The electrochemical corrosion behavior of the dental Ti50 Zr alloy with and without nanocrystalline(TiZr)N coating was comparatively investigated in artificial saliva solutions with different pH values and fluoride io...The electrochemical corrosion behavior of the dental Ti50 Zr alloy with and without nanocrystalline(TiZr)N coating was comparatively investigated in artificial saliva solutions with different pH values and fluoride ion concentrations. The chemical stability of the passive films on the coated and non-coated Ti50 Zr alloy was evaluated by calculating passive film thickness. The chemical compositions and valence structures of the passive films were analyzed by X-ray photoelectron spectroscopy(XPS). The results show that the(TiZr)N-coated alloy displays distinctly decreased corrosion rate and increased impedance compared with Ti50 Zr alloy in nonfluoridated and fluoridated acidic solutions. Particularly, in the solution of pH = 3.9 and 0.15% NaF-containing, the corrosion protection efficiency of(TiZr)N coating reaches90%. The excellent corrosion resistance of the coated alloy is attributed to that the nanocrystallines in(TiZr)N coating decreases micropores and crack defects, which strongly impedes the corrosive ions diffusion and electrode process at Ti substrate/coating interface. Meanwhile,(TiZr)N coating shows good passivation behavior in acidic solution and active–passive transition behavior in fluoridated acidic solution. The coated Ti50 Zr alloy with high chemical stability has potential application prospect for dental implants.展开更多
The aim of this work was to produce a nanoscale fluoridated and potassium containing hydroxyapatite via sol-gel method and to observe the effect of occlusion of the dentin tubule under scanning electron microscopy. H...The aim of this work was to produce a nanoscale fluoridated and potassium containing hydroxyapatite via sol-gel method and to observe the effect of occlusion of the dentin tubule under scanning electron microscopy. HF was selected as fluorine-containing rengent which was added into mixed Ca （ NO3 ）2-P2O5 ethanol solutions to obtain dipping sols. All of the resulting samples showed apatite structure in their X- ray diffraction pattern. The lattice parameter a and the crystallite size were calculated to demonstrate the crystalline structure of fluoridated and potassium containing HA. Extracted paired premolars were chosen to obtain a fiat surface with opened tubules. It was observed that the tubules were covered by a 10 μm layer of fluoridated and potassium containing HA under the SEM. As the experimental results show the nanoscale fluoridated and potassium containing hydroxyapatite occludes the dentin tubules.展开更多
Excessive levels of Fluoride(F−)and Cadmium(Cd)in drinking groundwater may pose health risks.This study assessed the health risks associated with F−and Cd contamination in rural drinking groundwater sources in Wutai C...Excessive levels of Fluoride(F−)and Cadmium(Cd)in drinking groundwater may pose health risks.This study assessed the health risks associated with F−and Cd contamination in rural drinking groundwater sources in Wutai County,Shanxi Province,China,to support population health protection,water resource management,and environmental decision-making.Groundwater samples were collected and analyzed,and a Human Health Risk Model(HHRA)was applied to evaluate groundwater quality.The results showed that both contents of F−and Cd in groundwater exceeded the Class III limits of China's national groundwater quality standard(GB/T 14848—2024).Fluoride levels met the Class V threshold,with enrichment area mainly located in the east part of the study area.Cadmium levels reached Class IV,with elevated concentrations primarily observed in the western and northwestern regions.Correlation analysis revealed that F−showed weak or no correlation with other measured substances,indicating independent sources.Health risk assessment results indicated that F−poses potential health risks to rural residents,while cadmium,due to its relatively low concentrations,does not currently present a significant health risk.Among different demographic groups,the health risk levels of F−exposure followed the order:Infants>children>adult females>adult males.The findings highlight that fluoride is the primary contributor to health risks associated with groundwater consumption in the study area.Strengthened monitoring and prevention of F−contamination are urgently needed.This research provides a scientific basis for the prevention and control of fluoride pollution in groundwater and offers practical guidance for safeguarding drinking water safety in rural China.展开更多
It is difficult to recover chrysocolla from sulfidation flotation which is closely related to the mineral surface composition.In this study,the effects of fluoride roasting on the surface composition of chrysocolla we...It is difficult to recover chrysocolla from sulfidation flotation which is closely related to the mineral surface composition.In this study,the effects of fluoride roasting on the surface composition of chrysocolla were investigated,its impact on sulfidation flotation was explored,and the mechanisms involved in both fluoride roasting and sulfidation flotation were discussed.With CaF_(2)as the roasting reagent,Na_(2)S·9H_(2)O as the sulfidation reagent,and sodium butyl xanthate(NaBX)as the collector,the results of the flotation experiments showed that fluoride roasting improved the floatability of chrysocolla,and the recovery rate increased from 16.87%to 82.74%.X-ray diffraction analysis revealed that after fluoride roasting,approximately all the Cu on the chrysocolla surface was exposed in the form of CuO,which could provide a basis for subsequent sulfidation flotation.The microscopy and elemental analyses revealed that large quantities of"pagoda-like"grains were observed on the sulfidation surface of the fluoride-roasted chrysocolla,indicating high crystallinity particles of copper sulfide.This suggests that the effect of sulfide formation on the chrysocolla surface was more pronounced.X-ray photoelectron spectroscopy revealed that fluoride roasting increased the relative contents of sulfur and copper on the surface and that both the Cu~+and polysulfide fractions on the surface of the minerals increased.This enhances the effect of sulfidation,which is conducive to flotation recovery.Therefore,fluoride roasting improved the effect of copper species transformation and sulfidation on the surface of chysocolla,promoted the adsorption of collectors,and improved the recovery of chrysocolla from sulfidation flotation.展开更多
Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,...Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,hazard quotient assessment,and geochemical analyses,such as mineral saturation index,ionic activities,and Gibbs diagrams,to investigate the hydrochemical characteristics,causes,and noncarcinogenic risks of fluoride in Red bed groundwater and geothermal water in the Guang'an area and neighboring regions.Approximately 9%of the Red bed groundwater samples contain fluoride concentrations exceeding 1 mg·L^(-1).The predominant water types identified are Cl-Na and HCO_(3)-Na,primarily influenced by evapotranspiration.Low-fluoride groundwater and high-fluoride geothermal water exhibit distinct hydrochemical types HCO_(3)-Ca and SO_(4)-Ca,respectively,which are mainly related to the weathering of carbonate,sulfate,and fluorite-containing rocks.Correlation analysis reveals that fluoride content in Red bed groundwater is positively associated with Na^(+),Cl^(-),SO_(4)^(2-),and TDS(r^(2)=0.45-0.64,p<0.01),while in geothermal water,it correlates strongly with pH,K^(+),Ca^(2+),and Mg^(2+)(r^(2)=0.52-0.80,p<0.05).Mineral saturation indices and ionic activities indicate that ion exchange processes and the dissolution of minerals such as carbonatite and fluorite are important sources of fluoride in groundwater.The enrichment of fluorine in the Red bed groundwater is linked to evaporation,cation exchange and dissolution of fluorite,caused by the lithologic characteristics of the red bed in this area.However,it exhibits minimal correlation with the geothermal water in the adjacent area.The noncarcinogenic health risk assessment indicates that 7%(n=5)of Red bed groundwater points exceed the fluoride safety limit for adults,while 12%(n=8)exceed the limit for children.These findings underscore the importance of avoiding highly fluoridated red bed groundwater as a direct drinking source and enhancing groundwater monitoring to mitigate health risks associated with elevated fluoride levels.展开更多
