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Multi-pass intermittent local loading process of large-scale rib-web component:Forming characteristics and implementing apparatus 认领 引用 被引量：3
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作者 Dawei ZHANG Peng DONG +2 位作者 Jingxiang LI Zijian YU Shengdun ZHAO 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第1期601-625,共25页
The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and redu... The multi-pass intermittent local loading process,which features a more flexible processing path,can further enhance the second material distribution during local loading,improve the formability of components,and reduce forming loads.However,the absence of compatible forming equipment makes it difficult to control the constraint in the unloaded zones during the forming process.This difficulty complicates coordination and control of deformation,particularly for asymmetric rib-web components.Additionally,the current implementation involves multi-fire heating,a long process flow,and high energy consumption,which limits the popularization and application of the local loading process.In this study,a new multi-pass local loading hydraulic forming apparatus that can quickly and reliably switch between heavy-load deformation and low-load constraint for different local loading sub-dies was developed.A 10-tonne laboratory prototype was developed,and the forming characteristics during the forming process as well as the response characteristics of the hydraulic system during the multi-pass intermittent local loading of rib-web component were investigated using numerical simulations and physical experiments.Results indicated that,compared to a whole loading process with the same initial geometry of billet,the total forming load(i.e.,the sum of loaded and restrained loads)is reduced by more than 40%with the local loading process,and by nearly 50%with multi-pass local loading.The multi-pass local loading process allows for more effective control of material flow compared to single-pass local loading,leading to improved cavity filling and reduced flow line disturbance.For a large-scale,complex titanium alloy bulkhead,the cavity filling problem was addressed by optimizing the multi-pass local loading path with an unequal thickness billet.The dynamic performance of the multi-pass local loading hydraulic system was found to be robust,with stable pressure transitions during motion and load switching for the sub-die(s).The dynamic characteristic of the hydraulic cylinder when switching from non-moving/unloaded state to a moving/loading state are consistent whether a load is present or not.However,the dynamic characteristics differ when switching from a moving/loading state to non-moving/unloaded state,showing opposite behavior.The developed hydraulic drive mechanism provides a way for implementation of multi-pass local loading without auxiliary operation and extra heating.The results of the study provide a foundation for the industrial production of large-scale,complex components with reduced force requirement and low-energy consumption. 展开更多
关键词 Forming characteristics Hydraulic system Intermittent local loading process Material flow Rib-web component
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Pullout response and failure characteristics of anchorage system in hard rocks 认领 引用 被引量：1
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作者 Chuanqing Zhang Qiangqiang Zhang +2 位作者 Qiang Cui Xunguo Zhu Qiming Xie 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第3期1966-1991,共26页
The axial load-bearing capacity of grouted anchorage systems is critical for rock reinforcement and reflects the interactions among system components.Hence,the mechanical response and failure characteristics of the an... The axial load-bearing capacity of grouted anchorage systems is critical for rock reinforcement and reflects the interactions among system components.Hence,the mechanical response and failure characteristics of the anchorage system under axial loading are of vital importance.They serve as the foundation for establishing the mechanical model of the anchorage system and provide significant guidance for the optimization design of bolts and the assessment of anchorage conditions.However,as the most widely used research method,current pullout tests have not paid sufficient attention to simulating actual rock mass stiffness,have not fully revealed the radial mechanical response during the pullout process,and have not clarified the locations and modes of pullout failure.To address these issues,a testing method simulating hard rock stiffness and strength was developed using elasticity and stiffness equivalence theories.Tests revealed three anchorage failure modes under equivalent hard rock stiffness:tooth cutting,sliding,and sliding-tooth cutting composite failure,with the composite failure being dominant.The pullout load-displacement curves exhibited bimodal patterns for composite failure and single peaks for tooth cutting and sliding failures.Post-peak softening showed up-convex curves for tooth cutting and down-concave curves for sliding failure,while bolt yielding displayed distinct plateaus.The radial stress trends at the rock-grout interface paralleled pullout load curves,with sliding failure exhibiting approximately 10 MPa lower peak radial stress compared to tooth cutting failure.Anchorage length most strongly affected peak load,while grout properties predominantly governed failure mode. 展开更多
