Wetting deformation in earth-rockfill dams is a critical factor influencingdam safety.Although numerous mathematical models have been developed to describe this phenomenon,most of them rely on empirical formulations a...Wetting deformation in earth-rockfill dams is a critical factor influencingdam safety.Although numerous mathematical models have been developed to describe this phenomenon,most of them rely on empirical formulations and lack prior knowledge of model parameters,which is essential for Bayesian parameter inversion to enhance accuracy and reduce uncertainty.This study introduces a datadriven approach to establishing prior knowledge of earth-rockfill dams.Driving factors are utilized to determine the potential range of model parameters,and settlement changes within this range are calculated.The results are iteratively compared with actual monitoring data until the calculated range encompasses the observed data,thereby providing prior knowledge of the model parameters.The proposed method is applied to the right-bank earth-rockfilldam of Danjiangkou.Employing a Gibbs sample size of 30,000,the proposed method effectively calibrates the prior knowledge of the wetting model parameters,achieving a root mean square error(RMSE)of 5.18 mm for the settlement predictions.By comparison,the use of non-informative priors with sample sizes of 30,000 and 50,000 results in significantly larger RMSE values of 11.97 mm and 16.07 mm,respectively.Furthermore,the computational efficiencyof the proposed method is demonstrated by an inversion computation time of 902 s for 30,000 samples,which is notably shorter than the 1026 s and 1558 s required for noninformative priors with 30,000 and 50,000 samples,respectively.These findingsunderscore the superior performance of the proposed approach in terms of both prediction accuracy and computational efficiency.These results demonstrate that the proposed method not only improves the predictive accuracy but also enhances the computational efficiency,enabling optimal parameter identificationwith reduced computational effort.This approach provides a robust and efficientframework for advancing dam safety assessments.展开更多
In the field of rock engineering,the influence of water is a dynamic process that exhibits varying effects over time and across different locations.To further understand how water influences the mechanical properties ...In the field of rock engineering,the influence of water is a dynamic process that exhibits varying effects over time and across different locations.To further understand how water influences the mechanical properties and acoustic emission(AE)behavior of rocks,this study conducted uniaxial compression experiments on sandstones with varying degrees of wetting under both natural conditions and water-chemical environments.In addition,the study combined AE equipment with digital image correlation(DIC)to monitor the entire failure process.Using the sliding window algorithm,the variation in the variance of AE characteristic parameters during the process of sandstone loading to failure is analyzed from the perspective of critical slowing down.This analysis enables the effective identification of the early warning signal before failure.The experimental findings suggest that an increase in wetting height results in a gradual decrease in peak stress,accompanied by a concomitant increase in the percentage of shear cracks.The characteristic parameters,including energy,amplitude,and ringing count,all exhibit critical slowing phenomena.The waveform of AE characteristic parameters of the same sample is similar,and the mutation time of the precursor signal is roughly the same.All signals appear in the irreversible plastic deformation stage of microcrack initiation.The integration of critical slowing down theory and the b-value early warning method facilitates a more comprehensive evaluation of the stability of rock mass,thereby significantly enhancing the efficiency and safety of disaster prevention measures.展开更多
Alternate wetting and drying irrigation(AWD)significantly influences the cooking and eating quality of rice(Oryza sativa L.).However,the mechanisms by which AWD affects rice cooking and eating quality remain unclear.L...Alternate wetting and drying irrigation(AWD)significantly influences the cooking and eating quality of rice(Oryza sativa L.).However,the mechanisms by which AWD affects rice cooking and eating quality remain unclear.Lipid and free fatty acid contents in grains correlate positively with cooking and eating quality of rice.This study examined Yangdao 6(YD6,a conventional taste indica inbred)and Nanjing 9108(NJ9108,a superior taste japonica inbred)cultivated under conventional irrigation(CI),alternate wetting and moderate drying irrigation(AWMD),and alternate wetting and severe drying irrigation(AWSD)from 10 days after transplanting to maturity.The research investigated the relationship between lipid and free fatty acid biosynthesis in grains and the cooking and eating quality of rice.Compared to CI treatment,AWMD significantly enhanced the contents of lipid,total free fatty acids(TFFAs),free unsaturated fatty acids(FUFAs),linoleic acid,and oleic acid in milled rice by increasing activities of enzymes associated with lipid synthesis,while AWSD produced opposite effects.Correlation analysis revealed that elevated levels of lipid,TFFAs,FUFAs,linoleic acid,and oleic acid contribute to improved rice cooking and eating quality.The findings demonstrate that AWMD enhances cooking and eating quality of milled rice through optimization of lipid and fatty acid synthesis in rice grains.展开更多
The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between t...The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between titanium-containing slag and tuyere coke remains lacking.The sessile drop method was employed to explore the effects of temperature,binary basicity,FeO,and TiO_(2) contents on the wetting behavior of titanium-containing slag and tuyere coke.The results indicate that increasing the temperature enhances the adhesion and wettability of the droplet,reducing the contact angle.Meanwhile,it accelerates the chemical reactions between slag and coke,leading to faster equilibrium.Conversely,increasing slag basicity elevates the contact angle by inhibiting chemical reactions at the slag–coke interface.This inhibition reduces both contact area and depth,thereby hindering slag droplet spreading on the coke surface.The contact angle decreases as the FeO content in the slag increases.Notably,the increase in TiO_(2) content has a dual effect on slag–coke wettability.Initially,it promotes wetting by reducing surface tension and lowering the contact angle.While the TiO_(2) content exceeds 20 wt.%,Ti(C,N)forms a barrier layer at the slag–coke interface,hindering the contact between slag and coke and resulting in an increased contact angle.展开更多
The wetting behavior of liquid tin(Sn)solder on copper(Cu)substrate at 250℃was investigated by the wetting balance method under the action of direct current(DC).The curves of wetting balance were measured and the mor...The wetting behavior of liquid tin(Sn)solder on copper(Cu)substrate at 250℃was investigated by the wetting balance method under the action of direct current(DC).The curves of wetting balance were measured and the morphology of the intermetallic compound(IMC)precipitated at the interface were observed.Results show that DC has a significant effect on the wettability and IMC.As the current increases,the balance wetting force and the thickness of the IMC layer increase.The direction of the DC also has a certain effect on the balance wetting force and IMC layer.When the current is negative,the final balance wetting force and the thickness of the Cu_(6)Sn_(5) layer are significantly higher than those in the positive current case,which is attributed to electromigration.The IMC precipitation at the interface provides a chemical driving force for the movement of the triple junction.The interaction of the interface atoms and the chemical reaction are enhanced by DC,thereby improving wettability.Meanwhile,the Marangoni convection caused by DC inside liquid Sn solder changes the structure of triple junction,which provides a physical driving force for the spread of the liquid Sn solder on the Cu substrate.展开更多
