The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient uti...The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient utilization of lepidolite as a lithium source.Therefore,the processes for the flotation of lepidolite have been studied in depth,particularly the development and use of lepidolite flotation collectors and the action mechanism of the collectors on the lepidolite surface.Based on the crystal-structure characteristics of lepidolite minerals,this review focuses on the application of anionic collectors,amine cationic collectors(primary amines,quaternary ammonium salts,ether amines,and Gemini amines),and combined collectors to the flotation behavior of lepidolite as well as the adsorption mechanisms.New directions and technologies for the controllable flotation of lepidolite are proposed,including process improvement,reagent synthesis,and mechanistic research.This analysis demonstrates the need for the further study of the complex environment inside lepidolite and pulp.By using modern analytical detection methods and quantum chemical calculations,research on reagents for the flotation of lepidolite has expanded,providing new concepts and references for the efficient flotation recovery and utilization of lepidolite.展开更多
Transition metal carbonates(TMCs)hold great potential as high-performance electrodes for alkali metal-ion batteries,owing to multiple-ion storage mechanisms involving conversion process and electrocatalytic reaction.H...Transition metal carbonates(TMCs)hold great potential as high-performance electrodes for alkali metal-ion batteries,owing to multiple-ion storage mechanisms involving conversion process and electrocatalytic reaction.However,they still suffer from inferior electronic conductivity and volume variation during delithiation/lithiation.Heterostructure and heteroatoms doping offer immense promise in enhancing reaction kinetics and structural integrity,which unfortunately have not been achieved in TMCs.Herein,a unique TMCs heterostructure with Ni-doped MnCO_(3)as“core”and Mn-doped NiCO_(3)as“shell”,which is wrapped by graphene(NM@MN/RGO),is achieved by cations differentiation strategy.The formation process for core-shell NM@MN consists of epitaxial growth of NiCO_(3)from MnCO_(3)and synchronously mutual doping,owing to the similar crystal structures but different solubility product constant/formation energy of MnCO_(3)and NiCO_(3).In-situ electrochemical impedance spectroscopy,galvanostatic intermittent titration technique,differential capacity versus voltage plots,theoretical calculation and kinetic analysis reveal the superior electrochemical activity of the NM@MN/RGO to MnCO_(3)/RGO.The NM@MN/RGO shows excellent lithium storage properties(1013.4 mAh·g^(-1)at 0.1 A·g^(-1)and 760 mAh·g^(-1)after 1000 cycles at 2 A·g^(-1))and potassium storage properties(capacity decay rate of 0.114 mAh·g^(-1)per cycle).This work proposes an efficient cation differentiation strategy for constructing advanced TMC electrodes.展开更多
Incorporating organic bulky cations in the precursor or post-treatment to achieve two-dimensional/thr ee-dimensional(2D/3D)heterojunction is an effective strategy for enhancing the stability of perovskite materials.Ho...Incorporating organic bulky cations in the precursor or post-treatment to achieve two-dimensional/thr ee-dimensional(2D/3D)heterojunction is an effective strategy for enhancing the stability of perovskite materials.However,the issue of insufficient charge transport in 2D perovskites limits their development,and the fundamental mechanism of out-of-plane carrier transport remains unclear.This study designed and synthesized seven organic phenyl-core cations,differentiated at the 1-and 1,4-positions,and identified the impacts on the corresponding properties of the 2D crystalline perovskite.Shorter cations facilitated a more compact arrangement of adjacent inorganic layers,aligning to favor charge transport along the vertical direction.In addition,introducing high electronegativity led to increased intermolecular interactions,resulting in enhanced structural stability and improved phenyl ring π-orbital overlap and interlayer electron coupling,yielding efficient charge transport.Resilience to thermal stressing of the perovskite was strongly correlated with the carbon chain length of the spacer cations.The increase in cation length and the reduction in the rigidity of the amino-terminal both aided in the dispersion of thermal stress in the inorganic framework.Additional hydrogen bonding also contributed to mitigating structural disorder.展开更多
The first-ever synthesis of the unknown furo[2,3:4,5]pyrimido[1,2-b]indazole skeleton was demonstrated based on the undiscovered tetra-functionalization of enaminones,with simple substrates and reaction conditions.The...The first-ever synthesis of the unknown furo[2,3:4,5]pyrimido[1,2-b]indazole skeleton was demonstrated based on the undiscovered tetra-functionalization of enaminones,with simple substrates and reaction conditions.The key to realizing this process lies in the multiple trapping of the in situ generated ketenimine cation by the 3-aminoindazole,which results in the formation of four new chemical bonds and two new rings in one pot.Moreover,the products of this new reaction were found to exhibit aggregationinduced emission(AIE)without modification.展开更多
Phonon coherence can reflect electron‒phonon coupling information and has been proven to modulate electronic states and charge transport.The manipulation of phonon coherence through spacer cation engineering in organi...Phonon coherence can reflect electron‒phonon coupling information and has been proven to modulate electronic states and charge transport.The manipulation of phonon coherence through spacer cation engineering in organic‒inorganic hybrid perovskites(OIHPs)has been extensively demonstrated;however,the underlying structural origin remains elusive at the molecular level.Herein,we present molecular structure and temperature-dependent coherent phonon studies via a combination of sum frequency generation vibrational spectroscopy(SFG-VS)and transient absorption spectroscopy(TAS).The conformational order of spacer cations dictates the coherent phonon oscillations in 2D OIHPs.Our study further analyzes the static order and dynamic disorder in 2D perovskites.This work provides molecular-level insights into the role of spacer cations in tuning structural order and may provide valuable guidance for advancing emergent optoelecltronics development.展开更多
