The tectono-stratigraphic sequences of the Kuqa foreland fold-thrust belt in the northern Tarim basin, northwest China, can be divided into the Mesozoic sub-salt sequence, the Paleocene-Eocene salt sequence and the Ol...The tectono-stratigraphic sequences of the Kuqa foreland fold-thrust belt in the northern Tarim basin, northwest China, can be divided into the Mesozoic sub-salt sequence, the Paleocene-Eocene salt sequence and the Oligocene-Quaternary supra-salt sequence. The salt sequence is composed mainly of light grey halite, gypsum, marl and brown elastics. A variety of salt-related structures have developed in the Kuqa foreland fold belt, in which the most fascinating structures are salt nappe complex. Based on field observation, seismic interpretation and drilling data, a large-scale salt nappe complex has been identified. It trends approximately east-west for over 200 km and occurs along the west Qiulitag Mountains. Its thrusting displacement is over 30 km. The salt nappe complex appears as an arcuate zone projecting southwestwards along the leading edge of the Kuqa foreland fold belt. The major thrust fault is developed along the Paleocene-Eocene salt beds. The allochthonous nappes comprise large north-dipping faulting monoclines which are made up of Paleocene-Pliocene sediments. Geological analysis and cross-section restoration revealed that the salt nappes were mainly formed at the late Himalayan stage (c.a. 1.64 Ma BP) and have been active until the present day. Because of inhomogeneous thrusting, a great difference may exist in thrust displacement, thrust occurrence, superimposition of allochthonous and autochthonous sequences and the development of the salt-related structures, which indicates the segmentation along the salt nappes. Regional compression, gravitational gliding and spreading controlled the formation and evolution of the salt nappe complex in the Kuqa foreland fold belt.展开更多
The eastern Sichuan-western Hunan and Hubei belt(ESWHHB) is an important fold-thrust belt in the Middle–Upper Yangtze region of China, and it is also an important area for petroleum and gas prospect in China. The inf...The eastern Sichuan-western Hunan and Hubei belt(ESWHHB) is an important fold-thrust belt in the Middle–Upper Yangtze region of China, and it is also an important area for petroleum and gas prospect in China. The influence of mechanical stratigraphy on the deformation evolution of the ESWHHB is a hot problem that has received widespread attention. However, due to the complexity of geological conditions, this issue has not been sufficiently addressed. Previews geological exploration studies show that the deformation evolution of the belt is closely related to the mechanical stratigraphy. Physical simulation has proven to be effective for studying the deformation evolution of fold-and-thrust belt. Based on the geological conditions of the ESWHHB, six groups of physical models were designed to analyze the influences of the ductile layer and overlap configuration on the structural deformation of the ESWHHB. The results show that the mechanical stratigraphy has significant control on the deformation evolution of the fold-thrust belt. The ESWHHB evolution is related to the lower viscosity of the ductile layer and the larger thickness of the ductile layer, while only gradual propagated fold-and-thrust belt can be resulted from the higher viscosity of the ductile layer and the smaller thickness of the ductile layer. Additionally, the overlap between the stratigraphy at various structural belts leads to significant differences in their mechanical properties, and it critically influences the structural patterns of the ESWHHB.展开更多
Apatite fission-track dating and thermal-history modeling were carried out on samples from the Dabashan （大巴山）, a fold-thrust belt, northeast of the Sichuan （四川） Basin and east of the Tibetan Plateau. A first ...Apatite fission-track dating and thermal-history modeling were carried out on samples from the Dabashan （大巴山）, a fold-thrust belt, northeast of the Sichuan （四川） Basin and east of the Tibetan Plateau. A first cooling event in the Late Cretaceous is followed by a prolonged period of ther- mal stability with exhumation rates of 〈0.025 mm/a, as determined from age vs. elevation relationships. The preservation of age vs. elevations relationships and the lack of distinct age changes across tectonic structures indicate that the Dabashan fold-thrust belt formed prior to the Late Cretaceous, consistent with the current view of Triassic-Early Cretaceous shortening. Relatively short mean track lengths （-12 μm） indicate that the samples remained in the partial annealing zone for a prolonged time. The knick points in the best-fitting temperature-time models suggest that the onset of late-stage accelerated cooling commenced at 〈11 Ma. Related exhumation rates are 0.3-0.2 mm/a assuming geothermal gra- dients of 20 and 30 ℃/km. We speculate that this late-stage event results from eastward growth of the Tibetan Plateau and overstepping of the Sichuan Basin, it is likely responsible for the youthful mor- phology of the Dabashan.展开更多
The map expression of ＂abrupt＂ changes in lateral stratigraphic level of a thrust fault has been traditionally interpreted to be a result of the presence of （1） a lateral （or oblique） thrust-ramp, or （2） a fro...The map expression of ＂abrupt＂ changes in lateral stratigraphic level of a thrust fault has been traditionally interpreted to be a result of the presence of （1） a lateral （or oblique） thrust-ramp, or （2） a frontal ramp with displacement gradient, and/or （3） a combination of these geometries. These geometries have been used to interpret the structures near transverse zones in fold-thrust belts （FTB）. This contribution outlines an alternative explanation that can result in the same map pattern by lateral variations in stratigraphy along the strike of a low angle thrust fault. We describe the natural example of the Leamington transverse zone, which marks the southern margin of the Pennsylvanian-Permian Oquirrh basin with genetically related lateral stratigraphic variations in the North American Sevier FTB. Thus, the observed map pattern at this zone is closely related to lateral stratigraphic variations along the strike of a horizontal fault. Even though the present-day erosional level shows the map pattern that could be interpreted as a lateral ramp, the observed structures along the Leamington zone most likely share the effects of the presence of a lateral （or oblique） ramp, lateral stratigraphic variations along the fault trace, and the displacement gradient.展开更多
Fold-thrust belts are common structural styles under the background of long-term regional tectonic shortening.The northern and northeastern margins of the Qinghai-Tibetan Plateau are located on the edge of the growth ...Fold-thrust belts are common structural styles under the background of long-term regional tectonic shortening.The northern and northeastern margins of the Qinghai-Tibetan Plateau are located on the edge of the growth and expansion of the Qinghai-Tibetan Plateau.Since nearly 10 Ma,some significant and typical fold thrust belt have been formed.The spatial-temporal evolution of these fold-thrust belts and the characteristics of surface deformations are significant issues in geodynamics.In this paper,we use the elastoplastic finite element model with considering the contact nonlinearity to study the spatialtemporal evolution of the fold-thrust belts in the northern and northeastern margins of the Qinghai-Tibetan Plateau,with particular attention to the details of the relationship between the depth and the shallow,the spatialtemporal order,and the characteristics of the surface deformation,etc.,in order to make a relatively complete mechanical interpretation of the spatial-temporal evolution of the foldthrust belts in the northern and northeastern margins of the Qinghai-Tibetan Plateau from the perspective of geodynamics.展开更多