In recent years,renewable energy sources,which aim to replace rapidly depleting fossil fuels,face challenges due to limited energy storage and conversion technologies.To enhance energy storage and conversion efficienc...In recent years,renewable energy sources,which aim to replace rapidly depleting fossil fuels,face challenges due to limited energy storage and conversion technologies.To enhance energy storage and conversion efficiency,extensive research has been conducted in the academic community on numerous potential materials.Among these materials,metal fluorides have attracted significant attention due to their ionic metal-fluorine bonds and tunable electronic structures,attributed to the highest electronegativity of fluorine in their chemical composition.This makes them promising candidates for future electrochemical applications in various fields.However,metal fluorides encounter various challenges in different application directions.Therefore,we comprehensively review the applications of metal fluorides in the field of energy storage and conversion,aiming to deepen our understanding of their exhibited characteristics in different electrochemical processes.In this paper,we summarize the difficulties and improvement methods encountered in different types of battery applications and several typical electrode optimization strategies in the field of supercapacitors.In the field of water electrolysis,we focus on surface reconstruction and the critical role of fluorine,demonstrating the catalytic performance of metal fluorides from the perspectives of reconstruction mechanism and process analysis.Finally,we provide a summary and outlook for this field,aiming to offer guidance for future breakthroughs in the energy storage and conversion applications of metal fluorides.展开更多
Fine tailoring the shape of nanosheets is still a big challenge as the difficult synthesis for highly controlled ultrathin nanosheets.Here we report a facile strategy for tailoring the shape of ultra-thin NdF_(3) nano...Fine tailoring the shape of nanosheets is still a big challenge as the difficult synthesis for highly controlled ultrathin nanosheets.Here we report a facile strategy for tailoring the shape of ultra-thin NdF_(3) nanosheets via a hot injection method.In this method,NdF_(3) nanosheets with only about 2 nm in thickness synthesized first via a hot injection method.The shape of the NdF_(3) nanosheets was able to be tailored from flower-like to the round or the triangular shapes simply by decreasing the reaction temperature from 300℃to 280℃or 260℃.The driven force of the NdF_(3) nanosheets’shape tailoring by the temperature could be that a lower crystal growth rate will guarantee the more stable facets exposed at lower temperature,while under the condition of slow precursor injection,a higher temperature will lead to a further decrease in the crystal growth rate.This shape control method of NdF_(3) nanosheets is highly robust,which could be promoted to other materials.展开更多
Metal fluoride materials with high theoretical capacities are considered the next generation of Li-free conversion cathodes.However,the inherently sluggish reaction kinetics of metal fluorides result in unsatisfactory...Metal fluoride materials with high theoretical capacities are considered the next generation of Li-free conversion cathodes.However,the inherently sluggish reaction kinetics of metal fluorides result in unsatisfactory electrochemical performance.In this study,CoF_(2)was combined with carbonaceous materials to obtain graphitic carbon-encapsulated CoF_(2)nanoparticles uniformly embedded in an interconnected N-doped carbon matrix(CoF_(2)@NC),significantly boosting the inert kinetics and electronic conductivity.The CoF_(2)@NC nanocomposites exhibited a notable reversible capacity of 352.0 mAh·g^(-1)at 0.2 A·g^(-1).Notably,it maintained superior long-term cycling stability even at a high current density of 2 A·g^(-1),with a capacity of 235.5 mAh·g^(-1)after 1200 cycles,evidently exceeding that of commercially available CoF_(2)electrodes.Kinetic analysis indicated that the enhanced electrochemical performance originated from the increased contribution of capacitive effects.Furthermore,in-situ electrochemical impedance spectroscopy(EIS)results verify that the improved cycling performance is associated with the enhanced interfacial stability of CoF_(2)@NC.This research not only proposes a solution for the challenges of conversion cathodes in lithium-ion batteries,but also offers novel synthesis strategies for designing high-energy metal fluoride materials.展开更多
Exploring novel superconductors is a crucial topic in condensed matter physics.There are few reports on the superconductivity of fluorine due to the extremely high pressures required for its metallization.Here,metalli...Exploring novel superconductors is a crucial topic in condensed matter physics.There are few reports on the superconductivity of fluorine due to the extremely high pressures required for its metallization.Here,metallization and superconductivity of fluorine were achieved in MgF_(5)at 120 GPa by exploiting the high-pressure s-d transition of doped Mg.The unexpected Mg-F covalent bonding induced by Mg-d and F-p orbital interactions led to fluorine metallization and the formation of an F skeleton similar to a H-cage.The high density of states(DOS)from the F skeleton and phonon softening from strong Fermi surface nesting contribute to a high superconducting transition temperature(Tc).The Tc of Pmmm-MgF_(5)at 120 GPa is 14.02 K,with strong electron-phonon coupling(λ=0.84),which is close to that of Li_(6)P at 270 GPa(λ=1.01).This is the first observation of superconductivity in main-group metal fluorides.Additionally,two near-monatomic F atoms exist in the interstitial region of MgF_(5),significantly enhancing electron-phonon coupling.This work challenges the traditional view of main-group metal fluorides and provides deeper insights into the superconductivity and physicochemical properties of fluorine.展开更多
High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluor...High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluoride for roasting.Under the optimal leaching conditions of a fluorine to aluminum molar ratio of 2.0,a liquid-to-solid ratio of 12,a temperature of 90℃,and time of 4 h,the fluorine leaching rate can reach 99.15%.Under the action of electrolysis,the H+is reduced to H2 in the cathode,while the remaining OH−combines with AlF^(2+)and AlF^(2+)to precipitate aluminium hydroxyfluoride hydrate.The results show that electrolysis is beneficial to reduce the impurity content of aluminium hydroxyfluoride hydrate.When the current density is 0.2 A/cm^(2),the temperature is 90℃,the stirring speed is 200 r/min,and the electrolysis endpoint pH is 3.0,the total content of Na,K and Ca impurities in the precipitation is only 0.64 wt.%.Moreover,the hydrolysis can be inhibited effectively by adding ammonium hydrogen fluoride in the mixed-roasting process.When the mass ratio of aluminium hydroxyfluoride hydrate to ammonium hydrogen fluoride is 2꞉1,the purity of the AlF3 product is even 99.51 wt.%.Conducively,the high-purity AlF_(3)can be returned to the aluminum electrolysis industry or used as a reagent.展开更多
This reconnaissance study was carried out in urgency as residents complained of groundwater contamination in a tribal stretch infectedwith chronic kidney disease of unknown etiology in central India where at least 100...This reconnaissance study was carried out in urgency as residents complained of groundwater contamination in a tribal stretch infectedwith chronic kidney disease of unknown etiology in central India where at least 100 people have already died and more than 300 hospitalized.Multi-indexing techniques were used to evaluate groundwater quality for drinking,irrigation,and industrial purposes.The comprehensive water quality index(CWQI)classifies∼52%of the 27 collected samples suitable for drinking,and∼37%partially suitable pending certain treatment.While the relative abundance of chemical parameters stands at Ca^(2+)>Na^(+)>Mg^(2+)>K^(+)for cations and HCO_(3)^(−)>Cl^(−)>NO_(3)^(−)>SO_(4)^(2−)>F^(−)for anions,the groundwater in the area suffers from general hardness,nitrate,and fluoride contamination.It is hypothesized that fluoride ions possibly couplewith excess alkaline earth elements and anions to form metal-complexes inviting Hofmeister phenomena to act in the human kidneys through ingested groundwater.For agricultural water quality assessment,historically developed 10 irrigation indices have been used that classify most groundwater samples suitable for agriculture.Corrosivity indices reveal that the groundwater has moderate to high corrosive affinity.Although the results of the irrigation and corrosivity indices are coherent with CWQI water classes,the use of so many indices based on certain chemical parameters to evaluate water samples for agricultural purposes delivers mixed results and confuses workers about the actual water quality in the field.This calls for the development of a new,robust,and comprehensive standard for appraisal of irrigation water quality that could be used uniformly worldwide.展开更多
