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Three-dimensional cooperative guidance law with practical predefined-time approach angle and time-to-go convergence 认领 引用 被引量：1
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作者 Zihao WU Wei FENG +3 位作者 Xiaofeng ZHANG Wenxing FU Zhang REN Tuo HAN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第5期530-546,共17页
This paper presents a Three-Dimensional(3D)cooperative guidance law with Practical Predefined-Time(PPT)convergence for multiple missiles considering approach angle(terminal lineof-sight)and simultaneous arrival constr... This paper presents a Three-Dimensional(3D)cooperative guidance law with Practical Predefined-Time(PPT)convergence for multiple missiles considering approach angle(terminal lineof-sight)and simultaneous arrival constraints.To achieve a salvo attack against a maneuvering target from various directions,the guidance problem is tackled by addressing two critical factors:ensuring that the time-of-arrival is consistent and that the desired approach angles can be met.Considering the short duration of the homing guidance process,the convergence with predefined time for guidance states(especially the approach angle and time-to-go)is factored in.First,for the simultaneous arrival,a PPT guidance law is developed,which can meet the same time-to-go convergence rate in the Line-of-Sight(LOS)direction.Then,in the normal LOS direction,a 3D PPT guidance law is presented considering the approach angle constraint so that the desired approach angles can be reached within a user-designed time.The time-based generator technique is employed in the proposed PPT Cooperative Guidance Law(PPTCGL)to avoid the time-varying gain singularity issue.Notably,this technique can allow the convergence time to be preset in advance,independent of initial system conditions and tuning parameters.Additionally,to avoid excessive gain and improve the robustness of guidance law,a PPT disturbance observer is designed against uncertainties and target maneuvers so that the guidance system perturbation can be compensated in real time.It is userfriendly that the convergence of disturbance estimation can be met with a flexible pre-setting time before achieving the terminal guidance constraints.Finally,extensive numerical simulations are conducted to verify the effectiveness and robustness of the proposed PPTCGL in both the nominal cases and the Monte Carlo test. 展开更多
关键词 Approach angle constraint Cooperative guidance law Maneuvering target Practical predefined-time consensus Three-dimensional guidance model
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Intelligent prediction of deep rock strength based on modified three-dimensional Hoek-Brown criterion 认领 引用 被引量：1
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作者 Jiaxin Wang Hongru Jiang +4 位作者 Shunchuan Wu Shihuai Zhang Chaoqun Chu Xiaoping Zhang Yingming Xiao 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2026年第7期2454-2472,I0020-I0030,共19页
To study the deep rock strength,this paper proposes a five-parameter deviatoric function to modify the deviatoric function of the Hoek-Brown(HB)criterion introduces an intelligent optimization algorithm(IOA)to determi... To study the deep rock strength,this paper proposes a five-parameter deviatoric function to modify the deviatoric function of the Hoek-Brown(HB)criterion introduces an intelligent optimization algorithm(IOA)to determine the material parameters,thereby constructing a modified three-dimensional(3D)HB criterion,namely MMCHB criterion.The MMCHB criterion avoids the defects of the traditional HB criterion,which neither considers the Intermediate principal stress(IPS)nor meets the smoothness requirement,and overcomes the shortcomings of parameter determination based on conventional methods,which can lead to a single deviatoric plane envelope shape.This modified criterion can be degenerated into the HB criterion under triaxial compression and tension.The proposed criterion is verified using true triaxial test data for six types of intact rock,and the modified 3D HB criteria are selected for comparative study.The results show that the proposed criterion under the IOA has the best prediction error for the six rock types,ranging from 1.6636% to 3.4023%.Overall,the MMCHB criterion outperforms the existing modified 3D HB criteria in prediction.Based on the proposed MMCHB criterion,an intelligent prediction system is developed,which provides a new approach for intelligent prediction of deep rock strength and dynamic construction of rock material parameters. 展开更多
关键词 rock strength Hoek-Brown criterion Intermediate principal stress intelligent optimization algorithm intelligent predictionsystem
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Research on dynamic three-dimensional terrain correction methods of quantitative inversion for airborne gamma-ray spectrometer 认领 引用
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作者 He-Xi Wu Wei-Cheng Li +6 位作者 Rui Qiu Chao Xiong Yi-Ming Lyu Yi-Qiang Xing De-Hao Zhang Zong-Shuo Tao Yang Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第5期199-214,共16页
