The adsorptive denitrification performance of MIL-101(Cr)-0.5 toward pyridine,aniline or quinoline in simulated fuels with basic nitrogen content of 1732μg/g was evaluated separately.Furthermore,the effects of adsorp...The adsorptive denitrification performance of MIL-101(Cr)-0.5 toward pyridine,aniline or quinoline in simulated fuels with basic nitrogen content of 1732μg/g was evaluated separately.Furthermore,the effects of adsorption temperature,adsorption time and adsorbent dosage on their adsorptive denitrification performance were systematically investigated.The experimental results demonstrated that under a fixed adsorbent dosage of 0.05 g and a simulated fuel volume of 10 mL,the optimal removal efficiency for aniline was achieved at 30℃ within 30 min,whereas higher temperatures and longer times(40℃and 40 min)were required for effective removal of pyridine and quinoline.Density Functional Theory(DFT)calculations were conducted via Materials Studio(MS)software to study the adsorptive denitrification mechanism of MIL-101(Cr)toward these three basic nitrogen-containing compounds.The simulation calculation results revealed that the interaction between pyridine and MIL-101(Cr)primarily involved coordination adsorption.In contrast,the interaction between aniline or quinoline and MIL-101(Cr)proceeded mainly through coordination,with additional contributions fromπ-complexation and hydrogen bonding.The overall adsorption strength order is pyridine>aniline>quinoline.During the adsorption process,pyridine and quinoline transfer electrons to the MIL-101(Cr)surface through the H→C→N→Cr^(3+)pathway,while aniline transfers electrons to the MIL-101(Cr)surface through various pathways,including N→Cr^(3+),N→C→Cr^(3+)and N→H→O.Furthermore,adsorption kinetics studies indicated that the adsorption processes for all three basic nitrogen-containing compounds followed the quasi second order kinetic models.The experimental results on the effect of benzene on the adsorptive denitrification performance of MIL-101(Cr)-0.5 demonstrated that benzene exerted a more significant impact on the adsorption of aniline and quinoline.Finally,the adsorbent was regenerated using ethanol washing.It was found that MIL-101(Cr)-0.5 retained stable denitrification performance after two regeneration cycles.展开更多
The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor ...The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion.展开更多
With the development of hydrate technology,more and more applications have been appeared in many areas.However,hydrate additive is always one research hotspot,it has attracted more and more attention.The influence of ...With the development of hydrate technology,more and more applications have been appeared in many areas.However,hydrate additive is always one research hotspot,it has attracted more and more attention.The influence of two biosurfactants on CO_(2) hydrate formation process were investigated.Through the investigation of experiment research,rhamnolipid and sophorolipid had the promotion effect on CO_(2) hydrate formation kinetics.Hydrate gas storage reached the maximum value 32.01(volume ratio)and conversion ratio of water to hydrate was 19.42%when sophorolipid concentration was 0.05%(mass).Hydrate gas storage capacity reached the maximum value 31.22(volume ratio)and conversion ratio of water to hydrate was 18.94%when rhamnolipid concentration was 0.05%(mass).Through the comparison of gas storage capacity and hydrate formation rate,sophorolipid had stronger promotion effect on CO_(2) hydrate formation kinetics than rhamnolipid.It increased the depth of gas hydration reaction.CO_(2) hydrate formation gas was carried out under the condition of constant temperature and volume.Hydration number was considered in the hydrate calculation process.Combined with hydrate formation kinetic theory of Chen–Guo model,the hydrated gas volume was compared with remaining volume of reactor.This model could calculate the change of CO_(2) hydrate gas storage capacity over time.The calculated values of gas storage was in good agreement with experimental values.So this study has the better guiding function for relevant hydrate technology application.展开更多
Four new sesquiterpenoids(1-4), including the first reported instance of a novel 2,3-seco oplopane carbon skeleton(1), together with 19 known analogues, were isolated from the flower buds of Tussilago farfara(coltsfoo...Four new sesquiterpenoids(1-4), including the first reported instance of a novel 2,3-seco oplopane carbon skeleton(1), together with 19 known analogues, were isolated from the flower buds of Tussilago farfara(coltsfoot). The challenging determination of relative and absolute configurations—particularly in flexible side chains and substituents—was achieved for the first time through an integrated approach combining spectroscopic analyses, chemical derivatization, chiral gas chromatography(GC), and quantum chemical calculations. All compounds were evaluated for anti-diabetic activity using an insulin-stimulated glucose uptake model in C2C12 myotubes and for anti-inflammatory activity via a lipopolysaccharide(LPS)-induced nitric oxide(NO) inhibition assay in RAW264.7 macrophages. Six compounds significantly enhanced glucose uptake, and mechanistic investigation of compound 3 revealed activation of the insulin receptor substrate 1(IRS-1)/protein kinase B(Akt)/glycogen synthase kinase 3β(GSK-3β) signaling pathway. Twenty-one compounds exhibited marked inhibition of NO production;among them, compounds 2 and 6 dose-dependently suppressed inducible nitric oxide synthase(iNOS) expression and nuclear factor κB(NF-κB) phosphorylation.展开更多
The hydrogen evolution reaction(HER) is a key process in electrocatalytic water splitting for hydrogen production,yet it is often limited by sluggish H^(*)-OH adsorption and H*binding kinetics.We obtained Rumodified N...The hydrogen evolution reaction(HER) is a key process in electrocatalytic water splitting for hydrogen production,yet it is often limited by sluggish H^(*)-OH adsorption and H*binding kinetics.We obtained Rumodified Ni O nanoparticles(Ru-Ni O/NF) with enhanced HER properties by substituting ruthenium(Ru)for Ni atoms in the Ni O(200) crystalline facets on nickel foam by a one-step electrodeposition technique.This novel catalyst exhibits a significantly reduced H^(*)-OH adsorption energy and improved kinetics,with an overpotential of only 60 mV at 10 mA/cm^(2) and a Tafel slope of 26.19 mV/dec.The Ru-Ni O/NF maintains its activity for over 115 h,outperforming NiO/NF by reducing the overpotential by 177 mV.DFT calculations confirm that the addition of Ru to NiO enhances the HER kinetics by modifying the electronic structure,optimizing the surface chemistry,stabilizing the intermediates,lowering the energy barriers,and facilitating efficient charge transfer through a robust three-dimensional structure,resulting in a change in the rate-limiting step and a significant reduction in the Gibbs free energy.This study presents a highly efficient HER catalyst and offers insights into designing advanced NiO-based electrocatalysts by reducing reaction energy barriers.展开更多
