The northern structural belt of Kuqa Depression is adjacent to the South Tianshan orogenic belt, which are characterized by complex geological conditions. The reservoir quality of the Jurassic Ahe Formation is control...The northern structural belt of Kuqa Depression is adjacent to the South Tianshan orogenic belt, which are characterized by complex geological conditions. The reservoir quality of the Jurassic Ahe Formation is controlled by sedimentation, diagenesis, and tectonics, and show complex pore structure and strong heterogeneity, thereby hindering effective natural gas exploration and development. Core, thin sections, cathodoluminescence (CL), scanning electron microscopy (SEM), conventional well logs and image logs are used to characterize the petrological characteristics and pore systems. Then a comprehensive analysis integrating sedimentation, diagenesis, and tectonics is performed to unravel the reservoir formation mechanism and distribution of reservoir quality. Results show that reservoir properties are generally environmentally selective. Coarse grained sandbodies (gravelly sandstones) formed in high depositional-energy have the best physical properties, while fine sandstone and mudstone with low depositional energy is easily to be tightly compacted, and have poor reservoir quality. Porosity usually decreases with compaction and cementation, and increases due to dissolution. Clay minerals filling pores result in a deterioration of the pore structure. Microfracture formed by fracturing can connect the matrix pores, effectively improving the reservoirs’ permeability. The differential distribution of fractures and in-situ stress plays an important role in modifying reservoir quality. The in-situ stress has obvious control over the matrix physical properties and fracture effectiveness. The matrix physical properties are negatively correlated with the value of horizontal stress difference (Δσ). As the value of Δσ increases, the pore structure becomes more complex, and the macroscopic reservoir quality becomes poor. The smaller the strike divergence between the natural fracture and SHmax, the lower the value of Δσ in the fracture layers is, and the better the fracture effectiveness is. Under the control of ternary factors on the reservoir, sedimentation-diagenesis jointly affect the matrix reservoir quality, while fractures and in-situ stress caused by tectonism affect the permeability and hydrocarbon productivity of the reservoir. Affected by ternary factors, reservoir quality and hydrocarbon productivity show obvious differences within the various structural location. Reservoir quality in tight sandstones can be predicted by integrating sedimentation, diagenesis, and tectonics (fracture and in-situ stress) in a compressional tectonic setting like Kuqa Depression. The research results will provide insights into the efficient exploration of oil and gas in Kuqa Depression as well as similar compressional tectonic settings elsewhere.展开更多
A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed here.This method can evaluate the longitudinal stress evolution of each composite layer as impregnated fila...A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed here.This method can evaluate the longitudinal stress evolution of each composite layer as impregnated filaments with fiber tension are wound layer by layer,and consider the effects of accumulated stress and deformation during filament winding on the bursting strength of composite case.Taking∅520 mm composite cases as a case study,the filament-winding-process-induced stress and deformation as well as progressive damage behavior are numerically predicted,followed by a comparison with experimental results.The numerical results show that the predicted bursting pressures for composite cases manufactured on the mandrels with and without a flexible component are 14.20 MPa and 21.40 MPa,respectively.These values exhibit slight deviation from the measured pressures of 13.50 MPa and 21.57 MPa.Moreover,the predicted damage locations,situated respectively in the dome and cylinder,agree well with the experimental observation.These observations indicate that use of flexible component reduces the load-bearing capacity of the domes.Furthermore,it validates the reliability and accuracy of the proposed numerical method in predicting the bursting strength of composite cases.展开更多
Coaly source rocks have attracted considerable attention for their significant hydrocarbon generation potential in recent years. However, limited study is performed on utilizing geochemical data and well log data to e...Coaly source rocks have attracted considerable attention for their significant hydrocarbon generation potential in recent years. However, limited study is performed on utilizing geochemical data and well log data to evaluate coaly hydrocarbon source rocks. In this study, geochemical data and well log data are selected from two key wells to conduct an evaluation of coaly hydrocarbon source rocks of Jurassic Kezilenuer Formation in Kuqa Depression of Tarim Basin. Initially, analysis was focused on geochemical parameters to assess organic matter type, source rock quality, and hydrocarbon generation potential.Lithology types of source rocks include mudstone, carbonaceous mudstone and coal. The predominant organic matter type identified was Type Ⅲ and Type Ⅱ_(2), indicating a favorable hydrocarbon generation potential. Well log data are integrated to predict total organic carbon(TOC) content, and the results indicate that multiple regression method is effective in predicting TOC of carbonaceous mudstone and coal. However, the ΔlgR method exhibited limited predictive capability for mudstone source rock.Additionally, machine learning methods including multilayer perceptron neural network(MLP), random forest(RF), and extreme gradient boosting(XGBoost) techniques are employed to predict TOC of mudstone source rock. The XGBoost performs best in TOC prediction with correlation coefficient(R2) of 0.9517, indicating a close agreement between measured and predicted TOC values. This study provides a reliable prediction method of coaly hydrocarbon source rocks through machine learning methods, and will provide guidance for resource assessment.展开更多