关键词 Anchorage system Pullout test Failure characteristics Mechanical responses Stiffness
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Planting density affects yield of indica-japonica hybrid rice by regulating population and photosynthetic characteristics 认领 引用 被引量：1
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作者 Kailiang Mi Yiyin Lu +3 位作者 Fangfu Xu Yanju Yang Haipeng Zhang Hongcheng Zhang 《The Crop Journal》 SCIE CSCD 2026年第2期592-605,共14页
To increase the yield of indica-japonica hybrid rice,it is crucial to explore their photosynthetic and population characteristics at different yield levels and quantify their response to varying planting densities.In ... To increase the yield of indica-japonica hybrid rice,it is crucial to explore their photosynthetic and population characteristics at different yield levels and quantify their response to varying planting densities.In this study,a two-year field experiment was conducted to test two indica-japonica hybrid rice varieties with different yield potentials(12 t ha-1and 15 t ha-1,respectively)at four planting densities(D1:21 cm×30 cm;D2:18 cm×30 cm;D3:16 cm×30 cm;D4:14 cm×30 cm).High yield indicajaponica hybrid rice was primarily charcterized by a high number of spikelets per panicle and a greater spikelet weight,which increased the single panicle's weight.In addition,rational material translocation and a coordinated source-sink relationship contributed to dry matter accumulation.Open plant morphology optimized leaf enzyme activity at all stages,improved photosynthesis,and increased yield by 20.54%-21.60%.Increasing the planting density of indica-japonica hybrid rice somewhat restricted the growth of the rice population,leading to decreases in spikelets per panicle,1000-grain weight,seed-setting rate,plant height,length of the top three leaves,leaf width,leaf angle,and the number of primary and secondary branches.However,the higher number of basic seedling resulted in more effective panicles and an increase in total spikelets,increasing the yield of each variety by 4.17%-8.48%and 2.39%-12.71%,respectively.Optimum dense planting of indica-japonica hybrid rice will benefit the sink capacity and a synergistic increase in both yield and economic benefit.This study offers crucial theoretical insights and practical significance for increasing indica-japonica hybrid rice yield and ensuring food security. 展开更多
关键词 Source-sink relationship Physiological characteristics Economic benefit Yield level Yield components
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Fracture characteristics and fracture interface buckling mechanism of cantilever rock mass under non-uniformly distributed load 认领 引用 被引量：1
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作者 Wenlong Shen Ziqiang Chen +7 位作者 Meng Wang Jianbiao Bai Zhengyuan Qin Tongqiang Xiao Ningkang Meng Juntao Liu Yan Gai Hua Nan 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2026年第2期375-397,共23页
This study examined non-uniform loading in goaf cantilever rock masses via testing,modeling,and mechanical analysis to solve instantaneous fracture and section buckling from mining abutment pressure.The study investig... This study examined non-uniform loading in goaf cantilever rock masses via testing,modeling,and mechanical analysis to solve instantaneous fracture and section buckling from mining abutment pressure.The study investigates the non-uniform load gradient effect on fracture characteristics,including load characteristics,fracture location,fracture distribution,and section roughness.A digital model for fracture interface buckling analysis was developed,elucidating the influence of non-uniform load gradients on Fracture Interface Curvature(FIC),Buckling Rate of Change(BRC),and Buckling Domain Field(BDF).The findings reveal that nonlinear tensile stress concentration and abrupt tensile-compressive-shear strain mutations under non-uniform loading are fundamental mechanisms driving fracture path buckling in cantilever rock mass structures.The buckling process of rock mass under non-uniform load can be divided into two stages:low load gradient and high gradient load.In the stage of low gradient load,the buckling behavior is mainly reflected in the compression-shear fracture of the edge.In the stage of high gradient load,a buckling band along the loading direction is gradually formed in the rock mass.These buckling principles establish a theoretical basis for accurately characterizing bearing fractures,fracture interface instability,and vibration sources within overlying cantilever rock masses in goaf. 展开更多
关键词 Cantilever rock mass Non-uniformly distributed load Fracture characteristics Buckling fracture Digital model
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Evolution Characteristics and Driving Mechanism of‘Bottom-up’and‘Top-down’Endogenous Automobile Industry Clusters:A Comparative Study in Taizhou and Wuhu,China 认领 引用 被引量：1
