Mass wasting is globally recognized as a key geomorphic agent in permanent gully expansion and greatly contributes to watershed sediment losses.Though its formation process has been assessed by some physical models,th...Mass wasting is globally recognized as a key geomorphic agent in permanent gully expansion and greatly contributes to watershed sediment losses.Though its formation process has been assessed by some physical models,the occurrence and rainfall threshold have been rarely documented.In this study,rainfall-induced mass wasting events in two permanent gullies located in the Mollisols region of Northeast China,with Mollisols(gully 1)and sandy soil(gully 2)underneath were observed,and their differences were explored based on their soil strengths,hydraulic properties,excess topographies,and theoretical rainfall amounts.The sandy soil had a higher strength,faster pore water pressure dissipation rate,and lower suction stress at a specific soil moisture content compared to the black soil.The erosion thickness of the gully bed and sidewalls in gully 1 was shallower compared to gully 2.This was confirmed by the relationship between the erosion thickness and excess topography.The differences in the mass wasting erosion of the gully bed and sidewalls were due to the higher shear strength and well-drained hydraulic properties of the sandy soil compared to the black-soil.An infinite model was chosen to examine the temporal order of the mass wasting in the two gullies.It was found that the mass wasting in gully 2 occurred earlier than that in gully 1.This was likely due to the occurrence of an intense storm with less rainfall at the location of gully 2,while a light storm with heavier rainfall occurred in the location of gully 1.As Mollisols and sandy soil are the typical soil horizons in the Mollisols region worldwide,the results of this work could provide insightful knowledge for understanding the physical process of permanent gully expansion,which may be helpful for developing prediction models for sediment losses in some watersheds with vast Mollisols and highly developed gully system.展开更多
During electrochemical machining(ECM),the passivation film formed on the surface of titanium alloy can lead to uneven dissolution and pitting.Solid particle erosion can effectively remove this passivation film.In this...During electrochemical machining(ECM),the passivation film formed on the surface of titanium alloy can lead to uneven dissolution and pitting.Solid particle erosion can effectively remove this passivation film.In this paper,the electrochemical dissolution behavior of Ti-6.5Al-2Zr-1Mo-1V(TA15)titanium alloy at without particle impact,low(15°)and high(90°)angle particle impact was investigated,and the influence of Al_(2)O_(3)particles on ECM was systematically expounded.It was found that under the condition of no particle erosion,the surface of electrochemically processed titanium alloy had serious pitting corrosion due to the influence of the passivation film,and the surface roughness(Sa)of the local area reached 10.088μm.Under the condition of a high-impact angle(90°),due to the existence of strain hardening and particle embedding,only the edge of the surface is dissolved,while the central area is almost insoluble,with the surface roughness(S_(a))reaching 16.086μm.On the contrary,under the condition of a low-impact angle(15°),the machining efficiency and surface quality of the material were significantly improved due to the ploughing effect and galvanic corrosion,and the surface roughness(S_(a))reached 2.823μm.Based on these findings,the electrochemical dissolution model of TA15 titanium alloy under different particle erosion conditions was established.展开更多
Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard...Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard types,ice-water phase change,and enhanced mobility of the mass flow.Scientifically simulating these physical phenomena proves challenging.This study introduces GMFA(glacier mass flow analysis),an integrated numerical model that advances the field by:(1)proposing depth-averaged fluctuation energy and internal energy equations,(2)incorporating the ice-water phase change and the entrainment-deposition process,and(3)capturing their effects on mass flow runout characteristics.The model employs the finite volume method to solve the multi-physics coupled governing equations,enabling efficient large-scale simulations.The model is verified through three numerical tests covering flow dynamics,temperature evolution,and thermo-hydro-mechanical runout processes.The model is applied to analyze a hazard chain that occurred on 10 September 2020 on the Tibetan Plateau.The multi-scenario simulation results indicate an entrained mass volume of(4.95±0.11)×10^(5)m^(3),and a ratio of entrained mass volume to source material volume of 0.44.The solid concentration decreases from 0.6-0.7 to 0.1-0.15 with increasing runout distance,indicating a transition from avalanche to debris flood.The internal energy rises by(3-4)×10^(3)kJ/m^(3),driving rapid ice melting from 0.1 to 0.2 to near-zero concentration.The model effectively quantifies volume amplification,ice-water phase changes,and multi-hazard transformations.This model pushes the geoscience frontier,extending computational capability from single-to multi-hazard simulations and providing a powerful tool for analyzing glacier cascading hazards.展开更多
To resolve severe slag penetration and erosion in Al_(2)O_(3)-SiC-C refractories during high scrap ratio iron ladle operation,a novel strategy utilizing exogenous MgAl_(2)O_(4) spinel as a sacrificial FeO_(x) scavenge...To resolve severe slag penetration and erosion in Al_(2)O_(3)-SiC-C refractories during high scrap ratio iron ladle operation,a novel strategy utilizing exogenous MgAl_(2)O_(4) spinel as a sacrificial FeO_(x) scavenger was proposed.Al_(2)O_(3)-SiC-C refractories produced with plate-like corundum,silicon carbide,and flake graphite incorporating MgAl_(2)O_(4) additives were cured at 1400℃ in the condition of carbon embedding.The impacts of additives on phase composition,microscopic morphology,and performance of materials were studied.The results indicated that Al_(2)O_(3)-SiC-C refractories with the addition of 2 wt.%MgAl_(2)O_(4) exhibited a smaller oxidation area after oxidation tests compared to samples without MgAl_(2)O_(4),resulting in 28%improvement in oxidation resistance compared to blank samples.In the erosion test,the results informed that adding 4 wt.%MgAl_(2)O_(4) induced significant interfacial slag modification:MgAl_(2)O_(4) dynamically dissolved FeO_(x) to form protective Mg(Fe,Al)_(2)O_(4) solid solution on the slag-refractory interface.This sacrificial dissolution effectively immobilized FeO_(x),elevated local slag viscosity,and fundamentally inhibited slag penetration and matrix dissolution.The erosion index decreased from 50%in the blank group to 27.4%.展开更多
To predict the erosion and abrasion of high bore pressure tank gun barrel, the least square support vector machine (LSSVM) algorithm was used. Based on the gun firing test data, the prediction model for barrel's e...To predict the erosion and abrasion of high bore pressure tank gun barrel, the least square support vector machine (LSSVM) algorithm was used. Based on the gun firing test data, the prediction model for barrel's erosion and abrasion was established. It was adopted to predict the wear increment of gun barrel. The results show that the prediction values given by the model coincide with the measured data better, and the model can predict the barrel's wear accurately and rapidly.展开更多