On September 5,2022,an M_(S)6.8 earthquake struck Luding County,Kardze Prefecture,Sichuan Province—an area that is particularly vulnerable to geological changes.The earthquake caused considerable damage along the hig...On September 5,2022,an M_(S)6.8 earthquake struck Luding County,Kardze Prefecture,Sichuan Province—an area that is particularly vulnerable to geological changes.The earthquake caused considerable damage along the highway,leading to road disruptions and blockages,further isolating earthquake-stricken areas.Accordingly,a rapid survey of the main highways in this area was conducted,and 507 damage points were identified.Roadbed damage accounted for more than 70%of the total damages.Co-seismic disasters were primarily distributed along the highways on both sides of the Dadu River in the reservoir area of the Dagangshan Hydropower Station,Caoke Township,and Detuo Township.Further,six factors under three categories of the spatial distribution of highway damage in the earthquake-stricken areas were analyzed.The rate of highway damage was positively correlated with the seismic intensity but negatively correlated with the fault and river distances.The earthquake intensity had the most significant impact:37.5%of road disruptions were found in areas with an intensity of IX;this percentage was 1.6 and 5.8 times greater than those found in areas with intensities of VIII and VII,respectively.The roads with the most significant damage were in regions with intensities above VIII,faults within 5 km,slopes within 30°–70°,rivers within 100 m,and the presence of granite.This indicated that these factors aggravated highway disruption,resulting in more than 90% of damaged highways in strongly shaken regions.Our findings may provide guidance for efficient highway recovery following earthquakes.展开更多
Isotropic pyrolytic carbon(IPC)is renowned for its robust mechanical,biological,and tribological prop-erties.However,the current mechanisms for modulating IPC microstructure are insufficient to achieve higher performa...Isotropic pyrolytic carbon(IPC)is renowned for its robust mechanical,biological,and tribological prop-erties.However,the current mechanisms for modulating IPC microstructure are insufficient to achieve higher performance.Herein,this study provides nanoscale insights into the formation and property reg-ulation of the core-shell structure of the IPC,integrating simulation and experimental approaches.Large-scale reactive molecular dynamics simulations elucidate the microstructural evolution and assembly pro-cesses from precursors to nanoparticles and intertwined graphene networks.Simulation process charac-terization enable versatile adjustment of IPC microstructural features and one-step deposition of hybrid structures with disordered cores and ordered shell layers.Compared to Pyrolytic carbon(PyC)with lam-inated graphene arrangement,the prepared hybrid structure enables rapid assembly of large-size stan-dalone carbon components.Moreover,the hybrid architecture effectively improves the core-shell phase connection and significantly increases the interfacial shear stress within the intertwined graphene shell layers.Consequently,it greatly improves load transfer efficiency and enhances crack-bridging toughening effect.The endeavor to establish precise microstructure formation and property regulation in IPC materi-als promises to steer high-performance carbon materials toward distinct developmental trajectories.展开更多
Larger-sized primary carbides lead to stress concentration during the application of H13 hot-work die steel,resulting in microcracks and fatigue failure.Rare earth was usually added to modify the carbides and inclusio...Larger-sized primary carbides lead to stress concentration during the application of H13 hot-work die steel,resulting in microcracks and fatigue failure.Rare earth was usually added to modify the carbides and inclusions.The existing literature is reviewed on the effect of rare earth on primary carbides in H13 steel.A comprehensive review on the effect of rare earth on the characteristics of primary carbides,i.e.,number,size,morphology,and thermal stability in H13 steel,was done.The precipitation mechanism and nucleation of primary carbides with rare earth were summarized.The position and form of rare earth in steel and their effects on alloying elements segregation were reviewed.The addition techniques of rare earth in H13 steel were compared,and the prospects for other uncommon rare earth and emerging technology were present.Based on the current references,it can be known that adding rare earth facilitated refined and dispersed primary carbides.The size of primary carbides would be reduced,and their morphology would be improved because the rare earth inclusions formed in H13 steel can act as nucleation cores forγ-Fe orδ-Fe,refining the dendritic structure.Besides,the number of primary carbides at grain boundaries would be significantly reduced.However,rare earth had little impact on thermal stability.The nucleation of primary carbides tended to be inhibited due to the modification of inclusions by rare earth which were likely to be nucleation cores for primary carbides.Rare earth had been reported to affect the mechanism and process of primary carbide precipitation.Additionally,the addition of rare earth can inhibit the segregation of alloying elements and carbon diffusion by calculation.Thus,laboratory experiments and theoretical calcu-lations need to be conducted to study the states and evolution of rare earth steels.展开更多
Coal chemical wastewater(CCW)is a type of refractory industrial wastewater,and its treatment has become the main bottleneck restricting the sustainable development of novel coal chemical industry.Biological treatment ...Coal chemical wastewater(CCW)is a type of refractory industrial wastewater,and its treatment has become the main bottleneck restricting the sustainable development of novel coal chemical industry.Biological treatment is considered as an economical,effective and environmentally friendly technology for CCW treatment.However,conventional biological process is difficult to achieve the efficient removal of refractory organics because of CCW with the characteristics of composition complexity and high toxicity.Therefore,seeking the novel enhancement strategy appears to be a favorable solution for enhancing biological treatment efficiency of CCW.This review focuses on presenting a comprehensive picture about the exogenous enhancement strategies for CCW biological treatment.The performance and potential application of exogenous enhancement strategies,including co-metabolic substrate enhancement,biofilm filler enhancement,adsorption material enhancement and conductive mediator enhancement,were expounded.Meanwhile,the enhancing mechanisms of different strategies were comprehensively discussed from a biological perspective.Furthermore,the prospects of enhancement strategies based on the engineering performance,economic cost and environmental impact(3E)evaluation were introduced.And novel enhancement strategy based on“low carbon emissions”,“resource recycling”and“water environment security”in the context of carbon neutrality was proposed.Taken together,this review provides technical reference and new direction to facilitate the regulation and optimization of typical industrial wastewater biological treatment.展开更多