Oxygen evolution reaction(OER)is widely recognized as a bottleneck of water electrolysis.To determine the underlying reaction mechanisms,particularly the relative contribution of the adsorbate evolution mechanism(AEM)...Oxygen evolution reaction(OER)is widely recognized as a bottleneck of water electrolysis.To determine the underlying reaction mechanisms,particularly the relative contribution of the adsorbate evolution mechanism(AEM)and lattice-oxygen participation mechanism(LOM),we conduct a comprehensive investigation combining Density Functional Theory(DFT)calculations and experimental validation.Our theoretical analysis of doped RuO_(2)catalysts reveals that heteroatom doping(Ni,Cu,and Zn)induces significant local charge transfer,leading to the increased charge state of Ru and the downshifted d-band center.This,in turn,enables the mechanism switching from the conventional AEM to the more efficient LOM,and finally improves OER activity.We also establish a simple yet powerful descriptor,Ne of Ru(representing charge density of Ru sites),which enables accurate prediction of both catalytic activity and stability.Guided by these theoretical predictions,we successfully synthesize a Ni-doped RuO_(2)catalyst,which exhibits excellent OER activity and stability in acidic media,achieving an overpotential of just 156 mV and maintaining stability for 4000 h at 10 mA cm^(−2),significantly surpassing the performance of the commercial RuO_(2).These findings not only provide fundamental insights into the mechanism-switching behavior in OER catalysis but also offer a practical strategy for designing high-performance,stable electrocatalysts for acidic water electrolysis.展开更多
Owing to their intricate molecular frameworks and copious chiral centers,the structural identification and configurational assignment of natural products are challenging tasks.Comprehensive spectral data analysis is c...Owing to their intricate molecular frameworks and copious chiral centers,the structural identification and configurational assignment of natural products are challenging tasks.Comprehensive spectral data analysis is crucial for the confirmation of absolute configurations.Ignoring critical parameters will lead to false structure,which may confuse the total synthesis and drug development.Herein,the configurations of seven heterogeneous Pallavicinia diterpenoids(PDs) isolated from Pallavicinia liverworts are revised using a combination of single-crystal X-ray diffraction and electronic circular dichroism(ECD) calculations.Meanwhile,identification of five unprecedented PD heterodimers PD-dimers A-E(18-22) along with eleven previously undescribed PDs(5-9,13-17,23) obtained by the reinvestigation of the Chinese liverwort Pallavicinia subciliata have resulted in corrections and support the revised conclusions.展开更多
Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of a...Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials.展开更多
MnO_(2) stands out among cathode materials for aqueous zinc-ion batteries(AZIBs)high capacity and voltage,it has poor stability and slow Zn^(2+) kinetics.Herein,we propose a dual-regulation strategy integrating copper...MnO_(2) stands out among cathode materials for aqueous zinc-ion batteries(AZIBs)high capacity and voltage,it has poor stability and slow Zn^(2+) kinetics.Herein,we propose a dual-regulation strategy integrating copper doping and carbon-based confinement.Residual carbon(RC),derived from acid-washed coal gasification fine slag(CGFS),serves as a conductive and porous framework for the directional growth of Cu-doped MnO_(2) nanowires(CMO@RC).The synergistic modulation of Cu-induced electronic structure tuning and carbon confinement induced mechanical/electrical stabilization significantly enhances Zn^(2+) transport and electrochemical performance.CMO@RC achieves a high capacity of 563 mA·h·g^(−1) at 0.1 A·g^(−1) and maintains 106%after 1000 cycles at 1 A·g^(−1).Kinetic analyses confirm the dual-path Zn^(2+) diffusion and accelerated reaction kinetics,while DFT calculations reveal that Cu doping enhances Mn 3d orbital hybridization and electron interaction with carbon,elevating the density of states near the Fermi level and reducing charge transfer barriers.Furthermore,pouch cell testing demonstrates outstanding flexibility and mechanical resilience.This study provides a cost-effective and scalable strategy for high-performance AZIBs,leveraging both experimental and theoretical validations.展开更多
First-principles calculations based on density functional theory(DFT)have had a significant impact on chemistry,physics,and materials science,enabling in-depth exploration of the structural and electronic properties o...First-principles calculations based on density functional theory(DFT)have had a significant impact on chemistry,physics,and materials science,enabling in-depth exploration of the structural and electronic properties of a wide variety of materials.Among different implementations of DFT,the plane-wave method is widely used for periodic systems because of its high accuracy.However,this method typically requires a large number of basis functions for large systems,leading to high computational costs.Localized basis sets,such as the muffin-tin orbital(MTO)method,have been introduced to provide a more efficient description of electronic structure with a reduced basis set,albeit at the cost of reduced computational accuracy.In this work,we propose an optimization strategy using machine-learning techniques to automate MTO basis-set parameters,thereby improving the accuracy and efficiency of MTO-based calculations.Default MTO parameter settings primarily focus on lattice structure and give less consideration to element-specific differences.In contrast,our optimized parameters incorporate both structural and elemental information.Based on these converged parameters,we successfully recovered missing bands for CrTe_(2).For the other three materials—Si,GaAs,and CrI_(3)—we achieved band improvements of up to 2 e V.Furthermore,the generalization of the machine-learned method is validated by perturbation,strain,and elemental substitution,resulting in improved band structures.Additionally,lattice-constant optimization for Ga As using the converged parameters yields closer agreement with experiment.展开更多