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作者 JIANG Haining ZHANG Jun +1 位作者 CHEN Jiaqi JIN Xingxing 《Chinese Geographical Science》 SCIE CAS CSCD 2026年第1期34-49,共16页
Bottom-up and top-down endogenous automobile clusters exhibit distinct evolutionary traits and driving mechanisms,yet their comparative analysis remains understudied.Therefore,using Taizhou automobile industry cluster... Bottom-up and top-down endogenous automobile clusters exhibit distinct evolutionary traits and driving mechanisms,yet their comparative analysis remains understudied.Therefore,using Taizhou automobile industry cluster(TAIC)and Wuhu automobile industry cluster(WAIC)as cases,using historical statistical data and field interview data from the 1980s to 2023,combined with qualitative research methods of thematic and diachronic analysis,and quantitative research methods of social network analysis,we compare both endogenous automobile clusters’evolutionary traits and driving mechanisms.The results confirm both clusters undergo multi-scale spatial reconfiguration,organizational complexification,and intelligent networking technological transformation,yet diverge fundamentally:TAIC evolves through market-driven progressive expansion,transitioning from single to dual-core structures via private enterprise networking,with innovation following market-integrated logic and institutional thickness built on demand-driven evolution.Conversely,WAIC follows planned expansion,maintaining state-led hierarchical single-core stability through policy-driven breakthrough innovation and supply-dominated institutional construction-though both ultimately require formal-informal system synergy.Their coevolution is driven by dynamic interactions of path dependence(weakening influence),learning-innovation(strengthening influence),and relationship selection(inverted U-shaped trajectory),with divergent development paths rooted in TAIC’s grassroots self-organization genes versus WAIC’s top-level design genes,amplified by core enterprises’strategic disparities.The research findings can not only provide decision-making support for China’s industrial upgrading,but also contribute China’s insights to global economic governance. 展开更多
关键词 endogenous automobile industrial clusters evolutionary characteristics driving mechanism Taizhou Wuhu China
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Experimental study on the frost jacking characteristics of bamboo joint conical piles in seasonally frozen regions 认领 引用 被引量：1
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作者 YaoHui Zhang HaiHong Yang +1 位作者 TieCheng Sun Jiao Zhang 《Research in Cold and Arid Regions》 CAS CSCD 2026年第1期11-21,共11页
The variation in pile types can to some extent reduce frost jacking displacement of pile foundations in seasonal frost regions,yet further research is needed on the anti-jacking-up performance of different pile types ... The variation in pile types can to some extent reduce frost jacking displacement of pile foundations in seasonal frost regions,yet further research is needed on the anti-jacking-up performance of different pile types under freeze-thaw cycles.This study conducted freeze-thaw cycle model tests under open-system conditions based on the proposed design concept of bamboo joint conical piles,analyzing variations in test fill temperature,moisture content,surface displacement,and pile-top displacement.The main findings are:(1)Pile type variation significantly affects pile foundation frost jacking,with bamboo joint conical piles demonstrating superior anti-jacking-up performance compared to straight piles and inferior performance to 9°conical piles.Moreover,the anti-jacking-up performance of bamboo joint conical piles follows a pattern of initial enhancement followed by attenuation with increasing cone angle,where a 7°cone angle provides optimal anti-jacking-up performance.(2)The moisture content of the soil fill increases with the number of freeze-thaw cycles in an open system environment,with the rate of increase decreasing over time,while the initial frozen core volume within the fill material tends to increase during the thawing phase.(3)The mechanisms underlying the frost heave and settlement of the fill surface and the frost jacking displacement at the pile top were clarified.The frost heave and settlement of the fill surface result from volume changes in the frozen soil due to the water-ice phase transition and the compaction effect on unfrozen soil.The thermal melting evolution of the frozen core in the fill material is the key factor determining the cumulative displacement at the pile top.(4)Differences in the thermophysical properties between the pile foundation and the fill material induce the migration of free water toward the vicinity of the pile,where the higher moisture content of the fill material is detrimental to the mitigation of frost jacking damage to the pile foundation.These findings provide a foundation for further elucidation of the frost jacking mechanism of bamboo joint conical piles in seasonally frozen regions under freeze-thaw cycles. 展开更多