Based on the latest geological,seismic,drilling and outcrop data,we studied the geological structure,tectonic evolution history and deformation process of the southwestern Sichuan fold-thrust belt to find out the pote...Based on the latest geological,seismic,drilling and outcrop data,we studied the geological structure,tectonic evolution history and deformation process of the southwestern Sichuan fold-thrust belt to find out the potential hydrocarbon exploration areas in deep layers.During key tectonic periods,the southwestern Sichuan fold-thrust belt developed some characteristic strata and structural deformation features,including the Pre-Sinian multi-row N-S strike rifts,step-shaped platform-margin structures of Sinian Dengying Formation,the western paleo-uplift in the early stage of Late Paleozoic,the Late Paleozoic–Middle Triassic carbonate platform,foreland slope and forebulge during Late Triassic to Cretaceous,and Cenozoic multi-strike rejuvenated fold-thrusting structures.The fold-thrust belt vertically shows a double-layer structural deformation controlled by the salt layer in the Middle Triassic Leikoupo Formation and the base detachment layer at present.The upper deformation layer develops the NE-SW strike thrusts propagating toward basin in long distance,while the deeper deformation layer had near north-south strike basement-involved folds,which deformed the detachment and thrusting structures formed earlier in the upper layer,with the deformation strength high in south part and weak in north part.The southern part of the fold-thrust belt is characterized by basement-involved fold-thrusts formed late,while the central-northern part is dominated by thin-skin thrusts in the shallow layer.The Wuzhongshan anticlinal belt near piedmont is characterized by over-thrust structure above the salt detachment,where the upper over-thrusting nappe consists of a complicated fold core and front limb of a fault-bend fold,while the deep layer has stable subtle in-situ structures.Favorable exploration strata and areas have been identified both in the upper and deeper deformation layers separated by regional salt detachment,wherein multiple anticlinal structures are targets for exploration.Other potential exploration strata and areas in southwestern Sichuan fold-thrust belt include the deep Sinian and Permian in the Wuzhongshan structure,pre-Sinian rifting sequences and related structures,platform-margin belt of Sinian Dengying Formation,and Indosinian paleo-uplift in the east of the Longquanshan structure.展开更多
The Yuxi （豫西） fold-thrust fracture belt is part of the gigantic fold-thrust fracture belt that extends NW in the southern North China plate. The contents of major elements of tectonites were analyzed by ICP-AES. T...The Yuxi （豫西） fold-thrust fracture belt is part of the gigantic fold-thrust fracture belt that extends NW in the southern North China plate. The contents of major elements of tectonites were analyzed by ICP-AES. The analysis of chemical compositions and new stress minerals indicates： extending from the surrounding country rocks to the center of the fracture belt, the Fe2O3 content gradually increases while the FeO content gradually decreases; regular increase, decrease or peak changes are shown for chemical compositions like SiO2, Al2O3, Fe2O3, MgO, CaO, FeO, loss on ignition, TIO：, K2O, Na2 O, etc.. New stress minerals are developed for the south branch and few for the north branch. The characteristics of chemical compositions and new stress minerals of the thrust fracture demonstrate that the fracture belt has undergone a process from a closed reducing environmental system to a relatively open. oxidizing environmental system, andcompressive fractures have resulted from compression in the late stages of evolution, and the dynamothermal metamorphism and thrusting intensities are different between the south and north branches of the belt, which is strong for the south branch but relatively weak for the north branch.展开更多
The roller is one of the fundamental elements of ore belt conveyor systems since it supports,guides,and directs material on the belt.This component comprises a body(the external tube)that rotates around a fixed shaft ...The roller is one of the fundamental elements of ore belt conveyor systems since it supports,guides,and directs material on the belt.This component comprises a body(the external tube)that rotates around a fixed shaft supported by easels.The external tube and shaft of rollers used in ore conveyor belts are mostly made of steel,resulting in high mass,hindering maintenance and replacement.Aiming to achieve mass reduction,we conducted a structural optimization of a roller with a polymeric external tube(hereafter referred to as a polymeric roller),seeking the optimal values for two design parameters:the inner diameter of the external tube and the shaft diameter.The optimization was constrained by admissible values for maximum stress,maximum deflection and misalignment angle between the shaft and bearings.A finite element model was built in Ansys Workbench to obtain the structural response of the system.The roller considered is composed of an external tube made of high-density polyethylene(HDPE),bearing seats of polyamide 6(PA6),and a steel shaft.To characterize the polymeric materials(HDPE and PA6),stress relaxation tests were conducted,and the data on shear modulus variation over time were inserted into the model to calculate Prony series terms to account for viscoelastic effects.The roller optimization was performed using surrogate modeling based on radial basis functions,with the Globalized Bounded Nelder-Mead(GBNM)algorithm as the optimizer.Two optimization cases were conducted.In the first case,concerning the roller’s initial material settings,the designs found violated the constraints and could not reduce mass.In the second case,by using PA6 in both bearing seats and the tube,a design configuration was found that respected all constraints and reduced the roller mass by 15.5%,equivalent to 5.15 kg.This study is among the first to integrate experimentally obtained viscoelastic data into the surrogate-based optimization of polymeric rollers,combining methodological innovation with industrial relevance.展开更多
The Jiao-Liao-Ji Belt within the North China Craton had undergone a complex tectonic evolution,marked by extensive Paleoproterozoic magmatism that produced a diverse range of mafic to felsic magmatic rocks.These event...The Jiao-Liao-Ji Belt within the North China Craton had undergone a complex tectonic evolution,marked by extensive Paleoproterozoic magmatism that produced a diverse range of mafic to felsic magmatic rocks.These events provide valuable geological records for understanding the tectonic evolution of the Jiao-Liao-Ji Belt.This study focuses on the Paleoproterozoic Chibaisong meta-gabbro in southern Jilin,investigating the source of mafic magma,petrogenesis,and tectonic setting through systematic petrological analysis,zircon U-Pb dating,and geochemical studies.The findings contribute to constraining the dynamic mechanisms of Paleoproterozoic extensional rifting in the Jiao-Liao-Ji orogenic belt.Geochemical data indicate that the samples exhibit low SiO₂(47.99–50.66 wt.%),TiO₂(0.75–3.20 wt.%),Nb(3.22–8.09 ppm),and Ta(0.22–0.51 ppm)contents,along with high TFeO₃(11.97–15.82 wt.%)and MgO(5.67–12.66 wt.%)concentrations.They also show low Nb/La ratios and high(Th/Nb)N values,consistent with the geochemical characteristics of tholeiitic basalts.The samples display low total rare earth element concentrations,weak or absent Eu anomalies,slight enrichment in light rare earth elements,relatively flat heavy rare earth element patterns,and depletion in Nb,Ta,and Ti.The meta-gabbro from southern Jilin exhibits geochemical similarities to Paleoproterozoic metamafic rocks from other regions of the Jiao-Liao-Ji Belt,resembling enriched mid-ocean ridge basalts(E-MORB)with Nb,Ta,and Ti depletion.Integration of previous studies and geochemical data suggests that the 2.16–2.10 Ga metamafic rocks in the Jiao-Liao-Ji Belt experienced contamination by older crustal material.These results indicate that the 2.16–2.10 Ga metamafic rocks are unlikely to be associated with island arc,continental arc,or mid-ocean ridge settings.Instead,they are more likely related to intraplate magmatism associated with continental rifting.展开更多