The development of high-performance solid electrolytes is pivotal for advancing solid-state battery technologies.In this work,we design an oxysulfide-based solid electrolyte Na MgPO_(3)S by combining bond valence theo...The development of high-performance solid electrolytes is pivotal for advancing solid-state battery technologies.In this work,we design an oxysulfide-based solid electrolyte Na MgPO_(3)S by combining bond valence theory and density functional theory calculations.The material features a wide band gap of 4.0 eV and a considerable reduced Na^(+)migration barrier of 0.44 eV,a 1.26-eV decrease compared to pristine Na MgPO_(4)(~1.70 eV).Ab initio molecular dynamics simulations further reveal significantly enhanced ionic conductivity in the oxysulfide-based system compared to the pristine oxide structure.In addition,the calculated decomposition energy indicates that the modified material exhibits good moisture stability.Our findings suggest that sulfur-doping strategy can simultaneously achieve improved ionic conductivity and high moisture stability in oxide solid electrolytes,which could pave the way for designing high-performance solid electrolytes.展开更多
4-Bromo-3-methylphenol(BMP)is an important chemical intermediate with wide applications in the fields of medicine and pesticides.The synthesis of BMP from m-cresol via bromination is easy to carry out on an industrial...4-Bromo-3-methylphenol(BMP)is an important chemical intermediate with wide applications in the fields of medicine and pesticides.The synthesis of BMP from m-cresol via bromination is easy to carry out on an industrial scale.However,due to the formation of regioisomeric impurities during bromination and the low melting point of BMP,the separation process is prone to the formation of oily substances,resulting in low yield and purity.In this work,a new cocrystallization engineering approach was proposed to separate and purify BMP.Through design of experiments,the cocrystallization process of BMP and triethylenediamine(DABCO)was optimized using a minimum-run resolution IV screening design combined with response surface methodology.In addition,the obtained 2BMP-DABCO powder was characterized by thermal analysis,powder X-ray diffraction,infrared spectroscopy,and scanning electron microscopy.Single crystals of 2BMP-DABCO were grown from acetone by slow evaporation,and detailed structural information was obtained through single-crystal X-ray diffraction.The self-assembly mechanism was further clarified by density functional theory calculations.This study provides a simple,robust,and scalable method for the production of BMP and offers a reference for the separation and purification of phenolic substances.展开更多
Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems cons...Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems consisting of two insulators.Here,motivated by the emergence of an insulator-metal transition in type-Ⅲ heterostructures and the superconductivity in some“special”two-dimensional(2D)semiconductors via electron doping,we predict that the 2D heterostructure SnSe_(2)/PtTe_(2) is a model system for realizing IS by using firstprinciples calculations.Our results show that due to slight but crucial interlayer charge transfer,SnSe_(2)/PtTe_(2) turns to be a type-Ⅲ heterostructure with metallic properties and shows a superconducting transition with the critical temperature(T_(c))of 3.73 K.Similar to the enhanced electron–phonon coupling(EPC)in the electrondoped SnSe_(2) monolayer,the IS in the SnSe_(2)/PtTe_(2) heterostructure mainly originates from the metallized SnSe_(2) layer.Furthermore,we find that its superconductivity is sensitive to tensile lattice strain,forming a domeshaped superconducting phase diagram.Remarkably,at 7%biaxial tensile strain,the superconducting T_(c) can increase more than twofold(8.80 K),resulting from softened acoustic phonons at the𝑀point and enhanced EPC strength.Our study provides a concrete example for realizing IS in type-Ⅲ heterostructures,which waits for future experimental verification.展开更多
High-performance intelligent protective materials are vital for nuclear energy systems exposed to extreme irradiation.Among them,tungsten-based alloys demonstrate exceptional potential owing to their superior irradiat...High-performance intelligent protective materials are vital for nuclear energy systems exposed to extreme irradiation.Among them,tungsten-based alloys demonstrate exceptional potential owing to their superior irradiation resistance.Recent experimental studies have demonstrated that W-Ta-Cr-V alloys exhibit excellent irradiation resistance under helium(He)ion irradiation.However,the underlying mechanisms,especially the migration behavior of He atoms,remain unclear.In this work,the influences of uniaxial tensile and compressive strain on He migration in W-Ta-Cr-V complex alloys have been systematically studied through first-principles calculations.Our results demonstrate that He atoms preferentially occupy the tetrahedral interstitial sites,with interstitial formation energies significantly reduced compared to pure W.The introduction of Ta,Cr,and V alloying elements markedly increases the He migration barriers,effectively suppressing He diffusion.Compressive strain increases the migration barriers,inhibiting He bubbles nucleation and growth,while tensile strain decreases the barriers,facilitating bubble formation.Compared to pure W,the W-Ta-Cr-V alloys exhibit both lower He interstitial formation energies and higher migration barriers,with further enhancement under compressive strain.Specifically,compressive strain of 6%increases the He migration barrier of the W-Ta-Cr-V alloy by 0.166 e V,which further widens the difference relative to pure W.These findings provide a theoretical explanation for the superior irradiation resistance of tungsten-based alloys observed experimentally and promote the understanding of irradiation damage in these alloys under strain.展开更多
Strong long-wavelength laser pulses enable direct manipulation of atomic lattices for engineering novel quantum states in complex materials.Nonlinear coupling between two infrared-active phonon modes(TO_(1) and TO_(2)...Strong long-wavelength laser pulses enable direct manipulation of atomic lattices for engineering novel quantum states in complex materials.Nonlinear coupling between two infrared-active phonon modes(TO_(1) and TO_(2)),induced by intense terahertz light fields,significantly enhances the amplitude of the TO_(1) mode and facilitates ultrafast control of transient structural distortions.This light-induced distortion reduces the lattice thermal conductivity from 8.1 W·m^(-1)·K^(-1)to 3.0 W·m^(-1)·K^(-1).The reduction originates from the nonlinear coupling,which enhances anharmonic interactions in the lattice potential energy and substantially shortens the phonon lifetime(τ).This work demonstrates a strategy applicable to other perovskite materials and provides a framework for investigating light-induced electrical,optical,and thermodynamic phase transitions.展开更多
