The three-dimensional(3D)geometry of a fault is a critical control on earthquake nucleation,dynamic rupture,stress triggering,and related seismic hazards.Therefore,a 3D model of an active fault can significantly impro...The three-dimensional(3D)geometry of a fault is a critical control on earthquake nucleation,dynamic rupture,stress triggering,and related seismic hazards.Therefore,a 3D model of an active fault can significantly improve our understanding of seismogenesis and our ability to evaluate seismic hazards.Utilising the SKUA GoCAD software,we constructed detailed seismic fault models for the 2021 M_(S)6.4 Yangbi earthquake in Yunnan,China,using two sets of relocated earthquake catalogs and focal mechanism solutions following a convenient 3D fault modeling workflow.Our analysis revealed a NW-striking main fault with a high-angle SW dip,accompanied by two branch faults.Interpretation of one dataset revealed a single NNW-striking branch fault SW of the main fault,whereas the other dataset indicated four steep NNE-striking segments with a left-echelon pattern.Additionally,a third ENE-striking short fault was identified NE of the main fault.In combination with the spatial distribution of pre-existing faults,our 3D fault models indicate that the Yangbi earthquake reactivated pre-existing NW-and NE-striking fault directions rather than the surface-exposed Weixi-Qiaohou-Weishan Fault zone.The occurrence of the Yangbi earthquake demonstrates that the reactivation of pre-existing faults away from active fault zones,through either cascade or conjugate rupture modes,can cause unexpected moderate-large earthquakes and severe disasters,necessitating attention in regions like southeast Xizang,which have complex fault systems.展开更多
Highway planning requires geological surveys and stability analysis of the surrounding area.In the early stage of the survey,the modeling and stability analysis of the survey area can be carried out by using GIS softw...Highway planning requires geological surveys and stability analysis of the surrounding area.In the early stage of the survey,the modeling and stability analysis of the survey area can be carried out by using GIS software to intuitively understand the topography of the study area.The use of DEM to extract terrain factors can be used for simple stability analysis and the source data is easy to obtain,simple to operate,fast to analyze,and reliable analysis results.In this paper,taking the X104 road section in Ganxian County as an example,the ArcGIS platform is used to carry out 3D modeling visualization and stability analysis,and the stability evaluation map of the study area is obtained.展开更多
With the widespread application of 3D visualization in digital exhibition halls and virtual reality,achieving efficient rendering and high-fidelity presentation has become a key challenge.This study proposes a hybrid ...With the widespread application of 3D visualization in digital exhibition halls and virtual reality,achieving efficient rendering and high-fidelity presentation has become a key challenge.This study proposes a hybrid point cloud generation method that combines traditional sampling with 3D Gaussian splatting,aiming to address the issues of rendering delay and missing details in existing 3D displays.By improving the OBJ model parsing process and incorporating an adaptive area-weighted sampling algorithm,we achieve adaptive point cloud generation based on triangle density.Innovatively,we advance the ellipsoidal parameter estimation process of 3D Gaussian splatting to the point cloud generation stage.By establishing a mathematical relationship between the covariance matrix and local curvature,the generated point cloud naturally exhibits Gaussian distribution characteristics.Experimental results show that,compared to traditional methods,our approach reduces point cloud data by 38% while maintaining equivalent visual quality at a 4096×4096 texture resolution.By introducing mipmap texture optimization strategies and a GPU-accelerated rasterization pipeline,stable rendering at 60 frames per second is achieved in a WebGL environment.Additionally,we quantize and compress the spherical harmonic function parameters specific to 3D Gaussian splatting,reducing network transmission bandwidth to 52% of the original data.This study provides a new technical pathway for fields requiring high-precision display,such as the digitization of cultural heritage.展开更多
Given the severe toxicity and widespread presence of cadmium(Cd)in staple foods such as rice,accurate dietary exposure assessments are imperative for public health.In vitro bioavailability is commonly used to adjust d...Given the severe toxicity and widespread presence of cadmium(Cd)in staple foods such as rice,accurate dietary exposure assessments are imperative for public health.In vitro bioavailability is commonly used to adjust dietary exposure levels of risk factors;however,traditional planar Transwell models have limitations,such as cell dedifferentiation and lack of key intestinal components,necessitating a more physiologically relevant in vitro platform.This study introduces an innovative three-dimensional(3D)intestinal organoid model using a microfluidic chip to evaluate Cd bioavailability in food.Caco-2 cells were cultured on the chip to mimic small intestinal villi's 3D structure,mucus production,and absorption functions.The model's physiological relevance was thoroughly characterized,demonstrating the formation of a confluent epithelial monolayer with well-developed tight junctions(ZO-1),high microvilli density(F-actin),and significant mucus secretion(Alcian blue staining),closely resembling the physiological intestinal epithelium.Fluorescent particle tracking confirmed its ability to simulate intestinal transport and diffusion.The Cd bioavailability in rice measured by the 3D intestinal organoid model((9.07±0.21)%)was comparable to the mouse model((12.82±3.42)%)but significantly lower than the Caco-2 monolayer model((26.97±1.11)%).This 3D intestinal organoid model provides a novel and reliable strategy for in vitro assessment of heavy metal bioavailability in food,with important implications for food safety and risk assessment.展开更多
Accurate vector extraction from design drawings is required first to automatically create 3D models from pixel-level engineering design drawings. However, this task faces the challenges of complicated design shapes as...Accurate vector extraction from design drawings is required first to automatically create 3D models from pixel-level engineering design drawings. However, this task faces the challenges of complicated design shapes as well as cumbersome and cluttered annotations on drawings, which interfere with the vector extraction heavily. In this article, the transmission tower containing the most complex structure is taken as the research object, and a semantic segmentation network is constructed to first segment the shape masks from the pixel-level drawings. Preprocessing and postprocessing are also proposed to ensure the stability and accuracy of the shape mask segmentation. Then, based on the obtained shape masks, a vector extraction network guided by heatmaps is designed to extract structural vectors by fusing the features from node heatmap and skeleton heatmap, respectively. Compared with the state-of-the-art methods, experiment results illustrate that the proposed semantic segmentation method can effectively eliminate the interference of many elements on drawings to segment the shape masks effectively, meanwhile, the model trained by the proposed vector extraction network can accurately extract the vectors such as nodes and line connections, avoiding redundant vector detection. The proposed method lays a solid foundation for automatic 3D model reconstruction and contributes to technological advancements in relevant fields.展开更多