The low surface energy and hierarchical micro/nanostructures endow microwave-absorbing materials with superhydrophobicity to avoid the adverse effects of high-humidity environments on their perfor-mance and structure....The low surface energy and hierarchical micro/nanostructures endow microwave-absorbing materials with superhydrophobicity to avoid the adverse effects of high-humidity environments on their perfor-mance and structure.Notably,fluoridizing engineering can meet these requirements by regulating the material morphology,defect distribution,surface polarization and forming hydrophobic structures.In this study,we designed a combined oxidation-fluoridizing method to obtain an electromagnetic wave ab-sorbing and superhydrophobic material,namely,fluoridizing graphene@copper(F-GE@Cu)hybrids with multi-interfacial heterostructures.This strategy involved the oxidation of graphene-wrapped Cu nanopar-ticles(GE@Cu)prepared by the thermal decomposition of cupric tartrate to GE@Cu_(x) O(x=1 and 2)and further fluorination by PTFE pyrolysis to obtain F-GE@Cu with a yolk-shell structure.Multi-interfacial heterostructures were achieved using precise modulation of the Cu particle,carbon-cladding layer,and fluoridizing products such as CuF_(2) and fluorinated graphene(FGE),this resulted in improved interfacial polarization and impedance matching to achieve satisfactory broadband and electromagnetic wave loss performance.Consequently,the as-prepared fluorinated graphene@copper fluoride(FGE@CuF_(2))exhibited high performance for electromagnetic wave(EMW)absorption with an intense reflection loss(RLmin)of−53.0 dB and a broad effective bandwidth(EAB)of 8.9 GHz(9.1-18.0 GHz).Additionally,the FGE cladding conferred the hybrids with excellent superhydrophobic properties(WAC=154.0°),allowing it to tolerate diverse and harsh water-containing environments,providing the microwave-absorbing coatings with a universal waterproofing capability.This study presents a new strategy for preparing multifunctional elec-tromagnetic wave-absorbing materials.展开更多
Fluoride(F^(-))and arsenic,present as As(Ⅲ)and As(Ⅴ),are widespread toxins in groundwater across India,as well as in other countries or regions like Pakistan,China,Kenya,Africa,Thailand,and Latin America.Their prese...Fluoride(F^(-))and arsenic,present as As(Ⅲ)and As(Ⅴ),are widespread toxins in groundwater across India,as well as in other countries or regions like Pakistan,China,Kenya,Africa,Thailand,and Latin America.Their presence in water resources poses significant environmental and health risks,including fluorosis and arsenicosis.To address this issue,this study developed an integrated process combining biosorbents and ultrafiltration(UF)for the removal of F^(-),As,and turbidity from contaminated water.Laboratory-scale adsorption experiments were conducted using low-cost biosorbents with different biosorbent dosages,specifically Moringa oleifera seed powder(MSP)and sorghum bicolor husk(SBH),along with sand as a binding medium.F^(-)and As concentrations ranging from 2 to 10 mg/L and 3 to 12 mg/L,respectively,were investigated.Biosorbents and their different combinations were tested to determine their efficacy in removing dissolved F^(-)and As.The results showed that a blend of 10-g/L MSP with SBH achieved the highest F^(-)(97.20%)and As(78.63%)removal efficiencies.Subsequent treatment with a UF membrane effectively reduced turbidity and colloidal impurities in the treated water,achieving a maximum turbidity removal efficiency of 95.40%.Equilibrium kinetic and isotherm models were employed to analyze the experimental data,demonstrating good fit.Preliminary cost analysis indicated that the hybrid technology is economically viable and suitable for the separation of hazardous contaminants from aqueous solutions.This study underscores the potential of inexpensive biosorption technologies in providing clean and safe drinking water,particularly in industrial,rural,and urban areas.展开更多
The influence of grain size or grain refinement on the corrosion of Zr alloy is clarified by employing a series of electrochemical analyses and characterization techniques.The corrosion resistance,as a function of exp...The influence of grain size or grain refinement on the corrosion of Zr alloy is clarified by employing a series of electrochemical analyses and characterization techniques.The corrosion resistance,as a function of exposure time,F−concentration,and solution temperatures,of Zr alloys with different grain sizes is ascertained.The results confirm that refining the grain size can effectively enhance the short-time corrosion properties of Zr alloy in HNO_(3) with F−.The fine grained Zr alloy(~10μm in diameter)consistently exhibits a lower corrosion current density,ranging from 18%to 46%lower than that of the coarse-grained Zr alloy(~44μm).The enhanced corrosion resistance is attributed to the high density grain boundaries,which promote oxide stability,and accelerate the creation of the protective layer.The high corrosion rate and pseudo-passivation behavior of Zr alloys in fluorinated nitric acid originate from the accelerated“dissolution-passivation”of the oxide film.However,the grain refinement does not provide enduring anti-corrosion for Zr alloys.To meet the operation of spent fuel reprocessing,additional systematic efforts are required to evaluate the long term effect of grain refinement.展开更多
The primary objective of this study is to measure fluoride levels in groundwater samples using machine learning approaches alongside traditional and fuzzy logic models based health risk assessment in the hard rock Arj...The primary objective of this study is to measure fluoride levels in groundwater samples using machine learning approaches alongside traditional and fuzzy logic models based health risk assessment in the hard rock Arjunanadi River basin,South India.Fluoride levels in the study area vary between 0.1 and 3.10 mg/L,with 32 samples exceeding the World Health Organization(WHO)standard of 1.5 mg/L.Hydrogeochemical analyses(Durov and Gibbs)clearly show that the overall water chemistry is primarily influenced by simple dissolution,mixing,and rock-water interactions,indicating that geogenic sources are the predominant contributors to fluoride in the study area.Around 446.5 km^(2)is considered at risk.In predictive analysis,five Machine Learning(ML)models were used,with the AdaBoost model performing better than the other models,achieving 96%accuracy and 4%error rate.The Traditional Health Risk Assessment(THRA)results indicate that 65%of samples pose highly susceptible for dental fluorosis,while 12%of samples pose highly susceptible for skeletal fluorosis in young age groups.The Fuzzy Inference System(FIS)model effectively manages ambiguity and linguistic factors,which are crucial when addressing health risks linked to groundwater fluoride contamination.In this model,input variables include fluoride concentration,individual age,and ingestion rate,while output variables consist of dental caries risk,dental fluorosis,and skeletal fluorosis.The overall results indicate that increased ingestion rates and prolonged exposure to contaminated water make adults and the elderly people vulnerable to dental and skeletal fluorosis,along with very young and young age groups.This study is an essential resource for local authorities,healthcare officials,and communities,aiding in the mitigation of health risks associated with groundwater contamination and enhancing quality of life through improved water management and health risk assessment,aligning with Sustainable Development Goals(SDGs)3 and 6,thereby contributing to a cleaner and healthier society.展开更多
