Black soils represent only one-sixth of the global arable land area but play an important role in maintaining world food security due to their high fertility and gigantic potential for food production.With the ongoing...Black soils represent only one-sixth of the global arable land area but play an important role in maintaining world food security due to their high fertility and gigantic potential for food production.With the ongoing intensification of agricultural practices and negative natural factors,black soils are confronting enhanced degradation.The holistic overview of black soil degradation and the underlying mechanisms for soil health improvement will be key for agricultural sustainability and food security.In this review,the current status and driving factors of soil degradation in the four major black soil regions of the world are summarized,and effective measures for black soil conservation are proposed.The Northeast Plain of China is the research hotspot with 41.5%of the published studies related to black soil degradation,despite its relatively short history of agricultural reclamation,followed by the East European Plain(28.3%),the Great Plains of North America(20.7%),and the Pampas of South American(7.9%).Among the main types of soil degradation,soil erosion and soil fertility decline(especially organic matter loss)have been reported as the most common problems,with 27.6%and 39.4%of the published studies,respectively.In addition to the natural influences of climate and topography,human activities have been reported to have great influences on the degradation of black soils globally.Unsustainable farming practices and excess in agrochemical applications are common factors reported to accelerate the degradation process and threaten the sustainable use of black soils.Global efforts for black soil conservation and utilization should focus on standardizing evaluation criteria including real-time monitoring and the measures of prevention and restoration for sustainable management.International cooperation in technology and policy is crucial for overcoming the challenges and thus achieving the protection,sustainable use,and management of global black soil resources.展开更多
To verify the wear resistance and erosion resistance of Ti-doped Ta_(2)O_(5)coating(TTO),a series of TTOs were prepared by magnetron sputtering technology by controlling the power of the Ti target.The change of growth...To verify the wear resistance and erosion resistance of Ti-doped Ta_(2)O_(5)coating(TTO),a series of TTOs were prepared by magnetron sputtering technology by controlling the power of the Ti target.The change of growth structure,microstructure,and tribological properties of TTOs with Ti target power was studied.After the erosion test,the variation of erosion damage behavior of TTOs with mechanical properties under different erosion conditions was further studied.The results show that the TTOs eliminate the roughness,voids,and defects in the material due to the mobility of the adsorbed atoms during the growth process,and a flat and dense smooth surface is obtained.Tribological tests show that the TTOs are mainly characterized by plastic deformation and microcrack wear mechanism.Higher Ti target power can improve the wear resistance of TTOs.Erosion test results reveal that the impact crater,furrow,micro-cutting,brittle spalling,and crack formation are the main wear mechanisms of the TTOs samples under erosion conditions.展开更多
Vegetation plays a major role in soil protection against erosion effects,and studies have also highlighted its importance in retaining sediments from roadside slopes.Yet,hydro-sedimentological studies under natural pr...Vegetation plays a major role in soil protection against erosion effects,and studies have also highlighted its importance in retaining sediments from roadside slopes.Yet,hydro-sedimentological studies under natural precipitation conditions are still scarce in semi-arid areas due to difficulties in monitoring the few and very concentrated precipitation events.Quantifying sediment connectivity and yield at watershed scale,often highly impacted by the erosion of unpaved roads,is necessary for management plans.This study aims to evaluate the efficiency of native vegetation on roadside slope segments in Caatinga biome in retaining sediments and conserving the soil in a semi-arid area of Brazil.Surface runoff,sediment concentration,and yield measurements were measured from 34 natural precipitation events in four years on two slopes with and without vegetation.The runoff coefficients of the plot with no vegetation varied from 3.0%to 58.0%,while in the vegetated plot,they showed variation from 1.0%to 21.0%.The annual specific sediment yield ranged from 4.6 to 138.7 kg/(hm^(2)•a)for the vegetated plot and from 34.9 to 608.5 kg/(hm^(2)•a)for the unvegetated one.These results indicate a 4 to 12 times higher soil loss on the unvegetated slope in relation to the vegetated one and demonstrate that natural Caatinga vegetation acts as an effective barrier against surface-transported sediments.Moreover,natural Caatinga vegetation present on the slope plays an important role in breaking connectivity between sediment flows from unpaved roads and the watershed drainage system.These findings indicate that investments in unpaved road and roadside slope restoration,not only enhance road infrastructure but also promote environmental gains by reducing the impact of erosion.展开更多
In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design st...In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design stage of ion engine.As one of the core components of ion engine,the grid assembly of ion optic systems may experience long-term ion sputtering in extreme electro-thermal environments,which will eventually lead to its structural and electron-backstreaming failures.In this paper,the current studies of the grid assembly erosion process are systematically analyzed from the aspects of sputtering damage process of grid materials,numerical simulations,and measurements of erosion characteristics of grid assembly.The advantages and disadvantages of various erosion prediction models are highlighted,and the key factors and processes affecting the prediction accuracy of grid assembly erosion patterns are analyzed.Three different types of experimental methods of grid assembly erosion patterns are compared.The analysis in this paper is of great importance for selecting the sputter-resistant grid materials,as well as establishing the erosion models and measurement methods to accurately determine the erosion rate and failure modes of grid assembly.Consequently,the working conditions and structure parameters of ion optic systems could be optimized based on erosion models to promote the ion engine lifetime.展开更多
This study evaluates the efficacy of sustainable erosion control using slag-based alkali-activated cement crusts under varying rainfall and wind conditions. The rainfall intensities ranged from 30 mm/h to 120 mm/h, wi...This study evaluates the efficacy of sustainable erosion control using slag-based alkali-activated cement crusts under varying rainfall and wind conditions. The rainfall intensities ranged from 30 mm/h to 120 mm/h, with durations ranging from 15 min to 90 min, and crust slopes of ∼2° (gentle) and 30° (steep). Wind tunnel experiments were conducted at wind velocities of 14 m/s, 21 m/s, and 28 m/s to investigate post-rainfall wind erodibility, along with changes in crust strength and microstructure analysis. The findings show the development of hydrated cementitious phases in alkali-activated material, which form around and between the particles during the alkaline activation process. Alkali-activated cement crusts significantly reduced erosion caused by rainfall and subsequent wind by several orders of magnitude. At the highest rainfall intensity of 120 mm/h, rainfall erosion was measured to be 1654.81 kg/m2 for untreated samples and 0.89 kg/m2 for treated samples, demonstrating a substantial 99.95% reduction in erosion due to the treatment. Similarly, at the highest wind speed tested, wind erosion was 122.75 kg/m2 for untreated samples and 0.095 kg/m2 for treated samples, indicating a significant 99.92% reduction in erosion due to the formation of an alkali-activated cement crust on the soil surface. However, exposure of the samples to 120 mm/h rainfall for 90 min resulted in a 5.2-fold increase in wind erosion compared to pre-rainfall conditions. Similarly, penetrometer results indicated a 37%–54% reduction in post-rainfall surface strength.展开更多