The wetting phenomenon of composite substrates in hypergravitational environment has a huge application in electronic devices and astronaut healthcare in aerospace missions.In the present contribution,the governing eq...The wetting phenomenon of composite substrates in hypergravitational environment has a huge application in electronic devices and astronaut healthcare in aerospace missions.In the present contribution,the governing equation of high-G droplets on the composite substrate is firstly established in the hypergravitational environment.Meanwhile,the apparent contact angles at the contact line between droplets and substrates with different stiffness gradients are achieved.Then,we analyze the effects of hypergravity factor and the substrate stiffness on the wetting profile of high-G droplets.By introducing the droplet volume and contact angle into the Bond number,the scaling law of the high-G droplet profile is established,and we find that the contact radius of the droplet R/S^(0.5)has a linear relationship withρω^(2)rl^(2)S/(γ_(LV)^(θ)),while the droplet height H/S^(0.5)has a power-law relationship withρω^(2)rl^(2)S/(γ_(LV)^(θ)).Finally,we explain the profiles of high-G droplets during the wetting process by illustrating energy components of the entire system and find that the substrate with positive triangular stiffness and inverted triangular stiffness show opposite evolution laws.On a substrate with inverted triangular stiffness,the gravitational potential energy is more dominant.展开更多
Antarctica contains numerous scientific mysteries,and the Antarctic ice sheet and its underlying bedrock contain important information about the geological structure of Antarctica and the evolutionary history of the i...Antarctica contains numerous scientific mysteries,and the Antarctic ice sheet and its underlying bedrock contain important information about the geological structure of Antarctica and the evolutionary history of the ice sheet.In order to obtain the focus of these scientific explorations,the Antarctic drilling engineering is constantly developing.The drilling fluid performance directly determines the success or failure of drilling engineering.In order to enhance the poor performance for drilling fluids due to poor dispersion stability and easy settling of organoclay at ultra-low temperatures,the small-molecule wetting agent(HSR)for drilling fluid suitable for Antarctica was prepared by oleic acid,diethanolamine and benzoic acid as raw materials.Its chemical structure,properties and action mechanism were investigated by various experimental methods.The experimental results showed that 2%HSR could improve the colloidal rate for drilling fluid from 6.4%to 84.8%,and the increase rate of yield point was up to 167%.Meanwhile,it also made the drilling fluid excellent in shear dilution and thixotropy.In addition,2%HSR could increase the density from 0.872 to 0.884 g/cm^(3) at-55 ficial.And the drilling fluid with 2%HSR had a good thermal conductivity of 0.1458 W/(m·K)at-55 ficial.This study gives a new direction for the research of drilling fluid treatment agents suitable for the Antarctic region,which will provide strong support for the scientific exploration of the Antarctic region.展开更多
As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD ...As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD cycles.X-ray micro-computed tomography(micro-CT)was used as a non-destructive tool to quantitatively analyze microstructural changes of the mudstone due to the first cycle of WD.The test results show that WD leads to an increase of pore volume and pore connectivity in the mudstone.The porosity and fractal dimension of each slice of mudstone not only increase in value,but also in fluctuation amplitude.The pattern of variation in the frequency distribution of the equivalent radii of connected,isolated pores and pore throats in mudstone under WD effect satisfies the Gaussian distribution.Under the effect of WD,pores and pore throats with relatively small sizes increase the most.The sphericity of the pores in mudstones is positively correlated with the pore radius.The WD effect transforms the originally angular and flat pores into round and regular pores.This paper can provide a reference for the study of the deterioration and catastrophic mechanisms of mudstone under wetting and drying cycles.展开更多
Alkaline slag is vital in rare earth steel refining,making it crucial to study the wetting and penetration mechanisms between refractory materials and slag.The effect of Eu_(2)O_(3) doping on the sintering properties ...Alkaline slag is vital in rare earth steel refining,making it crucial to study the wetting and penetration mechanisms between refractory materials and slag.The effect of Eu_(2)O_(3) doping on the sintering properties of MgO-MgAl_(2)O_(4) refractory materials was investigated while simulating the wetting behavior between the refractory and the CaO-Al_(2)O_(3)-SiO_(2)-MgO quaternary alkaline slag during rare earth steel smelting to improve the material’s resistance to alkaline slag corrosion.The doping of Eu_(2)O_(3) can alter the crystal structure parameters of MgAl_(2)O_(4) and MgO,causing lattice distortion.This lattice activation promotes interionic mass and diffusion,helping reduce porosity and promote densification of the material,further improving sintering properties.At the equilibrium wetting temperature(1723 K),Eu_(2)O_(3) doping increases the interfacial free energy between the slag and refractory material,reducing the spreading coefficient of the molten slag.The contact angle increases from 32.1°to 42.2°,and the residual slag volume increases from 17.9%to 23.5%.The results of thermodynamic analysis show that MgAl_(2)O_(4) and EuAlO3 formed at the interface block the penetration of molten slag at high temperatures,improving the resistance of MgO-MgAl_(2)O_(4) refractories to alkaline slag corrosion.Based on the capillary theory model,it was calculated that the capillary tension of the slag gradually increases with the addition of Eu_(2)O_(3),while the theoretical penetration depth of the slag gradually decreases.The experimental results showed that the slag erosion depth of the sample decreased from 102.54 to 68.28μm.展开更多
Alternate wetting and soil drying irrigation(AWD)technique is crucial in infuencing grain quality in rice(Oryza sativa L.).Lipids are the third most abundant constituents in rice grains,after starch and proteins,and a...Alternate wetting and soil drying irrigation(AWD)technique is crucial in infuencing grain quality in rice(Oryza sativa L.).Lipids are the third most abundant constituents in rice grains,after starch and proteins,and are closely related to grain quality.However,it remains unclear about the changes in lipids profling under different AWD regimes.This study set up three irrigation regimes including conventional irrigation(CI),alternate wetting and moderate soil drying irrigation(AWMD),and alternate wetting and severe soil drying irrigation(AWSD).It explored lipidome changes in milled rice of Yangdao 6(YD6)using the untargeted lipidomics approach and analyzed rice cooking and eating quality.The results identifed seven lipid classes,55 lipid subclasses,and 1,086 lipid molecular species.Compared with the CI regime,the AWMD regime mainly altered lipid subclasses consisting of triglyceride(TG),ceramide(Cer),diglyceride(DG),bis-methyl lysophosphatidic acid(BisMePA),phosphocholine(PC),phosphoethanolamine(PE),monogalactosyldiacylglycerol(MGDG),and digalactosyl diglyceride(DGDG)in milled rice and improved cooking and eating quality of rice;in contrast,the AWSD regime distinctly changed lipid subclasses like TG,Cer,DG,PC,PE,hexosylceramide(Hex1Cer),DGDG,and BisMePA and degraded cooking and eating quality of rice.Specifcally,AWMD most signifcantly altered the expressions of lipid molecules,including DGDG(18:0_18:2),DGDG(16:0_14:0),PC(33:1),Cer(t17:0_26:0),and Cer(t17:0_16:0);AWSD most obviously influenced the expressions of TG(6:0_14:0_18:3),PC(41:1),TG(19:1_18:4_18:4),Hex1Cer(d18:2_24:0+O),and Hex1Cer(d18:2_24:1).These 10 altered lipid molecules in milled rice can be preferentially used for investigating their relationships with grain quality in rice.展开更多
