High-locality landslides are located on slopes at high elevations and are characterized by long sliding distances, large gravitational potential energy, high movement velocities, tremendous kinetic energy, and sudden ...High-locality landslides are located on slopes at high elevations and are characterized by long sliding distances, large gravitational potential energy, high movement velocities, tremendous kinetic energy, and sudden onset. Thus, they often cause catastrophic damage to human lives and engineering facilities. It is of great significance to identify active high-locality landslides in their early deformational stages and to reveal their deformational rules for effective disaster mitigation. Due to alpinecanyon landforms, Mao County is a representative source of high-locality landslides. This work employs multisource data(geological, terrain, meteorological, ground sensor, and remote sensing data) and timeseries In SAR technology to recognize active high-locality landslides in Mao County and to reveal their laws of development. Some new viewpoints are suggested.(1) Nineteen active high-locality landslides are identified by the time-series In SAR technique, of which 7 are newly discovered in this work. All these high-locality landslides possessed good concealment during their early deformational stages. The newly discovered HL-16 landslide featured a large scale and a great slope height, posing a large threat to the surrounding buildings and residents.(2) The high-locality landslides in Mao County were mainly triggered by three factors: earthquakes, precipitation, and road construction.(3) Three typical high-locality landslides that were triggered by different factors are highlighted with their deformational rules under the functions of steep terrain, shattered rocks, fissure-water penetration, precipitation, and road construction. This work may provide clues to the prevention and control of high-locality landslides and can be applied to the determination of active high-locality landslides in other hard-hit areas.展开更多
Geobelt deformation is of significance when making prejudgments on potential failure planes in reinforced structures.A failure plane results from two geobelt failure modes,tensile failure and pullout.In order to inves...Geobelt deformation is of significance when making prejudgments on potential failure planes in reinforced structures.A failure plane results from two geobelt failure modes,tensile failure and pullout.In order to investigate the deformation characteristics of geobelts in two failure modes,results from pullout tests on sensor-enabled geobelts(SEGBs)with various lengths in sand are reported here across a range of normal pressures.Self-measurements of SEGB can provide data during the tests regarding distributions of strain,stress,and displacement.Data collected during pullout tests reveal the effects of normal pressures and specimen lengths on failure mode.A critical line considering normal pressure and specimen length is derived to describe the transition between two failure modes,an approach which can be utilized for preliminary predictions of failure mode in pullout tests.Warning criteria established based on critical line and data from the self-measurements of SEGB are proposed for failure mode prediction which can contribute to prejudgments of potential failure plane in geosynthetically reinforced soil structures.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
Under the same conditions of external force, simulations on differences of deformational energy in structural zones, which have different deformational behavior, and that on the distribution of the differences have be...Under the same conditions of external force, simulations on differences of deformational energy in structural zones, which have different deformational behavior, and that on the distribution of the differences have been carried out by means of finite-element method. Shear deformational energy U_w is higher than volume deformational energy U_T by about one order of magnitude, and deformationat energy U_B( = U_w + U_T) and U_w show a trend to be larger→largest→small in quantity in structural zones of different deformational properties, which correspond to compressive, shear, tensile zones, respectively, but U_T shows a trend to be large→small gradually. This has a considerable significance in the study of tectonic heat and mineral liquid migration in association with the research on tectonic additional hydrostatic pressure.展开更多
The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from...The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from 0.001 s^(-1) to 1 s^(-1).The results show that the addition of Sn promotes dynamic recrystallization(DRX),and CaMgSn phases can act as nucleation sites during the compression deformation.Flow stress increases with increasing the strain rate and decreasing the temperature.Both the ZM61-0.5Ca and ZMT612-0.5Ca alloys exhibit obvious DRX characteristics.CaMgSn phases can effectively inhibit dislocation motion with the addition of Sn,thus increasing the peak fl ow stress of the alloy.The addition of Sn increases the hot deformation activation energy of the ZM61-0.5Ca alloy from 199.654 kJ/mol to 276.649 kJ/mol,thus improving the thermal stability of the alloy.For the ZMT612-0.5Ca alloy,the optimal hot deformation parameters are determined to be a deformation temperature range of 350–400℃and a strain rate range of 0.001–0.01 s^(-1).展开更多
Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust...Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust in kimberlite pipes whose diamonds are largely colourless and light yellow related to trace element N(Ia type),although brown,green,and more rarely blue-coloured diamonds are related to lattice defect and trace amounts of H,more rarely B and Ni.Pink diamonds are extremely rare in the approximately 90 diamondiferous pipes mined globally.Although small quantities have been discovered elsewhere,about 90%have been mined from the ca.1.3Ga Argyle diamond pipe in Western Australia,with the Arkhangelskaya diamond pipe in Russia the only other significant source.The pink colour at both Argyle and Arkhangelskaya is unrelated to trace elements and instead results from absorption of light from nanoscale(550nm)defects related to shear stress and plastic deformation.Macroscopically,defects are shown by glide planes,lamellae,and grain lines imposed on the originally colourless diamonds derived from their mantle source.The key question is why these defects were uniquely acquired in diamonds in the Argyle and Arkhangelskaya pipes.Unlike most diamondiferous pipes,Argyle is a rare diamondiferous volatile-rich lamproite pipe that was emplaced into the multiply deformed and rifted NNE-trending Halls Creek Orogen on the margin of the Kimberley Craton.Similarly,Arkhangelskaya in the Devonian Lomonosov kimberlite cluster is a volatile-rich low-Ti type kimberlite,a close