One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific object...One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water.展开更多
Calcium ions(Ca^(2+))and manganese ions(Mn^(2+))are essential for sustaining life activities and are key monitoring indicators in drinking water.Developing highly sensitive,selective,and portable detection methods for...Calcium ions(Ca^(2+))and manganese ions(Mn^(2+))are essential for sustaining life activities and are key monitoring indicators in drinking water.Developing highly sensitive,selective,and portable detection methods for Ca^(2+)and Mn^(2+)is significant for water quality monitoring and human health.In this paper,blue fluorescent Ti3C2 MXene-based quantum dots(MQDs,λ_(em)=445 nm)are prepared using Ti_(3)C_(2)MXene as the precursor.Through the chelation effect of ethylene diamine tetraacetic acid(EDTA),a blue and red dual-emission fluorescent probe,MQDs-EDTA-Eu^(3+)-DPA,was constructed.Herein,dipicolinic acid(DPA)acts as an absorbing ligand and significantly enhances the red fluorescence of europium ions(Eu^(3+))at 616 nm through the“antenna effect”.The blue fluorescence of MQDs serves as an internal reference signal.High concentrations of Ca^(2+)can quench the red fluorescence of Eu^(3+)-DPA;Mn^(2+)can be excited to emit purple fluorescence at 380 nm after coordinating with DPA,red fluorescence of Eu^(3+)-DPA serves as the internal reference signal.Based on the above two fluorescence intensity changes,ratiometric fluorescence detection methods for Ca^(2+)and Mn^(2+)are established.The fluorescence intensity ratio(IF_(616)/IF_(445))exhibits a linear relationship with Ca^(2+)in the range of 35-120μmol/L,with a detection limit of 5.98μmol/L.The fluorescence intensity ratio(IF_(380)/IF_(616))shows good linearity with Mn^(2+)in the range of 0-14μmol/L,with a detection limit of 28.6 nmol/L.This method was successfully applied to the quantitative analysis of Ca^(2+)and Mn^(2+)in commercially available mineral water(Nongfu Spring,Ganten,and Evergrande),with recovery rates of 80.6%-117%and relative standard deviations(RSD)of 0.76%-4.6%.Additionally,by preparing MQD-based fluorescent test strips,visual detections of Ca^(2+)and Mn^(2+)are achieved.This work demonstrates the application potential of MQDs in the field of visual fluorescence sensing of ions in water quality.展开更多
Functionally graded composite/hybrid materials(FGCM/FGHCM)were produced by adding B_(4)C,TiO_(2),and B_(4)C+TiO_(2)ceramic materials at various ratios(0-50%)into the AA6082 matrix.The analysis of the damage caused by^...Functionally graded composite/hybrid materials(FGCM/FGHCM)were produced by adding B_(4)C,TiO_(2),and B_(4)C+TiO_(2)ceramic materials at various ratios(0-50%)into the AA6082 matrix.The analysis of the damage caused by^(60) ions'(1.173-1.1332 MeV)on the material was examined using the SRIM/TRIM Monte Carlo simulation software.In the simulation,the following data regarding the atoms of the target materials were obtained:ion distribution,target ionization,total displacements,surface binding energy,lattice binding energy,and displacement energy.Among the studied four materials,the one with the highest ion range value was found to be AA6082 with 8550A.TiO_(2)was found to be the reinforcement material that reduced the ion range the most in the material.Due to its high binding energy,B_(4)C reinforced AA6082+(0-50%)B_(4)C FGCM was found to have the least vacancy with 4782/ion.展开更多
Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 ...Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 in complex environmental samples.Here,solid-state nanochannels,modified with metal-organic frameworks(MOF)and specific aptamers,were engineered for highly sensitive detection of strontium ion(Sr^(2+)).The synergistic effect between the reduced effective diameter of the nanochannels due to MOF and the specific binding of Sr^(2+) by aptamers amplifies the difference in ionic current signals,enhancing detection sensitivity significantly.The MOF-modified nanochannels exhibit highly sensitive detection of Sr^(2+),with a limit of detection(LOD)being 0.03 nmol·L^(-1),whereas the LOD for anodized aluminum oxide(AAO)without the modified MOF nanosheets is only 1000 nmol·L^(-1).These findings indicate that the LOD of Sr^(2+) detected by the MOF-modified nanochannels is approximately 33,000 times higher than that by the nanochannels without MOF modification.Additionally,the highly reliable detection of Sr^(2+) in various water samples was achieved,with a recovery rate ranging from 94.00%to 118.70%.This study provides valuable insights into the rapidly advancing field of advanced nanochannel-based sensors and their diverse applications for analyzing complex samples,including environmental contaminant detection,food analysis,medical diagnostics,and more.展开更多
Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O soluti...Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O solution.The assembly and fluorescence behavior of PDI-COOH/Ca^(2+)were studied in detail by changing hydration state with different concentrations.Based on the differences in assembly morphology and stoichiometric ratios of PDICOOH/Ca^(2+),we proposed the fluorescence emission mechanism of PDI-COOH/Ca^(2+)in THF/H_(2)O and THF,respectively.This work reveals a novel strategy of aggregated state fluorescence enhancement and reminds us of the important role of water in molecular fluorescence emission and assembly.展开更多
Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yiel...Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.展开更多
To address the lack of systematic studies on heavy metal fluorescent probes in typical buffer solutions,this study developed a Fe^(3+)and Cu^(2+)fluorescent probe,DHU‑NP‑4,based on a naphthalimide fluorophore.Comparat...To address the lack of systematic studies on heavy metal fluorescent probes in typical buffer solutions,this study developed a Fe^(3+)and Cu^(2+)fluorescent probe,DHU‑NP‑4,based on a naphthalimide fluorophore.Comparative analysis of the probe's performance in various buffer systems revealed that buffers with high organic content are unsuitable for evaluating such probes.Furthermore,the pH of the solvent system was found to significantly influence the probe's behavior.Under highly acidic conditions(pH≤2),DHU‑NP‑4 exhibited exceptional specificity for Fe^(3+),while in alkaline conditions,it demonstrated high specificity for Cu^(2+).Leveraging these properties,the probe enabled the quantitative detection of Fe^(3+)and Cu^(2+)in solution.展开更多
V_(2)O_(5)·nH_(2)O has been widely studied for aqueous zinc-ion batteries.The intercalation of inorganic ions has been used as a feasible method to improve the capacity of vanadium pentoxide.To further improve th...V_(2)O_(5)·nH_(2)O has been widely studied for aqueous zinc-ion batteries.The intercalation of inorganic ions has been used as a feasible method to improve the capacity of vanadium pentoxide.To further improve the stability,organic small molecule choline chloride intercalation is used to expand the spacing of the vanadium pentoxide layers and increase the cycling stability.Therefore,we consider the introduction of Sr^(2+)to cointercalate with choline chloride.Here,we synthes-ized vanadium pentoxide cointercalated with Sr^(2+)and choline ions(Ch^(+))via a simple hydrothermal method.The electro-chemical performance shows an enhanced cathode capacitance contribution of Sr&Ch-V_(2)O_(5),with a discharge capacity of 526 mAh·g^(-1)at 0.1 A·g^(-1)and a retention rate of 78.9%after 2000 cycles at 5 A·g^(-1).This work offers a novel strategy for the design of organic‒inorganic hybrid materials for use as cathodes in aqueous zinc-ion batteries.展开更多
The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this wor...The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this work,a series of microwave dielectric ceramic SrAl_(2-x)Ga_(x)Si_(2)O_(8)(0.1≤x≤2.0)was synthesized using the traditional solid-state method.X-ray diffraction pattern indicates that Ga^(3+)can be dissolved into Al^(3+),forming a solid solution.Meanwhile,substitution of Ga^(3+)for Al^(3+)can promote the space group transition from I2/c(0.1≤x≤1.4)to P21/a(1.6≤x≤2.0)with coefficient of thermal expansion(CTE)increasing from 2.9×10^(-6)℃^(-1) to 5.2×10^(-6)℃^(-1).During this substitution,the phase transition can significantly improve the structural symmetry to enhance the dielectric properties and mechanical properties.Rietveld refinement results indicate that Ga^(3+)averagely occupied four Al^(3+)compositions to form solid solution.All ceramics have a dense microstructure and high relative density above 95%.An ultralower of 5.8 was obtained at x=1.6 composition with high quality factor(Q´f)of 50700 GHz and negative temperature coefficients of resonant frequency(tf)of approximately−35×10^(-6)℃^(-1).The densification temperature can be reduced to 940℃by adding 4%(in mass)LiF,resulting in good chemical compatibility with Ag electrode.Meanwhile,negativetf can be tuned to near-zero(+3.7×10^(-6)℃^(-1))by adding CaTiO_(3) ceramic.展开更多
Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cr...Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.展开更多
Removing copper from nickel electrolysis anode solution has been a major keypoint in the nickel metallurgy industry.In this study,we proposed a novel process flow to promote removing copper from nickel electrolysis an...Removing copper from nickel electrolysis anode solution has been a major keypoint in the nickel metallurgy industry.In this study,we proposed a novel process flow to promote removing copper from nickel electrolysis anode solution.A simulated nickel anode solution was designed,and static and dynamic adsorption experiments were conducted to determine the best of solution pH,adsorption time and temperature,resin dosage and particle size,and stirring speed.The optimal conditions were explored for copper removal from nickel electrolysis anode solution.Based on the optimal experimental conditions and the relevant experimental data,a novel process for copper removal from nickel electrolysis anodes was designed and verified.This novel process of copper removal from nickel electrolysis anodes was confirmed with nickel anolyte solution with nickel 50−60 g/L and copper 0.5 g/L.After finishing the novel process of copper removal,the nickel in the purified nickel anolyte became undetectable and copper concentration was 3 mg/L,the novel process of resin adsorption to remove copper from nickel anode solution through static and dynamic adsorptions has an efficacious copper removal.It is a beneficial supplement to traditional methods.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