The northern segment of the North-South Seismic Belt is characterized by intense crustal deformation,well-developed active tectonics,and frequent occurrences of strong earthquakes.Therefore,conducting a Probabilistic ...The northern segment of the North-South Seismic Belt is characterized by intense crustal deformation,well-developed active tectonics,and frequent occurrences of strong earthquakes.Therefore,conducting a Probabilistic Seismic Hazard Analysis(PSHA)for this region is of significant importance for supporting seismic fortification in major engineering projects and formulating disaster prevention and mitigation policies.In this study,a composite seismic source model was constructed by integrating data on historical earthquakes,active faults,and paleoseismicity.Furthermore,a logic tree framework was employed to quantify epistemic uncertainties,enabling a systematic seismic hazard assessment of the region.To more accurately characterize the spatial heterogeneity of seismic activity,improvements were made to both the Circular Spatial Smoothing Model(CSSM)with a fixed radius and the Adaptive Spatial Smoothing Model(ASSM),with full consideration given to the spatiotemporal completeness of historical earthquake magnitudes.Regarding the CSSM,for scenarios involving small sample sizes in earthquake catalogs,the cross-validation method proposed in this study demonstrated higher robustness than the maximum likelihood method in determining the optimal correlation distance.Performance evaluation results indicate that while both models effectively characterize seismic activity,the ASSM exhibits superior overall predictive performance compared to the CSSM,owing to its ability to adaptively adjust the smoothing radius according to seismic density.Significant discrepancies were observed in the Peak Ground Acceleration(PGA)results calculated with a 10%probability of exceedance in 50 years across different combinations of seismic source models.The single spatially smoothed point-source model yielded a maximum PGA of approximately 0.52 g,with high-value areas concentrated near historical epicenters,thereby significantly underestimating the hazard associated with major fault zones.When combined with the simple fault-source model,the maximum PGA increased to 0.8 g,with high-value zones exhibiting a zonal distribution along faults;however,the risk remained underestimated for faults with low slip rates that are nevertheless approaching their recurrence cycles.Following the introduction of the time-dependent characteristic fault-source model,local PGA values for faults in the middle-to-late stages of their recurrence cycles increased by a factor of 2 to 7 compared to the single model.These results demonstrate that the characteristic fault-source model reasonably delineates the time-dependence of large earthquake recurrence,thereby providing a more accurate assessment of imminent seismic risks.By comprehensively applying the improved spatially smoothed pointsource model,the simple fault-source model,and the characteristic fault-source model,the following faults within the region were identified as having high seismic hazard:the Huangxianggou,Zhangxian,and Tianshui segments of the Xiqinling northern edge fault;the Maqin-Maqu segment of the Dongkunlun fault;the Longriqu fault;the Maoergai fault;the Elashan fault;the Riyueshan fault;the eastern segment of the Lenglongling fault;the Maxianshan segment of the Maxianshan northern Margin fault;and the Maomaoshan-Jinqianghe segment of the Laohushan-Maomaoshan fault.As these faults are located within seismic gaps or are approaching the recurrence periods of large earthquakes,they should be prioritized for current and future seismic monitoring as well as disaster prevention and mitigation efforts.展开更多
Foreign body classification on coal conveyor belts is a critical component of intelligent coal mining systems.Previous approaches have primarily utilized convolutional neural networks(CNNs)to effectively integrate spa...Foreign body classification on coal conveyor belts is a critical component of intelligent coal mining systems.Previous approaches have primarily utilized convolutional neural networks(CNNs)to effectively integrate spatial and semantic information.However,the performance of CNN-based methods remains limited in classification accuracy,primarily due to insufficient exploration of local image characteristics.Unlike CNNs,Vision Transformer(ViT)captures discriminative features by modeling relationships between local image patches.However,such methods typically require a large number of training samples to perform effectively.In the context of foreign body classification on coal conveyor belts,the limited availability of training samples hinders the full exploitation of Vision Transformer’s(ViT)capabilities.To address this issue,we propose an efficient approach,termed Key Part-level Attention Vision Transformer(KPA-ViT),which incorporates key local information into the transformer architecture to enrich the training information.It comprises three main components:a key-point detection module,a key local mining module,and an attention module.To extract key local regions,a key-point detection strategy is first employed to identify the positions of key points.Subsequently,the key local mining module extracts the relevant local features based on these detected points.Finally,an attention module composed of self-attention and cross-attention blocks is introduced to integrate global and key part-level information,thereby enhancing the model’s ability to learn discriminative features.Compared to recent transformer-based frameworks—such as ViT,Swin-Transformer,and EfficientViT—the proposed KPA-ViT achieves performance improvements of 9.3%,6.6%,and 2.8%,respectively,on the CUMT-BelT dataset,demonstrating its effectiveness.展开更多
The west Kunlun fold-thrust belt (WKFTB) and the Altun fold-thrust belt (AFTB) are respectively located in the southern margin of the Tarim basin, NW China. The analyses of typical structures and regional dynamics of ...The west Kunlun fold-thrust belt (WKFTB) and the Altun fold-thrust belt (AFTB) are respectively located in the southern margin of the Tarim basin, NW China. The analyses of typical structures and regional dynamics of the fold-thrust belts reveal their different structural and pe-troleum features and mechanisms. WKFTB differs from AFTB by abundant fault-related folds and triangles zones, and was formed by northward extrusion of the west Kunlun orogen. AFTB was affected synchronously by northward extrusion of the Altun orogen and the sinistral strike-slipping of the Altun Fault, so it is characterized by the minor scale and the monotonous structural styles. The Aqike anticline and the Aqike fault, of which the strikes are orthogonal to the strike of the fold-thrust belts, are regarded as the adjustive structures between both of the fold-thrust belts. The oil-gas pools of WKFTB develop mainly in the faulted-related anticline traps, but the oil-gas pools of AFTB develop mainly in the low fault-block and anticlines traps related with the pa-leo-uplifts. There are different exploration countermeasures for both of the fold-thrust belts.展开更多
The evolution of the Tarim southwest depression lying at the piedmont of the West Kunlun orogen differs completely from the evolution of the main part of Tarim basin after Later Palaeozoic because the former strongly ...The evolution of the Tarim southwest depression lying at the piedmont of the West Kunlun orogen differs completely from the evolution of the main part of Tarim basin after Later Palaeozoic because the former strongly subsides many times.. Subsidence is related closely to the West Kunlun fold thrust\|belt, thus the evolution of the Depression and the fold\|thrust\|belt reflects clearly the formation and evolution of the West Kunlun and even the Tibet.1 Evolution of the West Kunlun fold\|thrust\|belt\;Thrusting of the fold\|thrust\|belt can be classified into three stages:(1) Devonian thrusting:This is the oldest thrusting distinguished in the northern margin of the West Kunlun while the Silurian—Devonian thrusting was discriminated a few years ago by seismic data in the northern part of the East Kunlun. The Devonian thrusting is proved by the Upper Devonian dynamometamorphic rocks outcropping at the core of the anticline in the Sangzhu lying at the fold\|thrust\|belt. The rocks consist of slightly metamorphic clastic rock and have always been regarded as the Mid\|Proterozoic strata. But they are actually Upper Devonian strata according to the amount of perfect plant fossils that we found recently in the metamorphic rock, and they are overburdened `with an angular unconformity by another reliable Upper\|Devonian conglomerate in the core of the Aqike anticline. A possible explanation for this and its limited lined distribution parallel to the West Kunlun orogen is that they are subjected to metamorphism during the Later Devonian thrusting.展开更多