relative to lamproite,that was emplaced into the multiply deformed Lapland-Kola Orogen on the rifted margin of the Kola Craton.These craton margins are underlain by subduction-induced volatile-enriched metasomatized mantle lithosphere in contrast to the more primeval mantle under craton centres.It is thus likely that shear stresses were exacerbated at Argyle and Arkangelskaya by rapid vertical emplacement of the anomalous volatile-enriched magmas at supercritical pressures and temperatures,that induced catastrophic phase separation of these volatiles and'mini seismic events'during rapid pressure drops during ascent from 200km depth to the surface.Such a mechanism is consistent with the presence of strongly resorbed and plastically deformed small brown industrial diamonds in the Argyle pipe.From a China perspective,it is potentially important that at 1.3Ga the alkaline Argyle pipe in northern Australia is placed adjacent to the North China Craton(NCC),with numerous world-class mineral deposits including the giant ca.1.4~1.2Ga alkaline Bayan Obo REE system on its margin.However,it is the southeastern margin of the Yangtze Craton and the Jiangnan Orogen with their lamproite pipes derived from metasomatized mantle lithosphere that present the most prospective regions for pink diamond occurrences.展开更多
The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance You...The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance Young's modulus measurements,and microstructure analysis,the effects of dislocation density,vacancy formation,and recrystallization on the alloy performance were clarified.Results indicate that increasing the rolling reduction enhances damping property due to higher dislocation density,whereas aging below the recrystallization temperature reduces damping property via dislocation pinning by the Suzuki effect.Recrystallization heat treatment restores the original structure and damping level.This alloy possesses tensile strength of approximately 1500 MPa and logarithmic decrement valueδ^(-1) in the range of 2×10^(-4)–3×10^(-4),demonstrating superior mechanical properties compared with the Ti-based alloys,which makes it an excellent candidate material for ultrasonic tools and medical applications.展开更多
The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing t...The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing to this multi-principal element nature,high-entropy alloys exhibit complex deformation behavior dominated by alternating and coupled deformation mechanisms.Therefore,elucidating these intricate deformation mechanisms remains a key challenge in current research.Neutron diffraction(ND)techniques offer distinct advantages over traditional microscopic methods for characterizing such complex deformation behavior.The strong penetration capability of neutrons enables in-situ,real-time,and non-destructive detection of structural evolution in most centimeter-level bulk samples under complex environments,and ND allows precise characterization of lattice site occupations for light elements,such as C and O,and neighboring elements.This review discussed the principles of ND,experiment procedures,and data analysis.Combining with recent advances in the research about face-centered cubic high-entropy alloy,typical examples of using ND to investigate the deformation behavior were summarized,ultimately revealing deformation mechanisms dominated by dislocations,stacking faults,twinning,and phase transformations.展开更多
Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing addit...Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.展开更多
This study investigates the transient deformation signals associated with the Ludian M6.8 earthquake,which occurred on June 22,2014,in southwestern China,using Global Navigation Satellite System(GNSS)data.Within the f...This study investigates the transient deformation signals associated with the Ludian M6.8 earthquake,which occurred on June 22,2014,in southwestern China,using Global Navigation Satellite System(GNSS)data.Within the framework of the Kalman filter,the study employs a First-Order Gauss-Markov(FOGM)model to construct and isolate transient deformation signals,extracting the FOGM time series.Principal Component Analysis(PCA)is then applied to decompose the extracted time series and analyze the spatiotemporal evolution of the top two Principal Components(PCs)of the East-West(EW)and North-South(NS)components,revealing their correlation with the Ludian earthquake.Furthermore,a quantitative analysis of the spatial response characteristics of the second Principal Component(PC2)of the EW component and the first Principal Component(PC1)of the NS component is conducted to characterize the spatial evolution pattern of transient deformation.Finally,the spatial distribution of transient deformation signals is compared with the known co-seismic rupture characteristics,providing further evidence that the extracted signals represent real post-seismic deformation rather than noise.The key findings of this study are as follows:1.The PC2 of the EW component and the PC1 of the NS component primarily represent post-seismic transient deformation signals associated with the Ludian earthquake.The post-seismic deformation evolution exhibits two distinct phases:a sustained deformation phase from the earthquake occurrence to early 2016 and a recovery phase starting from early2016,reflecting the time-dependent characteristics of the post-seismic relaxation process.2.In addition to the well-known linear trend and periodic components,the GNSS displacement time series may also contain non-linear periodic components,suggesting that GNSS data are influenced by a combination of crustal dynamics,surface environmental changes,and anthropogenic factors.3.The integration of Kalman filtering and PCA-based dimensionality reduction analysis effectively isolates transient deformation signals and nonlinear periodic signals from complex background noise,enhancing the interpretability of GNSS data.This approach provides a highly efficient data processing method for analyzing earthquake-induced deformation.展开更多
Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been abl...Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been able to dynamically measure the deformation fields of rapidly evolving slip activities at the microscale.In this study,we used the Sampling Moire?Method(SMM)to directly measure the dynamic deformation fields of slip activities in Nickel-Based Single-Crystal(NBSC)superalloy under in-situ tensile test,and the strain and displacement fields under the evolving microplastic events with intense slip activities around the notch of the NBSC superalloy specimen were obtained for the first time.The dynamic evolution of slip bands was quantitatively characterized through detailed statistical analysis of strains and displacements under different loads.The locations of the initial appearance of slip traces were successfully predicted by the regions of plasticity localization.The results show that the deformation fields exhibit both high spatial and temporal resolutions,enabling the capture of nanometer-scale displacement fields and visualization of the dynamic fluidity of slip accumulation.This method demonstrates the superiority of the dynamic characterization of the plastic deformation field at the microscale and the promise of its application for characterizing the slip activities of various crystalline metals.展开更多