Underwater gas-liquid two-phase propulsion technology is an emerging propulsion method that offers high efficiency and unrestricted navigation speed.The integration of this technology into water ramjet engines can sig...Underwater gas-liquid two-phase propulsion technology is an emerging propulsion method that offers high efficiency and unrestricted navigation speed.The integration of this technology into water ramjet engines can significantly enhance propulsion efficiency and holds substantial potential for broad applications.However,forming a gas-liquid two-phase flow within the nozzle requires introducing a large amount of rammed seawater.At this time,there is a complex phase transition problem of combustion products in the combustion chamber,which makes the thermodynamic calculation for gas-liquid two-phase water ramjet engines particularly challenging.This paper proposes a thermodynamic calculation method for gas-liquid two-phase water ramjet engines,based on the energy equation for gas-liquid two-phase flow and traditional thermodynamic principles,enabling thermodynamic calculations under conditions of ultra-high water-fuel ratios.Additionally,ground ignition tests of the gas-liquid two-phase engine were conducted,yielding critical engine test parameters.The results demonstrate that the gas-liquid two-phase water ramjet engine achieves a high specific impulse,with a theoretical maximum specific impulse of up to 7000(N s)/kg.The multiphase flow effects significantly impact engine performance,with specific impulse losses reaching up to 25.86%.The error between the thrust and specific impulse in the ground test and the theoretical values is within 10%,validating the proposed thermodynamic calculation method as a reliable reference for further research on gas-liquid two-phase water ramjet engines.展开更多
Industrial trials and thermodynamic calculations were carried out to investigate the effect of steel cleanliness on the composition of inclusions both in the molten steel and in the solidified steel of Al-killed Ca-tr...Industrial trials and thermodynamic calculations were carried out to investigate the effect of steel cleanliness on the composition of inclusions both in the molten steel and in the solidified steel of Al-killed Ca-treated low-sulfur steels.The composition of inclusions changed significantly at the Ca treatment stage with the modification of Al_(2)O_(3) into calcium aluminate and a slight decrease in the inclusion size and at the casting stage with the transformation of CaO into CaS with an increase in the inclusion size.Based on experimental results and thermodynamic calculations,the Al_(2)O_(3) content in inclusions in the molten steel showed a nearly linear inverse relationship with the total calcium(TCa)/total oxygen(TO)in the steel when TCa/TO<3 and kept less than 10 wt.%under TCa/TO>3.The CaO content in inclusions firstly increased until the TCa/TO reached 1-2 and then slightly decreased with the increase in TCa/TO.The CaS content in inclusions was less than 10 wt.%when TCa/TO<1.5 and increased with the increase in the TCa/TO and total sulfur(TS)content in the steel.After solidification and cooling,the CaO/CaS in inclusions increased with the increase in the TO/TS and TCa contents in the steel;however,the CaO/CaS was less than 1.0 regardless of the TCa content when TO/TS<1.Accordingly,the composition of inclusions after solidification could be adjusted by controlling the cleanliness and calcium content of the steel,thereby adjusting the property of inclusions.展开更多
The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter per...The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.展开更多
Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The ...Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The Co−30Ni−10Al−3V−6Ti−2Ta alloy,designed based onγʹphase dissolution temperature and phase fraction,was synthesized via arc melting and heat treatment.Phase transition temperatures,microstructure evolution,and hightemperature mechanical properties were characterized by differential scanning calorimetry,scanning electron microscopy,dual-beam TEM,and compression tests.Results show that the alloy has low density(8.15 g/cm^(3))and highγʹdissolution temperature(1234℃),along with unique yield strength retention from room temperature to 650℃.The yield strength anomaly(YSA)is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism,contributing to superior high-temperature stability of the alloy.The yield strength of this alloy outperforms other lowdensity Co-based superalloys in the temperature range of 23−650℃.展开更多
基金Supported by Basic Scientific Research Project of the Liaoning Provincial Department of Education Has Been Unveiled to Facilitate Local Project Funding (JYTMS20230835)Enhanced Scientific Research Project Funded by the Departmentof Higher Education in Liaoning Province (General program)(JYTMS20230852)。
文摘The adsorptive denitrification performance of MIL-101(Cr)-0.5 toward pyridine,aniline or quinoline in simulated fuels with basic nitrogen content of 1732μg/g was evaluated separately.Furthermore,the effects of adsorption temperature,adsorption time and adsorbent dosage on their adsorptive denitrification performance were systematically investigated.The experimental results demonstrated that under a fixed adsorbent dosage of 0.05 g and a simulated fuel volume of 10 mL,the optimal removal efficiency for aniline was achieved at 30℃ within 30 min,whereas higher temperatures and longer times(40℃and 40 min)were required for effective removal of pyridine and quinoline.Density Functional Theory(DFT)calculations were conducted via Materials Studio(MS)software to study the adsorptive denitrification mechanism of MIL-101(Cr)toward these three basic nitrogen-containing compounds.The simulation calculation results revealed that the interaction between pyridine and MIL-101(Cr)primarily involved coordination adsorption.In contrast,the interaction between aniline or quinoline and MIL-101(Cr)proceeded mainly through coordination,with additional contributions fromπ-complexation and hydrogen bonding.The overall adsorption strength order is pyridine>aniline>quinoline.During the adsorption process,pyridine and quinoline transfer electrons to the MIL-101(Cr)surface through the H→C→N→Cr^(3+)pathway,while aniline transfers electrons to the MIL-101(Cr)surface through various pathways,including N→Cr^(3+),N→C→Cr^(3+)and N→H→O.Furthermore,adsorption kinetics studies indicated that the adsorption processes for all three basic nitrogen-containing compounds followed the quasi second order kinetic models.The experimental results on the effect of benzene on the adsorptive denitrification performance of MIL-101(Cr)-0.5 demonstrated that benzene exerted a more significant impact on the adsorption of aniline and quinoline.Finally,the adsorbent was regenerated using ethanol washing.It was found that MIL-101(Cr)-0.5 retained stable denitrification performance after two regeneration cycles.