WC M hard faced ceramic coating was made on the substrate of steel by means of high velocity oxygen fuel flame (HVOF) thermal spraying. The resistance of this coating to cavitation erosion and abrasion (CEA) is about ...WC M hard faced ceramic coating was made on the substrate of steel by means of high velocity oxygen fuel flame (HVOF) thermal spraying. The resistance of this coating to cavitation erosion and abrasion (CEA) is about 2.5 times higher than that of 188 stainless steel, and is about 1.5 times higher than that of Stellite alloy (CoCrWC) made in America. When this coating were applied to the hydraulic power stations with more silt content in the flow water, which reaches 50 kg/m 3, the resistance of above mentioned coating to CEA was about 2 times to that of NiCr alloy coating, and is about 45 times to that of OCr13Ni4Mo stainless steel. In addition, the micro hardness, microstructures and electron probe analyzing of the WC M coating are all discussed.展开更多
To make clear the influence of abrasive hardness on the erosion effect,the erosion experiments of abrasive air jet with the same impact energy were carried out.The influence of abrasive hardness on the erosion effect ...To make clear the influence of abrasive hardness on the erosion effect,the erosion experiments of abrasive air jet with the same impact energy were carried out.The influence of abrasive hardness on the erosion effect is clarified by comparing the different erosion depths.The main conclusions are as follows.Under the same mass flow rate and mesh number,the abrasive with a higher density needs greater pressure irrespective of hardness.After erosion damage,the abrasive size exhibits a Weibull distribution.The shape parameterβand Weibull distribution function of four types of abrasives are derived by the least squares method;moreover,βis found to have a quadratic relation with abrasive hardness.The results of the erosion experiments show that abrasive hardness and erosion depth are quadratically related.By calculating the increase in surface energy after abrasive erosion crushing,it is found that abrasive hardness has a quadratic relation with surface energy and that the increases in erosion depth and surface energy consumption are basically identical.In conclusion,the effect is a soft abrasive impact when the ratio of abrasive hardness(Ha)to the material hardness(Hm)is<2.6,and it is a hard abrasive impact when Ha/Hm>3.展开更多
In this paper, we investigates the concretes respec- tively incorporated with 5% （m ： rn） nano-SiO2 （NS）, 40% （rn ： m） super- fine slag （SS）, as well as 40% （m ： m） SS combining 20% replacement of sand vo...In this paper, we investigates the concretes respec- tively incorporated with 5% （m ： rn） nano-SiO2 （NS）, 40% （rn ： m） super- fine slag （SS）, as well as 40% （m ： m） SS combining 20% replacement of sand volume with RP. The tested mechanical properties include compressive strength, abrasion resistant strength, and elastic modulus. The results indicate that among these concretes, the SS-RP concrete has the highest abrasion re- sistant strength with increment ratios of 1.71 and 1.35 at 28 days and 90 days, respectively; the SS concrete has the highest com- pressive strength with increment ratios of 2.03 and 1.95 at 28 days and 90 days, respectively; the elastic modulus of SS-RP concrete significantly decrease compared with the SS concrete and is slightly higher than that of the reference concrete. It is concluded that NS, SS, and RP all can improve the abrasion resistance of concrete, and it will be significantly improved when SS combining RP is incorporated.展开更多
Transparent materials utilized as underwater optical windows are highly vulnerable to various forms of pollution or abrasion due to their intrinsic hydrophilic properties.This susceptibility is particularly pronounced...Transparent materials utilized as underwater optical windows are highly vulnerable to various forms of pollution or abrasion due to their intrinsic hydrophilic properties.This susceptibility is particularly pronounced in underwater environments where pollutants can impede the operation of these optical devices,significantly degrading or even compromising their optical properties.The glass catfish,known for its remarkable transparency in water,maintains surface cleanliness and clarity despite exposure to contaminants,impurities abrasion,and hydraulic pressure.Inspired by the glass catfish’s natural attributes,this study introduces a new solution named subaquatic abrasion-resistant and anti-fouling window(SAAW).Utilizing femtosecond laser ablation and electrodeposition,the SAAW is engineered by embedding fine metal bone structures into a transparent substrate and anti-fouling sliding layer,akin to the sturdy bones among catfish’s body.This approach significantly bolsters the window’s abrasion resistance and anti-fouling performance while maintaining high light transmittance.The sliding layer on the SAAW’s surface remarkably reduces the friction of various liquids,which is the reason that SAAW owns the great anti-fouling property.The SAAW demonstrates outstanding optical clarity even after enduring hundreds of sandpaper abrasions,attributing to the fine metal bone structures bearing all external forces and protecting the sliding layer of SAAW.Furthermore,it exhibits exceptional resistance to biological adhesion and underwater pressure.In a green algae environment,the window remains clean with minimal change in transmittance over one month.Moreover,it retains its wettability and anti-fouling properties when subjected to a depth of 30 m of underwater pressure for 30 d.Hence,the SAAW prepared by femtosecond laser ablation and electrodeposition presents a promising strategy for developing stable optical windows in liquid environments.展开更多
The fabrication of miniature structures on components with high-integrity surface quality represents one of the cutting edge technologies in the 21st century.The materials used to construct such small structures are o...The fabrication of miniature structures on components with high-integrity surface quality represents one of the cutting edge technologies in the 21st century.The materials used to construct such small structures are often difficult-to-machine.Many other readily available technologies either cannot realise necessary precision or are costly.Abrasive waterjet(AWJ)is a favourable technology for the machining of difficult-to-machine materials.However,this technology is generally aimed at large stock removal.A reduction in the scale of this technology is an attractive avenue for meeting the pressing need of industry in the production of damage-free micro features.This paper reviews some of the work that has been undertaken at UNSW Sydney about the development of such an AWJ technology,focusing on the system design currently employed to generate a micro abrasive jet,the erosion mechanisms associated with processing some typical brittle materials of both single-and two-phased.Processing models based on the findings are also presented.The review concludes on the viability of the technology and the prevailing trend in its development.展开更多
