The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode compri...The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode comprising Ce-doped Ni-Fe-Se nanosheets grown on carbon cloth(Ni-Fe-Ce-Se/CC).This electrode was synthesized through a selenylation process,utilizing Ni-Fe-Ce-layered double hydroxide/carbon cloth(Ni-Fe-Ce LDH/CC)as the precursor.Notably,Ni-Fe-Ce-Se/CC electrode demonstrates remarkable performance,requiring a low overpotential of 300 mV to attain a current density of 100 mA·cm^(-2)under harsh alkaline conditions.Furthermore,the electrode exhibits exceptional stability during continuous operation for 100 h.Insight into the underlying mechanisms was gained through a combination of experimental results and density functional theory calculations.Our findings reveal that Ce doping induces crystal structure deformation in Ni-Fe-Se and enhances electron enrichment around Ni atoms.This structural modification optimizes the adsorption energy of oxygen-based intermediates on the Ni-Fe-Se surface.This work offers a valuable strategy for regulating the electron transfer and adsorption capabilities of transition metal selenide electrocatalysts through RE atoms doping,opening new avenues for enhanced electrocatalytic performance.展开更多
The structural deformation velocity plays a significant role in the dynamic calculation of underground blast-resistant structures. The motion differentiating equation of a structure system taking into account the role...The structural deformation velocity plays a significant role in the dynamic calculation of underground blast-resistant structures. The motion differentiating equation of a structure system taking into account the role of deformation velocity of the structure will truthfully describe the actual situation of structural vibration. With the one-dimensional plane wave theory, the expression of load on the structural periphery is developed, and the generalized variation principle for the dynamic analysis of underground arched-bar structures is given. At the same time, the results of the numerical calculation are compared.展开更多
Deformed soft-sediment deformation structures(SSDS)can indicate polyphase deformation events and provide valuable insights into the inversion process of a basin.Herein,we present the Miocene–Quaternary deformation in...Deformed soft-sediment deformation structures(SSDS)can indicate polyphase deformation events and provide valuable insights into the inversion process of a basin.Herein,we present the Miocene–Quaternary deformation inversion history of the Bomun sub-basin in the Gyeongju area of SE Korea.The inferred ENE compression direction(σHmax)based on paleostress analysis of the fault system,displacing Miocene sediments and SSDS,corresponds to the current stress field.The widespread occurrence of clear liquefaction structures and the vertical repetition of SSDS indicate substantial seismic activity during the basin opening stage.Brittle deformation features observed at both outcrop-and microstructural-scale along the faults suggest a reactivation as reverse faulting associated with a tilting process.The tectonic history of the study area is distinguished by SSDS associated with seismic activity,and reverse faulting associated with inversion process under ENE orientedσHmax.The Environmental Seismic Intensity Scale(ESI-07)based on the SSDS indicates seismic intensity of IX-X,which might be related with the opening of the Bomun sub-basin.Therefore,detailed analyses of SSDS could provide valuable insights on the dynamics of local geology and contribute to further extensive research on seismic hazards and basin inversion.展开更多
For deep prospects in the foreland thrust belt,southern Junggar Basin,NW China,there are uncertainties in factors controlling the structural deformation,distribution of paleo-structures and detachment layers,and distr...For deep prospects in the foreland thrust belt,southern Junggar Basin,NW China,there are uncertainties in factors controlling the structural deformation,distribution of paleo-structures and detachment layers,and distribution of major hydrocarbon source rocks.Based on the latest 3D seismic,gravity-magnetic,and drilling data,together with the results of previous structural physical simulation and discrete element numerical simulation experiments,the spatial distribution of pre-existing paleo-structures and detachment layers in deep strata of southern Junggar Basin were systematically characterized,the structural deformation characteristics and formation mechanisms were analyzed,the distribution patterns of multiple hydrocarbon source rock suites were clarified,and hydrocarbon accumulation features in key zones were reassessed.The exploration targets in deep lower assemblages with possibility of breakthrough were expected.Key results are obtained in three aspects.First,structural deformation is controlled by two-stage paleo-structures and three detachment layers with distinct lateral variations:the Jurassic layer(moderate thickness,wide distribution),the Cretaceous layer(thickest but weak detachment),and the Paleogene layer(thin but long-distance lateral thrusting).Accordingly,a four-layer composite deformation sequence was identified,and the structural genetic model with paleo-bulge controlling zonation by segments laterally and multiple detachment layers controlling sequence vertically.Second,the Permian source rocks show a distribution pattern with narrow trough(west),multiple sags(central),and broad basin(east),which is depicted by combining high-precision gravity-magnetic data and time-frequency electromagnetic data for the first time,and the Jurassic source rocks feature thicker mudstones in the west and rich coals in the east according to the reassessment.Third,two petroleum systems and a four-layer composite hydrocarbon accumulation model are established depending on the structural deformation strength,trap effectiveness and source-trap configuration.The southern Junggar Basin is divided into three segments with ten zones,and a hierarchical exploration strategy is proposed for deep lower assemblages in this region,that is,focusing on five priority zones,expanding to three potential areas,and challenging two high-risk targets.展开更多