Carbonyls play an important role in the atmospheric chemistry as the main precursor for reactive radicals and peroxyacetyl nitrate.However,little research has been conducted so far on the seasonal variations of carbon...Carbonyls play an important role in the atmospheric chemistry as the main precursor for reactive radicals and peroxyacetyl nitrate.However,little research has been conducted so far on the seasonal variations of carbonyls in China’s urban atmosphere.In this study,ambient carbonyls were 24-hourly observed in four seasons in Hangzhou,a mega-city in the Yangtze River Delta Region,China.The concentration of total carbonyls was the highest in summer(44.35μg/m^(3)),the second in winter(44.05μg/m^(3)),the third in spring(29.31μg/m^(3))and autumn(27.11μg/m^(3)).The most abundant species were found to be acetone in spring,summer,and winter,while formaldehyde in autumn.Rainfall can significantly reduce the concentrations of most ambient carbonyls,with the largest decrease observed in the wet precipitation events occurring in spring and summer,while acetone concentrations remained invariable due to its lower water solubility.Multiple linear regression analysis and carbonyls ratios indicated that anthropogenic emissions were the predominant sources of carbonyls,and atmospheric formaldehyde was mainly emitted from primary sources other than secondary sources.Vehicular exhaust was identified as the primary source of ambient carbonyls,particularly in winter,and its contribution reached 92.80%to formaldehyde.Additionally,photochemical reactions were closely associated with the secondary production of formaldehyde in summer.Carbonyls showed strong ozone formation potential in all four seasons.Based on the health risk assessment,the exposure to ambient carbonyls is harmful to outdoor pedestrians.The results could provide essential information and references for simulating regional air quality and analyzing ozone pollution,which is essential for improving air quality in the Yangtze River Delta region.展开更多
BACKGROUND Orthopaedic surgical education has traditionally depended on the apprenticeship model of“see one,do one,teach one”.However,reduced operative exposure,stricter work-hour regulations,medicolegal constraints...BACKGROUND Orthopaedic surgical education has traditionally depended on the apprenticeship model of“see one,do one,teach one”.However,reduced operative exposure,stricter work-hour regulations,medicolegal constraints,and patient safety concerns have constrained its practicality.Simulation-based training has become a reliable,safe,and cost-efficient alternative.Dry lab techniques,especially virtual and augmented reality,make up 78%of current dry lab research,whereas wet labs still set the standard for anatomical realism.AIM To evaluate the effectiveness,limitations,and future directions of wet and dry lab simulation in orthopaedic training.METHODS A scoping review was carried out across four databases-PubMed,Cochrane Library,Web of Science,and EBSCOhost-up to 2025.Medical Subject Headings included:"Orthopaedic Education","Wet Lab","Dry Lab","Simulation Training","Virtual Reality",and"Surgical Procedure".Eligible studies focused on orthopaedic or spinal surgical education,employed wet or dry lab techniques,and assessed training effectiveness.Exclusion criteria consisted of non-English publications,abstracts only,non-orthopaedic research,and studies unrelated to simulation.Two reviewers independently screened titles,abstracts,and full texts,resolving discrepancies with a third reviewer.RESULTS From 1851 records,101 studies met inclusion:78 on dry labs,7 on wet labs,4 on both.Virtual reality(VR)simulations were most common,with AI increasingly used for feedback and assessment.Cadaveric training remains the gold standard for accuracy and tactile feedback,while dry labs-especially VR-offer scalability,lower cost(40%-60%savings in five studies),and accessibility for novices.Senior residents prefer wet labs for complex tasks;juniors favour dry labs for basics.Challenges include limited transferability data,lack of standard outcome metrics,and ethical concerns about cadaver use and AI assessment.CONCLUSION Wet and dry labs each have unique strengths in orthopaedic training.A hybrid approach combining both,supported by standardised assessments and outcome studies,is most effective.Future efforts should aim for uniform reporting,integrating new technologies,and policy support for hybrid curricula to enhance skills and patient care.展开更多
Based on the conventional observation data,daily reanalysis data from NCAR/NCEP,and TBB data derived from FY-2G infrared cloud images in April 2018,a heavy snowfall weather process in central Inner Mongolia from April...Based on the conventional observation data,daily reanalysis data from NCAR/NCEP,and TBB data derived from FY-2G infrared cloud images in April 2018,a heavy snowfall weather process in central Inner Mongolia from April 4 to 6 in 2018 was analyzed.The results show that the low trough at 500 hPa,the southerly wind jet stream at 700 hPa,and the inverted trough on the ground were the main influencing systems causing this blizzard.The transportation of warm and humid air by the southerly wind jet stream at 700 hPa and intense water vapor convergence provided sufficient water vapor conditions for the blizzard,and the moist layer in the blizzard area was deep.The low-level MPV in the blizzard area was<0,and the atmosphere was in a conditional symmetric instability state.The coupling of the upper and lower-level jets induced strong ascending motion.With the invasion of cold air,a low-level cold pad was formed,so that the warm and humid air tilted upward.The secondary circulation updraft triggered by the wet Q vector system released the conditional symmetric instability energy,so that the sloping motion was more intense,and the heavy snowfall appeared.Meanwhile,there was a good correspondence relationship between the blizzard area and the large-value area of low-level wet Q vector divergence.The mesoscale cloud clusters continuously generating,merging,and moving eastward in Hetao area were the direct cause of this blizzard,and the TBB of the cloud clusters was≤-56℃.The blizzard happened in the the edge gradient and large-value area of TBB.展开更多
In order to reveal the physical essence of the spreading process of reactive wetting,a sort of model of energy to explain the driving force and wetting mechanism was presented.The reactive wetting of molten A1 and Cu ...In order to reveal the physical essence of the spreading process of reactive wetting,a sort of model of energy to explain the driving force and wetting mechanism was presented.The reactive wetting of molten A1 and Cu Si on graphite was studied by a modified sessile drop method under a vacuum,in which the contact angles were measured by ADSA software.The thermodynamic and kinetic processes of the typical reactive wetting were focused on,the thermodynamic equations of energy relations were derived,the interfacial energy of graphite and solid-liquid interfacial energy versus time at the triple line were calculated,and the dynamics model of interface energy is established.The presented dynamics model is verified by means of experimental results,and it is shown that solid liquid interfacial energy decreases with time in exponential relationship.It provides a new method for reference to explain the process from the angle of energy.展开更多