The accurate measurement of magnesium oxide(MgO)solubility in molten fluoride salts is crucial to optimize the electrolytic process for producing high-purity magnesium(Mg)metal from MgO.In this study,the influences of...The accurate measurement of magnesium oxide(MgO)solubility in molten fluoride salts is crucial to optimize the electrolytic process for producing high-purity magnesium(Mg)metal from MgO.In this study,the influences of time,temperature,and composition of molten salts such as magnesium fluoride(MgF_(2))-lithium fluoride(LiF),MgF_(2)-LiF-calcium fluoride(CaF_(2)),and MgF_(2)-LiF-barium fluoride(BaF_(2))on the solubility of MgO were investigated.Before the MgO solubility experiments,electrolytic removal of oxygen ions(O^(2-))in the molten salts was conducted to decrease the oxygen(O)concentration to below 88 ppm.The results showed that the MgO concentrations in the(MgF_(2)-LiF)_(eut),(MgF_(2)-LiF)_(eut)-15 mol%CaF_(2),and(MgF_(2)-LiF)_(eut)-15 mol%BaF_(2) molten salts at 1053 K reached saturation to 0.210 mass%,0.188 mass%,and 0.148 mass%,respectively,after 30 h.Additionally,MgO solubility at 1053 K decreased with increasing concentrations of CaF_(2) or BaF_(2) in the molten salt.However,the MgO solubility in the molten salts increased with increasing temperature,reaching 0.264 mass% in the(MgF_(2)-LiF)eut molten salt at 1203 K.Moreover,increasing the concentration of MgF_(2) in the MgF_(2)-LiF molten salt increased the MgO solubility at 1103 K.This study provides valuable insights into the MgO solubility in molten fluoride salts used for the electrolytic process using MgO feed for the production of Mg metal.展开更多
Microplastics (MPs), fluoride (FR), and fungicide mancozeb (MZ) are common contaminants in soil. However, there is no information about the combined impacts of MPs, FR, and MZ on tomato plant growth features in the li...Microplastics (MPs), fluoride (FR), and fungicide mancozeb (MZ) are common contaminants in soil. However, there is no information about the combined impacts of MPs, FR, and MZ on tomato plant growth features in the literature. This study aimed to investigate the effects of combined application of MPs, FR, and MZ (both analytical grade and commercial) on the growth and development of tomato plants and metagenomics of rhizosphere soil. A pot experiment was set up in an artificial greenhouse with two sets of treatments. One set was the combined application of MPs, FR, and analytical grade MZ (B2) and a control without the application of MPs, FR, and MZ (W2), and the other set was the combined application of MPs, FR, and commercial MZ (B3) and a control without the application of MPs, FR, and MZ (W3). No detrimental effects of MPs, FR, and MZ were detected on the growth parameters of tomato plants, including the number of leaves and chlorophyll concentration. However, tomato roots showed knot and nodulation-type structures, and metabolomic profiling revealed that combined exposure to MPs, FR, and MZ profoundly reprogrammed the primary metabolism in tomato roots, with marked alterations in carbohydrate and amino acid pathways. Metagenome whole genome sequencing showed that the B2 and B3 treatments profoundly affected soil microbial community composition, diversity, gene abundances, and functional gene variations compared to W2 and W3. Proteobacteria became the dominating phylum in B2 and B3, causing a significant shift in the microbiome. Its abundance soared to 66.7% in B2 and 75.4% in B3, compared to only 35.9% in W2 and 28.9% in W3. On the other hand, Actinobacteria decreased significantly from 55.6% in W2 and 63.8% in W3 to 18.1% in B2 and 9.6% in B3. This study highlights the microbial shifts due to combined application of MPs, FR, and MZ, providing evidence for understanding their environmental risks.展开更多
Boron-based fuels,recognized for their high energy density and potential in energetic applications,encounter challenges such as long ignition delays and incomplete combustion,which result in reduced combustion efficie...Boron-based fuels,recognized for their high energy density and potential in energetic applications,encounter challenges such as long ignition delays and incomplete combustion,which result in reduced combustion efficiency and limited performance in aerospace propulsion.In this study,boron carbide(B4C)is investigated as an alternative fuel to pristine boron due to its favorable gas-phase combustion.Both metal oxide(nickel oxide(NiO))and metal fluoride(nickel fluoride(NiF_(2)))are selected as oxidizing modifiers to enhance the reactivity of B4C.A method combining laser ignition with optical diagnostics is employed to investigate the enhancing effects of different oxidizers on the ignition and combustion characteristics of B4C.Both NiO and NiF_(2)can significantly increase the combustion radiation intensity and reduce the time to maximum intensity of B4C.Differential scanning calorimetry,in-situ X-ray diffraction,and Fourier transform infrared spectroscopy were used for simultaneous thermal analysis of the B4C composite powders.Combined thermal analysis showed that the effects of NiO and NiF_(2)on promoting B4C combustion is mainly achieved via the formation of NimBn and the release of a large number of gas products.It is reasonable to speculate that the phase separation at the B2O3/NimBn interface forms new pathways for oxygen diffusion and reaction with the B core.The difference in the combustion mechanism of B4C with NiO and NiF_(2)lies in the gas phase products,i.e.,CO_(2)and BF3,respectively,thus leading to significant differences in their reaction processes.展开更多
In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be ...In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be deleted.The correct sentence is as below.展开更多
This research examines the hard-rock aquifer system within the Nagavathi River Basin(NRB)South India,by evaluating seasonal fluctuations in groundwater composition during the pre-monsoon(PRM)and post-monsoon(POM)perio...This research examines the hard-rock aquifer system within the Nagavathi River Basin(NRB)South India,by evaluating seasonal fluctuations in groundwater composition during the pre-monsoon(PRM)and post-monsoon(POM)periods.Seasonal variations significantly influence the groundwater quality,particularly fluoride(F−)concentrations,which can fluctuate due to changes in recharge,evaporation,and anthropogenic activities.This study assesses the dynamics of F−levels in PRM and POM seasons,and identifies elevated health risks using USEPA guidelines and Monte Carlo Simulations(MCS).Groundwater in the study area exhibits alkaline pH,with NaCl and Ca-Na-HCO_(3) facies increasing in the POM season due to intensified ion exchange and rock-water interactions,as indicated in Piper and Gibb’s diagrams.Correlation and dendrogram analyses indicate that F−contamination is from geogenic and anthropogenic sources.F−levels exceed the WHO limit(1.5 mg/L)in 51 PRM and 28 POM samples,affecting 371.74 km^(2) and 203.05 km^(2),respectively.Geochemical processes,including mineral weathering,cation exchange,evaporation,and dilution,are identified through CAI I&II.Health risk assessments reveal that HQ values>1 in 78%of children,73%of teens,and 68%of adults during PRM,decreasing to 45%,40%,and 38%,respectively,in POM.MCS show maximum HQ values of 5.67(PRM)and 4.73(POM)in children,with all age groups facing significant risks from fluoride ingestion.Managed Aquifer Recharge(MAR)is recommended in this study to minimize F−contamination,ensuring safe drinking water for the community.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51525101)。
文摘The electrochemical corrosion behavior of the dental Ti50 Zr alloy with and without nanocrystalline(TiZr)N coating was comparatively investigated in artificial saliva solutions with different pH values and fluoride ion concentrations. The chemical stability of the passive films on the coated and non-coated Ti50 Zr alloy was evaluated by calculating passive film thickness. The chemical compositions and valence structures of the passive films were analyzed by X-ray photoelectron spectroscopy(XPS). The results show that the(TiZr)N-coated alloy displays distinctly decreased corrosion rate and increased impedance compared with Ti50 Zr alloy in nonfluoridated and fluoridated acidic solutions. Particularly, in the solution of pH = 3.9 and 0.15% NaF-containing, the corrosion protection efficiency of(TiZr)N coating reaches90%. The excellent corrosion resistance of the coated alloy is attributed to that the nanocrystallines in(TiZr)N coating decreases micropores and crack defects, which strongly impedes the corrosive ions diffusion and electrode process at Ti substrate/coating interface. Meanwhile,(TiZr)N coating shows good passivation behavior in acidic solution and active–passive transition behavior in fluoridated acidic solution. The coated Ti50 Zr alloy with high chemical stability has potential application prospect for dental implants.