In this article,the contemporary stress state of the Zhao-Ping metallogenic belt in eastern China was revealed using overcoring and hydraulic fracturing stress data,the relation between the stress field and geological...In this article,the contemporary stress state of the Zhao-Ping metallogenic belt in eastern China was revealed using overcoring 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 σ_(H)>σ_(v)>σ_(h).The σ_(H) orientation is well-oriented in the WNW-ESE,which is roughly identical to other stress indicators.Moreover,theσH direction reflected by joint strikes and inferred based on the fault characteristics agrees fairly with the identified stress orientation.The modern stress field basically inherited the tectonic stress field of the Yanshanian and Himalayan periods but is principally dominated by the Himalayan period.Additionally,the calculatedμm 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 predicting and analyzing future fault activity in the area,respectively.展开更多
Cross-border e-commerce,as a new form of international trade,has shown great development potential in the context of the“Belt and Road”initiative.Based on the cross-border e-commerce export data from 2015 to 2024,th...Cross-border e-commerce,as a new form of international trade,has shown great development potential in the context of the“Belt and Road”initiative.Based on the cross-border e-commerce export data from 2015 to 2024,this paper analyzes the influencing factors of China's cross-border e-commerce exports to countries along the“Belt and Road”by constructing an econometric model.The study found that factors such as the perfection of digital infrastructure,the efficiency of logistics and transportation,the convenience of payment and settlement,and the penetration rate of consumers online shopping significantly affect the export scale of cross-border e-commerce.Institutional factors such as the development level of e-commerce platforms in countries along the route,market access thresholds,and tariff policies also play an important role.Based on the research results,suggestions are put forward to strengthen the construction of cross-border payment system,optimize the logistics distribution network,promote customs clearance facilitation,and deepen cooperation in the field of e-commerce,to provide references for promoting the development of China's crossborder e-commerce exports to countries along the“Belt and Road.”展开更多
The scientific assessment of ecosystem ser-vice value(ESV)plays a critical role in regional ecologi-cal protection and management,rational land use planning,and the establishment of ecological security barriers.The ec...The scientific assessment of ecosystem ser-vice value(ESV)plays a critical role in regional ecologi-cal protection and management,rational land use planning,and the establishment of ecological security barriers.The ecosystem service value of the Northeast Forest Belt from 2005 to 2020 was assessed,focusing on spatial–temporal changes and the driving forces behind these dynamics.Using multi-source data,the equivalent factor method,and geo-graphic detectors,we analyzed natural and socio-economic factors affecting the region.which was crucial for effective ecological conservation and land-use planning.Enhanced the effectiveness of policy formulation and land use plan-ning.The results show that the ESV of the Northeast Forest Belt exhibits an overall increasing trend from 2005 to 2020,with forests and wetlands contributing the most.However,there are significant differences between forest belts.Driven by natural and socio-economic factors,the ESV of forest belts in Heilongjiang and Jilin provinces showed significant growth.In contrast,the ESV of Forest Belts in Liaoning and Inner Mongolia of China remains relatively stable,but the spatial differentiation within these regions is characterized by significant clustering of high-value and low-value areas.Furthermore,climate regulation and hydrological regulation services were identified as the most important ecological functions in the Northeast Forest Belt,contributing greatly to regional ecological stability and human well-being.The ESV in the Northeast Forest Belt is improved during the study period,but the stability of the ecosystem is still chal-lenged by the dual impacts of natural and socio-economic factors.To further optimize regional land use planning and ecological protection policies,it is recommended to prior-itize the conservation of high-ESV areas,enhance ecological restoration efforts for wetlands and forests,and reasonably control the spatial layout of urban expansion and agricul-tural development.Additionally,this study highlights the importance of tailored ecological compensation policies and strategic land-use planning to balance environmental protec-tion and economic growth.展开更多
Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was ...Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was conducted on the structural characteristics and evolution,reservoir diagenesis and densification processes,and types and stages of faults/fractures,and revealing the multi-stage and multi-factor dynamic coupled enrichment mechanisms of tight gas reservoirs.(1)In the early Yanshan period,the paleo-structural traps were formed with low-medium maturity hydrocarbons accumulating in structural highs driven by buoyancy since reservoirs were not fully densified in this stage,demonstrating paleo-structure control on traps and early hydrocarbon accumulation.(2)In the middle-late Yanshan period,the source rocks became mature to generate and expel a large quantity of hydrocarbons.Grain size and type of sandstone controlled the time of reservoir densification,which restricted the scale of hydrocarbon charging,allowing for only a small-scale migration through sand bodies near the fault/fracture or less-densified matrix reservoirs.(3)During the Himalayan period,the source rocks reached overmaturity,and the residual oil cracking gas was efficiently transported along the late-stage faults/fractures.Wells with high production capacity were mainly located in Type I and II fault/fracture zones comprising the late-stage north-south trending fourth-order faults and the late-stage fractures.The productivity of the wells was controlled by the transformation of the late-stage faults/fractures.(4)The Xinchang structural belt underwent three stages of tectonic evolution,two stages of reservoir formation,and three stages of fault/fractures development.Hydrocarbons mainly accumulated in the paleo-structure highs.After reservoir densification and late fault/fracture adjustment,a complex gas-water distribution pattern was formed.Thus,it is summarized as the model of“near-source and low-abundance hydrocarbon charging in the early stage,and differential enrichment of natural gas under the joint control of fault-fold-fracture complex,high-quality reservoirs and structural highs in the late stage”.Faults/fractures with well-coupled fault-fold-fracture-pore are favorable exploration targets with high exploration effectiveness.展开更多
In the 12 years since the Belt and Road Initiative was first proposed,many Chinese enterprises have made fruitful achievements in the participating countries of the Belt and Road Initiative.