To explore mix proportion design of RAC with aggregates tightly packed,the dry and wet packing density of recycled coarse aggregates mixture system and recycled coarse and fine aggregates were tested,then the influenc...To explore mix proportion design of RAC with aggregates tightly packed,the dry and wet packing density of recycled coarse aggregates mixture system and recycled coarse and fine aggregates were tested,then the influence of replacement rate and particle size ratio on the packing density of particle system was explored,the packing density prediction model of recycled coarse aggregates based on particle morphology was constructed,and the mix proportion optimization for recycled aggregate concrete with dry-wet packing model was carried out.The experimental results show that,with the increasing of recycled aggregate replacement rate or fine-grained volume ratio,the dry packing density of recycled coarse aggregates decreases gradually.With the increasing of replacement rate,the particle gradation can be optimized by increasing coarsegrained volume ratio.There is a significant effect for particle morphology parameter K and the particle size ratio on the packing density of the binary mixed system,and the packing density prediction model of recycled coarse aggregates based on particle morphology was constructed.The maximum increase in compressive strength and tensile strength of RAC with mix proportion optimized by the dry-wet packing model are 12.94%and 11.09%,and the cementitious materials is reduced by 21.83%,then the superiority of the mix proportion optimization of RAC with the dry-wet close packing model is confirmed.The results of this paper can provide a theoretical basis for the mix proportion design of RAC.展开更多
Tropospheric zenith wet delay(ZWD)plays a vital role in the analysis of space geodetic observations.In recent years,machine learning methods have been increasingly applied to improve the accuracy of ZWD calculations.H...Tropospheric zenith wet delay(ZWD)plays a vital role in the analysis of space geodetic observations.In recent years,machine learning methods have been increasingly applied to improve the accuracy of ZWD calculations.However,a single machine learning model has limited generalization capabilities.To address these limitations,this study introduces a novel machine learning fusion(MLF)algorithm with stronger generalization capabilities to enhance ZWD modeling and prediction accuracy.The MLF algorithm utilizes a two-layer structure integrating extra trees(ET),backpropagation neural network(BPNN),and linear regression models.By comparing the root mean square error(RMSE)of these models,we found that both ET-based and MLF-based models outperform RF-based and BPNN-based models in terms of internal and external accuracy,across both surface meteorological data-based and blind models.The improvement in exte rnal accuracy is particularly significant in the blind models.Our re sults show that the MLF(with an RMSE of 3.93 cm)and ET(3.99 cm)models outperform the traditional GPT3model(4.07 cm),while the RF(4.21 cm)and BPNN(4.14 cm)have worse external accuracies than the GPT3 model.It is worth noting that the BPNN suffered from overfitting during external accuracy tests,which was avoided by the MLF.In summary,regardless of the availability of surface meteorological data,the MLF-based empirical models demonstrate superior internal and external accuracy compared to the other tested models in this study.展开更多
On November 26th,Zhengzhou Textile Machinery Co.,Ltd.(hereinafter referred to as"ZFJ")signed an order for a high-speed intelligent wide-width wetmethod spunlace production line with Hubei Lijie New Material ...On November 26th,Zhengzhou Textile Machinery Co.,Ltd.(hereinafter referred to as"ZFJ")signed an order for a high-speed intelligent wide-width wetmethod spunlace production line with Hubei Lijie New Material Technology Co.,Ltd.(hereinafter referred to as"Hubei Lijie").This cooperation marks a further consolidation of ZFJ's leading position in the nonwoven fabric equipment market in Hubei Province and lays a solid foundation for deeper cooperation between the two companies in the future.展开更多
Extensive engineering experience and research findings suggest that rock mass instability is typically attributed to human engineering activities and natural disturbances,resulting in general dynamic mechanical proper...Extensive engineering experience and research findings suggest that rock mass instability is typically attributed to human engineering activities and natural disturbances,resulting in general dynamic mechanical properties.This is attributed to external interference resulting from the extensive use of the mechanical and blasting techniques necessary for mineral extraction.Quantifying the impact of dynamic disturbances on rock deformation behavior is essential for comprehending the long-term response of surrounding rock during excavation.This study placed the rock to sustained pressure and investigated the impact of varying hammer heights and dry and wet(W-D)damage on its shear failure behavior.This study investigated the fatigue disturbance studies on W-D damaged sandstone samples via W-D equipment,a disturbance creep device,digital image correlation(DIC),and acoustic emission(AE)technology.The experimental findings suggest that acoustic emission sensors can be utilized to quantify the internal damage of rock samples during cyclic impact,whereas DIC technology(optical measurement)is capable of capturing the surface crack propagation of samples.Under repeated impact and the combined action of W-D conditions,the bearing capacity of sandstone decreases,whereas the deformation capacity increases.Furthermore,the W-D cycles and impact strength are inversely related to the fatigue life.The intensity of W-D damage and disturbances further accelerates the development and propagation of cracks under cyclic disturbances.The research results are of preventive significance to ensure the safety and sustainable development of engineering construction.展开更多
This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency （WUE） under alternate wetting and drying （AWD） irrigation than...This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency （WUE） under alternate wetting and drying （AWD） irrigation than check rice. Two super rice cultivars and two elite check rice cultivars were grown in pots with three soil moisture levels, well watered （WW）, moderate water deficit （MWD） and severe water deficit （SWD）. Two cultivars, each for super rice and check rice, were grown in field with three irrigation regimes, alternate wetting and moderate drying （AWMD）, alternate wetting and severe drying （AWSD） and conventional irrigation （CI）. Compared with that under WW, grain yield was significantly decreased under MWD and SWD treatments, with less reduction for super rice than for check rice. Super rice had higher percentage of productive tillers, deeper root distribution, higher root oxidation activity, and greater aboveground biomass production at mid and late growth stages than check rice, especially under WMD and WSD. Compared with CI,AWMD increased, whereasAWSD decreased grain yield, with more increase or less decrease for super rice than for check rice. Both MWD and SWD treatments and eitherAWMD orAWSD regime significantly increased WUE compared with WW treatment or CI regime, with more increase for super rice than for check rice. The results suggest that super rice has a stronger ability to cope with soil water deficit and holds greater promising to increase both grain yield and WUE by adoption of moderate AWD irrigation.展开更多
Mine dust is classified as one of five natural coal mining disasters because it can harm the health of miners and poses a serious threat to the safety of the coal mine. Therefore, preparation of an effective dust supp...Mine dust is classified as one of five natural coal mining disasters because it can harm the health of miners and poses a serious threat to the safety of the coal mine. Therefore, preparation of an effective dust suppression agent is highly desired. To improve the capture efficiency of fine dust, this study examines the dust suppression effects of various combinations of wetting agents, additives, and coagulation agents by using the optimum seeking method to reduce mine dust, particularly respirable particles. The optimal formula is shown to contain 10wt% fatty alcohol polyoxyethylene ether（JFC）, 4.96wt% cationic polyacrylamide, and 4wt% calcium chloride. The dust suppression effect can be achieved at 96.1% in 5 min by using the optimal formula.展开更多
基金supported by the National Key R&D Program of China(Grant No.2023YFC3209504)Natural Science Foundation of Wuhan(Grant No.2024040801020271)the Fundamental Research Funds for Central Public Welfare Research Institutes(Grant No.CKSF2025718/YT).