Multistage fracturing technology has been used to enhance tight hydrocarbon resource recovery.Determining the proper well spacing and fracturing strategy is crucial for generating a complex fracture network that facil...Multistage fracturing technology has been used to enhance tight hydrocarbon resource recovery.Determining the proper well spacing and fracturing strategy is crucial for generating a complex fracture network that facilitates oil and gas flow in reservoirs.The stress-shadow effect that occurs between multiple wells significantly affects the development of fracture networks in reservoirs.However,the quantification of the stress-shadow effect and its influence on fracture networks has not been satisfactorily resolved because of the difficulties in detecting and identifying fracture propagation and reorientation in reservoirs.In this study,based on the geological information from the Shengli oilfield,we applied a hybrid finite element-discrete element method to analyze engineering-scale three-dimensional fracture propagation and reorientation by altering well spacings and fracturing strategies.The results indicate that the fracturing area generated by the synchronous fracturing scheme is much smaller than those generated by the sequential and alternative schemes.An alternative hydrofracturing scheme is optimal with respect to fracturing area.The stress-blind area was defined to quantify the mechanical disturbance between adjacent wells.Our study improves the understanding of the effect of fracturing schemes on fracture networks and the impact of independent factors contributing to stress-shadow effects.展开更多
The Kunene Complex(KC)represents a very large Mesoproterozoic igneous body,mainly composed of anorthosites and gabbroic rocks that extends from SW Angola to NW Namibia(outcropping 18,000 km^(2),NE-SW trend,and ca.350 ...The Kunene Complex(KC)represents a very large Mesoproterozoic igneous body,mainly composed of anorthosites and gabbroic rocks that extends from SW Angola to NW Namibia(outcropping 18,000 km^(2),NE-SW trend,and ca.350 km long and up to 50 km wide).Little is known about its structure at depth.Here,we use recently acquired aerogeophysical data to accurately determine its hidden extent and to unravel its morphology at depth.These data have been interpreted and modelled to investigate the unexposed KC boundaries,reconstructing the upper crustal structure(between 0 and 15 km depth)overlain by the thin sedimentary cover of the Kalahari Basin.The modelling reveals that the KC was emplaced in the upper crust and extends in depth up to ca.5 km,showing a lobular geometry and following a large NE-SW to NNE-SSW linear trend,presumably inherited from older Paleoproterozoic structures.The lateral continuation of the KC to the east(between 50 and 125 km)beneath the Kalahari Cenozoic sediments suggests an overall size three times the outcropping dimension(about 53,500 km^(2)).This affirmation clearly reinforces the economic potential of this massif,related to the prospecting of raw materials and certain types of economic mineralization(Fe-Ti oxides,metallic sulphides or platinum group minerals).Up to 11 lobes have been isolated with dimensions ranging from 135.5 to 37.3 km in length and 81.9 to 20.7 km in width according to remanent bodies revealed by TMI mapping.A total volume of 65,184 km3 was calculated only for the magnetically remanent bodies of the KC.A long-lasting complex contractional regime,where large strike-slip fault systems were involved,occurred in three kinematic pulses potentially related to a change of velocity or convergence angle acting on previous Paleoproterozoic inherited sutures.The coalescent magmatic pulses can be recognized by means of magnetic anomalies,age of the bodies as well as the lineations inferred in this work:(i)Emplacement of the eastern mafic bodies and granites in a stage of significant lateral extension in a transtensional context between 1500 Ma and 1420 Ma;(ii)Migration of the mantle derived magmas westwards with deformation in a complex contractional setting with shearing structures involving western KC bodies and basement from 1415 Ma to 1340 Ma;(iii)NNW-SSE extensional structures are relocated westwards,involving mantle magmas,negative flower structures and depression that led to the formation of late Mesoproterozoic basins from 1325 Ma to 1170 Ma.Additionally,we detect several first and second order structures to place the structuring of the KC in a craton-scale context in relation to the crustal structures detected in NW Namibia.展开更多
Research on scale effects on flows over weirs has been conducted on a limited basis, primarily focusing on flows upstream of a single-type weir, such as ogee, broad-crested, and sharp-crested (linear and non-linear) w...Research on scale effects on flows over weirs has been conducted on a limited basis, primarily focusing on flows upstream of a single-type weir, such as ogee, broad-crested, and sharp-crested (linear and non-linear) weirs. However, the scale effects downstream of these single-type weirs have not been thoroughly investigated. This study examined the scale effects on flows over a combined weir system consisting of an ogee weir and a sharp-crested weir, both upstream and downstream, utilizing physical modeling at a 1:33.33 scale based on Froude similarity and three-dimensional (3D) computational fluid dynamics (CFD) modeling. The sharp-crested weir in this study was represented by two sluice gates that remain closed and submerged during flood events. The experimental data confirmed that the equivalent discharge coefficients of the combined weir system behaved similarly to those of a sharp-crested weir across various H/P (where H is the total head, and P is the weir height) values. However, scale effects on the discharge rating curve due to surface tension and viscosity could only be minimized when H/P > 0.4, Re > 26 959, and We > 240 (where Re and We are the Reynolds and Weber numbers, respectively), provided that the water depth exceeded 0.042 m above the crest. Additionally, Re greater than 4 × 104 was necessary to minimize scale effects caused by viscosity in flows in the spillway channel and stilling basin (with baffle blocks). The limiting criteria aligned closely with existing literature. This study offers valuable insights for practical applications in hydraulic engineering in the future.展开更多
This research establishes a methodological framework for generating geometrically accurate 3D representations of human crystalline lenses through scanning technologies and digital reconstruction. Multiple scanning sys...This research establishes a methodological framework for generating geometrically accurate 3D representations of human crystalline lenses through scanning technologies and digital reconstruction. Multiple scanning systems were evaluated to identify optimal approaches for point cloud processing and subsequent development of parameterized solid models, facilitating comprehensive morpho-geometric characterization. Experimental work was performed at the 3D Scanning Laboratory of SEDIC (Industrial Design and Scientific Calculation Service) at the Technical University of Cartagena, employing five distinct scanner types based on structured light, laser, and infrared technologies. Test specimens—including preliminary calibration using a lentil and biological analysis of a human crystalline lens—were digitized under rigorously controlled environmental conditions. Acquired point clouds underwent processing in Rhinoceros software to produce digital surface meshes, which were subsequently converted into solid CAD models via SolidWorks. Model fidelity and biomedical relevance were assessed through quantification of geometric and physical properties. Scanner performance varied significantly in reconstruction precision and resolution, with structured blue light systems (e.g., Artec SPIDER) exhibiting superior capability for capturing lens surface topography compared to infrared or white light alternatives. Resultant models enabled accurate dimensional analysis of clinically relevant parameters including volumetric and surface area measurements. Technology-specific advantages and constraints were rigorously cataloged relative to sample attributes. Findings indicate that structured blue light scanning provides the most effective foundation for crystalline lens digitization and modeling. The presented methodological approach not only ensures high-fidelity solid model generation but also demonstrates translational potential in medical domains, from custom intraocular lens design to refinement of ophthalmic therapeutic interventions.展开更多
