,we introduced multiple dimensionless numbers(including capillary number,viscosity ratio,and Bond number)and conducted a series of numerical simulations.The results demonstrate that gravity enhances the stability of the oil-gas interface but causes unstable pressure fluctuations when passing through different-sized throat regions,particularly leading to front advancement in smaller throats.Although strong heterogeneity has negative impacts on GAGD,they can be mitigated by reducing injection velocity.Increasing oil-wettability promotes oil displacement by overcoming capillary forces,particularly in narrower pores,allowing residual oils to be expelled.Among the dimensionless numbers,the recovery efficiency is directly proportional to the Bond number and inversely proportional to the capillary number and viscosity ratio.Through sensitivity analysis of the dimensionless numbers'impact on the recovery efficiency,a new dimensionless NGlu considering heterogeneity is proposed to accurately predict GAGD recovery of tight glutenite reservoirs.

摘要：Coal-based soild wastes(CBSWs)are industrial byproducts that can be harmful to the environment.The exploitation and utilization of CBSWs offer societal advantages such as resource conservation,pollution reduction,and cost-effective production.However,environmentally sustainable management remains a worldwide challenge due to the substantial production volume and limited disposal capacity of CBSWs.The physicochemical properties and utilization of CBSWs are summarized,including fly ash,coal gangue and coal gasification slag.It also presents the current global applications status of CBSWs resources and examines market supply and demand.Subsequently,the paper provides an overview of studies on ways to utilise CBSWs,highlighting the primary avenues of CBSWs resource utilization which are mainly from the fields of chemical materials,metallurgy and agriculture.Furthermore,a comparative evaluation of the various methods for CBSWs resource recovery is conducted,outlining their respective advantages and disadvantages.The future development of CBSWs recycling processes is also discussed.The review concludes that while there is a growing need for attention in CBSWs recycling,its utilization will involve a combination of both large-scale treatment and refinement processes.The paper aims to offer references and insights for the effective utilization and environmental protection of CBSWs.Future direction will focus on the collaborative utilization of CBSWs,emphasizing on the combination of large-scale and high-value utilization.In addition,there is a need to establish a comprehensive database based on on-site production practices,explore on-site solutions to reduce transportation costs,and improve physicochemical properties during the production process.

摘要：The increasing atmospheric CO2 concentration linked to human activity results in global warming by the greenhouse effect.This anthropogenic CO2 may be sequestrated into geological formations,e.g.,porous basalts,saline aquifers,depleted oil or gas reservoirs,and unmineable coal seams.Furthermore,carbon capture,utilization,and storage(CCUS)methods are an acceptable and sustainable technology to meet the goals of the Paris Agreement,in which Kazakhstan is expected to reduce greenhouse gas emissions by 25％compared with the 1990 level.Unmineable coal seams are an attractive option among all geostorage solutions,as CO2 sequestration in coal comes with an income stream via enhanced coalbed methane(ECBM)recovery.This paper identifies four carboniferous coal formations,namely Karagandy,Teniz-Korzhinkol,Ekibustuz,and Chu coal basins of Kazakhstan,as CO2 geostorage solutions for their unmineable coal seams.The ideal depth of CO2 storage is identified as 800 m to ensure the supercritical state of CO2.However,the Ekibustuz coal basin fails to meet the required depth of 800 m in its unmineable coal seams.The conventional formula for calculating CO2 storage in coal basins has been modified,and a new formula has been proposed for assessing the CO2 storage potential in a coal seam.The CO2 storage capacities of unmineable coal seam of these coal basins are 24.60 Bt,0.61 Bt,14.02 Bt,and 5.42 Bt,respectively.The Langmuir volume of the coal fields was calculated using the proximate analysis of coalfields and found to vary between 36.42 and 98.90 m3/ton.This paper is the first to outline CO2 storage potential in Kazakhstani coal basins,albeit with lim-ited data,along with a detailed geological and paleographic review of the carboniferous coalfields of Kazakhstan.A short overview of the CO2-ECBM process was also included in the paper.Instead of any experimental work for CO2 storage,this paper attempts to present the CO2 storage capacity of carboniferous coal formation using the modified version of previously determined formulas for CO2 storage.