Understanding the vertical distribution of ozone is crucial when assessing both its horizontal and vertical transport,as well as when analyzing the physical and chemical properties of the atmosphere.One of the most ef...Understanding the vertical distribution of ozone is crucial when assessing both its horizontal and vertical transport,as well as when analyzing the physical and chemical properties of the atmosphere.One of the most effective ways to obtain high spatial resolution ozone profiles is through satellite observations.The Environmental Trace Gases Monitoring Instrument(EMI)deployed on the Gaofen-5 satellite is the first Chinese ultraviolet-visible hyperspectral spectrometer.However,retrieving ozone profiles using backscattered radiance values measured by the EMI is challenging due to unavailable measurement errors and a low signal-to-noise ratio.The algorithm developed for the Tropospheric Monitoring Instrument did not allow us to retrieve 87%of the EMI pixels.Therefore,we developed an algorithm specific to the characteristics of the EMI.The fitting residuals are smaller than 0.3%in most regions.The retrieved ozone profiles were in good agreement with ozonesonde data,with maximum mean biases of 20%at five latitude bands.By applying EMI averaging kernels to the ozonesonde profiles,the integrated stratospheric column ozone and tropospheric column ozone also showed excellent agreement with ozonesonde data,The lower layers(0-7.5 km)of the EMI ozone profiles reflected the seasonal variation in surface ozone derived from the China National Environmental Monitoring Center(CNEMC).However,the upper layers(9.7-16.7 km)of the ozone profiles show different trends,with the ozone peak occurring at an altitude of 9.7-16.7 km in March,2019.A stratospheric intrusion event in central China from August 11 to 15,2019,is captured using the EMI ozone profiles,potential vorticity data,and relative humidity data.The increase in the CNEMC ozone co ncentration showed that downward transport enhanced surface ozone pollution.展开更多
It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotox...It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotoxicity reduction of industrial wastewater are still limited.In this study,the toxic organics removal and biotoxicity reduction of coal chemical wastewater(CCW)along a novel full-scale treatment process based on the pretreatment process-anaerobic process-biological enhanced(BE)process-anoxic/oxic(A/O)process-advanced treatment process was evaluated.This process performed great removal efficiency of COD,total phenol,NH_(4)^(+)-N and total nitrogen.And the biotoxicity variation along the treatment units was analyzed from the perspective of acute biotoxicity,genotixicity and oxidative damage.The results indicated that the effluent of pretreatment process presented relatively high acute biotoxicity to Tetrahymena thermophila.But the acute biotoxicity was significantly reduced in BE-A/O process.And the genotoxicity and oxidative damage to Tetrahymena thermophila were significantly decreased after advanced treatment.The polar organics in CCW were identified as the main biotoxicity contributors.Phenols were positively correlated with acute biotoxicity,while the nitrogenous heterocyclic compounds and polycyclic aromatic hydrocarbons were positively correlated with genotoxicity.Although the biotoxicity was effectively reduced in the novel full-scale treatment process,the effluent still performed potential biotoxicity,which need to be further explored in order to reduce environmental risk.展开更多
The sodium smelting of vanadium-titanium magnetite can achieve the comprehensive utilization of Fe,V,and Ti.However,the generation of alkaline slag during this process may cause damage to refractory materials.The wett...The sodium smelting of vanadium-titanium magnetite can achieve the comprehensive utilization of Fe,V,and Ti.However,the generation of alkaline slag during this process may cause damage to refractory materials.The wettability and corrosion behavior of alkaline slag on three types of refractory(MgO-C,SiC,and high alumina refractory)substrates were investigated at temperatures up to 1200℃.The effects of duration on the wettability of molten slag on SiC substrates were also investigated.Results showed that the high alumina refractory exhibited better wettability with the molten slag than the others,and thus,it is easier to be corroded.The results of scanning electron microscopy coupled with energy dispersive spectroscopy showed that MgO-C and high alumina refractory substrates were severely eroded.There was a visible and regular interfacial reaction layer between the slag and SiC refractory substrate,which was produced by the redox reaction between the metal oxides in the slag and the SiC refractory substrate.With the increase in holding time,the interface layer expands and silico-ferrite phases are generated at the interface.The redox reaction between Fe_(2)O_(3) and SiC substrate is the main reason for the corrosion.By comparing the differences in wettability and corrosion behavior between the alkaline slag from sodium smelting of vanadium-titanium magnetite and MgO-C,SiC and high alumina refractories,it is concluded that SiC refractory has good corrosion resistance to the slag.Iron oxides in the slag accelerate the oxidation rate of SiC refractory.展开更多