A carcass is the innermost layer of a deep-sea unbonded flexible pipe,which is in direct contact with the gas/liquid-solid multi-phase flow.Considering that stress-accelerated erosion is common for carcasses,this stud...A carcass is the innermost layer of a deep-sea unbonded flexible pipe,which is in direct contact with the gas/liquid-solid multi-phase flow.Considering that stress-accelerated erosion is common for carcasses,this study proposes a general model and simulation method for stress-accelerated erosion(SE)of carcasses under external water pressure.First,an SE model suitable for 316 stainless steel was developed,which was then used for stress-erosion simulation for an external pressurized carcass,and the solid domain,fluid domain and rough inner surface of the carcass were carefully considered.Moreover,a simplified model(equivalent smooth pipe)was also established on the basis of the main geometric characteristics of the carcass,and the stress-erosion characteristics under different operating conditions,including the effects of the elastic stress level,flow velocity,particle diameter and concentration,were carefully compared,and the key factors governing the elastic stress-erosion of the carcass were discussed.Finally,a modified geometry factor(GF)for carcasses was proposed considering the stress acceleration effect.展开更多
A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion...A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion.Furthermore,damage can impact the response characteristics of the riser,but varying environmental loadings easily mask it.Thus,distin-guishing between riser damage and environmental effects poses a considerable challenge.To address this issue,a cantilevered model is created for a deep-sea mining riser via the concentrated mass method,and a time-domain analytical strategy is developed.The vortex-induced vibration(VIV)response characteristics of the riser are initially examined,considering various damage conditions and flow velocities.The study results revealed four primary observations:(a)effective tension can serve as a reliable indicator for identifying damage at lower velocities;(b)there are noticeable differences in displacement between the healthy and damaged risers in the in-line direction rather than the cross-flow direction;(c)frequency characteristics can more effectively distinguish the damage conditions at high flow velocities,with the mean square frequency and frequency variance being more effective than the centroid frequency and root variance frequency;(d)displacement differences are more sensitive to damage occurring near the top and bottom of the riser,while both velocity variations and structural damage can influence displacements,especially in regions between modal nodes.The vibrational behavior and damage indicators are clarified for structural health monitoring of deep-sea mining risers during lifting operations.展开更多
Carbon Carbon(C/C)composites in thermal-protection system are exposed to severe thermochemical ablation and mechanical erosion,and their thermal-protection performance is of vital importance to the structural safety a...Carbon Carbon(C/C)composites in thermal-protection system are exposed to severe thermochemical ablation and mechanical erosion,and their thermal-protection performance is of vital importance to the structural safety and flight status of hypersonic vehicles.We numerically analyzes the mesoscopic ablation-erosion of C/C Composites with Inclined Fibers(CCIF).First,a thermochemical ablation model describing the reaction-diffusion coupled problem of C/C composites on mesoscale is employed to analyze ablative process,and the corresponding surface ablation morphology is obtained.Then,the ablation morphology of CCIF is taken as the geometrical model for mechanical erosion analysis,and their damage and failure behavior under high-speed airflow shear is analyzed by using progressive damage method.Moreover,the effects of fiber inclined angle and airflow direction on the mechanical erosion of CCIF are investigated,and the ablationerosion behavior is analyzed and discussed.The results show that the failure modes of mechanical erosion in inner and edge regions are obviously different,showing granular and block erosion phenomena respectively.The mechanical erosion of CCIF in the direction of reverse flow is easier than that in the direction of forward flow.These results can provide a theoretical basis for the design and optimization of thermal protection system materials.展开更多
Abrasive waterjet(AWJ)fracturing has become an accepted horizontal multistage stimulation technique due to its flexibility and high efficiency of extensive fracture placement.The downhole tool failure of AWJ fracturin...Abrasive waterjet(AWJ)fracturing has become an accepted horizontal multistage stimulation technique due to its flexibility and high efficiency of extensive fracture placement.The downhole tool failure of AWJ fracturing becomes an issue in the massive hydraulic fracturing because of high velocity and proppant erosion.This paper proposed a 3D computational fluid dynamics(CFD)-based erosion model by considering high-velocity waterjet impact,proppant shear erosion,and specific inner structure of hydra-jet tool body.The discrete phase approach was used to track the proppant transport and its concentration distribution.Field observation provides strong evidence of erosion patterns and mechanisms obtained from CFD simulation.The results show that the erosion rate has a space dependence in the inner wall of the tool body.The severe erosion areas are primarily located at the entries of the nozzle.Evident erosion patterns are found including a‘Rabbit’s ear’erosion at the upper-layer nozzles and a half bottom loop erosion at the lower-layer nozzles.Erosion mechanisms attribute to high flow velocity at the entry of nozzles and the inertia force of proppant.Sensitivity analysis demonstrates that the pumping rate is a primary factor contributing to erosion intensity.展开更多
To address the challenges posed by tunnel construction in the alpine region,silica fume mixed concrete is commonly used as a construction material.The correlation between silica fume content and the lining life requir...To address the challenges posed by tunnel construction in the alpine region,silica fume mixed concrete is commonly used as a construction material.The correlation between silica fume content and the lining life requires immediate investigation.In view of this phenomenon,the durability of unit lining concrete is predicted by analyzing three key indicators:carbonation depth,relative dynamic elastic modulus,and residual quality.This prediction is achieved by integrating the Entropy Weight Method,Grey theory life prediction model and BP artificial neural networks using data from tests and predictions of these indicators.Then,the Entropy Weight-Grey theory-BP Network Model is compared with other methods to analyze the predicted life.Finally,verify the sci-entificity of this model,and the optimum silica fume content of unit concrete lining is verified.The results showed,1)The addition of silica fume will accelerate the carbonization of unit concrete lining,and slow down the freeze-thaw cycle and sulfate erosion.2)The utilization of artificial neural networks is essential for enhancing the realism of the data,as it emphasizes the significance of silica fume content.3)Silica fume content of 10%results in the longest life and is the most suitable for lining construction.4)A comparison between single-factor and multi-factor predictions indicates that the multi-factor approach yields a longer maximum life.This improvement can be attributed to the inclusion of additional factors,such as freeze-thaw cycles and carbonation,which enhance the predicted life when employing these methods.In conclusion,the Entropy Weight-Grey Theory-BP Network life prediction Model is well-suited for tunnel lining in the alpine sulfate area of northwest China.展开更多