With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Sa...With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Safety,and Energy Standardized ISO Management System,NYBELT can produce all kinds of flat transmission belts,roller coverings and conveyor belts applicable to textile,printing&packaging,electronics and other industries.Due to the superior quality and the reasonable prices,we have become well known in providing high quality belting products and excellent service to customers all over the world.Our success in the past gives us the confidence to look into the future with great expectations.展开更多
基金This research received financial supports from the National Natural Science Foundation of China(grant 40172076)the National Major Fundamental Research and Development Project(grant G1999043305)the National Key Project of the Ninth Five—Year Plan(grant 99—1111)
文摘The tectono-stratigraphic sequences of the Kuqa foreland fold-thrust belt in the northern Tarim basin, northwest China, can be divided into the Mesozoic sub-salt sequence, the Paleocene-Eocene salt sequence and the Oligocene-Quaternary supra-salt sequence. The salt sequence is composed mainly of light grey halite, gypsum, marl and brown elastics. A variety of salt-related structures have developed in the Kuqa foreland fold belt, in which the most fascinating structures are salt nappe complex. Based on field observation, seismic interpretation and drilling data, a large-scale salt nappe complex has been identified. It trends approximately east-west for over 200 km and occurs along the west Qiulitag Mountains. Its thrusting displacement is over 30 km. The salt nappe complex appears as an arcuate zone projecting southwestwards along the leading edge of the Kuqa foreland fold belt. The major thrust fault is developed along the Paleocene-Eocene salt beds. The allochthonous nappes comprise large north-dipping faulting monoclines which are made up of Paleocene-Pliocene sediments. Geological analysis and cross-section restoration revealed that the salt nappes were mainly formed at the late Himalayan stage (c.a. 1.64 Ma BP) and have been active until the present day. Because of inhomogeneous thrusting, a great difference may exist in thrust displacement, thrust occurrence, superimposition of allochthonous and autochthonous sequences and the development of the salt-related structures, which indicates the segmentation along the salt nappes. Regional compression, gravitational gliding and spreading controlled the formation and evolution of the salt nappe complex in the Kuqa foreland fold belt.
基金supported by Project of the State Key Laboratory of Petroleum Resource and Prospecting,China University of PetroleumBeijing (No. PRP/Open-1903)the Zunyi Normal University Project (No. BS201804)。
文摘The eastern Sichuan-western Hunan and Hubei belt(ESWHHB) is an important fold-thrust belt in the Middle–Upper Yangtze region of China, and it is also an important area for petroleum and gas prospect in China. The influence of mechanical stratigraphy on the deformation evolution of the ESWHHB is a hot problem that has received widespread attention. However, due to the complexity of geological conditions, this issue has not been sufficiently addressed. Previews geological exploration studies show that the deformation evolution of the belt is closely related to the mechanical stratigraphy. Physical simulation has proven to be effective for studying the deformation evolution of fold-and-thrust belt. Based on the geological conditions of the ESWHHB, six groups of physical models were designed to analyze the influences of the ductile layer and overlap configuration on the structural deformation of the ESWHHB. The results show that the mechanical stratigraphy has significant control on the deformation evolution of the fold-thrust belt. The ESWHHB evolution is related to the lower viscosity of the ductile layer and the larger thickness of the ductile layer, while only gradual propagated fold-and-thrust belt can be resulted from the higher viscosity of the ductile layer and the smaller thickness of the ductile layer. Additionally, the overlap between the stratigraphy at various structural belts leads to significant differences in their mechanical properties, and it critically influences the structural patterns of the ESWHHB.
基金supported by the National Natural Science Foundation of China (No. 40902038)the Petro China Innova-tion Foundation (No. 2009D-5006-01-08)the Project of China Geological Survey (No. 12120113094200)
文摘Apatite fission-track dating and thermal-history modeling were carried out on samples from the Dabashan （大巴山）, a fold-thrust belt, northeast of the Sichuan （四川） Basin and east of the Tibetan Plateau. A first cooling event in the Late Cretaceous is followed by a prolonged period of ther- mal stability with exhumation rates of 〈0.025 mm/a, as determined from age vs. elevation relationships. The preservation of age vs. elevations relationships and the lack of distinct age changes across tectonic structures indicate that the Dabashan fold-thrust belt formed prior to the Late Cretaceous, consistent with the current view of Triassic-Early Cretaceous shortening. Relatively short mean track lengths （-12 μm） indicate that the samples remained in the partial annealing zone for a prolonged time. The knick points in the best-fitting temperature-time models suggest that the onset of late-stage accelerated cooling commenced at 〈11 Ma. Related exhumation rates are 0.3-0.2 mm/a assuming geothermal gra- dients of 20 and 30 ℃/km. We speculate that this late-stage event results from eastward growth of the Tibetan Plateau and overstepping of the Sichuan Basin, it is likely responsible for the youthful mor- phology of the Dabashan.
基金supported by MLTM of Korean Government Program 20052004 to S.Kwon
文摘The map expression of ＂abrupt＂ changes in lateral stratigraphic level of a thrust fault has been traditionally interpreted to be a result of the presence of （1） a lateral （or oblique） thrust-ramp, or （2） a frontal ramp with displacement gradient, and/or （3） a combination of these geometries. These geometries have been used to interpret the structures near transverse zones in fold-thrust belts （FTB）. This contribution outlines an alternative explanation that can result in the same map pattern by lateral variations in stratigraphy along the strike of a low angle thrust fault. We describe the natural example of the Leamington transverse zone, which marks the southern margin of the Pennsylvanian-Permian Oquirrh basin with genetically related lateral stratigraphic variations in the North American Sevier FTB. Thus, the observed map pattern at this zone is closely related to lateral stratigraphic variations along the strike of a horizontal fault. Even though the present-day erosional level shows the map pattern that could be interpreted as a lateral ramp, the observed structures along the Leamington zone most likely share the effects of the presence of a lateral （or oblique） ramp, lateral stratigraphic variations along the fault trace, and the displacement gradient.
基金financially supported by the National Science Foundation of China(42074117)supported by the Fundamental Research Funds for the Central Universities。
文摘Fold-thrust belts are common structural styles under the background of long-term regional tectonic shortening.The northern and northeastern margins of the Qinghai-Tibetan Plateau are located on the edge of the growth and expansion of the Qinghai-Tibetan Plateau.Since nearly 10 Ma,some significant and typical fold thrust belt have been formed.The spatial-temporal evolution of these fold-thrust belts and the characteristics of surface deformations are significant issues in geodynamics.In this paper,we use the elastoplastic finite element model with considering the contact nonlinearity to study the spatialtemporal evolution of the fold-thrust belts in the northern and northeastern margins of the Qinghai-Tibetan Plateau,with particular attention to the details of the relationship between the depth and the shallow,the spatialtemporal order,and the characteristics of the surface deformation,etc.,in order to make a relatively complete mechanical interpretation of the spatial-temporal evolution of the foldthrust belts in the northern and northeastern margins of the Qinghai-Tibetan Plateau from the perspective of geodynamics.