Pore pressure is essential data in drilling design,and its accurate prediction is necessary to ensure drilling safety and improve drilling efficiency.Traditional methods for predicting pore pressure are limited when f...Pore pressure is essential data in drilling design,and its accurate prediction is necessary to ensure drilling safety and improve drilling efficiency.Traditional methods for predicting pore pressure are limited when forming particular structures and lithology.In this paper,a machine learning algorithm and effective stress theorem are used to establish the transformation model between rock physical parameters and pore pressure.This study collects data from three wells.Well 1 had 881 data sets for model training,and Wells 2 and 3 had 538 and 464 data sets for model testing.In this paper,support vector machine(SVM),random forest(RF),extreme gradient boosting(XGB),and multilayer perceptron(MLP)are selected as the machine learning algorithms for pore pressure modeling.In addition,this paper uses the grey wolf optimization(GWO)algorithm,particle swarm optimization(PSO)algorithm,sparrow search algorithm(SSA),and bat algorithm(BA)to establish a hybrid machine learning optimization algorithm,and proposes an improved grey wolf optimization(IGWO)algorithm.The IGWO-MLP model obtained the minimum root mean square error(RMSE)by using the 5-fold cross-validation method for the training data.For the pore pressure data in Well 2 and Well 3,the coefficients of determination(R^(2))of SVM,RF,XGB,and MLP are 0.9930 and 0.9446,0.9943 and 0.9472,0.9945 and 0.9488,0.9949 and 0.9574.MLP achieves optimal performance on both training and test data,and the MLP model shows a high degree of generalization.It indicates that the IGWO-MLP is an excellent predictor of pore pressure and can be used to predict pore pressure.展开更多
Phlomoides,with 150-170 species,is the second largest and perhaps most taxonomically challenging genus within the subfamily Lamioideae(Lamiaceae).With about 60 species,China is one of three major biodiversity centers ...Phlomoides,with 150-170 species,is the second largest and perhaps most taxonomically challenging genus within the subfamily Lamioideae(Lamiaceae).With about 60 species,China is one of three major biodiversity centers of Phlomoides.Although some Phlomoides species from China have been included in previous molecular phylogenetic studies,a robust and broad phylogeny of this lineage has yet to be completed.Moreover,given the myriad new additions to the genus,the existing infrageneric classification needs to be evaluated and revised.Here,we combine molecular and morphological data to investigate relationships within Phlomoides,with a focus on Chinese species.We observed that plastid DNA sequences can resolve relationships within Phlomoides better than nuclear ribosomal internal and external transcribed spacer regions(nrITS and nrETS).Molecular phylogenetic analyses confirm the monophyly of Phlomoides,but most previously defined infrageneric groups are not monophyletic.In addition,morphological analysis demonstrates the significant taxonomic value of eight characters to the genus.Based on our molecular phylogenetic analyses and morphological data,we establish a novel section Notochaete within Phlomoides,and propose three new combinations as well as three new synonyms.This study presents the first molecular phylogenetic analyses of Phlomoides in which taxa representative of the entire genus are included,and highlights the phylogenetic and taxonomic value of several morphological characters from species of Phlomoides from China.Our study suggests that a taxonomic revision and reclassification for the entire genus is necessary in the future.展开更多
In order to enhance the fatigue properties of metallic materials,a feasible rationale is to delay or prevent the interior and surface fatigue crack initiation.Based on this rationale,the study investigates the approac...In order to enhance the fatigue properties of metallic materials,a feasible rationale is to delay or prevent the interior and surface fatigue crack initiation.Based on this rationale,the study investigates the approach of improving the very high cycle fatigue properties of TC6 titanium alloys through near-βforging coupled with shot peening,conducted at 930℃and ambient temperature,respectively.To unveil the associated mechanisms,microstructure,microhardness,residual stress,and fatigue properties are thoroughly analyzed after each process.Results indicate a considerable refinement in microstructure and significant mitigation of the initially existed strong texture post near-βforging and annealing,efficiently delaying crack initiation and propagation.As a result,the very high cycle fatigue property of TC6 achieves remarkable enhancement after forging.Compared to near-βforging,shot peening might not necessarily improve the very high cycle fatigue performance,particularly beyond 10^(6)cycles.展开更多
Geothermal energy is a renewable and environmentally sustainable resource of increasing importance.However,areas with geothermal potential are not easily detected by traditional field investigations,requiring the deve...Geothermal energy is a renewable and environmentally sustainable resource of increasing importance.However,areas with geothermal potential are not easily detected by traditional field investigations,requiring the development of new,robust,and reliable models for detection.In this study,remote sensing data and ground-based variables were used to detect and analyze geothermal resource potential areas.General Land Surface Temperature(GLST)was integrated using 5 years of remote sensing data.Landsat 8 daytime GLST(Landsat-GLST),Moderate Resolution Imaging Spectroradiometer(MODIS)daytime GLST(MODIS-DLST),and MODIS nighttime GLST(MODIS-NLST)data were integrated with Landsat Nighttime Land Surface Temperature(Night-LST),which not only filled the gap of Landsat Night-LST but also improved the spatial resolution of MODIS nighttime temperatures.Specifically,three independent variables(Night-LST,Distance From Known Geothermal Resource Points[DFGP],and Distance From Geological Faults[DFF])were used to develop a weighted model to form a Geothermal Detection Index(GDI)based on Principal Component Analysis(PCA).Along with field verification,the GDI was successfully used to identify three geothermal activity areas in Tengchong City,Yunnan Province.Overall,this work provides a novel method for detecting geothermal potential to support the successful exploitation of geothermal resources.展开更多
基金supported by Science Foundation of China University of Petroleum,Beijing(No.2462023QNXZ010,No.2462023XKBH012,No.2462024XKBH009)China Postdoctoral Science Foundation(No.2024M753612,No.GZC20233101).
