CuInSe_(2) is an N-type diamond-like semiconductors thermoelectric candidate for power generation at medium temperature with its environmentally friendly and cost-effective properties.However,the intrinsic high therma...CuInSe_(2) is an N-type diamond-like semiconductors thermoelectric candidate for power generation at medium temperature with its environmentally friendly and cost-effective properties.However,the intrinsic high thermal conductivity of CuInSe_(2) limits the enhancement of its thermoelectric performance.Herein,we investigate the thermoelectric performance of N-type CuInSe_(2) materials by incorporating ZnSe through a solid solution strategy.A series of(CuInSe_(2))_(1-x)(ZnSe)_(x)(x=0.0,0.2,0.4,0.6,0.8,1.0)samples were synthesized,forming continuous solid solutions,while introducing minor porosity.ZnSe solid solution effectively reduces the lattice thermal conductivity of the CuInSe_(2) matrix at near-room temperatures,but has a weaker effect at higher temperatures.Due to the intrinsic low carrier concentration of the system,resulting in high resistivity,the maximum figure of merit(ZT)of(CuInSe_(2))0.8(ZnSe)0.2 reaches 0.08 at 773 K.Despite the relatively low ZT,the solid solution strategy proves effective in reducing the lattice thermal conductivity near-room temperature and offers potential for cost-effective thermoelectric materials.展开更多
Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)ca...Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)capture performances,aswell as on their catalytic properties for H_(2)production via dry reforming of methane(DRM).The crystal structures of Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples were determined through X-ray diffraction,which confirmed the integration of nickel ions up to a concentration around 20 mol%,meanwhile beyond this value,a secondary phase was detected.These results were supported by XPS and TEM analyses.Then,dynamic and isothermal thermogravimetric analyses of CO_(2)capture revealed that Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples exhibited good CO_(2)chemisorption efficiencies,similarly to the pristine Li_(6)ZnO_(4)chemisorption trends observed.Moreover,a kinetic analysis of CO_(2)isothermal chemisorptions,using the Avrami-Erofeev model,evidenced an increment of the constant rates as a function of the Ni content.Since Ni^(2+)ions incorporation did not reduce the CO_(2)capture efficiency and kinetics,the catalytic properties of thesematerialswere evaluated in the DRM process.Results demonstrated that nickel ions favored hydrogen(H_(2))production over the pristine Li_(6)ZnO_(4)phase,despite a second H2 production reaction was determined,methane decomposition.Thereby,Li_(6)Zn_(1-x)Ni_(x)O_(4)ceramics can be employed as bifunctional materials.展开更多
Most studies have shown that oxygen vacancies on Ce_(x)Zr_(1-x)O_(2) solid solution are important for enhancing the catalytic oxidation performance.However,a handful of studies investigated the different roles of surf...Most studies have shown that oxygen vacancies on Ce_(x)Zr_(1-x)O_(2) solid solution are important for enhancing the catalytic oxidation performance.However,a handful of studies investigated the different roles of surface and subsurface oxygen vacancies on the performance and mechanisms of catalysts.Herein,a series of zirconium doping on CeO_(2) samples(CeO_(2),Ce_(0.95)Zr_(0.05)O_(2),and Ce_(0.8)5Zr_(0.15)O_(2))with various surface-to-subsurface oxygen vacancies ratios have been synthesized and applied in toluene catalytic oxidation.The obtained Ce_(0.95)Zr_(0.05)O_(2) exhibits an excellent catalytic performance with a 90%toluene conversion at 295℃,which is 68℃lower than that of CeO_(2).Additionally,the obtained Ce_(0.95)Zr_(0.05)O_(2)catalyst also exhibited good catalytic stability and water resistance.The XRD and HRTEM results show that Zr ions are incorporated into CeO_(2) lattice,forming Ce_(x)Zr_(1-x)O_(2) solid solution.Temperature-programmed experiments reveal that Ce_(0.95)Zr_(0.05)O_(2) shows excellent lowtemperature reducibility and abundant surface oxygen species.In-situ DRIFTS tests were used to probe the reaction mechanism,and the function of Zr doping in promoting the activation of oxygen was further determined.Density functional theory(DFT)calculations indicate that the vacancy formation energy and O_(2) adsorption energy are both lower on Ce_(0.95)Zr_(0.05)O_(2),confirming the reason for its superior catalytic performance.展开更多
To separate the phosphorus-containing phase from steel slag,the effects of B_(2)O_(3)and Na_(2)B_(4)O_(7)on the enrichment of phosphorus-containing phases in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2)(C_(2)S–C_(3)P)solid solu...To separate the phosphorus-containing phase from steel slag,the effects of B_(2)O_(3)and Na_(2)B_(4)O_(7)on the enrichment of phosphorus-containing phases in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2)(C_(2)S–C_(3)P)solid solution were comparatively analyzed through theoretical calculations and experimental investigations.The results indicate that the optimum reaction temperature between B_(2)O_(3)and C_(2)S–C_(3)P is 800℃.The phase compositions of C_(2)S–C_(3)P equilibrium system with 5 wt.%B_(2)O_(3)at 800℃ included Ca_(3)(PO_(4))_(2),CaSiO_(3)and Ca11B_(2)Si_(4)O_(22),among which the content of Ca_(3)(PO_(4))_(2)was the highest.For C_(2)S–C_(3)P with 5 wt.%Na_(2)B_(4)O_(7)equilibrium system,Ca_(3)(PO_(4))_(2),CaSiO_(3),Ca11B_(2)Si_(4)O_(22)and Na_(2)Ca_(2)P_(2)O_(8)were independent at 390–690℃.Ca_(3)(PO_(4))_(2)and Ca_(2)SiO_(4)precipitated in the solid solution when the addition of B_(2)O_(3)was more than 6 wt.%,and the content of Ca_(3)(PO_(4))_(2)raised with the increase in the addition of B_(2)O_(3).The main phases in the C_(2)S–C_(3)P solid solution with Na_(2)B_(4)O_(7)were(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],Ca_(2)SiO_(4)and Na_(3)Ca_(6)(PO_(4))_(5)at 650℃.And when the addition of Na_(2)B_(4)O_(7)exceeded 6 wt.%,the content of Na_(3)Ca_(6)(PO_(4))_(5)increased significantly.There was no precipitation of Ca_(3)(PO_(4))_(2)or boron-containing phase in the samples with Na_(2)B_(4)O_(7),but a small proportion of Ca_(3)(PO_(4))_(2)transformed into(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],and Ca^(2+)was partially replaced by Na^(+)to generate Na_(3)Ca_(6)(PO_(4))_(5).As a result,the temperature for Na_(2)B_(4)O_(7)to enrich the phosphorus-containing phase in C_(2)S–C_(3)P solid solution was lower than that for B_(2)O_(3).However,the grade of the phosphorus-containing phase for Na_(2)B_(4)O_(7)was lower than that for B_(2)O_(3).展开更多