Aerial surveys are dynamic and continuous processes,and there are different height distributions of the ground in the measurement area,which leads to problems such as overlapping measurement areas and inaccurate altit... Aerial surveys are dynamic and continuous processes,and there are different height distributions of the ground in the measurement area,which leads to problems such as overlapping measurement areas and inaccurate altitude correction during the survey process.Commonly used terrain correction methods are based on the concept of finite elementization of ground surface radioactive sources,using GPS coordinates,radar altitude,and ground elevation distribution information from aerial surveys,combined with the sourceless efficiency calibration method to construct a response matrix,which is then inverted for surface nuclide content.However,most of the sourceless efficiency calibration methods used are numerical calculations that consider the body detector as a point detector and do not consider the changes in intrinsic detection efficiency under different incident directions of gamma rays.Therefore,when the altitude of the measurement area varies significantly or the flight altitude of the aerial survey is relatively low,such sourceless efficiency calibration method calculations tend to have a large bias,which affects the accuracy of the terrain correction.To address the above problems,this study employs a novel sourceless efficiency calibration method based on the Boolean operation of the ray deposition process and simplifies the traditional body source measurement model to a surface source measurement model to achieve fast and accurate efficiency calibration.Then,through the discretization of the measurement process,the static measurement process is superposed as equivalent to the dynamic measurement process,and the dynamic measurement response matrix is built and optimized based on the calibration method.Finally,the PSO-MLEM algorithm was used to solve the dynamic measurement response matrix to achieve dynamic terrain correction of aerial survey data.Analysis of the Baiyun'ebo test area revealed that,after applying dynamic terrain correction,the inverted anomalies in uranium(eU),thorium(eTh),and potassium(K)concentrations were closer to ground measurements(within 5.72%-30.79%)and exhibited clearer anomaly boundaries compared to traditional height-based corrections.However,owing to the inherent statistical fluctuations and characteristics of matrix inversion,higher measurement values tend to absorb lower ones,potentially enlarging the anomalous regions.Nevertheless,the highanomaly regions after inversion largely coincided with the ground truth validation,demonstrating that the proposed method can effectively correct airborne gamma spectrometry data. 展开更多
关键词 Airborne gamma-ray spectrum Dynamic three-dimensional Terrain correction
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Characteristics of three-dimensional oceanic eddy in the Southern Ocean from 2021 to 2023 认领 引用
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作者 Tao Jiang Weizeng Shao +3 位作者 Yuyi Hu Xingwei Jiang Qingping Zou Yongliang Wei 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2026年第4期1-16,共16页
This study explores the three-dimensional(3-D)characteristics of oceanic eddies in the Southern Ocean from 2021 to 2023.Copernicus Marine Environment Monitoring Service(CMEMS)GLORYS12V1 product,which provides daily cu... This study explores the three-dimensional(3-D)characteristics of oceanic eddies in the Southern Ocean from 2021 to 2023.Copernicus Marine Environment Monitoring Service(CMEMS)GLORYS12V1 product,which provides daily current field data at a(1/12)°grid resolution,is used to identify eddies with radii>10 km.Additionally,the daily sea level anomaly product from Haiyang-2(HY-2)altimeters is used to detect mesoscale eddies with radii>40 km.GLORYS12V1 detects over ten times more surface eddies than HY-2,likely due to its higher spatial and temporal resolution,which allows better identification of smaller-scale features.Both eddy radius and eddy kinetic energy(EKE)differences between layers decrease with depth.At 0.5 m,EKE is lower than at 300–600 m,where it stabilizes.Over 90%of eddies at these depths show center deflection angles under 3°,defined as the angular offset between eddy centers in adjacent layers relative to the vertical(0°)axis.In a 3-D eddy,the center may shift with depth due to physical processes,causing non-zero center deflection angles between layers.Below 300 m,eddy radius differences are more frequently under 20 km than in the upper 0.5–300 m,where baroclinic instability amplifies,and barotropic instability suppresses cross-layer variability.The influence of both instabilities weakens with depth.In the upper ocean(0.5–300 m),baroclinic instability increases the angular offsets between eddy centers.In contrast,barotropic instability reduces these offsets.At 300–600 m,both promote better vertical alignment,indicating greater structural stability.Overall,this study enhances the understanding of the vertical structure and dynamics of oceanic eddies in the Southern Ocean. 展开更多
关键词 three-dimensional characteristics oceanic eddy Southern Ocean
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Data-and knowledge-driven three-dimensional geological reconstruction method for tunnel engineering 认领 引用
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作者 Qiming Li Qian Fang +2 位作者 Jun Wang Gan Wang Peipei Shang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第6期4318-4336,共19页
The creation of a three-dimensional(3D)geological model plays a crucial guiding role in engineering.However,in practice,due to the sparsity of boreholes and the invisibility of strata,accurately reconstructing a 3D ge... The creation of a three-dimensional(3D)geological model plays a crucial guiding role in engineering.However,in practice,due to the sparsity of boreholes and the invisibility of strata,accurately reconstructing a 3D geological model has always been a challenging task.In this study,a data-and knowledge-driven 3D geological reconstruction method is proposed,where the Inverse Distance Weighting(IDW)method is integrated with computer vision techniques to improve the accuracy and reliability of geological modeling.The reconstruction of the geological model is realized by the reconstruction of continuous cross-sections in one direction.The reconstruction method integrates two deep learning models:a repair model that learns stratigraphic relationships from borehole data to reconstruct cross-sections,and an interpolation model that predicts intermediate sections by capturing stratigraphic distribution and variation patterns.The comparison with the IDW method and the ordinary kriging method on the virtual data verifies that the proposed method can capture the spatial distribution characteristics of the strata.An engineering example proves that the proposed method can be successfully applied to complex stratum modeling.The proposed method enhances and facilitates intuitive observation of both the reconstructed results and their uncertainties.The proposed method can provide guidance for underground engineering construction sites and contribute to their digital transformation. 展开更多
