A pre-reduction sintering process with flue gas recirculation(PSP_(fsg)-FGR)was developed to mitigate alkalis harm to the blast furnace and reduce the flue gas emission in the whole ironmaking process.The results indi...A pre-reduction sintering process with flue gas recirculation(PSP_(fsg)-FGR)was developed to mitigate alkalis harm to the blast furnace and reduce the flue gas emission in the whole ironmaking process.The results indicated that the pre-reduction sintering process(PSP)can effectively remove 58.02%of K and 30.68%of Na from raw mixtures and improve yield and tumbler index to 74.40%and 68.69%,respectively.Moreover,PSP was conducive to reducing NO_(x) and SO_(2)emissions and simultaneously increasing CO content in flue gas.Circulating CO-containing flue gas to sintering bed effectively recycled CO and further improved K and Na removal ratio to 74.11%and 32.92%,respectively.Microstructural analysis revealed that the pre-reduced sinter mainly consisted of magnetite,wustite and a small quantity of metallic iron,and very few silicate glass phase was also formed.This process can simultaneously realize alkali metal elements removal as well as flue gas emission reduction from the integrated ironmaking process.展开更多
Influences of alkali oxides doping on the crystal structure, defects and hydration behavior of tricalcium silicate C_3S were investigated by X-ray powder diffraction with the Rietveld method, inductively coupled plasm...Influences of alkali oxides doping on the crystal structure, defects and hydration behavior of tricalcium silicate C_3S were investigated by X-ray powder diffraction with the Rietveld method, inductively coupled plasma optical emission spectroscopy, thermoluminescence and isothermal calorimetry. All the samples were stabilized as T1 form C_3S. Changes in the crystal structure of C_3S could mainly be monitored by changes in lattice parameters, which were closely correlated with the incorporation concentration and substitution types of alkalis. Although alkalis were incorporated at trace level in C_3S, the thermoluminescence and hydration behavior of C_3S were significantly influenced. Initial hydration activity was dramatically increased and highly related to the intensity of the irradiation-induced thermoluminescence peaks at low temperatures due to their direct correlation with defects. The oxygen vacancy sites resulting from the substitution of alkalis for Ca could readily account for the acceleration of the initial hydration of C_3S.展开更多
Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR).Here,we investigated the adsorption behaviors of anionic surfactants and alkali...Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR).Here,we investigated the adsorption behaviors of anionic surfactants and alkalis on silica for the first time as a function of temperature using quartz crystal microbalance with dissipation(QCM-D).The results demonstrated that the temperature dependent critical micelle concentration of alcohol alkoxy sulfate(AAS)surfactant can be quantitatively described by the thermodynamics parameters of micellization,showing a mainly entropy-driven process.AAS adsorption was mediated under varying temperature conditions,by divalent cations for bridging effect,monovalent cations competitive for adsorption sites but not giving cation bridging,pH regulation of deprotonated sites of silica,presence of alkoxy groups in the surfactants,and synergistic effect of surfactant coinjection.The addition of organic alkalis can enhance the overall adsorption of the species with AAS,whereas inorganic alkali of Na_(2)CO_(3)had capability of the sequestration of the divalent ions,whose addition would reduce AAS adsorption.The typical AAS adsorption indicated a non-rigid multilayer,estimated to have between 2 and 5 layers,with a likely compact bilayer followed by disorganized and unstable further layering.The new fundamental understanding about temperature effect on surfactants and alkalis adsorption contributes to optimizing the flooding conditions of chemicals and developing more efficient mitigation strategies.展开更多
Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes...Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes with SiO_(2)and Al_(2)O_(3)ratios were investigated using various techniques.It is found that when SiO_(2)is replaced by Al_(2)O_(3),the Q^(4) to Q^(3) transition of silicon-oxygen network decreases while the aluminum-oxygen network increases,which result in the transformation of Si-O-Si bonds to Si-O-Al bonds and an increase in glass network connectivity even though the intermolecular bond strength decreases.The glass transition temperature(T_(g))increases continuously,while the thermal expansion coefficient increases and high-temperature viscosity first decreases and then increases.Meanwhile,the elastic modulus values increase from 93 to 102 GPa.This indicates that the elastic modulus is mainly affected by packing factor and dissociation energy,and elements with higher packing factors and dissociation energies supplant those with lower values,resulting in increased rigidity within the glass.展开更多
In order to realize the comprehensive utilization of industrial solid waste rice husk ash and heavy metal cadmium contaminated soil,rice husk ash-based geopolymer prepared by alkaline activator was used to modify cadm...In order to realize the comprehensive utilization of industrial solid waste rice husk ash and heavy metal cadmium contaminated soil,rice husk ash-based geopolymer prepared by alkaline activator was used to modify cadmium contaminated soil.The main physical and chemical properties of rice husk ash were clarified by SEM,XRF and X-ray diffraction.The unconfined compressive strength test and toxicity leaching test were carried out on the modified soil.Combined with FTIR and TG micro-level,the solidification mechanism of rice husk ash-based geopolymer solidified cadmium contaminated soil was discussed.The results show that the strength of geopolymer modified soil is significantly higher than that of plain soil,and the unconfined compressive strength at 7 d age is 4.2 times that of plain soil.The strength of modified soil with different dosage of geopolymer at 28 d age is about 36% to 40% higher than that of modified soil at 7 d age.Geopolymer has a significant effect on the leaching of heavy metals in contaminated soil.When the cadmium content is 100 mg/kg,it meets the standard limit.In the process of complex depolymerization-condensation reaction,on the one hand,geopolymers are cemented and agglomerated to form a complex spatial structure,which affects the macro and micro characteristics of soil.On the other hand,it has significant adsorption,precipitation and replacement effects on heavy metal ions in soil,showing good strength and low heavy metal leaching toxicity.展开更多