The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd...The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions,which possesses a cubic spinel structure with Fd3m space group.The formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions induces the obvious increase of long afterglow near infrared luminescence excited by low-dose X-ray,When the content of doped Cd^(2+)reaches 0.1,the low-dose X-ray induced long afterglow NIR luminescence is the maximum.More importantly,only 5 s Xray irradiation can induce more than 6 h NIR afterglow emission,of which the afterglow luminescent intensity is still 5 times stronger than the background intensity after 6 h.The thermoluminescent results show that under the 5 s exposure of X-ray,the trap density of Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):Cr^(3+)is much higher than that of ZnGa_(2)O_(4):Cr^(3+).The replacement of Cd^(2+)ions with large radius at Zn^(2+)sites causes the increase of de fects and dislocations,which results in the obvious increase of trap co ncentrations.And the addition of high-z number elements Cd^(2+)would enhance the X-ray absorption of the solid solutions,which thus can be easily excited by low-dose X-ray.Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):1%Cr^(3+)solid solution is a potential candidate of lowdose X-ray induced long afterglow luminescent materials.展开更多
Red mud is an important secondary resource for scandium production.The red mud leaching solution containing scandium in this study was derived from environmentally friendly ammonium sulfate roasting and water leaching...Red mud is an important secondary resource for scandium production.The red mud leaching solution containing scandium in this study was derived from environmentally friendly ammonium sulfate roasting and water leaching process.A synergistic extraction with a mixture of di(2-ethylhexyl)phosphate acid(D2EHPA)and tributyl phosphate(TBP)for recovery of scandium from red mud leaching solution is proposed.The effects of D2EHPA concentration,H_(2)SO_(4)concentration,rare earth elements,dosage of TBP,phase ratio(A/O),contact time and H_(2)O_(2)concentration on scandium extraction were investigated.The results show that more than 99%scandium is extracted under the optimal conditions while Fe,Al,Ti,Ca and rare earth elements(Ce,Y,La,Nd,Er,etc.)are hardly extracted.The stripping efficiency of Sc reaches above 92.37%under the optimal stripping conditions of 5 mol/L NaOH with an A/O of 1 at 90℃for 30 min.The proposed technology could provide an effective method for extraction of scandium from red mud leaching solution.展开更多
For a highly efficient recycling of a wastewater containing a high concentration of MgCl_(2),Al(Ⅲ)and P507 were scheduled to be removed in advance.In this study,the in-situ removal of Al(Ⅲ)and P507 from a high conce...For a highly efficient recycling of a wastewater containing a high concentration of MgCl_(2),Al(Ⅲ)and P507 were scheduled to be removed in advance.In this study,the in-situ removal of Al(Ⅲ)and P507 from a high concentration MgCl_(2)solution at different pH values and Al/P molar ratios was investigated.The results showed that P507 formed organic complexes of Al_(x)(OH)_y^(Z+)-P507 at pH of 2.0-4.0.At pH of 4.0-5.0,Al(Ⅲ)precipitated and transferred into Al(OH)_(3)with a flocculent amorphous morphology.Active sites on the Al(OH)_(3)surface enhanced the removal efficiency of P507.At pH of 6.0-6.5,Al(Ⅲ)and Mg(Ⅱ)formed layered crystalline Al(OH)_(3)and MgAl_(2)(OH)_(8with)small pore channels and fewer active sites,resulting in a reduced removal efficiency of P507.When the Al/P molar ratio exceeded 13 and the pH was between 4.0 and 5.0,the removal rates of both Al(Ⅲ)and P507 were higher than98%,while the concentration loss of Mg(Ⅱ)was only 0.2%-0.9%.展开更多
Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and on...Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.展开更多
With the development of vanadium redox flow battery technology,the demand for pure vanadium is rapidly increasing.The separation of vanadium from vanadium-chromium leaching solutions are critical step in the productio...With the development of vanadium redox flow battery technology,the demand for pure vanadium is rapidly increasing.The separation of vanadium from vanadium-chromium leaching solutions are critical step in the production of purity-vanadium.This study presents an innovative adsorption process that utilizes amorphous ZrO_(2)(AZrO) for the selective separation of V(Ⅴ) and Cr(Ⅵ).In this process,a high adsorption capacity for V(V) at 64.5 mg·g^(-1) was achieved,while the capacity for Cr(Ⅵ) is relatively low at 24.1 mg·g^(-1),demonstrating good separation performance.This is mainly caused by the large specific surface area and mesoporous structure,which are favorable for molecular diffusion and mass transfer.The kinetic analysis shows that the adsorption process follows pseudo-second-order kinetic process with chemisorption being the rate-controlling process.AZrO showed excellent separation performance in mixed solutions over a wide range of concentrations.After five cycles,AZrO retained over 73% of its capacity,indicating good stability.In mixed solutions containing up to 40 g·L^(-1) of V(Ⅴ) and 3 g·L^(-1) of Cr(Ⅵ),the innovative adsorption process successfully achieved effective separation and purification.By an adsorption-desorption process using 0.1 mol·L^(-1) NaOH,a 99.02% V(Ⅴ)-rich solution was obtained from a high concentration sodium vanadium slag leaching solution,demonstrating its effectiveness for practical industrial applications.展开更多
The blockchain trilemma—balancing decentralization,security,and scalability—remains a critical challenge in distributed ledger technology.Despite significant advancements,achieving all three attributes simultaneousl...The blockchain trilemma—balancing decentralization,security,and scalability—remains a critical challenge in distributed ledger technology.Despite significant advancements,achieving all three attributes simultaneously continues to elude most blockchain systems,often forcing trade-offs that limit their real-world applicability.This review paper synthesizes current research efforts aimed at resolving the trilemma,focusing on innovative consensus mechanisms,sharding techniques,layer-2 protocols,and hybrid architectural models.We critically analyze recent breakthroughs,including Directed Acyclic Graph(DAG)-based structures,cross-chain interoperability frameworks,and zero-knowledge proof(ZKP)enhancements,which aimto reconcile scalability with robust security and decentralization.Furthermore,we evaluate the trade-offs inherent in these approaches,highlighting their practical implications for enterprise adoption,decentralized finance(DeFi),and Web3 ecosystems.By mapping the evolving landscape of solutions,this review identifies gaps in currentmethodologies and proposes future research directions,such as adaptive consensus algorithms and artificial intelligence-driven(AI-driven)governance models.Our analysis underscores that while no universal solution exists,interdisciplinary innovations are progressively narrowing the trilemma’s constraints,paving the way for next-generation blockchain infrastructures.展开更多