关键词 Three-dimensional geological modeling Machine learning Borehole data Stratigraphic uncertainty Voxel model
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Three-dimensional full-scale neutronics/thermal-hydraulics/mechanics coupling analysis-based structural assessment of helium-cooled ceramic breeder blanket for fusion reactor 认领 引用
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作者 Qiang Lian Kui Zhang +6 位作者 Shan-Shan Bu Liang-Ming Pan Wen-Xi Tian Sui-Zheng Qiu Guang-Hui Su Xing-Hua Wu Xiao-Yu Wang 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2026年第6期178-195,共18页
To accelerate the development and utilization of fusion energy,the China Fusion Engineering Test Reactor(CFETR)has been proposed as a bridge between the International Thermonuclear Experimental Reactor and demonstrati... To accelerate the development and utilization of fusion energy,the China Fusion Engineering Test Reactor(CFETR)has been proposed as a bridge between the International Thermonuclear Experimental Reactor and demonstration fusion reactors.The primary objective of the CFETR is to achieve fusion energy transformation and tritium self-sufficiency,which is realized through the function of the blanket.In this study,a neutronicshermal-hydraulics/mechanics coupling method is developed and applied to a helium-cooled ceramic breeder(HCCB)blanket,which is one of the two blanket candidates for the CFETR.A three-dimensional full-scale model is utilized in the coupling analysis to obtain the distributions of the neutronic,thermal-hydraulic,and mechanical parameters.A structural assessment of the CFETR HCCB blanket is then conducted considering steady-state conditions and two transient scenarios.The results demonstrate that following optimization of the blanket structure,the maximum temperatures of the different components remain below the safety limit of the corresponding materials.The structural assessment indicates that the blanket maintains its structural integrity under steady-state conditions.However,immediately after an in-box loss-of-coolant accident,structural failure owing to stress concentration may occur.Additionally,in the early stage of a loss-of-flow accident,the stress at the joint point between the cooling plate and cap exceeds the allowable stress of the material,potentially leading to structural failure within 17 s if no protective response is implemented.These findings provide comprehensive insights into the performance and safety of the CFETR HCCB blanket design. 展开更多
关键词 Structural assessment Fusion blanket Three-dimensional full-scale model Coupling analysis CFETR
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Investigation on three-dimensional unsteady flow characteristics during TBCC inlet mode transition using fast-responding PSP 认领 引用
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作者 Liang CHEN Yue ZHANG +4 位作者 Xu LIU Huijun TAN Haicheng ZHU Mingchi PANG Ziyun WANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第7期231-245,共15页
This study investigates the three-dimensional unsteady flow characteristics during the mode transition process of a Turbine-Based Combined Cycle(TBCC)inlet under side-wall constraints.The research focuses on an over-u... This study investigates the three-dimensional unsteady flow characteristics during the mode transition process of a Turbine-Based Combined Cycle(TBCC)inlet under side-wall constraints.The research focuses on an over-under TBCC inlet with a design transition Mach number of 3.5 and a transition speed of 1.65(°)/s,in a wind tunnel with incoming flow Mach number 2.9.A novel approach combining fast-responding Pres sure-Sensitive Paint(PSP)measurement technique with high-speed schlieren imaging and dynamic pressure transducers was employed to achieve the three-dimensional dynamic measurement of shock-dominated flow evolution during mode transition.The Proper Orthogonal Decomposition(POD)method was utilized to reveal the threedimensional dynamic mechanisms of two typical unsteady flows following the high-speed duct unstart.When the duct is fully open,the flow separation caused by throat congestion exhibits significant span wise asymmetry under side-wall constraints.The phase difference between separation vortices in the central and corner regions induces a low-frequency oscillation of the separation shock,predominantly characterized by span wise fluctuations.Conversely,in the hysteresis state,the corner effect is substantially diminished,leading to increased spanwise flow uniformity.The separation shock oscillation converts to a streamwise motion mode,primarily governed by the selfexcited oscillation of the downstream separation bubble and the shoulder shock train.This study provides comprehensive clarification of the multi-scale flow coupling mechanism during the TBCC inlet mode transition process from a three-dimensional spatiotemporal evolution perspective.The findings offer crucial theoretical support for the dynamic stability control of hypersonic combined cycle inlets. 展开更多
关键词 Fast-responding PSP Hysteresis characteristics Mode transition Over-under TBCC inlet Three-dimensional unsteady flows
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The three-dimensional meshfree numerical manifold method based on parallel computing 认领 引用
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作者 Keqin Zhang Wei Wu +2 位作者 Danfeng Zhang Yanfei Kang Hehua Zhu 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第2期360-371,共12页