Aqueous alkali metal-ion batteries(AAMIBs)have been recognized as emerging electrochemical energy storage technologies for grid-scale applications owning to their intrinsic safety,cost-effectiveness,and environmental ...Aqueous alkali metal-ion batteries(AAMIBs)have been recognized as emerging electrochemical energy storage technologies for grid-scale applications owning to their intrinsic safety,cost-effectiveness,and environmental sustainability.However,the practical application of AAMIBs is still severely constrained by the tendency of aqueous electrolytes to freeze at low temperatures and decompose at high temperatures,limiting their operational temperature range.Considering the urgent need for energy systems with higher adaptability and resilience at various application scenarios,designing novel electrolytes via structure modulation has increasingly emerged as a feasible and economical strategy for the performance optimization of wide-temperature AAMIBs.In this review,the latest advancement of wide-temperature electrolytes for AAMIBs is systematically and comprehensively summarized.Specifically,the key challenges,failure mechanisms,correlations between hydrogen bond behaviors and physicochemical properties,and thermodynamic and kinetic interpretations in aqueous electrolytes are discussed firstly.Additionally,we offer forward-looking insights and innovative design principles for developing aqueous electrolytes capable of operating across a broad temperature range.This review is expected to provide some guidance and reference for the rational design and regulation of widetemperature electrolytes for AAMIBs and promote their future development.展开更多
Rechargeable alkali metal-sulfur(M-S)batteries,including Li/Na/K-S chemistries,have the potential to utilize abundant and low-cost sulfur cathodes yet offer high theoretical energy densities.However,their practical el...Rechargeable alkali metal-sulfur(M-S)batteries,including Li/Na/K-S chemistries,have the potential to utilize abundant and low-cost sulfur cathodes yet offer high theoretical energy densities.However,their practical electrochemical performance is fundamentally limited by the polysulfide shuttle effect.This challenge is particularly exacerbated in Na-S and K-S systems owing to larger metal-ion radii,weaker solvation energies,slower redox kinetics,and greater electrolyte-electrode incompatibilities compared to Li-S batteries.This review presents a comparative analysis of interface engineering strategies designed to suppress the shuttle effect across these three systems.Following a summary of sulfur cathode properties and reaction mechanisms,we systematically examine the origins of polysulfide shuttling.Our analysis progresses from functional separator design and interlayer enhancements to the implementation of solid-state electrolytes for root-cause inhibition.By evaluating interface engineering research specific to Na-S and K-S batteries,we elucidate both shared principles and unique challenges inherent to alkali M-S systems.Finally,we propose multifaceted solutions to achieve shuttlefree operation and enhance overall battery performance,thereby establishing a foundation for future advancements.展开更多
The hydrogen evolution reaction(HER)is crucial for hydrogen production and sustainable energy storage.Molybdenum disulfide(MoS_(2)),a representative transition metal dichalcogenides(TMDs),shows potential as an HER cat...The hydrogen evolution reaction(HER)is crucial for hydrogen production and sustainable energy storage.Molybdenum disulfide(MoS_(2)),a representative transition metal dichalcogenides(TMDs),shows potential as an HER catalyst but suffers from limited performance due to poor charge transfer and interfacial effects.Here,we report a salt-assisted chemical vapor deposition(CVD)method for synthesizing high-quality tungsten ditelluride(WTe_(2))with tunable morphologies using alkali halides(NaCl,KCl and LiCl).The prepared WTe_(2) nanoribbons and hexagonal nanosheets exhibit morphology-dependent electrical conductivity,with nanosheets showing superior performance.To evaluate WTe_(2) as a contact electrode,WTe_(2)−MoS_(2) heterostructures were fabricated and compared with graphene-MoS_(2) counterparts.The WTe_(2)−MoS_(2) heterostructure exhibits a superior Tafel slope of 111.57 mV/dec and an overpotential of 298 mV at-10 mA/cm^(2),significantly outperforming graphene-based electrodes.This improvement is attributed to the excellent conductivity of WTe_(2) and reduced interfacial Schottky barriers.Moreover,we systematically investigate the influence of WTe_(2) thickness on HER performance and assess the electrochemical durability and structural stability of the heterostructure,further confirming the effectiveness of WTe_(2) as a contact electrode for enhancing the HER activity of MoS_(2).This study offers a novel approach for enhancing the HER performance of MoS_(2) through controlled WTe_(2) growth and application as a contact electrode.Our findings provide valuable insights into the synthesis of high-quality WTe_(2) and broaden the potential applications of two-dimensional materials in energy catalysis.展开更多
We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X...We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X represents transition metal elements.Systematic analysis of electronic band structures,phonon dispersions,and electron-phonon coupling reveals that substitution of MA binary metal combinations and X metal atoms can create favorable conditions for superconductivity.Mapping of superconducting critical temperatures,combined with dynamical stability analysis through phonon calculations,identifies ten superconducting candidates at ambient pressure.Among these,LiNaAgH_(6) exhibits nearly-free-electron behavior reminiscent of monovalent electron superconductors.It demonstrates exceptional superconducting properties with electron–phonon coupling λ=2.707,which yields a superconducting transition temperature T_(c) of 206.4 K using the Allen–Dynes formula.Its structural analogs MgNaPdH_(6),LiMgPdH_(6),LiMgAgH_(6),LiMgAuH_(6) all exhibit superconducting transition temperatures above 110 K.These findings advance our fundamental understanding of superconductivity in quaternary hydrides and provide guidance for rational design of new high-temperature superconducting materials.展开更多
Substitution of lead(Pb)with tin(Sn)is a very important way to reduce the bandgap of metal halide perovskite for applications in solar cells,and near infrared(NIR)light-emitting diodes(LEDs),etc.However,mixed Pb/Sn pe...Substitution of lead(Pb)with tin(Sn)is a very important way to reduce the bandgap of metal halide perovskite for applications in solar cells,and near infrared(NIR)light-emitting diodes(LEDs),etc.However,mixed Pb/Sn perovskite becomes very disordered with high trap density when the Sn molar ratio is less than 20%.This limits the applications of mixed Pb/Sn perovskites in optoelectronic devices such as wavelength tunable NIR perovskite LEDs(Pe LEDs).In this work,we demonstrate that alkali cations doping can release the microstrain and passivate the traps in mixed Pb/Sn perovskites with Sn molar ratios of less than 20%,leading to higher carrier lifetime and photoluminescence quantum yield(PLQY).The external quantum efficiency(EQE)of Sn_(0.2)Pb_(0.8)-based NIR Pe LEDs is dramatically enhanced from 0.1%to a record value of 9.6%(emission wavelength:868 nm).This work provides a way of making high quality mixed Pb/Sn optoelectronic devices with small Sn molar ratios.展开更多
This paper presents experimental results on the effect of alkalis such as NaOH, KOH and Ca（OH）2 on deacetylation of a konjac glucomannan （KGM） powder under mechano-chemical （MC） treatment, The results show that ...This paper presents experimental results on the effect of alkalis such as NaOH, KOH and Ca（OH）2 on deacetylation of a konjac glucomannan （KGM） powder under mechano-chemical （MC） treatment, The results show that the alkalinity of modifiers is a dominant factor for deacetylation of KGM, In addition, characteristics, such as swelling property, viscous stability and thermal behavior of the deacetylated KGM are analyzed展开更多