The study aims to investigate the carbonated water erosion mechanism of lining concrete in tunnels traversing karst environment and enhance its resistance.In this study,dynamic carbonated water erosion was simulated t...The study aims to investigate the carbonated water erosion mechanism of lining concrete in tunnels traversing karst environment and enhance its resistance.In this study,dynamic carbonated water erosion was simulated to assess erosion depth,microstructure,phase migrations,and pore structure in various tunnel lining cement-based materials.Additionally,Ca^(2+)leaching was analyzed,and impact of Ca/Si molar ratio in hydration products on erosion resistance was discussed by thermodynamic calculations.The results indicate that carbonated water erosion caused rough and porous surface on specimens,with reduced portlandite and CaCO_(3) content,increased porosity,and an enlargement of pore size.The thermodynamic calculations indicate that the erosion is spontaneous,driven by physical dissolution and chemical reactions dominated by Gibbs free energy.And the erosion reactions proceed more spontaneously and extensively when Ca/Si molar ratio in hydration products was higher.Therefore,cement-based materials with higher portlandite content exhibit weaker erosion resistance.Model-building concrete,with C-S-H gel and portlandite as primary hydration products,has greater erosion susceptibility than shotcrete with ettringite as main hydration product.Moreover,adding silicon-rich mineral admixtures can enhance the erosion resistance.This research offers theory and tech insights to boost cement-based material resistance against carbonated water erosion in karst tunnel engineering.展开更多
Soil erosion is the primary factor causing the loss of soil resources and land degradation.Clarifying the current status of soil erosion in China and the characteristics of future changes under different pathways of d...Soil erosion is the primary factor causing the loss of soil resources and land degradation.Clarifying the current status of soil erosion in China and the characteristics of future changes under different pathways of development is important to the global management of soil resources,food security,and ecosystem services.We used the revised universal soil loss equation and the most recent and reliable soil and environmental data to characterize soil erosion in China at present and under typical Shared Socioeconomic Pathways and Representative Concentration Pathways(i.e.,SSP1–2.6 and SSP5–8.5)in the medium-and long-term future(2050 and 2100).The current average rate of soil erosion in China was 14.78 t ha^(-1)yr^(-1),with a total amount of about 14.0 Pg yr^(-1).The amount of total erosion increased by 5.0%,10.8%,9.9%,and 25.9%for scenarios 2050_SSP1–2.6,2050_SSP5–8.5,2100_SSP1–2.6,and 2100_SSP5–8.5,respectively,compared to the baseline amount in 2010.The contribution of climate change and land use to the increase in erosion ranged from 9.5%to 31.5%and-6.95%to-1.78%,respectively,with the contribution of climate change about 2.36-to 7.54-fold larger than the contribution of land use.Converting arable barren land into forest and grassland or adopting conservation tillage practices for farmland,could nevertheless effectively offset the increase in erosion under the four future scenarios.This study provides data and a scientific basis for managing soil erosion in China and provides a useful reference for conserving global land resources and formulating policies to cope with climatic and environmental changes.展开更多
The increased erosion of mangrove forests has alarmed the government about the damage to both the economy and livelihoods.To evaluated forest and land erosion the coast.Based on survey data is divided into five levels...The increased erosion of mangrove forests has alarmed the government about the damage to both the economy and livelihoods.To evaluated forest and land erosion the coast.Based on survey data is divided into five levels(F1:no erosion;F2:little erosion;F3:moderate erosion;F4:high erosion;F5:strong erosion),and ecological conditions,the coast is divided into sub-regions for investigation.From the surveyed indicators at each erosion level,forest structure is analyzed for comparison.The erosion level is defined as an erosion function(Er)from 1 to 5(+),where(1)parameters include the number of trees per hectare(Ntr/ha),height to top(Ht),trunk diameter at 1.3 m(D1.3),tree canopy diameter(Dc),and width of the forest range(Wf);(2)land erosion is a function(Erl=Erlte+Erlsa+Erlsi+Erlcl),with parameters including erosion by terrain(Erlte),sand(Erlsa),silt(Erlsi),and clay(Erlcl);and(3)climate change leading to erosion is an inverse function(Cl)from 1 to 5(-),with parameters including erosion by rainfall(Clra),wind(Clwi),waves(Clwa),and tide(Clti).The resulting function output is Er=(Erf+Erl)-Cl.On eroded forest land,species were tested under climate change conditions and their growth in the next rainy season to assess survival rates affected by rainfall,waves,wind,and tides.These results help to plan planting mangrove forest anti-erosion models and construct a theoretical function of mangrove erosion and proposes restore forests using pioneer species.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
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
基金primarily supported by the National Key Research and Development Program of China(Grant No.2024YFD1501201-3)partially supported by the National Key Research and Development Program of China(Grant No.2021YFD1500700)。
文摘Mass wasting is globally recognized as a key geomorphic agent in permanent gully expansion and greatly contributes to watershed sediment losses.Though its formation process has been assessed by some physical models,the occurrence and rainfall threshold have been rarely documented.In this study,rainfall-induced mass wasting events in two permanent gullies located in the Mollisols region of Northeast China,with Mollisols(gully 1)and sandy soil(gully 2)underneath were observed,and their differences were explored based on their soil strengths,hydraulic properties,excess topographies,and theoretical rainfall amounts.The sandy soil had a higher strength,faster pore water pressure dissipation rate,and lower suction stress at a specific soil moisture content compared to the black soil.The erosion thickness of the gully bed and sidewalls in gully 1 was shallower compared to gully 2.This was confirmed by the relationship between the erosion thickness and excess topography.The differences in the mass wasting erosion of the gully bed and sidewalls were due to the higher shear strength and well-drained hydraulic properties of the sandy soil compared to the black-soil.An infinite model was chosen to examine the temporal order of the mass wasting in the two gullies.It was found that the mass wasting in gully 2 occurred earlier than that in gully 1.This was likely due to the occurrence of an intense storm with less rainfall at the location of gully 2,while a light storm with heavier rainfall occurred in the location of gully 1.As Mollisols and sandy soil are the typical soil horizons in the Mollisols region worldwide,the results of this work could provide insightful knowledge for understanding the physical process of permanent gully expansion,which may be helpful for developing prediction models for sediment losses in some watersheds with vast Mollisols and highly developed gully system.
