This study presents an investigation into shock-induced exothermic reactions within three distinct aluminum-based energetic mixtures:aluminum/sulfur(Al/S),aluminum/copper oxide(Al/CuO),and aluminum/polytetrafluoroethy...This study presents an investigation into shock-induced exothermic reactions within three distinct aluminum-based energetic mixtures:aluminum/sulfur(Al/S),aluminum/copper oxide(Al/CuO),and aluminum/polytetrafluoroethylene(Al/PTFE).A challenge in current modeling efforts is accurately capturing the complex physical and chemical coupling under extreme loading,especially the influence of rapidly forming gaseous products in Al/PTFE mixtures on material integrity.To address this,a wide-range numerical model based on the Smoothed Particle Hydrodynamics(SPH)method was developed.This mesh-free approach manages large deformations and incorporates elastic-plastic flow,heat transfer,component diffusion,and chemical kinetics simulated using both zero-and first-order reaction schemes,favoring the latter for surface-reaction mechanisms.The proposed model takes into account gaseous reaction products,specifically aluminum fluoride(AlF3)to assess their impact on ampoule fracture dynamics.Numerical simulations,validated against experimental data,demonstrated that reaction rate,local pressure,and temperature are the primary controlling factors governing energy release and structural response.Comparative analysis revealed that although Al/CuO initiates reaction more readily(lower critical pressure/temperature),the Al/S mixture exhibits superior overall reaction efficiency under shock-wave loading,highlighting the significance of post-initiation kinetic factors.Furthermore,simulations using the conical ampoule geometry confirmed its effectiveness in generating a continuous pressure gradient,enabling systematic characterization of pressure-dependent reaction kinetics.This validated SPH model provides a powerful and predictive tool for understanding the complex behavior of energetic materials under shock-wave loading and aids in optimizing material composition for desired performance characteristics.展开更多
Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,a...Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.展开更多
The atom-realm effect(AR)represents a transformative paradigm in catalytic materials design,enabling dynamic electronic reconstruction and reaction pathway engineering through localized microenvironment modulation.By ...The atom-realm effect(AR)represents a transformative paradigm in catalytic materials design,enabling dynamic electronic reconstruction and reaction pathway engineering through localized microenvironment modulation.By introducing heteroatoms to induce atomic-scale rearrangements of electronic structures,geometric configurations,and quantum wavefunctions,this strategy overcomes the limitations of traditional catalysts constrained by static active sites and global electronic regulation.The AR mechanism facilitates selective bond cleavage and directional reassembly via dual-atom communicative effects and spin-polarization control,as demonstrated in electrocatalytic reaction,thermal-catalytic reaction,and fuel cells.Advanced synthesis strategies incorporating vacancy engineering and atomic layer deposition,coupled with operando characterization techniques,reveal dynamic interface evolution at sub-angstrom resolution.While significantprogress has been achieved,future development requires time-resolved bond dynamics analysis,machine learning-driven multiscale modeling,and continuous-flowfabrication to realize photonic-magnetic-thermal synergies in next-generation catalytic systems.This perspective establishes AR as a universal framework bridging quantum-level electronic manipulation with macroscopic catalytic performance optimization.展开更多
It is challenging to rationally construct synergistic charge-regulation of active sites and a lower energy barrier of the determining step for efficient oxygen reduction reaction(ORR).In this work,a novel catalyst(MnO...It is challenging to rationally construct synergistic charge-regulation of active sites and a lower energy barrier of the determining step for efficient oxygen reduction reaction(ORR).In this work,a novel catalyst(MnO_(2))_(cluster)/Fe,Mn-N-C with Fe-N_(4)O_(1) site coupled by MnO_(2) sub-nanometer clusters was successfully synthesized,which is attributed to the dicyanodiamine-glycine(DCD-Gly)dual-ligand effect.Specifically,the higher electrophilic index and the preferential coordination with Fe of N in DCD,and the chelating coordination of Gly with Mn.Experimental and theoretical calculation results indicate that preferential coordination of Fe with N atoms in DCD generates Fe-N_(4)O_(1) sites with axial oxygen coordination,while the coordination of Mn with Gly generates a large number of MnO_(2) sub-nanometer clusters.DFT calculations showed that axial oxygen altered the reaction-determining step of ORR at the FeN_(4)O_(1) site.Meanwhile,the MnO_(2) sub-nanoclusters further lowered the adsorption energy barriers of the reaction intermediates.This synergistic charge-regulation improved the ORR performance of(MnO_(2))_(cluster)/Fe,Mn-N-C(E_(1/2)=0.90 V).Meanwhile,(MnO_(2))_(cluster/)Fe,Mn-N-C catalyst also exhibits a discharge power density of 201 mW cm~(-2)in Zn-air batteries,which was much higher than the commercial Pt/C+RuO_(2).The strategy of ligand effect-driven construction provided a new idea for the electronic structure modulation of a monatomic catalyst.展开更多
Currently,simultaneous regulation of external morphology and internal electronic structure for Na_(3)V_(2)(PO_(4))_(3)(NVP)is rarely realized.Herein,complexes of β-cyclodextrin(βCD)and ethylenediaminetetraacetic aci...Currently,simultaneous regulation of external morphology and internal electronic structure for Na_(3)V_(2)(PO_(4))_(3)(NVP)is rarely realized.Herein,complexes of β-cyclodextrin(βCD)and ethylenediaminetetraacetic acid ferric sodium salt(EDTAFeNa)are utilized for the one-step preparation of NVP with spherical morphology as well as Fe substitution.βCD is initially hydrolyzed into glucose,and then carbon microspheres with numerous pores are formed through continuous dehydration and carbonization.The intermediate hydroxymethylfurfural is rich in active functional groups,which are attractive for the V/P-contained raw materials.Accordingly,the nucleation sites for NVP are successfully limited in the spherical framework,possessing a superior surface area of 97.15 g m^(-2).Furthermore,the beneficial Fe in EDTAFeNa enters into the NVP bulk to construct a novel Fe-doped Na_(3)V_(1.95)Fe_(0.05)(PO_(4))_(3)(NVP/β-ISC)material.Fe-substitution induces significant optimizations of electronic structure for NVP,which has been verified by the newly generated abundant oxygen vacancies and extended V-O bond length.Moreover,a multielectron reaction is activated,resulting from the V^(4+)/V^(5+)redox couple.The charge compensation mechanism of NVP/β-ISC is also deeply investigated.Density functional theory(DFT)calculations theoretically elaborate the mechanism of Fe-doping.Consequently,NVP/β-ISC reveals superior sodium storage performance in both half and full cells and even at different extreme conditions(needling,soaking,bending,and freezing).展开更多