CO_(2)reduction by CH4(CRM)to produce fuel is of great significance for solar energy storage and eliminating greenhouse gas.Herein,the catalyst of ultrafine Ni nanoparticles supported on CeZrNiO_(2)solid solution(Ni@C...CO_(2)reduction by CH4(CRM)to produce fuel is of great significance for solar energy storage and eliminating greenhouse gas.Herein,the catalyst of ultrafine Ni nanoparticles supported on CeZrNiO_(2)solid solution(Ni@CZNO)was synthesized by the sol-gel method.High yield of H_(2)and CO(58.0 and 69.8 mmol min^(-1)g^(-1))and excellent durability(50 h)were achieved by photothermal catalytic CRM merely under focused light irradiation.Structural characterization and DFT calculations reveal that CZNO has rich oxygen vacancies that can adsorb and activate CO_(2)to produce reactive oxygen species.Oxygen species are transferred to ultrafine Ni nanoparticles through the rich Ni-CZNO interface to accelerate carbon oxidation,thereby maintaining the excellent catalytic stability of the catalyst.Moreover,the experimental results reveal that light irradiation can not only enhance the photothermal catalytic CRM activity through photothermal conversion and molecular activation,but also improve the stability by increasing the concentration of oxygen vacancies and inhibiting CO disproportionation.展开更多
This paper studies the(2+1)-dimensional Hirota-Satsuma-Ito equation.Based on an associated Hirota bilinear form,lump-type solution,two types of interaction solutions,and breather wave solution of the(2+1)-dimensional ...This paper studies the(2+1)-dimensional Hirota-Satsuma-Ito equation.Based on an associated Hirota bilinear form,lump-type solution,two types of interaction solutions,and breather wave solution of the(2+1)-dimensional Hirota-Satsuma-Ito equation are obtained,which are all related to the seed solution of the equation.It is interesting that the rogue wave is aroused by the interaction between one-lump soliton and a pair of resonance stripe solitons,and the fusion and fission phenomena are also found in the interaction between lump solitons and one-stripe soliton.Furthermore,the breather wave solution is also obtained by reducing the two-soliton solutions.The trajectory and period of the one-order breather wave are analyzed.The corresponding dynamical characteristics are demonstrated by the graphs.展开更多
For the (2 + 1)-dimensional nonlinear dispersive Boussinesq equation, by using the bifurcation theory of planar dynamical systems to study its corresponding traveling wave system, the bifurcations and phase portraits ...For the (2 + 1)-dimensional nonlinear dispersive Boussinesq equation, by using the bifurcation theory of planar dynamical systems to study its corresponding traveling wave system, the bifurcations and phase portraits of the regular system are obtained. Under different parametric conditions, various sufficient conditions to guarantee the existence of analytical and non-analytical solutions of the singular system are given by using singular traveling wave theory. For certain special cases, some explicit and exact parametric representations of traveling wave solutions are derived such as analytical periodic waves and non-analytical periodic cusp waves. Further, two-dimensional wave plots of analytical periodic solutions and non-analytical periodic cusp wave solutions are drawn to visualize the dynamics of the equation.展开更多
Aqueous zinc(Zn)-ion batteries(AZIBs)have gained significant interest in energy storage due to several unique advantages.Utilizing waterbased electrolytes enhances environmental sustainability,while the abundance and ...Aqueous zinc(Zn)-ion batteries(AZIBs)have gained significant interest in energy storage due to several unique advantages.Utilizing waterbased electrolytes enhances environmental sustainability,while the abundance and affordability of Zn offer economic benefits.Manganese(Mn)-based materials,commonly used as cathodes in these batteries,provide high theoretical capacity,high electrical conductivity,and good structural stability.However,these materials suffer from capacity degradation over repeated cycles due to structural collapse and limited conductivity.To address this problem,we synthesized a magnesium(Mg)-and Mn-based composite,Mg^(2+)-Mn_(3)O_(4),using the hydrothermal method with an optimized amount of ammonium hydroxide(NH_(4)OH)solution.This approach effectively stabilizes the structure during cycling,enhancing both capacity retention and conductivity.The Zn^(2+)/H+intercalation/deintercalation process was confirmed by experimental results and ex-situ X-ray diffraction analysis,which demonstrates that Mg^(2+),along with optimized NH_(4)OH amount,prevents structural collapse and improves conductivity.Under optimal process conditions,the composite electrode(Mg^(2+)-Mn_(3)O_(4)–8 ml)achieved a capacity of 173.58 mA h g^(-1) at 0.5 A g^(-1),with excellent rate performance of 71.39 mA h g^(-1) at 10 A g^(-1).Remarkably,even at 5 A g^(-1),the electrode maintained a capacity of 86.87 mA h g^(-1) over 2100 cycles,underscoring the role of Mg^(2+)and NH_(4)OH in enhancing the reversible insertion/extraction stability of Zn^(2+)in Mn-based layered materials.This study presents a novel strategy for metal-ion incorporation in Mn-based AZIBs,offering insights into the optimization of cathode materials and advancing research on associated storage mechanisms.展开更多
The ammonium salt precipitation method is frequently utilized for extracting vanadium from the leaching solution obtained through sodium roasting of vanadium slag.However,Na^(+)and NH_(4)^(+)ions in the vanadium preci...The ammonium salt precipitation method is frequently utilized for extracting vanadium from the leaching solution obtained through sodium roasting of vanadium slag.However,Na^(+)and NH_(4)^(+)ions in the vanadium precipitation solution can not be effectively separated,leading to a large amount of ammonia-nitrogen wastewater which is difficult to treat.In this study,the manganese salt pretreatment process is used to extract vanadium from a sodium roasting leaching solution,enabling the separation of vanadium and sodium.The vanadium extraction product of manganese salt is dissolved in acid to obtain vanadium-containing leaching solution,then vanadium is extracted by hydrolysis and vanadium precipitation,and V_(2)O_(5)is obtained after impurity removal and calcination.The results show that the rate of vanadium extraction by manganese salt is 98.23%.The vanadium extraction product by manganese salt is Mn_(2)V_(2)O_(7),and its sodium content is only 0.167%.Additionally,the acid solubility of vanadium extraction products by manganese salt is 99.52%,and the vanadium precipitation rate of manganese vanadate solution is 92.34%.After the removal of manganese and calcination process,the purity of V_(2)O_(5)product reached 97.73%,with a mere 0.64%loss of vanadium.The Mn_(2)^(+)and NH_(4)^(+)ions in the solution after vanadium precipitation are separated by precipitation method,which reduces the generation of ammonia-nitrogen wastewater.This is conducive to the green and sustainable development of the vanadium industry.展开更多