文摘The northern structural belt of Kuqa Depression is adjacent to the South Tianshan orogenic belt, which are characterized by complex geological conditions. The reservoir quality of the Jurassic Ahe Formation is controlled by sedimentation, diagenesis, and tectonics, and show complex pore structure and strong heterogeneity, thereby hindering effective natural gas exploration and development. Core, thin sections, cathodoluminescence (CL), scanning electron microscopy (SEM), conventional well logs and image logs are used to characterize the petrological characteristics and pore systems. Then a comprehensive analysis integrating sedimentation, diagenesis, and tectonics is performed to unravel the reservoir formation mechanism and distribution of reservoir quality. Results show that reservoir properties are generally environmentally selective. Coarse grained sandbodies (gravelly sandstones) formed in high depositional-energy have the best physical properties, while fine sandstone and mudstone with low depositional energy is easily to be tightly compacted, and have poor reservoir quality. Porosity usually decreases with compaction and cementation, and increases due to dissolution. Clay minerals filling pores result in a deterioration of the pore structure. Microfracture formed by fracturing can connect the matrix pores, effectively improving the reservoirs’ permeability. The differential distribution of fractures and in-situ stress plays an important role in modifying reservoir quality. The in-situ stress has obvious control over the matrix physical properties and fracture effectiveness. The matrix physical properties are negatively correlated with the value of horizontal stress difference (Δσ). As the value of Δσ increases, the pore structure becomes more complex, and the macroscopic reservoir quality becomes poor. The smaller the strike divergence between the natural fracture and SHmax, the lower the value of Δσ in the fracture layers is, and the better the fracture effectiveness is. Under the control of ternary factors on the reservoir, sedimentation-diagenesis jointly affect the matrix reservoir quality, while fractures and in-situ stress caused by tectonism affect the permeability and hydrocarbon productivity of the reservoir. Affected by ternary factors, reservoir quality and hydrocarbon productivity show obvious differences within the various structural location. Reservoir quality in tight sandstones can be predicted by integrating sedimentation, diagenesis, and tectonics (fracture and in-situ stress) in a compressional tectonic setting like Kuqa Depression. The research results will provide insights into the efficient exploration of oil and gas in Kuqa Depression as well as similar compressional tectonic settings elsewhere.
基金supported by the National Natural Science Foundation of China(No.11902231)the Major Program(JD)of Hubei Province,China(No.2023BAA004).
文摘A numerical method to predict the bursting strength of filament wound composite rocket motor case is proposed here.This method can evaluate the longitudinal stress evolution of each composite layer as impregnated filaments with fiber tension are wound layer by layer,and consider the effects of accumulated stress and deformation during filament winding on the bursting strength of composite case.Taking∅520 mm composite cases as a case study,the filament-winding-process-induced stress and deformation as well as progressive damage behavior are numerically predicted,followed by a comparison with experimental results.The numerical results show that the predicted bursting pressures for composite cases manufactured on the mandrels with and without a flexible component are 14.20 MPa and 21.40 MPa,respectively.These values exhibit slight deviation from the measured pressures of 13.50 MPa and 21.57 MPa.Moreover,the predicted damage locations,situated respectively in the dome and cylinder,agree well with the experimental observation.These observations indicate that use of flexible component reduces the load-bearing capacity of the domes.Furthermore,it validates the reliability and accuracy of the proposed numerical method in predicting the bursting strength of composite cases.
基金supported by Science Foundation of China University of Petroleum(Beijing)(No.2462023QNXZ010).
文摘Coaly source rocks have attracted considerable attention for their significant hydrocarbon generation potential in recent years. However, limited study is performed on utilizing geochemical data and well log data to evaluate coaly hydrocarbon source rocks. In this study, geochemical data and well log data are selected from two key wells to conduct an evaluation of coaly hydrocarbon source rocks of Jurassic Kezilenuer Formation in Kuqa Depression of Tarim Basin. Initially, analysis was focused on geochemical parameters to assess organic matter type, source rock quality, and hydrocarbon generation potential.Lithology types of source rocks include mudstone, carbonaceous mudstone and coal. The predominant organic matter type identified was Type Ⅲ and Type Ⅱ_(2), indicating a favorable hydrocarbon generation potential. Well log data are integrated to predict total organic carbon(TOC) content, and the results indicate that multiple regression method is effective in predicting TOC of carbonaceous mudstone and coal. However, the ΔlgR method exhibited limited predictive capability for mudstone source rock.Additionally, machine learning methods including multilayer perceptron neural network(MLP), random forest(RF), and extreme gradient boosting(XGBoost) techniques are employed to predict TOC of mudstone source rock. The XGBoost performs best in TOC prediction with correlation coefficient(R2) of 0.9517, indicating a close agreement between measured and predicted TOC values. This study provides a reliable prediction method of coaly hydrocarbon source rocks through machine learning methods, and will provide guidance for resource assessment.
基金funded by Sichuan Science and Technology Program(Nos.2023NSFSC1414 and 2023NSFSC0263)Sichuan Transportation Science and Technology Program(No.2018-B-05)Sichuan Communication Surveying&Design Institute CO.,LTD(No.232023002).
文摘On September 5,2022,an M_(S)6.8 earthquake struck Luding County,Kardze Prefecture,Sichuan Province—an area that is particularly vulnerable to geological changes.The earthquake caused considerable damage along the highway,leading to road disruptions and blockages,further isolating earthquake-stricken areas.Accordingly,a rapid survey of the main highways in this area was conducted,and 507 damage points were identified.Roadbed damage accounted for more than 70%of the total damages.Co-seismic disasters were primarily distributed along the highways on both sides of the Dadu River in the reservoir area of the Dagangshan Hydropower Station,Caoke Township,and Detuo Township.Further,six factors under three categories of the spatial distribution of highway damage in the earthquake-stricken areas were analyzed.The rate of highway damage was positively correlated with the seismic intensity but negatively correlated with the fault and river distances.The earthquake intensity had the most significant impact:37.5%of road disruptions were found in areas with an intensity of IX;this percentage was 1.6 and 5.8 times greater than those found in areas with intensities of VIII and VII,respectively.The roads with the most significant damage were in regions with intensities above VIII,faults within 5 km,slopes within 30°–70°,rivers within 100 m,and the presence of granite.This indicated that these factors aggravated highway disruption,resulting in more than 90% of damaged highways in strongly shaken regions.Our findings may provide guidance for efficient highway recovery following earthquakes.