The Glauber/eikonal model is a widely used tool for studying intermediate-and high-energy nuclear reactions.When calculating the Glauber/eikonal model phase shift functions,the optical limit approximation(OLA)is often...The Glauber/eikonal model is a widely used tool for studying intermediate-and high-energy nuclear reactions.When calculating the Glauber/eikonal model phase shift functions,the optical limit approximation(OLA)is often used.The OLA neglects the multiple scattering of the constituent nucleons in the projectile and target nuclei.However,the nucleon-target version of the Glauber model(the NTG model)proposed by Abu-Ibrahim and Suzuki includes multiple scattering effects between the projectile nucleons and target nuclei.The NTG model was found to improve the description of the elastic scattering angular distributions and total reaction cross sections of some light heavy-ion systems with respect to the OLA.In this work,we study the single-nucleon removal reactions(SNRRs)induced by carbon isotopes on ^(12)C and ^(9)Be targets using both the NTG model and the OLA.Reduction factors(RFs)of the single-nucleon spectroscopic factors were obtained by comparing the experimental and theoretical SNRR cross sections.On average,the RFs obtained with the NTG model were smaller than those obtained using the OLA by 7.8%,in which the average difference in one-neutron removal was 10.6% and that in one-proton removal was 4.2%.However,the RFs were still strongly dependent on the neutron-proton asymmetryΔS of the projectile nuclei,even when the NTG model was used.展开更多
In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion redu...In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion reduction,and water reduction)using a cylindrical stirring system.The corrosion-enhanced erosion(C-E)rates were determined for each condition.The results revealed that pure iron displayed similar pure erosion behaviour across all three cathodic reactions.When the cathodic reactions involve hydrogen ion reduction or water reduction,the erosion-corrosion of pure iron manifested as uniform damage,with the reduction in hardness being the main cause of the C-E in this case.Conversely,in the case of oxy-gen reduction reaction as the cathodic reaction,the erosion-corrosion presented as pitting damage,with the reduction in hardness resulting from localized concentration of anodic current and the formation of easily worn protruding flaky iron structures at the edges of the pits as the main mechanism of the C-E.Moreover,linear and exponential relationships were found between the C-E rate and the anodic current density for uniform damage and pitting damage,respectively.Finally,the concept of surface equivalent hardness was proposed,along with the establishment of a mathematical model for surface equivalent hardness based on the relationships between the C-E rate and the anodic current density.Utilizing the surface equivalent hardness enables the evaluation of the erosion rate on material surfaces considering the coupled effect.展开更多
Constructing highly efficient and durable water electrolysis cell system is of crucial importance to meet the requirements of renewable hydrogen energy conversion strategy.However,the underdevelopment of water oxidati...Constructing highly efficient and durable water electrolysis cell system is of crucial importance to meet the requirements of renewable hydrogen energy conversion strategy.However,the underdevelopment of water oxidation half-reaction is well-known to greatly hinder the practical hydrogen production.Although there have been numerous efforts in the design of oxygen evolution reaction(OER) electrocatalysts,the roles of electrolytes in OER activity are less systematically studied.In this review,the pivotal roles pH,cations,anions and salt ions within electrolyte in altering the intrinsic mechanism of OER have been especially discussed,respectively,based on some recent advances in understanding electrolyte effects on OER.Therefore,we highlight the importance of electrolyte compositions in affecting(de)protonation,catalyst structure evolution,reaction intermediates,water structure/network and stability.These insights could profoundly reveal how the electrolyte engineering determines catalytic performance,modulates catalytic active sites and alters change transfer mechanisms at the electrode interface.Such understandings could pave the way for the rational design of highly efficient electrocatalytic OER,CO_(2) reduction and N2 reduction systems.Finally,we discuss the challenges and future perspectives of electrolyte effects on OER,the intrinsic charge transfer mechanisms in electrocatalysis systems and the potential applications of electrolyte engineering in industrial settings.展开更多
Based on the Skyrme energy density functional and reaction Q-value,this study proposed an effective nucleus-nucleus poten-tial for describing the capture barrier in heavy-ion fusion processes.The 443 extracted barrier...Based on the Skyrme energy density functional and reaction Q-value,this study proposed an effective nucleus-nucleus poten-tial for describing the capture barrier in heavy-ion fusion processes.The 443 extracted barrier heights were well reproduced with a root-mean-square(RMS)error of 1.53 MeV,and the RMS deviations with respect to 144 time-dependent Hartree-Fock capture barrier heights were only 1.05 MeV.Coupled with the Siwek-Wilczyński formula,wherein three parameters were determined by the proposed effective potentials,the measured capture cross sections at energies around the barriers were reasonably well reproduced for several fusion reactions induced by nearly spherical nuclei as well as by nuclei with large deformations,such as^(154)Sm and^(238)U.The shallow capture pockets and small values of the average barrier radii resulted in the reduction of the capture cross sections for 52,54Cr-and 64 Ni-induced reactions,which were related to the synthesis of new super-heavy nuclei.展开更多