文摘The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion.
基金supported by the Science Foundation of Zhejiang Pharmaceutical University Science Foundation of XIAO2024006General project of Education Department of Zhejiang Province(2024116/Y202456535)Fenghua District Science and Technology Association Natural Science Foundation Project 05,which were greatly acknowledged.
文摘With the development of hydrate technology,more and more applications have been appeared in many areas.However,hydrate additive is always one research hotspot,it has attracted more and more attention.The influence of two biosurfactants on CO_(2) hydrate formation process were investigated.Through the investigation of experiment research,rhamnolipid and sophorolipid had the promotion effect on CO_(2) hydrate formation kinetics.Hydrate gas storage reached the maximum value 32.01(volume ratio)and conversion ratio of water to hydrate was 19.42%when sophorolipid concentration was 0.05%(mass).Hydrate gas storage capacity reached the maximum value 31.22(volume ratio)and conversion ratio of water to hydrate was 18.94%when rhamnolipid concentration was 0.05%(mass).Through the comparison of gas storage capacity and hydrate formation rate,sophorolipid had stronger promotion effect on CO_(2) hydrate formation kinetics than rhamnolipid.It increased the depth of gas hydration reaction.CO_(2) hydrate formation gas was carried out under the condition of constant temperature and volume.Hydration number was considered in the hydrate calculation process.Combined with hydrate formation kinetic theory of Chen–Guo model,the hydrated gas volume was compared with remaining volume of reactor.This model could calculate the change of CO_(2) hydrate gas storage capacity over time.The calculated values of gas storage was in good agreement with experimental values.So this study has the better guiding function for relevant hydrate technology application.
基金supported by the National Natural Science Foundation of China (No. 22077111)the Department of Education of Guangdong Province (No. 2022ZDJS025)+1 种基金the Hong Kong/Macao Joint Research and Development Fund Project of Wuyi University (No. 2022WGALH15)Zhejiang Medical and Health Science and Technology Plan Project of China (No.2022KY231)。
文摘Four new sesquiterpenoids(1-4), including the first reported instance of a novel 2,3-seco oplopane carbon skeleton(1), together with 19 known analogues, were isolated from the flower buds of Tussilago farfara(coltsfoot). The challenging determination of relative and absolute configurations—particularly in flexible side chains and substituents—was achieved for the first time through an integrated approach combining spectroscopic analyses, chemical derivatization, chiral gas chromatography(GC), and quantum chemical calculations. All compounds were evaluated for anti-diabetic activity using an insulin-stimulated glucose uptake model in C2C12 myotubes and for anti-inflammatory activity via a lipopolysaccharide(LPS)-induced nitric oxide(NO) inhibition assay in RAW264.7 macrophages. Six compounds significantly enhanced glucose uptake, and mechanistic investigation of compound 3 revealed activation of the insulin receptor substrate 1(IRS-1)/protein kinase B(Akt)/glycogen synthase kinase 3β(GSK-3β) signaling pathway. Twenty-one compounds exhibited marked inhibition of NO production;among them, compounds 2 and 6 dose-dependently suppressed inducible nitric oxide synthase(iNOS) expression and nuclear factor κB(NF-κB) phosphorylation.
基金supported by the National Natural Science Foundation of China (No.22275052)Department of Science and Technology of Hubei Province (Nos.2025AFA111 and 2024CSA076)。
文摘The hydrogen evolution reaction(HER) is a key process in electrocatalytic water splitting for hydrogen production,yet it is often limited by sluggish H^(*)-OH adsorption and H*binding kinetics.We obtained Rumodified Ni O nanoparticles(Ru-Ni O/NF) with enhanced HER properties by substituting ruthenium(Ru)for Ni atoms in the Ni O(200) crystalline facets on nickel foam by a one-step electrodeposition technique.This novel catalyst exhibits a significantly reduced H^(*)-OH adsorption energy and improved kinetics,with an overpotential of only 60 mV at 10 mA/cm^(2) and a Tafel slope of 26.19 mV/dec.The Ru-Ni O/NF maintains its activity for over 115 h,outperforming NiO/NF by reducing the overpotential by 177 mV.DFT calculations confirm that the addition of Ru to NiO enhances the HER kinetics by modifying the electronic structure,optimizing the surface chemistry,stabilizing the intermediates,lowering the energy barriers,and facilitating efficient charge transfer through a robust three-dimensional structure,resulting in a change in the rate-limiting step and a significant reduction in the Gibbs free energy.This study presents a highly efficient HER catalyst and offers insights into designing advanced NiO-based electrocatalysts by reducing reaction energy barriers.