The structures of even-even Gd and Dy isotopes around N=100 were investigated using a fully self-consistent microscopic model.The systematics of the exited 2_(1)^(+)and 4_(1)^(+)energies reveal a peak-like structure a...The structures of even-even Gd and Dy isotopes around N=100 were investigated using a fully self-consistent microscopic model.The systematics of the exited 2_(1)^(+)and 4_(1)^(+)energies reveal a peak-like structure at N=100 along the Gd(Z=64)and Dy(Z=66)isotopic chains.This supports the evidence for a subshell gap near N=100.The nuclear structure properties studied are important to understand the r-process elemental abundance peak at A~160.展开更多
A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.T...A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.The proposed method enables high-fidelity parameterized deformation for both flat and curved perforated surfaces while maintaining mesh quality with minimal geometric distortion.To evaluate its effectiveness,comparative studies between HFFD and conventional FFD methods are conducted,demonstrating superior performance in mesh quality and geometric fidelity.The HFFD-based framework is further applied to the Multidisciplinary Design Optimization(MDO)of a double-wall turbine blade leading edge.Results indicate an 11.6%increase in cooling efficiency and a 16.21%reduction in maximum stress.Additionally,compared to traditional geometry-based parameterization in MDO,the HFFD approach improves model processing efficiency by 84.15%and overall optimization efficiency by20.05%.These findings demonstrate HFFD's potential to significantly improve complex engineering design optimization by achieving precise shape preservation and improving computational efficiency.展开更多
Climate change is causing extensive and quantifiable surface deformation by moving mass in the cryosphere,hydrosphere,atmosphere,and oceans.These deformations can give a great deal of information on the dynamics of th...Climate change is causing extensive and quantifiable surface deformation by moving mass in the cryosphere,hydrosphere,atmosphere,and oceans.These deformations can give a great deal of information on the dynamics of the Earth system and interactions between climate processes and solid Earth processes.Global Navigation Satellite Systems(GNSS),Interferometric Synthetic Aperture Radar(InSAR),satellite gravimetry,and other supplementary techniques have become important tools to be used to monitor and quantify these deformations.The insight of this review is the understanding of the mechanisms that cause deformation on the surface due to climate change,the strengths and weaknesses of the modern geodetic observation methods,and the way in which these geodetic observations are reconciled with the Earth’s response models and climate simulations.Polar,alpine,hydrologically sensitive,and coastal case studies demonstrate that geodesy can be used globally in climate change studies.Although there has been a lot of improvement,there have been many problems in signal separation,data coverage,and uncertainties in models,but new emerging technologies are promising solutions.A combined climate/geodetic observing system will be critical in enhancing long-term monitoring and in further developing the knowledge on how the Earth responds to climate change.展开更多
Wetting deformation in earth-rockfill dams is a critical factor influencingdam safety.Although numerous mathematical models have been developed to describe this phenomenon,most of them rely on empirical formulations a...Wetting deformation in earth-rockfill dams is a critical factor influencingdam safety.Although numerous mathematical models have been developed to describe this phenomenon,most of them rely on empirical formulations and lack prior knowledge of model parameters,which is essential for Bayesian parameter inversion to enhance accuracy and reduce uncertainty.This study introduces a datadriven approach to establishing prior knowledge of earth-rockfill dams.Driving factors are utilized to determine the potential range of model parameters,and settlement changes within this range are calculated.The results are iteratively compared with actual monitoring data until the calculated range encompasses the observed data,thereby providing prior knowledge of the model parameters.The proposed method is applied to the right-bank earth-rockfilldam of Danjiangkou.Employing a Gibbs sample size of 30,000,the proposed method effectively calibrates the prior knowledge of the wetting model parameters,achieving a root mean square error(RMSE)of 5.18 mm for the settlement predictions.By comparison,the use of non-informative priors with sample sizes of 30,000 and 50,000 results in significantly larger RMSE values of 11.97 mm and 16.07 mm,respectively.Furthermore,the computational efficiencyof the proposed method is demonstrated by an inversion computation time of 902 s for 30,000 samples,which is notably shorter than the 1026 s and 1558 s required for noninformative priors with 30,000 and 50,000 samples,respectively.These findingsunderscore the superior performance of the proposed approach in terms of both prediction accuracy and computational efficiency.These results demonstrate that the proposed method not only improves the predictive accuracy but also enhances the computational efficiency,enabling optimal parameter identificationwith reduced computational effort.This approach provides a robust and efficientframework for advancing dam safety assessments.展开更多
Investigating the spatial distribution of coseismic rupture,postseismic afterslip,and their interactions is essential for understanding the heterogeneous frictional characteristics of faults,and seismic hazard assessm...Investigating the spatial distribution of coseismic rupture,postseismic afterslip,and their interactions is essential for understanding the heterogeneous frictional characteristics of faults,and seismic hazard assessments.This study offers a comprehensive analysis of both seismic and aseismic slip of the 2022 MW6.7 Menyuan earthquake,which took place at the western terminus of the Tianzhu seismic gap located in the northeastern Qinghai-Xizang Plateau.By integrating near-field GNSS measurements,In SAR line-of-sight(LOS)displacements,and surface rupture data,we refined the coseismic slip distribution using a kinematic inversion and a mechanically constrained model.Our results reveal an unexpectedly large coseismic slip of about 3.3 m at shallow depths(less than about 6 km),along with minimal shallow slip deficit—features rarely observed in earthquakes of similar magnitude globally.The mechanically constrained approach yields a static stress drop of about 6.4 MPa.Additionally,we invert for the afterslip distribution from cumulative postseismic GNSS displacements recorded during the initial 2.7 years subsequent to the mainshock.The afterslip is predominantly situated downdip of the coseismic rupture zone,releasing 28.5%of the coseismic moment.There is a tight correlation between the spatiotemporal evolution of aftershocks and the downdip afterslip,with limited contributions from viscoelastic relaxation and poroelastic rebound which indicates that the afterslip mechanism primarily controls early postseismic deformation.展开更多
Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted dru...Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted drug delivery.For implants,mechanical properties are key performance characteristics,so understanding the deformation and failure mechanisms is essential for selecting the appropriate implant structure.The deformation and fracture processes in PLA samples with different interior architectures have been studied through computer simulation and experimental research.Two TPMS topologies,the Schwarz Diamond and Gyroid architectures,were used for the sample construction by 3D printing.ANSYS software was utilized to simulate compressive deformation.It was found that under the same load,the vonMises stresses in the Gyroid structure are higher than those in the Schwartz Diamond structure,which was associated with the different orientations of the cells in the studied structures in relation to the direction of the loading axis.The deformation process occurs in the local regions of the studied TPMS structures.Maximum von Mises stresses were observed in the vertical parts of the structures oriented along the load direction.It was found that,unlike the Gyroid,the Schwartz Diamond structure contains a frame that forms unique stiffening ribs,which ensures the redistribution of the load under the vertical loading direction.An analysis of the mechanical characteristics of PLA samples with the Schwartz Diamond and Gyroid structures produced by the Fused Deposition Modeling(FDM)method was correlated with computer simulation.The Schwarz Diamond-type structure was shown to have a higher absorption energy than the Gyroid one.A study of the fracture in PLA samples with various cell sizes revealed a particular feature related to the samples’periodic surface topology and the 3D printing process.Scanning electron microscopic(SEM)studies of the samples deformed by compression showed thatwith an increase in the density of the samples,the failure mechanism changes from ductile to quasi-brittle due to the complex participation of both cell deformation and fiber deformation.展开更多
Strain measurements during uniaxial compressive strength(UCS)testing and their subsequent interpretation to obtain elastic parameters are relatively straightforward for most rocks.However,for slates,which are foliated...Strain measurements during uniaxial compressive strength(UCS)testing and their subsequent interpretation to obtain elastic parameters are relatively straightforward for most rocks.However,for slates,which are foliated metamorphic rocks characterized by significant anisotropy,the dependence of elastic properties on the orientation of foliation complicates the measurement and interpretation of strain data.In this study,a series of wave propagation velocity tests and UCS tests are conducted on cylindrical and prismatic slate specimens to gain a better understanding of how to obtain and process deformability and strength results.Wave propagation velocity results demonstrate an increase with the dip of foliation planes crossed,which is consistent with previous studies.Based on UCS test results,two methodologies are considered for obtaining transversely isotropic deformability parameters:the least-squares method and the recently proposed generalized reduction gradient(GRG)algorithm.Their performance is assessed in the context of potentially variable and limited amounts of data.GRG algorithms provide an enhanced analysis technique for estimating anisotropic elastic properties when dealing with limited or heterogeneous laboratory test data.Different strength models have also been considered,including the classic Jaeger's weakness plane(JPW)and its subsequent modification,i.e.2HBJPW.The 2HBJPW approach has proven to be more consistent with the obtained results and enhances the representation of the strength properties of slates.Additionally,a finite element method(FEM)numerical approach is employed to compare results with analytical and experimental ones,demonstrating a good match,thereby offering calibrated inputs for rock engineering applications.展开更多
基金supported by the National Key Research and Development Program of China (No.2019YFC1511 304)the National Natural Science Foundation of China (Nos.U21A2013,42311530065)Hunan Provincial Natural Science Foundation of China (No.2021JC0009)。
文摘High-locality landslides are located on slopes at high elevations and are characterized by long sliding distances, large gravitational potential energy, high movement velocities, tremendous kinetic energy, and sudden onset. Thus, they often cause catastrophic damage to human lives and engineering facilities. It is of great significance to identify active high-locality landslides in their early deformational stages and to reveal their deformational rules for effective disaster mitigation. Due to alpinecanyon landforms, Mao County is a representative source of high-locality landslides. This work employs multisource data(geological, terrain, meteorological, ground sensor, and remote sensing data) and timeseries In SAR technology to recognize active high-locality landslides in Mao County and to reveal their laws of development. Some new viewpoints are suggested.(1) Nineteen active high-locality landslides are identified by the time-series In SAR technique, of which 7 are newly discovered in this work. All these high-locality landslides possessed good concealment during their early deformational stages. The newly discovered HL-16 landslide featured a large scale and a great slope height, posing a large threat to the surrounding buildings and residents.(2) The high-locality landslides in Mao County were mainly triggered by three factors: earthquakes, precipitation, and road construction.(3) Three typical high-locality landslides that were triggered by different factors are highlighted with their deformational rules under the functions of steep terrain, shattered rocks, fissure-water penetration, precipitation, and road construction. This work may provide clues to the prevention and control of high-locality landslides and can be applied to the determination of active high-locality landslides in other hard-hit areas.