Changes in the coastline are characterized by accretion and erosion. The aim of this study is to contribute to a better understanding of the dynamics of the coastline and the study areas with a view to mitigating and ...Changes in the coastline are characterized by accretion and erosion. The aim of this study is to contribute to a better understanding of the dynamics of the coastline and the study areas with a view to mitigating and preventing the risk of coastal erosion in order to propose a coastal occupation model with planned development policies in the future. These phenomena lead to changes in the position of the coastline. After extraction, the satellite images are compiled, then superimposed and processed using Geographic Information Systems (GIS) for statistical calculation of coastline change rates. A morphosedimentary study is carried out using topography and sedimentology. The topographic method is used to calculate sediment volumes using monthly profiles. The sedimentological method is used to determine the granulometric variations in the morphological units by calculating sedimentological indices. With erosion rates of −2.13 m/yr and −2.17 m/yr respectively at Djiffère (Palmarin and Sangomar breccia) and Joal (Joal Fadhiouth and Ngazobil), the EPR index revealed a sediment deficit. Palmarin Ngallou and the island of Fadhiouth are undergoing accretion at rates of +1.43 m/yr and +1.14 m/yr respectively. From a topographical point of view, the respective accumulations of −13.74 m3/m of beach and −8.65 m3/m of beach at Djiffère and Joal respectively point to significant erosion on all the aerial beach units, while for the underwater beaches, accretion was noted with accumulations of +4.00 m3/m of beach and +5.94 m3/m at Djiffère and Joal respectively. As for the sedimentological results, the Mz index shows a decrease in grain size from the high beach to the surf zone. Some points show bimodal deposits, showing the impact of the dune on beach activity, confirmed by the dispersion on the Mz-sigma diagram. The three methods used in this work show that the Djiffère sector in Joal is dominated by erosion, even though accretion points can be noted.展开更多
In many developing countries with poorly managed landscapes,soil erosion threatens the sustainability of water bodies.The main limitations of this study are the lack of daily sediment data,lithology,higher-resolution ...In many developing countries with poorly managed landscapes,soil erosion threatens the sustainability of water bodies.The main limitations of this study are the lack of daily sediment data,lithology,higher-resolution DEM data,and socioeconomic factors.Poor land use policy and resource management in the Upper Awash Sub-basin lead to soil erosion and sedimentation of hydrological infrastructure,Effective watershed prioritization requires integrating land use,hydrology,sediment load,and morphometric factors but often faces gaps,especially in the study area.This research aims to prioritise the Upper Awash Sub-Basin by its morphometric,land use and cover(LULC),and sediment yield characteristics.We used the integrated AHP-VIKOR multi-attribute decision-making method to prioritise watersheds,incorporating morphometry,LULC,and sediment load attributes in the simple matrix approach.The findings showed the following classes of erosion:exceedingly high(2722.14 km2),high(2524.46 km2),moderate(2205.48 km2),low(1611.43 km2),and extremely low(854.35 km2).Sub-watersheds WS6,WS8,WS10,WS13,and WS24 are the top priority for watershed management.The study ranked watersheds based on various attributes but encountered limitations such as the lack of daily sediment data,geological structure,and lithology.It can be concluded that this approach is very important to identify and categorize hotspots of soil erosion sub-watersheds for planners and decision-makers for conserving water and soil and for different environmental management purposes.展开更多
Soil erosion from water has become a relevant issue at global level.In Guinea in particular,erosion has worrying effects,due to natural conditions and human impact,especially in the Nzérékore city in forest ...Soil erosion from water has become a relevant issue at global level.In Guinea in particular,erosion has worrying effects,due to natural conditions and human impact,especially in the Nzérékore city in forest region.This paper proposed a soil erosion modeling by rainfall effect in the prefecture of N'Zérékoré.To achieve this objective,monthly and annual rainfall data for the N'Zérékorécity were collected at the meteorological station over the period from 1980 to 2024.The analysis of rainfall aggressiveness was possible using the Fournier index.For data processing,we used Microsoft Excel,Python and the ARIMA(AutoRegressive Integrated Moving Average)model for soil aggressiveness predicted by rainfall.It was found that,from 2000 to 2009,erosion was higher compared to other periods with a rate of 60%,or 6 years of high rainfall aggression.From the periods 1990 to 1999 and 2010 to 2019,the lowest rainfall aggressiveness was recorded,with 60%or 6 years of low erosivity.However,from period 1980 to 1989 the highest rate(70%)of very high rainfall erosivity was recorded.The results show three levels of rainfall aggressiveness on an annual scale:a very high level of erosivity with a rate of 22.2%or 10 years,followed by a high level of 35.6%or 16 years of strong erosion.The moderate erosivity level corresponds to 42.2%or 19 years.The model predicts a stability of the erosivity index around 77.14 over the period 2025-2034.During the forty(45)years the rainfall erosivity index was very unstable characterized by strong erosion,however it would be stable in the next ten(10)years.展开更多
Since the 1950's,212 earth fissures have been discovered in the Wei River Basin.During a field survey in 2016,an additional 48 earth fissures were discovered in Anren area,northeast of the Wei River Basin.The char...Since the 1950's,212 earth fissures have been discovered in the Wei River Basin.During a field survey in 2016,an additional 48 earth fissures were discovered in Anren area,northeast of the Wei River Basin.The characteristics and formation mechanisms of these fissures were studied through field investigations,measurements,trench excavation,and drilling.On-site investigations indicated that these earth fissures were distributed along a fault-controlled geomorphic boundary.Fissures trended at 60°-80°NE and were divided into five groups.Trenches revealed multiple secondary fissures,exposing severe soil ruptures in the shallow earth surfaces.Drilling profiles revealed that earth fissures dislocated several strata,and resembled synsedimentary faults.Seismic reflection profiles revealed buried faults beneath the earth fissures.The Anren area fissures formed in the following three stages:regional extension that initially generated multiple buried faults;seismic activity rupturing multiple strata,resulting in multiple buried fractures;and finally,erosion processes that propagated the buried fractures to the surface,forming the current earth fissures.展开更多
Soil erosion(SE)is a critical form of land degradation that significantly threatens the health of terrestrial ecosystems worldwide.The Qinba Mountains represent a vital geo-ecological transition zone in China.Therefor...Soil erosion(SE)is a critical form of land degradation that significantly threatens the health of terrestrial ecosystems worldwide.The Qinba Mountains represent a vital geo-ecological transition zone in China.Therefore,analyzing the dynamics of SE in relation to climate changes and land use/cover(LULC)change is essential for guiding ecological conservation efforts in this region.The soil erosion intensity(SEI)from 2001 to 2020 was estimated using the Revised Universal Soil Loss Equation(RUSLE).For the period of 2021–2040,SEI projections were made based on CMIP6 data,utilizing the Statistical Downscaling Model alongside the CA-Markov model.Variations in SEI under four distinct shared socio-economic pathways were compared.Additionally,statistical methods were employed to evaluate the long-term impacts of climate and LULC change on SE.Findings indicate that between 2021and 2040,both precipitation and rainfall erosivity are expected to increase by approximately 8%–12%and 3%–14%,respectively.Based on differing socio-economic pathways,the soil erosion rate(SER)is predicted to rise by 12%–32%,with SSP2-4.5 anticipated to result in the highest SER.An analysis of contributing factors revealed that precipitation intensity and total precipitation are likely to escalate SE,while elevated temperatures may mitigate it.Among all types of LULC,barren land is particularly susceptible to erosion and remains a priority for conservation.The generated SEI maps will aid in promoting sustainable land use and provide crucial support for mitigating ecological risks from climate change.展开更多