基金supported by the National Natural Science Foundation of China(No.52175414)the Natural Science Foundation of Jiangsu Province of China(No.BK20220134)+1 种基金the Fundamental Research Funds for the Central Universities,China(No.NE2023002)the Postgraduate Research&Practice Innovation Program of Jiangsu Province,China(No.KYCX24_0559)。
文摘During electrochemical machining(ECM),the passivation film formed on the surface of titanium alloy can lead to uneven dissolution and pitting.Solid particle erosion can effectively remove this passivation film.In this paper,the electrochemical dissolution behavior of Ti-6.5Al-2Zr-1Mo-1V(TA15)titanium alloy at without particle impact,low(15°)and high(90°)angle particle impact was investigated,and the influence of Al_(2)O_(3)particles on ECM was systematically expounded.It was found that under the condition of no particle erosion,the surface of electrochemically processed titanium alloy had serious pitting corrosion due to the influence of the passivation film,and the surface roughness(Sa)of the local area reached 10.088μm.Under the condition of a high-impact angle(90°),due to the existence of strain hardening and particle embedding,only the edge of the surface is dissolved,while the central area is almost insoluble,with the surface roughness(S_(a))reaching 16.086μm.On the contrary,under the condition of a low-impact angle(15°),the machining efficiency and surface quality of the material were significantly improved due to the ploughing effect and galvanic corrosion,and the surface roughness(S_(a))reached 2.823μm.Based on these findings,the electrochemical dissolution model of TA15 titanium alloy under different particle erosion conditions was established.
基金supports from the National Natural Science Foundation of China(Grant No.U20A20112)the Research Grants Council of the Hong Kong SAR Government,China(Grant Nos.T22-606/23-R and 16206923).
文摘Glacier landslide cascading hazards pose threats to communities and infrastructure,affected by complex processes including the amplification of mass flow volume through erosion and entrainment,transformation of hazard types,ice-water phase change,and enhanced mobility of the mass flow.Scientifically simulating these physical phenomena proves challenging.This study introduces GMFA(glacier mass flow analysis),an integrated numerical model that advances the field by:(1)proposing depth-averaged fluctuation energy and internal energy equations,(2)incorporating the ice-water phase change and the entrainment-deposition process,and(3)capturing their effects on mass flow runout characteristics.The model employs the finite volume method to solve the multi-physics coupled governing equations,enabling efficient large-scale simulations.The model is verified through three numerical tests covering flow dynamics,temperature evolution,and thermo-hydro-mechanical runout processes.The model is applied to analyze a hazard chain that occurred on 10 September 2020 on the Tibetan Plateau.The multi-scenario simulation results indicate an entrained mass volume of(4.95±0.11)×10^(5)m^(3),and a ratio of entrained mass volume to source material volume of 0.44.The solid concentration decreases from 0.6-0.7 to 0.1-0.15 with increasing runout distance,indicating a transition from avalanche to debris flood.The internal energy rises by(3-4)×10^(3)kJ/m^(3),driving rapid ice melting from 0.1 to 0.2 to near-zero concentration.The model effectively quantifies volume amplification,ice-water phase changes,and multi-hazard transformations.This model pushes the geoscience frontier,extending computational capability from single-to multi-hazard simulations and providing a powerful tool for analyzing glacier cascading hazards.
基金support from the project supported by the National Natural Science Foundation of China(Grant No.52402034)the Science and Technology Innovation Team Foundation of Hubei Province(Grant No.T2023001)+1 种基金the Natural Science Foundation of Hubei Province(Grant No.2023BAB106)the Natural Science Foundation of Wuhan(Grant No.2024040701010051).
文摘To resolve severe slag penetration and erosion in Al_(2)O_(3)-SiC-C refractories during high scrap ratio iron ladle operation,a novel strategy utilizing exogenous MgAl_(2)O_(4) spinel as a sacrificial FeO_(x) scavenger was proposed.Al_(2)O_(3)-SiC-C refractories produced with plate-like corundum,silicon carbide,and flake graphite incorporating MgAl_(2)O_(4) additives were cured at 1400℃ in the condition of carbon embedding.The impacts of additives on phase composition,microscopic morphology,and performance of materials were studied.The results indicated that Al_(2)O_(3)-SiC-C refractories with the addition of 2 wt.%MgAl_(2)O_(4) exhibited a smaller oxidation area after oxidation tests compared to samples without MgAl_(2)O_(4),resulting in 28%improvement in oxidation resistance compared to blank samples.In the erosion test,the results informed that adding 4 wt.%MgAl_(2)O_(4) induced significant interfacial slag modification:MgAl_(2)O_(4) dynamically dissolved FeO_(x) to form protective Mg(Fe,Al)_(2)O_(4) solid solution on the slag-refractory interface.This sacrificial dissolution effectively immobilized FeO_(x),elevated local slag viscosity,and fundamentally inhibited slag penetration and matrix dissolution.The erosion index decreased from 50%in the blank group to 27.4%.