关键词 Freeze-thaw cycles Bamboo joint conical piles Frost jacking characteristics Model test Open system
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Sensitivity analysis of vibration characteristics and dynamic responses of a tracked vehicle 认领 引用 被引量：1
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作者 Xun Wang Xue Rui +3 位作者 Jinghong Wang Xiaoting Rui Guoping Wang Pingxin Wang 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2026年第3期323-348,共26页
This study aims to establish an integrated sensitivity analysis framework for optimization and design of the dynamic performance of mechanical systems such as tracked vehicles,by combining the direct differentiation m... This study aims to establish an integrated sensitivity analysis framework for optimization and design of the dynamic performance of mechanical systems such as tracked vehicles,by combining the direct differentiation method(DDM)with the linear multibody system transfer matrix method(linear MSTMM).The rigid-flexible coupled multibody system dynamics model of a tracked vehicle is established using the linear MSTMM and validated through the modal test.Building upon the existing DDM-based eigenvalue sensitivity analysis method within the linear MSTMM,the DDM is embedded into it to enable programmable and efficient computation of dynamic response sensitivities for mechanical systems.The proposed approach is used to quantitatively evaluate the sensitivities of both natural vibration characteristics(e.g.,natural frequencies and mode shapes)and transient dynamic responses of the tracked vehicle with respect to system parameters,successfully identifying critical structural parameters.Compared to conventional finite difference methods,the developed methodology eliminates sensitivity to perturbation step sizes.The contributions of this work lie in establishing a unified theoretical foundation and analysis framework for guiding dynamics optimization and design of mechanical systems,and extending the applicability of the linear MSTMM to sensitivity analysis of transient dynamic responses. 展开更多
关键词 Tracked vehicle Sensitivity analysis Vibration characteristics Dynamic responses Direct differentiation method Linear multibody system transfer matrix method
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Stress wave propagation and energy characteristics of impact-damaged and water-soaked sandstone with different length-to-diameter ratios 认领 引用 被引量：1
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作者 Kang Peng Kun Luo +4 位作者 Yuanmin Wang Song Luo Tianxing Ma Jing Mao Jie Zhang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第3期1876-1891,共16页
In mining engineering,dynamic loads acting on the surrounding rock induce irreversible damage.The damage is further exacerbated by water exudation from filling bodies or groundwater in the surrounding rock.Understandi... In mining engineering,dynamic loads acting on the surrounding rock induce irreversible damage.The damage is further exacerbated by water exudation from filling bodies or groundwater in the surrounding rock.Understanding the propagation and energy characteristics of stress waves in damaged surrounding rock is essential for improving the stability of underground structures.Hence,in this study,an improved triaxial Split Hopkinson Pressure Bar(SHPB)testing system was used to prepare four sets of impact-damaged and water-soaked specimens with varying length-to-diameter ratios in the laboratory,followed by dynamic triaxial compression testing.Test results indicate that,following dynamic impact and water soaking,the propagation of stress waves in rock is altered.Compared with intact specimens,impact-damaged and water-soaked specimens(IDWS)show a reduction in both transmission and reflection coefficients,thereby enhancing their energy absorption capacity and decreasing transmitted and reflected energy.The length(length-to-diameter ratio)of the specimen and the peak of the incident wave also affect stress wave propagation.Under the same incident peak value,the transmission coefficient increases with larger length-to-diameter ratios,whereas the reflection coefficient decreases.Similarly,the energy carried by the stress wave is influenced by specimen length:as the length grows,the energy absorbed per unit volume declines.When using energy absorbed per unit volume to characterize the dynamic triaxial strength of rock,the length-to-diameter ratio effect on strength is not pronounced. 展开更多
关键词 Impact-damaged and water-soaked rocks Dynamic triaxial compression Stress wave propagation Split hopkinson pressure bar(SHPB) Energy characteristics Length-to-diameter ratio effect
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Correction:Bubble and flow characteristics in EAF with multi-mode bottom blowing 认领 引用
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作者 Xing-Yu Liu Xiao-Yu Guo +4 位作者 Li-Hui Han Liang Ren Gui-Bin Jia Wei Yan Jing Li 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2026年第5期224-225,共2页
The publication of this article unfortunately contained mistakes.Figures 11 and 12 were the same.The corrected Fig.12 is given below.