The popularity of deep learning has boosted computer-generated holography(CGH)as a vibrant research field,particularly physics-driven unsupervised learning.Nevertheless,present unsupervised CGH models have not yet exp...The popularity of deep learning has boosted computer-generated holography(CGH)as a vibrant research field,particularly physics-driven unsupervised learning.Nevertheless,present unsupervised CGH models have not yet explored the potential of generating full-color 3D holograms through a unified framework.In this study,we propose a lightweight multiwavelength network model capable of high-fidelity and efficient full-color hologram generation in both 2D and 3D display,called IncepHoloRGB.The high-speed simultaneous generation of RGB holograms at 191 frames per second(FPS)is based on Inception sampling blocks and multi-wavelength propagation module integrated with depth-traced superimposition,achieving an average structural similarity(SSIM)of 0.88 and peak signal-to-noise ratio(PSNR)of 29.00 on the DIV2K test set in reconstruction.Full-color reconstruction of numerical simulations and optical experiments shows that IncepHoloRGB is versatile to diverse scenarios and can obtain authentic full-color holographic 3D display within a unified network model,paving the way for applications towards real-time dynamic naked-eye 3D display,virtual and augmented reality(VR/AR)systems.展开更多
Anticancer drug resistance remains a major challenge in cancer treatment hindering the efficacy of chemotherapy and targeted therapies.Conventional two-dimensional(2D)cell cultures cannot replicate the complexity of t...Anticancer drug resistance remains a major challenge in cancer treatment hindering the efficacy of chemotherapy and targeted therapies.Conventional two-dimensional(2D)cell cultures cannot replicate the complexity of the in vivo tumor microenvironment(TME),limiting their utility for drug resistance research.Therefore,three-dimensional(3D)tumor models have proven to be a promising alternative for investigating chemoresistance mechanisms.In this review,various cancer 3D models,including spheroids,organoids,scaffold-based models,and bioprinted models,are comprehensively evaluated with a focus on their application in drug resistance studies.We discuss the materials,properties,and advantages of each model,highlighting their ability to better mimic the TME and represent complex mechanisms of drug resistance such as epithelial-mesenchymal transition(EMT),drug efflux,and tumor-stroma interactions.Furthermore,we investigate the limitations of these models,including scalability,reproducibility and technical challenges,as well as their potential therapeutic impact on personalized medicine.Through a thorough comparison of model performance,we provide insights into the strengths and weaknesses of each approach and offer guidance for model selection based on specific research needs.展开更多
The excavation of deep tunnels crossing faults is highly prone to triggering rockburst disasters,which has become a significant engineering issue.In this study,taking the fault-slip rockbursts from a deep tunnel in so...The excavation of deep tunnels crossing faults is highly prone to triggering rockburst disasters,which has become a significant engineering issue.In this study,taking the fault-slip rockbursts from a deep tunnel in southwestern China as the engineering prototype,large-scale three-dimensional(3D)physical model tests were conducted on a 3D-printed complex geological model containing two faults.Based on the selfdeveloped 3D loading system and excavation device,the macroscopic failure of fault-slip rockbursts was simulated indoors.The stress,strain,and fracturing characteristics of the surrounding rock near the two faults were systematically evaluated during excavation and multistage loading.The test results effectively revealed the evolution and triggering mechanism of fault-slip rockbursts.After the excavation of a highstress tunnel,stress readjustment occurred.Owing to the presence of these two faults,stress continued to accumulate in the rock mass between them,leading to the accumulation of fractures.When the shear stress on a fault surface exceeded its shear strength,sudden fault slip and dislocation occurred,thus triggering rockbursts.Rockbursts occurred twice in the vault between the two faults,showing obvious intermittent characteristics.The rockburst pit was controlled by two faults.When the faults remained stable,tensile failure predominated in the surrounding rock.However,when the fault slip was triggered,shear failure in the surrounding rock increased.These findings provide valuable insights for enhancing the comprehension of fault-slip rockbursts.展开更多
In this work,the microstructure evolution and mechanical behavior of extruded SiC/ZA63 Mg matrix composites are investigated via combined experimental study and three-dimensionalfinite element modelling(3D FEM)based on...In this work,the microstructure evolution and mechanical behavior of extruded SiC/ZA63 Mg matrix composites are investigated via combined experimental study and three-dimensionalfinite element modelling(3D FEM)based on the actual 3D microstructure achieved by synchrotron tomography.The results show that the average grain size of composite increases from 0.57μm of 8μm-SiC/ZA63 to 8.73μm of 50μm-SiC/ZA63.The type of texture transforms from the typicalfiber texture in 8μm-SiC/ZA63 to intense basal texture in 50μm-SiC/ZA63 composite and the intensity of texture increases sharply with increase of SiC particle size.The dynamic recrystallization(DRX)mechanism is also changed with increasing SiC particle size.Experimental and simulation results verify that the strength and elongation both decrease with increase of SiC particle size.The 8μm-SiC/ZA63 composite possesses the optimal mechanical property with yield strength(YS)of 383 MPa,ultimate tensile strength(UTS)of 424 MPa and elongation of 6.3%.The outstanding mechanical property is attributed to the ultrafine grain size,high-density precipitates and dislocation,good loading transfer effect and the interface bonding between SiC and matrix,as well as the weakened basal texture.The simulation results reveal that the micro-cracks tend to initiate at the interface between SiC and matrix,and then propagate along the interface between particle and Mg matrix or at the high strain and stress regions,and further connect with other micro-cracks.The main fracture mechanism in 8μm-SiC/ZA63 composite is ductile damage of matrix and interfacial debonding.With the increase of particle size,interface strength and particle strength decrease,and interface debonding and particle rupture become the main fracture mechanism in the 30μm-and 50μm-SiC/ZA63 composites.展开更多
Vulnerability assessment is a systematic process to identify security gaps in the design and evaluation of physical protection systems.Adversarial path planning is a widely used method for identifying potential vulner...Vulnerability assessment is a systematic process to identify security gaps in the design and evaluation of physical protection systems.Adversarial path planning is a widely used method for identifying potential vulnerabilities and threats to the security and resilience of critical infrastructures.However,achieving efficient path optimization in complex large-scale three-dimensional(3D)scenes remains a significant challenge for vulnerability assessment.This paper introduces a novel A^(*)-algorithmic framework for 3D security modeling and vulnerability assessment.Within this framework,the 3D facility models were first developed in 3ds Max and then incorporated into Unity for A^(*)heuristic pathfinding.The A^(*)-heuristic pathfinding algorithm was implemented with a geometric probability model to refine the detection and distance fields and achieve a rational approximation of the cost to reach the goal.An admissible heuristic is ensured by incorporating the minimum probability of detection(P_(D)^(min))and diagonal distance to estimate the heuristic function.The 3D A^(*)heuristic search was demonstrated using a hypothetical laboratory facility,where a comparison was also carried out between the A^(*)and Dijkstra algorithms for optimal path identification.Comparative results indicate that the proposed A^(*)-heuristic algorithm effectively identifies the most vulnerable adversarial pathfinding with high efficiency.Finally,the paper discusses hidden phenomena and open issues in efficient 3D pathfinding for security applications.展开更多