This study identified soft-sediment deformation structures （SSDS） of seismic origin from lacustrine sediments in the late Quaternary paleo-dammed lake at Tashkorgan, northeastern Pamir. The observed deformation stru...This study identified soft-sediment deformation structures （SSDS） of seismic origin from lacustrine sediments in the late Quaternary paleo-dammed lake at Tashkorgan, northeastern Pamir. The observed deformation structures include sand dykes, liquefied diapir and convolute structures, gravity induced SSDS, and thixotropic pillar and tabular structures. We conducted a preliminary study on the morphology, formation and trigger mechanisms of pillar and tabular structures formed by liquefaction of underlying coarse sand and thixotropy of the upper silty clay. The regional tectonic setting and distribution of lacustrine strata indicate that the most probable trigger for the SSDS in lacustrine sediments was seismic activity, with an approximate earthquake magnitude of M〉6.0; the potential seismogenic fault is the southern part of the Kongur normal fault extensional system. AMS ^4C dating results indicate that the SSDS were formed by seismic events occurring between 26050±100 yrBP and 22710±80 yrBP, implying intense fault activity in this region during the late Pleistocene. This study provides new evidence for understanding tectonic activity and regional geodynamics in western China.展开更多
Intervals of soft-sediment deformation structures are well-exposed in Jurassic lacustrine deposits in the western Qaidamu basin. Through field observation, many soft-sediment deformation structures can be identified, ...Intervals of soft-sediment deformation structures are well-exposed in Jurassic lacustrine deposits in the western Qaidamu basin. Through field observation, many soft-sediment deformation structures can be identified, such as convoluted bedding, liquefied sand veins, load and flame structures, slump structures and sliding-overlapping structures. Based on their genesis, soft-sediment deformation structures can be classified as three types： seismic induced structures, vertical loading structures, and horizontal shear structures. Based on their geometry and genesis analysis, they are seismic-induced structures. According to the characteristics of convoluted bedding structures and liquefied sand veins, it can be inferred that there were earthquakes greater than magnitude 6 in the study area during the middle Jurassic. Furthermore, the study of the slump structures and sliding- overlapping structures indicates that there was a southeastern slope during the middle Jurassic. Since the distance from the study area to the Altyn Mountain and the Altyn fault is no more than 10km, it can be also inferred that the Altyn Mountain existed then and that the AItyn strike-slip fault was active during the middle Jurassic.展开更多
Soft-sediment deformation structures are abundant in the Cambrian Zhushadong and Mantou formations of the Dengfeng area, Henan Province, China. Soft-sediment deformation structures of the Zhushadong Formation consist ...Soft-sediment deformation structures are abundant in the Cambrian Zhushadong and Mantou formations of the Dengfeng area, Henan Province, China. Soft-sediment deformation structures of the Zhushadong Formation consist of fluidized deformation, synsedimentary faults, seismo-folds and plastic deformation; the Mantou Formation is dominated by small-scale horst faults, intruded dikes, fluidized veins, and seismo-cracks. These structures are demonstrated to be earthquake-related by analysis of trigger mechanisms, and may indicate the activity of the Qinling tectonic belt during the early Cambrian. Furthermore, the assemblages of soft-sediment deformation structures altered with time： large-scale, intense deformation in the Zhushadong Formation alters to small-scale, weak deformation in the Mantou Formation. This striking feature may have been caused by changes in hypocentral depth from deep-focus to shallow-focus earthquakes, indicating that the Qinling tectonic belt developed from the subduction of the Shangdan Ocean to the extension of the Erlangping back-arc basin. This study suggests that soft-sediment deformation structures can be used to reveal the activity of a tectonic belt, and, more importantly, changes in deformation assemblages can track the evolution of a tectonic belt.展开更多
The traces left by earthquakes in lacustrine sediments are studied to determine the occurrence of ancient earthquakes by identifying seismically induced soft-sediment deformation structures(SSDS).Dating can help recon...The traces left by earthquakes in lacustrine sediments are studied to determine the occurrence of ancient earthquakes by identifying seismically induced soft-sediment deformation structures(SSDS).Dating can help reconstruct the relative frequency of earthquakes.Identifying seismically induced seismites,which carry abundant seismic information from numerous SSDS,is both critical and challenging.Studying the deformation mechanism of SSDS and learning about the common criteria of seismically induced SSDS improve the identification of earthquake triggers.With better research into SSDS,seismic events can be effectively captured,and temporal constraints can be carried out by 14C dating and optically stimulated luminescence(OSL)dating to identify and date the occurrence of ancient earthquakes.The present contribution primarily addresses the meaning and mechanism of SSDS and their relationship with earthquake magnitude as well as the common criteria of the SSDS induced by earthquakes.展开更多
Field investigation and laboratory work reveal that inhomogeneity of the deformation of the Xiannushan fault is mainly characterized by lateral zonation, longitudinal segmentation and downward stratification. Based on...Field investigation and laboratory work reveal that inhomogeneity of the deformation of the Xiannushan fault is mainly characterized by lateral zonation, longitudinal segmentation and downward stratification. Based on these results, a 3-D deformational structure model of the fault was established and its geometrical and kinematic characteristics in two main deformational stages i.e. the main Yanshanian and Himalayan were discussed. The directions of principal and the differential stresses in these two stages were determined by using conjugate joints, striations of fault planes and microstructures of the fault zone. The direction of σI is N-S in direction with differential stresses of 150-250 MPa in the Yanshanian, and N70E with a differential stress ranging from 80-120 MPa in the Himalayan.展开更多