Additive manufacturing(AM)methods have garnered considerable attention owing to their flexibility in fabricating complex parts with desirable mechanical properties.However,the poor surface quality of the resulting met...Additive manufacturing(AM)methods have garnered considerable attention owing to their flexibility in fabricating complex parts with desirable mechanical properties.However,the poor surface quality of the resulting metal parts remains a severe challenge for the applications.Here,a novel dual-additive synergy strategy is presented,which simultaneously enhances material removal efficiency and regulates electrode surface reactions during electrochemical polishing(ECP)of AM AlSi10Mg.Theoretical studies and experimental characterizations confirm that NaF promotes selective dissolution at the peaks,while glucose acts as a stabilizer for the surface valleys.This approach effectively facilitates the selective removal of surface protrusions,achieving a smoother and more uniform surface finish,resulting in a surface roughness reduction of approximately 86%,compared to a 63%reduction without additives.This study not only provides a new approach for optimizing surface quality of AM AlSi10Mg but also offers new insights into electrolyte design and the stabilization of metal anodes.展开更多
Cobalt is undoubtedly the most promising alternative metal to rhodium for a highly active and stable hydroformylation process under mild conditions.In this study,two cobalt-based heterogeneous catalysts were synthesiz...Cobalt is undoubtedly the most promising alternative metal to rhodium for a highly active and stable hydroformylation process under mild conditions.In this study,two cobalt-based heterogeneous catalysts were synthesized via impregnating a cobalt precursor into polymers(POPs-NVP).Comprehensive characterization revealed that the cobalt species on the catalysts exist as CoO with two distinct sizes:nanoparticles and single sites.The CoO nanoparticles on POPs-NVP exhibited outstanding hydroformylation activity(81.7%yield of aldehyde and alcohol,13.5%yield of alkane),while CoO single sites displayed robust olefin hydrogenation performance(62.6%yield of alkane,27.3% yield of aldehyde and alcohol).These divergent catalytic behaviors were attributed to distinct electron density distributions around surface-exposed cobalt species,which were critically governed by CoO sizes on catalysts.By elucidating the size-dependent effects of CoO/POPs-NVP catalysts,this work provided insights into the complex active species states in heterogeneous cobalt-based catalysts,and established valuable experimental and theoretical foundations for designing highly efficient cobalt-based heterogeneous catalysts for hydroformylation.展开更多
Magnetohydrodynamic(MHD)radiative chemically reactive mixed convection flow of a hybrid nanofluid(Al_(2)O_(3)–Cu/H_(2)O)across an inclined,porous,and stretched sheet is examined in this study,along with its unsteady ...Magnetohydrodynamic(MHD)radiative chemically reactive mixed convection flow of a hybrid nanofluid(Al_(2)O_(3)–Cu/H_(2)O)across an inclined,porous,and stretched sheet is examined in this study,along with its unsteady heat and mass transport properties.The hybrid nanofluid’s enhanced heat transfer efficiency is a major benefit in high-performance engineering applications.It is composed of two separate nanoparticles suspended in a base fluid and is chosen for its improved thermal properties.Thermal radiation,chemical reactions,a transverse magnetic field,surface stretching with time,injection or suction through the porous medium,and the effect of inclination,which introduces gravity-induced buoyancy forces,are all important physical phenomena that are taken into account in the analysis.A system of nonlinear ordinary differential equations(ODEs)is derived from the governing partial differential equations for mass,momentum,and energy by applying suitable similarity transformations.This simplifies the modeling procedure.The bvp4c solver in MATLAB is then used to numerically solve these equations.Different governing parameters modify temperature,concentration,and velocity profiles in graphs and tables.These factors include radiation intensity,chemical reaction rate,magnetic field strength,unsteadiness,suction/injection velocity,inclination angle,and nanoparticle concentration.A complex relationship between buoyancy and magnetic factors makes hybrid nanofluids better at heat transmission than regular ones.Thermal systems including cooling technologies,thermal coatings,and electronic heat management benefit from these findings.展开更多
Brown carbon(BrC)has attracted widespread attention because of its strong absorption of solar radiation in the ultraviolet-visible wavelength range,which causes adverse impacts on human health.Originally,BrC was a phy...Brown carbon(BrC)has attracted widespread attention because of its strong absorption of solar radiation in the ultraviolet-visible wavelength range,which causes adverse impacts on human health.Originally,BrC was a physically defined class of substances.However,current research has gradually shifted towards the identification of its chemical groups,because its light-absorbing capability,chemical properties and health effects mainly depend on the chemical composition of its chromophores.Therefore,this review mainly focuses on the chemical understanding of BrC based on chromophores,and the secondary formation mechanism of chromophores,photosensitized reactions,and human health effects of BrC were detailly summarized.Firstly,BrC chromophores are divided into five categories:nitrogen-heterocycles,nitrogen-chain,aromatic species,oligomers and sulfur-containing organic compounds.Different chromophore precursor species exhibit variations,and their formation mechanisms are also distinct.Secondly,BrC can trigger the production of secondary organic aerosol(SOA)precursors or cause SOA growth because BrC is an important component of light-absorbing particles formed during incomplete combustion of biomass and fossil fuels,potentially exerting adverse effects on human health.Finally,developing sufficiently separated methods for BrC and refining algorithms and machine learning can lead to a more effective understanding of the chemical composition of chromophores,thus enabling better evaluation of the atmospheric effects and health impacts of BrC.In all,this review provides new insights into the categories of BrC chromophores and new advance in secondary formation mechanisms,photosensitized reactions,and human health effects on the basis of chemical structures.展开更多
Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demons...Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demonstrated substantial potential for the advancement of electrocatalytic CO_(2) reduction to formate.However,due to the weak bonding of protons(H^(*)) of Bi,the available protonate of CO_(2) on Bi is insufficient,which limits the formation of OCHO^(*).Prediction by theoretical calculation,chlorine doping can effectively promote the dissociation of H_(2)O and thus achieve effective proton supply.We prepare chlorine-doped Bi(Cl-Bi) via an electrochemical conversion strategy for electroreduction of CO_(2) .An obvious improvement of faradaic efficiency(FE) of formate(96.7% at-0.95 V vs.RHE) can be achieved on Cl-Bi,higher than that of Bi(89.4%).Meanwhile,Cl-Bi has the highest formate production rate of 275 μmol h^(-1)cm^(-2)at-0.95 V vs.RHE,which is 1.2 times higher than that of Bi(224 μmol h^(-1)cm^(-2)).In situ characterizations and kinetic analysis reveal that chlorine doping promotes the activation of H_(2)O and supply sufficient protons to promote the protonation of CO_(2) to OCHO^(*),which is consistent with theoretical calculation.The study presents an effective strategy for rational design of highly efficient electrocatalysts to promote green chemical production.展开更多