Tongbo Anpeng Alkalis Ore Co.,Ltd.(Tongbo Alkalis,former Anpeng Alkalis Ore Co.,Ltd.),located in Nanyang ,Henan province,was a joint venture built by Inner Mongolian Yuanxing Natural Alkali Co.,Ltd.,Henan Petroleum Ex...Tongbo Anpeng Alkalis Ore Co.,Ltd.(Tongbo Alkalis,former Anpeng Alkalis Ore Co.,Ltd.),located in Nanyang ,Henan province,was a joint venture built by Inner Mongolian Yuanxing Natural Alkali Co.,Ltd.,Henan Petroleum Exploration Bureau of Sinopec Group and the State-owned Asset Operation Co.,Ltd.of Tongbo county in 1998,holding 60%,35%,5% of stock respectively.The company uses the new technique of sesqui alkali to produce soda ash containing low salt.At present,the company is operating two trona-based soda ash production units with capacities of 200 000 t/a and 400 000 t/a respectively.The company reports that its trona reserve is more than 50% of the national total.In the third quarter of 2008,Tongbo Alkalis produced 147 700 tons of soda ash,reaping a sales revenue of RMB230 million.展开更多
Using cemented rockfill to replace coal pillars offers an effective solution for reducing solid waste while ensuring the safety of gob-side entries.However,achieving the balance among low cost,high waste recycling rat...Using cemented rockfill to replace coal pillars offers an effective solution for reducing solid waste while ensuring the safety of gob-side entries.However,achieving the balance among low cost,high waste recycling rates,and adequate strength remains a significant challenge for cemented rockfill.This study used a composite alkali activator to activate gangue cemented rockfill.The compressive strength,scanning electron microscopy,energy dispersive spectrometer,mercury intrusion porosimetry,X-ray diffraction,and thermogra-vimetric tests were carried out to investigate the effect of the composite alkali activator proportion on the compressive strength,micro-structure,and composition of the cemented rockfill.The calcium silicate hydrate(C–S–H)molecular model of cemented rockfill was con-structed to explore the fracture evolution of the nucleated molecular structure under tension.The results show that compressive strength initially increased and then decreased with the activator proportion,the optimal activator proportion of 1:2 resulted in a 31.25%increase in strength at 3 d.This reasonable activator proportion strengthens the pozzolanic effect of gangue,and consumes more calcium hydroxide to inhibit its agglomeration,ultimately achieving the densification of microstructure.The activator proportion inevitably substitutes calcium ions with sodium ions in the C–S–H molecular model.The 12%substitution of calcium ions increases the adhesion between silicon chain layers,which is beneficial to the interlayer stress transfer.This work proposes a method for preparing low-cost cemented rockfill from al-kali-activated gangue,which can be used for solid waste recycling and reducing cement consumption to achieve low-carbon goals.展开更多
Granite residual soil (GRS) is a type of weathering soil that can decompose upon contact with water, potentially causing geological hazards. In this study, cement, an alkaline solution, and glass fiber were used to re...Granite residual soil (GRS) is a type of weathering soil that can decompose upon contact with water, potentially causing geological hazards. In this study, cement, an alkaline solution, and glass fiber were used to reinforce GRS. The effects of cement content and SiO_(2)/Na2O ratio of the alkaline solution on the static and dynamic strengths of GRS were discussed. Microscopically, the reinforcement mechanism and coupling effect were examined using X-ray diffraction (XRD), micro-computed tomography (micro-CT), and scanning electron microscopy (SEM). The results indicated that the addition of 2% cement and an alkaline solution with an SiO_(2)/Na2O ratio of 0.5 led to the densest matrix, lowest porosity, and highest static compressive strength, which was 4994 kPa with a dynamic impact resistance of 75.4 kN after adding glass fiber. The compressive strength and dynamic impact resistance were a result of the coupling effect of cement hydration, a pozzolanic reaction of clay minerals in the GRS, and the alkali activation of clay minerals. Excessive cement addition or an excessively high SiO_(2)/Na2O ratio in the alkaline solution can have negative effects, such as the destruction of C-(A)-S-H gels by the alkaline solution and hindering the production of N-A-S-H gels. This can result in damage to the matrix of reinforced GRS, leading to a decrease in both static and dynamic strengths. This study suggests that further research is required to gain a more precise understanding of the effects of this mixture in terms of reducing our carbon footprint and optimizing its properties. The findings indicate that cement and alkaline solution are appropriate for GRS and that the reinforced GRS can be used for high-strength foundation and embankment construction. The study provides an analysis of strategies for mitigating and managing GRS slope failures, as well as enhancing roadbed performance.展开更多
The technology of solid-state lighting has developed for decades in various industries.Phosphor,as an element part,determines the application domain of lighting products.For instance,blue and redemitting phosphors are...The technology of solid-state lighting has developed for decades in various industries.Phosphor,as an element part,determines the application domain of lighting products.For instance,blue and redemitting phosphors are required in the process of plant supplementing light,arrow-band emitting phosphors are applied to backlight displays,etc.In this work,a Bi^(3+)-activated blue phosphor was obtained in a symmetrical and co mpact crystal structure of Gd3Sb07(GSO).Then,the co-doping strategy of alkali metal ions(Li^(+),Na^(+),and K^(+))was used to optimize the performance.The result shows that the photoluminescence intensity is increased by 2.1 times and 1.3 times respectively by introducing Li~+and K^(+)ions.Not only that,it also achieves narrow-band emitting with the full width of half-maximum(FWHM)reaching 42 nm through Na^(+)doping,and its excitation peak position also shifts from 322 to 375 nm,which can be well excited by near-ultraviolet(NUV)light emitting diode(LED)chips(365 nm).Meanwhile,the electroluminescence spectrum of GSO:0.6 mol%Bi^(3+),3 wt%Na^(+)matches up to 93.39%of the blue part of the absorption spectrum of chlorophyll a.In summary,the Bi^(3+)-activated blue phosphor reported in this work can synchronously meet the requirements of plant light replenishment and field emission displays.展开更多
In this study,the catalysis function of Na_(2)CO_(3) to the structural properties of xylan char was well investigated with Na_(2)CO_(3) on,and the electrochemical performance of xylan char as an anode material for sod...In this study,the catalysis function of Na_(2)CO_(3) to the structural properties of xylan char was well investigated with Na_(2)CO_(3) on,and the electrochemical performance of xylan char as an anode material for sodium-ion batteries was tested.The characterization of X-ray microscopy and scanning electron microscopy demonstrated that the morphological structure of xylan char was altered due to the addition of Na_(2)CO_(3) catalyst.The increasement of the Na_(2)CO_(3)/xylan ratio resulted in a slenderization of the triangular prism shape of the char skeleton and a reduction in porosity.X-ray diffraction analysis revealed that Na_(2)CO_(3) promoted the growth of the(004)crystal plane of graphite during xylan pyrolysis,while inhibiting the formation of the(100/101)crystal planes.Raman spectroscopy analysis indicated that the presence of Na_(2)CO_(3)had changed the graphitization degree of xylan char.Electrochemical tests further showed that char prepared with a Na_(2)CO_(3)/xylan mass ratio of 1∶1 exhibited the highest sodium storage capacity.This study provides a pathway for the rational design carbon materials derived from xylan for future applications in energy storage devices.展开更多