One of the focus views of the uplifting of Tibetan Plateau is the growth history of the plateau. This is an unresolved question because of the poor study in north margin, where the ATF (Altyn Tagh Fault) is acting an ...One of the focus views of the uplifting of Tibetan Plateau is the growth history of the plateau. This is an unresolved question because of the poor study in north margin, where the ATF (Altyn Tagh Fault) is acting an important role in the growth and deformation of the plateau. The fault links two huge contractional belts, e.g. Qilian Nan Shan and West Kunlun, and merges a series of thrusting\|folding arcs in southeast. Mapping of piercing points, such as unconformities between Cenozoic, Mesozoic and Paleozoic strata, and magmatic arcs, shows left slips of ca. 240km and ca. 550km along the middle and western segments of the ATF. About 140～450km of crustal shortening, approximately the same magnitude as the west segment of the ATF, is deduced from balanced sections in West Kunlun foreland thrusting belt. This implies that left\|slip displacement along the west segment of the ATF was absorbed by the contraction in West Kunlun. The ATF system merged bunches of WNW arcuated fold\|fault belts in Qaidam basin, implying anti\|clockwise rotation. Tertiary and some Lower to Middle Pleistocene strata involved in fold\|fault belts, and dip in ESE due to the uplifting of Altyn Tagh. The newest strata involved in the deformation is more and more younger from south to north, that is, from Lower Pliocene to Middle Pleistocene, showing the uplifting trends from south to north in the SE side of the fault.展开更多
The effect of solution conditions on the depression of chlorite using CMC (carboxymethyl cellulose) as depressant was studied through flotation tests and adsorption measurements. Flotation and adsorption tests were fi...The effect of solution conditions on the depression of chlorite using CMC (carboxymethyl cellulose) as depressant was studied through flotation tests and adsorption measurements. Flotation and adsorption tests were first studied as a function of initial solution conditions. The results show that electrostatic repulsion between CMC molecules and chlorite surface hinders the approach of the CMC molecules to the chlorite surface and CMC adsorbs to a great extent at high ionic concentration (10-4 mol/L ions as opposed to 0 mol/L ions) or low pH (3 as opposed to 9). The enhanced adsorption density is attributed to the decreased electrostatic repulsion between CMC and mineral surface. The solution condition that yielded the lowest initial adsorbed amount (0 mol/L ions, pH 9) was used as a reference to investigate the response of the adsorbed CMC layer to a switch in solution conditions after adsorption. The two kinds of solution switches (reducing the solution pH or increasing ionic concentration) result in an increased depression effect of CMC on chlorite flotation, as a result of conformational change of CMC pre-adsorbed layer. The change in the flotation recovery of the CMC-coated chlorite following the solution switches is reversible.展开更多
A process of removing impurities,such as Fe,Zr,Ti,Al,Si,from scandium solution by ion exchange was proposed.Various resins’selectivity was studied in scandium chloride solution.The results indicated that D851resin ha...A process of removing impurities,such as Fe,Zr,Ti,Al,Si,from scandium solution by ion exchange was proposed.Various resins’selectivity was studied in scandium chloride solution.The results indicated that D851resin had high selectivity of Sc at low acidity,and high selectivity of Zr at high acidity;D370resin had high selectivity of Fe and Si in high acidity.A new technical process of removing impurities from scandium chloride solution was proposed,which includes D370resin adsorbing Fe in high acidity,D851resin adsorbing Zr in medium acidity and D851resin adsorbing Sc at low acidity.Flow experimental results show that removal rates of Al,Ca,Fe,Zr,Ti and Si,were100%,99.6%,100%,100%,99.5%and100%respectively.展开更多
A novel three-dimension(3D)graphene/MgO composite was synthesized through self-assembly and embedding MgO nanoparticle in reduced graphene in situ.Fourier transform infrared(FT-IR)spectroscopy,thermal gravimetric anal...A novel three-dimension(3D)graphene/MgO composite was synthesized through self-assembly and embedding MgO nanoparticle in reduced graphene in situ.Fourier transform infrared(FT-IR)spectroscopy,thermal gravimetric analysis(TGA),scanning electron microscopy(SEM),transmission electron microscope(TEM),powder X-raydiffraction(XRD)and X-rayphotoelectron spectroscopy(XPS)were employed to characterize the prepared 3D graphene/MgO composite.The adsorption performance of some metal ions on 3D graphene/MgO was investigated.The results showed that the adsorption capacity was greater than 3D graphene and the maximum adsorption capacity at 25℃was found to be 358.96 mg/g,388.4 mg/g and 169.8 mg/g for Pb^2+,Cd^2+and Cu^2+,respectively.The adsorption kinetic conformed to the pseudo-second-order kinetic model and the adsorption isotherm was well described by Langmuir model.The thermodynamic constants revealed that the sorption process was endothermic and spontaneous in nature.Based on the results of the removal of heavy metal ions from metal smelting wastewater,it can be concluded that the prepared 3D graphene/MgO composite is an effective and potential adsorbent.展开更多