This study introduces a novel method for reconstructing the 3D model of aluminum foam using cross-sectional sequence images.Combining precision milling and image acquisition,high-qual-ity cross-sectional images are ob...This study introduces a novel method for reconstructing the 3D model of aluminum foam using cross-sectional sequence images.Combining precision milling and image acquisition,high-qual-ity cross-sectional images are obtained.Pore structures are segmented by the U-shaped network(U-Net)neural network integrated with the Canny edge detection operator,ensuring accurate pore delineation and edge extraction.The trained U-Net achieves 98.55%accuracy.The 2D data are superimposed and processed into 3D point clouds,enabling reconstruction of the pore structure and aluminum skeleton.Analysis of pore 01 shows the cross-sectional area initially increases,and then decreases with milling depth,with a uniform point distribution of 40 per layer.The reconstructed model exhibits a porosity of 77.5%,with section overlap rates between the 2D pore segmentation and the reconstructed model exceeding 96%,confirming high fidelity.Equivalent sphere diameters decrease with size,averaging 1.95 mm.Compression simulations reveal that the stress-strain curve of the 3D reconstruction model of aluminum foam exhibits fluctuations,and the stresses in the reconstruction model concentrate on thin cell walls,leading to localized deformations.This method accurately restores the aluminum foam’s complex internal structure,improving reconstruction preci-sion and simulation reliability.The approach offers a cost-efficient,high-precision technique for optimizing material performance in engineering applications.展开更多
The spatial distribution of discontinuities and the size of rock blocks are the key indicators for rock mass quality evaluation and rockfall risk assessment.Traditional manual measurement is often dangerous or unreach...The spatial distribution of discontinuities and the size of rock blocks are the key indicators for rock mass quality evaluation and rockfall risk assessment.Traditional manual measurement is often dangerous or unreachable at some high-steep rock slopes.In contrast,unmanned aerial vehicle(UAV)photogrammetry is not limited by terrain conditions,and can efficiently collect high-precision three-dimensional(3D)point clouds of rock masses through all-round and multiangle photography for rock mass characterization.In this paper,a new method based on a 3D point cloud is proposed for discontinuity identification and refined rock block modeling.The method is based on four steps:(1)Establish a point cloud spatial topology,and calculate the point cloud normal vector and average point spacing based on several machine learning algorithms;(2)Extract discontinuities using the density-based spatial clustering of applications with noise(DBSCAN)algorithm and fit the discontinuity plane by combining principal component analysis(PCA)with the natural breaks(NB)method;(3)Propose a method of inserting points in the line segment to generate an embedded discontinuity point cloud;and(4)Adopt a Poisson reconstruction method for refined rock block modeling.The proposed method was applied to an outcrop of an ultrahigh steep rock slope and compared with the results of previous studies and manual surveys.The results show that the method can eliminate the influence of discontinuity undulations on the orientation measurement and describe the local concave-convex characteristics on the modeling of rock blocks.The calculation results are accurate and reliable,which can meet the practical requirements of engineering.展开更多
This research pioneers the integration of geographic information systems(GIS)and 3D modeling within a virtual reality(VR)framework to assess the viability and planning of a 20 MW hybrid wind-solarphotovoltaic(PV)syste...This research pioneers the integration of geographic information systems(GIS)and 3D modeling within a virtual reality(VR)framework to assess the viability and planning of a 20 MW hybrid wind-solarphotovoltaic(PV)system connected to the local grid.The study focuses on Dakhla,Morocco,a region with vast untapped renewable energy potential.By leveraging GIS,we are innovatively analyzing geographical and environmental factors that influence optimal site selection and system design.The incorporation of VR technologies offers an unprecedented level of realism and immersion,allowing stakeholders to virtually experience the project's impact and design in a dynamic,interactive environment.This novel methodology includes extensive data collection,advanced modeling,and simulations,ensuring that the hybrid system is precisely tailored to the unique climatic and environmental conditions of Dakhla.Our analysis reveals that the region possesses a photovoltaic solar potential of approximately2400 k Wh/m^(2) per year,with an average annual wind power density of about 434 W/m^(2) at an 80-meter hub height.Productivity simulations indicate that the 20 MW hybrid system could generate approximately 60 GWh of energy per year and 1369 GWh over its 25-year lifespan.To validate these findings,we employed the System Advisor Model(SAM)software and the Global Solar Photovoltaic Atlas platform.This comprehensive and interdisciplinary approach not only provides a robust assessment of the system's feasibility but also offers valuable insights into its potential socio-economic and environmental impact.展开更多
基金financial support from the National Key R&D Program of China (No. 2021YFC3000600)National Natural Science Foundation of China (No. 41872206)National Nonprofit Fundamental Research Grant of China, Institute of Geology, China, Earthquake Administration (No. IGCEA2010)
文摘The three-dimensional(3D)geometry of a fault is a critical control on earthquake nucleation,dynamic rupture,stress triggering,and related seismic hazards.Therefore,a 3D model of an active fault can significantly improve our understanding of seismogenesis and our ability to evaluate seismic hazards.Utilising the SKUA GoCAD software,we constructed detailed seismic fault models for the 2021 M_(S)6.4 Yangbi earthquake in Yunnan,China,using two sets of relocated earthquake catalogs and focal mechanism solutions following a convenient 3D fault modeling workflow.Our analysis revealed a NW-striking main fault with a high-angle SW dip,accompanied by two branch faults.Interpretation of one dataset revealed a single NNW-striking branch fault SW of the main fault,whereas the other dataset indicated four steep NNE-striking segments with a left-echelon pattern.Additionally,a third ENE-striking short fault was identified NE of the main fault.In combination with the spatial distribution of pre-existing faults,our 3D fault models indicate that the Yangbi earthquake reactivated pre-existing NW-and NE-striking fault directions rather than the surface-exposed Weixi-Qiaohou-Weishan Fault zone.The occurrence of the Yangbi earthquake demonstrates that the reactivation of pre-existing faults away from active fault zones,through either cascade or conjugate rupture modes,can cause unexpected moderate-large earthquakes and severe disasters,necessitating attention in regions like southeast Xizang,which have complex fault systems.