The erosion process and kinetics of PbTe particles in a selenium melt were investigated.The results reveal that the limiting step of the reaction is controlled by product layer diffusion and the interfacial chemical r...The erosion process and kinetics of PbTe particles in a selenium melt were investigated.The results reveal that the limiting step of the reaction is controlled by product layer diffusion and the interfacial chemical reaction at low temperatures(573,583,and 593 K),but the limiting step is controlled by boundary layer diffusion at high temperatures(603 and 613 K).The Se-and Te-atom diffusion in the product layer becomes unbalanced as the product layer thickens,with Kirkendall voids generating in the product layer accelerating PbTe particle erosion.After the PbTe impurities in the selenium melt evolve into PbSe and Te,Te is evenly distributed in the selenium melt owing to the solubility of Se and Te.This study serves to clarify the evolution behavior of PbTe impurities in the selenium melt and the reason that Te often occurs in Se.展开更多
The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS ...The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS factor always varies with the changing DEM resolution,i.e.,the LS factor scale effect.Previous studies have found the phenomenon of the LS factor scale effect,but the underlying causes of this phenomenon has not been well explored.Therefore,how the DEM resolution affects the LS factor and how the scale effect of the L and S factors influence the LS factor scale effect remains unclear.To address these problems,we collected 20 watersheds from the Guangdong Province with different topographic reliefs,and compared the corresponding L,S and LS factors at 10-m and 30-m resolution DEMs.Our results indicate that the S factor,heavily influenced by slope underestimation in coarse-resolution DEMs,makes a difference in the LS factor scale effect.In addition,the LS factor scale effect becomes less significant with increasing reliefs,suggesting the possibility of using 30-m DEM for LS calculation in rugged terrains.Our findings on the underlying mechanisms of the LS factor scale effect help to identify the uncertainty in the LS factor estimation,thereby enhancing the accuracy of soil erosion assessment,particularly in regions with different topographic characteristics and contribute to more effective soil conservation strategies and decision-making.展开更多
The particle size distribution plays a crucial role in the transportation and deposition of eroded sediments.Gaining insights into the related sorting mechanism can significantly enhance our understanding of such proc...The particle size distribution plays a crucial role in the transportation and deposition of eroded sediments.Gaining insights into the related sorting mechanism can significantly enhance our understanding of such processes.In this study,sand-covered slopes were examined.A controlled indoor rainfall simulation was conducted on loess slopes with a 12°incline and a rainfall intensity of 1.5 mm/min.These slopes were then covered with sand layers of varying thicknesses—0.5,1.0,and 1.5 cm—to observe their effects.The findings have revealed that as the thickness of the sand cover increases,the content of sediment particles smaller than 0.054 mm decreases.In contrast,the content of particles larger than 0.054 mm increases after the sixth minute of runoff.The eroded sediment was predominantly composed of silt.During the inter-rill erosion stage,runoff primarily transported particles larger than 0.054 mm.However,in the subsequent rill erosion and combined rill and inter-rill erosion stages,the runoff predominantly carried finer particles,smaller than 0.054 mm.Moreover,the presence of the sand layer significantly influenced the size and form of the eroded sediment particles.Initially,during the first 10 min of runoff,the eroded particles were predominantly larger than 0.054 mm.After this period,however,the particle size shifted,with the majority of particles being smaller than 0.054 mm.This study highlights the intricate relationship between sediment sorting,the thickness of sand covers,and the dynamics of sediment transport under rainfall-induced erosion.展开更多
The paper delved into specific causes of soil erosion during the construction phase of highway projects,analyzed the intrinsic mechanisms behind erosion formation,and examined in detail external dynamic factors contri...The paper delved into specific causes of soil erosion during the construction phase of highway projects,analyzed the intrinsic mechanisms behind erosion formation,and examined in detail external dynamic factors contributing to soil erosion,such as rainfall scouring and wind erosion.Additionally,this paper summarized the unique characteristics of soil and water loss during road construction and the potential severe hazards it may bring,aiming to provide valuable reference for professionals in related fields and to promote further development in the study of natural slope erosion.展开更多
Low erosion high-energy propellant is one of the research directions to extend the weapon’s life and improve the weapon’s capability.In this study,energetic propellants containing different corrosion inhibitors were...Low erosion high-energy propellant is one of the research directions to extend the weapon’s life and improve the weapon’s capability.In this study,energetic propellants containing different corrosion inhibitors were designed and prepared.Close bomb tests and semi-confined bomb experiments were used to investigate the burning and erosion properties of the propellants.The mechanism of erosion-reducing of titanium dioxide(titania,TiO_(2)),talc,and octaphenylsilsesquioxane(OPS)on the propellant was comparatively analyzed.The results show that OPS has the lowest burning rate and the longest burning time,and a minimized loss of fire force,with the best effect of explosion heat reduction.The erosion reduction efficiency of OPS is twice that of TiO_(2) and talc.The mechanism analysis shows that the decomposition and heat absorption of OPS can effectively reduce the thermal erosion effect and carbon erosion,and the gas produced can reduce the loss of chamber pressure and form a uniformly distributed nano-SiO_(2) protective layer.This solid-state high-efficiency organosilicon erosion inhibitor is an important guide for designing high-energy low-erosion gun propellants.展开更多
In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion redu...In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion reduction,and water reduction)using a cylindrical stirring system.The corrosion-enhanced erosion(C-E)rates were determined for each condition.The results revealed that pure iron displayed similar pure erosion behaviour across all three cathodic reactions.When the cathodic reactions involve hydrogen ion reduction or water reduction,the erosion-corrosion of pure iron manifested as uniform damage,with the reduction in hardness being the main cause of the C-E in this case.Conversely,in the case of oxy-gen reduction reaction as the cathodic reaction,the erosion-corrosion presented as pitting damage,with the reduction in hardness resulting from localized concentration of anodic current and the formation of easily worn protruding flaky iron structures at the edges of the pits as the main mechanism of the C-E.Moreover,linear and exponential relationships were found between the C-E rate and the anodic current density for uniform damage and pitting damage,respectively.Finally,the concept of surface equivalent hardness was proposed,along with the establishment of a mathematical model for surface equivalent hardness based on the relationships between the C-E rate and the anodic current density.Utilizing the surface equivalent hardness enables the evaluation of the erosion rate on material surfaces considering the coupled effect.展开更多
The rhizosphere bacteria play crucial roles in plant health and growth as they are involved in assimilating nutrients and resisting adverse conditions such as nutrient stress,drought,and wind erosion.Agriophyllum squa...The rhizosphere bacteria play crucial roles in plant health and growth as they are involved in assimilating nutrients and resisting adverse conditions such as nutrient stress,drought,and wind erosion.Agriophyllum squarrosum(L.)Moq.is a pioneer plant used in sand fixation due to its strong resistance to drought and wind erosion.However,the bacterial community characteristics and ecological function in the rhizosphere of A.squarrosum are poorly understood.In this study,soil samples were collected from different developmental stages(seedling stage,vegetative stage,reproductive stage,and withering stage)of A.squarrosum.Illumina Miseq sequencing was used to detect differences in soil bacterial abundance.The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt)program was used to predict bacterial functions,and the relationships among bacteria,functional populations,and soil nutrients were examined using a heatmap analysis.The results showed that the Shannon and Sobs indices of rhizosphere bacteria were significantly higher during the reproductive stage than during the other stages.Pantoea sp.(7.03%)was the dominant genus during the seedling stage;Arthrobacter sp.was the dominant genus during the vegetative(13.94%),reproductive(7.57%),and withering(12.30%)stages.The relative abundances of Chloroflexi,Acidobacteria,and Gemmatimonadetes were significantly high during the reproductive stage.According to the PICRUSt analysis,membrane transport,signal transduction,and environmental adaptation of the bacterial functional population occurred during the seedling stage.Carbohydrate metabolism increased during the vegetative stage,while energy metabolism,lipid metabolism,and biosynthesis of other secondary metabolites of the bacterial functional population significantly increased during the reproductive stage.The abundances of bacterial communities,functional genes,and soil nutrients were synergistically altered during various developmental stages.Our findings suggest that the developmental stages of A.squarrosum play a significant role in defining the composition and structure of bacterial communities in the rhizosphere.The results will provide a basis for better prediction and understanding of soil bacterial metabolic potential and functions of A.squarrosum rhizosphere in sandy areas.展开更多