A(2+1)-dimensional modified KdV(2DmKdV)system is considered from several perspectives.Firstly,residue symmetry,a type of nonlocal symmetry,and the Bäcklund transformation are obtained via the truncated Painlev...A(2+1)-dimensional modified KdV(2DmKdV)system is considered from several perspectives.Firstly,residue symmetry,a type of nonlocal symmetry,and the Bäcklund transformation are obtained via the truncated Painlevéexpansion method.Subsequently,the residue symmetry is localized to a Lie point symmetry of a prolonged system,from which the finite transformation group is derived.Secondly,the integrability of the 2DmKdV system is examined under the sense of consistent tanh expansion solvability.Simultaneously,explicit soliton-cnoidal wave solutions are provided.Finally,abundant patterns of soliton molecules are presented by imposing the velocity resonance condition on the multiple-soliton solution.展开更多
This paper presents a study on CO<sub>2</sub> atmospheric transformation which was reacted directly with lithium hydroxide solution and metallic lithium. This solution was obtained through the reaction bet...This paper presents a study on CO<sub>2</sub> atmospheric transformation which was reacted directly with lithium hydroxide solution and metallic lithium. This solution was obtained through the reaction between metallic lithium and deionized water where hydrogen is produced and by exposing the metal at ambient conditions. In the transformation process, atmospheric CO<sub>2</sub> gas reacts directly with LiOH solution, in both cases, the CO<sub>2</sub> transformation kinetics was different. For this purpose, reactions between CO<sub>2</sub> and LiOH solution were carried out under controlled temperature and the second process only with metallic lithium, which was exposed at room temperature, however, in these two processes lithium carbonate oxide was formed and identified. According to the results, the efficiency in CO<sub>2</sub> transformation is a function of temperature value which was variable until completely obtaining the by-product, its XRD characterization indicated the formation only of Li<sub>2</sub>CO<sub>3</sub> in both procedures. Under laboratory conditions lithium compounds selectively reacted with CO<sub>2</sub>. In the same way, there is an alternative procedure to obtain LiOH and Li<sub>2</sub>CO<sub>3</sub> for different applications in various areas.展开更多
Using the modified CK＇s direct method, we derive a symmetry group theorem of （2＋1）-dimensional dispersive long-wave equations. Based upon the theorem, Lie point symmetry groups and new exact solutions of （2＋1）-...Using the modified CK＇s direct method, we derive a symmetry group theorem of （2＋1）-dimensional dispersive long-wave equations. Based upon the theorem, Lie point symmetry groups and new exact solutions of （2＋1）- dimensional dispersive long-wave equations are obtained.展开更多
The selective recovery of lead from the zinc oxide dust using an alkaline Na2EDTA solution was investigated. The effects of temperature, leaching time, Na2EDTA concentration and initial NaOH concentration on the leach...The selective recovery of lead from the zinc oxide dust using an alkaline Na2EDTA solution was investigated. The effects of temperature, leaching time, Na2EDTA concentration and initial NaOH concentration on the leaching rates of lead and zinc were studied. The following optimized leaching conditions were obtained： liquid-to-solid ratio 5：1 mL/g, stirring speed 650 r/min, Na2EDTA concentration 0.12 mol/L, initial NaOH concentration 0.5 mol/L, leaching temperature 70 ℃, leaching time 120 min. Under the optimized conditions, the average leaching rates of lead, zinc, fluoride and chloride are 89.92%, 0.94%, 62.84% and 90.02%, respectively. The filtrate was used to electrowin lead powders. The average current efficiency of electrowinning is about 93% and lead content is higher than 98% under the conditions of temperature of 60 ℃, current density of 200 A/m2, H3PO4 concentration of 1.5 g/L, and lead ion concentration of above 5 g/L. The consumption of Na2EDTA and the direct current are about respectively 0.218 kg and 0.958 kW·h for per kilogram of lead powder.展开更多
The synthesis of sodium ferrite and its desulfurization performance in S2 -bearing sodium aluminate solutions were investigated. The thermodynamic analysis shows that the lowest temperature is about 810 K for synthesi...The synthesis of sodium ferrite and its desulfurization performance in S2 -bearing sodium aluminate solutions were investigated. The thermodynamic analysis shows that the lowest temperature is about 810 K for synthesizing sodium ferrite by roasting the mixture of ferric oxide and sodium carbonate. The results indicate that the formation process of sodium ferrite can be completed at 1173 K for 60 min, meanwhile raising temperature and reducing NazCO3 particle size are beneficial to accelerating the formation of sodium ferrite. Sodium ferrite is an efficient desulfurizer to remove the S2- in aluminate solution, and the desulfurization rate can reach approximately 70% at 373 K for 60 min with the molar ratio of iron to sulfur of 1：1-1.5：1. Furthermore, the desulfurization is achieved by NaFeS2·2H2O precipitation through the reaction of Fe（OH）4 and S^2- in aluminate solution, and the desulfurization efficiency relies on the Fe（OH）4^- generated by dissolving sodium ferrite.展开更多
基金supported by the Fundamental Research Funds for the Central Universities under Grant No.2024BRB010。
文摘CuInSe_(2) is an N-type diamond-like semiconductors thermoelectric candidate for power generation at medium temperature with its environmentally friendly and cost-effective properties.However,the intrinsic high thermal conductivity of CuInSe_(2) limits the enhancement of its thermoelectric performance.Herein,we investigate the thermoelectric performance of N-type CuInSe_(2) materials by incorporating ZnSe through a solid solution strategy.A series of(CuInSe_(2))_(1-x)(ZnSe)_(x)(x=0.0,0.2,0.4,0.6,0.8,1.0)samples were synthesized,forming continuous solid solutions,while introducing minor porosity.ZnSe solid solution effectively reduces the lattice thermal conductivity of the CuInSe_(2) matrix at near-room temperatures,but has a weaker effect at higher temperatures.Due to the intrinsic low carrier concentration of the system,resulting in high resistivity,the maximum figure of merit(ZT)of(CuInSe_(2))0.8(ZnSe)0.2 reaches 0.08 at 773 K.Despite the relatively low ZT,the solid solution strategy proves effective in reducing the lattice thermal conductivity near-room temperature and offers potential for cost-effective thermoelectric materials.
