Mass loss should be considered while calculating the penetration depth of concrete by eroding long-rod projectiles of high velocity.The penetration process is divided into two phases：eroding phase and rigid phase.Dur...Mass loss should be considered while calculating the penetration depth of concrete by eroding long-rod projectiles of high velocity.The penetration process is divided into two phases：eroding phase and rigid phase.During eroding phase,a model to predict the penetration depth is established on the assumption that there is a chipping region in the bottom of crater.During rigid phase,Forrestal formula is adopted to calculate the penetration depth.Using this model,the depth of concrete penetration by a tungsten alloy long-rod projectile is calculated.When the critical eroding velocity is between 950 m/s and 1 000 m/s,the result is in good agreement with the experimental data.展开更多
A comprehensive understanding of aggregate dynamics is the foundation for establishing sustainable sugarcane production systems,especially in vulnerable red soil ecosystems.While existing studies have established a ba...A comprehensive understanding of aggregate dynamics is the foundation for establishing sustainable sugarcane production systems,especially in vulnerable red soil ecosystems.While existing studies have established a basic understanding of aggregate formation and stabilization,the functional relationship between aggregate stability and erosion resistance under extended sugarcane monoculture remains inadequately characterized.We employed an integrated methodology combining dry/wet sieving,the Le Bissonnais method and scanning electron microscopy to quantitatively evaluate the soil aggregate stability and erosion resistance across six distinct cultivation chrono-sequences(3–32 years)and two soil depths(0–15 cm and 15–30 cm)in the sugarcane cultivation area of Qingshui Village,Wuxuan County,Guangxi Zhuang Autonomous Region,China,aiming at providing insights for developing soil conservation strategies in sugarcane cultivation systems.The results reveal three core findings.First,planting years significantly influence the proportions of soil aggregates with varying particle sizes.Under the treatments with Le Bissonais methods,the mean weight diameter(MWD)under fast wetting,disturbance after pre-wetting,and slow wetting decrease with increasing planting years,while the relative dissipation index,relative mechanical fragmentation index,and erodibility factor(K)exhibit varying degrees of change,indicating progressive soil structural degradation and increased erosion susceptibility.Second,long-term sugarcane monocropping leads to declining soil organic carbon,liquid limit,plastic limit,and clay content,likely due to factors such as soil-forming materials and rainfall.Concurrently,the increased sand content and porosity weaken interparticle bonding and reducing aggregate stability over time.Third,correlation analysis demonstrates that MWD and geometric mean diameter(GMD)under disturbance after pre-wetting and slow wetting treatments show strong positive correlations with soil organic carbon,p H,clay content,liquid limit,and plastic limit but negative correlations with sand content,total porosity,and capillary porosity.Furthermore,K is significantly negatively correlated with soil physicochemical properties as well as GMD and MWD.These results help us understand the mechanism of aggregate stability variation in sugarcane-cultivated red soils and support the development of soil conservation strategies for sustaining sugarcane productivity in subtropical regions.展开更多
The mound-making behavior of plateau zokors is one of the most important factors in remodeling meadow microtopography and causing soil erosion in the Yellow River source area of western China,but little is known about...The mound-making behavior of plateau zokors is one of the most important factors in remodeling meadow microtopography and causing soil erosion in the Yellow River source area of western China,but little is known about the effects of microtopography on particle size characteristics(PSC)of eroded sediments from the bare slopes of zokor mounds during different rainfall events.In this study,we analyzed the relationship of microtopographic features derived from laser point cloud data and PSC of eroded sediments at six simulated rainfall intensities(all lasting 60 min).The effects of microtopography on PSC of eroded sediments were studied via partial least squares regression(PLSR)and structural equation modeling(SEM).The results showed that:(1)15-20 minutes from the beginning of rainfall was the sensitive period of soil loss from the slopes,and the function relationship between the rate of sediment and runoff and rainfall intensity can better predict the development trend of soil erosion;(2)Intense erosion occurred mainly in the upper half of the zokor mound,while deposition was mainly limited to its lower half.It is suggested that diminished plateau zokor activity intensity can effectively prevent and control soil erosion;(3)The PSC of eroded sediment is dominated by silt,followed by sand,with clay being the least abundant,and the eroded sediments with a particle size of 10-20μm were sensitive and highly susceptible to rainfall erosion.This finding facilitates the understanding of the formation process of surface geomorphology and the mechanism of soil erosion;(4)The PLSR model indicates that microtopography has an extensive influence on eroded sediments during hydraulic erosion,and the SEM analysis results further confirm that the fractal dimension was the best parameter to represent the PSC of eroded sediments,whereas surface cutting degree was the dominant factor controlling the PSC of eroded sediments.These findings are crucial for predicting soil erosion in the Yellow River source area and provide a new perspective for understanding soil erosion mechanisms in alpine meadow ecosystems.展开更多
基金Sponsored by State Key Laboratory of Explosion Science and Technology Foundation(ZDKT08-04,YBKT09-03)
文摘Mass loss should be considered while calculating the penetration depth of concrete by eroding long-rod projectiles of high velocity.The penetration process is divided into two phases：eroding phase and rigid phase.During eroding phase,a model to predict the penetration depth is established on the assumption that there is a chipping region in the bottom of crater.During rigid phase,Forrestal formula is adopted to calculate the penetration depth.Using this model,the depth of concrete penetration by a tungsten alloy long-rod projectile is calculated.When the critical eroding velocity is between 950 m/s and 1 000 m/s,the result is in good agreement with the experimental data.