摘要：Soft rock is one of the common geological conditions in coal mine underground water reservoir engineering.The cross-scale correlation analysis of water erosion soft lithology deterioration is very important for the safety and stability of coal mine underground reservoir(CMUR)engineering.To address the issues of grain crowding and segmentation difficulties in cross-scale correlation analysis,as well as the limitations of traditional etching methods,this study proposes an image grain segmentation method based on deep learning algorithms,utilizing scanning electron microscopy and image process-ing techniques.The method successfully segments crowded grains and eliminates the interference from misplaced particles.In addition,indoor uniaxial compression tests were conducted to obtain the mechanical properties of sandstone samples with different water content.By quantitatively characterizing the macroscopic and microscopic deterioration degree of red sandstone samples with different water contents,the relationship between the strength changes of rock samples and the pet-rographic parameters such as grain size and grain shape is analyzed,and the influence law of soft lithology deterioration in CMUR engineering is revealed.The results indicate:(1)Water significantly weakens the mechanical properties and stability of soft rock.With increasing water content,the strength of sandstone samples continuously decreases,and the failure mode transitions from brittle to ductile failure.(2)The deterioration of micro-micro structures is the main cause of the decrease in mechanical properties of water-eroded soft rock.Grain size,grain area,and aspect ratio are negatively correlated with water content,indicating that hydrophilic minerals in soft rock dissolve under the action of water,leading to rock damage.(3)Grain size,area,and aspect ratio can serve as significant indicators for quantifying the strength changes of water-eroded soft rock.The research findings can be applied to stability assessment and disaster prevention in CMUR engineering.

摘要：This paper investigates China's coal price volatility spreaders(CPVSs)from the supply side to locate the volatility source since coal price volatility may destabilize many downstream products' prices or even bring uncertainties to macroeconomic output.Especially in the carbon neutrality context,China's coal market is being reconstructed and responding to imbalances between supply and demand;identifying the CPVSs helps alleviate rising market instability and prevent energy-induced system risk.To achieve this objective,we explore causalities among 938 weekly coal prices reported by different coal-producing areas of China from 2006.9.4 to 2021.7.12 using the transfer entropy method.Then,coal price volatility influence is quantified to identify the CPVSs by conjointly using complex network theory and a rank aggregation method.The validity test demonstrates that the proposed hybrid method efficiently identifies the CPVSs as it correlates to many price determinants,e.g.,electricity and coal consumption and generation.The empirical results show that causalities among coal prices changed dramatically in 2016,2018,and 2020,affected by coal decapacity and carbon neutrality policies.Before 2018,coal-producing provinces with strong demand for coal and electricity,e.g.,Jiangxi,Chongqing,and Sichuan,were CPVSs;after 2019,those with comparative advantages in coal supply,e.g.,Gansu and Ningxia,were CPVSs.Overall,the coal market is unstable and sensitive to energy policy and external shocks.Policymakers and market participants are recommended to monitor and manage the CPVSs to improve energy security,avoid policy-induced instability and prevent risks caused by coal price fluctuations.

摘要：With the continuous development of various industries and the increasing use of electricity and fuel,the emission of large amounts of greenhouse gases has seriously affected the ecosystem.Bulk coal is often used as a fuel for metallurgy and power generation,but the harmful gases produced by its combustion cause serious pollution to the environment.To reduce the emission of harmful gases,we found that biomass briquette has the characteristics of low heavy metal content and less pollutant release when burned.In this paper,the preparation and influencing factors of biomass briquette,the characteristics of different types of biomass briquette and the pollution characteristics of biomass briquette are reviewed.The potential pollution during the preparation and combustion of biomass briquette was also discussed from the perspective of life cycle assessment.Compared with bulk coal,biomass briquette emits fewer toxic gases during preparation and combustion,such as NOx and SO2.Secondly,the preparation of biomass briquette can also reduce the burden of water resources and soil.To that end,we explore the hazards caused by the preparation and combustion of biomass briquette,analyze its impact on the environment and human body,and summarize the sulfur and nitrogen retention capacity of biomass briquette to achieve the purpose of reducing harmful gas emissions.The results show that biomass briquette can be used as clean coal-based energy instead of traditional energy because of its low harmful substance content.The development and application prospect of biomass briquette under the framework of sustainable development are discussed.