基金This work was carried out in the framework of PAPIIT-UNAM(IN-205823)project.
文摘Li_(6)ZnO_(4)was chemically modified by nickel addition,in order to develop different compositions of the solid solution Li_(6)Zn_(1-x)Ni_(x)O_(4).These materials were evaluated bifunctionally;analyzing their CO_(2)capture performances,aswell as on their catalytic properties for H_(2)production via dry reforming of methane(DRM).The crystal structures of Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples were determined through X-ray diffraction,which confirmed the integration of nickel ions up to a concentration around 20 mol%,meanwhile beyond this value,a secondary phase was detected.These results were supported by XPS and TEM analyses.Then,dynamic and isothermal thermogravimetric analyses of CO_(2)capture revealed that Li_(6)Zn_(1-x)Ni_(x)O_(4)solid solution samples exhibited good CO_(2)chemisorption efficiencies,similarly to the pristine Li_(6)ZnO_(4)chemisorption trends observed.Moreover,a kinetic analysis of CO_(2)isothermal chemisorptions,using the Avrami-Erofeev model,evidenced an increment of the constant rates as a function of the Ni content.Since Ni^(2+)ions incorporation did not reduce the CO_(2)capture efficiency and kinetics,the catalytic properties of thesematerialswere evaluated in the DRM process.Results demonstrated that nickel ions favored hydrogen(H_(2))production over the pristine Li_(6)ZnO_(4)phase,despite a second H2 production reaction was determined,methane decomposition.Thereby,Li_(6)Zn_(1-x)Ni_(x)O_(4)ceramics can be employed as bifunctional materials.
基金supported by the National Natural Science Foundation(No.51678291)the Basic Science(Natural Science)Research in Higher Education in Jiangsu Province(No.23KJA610003)the High-level Scientific Research Foundation for the introduction of talent in Nanjing Institute of Technology(No.YKJ201999)。
文摘Most studies have shown that oxygen vacancies on Ce_(x)Zr_(1-x)O_(2) solid solution are important for enhancing the catalytic oxidation performance.However,a handful of studies investigated the different roles of surface and subsurface oxygen vacancies on the performance and mechanisms of catalysts.Herein,a series of zirconium doping on CeO_(2) samples(CeO_(2),Ce_(0.95)Zr_(0.05)O_(2),and Ce_(0.8)5Zr_(0.15)O_(2))with various surface-to-subsurface oxygen vacancies ratios have been synthesized and applied in toluene catalytic oxidation.The obtained Ce_(0.95)Zr_(0.05)O_(2) exhibits an excellent catalytic performance with a 90%toluene conversion at 295℃,which is 68℃lower than that of CeO_(2).Additionally,the obtained Ce_(0.95)Zr_(0.05)O_(2)catalyst also exhibited good catalytic stability and water resistance.The XRD and HRTEM results show that Zr ions are incorporated into CeO_(2) lattice,forming Ce_(x)Zr_(1-x)O_(2) solid solution.Temperature-programmed experiments reveal that Ce_(0.95)Zr_(0.05)O_(2) shows excellent lowtemperature reducibility and abundant surface oxygen species.In-situ DRIFTS tests were used to probe the reaction mechanism,and the function of Zr doping in promoting the activation of oxygen was further determined.Density functional theory(DFT)calculations indicate that the vacancy formation energy and O_(2) adsorption energy are both lower on Ce_(0.95)Zr_(0.05)O_(2),confirming the reason for its superior catalytic performance.
基金funding support from the National Key R&D Program of China(2020YFC1909105)the 2023 Basic Research Foundation Project for Universities in the Inner Mongolia Autonomous Region(2023RCTD006)+1 种基金the Major Science and Technology Project of Inner Mongolia Autonomous Region(2021ZD0016)the National Natural Science Foundation of China(51664044).
文摘To separate the phosphorus-containing phase from steel slag,the effects of B_(2)O_(3)and Na_(2)B_(4)O_(7)on the enrichment of phosphorus-containing phases in Ca_(2)SiO_(4)–Ca_(3)(PO_(4))_(2)(C_(2)S–C_(3)P)solid solution were comparatively analyzed through theoretical calculations and experimental investigations.The results indicate that the optimum reaction temperature between B_(2)O_(3)and C_(2)S–C_(3)P is 800℃.The phase compositions of C_(2)S–C_(3)P equilibrium system with 5 wt.%B_(2)O_(3)at 800℃ included Ca_(3)(PO_(4))_(2),CaSiO_(3)and Ca11B_(2)Si_(4)O_(22),among which the content of Ca_(3)(PO_(4))_(2)was the highest.For C_(2)S–C_(3)P with 5 wt.%Na_(2)B_(4)O_(7)equilibrium system,Ca_(3)(PO_(4))_(2),CaSiO_(3),Ca11B_(2)Si_(4)O_(22)and Na_(2)Ca_(2)P_(2)O_(8)were independent at 390–690℃.Ca_(3)(PO_(4))_(2)and Ca_(2)SiO_(4)precipitated in the solid solution when the addition of B_(2)O_(3)was more than 6 wt.%,and the content of Ca_(3)(PO_(4))_(2)raised with the increase in the addition of B_(2)O_(3).The main phases in the C_(2)S–C_(3)P solid solution with Na_(2)B_(4)O_(7)were(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],Ca_(2)SiO_(4)and Na_(3)Ca_(6)(PO_(4))_(5)at 650℃.And when the addition of Na_(2)B_(4)O_(7)exceeded 6 wt.%,the content of Na_(3)Ca_(6)(PO_(4))_(5)increased significantly.There was no precipitation of Ca_(3)(PO_(4))_(2)or boron-containing phase in the samples with Na_(2)B_(4)O_(7),but a small proportion of Ca_(3)(PO_(4))_(2)transformed into(Ca_(2)SiO_(4))0.05[Ca_(3)(PO_(4))_(2)],and Ca^(2+)was partially replaced by Na^(+)to generate Na_(3)Ca_(6)(PO_(4))_(5).As a result,the temperature for Na_(2)B_(4)O_(7)to enrich the phosphorus-containing phase in C_(2)S–C_(3)P solid solution was lower than that for B_(2)O_(3).However,the grade of the phosphorus-containing phase for Na_(2)B_(4)O_(7)was lower than that for B_(2)O_(3).