基金Supported by the Petro China Science and Technology Project(2016E-0601,2019B-0503)China National Science and Technology Major Project(2016ZX05003-001)
文摘Based on the latest geological,seismic,drilling and outcrop data,we studied the geological structure,tectonic evolution history and deformation process of the southwestern Sichuan fold-thrust belt to find out the potential hydrocarbon exploration areas in deep layers.During key tectonic periods,the southwestern Sichuan fold-thrust belt developed some characteristic strata and structural deformation features,including the Pre-Sinian multi-row N-S strike rifts,step-shaped platform-margin structures of Sinian Dengying Formation,the western paleo-uplift in the early stage of Late Paleozoic,the Late Paleozoic–Middle Triassic carbonate platform,foreland slope and forebulge during Late Triassic to Cretaceous,and Cenozoic multi-strike rejuvenated fold-thrusting structures.The fold-thrust belt vertically shows a double-layer structural deformation controlled by the salt layer in the Middle Triassic Leikoupo Formation and the base detachment layer at present.The upper deformation layer develops the NE-SW strike thrusts propagating toward basin in long distance,while the deeper deformation layer had near north-south strike basement-involved folds,which deformed the detachment and thrusting structures formed earlier in the upper layer,with the deformation strength high in south part and weak in north part.The southern part of the fold-thrust belt is characterized by basement-involved fold-thrusts formed late,while the central-northern part is dominated by thin-skin thrusts in the shallow layer.The Wuzhongshan anticlinal belt near piedmont is characterized by over-thrust structure above the salt detachment,where the upper over-thrusting nappe consists of a complicated fold core and front limb of a fault-bend fold,while the deep layer has stable subtle in-situ structures.Favorable exploration strata and areas have been identified both in the upper and deeper deformation layers separated by regional salt detachment,wherein multiple anticlinal structures are targets for exploration.Other potential exploration strata and areas in southwestern Sichuan fold-thrust belt include the deep Sinian and Permian in the Wuzhongshan structure,pre-Sinian rifting sequences and related structures,platform-margin belt of Sinian Dengying Formation,and Indosinian paleo-uplift in the east of the Longquanshan structure.
基金This paper is supported by the Key Basic Research Project funded by theChinese Academy of Sciences (No . KZCX2-SW-117) .
文摘The Yuxi （豫西） fold-thrust fracture belt is part of the gigantic fold-thrust fracture belt that extends NW in the southern North China plate. The contents of major elements of tectonites were analyzed by ICP-AES. The analysis of chemical compositions and new stress minerals indicates： extending from the surrounding country rocks to the center of the fracture belt, the Fe2O3 content gradually increases while the FeO content gradually decreases; regular increase, decrease or peak changes are shown for chemical compositions like SiO2, Al2O3, Fe2O3, MgO, CaO, FeO, loss on ignition, TIO：, K2O, Na2 O, etc.. New stress minerals are developed for the south branch and few for the north branch. The characteristics of chemical compositions and new stress minerals of the thrust fracture demonstrate that the fracture belt has undergone a process from a closed reducing environmental system to a relatively open. oxidizing environmental system, andcompressive fractures have resulted from compression in the late stages of evolution, and the dynamothermal metamorphism and thrusting intensities are different between the south and north branches of the belt, which is strong for the south branch but relatively weak for the north branch.
基金funded by Vale S.A.company(www.vale.com)and the Institute of Technology Vale(ITV—www.itv.org),grant number SAP 4600048682.
文摘The roller is one of the fundamental elements of ore belt conveyor systems since it supports,guides,and directs material on the belt.This component comprises a body(the external tube)that rotates around a fixed shaft supported by easels.The external tube and shaft of rollers used in ore conveyor belts are mostly made of steel,resulting in high mass,hindering maintenance and replacement.Aiming to achieve mass reduction,we conducted a structural optimization of a roller with a polymeric external tube(hereafter referred to as a polymeric roller),seeking the optimal values for two design parameters:the inner diameter of the external tube and the shaft diameter.The optimization was constrained by admissible values for maximum stress,maximum deflection and misalignment angle between the shaft and bearings.A finite element model was built in Ansys Workbench to obtain the structural response of the system.The roller considered is composed of an external tube made of high-density polyethylene(HDPE),bearing seats of polyamide 6(PA6),and a steel shaft.To characterize the polymeric materials(HDPE and PA6),stress relaxation tests were conducted,and the data on shear modulus variation over time were inserted into the model to calculate Prony series terms to account for viscoelastic effects.The roller optimization was performed using surrogate modeling based on radial basis functions,with the Globalized Bounded Nelder-Mead(GBNM)algorithm as the optimizer.Two optimization cases were conducted.In the first case,concerning the roller’s initial material settings,the designs found violated the constraints and could not reduce mass.In the second case,by using PA6 in both bearing seats and the tube,a design configuration was found that respected all constraints and reduced the roller mass by 15.5%,equivalent to 5.15 kg.This study is among the first to integrate experimentally obtained viscoelastic data into the surrogate-based optimization of polymeric rollers,combining methodological innovation with industrial relevance.
基金Supported by National Natural Science Foundation of China(No.42172212).
文摘The Jiao-Liao-Ji Belt within the North China Craton had undergone a complex tectonic evolution,marked by extensive Paleoproterozoic magmatism that produced a diverse range of mafic to felsic magmatic rocks.These events provide valuable geological records for understanding the tectonic evolution of the Jiao-Liao-Ji Belt.This study focuses on the Paleoproterozoic Chibaisong meta-gabbro in southern Jilin,investigating the source of mafic magma,petrogenesis,and tectonic setting through systematic petrological analysis,zircon U-Pb dating,and geochemical studies.The findings contribute to constraining the dynamic mechanisms of Paleoproterozoic extensional rifting in the Jiao-Liao-Ji orogenic belt.Geochemical data indicate that the samples exhibit low SiO₂(47.99–50.66 wt.%),TiO₂(0.75–3.20 wt.%),Nb(3.22–8.09 ppm),and Ta(0.22–0.51 ppm)contents,along with high TFeO₃(11.97–15.82 wt.%)and MgO(5.67–12.66 wt.%)concentrations.They also show low Nb/La ratios and high(Th/Nb)N values,consistent with the geochemical characteristics of tholeiitic basalts.The samples display low total rare earth element concentrations,weak or absent Eu anomalies,slight enrichment in light rare earth elements,relatively flat heavy rare earth element patterns,and depletion in Nb,Ta,and Ti.The meta-gabbro from southern Jilin exhibits geochemical similarities to Paleoproterozoic metamafic rocks from other regions of the Jiao-Liao-Ji Belt,resembling enriched mid-ocean ridge basalts(E-MORB)with Nb,Ta,and Ti depletion.Integration of previous studies and geochemical data suggests that the 2.16–2.10 Ga metamafic rocks in the Jiao-Liao-Ji Belt experienced contamination by older crustal material.These results indicate that the 2.16–2.10 Ga metamafic rocks are unlikely to be associated with island arc,continental arc,or mid-ocean ridge settings.Instead,they are more likely related to intraplate magmatism associated with continental rifting.