文摘To predict the erosion and abrasion of high bore pressure tank gun barrel, the least square support vector machine (LSSVM) algorithm was used. Based on the gun firing test data, the prediction model for barrel's erosion and abrasion was established. It was adopted to predict the wear increment of gun barrel. The results show that the prediction values given by the model coincide with the measured data better, and the model can predict the barrel's wear accurately and rapidly.
文摘WC M hard faced ceramic coating was made on the substrate of steel by means of high velocity oxygen fuel flame (HVOF) thermal spraying. The resistance of this coating to cavitation erosion and abrasion (CEA) is about 2.5 times higher than that of 188 stainless steel, and is about 1.5 times higher than that of Stellite alloy (CoCrWC) made in America. When this coating were applied to the hydraulic power stations with more silt content in the flow water, which reaches 50 kg/m 3, the resistance of above mentioned coating to CEA was about 2 times to that of NiCr alloy coating, and is about 45 times to that of OCr13Ni4Mo stainless steel. In addition, the micro hardness, microstructures and electron probe analyzing of the WC M coating are all discussed.
基金Projects(51704096,51574112)supported by the National Natural Science Foundation of ChinaProject(192102310236)supported by the Key Scientific and Technological Project of Henan Province,China+2 种基金Project(2019M662496)supported by Postdoctoral Science Foundation of ChinaProject(2017YFC0804209)supported by the National Key Research and Development Program of ChinaProject(J2018-4)supported by the Science Research Funds for the Universities of Henan Province,China
文摘To make clear the influence of abrasive hardness on the erosion effect,the erosion experiments of abrasive air jet with the same impact energy were carried out.The influence of abrasive hardness on the erosion effect is clarified by comparing the different erosion depths.The main conclusions are as follows.Under the same mass flow rate and mesh number,the abrasive with a higher density needs greater pressure irrespective of hardness.After erosion damage,the abrasive size exhibits a Weibull distribution.The shape parameterβand Weibull distribution function of four types of abrasives are derived by the least squares method;moreover,βis found to have a quadratic relation with abrasive hardness.The results of the erosion experiments show that abrasive hardness and erosion depth are quadratically related.By calculating the increase in surface energy after abrasive erosion crushing,it is found that abrasive hardness has a quadratic relation with surface energy and that the increases in erosion depth and surface energy consumption are basically identical.In conclusion,the effect is a soft abrasive impact when the ratio of abrasive hardness(Ha)to the material hardness(Hm)is<2.6,and it is a hard abrasive impact when Ha/Hm>3.
基金Supported by the National Basic Research Program of China(973 Program)(2009CB623201 and 2013CB035901)the National Natural Science Foundation of China(50972109 and 51109170)the Doctoral Program of Higher Education of China(20090141110021)
文摘In this paper, we investigates the concretes respec- tively incorporated with 5% （m ： rn） nano-SiO2 （NS）, 40% （rn ： m） super- fine slag （SS）, as well as 40% （m ： m） SS combining 20% replacement of sand volume with RP. The tested mechanical properties include compressive strength, abrasion resistant strength, and elastic modulus. The results indicate that among these concretes, the SS-RP concrete has the highest abrasion re- sistant strength with increment ratios of 1.71 and 1.35 at 28 days and 90 days, respectively; the SS concrete has the highest com- pressive strength with increment ratios of 2.03 and 1.95 at 28 days and 90 days, respectively; the elastic modulus of SS-RP concrete significantly decrease compared with the SS concrete and is slightly higher than that of the reference concrete. It is concluded that NS, SS, and RP all can improve the abrasion resistance of concrete, and it will be significantly improved when SS combining RP is incorporated.
基金supported by the National Science Foundation of China under Grant Nos(Nos.12127806,62175195)the International Joint Research Laboratory for Micro/Nano Manufacturing and Measurement Technologies。
文摘Transparent materials utilized as underwater optical windows are highly vulnerable to various forms of pollution or abrasion due to their intrinsic hydrophilic properties.This susceptibility is particularly pronounced in underwater environments where pollutants can impede the operation of these optical devices,significantly degrading or even compromising their optical properties.The glass catfish,known for its remarkable transparency in water,maintains surface cleanliness and clarity despite exposure to contaminants,impurities abrasion,and hydraulic pressure.Inspired by the glass catfish’s natural attributes,this study introduces a new solution named subaquatic abrasion-resistant and anti-fouling window(SAAW).Utilizing femtosecond laser ablation and electrodeposition,the SAAW is engineered by embedding fine metal bone structures into a transparent substrate and anti-fouling sliding layer,akin to the sturdy bones among catfish’s body.This approach significantly bolsters the window’s abrasion resistance and anti-fouling performance while maintaining high light transmittance.The sliding layer on the SAAW’s surface remarkably reduces the friction of various liquids,which is the reason that SAAW owns the great anti-fouling property.The SAAW demonstrates outstanding optical clarity even after enduring hundreds of sandpaper abrasions,attributing to the fine metal bone structures bearing all external forces and protecting the sliding layer of SAAW.Furthermore,it exhibits exceptional resistance to biological adhesion and underwater pressure.In a green algae environment,the window remains clean with minimal change in transmittance over one month.Moreover,it retains its wettability and anti-fouling properties when subjected to a depth of 30 m of underwater pressure for 30 d.Hence,the SAAW prepared by femtosecond laser ablation and electrodeposition presents a promising strategy for developing stable optical windows in liquid environments.