Chemical hydrogen storage in organic materials is a promising method thanks to its high storage density,reversibility,and safety.However,the dehydrogenation process of organic materials requires high temperatures due ...Chemical hydrogen storage in organic materials is a promising method thanks to its high storage density,reversibility,and safety.However,the dehydrogenation process of organic materials requires high temperatures due to their unfavorable thermodynamic properties.This study proposes a strategy to design a new type of hydrogen storage materials,i.e.,alkali metal pyridinolate/piperidinolate pairs,by combining the effects of a heteroatom and an alkali metal in one molecule to achieve suitable dehydrogenation thermodynamics along with high hydrogen storage capacities.These air-stable compounds can be synthesized using low-cost reactants and water as a green solvent.Thermodynamic predictions indicate that enthalpy changes of dehydrogenation(ΔH_(d))can be significantly reduced to the optimal range for efficient hydrogen release,exemplified by lithium 2-piperidinolate with a 5.6 wt%hydrogen capacity and a suitableΔH_(d)of 32.2 kJ/mol-H_(2).Experimental results obtained using sodium systems validate the computational predictions,demonstrating reversible hydrogen storage even below 100℃.The superior hydrogen desorption performance of alkali metal piperidinolates could be attributed to their suitableΔH_(d)induced by the combined effect of ring nitrogen and metal substitution on their structures.This study not only reports new low-cost hydrogen storage materials but also provides a rational design strategy for developing metalorganic compounds possessing high hydrogen capacities and suitable thermodynamics for efficient hydrogen storage.展开更多
Ln-containing polyoxoniobates(PONbs)have appealing applications in luminescence,information encryption and magnetic fields,but the synthesis of PONbs containing high-nuclearity Ln-O clusters is challenging due to the ...Ln-containing polyoxoniobates(PONbs)have appealing applications in luminescence,information encryption and magnetic fields,but the synthesis of PONbs containing high-nuclearity Ln-O clusters is challenging due to the easy hydrolysis of Ln^(3+)ions in alkaline environments.In this paper,we are able to integrate CO_(3)^(2-)and high-nuclearity Ln-O clusters into PONb to construct an inorganic giant Eu_(19)-embedded PONb H_(49)K_(16)Na_(13)(H_(2)O)_(63)[Eu_(21)O_(2)(OH)_(7)(H_(2)O)_(5)(Nb_(7)O_(22))_(10)(Nb_(2)O_(6))_(2)(CO_(3))_(18)]·91H_(2)O(1),which contains the highest nuclearity Eu-O clusters and the largest number of Eu^(3+)ions among PONbs.In addition,the film that was prepared by mixing 1 with gelatin and glycerol,exhibits reversible luminescence switching behavior under acid/alkali stimulation and has been used to create a fluorescence-encoded information approach.This work paves a feasible strategy for the construction of high-nuclearity Ln-O cluster-containing PONbs and the expansion of the application of Ln-containing PONbs in information encryption.展开更多
We read with great interest the investigations conducted by Pourakbar et al.(2024)on the“Stabilization of clay soil using alkali-activated sewage sludge.”The authors have investigated the feasibility of utilizing al...We read with great interest the investigations conducted by Pourakbar et al.(2024)on the“Stabilization of clay soil using alkali-activated sewage sludge.”The authors have investigated the feasibility of utilizing alkali-activated sewage sludge(AASS)as a binder for stabilizing the clayey soil.Sewage sludge(SS)in varying proportions of 1.5%,2%,2.5%,3.5%,and 4.5%was utilized to prepare geopolymer binders using sodium and potassium-based alkali activators.Furthermore,unconfined compressive strength(UCS)and direct shear tests were conducted to examine the strength development of clayey soil stabilized with AASS.While the study presented some intriguing results,we have identified critical concerns regarding(i)the selection of SS as a precursor for alkali activation,(ii)technical inconsistencies associated with the compaction characteristics and microstructural analysis,and(iii)the feasibility of the proposed methodology for practical applications.Through our discussion,we seek to highlight these issues and provide constructive feedback to advance the understanding of alkali activation processes and their implications for soil stabilization.展开更多
Among their several unique properties,the high electrical conductivity and mechanical strength of carbon nanofibers make them suitable for applications such as catalyst support for fuel cells,flexible electrode materi...Among their several unique properties,the high electrical conductivity and mechanical strength of carbon nanofibers make them suitable for applications such as catalyst support for fuel cells,flexible electrode materials for secondary batteries,and sensors.However,their performance requires improvement for practical applications.Several methods have been pursued to achieve this,such as growing carbon nanotubes from carbon nanofibers;however,the transition metal catalyst used to grow carbon nanotubes causes problems,including side reactions.This study attempts to address this issue by growing numerous branched carbon nanofibers from the main carbon nanofibers using alkali metals.Excellent electrical conductivity is achieved by growing densely branched carbon nanofibers.Consequently,a current collector,binder,and conductive material-free anode material is realized,exhibiting excellent electrochemical performance compared with existing carbon nanofibers.The proposed method is expected to be a powerful tool for secondary batteries and have broad applicability to various fields.展开更多
基金Project(52274290)supported by the National Natural Science Foundation of ChinaProject(72088101)supported by the Basic Science Center Project for National Natural Science Foundation of China。
文摘A pre-reduction sintering process with flue gas recirculation(PSP_(fsg)-FGR)was developed to mitigate alkalis harm to the blast furnace and reduce the flue gas emission in the whole ironmaking process.The results indicated that the pre-reduction sintering process(PSP)can effectively remove 58.02%of K and 30.68%of Na from raw mixtures and improve yield and tumbler index to 74.40%and 68.69%,respectively.Moreover,PSP was conducive to reducing NO_(x) and SO_(2)emissions and simultaneously increasing CO content in flue gas.Circulating CO-containing flue gas to sintering bed effectively recycled CO and further improved K and Na removal ratio to 74.11%and 32.92%,respectively.Microstructural analysis revealed that the pre-reduced sinter mainly consisted of magnetite,wustite and a small quantity of metallic iron,and very few silicate glass phase was also formed.This process can simultaneously realize alkali metal elements removal as well as flue gas emission reduction from the integrated ironmaking process.