In order to study the failure process of an anchorage structure and the evolution law of the body＇s defor- mation field, anchor push-out tests were carried out based on digital speckle correlation methods （DSCM）. T...In order to study the failure process of an anchorage structure and the evolution law of the body＇s defor- mation field, anchor push-out tests were carried out based on digital speckle correlation methods （DSCM）. The stress distribution of the anchorage interface was investigated using the particle flow numerical simulation method. The results indicate that there are three stages in the deformation and fail- ure process of an anchorage structure： elastic bonding stage, a de-bonding stage and a failure stage. The stress distribution in the interface controls the stability of the structure. In the elastic bonding stage, the shear stress peak point of the interface is close to the loading end, and the displacement field gradually develops into a ＂V＂ shape, in the de-bonding stage, there is a shear stress plateau in the center of the anchorage section, and shear strain localization begins to form in the deformation field. In the failure stage, the bonding of the interface fails rapidly and the shear stress peak point moves to the anchorage free end. The anchorage structure moves integrally along the macro-cracl~ The de-bonding stage is a research focus in the deformation and failure process of an anchorage structure, and plays an important guiding role in roadway support design and prediction of the stability of the surrounding rock.展开更多
Intermetallic beryllides are potential light-weight, high-temperature structural materials. In this paper. the processing techniques, microstructure. deformation, and oxidation properties of intermetallic beryllides a...Intermetallic beryllides are potential light-weight, high-temperature structural materials. In this paper. the processing techniques, microstructure. deformation, and oxidation properties of intermetallic beryllides are described. In addition to nickel beryllides (NiBe). which is treated as a model system.other high beryllium-containing refractory beryllides, such as Nb2 Be17. VBe12. are also studied.The room temperature deformation and high-temperature creep properties of these beryllides are repor4ed. At room temperature. NiBe exhibits certain tensile ductility (~ 1 .3%). but all other beryllides are essentially brittle. Nonetheless, these beryllides become ductile at temperatures above approximately 1000℃. Their creep properties are presented. The creep properties are compared with those of intermetallic aluminides. Also. a comparison is made between the ductile-to-brittle transition behaviour of intermetallic beryllides and that of aluminides. Although beryllides are generally oxidation resistant at high temperatures, some beryllides, e.g., ZrBe13, suffer the pest reaction during oxidation at intermediate tem peratures. The pest mechanisms are proposed展开更多
The deformation behaviour and the nature of dislocations of the Al3Ti-base L12 alloya modified with Fe and Mn etc, were investigated. The results show that the deformation and fracture character istics are closely rel...The deformation behaviour and the nature of dislocations of the Al3Ti-base L12 alloya modified with Fe and Mn etc, were investigated. The results show that the deformation and fracture character istics are closely related to the alloy compositions. The effect of hot-working process on the room tem perature ductility is remarkable, not only resulting in an appreciable improvement of compressive properties but also showing a 0.28% plastic strain in tensile test. The SISF dissociation of a < 110>dislocations on {111} planes was found at room temperature. The determined dissociation scheme is consistent with the mechanical behaviour of these alloys in the lower temperature region.展开更多
Detailed fieldwork carried out in the southern part of Bida Basin, Nigeria, allowed the documentation of soft sediment deformation structures (SSDS) in the Maastrichtian Patti Formation. The aim of this study is to ex...Detailed fieldwork carried out in the southern part of Bida Basin, Nigeria, allowed the documentation of soft sediment deformation structures (SSDS) in the Maastrichtian Patti Formation. The aim of this study is to examine the sedimentary successions, describe and analyse these deformation features, discuss their deformation mechanisms and potential triggers. The Maastrichtian Patti Formation is composed of lithofacies interpreted to have been deposited in tidal and fluvial sedimentary environments. Soft sediment deformation structures recognised in the tidal sediments were clastic dykes, load cast, isolated sand balls, dish-and-pillar structures, convolute lamination, diapiric structures and recumbent folds. Severely deformed cross beds, ring structures, associated sand balls, normal folds and recumbent folds were identified in the fluvial sediments. SSDS recognised were interpreted to have been caused by effects of liquefaction and fluidization. Field observations, facies analysis and morphology of the SSDS indicate that there are relationship between the depositional environments and SSDS. Endogenic processes are considered as the trigger agents and they are represented by rapid sedimentation and overloading, impact of breaking waves, pressure fluctuations caused by turbulent water flow, cyclic stress and current generated by storm waves and changes in water table. The present study did not identify exogenic processes as trigger agent. The occurrence of SSDS in southern Bida Basin strongly favoured a non-tectonic origin but a clear relationship high energy processes in tidal and fluvial depositional environments.展开更多
In this paper, based on the idea of finite element method, the initial parametric method in bending, problem of a beam is extended to analyse the bar-system structure by employing Dirac function and llcavisidc step fu...In this paper, based on the idea of finite element method, the initial parametric method in bending, problem of a beam is extended to analyse the bar-system structure by employing Dirac function and llcavisidc step function.Then a new method for analysing the internal forces and deformations of bar-system structure in space is suggested by improving the mixed method in statically indeterminate structure.The inferred process and obtained answer will be more succinct and accurate when the problem of internal forces and deformations of bar-system structure is analysed by using the new method provided in this paper.展开更多
To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and str...To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface subsidence.The curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath it.The torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite directions.The first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the second traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing structure.The shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence becomes slower as the excavation continues.展开更多