文摘The aim of this work was to produce a nanoscale fluoridated and potassium containing hydroxyapatite via sol-gel method and to observe the effect of occlusion of the dentin tubule under scanning electron microscopy. HF was selected as fluorine-containing rengent which was added into mixed Ca （ NO3 ）2-P2O5 ethanol solutions to obtain dipping sols. All of the resulting samples showed apatite structure in their X- ray diffraction pattern. The lattice parameter a and the crystallite size were calculated to demonstrate the crystalline structure of fluoridated and potassium containing HA. Extracted paired premolars were chosen to obtain a fiat surface with opened tubules. It was observed that the tubules were covered by a 10 μm layer of fluoridated and potassium containing HA under the SEM. As the experimental results show the nanoscale fluoridated and potassium containing hydroxyapatite occludes the dentin tubules.
基金supported by the Northeast Geological Science and Technology Innovation Center of China Geological Survey(Grant NO.QCJJ2022-43)the Natural Resources Comprehensive Survey Project(Grant Nos.DD20230470,DD20230508)the National Groundwater Monitoring Network Operation and Maintenance Program(Grant No.DD20251300109).
文摘Excessive levels of Fluoride(F−)and Cadmium(Cd)in drinking groundwater may pose health risks.This study assessed the health risks associated with F−and Cd contamination in rural drinking groundwater sources in Wutai County,Shanxi Province,China,to support population health protection,water resource management,and environmental decision-making.Groundwater samples were collected and analyzed,and a Human Health Risk Model(HHRA)was applied to evaluate groundwater quality.The results showed that both contents of F−and Cd in groundwater exceeded the Class III limits of China's national groundwater quality standard(GB/T 14848—2024).Fluoride levels met the Class V threshold,with enrichment area mainly located in the east part of the study area.Cadmium levels reached Class IV,with elevated concentrations primarily observed in the western and northwestern regions.Correlation analysis revealed that F−showed weak or no correlation with other measured substances,indicating independent sources.Health risk assessment results indicated that F−poses potential health risks to rural residents,while cadmium,due to its relatively low concentrations,does not currently present a significant health risk.Among different demographic groups,the health risk levels of F−exposure followed the order:Infants>children>adult females>adult males.The findings highlight that fluoride is the primary contributor to health risks associated with groundwater consumption in the study area.Strengthened monitoring and prevention of F−contamination are urgently needed.This research provides a scientific basis for the prevention and control of fluoride pollution in groundwater and offers practical guidance for safeguarding drinking water safety in rural China.
基金financially supported by the National Natural Science Foundation of China(No.52374259)the Open Fund of the State Key Laboratory of Mineral Processing Science and Technology,China(No.BGRIMM-KJSKL-2023-11)the Major Science and Technology Projects in Yunnan Province,China(No.202302 AF080004)。
文摘It is difficult to recover chrysocolla from sulfidation flotation which is closely related to the mineral surface composition.In this study,the effects of fluoride roasting on the surface composition of chrysocolla were investigated,its impact on sulfidation flotation was explored,and the mechanisms involved in both fluoride roasting and sulfidation flotation were discussed.With CaF_(2)as the roasting reagent,Na_(2)S·9H_(2)O as the sulfidation reagent,and sodium butyl xanthate(NaBX)as the collector,the results of the flotation experiments showed that fluoride roasting improved the floatability of chrysocolla,and the recovery rate increased from 16.87%to 82.74%.X-ray diffraction analysis revealed that after fluoride roasting,approximately all the Cu on the chrysocolla surface was exposed in the form of CuO,which could provide a basis for subsequent sulfidation flotation.The microscopy and elemental analyses revealed that large quantities of"pagoda-like"grains were observed on the sulfidation surface of the fluoride-roasted chrysocolla,indicating high crystallinity particles of copper sulfide.This suggests that the effect of sulfide formation on the chrysocolla surface was more pronounced.X-ray photoelectron spectroscopy revealed that fluoride roasting increased the relative contents of sulfur and copper on the surface and that both the Cu~+and polysulfide fractions on the surface of the minerals increased.This enhances the effect of sulfidation,which is conducive to flotation recovery.Therefore,fluoride roasting improved the effect of copper species transformation and sulfidation on the surface of chysocolla,promoted the adsorption of collectors,and improved the recovery of chrysocolla from sulfidation flotation.
基金supported by the China Geological Survey Project(Nos.DD20220864 and DD20243077).
文摘Understanding the levels,causes,and sources of fluoride in groundwater is critical for public health,effective water resource management,and sustainable utilization.This study employs multivariate statistical methods,hazard quotient assessment,and geochemical analyses,such as mineral saturation index,ionic activities,and Gibbs diagrams,to investigate the hydrochemical characteristics,causes,and noncarcinogenic risks of fluoride in Red bed groundwater and geothermal water in the Guang'an area and neighboring regions.Approximately 9%of the Red bed groundwater samples contain fluoride concentrations exceeding 1 mg·L^(-1).The predominant water types identified are Cl-Na and HCO_(3)-Na,primarily influenced by evapotranspiration.Low-fluoride groundwater and high-fluoride geothermal water exhibit distinct hydrochemical types HCO_(3)-Ca and SO_(4)-Ca,respectively,which are mainly related to the weathering of carbonate,sulfate,and fluorite-containing rocks.Correlation analysis reveals that fluoride content in Red bed groundwater is positively associated with Na^(+),Cl^(-),SO_(4)^(2-),and TDS(r^(2)=0.45-0.64,p<0.01),while in geothermal water,it correlates strongly with pH,K^(+),Ca^(2+),and Mg^(2+)(r^(2)=0.52-0.80,p<0.05).Mineral saturation indices and ionic activities indicate that ion exchange processes and the dissolution of minerals such as carbonatite and fluorite are important sources of fluoride in groundwater.The enrichment of fluorine in the Red bed groundwater is linked to evaporation,cation exchange and dissolution of fluorite,caused by the lithologic characteristics of the red bed in this area.However,it exhibits minimal correlation with the geothermal water in the adjacent area.The noncarcinogenic health risk assessment indicates that 7%(n=5)of Red bed groundwater points exceed the fluoride safety limit for adults,while 12%(n=8)exceed the limit for children.These findings underscore the importance of avoiding highly fluoridated red bed groundwater as a direct drinking source and enhancing groundwater monitoring to mitigate health risks associated with elevated fluoride levels.