基金supported by the National Natural Science Foundation of China(Nos.52293371,52222204 and 52172103).
文摘Isotropic pyrolytic carbon(IPC)is renowned for its robust mechanical,biological,and tribological prop-erties.However,the current mechanisms for modulating IPC microstructure are insufficient to achieve higher performance.Herein,this study provides nanoscale insights into the formation and property reg-ulation of the core-shell structure of the IPC,integrating simulation and experimental approaches.Large-scale reactive molecular dynamics simulations elucidate the microstructural evolution and assembly pro-cesses from precursors to nanoparticles and intertwined graphene networks.Simulation process charac-terization enable versatile adjustment of IPC microstructural features and one-step deposition of hybrid structures with disordered cores and ordered shell layers.Compared to Pyrolytic carbon(PyC)with lam-inated graphene arrangement,the prepared hybrid structure enables rapid assembly of large-size stan-dalone carbon components.Moreover,the hybrid architecture effectively improves the core-shell phase connection and significantly increases the interfacial shear stress within the intertwined graphene shell layers.Consequently,it greatly improves load transfer efficiency and enhances crack-bridging toughening effect.The endeavor to establish precise microstructure formation and property regulation in IPC materi-als promises to steer high-performance carbon materials toward distinct developmental trajectories.
基金supported by the National Natural Science Foundation of China(Grant Nos.52064011 and 52274331)Guizhou Provincial Basic Research Program(Natural Science)(Nos.ZK[2021]258 and ZK[2022]Zhongdian 023)+1 种基金Guizhou Provincial Program on Commercialization of Scientific and Technological Achievements(No.[2022]089)Natural Science Research Project of Guizhou Provincial Department of Education(No.[2022]041).
文摘Larger-sized primary carbides lead to stress concentration during the application of H13 hot-work die steel,resulting in microcracks and fatigue failure.Rare earth was usually added to modify the carbides and inclusions.The existing literature is reviewed on the effect of rare earth on primary carbides in H13 steel.A comprehensive review on the effect of rare earth on the characteristics of primary carbides,i.e.,number,size,morphology,and thermal stability in H13 steel,was done.The precipitation mechanism and nucleation of primary carbides with rare earth were summarized.The position and form of rare earth in steel and their effects on alloying elements segregation were reviewed.The addition techniques of rare earth in H13 steel were compared,and the prospects for other uncommon rare earth and emerging technology were present.Based on the current references,it can be known that adding rare earth facilitated refined and dispersed primary carbides.The size of primary carbides would be reduced,and their morphology would be improved because the rare earth inclusions formed in H13 steel can act as nucleation cores forγ-Fe orδ-Fe,refining the dendritic structure.Besides,the number of primary carbides at grain boundaries would be significantly reduced.However,rare earth had little impact on thermal stability.The nucleation of primary carbides tended to be inhibited due to the modification of inclusions by rare earth which were likely to be nucleation cores for primary carbides.Rare earth had been reported to affect the mechanism and process of primary carbide precipitation.Additionally,the addition of rare earth can inhibit the segregation of alloying elements and carbon diffusion by calculation.Thus,laboratory experiments and theoretical calcu-lations need to be conducted to study the states and evolution of rare earth steels.
基金supported by the Natural Science Foundation of Shandong Province (No.ZR2021QE227)the Open Project of State Key Laboratory of Urban Water Resource and Environment (No.ES202120)+1 种基金the Taishan Scholars Program of Shandong Province,China (No.tsqn201812091)Key Research and Development Program (Major technical innovation projects)of Shandong Province (No.2020CXGC011204)。
文摘Coal chemical wastewater(CCW)is a type of refractory industrial wastewater,and its treatment has become the main bottleneck restricting the sustainable development of novel coal chemical industry.Biological treatment is considered as an economical,effective and environmentally friendly technology for CCW treatment.However,conventional biological process is difficult to achieve the efficient removal of refractory organics because of CCW with the characteristics of composition complexity and high toxicity.Therefore,seeking the novel enhancement strategy appears to be a favorable solution for enhancing biological treatment efficiency of CCW.This review focuses on presenting a comprehensive picture about the exogenous enhancement strategies for CCW biological treatment.The performance and potential application of exogenous enhancement strategies,including co-metabolic substrate enhancement,biofilm filler enhancement,adsorption material enhancement and conductive mediator enhancement,were expounded.Meanwhile,the enhancing mechanisms of different strategies were comprehensively discussed from a biological perspective.Furthermore,the prospects of enhancement strategies based on the engineering performance,economic cost and environmental impact(3E)evaluation were introduced.And novel enhancement strategy based on“low carbon emissions”,“resource recycling”and“water environment security”in the context of carbon neutrality was proposed.Taken together,this review provides technical reference and new direction to facilitate the regulation and optimization of typical industrial wastewater biological treatment.
基金supported by the National Natural Science Foundation of China(42225504 and 41977184)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23020301)+3 种基金the Key Research and Development Project of Anhui Province(202104i07020002)the Major Projects of High Resolution Earth Observation Systems of National Science and Technology(05-Y30B01-9001-19/20-3)the Key Laboratory of Atmospheric Chemistry/China Meteorological Administration(LAC/CMA)(2022B06)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021443).