摘要：Fissured coal mass under triaxial unloading condition exhibits higher burst potential than the triaxial loading condition,which poses challenge to safety and productivity of resources extraction and underground space utilization.To compre-hensively understand the mechanism of unloading-induced burst during excavation process,this study investigated the fracture and energy evolution of samples with different fissure types such as single,two parallel,and two coplanar-parallel using PFC2D modelling.Triaxial loading tests were conducted to determine the compressive strengths and other parame-ters.With increase of fissure inclination angle,the triaxial compressive strength decreases for β=0°-30°,and then increase forβ=30°-90°.The strength of samples with two coplanar-parallel fissures is the highest.Fissure can significantly change the distribution of fracture and elastic energy.Secondary cracks were generated starting from both ends of the fissure.Forβ=0°-60°,low elastic strain energy area was produced around the fissure along the loading direction.The elastic strain energy is transferred to the outside of fissures.For β=75°-90°,only a small amount of high elastic strain energy was generated on both sides of the fissure.The fracture expansion under unloading conditions occurred due to tensile stress T caused by unloading differential rebound deformation and the shear stress on the fissure surface.

摘要：This work investigates the influence of carbon residue on the crystallization and solidification behavior of slag at different temperatures and cooling methods as it has a significant impact on the flow and discharge of slag,as well as the proper func-tioning of gasification equipment.The experimental approach involves the utilization of various techniques,namely ash fusion temperature(AFT)tests,X-ray fluorescence spectroscopy,X-ray diffraction(XRD),scanning electron microscopy(SEM),differential thermal analysis(DSC),and K-value semiquantitative analysis.The results obtained from ash fusion temperature(AFT)tests indicate that the coarse slag exhibits a relatively higher flow temperature compared to the decarburized coarse slag.XRD analysis reveals the presence of diffraction peaks corresponding to Fe and Fe3Si when residue carbon is present in the slag.In contrast,no such peaks are observed in the decarburized coarse slag subjected to the same temperature and cooling mode.This implying that the carbothermal reaction affects the slag's crystallization behavior,consequently influencing the flow temperature in the presence of residual carbon.SEM analysis illustrates that the spheroidization phenomenon is obvious when there is residual carbon in the coarse slag,but there is no spheroidization phenomenon in the decarburized coarse slag.This shows that the surface tension of slag is affected by the presence of residual carbon.Furthermore,DSC results confirm the crystallization transformation and mineral decomposition of the slag at high temperatures.For both carbon-containing slag and decarburized coarse slag,the content of crystals obtained under quenching condition is obviously lower than that under natural cooling condition.

摘要：A novel block-particle discrete-element simulation method that matches the double medium of overlying rock(OLR)and loose layer(LSL)in coal mining is developed in this study.This method achieves the collaborative failure characteristics of mining damage under the conduction of double media between the OLR and LSL by combining the self-weight stress load-ing of the LSL and the breakage morphology of the bedrock top.Based on this,the conduction law of high-strength mining damage in the double medium in a western mining area is simulated and analyzed.The combining effect of the OLR break-age morphology and LSL characteristics on the surface-subsidence characteristics is analyzed and verified based on on-site measurements.The results indicate that the OLR is guided by the"double-control layer and thick-soft rock buffer layer"and shows"grouping subsidence",whereas the surface forms collaborative subsidence with the thick-soft rock buffer layer.In the ultra-full mining stage,the surface presents an"asymmetric inverted trapezoidal"subsidence trough shape.The simulation results agree well the on-site measurements in terms of the surface-subsidence and bedrock-subsidence coefficients.The proposed simulation method provides a scientific approach for investigating the micro-conduction mechanism of mining damage under the effect of high-strength mining in western mining areas.It will benefit future investigations pertaining to the characteristics of OLR breakage and surface subsidence under conditions such as LSL thickness and proportion.