Port structures constitute the main link in the maritime transport chain of coastal countries and therefore contribute to their economic development. But it should be noted that the installation of said works is not w...Port structures constitute the main link in the maritime transport chain of coastal countries and therefore contribute to their economic development. But it should be noted that the installation of said works is not without consequences for the countries concerned. Benin, a country in the Gulf of Guinea, is no exception to this phenomenon because, due to its maritime history, it has a heritage of port structures. These structures, built on its coastline, cause a wide variety of environmental problems such as silting and erosion on either side of them. The general objective of this article is to contribute to the proper functionality of port facilities while minimizing environmental problems that may arise. It aims to provide managers with a tool allowing them to fully understand the state of their assets in order to rationalize maintenance actions. In order to achieve this objective, an assessment of the state of the structure, and then a structural diagnosis are necessary and recommendations can be established to restore the level of service of the latter. As a result, two examples were presented: the wharf of the Sèmè-Podji pipeline project and the maritime piles project of the Wasco de Gama bridge (control project), and recommendations adapted to this objective were established. The comparative analysis of the two examples, both maritime works, revealed an under-sizing at the level of the spans of the wharf bridge of the Sèmè-Podji pipeline project (spans of 7 m in length), while these spans vary on average by 45 m to 62 m for the Wasco da Gama bridge. Bringing the piles closer together at the Sèmè-Podji wharf reduces the energy of the current which promotes the accumulation of sediment. The structure no longer experiences a flow capable of setting in motion the sands accumulated since at least 2022. This element appears to be a fundamental characteristic explaining the erosion observed to the east of the structure.展开更多
Erosion in slurry pumps presents a persistent challenge in industrial applications.This study examines the erosion of the static components of a 150ZJ-C42 centrifugal slurry pump,currently in operation at a beneficiat...Erosion in slurry pumps presents a persistent challenge in industrial applications.This study examines the erosion of the static components of a 150ZJ-C42 centrifugal slurry pump,currently in operation at a beneficiation plant,under varying particle conditions.Utilizing high-precision three-dimensional reverse engineering,the pump’s flow passage geometry was reconstructed to facilitate detailed erosion analysis.Focusing on the front and rear baffles of the pump chamber,as well as the volute,erosion patterns were analyzed for different particle volume concentrations and sizes.The results reveal that the highest erosion damage consistently occurs near the volute tongue,with wear being most severe in regions adjacent to the partition plate near the rear cover.Erosion damage intensity in this area correlates positively with particle diameter.Notably,the average erosion rate in the volute surpasses that of the front and rear chamber liners,reaching a value as high as 6.03×10^(-7)kg·m^(-2)·s^(-1)at a particle concentration of 9%and diameter of 0.1 mm,adversely impacting pump stability.For the pump chamber baffles,increased erosion is observed at a particle diameter of 0.05 mm under constant volume concentration conditions,while higher particle concentrations exacerbate localized erosion.展开更多
Soil erosion is one of the major global hazards threatening the food security of the world population.Soil erosion can be a result of both natural and anthropogenic processes.Field monitoring and models(numerical and ...Soil erosion is one of the major global hazards threatening the food security of the world population.Soil erosion can be a result of both natural and anthropogenic processes.Field monitoring and models(numerical and physical)are commonly used to quantify soil erosion.However,field methods are time-consuming and the models inherently work with a level of uncertainty.Soil erosion studies in the Himalayas have been mostly carried out using modelling but there is a lack of sufficient field data to validate the results.We quantified soil erosion in a small catchment(Pranmati)in the Himalayas using the fallout meteoric^(10)Be nuclide for the first time.Based on the^(10)Be flux delivery rates determined from global circulation models(GCM),we calculated the rates of soil erosion at discrete points in the hilltop and mid-slope regions of hillslopes.The erosion rates vary between 17 mm kyr^(-1)to 68 mm kyr^(-1).These rates were determined in pristine areas that are unaffected by anthropogenic activities,thus,indicate the background erosion rates in the region.We established empirical relationships with estimated erosion rates and topographic parameters to assess the sediment dynamics in the hillslopes.It was observed that the sediment redistribution process operates differently in the mid-slope region compared to the hilltop region,due to increasing complexity of the active processes in the mid-slope region.展开更多
基金funded by the Science and Technology Plan for the Belt and Road Innovation Cooperation Project of Jiangsu Province,China(No.BZ2023003)the National Key Research and Development Program of China(No.2021YFD1500202)+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDA28010100)the“14th Five-Year Plan”Self-Deployment Project of the Institute of Soil Science,Chinese Academy of Sciences(No.ISSAS2418)the National Natural Science Foundation of China(No.42107334)。
文摘Black soils represent only one-sixth of the global arable land area but play an important role in maintaining world food security due to their high fertility and gigantic potential for food production.With the ongoing intensification of agricultural practices and negative natural factors,black soils are confronting enhanced degradation.The holistic overview of black soil degradation and the underlying mechanisms for soil health improvement will be key for agricultural sustainability and food security.In this review,the current status and driving factors of soil degradation in the four major black soil regions of the world are summarized,and effective measures for black soil conservation are proposed.The Northeast Plain of China is the research hotspot with 41.5%of the published studies related to black soil degradation,despite its relatively short history of agricultural reclamation,followed by the East European Plain(28.3%),the Great Plains of North America(20.7%),and the Pampas of South American(7.9%).Among the main types of soil degradation,soil erosion and soil fertility decline(especially organic matter loss)have been reported as the most common problems,with 27.6%and 39.4%of the published studies,respectively.In addition to the natural influences of climate and topography,human activities have been reported to have great influences on the degradation of black soils globally.Unsustainable farming practices and excess in agrochemical applications are common factors reported to accelerate the degradation process and threaten the sustainable use of black soils.Global efforts for black soil conservation and utilization should focus on standardizing evaluation criteria including real-time monitoring and the measures of prevention and restoration for sustainable management.International cooperation in technology and policy is crucial for overcoming the challenges and thus achieving the protection,sustainable use,and management of global black soil resources.