文摘Understanding the vertical distribution of ozone is crucial when assessing both its horizontal and vertical transport,as well as when analyzing the physical and chemical properties of the atmosphere.One of the most effective ways to obtain high spatial resolution ozone profiles is through satellite observations.The Environmental Trace Gases Monitoring Instrument(EMI)deployed on the Gaofen-5 satellite is the first Chinese ultraviolet-visible hyperspectral spectrometer.However,retrieving ozone profiles using backscattered radiance values measured by the EMI is challenging due to unavailable measurement errors and a low signal-to-noise ratio.The algorithm developed for the Tropospheric Monitoring Instrument did not allow us to retrieve 87%of the EMI pixels.Therefore,we developed an algorithm specific to the characteristics of the EMI.The fitting residuals are smaller than 0.3%in most regions.The retrieved ozone profiles were in good agreement with ozonesonde data,with maximum mean biases of 20%at five latitude bands.By applying EMI averaging kernels to the ozonesonde profiles,the integrated stratospheric column ozone and tropospheric column ozone also showed excellent agreement with ozonesonde data,The lower layers(0-7.5 km)of the EMI ozone profiles reflected the seasonal variation in surface ozone derived from the China National Environmental Monitoring Center(CNEMC).However,the upper layers(9.7-16.7 km)of the ozone profiles show different trends,with the ozone peak occurring at an altitude of 9.7-16.7 km in March,2019.A stratospheric intrusion event in central China from August 11 to 15,2019,is captured using the EMI ozone profiles,potential vorticity data,and relative humidity data.The increase in the CNEMC ozone co ncentration showed that downward transport enhanced surface ozone pollution.
基金supported by the Natural Science Foundation of Shandong Province,China(No.ZR2021QE227)the Natural Science Foundation of Shandong Province,China(No.ZR2021QE272)+1 种基金the Open Project of State Key Laboratory of Urban Water Resource and Environment,Harbin Institute of Technology(No.ES202120)the Taishan Scholars Program of Shandong Province,China(No.tsqn201812091)。
文摘It is particularly important to comprehensively assess the biotoxicity variation of industrial wastewater along the treatment process for ensuring the water environment security.However,intensive studies on the biotoxicity reduction of industrial wastewater are still limited.In this study,the toxic organics removal and biotoxicity reduction of coal chemical wastewater(CCW)along a novel full-scale treatment process based on the pretreatment process-anaerobic process-biological enhanced(BE)process-anoxic/oxic(A/O)process-advanced treatment process was evaluated.This process performed great removal efficiency of COD,total phenol,NH_(4)^(+)-N and total nitrogen.And the biotoxicity variation along the treatment units was analyzed from the perspective of acute biotoxicity,genotixicity and oxidative damage.The results indicated that the effluent of pretreatment process presented relatively high acute biotoxicity to Tetrahymena thermophila.But the acute biotoxicity was significantly reduced in BE-A/O process.And the genotoxicity and oxidative damage to Tetrahymena thermophila were significantly decreased after advanced treatment.The polar organics in CCW were identified as the main biotoxicity contributors.Phenols were positively correlated with acute biotoxicity,while the nitrogenous heterocyclic compounds and polycyclic aromatic hydrocarbons were positively correlated with genotoxicity.Although the biotoxicity was effectively reduced in the novel full-scale treatment process,the effluent still performed potential biotoxicity,which need to be further explored in order to reduce environmental risk.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDC04010100)National Key Research and Development Program of China(Grant No.2018YFC1900500)+1 种基金the Special Project for Transformation of Major Technological Achievements in Hebei Province(Grant No.19044012Z)the Science and Technology Program of Hengshui(Grant No.2020016004B).
文摘The sodium smelting of vanadium-titanium magnetite can achieve the comprehensive utilization of Fe,V,and Ti.However,the generation of alkaline slag during this process may cause damage to refractory materials.The wettability and corrosion behavior of alkaline slag on three types of refractory(MgO-C,SiC,and high alumina refractory)substrates were investigated at temperatures up to 1200℃.The effects of duration on the wettability of molten slag on SiC substrates were also investigated.Results showed that the high alumina refractory exhibited better wettability with the molten slag than the others,and thus,it is easier to be corroded.The results of scanning electron microscopy coupled with energy dispersive spectroscopy showed that MgO-C and high alumina refractory substrates were severely eroded.There was a visible and regular interfacial reaction layer between the slag and SiC refractory substrate,which was produced by the redox reaction between the metal oxides in the slag and the SiC refractory substrate.With the increase in holding time,the interface layer expands and silico-ferrite phases are generated at the interface.The redox reaction between Fe_(2)O_(3) and SiC substrate is the main reason for the corrosion.By comparing the differences in wettability and corrosion behavior between the alkaline slag from sodium smelting of vanadium-titanium magnetite and MgO-C,SiC and high alumina refractories,it is concluded that SiC refractory has good corrosion resistance to the slag.Iron oxides in the slag accelerate the oxidation rate of SiC refractory.
文摘Pore pressure is essential data in drilling design,and its accurate prediction is necessary to ensure drilling safety and improve drilling efficiency.Traditional methods for predicting pore pressure are limited when forming particular structures and lithology.In this paper,a machine learning algorithm and effective stress theorem are used to establish the transformation model between rock physical parameters and pore pressure.This study collects data from three wells.Well 1 had 881 data sets for model training,and Wells 2 and 3 had 538 and 464 data sets for model testing.In this paper,support vector machine(SVM),random forest(RF),extreme gradient boosting(XGB),and multilayer perceptron(MLP)are selected as the machine learning algorithms for pore pressure modeling.In addition,this paper uses the grey wolf optimization(GWO)algorithm,particle swarm optimization(PSO)algorithm,sparrow search algorithm(SSA),and bat algorithm(BA)to establish a hybrid machine learning optimization algorithm,and proposes an improved grey wolf optimization(IGWO)algorithm.The IGWO-MLP model obtained the minimum root mean square error(RMSE)by using the 5-fold cross-validation method for the training data.For the pore pressure data in Well 2 and Well 3,the coefficients of determination(R^(2))of SVM,RF,XGB,and MLP are 0.9930 and 0.9446,0.9943 and 0.9472,0.9945 and 0.9488,0.9949 and 0.9574.MLP achieves optimal performance on both training and test data,and the MLP model shows a high degree of generalization.It indicates that the IGWO-MLP is an excellent predictor of pore pressure and can be used to predict pore pressure.