文摘Wetting deformation in earth-rockfill dams is a critical factor influencingdam safety.Although numerous mathematical models have been developed to describe this phenomenon,most of them rely on empirical formulations and lack prior knowledge of model parameters,which is essential for Bayesian parameter inversion to enhance accuracy and reduce uncertainty.This study introduces a datadriven approach to establishing prior knowledge of earth-rockfill dams.Driving factors are utilized to determine the potential range of model parameters,and settlement changes within this range are calculated.The results are iteratively compared with actual monitoring data until the calculated range encompasses the observed data,thereby providing prior knowledge of the model parameters.The proposed method is applied to the right-bank earth-rockfilldam of Danjiangkou.Employing a Gibbs sample size of 30,000,the proposed method effectively calibrates the prior knowledge of the wetting model parameters,achieving a root mean square error(RMSE)of 5.18 mm for the settlement predictions.By comparison,the use of non-informative priors with sample sizes of 30,000 and 50,000 results in significantly larger RMSE values of 11.97 mm and 16.07 mm,respectively.Furthermore,the computational efficiencyof the proposed method is demonstrated by an inversion computation time of 902 s for 30,000 samples,which is notably shorter than the 1026 s and 1558 s required for noninformative priors with 30,000 and 50,000 samples,respectively.These findingsunderscore the superior performance of the proposed approach in terms of both prediction accuracy and computational efficiency.These results demonstrate that the proposed method not only improves the predictive accuracy but also enhances the computational efficiency,enabling optimal parameter identificationwith reduced computational effort.This approach provides a robust and efficientframework for advancing dam safety assessments.
基金support from the National Natural Science Foundation of China(Grant Nos.52104207 and 52374214)the Shandong Provincial Youth Innovation Team Development Program for Higher Education Institutions(Grant No.2023KJ305).
文摘In the field of rock engineering,the influence of water is a dynamic process that exhibits varying effects over time and across different locations.To further understand how water influences the mechanical properties and acoustic emission(AE)behavior of rocks,this study conducted uniaxial compression experiments on sandstones with varying degrees of wetting under both natural conditions and water-chemical environments.In addition,the study combined AE equipment with digital image correlation(DIC)to monitor the entire failure process.Using the sliding window algorithm,the variation in the variance of AE characteristic parameters during the process of sandstone loading to failure is analyzed from the perspective of critical slowing down.This analysis enables the effective identification of the early warning signal before failure.The experimental findings suggest that an increase in wetting height results in a gradual decrease in peak stress,accompanied by a concomitant increase in the percentage of shear cracks.The characteristic parameters,including energy,amplitude,and ringing count,all exhibit critical slowing phenomena.The waveform of AE characteristic parameters of the same sample is similar,and the mutation time of the precursor signal is roughly the same.All signals appear in the irreversible plastic deformation stage of microcrack initiation.The integration of critical slowing down theory and the b-value early warning method facilitates a more comprehensive evaluation of the stability of rock mass,thereby significantly enhancing the efficiency and safety of disaster prevention measures.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20241931 and BK 20221371)the National Natural Science Foundation of China(32071943,32372214,and 31901444)the National Key Research and Development Program of China(2022YFD2300304)。
文摘Alternate wetting and drying irrigation(AWD)significantly influences the cooking and eating quality of rice(Oryza sativa L.).However,the mechanisms by which AWD affects rice cooking and eating quality remain unclear.Lipid and free fatty acid contents in grains correlate positively with cooking and eating quality of rice.This study examined Yangdao 6(YD6,a conventional taste indica inbred)and Nanjing 9108(NJ9108,a superior taste japonica inbred)cultivated under conventional irrigation(CI),alternate wetting and moderate drying irrigation(AWMD),and alternate wetting and severe drying irrigation(AWSD)from 10 days after transplanting to maturity.The research investigated the relationship between lipid and free fatty acid biosynthesis in grains and the cooking and eating quality of rice.Compared to CI treatment,AWMD significantly enhanced the contents of lipid,total free fatty acids(TFFAs),free unsaturated fatty acids(FUFAs),linoleic acid,and oleic acid in milled rice by increasing activities of enzymes associated with lipid synthesis,while AWSD produced opposite effects.Correlation analysis revealed that elevated levels of lipid,TFFAs,FUFAs,linoleic acid,and oleic acid contribute to improved rice cooking and eating quality.The findings demonstrate that AWMD enhances cooking and eating quality of milled rice through optimization of lipid and fatty acid synthesis in rice grains.
基金supported by the Postdoctor Project of Hubei Province(2024HBBHCXA074)National Natural Science Foundation of China(51974212)+2 种基金China Baowu Low Carbon Metallurgy Innovation Foundation(BWLCF202116)Foundation of Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking(NPISlab25-03)Science and Technology Major Project of Wuhan(2023020302020572).
文摘The wetting behavior of slag–coke is a crucial factor influencing the permeability of the lower part of the blast furnace.However,a systematic understanding of the wetting behavior and underlying mechanisms between titanium-containing slag and tuyere coke remains lacking.The sessile drop method was employed to explore the effects of temperature,binary basicity,FeO,and TiO_(2) contents on the wetting behavior of titanium-containing slag and tuyere coke.The results indicate that increasing the temperature enhances the adhesion and wettability of the droplet,reducing the contact angle.Meanwhile,it accelerates the chemical reactions between slag and coke,leading to faster equilibrium.Conversely,increasing slag basicity elevates the contact angle by inhibiting chemical reactions at the slag–coke interface.This inhibition reduces both contact area and depth,thereby hindering slag droplet spreading on the coke surface.The contact angle decreases as the FeO content in the slag increases.Notably,the increase in TiO_(2) content has a dual effect on slag–coke wettability.Initially,it promotes wetting by reducing surface tension and lowering the contact angle.While the TiO_(2) content exceeds 20 wt.%,Ti(C,N)forms a barrier layer at the slag–coke interface,hindering the contact between slag and coke and resulting in an increased contact angle.
基金Doctoral Research Start-up Fund of Lanzhou University of Arts and Science(2021-9)Innovation Fund for Colleges and Universities of Gansu Province,China(2022B-265)。
文摘The wetting behavior of liquid tin(Sn)solder on copper(Cu)substrate at 250℃was investigated by the wetting balance method under the action of direct current(DC).The curves of wetting balance were measured and the morphology of the intermetallic compound(IMC)precipitated at the interface were observed.Results show that DC has a significant effect on the wettability and IMC.As the current increases,the balance wetting force and the thickness of the IMC layer increase.The direction of the DC also has a certain effect on the balance wetting force and IMC layer.When the current is negative,the final balance wetting force and the thickness of the Cu_(6)Sn_(5) layer are significantly higher than those in the positive current case,which is attributed to electromigration.The IMC precipitation at the interface provides a chemical driving force for the movement of the triple junction.The interaction of the interface atoms and the chemical reaction are enhanced by DC,thereby improving wettability.Meanwhile,the Marangoni convection caused by DC inside liquid Sn solder changes the structure of triple junction,which provides a physical driving force for the spread of the liquid Sn solder on the Cu substrate.
基金supported by the National Natural Science Foundation of China(Grant Nos.12322206,12272340,and 11925206)Basic Science Center Program for Multiphase Media Evolution in Hypergravity of the National Natural Science Foundation of China(Grant No.51988101)the Zhejiang Provincial Natural Science Foundation of China(Grant No.LD21A020002).