基金supported by the National Natural Science Foundation of China(22472104)Guangdong Basic and Applied Basic Research Foundation(2024A1515012075,2024A1515010028)the Postdoctoral Fellowship Program of CPS Funder(GZC20241083,2025M771117)。
文摘Oxygen evolution reaction(OER)is widely recognized as a bottleneck of water electrolysis.To determine the underlying reaction mechanisms,particularly the relative contribution of the adsorbate evolution mechanism(AEM)and lattice-oxygen participation mechanism(LOM),we conduct a comprehensive investigation combining Density Functional Theory(DFT)calculations and experimental validation.Our theoretical analysis of doped RuO_(2)catalysts reveals that heteroatom doping(Ni,Cu,and Zn)induces significant local charge transfer,leading to the increased charge state of Ru and the downshifted d-band center.This,in turn,enables the mechanism switching from the conventional AEM to the more efficient LOM,and finally improves OER activity.We also establish a simple yet powerful descriptor,Ne of Ru(representing charge density of Ru sites),which enables accurate prediction of both catalytic activity and stability.Guided by these theoretical predictions,we successfully synthesize a Ni-doped RuO_(2)catalyst,which exhibits excellent OER activity and stability in acidic media,achieving an overpotential of just 156 mV and maintaining stability for 4000 h at 10 mA cm^(−2),significantly surpassing the performance of the commercial RuO_(2).These findings not only provide fundamental insights into the mechanism-switching behavior in OER catalysis but also offer a practical strategy for designing high-performance,stable electrocatalysts for acidic water electrolysis.
基金supported by the National Natural Science Foundation of China (Nos.82293682,82293684,and 82173703)。
文摘Owing to their intricate molecular frameworks and copious chiral centers,the structural identification and configurational assignment of natural products are challenging tasks.Comprehensive spectral data analysis is crucial for the confirmation of absolute configurations.Ignoring critical parameters will lead to false structure,which may confuse the total synthesis and drug development.Herein,the configurations of seven heterogeneous Pallavicinia diterpenoids(PDs) isolated from Pallavicinia liverworts are revised using a combination of single-crystal X-ray diffraction and electronic circular dichroism(ECD) calculations.Meanwhile,identification of five unprecedented PD heterodimers PD-dimers A-E(18-22) along with eleven previously undescribed PDs(5-9,13-17,23) obtained by the reinvestigation of the Chinese liverwort Pallavicinia subciliata have resulted in corrections and support the revised conclusions.
基金supported by the Fundamental Research Funds for the Central Universities(WUT:2024IVA052 and Grant No.104972025KFYjc0089)。
文摘Two-dimensional(2D)multilayer kagome materials hold significant research value for regulating kagome-related physical properties and exploring quantum effects.However,their development is hindered by the scarcity of available material systems,making the identification of novel 2D multilayer kagome candidates particularly important.In this work,three types of 2D materials with trilayer kagome lattices,namely Sc_(6)S_(5)X_(6)(X=Cl,Br,I),are predicted based on first-principles calculations.These 2D materials feature two kagome lattices composed of Sc atoms and one kagome lattice composed of S atoms.Stability analysis indicates that these materials can exist as free-standing 2D materials.Electronic structure calculations reveal that Sc_(6)S_(5)X_(6)are narrow-bandgap semiconductors(0.76–0.95 e V),with their band structures exhibiting flat bands contributed by Sc-based kagome lattices and Dirac band gaps resulting from symmetry breaking.The sulfur-based kagome lattice in the central layer contributes an independent flat band below the Fermi level.Additionally,Sc_(6)S_(5)X_(6)exhibit high carrier mobility,with hole and electron mobilities reaching up to 10^(3)cm^(2)·V^(-1)·s^(-1),indicating potential applications in low-dimensional electronic devices.This work provides an excellent example for the development of novel multilayer 2D kagome materials.
基金support from the Key projects of scientific research projects of universities in Anhui Province(2024AH050360).
文摘MnO_(2) stands out among cathode materials for aqueous zinc-ion batteries(AZIBs)high capacity and voltage,it has poor stability and slow Zn^(2+) kinetics.Herein,we propose a dual-regulation strategy integrating copper doping and carbon-based confinement.Residual carbon(RC),derived from acid-washed coal gasification fine slag(CGFS),serves as a conductive and porous framework for the directional growth of Cu-doped MnO_(2) nanowires(CMO@RC).The synergistic modulation of Cu-induced electronic structure tuning and carbon confinement induced mechanical/electrical stabilization significantly enhances Zn^(2+) transport and electrochemical performance.CMO@RC achieves a high capacity of 563 mA·h·g^(−1) at 0.1 A·g^(−1) and maintains 106%after 1000 cycles at 1 A·g^(−1).Kinetic analyses confirm the dual-path Zn^(2+) diffusion and accelerated reaction kinetics,while DFT calculations reveal that Cu doping enhances Mn 3d orbital hybridization and electron interaction with carbon,elevating the density of states near the Fermi level and reducing charge transfer barriers.Furthermore,pouch cell testing demonstrates outstanding flexibility and mechanical resilience.This study provides a cost-effective and scalable strategy for high-performance AZIBs,leveraging both experimental and theoretical validations.