基金Funded by the National Natural Science Foundation of China(Nos.51302256 and 51672260)the Synergetic Innovation Center for Advanced Materials and State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)
文摘Influences of alkali oxides doping on the crystal structure, defects and hydration behavior of tricalcium silicate C_3S were investigated by X-ray powder diffraction with the Rietveld method, inductively coupled plasma optical emission spectroscopy, thermoluminescence and isothermal calorimetry. All the samples were stabilized as T1 form C_3S. Changes in the crystal structure of C_3S could mainly be monitored by changes in lattice parameters, which were closely correlated with the incorporation concentration and substitution types of alkalis. Although alkalis were incorporated at trace level in C_3S, the thermoluminescence and hydration behavior of C_3S were significantly influenced. Initial hydration activity was dramatically increased and highly related to the intensity of the irradiation-induced thermoluminescence peaks at low temperatures due to their direct correlation with defects. The oxygen vacancy sites resulting from the substitution of alkalis for Ca could readily account for the acceleration of the initial hydration of C_3S.
基金supported by the Shanxi Provincial Key Research and Development Project(No.20201102002)Science Foundation of China University of Petroleum,Beijing(No.2462020BJRC007,2462020YXZZ003)+1 种基金State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum(No.PRP/DX-2216)Shell Global Solutions。
文摘Chemical loss such as surfactants and alkalis by adsorption to reservoir rock surface is an important issue in enhanced oil recovery(EOR).Here,we investigated the adsorption behaviors of anionic surfactants and alkalis on silica for the first time as a function of temperature using quartz crystal microbalance with dissipation(QCM-D).The results demonstrated that the temperature dependent critical micelle concentration of alcohol alkoxy sulfate(AAS)surfactant can be quantitatively described by the thermodynamics parameters of micellization,showing a mainly entropy-driven process.AAS adsorption was mediated under varying temperature conditions,by divalent cations for bridging effect,monovalent cations competitive for adsorption sites but not giving cation bridging,pH regulation of deprotonated sites of silica,presence of alkoxy groups in the surfactants,and synergistic effect of surfactant coinjection.The addition of organic alkalis can enhance the overall adsorption of the species with AAS,whereas inorganic alkali of Na_(2)CO_(3)had capability of the sequestration of the divalent ions,whose addition would reduce AAS adsorption.The typical AAS adsorption indicated a non-rigid multilayer,estimated to have between 2 and 5 layers,with a likely compact bilayer followed by disorganized and unstable further layering.The new fundamental understanding about temperature effect on surfactants and alkalis adsorption contributes to optimizing the flooding conditions of chemicals and developing more efficient mitigation strategies.
基金Supported by the National Key Research Program(No.2024-1129-954-112)National Natural Science Foundation of China(No.52372033)Guangxi Science and Technology Major Program(No.AA24263054)。
文摘Alkali-free SiO_(2)-Al_(2)O_(3)-CaO-MgO with different SiO_(2)/Al_(2)O_(3)mass ratios was prepared by conventional melt quenching method.The glass network structure,thermodynamic properties and elastic modulus changes with SiO_(2)and Al_(2)O_(3)ratios were investigated using various techniques.It is found that when SiO_(2)is replaced by Al_(2)O_(3),the Q^(4) to Q^(3) transition of silicon-oxygen network decreases while the aluminum-oxygen network increases,which result in the transformation of Si-O-Si bonds to Si-O-Al bonds and an increase in glass network connectivity even though the intermolecular bond strength decreases.The glass transition temperature(T_(g))increases continuously,while the thermal expansion coefficient increases and high-temperature viscosity first decreases and then increases.Meanwhile,the elastic modulus values increase from 93 to 102 GPa.This indicates that the elastic modulus is mainly affected by packing factor and dissociation energy,and elements with higher packing factors and dissociation energies supplant those with lower values,resulting in increased rigidity within the glass.
基金Funded by Central Guiding Local Science and Technology Development Special Fund Project(No.ZYYD2023B02)Innovation and Entrepreneurship Training Program for College Students in Xinjiang Uygur Autonomous Region(No.S202410994015)+2 种基金China University of Mining and Technology Coal Fine Exploration and Intelligent Development National Key Laboratory Xinjiang Engineering College Joint Fund(No.SKLCRSM-XJIE24KF001)Basic Research Funds for Autonomous Region Universities(No.XJEDU2024P082)National Natural Science Foundation of China(No.41662017)。
文摘In order to realize the comprehensive utilization of industrial solid waste rice husk ash and heavy metal cadmium contaminated soil,rice husk ash-based geopolymer prepared by alkaline activator was used to modify cadmium contaminated soil.The main physical and chemical properties of rice husk ash were clarified by SEM,XRF and X-ray diffraction.The unconfined compressive strength test and toxicity leaching test were carried out on the modified soil.Combined with FTIR and TG micro-level,the solidification mechanism of rice husk ash-based geopolymer solidified cadmium contaminated soil was discussed.The results show that the strength of geopolymer modified soil is significantly higher than that of plain soil,and the unconfined compressive strength at 7 d age is 4.2 times that of plain soil.The strength of modified soil with different dosage of geopolymer at 28 d age is about 36% to 40% higher than that of modified soil at 7 d age.Geopolymer has a significant effect on the leaching of heavy metals in contaminated soil.When the cadmium content is 100 mg/kg,it meets the standard limit.In the process of complex depolymerization-condensation reaction,on the one hand,geopolymers are cemented and agglomerated to form a complex spatial structure,which affects the macro and micro characteristics of soil.On the other hand,it has significant adsorption,precipitation and replacement effects on heavy metal ions in soil,showing good strength and low heavy metal leaching toxicity.
基金supported by the National Natural Science Foundation of China(52002297)National Key R&D Program of China(2022VFB2404800)+1 种基金Wuhan Yellow Crane Talents Program,China Postdoctoral Science Foundation(No.2024M752495)the Postdoctoral Fellowship Program of CPSF(No.GZB20230552).