Microbiologically-induced concrete corrosion(MICC)refers to chemical reactions between biologically produced sulphuric acid and with hydration products in the hardened concrete paste,resulting in an early reduction of...Microbiologically-induced concrete corrosion(MICC)refers to chemical reactions between biologically produced sulphuric acid and with hydration products in the hardened concrete paste,resulting in an early reduction of strength,deterioration,and very severe circumstances,structural failure.This paper explores the bactericidal characteristics of cementitious materials with surface coated with modified zeolite-polyurethane.The zeolite-polyurethane coating incorporated with silver was studied in environments inoculated with A.thiooxidans bacteria for 8 consecutive weeks.The antibacterial characteristics were evaluated in terms of pH,optical density(OD),sulphate production and bacteria count to determine the effectiveness of the zeolite-polyurethane coatings in environments inoculated with A.thiooxidans bacteria producing the sulphuric acid.The results revealed that the samples incorporated with silver modified zeolites generally showed antibacterial performance(regardless of the zeolite type)compared with unmodified polyurethane coating.This was evaluated by the lack of bacteria attachment and the deformed microcolonies on the sample surface,lag in pH reduction,increase in OD,and sulphate production.The silver zeolites gained their antibacterial performance from the release of silver ions(Ag^(+))when the sample comes into contact with aqueous solutions.This results in the inhibition of cell functions of the bacteria and subsequently causes cell damage.展开更多
Bauxite residue disposal areas(BRDAs)are physically degraded and hostile to plant growth.Nevertheless,natural plant colonization was observed in an abandoned BRDA in Central China.The pioneer plant species at the disp...Bauxite residue disposal areas(BRDAs)are physically degraded and hostile to plant growth.Nevertheless,natural plant colonization was observed in an abandoned BRDA in Central China.The pioneer plant species at the disposal area were identified,whilst distribution characteristics of salt ions such as Na^+,K^+,and Ca^2+in plant tissues and rhizosphere residues were investigated.The mean concentration of exchangeable Na^+in the rhizosphere soils was 19.5 cmol/kg,which suggested that these pioneer plants had relatively high salinity resistance.Sodium content varied from 0.84 cmol/kg(Digitaria sanguinalis)to 39.7 cmol/kg(Kochia scoparia),whilst K to Na ratio varied from 0.71(Myricaria bracteata)to 32.39(Digitaria sanguinalis)in the shoots,which demonstrated that the salinity tolerance mechanisms of these pioneer species differed significantly.Accumulation factors of Na^+in local plant species ranged from 0.04(D.sanguinalis)to 3.29(M.bracteata),whilst the translocation factor varied from 0.13(D.sanguinalis)to 2.92(M.bracteata).The results suggested that four pioneer plant species including K.scoparia,M.bracteate,Cynodon dactylon and D.sanguinalis could be suitable for revegetation at other disposal areas.展开更多
基金Supported by the National Natural Science Foundation of China(42474239,41204128)China National Space Administration(Pre-research project on Civil Aerospace Technologies No.D010301)Strategic Priority Research Program of the Chinese Academy of Sciences(XDA17010303)。
文摘One of the detection objectives of the Chinese Asteroid Exploration mission is to investigate the space environment near the Main-belt Comet(MBC,Active Asteroid)311P/PANSTARRS.This paper outlines the scientific objectives,measurement targets,and measurement requirements for the proposed Gas and Ion Analyzer(GIA).The GIA is designed for in-situ mass spectrometry of neutral gases and low-energy ions,such as hydrogen,carbon,and oxygen,in the vicinity of 311P.Ion sampling techniques are essential for the GIA's Time-of-Flight(TOF)mass analysis capabilities.In this paper,we present an enhanced ion sampling technique through the development of an ion attraction model and an ion source model.The ion attraction model demonstrates that adjusting attraction grid voltage can enhance the detection efficiency of low-energy ions and mitigate the repulsive force of ions during sampling,which is influenced by the satellite's surface positive charging.The ion source model simulates the processes of gas ionization and ion multiplication.Simulation results indicate that the GIA can achieve a lower pressure limit below 10-13Pa and possess a dynamic range exceeding 10~9.These performances ensure the generation of ions with stable and consistent current,which is crucial for high-resolution and broad dynamic range mass spectrometer analysis.Preliminary testing experiments have verified GIA's capability to detect gas compositions such as H2O and N2.In-situ measurements near 311P using GIA are expected to significantly contribute to our understanding of asteroid activity mechanisms,the evolution of the atmospheric and ionized environments of main-belt comets,the interactions with solar wind,and the origin of Earth's water.