The Mio-Pliocene Middle Siwalik Subgroup,in the Lish River Section in the Darjiling District of the Eastern Himalaya,consists of sandstone,mudrocks,heterolithic units and conglomerates preserving six distinct associat...The Mio-Pliocene Middle Siwalik Subgroup,in the Lish River Section in the Darjiling District of the Eastern Himalaya,consists of sandstone,mudrocks,heterolithic units and conglomerates preserving six distinct associations of soft-sediment deformation structures at different stratigraphic levels.The foreland basin sediments of the Himalayan orogen were deposited in alluvial fan settings.Deformation structures present are:folds of variable geometry,pseudonodules,water escape features,flame structures and chaotic laminae.展开更多
Nowadays,an increasing number of ships and marine structures are manufactured and inevitably operated in rough sea.As a result,some phenomena related to the violent fluid-elastic structure interactions(e.g.,hydrodynam...Nowadays,an increasing number of ships and marine structures are manufactured and inevitably operated in rough sea.As a result,some phenomena related to the violent fluid-elastic structure interactions(e.g.,hydrodynamic slamming on marine vessels,tsunami impact on onshore structures,and sloshing in liquid containers)have aroused huge challenges to ocean engineering fields.In this paper,the moving particle semi-implicit(MPS)method and finite element method(FEM)coupled method is proposed for use in numerical investigations of the interaction between a regular wave and a horizontal suspended structure.The fluid domain calculated by the MPS method is dispersed into fluid particles,and the structure domain solved by the FEM method is dispersed into beam elements.The generation of the 2D regular wave is firstly conducted,and convergence verification is performed to determine appropriate particle spacing for the simulation.Next,the regular wave interacting with a rigid structure is initially performed and verified through the comparison with the laboratory experiments.By verification,the MPS-FEM coupled method can be applied to fluid-structure interaction(FSI)problems with waves.On this basis,taking the flexibility of structure into consideration,the elastic dynamic response of the structure subjected to the wave slamming is investigated,including the evolutions of the free surface,the variation of the wave impact pressures,the velocity distribution,and the structural deformation response.By comparison with the rigid case,the effects of the structural flexibility on wave-elastic structure interaction can be obtained.展开更多
To examine the similarities and differences in the evolution of cavity,wetting and dynamics of a highspeed,oblique water-entry projectile with different positive angles of attack,a comparative analysis has been conduc...To examine the similarities and differences in the evolution of cavity,wetting and dynamics of a highspeed,oblique water-entry projectile with different positive angles of attack,a comparative analysis has been conducted based on the numerical results of two mathematical models,the rigid-body model and fluid-structure interaction model.In addition,the applicable scope of the above two methods,and the structural response characteristics of the projectile have also been investigated.Our results demonstrate that:(1) The impact loads and angular motion of the projectile of the rigid-body method are more likely to exhibit periodic variations due to the periodic tail slap,its range of positive angles of attack is about α<2°.(2) When the projectile undergone significant wetting,a strong coupling effect is observed among wetting,structural deformation,and projectile motion.With the applied projectile shape,it is observed that,when the projectile bends,the final wetting position is that of Part B(cylinder of body).With the occu rrence of this phenomenon,the projectile ballistics beco me completely unstable.(3) The force exerted on the lower surface of the projectile induced by wetting is the primary reason of the destabilization of the projectile traj ectory and structu ral deformation failure.Bending deformation is most likely to appear at the junction of Part C(cone of body) and Part D(tail).The safe angles of attack of the projectile stability are found to be about α≤2°.展开更多
The deformation behavior and formability of gradient nano-grained（GNG） AISI 304 stainless steel in uniaxial and biaxial states were investigated by means of tensile test and small punch test（SPT）. The GNG top laye...The deformation behavior and formability of gradient nano-grained（GNG） AISI 304 stainless steel in uniaxial and biaxial states were investigated by means of tensile test and small punch test（SPT）. The GNG top layer was fabricated on coarse grains（CG） AISI 304 by ultrasonic impact treatment. The results showed that the CG substrate could effectively suppress the strain localization of NC in GNG layer, and an approximate linear relationship existed between the thickness of substrate（h） and uniform true strain before necking（ε_（unif））. Grain growth of NC was observed at the stress state with high Stress triaxiality T, which led to better ductility of GNG/CG 304 in SPT, as well as similar true strain after the onset of necking（ε_（neck）） compared with coarse 304 in tensile test. Ei-values of GNG/CG 304 with different structures were nearly the same at different punch speeds, and good formability of GNG/CG 304 was demonstrated. However, punch speed and microstructure needed to be optimized to avoid much lost of membrane strain region in biaxial stress state.展开更多
Submicrometer-grained （SMG） Al-3%Mn （mass fraction） alloy specimens with initial grain size of -0.3 μm were produced by ball milling for 3 h. The Al-3%Mn specimens which were cold rolled with a strain rate of 1&#...Submicrometer-grained （SMG） Al-3%Mn （mass fraction） alloy specimens with initial grain size of -0.3 μm were produced by ball milling for 3 h. The Al-3%Mn specimens which were cold rolled with a strain rate of 1×10^-3- 1×10^-2 s-1 at room temperature show high extensibility to failure more than 2500%. Microstructures of pure Al and Al-3%Mn alloy at as-milled and cold-rolled state were examined using X-ray diffraction and transmission electron microscopy （TEM）. Based on the microstructure analysis, it is established that the mechanism of the continued plastic deformation in SMG Al-3%Mn alloy consists of dislocation slip, grain boundary sliding companied by dynamic recovery and recrystallization, and dynamic recrystallization is a main control factor of the large plastic deformation.展开更多
基金supported by the National Key Technology R&D Program of China(Nos.2021YFB3500801,2022YFB3504302 and 2022YFC3901503)the Natural Science Foundation and Overseas Talent Projects of Jiangxi Province(Nos.0232BAB214025 and 20232BCJ25044)the Double Thousand Plan of Jiangxi Province(No.jxsq2023201002).