基金National Undergraduate Training Program for Innovation and Entrepreneurship(Project No.:202310407006)。
文摘Highway planning requires geological surveys and stability analysis of the surrounding area.In the early stage of the survey,the modeling and stability analysis of the survey area can be carried out by using GIS software to intuitively understand the topography of the study area.The use of DEM to extract terrain factors can be used for simple stability analysis and the source data is easy to obtain,simple to operate,fast to analyze,and reliable analysis results.In this paper,taking the X104 road section in Ganxian County as an example,the ArcGIS platform is used to carry out 3D modeling visualization and stability analysis,and the stability evaluation map of the study area is obtained.
文摘With the widespread application of 3D visualization in digital exhibition halls and virtual reality,achieving efficient rendering and high-fidelity presentation has become a key challenge.This study proposes a hybrid point cloud generation method that combines traditional sampling with 3D Gaussian splatting,aiming to address the issues of rendering delay and missing details in existing 3D displays.By improving the OBJ model parsing process and incorporating an adaptive area-weighted sampling algorithm,we achieve adaptive point cloud generation based on triangle density.Innovatively,we advance the ellipsoidal parameter estimation process of 3D Gaussian splatting to the point cloud generation stage.By establishing a mathematical relationship between the covariance matrix and local curvature,the generated point cloud naturally exhibits Gaussian distribution characteristics.Experimental results show that,compared to traditional methods,our approach reduces point cloud data by 38% while maintaining equivalent visual quality at a 4096×4096 texture resolution.By introducing mipmap texture optimization strategies and a GPU-accelerated rasterization pipeline,stable rendering at 60 frames per second is achieved in a WebGL environment.Additionally,we quantize and compress the spherical harmonic function parameters specific to 3D Gaussian splatting,reducing network transmission bandwidth to 52% of the original data.This study provides a new technical pathway for fields requiring high-precision display,such as the digitization of cultural heritage.
基金supported by National key research and development program of China(2022YFF1102500)。
文摘Given the severe toxicity and widespread presence of cadmium(Cd)in staple foods such as rice,accurate dietary exposure assessments are imperative for public health.In vitro bioavailability is commonly used to adjust dietary exposure levels of risk factors;however,traditional planar Transwell models have limitations,such as cell dedifferentiation and lack of key intestinal components,necessitating a more physiologically relevant in vitro platform.This study introduces an innovative three-dimensional(3D)intestinal organoid model using a microfluidic chip to evaluate Cd bioavailability in food.Caco-2 cells were cultured on the chip to mimic small intestinal villi's 3D structure,mucus production,and absorption functions.The model's physiological relevance was thoroughly characterized,demonstrating the formation of a confluent epithelial monolayer with well-developed tight junctions(ZO-1),high microvilli density(F-actin),and significant mucus secretion(Alcian blue staining),closely resembling the physiological intestinal epithelium.Fluorescent particle tracking confirmed its ability to simulate intestinal transport and diffusion.The Cd bioavailability in rice measured by the 3D intestinal organoid model((9.07±0.21)%)was comparable to the mouse model((12.82±3.42)%)but significantly lower than the Caco-2 monolayer model((26.97±1.11)%).This 3D intestinal organoid model provides a novel and reliable strategy for in vitro assessment of heavy metal bioavailability in food,with important implications for food safety and risk assessment.
基金funded by the Chinese State Grid Jiangsu Electric Power Co.,Ltd.Science and Technology Project Funding,Grant Number J2023031.
文摘Accurate vector extraction from design drawings is required first to automatically create 3D models from pixel-level engineering design drawings. However, this task faces the challenges of complicated design shapes as well as cumbersome and cluttered annotations on drawings, which interfere with the vector extraction heavily. In this article, the transmission tower containing the most complex structure is taken as the research object, and a semantic segmentation network is constructed to first segment the shape masks from the pixel-level drawings. Preprocessing and postprocessing are also proposed to ensure the stability and accuracy of the shape mask segmentation. Then, based on the obtained shape masks, a vector extraction network guided by heatmaps is designed to extract structural vectors by fusing the features from node heatmap and skeleton heatmap, respectively. Compared with the state-of-the-art methods, experiment results illustrate that the proposed semantic segmentation method can effectively eliminate the interference of many elements on drawings to segment the shape masks effectively, meanwhile, the model trained by the proposed vector extraction network can accurately extract the vectors such as nodes and line connections, avoiding redundant vector detection. The proposed method lays a solid foundation for automatic 3D model reconstruction and contributes to technological advancements in relevant fields.
基金supported in part by the National Key Research and Development Project of China(No.2022YFC3004602)in part by the National Natural Science Foundation of China(Nos.52121003 and 52342403).