The numerical manifold method,extensively utilized in numerical computations,faces significant challenges in generating complex manifold elements,particularly for three-dimensional applications.To overcome this challe... The numerical manifold method,extensively utilized in numerical computations,faces significant challenges in generating complex manifold elements,particularly for three-dimensional applications.To overcome this challenge,the meshfree numerical manifold method is developed by integrating the moving least-squares method into the numerical manifold method,effectively bypassing the need for meshing complex geometric objects.However,the implementation of the moving least-squares method introduces computational efficiency issues.To mitigate these,parallel computing methods have been incorporated,resulting in a tenfold increase in the speed of assembling the stiffness matrix with central processing unit parallelism,and a twentyfold increase with graphics processing unit parallelism.The static mechanical system equations for the meshfree numerical manifold method are derived using the Galerkin method.The method’s effectiveness and accuracy are then validated through a series of numerical experiments.The experiments demonstrated that the meshfree numerical manifold method achieves a high precision with minimal nodes and integration points.Additionally,positioning nodes outside the domain significantly improves computational accuracy at the boundaries. 展开更多
关键词 Meshfree numerical manifold method Three-dimensional computation Parallel computation Elastostatics Moving least-squares
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Dynamic conditions and processes of three-dimensional accumulation of Sinian-Permian natural gas in Penglai gas area,central Sichuan Basin,SW China 认领 引用
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作者 LUO Bing ZHANG Benjian +8 位作者 ZHOU Gang WU Luya YAN Wei ZHANG Baoshou ZHANG Xihua ZHONG Yuan MA Kui LUO Xiaorong LI Yishu 《Petroleum Exploration and Development》 SCIE 2026年第2期327-342,共16页
Considering the complexities of gas-water relationships in the gas reservoirs,unclear natural gas distribution and difficult exploration expansion of the Sinian–Permian natural gas in the Penglai gas area of the cent... Considering the complexities of gas-water relationships in the gas reservoirs,unclear natural gas distribution and difficult exploration expansion of the Sinian–Permian natural gas in the Penglai gas area of the central Sichuan Basin,this study investigates the gas source,charging processes and enrichment patterns of gas reservoirs based on reservoir characterization,natural gas geochemical analysis,reservoir testing,well logging-seismic data interpretation,as well as basin modeling and dynamic analysis.The results are obtained in three aspects.First,four sets of highly efficient source rocks are developed beneath the salt of the Triassic Jialingjiang Formation,dominated by the Cambrian source rocks.The reservoirs exhibit strong heterogeneity,with six sets of effective reservoirs being isolated from each other yet dynamically connected.Multi-stage strike-slip fault-related fault-fracture-cavity-unconformity systems constitute the hydrocarbon migration network.Second,overpressure generated by hydrocarbon generation in the Cambrian source rocks drove bidirectional hydrocarbon expulsion from the source kitchen.Multiple sources,including cracked gas from paleo-oil reservoirs and residual hydrocarbons within source rocks,contributed to the hydrocarbon supply.The Sinian–Permian system underwent multiple dynamic hydrocarbon accumulation processes,resulting in the formation of extensive“sweet spots”within multi-layered heterogeneous reservoirs,which were subsequently modified by late-stage gas adjustments to their current form.Third,a three-dimensional accumulation model for deep marine natural gas is established,with multi-source hydrocarbon supply,three-dimensional migration,multi-stage accumulation,dynamic adjustment and lithology-controlled distribution.Large-scale reservoirs within positive structural settings,late-stage structurally stable areas,and slope structures are identified as favorable plays for gas exploration. 展开更多
关键词 Sinian Cambrian Permian natural gas dynamic condition three-dimensional accumulation Penglai gas area Sichuan Basin
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Three-dimensional time-dependent fracturing model for hard rock involving stress-induced anisotropic cracks 认领 引用
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作者 Chen Fan Xia-Ting Feng +2 位作者 Jun Zhao Chengxiang Yang Mengfei Jiang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第5期3333-3347,共15页
The time-dependent failure of surrounding rock in deep engineering is essentially controlled by the evolution of microcracks,with the pre-existing fracturing state induced by excavation playing a crucial role in the s... The time-dependent failure of surrounding rock in deep engineering is essentially controlled by the evolution of microcracks,with the pre-existing fracturing state induced by excavation playing a crucial role in the subsequent time-dependent fracturing process.From the perspective of microcrack development,it is a continuous,dynamic process.Therefore,taking the microcrack propagation process as the fundamental principle,this paper proposes a novel three-dimensional(3D)time-dependent model for hard rock that can depict the entire fracturing process within a unified theoretical framework.This developed model discards the traditional tri-modal partition method based on deformation,and instead adopts an analysis approach centred on time-dependent tensile and shear fracturing.The results show that the time-dependent deformation of hard rock is the macroscopic manifestation of the progressive evolution of microcracks over time.Under true triaxial stress,the growth tendency of cracks in hard rock is orientation-dependent throughout the entire loading process.This developed model provides a mechanical explanation for key time-dependent fracture characteristics observed in true triaxial creep tests,including the anisotropy of time-dependent deformation and the preferred orientation of macroscopic failure plane,and provides a novel framework for elucidating the time-dependent failure process of hard rock. 展开更多