关键词 multi mode bottom blowing bubble characteristics EAF flow characteristics
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3D morphological characteristics of shrinkage porosities and their relationship with microstructures in Mg−12Al magnesium alloy 认领 引用
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作者 Chuang-ming LI Ang ZHANG +6 位作者 Yong-feng LI Heng-rui HU He LIU Yu-yang GAO Zhi-hua DONG Bin JIANG Fu-sheng PAN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2026年第1期96-111,共16页
The dependence of shrinkage porosities on microstructure characteristics of Mg−12Al alloy was investigated.The distribution,morphology,size,and number density of shrinkage porosities were analyzed under different cool... The dependence of shrinkage porosities on microstructure characteristics of Mg−12Al alloy was investigated.The distribution,morphology,size,and number density of shrinkage porosities were analyzed under different cooling rates.The relationship between shrinkage porosities and microstructure characteristics was discussed in terms of temperature conditions,feeding channel characteristics,and feeding capacity.Further,the feeding behavior of the residual liquid phase in the solid skeleton was quantified by introducing permeability.Results show a strong correlation between the solid microstructure skeleton and shrinkage porosity characteristics.An increase in permeability corresponds to a declining number density of shrinkage porosities.This study aims to provide a more complete understanding how to reduce shrinkage porosities by controlling microstructure characteristics. 展开更多
关键词 Mg−12Al alloy shrinkage porosity solidification microstructure characteristics morphological characteristics
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A method of characteristics for supersonic viscous flows 认领 引用
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作者 Bo ZHANG Yuxin ZHAO Shihe YI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第3期282-293,共12页
This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations ... This paper develops a method of characteristics for supersonic viscous flows.The proposed method removes the inviscid and isentropic assumptions of the classical method of characteristics.The characteristic equations and compatibility equations are derived from the governing equations for compressible viscous flow.By combining the characteristic lines,the triangular interior unit process,quadrilateral interior unit process,and direct sonic point unit process are developed.The unit processes make up the characteristic net.The numerical algorithms consider the path of flow signal propagation.The inviscid terms are solved along characteristic lines,while the viscous terms are corrected through iterative whole-field computations.The proposed method has been applied to supersonic flat-plate boundary layer and verified by the similarity solution.The errors of velocity and temperature profiles are on the order of 0.1%,while the computation efficiency is the same as the classical method of characteristics.The accuracy and efficiency make the proposed method potential to become a basic tool of analysis and design for supersonic viscous flows. 展开更多
关键词 Characteristic line Compatibility equation Compressible flow Method of characteristics Supersonic flow Viscous flow
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Identification of coal characteristics by near-infrared spectroscopy:Machine learning predictions and experimental validations 认领 引用
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作者 AN Haiquan LIU Zhen +1 位作者 LI Ye PENG Baozi 《燃料化学学报（中英文）》 EI CAS CSCD 北大核心 2026年第5期201-212,共12页
In this study,near-infrared spectroscopy was used along with various machine learning algorithms to develop a fast and reliable framework for identifying coal components,which significantly improved the accuracy and e... In this study,near-infrared spectroscopy was used along with various machine learning algorithms to develop a fast and reliable framework for identifying coal components,which significantly improved the accuracy and efficiency of predictions.Support vector machine(SVM),random forest(RF),temporal convolutional network(TCN),one-dimensional convolutional neural network(1D CNN),and gated recurrent unit(GRU)algorithms were used for regression modeling of coal properties.Among the various models considered herein,the TCN model was shown to provide the lowest Mean Absolute Error(MAE)value,which was 0.505.In addition,the RF model demonstrated the lowest Root Mean Square Error(RMSE)value of 0.618,indicating its robustness in prediction on the test set.The TCN model,on the other hand,had the lowest Coefficient of Variation(CV)value of 0.042,which demonstrated its good generalization ability and stability.Furthermore,the developed single-output models revealed that different models have different predictive effects on coal components.For example,it was found that the TCN model is optimal for predicting ash content,while the RF model is the most accurate model for predicting fixed carbon and low calorific value.Taking into account the quantity of model parameters,computation time,and accuracy analysis,the results showed that the RF,1D CNN and TCN models are more efficient.Finally,the influence of key characteristic peaks on prediction results was revealed through SHAP value analysis.The results showed a relationship between absorption intensity and composition of organic and inorganic values in coal to near-infrared light,suggesting important characteristic spectral ranges for ash,moisture,and fixed carbon.This research not only provides a new method for rapid detection in the coal industry,but also serves as a reference for component analysis in other fields. 展开更多