The investigation of thermal transport properties of materials has become increasingly important in technological applications,including thermal management and energy conversion.Recently,ultrahigh or low thermal condu...The investigation of thermal transport properties of materials has become increasingly important in technological applications,including thermal management and energy conversion.Recently,ultrahigh or low thermal conductivity has been reported in nitride,boride,and chalcogenide by different strategies.However,the strategy to design oxide crystals with unique thermal properties is also a challenge.In this work,a new ternary oxide crystal Ga_(2)TeO_(6) is designed and expected to show high thermal conductivity due to its lone pairs-free octahedra connected along the caxis by sharing edges.The thermal conductivities of Ga_(2)TeO_(6) crystal are determined to be 19.2 and 23.9Wm^(-1) K^(-1) along the a-and c-axis directions at 323 K,respectively,which are significantly higher than those of most reported oxide crystals.First-principles calculations and crystal structure analyses reveal that the Ga_(2)TeO_(6) crystal shows high sound velocity and weak lattice anharmonicity due to lone pairs-free octahedra and highly symmetric group arrangement.The results suggest that much attention must be paid to the polyhedron with lone pairs and its arrangement in materials design to balance the functions and thermal properties.展开更多
Mussels are common anchoring organisms that adhere to the surfaces of various substrates with their byssus.The adhesion of mussel to substrates is contingent upon the presence of mussel foot proteins,of which Mytilus ...Mussels are common anchoring organisms that adhere to the surfaces of various substrates with their byssus.The adhesion of mussel to substrates is contingent upon the presence of mussel foot proteins,of which Mytilus edulis foot protein-1(Mefp-1)has been identified as the most abundant protein.It has been found that lipids are involved in the mussel adhesion process and can facilitate Mefp-1adhesion.In this research,the adhesion behavior of Mefp-1 on various substrate surfaces under the effect of typical seawater cations with or without the presence of lipid were investigated using a quartz crystal microbalance with dissipation(QCM-D).Results indicate that the presence of cations Ca^(2+),Mg^(2+),Na^(+),and K^(+)leads to varying degrees of reduction in the adhesion performance of Mefp-1 on different substrates.The degree of this reduction,however,was much alleviated in the presence of palmitic acid,which is involved in the mussel adhesion process.Therefore,the involvement of palmitic acid is advantageous for mussel protein adhesion to the substrate surface in the marine environment.This study illustrated the significant contribution of palmitic acid to mussel adhesion,which can help to better understand biofouling mechanisms and develop biomimetic adhesive materials.展开更多
The mutual effects of metal cations （Cu2＋, Pb2＋, Zn2＋, and Cd2＋） and p-nitrophenol （NP） on their adsorption desorption behavior onto wheat ash were studied. Results suggested that Cu2＋, Pb2＋, and Zn2＋ dimin...The mutual effects of metal cations （Cu2＋, Pb2＋, Zn2＋, and Cd2＋） and p-nitrophenol （NP） on their adsorption desorption behavior onto wheat ash were studied. Results suggested that Cu2＋, Pb2＋, and Zn2＋ diminished the adsorption and increased the desorption of NP remarkably, while Cd2＋ had no such effect. In contrast, NP diminished the adsorption of Cu2＋, Pb2＋, and Zn2＋ onto ash, however, this suppression effect depended on the initial concentrations of metal cations. NP had no effect on Cd〉 adsorption on ash. Fourier transform infrared （FT-IR） and X-ray absorption spectroscopic （XAS） studies suggested the following mechanisms responsible for the metal suppression effect on NP adsorption： （1） large hydrated Cu2＋, Pb2＋, and Zn〉 shells occupied the surface of ash and prevent nonspecific adsorption of NP onto ash surface; （2） Cu2＋, Pb2＋, and Zn2＋ may block the micropores of ash, resulting in decreased adsorption of NP; （3） cornplexation of Cu2＋, Pb2＋, and Zn2＋ was likely via carboxyl, hydroxylic and phenolic groups of wheat ash and these same groups may also react with NP during adsorption. As a ＂soft acid＂, Cd2＋ is less efficient in the complexation of oxygencontaining acid groups than Cu2＋, Pb2＋, and Zn2＋. Thus, Cd2＋ had no effect on the adsorption of NP on wheat ash.展开更多
Information on the distribution patterns of soil water content （SWC）, soil organic matter （SOM）, and soil exchangeable cations （SEC） is important for managing forest ecosystems in a sustainable manner. This stud...Information on the distribution patterns of soil water content （SWC）, soil organic matter （SOM）, and soil exchangeable cations （SEC） is important for managing forest ecosystems in a sustainable manner. This study investigated how SWC, SOM, and SEC were influenced in forests along a successional gradient, including a regional climax （monsoon evergreen broad-leaved forest, or MEBF）, a transitional forest （coniferous and broad-leaved mixed forest, or MF）, and a pioneer forest （coniferous Masson pine （Pinus rnassoniana） forest, or MPF） of the Dinghushan Biosphere Reserve in the subtropical region of southern China. SWC, SOM, and SEC excluding Ca^2＋ were found to increase in the soil during forest succession, being highest in the top soil layer （0 to 15 cm depth） except for Na^＋. The differences between soil layers were largest in MF. This finding also suggested that the nutrients were enriched in the topsoil when they became increasingly scarce in the soil. There were no significant differences （P = 0.05） among SWC, SOM, and SEC. A linear, positive correlation was found between SWC and SOM. The correlation between SOM and cation exchange capacity （CEC） was statistically significant, which agreed with the theory that the most important factor determining SEC is SOM. The ratio of K^＋ to Na^＋ in the topsoil was about a half of that in the plants of each forest. MF had the lowest exchangeable Ca^2＋ concentration among the three forests and Ca^2＋：K^＋ in MPF was two times higher than that in MF. Understanding the changes of SWC, SOM, and CEC during forest succession would be of great help in protecting all three forests in southern China.展开更多
MgH_(2) is regarded as a potential hydrolysis material for the hydrogen generation due to its high theoretical hydrogen yield,abundant source on earth and environmentally friendly hydrolysates.However,the quickly form...MgH_(2) is regarded as a potential hydrolysis material for the hydrogen generation due to its high theoretical hydrogen yield,abundant source on earth and environmentally friendly hydrolysates.However,the quickly formed passive magnesium hydroxide layer on the surface of MgH_(2) will hinder its further hydrolysis reaction,leading to sluggish reaction kinetics and low H_(2) yield.In this paper,we explore the improvement of different anions and cations in solutions for the hydrolysis of MgH_(2).It is found that the cations in the solution promote the reaction rate of MgH_(2) hydrolysis through the hydrolysate-induced growth effect,among which the fastest hydrogen yield can get 1664 m L/g within a few minutes in the Fe_(2)(SO_(4))_(3) solution.As for the anions,it enables different microstructures of the Mg(OH)_(2) hydrolysate which give rise to enhanced water utilization.Specially,for the mixed 0.5 M MgCl_(2)+0.05 M MgSO_(4) solution,the water utilization rate attains the optimum value of 51.3%,much higher than that of the single MgCl_(2) or MgSO_(4) solutions.These findings are of great significance for the application of MgH_(2) hydrolysis as hydrogen generation.展开更多