文摘The fabrication of miniature structures on components with high-integrity surface quality represents one of the cutting edge technologies in the 21st century.The materials used to construct such small structures are often difficult-to-machine.Many other readily available technologies either cannot realise necessary precision or are costly.Abrasive waterjet(AWJ)is a favourable technology for the machining of difficult-to-machine materials.However,this technology is generally aimed at large stock removal.A reduction in the scale of this technology is an attractive avenue for meeting the pressing need of industry in the production of damage-free micro features.This paper reviews some of the work that has been undertaken at UNSW Sydney about the development of such an AWJ technology,focusing on the system design currently employed to generate a micro abrasive jet,the erosion mechanisms associated with processing some typical brittle materials of both single-and two-phased.Processing models based on the findings are also presented.The review concludes on the viability of the technology and the prevailing trend in its development.
基金financially supported by the National Natural Science Foundation of China(Grant No.52301339)the Natural Science Foundation of Fujian Province(Grant No.2021J05004)+1 种基金the State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation,Tianjin University(Grant No.HESS-2402)the Fundamental Research Funds for the Central Universities(Grant No.20720240038).
文摘A carcass is the innermost layer of a deep-sea unbonded flexible pipe,which is in direct contact with the gas/liquid-solid multi-phase flow.Considering that stress-accelerated erosion is common for carcasses,this study proposes a general model and simulation method for stress-accelerated erosion(SE)of carcasses under external water pressure.First,an SE model suitable for 316 stainless steel was developed,which was then used for stress-erosion simulation for an external pressurized carcass,and the solid domain,fluid domain and rough inner surface of the carcass were carefully considered.Moreover,a simplified model(equivalent smooth pipe)was also established on the basis of the main geometric characteristics of the carcass,and the stress-erosion characteristics under different operating conditions,including the effects of the elastic stress level,flow velocity,particle diameter and concentration,were carefully compared,and the key factors governing the elastic stress-erosion of the carcass were discussed.Finally,a modified geometry factor(GF)for carcasses was proposed considering the stress acceleration effect.
基金financially supported by the National Key Research and Development Program of China(Grant No.2023YFC2811600)the National Natural Science Foundation of China(Grant Nos.52301349 and 52088102)+1 种基金the Qingdao Post-Doctorate Science Fund(No.QDBSH20220202070)the Major Scientific and Technological Innovation Project of Shandong Province(Grant No.2019JZZY010820).
文摘A deep-sea mining riser is a crucial component of the system used to lift seafloor mineral resources to the vessel.It is prone to damage and failure because of harsh environmental conditions and internal fluid erosion.Furthermore,damage can impact the response characteristics of the riser,but varying environmental loadings easily mask it.Thus,distin-guishing between riser damage and environmental effects poses a considerable challenge.To address this issue,a cantilevered model is created for a deep-sea mining riser via the concentrated mass method,and a time-domain analytical strategy is developed.The vortex-induced vibration(VIV)response characteristics of the riser are initially examined,considering various damage conditions and flow velocities.The study results revealed four primary observations:(a)effective tension can serve as a reliable indicator for identifying damage at lower velocities;(b)there are noticeable differences in displacement between the healthy and damaged risers in the in-line direction rather than the cross-flow direction;(c)frequency characteristics can more effectively distinguish the damage conditions at high flow velocities,with the mean square frequency and frequency variance being more effective than the centroid frequency and root variance frequency;(d)displacement differences are more sensitive to damage occurring near the top and bottom of the riser,while both velocity variations and structural damage can influence displacements,especially in regions between modal nodes.The vibrational behavior and damage indicators are clarified for structural health monitoring of deep-sea mining risers during lifting operations.
基金supported by the National Natural Science Foundation of China(Nos.U2241240,12172045 and 12221002)the Opening Fund of State Key Laboratory of Explosion Science and Technology of Beijing Institute of Technology,China(No.ZDKT23-02)。
文摘Carbon Carbon(C/C)composites in thermal-protection system are exposed to severe thermochemical ablation and mechanical erosion,and their thermal-protection performance is of vital importance to the structural safety and flight status of hypersonic vehicles.We numerically analyzes the mesoscopic ablation-erosion of C/C Composites with Inclined Fibers(CCIF).First,a thermochemical ablation model describing the reaction-diffusion coupled problem of C/C composites on mesoscale is employed to analyze ablative process,and the corresponding surface ablation morphology is obtained.Then,the ablation morphology of CCIF is taken as the geometrical model for mechanical erosion analysis,and their damage and failure behavior under high-speed airflow shear is analyzed by using progressive damage method.Moreover,the effects of fiber inclined angle and airflow direction on the mechanical erosion of CCIF are investigated,and the ablationerosion behavior is analyzed and discussed.The results show that the failure modes of mechanical erosion in inner and edge regions are obviously different,showing granular and block erosion phenomena respectively.The mechanical erosion of CCIF in the direction of reverse flow is easier than that in the direction of forward flow.These results can provide a theoretical basis for the design and optimization of thermal protection system materials.
基金financially supported by the National Science and Technology Major Project(Nos.2017 ZX05009-003&2016 ZX05028)PetroChina Innovation Foundation(No.2018D-5007-0308)
文摘Abrasive waterjet(AWJ)fracturing has become an accepted horizontal multistage stimulation technique due to its flexibility and high efficiency of extensive fracture placement.The downhole tool failure of AWJ fracturing becomes an issue in the massive hydraulic fracturing because of high velocity and proppant erosion.This paper proposed a 3D computational fluid dynamics(CFD)-based erosion model by considering high-velocity waterjet impact,proppant shear erosion,and specific inner structure of hydra-jet tool body.The discrete phase approach was used to track the proppant transport and its concentration distribution.Field observation provides strong evidence of erosion patterns and mechanisms obtained from CFD simulation.The results show that the erosion rate has a space dependence in the inner wall of the tool body.The severe erosion areas are primarily located at the entries of the nozzle.Evident erosion patterns are found including a‘Rabbit’s ear’erosion at the upper-layer nozzles and a half bottom loop erosion at the lower-layer nozzles.Erosion mechanisms attribute to high flow velocity at the entry of nozzles and the inertia force of proppant.Sensitivity analysis demonstrates that the pumping rate is a primary factor contributing to erosion intensity.