文摘The wetting phenomenon of composite substrates in hypergravitational environment has a huge application in electronic devices and astronaut healthcare in aerospace missions.In the present contribution,the governing equation of high-G droplets on the composite substrate is firstly established in the hypergravitational environment.Meanwhile,the apparent contact angles at the contact line between droplets and substrates with different stiffness gradients are achieved.Then,we analyze the effects of hypergravity factor and the substrate stiffness on the wetting profile of high-G droplets.By introducing the droplet volume and contact angle into the Bond number,the scaling law of the high-G droplet profile is established,and we find that the contact radius of the droplet R/S^(0.5)has a linear relationship withρω^(2)rl^(2)S/(γ_(LV)^(θ)),while the droplet height H/S^(0.5)has a power-law relationship withρω^(2)rl^(2)S/(γ_(LV)^(θ)).Finally,we explain the profiles of high-G droplets during the wetting process by illustrating energy components of the entire system and find that the substrate with positive triangular stiffness and inverted triangular stiffness show opposite evolution laws.On a substrate with inverted triangular stiffness,the gravitational potential energy is more dominant.
基金financially supported by the National Natural Science Foundation of China(No.52274021)the National Key Research and Development Program of China(No.2021YFA0719102)。
文摘Antarctica contains numerous scientific mysteries,and the Antarctic ice sheet and its underlying bedrock contain important information about the geological structure of Antarctica and the evolutionary history of the ice sheet.In order to obtain the focus of these scientific explorations,the Antarctic drilling engineering is constantly developing.The drilling fluid performance directly determines the success or failure of drilling engineering.In order to enhance the poor performance for drilling fluids due to poor dispersion stability and easy settling of organoclay at ultra-low temperatures,the small-molecule wetting agent(HSR)for drilling fluid suitable for Antarctica was prepared by oleic acid,diethanolamine and benzoic acid as raw materials.Its chemical structure,properties and action mechanism were investigated by various experimental methods.The experimental results showed that 2%HSR could improve the colloidal rate for drilling fluid from 6.4%to 84.8%,and the increase rate of yield point was up to 167%.Meanwhile,it also made the drilling fluid excellent in shear dilution and thixotropy.In addition,2%HSR could increase the density from 0.872 to 0.884 g/cm^(3) at-55 ficial.And the drilling fluid with 2%HSR had a good thermal conductivity of 0.1458 W/(m·K)at-55 ficial.This study gives a new direction for the research of drilling fluid treatment agents suitable for the Antarctic region,which will provide strong support for the scientific exploration of the Antarctic region.
基金Project(41877240)supported by the National Natural Science Foundation of China。
文摘As a typical sedimentary soft rock,mudstone has the characteristics of being easily softened and disintegrated under the effect of wetting and drying(WD).The first cycle of WD plays an important role in the entire WD cycles.X-ray micro-computed tomography(micro-CT)was used as a non-destructive tool to quantitatively analyze microstructural changes of the mudstone due to the first cycle of WD.The test results show that WD leads to an increase of pore volume and pore connectivity in the mudstone.The porosity and fractal dimension of each slice of mudstone not only increase in value,but also in fluctuation amplitude.The pattern of variation in the frequency distribution of the equivalent radii of connected,isolated pores and pore throats in mudstone under WD effect satisfies the Gaussian distribution.Under the effect of WD,pores and pore throats with relatively small sizes increase the most.The sphericity of the pores in mudstones is positively correlated with the pore radius.The WD effect transforms the originally angular and flat pores into round and regular pores.This paper can provide a reference for the study of the deterioration and catastrophic mechanisms of mudstone under wetting and drying cycles.
基金financially supported by the National Natural Science Foundation of China(Grant Nos.U21A2057 and U1908223)the open research fund for the State Key Laboratory of Advanced Refractories(Grant No.SKLAR202405).
文摘Alkaline slag is vital in rare earth steel refining,making it crucial to study the wetting and penetration mechanisms between refractory materials and slag.The effect of Eu_(2)O_(3) doping on the sintering properties of MgO-MgAl_(2)O_(4) refractory materials was investigated while simulating the wetting behavior between the refractory and the CaO-Al_(2)O_(3)-SiO_(2)-MgO quaternary alkaline slag during rare earth steel smelting to improve the material’s resistance to alkaline slag corrosion.The doping of Eu_(2)O_(3) can alter the crystal structure parameters of MgAl_(2)O_(4) and MgO,causing lattice distortion.This lattice activation promotes interionic mass and diffusion,helping reduce porosity and promote densification of the material,further improving sintering properties.At the equilibrium wetting temperature(1723 K),Eu_(2)O_(3) doping increases the interfacial free energy between the slag and refractory material,reducing the spreading coefficient of the molten slag.The contact angle increases from 32.1°to 42.2°,and the residual slag volume increases from 17.9%to 23.5%.The results of thermodynamic analysis show that MgAl_(2)O_(4) and EuAlO3 formed at the interface block the penetration of molten slag at high temperatures,improving the resistance of MgO-MgAl_(2)O_(4) refractories to alkaline slag corrosion.Based on the capillary theory model,it was calculated that the capillary tension of the slag gradually increases with the addition of Eu_(2)O_(3),while the theoretical penetration depth of the slag gradually decreases.The experimental results showed that the slag erosion depth of the sample decreased from 102.54 to 68.28μm.
基金supported by the Natural Science Foundation of Jiangsu Province,China(BK20241931 and BK20221371)the National Natural Science Foundation of China(32071943 and 32372214)the National Key Research and Development Program of China(2022YFD2300304)。
文摘Alternate wetting and soil drying irrigation(AWD)technique is crucial in infuencing grain quality in rice(Oryza sativa L.).Lipids are the third most abundant constituents in rice grains,after starch and proteins,and are closely related to grain quality.However,it remains unclear about the changes in lipids profling under different AWD regimes.This study set up three irrigation regimes including conventional irrigation(CI),alternate wetting and moderate soil drying irrigation(AWMD),and alternate wetting and severe soil drying irrigation(AWSD).It explored lipidome changes in milled rice of Yangdao 6(YD6)using the untargeted lipidomics approach and analyzed rice cooking and eating quality.The results identifed seven lipid classes,55 lipid subclasses,and 1,086 lipid molecular species.Compared with the CI regime,the AWMD regime mainly altered lipid subclasses consisting of triglyceride(TG),ceramide(Cer),diglyceride(DG),bis-methyl lysophosphatidic acid(BisMePA),phosphocholine(PC),phosphoethanolamine(PE),monogalactosyldiacylglycerol(MGDG),and digalactosyl diglyceride(DGDG)in milled rice and improved cooking and eating quality of rice;in contrast,the AWSD regime distinctly changed lipid subclasses like TG,Cer,DG,PC,PE,hexosylceramide(Hex1Cer),DGDG,and BisMePA and degraded cooking and eating quality of rice.Specifcally,AWMD most signifcantly altered the expressions of lipid molecules,including DGDG(18:0_18:2),DGDG(16:0_14:0),PC(33:1),Cer(t17:0_26:0),and Cer(t17:0_16:0);AWSD most obviously influenced the expressions of TG(6:0_14:0_18:3),PC(41:1),TG(19:1_18:4_18:4),Hex1Cer(d18:2_24:0+O),and Hex1Cer(d18:2_24:1).These 10 altered lipid molecules in milled rice can be preferentially used for investigating their relationships with grain quality in rice.