基金Project supported by the State Key Research Project of Shandong Natural Science Foundation(ZR2020KB019)the fund of"Two-Hundred Talent"Plan of Yantai City+1 种基金the National Natural Science Foundation of China(11974013)the Natural Science Foundation of Fujian Province(2022J011270)。
文摘The low-dose X-ray induced long afterglow near infrared(NIR)luminescence from Cr^(3+)doped Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions was investigated.The structure analysis shows the good formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions,which possesses a cubic spinel structure with Fd3m space group.The formation of Zn_(1-x)Cd_(x)Ga_(2)O_(4)spinel solid solutions induces the obvious increase of long afterglow near infrared luminescence excited by low-dose X-ray,When the content of doped Cd^(2+)reaches 0.1,the low-dose X-ray induced long afterglow NIR luminescence is the maximum.More importantly,only 5 s Xray irradiation can induce more than 6 h NIR afterglow emission,of which the afterglow luminescent intensity is still 5 times stronger than the background intensity after 6 h.The thermoluminescent results show that under the 5 s exposure of X-ray,the trap density of Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):Cr^(3+)is much higher than that of ZnGa_(2)O_(4):Cr^(3+).The replacement of Cd^(2+)ions with large radius at Zn^(2+)sites causes the increase of de fects and dislocations,which results in the obvious increase of trap co ncentrations.And the addition of high-z number elements Cd^(2+)would enhance the X-ray absorption of the solid solutions,which thus can be easily excited by low-dose X-ray.Zn_(0.9)Cd_(0.1)Ga_(2)O_(4):1%Cr^(3+)solid solution is a potential candidate of lowdose X-ray induced long afterglow luminescent materials.
基金Project supported by the National Natural Science Foundation of China(52064002)Guangxi Zhuang Autonomous Region Administration for Market Regulation(GSJKJZC2022-9)。
文摘Red mud is an important secondary resource for scandium production.The red mud leaching solution containing scandium in this study was derived from environmentally friendly ammonium sulfate roasting and water leaching process.A synergistic extraction with a mixture of di(2-ethylhexyl)phosphate acid(D2EHPA)and tributyl phosphate(TBP)for recovery of scandium from red mud leaching solution is proposed.The effects of D2EHPA concentration,H_(2)SO_(4)concentration,rare earth elements,dosage of TBP,phase ratio(A/O),contact time and H_(2)O_(2)concentration on scandium extraction were investigated.The results show that more than 99%scandium is extracted under the optimal conditions while Fe,Al,Ti,Ca and rare earth elements(Ce,Y,La,Nd,Er,etc.)are hardly extracted.The stripping efficiency of Sc reaches above 92.37%under the optimal stripping conditions of 5 mol/L NaOH with an A/O of 1 at 90℃for 30 min.The proposed technology could provide an effective method for extraction of scandium from red mud leaching solution.
基金financial supports from the National Key Research and Development Program of China(No.2022YFB3504501)the National Natural Science Foundation of China(Nos.52274355,91962211)the Gansu Province Science and Technology Major Special Project,China(No.22ZD6GD061)。
文摘For a highly efficient recycling of a wastewater containing a high concentration of MgCl_(2),Al(Ⅲ)and P507 were scheduled to be removed in advance.In this study,the in-situ removal of Al(Ⅲ)and P507 from a high concentration MgCl_(2)solution at different pH values and Al/P molar ratios was investigated.The results showed that P507 formed organic complexes of Al_(x)(OH)_y^(Z+)-P507 at pH of 2.0-4.0.At pH of 4.0-5.0,Al(Ⅲ)precipitated and transferred into Al(OH)_(3)with a flocculent amorphous morphology.Active sites on the Al(OH)_(3)surface enhanced the removal efficiency of P507.At pH of 6.0-6.5,Al(Ⅲ)and Mg(Ⅱ)formed layered crystalline Al(OH)_(3)and MgAl_(2)(OH)_(8with)small pore channels and fewer active sites,resulting in a reduced removal efficiency of P507.When the Al/P molar ratio exceeded 13 and the pH was between 4.0 and 5.0,the removal rates of both Al(Ⅲ)and P507 were higher than98%,while the concentration loss of Mg(Ⅱ)was only 0.2%-0.9%.
基金National Natural Science Foundation of China,Grant/Award Numbers:21972108,U20A20249,U22A20438Changzhou Science and Technology Bureau,Grant/Award Number:CM20223017Innovation and Technology Commission(ITC)of Hong Kong,The Innovation&Technology Fund(ITF)with Project No.ITS/126/21。
文摘Iron‐based pyrophosphates are attractive cathodes for sodium‐ion batteries due to their large framework,cost‐effectiveness,and high energy density.However,the understanding of the crystal structure is scarce and only a limited candidates have been reported so far.In this work,we found for the first time that a continuous solid solution,Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2)(0≤α≤1,could be obtained by mutual substitution of cations at center‐symmetric Na3 and Na4 sites while keeping the crystal building blocks of anionic P_(2)O_(7) unchanged.In particular,a novel off‐stoichiometric Na_(3)Fe(2.5)(P_(2)O_(7))_(2)is thus proposed,and its structure,energy storage mechanism,and electrochemical performance are extensively investigated to unveil the structure–function relationship.The as‐prepared off‐stoichiometric electrode delivers appealing performance with a reversible discharge capacity of 83 mAh g^(−1),a working voltage of 2.9 V(vs.Na^(+)/Na),the retention of 89.2%of the initial capacity after 500 cycles,and enhanced rate capability of 51 mAh g^(−1)at a current density of 1600 mA g^(−1).This research shows that sodium ferric pyrophosphate could form extended solid solution composition and promising phase is concealed in the range of Na_(4−α)Fe_(2+α)_(2)(P_(2)O_(7))_(2),offering more chances for exploration of new cathode materials for the construction of high‐performance SIBs.