基金funded by the Technology Funding Scheme of China Construction Second Engineering Bureau LTD(2020ZX150002)the National Natural Science Foundation Project of China(12262018).
文摘To address the challenges posed by tunnel construction in the alpine region,silica fume mixed concrete is commonly used as a construction material.The correlation between silica fume content and the lining life requires immediate investigation.In view of this phenomenon,the durability of unit lining concrete is predicted by analyzing three key indicators:carbonation depth,relative dynamic elastic modulus,and residual quality.This prediction is achieved by integrating the Entropy Weight Method,Grey theory life prediction model and BP artificial neural networks using data from tests and predictions of these indicators.Then,the Entropy Weight-Grey theory-BP Network Model is compared with other methods to analyze the predicted life.Finally,verify the sci-entificity of this model,and the optimum silica fume content of unit concrete lining is verified.The results showed,1)The addition of silica fume will accelerate the carbonization of unit concrete lining,and slow down the freeze-thaw cycle and sulfate erosion.2)The utilization of artificial neural networks is essential for enhancing the realism of the data,as it emphasizes the significance of silica fume content.3)Silica fume content of 10%results in the longest life and is the most suitable for lining construction.4)A comparison between single-factor and multi-factor predictions indicates that the multi-factor approach yields a longer maximum life.This improvement can be attributed to the inclusion of additional factors,such as freeze-thaw cycles and carbonation,which enhance the predicted life when employing these methods.In conclusion,the Entropy Weight-Grey Theory-BP Network life prediction Model is well-suited for tunnel lining in the alpine sulfate area of northwest China.
基金Project(2021YJ059)supported by the Research Project of China Academy of Railway Sciences。
文摘The study aims to investigate the carbonated water erosion mechanism of lining concrete in tunnels traversing karst environment and enhance its resistance.In this study,dynamic carbonated water erosion was simulated to assess erosion depth,microstructure,phase migrations,and pore structure in various tunnel lining cement-based materials.Additionally,Ca^(2+)leaching was analyzed,and impact of Ca/Si molar ratio in hydration products on erosion resistance was discussed by thermodynamic calculations.The results indicate that carbonated water erosion caused rough and porous surface on specimens,with reduced portlandite and CaCO_(3) content,increased porosity,and an enlargement of pore size.The thermodynamic calculations indicate that the erosion is spontaneous,driven by physical dissolution and chemical reactions dominated by Gibbs free energy.And the erosion reactions proceed more spontaneously and extensively when Ca/Si molar ratio in hydration products was higher.Therefore,cement-based materials with higher portlandite content exhibit weaker erosion resistance.Model-building concrete,with C-S-H gel and portlandite as primary hydration products,has greater erosion susceptibility than shotcrete with ettringite as main hydration product.Moreover,adding silicon-rich mineral admixtures can enhance the erosion resistance.This research offers theory and tech insights to boost cement-based material resistance against carbonated water erosion in karst tunnel engineering.
基金supported by the National Key Research and Development Program of China(Grant No.2024YFD1501102)the Natural Science Foundation of Jiangsu Province,China(Grant No.BK20220163)+2 种基金the Jiangxi Province Natural Science Foundation(Grant No.20224BAB203031)Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA0440202)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2023327)。
文摘Soil erosion is the primary factor causing the loss of soil resources and land degradation.Clarifying the current status of soil erosion in China and the characteristics of future changes under different pathways of development is important to the global management of soil resources,food security,and ecosystem services.We used the revised universal soil loss equation and the most recent and reliable soil and environmental data to characterize soil erosion in China at present and under typical Shared Socioeconomic Pathways and Representative Concentration Pathways(i.e.,SSP1–2.6 and SSP5–8.5)in the medium-and long-term future(2050 and 2100).The current average rate of soil erosion in China was 14.78 t ha^(-1)yr^(-1),with a total amount of about 14.0 Pg yr^(-1).The amount of total erosion increased by 5.0%,10.8%,9.9%,and 25.9%for scenarios 2050_SSP1–2.6,2050_SSP5–8.5,2100_SSP1–2.6,and 2100_SSP5–8.5,respectively,compared to the baseline amount in 2010.The contribution of climate change and land use to the increase in erosion ranged from 9.5%to 31.5%and-6.95%to-1.78%,respectively,with the contribution of climate change about 2.36-to 7.54-fold larger than the contribution of land use.Converting arable barren land into forest and grassland or adopting conservation tillage practices for farmland,could nevertheless effectively offset the increase in erosion under the four future scenarios.This study provides data and a scientific basis for managing soil erosion in China and provides a useful reference for conserving global land resources and formulating policies to cope with climatic and environmental changes.
文摘The increased erosion of mangrove forests has alarmed the government about the damage to both the economy and livelihoods.To evaluated forest and land erosion the coast.Based on survey data is divided into five levels(F1:no erosion;F2:little erosion;F3:moderate erosion;F4:high erosion;F5:strong erosion),and ecological conditions,the coast is divided into sub-regions for investigation.From the surveyed indicators at each erosion level,forest structure is analyzed for comparison.The erosion level is defined as an erosion function(Er)from 1 to 5(+),where(1)parameters include the number of trees per hectare(Ntr/ha),height to top(Ht),trunk diameter at 1.3 m(D1.3),tree canopy diameter(Dc),and width of the forest range(Wf);(2)land erosion is a function(Erl=Erlte+Erlsa+Erlsi+Erlcl),with parameters including erosion by terrain(Erlte),sand(Erlsa),silt(Erlsi),and clay(Erlcl);and(3)climate change leading to erosion is an inverse function(Cl)from 1 to 5(-),with parameters including erosion by rainfall(Clra),wind(Clwi),waves(Clwa),and tide(Clti).The resulting function output is Er=(Erf+Erl)-Cl.On eroded forest land,species were tested under climate change conditions and their growth in the next rainy season to assess survival rates affected by rainfall,waves,wind,and tides.These results help to plan planting mangrove forest anti-erosion models and construct a theoretical function of mangrove erosion and proposes restore forests using pioneer species.
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.