基金National Natural Science Foundation of China,Grant/Award Number:51073067Scientific and Technological Development Program of Jilin Province,Grant/Award Number:20220201138GX.
文摘In recent years,renewable energy sources,which aim to replace rapidly depleting fossil fuels,face challenges due to limited energy storage and conversion technologies.To enhance energy storage and conversion efficiency,extensive research has been conducted in the academic community on numerous potential materials.Among these materials,metal fluorides have attracted significant attention due to their ionic metal-fluorine bonds and tunable electronic structures,attributed to the highest electronegativity of fluorine in their chemical composition.This makes them promising candidates for future electrochemical applications in various fields.However,metal fluorides encounter various challenges in different application directions.Therefore,we comprehensively review the applications of metal fluorides in the field of energy storage and conversion,aiming to deepen our understanding of their exhibited characteristics in different electrochemical processes.In this paper,we summarize the difficulties and improvement methods encountered in different types of battery applications and several typical electrode optimization strategies in the field of supercapacitors.In the field of water electrolysis,we focus on surface reconstruction and the critical role of fluorine,demonstrating the catalytic performance of metal fluorides from the perspectives of reconstruction mechanism and process analysis.Finally,we provide a summary and outlook for this field,aiming to offer guidance for future breakthroughs in the energy storage and conversion applications of metal fluorides.
文摘Fine tailoring the shape of nanosheets is still a big challenge as the difficult synthesis for highly controlled ultrathin nanosheets.Here we report a facile strategy for tailoring the shape of ultra-thin NdF_(3) nanosheets via a hot injection method.In this method,NdF_(3) nanosheets with only about 2 nm in thickness synthesized first via a hot injection method.The shape of the NdF_(3) nanosheets was able to be tailored from flower-like to the round or the triangular shapes simply by decreasing the reaction temperature from 300℃to 280℃or 260℃.The driven force of the NdF_(3) nanosheets’shape tailoring by the temperature could be that a lower crystal growth rate will guarantee the more stable facets exposed at lower temperature,while under the condition of slow precursor injection,a higher temperature will lead to a further decrease in the crystal growth rate.This shape control method of NdF_(3) nanosheets is highly robust,which could be promoted to other materials.
基金supported by the National Natural Science Foundation of China(Nos.22279101,22172117 and 52072298)Foshan Science and Technology Innovation Team Project(No.1920001004098)+1 种基金Scientific Research Program Funded by Education Department of Shaanxi Provincial Government(No.22JP056)the Natural Science Basic Research Program of Shaanxi(No.2024JC-YBQN-0141).
文摘Metal fluoride materials with high theoretical capacities are considered the next generation of Li-free conversion cathodes.However,the inherently sluggish reaction kinetics of metal fluorides result in unsatisfactory electrochemical performance.In this study,CoF_(2)was combined with carbonaceous materials to obtain graphitic carbon-encapsulated CoF_(2)nanoparticles uniformly embedded in an interconnected N-doped carbon matrix(CoF_(2)@NC),significantly boosting the inert kinetics and electronic conductivity.The CoF_(2)@NC nanocomposites exhibited a notable reversible capacity of 352.0 mAh·g^(-1)at 0.2 A·g^(-1).Notably,it maintained superior long-term cycling stability even at a high current density of 2 A·g^(-1),with a capacity of 235.5 mAh·g^(-1)after 1200 cycles,evidently exceeding that of commercially available CoF_(2)electrodes.Kinetic analysis indicated that the enhanced electrochemical performance originated from the increased contribution of capacitive effects.Furthermore,in-situ electrochemical impedance spectroscopy(EIS)results verify that the improved cycling performance is associated with the enhanced interfacial stability of CoF_(2)@NC.This research not only proposes a solution for the challenges of conversion cathodes in lithium-ion batteries,but also offers novel synthesis strategies for designing high-energy metal fluoride materials.
基金supported by the National Natural Science Foundation of China(Nos.12374004 and 12174141)the National Key R&D Program of China(No.2023YFA1406200)。
文摘Exploring novel superconductors is a crucial topic in condensed matter physics.There are few reports on the superconductivity of fluorine due to the extremely high pressures required for its metallization.Here,metallization and superconductivity of fluorine were achieved in MgF_(5)at 120 GPa by exploiting the high-pressure s-d transition of doped Mg.The unexpected Mg-F covalent bonding induced by Mg-d and F-p orbital interactions led to fluorine metallization and the formation of an F skeleton similar to a H-cage.The high density of states(DOS)from the F skeleton and phonon softening from strong Fermi surface nesting contribute to a high superconducting transition temperature(Tc).The Tc of Pmmm-MgF_(5)at 120 GPa is 14.02 K,with strong electron-phonon coupling(λ=0.84),which is close to that of Li_(6)P at 270 GPa(λ=1.01).This is the first observation of superconductivity in main-group metal fluorides.Additionally,two near-monatomic F atoms exist in the interstitial region of MgF_(5),significantly enhancing electron-phonon coupling.This work challenges the traditional view of main-group metal fluorides and provides deeper insights into the superconductivity and physicochemical properties of fluorine.
文摘High-purity AlF3 was prepared by the combined process of leaching the raw material of waste aluminum electrolytes with aluminum chloride,electrolyzing the leaching solution,and then mixing with ammonium hydrogen fluoride for roasting.Under the optimal leaching conditions of a fluorine to aluminum molar ratio of 2.0,a liquid-to-solid ratio of 12,a temperature of 90℃,and time of 4 h,the fluorine leaching rate can reach 99.15%.Under the action of electrolysis,the H+is reduced to H2 in the cathode,while the remaining OH−combines with AlF^(2+)and AlF^(2+)to precipitate aluminium hydroxyfluoride hydrate.The results show that electrolysis is beneficial to reduce the impurity content of aluminium hydroxyfluoride hydrate.When the current density is 0.2 A/cm^(2),the temperature is 90℃,the stirring speed is 200 r/min,and the electrolysis endpoint pH is 3.0,the total content of Na,K and Ca impurities in the precipitation is only 0.64 wt.%.Moreover,the hydrolysis can be inhibited effectively by adding ammonium hydrogen fluoride in the mixed-roasting process.When the mass ratio of aluminium hydroxyfluoride hydrate to ammonium hydrogen fluoride is 2꞉1,the purity of the AlF3 product is even 99.51 wt.%.Conducively,the high-purity AlF_(3)can be returned to the aluminum electrolysis industry or used as a reagent.