文摘The development of cost-effective and highly stable electrocatalysts for oxygen evolution reactions holds paramount importance in practical hydrogen production.Herein,we present a novel self-supported electrode comprising Ce-doped Ni-Fe-Se nanosheets grown on carbon cloth(Ni-Fe-Ce-Se/CC).This electrode was synthesized through a selenylation process,utilizing Ni-Fe-Ce-layered double hydroxide/carbon cloth(Ni-Fe-Ce LDH/CC)as the precursor.Notably,Ni-Fe-Ce-Se/CC electrode demonstrates remarkable performance,requiring a low overpotential of 300 mV to attain a current density of 100 mA·cm^(-2)under harsh alkaline conditions.Furthermore,the electrode exhibits exceptional stability during continuous operation for 100 h.Insight into the underlying mechanisms was gained through a combination of experimental results and density functional theory calculations.Our findings reveal that Ce doping induces crystal structure deformation in Ni-Fe-Se and enhances electron enrichment around Ni atoms.This structural modification optimizes the adsorption energy of oxygen-based intermediates on the Ni-Fe-Se surface.This work offers a valuable strategy for regulating the electron transfer and adsorption capabilities of transition metal selenide electrocatalysts through RE atoms doping,opening new avenues for enhanced electrocatalytic performance.
文摘The structural deformation velocity plays a significant role in the dynamic calculation of underground blast-resistant structures. The motion differentiating equation of a structure system taking into account the role of deformation velocity of the structure will truthfully describe the actual situation of structural vibration. With the one-dimensional plane wave theory, the expression of load on the structural periphery is developed, and the generalized variation principle for the dynamic analysis of underground arched-bar structures is given. At the same time, the results of the numerical calculation are compared.
基金supported by a grant(2022-MOIS62-001(RS-2022-ND640011))from the National Disaster Risk AnalysisManagement Technology in Earthquake funded by the Ministry of Interior and Safety(MOIS,Korea).
文摘Deformed soft-sediment deformation structures(SSDS)can indicate polyphase deformation events and provide valuable insights into the inversion process of a basin.Herein,we present the Miocene–Quaternary deformation inversion history of the Bomun sub-basin in the Gyeongju area of SE Korea.The inferred ENE compression direction(σHmax)based on paleostress analysis of the fault system,displacing Miocene sediments and SSDS,corresponds to the current stress field.The widespread occurrence of clear liquefaction structures and the vertical repetition of SSDS indicate substantial seismic activity during the basin opening stage.Brittle deformation features observed at both outcrop-and microstructural-scale along the faults suggest a reactivation as reverse faulting associated with a tilting process.The tectonic history of the study area is distinguished by SSDS associated with seismic activity,and reverse faulting associated with inversion process under ENE orientedσHmax.The Environmental Seismic Intensity Scale(ESI-07)based on the SSDS indicates seismic intensity of IX-X,which might be related with the opening of the Bomun sub-basin.Therefore,detailed analyses of SSDS could provide valuable insights on the dynamics of local geology and contribute to further extensive research on seismic hazards and basin inversion.
基金Supported by the Science and Technology Special Project of CNPC(2023YQX10111)Key Research and Development Special Project of Xinjiang Uygur Autonomous Region(2024B01015-3)。
文摘For deep prospects in the foreland thrust belt,southern Junggar Basin,NW China,there are uncertainties in factors controlling the structural deformation,distribution of paleo-structures and detachment layers,and distribution of major hydrocarbon source rocks.Based on the latest 3D seismic,gravity-magnetic,and drilling data,together with the results of previous structural physical simulation and discrete element numerical simulation experiments,the spatial distribution of pre-existing paleo-structures and detachment layers in deep strata of southern Junggar Basin were systematically characterized,the structural deformation characteristics and formation mechanisms were analyzed,the distribution patterns of multiple hydrocarbon source rock suites were clarified,and hydrocarbon accumulation features in key zones were reassessed.The exploration targets in deep lower assemblages with possibility of breakthrough were expected.Key results are obtained in three aspects.First,structural deformation is controlled by two-stage paleo-structures and three detachment layers with distinct lateral variations:the Jurassic layer(moderate thickness,wide distribution),the Cretaceous layer(thickest but weak detachment),and the Paleogene layer(thin but long-distance lateral thrusting).Accordingly,a four-layer composite deformation sequence was identified,and the structural genetic model with paleo-bulge controlling zonation by segments laterally and multiple detachment layers controlling sequence vertically.Second,the Permian source rocks show a distribution pattern with narrow trough(west),multiple sags(central),and broad basin(east),which is depicted by combining high-precision gravity-magnetic data and time-frequency electromagnetic data for the first time,and the Jurassic source rocks feature thicker mudstones in the west and rich coals in the east according to the reassessment.Third,two petroleum systems and a four-layer composite hydrocarbon accumulation model are established depending on the structural deformation strength,trap effectiveness and source-trap configuration.The southern Junggar Basin is divided into three segments with ten zones,and a hierarchical exploration strategy is proposed for deep lower assemblages in this region,that is,focusing on five priority zones,expanding to three potential areas,and challenging two high-risk targets.