关键词 Three-dimensional(3D)time-dependent model Continuous fracturing process Microcrack development Time-dependent anisotropic fracturing True triaxial stress
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Early gastric dilation after laparoscopic sleeve gastrectomy:Insights from a three-dimensional computed tomography reconstruction study 认领 引用
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作者 Zhao Li Wen-Zhi Wu +3 位作者 Yi Song Zhao-Peng Li Dong Guo Yu Li 《World Journal of Gastrointestinal Surgery》 SCIE 2026年第1期111-122,共12页
BACKGROUND Laparoscopic sleeve gastrectomy(LSG)is currently the most commonly performed bariatric surgery owing to its effective weight loss and low complication rates.Nonetheless,some patients experience weight regai... BACKGROUND Laparoscopic sleeve gastrectomy(LSG)is currently the most commonly performed bariatric surgery owing to its effective weight loss and low complication rates.Nonetheless,some patients experience weight regain or insufficient weight loss due to residual gastric dilation,the factors of which remain unclear.AIM To evaluate changes in residual gastric volume after LSG using three-dimensional computed tomography reconstruction and to investigate the factors contributing to gastric dilation.METHODS This retrospective study included 50 patients who underwent LSG.Preoperative clinical and laboratory data were obtained.The residual gastric volume was measured using three-dimensional computed tomography reconstruction at 1 month and 3 months postoperatively.The total sleeve volume,tube volume,antral volume,and tube-to-antral volume ratio were also assessed.Resected gastric volume and staple line length were measured during surgery.Weight metrics and laboratory indices were recorded at 1 month,3 months,6 months,and 12 months postoperatively.The Eating Behavior After Bariatric Surgery Questionnaire and Gastroesophageal Reflux Disease Questionnaire(GERD-Q)were used to assess the dietary behavior of patients after LSG.Correlation between the degree of residual gastric dilation and percent total weight loss(%TWL)at 12 months postoperatively was analyzed.Univariate and multivariate correlation analyses were conducted to identify risk factors for residual gastric dilation after LSG.RESULTS The 50 included patients had a mean preoperative body mass index of 42.27±7.19 kg/m2 and average%TWL of 34%±7%at 1 year after LSG.At 1 month after LSG,the mean tube volume,antral volume,and total sleeve volume were 45.93±16.75 mL,115.85±44.92 mL,and 161.77±55.37 mL,respectively.At 3 months after LSG,the residual gastric volume showed statistically significant dilation(average dilation degree:13.50%±17.35%).%TWL at 1 year significantly correlated with residual gastric dilation(P<0.05).Univariate and multivariate linear regression analyses revealed that preoperative type 2 diabetes,residual gastric volume at 1 month after LSG,and GERD-Q scores were independent risk factors influencing the degree of residual gastric dilation.CONCLUSION In conclusion,residual gastric dilation after LSG significantly affected the efficacy of weight loss.Preoperative type 2 diabetes,residual gastric volume at 1 month after LSG,and GERD-Q scores were independent risk factors affecting the degree of residual gastric dilation. 展开更多
关键词 Laparoscopic sleeve gastrectomy Residual gastric dilation Three-dimensional computed tomography reconstruction Weight loss efficacy Residual gastric volume Bariatric surgery
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Mechanisms of efficient three-dimensional fracture network construction in deep shale reservoirs via methane multistage explosive fracturing 认领 引用
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作者 Yabo Chai Ning Luo +6 位作者 Jianan Zhou Yucheng Wei Hu Zhang Chen Lin Guangrui Ma Cheng Zhai Yu Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第4期2831-2858,共28页
Methane in situ multistage explosive fracturing(MISMEF)presents a promising technique for enhancing complex fracture networks in deep,low-permeability shale reservoirs.This study employed highfidelity3D simulations,in... Methane in situ multistage explosive fracturing(MISMEF)presents a promising technique for enhancing complex fracture networks in deep,low-permeability shale reservoirs.This study employed highfidelity3D simulations,integrating a characteristic methane–oxygen explosion load model with dynamic relaxation and full-restart methods,to elucidate the coupled interactions between explosive loading and in situ stress.A damage-based zoning approach was developed to quantify fracture characteristics,leading to the proposal of a novel dimensionless evaluation index,Fmef.Results showed that in situ stress predominantly suppressed longitudinal fracture growth,while multistage loading effectively enhanced both lateral and longitudinal propagation following a"delayed initiation–accelerated propagation"pattern.Fracture volume exhibited nonlinear amplificationwith increasing stages,and the continuous increase in fractal dimension suggested improved network connectivity.Energy redistribution driven by the coupled effects of in situ stress and staged loading promoted complex network formation near the wellbore,with MISMEF progressively reducing fracture thresholds through rock mass weakening.Fmef analysis confirmedsignificantimprovement in fracture network quality across all stress conditions,particularly under medium to high in situ stress.This work provides critical mechanistic insights and a theoretical foundation for optimizing MISMEF in deep shale reservoir stimulation. 展开更多
关键词 Methane in situ multistage explosive fracturing(mismef) In situ stress Multistage explosion Three-dimensional fracture network Multidimensional evaluation index