基金supported by the National Natural Science Founda-tion of China(Nos.42327806 and 52370108)Zhejiang Provincial Leading Project for Leading Geese Plan(No.2025C03073).
文摘Carbonyls play an important role in the atmospheric chemistry as the main precursor for reactive radicals and peroxyacetyl nitrate.However,little research has been conducted so far on the seasonal variations of carbonyls in China’s urban atmosphere.In this study,ambient carbonyls were 24-hourly observed in four seasons in Hangzhou,a mega-city in the Yangtze River Delta Region,China.The concentration of total carbonyls was the highest in summer(44.35μg/m^(3)),the second in winter(44.05μg/m^(3)),the third in spring(29.31μg/m^(3))and autumn(27.11μg/m^(3)).The most abundant species were found to be acetone in spring,summer,and winter,while formaldehyde in autumn.Rainfall can significantly reduce the concentrations of most ambient carbonyls,with the largest decrease observed in the wet precipitation events occurring in spring and summer,while acetone concentrations remained invariable due to its lower water solubility.Multiple linear regression analysis and carbonyls ratios indicated that anthropogenic emissions were the predominant sources of carbonyls,and atmospheric formaldehyde was mainly emitted from primary sources other than secondary sources.Vehicular exhaust was identified as the primary source of ambient carbonyls,particularly in winter,and its contribution reached 92.80%to formaldehyde.Additionally,photochemical reactions were closely associated with the secondary production of formaldehyde in summer.Carbonyls showed strong ozone formation potential in all four seasons.Based on the health risk assessment,the exposure to ambient carbonyls is harmful to outdoor pedestrians.The results could provide essential information and references for simulating regional air quality and analyzing ozone pollution,which is essential for improving air quality in the Yangtze River Delta region.
文摘BACKGROUND Orthopaedic surgical education has traditionally depended on the apprenticeship model of“see one,do one,teach one”.However,reduced operative exposure,stricter work-hour regulations,medicolegal constraints,and patient safety concerns have constrained its practicality.Simulation-based training has become a reliable,safe,and cost-efficient alternative.Dry lab techniques,especially virtual and augmented reality,make up 78%of current dry lab research,whereas wet labs still set the standard for anatomical realism.AIM To evaluate the effectiveness,limitations,and future directions of wet and dry lab simulation in orthopaedic training.METHODS A scoping review was carried out across four databases-PubMed,Cochrane Library,Web of Science,and EBSCOhost-up to 2025.Medical Subject Headings included:"Orthopaedic Education","Wet Lab","Dry Lab","Simulation Training","Virtual Reality",and"Surgical Procedure".Eligible studies focused on orthopaedic or spinal surgical education,employed wet or dry lab techniques,and assessed training effectiveness.Exclusion criteria consisted of non-English publications,abstracts only,non-orthopaedic research,and studies unrelated to simulation.Two reviewers independently screened titles,abstracts,and full texts,resolving discrepancies with a third reviewer.RESULTS From 1851 records,101 studies met inclusion:78 on dry labs,7 on wet labs,4 on both.Virtual reality(VR)simulations were most common,with AI increasingly used for feedback and assessment.Cadaveric training remains the gold standard for accuracy and tactile feedback,while dry labs-especially VR-offer scalability,lower cost(40%-60%savings in five studies),and accessibility for novices.Senior residents prefer wet labs for complex tasks;juniors favour dry labs for basics.Challenges include limited transferability data,lack of standard outcome metrics,and ethical concerns about cadaver use and AI assessment.CONCLUSION Wet and dry labs each have unique strengths in orthopaedic training.A hybrid approach combining both,supported by standardised assessments and outcome studies,is most effective.Future efforts should aim for uniform reporting,integrating new technologies,and policy support for hybrid curricula to enhance skills and patient care.
基金Supported by the Meteorological Science and Technology Innovation Project of North China(HBXM202415)Research Project of the Meteorological Bureau of Inner Mongolia Autonomous Region(nmqxkjcx202311).
文摘Based on the conventional observation data,daily reanalysis data from NCAR/NCEP,and TBB data derived from FY-2G infrared cloud images in April 2018,a heavy snowfall weather process in central Inner Mongolia from April 4 to 6 in 2018 was analyzed.The results show that the low trough at 500 hPa,the southerly wind jet stream at 700 hPa,and the inverted trough on the ground were the main influencing systems causing this blizzard.The transportation of warm and humid air by the southerly wind jet stream at 700 hPa and intense water vapor convergence provided sufficient water vapor conditions for the blizzard,and the moist layer in the blizzard area was deep.The low-level MPV in the blizzard area was<0,and the atmosphere was in a conditional symmetric instability state.The coupling of the upper and lower-level jets induced strong ascending motion.With the invasion of cold air,a low-level cold pad was formed,so that the warm and humid air tilted upward.The secondary circulation updraft triggered by the wet Q vector system released the conditional symmetric instability energy,so that the sloping motion was more intense,and the heavy snowfall appeared.Meanwhile,there was a good correspondence relationship between the blizzard area and the large-value area of low-level wet Q vector divergence.The mesoscale cloud clusters continuously generating,merging,and moving eastward in Hetao area were the direct cause of this blizzard,and the TBB of the cloud clusters was≤-56℃.The blizzard happened in the the edge gradient and large-value area of TBB.
基金Project(50471007)supported by the National Natural Science Foundation of China
文摘In order to reveal the physical essence of the spreading process of reactive wetting,a sort of model of energy to explain the driving force and wetting mechanism was presented.The reactive wetting of molten A1 and Cu Si on graphite was studied by a modified sessile drop method under a vacuum,in which the contact angles were measured by ADSA software.The thermodynamic and kinetic processes of the typical reactive wetting were focused on,the thermodynamic equations of energy relations were derived,the interfacial energy of graphite and solid-liquid interfacial energy versus time at the triple line were calculated,and the dynamics model of interface energy is established.The presented dynamics model is verified by means of experimental results,and it is shown that solid liquid interfacial energy decreases with time in exponential relationship.It provides a new method for reference to explain the process from the angle of energy.