基金The Tertiary Education Scientific Research Project of the Guangzhou Municipal Education Bureau(2024312227)Innovative and Entrepreneurial Projects of Guangzhou University Students(202411078014)+2 种基金Guangzhou University Open Sharing Fund for Instruments and Equipment(2025)National Major Scientific Research Instrument Development Project(22227804)Sub-subject of the National Key Research Project(2023YFB3210100)。
文摘Calcium ions(Ca^(2+))and manganese ions(Mn^(2+))are essential for sustaining life activities and are key monitoring indicators in drinking water.Developing highly sensitive,selective,and portable detection methods for Ca^(2+)and Mn^(2+)is significant for water quality monitoring and human health.In this paper,blue fluorescent Ti3C2 MXene-based quantum dots(MQDs,λ_(em)=445 nm)are prepared using Ti_(3)C_(2)MXene as the precursor.Through the chelation effect of ethylene diamine tetraacetic acid(EDTA),a blue and red dual-emission fluorescent probe,MQDs-EDTA-Eu^(3+)-DPA,was constructed.Herein,dipicolinic acid(DPA)acts as an absorbing ligand and significantly enhances the red fluorescence of europium ions(Eu^(3+))at 616 nm through the“antenna effect”.The blue fluorescence of MQDs serves as an internal reference signal.High concentrations of Ca^(2+)can quench the red fluorescence of Eu^(3+)-DPA;Mn^(2+)can be excited to emit purple fluorescence at 380 nm after coordinating with DPA,red fluorescence of Eu^(3+)-DPA serves as the internal reference signal.Based on the above two fluorescence intensity changes,ratiometric fluorescence detection methods for Ca^(2+)and Mn^(2+)are established.The fluorescence intensity ratio(IF_(616)/IF_(445))exhibits a linear relationship with Ca^(2+)in the range of 35-120μmol/L,with a detection limit of 5.98μmol/L.The fluorescence intensity ratio(IF_(380)/IF_(616))shows good linearity with Mn^(2+)in the range of 0-14μmol/L,with a detection limit of 28.6 nmol/L.This method was successfully applied to the quantitative analysis of Ca^(2+)and Mn^(2+)in commercially available mineral water(Nongfu Spring,Ganten,and Evergrande),with recovery rates of 80.6%-117%and relative standard deviations(RSD)of 0.76%-4.6%.Additionally,by preparing MQD-based fluorescent test strips,visual detections of Ca^(2+)and Mn^(2+)are achieved.This work demonstrates the application potential of MQDs in the field of visual fluorescence sensing of ions in water quality.
基金the Scientific Research Projects Office of Gazi University,Turkiye(Grant Nos.FGA-2022-7521 and FKA-2023-8617)the financial support of TUBITAK 2211-C and YOK 100/2000 programs。
文摘Functionally graded composite/hybrid materials(FGCM/FGHCM)were produced by adding B_(4)C,TiO_(2),and B_(4)C+TiO_(2)ceramic materials at various ratios(0-50%)into the AA6082 matrix.The analysis of the damage caused by^(60) ions'(1.173-1.1332 MeV)on the material was examined using the SRIM/TRIM Monte Carlo simulation software.In the simulation,the following data regarding the atoms of the target materials were obtained:ion distribution,target ionization,total displacements,surface binding energy,lattice binding energy,and displacement energy.Among the studied four materials,the one with the highest ion range value was found to be AA6082 with 8550A.TiO_(2)was found to be the reinforcement material that reduced the ion range the most in the material.Due to its high binding energy,B_(4)C reinforced AA6082+(0-50%)B_(4)C FGCM was found to have the least vacancy with 4782/ion.
基金supported by the National Natural Science Foundation of China(No.22090050,No.22090052,No.22176180)National Basic Research Program of China(No.2021YFA1200400)+1 种基金the Natural Science Foundation of Hubei Province(No.2024AFA001)Shenzhen Science and Technology Program(No.JCYJ20220530162406014)。
文摘Strontium-90,a highly radioactive isotope,accumulates within the food chain and skeletal structure,posing significant risks to human health.There is a critical need for a sensitive detection strategy for Strontium-90 in complex environmental samples.Here,solid-state nanochannels,modified with metal-organic frameworks(MOF)and specific aptamers,were engineered for highly sensitive detection of strontium ion(Sr^(2+)).The synergistic effect between the reduced effective diameter of the nanochannels due to MOF and the specific binding of Sr^(2+) by aptamers amplifies the difference in ionic current signals,enhancing detection sensitivity significantly.The MOF-modified nanochannels exhibit highly sensitive detection of Sr^(2+),with a limit of detection(LOD)being 0.03 nmol·L^(-1),whereas the LOD for anodized aluminum oxide(AAO)without the modified MOF nanosheets is only 1000 nmol·L^(-1).These findings indicate that the LOD of Sr^(2+) detected by the MOF-modified nanochannels is approximately 33,000 times higher than that by the nanochannels without MOF modification.Additionally,the highly reliable detection of Sr^(2+) in various water samples was achieved,with a recovery rate ranging from 94.00%to 118.70%.This study provides valuable insights into the rapidly advancing field of advanced nanochannel-based sensors and their diverse applications for analyzing complex samples,including environmental contaminant detection,food analysis,medical diagnostics,and more.