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Sustainable three-dimensional(3D)space optimization in high-density urban areas:Drivers,synergies,and multi-method insights 认领 引用
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作者 KONG Bowen LIU Haoxuan +2 位作者 ZHANG Luyao TANG Chun’an ZOU Baoping 《Regional Sustainability》 CAS CSCD 2026年第3期18-37,共20页
Spatial conflicts in high-density urban areas impede sustainable development,therefore,such cities urgently require sustainable three-dimensional(3D)space optimization.However,existing studies lack a systematic unders... Spatial conflicts in high-density urban areas impede sustainable development,therefore,such cities urgently require sustainable three-dimensional(3D)space optimization.However,existing studies lack a systematic understanding of driving factors and stakeholder differences.This study established an integrated framework using grounded theory analysis of stakeholder interviews,a bibliometric review of academic literature,and system dynamic model and identified five core drivers(regional suitability,human-centred philosophy,innovative design,management capacity,and transformative technology)for sustainable 3D space optimization in high-density urban areas of Zhejiang Province,China.We compared word frequency counts from interviews using co-occurrence analysis in the literature to highlight divergent stakeholder priorities.Word frequency analysis revealed that residents mentioned keywords about human-centred philosophy approximately three times more frequently than experts,highlighting notable divergences in priorities among the stakeholders.Moreover,while co-occurrence analysis identified management capacity as a central theme in scholarly discourse,word frequency analysis ranked it the last among practitioners,underscoring a notable academic–practical difference.Ultimately,based on grounded theory and co-occurrence analyses,we developed a conceptual framework reflecting the relationships between the five core factors and their internal functions.This framework integrates urban research methodologies,providing planners with flexible tools and suggesting the formulation of policies based on actual circumstances,to achieve sustainable development in high-density urban areas. 展开更多
关键词 Three-dimensional(3D)space Co-occurrence analysis Grounded theory(GT)analysis System dynamic model High-density urban areas Zhejiang Province
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Research on three-dimensional attack area based on improved backtracking and ALPS-GP algorithms of air-to-air missile 认领 引用
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作者 ZHANG Haodi WANG Yuhui HE Jiale 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2025年第1期292-310,共19页
In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of t... In the field of calculating the attack area of air-to-air missiles in modern air combat scenarios,the limitations of existing research,including real-time calculation,accuracy efficiency trade-off,and the absence of the three-dimensional attack area model,restrict their practical applications.To address these issues,an improved backtracking algorithm is proposed to improve calculation efficiency.A significant reduction in solution time and maintenance of accuracy in the three-dimensional attack area are achieved by using the proposed algorithm.Furthermore,the age-layered population structure genetic programming(ALPS-GP)algorithm is introduced to determine an analytical polynomial model of the three-dimensional attack area,considering real-time requirements.The accuracy of the polynomial model is enhanced through the coefficient correction using an improved gradient descent algorithm.The study reveals a remarkable combination of high accuracy and efficient real-time computation,with a mean error of 91.89 m using the analytical polynomial model of the three-dimensional attack area solved in just 10-4s,thus meeting the requirements of real-time combat scenarios. 展开更多
关键词 air combat three-dimensional attack area improved backtracking algorithm age-layered population structure genetic programming(ALPS-GP) gradient descent algorithm
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A New Three-Dimensional Voronoi Cell Finite Element Method for Particle-Reinforced Composites 认领 引用 被引量：1
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作者 Huici Dong Ran Guo 《Acta Mechanica Solida Sinica》 SCIE EI CSCD 2026年第1期90-100,共11页
This paper proposes a state-of-the-art three-dimensional Voronoi cell finite element method(3D VCFEM)aimed at investigating the mechanical properties of particle-reinforced composites(PRCs)in space under different mic... This paper proposes a state-of-the-art three-dimensional Voronoi cell finite element method(3D VCFEM)aimed at investigating the mechanical properties of particle-reinforced composites(PRCs)in space under different microstructural properties.Firstly,the modified residual energy generalized function of 3D VCFEM was proposed by applying the hybrid stress element method,and the element format of the 3D Voronoi element was constructed.On this basis,the interaction between the matrix and the inclusions was considered,and the higher-order stress function including the interaction stress term was constructed.Secondly,to solve the difficulty of integrating easily due to the complexity and irregularity of the integration region in space,Delaunay tetrahedra were introduced within the 3D Voronoi element for mesh refinement.It simplified the integration process.Finally,to verify the accuracy and efficiency of the 3D VCFEM model,comparative models of 3D VCFENM and FEM were established for analysis and discussion.The stress field and strain field were compared and analyzed for the first time.An example was also given for the presence of a large number of randomly distributed inclusion particles.The results showed that under the same accuracy,3D VCFEM had the advantages of convenient mesh delineation and high computational efficiency compared with FEM,which provided a new way of thinking to analyze the actual PCRs. 展开更多