摘要：The 3D reconstruction of digital rocks assumes a paramount role within various engineering applications,necessitating careful consideration of the methods employed.The available approaches are divided into two groups,i.e.,the physical experimental method and the numerical simulation method.Although the former is reliable,it incurs high costs and is limited by sample size constraints.The latter is cost-effective but suffers from prolonged processing times and sometimes suboptimal performance.However,the advent of deep learning has paved the way for integrating these techniques into 3D digital rock reconstruction.A standout amongst the method of deep learning techniques is the generative adversarial network(GAN).Nonetheless,existing models of GAN lack complete integration of multi-scale information.To address this issue,this study proposed style-transformer GAN(STGAN),a novel GAN model founded upon style-based GAN(StyleGAN)and Transformer.By utilizing the attention mechanisms of Transformer,STGAN ameliorates its ability to extract features from multi-scale training images.Additionally,the incorporation of style transfer further enhances the quality of the generated images.By comparing it with other deep learning algorithms,the efficiency and applicability of the proposed method are demonstrated.

摘要：As the mine depth around the world increases,the temperature of the surrounding rock of the mining workface increases significantly.To control the heat hazards,the hot water in the mining floor is developed during mining to decrease the min-ing workface temperature while also developing geothermal energy.This method is called the co-exploitation of mine and geothermal energy(CMGE).The geothermal development may precipitate the large-scale failure of the nearby fault zone during the mining process.However,the evolution of shear slide and shear failure of fault under geothermal production/rein-jection during mining is missing.Therefore,a fully-coupled hydraulic mechanism(HM)double-medium model for CMGE was developed based on the measured data of the Chensilou mine.A comparative analysis of the mechanical response of fault between CMGE and single mining was conducted.The disturbance of geothermal production pressure and reinjection pressure under mining on fault stability were respectively expounded.The results indicate that:(1)The disturbance of geo-thermal reinjection amplifies the disturbance of mining on fault stability.The amplified effect resulted in a normal stress drop of the fault,further leading to a substantial increase in shear slide distance,failure area,and cumulative seismic moment of fault compared with the single mining process.(2)As the distance of reinjection well to the fault decreases,the fault failure intensity increases.Setting the production well within the fault is advantageous for controlling fault stability under CMGE.(3)The essence of the combined disturbance of CMGE on the nearby fault is the overlay of tensile stress disturbance on the fault rock mass of the mining and geothermal reinjection.Though the geothermal reinjection causes a minor normal stress drop of fault,it can result in a more serious fault failure under CMGE.This paper supplies a significant gap in understanding the nearby faults failure under CMGE.

摘要：The oil and gas industry is increasingly focusing on exploring and developing resources in deep earth layers.At high tempera-tures,confining pressures,and geostress differences,rock has the mechanical characteristics of plastic enhancement,which leads to the unclear mechanism of hydraulic fracture expansion.The current fracturing model and construction design lack pertinence,and the fracturing reform is difficult to achieve the expected effect.This paper established a model of elastoplastic hydraulic fracture propagation in deep reservoirs.It considered the enhancement of plasticity by examining the elastoplastic deformation and nonlinear fracturing characteristics of the rock.The results confirmed that the hydraulic fractures in deep reservoirs propagated due to plastic energy dissipation after fracture tip passivation,while the stress concentration declined,which increased propagation resistance.The relationship between geology,engineering factors,degree of plasticity,and fracture propagation is discussed,while the conditions that promote fracture propagation are analyzed to provide theoretical support for deep reservoir fracturing design.

摘要：In this article,the contemporary stress state of the Zhao-Ping metallogenic belt in eastern China was revealed using over-coring and hydraulic fracturing stress data,the relation between the stress field and geological tectonics was discussed,and the stability of regional faults under the present-day stress environment was evaluated.The results indicate that the stress level is considerably high,and the distribution of stress intensity is uneven.The stress regime is primarily characterized by σH＞σv＞σh.The σH orientation is well-oriented in the WNW-ESE,which is roughly identical to other stress indica-tors.Moreover,the σH direction reflected by joint strikes and inferred based on the fault characteristics agrees fairly with the identified stress orientation.The modem stress field basically inherited the tectonic stress field of the Yanshanian and Himalayan periods but is principally dominated by the Himalayan period.Additionally,the calculated μm ranges from 0.2 to 0.7,indicating that the possibility of shallow faults across this area being reactivated and experiencing shear failure is small overall under the current stress conditions.μm=0.2 and 0.5 are suggested as the lower and upper limits for predict-ing and analyzing future fault activity in the area,respectively.