基金supported by the National Key R&D Program of China(No.2022YFC3003502).
文摘The northern segment of the North-South Seismic Belt is characterized by intense crustal deformation,well-developed active tectonics,and frequent occurrences of strong earthquakes.Therefore,conducting a Probabilistic Seismic Hazard Analysis(PSHA)for this region is of significant importance for supporting seismic fortification in major engineering projects and formulating disaster prevention and mitigation policies.In this study,a composite seismic source model was constructed by integrating data on historical earthquakes,active faults,and paleoseismicity.Furthermore,a logic tree framework was employed to quantify epistemic uncertainties,enabling a systematic seismic hazard assessment of the region.To more accurately characterize the spatial heterogeneity of seismic activity,improvements were made to both the Circular Spatial Smoothing Model(CSSM)with a fixed radius and the Adaptive Spatial Smoothing Model(ASSM),with full consideration given to the spatiotemporal completeness of historical earthquake magnitudes.Regarding the CSSM,for scenarios involving small sample sizes in earthquake catalogs,the cross-validation method proposed in this study demonstrated higher robustness than the maximum likelihood method in determining the optimal correlation distance.Performance evaluation results indicate that while both models effectively characterize seismic activity,the ASSM exhibits superior overall predictive performance compared to the CSSM,owing to its ability to adaptively adjust the smoothing radius according to seismic density.Significant discrepancies were observed in the Peak Ground Acceleration(PGA)results calculated with a 10%probability of exceedance in 50 years across different combinations of seismic source models.The single spatially smoothed point-source model yielded a maximum PGA of approximately 0.52 g,with high-value areas concentrated near historical epicenters,thereby significantly underestimating the hazard associated with major fault zones.When combined with the simple fault-source model,the maximum PGA increased to 0.8 g,with high-value zones exhibiting a zonal distribution along faults;however,the risk remained underestimated for faults with low slip rates that are nevertheless approaching their recurrence cycles.Following the introduction of the time-dependent characteristic fault-source model,local PGA values for faults in the middle-to-late stages of their recurrence cycles increased by a factor of 2 to 7 compared to the single model.These results demonstrate that the characteristic fault-source model reasonably delineates the time-dependence of large earthquake recurrence,thereby providing a more accurate assessment of imminent seismic risks.By comprehensively applying the improved spatially smoothed pointsource model,the simple fault-source model,and the characteristic fault-source model,the following faults within the region were identified as having high seismic hazard:the Huangxianggou,Zhangxian,and Tianshui segments of the Xiqinling northern edge fault;the Maqin-Maqu segment of the Dongkunlun fault;the Longriqu fault;the Maoergai fault;the Elashan fault;the Riyueshan fault;the eastern segment of the Lenglongling fault;the Maxianshan segment of the Maxianshan northern Margin fault;and the Maomaoshan-Jinqianghe segment of the Laohushan-Maomaoshan fault.As these faults are located within seismic gaps or are approaching the recurrence periods of large earthquakes,they should be prioritized for current and future seismic monitoring as well as disaster prevention and mitigation efforts.
基金funded by the National Key Research and Development Program of China(grant number 2023YFC2907600)the National Natural Science Foundation of China(grant number 52504132)Tiandi Science and Technology Co.,Ltd.Science and Technology Innovation Venture Capital Special Project(grant number 2023-TD-ZD011-004).
文摘Foreign body classification on coal conveyor belts is a critical component of intelligent coal mining systems.Previous approaches have primarily utilized convolutional neural networks(CNNs)to effectively integrate spatial and semantic information.However,the performance of CNN-based methods remains limited in classification accuracy,primarily due to insufficient exploration of local image characteristics.Unlike CNNs,Vision Transformer(ViT)captures discriminative features by modeling relationships between local image patches.However,such methods typically require a large number of training samples to perform effectively.In the context of foreign body classification on coal conveyor belts,the limited availability of training samples hinders the full exploitation of Vision Transformer’s(ViT)capabilities.To address this issue,we propose an efficient approach,termed Key Part-level Attention Vision Transformer(KPA-ViT),which incorporates key local information into the transformer architecture to enrich the training information.It comprises three main components:a key-point detection module,a key local mining module,and an attention module.To extract key local regions,a key-point detection strategy is first employed to identify the positions of key points.Subsequently,the key local mining module extracts the relevant local features based on these detected points.Finally,an attention module composed of self-attention and cross-attention blocks is introduced to integrate global and key part-level information,thereby enhancing the model’s ability to learn discriminative features.Compared to recent transformer-based frameworks—such as ViT,Swin-Transformer,and EfficientViT—the proposed KPA-ViT achieves performance improvements of 9.3%,6.6%,and 2.8%,respectively,on the CUMT-BelT dataset,demonstrating its effectiveness.
文摘The west Kunlun fold-thrust belt (WKFTB) and the Altun fold-thrust belt (AFTB) are respectively located in the southern margin of the Tarim basin, NW China. The analyses of typical structures and regional dynamics of the fold-thrust belts reveal their different structural and pe-troleum features and mechanisms. WKFTB differs from AFTB by abundant fault-related folds and triangles zones, and was formed by northward extrusion of the west Kunlun orogen. AFTB was affected synchronously by northward extrusion of the Altun orogen and the sinistral strike-slipping of the Altun Fault, so it is characterized by the minor scale and the monotonous structural styles. The Aqike anticline and the Aqike fault, of which the strikes are orthogonal to the strike of the fold-thrust belts, are regarded as the adjustive structures between both of the fold-thrust belts. The oil-gas pools of WKFTB develop mainly in the faulted-related anticline traps, but the oil-gas pools of AFTB develop mainly in the low fault-block and anticlines traps related with the pa-leo-uplifts. There are different exploration countermeasures for both of the fold-thrust belts.
文摘The evolution of the Tarim southwest depression lying at the piedmont of the West Kunlun orogen differs completely from the evolution of the main part of Tarim basin after Later Palaeozoic because the former strongly subsides many times.. Subsidence is related closely to the West Kunlun fold thrust\|belt, thus the evolution of the Depression and the fold\|thrust\|belt reflects clearly the formation and evolution of the West Kunlun and even the Tibet.1 Evolution of the West Kunlun fold\|thrust\|belt\;Thrusting of the fold\|thrust\|belt can be classified into three stages:(1) Devonian thrusting:This is the oldest thrusting distinguished in the northern margin of the West Kunlun while the Silurian—Devonian thrusting was discriminated a few years ago by seismic data in the northern part of the East Kunlun. The Devonian thrusting is proved by the Upper Devonian dynamometamorphic rocks outcropping at the core of the anticline in the Sangzhu lying at the fold\|thrust\|belt. The rocks consist of slightly metamorphic clastic rock and have always been regarded as the Mid\|Proterozoic strata. But they are actually Upper Devonian strata according to the amount of perfect plant fossils that we found recently in the metamorphic rock, and they are overburdened `with an angular unconformity by another reliable Upper\|Devonian conglomerate in the core of the Aqike anticline. A possible explanation for this and its limited lined distribution parallel to the West Kunlun orogen is that they are subjected to metamorphism during the Later Devonian thrusting.