The slow conversion of polyphase in lithium-sulfur(Li-S)batteries not only intensifies the shuttle effect of lithium polysulfides(LiPSs),but also causes the continuous accumulation of inactive sulfur species,resulting...The slow conversion of polyphase in lithium-sulfur(Li-S)batteries not only intensifies the shuttle effect of lithium polysulfides(LiPSs),but also causes the continuous accumulation of inactive sulfur species,resulting in rapid capacity attenuation and sluggish dynamic performance.Herein,the promoting effect of atomic interface stress on sulfur reaction was investigated via CoFe-CoFe_(2)O_(4)heterogeneous nanosheets with a cavity structure.The strain force induced by the in-situ precipitation of Co Fe bimetallic alloy in oxide matrix increased the d-band center,which was conducive to the interaction between catalyst and Li PSs.The sulfur cathode based on this two-dimensional(2D)nanosheet design showed an extremely high capacity of 751 mAh g^(-1)at 4 C.Even with a sulfur loading of 5.55 mg cm^(-2),its area capacity was still as high as 7.15 mAh cm^(-2).Meanwhile,the enhanced stability greatly improved the practical potential of Li-S batteries.展开更多
A PPh_(3)-catalyzed ring-opening addition reaction of cyclopropenones with alkyl bromides has been successfully established.This reaction offers a concise and practical approach for the assembly ofα,β-disubstituted ...A PPh_(3)-catalyzed ring-opening addition reaction of cyclopropenones with alkyl bromides has been successfully established.This reaction offers a concise and practical approach for the assembly ofα,β-disubstituted acrylates with exclusive E-stereoselectivity at room temperature.Mechanistic investigations indicated that both the hydrogen atom on vinyl group and one oxygen atom on ester group ofα,β-disubstituted acrylates derive from H2O in dimethyl sulfoxide(DMSO).Furthermore,a gram-scale experiment and late-stage modification of the products were accomplished,thereby expanding the application potential of this methodology in organic synthesis.展开更多
Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms lig...Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms ligand bonds or hydrogen bonds with sulfur ions in lithium polysulfides(LiPSs),thus inhibiting the shuttle effect.Electrochemical analyses demonstrated that lithium‑sulfur(Li‑S)batteries employing the NH2‑SS interlayer exhibited discharge specific capacities of 1048 and 789 mAh·g^(-1) at 0.2C and 2C,respectively,and even at 4C,the initial discharge specific capacity remained at 590 mAh·g^(-1),outperforming the Li‑S battery with unmodified SS as the interlayer.展开更多
To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretre...To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.展开更多
The shortage of CO_(2) source and the challenges associated with the separation of pure CO_(2) have led to a growing interest in the potential utilization of CO_(2)-contained IWG.Therefore,this study has established a...The shortage of CO_(2) source and the challenges associated with the separation of pure CO_(2) have led to a growing interest in the potential utilization of CO_(2)-contained IWG.Therefore,this study has established an acid-rock interaction kinetic model to characterize the long-term interactions between CO_(2)-contained IWG and shale.The findings delineate the reaction process into three phases:during the initial 10 years,solubility trapping predominates,with minimal mineral dissolution.This increases shale porosity,promoting the diffusion and storage range of CO_(2)-contained IWG.Between 10 and 300 years,mineral dissolution/precipitation assumes primacy,with mineral trapping gradually supplanting dissolution.Notably,shale porosity diminishes by a minimum of approximately 40%,effectively inhibiting gas leakage.After 300 years,equilibrium is reached,with rock porosity consistently lower than the initial porosity.Throughout the entire reaction process,as the initial CO_(2) concentration decreases,the initial pH drops from 4.42 to 3.61,resulting in a roughly 20%increase in porosity.Additionally,it is necessary to regulate its concentration to avoid H_(2)S leakage during CO_(2)-contained IWG geological sequestration.And particular attention should be directed towards the risk of gas leakage when the IWG exhibit high levels of SO_(2) or NO_(2).展开更多
基金conducted under the public contract for the Tomsk Scientific Center of the Siberian Branch of the Russian Academy of Sciences(Project No.FWRF-2024-0009).
文摘This study presents an investigation into shock-induced exothermic reactions within three distinct aluminum-based energetic mixtures:aluminum/sulfur(Al/S),aluminum/copper oxide(Al/CuO),and aluminum/polytetrafluoroethylene(Al/PTFE).A challenge in current modeling efforts is accurately capturing the complex physical and chemical coupling under extreme loading,especially the influence of rapidly forming gaseous products in Al/PTFE mixtures on material integrity.To address this,a wide-range numerical model based on the Smoothed Particle Hydrodynamics(SPH)method was developed.This mesh-free approach manages large deformations and incorporates elastic-plastic flow,heat transfer,component diffusion,and chemical kinetics simulated using both zero-and first-order reaction schemes,favoring the latter for surface-reaction mechanisms.The proposed model takes into account gaseous reaction products,specifically aluminum fluoride(AlF3)to assess their impact on ampoule fracture dynamics.Numerical simulations,validated against experimental data,demonstrated that reaction rate,local pressure,and temperature are the primary controlling factors governing energy release and structural response.Comparative analysis revealed that although Al/CuO initiates reaction more readily(lower critical pressure/temperature),the Al/S mixture exhibits superior overall reaction efficiency under shock-wave loading,highlighting the significance of post-initiation kinetic factors.Furthermore,simulations using the conical ampoule geometry confirmed its effectiveness in generating a continuous pressure gradient,enabling systematic characterization of pressure-dependent reaction kinetics.This validated SPH model provides a powerful and predictive tool for understanding the complex behavior of energetic materials under shock-wave loading and aids in optimizing material composition for desired performance characteristics.