文摘Multistage fracturing technology has been used to enhance tight hydrocarbon resource recovery.Determining the proper well spacing and fracturing strategy is crucial for generating a complex fracture network that facilitates oil and gas flow in reservoirs.The stress-shadow effect that occurs between multiple wells significantly affects the development of fracture networks in reservoirs.However,the quantification of the stress-shadow effect and its influence on fracture networks has not been satisfactorily resolved because of the difficulties in detecting and identifying fracture propagation and reorientation in reservoirs.In this study,based on the geological information from the Shengli oilfield,we applied a hybrid finite element-discrete element method to analyze engineering-scale three-dimensional fracture propagation and reorientation by altering well spacings and fracturing strategies.The results indicate that the fracturing area generated by the synchronous fracturing scheme is much smaller than those generated by the sequential and alternative schemes.An alternative hydrofracturing scheme is optimal with respect to fracturing area.The stress-blind area was defined to quantify the mechanical disturbance between adjacent wells.Our study improves the understanding of the effect of fracturing schemes on fracture networks and the impact of independent factors contributing to stress-shadow effects.
基金supported by the subsidiary programme“Ayudas Extraordinarias Menciones Excelencia Severo Ochoa”of the CN IGME-CSIC(project AECEX2021,grant 15903)the University of Minnesota and National Science Foundation(award NSF-EAR 2153786)+1 种基金the Portuguese Foundation for Science and Technology(FCT)support,Geosciences Center project UIDB/00073/2020(doi:10.54499/UIDB/00073/2020)University of Coimbra and and GeoBioTec project UIDB/04035/2020(doi:10.54499/UIDB/04035/2020),Nova School of Science and Technology.
文摘The Kunene Complex(KC)represents a very large Mesoproterozoic igneous body,mainly composed of anorthosites and gabbroic rocks that extends from SW Angola to NW Namibia(outcropping 18,000 km^(2),NE-SW trend,and ca.350 km long and up to 50 km wide).Little is known about its structure at depth.Here,we use recently acquired aerogeophysical data to accurately determine its hidden extent and to unravel its morphology at depth.These data have been interpreted and modelled to investigate the unexposed KC boundaries,reconstructing the upper crustal structure(between 0 and 15 km depth)overlain by the thin sedimentary cover of the Kalahari Basin.The modelling reveals that the KC was emplaced in the upper crust and extends in depth up to ca.5 km,showing a lobular geometry and following a large NE-SW to NNE-SSW linear trend,presumably inherited from older Paleoproterozoic structures.The lateral continuation of the KC to the east(between 50 and 125 km)beneath the Kalahari Cenozoic sediments suggests an overall size three times the outcropping dimension(about 53,500 km^(2)).This affirmation clearly reinforces the economic potential of this massif,related to the prospecting of raw materials and certain types of economic mineralization(Fe-Ti oxides,metallic sulphides or platinum group minerals).Up to 11 lobes have been isolated with dimensions ranging from 135.5 to 37.3 km in length and 81.9 to 20.7 km in width according to remanent bodies revealed by TMI mapping.A total volume of 65,184 km3 was calculated only for the magnetically remanent bodies of the KC.A long-lasting complex contractional regime,where large strike-slip fault systems were involved,occurred in three kinematic pulses potentially related to a change of velocity or convergence angle acting on previous Paleoproterozoic inherited sutures.The coalescent magmatic pulses can be recognized by means of magnetic anomalies,age of the bodies as well as the lineations inferred in this work:(i)Emplacement of the eastern mafic bodies and granites in a stage of significant lateral extension in a transtensional context between 1500 Ma and 1420 Ma;(ii)Migration of the mantle derived magmas westwards with deformation in a complex contractional setting with shearing structures involving western KC bodies and basement from 1415 Ma to 1340 Ma;(iii)NNW-SSE extensional structures are relocated westwards,involving mantle magmas,negative flower structures and depression that led to the formation of late Mesoproterozoic basins from 1325 Ma to 1170 Ma.Additionally,we detect several first and second order structures to place the structuring of the KC in a craton-scale context in relation to the crustal structures detected in NW Namibia.
基金supported by the Ministry of Public Works and Housing of Indonesia and Parahyangan Catholic University(Grant No.II/PD/2023-07/02-SJ).
文摘Research on scale effects on flows over weirs has been conducted on a limited basis, primarily focusing on flows upstream of a single-type weir, such as ogee, broad-crested, and sharp-crested (linear and non-linear) weirs. However, the scale effects downstream of these single-type weirs have not been thoroughly investigated. This study examined the scale effects on flows over a combined weir system consisting of an ogee weir and a sharp-crested weir, both upstream and downstream, utilizing physical modeling at a 1:33.33 scale based on Froude similarity and three-dimensional (3D) computational fluid dynamics (CFD) modeling. The sharp-crested weir in this study was represented by two sluice gates that remain closed and submerged during flood events. The experimental data confirmed that the equivalent discharge coefficients of the combined weir system behaved similarly to those of a sharp-crested weir across various H/P (where H is the total head, and P is the weir height) values. However, scale effects on the discharge rating curve due to surface tension and viscosity could only be minimized when H/P > 0.4, Re > 26 959, and We > 240 (where Re and We are the Reynolds and Weber numbers, respectively), provided that the water depth exceeded 0.042 m above the crest. Additionally, Re greater than 4 × 104 was necessary to minimize scale effects caused by viscosity in flows in the spillway channel and stilling basin (with baffle blocks). The limiting criteria aligned closely with existing literature. This study offers valuable insights for practical applications in hydraulic engineering in the future.
基金funded by“Programa de Ayuda para la Puesta en Marcha o Mantenimiento de Líneas de Investigación Competitivas(LANZADERA)2025”of the Technical University of Cartagena.This study was also carried out in collaboration with the Association for the Integration of the Disabled in the Comarca del Mar Menor(AIDEMAR,collaboration protocol UPCT-AIDEMAR)Ophthalmology team at the“Hospital General Universitario Santa Lucia”in Cartagena for their support during this research.