基金funded by the National Natural Science Foundation of China (No.32161143015)International Partnership Program of Chinese Academy of Sciences (070GJHZ202211FN)+5 种基金the Natural Science Foundation of Yunnan Province (202001AS070016)the"Ten Thousand Talents Program of Yunnan" (Top-notch Young Talents Project,No.YNWR-QNBJ-2018-279)the CAS Interdisciplinary Team of the"Light of West China"programYunnan Revitalization Talent Support Program"Innovation Team"project to CLXthe Iran National Science Foundation to YS (4001651)the open research project of the Germplasm Bank of Wild Species,Kunming Institute of Botany,Chinese Academy of Sciences。
文摘Phlomoides,with 150-170 species,is the second largest and perhaps most taxonomically challenging genus within the subfamily Lamioideae(Lamiaceae).With about 60 species,China is one of three major biodiversity centers of Phlomoides.Although some Phlomoides species from China have been included in previous molecular phylogenetic studies,a robust and broad phylogeny of this lineage has yet to be completed.Moreover,given the myriad new additions to the genus,the existing infrageneric classification needs to be evaluated and revised.Here,we combine molecular and morphological data to investigate relationships within Phlomoides,with a focus on Chinese species.We observed that plastid DNA sequences can resolve relationships within Phlomoides better than nuclear ribosomal internal and external transcribed spacer regions(nrITS and nrETS).Molecular phylogenetic analyses confirm the monophyly of Phlomoides,but most previously defined infrageneric groups are not monophyletic.In addition,morphological analysis demonstrates the significant taxonomic value of eight characters to the genus.Based on our molecular phylogenetic analyses and morphological data,we establish a novel section Notochaete within Phlomoides,and propose three new combinations as well as three new synonyms.This study presents the first molecular phylogenetic analyses of Phlomoides in which taxa representative of the entire genus are included,and highlights the phylogenetic and taxonomic value of several morphological characters from species of Phlomoides from China.Our study suggests that a taxonomic revision and reclassification for the entire genus is necessary in the future.
基金financial support from the National Science and Technology Major Project(Grant No.J2019-IV-0010-0078)the National Natural Science Foundation of China(Grant Nos.12172139 and 11972012)funding from the Fundamental Research Funds for the Central Universities(Grant No.2019kfyXJJS141).
文摘In order to enhance the fatigue properties of metallic materials,a feasible rationale is to delay or prevent the interior and surface fatigue crack initiation.Based on this rationale,the study investigates the approach of improving the very high cycle fatigue properties of TC6 titanium alloys through near-βforging coupled with shot peening,conducted at 930℃and ambient temperature,respectively.To unveil the associated mechanisms,microstructure,microhardness,residual stress,and fatigue properties are thoroughly analyzed after each process.Results indicate a considerable refinement in microstructure and significant mitigation of the initially existed strong texture post near-βforging and annealing,efficiently delaying crack initiation and propagation.As a result,the very high cycle fatigue property of TC6 achieves remarkable enhancement after forging.Compared to near-βforging,shot peening might not necessarily improve the very high cycle fatigue performance,particularly beyond 10^(6)cycles.
基金supported by the National Natural Science Foundation of China[Grant No.41961064]Yunnan Fundamental Research Projects[Grant No.202001BB050030]+2 种基金the Plateau Mountain Ecology and Earth’s Environment Discipline Construction Project[Grant No.C1762101030017]Joint Foundation Project between Yunnan Science and Technology Department and Yunnan University[Grant No.C176240210019]Joint Foundation Project between Yunnan Science and Technology Department and Yunnan University[Grant No.2018FY-019].
文摘Geothermal energy is a renewable and environmentally sustainable resource of increasing importance.However,areas with geothermal potential are not easily detected by traditional field investigations,requiring the development of new,robust,and reliable models for detection.In this study,remote sensing data and ground-based variables were used to detect and analyze geothermal resource potential areas.General Land Surface Temperature(GLST)was integrated using 5 years of remote sensing data.Landsat 8 daytime GLST(Landsat-GLST),Moderate Resolution Imaging Spectroradiometer(MODIS)daytime GLST(MODIS-DLST),and MODIS nighttime GLST(MODIS-NLST)data were integrated with Landsat Nighttime Land Surface Temperature(Night-LST),which not only filled the gap of Landsat Night-LST but also improved the spatial resolution of MODIS nighttime temperatures.Specifically,three independent variables(Night-LST,Distance From Known Geothermal Resource Points[DFGP],and Distance From Geological Faults[DFF])were used to develop a weighted model to form a Geothermal Detection Index(GDI)based on Principal Component Analysis(PCA).Along with field verification,the GDI was successfully used to identify three geothermal activity areas in Tengchong City,Yunnan Province.Overall,this work provides a novel method for detecting geothermal potential to support the successful exploitation of geothermal resources.