基金supported by the National Natural Science Foundation of China (No. 52374292)China Baowu Low Carbon Metallurgy Innovation Foundation, China (No. BWLCF202309)the Natural Science Foundation of Changsha City, China (No. KQ2208271)。
文摘Some active metal oxides(Al_(2)O_(3),TiO_(2),and Cr_(2)O_(3))were selected as dopants to the Al_(2)O_(3)-based ceramic shells for investment casting of K417G superalloy.The effects of dopant types and contents(0,2,5,and 8 wt.%)on the wettability and interfacial reaction between the alloy and shell were investigated by a sessile-drop experiment.The results show that increasing the Al_(2)O_(3) doping contents(0−8 wt.%)reduces the porosity(21.74%−10.08%)and roughness(3.22−1.34μm)of the shell surface.The increase in Cr_(2)O_(3) dopant content(2−8 wt.%)further exacerbates the interfacial reaction,leading to an increase in the thickness of the reaction layer(2.6−3.1μm)and a decrease in the wetting angle(93.9°−91.0°).The addition of Al_(2)O_(3) and TiO_(2) dopants leads to the formation of Al_(2)TiO_(5) composite oxides in the reaction products,which effectively inhibits the interfacial reaction.The increase in TiO_(2) dopant contents(0−8 wt.%)further promotes the formation of Al_(2)TiO_(5),which decreases the thickness of the interfacial reaction layer(3.9−1.2μm)and increases the wetting angle(95.0°−103.8°).The introduced dopants enhance the packing density of the shell surface,while simultaneously suppress the diffusion of active metal elements from the alloy matrix to the interface.
基金supported by the Guangdong S&T Program(2020B0101370001,X.W.).
文摘The atom-realm effect(AR)represents a transformative paradigm in catalytic materials design,enabling dynamic electronic reconstruction and reaction pathway engineering through localized microenvironment modulation.By introducing heteroatoms to induce atomic-scale rearrangements of electronic structures,geometric configurations,and quantum wavefunctions,this strategy overcomes the limitations of traditional catalysts constrained by static active sites and global electronic regulation.The AR mechanism facilitates selective bond cleavage and directional reassembly via dual-atom communicative effects and spin-polarization control,as demonstrated in electrocatalytic reaction,thermal-catalytic reaction,and fuel cells.Advanced synthesis strategies incorporating vacancy engineering and atomic layer deposition,coupled with operando characterization techniques,reveal dynamic interface evolution at sub-angstrom resolution.While significantprogress has been achieved,future development requires time-resolved bond dynamics analysis,machine learning-driven multiscale modeling,and continuous-flowfabrication to realize photonic-magnetic-thermal synergies in next-generation catalytic systems.This perspective establishes AR as a universal framework bridging quantum-level electronic manipulation with macroscopic catalytic performance optimization.
基金financially supported by the Major Science and Technology Projects in Yunnan Province(202402AG050008)the Science and Technology Plan Project of Yunnan Province(202303AK140022)+1 种基金the Scientific and Technological Project of Yunnan Precious Metals Laboratory(YPML-20240502003)the Analysis and Testing Foundation of Kunming University of Science and Technology。
文摘It is challenging to rationally construct synergistic charge-regulation of active sites and a lower energy barrier of the determining step for efficient oxygen reduction reaction(ORR).In this work,a novel catalyst(MnO_(2))_(cluster)/Fe,Mn-N-C with Fe-N_(4)O_(1) site coupled by MnO_(2) sub-nanometer clusters was successfully synthesized,which is attributed to the dicyanodiamine-glycine(DCD-Gly)dual-ligand effect.Specifically,the higher electrophilic index and the preferential coordination with Fe of N in DCD,and the chelating coordination of Gly with Mn.Experimental and theoretical calculation results indicate that preferential coordination of Fe with N atoms in DCD generates Fe-N_(4)O_(1) sites with axial oxygen coordination,while the coordination of Mn with Gly generates a large number of MnO_(2) sub-nanometer clusters.DFT calculations showed that axial oxygen altered the reaction-determining step of ORR at the FeN_(4)O_(1) site.Meanwhile,the MnO_(2) sub-nanoclusters further lowered the adsorption energy barriers of the reaction intermediates.This synergistic charge-regulation improved the ORR performance of(MnO_(2))_(cluster)/Fe,Mn-N-C(E_(1/2)=0.90 V).Meanwhile,(MnO_(2))_(cluster/)Fe,Mn-N-C catalyst also exhibits a discharge power density of 201 mW cm~(-2)in Zn-air batteries,which was much higher than the commercial Pt/C+RuO_(2).The strategy of ligand effect-driven construction provided a new idea for the electronic structure modulation of a monatomic catalyst.
基金financially supported by the Key Research and Development(R&D)Projects of Shanxi Province(202202040201005)the Graduate Innovation Project of Shanxi Province(No.2024SJ261)。
文摘Currently,simultaneous regulation of external morphology and internal electronic structure for Na_(3)V_(2)(PO_(4))_(3)(NVP)is rarely realized.Herein,complexes of β-cyclodextrin(βCD)and ethylenediaminetetraacetic acid ferric sodium salt(EDTAFeNa)are utilized for the one-step preparation of NVP with spherical morphology as well as Fe substitution.βCD is initially hydrolyzed into glucose,and then carbon microspheres with numerous pores are formed through continuous dehydration and carbonization.The intermediate hydroxymethylfurfural is rich in active functional groups,which are attractive for the V/P-contained raw materials.Accordingly,the nucleation sites for NVP are successfully limited in the spherical framework,possessing a superior surface area of 97.15 g m^(-2).Furthermore,the beneficial Fe in EDTAFeNa enters into the NVP bulk to construct a novel Fe-doped Na_(3)V_(1.95)Fe_(0.05)(PO_(4))_(3)(NVP/β-ISC)material.Fe-substitution induces significant optimizations of electronic structure for NVP,which has been verified by the newly generated abundant oxygen vacancies and extended V-O bond length.Moreover,a multielectron reaction is activated,resulting from the V^(4+)/V^(5+)redox couple.The charge compensation mechanism of NVP/β-ISC is also deeply investigated.Density functional theory(DFT)calculations theoretically elaborate the mechanism of Fe-doping.Consequently,NVP/β-ISC reveals superior sodium storage performance in both half and full cells and even at different extreme conditions(needling,soaking,bending,and freezing).