基金supported by the National Natural Science Foundation of China(52204084)the Open Research Fund of The State Key Laboratory of Coal Resources and safe Mining,CUMT(SKLCRSM23KF004)+3 种基金the Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities)(FRF-IDRY-GD22-002)the Fundamen〓〓tal Research Funds for the Central Universities and the Youth Teacher International Exchange and Growth Program(QNXM20220009)the National Key R&D Program of China(2022YFC2905600 and 2022YFC3004601)the Science,Technology&Innovation Proj〓〓ect of Xiongan New Area(2023XAGG0061).
文摘In this article,the contemporary stress state of the Zhao-Ping metallogenic belt in eastern China was revealed using overcoring 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 σ_(H)>σ_(v)>σ_(h).The σ_(H) orientation is well-oriented in the WNW-ESE,which is roughly identical to other stress indicators.Moreover,theσH direction reflected by joint strikes and inferred based on the fault characteristics agrees fairly with the identified stress orientation.The modern stress field basically inherited the tectonic stress field of the Yanshanian and Himalayan periods but is principally dominated by the Himalayan period.Additionally,the calculatedμm 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 predicting and analyzing future fault activity in the area,respectively.
文摘Cross-border e-commerce,as a new form of international trade,has shown great development potential in the context of the“Belt and Road”initiative.Based on the cross-border e-commerce export data from 2015 to 2024,this paper analyzes the influencing factors of China's cross-border e-commerce exports to countries along the“Belt and Road”by constructing an econometric model.The study found that factors such as the perfection of digital infrastructure,the efficiency of logistics and transportation,the convenience of payment and settlement,and the penetration rate of consumers online shopping significantly affect the export scale of cross-border e-commerce.Institutional factors such as the development level of e-commerce platforms in countries along the route,market access thresholds,and tariff policies also play an important role.Based on the research results,suggestions are put forward to strengthen the construction of cross-border payment system,optimize the logistics distribution network,promote customs clearance facilitation,and deepen cooperation in the field of e-commerce,to provide references for promoting the development of China's crossborder e-commerce exports to countries along the“Belt and Road.”
基金funded by the Central University D Project(HFW230600022)National Natural Science Foundation of China(71973021)+1 种基金National Natural Science Foundation Youth Funding Project(72003022)Heilongjiang Province University Think Tank Open Topic(ZKKF2022173).
文摘The scientific assessment of ecosystem ser-vice value(ESV)plays a critical role in regional ecologi-cal protection and management,rational land use planning,and the establishment of ecological security barriers.The ecosystem service value of the Northeast Forest Belt from 2005 to 2020 was assessed,focusing on spatial–temporal changes and the driving forces behind these dynamics.Using multi-source data,the equivalent factor method,and geo-graphic detectors,we analyzed natural and socio-economic factors affecting the region.which was crucial for effective ecological conservation and land-use planning.Enhanced the effectiveness of policy formulation and land use plan-ning.The results show that the ESV of the Northeast Forest Belt exhibits an overall increasing trend from 2005 to 2020,with forests and wetlands contributing the most.However,there are significant differences between forest belts.Driven by natural and socio-economic factors,the ESV of forest belts in Heilongjiang and Jilin provinces showed significant growth.In contrast,the ESV of Forest Belts in Liaoning and Inner Mongolia of China remains relatively stable,but the spatial differentiation within these regions is characterized by significant clustering of high-value and low-value areas.Furthermore,climate regulation and hydrological regulation services were identified as the most important ecological functions in the Northeast Forest Belt,contributing greatly to regional ecological stability and human well-being.The ESV in the Northeast Forest Belt is improved during the study period,but the stability of the ecosystem is still chal-lenged by the dual impacts of natural and socio-economic factors.To further optimize regional land use planning and ecological protection policies,it is recommended to prior-itize the conservation of high-ESV areas,enhance ecological restoration efforts for wetlands and forests,and reasonably control the spatial layout of urban expansion and agricul-tural development.Additionally,this study highlights the importance of tailored ecological compensation policies and strategic land-use planning to balance environmental protec-tion and economic growth.
基金Supported by the National Natural Science Foundation of China(42302141).
文摘Taking the second member of the Xujiahe Formation of the Upper Triassic in the Xinchang structural belt as an example,based on data such as logging,production,seismic interpretation and test,a systematic analysis was conducted on the structural characteristics and evolution,reservoir diagenesis and densification processes,and types and stages of faults/fractures,and revealing the multi-stage and multi-factor dynamic coupled enrichment mechanisms of tight gas reservoirs.(1)In the early Yanshan period,the paleo-structural traps were formed with low-medium maturity hydrocarbons accumulating in structural highs driven by buoyancy since reservoirs were not fully densified in this stage,demonstrating paleo-structure control on traps and early hydrocarbon accumulation.(2)In the middle-late Yanshan period,the source rocks became mature to generate and expel a large quantity of hydrocarbons.Grain size and type of sandstone controlled the time of reservoir densification,which restricted the scale of hydrocarbon charging,allowing for only a small-scale migration through sand bodies near the fault/fracture or less-densified matrix reservoirs.(3)During the Himalayan period,the source rocks reached overmaturity,and the residual oil cracking gas was efficiently transported along the late-stage faults/fractures.Wells with high production capacity were mainly located in Type I and II fault/fracture zones comprising the late-stage north-south trending fourth-order faults and the late-stage fractures.The productivity of the wells was controlled by the transformation of the late-stage faults/fractures.(4)The Xinchang structural belt underwent three stages of tectonic evolution,two stages of reservoir formation,and three stages of fault/fractures development.Hydrocarbons mainly accumulated in the paleo-structure highs.After reservoir densification and late fault/fracture adjustment,a complex gas-water distribution pattern was formed.Thus,it is summarized as the model of“near-source and low-abundance hydrocarbon charging in the early stage,and differential enrichment of natural gas under the joint control of fault-fold-fracture complex,high-quality reservoirs and structural highs in the late stage”.Faults/fractures with well-coupled fault-fold-fracture-pore are favorable exploration targets with high exploration effectiveness.
文摘In the 12 years since the Belt and Road Initiative was first proposed,many Chinese enterprises have made fruitful achievements in the participating countries of the Belt and Road Initiative.
文摘With the most advanced and sophisticated technologies and equipment,NYBELT is one of the largest manufacturers of flat transmission belts in the world.Under the Certified Quality,Environment,Occupational Health&Safety,and Energy Standardized ISO Management System,NYBELT can produce all kinds of flat transmission belts,roller coverings and conveyor belts applicable to textile,printing&packaging,electronics and other industries.Due to the superior quality and the reasonable prices,we have become well known in providing high quality belting products and excellent service to customers all over the world.Our success in the past gives us the confidence to look into the future with great expectations.