The effects of alkaline cations （M^＋ = Li^＋, Na^＋, K^＋, Cs^＋）on the electrochemical synthesis of polyaniline were carfled out under cyclovoltammetric conditions using nitrates of Li^＋, Na^＋, K^＋, and Cs^＋ a...The effects of alkaline cations （M^＋ = Li^＋, Na^＋, K^＋, Cs^＋）on the electrochemical synthesis of polyaniline were carfled out under cyclovoltammetric conditions using nitrates of Li^＋, Na^＋, K^＋, and Cs^＋ as the supporting electrolytes. The results show that the oxidation potentials of aniline in the electrolytes decrease as the protonation extent of aniline decreases from the fast scan, which is caused by the decrease of the ionic radius of alkaline metal ions at the same concentration of alkaline cations. With the scan number increasing, the deposit charge Q as the characteristic growth function also depends on the protonation of aniline, and it increases with the ionic radius of alkaline cations increasing. SEM images show the effect of alkaline cations on the morphology of polyaniline. It is clear that the ionic mobility of alkaline cations is further lower than that of W. Alkaline cations and counter-ions were the species responsible for the enhancement of Pani electrosynthesis. Therefore, this is exactly what SEM images show： a relatively rough fibrous structure in the case of Pani-H^＋ suggesting a sponge-like structure and a highly orderly fiber-like structure in the case of Pani-M^＋.展开更多
It is well-known that the electrolytes can influence the electrochemical reduction of carbon dioxide(ERCO2)in aqueous media.In this work,we explore the effects of alkali metal cations and anions(Li^+,Na^+,K^+,Rb^+,Cs^...It is well-known that the electrolytes can influence the electrochemical reduction of carbon dioxide(ERCO2)in aqueous media.In this work,we explore the effects of alkali metal cations and anions(Li^+,Na^+,K^+,Rb^+,Cs^+,HCO3^-,Cl^-,Br^-,I^-)on the current density and product selectivity for the ERCO2 into formic acid(HCOOH)on the SnO2/carbon paper(Sn O2/C)electrode.Results of the ERCO2 experiments show that for the cations,the promotion effects on current density and faradaic efficiencies(FEs)are in the order of Li^+b Na^+b K^+b Cs^+b Rb^+.For the anions,the current density values are in the order of Na HCO3 b NaClb Na Br b Na I and KHCO3 b KCl≈KI b KBr,respectively,and that on the FEs for the formation of the HCOOH(FEHCOOH)is HCO3-b Cl-b Br-b I-.Based on this result,the effects of alkali metal cations and anions on ERCO2 are discussed.展开更多
Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local io...Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local ionic structure,atomic dynamics and bond stability were analyzed to elucidate the interaction between cations and chloride ions.The results show that interfacial chloride is absorbed through the ion pairing formation in the vicinity of C-A-S-H substrate.Interfacial cations can simultaneously interact aluminosilicate chains,water molecules and Cl^(-)ions,which restrict the motion of interfacial Cl^(-)ions.Pore solution chloride can be immobilized through the solvation effect of cations.Cations along with their hydration shell can connect to neighboring Cl^(-)ions to decrease their mobility.Owing to the varied ionic chemistry,cations show different interaction strength with neighboring water molecules and anions,which determines the chloride transport behavior in the nanopore of C-A-S-H.The chloride immobilization capacity of C-A-S-H nanopore with different associated cations is listed in following order:Mg^(2+)Ca^(2+)<Na^(+)≈K^(+),which agrees reasonably with previous experiments.展开更多
The self-aldol condensation of aldehydes was investigated with rare-earth cations stabilized by[Si]Beta zeolites in parallel with bulk rare-earth metal oxides.Good catalytic performance was achieved with all Lewis aci...The self-aldol condensation of aldehydes was investigated with rare-earth cations stabilized by[Si]Beta zeolites in parallel with bulk rare-earth metal oxides.Good catalytic performance was achieved with all Lewis acidic rare-earth cations stabilized by zeolites and yttrium appeared to be the best metal choice.According to the results of several complementary techniques,i.e.,temperature-programmed surface reactions,in situ diffuse reflectance infrared Fourier transform spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,the reaction pathway and mechanism of the aldehyde self-aldol condensation over Y/Beta catalyst were studied in more detail.Density functional theory calculations revealed that aldol dehydration was the rate-limiting step.The hydroxyl group at the open yttrium site played an important role in stabilizing the transition state of the aldol dimer reducing the energy barrier for its hydration.Lewis acidic Y(OSi)(OH)2 stabilized by zeolites in open configurations were identified as the preferred active sites for the self-aldol condensation of aldehydes.展开更多
This paper determined cations and anions concentrations, Total Kjeldahl Nitrogen (TKN), and heavy metals content in sewage sludge collected from the drying beds of wastewater treatment plant in Gaza. The aim was to te...This paper determined cations and anions concentrations, Total Kjeldahl Nitrogen (TKN), and heavy metals content in sewage sludge collected from the drying beds of wastewater treatment plant in Gaza. The aim was to test the possibility of using this sewage sludge as an alternative source of mineral fertilizers. Many instruments were used in this work: flame photometry (K, Na), EDTA titration (Ca, Mg), the turbidity method () , spectrophotometer (turbidity), ascorbic acid method (orthophosphate), titrimetric method (Cl﹣), inductive coupled plasma analyzer (ICP, heavy metals). All the processes of experiments and analyses were described clearly for reference. Results showed that concentrations of Na﹢, K﹢, Ca2﹢ and Mg2﹢ were 28.93, 2.53, 271 and 177 mg/kg respectively whereas? were 0.434, 18.59, 0.87 and 0.026 g/kg respectively. The concentrations of Fe, Cu, Pb, Zn and Mn were 125.12, 172.56, 76.88, 218.73 and 157.56 mg/kg respectively. These results indicate that sewage sludge from Gaza contained high fractions of most plant nutrients accordingly, and it may be advantageous to use the sludge as a natural source of plant fertilizers.展开更多
High rainfall in subtropical regions can leach cation elements from ecosystems,which may limit plant growth.Plants often develop efficient resorption patterns to recycle elements,but there is relatively little availab...High rainfall in subtropical regions can leach cation elements from ecosystems,which may limit plant growth.Plants often develop efficient resorption patterns to recycle elements,but there is relatively little available information on this topic.In February 2012,a common garden was established in a subtropical forest by planting dominant trees from the area.Green and senescent leaves were sampled from 11 tree species.The concentrations of potassium(K),calcium(Ca),sodium(Na)and magnesium(Mg)were determined,and the resorption efficiencies were calculated.The results showed significant K,Na and Mg resorption in most of the investigated tree species,while Ca mainly displayed accumulation.Evergreen coniferous and evergreen broad-leaved trees(such as Cunninghamia lanceolata,Pinus massoniana,Cinnamomum camphora,and Michelia macclurei)exhibited relatively higher resorption efficiencies of K(39.0%-87.5%)and Na(18.3%-50.2%)than deciduous broad-leaved trees.Higher Mg resorption efficiencies(>50%)were detected in Liriodendron chinense,C.lanceolata and P.massoniana than in other trees.Overall,evergreen coniferous and evergreen broad-leaved trees could show higher cation resorption than deciduous broad-leaved trees.K and Mg resorption efficiencies and Ca accumulation decrease with increasing nutrient concentrations in green leaves.Our results emphasize that nutrient resorption patterns largely depend on elements and plant functions,which provides new insights into the nutrient use strategies of subtropical plants and a reference for the selection of suitable tree species in this region.展开更多