基金financially supported by the National Key R&D Program of China(No.2023YFA1606702)the National Natural Science Foundation of China(Nos.U2067205 and 12205098).
文摘The Glauber/eikonal model is a widely used tool for studying intermediate-and high-energy nuclear reactions.When calculating the Glauber/eikonal model phase shift functions,the optical limit approximation(OLA)is often used.The OLA neglects the multiple scattering of the constituent nucleons in the projectile and target nuclei.However,the nucleon-target version of the Glauber model(the NTG model)proposed by Abu-Ibrahim and Suzuki includes multiple scattering effects between the projectile nucleons and target nuclei.The NTG model was found to improve the description of the elastic scattering angular distributions and total reaction cross sections of some light heavy-ion systems with respect to the OLA.In this work,we study the single-nucleon removal reactions(SNRRs)induced by carbon isotopes on ^(12)C and ^(9)Be targets using both the NTG model and the OLA.Reduction factors(RFs)of the single-nucleon spectroscopic factors were obtained by comparing the experimental and theoretical SNRR cross sections.On average,the RFs obtained with the NTG model were smaller than those obtained using the OLA by 7.8%,in which the average difference in one-neutron removal was 10.6% and that in one-proton removal was 4.2%.However,the RFs were still strongly dependent on the neutron-proton asymmetryΔS of the projectile nuclei,even when the NTG model was used.
基金supported by the National Key Research and Development Program(No.2022YFC2806200)the National Key Research and Development Program(No.2023YFC2810800)the Natural Science Foundation of China(No.52001055).
文摘In this study,the pure erosion behaviour of pure iron and its erosion-corrosion behaviour under different anodic polarization currents were investigated in various cathodic reactions(oxygen reduction,hydrogen ion reduction,and water reduction)using a cylindrical stirring system.The corrosion-enhanced erosion(C-E)rates were determined for each condition.The results revealed that pure iron displayed similar pure erosion behaviour across all three cathodic reactions.When the cathodic reactions involve hydrogen ion reduction or water reduction,the erosion-corrosion of pure iron manifested as uniform damage,with the reduction in hardness being the main cause of the C-E in this case.Conversely,in the case of oxy-gen reduction reaction as the cathodic reaction,the erosion-corrosion presented as pitting damage,with the reduction in hardness resulting from localized concentration of anodic current and the formation of easily worn protruding flaky iron structures at the edges of the pits as the main mechanism of the C-E.Moreover,linear and exponential relationships were found between the C-E rate and the anodic current density for uniform damage and pitting damage,respectively.Finally,the concept of surface equivalent hardness was proposed,along with the establishment of a mathematical model for surface equivalent hardness based on the relationships between the C-E rate and the anodic current density.Utilizing the surface equivalent hardness enables the evaluation of the erosion rate on material surfaces considering the coupled effect.
基金financially supported by the Talent Introduction Start-Up Foundation of Guangxi Minzu University(No.2021KJQD11)Guangxi Science and Technology Base and Talent Special Project(No.GuikeAD22080017)
文摘Constructing highly efficient and durable water electrolysis cell system is of crucial importance to meet the requirements of renewable hydrogen energy conversion strategy.However,the underdevelopment of water oxidation half-reaction is well-known to greatly hinder the practical hydrogen production.Although there have been numerous efforts in the design of oxygen evolution reaction(OER) electrocatalysts,the roles of electrolytes in OER activity are less systematically studied.In this review,the pivotal roles pH,cations,anions and salt ions within electrolyte in altering the intrinsic mechanism of OER have been especially discussed,respectively,based on some recent advances in understanding electrolyte effects on OER.Therefore,we highlight the importance of electrolyte compositions in affecting(de)protonation,catalyst structure evolution,reaction intermediates,water structure/network and stability.These insights could profoundly reveal how the electrolyte engineering determines catalytic performance,modulates catalytic active sites and alters change transfer mechanisms at the electrode interface.Such understandings could pave the way for the rational design of highly efficient electrocatalytic OER,CO_(2) reduction and N2 reduction systems.Finally,we discuss the challenges and future perspectives of electrolyte effects on OER,the intrinsic charge transfer mechanisms in electrocatalysis systems and the potential applications of electrolyte engineering in industrial settings.
基金supported by the National Natural Science Foundation of China(Nos.12265006,12375129,U1867212)the Innovation Project of Guangxi Graduate Education(No.YCSWYCSW2022176)the Guangxi Natural Science Foundation(2017GXNSFGA198001).
文摘Based on the Skyrme energy density functional and reaction Q-value,this study proposed an effective nucleus-nucleus poten-tial for describing the capture barrier in heavy-ion fusion processes.The 443 extracted barrier heights were well reproduced with a root-mean-square(RMS)error of 1.53 MeV,and the RMS deviations with respect to 144 time-dependent Hartree-Fock capture barrier heights were only 1.05 MeV.Coupled with the Siwek-Wilczyński formula,wherein three parameters were determined by the proposed effective potentials,the measured capture cross sections at energies around the barriers were reasonably well reproduced for several fusion reactions induced by nearly spherical nuclei as well as by nuclei with large deformations,such as^(154)Sm and^(238)U.The shallow capture pockets and small values of the average barrier radii resulted in the reduction of the capture cross sections for 52,54Cr-and 64 Ni-induced reactions,which were related to the synthesis of new super-heavy nuclei.
基金financially supported by the National Natural Science Foundation of China(Nos.52175444,51905506,21871065 and 22071038)the Sichuan Science and Technology Program(No.2021JDJQ0014).
文摘Additive manufacturing(AM)methods have garnered considerable attention owing to their flexibility in fabricating complex parts with desirable mechanical properties.However,the poor surface quality of the resulting metal parts remains a severe challenge for the applications.Here,a novel dual-additive synergy strategy is presented,which simultaneously enhances material removal efficiency and regulates electrode surface reactions during electrochemical polishing(ECP)of AM AlSi10Mg.Theoretical studies and experimental characterizations confirm that NaF promotes selective dissolution at the peaks,while glucose acts as a stabilizer for the surface valleys.This approach effectively facilitates the selective removal of surface protrusions,achieving a smoother and more uniform surface finish,resulting in a surface roughness reduction of approximately 86%,compared to a 63%reduction without additives.This study not only provides a new approach for optimizing surface quality of AM AlSi10Mg but also offers new insights into electrolyte design and the stabilization of metal anodes.