关键词 Three-dimensional Voronoi cell finite element method Particle-reinforced composites Integral domain refinement Hybrid stress element method
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FlexCENT:A frequency-flexible CEST imaging network combining frequency offset encoding and three-dimensional U-Net 认领 引用
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作者 Jingyi Yu Mengying Zhu +2 位作者 Yonggui Yang Congbo Cai Shuhui Cai 《Magnetic Resonance Letters》 EI CAS 2026年第2期40-57,共18页
This study proposes a deep learning-based method termed frequency-flexible chemical exchange saturation transfer(CEST)imaging network(FlexCENT),which enables robust CEST quantification across variable frequency offset... This study proposes a deep learning-based method termed frequency-flexible chemical exchange saturation transfer(CEST)imaging network(FlexCENT),which enables robust CEST quantification across variable frequency offset schemes without requiring retraining.FlexCENT integrates frequency offset encoding with a three-dimensional(3D)U-Net to process CEST images and frequency offsets as inputs and predict Lorentzian parameters of the 4-pool model(water,MT,APT,rNOE),including B0 inhomogeneity.By transforming frequency offsets into a continuous spectral feature representation,the frequency offset encoding allows FlexCENT to generalize to unseen frequency offset schemes.Trained on synthetic data generated from the 4-pool Lorentzian model,FlexCENT was validated through numerical simulations,tumor-bearing mouse experiments,and a human brain experiment,alongside comparisons with 4-pool Lorentzian fitting,DeepCEST,and LKAN networks.The results demonstrate that FlexCENT successfully quantified CEST parameters across all experiments,maintaining consistent performance under varying frequency offset conditions without retraining.It exhibited superior noise robustness in numerical simulations and enhanced anatomical delineation in vivo parametric mapping compared to other methods.In conclusion,by combining spectral information with spatial information,FlexCENT provides an efficient,flexible,and robust quantitative approach for CEST imaging.It significantly enhance the quantification capability and clinical potential of CEST imaging. 展开更多
关键词 Chemical exchange saturation transfer Deep learning Three-dimensional U-Net Frequency offset encoding
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Comparison of three-dimensional surgical system versus binocular microscope for implantable Collamer lens implantation:a randomized clinical trial 认领 引用
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作者 An-Ran Xuan Wei Liu +5 位作者 Ya-Ning Zhang Chen Zhang Rui-Bo Yang Yue Huang Hui Liu Shao-Zhen Zhao 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2026年第8期1526-1532,共7页
●AIM:To compare the efficacy,safety,visual outcomes,satisfaction,and comfort of three-dimensional(3D)heads-up visualization system-assisted and conventional microscopic implantable Collamer lens(ICL)surgery.●METHODS... ●AIM:To compare the efficacy,safety,visual outcomes,satisfaction,and comfort of three-dimensional(3D)heads-up visualization system-assisted and conventional microscopic implantable Collamer lens(ICL)surgery.●METHODS:Patients undergoing ICL or Toric ICL(TICL)implantation were enrolled and randomized into two groups:TM group(under a conventional microscope)and 3DM group(under NGENUITY 3D visualization system).Ocular parameters were assessed preoperatively and at 1wk,1,3,and 6mo postoperatively.The duration of key surgical steps and the incidence of complications were recorded.Patient-reported outcomes(dry eye,visual quality,comfort)and surgeon satisfaction were assessed using standardized questionnaires.●RESULTS:The study included 98 eyes of 98 refractive error patients(17 males),50 eyes in TM group(age 27.74±5.65y),and 48 eyes in 3DM group(age 29.20±4.89y).Efficacy,safety,quality of vision(QoV),dry eye symptoms,and patients’satisfaction at 6mo were not significant across the time points of 1wk,1,3 and 6mo.No complication was observed in either group.The 3DM group was associated with a longer main step operation time(P=0.037)but better patient visual comfort(P<0.001).The difference in surgical fluency was not statistically significant(P=0.067).Notably,surgeons reported no delays or discomfort and rated the 3DM system significantly higher in image resolution,range of view,depth perception,color contrast,and postural comfort(all P<0.001).●CONCLUSION:For ICL surgery,the use of the NGENUITY 3D visualization system achieves comparable surgical efficacy,safety,and patient satisfaction to procedures performed under a traditional microscope,while delivering superior intraoperative visual performance and postural comfort for the surgeon.These ergonomic and visual advantages make it a promising tool for enhancing clinical practice and surgical training. 展开更多
关键词 three-dimensional surgical visualization system implantable Collamer lens V4c myopia visual outcome
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Three-dimensional ground motion of coupled basin-mountain topography near a reverse fault:Insights from dynamic rupture source modeling 认领 引用
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作者 DENG Shuai DAI Kaoshan +1 位作者 WU Mengtao ZHAO Jingxuan 《Journal of Mountain Science》 SCIE CSCD 2026年第4期1564-1580,共17页