The existence of electrolytes in aquatic environment on the photocatalytic performance and coagulation of nanodispersed TiO2 hydrosol and the corresponding photocatalytic alteration were investigated by studying catio...The existence of electrolytes in aquatic environment on the photocatalytic performance and coagulation of nanodispersed TiO2 hydrosol and the corresponding photocatalytic alteration were investigated by studying cations(Na^+, K^+, Ca^2+, Mg^2+, and Al^3+).The photocatalysis reactions of nano TiO2 with different dosages of electrolytes were measured by monitoring the degradation of Rhodamine B(Rh B) under ultraviolet A(UV-A) irradiation over time.The results showed that the photocatalytic performance of TiO2 was improved by the presence of Al^3+, while the performance was impaired by the other tested cations.The negative influences of divalent ions on the photocatalytic performance of TiO2 were more significant than monovalent ions.The TiO2 sol dispersed stable at nano scale at low concentration of electrolyte(< 0.01 mol/L) with slight change of pH, and coagulated into micro sizes at high concentration of electrolytes(> 0.1 mol/L) with larger increase or decrease of pH.The positive effects of Al^3+on the photodegradation rate of Rh B might relate to the strong hydrolytic action of Al^3+in aquatic solutions.The photocatalytic processes of TiO2 in the presence of all ions followed the Langmuir-Hinshelwood model, and the reaction kinetic constant was increased with the decrease of pH caused by different cations.These work suggested a new perspective about the relationship between coagulation and photocatalytic performance of TiO2 hydrosols in electrolyte with hydrolysable cations, which demonstrated that TiO2 hydrosols may be suitable as photocatalysts in aquatic environments.展开更多
Fluorescence mode is influenced by the substituents, the polarity of the solvent, the steric factor and even the aggregation state of molecules in solvent under the testing environment. By comparing the fluorescent be...Fluorescence mode is influenced by the substituents, the polarity of the solvent, the steric factor and even the aggregation state of molecules in solvent under the testing environment. By comparing the fluorescent behavior of three anthracene derivatives, we observe that the hydrophobic interaction and steric effect in structures reduce fluorescence intensity, quantum yield and fluorescence lifetime. The emitting mode of two amphiphilic salts changes from aggregation emission in weak polar solvent to monomer emission in strong polar solvent and gives the similar variety in mixed solvent.展开更多
A method for rapid and simultaneous determination of multiple pyrrolidinium ionic liquid cations by ion chromatography with direct conductivity detection was developed.Chromatographic separations were performed on a c...A method for rapid and simultaneous determination of multiple pyrrolidinium ionic liquid cations by ion chromatography with direct conductivity detection was developed.Chromatographic separations were performed on a cation exchange column using ethylenediamine-acetonitrile as the mobile phase.The effects of chromatographic column and the mobile phase,as well as the column temperature on the retention of the cations were investigated.The retention rules of the cations under different chromatographic conditions were formulated.The retention of the cations followed the carbon number rule.The method has been successfully applied to the determination of three ionic liquids synthesized by a chemical laboratory.展开更多
Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate.Compared to the enantiomeric excess(e.e....Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate.Compared to the enantiomeric excess(e.e.)value(71.4%) obtained without the presence of metal cations,obvious e.e.enhancement(up to 82.5%)was resulted from the addition of Zn^(2+) but with a certain decrease in activity.The reaction parameters in the presence of Zn^(2+) were also studied.It was found that the Pt colloidal catalysts in the presence of metal cations performed very differently from that in the absence of metal cations.展开更多
基金financially supported by the Excellent Youth Scholars Program of State Key Laboratory of Complex Nonferrous Metal Resource Clean Utilization,Kunming University of Science and Technology,China(No.YXQN-2024003)the Central Government-Guided Local Science and Technology Development Fund Project,China(No.202407AB110022)。
文摘The rapid advancement of modern science and technology,coupled with the recent surge in new-energy electric vehicles,has significantly boosted the demand for lithium.This has promoted the development and efficient utilization of lepidolite as a lithium source.Therefore,the processes for the flotation of lepidolite have been studied in depth,particularly the development and use of lepidolite flotation collectors and the action mechanism of the collectors on the lepidolite surface.Based on the crystal-structure characteristics of lepidolite minerals,this review focuses on the application of anionic collectors,amine cationic collectors(primary amines,quaternary ammonium salts,ether amines,and Gemini amines),and combined collectors to the flotation behavior of lepidolite as well as the adsorption mechanisms.New directions and technologies for the controllable flotation of lepidolite are proposed,including process improvement,reagent synthesis,and mechanistic research.This analysis demonstrates the need for the further study of the complex environment inside lepidolite and pulp.By using modern analytical detection methods and quantum chemical calculations,research on reagents for the flotation of lepidolite has expanded,providing new concepts and references for the efficient flotation recovery and utilization of lepidolite.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.52202371 and 51902102)the Natural Science Foundation of Shandong Province(Nos.ZR202211230173,ZR2020QE066 and ZR2021QE200)+2 种基金the Opening Project of State Key Laboratory of Advanced Technology for Float Glass(No.2020KF08)the SDUT&Zibo City Integration Development Project(No.2021SNPT0045)the fellowship of China Postdoctoral Science Foundation(No.2020M672081).