摘要：The increasingly severe state of coal burst disaster has emerged as a critical factor constraining coal mine safety production,and it has become a challenging task to enhance the accuracy of coal burst disaster prediction.To address the issue of insuf-ficient exploration of the spatio-temporal characteristic of microseismic data and the challenging selection of the optimal time window size in spatio-temporal prediction,this paper integrates deep learning methods and theory to propose a novel coal burst spatio-temporal prediction method based on Bidirectional Long Short-Term Memory(Bi-LSTM)network.The method involves three main modules,including microseismic spatio-temporal characteristic indicators construction,temporal prediction model,and spatial prediction model.To validate the effectiveness of the proposed method,engineering applica-tion tests are conducted at a high-risk working face in the Ordos mining area of Inner Mongolia,focusing on 13 high-energy microseismic events with energy levels greater than 105 J.In terms of temporal prediction,the analysis indicates that the temporal prediction results consist of 10 strong predictions and 3 medium predictions,and there is no false alarm detected throughout the entire testing period.Moreover,compared to the traditional threshold-based coal burst temporal prediction method,the accuracy of the proposed method is increased by 38.5％.In terms of spatial prediction,the distribution of spatial prediction results for high-energy events comprises 6 strong hazard predictions,3 medium hazard predictions,and 4 weak hazard predictions.

摘要：The Middle Pennsylvanian,Langsettian sub-stage Clintwood coal,along with its correlatives,was one of the more important energy resources in eastern Kentucky.The coal thickens from the NE-SW-trending Belfry anticline in central Pike County to the southeast,towards the Virginia-Kentucky border.Much of the thickness increase is in the bright lithotypes below a dull lithology.The bright lithologies transition from a bright clarain+vitrain+fusain lithology to a clarain+fusain lithol-ogy to the southeast.Half of the lithotypes in the three analyzed sections exceed 1000-μg/g Rare earth elements+Y+Sc(REYSc)(ash basis).The LaN/SmN vs.GdN/YbN and LaN/SmN vs.CeN/CeN* plots suggest that the top lithotype may have had best indication of an oxidizing environment.Positive GdN/GdN* and EuN/EuN* in some of the lithologies suggests that there may have been a hydrothermal influence in the sediment sources and/or in the diagenesis of the coal.Consideration of LaN/SmN and Zr(μg/g;ash basis),Zr vs.Sr,and V/Cr vs.inertinite/(inertinite+vitrinite)indicates that the dull lithotypes existed in a distinct geochemical environment compared to the brighter lithotypes.The isolation of the dull lithotypes from the bright lithotypes is supported by principal components analysis on inertinite/(inertinite+vitrinite),LaN/SmN,V/Cr,Sr,and either Zr or Ln(100(TiO2)/Al2O3).

摘要：The Grey Wolf Optimization(GWO)algorithm is acknowledged as an effective method for rock acoustic emission localiza-tion.However,the conventional GWO algorithm encounters challenges related to solution accuracy and convergence speed.To address these concerns,this paper develops a Simplex Improved Grey Wolf Optimizer(SMIGWO)algorithm.The randomly generating initial populations are replaced with the iterative chaotic sequences.The search process is optimized using the convergence factor optimization algorithm based on the inverse incomplete Γ function.The simplex method is utilized to address issues related to poorly positioned grey wolves.Experimental results demonstrate that,compared to the conventional GWO algorithm-based AE localization algorithm,the proposed algorithm achieves a higher solution accuracy and showcases a shorter search time.Additionally,the algorithm demonstrates fewer convergence steps,indicating superior convergence efficiency.These findings highlight that the proposed SMIGWO algorithm offers enhanced solution accuracy,stability,and optimization performance.The benefits of the SMIGWO algorithm extend universally across various materials,such as aluminum,granite,and sandstone,showcasing consistent effectiveness irrespective of material type.Consequently,this algorithm emerges as a highly effective tool for identifying acoustic emission signals and improving the precision of rock acoustic emission localization.