文摘Bay-site carboxyl functionalized perylene diimide derivative 1,7-COOH-PDI-C_(12)(PDI-COOH)was synthesized and distinct enhanced fluorescence was observed through combining with calcium ion(Ca^(2+))in THF/H_(2)O solution.The assembly and fluorescence behavior of PDI-COOH/Ca^(2+)were studied in detail by changing hydration state with different concentrations.Based on the differences in assembly morphology and stoichiometric ratios of PDICOOH/Ca^(2+),we proposed the fluorescence emission mechanism of PDI-COOH/Ca^(2+)in THF/H_(2)O and THF,respectively.This work reveals a novel strategy of aggregated state fluorescence enhancement and reminds us of the important role of water in molecular fluorescence emission and assembly.
文摘Perovskite quantum dot light-emitting diodes(Pe-QLEDs)have shown immense application potential in display and lighting fields due to their narrow full-width at half maximum(FWHM)and high photoluminescence quantum yield(PLQY).Despite significant advancements in their performance,challenges such as defects and ion migration still hinder their long-term stability and operational efficiency.To address these issues,various optimization strategies,including ligand engineering,interface passivation,and self-assembly strategy,are being actively researched.This review focuses on the synthesis methods,challenges and optimization of perovskite quantum dots,which are critical for the commercialization and large-scale production of high-performance and stable Pe-QLEDs.
文摘To address the lack of systematic studies on heavy metal fluorescent probes in typical buffer solutions,this study developed a Fe^(3+)and Cu^(2+)fluorescent probe,DHU‑NP‑4,based on a naphthalimide fluorophore.Comparative analysis of the probe's performance in various buffer systems revealed that buffers with high organic content are unsuitable for evaluating such probes.Furthermore,the pH of the solvent system was found to significantly influence the probe's behavior.Under highly acidic conditions(pH≤2),DHU‑NP‑4 exhibited exceptional specificity for Fe^(3+),while in alkaline conditions,it demonstrated high specificity for Cu^(2+).Leveraging these properties,the probe enabled the quantitative detection of Fe^(3+)and Cu^(2+)in solution.
文摘V_(2)O_(5)·nH_(2)O has been widely studied for aqueous zinc-ion batteries.The intercalation of inorganic ions has been used as a feasible method to improve the capacity of vanadium pentoxide.To further improve the stability,organic small molecule choline chloride intercalation is used to expand the spacing of the vanadium pentoxide layers and increase the cycling stability.Therefore,we consider the introduction of Sr^(2+)to cointercalate with choline chloride.Here,we synthes-ized vanadium pentoxide cointercalated with Sr^(2+)and choline ions(Ch^(+))via a simple hydrothermal method.The electro-chemical performance shows an enhanced cathode capacitance contribution of Sr&Ch-V_(2)O_(5),with a discharge capacity of 526 mAh·g^(-1)at 0.1 A·g^(-1)and a retention rate of 78.9%after 2000 cycles at 5 A·g^(-1).This work offers a novel strategy for the design of organic‒inorganic hybrid materials for use as cathodes in aqueous zinc-ion batteries.
基金National Natural Science Foundation of China (52302140)Major Scientific and Technological Innovation Project of Wenzhou (ZG2023040, ZG2023042)Joint Funds of the National Natural Science Foundation of China Key Program (U21B2068)。
文摘The feldspar-based microwave dielectric ceramic with low relative permittivity(εr)and excellent mechanical properties has attracted much attention in the fifth-generation wireless communication technology.In this work,a series of microwave dielectric ceramic SrAl_(2-x)Ga_(x)Si_(2)O_(8)(0.1≤x≤2.0)was synthesized using the traditional solid-state method.X-ray diffraction pattern indicates that Ga^(3+)can be dissolved into Al^(3+),forming a solid solution.Meanwhile,substitution of Ga^(3+)for Al^(3+)can promote the space group transition from I2/c(0.1≤x≤1.4)to P21/a(1.6≤x≤2.0)with coefficient of thermal expansion(CTE)increasing from 2.9×10^(-6)℃^(-1) to 5.2×10^(-6)℃^(-1).During this substitution,the phase transition can significantly improve the structural symmetry to enhance the dielectric properties and mechanical properties.Rietveld refinement results indicate that Ga^(3+)averagely occupied four Al^(3+)compositions to form solid solution.All ceramics have a dense microstructure and high relative density above 95%.An ultralower of 5.8 was obtained at x=1.6 composition with high quality factor(Q´f)of 50700 GHz and negative temperature coefficients of resonant frequency(tf)of approximately−35×10^(-6)℃^(-1).The densification temperature can be reduced to 940℃by adding 4%(in mass)LiF,resulting in good chemical compatibility with Ag electrode.Meanwhile,negativetf can be tuned to near-zero(+3.7×10^(-6)℃^(-1))by adding CaTiO_(3) ceramic.