基金supported by the National Key Research and Development Program of China(Grant Nos.2023YFA1406600 and 2021YFA1202200)。
文摘First-principles calculations based on density functional theory(DFT)have had a significant impact on chemistry,physics,and materials science,enabling in-depth exploration of the structural and electronic properties of a wide variety of materials.Among different implementations of DFT,the plane-wave method is widely used for periodic systems because of its high accuracy.However,this method typically requires a large number of basis functions for large systems,leading to high computational costs.Localized basis sets,such as the muffin-tin orbital(MTO)method,have been introduced to provide a more efficient description of electronic structure with a reduced basis set,albeit at the cost of reduced computational accuracy.In this work,we propose an optimization strategy using machine-learning techniques to automate MTO basis-set parameters,thereby improving the accuracy and efficiency of MTO-based calculations.Default MTO parameter settings primarily focus on lattice structure and give less consideration to element-specific differences.In contrast,our optimized parameters incorporate both structural and elemental information.Based on these converged parameters,we successfully recovered missing bands for CrTe_(2).For the other three materials—Si,GaAs,and CrI_(3)—we achieved band improvements of up to 2 e V.Furthermore,the generalization of the machine-learned method is validated by perturbation,strain,and elemental substitution,resulting in improved band structures.Additionally,lattice-constant optimization for Ga As using the converged parameters yields closer agreement with experiment.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.22473010,22303114,and 12474372)the Fundamental Research Funds for the Central Universities,Jilin University,the National Key Research and Development Program of China(Grant No.SQ2023YFB2805600)+4 种基金the Natural Science Foundation of Beijing Municipality(Grant No.Z210004)the Fund from the State Key Laboratory of Information Photonics and Optical Communications(Grant No.IPOC2021ZT01)Beijing Nova Program from Beijing Municipal Science and Technology Commission(Grant No.20230484433)Beijing University of Posts and Telecommunications Excellent Ph.D.Students Foundation(Grant No.CX20241078)Beijing Natural Science Foundation(Undergraduate Program)(Grant No.QY24218)。
文摘The development of high-performance solid electrolytes is pivotal for advancing solid-state battery technologies.In this work,we design an oxysulfide-based solid electrolyte Na MgPO_(3)S by combining bond valence theory and density functional theory calculations.The material features a wide band gap of 4.0 eV and a considerable reduced Na^(+)migration barrier of 0.44 eV,a 1.26-eV decrease compared to pristine Na MgPO_(4)(~1.70 eV).Ab initio molecular dynamics simulations further reveal significantly enhanced ionic conductivity in the oxysulfide-based system compared to the pristine oxide structure.In addition,the calculated decomposition energy indicates that the modified material exhibits good moisture stability.Our findings suggest that sulfur-doping strategy can simultaneously achieve improved ionic conductivity and high moisture stability in oxide solid electrolytes,which could pave the way for designing high-performance solid electrolytes.
基金supported by the National Natural Science Foundation of China(22177011(R.Z.Qiao),21977012(R.Z.Qiao),and 21572018(C.Li))the National High-Level Hospital Clinical Research Funding(2023-NHLHCRF-YXHZ-ZRMS-02)the Joint Project of BRCBC(Biomedical Translational Engineering Research Center of BUCT-CJFH)(XK2020-06).
文摘4-Bromo-3-methylphenol(BMP)is an important chemical intermediate with wide applications in the fields of medicine and pesticides.The synthesis of BMP from m-cresol via bromination is easy to carry out on an industrial scale.However,due to the formation of regioisomeric impurities during bromination and the low melting point of BMP,the separation process is prone to the formation of oily substances,resulting in low yield and purity.In this work,a new cocrystallization engineering approach was proposed to separate and purify BMP.Through design of experiments,the cocrystallization process of BMP and triethylenediamine(DABCO)was optimized using a minimum-run resolution IV screening design combined with response surface methodology.In addition,the obtained 2BMP-DABCO powder was characterized by thermal analysis,powder X-ray diffraction,infrared spectroscopy,and scanning electron microscopy.Single crystals of 2BMP-DABCO were grown from acetone by slow evaporation,and detailed structural information was obtained through single-crystal X-ray diffraction.The self-assembly mechanism was further clarified by density functional theory calculations.This study provides a simple,robust,and scalable method for the production of BMP and offers a reference for the separation and purification of phenolic substances.
基金supported by the National Key R&D Program of China (Grant Nos.2022YFA1403103 and 2019YFA0308603)the National Natural Science Foundation of China (Grant No.12304167)the Shandong Provincial Natural Science Foundation of China (Grant No.ZR2023QA020)。
文摘Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems consisting of two insulators.Here,motivated by the emergence of an insulator-metal transition in type-Ⅲ heterostructures and the superconductivity in some“special”two-dimensional(2D)semiconductors via electron doping,we predict that the 2D heterostructure SnSe_(2)/PtTe_(2) is a model system for realizing IS by using firstprinciples calculations.Our results show that due to slight but crucial interlayer charge transfer,SnSe_(2)/PtTe_(2) turns to be a type-Ⅲ heterostructure with metallic properties and shows a superconducting transition with the critical temperature(T_(c))of 3.73 K.Similar to the enhanced electron–phonon coupling(EPC)in the electrondoped SnSe_(2) monolayer,the IS in the SnSe_(2)/PtTe_(2) heterostructure mainly originates from the metallized SnSe_(2) layer.Furthermore,we find that its superconductivity is sensitive to tensile lattice strain,forming a domeshaped superconducting phase diagram.Remarkably,at 7%biaxial tensile strain,the superconducting T_(c) can increase more than twofold(8.80 K),resulting from softened acoustic phonons at the𝑀point and enhanced EPC strength.Our study provides a concrete example for realizing IS in type-Ⅲ heterostructures,which waits for future experimental verification.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11505003 and 52325103)the Anhui Provincial Natural Science Foundation(Grant No.2108085MA25)。
文摘High-performance intelligent protective materials are vital for nuclear energy systems exposed to extreme irradiation.Among them,tungsten-based alloys demonstrate exceptional potential owing to their superior irradiation resistance.Recent experimental studies have demonstrated that W-Ta-Cr-V alloys exhibit excellent irradiation resistance under helium(He)ion irradiation.However,the underlying mechanisms,especially the migration behavior of He atoms,remain unclear.In this work,the influences of uniaxial tensile and compressive strain on He migration in W-Ta-Cr-V complex alloys have been systematically studied through first-principles calculations.Our results demonstrate that He atoms preferentially occupy the tetrahedral interstitial sites,with interstitial formation energies significantly reduced compared to pure W.The introduction of Ta,Cr,and V alloying elements markedly increases the He migration barriers,effectively suppressing He diffusion.Compressive strain increases the migration barriers,inhibiting He bubbles nucleation and growth,while tensile strain decreases the barriers,facilitating bubble formation.Compared to pure W,the W-Ta-Cr-V alloys exhibit both lower He interstitial formation energies and higher migration barriers,with further enhancement under compressive strain.Specifically,compressive strain of 6%increases the He migration barrier of the W-Ta-Cr-V alloy by 0.166 e V,which further widens the difference relative to pure W.These findings provide a theoretical explanation for the superior irradiation resistance of tungsten-based alloys observed experimentally and promote the understanding of irradiation damage in these alloys under strain.