文摘Transition metal carbonates(TMCs)hold great potential as high-performance electrodes for alkali metal-ion batteries,owing to multiple-ion storage mechanisms involving conversion process and electrocatalytic reaction.However,they still suffer from inferior electronic conductivity and volume variation during delithiation/lithiation.Heterostructure and heteroatoms doping offer immense promise in enhancing reaction kinetics and structural integrity,which unfortunately have not been achieved in TMCs.Herein,a unique TMCs heterostructure with Ni-doped MnCO_(3)as“core”and Mn-doped NiCO_(3)as“shell”,which is wrapped by graphene(NM@MN/RGO),is achieved by cations differentiation strategy.The formation process for core-shell NM@MN consists of epitaxial growth of NiCO_(3)from MnCO_(3)and synchronously mutual doping,owing to the similar crystal structures but different solubility product constant/formation energy of MnCO_(3)and NiCO_(3).In-situ electrochemical impedance spectroscopy,galvanostatic intermittent titration technique,differential capacity versus voltage plots,theoretical calculation and kinetic analysis reveal the superior electrochemical activity of the NM@MN/RGO to MnCO_(3)/RGO.The NM@MN/RGO shows excellent lithium storage properties(1013.4 mAh·g^(-1)at 0.1 A·g^(-1)and 760 mAh·g^(-1)after 1000 cycles at 2 A·g^(-1))and potassium storage properties(capacity decay rate of 0.114 mAh·g^(-1)per cycle).This work proposes an efficient cation differentiation strategy for constructing advanced TMC electrodes.
基金financially supported by the Key Fund Project of Tianjin Natural Science Foundation(24JCZDJC00510)the Fundamental Research Funds for the Central Universitiespartially supported by the U.S.Department of Energy under Contract No.DE-AC3608GO28308 with Alliance for Sustainable Energy,Limited Liability Company(LLC),the Manager and Operator of the National Renewable Energy Laboratory,through Grant No.DE-SC0020718。
文摘Incorporating organic bulky cations in the precursor or post-treatment to achieve two-dimensional/thr ee-dimensional(2D/3D)heterojunction is an effective strategy for enhancing the stability of perovskite materials.However,the issue of insufficient charge transport in 2D perovskites limits their development,and the fundamental mechanism of out-of-plane carrier transport remains unclear.This study designed and synthesized seven organic phenyl-core cations,differentiated at the 1-and 1,4-positions,and identified the impacts on the corresponding properties of the 2D crystalline perovskite.Shorter cations facilitated a more compact arrangement of adjacent inorganic layers,aligning to favor charge transport along the vertical direction.In addition,introducing high electronegativity led to increased intermolecular interactions,resulting in enhanced structural stability and improved phenyl ring π-orbital overlap and interlayer electron coupling,yielding efficient charge transport.Resilience to thermal stressing of the perovskite was strongly correlated with the carbon chain length of the spacer cations.The increase in cation length and the reduction in the rigidity of the amino-terminal both aided in the dispersion of thermal stress in the inorganic framework.Additional hydrogen bonding also contributed to mitigating structural disorder.
基金supported by the National Natural Science Foundation of China(Nos.21971080,22171098)supported by Chengdu Guibao Science&Technology Co.,Ltd.This work was also supported by the 111 Project(No.B17019)。
文摘The first-ever synthesis of the unknown furo[2,3:4,5]pyrimido[1,2-b]indazole skeleton was demonstrated based on the undiscovered tetra-functionalization of enaminones,with simple substrates and reaction conditions.The key to realizing this process lies in the multiple trapping of the in situ generated ketenimine cation by the 3-aminoindazole,which results in the formation of four new chemical bonds and two new rings in one pot.Moreover,the products of this new reaction were found to exhibit aggregationinduced emission(AIE)without modification.
基金supported by the National Natural Science Foundation of China(Nos.21925302,92250306)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB0450202)+1 种基金the Innovation Program for Quantum Science and Technology(2021ZD0303303)the National Key Research and Development Program of China(2018YFA0208702).
文摘Phonon coherence can reflect electron‒phonon coupling information and has been proven to modulate electronic states and charge transport.The manipulation of phonon coherence through spacer cation engineering in organic‒inorganic hybrid perovskites(OIHPs)has been extensively demonstrated;however,the underlying structural origin remains elusive at the molecular level.Herein,we present molecular structure and temperature-dependent coherent phonon studies via a combination of sum frequency generation vibrational spectroscopy(SFG-VS)and transient absorption spectroscopy(TAS).The conformational order of spacer cations dictates the coherent phonon oscillations in 2D OIHPs.Our study further analyzes the static order and dynamic disorder in 2D perovskites.This work provides molecular-level insights into the role of spacer cations in tuning structural order and may provide valuable guidance for advancing emergent optoelecltronics development.
基金supported by the National Natural Science Foundation of China(No.62175129)the Taishan Scholar of Shandong Province(No.tsqn202306014)the Qilu Young Scholar of Shandong University.