基金financially supported by the National Natural Science Foundation of China (41702372)the Open Fund of State Key Laboratory of Earthquake Dynamics (LED2017B03)
文摘This study identified soft-sediment deformation structures （SSDS） of seismic origin from lacustrine sediments in the late Quaternary paleo-dammed lake at Tashkorgan, northeastern Pamir. The observed deformation structures include sand dykes, liquefied diapir and convolute structures, gravity induced SSDS, and thixotropic pillar and tabular structures. We conducted a preliminary study on the morphology, formation and trigger mechanisms of pillar and tabular structures formed by liquefaction of underlying coarse sand and thixotropy of the upper silty clay. The regional tectonic setting and distribution of lacustrine strata indicate that the most probable trigger for the SSDS in lacustrine sediments was seismic activity, with an approximate earthquake magnitude of M〉6.0; the potential seismogenic fault is the southern part of the Kongur normal fault extensional system. AMS ^4C dating results indicate that the SSDS were formed by seismic events occurring between 26050±100 yrBP and 22710±80 yrBP, implying intense fault activity in this region during the late Pleistocene. This study provides new evidence for understanding tectonic activity and regional geodynamics in western China.
基金The National Natural Science Fund(No:41172093)the research fund(No:2003042500820060425509)for the doctoral program of higher education from Ministry of Education for their financial support
文摘Intervals of soft-sediment deformation structures are well-exposed in Jurassic lacustrine deposits in the western Qaidamu basin. Through field observation, many soft-sediment deformation structures can be identified, such as convoluted bedding, liquefied sand veins, load and flame structures, slump structures and sliding-overlapping structures. Based on their genesis, soft-sediment deformation structures can be classified as three types： seismic induced structures, vertical loading structures, and horizontal shear structures. Based on their geometry and genesis analysis, they are seismic-induced structures. According to the characteristics of convoluted bedding structures and liquefied sand veins, it can be inferred that there were earthquakes greater than magnitude 6 in the study area during the middle Jurassic. Furthermore, the study of the slump structures and sliding- overlapping structures indicates that there was a southeastern slope during the middle Jurassic. Since the distance from the study area to the Altyn Mountain and the Altyn fault is no more than 10km, it can be also inferred that the Altyn Mountain existed then and that the AItyn strike-slip fault was active during the middle Jurassic.
基金granted by the doctor foundation of Henan Polytechnic University(NO:B2013-076)the National Nature Science Foundation of China(NO:4147208341440016)
文摘Soft-sediment deformation structures are abundant in the Cambrian Zhushadong and Mantou formations of the Dengfeng area, Henan Province, China. Soft-sediment deformation structures of the Zhushadong Formation consist of fluidized deformation, synsedimentary faults, seismo-folds and plastic deformation; the Mantou Formation is dominated by small-scale horst faults, intruded dikes, fluidized veins, and seismo-cracks. These structures are demonstrated to be earthquake-related by analysis of trigger mechanisms, and may indicate the activity of the Qinling tectonic belt during the early Cambrian. Furthermore, the assemblages of soft-sediment deformation structures altered with time： large-scale, intense deformation in the Zhushadong Formation alters to small-scale, weak deformation in the Mantou Formation. This striking feature may have been caused by changes in hypocentral depth from deep-focus to shallow-focus earthquakes, indicating that the Qinling tectonic belt developed from the subduction of the Shangdan Ocean to the extension of the Erlangping back-arc basin. This study suggests that soft-sediment deformation structures can be used to reveal the activity of a tectonic belt, and, more importantly, changes in deformation assemblages can track the evolution of a tectonic belt.
基金the National Institute of Natural Hazards,Ministry of Emergency Management of China(ZDJ2019-21)the National Natural Science Foundation of China(Nos.41872227 and 41602221).
文摘The traces left by earthquakes in lacustrine sediments are studied to determine the occurrence of ancient earthquakes by identifying seismically induced soft-sediment deformation structures(SSDS).Dating can help reconstruct the relative frequency of earthquakes.Identifying seismically induced seismites,which carry abundant seismic information from numerous SSDS,is both critical and challenging.Studying the deformation mechanism of SSDS and learning about the common criteria of seismically induced SSDS improve the identification of earthquake triggers.With better research into SSDS,seismic events can be effectively captured,and temporal constraints can be carried out by 14C dating and optically stimulated luminescence(OSL)dating to identify and date the occurrence of ancient earthquakes.The present contribution primarily addresses the meaning and mechanism of SSDS and their relationship with earthquake magnitude as well as the common criteria of the SSDS induced by earthquakes.
文摘Field investigation and laboratory work reveal that inhomogeneity of the deformation of the Xiannushan fault is mainly characterized by lateral zonation, longitudinal segmentation and downward stratification. Based on these results, a 3-D deformational structure model of the fault was established and its geometrical and kinematic characteristics in two main deformational stages i.e. the main Yanshanian and Himalayan were discussed. The directions of principal and the differential stresses in these two stages were determined by using conjugate joints, striations of fault planes and microstructures of the fault zone. The direction of σI is N-S in direction with differential stresses of 150-250 MPa in the Yanshanian, and N70E with a differential stress ranging from 80-120 MPa in the Himalayan.