文摘To verify the wear resistance and erosion resistance of Ti-doped Ta_(2)O_(5)coating(TTO),a series of TTOs were prepared by magnetron sputtering technology by controlling the power of the Ti target.The change of growth structure,microstructure,and tribological properties of TTOs with Ti target power was studied.After the erosion test,the variation of erosion damage behavior of TTOs with mechanical properties under different erosion conditions was further studied.The results show that the TTOs eliminate the roughness,voids,and defects in the material due to the mobility of the adsorbed atoms during the growth process,and a flat and dense smooth surface is obtained.Tribological tests show that the TTOs are mainly characterized by plastic deformation and microcrack wear mechanism.Higher Ti target power can improve the wear resistance of TTOs.Erosion test results reveal that the impact crater,furrow,micro-cutting,brittle spalling,and crack formation are the main wear mechanisms of the TTOs samples under erosion conditions.
基金the National Council for Scientific and Technological Development (CNPq) for funding the field studies and for the research productivity fellowship (CNPq/PQ) awarded to Pedro Henrique Augusto MEDEIROS and José Carlos de ARAúJOthe Coordination for the Improvement of Higher Education Personnel (CAPES) for the doctoral scholarship awarded to Teresa Raquel Lima FARIAS (2117/13-4)the Foundation for the Support of Scientific and Technological Development in the State of Ceará (FUNCAP) for the master scholarship awarded to Maria Thereza Rocha CHAVES。
文摘Vegetation plays a major role in soil protection against erosion effects,and studies have also highlighted its importance in retaining sediments from roadside slopes.Yet,hydro-sedimentological studies under natural precipitation conditions are still scarce in semi-arid areas due to difficulties in monitoring the few and very concentrated precipitation events.Quantifying sediment connectivity and yield at watershed scale,often highly impacted by the erosion of unpaved roads,is necessary for management plans.This study aims to evaluate the efficiency of native vegetation on roadside slope segments in Caatinga biome in retaining sediments and conserving the soil in a semi-arid area of Brazil.Surface runoff,sediment concentration,and yield measurements were measured from 34 natural precipitation events in four years on two slopes with and without vegetation.The runoff coefficients of the plot with no vegetation varied from 3.0%to 58.0%,while in the vegetated plot,they showed variation from 1.0%to 21.0%.The annual specific sediment yield ranged from 4.6 to 138.7 kg/(hm^(2)•a)for the vegetated plot and from 34.9 to 608.5 kg/(hm^(2)•a)for the unvegetated one.These results indicate a 4 to 12 times higher soil loss on the unvegetated slope in relation to the vegetated one and demonstrate that natural Caatinga vegetation acts as an effective barrier against surface-transported sediments.Moreover,natural Caatinga vegetation present on the slope plays an important role in breaking connectivity between sediment flows from unpaved roads and the watershed drainage system.These findings indicate that investments in unpaved road and roadside slope restoration,not only enhance road infrastructure but also promote environmental gains by reducing the impact of erosion.
基金co-supported by the National Key R&D Program of China(No.2022YFB3403500)the National Natural Science Foundation of China(No.NSFC52202460)the China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036,and 2023TQ0031)。
文摘In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design stage of ion engine.As one of the core components of ion engine,the grid assembly of ion optic systems may experience long-term ion sputtering in extreme electro-thermal environments,which will eventually lead to its structural and electron-backstreaming failures.In this paper,the current studies of the grid assembly erosion process are systematically analyzed from the aspects of sputtering damage process of grid materials,numerical simulations,and measurements of erosion characteristics of grid assembly.The advantages and disadvantages of various erosion prediction models are highlighted,and the key factors and processes affecting the prediction accuracy of grid assembly erosion patterns are analyzed.Three different types of experimental methods of grid assembly erosion patterns are compared.The analysis in this paper is of great importance for selecting the sputter-resistant grid materials,as well as establishing the erosion models and measurement methods to accurately determine the erosion rate and failure modes of grid assembly.Consequently,the working conditions and structure parameters of ion optic systems could be optimized based on erosion models to promote the ion engine lifetime.
文摘This study evaluates the efficacy of sustainable erosion control using slag-based alkali-activated cement crusts under varying rainfall and wind conditions. The rainfall intensities ranged from 30 mm/h to 120 mm/h, with durations ranging from 15 min to 90 min, and crust slopes of ∼2° (gentle) and 30° (steep). Wind tunnel experiments were conducted at wind velocities of 14 m/s, 21 m/s, and 28 m/s to investigate post-rainfall wind erodibility, along with changes in crust strength and microstructure analysis. The findings show the development of hydrated cementitious phases in alkali-activated material, which form around and between the particles during the alkaline activation process. Alkali-activated cement crusts significantly reduced erosion caused by rainfall and subsequent wind by several orders of magnitude. At the highest rainfall intensity of 120 mm/h, rainfall erosion was measured to be 1654.81 kg/m2 for untreated samples and 0.89 kg/m2 for treated samples, demonstrating a substantial 99.95% reduction in erosion due to the treatment. Similarly, at the highest wind speed tested, wind erosion was 122.75 kg/m2 for untreated samples and 0.095 kg/m2 for treated samples, indicating a significant 99.92% reduction in erosion due to the formation of an alkali-activated cement crust on the soil surface. However, exposure of the samples to 120 mm/h rainfall for 90 min resulted in a 5.2-fold increase in wind erosion compared to pre-rainfall conditions. Similarly, penetrometer results indicated a 37%–54% reduction in post-rainfall surface strength.