文摘Sm^(3+)-doped materials exhibit red and orange emissions in the visible light region,showing broad applica⁃tion prospects in both laser and display material fields.However,the inherent small emission and absorption cross-sections of Sm^(3+)result in low luminous efficiency,posing challenges for achieving high-quality solid-state lighting.Here,the excellent white emission of Sm^(3+)doped lithium aluminum silicate(LAS)glass was realized by introducing the Ag aggregates through Ag ion exchange.Under 395 nm excitation,the Ag-doped samples exhibit significant fluo⁃rescence enhancement with color coordinates close to the equal energy white point E(0.33,0.33)and a color ren⁃dering index(CRI)of 81.8.The study reveals that the surface plasmon resonance(SPR)effect of Ag nanoparticles enhances the luminescence of Sm^(3+),while the energy transfer mechanism between Ag^(+)and Sm^(3+)also promotes fluores⁃cence enhancement.By adjusting the concentration of AgNO_(3) and the exchange time,a series of high-quality full-spectrum white light emissions were obtained,indicating that the Ag ion-exchanged Sm^(3+)-doped LAS glass has good application potential in the development of solid-state lighting devices.Moreover,variations in the excitation wave⁃length can effectively tune the emission color,further demonstrating the tunability and practicality of this material in optoelectronic applications.
基金Project(2019yff0216502)supported by the National Key Research&Development Plan of Ministry of Science and Technology of ChinaProject(2021SK1020-4)supported by the Major Science and Technological Innovation Project of Hunan Province,China。
文摘Removing copper from nickel electrolysis anode solution has been a major keypoint in the nickel metallurgy industry.In this study,we proposed a novel process flow to promote removing copper from nickel electrolysis anode solution.A simulated nickel anode solution was designed,and static and dynamic adsorption experiments were conducted to determine the best of solution pH,adsorption time and temperature,resin dosage and particle size,and stirring speed.The optimal conditions were explored for copper removal from nickel electrolysis anode solution.Based on the optimal experimental conditions and the relevant experimental data,a novel process for copper removal from nickel electrolysis anodes was designed and verified.This novel process of copper removal from nickel electrolysis anodes was confirmed with nickel anolyte solution with nickel 50−60 g/L and copper 0.5 g/L.After finishing the novel process of copper removal,the nickel in the purified nickel anolyte became undetectable and copper concentration was 3 mg/L,the novel process of resin adsorption to remove copper from nickel anode solution through static and dynamic adsorptions has an efficacious copper removal.It is a beneficial supplement to traditional methods.
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.
文摘One of the focus views of the uplifting of Tibetan Plateau is the growth history of the plateau. This is an unresolved question because of the poor study in north margin, where the ATF (Altyn Tagh Fault) is acting an important role in the growth and deformation of the plateau. The fault links two huge contractional belts, e.g. Qilian Nan Shan and West Kunlun, and merges a series of thrusting\|folding arcs in southeast. Mapping of piercing points, such as unconformities between Cenozoic, Mesozoic and Paleozoic strata, and magmatic arcs, shows left slips of ca. 240km and ca. 550km along the middle and western segments of the ATF. About 140～450km of crustal shortening, approximately the same magnitude as the west segment of the ATF, is deduced from balanced sections in West Kunlun foreland thrusting belt. This implies that left\|slip displacement along the west segment of the ATF was absorbed by the contraction in West Kunlun. The ATF system merged bunches of WNW arcuated fold\|fault belts in Qaidam basin, implying anti\|clockwise rotation. Tertiary and some Lower to Middle Pleistocene strata involved in fold\|fault belts, and dip in ESE due to the uplifting of Altyn Tagh. The newest strata involved in the deformation is more and more younger from south to north, that is, from Lower Pliocene to Middle Pleistocene, showing the uplifting trends from south to north in the SE side of the fault.
基金Project(51174229) supported by the National Natural Science Foundation of China
文摘The effect of solution conditions on the depression of chlorite using CMC (carboxymethyl cellulose) as depressant was studied through flotation tests and adsorption measurements. Flotation and adsorption tests were first studied as a function of initial solution conditions. The results show that electrostatic repulsion between CMC molecules and chlorite surface hinders the approach of the CMC molecules to the chlorite surface and CMC adsorbs to a great extent at high ionic concentration (10-4 mol/L ions as opposed to 0 mol/L ions) or low pH (3 as opposed to 9). The enhanced adsorption density is attributed to the decreased electrostatic repulsion between CMC and mineral surface. The solution condition that yielded the lowest initial adsorbed amount (0 mol/L ions, pH 9) was used as a reference to investigate the response of the adsorbed CMC layer to a switch in solution conditions after adsorption. The two kinds of solution switches (reducing the solution pH or increasing ionic concentration) result in an increased depression effect of CMC on chlorite flotation, as a result of conformational change of CMC pre-adsorbed layer. The change in the flotation recovery of the CMC-coated chlorite following the solution switches is reversible.