文摘Aqueous alkali metal-ion batteries(AAMIBs)have been recognized as emerging electrochemical energy storage technologies for grid-scale applications owning to their intrinsic safety,cost-effectiveness,and environmental sustainability.However,the practical application of AAMIBs is still severely constrained by the tendency of aqueous electrolytes to freeze at low temperatures and decompose at high temperatures,limiting their operational temperature range.Considering the urgent need for energy systems with higher adaptability and resilience at various application scenarios,designing novel electrolytes via structure modulation has increasingly emerged as a feasible and economical strategy for the performance optimization of wide-temperature AAMIBs.In this review,the latest advancement of wide-temperature electrolytes for AAMIBs is systematically and comprehensively summarized.Specifically,the key challenges,failure mechanisms,correlations between hydrogen bond behaviors and physicochemical properties,and thermodynamic and kinetic interpretations in aqueous electrolytes are discussed firstly.Additionally,we offer forward-looking insights and innovative design principles for developing aqueous electrolytes capable of operating across a broad temperature range.This review is expected to provide some guidance and reference for the rational design and regulation of widetemperature electrolytes for AAMIBs and promote their future development.
基金supported by the National Natural Science Foundation of China(52371131)the 10th Youth Talent Lifting Project of the China Association for Science and Technology.
文摘Rechargeable alkali metal-sulfur(M-S)batteries,including Li/Na/K-S chemistries,have the potential to utilize abundant and low-cost sulfur cathodes yet offer high theoretical energy densities.However,their practical electrochemical performance is fundamentally limited by the polysulfide shuttle effect.This challenge is particularly exacerbated in Na-S and K-S systems owing to larger metal-ion radii,weaker solvation energies,slower redox kinetics,and greater electrolyte-electrode incompatibilities compared to Li-S batteries.This review presents a comparative analysis of interface engineering strategies designed to suppress the shuttle effect across these three systems.Following a summary of sulfur cathode properties and reaction mechanisms,we systematically examine the origins of polysulfide shuttling.Our analysis progresses from functional separator design and interlayer enhancements to the implementation of solid-state electrolytes for root-cause inhibition.By evaluating interface engineering research specific to Na-S and K-S batteries,we elucidate both shared principles and unique challenges inherent to alkali M-S systems.Finally,we propose multifaceted solutions to achieve shuttlefree operation and enhance overall battery performance,thereby establishing a foundation for future advancements.
基金support from the National Natural Science Foundation of China(No.22175060).
文摘The hydrogen evolution reaction(HER)is crucial for hydrogen production and sustainable energy storage.Molybdenum disulfide(MoS_(2)),a representative transition metal dichalcogenides(TMDs),shows potential as an HER catalyst but suffers from limited performance due to poor charge transfer and interfacial effects.Here,we report a salt-assisted chemical vapor deposition(CVD)method for synthesizing high-quality tungsten ditelluride(WTe_(2))with tunable morphologies using alkali halides(NaCl,KCl and LiCl).The prepared WTe_(2) nanoribbons and hexagonal nanosheets exhibit morphology-dependent electrical conductivity,with nanosheets showing superior performance.To evaluate WTe_(2) as a contact electrode,WTe_(2)−MoS_(2) heterostructures were fabricated and compared with graphene-MoS_(2) counterparts.The WTe_(2)−MoS_(2) heterostructure exhibits a superior Tafel slope of 111.57 mV/dec and an overpotential of 298 mV at-10 mA/cm^(2),significantly outperforming graphene-based electrodes.This improvement is attributed to the excellent conductivity of WTe_(2) and reduced interfacial Schottky barriers.Moreover,we systematically investigate the influence of WTe_(2) thickness on HER performance and assess the electrochemical durability and structural stability of the heterostructure,further confirming the effectiveness of WTe_(2) as a contact electrode for enhancing the HER activity of MoS_(2).This study offers a novel approach for enhancing the HER performance of MoS_(2) through controlled WTe_(2) growth and application as a contact electrode.Our findings provide valuable insights into the synthesis of high-quality WTe_(2) and broaden the potential applications of two-dimensional materials in energy catalysis.
基金supported by the National Key R&D Program of China (Grant No.2022YFA1403201)the National Natural Science Foundation of China (Grant Nos.12125404,T2495231,123B2049,and 12204138)+9 种基金the Advanced MaterialsNational Science and Technology Major Project (Grant No.2024ZD0607000)the Natural Science Foundation of Jiangsu Province (Grant Nos.BK20233001 and BK20253009)the Jiangsu Funding Program for Excellent Postdoctoral Talent (Grant No.2024ZB002)the China Postdoctoral Science Foundation (Grant No.2025M773331)the Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of Chinathe AI&AI for Science program of Nanjing UniversityArtificial Intelligence and Quantum physics (AIQ) program of Nanjing Universitythe Fundamental Research Funds for the Central Universitiesthe Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant Nos.NY224165,NY220038,and NY219087)the Hua Li Talents Program of Nanjing University of Posts and Telecommunications。
文摘We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X represents transition metal elements.Systematic analysis of electronic band structures,phonon dispersions,and electron-phonon coupling reveals that substitution of MA binary metal combinations and X metal atoms can create favorable conditions for superconductivity.Mapping of superconducting critical temperatures,combined with dynamical stability analysis through phonon calculations,identifies ten superconducting candidates at ambient pressure.Among these,LiNaAgH_(6) exhibits nearly-free-electron behavior reminiscent of monovalent electron superconductors.It demonstrates exceptional superconducting properties with electron–phonon coupling λ=2.707,which yields a superconducting transition temperature T_(c) of 206.4 K using the Allen–Dynes formula.Its structural analogs MgNaPdH_(6),LiMgPdH_(6),LiMgAgH_(6),LiMgAuH_(6) all exhibit superconducting transition temperatures above 110 K.These findings advance our fundamental understanding of superconductivity in quaternary hydrides and provide guidance for rational design of new high-temperature superconducting materials.
基金the financial support of the National Natural Science Foundation of China(51872161)Major Program of Shandong Provincial Natural Science Foundation(ZR2017ZB0316)+3 种基金the financial support of the National Natural Science Foundation of China(51872274)the Fundamental Research Funds for the Central Universities(WK2060190100)the National Key Research and Development Program of China(2017YFA0206600)the National Natural Science Foundation of China(51773045,21772030,51922032,and 21961160720)for financial support。
文摘Substitution of lead(Pb)with tin(Sn)is a very important way to reduce the bandgap of metal halide perovskite for applications in solar cells,and near infrared(NIR)light-emitting diodes(LEDs),etc.However,mixed Pb/Sn perovskite becomes very disordered with high trap density when the Sn molar ratio is less than 20%.This limits the applications of mixed Pb/Sn perovskites in optoelectronic devices such as wavelength tunable NIR perovskite LEDs(Pe LEDs).In this work,we demonstrate that alkali cations doping can release the microstrain and passivate the traps in mixed Pb/Sn perovskites with Sn molar ratios of less than 20%,leading to higher carrier lifetime and photoluminescence quantum yield(PLQY).The external quantum efficiency(EQE)of Sn_(0.2)Pb_(0.8)-based NIR Pe LEDs is dramatically enhanced from 0.1%to a record value of 9.6%(emission wavelength:868 nm).This work provides a way of making high quality mixed Pb/Sn optoelectronic devices with small Sn molar ratios.