基金supported financially by the National Natural Science Foundation of China(22178229)the Natural Science Foundation of Sichuan Province(2022NSFSC1190)。
文摘With the development of vanadium redox flow battery technology,the demand for pure vanadium is rapidly increasing.The separation of vanadium from vanadium-chromium leaching solutions are critical step in the production of purity-vanadium.This study presents an innovative adsorption process that utilizes amorphous ZrO_(2)(AZrO) for the selective separation of V(Ⅴ) and Cr(Ⅵ).In this process,a high adsorption capacity for V(V) at 64.5 mg·g^(-1) was achieved,while the capacity for Cr(Ⅵ) is relatively low at 24.1 mg·g^(-1),demonstrating good separation performance.This is mainly caused by the large specific surface area and mesoporous structure,which are favorable for molecular diffusion and mass transfer.The kinetic analysis shows that the adsorption process follows pseudo-second-order kinetic process with chemisorption being the rate-controlling process.AZrO showed excellent separation performance in mixed solutions over a wide range of concentrations.After five cycles,AZrO retained over 73% of its capacity,indicating good stability.In mixed solutions containing up to 40 g·L^(-1) of V(Ⅴ) and 3 g·L^(-1) of Cr(Ⅵ),the innovative adsorption process successfully achieved effective separation and purification.By an adsorption-desorption process using 0.1 mol·L^(-1) NaOH,a 99.02% V(Ⅴ)-rich solution was obtained from a high concentration sodium vanadium slag leaching solution,demonstrating its effectiveness for practical industrial applications.
文摘The blockchain trilemma—balancing decentralization,security,and scalability—remains a critical challenge in distributed ledger technology.Despite significant advancements,achieving all three attributes simultaneously continues to elude most blockchain systems,often forcing trade-offs that limit their real-world applicability.This review paper synthesizes current research efforts aimed at resolving the trilemma,focusing on innovative consensus mechanisms,sharding techniques,layer-2 protocols,and hybrid architectural models.We critically analyze recent breakthroughs,including Directed Acyclic Graph(DAG)-based structures,cross-chain interoperability frameworks,and zero-knowledge proof(ZKP)enhancements,which aimto reconcile scalability with robust security and decentralization.Furthermore,we evaluate the trade-offs inherent in these approaches,highlighting their practical implications for enterprise adoption,decentralized finance(DeFi),and Web3 ecosystems.By mapping the evolving landscape of solutions,this review identifies gaps in currentmethodologies and proposes future research directions,such as adaptive consensus algorithms and artificial intelligence-driven(AI-driven)governance models.Our analysis underscores that while no universal solution exists,interdisciplinary innovations are progressively narrowing the trilemma’s constraints,paving the way for next-generation blockchain infrastructures.
基金supported by the National Natural Science Foundation of China(22202121,22005340)Shandong Provincial Natural Science Foundation(ZR2021QB079).
文摘CO_(2)reduction by CH4(CRM)to produce fuel is of great significance for solar energy storage and eliminating greenhouse gas.Herein,the catalyst of ultrafine Ni nanoparticles supported on CeZrNiO_(2)solid solution(Ni@CZNO)was synthesized by the sol-gel method.High yield of H_(2)and CO(58.0 and 69.8 mmol min^(-1)g^(-1))and excellent durability(50 h)were achieved by photothermal catalytic CRM merely under focused light irradiation.Structural characterization and DFT calculations reveal that CZNO has rich oxygen vacancies that can adsorb and activate CO_(2)to produce reactive oxygen species.Oxygen species are transferred to ultrafine Ni nanoparticles through the rich Ni-CZNO interface to accelerate carbon oxidation,thereby maintaining the excellent catalytic stability of the catalyst.Moreover,the experimental results reveal that light irradiation can not only enhance the photothermal catalytic CRM activity through photothermal conversion and molecular activation,but also improve the stability by increasing the concentration of oxygen vacancies and inhibiting CO disproportionation.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.12275172 and 11905124)。
文摘This paper studies the(2+1)-dimensional Hirota-Satsuma-Ito equation.Based on an associated Hirota bilinear form,lump-type solution,two types of interaction solutions,and breather wave solution of the(2+1)-dimensional Hirota-Satsuma-Ito equation are obtained,which are all related to the seed solution of the equation.It is interesting that the rogue wave is aroused by the interaction between one-lump soliton and a pair of resonance stripe solitons,and the fusion and fission phenomena are also found in the interaction between lump solitons and one-stripe soliton.Furthermore,the breather wave solution is also obtained by reducing the two-soliton solutions.The trajectory and period of the one-order breather wave are analyzed.The corresponding dynamical characteristics are demonstrated by the graphs.
文摘For the (2 + 1)-dimensional nonlinear dispersive Boussinesq equation, by using the bifurcation theory of planar dynamical systems to study its corresponding traveling wave system, the bifurcations and phase portraits of the regular system are obtained. Under different parametric conditions, various sufficient conditions to guarantee the existence of analytical and non-analytical solutions of the singular system are given by using singular traveling wave theory. For certain special cases, some explicit and exact parametric representations of traveling wave solutions are derived such as analytical periodic waves and non-analytical periodic cusp waves. Further, two-dimensional wave plots of analytical periodic solutions and non-analytical periodic cusp wave solutions are drawn to visualize the dynamics of the equation.
基金supported by a National Research Foundation of Korea(NRF)grant funded by the Korean government(MSIT)(No.2018R1A6A1A03025708).
文摘Aqueous zinc(Zn)-ion batteries(AZIBs)have gained significant interest in energy storage due to several unique advantages.Utilizing waterbased electrolytes enhances environmental sustainability,while the abundance and affordability of Zn offer economic benefits.Manganese(Mn)-based materials,commonly used as cathodes in these batteries,provide high theoretical capacity,high electrical conductivity,and good structural stability.However,these materials suffer from capacity degradation over repeated cycles due to structural collapse and limited conductivity.To address this problem,we synthesized a magnesium(Mg)-and Mn-based composite,Mg^(2+)-Mn_(3)O_(4),using the hydrothermal method with an optimized amount of ammonium hydroxide(NH_(4)OH)solution.This approach effectively stabilizes the structure during cycling,enhancing both capacity retention and conductivity.The Zn^(2+)/H+intercalation/deintercalation process was confirmed by experimental results and ex-situ X-ray diffraction analysis,which demonstrates that Mg^(2+),along with optimized NH_(4)OH amount,prevents structural collapse and improves conductivity.Under optimal process conditions,the composite electrode(Mg^(2+)-Mn_(3)O_(4)–8 ml)achieved a capacity of 173.58 mA h g^(-1) at 0.5 A g^(-1),with excellent rate performance of 71.39 mA h g^(-1) at 10 A g^(-1).Remarkably,even at 5 A g^(-1),the electrode maintained a capacity of 86.87 mA h g^(-1) over 2100 cycles,underscoring the role of Mg^(2+)and NH_(4)OH in enhancing the reversible insertion/extraction stability of Zn^(2+)in Mn-based layered materials.This study presents a novel strategy for metal-ion incorporation in Mn-based AZIBs,offering insights into the optimization of cathode materials and advancing research on associated storage mechanisms.