关键词 machine learning coal characteristics NIR rapid testing
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Crushing characteristics of granite during ultra-high speed penetration:experiments and simulations 认领 引用
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作者 Yizhe Liu Quanyu Jiang +6 位作者 Zheng Hu Zishang Liu Jiayi Zheng Yi Liu Yanpeng Wei Kun Zhang Bingchen Wei 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第4期672-683,共12页
Escaping ejecta enhanced momentum transfer due to recoil produced by the impact,depending on the complex interaction of the projectile remove with to target.The crushing behavior of the target in the initial stage of ... Escaping ejecta enhanced momentum transfer due to recoil produced by the impact,depending on the complex interaction of the projectile remove with to target.The crushing behavior of the target in the initial stage of impact is often neglected,especially in meteorite-like brittle materials.Whereas,the relationship between crack evolution and stress wave propagation is vague under ultra-high speed impact.The experiments of Al sphere impacting into granite were carried out at velocities between 1800 and 4000 m/s by a two-stage light-gas gun(DBR30),revealing distinct fragmentation characteristics on granite.As the speed increases,transitions from intact to fractured,then fragmented,exhibiting distinct failure modes under shock wave loading.Smoothed particle hydrodynamics-finite element method(SPH-FEM)simulation was employed to describe the geometrical evolution of the projectile and the propagation crack in the target.It was found that the shape of the projectile gradually changes from a cone to spherical as speeds increase.Further crack fractal dimension analysis revealed that the penetration mode transition occurs within 1500-2000 m/s.This method provides a novel framework to evaluate the ultrahigh speed penetration while quantifying the penetration mode and crushing effect. 展开更多
关键词 Ultra-high speed Coupled SPH-FEM Crushing characteristics Penetration Fractal dimension
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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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Evolution and Causes of the Convective Structure and Microphysical Characteristics of Super Typhoon Saola 认领 引用
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作者 XIAO Liu-si ZHANG Hua-long +3 位作者 WU Nai-geng FENG Lu ZHANG A-si CHEN Sheng 《Journal of Tropical Meteorology》 SCIE CAS CSCD 2026年第2期158-175,共18页
Guangdong Province experienced heavy to extremely heavy rainstorms during Super Typhoon Saola(2023).Areas such as Yunfu,which are typically drier,experienced anomalously extreme rainfall during this event.We analyzed ... Guangdong Province experienced heavy to extremely heavy rainstorms during Super Typhoon Saola(2023).Areas such as Yunfu,which are typically drier,experienced anomalously extreme rainfall during this event.We analyzed the convective structure and microphysical characteristics of the typhoon using dual-polarization radar,disdrometer,and ERA5 reanalysis data.The results show that following Saola’s second landfall,convection redeveloped on the northern side,which was characterized by rich mid-level ice particles and low rain mixing ratios.This resulted in a phase difference in the precipitation particles along Saola’s path.Stations that recorded heavy rain were categorized into four types based on raindrop spectral,spatial,and temporal variables by employing the K-means clustering algorithm.Specifically,the particles observed at Doumen(DM)were classified into a different category from those observed at Yangchun(YC)and Luoding(LD).The microphysical characteristics of raindrop particles evolve under the influence of vertical motion.At DM,the convective structure exhibited a single center of vertical motion with fewer high-altitude ice particles,resulting in a uniform oceanic raindrop type.By contrast,YC was sequentially influenced by two vertically separated centers of vertical motion in the upper and lower atmospheres.These centers alternately dominated the ice-phase and warm-rain processes,resulting in a complex raindrop evolution that transitioned from an intermediate state to a continental type before rapidly reverting to an oceanic type.At LD,the structure showed more pronounced baroclinicity with a higher concentration of water vapor in lower levels,with raindrops tending towards an intermediate continental type.The evolution of vertical motion was driven by changes in environmental conditions.The addition of cold air complicated raindrop evolution in western Guangdong Province compared with that in the Pearl River Estuary.The upper-level vertical-motion center,induced by the uplifting effect of the frontal zone associated with cold air,promoted the development of ice-phase processes and an increase in raindrop size.Subsequently,the lower-level upward-motion center became dominant,which enhanced precipitation concentration.A unique circulation pattern created by the interaction of twin typhoons with each other and with cold air intensified the low-level easterly winds and moisture influx,contributing to extreme rainfall in a typically drier region.Orographic convergence and uplift also played a role in the microphysical evolution of raindrops. 展开更多
关键词 typhoon convective structure microphysical characteristics evolution and causes
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Numerical simulation study on intermittent swimming characteristics of octopus based on the eight-arm undulation mechanism 认领 引用
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作者 Wenhua Chu Liuyang Pan +3 位作者 Yaze Song Jifeng Yan Qiaoli Zhou Zijing Zhao 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第3期471-488,共18页