文摘Changes in the coastline are characterized by accretion and erosion. The aim of this study is to contribute to a better understanding of the dynamics of the coastline and the study areas with a view to mitigating and preventing the risk of coastal erosion in order to propose a coastal occupation model with planned development policies in the future. These phenomena lead to changes in the position of the coastline. After extraction, the satellite images are compiled, then superimposed and processed using Geographic Information Systems (GIS) for statistical calculation of coastline change rates. A morphosedimentary study is carried out using topography and sedimentology. The topographic method is used to calculate sediment volumes using monthly profiles. The sedimentological method is used to determine the granulometric variations in the morphological units by calculating sedimentological indices. With erosion rates of −2.13 m/yr and −2.17 m/yr respectively at Djiffère (Palmarin and Sangomar breccia) and Joal (Joal Fadhiouth and Ngazobil), the EPR index revealed a sediment deficit. Palmarin Ngallou and the island of Fadhiouth are undergoing accretion at rates of +1.43 m/yr and +1.14 m/yr respectively. From a topographical point of view, the respective accumulations of −13.74 m3/m of beach and −8.65 m3/m of beach at Djiffère and Joal respectively point to significant erosion on all the aerial beach units, while for the underwater beaches, accretion was noted with accumulations of +4.00 m3/m of beach and +5.94 m3/m at Djiffère and Joal respectively. As for the sedimentological results, the Mz index shows a decrease in grain size from the high beach to the surf zone. Some points show bimodal deposits, showing the impact of the dune on beach activity, confirmed by the dispersion on the Mz-sigma diagram. The three methods used in this work show that the Djiffère sector in Joal is dominated by erosion, even though accretion points can be noted.
基金financially supported by the Water and Land Resource Center(WLRC),Addis Ababa University(AAU),Water Security and Sustainable Development Hub funded by the UK Research and Innovation’s Global Challenges Research Fund(GCRF):ES/S008179/1.
文摘In many developing countries with poorly managed landscapes,soil erosion threatens the sustainability of water bodies.The main limitations of this study are the lack of daily sediment data,lithology,higher-resolution DEM data,and socioeconomic factors.Poor land use policy and resource management in the Upper Awash Sub-basin lead to soil erosion and sedimentation of hydrological infrastructure,Effective watershed prioritization requires integrating land use,hydrology,sediment load,and morphometric factors but often faces gaps,especially in the study area.This research aims to prioritise the Upper Awash Sub-Basin by its morphometric,land use and cover(LULC),and sediment yield characteristics.We used the integrated AHP-VIKOR multi-attribute decision-making method to prioritise watersheds,incorporating morphometry,LULC,and sediment load attributes in the simple matrix approach.The findings showed the following classes of erosion:exceedingly high(2722.14 km2),high(2524.46 km2),moderate(2205.48 km2),low(1611.43 km2),and extremely low(854.35 km2).Sub-watersheds WS6,WS8,WS10,WS13,and WS24 are the top priority for watershed management.The study ranked watersheds based on various attributes but encountered limitations such as the lack of daily sediment data,geological structure,and lithology.It can be concluded that this approach is very important to identify and categorize hotspots of soil erosion sub-watersheds for planners and decision-makers for conserving water and soil and for different environmental management purposes.
文摘Soil erosion from water has become a relevant issue at global level.In Guinea in particular,erosion has worrying effects,due to natural conditions and human impact,especially in the Nzérékore city in forest region.This paper proposed a soil erosion modeling by rainfall effect in the prefecture of N'Zérékoré.To achieve this objective,monthly and annual rainfall data for the N'Zérékorécity were collected at the meteorological station over the period from 1980 to 2024.The analysis of rainfall aggressiveness was possible using the Fournier index.For data processing,we used Microsoft Excel,Python and the ARIMA(AutoRegressive Integrated Moving Average)model for soil aggressiveness predicted by rainfall.It was found that,from 2000 to 2009,erosion was higher compared to other periods with a rate of 60%,or 6 years of high rainfall aggression.From the periods 1990 to 1999 and 2010 to 2019,the lowest rainfall aggressiveness was recorded,with 60%or 6 years of low erosivity.However,from period 1980 to 1989 the highest rate(70%)of very high rainfall erosivity was recorded.The results show three levels of rainfall aggressiveness on an annual scale:a very high level of erosivity with a rate of 22.2%or 10 years,followed by a high level of 35.6%or 16 years of strong erosion.The moderate erosivity level corresponds to 42.2%or 19 years.The model predicts a stability of the erosivity index around 77.14 over the period 2025-2034.During the forty(45)years the rainfall erosivity index was very unstable characterized by strong erosion,however it would be stable in the next ten(10)years.
基金the CMEC Technology Incubation Project(No.CMEC-KJFH-2018-02)the National Science Foundation of China(No.41877250)+2 种基金the Fundamental Research Funds for the Central Universities,CHD(Nos.300102263512 and 300102260401)Shaanxi Science and Technology Coordination Innovation Project(No.2011KTZB03-02-02)the National Geological Survey of China(No.DD20160264)。
文摘Since the 1950's,212 earth fissures have been discovered in the Wei River Basin.During a field survey in 2016,an additional 48 earth fissures were discovered in Anren area,northeast of the Wei River Basin.The characteristics and formation mechanisms of these fissures were studied through field investigations,measurements,trench excavation,and drilling.On-site investigations indicated that these earth fissures were distributed along a fault-controlled geomorphic boundary.Fissures trended at 60°-80°NE and were divided into five groups.Trenches revealed multiple secondary fissures,exposing severe soil ruptures in the shallow earth surfaces.Drilling profiles revealed that earth fissures dislocated several strata,and resembled synsedimentary faults.Seismic reflection profiles revealed buried faults beneath the earth fissures.The Anren area fissures formed in the following three stages:regional extension that initially generated multiple buried faults;seismic activity rupturing multiple strata,resulting in multiple buried fractures;and finally,erosion processes that propagated the buried fractures to the surface,forming the current earth fissures.
基金National Natural Science Foundation of China(Youth Program),No.42201110。
文摘Soil erosion(SE)is a critical form of land degradation that significantly threatens the health of terrestrial ecosystems worldwide.The Qinba Mountains represent a vital geo-ecological transition zone in China.Therefore,analyzing the dynamics of SE in relation to climate changes and land use/cover(LULC)change is essential for guiding ecological conservation efforts in this region.The soil erosion intensity(SEI)from 2001 to 2020 was estimated using the Revised Universal Soil Loss Equation(RUSLE).For the period of 2021–2040,SEI projections were made based on CMIP6 data,utilizing the Statistical Downscaling Model alongside the CA-Markov model.Variations in SEI under four distinct shared socio-economic pathways were compared.Additionally,statistical methods were employed to evaluate the long-term impacts of climate and LULC change on SE.Findings indicate that between 2021and 2040,both precipitation and rainfall erosivity are expected to increase by approximately 8%–12%and 3%–14%,respectively.Based on differing socio-economic pathways,the soil erosion rate(SER)is predicted to rise by 12%–32%,with SSP2-4.5 anticipated to result in the highest SER.An analysis of contributing factors revealed that precipitation intensity and total precipitation are likely to escalate SE,while elevated temperatures may mitigate it.Among all types of LULC,barren land is particularly susceptible to erosion and remains a priority for conservation.The generated SEI maps will aid in promoting sustainable land use and provide crucial support for mitigating ecological risks from climate change.