基金supported by the National Key Research and Development Program of China(2023YFA1508003)the National Natural Science Foundation of China(22408363,22302192)+6 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA29050300)the Youth Innovation Promotion Association CAS(2021181)the Key Research and Development Program of Liaoning(2023JH2/101800051)the Dalian of Science and Technology Project(2023RY012)the Postdoctoral Fellowship Program of CPSF(GZC20241677,GZB20230724)the Postdoctoral Science Foundation(2024T170900)the Doctoral Research Start-up Fund of Liaoning(2024-BSBA-28)。
文摘Cobalt is undoubtedly the most promising alternative metal to rhodium for a highly active and stable hydroformylation process under mild conditions.In this study,two cobalt-based heterogeneous catalysts were synthesized via impregnating a cobalt precursor into polymers(POPs-NVP).Comprehensive characterization revealed that the cobalt species on the catalysts exist as CoO with two distinct sizes:nanoparticles and single sites.The CoO nanoparticles on POPs-NVP exhibited outstanding hydroformylation activity(81.7%yield of aldehyde and alcohol,13.5%yield of alkane),while CoO single sites displayed robust olefin hydrogenation performance(62.6%yield of alkane,27.3% yield of aldehyde and alcohol).These divergent catalytic behaviors were attributed to distinct electron density distributions around surface-exposed cobalt species,which were critically governed by CoO sizes on catalysts.By elucidating the size-dependent effects of CoO/POPs-NVP catalysts,this work provided insights into the complex active species states in heterogeneous cobalt-based catalysts,and established valuable experimental and theoretical foundations for designing highly efficient cobalt-based heterogeneous catalysts for hydroformylation.
文摘Magnetohydrodynamic(MHD)radiative chemically reactive mixed convection flow of a hybrid nanofluid(Al_(2)O_(3)–Cu/H_(2)O)across an inclined,porous,and stretched sheet is examined in this study,along with its unsteady heat and mass transport properties.The hybrid nanofluid’s enhanced heat transfer efficiency is a major benefit in high-performance engineering applications.It is composed of two separate nanoparticles suspended in a base fluid and is chosen for its improved thermal properties.Thermal radiation,chemical reactions,a transverse magnetic field,surface stretching with time,injection or suction through the porous medium,and the effect of inclination,which introduces gravity-induced buoyancy forces,are all important physical phenomena that are taken into account in the analysis.A system of nonlinear ordinary differential equations(ODEs)is derived from the governing partial differential equations for mass,momentum,and energy by applying suitable similarity transformations.This simplifies the modeling procedure.The bvp4c solver in MATLAB is then used to numerically solve these equations.Different governing parameters modify temperature,concentration,and velocity profiles in graphs and tables.These factors include radiation intensity,chemical reaction rate,magnetic field strength,unsteadiness,suction/injection velocity,inclination angle,and nanoparticle concentration.A complex relationship between buoyancy and magnetic factors makes hybrid nanofluids better at heat transmission than regular ones.Thermal systems including cooling technologies,thermal coatings,and electronic heat management benefit from these findings.
基金supported by the National Natural Science Foundation of China(Nos.42020104001,42327806 and 42177354).
文摘Brown carbon(BrC)has attracted widespread attention because of its strong absorption of solar radiation in the ultraviolet-visible wavelength range,which causes adverse impacts on human health.Originally,BrC was a physically defined class of substances.However,current research has gradually shifted towards the identification of its chemical groups,because its light-absorbing capability,chemical properties and health effects mainly depend on the chemical composition of its chromophores.Therefore,this review mainly focuses on the chemical understanding of BrC based on chromophores,and the secondary formation mechanism of chromophores,photosensitized reactions,and human health effects of BrC were detailly summarized.Firstly,BrC chromophores are divided into five categories:nitrogen-heterocycles,nitrogen-chain,aromatic species,oligomers and sulfur-containing organic compounds.Different chromophore precursor species exhibit variations,and their formation mechanisms are also distinct.Secondly,BrC can trigger the production of secondary organic aerosol(SOA)precursors or cause SOA growth because BrC is an important component of light-absorbing particles formed during incomplete combustion of biomass and fossil fuels,potentially exerting adverse effects on human health.Finally,developing sufficiently separated methods for BrC and refining algorithms and machine learning can lead to a more effective understanding of the chemical composition of chromophores,thus enabling better evaluation of the atmospheric effects and health impacts of BrC.In all,this review provides new insights into the categories of BrC chromophores and new advance in secondary formation mechanisms,photosensitized reactions,and human health effects on the basis of chemical structures.
基金financially supported by the Natural Science Foundation of Shandong Province (No.ZR2022QE076)the National Natural Science Foundation of China (No.52202092)the Science and Technology Support Plan for Youth Innovation of Colleges and Universities of Shandong Province of China (No.2023KJ104)。
文摘Electrochemical CO_(2) reduction reaction(CO_(2)RR) into valuable formate provides a strategy for carbon neutrality.Bismuth(Bi) catalysts,attributed to their appropriate energy barrier of OCHO*intermediate,have demonstrated substantial potential for the advancement of electrocatalytic CO_(2) reduction to formate.However,due to the weak bonding of protons(H^(*)) of Bi,the available protonate of CO_(2) on Bi is insufficient,which limits the formation of OCHO^(*).Prediction by theoretical calculation,chlorine doping can effectively promote the dissociation of H_(2)O and thus achieve effective proton supply.We prepare chlorine-doped Bi(Cl-Bi) via an electrochemical conversion strategy for electroreduction of CO_(2) .An obvious improvement of faradaic efficiency(FE) of formate(96.7% at-0.95 V vs.RHE) can be achieved on Cl-Bi,higher than that of Bi(89.4%).Meanwhile,Cl-Bi has the highest formate production rate of 275 μmol h^(-1)cm^(-2)at-0.95 V vs.RHE,which is 1.2 times higher than that of Bi(224 μmol h^(-1)cm^(-2)).In situ characterizations and kinetic analysis reveal that chlorine doping promotes the activation of H_(2)O and supply sufficient protons to promote the protonation of CO_(2) to OCHO^(*),which is consistent with theoretical calculation.The study presents an effective strategy for rational design of highly efficient electrocatalysts to promote green chemical production.