文摘This research establishes a methodological framework for generating geometrically accurate 3D representations of human crystalline lenses through scanning technologies and digital reconstruction. Multiple scanning systems were evaluated to identify optimal approaches for point cloud processing and subsequent development of parameterized solid models, facilitating comprehensive morpho-geometric characterization. Experimental work was performed at the 3D Scanning Laboratory of SEDIC (Industrial Design and Scientific Calculation Service) at the Technical University of Cartagena, employing five distinct scanner types based on structured light, laser, and infrared technologies. Test specimens—including preliminary calibration using a lentil and biological analysis of a human crystalline lens—were digitized under rigorously controlled environmental conditions. Acquired point clouds underwent processing in Rhinoceros software to produce digital surface meshes, which were subsequently converted into solid CAD models via SolidWorks. Model fidelity and biomedical relevance were assessed through quantification of geometric and physical properties. Scanner performance varied significantly in reconstruction precision and resolution, with structured blue light systems (e.g., Artec SPIDER) exhibiting superior capability for capturing lens surface topography compared to infrared or white light alternatives. Resultant models enabled accurate dimensional analysis of clinically relevant parameters including volumetric and surface area measurements. Technology-specific advantages and constraints were rigorously cataloged relative to sample attributes. Findings indicate that structured blue light scanning provides the most effective foundation for crystalline lens digitization and modeling. The presented methodological approach not only ensures high-fidelity solid model generation but also demonstrates translational potential in medical domains, from custom intraocular lens design to refinement of ophthalmic therapeutic interventions.
基金supports from National Natural Science Foundation of China(Grant No.62205117,52275429)National Key Research and Development Program of China(Grant No.2021YFF0502700)+2 种基金Young Elite Scientists Sponsorship Program by CAST(Grant No.2022QNRC001)West Light Foundation of the Chinese Academy of Sciences(Grant No.xbzg-zdsys-202206)Hubei Natural Science Foundation Innovative Research Group Project(2024AFA025).
文摘The popularity of deep learning has boosted computer-generated holography(CGH)as a vibrant research field,particularly physics-driven unsupervised learning.Nevertheless,present unsupervised CGH models have not yet explored the potential of generating full-color 3D holograms through a unified framework.In this study,we propose a lightweight multiwavelength network model capable of high-fidelity and efficient full-color hologram generation in both 2D and 3D display,called IncepHoloRGB.The high-speed simultaneous generation of RGB holograms at 191 frames per second(FPS)is based on Inception sampling blocks and multi-wavelength propagation module integrated with depth-traced superimposition,achieving an average structural similarity(SSIM)of 0.88 and peak signal-to-noise ratio(PSNR)of 29.00 on the DIV2K test set in reconstruction.Full-color reconstruction of numerical simulations and optical experiments shows that IncepHoloRGB is versatile to diverse scenarios and can obtain authentic full-color holographic 3D display within a unified network model,paving the way for applications towards real-time dynamic naked-eye 3D display,virtual and augmented reality(VR/AR)systems.
基金funded by the Ministry of Science,Technological Development and Innovation of the Republic of Serbia(grant numbers 451-03-136/2025-03/200007 and 451-03-136/2025-03/200042).
文摘Anticancer drug resistance remains a major challenge in cancer treatment hindering the efficacy of chemotherapy and targeted therapies.Conventional two-dimensional(2D)cell cultures cannot replicate the complexity of the in vivo tumor microenvironment(TME),limiting their utility for drug resistance research.Therefore,three-dimensional(3D)tumor models have proven to be a promising alternative for investigating chemoresistance mechanisms.In this review,various cancer 3D models,including spheroids,organoids,scaffold-based models,and bioprinted models,are comprehensively evaluated with a focus on their application in drug resistance studies.We discuss the materials,properties,and advantages of each model,highlighting their ability to better mimic the TME and represent complex mechanisms of drug resistance such as epithelial-mesenchymal transition(EMT),drug efflux,and tumor-stroma interactions.Furthermore,we investigate the limitations of these models,including scalability,reproducibility and technical challenges,as well as their potential therapeutic impact on personalized medicine.Through a thorough comparison of model performance,we provide insights into the strengths and weaknesses of each approach and offer guidance for model selection based on specific research needs.
基金funding support from the National Natural Science Foundation of China(Grant Nos.42177136 and 52309126).
文摘The excavation of deep tunnels crossing faults is highly prone to triggering rockburst disasters,which has become a significant engineering issue.In this study,taking the fault-slip rockbursts from a deep tunnel in southwestern China as the engineering prototype,large-scale three-dimensional(3D)physical model tests were conducted on a 3D-printed complex geological model containing two faults.Based on the selfdeveloped 3D loading system and excavation device,the macroscopic failure of fault-slip rockbursts was simulated indoors.The stress,strain,and fracturing characteristics of the surrounding rock near the two faults were systematically evaluated during excavation and multistage loading.The test results effectively revealed the evolution and triggering mechanism of fault-slip rockbursts.After the excavation of a highstress tunnel,stress readjustment occurred.Owing to the presence of these two faults,stress continued to accumulate in the rock mass between them,leading to the accumulation of fractures.When the shear stress on a fault surface exceeded its shear strength,sudden fault slip and dislocation occurred,thus triggering rockbursts.Rockbursts occurred twice in the vault between the two faults,showing obvious intermittent characteristics.The rockburst pit was controlled by two faults.When the faults remained stable,tensile failure predominated in the surrounding rock.However,when the fault slip was triggered,shear failure in the surrounding rock increased.These findings provide valuable insights for enhancing the comprehension of fault-slip rockbursts.
基金supported by the National Natural Science Foundation of China[51974058,52371005,52022017,51927801]the Fundamental Research Funds for the Central Universities(DUT23YG104).
文摘In this work,the microstructure evolution and mechanical behavior of extruded SiC/ZA63 Mg matrix composites are investigated via combined experimental study and three-dimensionalfinite element modelling(3D FEM)based on the actual 3D microstructure achieved by synchrotron tomography.The results show that the average grain size of composite increases from 0.57μm of 8μm-SiC/ZA63 to 8.73μm of 50μm-SiC/ZA63.The type of texture transforms from the typicalfiber texture in 8μm-SiC/ZA63 to intense basal texture in 50μm-SiC/ZA63 composite and the intensity of texture increases sharply with increase of SiC particle size.The dynamic recrystallization(DRX)mechanism is also changed with increasing SiC particle size.Experimental and simulation results verify that the strength and elongation both decrease with increase of SiC particle size.The 8μm-SiC/ZA63 composite possesses the optimal mechanical property with yield strength(YS)of 383 MPa,ultimate tensile strength(UTS)of 424 MPa and elongation of 6.3%.The outstanding mechanical property is attributed to the ultrafine grain size,high-density precipitates and dislocation,good loading transfer effect and the interface bonding between SiC and matrix,as well as the weakened basal texture.The simulation results reveal that the micro-cracks tend to initiate at the interface between SiC and matrix,and then propagate along the interface between particle and Mg matrix or at the high strain and stress regions,and further connect with other micro-cracks.The main fracture mechanism in 8μm-SiC/ZA63 composite is ductile damage of matrix and interfacial debonding.With the increase of particle size,interface strength and particle strength decrease,and interface debonding and particle rupture become the main fracture mechanism in the 30μm-and 50μm-SiC/ZA63 composites.