Understanding the seismic response of complex sites near active reverse faults is crucial for mitigating earthquake-induced risks to infrastructure in geologically dynamic regions.However,existing research predominant... Understanding the seismic response of complex sites near active reverse faults is crucial for mitigating earthquake-induced risks to infrastructure in geologically dynamic regions.However,existing research predominantly focuses on isolated geomorphic units,leaving the seismic behavior of composite topographies under dynamic fault rupture largely unexplored.This study employs a dynamic rupture model and the spectral element method to simulate three-dimensional(3D)ground motion characteristics in environments with coupled basin and mountain topography.The analysis focuses on the role of topography and on inter-topographic interactions between adjacent geomorphic units to characterize their combined influence on ground motion.The results show that significant near-field effects occur in the near-fault region,including permanent displacements and velocity pulses attributed to fling-step phenomena,and that the ground motion on the hanging wall is more pronounced than on the footwall.Seismic waves,after being reflected and superimposed within mountains and basins,amplify ground motion amplitudes and increase shaking duration.These processes produce strong topographic amplification,with peak ground velocity(PGV)and peak ground acceleration(PGA)at the mountain summit increasing by 58%and 79%,respectively,while being amplified by factors of 6.2 and 2.9 within the basin.The barrier effect of the mountains reduces ground motion in the basin as their height increases,with peak ground displacement(PGD)attenuated by up to 20%.The modification of seismic waves by the basin,in turn,alters ground motion patterns in the mountains on the far side of the fault.This study elucidates the patterns of 3D ground motion heterogeneity and coupled topographic interactions,offering valuable insights for seismic risk management in near-fault complex sites. 展开更多
关键词 Three-dimensional mountain Coupled topography Reverse fault earthquake Dynamic rupture source Ground motion simulation
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Three-dimensional interferometric direction-finding for non-planar antenna arrays 认领 引用
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作者 CHEN Wangjie ZHU Weiqiang +2 位作者 FAN Zhenhong WU Li HE Yi 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2026年第2期377-392,共16页
This paper proposes a three-dimensional(3D)interferometer direction-finding(DF)method to address the reduced accuracy of conventional two-dimensional(2D)interferometer DF methods in non-planar antenna configurations.F... This paper proposes a three-dimensional(3D)interferometer direction-finding(DF)method to address the reduced accuracy of conventional two-dimensional(2D)interferometer DF methods in non-planar antenna configurations.First,we enhance the multi-channel soft synchronization(MCSS)technique by dynamically compensating for sampling point offsets,achieving phase estimation accuracy better than 0.01 sampling points.Second,we construct a 3D baseline model based on the 3D distribution characteristics of the antennas and introduce a 3D error allocation model to improve the system error estimation method,allowing for dynamic correction of calibration deviations.This effectively addresses the phase ambiguity issues caused by 3D mechanical errors.Finally,we develop a 3D DF algorithm and an optimized multi-pulse fusion approach utilizing the maximum-ratio combining(MFA-MRC)method to reduce DF errors and enhance system stability.Simulation experiments and flight tests demonstrate that the proposed method has a computational load of only 0.31%of the multiple signal classification(MUSIC)algorithm.When the baseline offset exceeds 10 mm,the angular accuracy improves from 0.9°to 0.3°,and the positioning accuracy is enhanced from approximately 10 km to around 1 km.The study holds significant theoretical and practical value in engineering. 展开更多
关键词 three-dimensional interferometric direction finding multi-channel soft synchronization system error estimation installation error correction
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Impact of three-dimensional reconstruction on ischaemic time and operative time in robot-assisted partial nephrectomy 认领 引用
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作者 Deerush Kannan Sakthivel Sindhu Sankaran +2 位作者 Madhav Tiwari Sandeep Bafna Narasimhan Ragavan 《Asian Journal of Urology》 CAS CSCD 2026年第1期52-55,共4页
Objective:Partial nephrectomy(PN)is the standard treatment for T1a renal masses,increasingly applied to T1b tumours due to advancements in robotic surgery and imaging.While CT urograms are standard,three-dimensional(3... Objective:Partial nephrectomy(PN)is the standard treatment for T1a renal masses,increasingly applied to T1b tumours due to advancements in robotic surgery and imaging.While CT urograms are standard,three-dimensional(3D)reconstruction is gaining traction for complex tumours to enhance preoperative planning.This study aimed to compare the impact of 3D reconstruction on operative time and ischaemic time during robot-assisted PN.Methods:A prospective,non-randomised study was conducted on 112 patients who underwent robot-assisted PN between January 2020 and October 2022.Patients were divided into two groups:Group A(n=56)with the aid of 3D reconstruction for complex tumours and Group B(n=56)without 3D reconstruction.Operative time and ischaemic time were analysed,along with other outcomes such as margin positivity and postoperative complications.Results:Despite higher tumour complexity in Group A,mean operative time(190.1[standard deviation,SD 38.5]min vs.189.3[SD 42.6]min)and mean ischaemic time(20.4[SD 5.6]min vs.20.3[SD 5.3]min)were comparable between Group A and Group B.Margin positivity and complications were also similar,suggesting that 3D reconstruction aids in efficient surgery even for complex cases.-Conclusion:3D reconstruction enhances understanding of complex renal tumours,maintaining operative efficiency comparable to less complex cases.Further randomized studies are needed to confirm these findings. 展开更多
关键词 Three-dimensional reconstruction Robot-assisted partial nephrectomy Nephron sparing surgery Augmented reality Robotic urological surgery Minimally invasive surgery
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