基金financially supported by the National Key Basic Research Program of China (No.2010CB226805)the National Natural Science Foundation of China (Nos.51474136 and 51474013)+1 种基金the Opening Project Fund of State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology (No.MDPC2013KF06)the Research Award Fund for the Excellent Youth of Shandong University of Science and Technology (No.2011KYJQ106)
文摘In order to study the failure process of an anchorage structure and the evolution law of the body＇s defor- mation field, anchor push-out tests were carried out based on digital speckle correlation methods （DSCM）. The stress distribution of the anchorage interface was investigated using the particle flow numerical simulation method. The results indicate that there are three stages in the deformation and fail- ure process of an anchorage structure： elastic bonding stage, a de-bonding stage and a failure stage. The stress distribution in the interface controls the stability of the structure. In the elastic bonding stage, the shear stress peak point of the interface is close to the loading end, and the displacement field gradually develops into a ＂V＂ shape, in the de-bonding stage, there is a shear stress plateau in the center of the anchorage section, and shear strain localization begins to form in the deformation field. In the failure stage, the bonding of the interface fails rapidly and the shear stress peak point moves to the anchorage free end. The anchorage structure moves integrally along the macro-cracl~ The de-bonding stage is a research focus in the deformation and failure process of an anchorage structure, and plays an important guiding role in roadway support design and prediction of the stability of the surrounding rock.
文摘Intermetallic beryllides are potential light-weight, high-temperature structural materials. In this paper. the processing techniques, microstructure. deformation, and oxidation properties of intermetallic beryllides are described. In addition to nickel beryllides (NiBe). which is treated as a model system.other high beryllium-containing refractory beryllides, such as Nb2 Be17. VBe12. are also studied.The room temperature deformation and high-temperature creep properties of these beryllides are repor4ed. At room temperature. NiBe exhibits certain tensile ductility (~ 1 .3%). but all other beryllides are essentially brittle. Nonetheless, these beryllides become ductile at temperatures above approximately 1000℃. Their creep properties are presented. The creep properties are compared with those of intermetallic aluminides. Also. a comparison is made between the ductile-to-brittle transition behaviour of intermetallic beryllides and that of aluminides. Although beryllides are generally oxidation resistant at high temperatures, some beryllides, e.g., ZrBe13, suffer the pest reaction during oxidation at intermediate tem peratures. The pest mechanisms are proposed
文摘The deformation behaviour and the nature of dislocations of the Al3Ti-base L12 alloya modified with Fe and Mn etc, were investigated. The results show that the deformation and fracture character istics are closely related to the alloy compositions. The effect of hot-working process on the room tem perature ductility is remarkable, not only resulting in an appreciable improvement of compressive properties but also showing a 0.28% plastic strain in tensile test. The SISF dissociation of a < 110>dislocations on {111} planes was found at room temperature. The determined dissociation scheme is consistent with the mechanical behaviour of these alloys in the lower temperature region.
文摘Detailed fieldwork carried out in the southern part of Bida Basin, Nigeria, allowed the documentation of soft sediment deformation structures (SSDS) in the Maastrichtian Patti Formation. The aim of this study is to examine the sedimentary successions, describe and analyse these deformation features, discuss their deformation mechanisms and potential triggers. The Maastrichtian Patti Formation is composed of lithofacies interpreted to have been deposited in tidal and fluvial sedimentary environments. Soft sediment deformation structures recognised in the tidal sediments were clastic dykes, load cast, isolated sand balls, dish-and-pillar structures, convolute lamination, diapiric structures and recumbent folds. Severely deformed cross beds, ring structures, associated sand balls, normal folds and recumbent folds were identified in the fluvial sediments. SSDS recognised were interpreted to have been caused by effects of liquefaction and fluidization. Field observations, facies analysis and morphology of the SSDS indicate that there are relationship between the depositional environments and SSDS. Endogenic processes are considered as the trigger agents and they are represented by rapid sedimentation and overloading, impact of breaking waves, pressure fluctuations caused by turbulent water flow, cyclic stress and current generated by storm waves and changes in water table. The present study did not identify exogenic processes as trigger agent. The occurrence of SSDS in southern Bida Basin strongly favoured a non-tectonic origin but a clear relationship high energy processes in tidal and fluvial depositional environments.
文摘In this paper, based on the idea of finite element method, the initial parametric method in bending, problem of a beam is extended to analyse the bar-system structure by employing Dirac function and llcavisidc step function.Then a new method for analysing the internal forces and deformations of bar-system structure in space is suggested by improving the mixed method in statically indeterminate structure.The inferred process and obtained answer will be more succinct and accurate when the problem of internal forces and deformations of bar-system structure is analysed by using the new method provided in this paper.
基金National Natural Science Foundation of China,Grant/Award Numbers:51878060,52078046。
文摘To understand the mechanical response pattern of the existing structure and ground due to the construction of metro tunnels underneath,the finite difference method is adopted to study the torsional deformation and stress variation of the existing structure and the effect of underground carriageway structures on the surface subsidence.The curves of the maximum differential subsidence,torsion angle,and distortion of the cross-section of the existing structure show two peaks in succession during traversing of two metro tunnels beneath it.The torsion angle of the existing structure changes when the two tunnels traverse beneath it in opposite directions.The first traversing of the shield tunnel mainly induces the magnitude variation in torsional deformation of the existing structure,but the second traversing of the subsurface tunnel may cause a dynamic change in the magnitude and form of torsional deformation in the existing structure.The shielding effect can reduce the surface subsidence caused by metro tunnel excavation to a certain extent,and the development trend of subsidence becomes slower as the excavation continues.
基金Abhik Kundu acknowledges the University Grants Commission,India,for the research grant PSW-035/10-11(ERO)Institutional support provided by Dr.Dipak Kar,Principal,Asutosh College is thankfully acknowledged.Patrick Eriksson thanks the University of Pretoria and the National Research Foundation,South Africa for research fundingAbdul Matin acknowledges the DST,Govt.of India research funding(Project No.SR/S4/ES:276/2007).