基金financial support for the research provided by the National Natural Science Foundation of China(No.42107350)the National Key Research,Development Program of China(No.2023YFD1902801)the Central Government Guides the Development of Local Science and Technology Project,Grant/Award Number:Guike ZY21195022。
文摘A comprehensive understanding of aggregate dynamics is the foundation for establishing sustainable sugarcane production systems,especially in vulnerable red soil ecosystems.While existing studies have established a basic understanding of aggregate formation and stabilization,the functional relationship between aggregate stability and erosion resistance under extended sugarcane monoculture remains inadequately characterized.We employed an integrated methodology combining dry/wet sieving,the Le Bissonnais method and scanning electron microscopy to quantitatively evaluate the soil aggregate stability and erosion resistance across six distinct cultivation chrono-sequences(3–32 years)and two soil depths(0–15 cm and 15–30 cm)in the sugarcane cultivation area of Qingshui Village,Wuxuan County,Guangxi Zhuang Autonomous Region,China,aiming at providing insights for developing soil conservation strategies in sugarcane cultivation systems.The results reveal three core findings.First,planting years significantly influence the proportions of soil aggregates with varying particle sizes.Under the treatments with Le Bissonais methods,the mean weight diameter(MWD)under fast wetting,disturbance after pre-wetting,and slow wetting decrease with increasing planting years,while the relative dissipation index,relative mechanical fragmentation index,and erodibility factor(K)exhibit varying degrees of change,indicating progressive soil structural degradation and increased erosion susceptibility.Second,long-term sugarcane monocropping leads to declining soil organic carbon,liquid limit,plastic limit,and clay content,likely due to factors such as soil-forming materials and rainfall.Concurrently,the increased sand content and porosity weaken interparticle bonding and reducing aggregate stability over time.Third,correlation analysis demonstrates that MWD and geometric mean diameter(GMD)under disturbance after pre-wetting and slow wetting treatments show strong positive correlations with soil organic carbon,p H,clay content,liquid limit,and plastic limit but negative correlations with sand content,total porosity,and capillary porosity.Furthermore,K is significantly negatively correlated with soil physicochemical properties as well as GMD and MWD.These results help us understand the mechanism of aggregate stability variation in sugarcane-cultivated red soils and support the development of soil conservation strategies for sustaining sugarcane productivity in subtropical regions.
基金financially supported by the Qinghai University Graduate Student Research and Practice Innovation Project(2025-GPKY-12)Basic Research Project of Qinghai Provincial Science and Technology Department(2021-ZJ-701)+1 种基金National Natural Science Foundation of China(U23A20159,42161068)the 111 Project of China(D18013)。
文摘The mound-making behavior of plateau zokors is one of the most important factors in remodeling meadow microtopography and causing soil erosion in the Yellow River source area of western China,but little is known about the effects of microtopography on particle size characteristics(PSC)of eroded sediments from the bare slopes of zokor mounds during different rainfall events.In this study,we analyzed the relationship of microtopographic features derived from laser point cloud data and PSC of eroded sediments at six simulated rainfall intensities(all lasting 60 min).The effects of microtopography on PSC of eroded sediments were studied via partial least squares regression(PLSR)and structural equation modeling(SEM).The results showed that:(1)15-20 minutes from the beginning of rainfall was the sensitive period of soil loss from the slopes,and the function relationship between the rate of sediment and runoff and rainfall intensity can better predict the development trend of soil erosion;(2)Intense erosion occurred mainly in the upper half of the zokor mound,while deposition was mainly limited to its lower half.It is suggested that diminished plateau zokor activity intensity can effectively prevent and control soil erosion;(3)The PSC of eroded sediment is dominated by silt,followed by sand,with clay being the least abundant,and the eroded sediments with a particle size of 10-20μm were sensitive and highly susceptible to rainfall erosion.This finding facilitates the understanding of the formation process of surface geomorphology and the mechanism of soil erosion;(4)The PLSR model indicates that microtopography has an extensive influence on eroded sediments during hydraulic erosion,and the SEM analysis results further confirm that the fractal dimension was the best parameter to represent the PSC of eroded sediments,whereas surface cutting degree was the dominant factor controlling the PSC of eroded sediments.These findings are crucial for predicting soil erosion in the Yellow River source area and provide a new perspective for understanding soil erosion mechanisms in alpine meadow ecosystems.