文摘The investigation of thermal transport properties of materials has become increasingly important in technological applications,including thermal management and energy conversion.Recently,ultrahigh or low thermal conductivity has been reported in nitride,boride,and chalcogenide by different strategies.However,the strategy to design oxide crystals with unique thermal properties is also a challenge.In this work,a new ternary oxide crystal Ga_(2)TeO_(6) is designed and expected to show high thermal conductivity due to its lone pairs-free octahedra connected along the caxis by sharing edges.The thermal conductivities of Ga_(2)TeO_(6) crystal are determined to be 19.2 and 23.9Wm^(-1) K^(-1) along the a-and c-axis directions at 323 K,respectively,which are significantly higher than those of most reported oxide crystals.First-principles calculations and crystal structure analyses reveal that the Ga_(2)TeO_(6) crystal shows high sound velocity and weak lattice anharmonicity due to lone pairs-free octahedra and highly symmetric group arrangement.The results suggest that much attention must be paid to the polyhedron with lone pairs and its arrangement in materials design to balance the functions and thermal properties.
基金Supported by the National Natural Science Foundation of China(No.41776177)the Qingdao Marine Science and Technology Pilot National Laboratory Fund(Nos.2016ASKJ14,QNLM2016ORP0403)。
文摘Mussels are common anchoring organisms that adhere to the surfaces of various substrates with their byssus.The adhesion of mussel to substrates is contingent upon the presence of mussel foot proteins,of which Mytilus edulis foot protein-1(Mefp-1)has been identified as the most abundant protein.It has been found that lipids are involved in the mussel adhesion process and can facilitate Mefp-1adhesion.In this research,the adhesion behavior of Mefp-1 on various substrate surfaces under the effect of typical seawater cations with or without the presence of lipid were investigated using a quartz crystal microbalance with dissipation(QCM-D).Results indicate that the presence of cations Ca^(2+),Mg^(2+),Na^(+),and K^(+)leads to varying degrees of reduction in the adhesion performance of Mefp-1 on different substrates.The degree of this reduction,however,was much alleviated in the presence of palmitic acid,which is involved in the mussel adhesion process.Therefore,the involvement of palmitic acid is advantageous for mussel protein adhesion to the substrate surface in the marine environment.This study illustrated the significant contribution of palmitic acid to mussel adhesion,which can help to better understand biofouling mechanisms and develop biomimetic adhesive materials.
基金supported by the National Natural Science Foundation of China (No.20707037,40603023)
文摘The mutual effects of metal cations （Cu2＋, Pb2＋, Zn2＋, and Cd2＋） and p-nitrophenol （NP） on their adsorption desorption behavior onto wheat ash were studied. Results suggested that Cu2＋, Pb2＋, and Zn2＋ diminished the adsorption and increased the desorption of NP remarkably, while Cd2＋ had no such effect. In contrast, NP diminished the adsorption of Cu2＋, Pb2＋, and Zn2＋ onto ash, however, this suppression effect depended on the initial concentrations of metal cations. NP had no effect on Cd〉 adsorption on ash. Fourier transform infrared （FT-IR） and X-ray absorption spectroscopic （XAS） studies suggested the following mechanisms responsible for the metal suppression effect on NP adsorption： （1） large hydrated Cu2＋, Pb2＋, and Zn〉 shells occupied the surface of ash and prevent nonspecific adsorption of NP onto ash surface; （2） Cu2＋, Pb2＋, and Zn2＋ may block the micropores of ash, resulting in decreased adsorption of NP; （3） cornplexation of Cu2＋, Pb2＋, and Zn2＋ was likely via carboxyl, hydroxylic and phenolic groups of wheat ash and these same groups may also react with NP during adsorption. As a ＂soft acid＂, Cd2＋ is less efficient in the complexation of oxygencontaining acid groups than Cu2＋, Pb2＋, and Zn2＋. Thus, Cd2＋ had no effect on the adsorption of NP on wheat ash.
基金Project supported by the National Natural Science Foundation of China (Nos. 30590381-03 and 30570350).
文摘Information on the distribution patterns of soil water content （SWC）, soil organic matter （SOM）, and soil exchangeable cations （SEC） is important for managing forest ecosystems in a sustainable manner. This study investigated how SWC, SOM, and SEC were influenced in forests along a successional gradient, including a regional climax （monsoon evergreen broad-leaved forest, or MEBF）, a transitional forest （coniferous and broad-leaved mixed forest, or MF）, and a pioneer forest （coniferous Masson pine （Pinus rnassoniana） forest, or MPF） of the Dinghushan Biosphere Reserve in the subtropical region of southern China. SWC, SOM, and SEC excluding Ca^2＋ were found to increase in the soil during forest succession, being highest in the top soil layer （0 to 15 cm depth） except for Na^＋. The differences between soil layers were largest in MF. This finding also suggested that the nutrients were enriched in the topsoil when they became increasingly scarce in the soil. There were no significant differences （P = 0.05） among SWC, SOM, and SEC. A linear, positive correlation was found between SWC and SOM. The correlation between SOM and cation exchange capacity （CEC） was statistically significant, which agreed with the theory that the most important factor determining SEC is SOM. The ratio of K^＋ to Na^＋ in the topsoil was about a half of that in the plants of each forest. MF had the lowest exchangeable Ca^2＋ concentration among the three forests and Ca^2＋：K^＋ in MPF was two times higher than that in MF. Understanding the changes of SWC, SOM, and CEC during forest succession would be of great help in protecting all three forests in southern China.