The swimming mechanism of octopuses has been a hot topic in the field of biology in recent years.Existing research primarily focuses on the influence of morphological parameters on octopus swimming ability;the impact ... The swimming mechanism of octopuses has been a hot topic in the field of biology in recent years.Existing research primarily focuses on the influence of morphological parameters on octopus swimming ability;the impact of kinematic parameters remains relatively unexplored.This study focuses on the swimming posture and movement characteristics of octopuses,formulating a synchronized flexible undulation equation for their eight arms.Based on this,computational fluid dynamics combined with dynamic mesh technology is employed to numerically simulate their propulsion mechanism and swimming characteristics.Furthermore,by varying the hover coast time ratio and duty cycle,the influence of different kinematic parameters on propulsion efficiency is explored(close phase after hover coast time ratio is defined as DSC;open phase after hover coast time ratio is defined as DSO,and the duty cycle is defined as DC).The results indicate that the periodic opening and closing motion of the octopus leads to the alternating generation and dissipation of reverse vortices in the wake field,with the jet effect between them being the primary source of propulsion.When DSC=0.30,the forward speed of the octopus after 1 s is only 6%lower than that without hover coast behavior.When DSO=0.30,the peak thrust coefficient of the octopus reaches 0.82,which is 15%higher than that without hover coast behavior,indicating the highest burst acceleration.On the other hand,when DC=0.67,under asymmetric periodic swimming with fast-closing-slow-opening,the average thrust coefficient reaches 0.26,an increase of 23.8%compared to uniform opening-closing periodic swimming,while the average lateral force coefficient decreases by 66.7%.In this scenario,the octopus can achieve better forward propulsion and maintain stable movement.The findings of this study provide valuable insights for research on the intermittent swimming behavior of octopuses and underwater vehicles. 展开更多
关键词 Octopus Swimming characteristics Eight-arm undulation motion Numerical simulation
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Bubble and flow characteristics in EAF with multi-mode bottom blowing 认领 引用
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作者 Xing-Yu Liu Xiao-Yu Guo +4 位作者 Li-Hui Han Liang Ren Gui-Bin Jia Wei Yan Jing Li 《Journal of Iron and Steel Research International》 SCIE EI CSCD 2026年第1期374-397,共24页
Understanding the bubble behaviours and flow characteristics of large-capacity bottom-blowing electric arc furnace(EAF)is crucial for potential exogenous gas-induced slag foaming process and enhancement of molten bath... Understanding the bubble behaviours and flow characteristics of large-capacity bottom-blowing electric arc furnace(EAF)is crucial for potential exogenous gas-induced slag foaming process and enhancement of molten bath dynamics.A physical model and a 3D gas-slag-steel transient bottom-blowing numerical model of a 150 t EAF were established to investigate the bubble behaviour and flow characteristics throughout the molten steel bath and slag layer under bottom-blowing,with referring to gas flow rate,plug diameter,plug arrangement and injection angle.Results indicate that the average bubble sizes experience increase,dynamic stability and decrease in molten steel bath and then undergo decrease and increase after entering into slag layer for all bottom-blowing modes.The bubble numbers exhibit the opposing trends during the process.Increase in gas flow rate leads to a significant rise in average bubble size but a decrease in number,average dwelling time and the spread area of bubbles in slag layer.Increase in plug diameter causes an opposite impact.The effect of plug arrangement radii on bubbles is almost negligible.Increasing the injection angle results in an increase in bubble size and a decrease in both bubble number and dwelling time in slag layer.The slag foaming potential was discussed referring to the bubble size,number and dwelling time in slag layer.Increase in gas flow rate and plug diameters can significantly enhance the fluids flow through increasing average flow velocity,decreasing mixing time and dead zone ratio of molten bath.Plug arrangement radius and injection angle express nonlinear correlation with average flow velocity and dead zone ratio,and the plug arrangement radius of 0.5R(R represents the radius of bottom circle of EAF model)and injection angle of 15°perform better in enhancing dynamics of molten bath.A group of bottom-blowing parameters are proposed to achieve better comprehensive performance of bubble-induced slag foaming and molten bath dynamics. 展开更多
关键词 EAF Bubble behaviour Flow characteristics Bottom blowing Numerical model
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Morphological and dynamic characteristics of abrasion on drainage structures in response to debris flow 认领 引用
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作者 YANG Dongxu LU Shuai +6 位作者 YOU Yong SUN Hao ZHAO Wanyu ZHOU Ziyi LI Yuanling ZHANG Jiajia WANG Dongpo 《Journal of Mountain Science》 SCIE CSCD 2026年第4期1635-1652,共18页