基金National Key Research and Development Program of China(No.2022YFC2904900)the National Natural Science Foundation of China(No.U1902221).
文摘The erosion process and kinetics of PbTe particles in a selenium melt were investigated.The results reveal that the limiting step of the reaction is controlled by product layer diffusion and the interfacial chemical reaction at low temperatures(573,583,and 593 K),but the limiting step is controlled by boundary layer diffusion at high temperatures(603 and 613 K).The Se-and Te-atom diffusion in the product layer becomes unbalanced as the product layer thickens,with Kirkendall voids generating in the product layer accelerating PbTe particle erosion.After the PbTe impurities in the selenium melt evolve into PbSe and Te,Te is evenly distributed in the selenium melt owing to the solubility of Se and Te.This study serves to clarify the evolution behavior of PbTe impurities in the selenium melt and the reason that Te often occurs in Se.
基金funded by the Guangdong Major Project of Basic and Applied Basic Research(2021B0301030007)the Supplemental Funds for Major Scientific Research Projects of Beijing Normal University,Zhuhai(ZHPT2023013)+1 种基金the National Natural Science Foundation of China(42301387)the Science and Technology Program of Guangdong(No.2024B1212070012)。
文摘The topographic factor(LS factor),derived from the multiplication of the slope length(L)and slope steepness(S)factors,is a vital parameter in soil erosion models.Generated from the digital elevation model(DEM),the LS factor always varies with the changing DEM resolution,i.e.,the LS factor scale effect.Previous studies have found the phenomenon of the LS factor scale effect,but the underlying causes of this phenomenon has not been well explored.Therefore,how the DEM resolution affects the LS factor and how the scale effect of the L and S factors influence the LS factor scale effect remains unclear.To address these problems,we collected 20 watersheds from the Guangdong Province with different topographic reliefs,and compared the corresponding L,S and LS factors at 10-m and 30-m resolution DEMs.Our results indicate that the S factor,heavily influenced by slope underestimation in coarse-resolution DEMs,makes a difference in the LS factor scale effect.In addition,the LS factor scale effect becomes less significant with increasing reliefs,suggesting the possibility of using 30-m DEM for LS calculation in rugged terrains.Our findings on the underlying mechanisms of the LS factor scale effect help to identify the uncertainty in the LS factor estimation,thereby enhancing the accuracy of soil erosion assessment,particularly in regions with different topographic characteristics and contribute to more effective soil conservation strategies and decision-making.
基金research was funded bymultiple sources,including the Guangxi Natural Science Foundation of Youth Fund(2020GXNSFBA159004)the National Natural Science Foundation Project of China(51779204)the Guilin University of Technology High-Level Talent Research Startup Project(GUTQDJJ2018069).
文摘The particle size distribution plays a crucial role in the transportation and deposition of eroded sediments.Gaining insights into the related sorting mechanism can significantly enhance our understanding of such processes.In this study,sand-covered slopes were examined.A controlled indoor rainfall simulation was conducted on loess slopes with a 12°incline and a rainfall intensity of 1.5 mm/min.These slopes were then covered with sand layers of varying thicknesses—0.5,1.0,and 1.5 cm—to observe their effects.The findings have revealed that as the thickness of the sand cover increases,the content of sediment particles smaller than 0.054 mm decreases.In contrast,the content of particles larger than 0.054 mm increases after the sixth minute of runoff.The eroded sediment was predominantly composed of silt.During the inter-rill erosion stage,runoff primarily transported particles larger than 0.054 mm.However,in the subsequent rill erosion and combined rill and inter-rill erosion stages,the runoff predominantly carried finer particles,smaller than 0.054 mm.Moreover,the presence of the sand layer significantly influenced the size and form of the eroded sediment particles.Initially,during the first 10 min of runoff,the eroded particles were predominantly larger than 0.054 mm.After this period,however,the particle size shifted,with the majority of particles being smaller than 0.054 mm.This study highlights the intricate relationship between sediment sorting,the thickness of sand covers,and the dynamics of sediment transport under rainfall-induced erosion.
基金Supported by Fundamental Research Fund for the Central Universities(2452021088,2452021081)Science and Technology Project of State Grid Shandong Electric Power Company(5200-202416091A-1-1-ZN)Sanmenxia Science and Technology Major Projec(2023L01002).
文摘The paper delved into specific causes of soil erosion during the construction phase of highway projects,analyzed the intrinsic mechanisms behind erosion formation,and examined in detail external dynamic factors contributing to soil erosion,such as rainfall scouring and wind erosion.Additionally,this paper summarized the unique characteristics of soil and water loss during road construction and the potential severe hazards it may bring,aiming to provide valuable reference for professionals in related fields and to promote further development in the study of natural slope erosion.
基金supported by the China Postdoc-toral Science Foundation(No.2023M732495)the Shanxi Provincial Basic Research Program(Nos.202103021223180 and 202203021221120)the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FPEJ-2024-1261-02”.
文摘Low erosion high-energy propellant is one of the research directions to extend the weapon’s life and improve the weapon’s capability.In this study,energetic propellants containing different corrosion inhibitors were designed and prepared.Close bomb tests and semi-confined bomb experiments were used to investigate the burning and erosion properties of the propellants.The mechanism of erosion-reducing of titanium dioxide(titania,TiO_(2)),talc,and octaphenylsilsesquioxane(OPS)on the propellant was comparatively analyzed.The results show that OPS has the lowest burning rate and the longest burning time,and a minimized loss of fire force,with the best effect of explosion heat reduction.The erosion reduction efficiency of OPS is twice that of TiO_(2) and talc.The mechanism analysis shows that the decomposition and heat absorption of OPS can effectively reduce the thermal erosion effect and carbon erosion,and the gas produced can reduce the loss of chamber pressure and form a uniformly distributed nano-SiO_(2) protective layer.This solid-state high-efficiency organosilicon erosion inhibitor is an important guide for designing high-energy low-erosion gun propellants.
基金supported by the National Key Research and Development Program(No.2022YFC2806200)the National Key Research and Development Program(No.2023YFC2810800)the Natural Science Foundation of China(No.52001055).
文摘In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion reduction,and water reduction)using a cylindrical stirring system.The corrosion-enhanced erosion(C-E)rates were determined for each condition.The results revealed that pure iron displayed similar pure erosion behaviour across all three cathodic reactions.When the cathodic reactions involve hydrogen ion reduction or water reduction,the erosion-corrosion of pure iron manifested as uniform damage,with the reduction in hardness being the main cause of the C-E in this case.Conversely,in the case of oxy-gen reduction reaction as the cathodic reaction,the erosion-corrosion presented as pitting damage,with the reduction in hardness resulting from localized concentration of anodic current and the formation of easily worn protruding flaky iron structures at the edges of the pits as the main mechanism of the C-E.Moreover,linear and exponential relationships were found between the C-E rate and the anodic current density for uniform damage and pitting damage,respectively.Finally,the concept of surface equivalent hardness was proposed,along with the establishment of a mathematical model for surface equivalent hardness based on the relationships between the C-E rate and the anodic current density.Utilizing the surface equivalent hardness enables the evaluation of the erosion rate on material surfaces considering the coupled effect.