文摘This reconnaissance study was carried out in urgency as residents complained of groundwater contamination in a tribal stretch infectedwith chronic kidney disease of unknown etiology in central India where at least 100 people have already died and more than 300 hospitalized.Multi-indexing techniques were used to evaluate groundwater quality for drinking,irrigation,and industrial purposes.The comprehensive water quality index(CWQI)classifies∼52%of the 27 collected samples suitable for drinking,and∼37%partially suitable pending certain treatment.While the relative abundance of chemical parameters stands at Ca^(2+)>Na^(+)>Mg^(2+)>K^(+)for cations and HCO_(3)^(−)>Cl^(−)>NO_(3)^(−)>SO_(4)^(2−)>F^(−)for anions,the groundwater in the area suffers from general hardness,nitrate,and fluoride contamination.It is hypothesized that fluoride ions possibly couplewith excess alkaline earth elements and anions to form metal-complexes inviting Hofmeister phenomena to act in the human kidneys through ingested groundwater.For agricultural water quality assessment,historically developed 10 irrigation indices have been used that classify most groundwater samples suitable for agriculture.Corrosivity indices reveal that the groundwater has moderate to high corrosive affinity.Although the results of the irrigation and corrosivity indices are coherent with CWQI water classes,the use of so many indices based on certain chemical parameters to evaluate water samples for agricultural purposes delivers mixed results and confuses workers about the actual water quality in the field.This calls for the development of a new,robust,and comprehensive standard for appraisal of irrigation water quality that could be used uniformly worldwide.
基金financially supported by the National Natural Science Foundation of China(No.51573149)。
文摘The low surface energy and hierarchical micro/nanostructures endow microwave-absorbing materials with superhydrophobicity to avoid the adverse effects of high-humidity environments on their perfor-mance and structure.Notably,fluoridizing engineering can meet these requirements by regulating the material morphology,defect distribution,surface polarization and forming hydrophobic structures.In this study,we designed a combined oxidation-fluoridizing method to obtain an electromagnetic wave ab-sorbing and superhydrophobic material,namely,fluoridizing graphene@copper(F-GE@Cu)hybrids with multi-interfacial heterostructures.This strategy involved the oxidation of graphene-wrapped Cu nanopar-ticles(GE@Cu)prepared by the thermal decomposition of cupric tartrate to GE@Cu_(x) O(x=1 and 2)and further fluorination by PTFE pyrolysis to obtain F-GE@Cu with a yolk-shell structure.Multi-interfacial heterostructures were achieved using precise modulation of the Cu particle,carbon-cladding layer,and fluoridizing products such as CuF_(2) and fluorinated graphene(FGE),this resulted in improved interfacial polarization and impedance matching to achieve satisfactory broadband and electromagnetic wave loss performance.Consequently,the as-prepared fluorinated graphene@copper fluoride(FGE@CuF_(2))exhibited high performance for electromagnetic wave(EMW)absorption with an intense reflection loss(RLmin)of−53.0 dB and a broad effective bandwidth(EAB)of 8.9 GHz(9.1-18.0 GHz).Additionally,the FGE cladding conferred the hybrids with excellent superhydrophobic properties(WAC=154.0°),allowing it to tolerate diverse and harsh water-containing environments,providing the microwave-absorbing coatings with a universal waterproofing capability.This study presents a new strategy for preparing multifunctional elec-tromagnetic wave-absorbing materials.
文摘Fluoride(F^(-))and arsenic,present as As(Ⅲ)and As(Ⅴ),are widespread toxins in groundwater across India,as well as in other countries or regions like Pakistan,China,Kenya,Africa,Thailand,and Latin America.Their presence in water resources poses significant environmental and health risks,including fluorosis and arsenicosis.To address this issue,this study developed an integrated process combining biosorbents and ultrafiltration(UF)for the removal of F^(-),As,and turbidity from contaminated water.Laboratory-scale adsorption experiments were conducted using low-cost biosorbents with different biosorbent dosages,specifically Moringa oleifera seed powder(MSP)and sorghum bicolor husk(SBH),along with sand as a binding medium.F^(-)and As concentrations ranging from 2 to 10 mg/L and 3 to 12 mg/L,respectively,were investigated.Biosorbents and their different combinations were tested to determine their efficacy in removing dissolved F^(-)and As.The results showed that a blend of 10-g/L MSP with SBH achieved the highest F^(-)(97.20%)and As(78.63%)removal efficiencies.Subsequent treatment with a UF membrane effectively reduced turbidity and colloidal impurities in the treated water,achieving a maximum turbidity removal efficiency of 95.40%.Equilibrium kinetic and isotherm models were employed to analyze the experimental data,demonstrating good fit.Preliminary cost analysis indicated that the hybrid technology is economically viable and suitable for the separation of hazardous contaminants from aqueous solutions.This study underscores the potential of inexpensive biosorption technologies in providing clean and safe drinking water,particularly in industrial,rural,and urban areas.
基金Project(U2067217)supported by the National Natural Science Foundation of ChinaProject(SASTIND)supported by the State Administration of Science,Technology and Industry for National Defense,ChinaProject(2020M683572)supported by China Postdoctoral Science Foundation。
文摘The influence of grain size or grain refinement on the corrosion of Zr alloy is clarified by employing a series of electrochemical analyses and characterization techniques.The corrosion resistance,as a function of exposure time,F−concentration,and solution temperatures,of Zr alloys with different grain sizes is ascertained.The results confirm that refining the grain size can effectively enhance the short-time corrosion properties of Zr alloy in HNO_(3) with F−.The fine grained Zr alloy(~10μm in diameter)consistently exhibits a lower corrosion current density,ranging from 18%to 46%lower than that of the coarse-grained Zr alloy(~44μm).The enhanced corrosion resistance is attributed to the high density grain boundaries,which promote oxide stability,and accelerate the creation of the protective layer.The high corrosion rate and pseudo-passivation behavior of Zr alloys in fluorinated nitric acid originate from the accelerated“dissolution-passivation”of the oxide film.However,the grain refinement does not provide enduring anti-corrosion for Zr alloys.To meet the operation of spent fuel reprocessing,additional systematic efforts are required to evaluate the long term effect of grain refinement.
基金the Anusandhan National Research Foundation(ANRF),New Delhi[Erstwhile,Science and Engineering Research Board(SERB)]Department of Science and Technology(DST)(Government of India)(File No.:CRG/2022/002618 Dated:22.08.2023)for providing the grant and support to carry out this work effectively.
文摘The primary objective of this study is to measure fluoride levels in groundwater samples using machine learning approaches alongside traditional and fuzzy logic models based health risk assessment in the hard rock Arjunanadi River basin,South India.Fluoride levels in the study area vary between 0.1 and 3.10 mg/L,with 32 samples exceeding the World Health Organization(WHO)standard of 1.5 mg/L.Hydrogeochemical analyses(Durov and Gibbs)clearly show that the overall water chemistry is primarily influenced by simple dissolution,mixing,and rock-water interactions,indicating that geogenic sources are the predominant contributors to fluoride in the study area.Around 446.5 km^(2)is considered at risk.In predictive analysis,five Machine Learning(ML)models were used,with the AdaBoost model performing better than the other models,achieving 96%accuracy and 4%error rate.The Traditional Health Risk Assessment(THRA)results indicate that 65%of samples pose highly susceptible for dental fluorosis,while 12%of samples pose highly susceptible for skeletal fluorosis in young age groups.The Fuzzy Inference System(FIS)model effectively manages ambiguity and linguistic factors,which are crucial when addressing health risks linked to groundwater fluoride contamination.In this model,input variables include fluoride concentration,individual age,and ingestion rate,while output variables consist of dental caries risk,dental fluorosis,and skeletal fluorosis.The overall results indicate that increased ingestion rates and prolonged exposure to contaminated water make adults and the elderly people vulnerable to dental and skeletal fluorosis,along with very young and young age groups.This study is an essential resource for local authorities,healthcare officials,and communities,aiding in the mitigation of health risks associated with groundwater contamination and enhancing quality of life through improved water management and health risk assessment,aligning with Sustainable Development Goals(SDGs)3 and 6,thereby contributing to a cleaner and healthier society.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)(Project No.:20024463)and(No.RS-2025-04442986)funded by the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Koreathe support of the Institute of Engineering Research at Seoul National University for providing research facilities for this study.