Abrasion,a complex physical phenomenon prevalent in natural and engineered structures,frequently causes significant functional failures in drainage channels under the debris flow impact force.This underscores critical... Abrasion,a complex physical phenomenon prevalent in natural and engineered structures,frequently causes significant functional failures in drainage channels under the debris flow impact force.This underscores critical knowledge gaps regarding abrasion effects on debris flow-scoured drainage structures.Through multi-stage field investigations and data analysis across four representative areas,this study proposes a classification system for abrasion phenomena and analyzes morphological characteristics across different drainage structures and debris flow types(rainy vs.glacial).Further,the study methodically uncovers the long-term spatiotemporal distribution,development,and progression of abrasion in drainage channels and check dams.Dynamic abrasion characteristics were evaluated using three key parameters per debris flow:average gully vertical drop,watershed relative cutting degree,and soil sample data.The findings indicate that rainy debris flows exhibit higher average vertical drops(max:0.933)compared to glacial debris flows(max:0.621).Glacial debris flows show greater relative watershed cutting degrees(range:0.15–0.3)than rainy types(range:0.075–0.2).Multiple influencing factors were compared to identify critical controls on abrasion intensity.Debris flow velocity distribution and particle gradation within channels emerged as the primary determinants of abrasion distribution.Notably,a higher proportion of viscous particles(grain size D20%).These findings quantitatively inform the optimization of debris flow mitigation,providing a critical foundation for improving structural design,wear repair techniques,and channel configuration. 展开更多
关键词 Debris flow Drainage structure Dynamics characteristics Abrasion morphology Abrasive severity
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Direct numerical simulations of high-pressure impinging-jet atomization:Interfacial evolutions and spray characteristics 认领 引用
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作者 Bo WANG Erjun WU +4 位作者 Anlong YANG Feng ZHANG Baoe YANG Qingquan LIU Xiaodong CHEN 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2026年第3期158-174,共17页
This study presents a numerical investigation of impinging-jet atomization across various Weber numbers(We) under high backpressure conditions.Using the volume-of-fluid method,adaptive mesh refinement,and the iso Adve... This study presents a numerical investigation of impinging-jet atomization across various Weber numbers(We) under high backpressure conditions.Using the volume-of-fluid method,adaptive mesh refinement,and the iso Advector interface reconstruction technique,atomization characteristics are simulated and analyzed for different values of We.The results indicate that the geometry induces turbulent jets,which drive turbulent atomization through the shear interactions at the gas–liquid interface.The key observed phenomena include the interaction of impact waves with liquid sheet perforation and the breakup of web of ligaments,both of which are prominent under high backpressure conditions.A novel method,based on the threshold velocity of spray droplet groups,is employed to quantitatively measure the spreading angle,showing that the angle increases with We in both front and side views.Additionally,the Sauter mean diameter of droplets follows power-law scaling with exponents of-1/3 in the upstream region and-1/2 in the downstream region,while the droplet size distribution conforms to a log-normal profile.This research provides valuable insights into interface evolution and droplet characteristics during impingingjet atomization under high backpressure,offering essential guidance for optimizing industrial atomization processes. 展开更多
关键词 Direct numerical simulations High-pressure Impinging-jet atomization Interfacial evolutions Spray characteristics
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Numerical Study of Hydrodynamic and Motion Interference Characteristics of Twin Projectiles Entering Water 认领 引用
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作者 QI Chao ZHAO Jia-zhen +3 位作者 WANG Xu HAN Ke-xin WAN Zong-hao LYU Xu-jian 《China Ocean Engineering》 SCIE EI CSCD 2026年第3期521-534,共14页
The water entry of multiple projectiles generates complex motion interference and cavity coupling between bodies,resulting in intricate flow field structures and motion characteristics.This study presents a computatio... The water entry of multiple projectiles generates complex motion interference and cavity coupling between bodies,resulting in intricate flow field structures and motion characteristics.This study presents a computational fluid dynamics(CFD)approach for simulating the hydrodynamic properties of high-speed vertical water entry by parallel projectiles.The numerical method’s validity is verified through experimental comparisons.The study investigates the interference characteristics of parallel projectiles in terms of axis distance,time interval,and water-entry velocity,and compares these behaviors with those of a single projectile.The numerical results reveal that parallel projectile water entry exhibits more complex characteristics,including cavity coupling,surface wetting,and load variations.At G=1.5,extensive shoulder wetting produces substantial lateral forces and yaw moments,affecting both projectiles’attitudes.This negatively impacts underwater trajectory stability and targeting precision.In supercavitating conditions(G≥6),multi-disturbances become negligible.The wake of the leading projectile generates a non-uniform initial flow field for the trailing projectile,while the entry of the trailing projectile subsequently influences the motion of the leading one.This mutual interaction is most pronounced at small time intervals(Δt=0.2 ms).Notably,water-entry velocity exerts less influence on the hydrodynamic characteristics than axis distance and time interval. 展开更多
关键词 parallel projectiles high-speed water entry hydrodynamic characteristics cavity evolution
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