基金supported by the National Natural Science Foundation of China(52204309,52374300 and 52174277)the Opening Foundation of State Key Laboratory of Vanadium and Titanium Resources Comprehensive Utilization,China(2022P4FZG11A).
文摘The ammonium salt precipitation method is frequently utilized for extracting vanadium from the leaching solution obtained through sodium roasting of vanadium slag.However,Na^(+)and NH_(4)^(+)ions in the vanadium precipitation solution can not be effectively separated,leading to a large amount of ammonia-nitrogen wastewater which is difficult to treat.In this study,the manganese salt pretreatment process is used to extract vanadium from a sodium roasting leaching solution,enabling the separation of vanadium and sodium.The vanadium extraction product of manganese salt is dissolved in acid to obtain vanadium-containing leaching solution,then vanadium is extracted by hydrolysis and vanadium precipitation,and V_(2)O_(5)is obtained after impurity removal and calcination.The results show that the rate of vanadium extraction by manganese salt is 98.23%.The vanadium extraction product by manganese salt is Mn_(2)V_(2)O_(7),and its sodium content is only 0.167%.Additionally,the acid solubility of vanadium extraction products by manganese salt is 99.52%,and the vanadium precipitation rate of manganese vanadate solution is 92.34%.After the removal of manganese and calcination process,the purity of V_(2)O_(5)product reached 97.73%,with a mere 0.64%loss of vanadium.The Mn_(2)^(+)and NH_(4)^(+)ions in the solution after vanadium precipitation are separated by precipitation method,which reduces the generation of ammonia-nitrogen wastewater.This is conducive to the green and sustainable development of the vanadium industry.
基金supported by the National Natural Science Foundation of China(No.12375006).
文摘A(2+1)-dimensional modified KdV(2DmKdV)system is considered from several perspectives.Firstly,residue symmetry,a type of nonlocal symmetry,and the Bäcklund transformation are obtained via the truncated Painlevéexpansion method.Subsequently,the residue symmetry is localized to a Lie point symmetry of a prolonged system,from which the finite transformation group is derived.Secondly,the integrability of the 2DmKdV system is examined under the sense of consistent tanh expansion solvability.Simultaneously,explicit soliton-cnoidal wave solutions are provided.Finally,abundant patterns of soliton molecules are presented by imposing the velocity resonance condition on the multiple-soliton solution.
文摘This paper presents a study on CO<sub>2</sub> atmospheric transformation which was reacted directly with lithium hydroxide solution and metallic lithium. This solution was obtained through the reaction between metallic lithium and deionized water where hydrogen is produced and by exposing the metal at ambient conditions. In the transformation process, atmospheric CO<sub>2</sub> gas reacts directly with LiOH solution, in both cases, the CO<sub>2</sub> transformation kinetics was different. For this purpose, reactions between CO<sub>2</sub> and LiOH solution were carried out under controlled temperature and the second process only with metallic lithium, which was exposed at room temperature, however, in these two processes lithium carbonate oxide was formed and identified. According to the results, the efficiency in CO<sub>2</sub> transformation is a function of temperature value which was variable until completely obtaining the by-product, its XRD characterization indicated the formation only of Li<sub>2</sub>CO<sub>3</sub> in both procedures. Under laboratory conditions lithium compounds selectively reacted with CO<sub>2</sub>. In the same way, there is an alternative procedure to obtain LiOH and Li<sub>2</sub>CO<sub>3</sub> for different applications in various areas.
基金supported by the Natural Science Foundation of Shandong Province of China under Grant Nos.Q2005A01
文摘Using the modified CK＇s direct method, we derive a symmetry group theorem of （2＋1）-dimensional dispersive long-wave equations. Based upon the theorem, Lie point symmetry groups and new exact solutions of （2＋1）- dimensional dispersive long-wave equations are obtained.
基金Project (50974138) supported by the National Natural Science Foundation of ChinaProject (2010ssxt158) supported by Graduate Student Innovation Foundation of Central South University,China
文摘The selective recovery of lead from the zinc oxide dust using an alkaline Na2EDTA solution was investigated. The effects of temperature, leaching time, Na2EDTA concentration and initial NaOH concentration on the leaching rates of lead and zinc were studied. The following optimized leaching conditions were obtained： liquid-to-solid ratio 5：1 mL/g, stirring speed 650 r/min, Na2EDTA concentration 0.12 mol/L, initial NaOH concentration 0.5 mol/L, leaching temperature 70 ℃, leaching time 120 min. Under the optimized conditions, the average leaching rates of lead, zinc, fluoride and chloride are 89.92%, 0.94%, 62.84% and 90.02%, respectively. The filtrate was used to electrowin lead powders. The average current efficiency of electrowinning is about 93% and lead content is higher than 98% under the conditions of temperature of 60 ℃, current density of 200 A/m2, H3PO4 concentration of 1.5 g/L, and lead ion concentration of above 5 g/L. The consumption of Na2EDTA and the direct current are about respectively 0.218 kg and 0.958 kW·h for per kilogram of lead powder.
基金Project(51374239)supported by the National Natural Science Foundation of China
文摘The synthesis of sodium ferrite and its desulfurization performance in S2 -bearing sodium aluminate solutions were investigated. The thermodynamic analysis shows that the lowest temperature is about 810 K for synthesizing sodium ferrite by roasting the mixture of ferric oxide and sodium carbonate. The results indicate that the formation process of sodium ferrite can be completed at 1173 K for 60 min, meanwhile raising temperature and reducing NazCO3 particle size are beneficial to accelerating the formation of sodium ferrite. Sodium ferrite is an efficient desulfurizer to remove the S2- in aluminate solution, and the desulfurization rate can reach approximately 70% at 373 K for 60 min with the molar ratio of iron to sulfur of 1：1-1.5：1. Furthermore, the desulfurization is achieved by NaFeS2·2H2O precipitation through the reaction of Fe（OH）4 and S^2- in aluminate solution, and the desulfurization efficiency relies on the Fe（OH）4^- generated by dissolving sodium ferrite.