基金the National Natural Science Foundation of China(No.52207227)the Fundamental Research Funds for the Central Universities(No.0213-14380196)+1 种基金the Science and Technology Project of Nanchang(No.2017-SJSYS-008)the Anhui Absorption Spectroscopy Analysis Instrument Co,Ltd.for XAFS measurements and analysis。
文摘The slow conversion of polyphase in lithium-sulfur(Li-S)batteries not only intensifies the shuttle effect of lithium polysulfides(LiPSs),but also causes the continuous accumulation of inactive sulfur species,resulting in rapid capacity attenuation and sluggish dynamic performance.Herein,the promoting effect of atomic interface stress on sulfur reaction was investigated via CoFe-CoFe_(2)O_(4)heterogeneous nanosheets with a cavity structure.The strain force induced by the in-situ precipitation of Co Fe bimetallic alloy in oxide matrix increased the d-band center,which was conducive to the interaction between catalyst and Li PSs.The sulfur cathode based on this two-dimensional(2D)nanosheet design showed an extremely high capacity of 751 mAh g^(-1)at 4 C.Even with a sulfur loading of 5.55 mg cm^(-2),its area capacity was still as high as 7.15 mAh cm^(-2).Meanwhile,the enhanced stability greatly improved the practical potential of Li-S batteries.
文摘A PPh_(3)-catalyzed ring-opening addition reaction of cyclopropenones with alkyl bromides has been successfully established.This reaction offers a concise and practical approach for the assembly ofα,β-disubstituted acrylates with exclusive E-stereoselectivity at room temperature.Mechanistic investigations indicated that both the hydrogen atom on vinyl group and one oxygen atom on ester group ofα,β-disubstituted acrylates derive from H2O in dimethyl sulfoxide(DMSO).Furthermore,a gram-scale experiment and late-stage modification of the products were accomplished,thereby expanding the application potential of this methodology in organic synthesis.
文摘Herein,3‑aminopropyltriethoxysilane(APTES)was used to modify F‑containing silica slag(SS)by simple grafting and served as a multifunctional barrier layer.The amino group(—NH2)in the amino‑modified SS(NH2‑SS)forms ligand bonds or hydrogen bonds with sulfur ions in lithium polysulfides(LiPSs),thus inhibiting the shuttle effect.Electrochemical analyses demonstrated that lithium‑sulfur(Li‑S)batteries employing the NH2‑SS interlayer exhibited discharge specific capacities of 1048 and 789 mAh·g^(-1) at 0.2C and 2C,respectively,and even at 4C,the initial discharge specific capacity remained at 590 mAh·g^(-1),outperforming the Li‑S battery with unmodified SS as the interlayer.
基金National Natural Science Foundation of China(52071274)Key Research and Development Projects of Shaanxi Province(2023-YBGY-442)Science and Technology Nova Project-Innovative Talent Promotion Program of Shaanxi Province(2020KJXX-062)。
文摘To mitigate the impact of interdiffusion reactions between the silicide slurry and Ta12W alloy substrate during vacuum sintering process on the oxidation resistance of the silicide coating,a micro-arc oxidation pretreatment was employed to construct a Ta_(2)O_(5)ceramic layer on the Ta12W alloy surface.Subsequently,a slurry spraying-vacuum sintering method was used to prepare a Si-Cr-Ti-Zr coating on the pretreated substrate.Comparative studies were conducted on the microstructure,phase composition,and isothermal oxidation resistance(at 1600℃)of the as-prepared coatings with and without the micro-arc oxidation ceramic layer.The results show that the Ta_(2)O_(5)layer prepared at 400 V is more continuous and has smaller pores than that prepared at 350 V.After microarc oxidation pretreatment,the Si-Cr-Ti-Zr coating on Ta12W alloy consists of three distinct layers:an upper layer dominated by Ti_(5)Si_(3),Ta_(5)Si_(3),and ZrSi;a middle layer dominated by TaSi_(2);a coating/substrate interfacial reaction layer dominated by Ta_(5)Si_(3).Both the Si-Cr-Ti-Zr coatings with and without the Ta_(2)O_(5)ceramic layer do not fail after isothermal oxidation at 1600℃for 5 h.Notably,the addition of the Ta2O5 ceramic layer reduces the high-temperature oxidation rate of the coating.
基金supported by the National Natural ScienceFoundation of China(No.52074316)PetroChina CompanyLimited(grant number 2019E-2608)。
文摘The shortage of CO_(2) source and the challenges associated with the separation of pure CO_(2) have led to a growing interest in the potential utilization of CO_(2)-contained IWG.Therefore,this study has established an acid-rock interaction kinetic model to characterize the long-term interactions between CO_(2)-contained IWG and shale.The findings delineate the reaction process into three phases:during the initial 10 years,solubility trapping predominates,with minimal mineral dissolution.This increases shale porosity,promoting the diffusion and storage range of CO_(2)-contained IWG.Between 10 and 300 years,mineral dissolution/precipitation assumes primacy,with mineral trapping gradually supplanting dissolution.Notably,shale porosity diminishes by a minimum of approximately 40%,effectively inhibiting gas leakage.After 300 years,equilibrium is reached,with rock porosity consistently lower than the initial porosity.Throughout the entire reaction process,as the initial CO_(2) concentration decreases,the initial pH drops from 4.42 to 3.61,resulting in a roughly 20%increase in porosity.Additionally,it is necessary to regulate its concentration to avoid H_(2)S leakage during CO_(2)-contained IWG geological sequestration.And particular attention should be directed towards the risk of gas leakage when the IWG exhibit high levels of SO_(2) or NO_(2).