基金supported by the National Key Research and Development Program of China(2017YFA0204600)the National Science Fund for Distinguished Young Scholars(51625102)+2 种基金the National Natural Science Foundation of China(51971065)the Innovation Program of Shanghai Municipal Education Commission(2019–01–07–00–07-E00028)the financial support from ARC(DP170101773)。
文摘MgH_(2) is regarded as a potential hydrolysis material for the hydrogen generation due to its high theoretical hydrogen yield,abundant source on earth and environmentally friendly hydrolysates.However,the quickly formed passive magnesium hydroxide layer on the surface of MgH_(2) will hinder its further hydrolysis reaction,leading to sluggish reaction kinetics and low H_(2) yield.In this paper,we explore the improvement of different anions and cations in solutions for the hydrolysis of MgH_(2).It is found that the cations in the solution promote the reaction rate of MgH_(2) hydrolysis through the hydrolysate-induced growth effect,among which the fastest hydrogen yield can get 1664 m L/g within a few minutes in the Fe_(2)(SO_(4))_(3) solution.As for the anions,it enables different microstructures of the Mg(OH)_(2) hydrolysate which give rise to enhanced water utilization.Specially,for the mixed 0.5 M MgCl_(2)+0.05 M MgSO_(4) solution,the water utilization rate attains the optimum value of 51.3%,much higher than that of the single MgCl_(2) or MgSO_(4) solutions.These findings are of great significance for the application of MgH_(2) hydrolysis as hydrogen generation.
基金This project was financially supported by the National Natural Science Foundation of China (No. 50274010)the National High-Tech Research and Development Program of China ("863" Program, No. 2002AA-302404).
文摘The effects of alkaline cations （M^＋ = Li^＋, Na^＋, K^＋, Cs^＋）on the electrochemical synthesis of polyaniline were carfled out under cyclovoltammetric conditions using nitrates of Li^＋, Na^＋, K^＋, and Cs^＋ as the supporting electrolytes. The results show that the oxidation potentials of aniline in the electrolytes decrease as the protonation extent of aniline decreases from the fast scan, which is caused by the decrease of the ionic radius of alkaline metal ions at the same concentration of alkaline cations. With the scan number increasing, the deposit charge Q as the characteristic growth function also depends on the protonation of aniline, and it increases with the ionic radius of alkaline cations increasing. SEM images show the effect of alkaline cations on the morphology of polyaniline. It is clear that the ionic mobility of alkaline cations is further lower than that of W. Alkaline cations and counter-ions were the species responsible for the enhancement of Pani electrosynthesis. Therefore, this is exactly what SEM images show： a relatively rough fibrous structure in the case of Pani-H^＋ suggesting a sponge-like structure and a highly orderly fiber-like structure in the case of Pani-M^＋.
基金financially supported by International Academic Cooperation and Exchange Program of Shanghai Science and Technology Committee(18160723600)Scientific Research and Technology Development Plan of Guangxi(GUIKE AD17195084)。
文摘It is well-known that the electrolytes can influence the electrochemical reduction of carbon dioxide(ERCO2)in aqueous media.In this work,we explore the effects of alkali metal cations and anions(Li^+,Na^+,K^+,Rb^+,Cs^+,HCO3^-,Cl^-,Br^-,I^-)on the current density and product selectivity for the ERCO2 into formic acid(HCOOH)on the SnO2/carbon paper(Sn O2/C)electrode.Results of the ERCO2 experiments show that for the cations,the promotion effects on current density and faradaic efficiencies(FEs)are in the order of Li^+b Na^+b K^+b Cs^+b Rb^+.For the anions,the current density values are in the order of Na HCO3 b NaClb Na Br b Na I and KHCO3 b KCl≈KI b KBr,respectively,and that on the FEs for the formation of the HCOOH(FEHCOOH)is HCO3-b Cl-b Br-b I-.Based on this result,the effects of alkali metal cations and anions on ERCO2 are discussed.
基金Funded by the National Natural Science Foundation of China(Nos.52008002,U21A20149,U2006224 and 51978352)the Open Foundation of the State Key Laboratory of Silicate Materials for Architectures(Wuhan University of Technology)(No.SYSJJ2022-22)Anhui Province Engineering Laboratory of Advanced Building Materials(No.JZCL2202ZR)。
文摘Molecular dynamics simulation was utilized to investigate the transport and adsorption of chloride in the nanopore of calcium aluminosilicate hydrate(C-A-S-H)with associated cation types of Ca,Mg,Na and K.The local ionic structure,atomic dynamics and bond stability were analyzed to elucidate the interaction between cations and chloride ions.The results show that interfacial chloride is absorbed through the ion pairing formation in the vicinity of C-A-S-H substrate.Interfacial cations can simultaneously interact aluminosilicate chains,water molecules and Cl^(-)ions,which restrict the motion of interfacial Cl^(-)ions.Pore solution chloride can be immobilized through the solvation effect of cations.Cations along with their hydration shell can connect to neighboring Cl^(-)ions to decrease their mobility.Owing to the varied ionic chemistry,cations show different interaction strength with neighboring water molecules and anions,which determines the chloride transport behavior in the nanopore of C-A-S-H.The chloride immobilization capacity of C-A-S-H nanopore with different associated cations is listed in following order:Mg^(2+)Ca^(2+)<Na^(+)≈K^(+),which agrees reasonably with previous experiments.
文摘The self-aldol condensation of aldehydes was investigated with rare-earth cations stabilized by[Si]Beta zeolites in parallel with bulk rare-earth metal oxides.Good catalytic performance was achieved with all Lewis acidic rare-earth cations stabilized by zeolites and yttrium appeared to be the best metal choice.According to the results of several complementary techniques,i.e.,temperature-programmed surface reactions,in situ diffuse reflectance infrared Fourier transform spectroscopy,ultraviolet-visible diffuse reflectance spectroscopy,the reaction pathway and mechanism of the aldehyde self-aldol condensation over Y/Beta catalyst were studied in more detail.Density functional theory calculations revealed that aldol dehydration was the rate-limiting step.The hydroxyl group at the open yttrium site played an important role in stabilizing the transition state of the aldol dimer reducing the energy barrier for its hydration.Lewis acidic Y(OSi)(OH)2 stabilized by zeolites in open configurations were identified as the preferred active sites for the self-aldol condensation of aldehydes.