文摘This paper presents experimental results on the effect of alkalis such as NaOH, KOH and Ca（OH）2 on deacetylation of a konjac glucomannan （KGM） powder under mechano-chemical （MC） treatment, The results show that the alkalinity of modifiers is a dominant factor for deacetylation of KGM, In addition, characteristics, such as swelling property, viscous stability and thermal behavior of the deacetylated KGM are analyzed
文摘Tongbo Anpeng Alkalis Ore Co.,Ltd.(Tongbo Alkalis,former Anpeng Alkalis Ore Co.,Ltd.),located in Nanyang ,Henan province,was a joint venture built by Inner Mongolian Yuanxing Natural Alkali Co.,Ltd.,Henan Petroleum Exploration Bureau of Sinopec Group and the State-owned Asset Operation Co.,Ltd.of Tongbo county in 1998,holding 60%,35%,5% of stock respectively.The company uses the new technique of sesqui alkali to produce soda ash containing low salt.At present,the company is operating two trona-based soda ash production units with capacities of 200 000 t/a and 400 000 t/a respectively.The company reports that its trona reserve is more than 50% of the national total.In the third quarter of 2008,Tongbo Alkalis produced 147 700 tons of soda ash,reaping a sales revenue of RMB230 million.
基金supported by the Key Research and Development Special Tasks of Xinjiang,China (No.2022B01051-2)the National Natural Science Foundation of China (Nos.U23B2091,42372328,and 52478253)+1 种基金the Natural Science Foundation of Jiangsu Province,China (No.BK20240209)the Science and Technology Program Special Fund of Jiangsu Province (Frontier Leading Technology Basic Research) Major projects,China (No.BK 20222004)
文摘Using cemented rockfill to replace coal pillars offers an effective solution for reducing solid waste while ensuring the safety of gob-side entries.However,achieving the balance among low cost,high waste recycling rates,and adequate strength remains a significant challenge for cemented rockfill.This study used a composite alkali activator to activate gangue cemented rockfill.The compressive strength,scanning electron microscopy,energy dispersive spectrometer,mercury intrusion porosimetry,X-ray diffraction,and thermogra-vimetric tests were carried out to investigate the effect of the composite alkali activator proportion on the compressive strength,micro-structure,and composition of the cemented rockfill.The calcium silicate hydrate(C–S–H)molecular model of cemented rockfill was con-structed to explore the fracture evolution of the nucleated molecular structure under tension.The results show that compressive strength initially increased and then decreased with the activator proportion,the optimal activator proportion of 1:2 resulted in a 31.25%increase in strength at 3 d.This reasonable activator proportion strengthens the pozzolanic effect of gangue,and consumes more calcium hydroxide to inhibit its agglomeration,ultimately achieving the densification of microstructure.The activator proportion inevitably substitutes calcium ions with sodium ions in the C–S–H molecular model.The 12%substitution of calcium ions increases the adhesion between silicon chain layers,which is beneficial to the interlayer stress transfer.This work proposes a method for preparing low-cost cemented rockfill from al-kali-activated gangue,which can be used for solid waste recycling and reducing cement consumption to achieve low-carbon goals.
基金the support provided by the National Natural Science Foundation of China(Grant Nos.52278336 and 42302032)Guangdong Basic and Applied Research Foundation(Grant Nos.2023B1515020061).
文摘Granite residual soil (GRS) is a type of weathering soil that can decompose upon contact with water, potentially causing geological hazards. In this study, cement, an alkaline solution, and glass fiber were used to reinforce GRS. The effects of cement content and SiO_(2)/Na2O ratio of the alkaline solution on the static and dynamic strengths of GRS were discussed. Microscopically, the reinforcement mechanism and coupling effect were examined using X-ray diffraction (XRD), micro-computed tomography (micro-CT), and scanning electron microscopy (SEM). The results indicated that the addition of 2% cement and an alkaline solution with an SiO_(2)/Na2O ratio of 0.5 led to the densest matrix, lowest porosity, and highest static compressive strength, which was 4994 kPa with a dynamic impact resistance of 75.4 kN after adding glass fiber. The compressive strength and dynamic impact resistance were a result of the coupling effect of cement hydration, a pozzolanic reaction of clay minerals in the GRS, and the alkali activation of clay minerals. Excessive cement addition or an excessively high SiO_(2)/Na2O ratio in the alkaline solution can have negative effects, such as the destruction of C-(A)-S-H gels by the alkaline solution and hindering the production of N-A-S-H gels. This can result in damage to the matrix of reinforced GRS, leading to a decrease in both static and dynamic strengths. This study suggests that further research is required to gain a more precise understanding of the effects of this mixture in terms of reducing our carbon footprint and optimizing its properties. The findings indicate that cement and alkaline solution are appropriate for GRS and that the reinforced GRS can be used for high-strength foundation and embankment construction. The study provides an analysis of strategies for mitigating and managing GRS slope failures, as well as enhancing roadbed performance.
基金Project supported by the Key R&D Projects in Hunan Province(2021SK2047,2022NK2044)Science and Technology Innovation Program of Hunan Province(2022WZ1022)Superior Youth Project of the Science Research Project of Hunan Provincial Department of Education(22B0211)。
文摘The technology of solid-state lighting has developed for decades in various industries.Phosphor,as an element part,determines the application domain of lighting products.For instance,blue and redemitting phosphors are required in the process of plant supplementing light,arrow-band emitting phosphors are applied to backlight displays,etc.In this work,a Bi^(3+)-activated blue phosphor was obtained in a symmetrical and co mpact crystal structure of Gd3Sb07(GSO).Then,the co-doping strategy of alkali metal ions(Li^(+),Na^(+),and K^(+))was used to optimize the performance.The result shows that the photoluminescence intensity is increased by 2.1 times and 1.3 times respectively by introducing Li~+and K^(+)ions.Not only that,it also achieves narrow-band emitting with the full width of half-maximum(FWHM)reaching 42 nm through Na^(+)doping,and its excitation peak position also shifts from 322 to 375 nm,which can be well excited by near-ultraviolet(NUV)light emitting diode(LED)chips(365 nm).Meanwhile,the electroluminescence spectrum of GSO:0.6 mol%Bi^(3+),3 wt%Na^(+)matches up to 93.39%of the blue part of the absorption spectrum of chlorophyll a.In summary,the Bi^(3+)-activated blue phosphor reported in this work can synchronously meet the requirements of plant light replenishment and field emission displays.