基金Project supported by the National Key Research and Development Program of China(No.2018YFB1600100)the National Natural Science Foundation of China(Nos.51778346 , 51608461)。
文摘Geobelt deformation is of significance when making prejudgments on potential failure planes in reinforced structures.A failure plane results from two geobelt failure modes,tensile failure and pullout.In order to investigate the deformation characteristics of geobelts in two failure modes,results from pullout tests on sensor-enabled geobelts(SEGBs)with various lengths in sand are reported here across a range of normal pressures.Self-measurements of SEGB can provide data during the tests regarding distributions of strain,stress,and displacement.Data collected during pullout tests reveal the effects of normal pressures and specimen lengths on failure mode.A critical line considering normal pressure and specimen length is derived to describe the transition between two failure modes,an approach which can be utilized for preliminary predictions of failure mode in pullout tests.Warning criteria established based on critical line and data from the self-measurements of SEGB are proposed for failure mode prediction which can contribute to prejudgments of potential failure plane in geosynthetically reinforced soil structures.
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.
文摘Under the same conditions of external force, simulations on differences of deformational energy in structural zones, which have different deformational behavior, and that on the distribution of the differences have been carried out by means of finite-element method. Shear deformational energy U_w is higher than volume deformational energy U_T by about one order of magnitude, and deformationat energy U_B( = U_w + U_T) and U_w show a trend to be larger→largest→small in quantity in structural zones of different deformational properties, which correspond to compressive, shear, tensile zones, respectively, but U_T shows a trend to be large→small gradually. This has a considerable significance in the study of tectonic heat and mineral liquid migration in association with the research on tectonic additional hydrostatic pressure.
基金Sichuan Science and Technology Program(2025ZNSFSC1341)Fundamental Research Funds for the Central Universities(J2022-090,25CAFUC04087)。
文摘The hot compression deformation behavior of Mg-6Zn-1Mn-0.5Ca(ZM61-0.5Ca)and Mg-6Zn-1Mn-2Sn-0.5Ca(ZMT612-0.5Ca)alloys was investigated at deformation temperatures ranging from 250℃to 400℃and strain rates varying from 0.001 s^(-1) to 1 s^(-1).The results show that the addition of Sn promotes dynamic recrystallization(DRX),and CaMgSn phases can act as nucleation sites during the compression deformation.Flow stress increases with increasing the strain rate and decreasing the temperature.Both the ZM61-0.5Ca and ZMT612-0.5Ca alloys exhibit obvious DRX characteristics.CaMgSn phases can effectively inhibit dislocation motion with the addition of Sn,thus increasing the peak fl ow stress of the alloy.The addition of Sn increases the hot deformation activation energy of the ZM61-0.5Ca alloy from 199.654 kJ/mol to 276.649 kJ/mol,thus improving the thermal stability of the alloy.For the ZMT612-0.5Ca alloy,the optimal hot deformation parameters are determined to be a deformation temperature range of 350–400℃and a strain rate range of 0.001–0.01 s^(-1).
文摘Diamonds were formed in the mantle lithosphere,mostly at depths of 150~200km in the centres of Precambrian cratons,the buoyant ancient cores of continents.From there they were normally transported into the upper crust in kimberlite pipes whose diamonds are largely colourless and light yellow related to trace element N(Ia type),although brown,green,and more rarely blue-coloured diamonds are related to lattice defect and trace amounts of H,more rarely B and Ni.Pink diamonds are extremely rare in the approximately 90 diamondiferous pipes mined globally.Although small quantities have been discovered elsewhere,about 90%have been mined from the ca.1.3Ga Argyle diamond pipe in Western Australia,with the Arkhangelskaya diamond pipe in Russia the only other significant source.The pink colour at both Argyle and Arkhangelskaya is unrelated to trace elements and instead results from absorption of light from nanoscale(550nm)defects related to shear stress and plastic deformation.Macroscopically,defects are shown by glide planes,lamellae,and grain lines imposed on the originally colourless diamonds derived from their mantle source.The key question is why these defects were uniquely acquired in diamonds in the Argyle and Arkhangelskaya pipes.Unlike most diamondiferous pipes,Argyle is a rare diamondiferous volatile-rich lamproite pipe that was emplaced into the multiply deformed and rifted NNE-trending Halls Creek Orogen on the margin of the Kimberley Craton.Similarly,Arkhangelskaya in the Devonian Lomonosov kimberlite cluster is a volatile-rich low-Ti type kimberlite,a close relative to lamproite,that was emplaced into the multiply deformed Lapland-Kola Orogen on the rifted margin of the Kola Craton.These craton margins are underlain by subduction-induced volatile-enriched metasomatized mantle lithosphere in contrast to the more primeval mantle under craton centres.It is thus likely that shear stresses were exacerbated at Argyle and Arkangelskaya by rapid vertical emplacement of the anomalous volatile-enriched magmas at supercritical pressures and temperatures,that induced catastrophic phase separation of these volatiles and'mini seismic events'during rapid pressure drops during ascent from 200km depth to the surface.Such a mechanism is consistent with the presence of strongly resorbed and plastically deformed small brown industrial diamonds in the Argyle pipe.From a China perspective,it is potentially important that at 1.3Ga the alkaline Argyle pipe in northern Australia is placed adjacent to the North China Craton(NCC),with numerous world-class mineral deposits including the giant ca.1.4~1.2Ga alkaline Bayan Obo REE system on its margin.However,it is the southeastern margin of the Yangtze Craton and the Jiangnan Orogen with their lamproite pipes derived from metasomatized mantle lithosphere that present the most prospective regions for pink diamond occurrences.