基金Project supported by the National Key Research and Development Program of China(Grant No.2024YFF0508503)。
文摘Strong long-wavelength laser pulses enable direct manipulation of atomic lattices for engineering novel quantum states in complex materials.Nonlinear coupling between two infrared-active phonon modes(TO_(1) and TO_(2)),induced by intense terahertz light fields,significantly enhances the amplitude of the TO_(1) mode and facilitates ultrafast control of transient structural distortions.This light-induced distortion reduces the lattice thermal conductivity from 8.1 W·m^(-1)·K^(-1)to 3.0 W·m^(-1)·K^(-1).The reduction originates from the nonlinear coupling,which enhances anharmonic interactions in the lattice potential energy and substantially shortens the phonon lifetime(τ).This work demonstrates a strategy applicable to other perovskite materials and provides a framework for investigating light-induced electrical,optical,and thermodynamic phase transitions.
基金supported by the Stable Support Fund forBasic Disciplines,China(No.3072024WD0201)。
文摘Underwater gas-liquid two-phase propulsion technology is an emerging propulsion method that offers high efficiency and unrestricted navigation speed.The integration of this technology into water ramjet engines can significantly enhance propulsion efficiency and holds substantial potential for broad applications.However,forming a gas-liquid two-phase flow within the nozzle requires introducing a large amount of rammed seawater.At this time,there is a complex phase transition problem of combustion products in the combustion chamber,which makes the thermodynamic calculation for gas-liquid two-phase water ramjet engines particularly challenging.This paper proposes a thermodynamic calculation method for gas-liquid two-phase water ramjet engines,based on the energy equation for gas-liquid two-phase flow and traditional thermodynamic principles,enabling thermodynamic calculations under conditions of ultra-high water-fuel ratios.Additionally,ground ignition tests of the gas-liquid two-phase engine were conducted,yielding critical engine test parameters.The results demonstrate that the gas-liquid two-phase water ramjet engine achieves a high specific impulse,with a theoretical maximum specific impulse of up to 7000(N s)/kg.The multiphase flow effects significantly impact engine performance,with specific impulse losses reaching up to 25.86%.The error between the thrust and specific impulse in the ground test and the theoretical values is within 10%,validating the proposed thermodynamic calculation method as a reliable reference for further research on gas-liquid two-phase water ramjet engines.
基金support from the National Key Research and Development Program(Nos.2023YFB3506802 and 2023YFB3709900)the National Natural Science Foundation of China(Grant Nos.52174293 and U22A20171)+1 种基金and the Fundamental Research Funds for the Central Universities(Grant No.FRF-BD-20-04A)the High Steel Center(HSC)at North China University of Technology and University of Science and Technology Beijing.
文摘Industrial trials and thermodynamic calculations were carried out to investigate the effect of steel cleanliness on the composition of inclusions both in the molten steel and in the solidified steel of Al-killed Ca-treated low-sulfur steels.The composition of inclusions changed significantly at the Ca treatment stage with the modification of Al_(2)O_(3) into calcium aluminate and a slight decrease in the inclusion size and at the casting stage with the transformation of CaO into CaS with an increase in the inclusion size.Based on experimental results and thermodynamic calculations,the Al_(2)O_(3) content in inclusions in the molten steel showed a nearly linear inverse relationship with the total calcium(TCa)/total oxygen(TO)in the steel when TCa/TO<3 and kept less than 10 wt.%under TCa/TO>3.The CaO content in inclusions firstly increased until the TCa/TO reached 1-2 and then slightly decreased with the increase in TCa/TO.The CaS content in inclusions was less than 10 wt.%when TCa/TO<1.5 and increased with the increase in the TCa/TO and total sulfur(TS)content in the steel.After solidification and cooling,the CaO/CaS in inclusions increased with the increase in the TO/TS and TCa contents in the steel;however,the CaO/CaS was less than 1.0 regardless of the TCa content when TO/TS<1.Accordingly,the composition of inclusions after solidification could be adjusted by controlling the cleanliness and calcium content of the steel,thereby adjusting the property of inclusions.
基金supported by the National Natural Science Foundation of China(52471240)the Natural Science Foundation of Zhejiang Province(LZ23B030003)+2 种基金the Fundamental Research Funds for the Central Universities(226-2024-00075)support from the Engineering and Physical Sciences Research Council(EPSRC,UK)RiR grant-RIR18221018-1EU COST CA23155。
文摘The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.
基金supported by the National Natural Science Foundation of China(Nos.51831007,52101135)the Shenzhen Science and Technology Program,China(No.SGDX20210823104002016)the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2021B1515120071,JCYJ20220531095217039)。
文摘Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The Co−30Ni−10Al−3V−6Ti−2Ta alloy,designed based onγʹphase dissolution temperature and phase fraction,was synthesized via arc melting and heat treatment.Phase transition temperatures,microstructure evolution,and hightemperature mechanical properties were characterized by differential scanning calorimetry,scanning electron microscopy,dual-beam TEM,and compression tests.Results show that the alloy has low density(8.15 g/cm^(3))and highγʹdissolution temperature(1234℃),along with unique yield strength retention from room temperature to 650℃.The yield strength anomaly(YSA)is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism,contributing to superior high-temperature stability of the alloy.The yield strength of this alloy outperforms other lowdensity Co-based superalloys in the temperature range of 23−650℃.