基金supported by the fundings from 2024 Young Talents Program for Science and Technology Thinking Tanks(No.XMSB20240711041)2024 Student Research Program on Dynamic Simulation and Force-on-Force Exercise of Nuclear Security in 3D Interactive Environment Using Reinforcement Learning,Natural Science Foundation of Top Talent of SZTU(No.GDRC202407)+2 种基金Shenzhen Science and Technology Program(No.KCXFZ20240903092603005)Shenzhen Science and Technology Program(No.JCYJ20241202124703004)Shenzhen Science and Technology Program(No.KJZD20230923114117032)。
文摘Vulnerability assessment is a systematic process to identify security gaps in the design and evaluation of physical protection systems.Adversarial path planning is a widely used method for identifying potential vulnerabilities and threats to the security and resilience of critical infrastructures.However,achieving efficient path optimization in complex large-scale three-dimensional(3D)scenes remains a significant challenge for vulnerability assessment.This paper introduces a novel A^(*)-algorithmic framework for 3D security modeling and vulnerability assessment.Within this framework,the 3D facility models were first developed in 3ds Max and then incorporated into Unity for A^(*)heuristic pathfinding.The A^(*)-heuristic pathfinding algorithm was implemented with a geometric probability model to refine the detection and distance fields and achieve a rational approximation of the cost to reach the goal.An admissible heuristic is ensured by incorporating the minimum probability of detection(P_(D)^(min))and diagonal distance to estimate the heuristic function.The 3D A^(*)heuristic search was demonstrated using a hypothetical laboratory facility,where a comparison was also carried out between the A^(*)and Dijkstra algorithms for optimal path identification.Comparative results indicate that the proposed A^(*)-heuristic algorithm effectively identifies the most vulnerable adversarial pathfinding with high efficiency.Finally,the paper discusses hidden phenomena and open issues in efficient 3D pathfinding for security applications.
基金supported by the Key Research and DevelopmentPlan in Shanxi Province of China(No.201803D421045)the Natural Science Foundation of Shanxi Province(No.2021-0302-123104)。
文摘This study introduces a novel method for reconstructing the 3D model of aluminum foam using cross-sectional sequence images.Combining precision milling and image acquisition,high-qual-ity cross-sectional images are obtained.Pore structures are segmented by the U-shaped network(U-Net)neural network integrated with the Canny edge detection operator,ensuring accurate pore delineation and edge extraction.The trained U-Net achieves 98.55%accuracy.The 2D data are superimposed and processed into 3D point clouds,enabling reconstruction of the pore structure and aluminum skeleton.Analysis of pore 01 shows the cross-sectional area initially increases,and then decreases with milling depth,with a uniform point distribution of 40 per layer.The reconstructed model exhibits a porosity of 77.5%,with section overlap rates between the 2D pore segmentation and the reconstructed model exceeding 96%,confirming high fidelity.Equivalent sphere diameters decrease with size,averaging 1.95 mm.Compression simulations reveal that the stress-strain curve of the 3D reconstruction model of aluminum foam exhibits fluctuations,and the stresses in the reconstruction model concentrate on thin cell walls,leading to localized deformations.This method accurately restores the aluminum foam’s complex internal structure,improving reconstruction preci-sion and simulation reliability.The approach offers a cost-efficient,high-precision technique for optimizing material performance in engineering applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.41941017 and 42177139)Graduate Innovation Fund of Jilin University(Grant No.2024CX099)。
文摘The spatial distribution of discontinuities and the size of rock blocks are the key indicators for rock mass quality evaluation and rockfall risk assessment.Traditional manual measurement is often dangerous or unreachable at some high-steep rock slopes.In contrast,unmanned aerial vehicle(UAV)photogrammetry is not limited by terrain conditions,and can efficiently collect high-precision three-dimensional(3D)point clouds of rock masses through all-round and multiangle photography for rock mass characterization.In this paper,a new method based on a 3D point cloud is proposed for discontinuity identification and refined rock block modeling.The method is based on four steps:(1)Establish a point cloud spatial topology,and calculate the point cloud normal vector and average point spacing based on several machine learning algorithms;(2)Extract discontinuities using the density-based spatial clustering of applications with noise(DBSCAN)algorithm and fit the discontinuity plane by combining principal component analysis(PCA)with the natural breaks(NB)method;(3)Propose a method of inserting points in the line segment to generate an embedded discontinuity point cloud;and(4)Adopt a Poisson reconstruction method for refined rock block modeling.The proposed method was applied to an outcrop of an ultrahigh steep rock slope and compared with the results of previous studies and manual surveys.The results show that the method can eliminate the influence of discontinuity undulations on the orientation measurement and describe the local concave-convex characteristics on the modeling of rock blocks.The calculation results are accurate and reliable,which can meet the practical requirements of engineering.
文摘This research pioneers the integration of geographic information systems(GIS)and 3D modeling within a virtual reality(VR)framework to assess the viability and planning of a 20 MW hybrid wind-solarphotovoltaic(PV)system connected to the local grid.The study focuses on Dakhla,Morocco,a region with vast untapped renewable energy potential.By leveraging GIS,we are innovatively analyzing geographical and environmental factors that influence optimal site selection and system design.The incorporation of VR technologies offers an unprecedented level of realism and immersion,allowing stakeholders to virtually experience the project's impact and design in a dynamic,interactive environment.This novel methodology includes extensive data collection,advanced modeling,and simulations,ensuring that the hybrid system is precisely tailored to the unique climatic and environmental conditions of Dakhla.Our analysis reveals that the region possesses a photovoltaic solar potential of approximately2400 k Wh/m^(2) per year,with an average annual wind power density of about 434 W/m^(2) at an 80-meter hub height.Productivity simulations indicate that the 20 MW hybrid system could generate approximately 60 GWh of energy per year and 1369 GWh over its 25-year lifespan.To validate these findings,we employed the System Advisor Model(SAM)software and the Global Solar Photovoltaic Atlas platform.This comprehensive and interdisciplinary approach not only provides a robust assessment of the system's feasibility but also offers valuable insights into its potential socio-economic and environmental impact.