文摘The strength and damping properties of Co-Ni-Cr-Mo-based alloys with 0.5wt%Nb addition after various plastic deformation and heat treatment processes were investigated.Through Vickers hardness tests,free resonance Young's modulus measurements,and microstructure analysis,the effects of dislocation density,vacancy formation,and recrystallization on the alloy performance were clarified.Results indicate that increasing the rolling reduction enhances damping property due to higher dislocation density,whereas aging below the recrystallization temperature reduces damping property via dislocation pinning by the Suzuki effect.Recrystallization heat treatment restores the original structure and damping level.This alloy possesses tensile strength of approximately 1500 MPa and logarithmic decrement valueδ^(-1) in the range of 2×10^(-4)–3×10^(-4),demonstrating superior mechanical properties compared with the Ti-based alloys,which makes it an excellent candidate material for ultrasonic tools and medical applications.
基金National Key R&D Program of China(2023YFB3711904,2022YFA1603801)National Natural Science Foundation of China(12404230,52471181,52301213,52130108,52471005)+2 种基金National Nature Science Foundation of Zhejiang Province(LY23E010002)Open Fund of the China Spallation Neutron Source,Songshan Lake Science City(KFKT2023B11)Guangdong Basic and Applied Basic Research Foundation(2022A1515110805,2024A1515010878)。
文摘The multi-principal element characteristic of high-entropy alloys has revolutionized the conventional alloy design concept of single-principal element,endowing them with excellent mechanical properties.However,owing to this multi-principal element nature,high-entropy alloys exhibit complex deformation behavior dominated by alternating and coupled deformation mechanisms.Therefore,elucidating these intricate deformation mechanisms remains a key challenge in current research.Neutron diffraction(ND)techniques offer distinct advantages over traditional microscopic methods for characterizing such complex deformation behavior.The strong penetration capability of neutrons enables in-situ,real-time,and non-destructive detection of structural evolution in most centimeter-level bulk samples under complex environments,and ND allows precise characterization of lattice site occupations for light elements,such as C and O,and neighboring elements.This review discussed the principles of ND,experiment procedures,and data analysis.Combining with recent advances in the research about face-centered cubic high-entropy alloy,typical examples of using ND to investigate the deformation behavior were summarized,ultimately revealing deformation mechanisms dominated by dislocations,stacking faults,twinning,and phase transformations.
基金National Key Research and Development Program of China(2022YFB4600902)Shandong Provincial Science Foundation for Outstanding Young Scholars(ZR2024YQ020)。
文摘Wire arc additive manufacturing(WAAM)has emerged as a promising approach for fabricating large-scale components.However,conventional WAAM still faces challenges in optimizing microstructural evolution,minimizing additive-induced defects,and alleviating residual stress and deformation,all of which are critical for enhancing the mechanical performance of the manufactured parts.Integrating interlayer friction stir processing(FSP)into WAAM significantly enhances the quality of deposited materials.However,numerical simulation research focusing on elucidating the associated thermomechanical coupling mechanisms remains insufficient.A comprehensive numerical model was developed to simulate the thermomechanical coupling behavior in friction stir-assisted WAAM.The influence of post-deposition FSP on the coupled thermomechanical response of the WAAM process was analyzed quantitatively.Moreover,the residual stress distribution and deformation behavior under both single-layer and multilayer deposition conditions were investigated.Thermal analysis of different deposition layers in WAAM and friction stir-assisted WAAM was conducted.Results show that subsequent layer deposition induces partial remelting of the previously solidified layer,whereas FSP does not cause such remelting.Furthermore,thermal stress and deformation analysis confirm that interlayer FSP effectively mitigates residual stresses and distortion in WAAM components,thereby improving their structural integrity and mechanical properties.
基金jointly supported by the National Observation and Research Station,Institute of Geology,China Earthquake Administration(NORSLS23-05)the National Natural Science Foundation of China projects(U2139205)+1 种基金the Natural Science Basic Research Program of Shaanxi(2024JC-YBQN-0313)the Science for Earthquake Resilience(XH24059YA)。
文摘This study investigates the transient deformation signals associated with the Ludian M6.8 earthquake,which occurred on June 22,2014,in southwestern China,using Global Navigation Satellite System(GNSS)data.Within the framework of the Kalman filter,the study employs a First-Order Gauss-Markov(FOGM)model to construct and isolate transient deformation signals,extracting the FOGM time series.Principal Component Analysis(PCA)is then applied to decompose the extracted time series and analyze the spatiotemporal evolution of the top two Principal Components(PCs)of the East-West(EW)and North-South(NS)components,revealing their correlation with the Ludian earthquake.Furthermore,a quantitative analysis of the spatial response characteristics of the second Principal Component(PC2)of the EW component and the first Principal Component(PC1)of the NS component is conducted to characterize the spatial evolution pattern of transient deformation.Finally,the spatial distribution of transient deformation signals is compared with the known co-seismic rupture characteristics,providing further evidence that the extracted signals represent real post-seismic deformation rather than noise.The key findings of this study are as follows:1.The PC2 of the EW component and the PC1 of the NS component primarily represent post-seismic transient deformation signals associated with the Ludian earthquake.The post-seismic deformation evolution exhibits two distinct phases:a sustained deformation phase from the earthquake occurrence to early 2016 and a recovery phase starting from early2016,reflecting the time-dependent characteristics of the post-seismic relaxation process.2.In addition to the well-known linear trend and periodic components,the GNSS displacement time series may also contain non-linear periodic components,suggesting that GNSS data are influenced by a combination of crustal dynamics,surface environmental changes,and anthropogenic factors.3.The integration of Kalman filtering and PCA-based dimensionality reduction analysis effectively isolates transient deformation signals and nonlinear periodic signals from complex background noise,enhancing the interpretability of GNSS data.This approach provides a highly efficient data processing method for analyzing earthquake-induced deformation.