文摘This paper determined cations and anions concentrations, Total Kjeldahl Nitrogen (TKN), and heavy metals content in sewage sludge collected from the drying beds of wastewater treatment plant in Gaza. The aim was to test the possibility of using this sewage sludge as an alternative source of mineral fertilizers. Many instruments were used in this work: flame photometry (K, Na), EDTA titration (Ca, Mg), the turbidity method () , spectrophotometer (turbidity), ascorbic acid method (orthophosphate), titrimetric method (Cl﹣), inductive coupled plasma analyzer (ICP, heavy metals). All the processes of experiments and analyses were described clearly for reference. Results showed that concentrations of Na﹢, K﹢, Ca2﹢ and Mg2﹢ were 28.93, 2.53, 271 and 177 mg/kg respectively whereas? were 0.434, 18.59, 0.87 and 0.026 g/kg respectively. The concentrations of Fe, Cu, Pb, Zn and Mn were 125.12, 172.56, 76.88, 218.73 and 157.56 mg/kg respectively. These results indicate that sewage sludge from Gaza contained high fractions of most plant nutrients accordingly, and it may be advantageous to use the sludge as a natural source of plant fertilizers.
基金The study was supported by grants from National Natural Science Foundation of China(Grants 31800521,31800373 and 31922052).Datasets for this research are included in this paper。
文摘High rainfall in subtropical regions can leach cation elements from ecosystems,which may limit plant growth.Plants often develop efficient resorption patterns to recycle elements,but there is relatively little available information on this topic.In February 2012,a common garden was established in a subtropical forest by planting dominant trees from the area.Green and senescent leaves were sampled from 11 tree species.The concentrations of potassium(K),calcium(Ca),sodium(Na)and magnesium(Mg)were determined,and the resorption efficiencies were calculated.The results showed significant K,Na and Mg resorption in most of the investigated tree species,while Ca mainly displayed accumulation.Evergreen coniferous and evergreen broad-leaved trees(such as Cunninghamia lanceolata,Pinus massoniana,Cinnamomum camphora,and Michelia macclurei)exhibited relatively higher resorption efficiencies of K(39.0%-87.5%)and Na(18.3%-50.2%)than deciduous broad-leaved trees.Higher Mg resorption efficiencies(>50%)were detected in Liriodendron chinense,C.lanceolata and P.massoniana than in other trees.Overall,evergreen coniferous and evergreen broad-leaved trees could show higher cation resorption than deciduous broad-leaved trees.K and Mg resorption efficiencies and Ca accumulation decrease with increasing nutrient concentrations in green leaves.Our results emphasize that nutrient resorption patterns largely depend on elements and plant functions,which provides new insights into the nutrient use strategies of subtropical plants and a reference for the selection of suitable tree species in this region.
基金supported by the National Natural Science Foundation of China (Nos.1706222, 51708108 and 51808188)the China Scholarship Council (No.201806090146)+1 种基金China Postdoctoral Science Foundation (No.2018M642151)State Key Laboratory of High Performance Civil Engineering Materials Open Fund (No.2018CEM001).
文摘The existence of electrolytes in aquatic environment on the photocatalytic performance and coagulation of nanodispersed TiO2 hydrosol and the corresponding photocatalytic alteration were investigated by studying cations(Na^+, K^+, Ca^2+, Mg^2+, and Al^3+).The photocatalysis reactions of nano TiO2 with different dosages of electrolytes were measured by monitoring the degradation of Rhodamine B(Rh B) under ultraviolet A(UV-A) irradiation over time.The results showed that the photocatalytic performance of TiO2 was improved by the presence of Al^3+, while the performance was impaired by the other tested cations.The negative influences of divalent ions on the photocatalytic performance of TiO2 were more significant than monovalent ions.The TiO2 sol dispersed stable at nano scale at low concentration of electrolyte(< 0.01 mol/L) with slight change of pH, and coagulated into micro sizes at high concentration of electrolytes(> 0.1 mol/L) with larger increase or decrease of pH.The positive effects of Al^3+on the photodegradation rate of Rh B might relate to the strong hydrolytic action of Al^3+in aquatic solutions.The photocatalytic processes of TiO2 in the presence of all ions followed the Langmuir-Hinshelwood model, and the reaction kinetic constant was increased with the decrease of pH caused by different cations.These work suggested a new perspective about the relationship between coagulation and photocatalytic performance of TiO2 hydrosols in electrolyte with hydrolysable cations, which demonstrated that TiO2 hydrosols may be suitable as photocatalysts in aquatic environments.
基金Supported by the Natural Science Foundation of Gansu(2016 Gansu Science and Technology Support Project)(1610RJZA072)the Key Laboratory of Traditional Chinese Medicine Quality and Standard,Gansu Province(Gansu University of Chinese Medicine)(ZYZL18-006)
文摘Fluorescence mode is influenced by the substituents, the polarity of the solvent, the steric factor and even the aggregation state of molecules in solvent under the testing environment. By comparing the fluorescent behavior of three anthracene derivatives, we observe that the hydrophobic interaction and steric effect in structures reduce fluorescence intensity, quantum yield and fluorescence lifetime. The emitting mode of two amphiphilic salts changes from aggregation emission in weak polar solvent to monomer emission in strong polar solvent and gives the similar variety in mixed solvent.
基金supported by the Natural Science Foundation of Heilongjiang Province(No.B200909)the Program for Scientific and Technological Innovation Team Construction in Universities of Heilongjiang Province(No.2011TD010)
文摘A method for rapid and simultaneous determination of multiple pyrrolidinium ionic liquid cations by ion chromatography with direct conductivity detection was developed.Chromatographic separations were performed on a cation exchange column using ethylenediamine-acetonitrile as the mobile phase.The effects of chromatographic column and the mobile phase,as well as the column temperature on the retention of the cations were investigated.The retention rules of the cations under different chromatographic conditions were formulated.The retention of the cations followed the carbon number rule.The method has been successfully applied to the determination of three ionic liquids synthesized by a chemical laboratory.
基金The project is partially supported by the Natural Science Foundation of Hubei Province Contract(No.2003ABA072)
文摘Modification of transition metal cations to polymer-stabilized Pt colloidal clusters modified with cinchonidine was studied in enantioselective hydrogenation of methyl pyruvate.Compared to the enantiomeric excess(e.e.)value(71.4%) obtained without the presence of metal cations,obvious e.e.enhancement(up to 82.5%)was resulted from the addition of Zn^(2+) but with a certain decrease in activity.The reaction parameters in the presence of Zn^(2+) were also studied.It was found that the Pt colloidal catalysts in the presence of metal cations performed very differently from that in the absence of metal cations.