文摘The Mio-Pliocene Middle Siwalik Subgroup,in the Lish River Section in the Darjiling District of the Eastern Himalaya,consists of sandstone,mudrocks,heterolithic units and conglomerates preserving six distinct associations of soft-sediment deformation structures at different stratigraphic levels.The foreland basin sediments of the Himalayan orogen were deposited in alluvial fan settings.Deformation structures present are:folds of variable geometry,pseudonodules,water escape features,flame structures and chaotic laminae.
基金supported by the National Natural Science Foundation of China(51879159,51490675,11432009,and 51579145)Chang Jiang Scholars Program(T2014099)+3 种基金Shanghai Excellent Academic Leaders Program(17XD1402300)Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning(2013022)Innovative Special Project of Numerical Tank of Ministry of Industry and Information Technology of China(2016-23/09)Lloyd’s Register Foundation for doctoral student
文摘Nowadays,an increasing number of ships and marine structures are manufactured and inevitably operated in rough sea.As a result,some phenomena related to the violent fluid-elastic structure interactions(e.g.,hydrodynamic slamming on marine vessels,tsunami impact on onshore structures,and sloshing in liquid containers)have aroused huge challenges to ocean engineering fields.In this paper,the moving particle semi-implicit(MPS)method and finite element method(FEM)coupled method is proposed for use in numerical investigations of the interaction between a regular wave and a horizontal suspended structure.The fluid domain calculated by the MPS method is dispersed into fluid particles,and the structure domain solved by the FEM method is dispersed into beam elements.The generation of the 2D regular wave is firstly conducted,and convergence verification is performed to determine appropriate particle spacing for the simulation.Next,the regular wave interacting with a rigid structure is initially performed and verified through the comparison with the laboratory experiments.By verification,the MPS-FEM coupled method can be applied to fluid-structure interaction(FSI)problems with waves.On this basis,taking the flexibility of structure into consideration,the elastic dynamic response of the structure subjected to the wave slamming is investigated,including the evolutions of the free surface,the variation of the wave impact pressures,the velocity distribution,and the structural deformation response.By comparison with the rigid case,the effects of the structural flexibility on wave-elastic structure interaction can be obtained.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(Grant No.KYCX24_0714).
文摘To examine the similarities and differences in the evolution of cavity,wetting and dynamics of a highspeed,oblique water-entry projectile with different positive angles of attack,a comparative analysis has been conducted based on the numerical results of two mathematical models,the rigid-body model and fluid-structure interaction model.In addition,the applicable scope of the above two methods,and the structural response characteristics of the projectile have also been investigated.Our results demonstrate that:(1) The impact loads and angular motion of the projectile of the rigid-body method are more likely to exhibit periodic variations due to the periodic tail slap,its range of positive angles of attack is about α<2°.(2) When the projectile undergone significant wetting,a strong coupling effect is observed among wetting,structural deformation,and projectile motion.With the applied projectile shape,it is observed that,when the projectile bends,the final wetting position is that of Part B(cylinder of body).With the occu rrence of this phenomenon,the projectile ballistics beco me completely unstable.(3) The force exerted on the lower surface of the projectile induced by wetting is the primary reason of the destabilization of the projectile traj ectory and structu ral deformation failure.Bending deformation is most likely to appear at the junction of Part C(cone of body) and Part D(tail).The safe angles of attack of the projectile stability are found to be about α≤2°.
基金Funded by the National National Natural Science Foundation of China(No.51505189)Open Project of Jiangsu Key Laboratory of Advanced Food Manufacturing Equipment&Technology(No.FM-2015-5)
文摘The deformation behavior and formability of gradient nano-grained（GNG） AISI 304 stainless steel in uniaxial and biaxial states were investigated by means of tensile test and small punch test（SPT）. The GNG top layer was fabricated on coarse grains（CG） AISI 304 by ultrasonic impact treatment. The results showed that the CG substrate could effectively suppress the strain localization of NC in GNG layer, and an approximate linear relationship existed between the thickness of substrate（h） and uniform true strain before necking（ε_（unif））. Grain growth of NC was observed at the stress state with high Stress triaxiality T, which led to better ductility of GNG/CG 304 in SPT, as well as similar true strain after the onset of necking（ε_（neck）） compared with coarse 304 in tensile test. Ei-values of GNG/CG 304 with different structures were nearly the same at different punch speeds, and good formability of GNG/CG 304 was demonstrated. However, punch speed and microstructure needed to be optimized to avoid much lost of membrane strain region in biaxial stress state.
文摘Submicrometer-grained （SMG） Al-3%Mn （mass fraction） alloy specimens with initial grain size of -0.3 μm were produced by ball milling for 3 h. The Al-3%Mn specimens which were cold rolled with a strain rate of 1×10^-3- 1×10^-2 s-1 at room temperature show high extensibility to failure more than 2500%. Microstructures of pure Al and Al-3%Mn alloy at as-milled and cold-rolled state were examined using X-ray diffraction and transmission electron microscopy （TEM）. Based on the microstructure analysis, it is established that the mechanism of the continued plastic deformation in SMG Al-3%Mn alloy consists of dislocation slip, grain boundary sliding companied by dynamic recovery and recrystallization, and dynamic recrystallization is a main control factor of the large plastic deformation.