基金supported by the Natural Science Foundation of China(No.12372176)the National Science and Technology Major Project of China(No.J2019-IV-0007-0075)。
文摘Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been able to dynamically measure the deformation fields of rapidly evolving slip activities at the microscale.In this study,we used the Sampling Moire?Method(SMM)to directly measure the dynamic deformation fields of slip activities in Nickel-Based Single-Crystal(NBSC)superalloy under in-situ tensile test,and the strain and displacement fields under the evolving microplastic events with intense slip activities around the notch of the NBSC superalloy specimen were obtained for the first time.The dynamic evolution of slip bands was quantitatively characterized through detailed statistical analysis of strains and displacements under different loads.The locations of the initial appearance of slip traces were successfully predicted by the regions of plasticity localization.The results show that the deformation fields exhibit both high spatial and temporal resolutions,enabling the capture of nanometer-scale displacement fields and visualization of the dynamic fluidity of slip accumulation.This method demonstrates the superiority of the dynamic characterization of the plastic deformation field at the microscale and the promise of its application for characterizing the slip activities of various crystalline metals.
文摘The structures of even-even Gd and Dy isotopes around N=100 were investigated using a fully self-consistent microscopic model.The systematics of the exited 2_(1)^(+)and 4_(1)^(+)energies reveal a peak-like structure at N=100 along the Gd(Z=64)and Dy(Z=66)isotopic chains.This supports the evidence for a subshell gap near N=100.The nuclear structure properties studied are important to understand the r-process elemental abundance peak at A~160.
基金supported by the National Science and Technology Major Project,China(No.2017-II-0006-0019)the National Natural Science Foundation of China(No.52375266)the Shaanxi Science Foundation for Distinguished Young Scholars,China(No.2022JC-36)。
文摘A Hybrid Free-Form Deformation(HFFD)method is developed to improve shape preservation in mesh deformation for perforated surfaces,which traditional Free-Form Deformation(FFD)techniques struggle to handle effectively.The proposed method enables high-fidelity parameterized deformation for both flat and curved perforated surfaces while maintaining mesh quality with minimal geometric distortion.To evaluate its effectiveness,comparative studies between HFFD and conventional FFD methods are conducted,demonstrating superior performance in mesh quality and geometric fidelity.The HFFD-based framework is further applied to the Multidisciplinary Design Optimization(MDO)of a double-wall turbine blade leading edge.Results indicate an 11.6%increase in cooling efficiency and a 16.21%reduction in maximum stress.Additionally,compared to traditional geometry-based parameterization in MDO,the HFFD approach improves model processing efficiency by 84.15%and overall optimization efficiency by20.05%.These findings demonstrate HFFD's potential to significantly improve complex engineering design optimization by achieving precise shape preservation and improving computational efficiency.
基金funded by the 2025 Jilin Provincial Earthquake Administration Youth Science and Technology Development Project(JZQ-202503).
文摘Climate change is causing extensive and quantifiable surface deformation by moving mass in the cryosphere,hydrosphere,atmosphere,and oceans.These deformations can give a great deal of information on the dynamics of the Earth system and interactions between climate processes and solid Earth processes.Global Navigation Satellite Systems(GNSS),Interferometric Synthetic Aperture Radar(InSAR),satellite gravimetry,and other supplementary techniques have become important tools to be used to monitor and quantify these deformations.The insight of this review is the understanding of the mechanisms that cause deformation on the surface due to climate change,the strengths and weaknesses of the modern geodetic observation methods,and the way in which these geodetic observations are reconciled with the Earth’s response models and climate simulations.Polar,alpine,hydrologically sensitive,and coastal case studies demonstrate that geodesy can be used globally in climate change studies.Although there has been a lot of improvement,there have been many problems in signal separation,data coverage,and uncertainties in models,but new emerging technologies are promising solutions.A combined climate/geodetic observing system will be critical in enhancing long-term monitoring and in further developing the knowledge on how the Earth responds to climate change.
基金supported by the National Key R&D Program of China(Grant No.2023YFC3209504)Natural Science Foundation of Wuhan(Grant No.2024040801020271)the Fundamental Research Funds for Central Public Welfare Research Institutes(Grant No.CKSF2025718/YT).
文摘Wetting deformation in earth-rockfill dams is a critical factor influencingdam safety.Although numerous mathematical models have been developed to describe this phenomenon,most of them rely on empirical formulations and lack prior knowledge of model parameters,which is essential for Bayesian parameter inversion to enhance accuracy and reduce uncertainty.This study introduces a datadriven approach to establishing prior knowledge of earth-rockfill dams.Driving factors are utilized to determine the potential range of model parameters,and settlement changes within this range are calculated.The results are iteratively compared with actual monitoring data until the calculated range encompasses the observed data,thereby providing prior knowledge of the model parameters.The proposed method is applied to the right-bank earth-rockfilldam of Danjiangkou.Employing a Gibbs sample size of 30,000,the proposed method effectively calibrates the prior knowledge of the wetting model parameters,achieving a root mean square error(RMSE)of 5.18 mm for the settlement predictions.By comparison,the use of non-informative priors with sample sizes of 30,000 and 50,000 results in significantly larger RMSE values of 11.97 mm and 16.07 mm,respectively.Furthermore,the computational efficiencyof the proposed method is demonstrated by an inversion computation time of 902 s for 30,000 samples,which is notably shorter than the 1026 s and 1558 s required for noninformative priors with 30,000 and 50,000 samples,respectively.These findingsunderscore the superior performance of the proposed approach in terms of both prediction accuracy and computational efficiency.These results demonstrate that the proposed method not only improves the predictive accuracy but also enhances the computational efficiency,enabling optimal parameter identificationwith reduced computational effort.This approach provides a robust and efficientframework for advancing dam safety assessments.