基金Funded by joint Funds of the National Natural Science Foundation of China(No.U1904188)the Key Research Project of Henan Province for Colleges and Universities(No.26A560009)+3 种基金the Jiaozuo City Science and Technology Planning Project(No.2025210099)the Henan Provincial Science and Technology Research Project(No.252102320305)the Natural Science Foundation of Henan Province(No.252300421917)the Project by Key Laboratory of Intelligent Construction and Safety Operation and Maintenance of Underground Engineering in Henan Province(No.KFKT2024-01)。
文摘To explore mix proportion design of RAC with aggregates tightly packed,the dry and wet packing density of recycled coarse aggregates mixture system and recycled coarse and fine aggregates were tested,then the influence of replacement rate and particle size ratio on the packing density of particle system was explored,the packing density prediction model of recycled coarse aggregates based on particle morphology was constructed,and the mix proportion optimization for recycled aggregate concrete with dry-wet packing model was carried out.The experimental results show that,with the increasing of recycled aggregate replacement rate or fine-grained volume ratio,the dry packing density of recycled coarse aggregates decreases gradually.With the increasing of replacement rate,the particle gradation can be optimized by increasing coarsegrained volume ratio.There is a significant effect for particle morphology parameter K and the particle size ratio on the packing density of the binary mixed system,and the packing density prediction model of recycled coarse aggregates based on particle morphology was constructed.The maximum increase in compressive strength and tensile strength of RAC with mix proportion optimized by the dry-wet packing model are 12.94%and 11.09%,and the cementitious materials is reduced by 21.83%,then the superiority of the mix proportion optimization of RAC with the dry-wet close packing model is confirmed.The results of this paper can provide a theoretical basis for the mix proportion design of RAC.
基金funded by National Natural Science Foundation of China Key Program(12431014)Key Project of Hunan Education Department(22A0126)+1 种基金Natural Science Foundation of Hunan Province(2022JJ30555)Postgraduate Scientific Research Innovation Project of Xiangtan University(XDCX2024Y172)。
文摘Tropospheric zenith wet delay(ZWD)plays a vital role in the analysis of space geodetic observations.In recent years,machine learning methods have been increasingly applied to improve the accuracy of ZWD calculations.However,a single machine learning model has limited generalization capabilities.To address these limitations,this study introduces a novel machine learning fusion(MLF)algorithm with stronger generalization capabilities to enhance ZWD modeling and prediction accuracy.The MLF algorithm utilizes a two-layer structure integrating extra trees(ET),backpropagation neural network(BPNN),and linear regression models.By comparing the root mean square error(RMSE)of these models,we found that both ET-based and MLF-based models outperform RF-based and BPNN-based models in terms of internal and external accuracy,across both surface meteorological data-based and blind models.The improvement in exte rnal accuracy is particularly significant in the blind models.Our re sults show that the MLF(with an RMSE of 3.93 cm)and ET(3.99 cm)models outperform the traditional GPT3model(4.07 cm),while the RF(4.21 cm)and BPNN(4.14 cm)have worse external accuracies than the GPT3 model.It is worth noting that the BPNN suffered from overfitting during external accuracy tests,which was avoided by the MLF.In summary,regardless of the availability of surface meteorological data,the MLF-based empirical models demonstrate superior internal and external accuracy compared to the other tested models in this study.
文摘On November 26th,Zhengzhou Textile Machinery Co.,Ltd.(hereinafter referred to as"ZFJ")signed an order for a high-speed intelligent wide-width wetmethod spunlace production line with Hubei Lijie New Material Technology Co.,Ltd.(hereinafter referred to as"Hubei Lijie").This cooperation marks a further consolidation of ZFJ's leading position in the nonwoven fabric equipment market in Hubei Province and lays a solid foundation for deeper cooperation between the two companies in the future.
基金supported by National Natural Science Foundation of China(Grant Nos.52364004 and 52264006)The Youth Talent Growth Project of Guizhou Provincial Department of Education(Grant No.QianJiaoJi[2024]18).
文摘Extensive engineering experience and research findings suggest that rock mass instability is typically attributed to human engineering activities and natural disturbances,resulting in general dynamic mechanical properties.This is attributed to external interference resulting from the extensive use of the mechanical and blasting techniques necessary for mineral extraction.Quantifying the impact of dynamic disturbances on rock deformation behavior is essential for comprehending the long-term response of surrounding rock during excavation.This study placed the rock to sustained pressure and investigated the impact of varying hammer heights and dry and wet(W-D)damage on its shear failure behavior.This study investigated the fatigue disturbance studies on W-D damaged sandstone samples via W-D equipment,a disturbance creep device,digital image correlation(DIC),and acoustic emission(AE)technology.The experimental findings suggest that acoustic emission sensors can be utilized to quantify the internal damage of rock samples during cyclic impact,whereas DIC technology(optical measurement)is capable of capturing the surface crack propagation of samples.Under repeated impact and the combined action of W-D conditions,the bearing capacity of sandstone decreases,whereas the deformation capacity increases.Furthermore,the W-D cycles and impact strength are inversely related to the fatigue life.The intensity of W-D damage and disturbances further accelerates the development and propagation of cracks under cyclic disturbances.The research results are of preventive significance to ensure the safety and sustainable development of engineering construction.
基金sponsored by the National Natural Science Foundation of China(31461143015,31271641,31471438)the National Key Technology Support Program of China(2014AA10A605,216YFD0300206-4)+1 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),Chinathe Jiangsu Creation Program for Post-graduation Students,China(KYZZ15_0364)
文摘This study investigated if super rice could better cope with soil water deficit and if it could have better yield performance and water use efficiency （WUE） under alternate wetting and drying （AWD） irrigation than check rice. Two super rice cultivars and two elite check rice cultivars were grown in pots with three soil moisture levels, well watered （WW）, moderate water deficit （MWD） and severe water deficit （SWD）. Two cultivars, each for super rice and check rice, were grown in field with three irrigation regimes, alternate wetting and moderate drying （AWMD）, alternate wetting and severe drying （AWSD） and conventional irrigation （CI）. Compared with that under WW, grain yield was significantly decreased under MWD and SWD treatments, with less reduction for super rice than for check rice. Super rice had higher percentage of productive tillers, deeper root distribution, higher root oxidation activity, and greater aboveground biomass production at mid and late growth stages than check rice, especially under WMD and WSD. Compared with CI,AWMD increased, whereasAWSD decreased grain yield, with more increase or less decrease for super rice than for check rice. Both MWD and SWD treatments and eitherAWMD orAWSD regime significantly increased WUE compared with WW treatment or CI regime, with more increase for super rice than for check rice. The results suggest that super rice has a stronger ability to cope with soil water deficit and holds greater promising to increase both grain yield and WUE by adoption of moderate AWD irrigation.
基金National Natural Science Funds-Coal Joint Funds Key Support Project (No. U1261205)Basic Research Plan Project of Science and Technology of Qingdao (No. 13-1-4-149-jch)Key Technology Development Projects of Qingdao Economic and Technological Development Zone (No. 2013-1-66) for providing the financial support to this research
文摘Mine dust is classified as one of five natural coal mining disasters because it can harm the health of miners and poses a serious threat to the safety of the coal mine. Therefore, preparation of an effective dust suppression agent is highly desired. To improve the capture efficiency of fine dust, this study examines the dust suppression effects of various combinations of wetting agents, additives, and coagulation agents by using the optimum seeking method to reduce mine dust, particularly respirable particles. The optimal formula is shown to contain 10wt% fatty alcohol polyoxyethylene ether（JFC）, 4.96wt% cationic polyacrylamide, and 4wt% calcium chloride. The dust suppression effect can be achieved at 96.1% in 5 min by using the optimal formula.