基金Project(2015BAB19B03)supported by the National Science and Technology Supporting Plan of China
文摘A process of removing impurities,such as Fe,Zr,Ti,Al,Si,from scandium solution by ion exchange was proposed.Various resins’selectivity was studied in scandium chloride solution.The results indicated that D851resin had high selectivity of Sc at low acidity,and high selectivity of Zr at high acidity;D370resin had high selectivity of Fe and Si in high acidity.A new technical process of removing impurities from scandium chloride solution was proposed,which includes D370resin adsorbing Fe in high acidity,D851resin adsorbing Zr in medium acidity and D851resin adsorbing Sc at low acidity.Flow experimental results show that removal rates of Al,Ca,Fe,Zr,Ti and Si,were100%,99.6%,100%,100%,99.5%and100%respectively.
基金Projects(21571191,51674292) supported by the National Natural Science Foundation of ChinaProject(2016JJ1023) supported by the Natural Science Foundation of Hunan Province,ChinaProject(2018TP1003) supported by the Key Laboratory of Hunan Province for Water Environment and Agriculture Product Safety,China
文摘A novel three-dimension(3D)graphene/MgO composite was synthesized through self-assembly and embedding MgO nanoparticle in reduced graphene in situ.Fourier transform infrared(FT-IR)spectroscopy,thermal gravimetric analysis(TGA),scanning electron microscopy(SEM),transmission electron microscope(TEM),powder X-raydiffraction(XRD)and X-rayphotoelectron spectroscopy(XPS)were employed to characterize the prepared 3D graphene/MgO composite.The adsorption performance of some metal ions on 3D graphene/MgO was investigated.The results showed that the adsorption capacity was greater than 3D graphene and the maximum adsorption capacity at 25℃was found to be 358.96 mg/g,388.4 mg/g and 169.8 mg/g for Pb^2+,Cd^2+and Cu^2+,respectively.The adsorption kinetic conformed to the pseudo-second-order kinetic model and the adsorption isotherm was well described by Langmuir model.The thermodynamic constants revealed that the sorption process was endothermic and spontaneous in nature.Based on the results of the removal of heavy metal ions from metal smelting wastewater,it can be concluded that the prepared 3D graphene/MgO composite is an effective and potential adsorbent.
基金Project(J130000.2524.04H87) supported by the Ministry of Higher Education of Malaysia and Universiti Teknologi Malaysia。
文摘Microbiologically-induced concrete corrosion(MICC)refers to chemical reactions between biologically produced sulphuric acid and with hydration products in the hardened concrete paste,resulting in an early reduction of strength,deterioration,and very severe circumstances,structural failure.This paper explores the bactericidal characteristics of cementitious materials with surface coated with modified zeolite-polyurethane.The zeolite-polyurethane coating incorporated with silver was studied in environments inoculated with A.thiooxidans bacteria for 8 consecutive weeks.The antibacterial characteristics were evaluated in terms of pH,optical density(OD),sulphate production and bacteria count to determine the effectiveness of the zeolite-polyurethane coatings in environments inoculated with A.thiooxidans bacteria producing the sulphuric acid.The results revealed that the samples incorporated with silver modified zeolites generally showed antibacterial performance(regardless of the zeolite type)compared with unmodified polyurethane coating.This was evaluated by the lack of bacteria attachment and the deformed microcolonies on the sample surface,lag in pH reduction,increase in OD,and sulphate production.The silver zeolites gained their antibacterial performance from the release of silver ions(Ag^(+))when the sample comes into contact with aqueous solutions.This results in the inhibition of cell functions of the bacteria and subsequently causes cell damage.
基金Project(41877511)supported by the National Natural Science Foundation of China
文摘Bauxite residue disposal areas(BRDAs)are physically degraded and hostile to plant growth.Nevertheless,natural plant colonization was observed in an abandoned BRDA in Central China.The pioneer plant species at the disposal area were identified,whilst distribution characteristics of salt ions such as Na^+,K^+,and Ca^2+in plant tissues and rhizosphere residues were investigated.The mean concentration of exchangeable Na^+in the rhizosphere soils was 19.5 cmol/kg,which suggested that these pioneer plants had relatively high salinity resistance.Sodium content varied from 0.84 cmol/kg(Digitaria sanguinalis)to 39.7 cmol/kg(Kochia scoparia),whilst K to Na ratio varied from 0.71(Myricaria bracteata)to 32.39(Digitaria sanguinalis)in the shoots,which demonstrated that the salinity tolerance mechanisms of these pioneer species differed significantly.Accumulation factors of Na^+in local plant species ranged from 0.04(D.sanguinalis)to 3.29(M.bracteata),whilst the translocation factor varied from 0.13(D.sanguinalis)to 2.92(M.bracteata).The results suggested that four pioneer plant species including K.scoparia,M.bracteate,Cynodon dactylon and D.sanguinalis could be suitable for revegetation at other disposal areas.