基金National Natural Science Foundation of China(No.42074116)the Open Foundation of Wuhan,Gravitation and Solid Earth Tides,National Observation and Research Station(WHYWZ202404)the Research grants from National Institute of Natural Hazards,Ministry of Emergency Management of China(ZDJ2024-31)。
文摘Investigating the spatial distribution of coseismic rupture,postseismic afterslip,and their interactions is essential for understanding the heterogeneous frictional characteristics of faults,and seismic hazard assessments.This study offers a comprehensive analysis of both seismic and aseismic slip of the 2022 MW6.7 Menyuan earthquake,which took place at the western terminus of the Tianzhu seismic gap located in the northeastern Qinghai-Xizang Plateau.By integrating near-field GNSS measurements,In SAR line-of-sight(LOS)displacements,and surface rupture data,we refined the coseismic slip distribution using a kinematic inversion and a mechanically constrained model.Our results reveal an unexpectedly large coseismic slip of about 3.3 m at shallow depths(less than about 6 km),along with minimal shallow slip deficit—features rarely observed in earthquakes of similar magnitude globally.The mechanically constrained approach yields a static stress drop of about 6.4 MPa.Additionally,we invert for the afterslip distribution from cumulative postseismic GNSS displacements recorded during the initial 2.7 years subsequent to the mainshock.The afterslip is predominantly situated downdip of the coseismic rupture zone,releasing 28.5%of the coseismic moment.There is a tight correlation between the spatiotemporal evolution of aftershocks and the downdip afterslip,with limited contributions from viscoelastic relaxation and poroelastic rebound which indicates that the afterslip mechanism primarily controls early postseismic deformation.
文摘Because of the developed surface of the Triply PeriodicMinimumSurface(TPMS)structures,polylactide(PLA)products with a TPMS structure are thought to be promising bio soluble implants with the potential for targeted drug delivery.For implants,mechanical properties are key performance characteristics,so understanding the deformation and failure mechanisms is essential for selecting the appropriate implant structure.The deformation and fracture processes in PLA samples with different interior architectures have been studied through computer simulation and experimental research.Two TPMS topologies,the Schwarz Diamond and Gyroid architectures,were used for the sample construction by 3D printing.ANSYS software was utilized to simulate compressive deformation.It was found that under the same load,the vonMises stresses in the Gyroid structure are higher than those in the Schwartz Diamond structure,which was associated with the different orientations of the cells in the studied structures in relation to the direction of the loading axis.The deformation process occurs in the local regions of the studied TPMS structures.Maximum von Mises stresses were observed in the vertical parts of the structures oriented along the load direction.It was found that,unlike the Gyroid,the Schwartz Diamond structure contains a frame that forms unique stiffening ribs,which ensures the redistribution of the load under the vertical loading direction.An analysis of the mechanical characteristics of PLA samples with the Schwartz Diamond and Gyroid structures produced by the Fused Deposition Modeling(FDM)method was correlated with computer simulation.The Schwarz Diamond-type structure was shown to have a higher absorption energy than the Gyroid one.A study of the fracture in PLA samples with various cell sizes revealed a particular feature related to the samples’periodic surface topology and the 3D printing process.Scanning electron microscopic(SEM)studies of the samples deformed by compression showed thatwith an increase in the density of the samples,the failure mechanism changes from ductile to quasi-brittle due to the complex participation of both cell deformation and fiber deformation.
文摘Strain measurements during uniaxial compressive strength(UCS)testing and their subsequent interpretation to obtain elastic parameters are relatively straightforward for most rocks.However,for slates,which are foliated metamorphic rocks characterized by significant anisotropy,the dependence of elastic properties on the orientation of foliation complicates the measurement and interpretation of strain data.In this study,a series of wave propagation velocity tests and UCS tests are conducted on cylindrical and prismatic slate specimens to gain a better understanding of how to obtain and process deformability and strength results.Wave propagation velocity results demonstrate an increase with the dip of foliation planes crossed,which is consistent with previous studies.Based on UCS test results,two methodologies are considered for obtaining transversely isotropic deformability parameters:the least-squares method and the recently proposed generalized reduction gradient(GRG)algorithm.Their performance is assessed in the context of potentially variable and limited amounts of data.GRG algorithms provide an enhanced analysis technique for estimating anisotropic elastic properties when dealing with limited or heterogeneous laboratory test data.Different strength models have also been considered,including the classic Jaeger's weakness plane(JPW)and its subsequent modification,i.e.2HBJPW.The 2HBJPW approach has proven to be more consistent with the obtained results and enhances the representation of the strength properties of slates.Additionally,a finite element method(FEM)numerical approach is employed to compare results with analytical and experimental ones,demonstrating a good match,thereby offering calibrated inputs for rock engineering applications.