文摘The accurate measurement of magnesium oxide(MgO)solubility in molten fluoride salts is crucial to optimize the electrolytic process for producing high-purity magnesium(Mg)metal from MgO.In this study,the influences of time,temperature,and composition of molten salts such as magnesium fluoride(MgF_(2))-lithium fluoride(LiF),MgF_(2)-LiF-calcium fluoride(CaF_(2)),and MgF_(2)-LiF-barium fluoride(BaF_(2))on the solubility of MgO were investigated.Before the MgO solubility experiments,electrolytic removal of oxygen ions(O^(2-))in the molten salts was conducted to decrease the oxygen(O)concentration to below 88 ppm.The results showed that the MgO concentrations in the(MgF_(2)-LiF)_(eut),(MgF_(2)-LiF)_(eut)-15 mol%CaF_(2),and(MgF_(2)-LiF)_(eut)-15 mol%BaF_(2) molten salts at 1053 K reached saturation to 0.210 mass%,0.188 mass%,and 0.148 mass%,respectively,after 30 h.Additionally,MgO solubility at 1053 K decreased with increasing concentrations of CaF_(2) or BaF_(2) in the molten salt.However,the MgO solubility in the molten salts increased with increasing temperature,reaching 0.264 mass% in the(MgF_(2)-LiF)eut molten salt at 1203 K.Moreover,increasing the concentration of MgF_(2) in the MgF_(2)-LiF molten salt increased the MgO solubility at 1103 K.This study provides valuable insights into the MgO solubility in molten fluoride salts used for the electrolytic process using MgO feed for the production of Mg metal.
基金the Department of Science and Technology(DST)-India for providing a departmental grant to the Department of Biochemistry,Central University of Punjab,Bathinda,India,in the form of a DST-Fund for Improvement of S&T Infrastructure(FIST)grant。
文摘Microplastics (MPs), fluoride (FR), and fungicide mancozeb (MZ) are common contaminants in soil. However, there is no information about the combined impacts of MPs, FR, and MZ on tomato plant growth features in the literature. This study aimed to investigate the effects of combined application of MPs, FR, and MZ (both analytical grade and commercial) on the growth and development of tomato plants and metagenomics of rhizosphere soil. A pot experiment was set up in an artificial greenhouse with two sets of treatments. One set was the combined application of MPs, FR, and analytical grade MZ (B2) and a control without the application of MPs, FR, and MZ (W2), and the other set was the combined application of MPs, FR, and commercial MZ (B3) and a control without the application of MPs, FR, and MZ (W3). No detrimental effects of MPs, FR, and MZ were detected on the growth parameters of tomato plants, including the number of leaves and chlorophyll concentration. However, tomato roots showed knot and nodulation-type structures, and metabolomic profiling revealed that combined exposure to MPs, FR, and MZ profoundly reprogrammed the primary metabolism in tomato roots, with marked alterations in carbohydrate and amino acid pathways. Metagenome whole genome sequencing showed that the B2 and B3 treatments profoundly affected soil microbial community composition, diversity, gene abundances, and functional gene variations compared to W2 and W3. Proteobacteria became the dominating phylum in B2 and B3, causing a significant shift in the microbiome. Its abundance soared to 66.7% in B2 and 75.4% in B3, compared to only 35.9% in W2 and 28.9% in W3. On the other hand, Actinobacteria decreased significantly from 55.6% in W2 and 63.8% in W3 to 18.1% in B2 and 9.6% in B3. This study highlights the microbial shifts due to combined application of MPs, FR, and MZ, providing evidence for understanding their environmental risks.
基金The National Natural Science Foundation of China(Grant Nos.523B2063 and 52376089)。
文摘Boron-based fuels,recognized for their high energy density and potential in energetic applications,encounter challenges such as long ignition delays and incomplete combustion,which result in reduced combustion efficiency and limited performance in aerospace propulsion.In this study,boron carbide(B4C)is investigated as an alternative fuel to pristine boron due to its favorable gas-phase combustion.Both metal oxide(nickel oxide(NiO))and metal fluoride(nickel fluoride(NiF_(2)))are selected as oxidizing modifiers to enhance the reactivity of B4C.A method combining laser ignition with optical diagnostics is employed to investigate the enhancing effects of different oxidizers on the ignition and combustion characteristics of B4C.Both NiO and NiF_(2)can significantly increase the combustion radiation intensity and reduce the time to maximum intensity of B4C.Differential scanning calorimetry,in-situ X-ray diffraction,and Fourier transform infrared spectroscopy were used for simultaneous thermal analysis of the B4C composite powders.Combined thermal analysis showed that the effects of NiO and NiF_(2)on promoting B4C combustion is mainly achieved via the formation of NimBn and the release of a large number of gas products.It is reasonable to speculate that the phase separation at the B2O3/NimBn interface forms new pathways for oxygen diffusion and reaction with the B core.The difference in the combustion mechanism of B4C with NiO and NiF_(2)lies in the gas phase products,i.e.,CO_(2)and BF3,respectively,thus leading to significant differences in their reaction processes.
文摘In the published version of our article(Shaji et al.,2024),in the last paragraph of the article,Hong Kong should be corrected to Hong Kong(China)and the repetition of Spain and Ireland in the same sentence need to be deleted.The correct sentence is as below.
文摘This research examines the hard-rock aquifer system within the Nagavathi River Basin(NRB)South India,by evaluating seasonal fluctuations in groundwater composition during the pre-monsoon(PRM)and post-monsoon(POM)periods.Seasonal variations significantly influence the groundwater quality,particularly fluoride(F−)concentrations,which can fluctuate due to changes in recharge,evaporation,and anthropogenic activities.This study assesses the dynamics of F−levels in PRM and POM seasons,and identifies elevated health risks using USEPA guidelines and Monte Carlo Simulations(MCS).Groundwater in the study area exhibits alkaline pH,with NaCl and Ca-Na-HCO_(3) facies increasing in the POM season due to intensified ion exchange and rock-water interactions,as indicated in Piper and Gibb’s diagrams.Correlation and dendrogram analyses indicate that F−contamination is from geogenic and anthropogenic sources.F−levels exceed the WHO limit(1.5 mg/L)in 51 PRM and 28 POM samples,affecting 371.74 km^(2) and 203.05 km^(2),respectively.Geochemical processes,including mineral weathering,cation exchange,evaporation,and dilution,are identified through CAI I&II.Health risk assessments reveal that HQ values>1 in 78%of children,73%of teens,and 68%of adults during PRM,decreasing to 45%,40%,and 38%,respectively,in POM.MCS show maximum HQ values of 5.67(PRM)and 4.73(POM)in children,with all age groups facing significant risks from fluoride ingestion.Managed Aquifer Recharge(MAR)is recommended in this study to minimize F−contamination,ensuring safe drinking water for the community.