基金supported by the Natural Science Foundation Project of Inner Mongolia Autonomous Region(2024LHMS03017)Research Capacity Enhancement“Unveiling and Leading”Project of Inner Mongolia Forestry Science Research Institute(2024NLTS03).
文摘The rhizosphere bacteria play crucial roles in plant health and growth as they are involved in assimilating nutrients and resisting adverse conditions such as nutrient stress,drought,and wind erosion.Agriophyllum squarrosum(L.)Moq.is a pioneer plant used in sand fixation due to its strong resistance to drought and wind erosion.However,the bacterial community characteristics and ecological function in the rhizosphere of A.squarrosum are poorly understood.In this study,soil samples were collected from different developmental stages(seedling stage,vegetative stage,reproductive stage,and withering stage)of A.squarrosum.Illumina Miseq sequencing was used to detect differences in soil bacterial abundance.The Phylogenetic Investigation of Communities by Reconstruction of Unobserved States(PICRUSt)program was used to predict bacterial functions,and the relationships among bacteria,functional populations,and soil nutrients were examined using a heatmap analysis.The results showed that the Shannon and Sobs indices of rhizosphere bacteria were significantly higher during the reproductive stage than during the other stages.Pantoea sp.(7.03%)was the dominant genus during the seedling stage;Arthrobacter sp.was the dominant genus during the vegetative(13.94%),reproductive(7.57%),and withering(12.30%)stages.The relative abundances of Chloroflexi,Acidobacteria,and Gemmatimonadetes were significantly high during the reproductive stage.According to the PICRUSt analysis,membrane transport,signal transduction,and environmental adaptation of the bacterial functional population occurred during the seedling stage.Carbohydrate metabolism increased during the vegetative stage,while energy metabolism,lipid metabolism,and biosynthesis of other secondary metabolites of the bacterial functional population significantly increased during the reproductive stage.The abundances of bacterial communities,functional genes,and soil nutrients were synergistically altered during various developmental stages.Our findings suggest that the developmental stages of A.squarrosum play a significant role in defining the composition and structure of bacterial communities in the rhizosphere.The results will provide a basis for better prediction and understanding of soil bacterial metabolic potential and functions of A.squarrosum rhizosphere in sandy areas.
文摘Port structures constitute the main link in the maritime transport chain of coastal countries and therefore contribute to their economic development. But it should be noted that the installation of said works is not without consequences for the countries concerned. Benin, a country in the Gulf of Guinea, is no exception to this phenomenon because, due to its maritime history, it has a heritage of port structures. These structures, built on its coastline, cause a wide variety of environmental problems such as silting and erosion on either side of them. The general objective of this article is to contribute to the proper functionality of port facilities while minimizing environmental problems that may arise. It aims to provide managers with a tool allowing them to fully understand the state of their assets in order to rationalize maintenance actions. In order to achieve this objective, an assessment of the state of the structure, and then a structural diagnosis are necessary and recommendations can be established to restore the level of service of the latter. As a result, two examples were presented: the wharf of the Sèmè-Podji pipeline project and the maritime piles project of the Wasco de Gama bridge (control project), and recommendations adapted to this objective were established. The comparative analysis of the two examples, both maritime works, revealed an under-sizing at the level of the spans of the wharf bridge of the Sèmè-Podji pipeline project (spans of 7 m in length), while these spans vary on average by 45 m to 62 m for the Wasco da Gama bridge. Bringing the piles closer together at the Sèmè-Podji wharf reduces the energy of the current which promotes the accumulation of sediment. The structure no longer experiences a flow capable of setting in motion the sands accumulated since at least 2022. This element appears to be a fundamental characteristic explaining the erosion observed to the east of the structure.
基金The authors gratefully acknowledge the filnancial support of the National Natural Science Foundation of China(Grant No.52369018)the Major Training Program of University Research and Innovation Platform of Gansu Provincial Department of Education(No.2024CXPT-09)+1 种基金the Administration of Central Funds Guiding the Local Science and Technology Development,China(Grant No.23ZYQA0320)the Double First-Class Key Program of Gansu Provincial Department of Education,Grant No.GCJ2022-38.
文摘Erosion in slurry pumps presents a persistent challenge in industrial applications.This study examines the erosion of the static components of a 150ZJ-C42 centrifugal slurry pump,currently in operation at a beneficiation plant,under varying particle conditions.Utilizing high-precision three-dimensional reverse engineering,the pump’s flow passage geometry was reconstructed to facilitate detailed erosion analysis.Focusing on the front and rear baffles of the pump chamber,as well as the volute,erosion patterns were analyzed for different particle volume concentrations and sizes.The results reveal that the highest erosion damage consistently occurs near the volute tongue,with wear being most severe in regions adjacent to the partition plate near the rear cover.Erosion damage intensity in this area correlates positively with particle diameter.Notably,the average erosion rate in the volute surpasses that of the front and rear chamber liners,reaching a value as high as 6.03×10^(-7)kg·m^(-2)·s^(-1)at a particle concentration of 9%and diameter of 0.1 mm,adversely impacting pump stability.For the pump chamber baffles,increased erosion is observed at a particle diameter of 0.05 mm under constant volume concentration conditions,while higher particle concentrations exacerbate localized erosion.
基金financially supported by Council of Scientific and Industrial Research(CSIR)(grant no.09/045(1399)/2015-EMR-I)the Ministry of Earth Sciences(Mo ES),Government of India(grant no.Mo ES/P.O.(Geo)/95/2017)。
文摘Soil erosion is one of the major global hazards threatening the food security of the world population.Soil erosion can be a result of both natural and anthropogenic processes.Field monitoring and models(numerical and physical)are commonly used to quantify soil erosion.However,field methods are time-consuming and the models inherently work with a level of uncertainty.Soil erosion studies in the Himalayas have been mostly carried out using modelling but there is a lack of sufficient field data to validate the results.We quantified soil erosion in a small catchment(Pranmati)in the Himalayas using the fallout meteoric^(10)Be nuclide for the first time.Based on the^(10)Be flux delivery rates determined from global circulation models(GCM),we calculated the rates of soil erosion at discrete points in the hilltop and mid-slope regions of hillslopes.The erosion rates vary between 17 mm kyr^(-1)to 68 mm kyr^(-1).These rates were determined in pristine areas that are unaffected by anthropogenic activities,thus,indicate the background erosion rates in the region.We established empirical relationships with estimated erosion rates and topographic parameters to assess the sediment dynamics in the hillslopes.It was observed that the sediment redistribution process operates differently in the mid-slope region compared to the hilltop region,due to increasing complexity of the active processes in the mid-slope region.