基金supported by the Foundation Project of Jihua Laboratory(X200191TL200).
文摘In this study,the catalysis function of Na_(2)CO_(3) to the structural properties of xylan char was well investigated with Na_(2)CO_(3) on,and the electrochemical performance of xylan char as an anode material for sodium-ion batteries was tested.The characterization of X-ray microscopy and scanning electron microscopy demonstrated that the morphological structure of xylan char was altered due to the addition of Na_(2)CO_(3) catalyst.The increasement of the Na_(2)CO_(3)/xylan ratio resulted in a slenderization of the triangular prism shape of the char skeleton and a reduction in porosity.X-ray diffraction analysis revealed that Na_(2)CO_(3) promoted the growth of the(004)crystal plane of graphite during xylan pyrolysis,while inhibiting the formation of the(100/101)crystal planes.Raman spectroscopy analysis indicated that the presence of Na_(2)CO_(3)had changed the graphitization degree of xylan char.Electrochemical tests further showed that char prepared with a Na_(2)CO_(3)/xylan mass ratio of 1∶1 exhibited the highest sodium storage capacity.This study provides a pathway for the rational design carbon materials derived from xylan for future applications in energy storage devices.
基金partially supported by the National Key R&D Program of China(2023YFE0198900)support provided by the National Natural Science Foundation of China(52171226,22309174)。
文摘Chemical hydrogen storage in organic materials is a promising method thanks to its high storage density,reversibility,and safety.However,the dehydrogenation process of organic materials requires high temperatures due to their unfavorable thermodynamic properties.This study proposes a strategy to design a new type of hydrogen storage materials,i.e.,alkali metal pyridinolate/piperidinolate pairs,by combining the effects of a heteroatom and an alkali metal in one molecule to achieve suitable dehydrogenation thermodynamics along with high hydrogen storage capacities.These air-stable compounds can be synthesized using low-cost reactants and water as a green solvent.Thermodynamic predictions indicate that enthalpy changes of dehydrogenation(ΔH_(d))can be significantly reduced to the optimal range for efficient hydrogen release,exemplified by lithium 2-piperidinolate with a 5.6 wt%hydrogen capacity and a suitableΔH_(d)of 32.2 kJ/mol-H_(2).Experimental results obtained using sodium systems validate the computational predictions,demonstrating reversible hydrogen storage even below 100℃.The superior hydrogen desorption performance of alkali metal piperidinolates could be attributed to their suitableΔH_(d)induced by the combined effect of ring nitrogen and metal substitution on their structures.This study not only reports new low-cost hydrogen storage materials but also provides a rational design strategy for developing metalorganic compounds possessing high hydrogen capacities and suitable thermodynamics for efficient hydrogen storage.
基金the financial support from the National Natural Science Foundation of China(Nos.21971040,22171045,and 22371046)。
文摘Ln-containing polyoxoniobates(PONbs)have appealing applications in luminescence,information encryption and magnetic fields,but the synthesis of PONbs containing high-nuclearity Ln-O clusters is challenging due to the easy hydrolysis of Ln^(3+)ions in alkaline environments.In this paper,we are able to integrate CO_(3)^(2-)and high-nuclearity Ln-O clusters into PONb to construct an inorganic giant Eu_(19)-embedded PONb H_(49)K_(16)Na_(13)(H_(2)O)_(63)[Eu_(21)O_(2)(OH)_(7)(H_(2)O)_(5)(Nb_(7)O_(22))_(10)(Nb_(2)O_(6))_(2)(CO_(3))_(18)]·91H_(2)O(1),which contains the highest nuclearity Eu-O clusters and the largest number of Eu^(3+)ions among PONbs.In addition,the film that was prepared by mixing 1 with gelatin and glycerol,exhibits reversible luminescence switching behavior under acid/alkali stimulation and has been used to create a fluorescence-encoded information approach.This work paves a feasible strategy for the construction of high-nuclearity Ln-O cluster-containing PONbs and the expansion of the application of Ln-containing PONbs in information encryption.
文摘We read with great interest the investigations conducted by Pourakbar et al.(2024)on the“Stabilization of clay soil using alkali-activated sewage sludge.”The authors have investigated the feasibility of utilizing alkali-activated sewage sludge(AASS)as a binder for stabilizing the clayey soil.Sewage sludge(SS)in varying proportions of 1.5%,2%,2.5%,3.5%,and 4.5%was utilized to prepare geopolymer binders using sodium and potassium-based alkali activators.Furthermore,unconfined compressive strength(UCS)and direct shear tests were conducted to examine the strength development of clayey soil stabilized with AASS.While the study presented some intriguing results,we have identified critical concerns regarding(i)the selection of SS as a precursor for alkali activation,(ii)technical inconsistencies associated with the compaction characteristics and microstructural analysis,and(iii)the feasibility of the proposed methodology for practical applications.Through our discussion,we seek to highlight these issues and provide constructive feedback to advance the understanding of alkali activation processes and their implications for soil stabilization.
基金supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF2023R1A2C2004191)supported by Korea Basic Science Institute(National research Facilities and Equipment Center)grant funded by Ministry of Education(grant No.2022R1A6C101B738).
文摘Among their several unique properties,the high electrical conductivity and mechanical strength of carbon nanofibers make them suitable for applications such as catalyst support for fuel cells,flexible electrode materials for secondary batteries,and sensors.However,their performance requires improvement for practical applications.Several methods have been pursued to achieve this,such as growing carbon nanotubes from carbon nanofibers;however,the transition metal catalyst used to grow carbon nanotubes causes problems,including side reactions.This study attempts to address this issue by growing numerous branched carbon nanofibers from the main carbon nanofibers using alkali metals.Excellent electrical conductivity is achieved by growing densely branched carbon nanofibers.Consequently,a current collector,binder,and conductive material-free anode material is realized,exhibiting excellent electrochemical performance compared with existing carbon nanofibers.The proposed method is expected to be a powerful tool for secondary batteries and have broad applicability to various fields.
