Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespr...Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.展开更多
Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when ta...Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when tackling high-dimensional optimization challenges.To effectively address these challenges,this study introduces cooperative metaheuristics integrating dynamic dimension reduction(DR).Building upon particle swarm optimization(PSO)and differential evolution(DE),the proposed cooperative methods C-PSO and C-DE are developed.In the proposed methods,the modified principal components analysis(PCA)is utilized to reduce the dimension of design variables,thereby decreasing computational costs.The dynamic DR strategy implements periodic execution of modified PCA after a fixed number of iterations,resulting in the important dimensions being dynamically identified.Compared with the static one,the dynamic DR strategy can achieve precise identification of important dimensions,thereby enabling accelerated convergence toward optimal solutions.Furthermore,the influence of cumulative contribution rate thresholds on optimization problems with different dimensions is investigated.Metaheuristic algorithms(PSO,DE)and cooperative metaheuristics(C-PSO,C-DE)are examined by 15 benchmark functions and two engineering design problems(speed reducer and composite pressure vessel).Comparative results demonstrate that the cooperative methods achieve significantly superior performance compared to standard methods in both solution accuracy and computational efficiency.Compared to standard metaheuristic algorithms,cooperative metaheuristics achieve a reduction in computational cost of at least 40%.The cooperative metaheuristics can be effectively used to tackle both high-dimensional unconstrained and constrained optimization problems.展开更多
In this paper,we report the design of ultrafine ordered PtFeZn ternary intermetallics uniformly supported on ZIF-8-derived Zn,N-codoped graphitic carbon(ZnNC)via a green aqueous impregnation method followed by a two-s...In this paper,we report the design of ultrafine ordered PtFeZn ternary intermetallics uniformly supported on ZIF-8-derived Zn,N-codoped graphitic carbon(ZnNC)via a green aqueous impregnation method followed by a two-step annealing protocol(H_(2)/Ar,600 and 800℃)to circumvent the sintering issues imposed by conventional thermodynamics.Physical characterizations(X-ray diffraction,high-angle annular dark-field scanning transmission electron microscopy,X-ray absorption spectroscopy)and theoretical calculations reveal that low-temperature annealing at 600℃stabilizes sub-nano disordered PtFe alloys via the strong metal-support interactions(SMSI)between Zn in ZnNC and Pt precursors,while high-temperature treatment at 800℃promotes Zn diffusion from the support into the alloy bulk and simultaneously triggers the disorder-to-order phase transition.The as-prepared ZnNC-15PtFeZn exhibits an initial mass activity of 0.769 mA/μgPt and retains 61.7%of its activity after 30000 cycles of accelerated stress testing(AST).Notably,when used as a cathode catalyst in MEA,ZnNC-15PtFeZn achieves superior power density(2.018 W/cm^(2)under H_(2)-O_(2))at half the Pt loading(0.05 mg/cm^(2))of state-of-the-art commercial Pt/C,highlighting its potential for low-Pt PEMFCs.Density functional theory confirms that Fe enhances ORR activity via ligand effects,while Zn strengthens Pt-Fe/Zn bonding(elevating vacancy formation energies),thereby improving structural stability.This mild,scalable aqueous impregnation strategy offers a general approach for synthesizing multi-component ordered alloys in electrocatalysis.展开更多
Zeolitic imidazolate frameworks（ZIFs） are widely employed in catalyst synthesis as parental materials for electrochemical energy storage and conversion. Herein, we have demonstrated a facile synthesis of highly effi...Zeolitic imidazolate frameworks（ZIFs） are widely employed in catalyst synthesis as parental materials for electrochemical energy storage and conversion. Herein, we have demonstrated a facile synthesis of highly efficient catalyst for oxygen reduction reaction in both alkaline and acidic medium, which is derived from ZIF-8 functionalized with ammonium ferric citrate via two-step pyrolysis in Ar and NHatmosphere.The results reveal that the catalytic activity improvement after NH3 pyrolysis benefits from mesoporedominated morphology and high utilization of Fe-containing active sites. The optimum catalyst shows excellent performance in zinc-air battery and polymer electrolyte membrane fuel cell tests.展开更多
The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large de...The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large deformation during the LCR process and to minimize the thickness of the slab in bending segments,the maximum theoretical reduction amount and the corresponding reduction scheme for the LCR process must be determined.With SPA-H weathering steel as a specific research steel grade,the distributions of tem-perature and deformation fields of a slab with the LCR process were analyzed using a three-dimensional thermal-mechanical finite ele-ment model.High-temperature tensile tests were designed to determine the critical strain of corner crack propagation and intermediate crack initiation with various strain rates and temperatures,and a prediction model of the critical strain for two typical cracks,combining the effects of strain rate and temperature,was proposed by incorporating the Zener-Hollomon parameter.The crack risks with different LCR schemes were calculated using the crack risk prediction model,and the maximum theoretical reduction amount for the SPA-H slab with a transverse section of 145 mm×1600 mm was 41.8 mm,with corresponding reduction amounts for Segment 0 to Segment 4 of 15.8,7.3,6.5,6.4,and 5.8 mm,respectively.展开更多
Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-perform...Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-performance biomass-derived ORR catalysts with an asymmetric Fe-N_(3)P configuration was prepared by a simple pyrolysis-etching technique,where carboxymethyl cellulose(CMC)was used as the carbon source,urea and 1,10-phenanthroline iron complex(FePhen)as additives,and Na_(3)PO_(4)as the phosphorus dopant and a pore-forming agent.The CMC-derived FeNPC catalyst displayed a large specific area(BET:1235 m^(2)g^(-1))with atomically dispersed Fe-N_(3)P active sites,which exhibited superior ORR activity and stability in alkaline solution(E_(1/2)=0.90 V vs.RHE)and Zn-air batteries(P_(max)=149 mW cm^(-2))to commercial Pt/C catalyst(E_(1/2)=0.87 V,P_(max)=118 mW cm^(-2))under similar experimental conditions.This work provides a feasible and costeffective route toward highly efficient ORR catalysts and their application to Zn-air batteries for energy conversion.展开更多
Mining and tailings deposition can cause serious heavy metal(loids)pollution to the surrounding soil environment.Soil microorganisms adapt their metabolism to such conditions,driving alterations in soil function.This ...Mining and tailings deposition can cause serious heavy metal(loids)pollution to the surrounding soil environment.Soil microorganisms adapt their metabolism to such conditions,driving alterations in soil function.This study aims to elucidate the response patterns of nitrogen-cycling microorganisms under long-term heavy metal(loids)exposure.The results showed that the diversity and abundance of nitrogen-cyclingmicroorganisms showed negative feedback to heavy metal(loids)concentrations.Denitrifying microorganisms were shown to be the dominant microorganisms with over 60%of relative abundance and a complex community structure including 27 phyla.Further,the key bacterial species in the denitrification process were calculated using a random forest model,where the top three key species(Pseudomonas stutzei,Sphingobium japonicum and Leifsonia rubra)were found to play a prominent role in nitrite reduction.Functional gene analysis and qPCR revealed that nirK,which is involved in nitrite reduction,significantly accumulated in the most metal-rich soil with the increase of absolute abundance of 63.86%.The experimental results confirmed that the activity of nitrite reductase(Nir)encoded by nirK in the soil was increased at high concentrations of heavy metal(loids).Partial least squares-path model identified three potential modes of nitrite reduction processes being stimulated by heavy metal(loids),the most prominent of which contributed to enhanced nirK abundance and soil Nir activity through positive stimulation of key species.The results provide new insights and preliminary evidence on the stimulation of nitrite reduction processes by heavy metal(loids).展开更多
Nitrogen-doping of carbon support(N-C)for platinum(Pt)nanoparticles to form Pt/N-C catalyst represents an effective strategy to promote the electrocatalysis of cathodic oxygen reduction reaction(ORR)in proton exchange...Nitrogen-doping of carbon support(N-C)for platinum(Pt)nanoparticles to form Pt/N-C catalyst represents an effective strategy to promote the electrocatalysis of cathodic oxygen reduction reaction(ORR)in proton exchange membrane fuel cells.For fundamental understanding,clearly identifying the metalsupport effect on enhancement mechanisms of ORR electrocatalysis is definitely needed.In this work,the impact of Pt-support interaction via interfacial Pt-N coordination on electrocatalytic ORR activity and stability in Pt/N-C catalyst is deeply studied through structural/compositional characterizations,electrochemical measurements and theoretical DFT-calculations/AIMD-simulations.The resulting Pt/N-C catalyst exhibits a superior electrocatalytic performance compared to the commercial Pt/C catalyst in both half-cell and H_(2)-O_(2)fuel cell.Experimental and theoretical results reveal that the interfacial Pt-N coordination enables electron transfer from N-C support to Pt nanoparticles,which can weaken the adsorption strength of oxygen intermediates on Pt surface to improve ORR activity and induce the strong Pt-support interaction to enhance electrochemical stability.展开更多
Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2)...Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2) solar reduction due to its excellent visible light response,suitable conduction band position,and good cost-effectiveness.However,the amorphous nature and low conductivity of PCN limit its photocatalytic efficiency by leading to low carrier concentrations and facile electron–hole recombination during photocatalysis.Addressing this bottleneck,in this study,potassium-doped PCN(KPCN)/copper(Ⅱ)-complexed bipyridine hydroxyquinoline carboxylic acid(Cu(Ⅱ)(bpy)(H_(2)hqc))composite catalysts were synthesized through a multistep microwave heating process.In the composite,the formation of an S-scheme junction facilitates the enrichment of more negative electrons on the conduction band of KPCN via intermolecular electron–hole recombination between Cu(Ⅱ)(bpy)(H_(2)hqc)(CuPyQc)and KPCN,thereby promoting efficient photoreduction of CO_(2) to CO.Microwave heating enhances the amidation reaction between these two components,achieving the immobilization of homogeneous molecular catalysts and forming amidation chemical bonds that serve as key channels for the S-scheme charge transfer.This work not only presents a new PCN-based catalytic system for CO_(2) reduction applications,but also offers a novel microwave-practical approach for immobilizing homogeneous catalysts.展开更多
The development of an e fficacious and easily prepared no nprecious metal electrocatalyst is crucial for the oxygen reduction reaction(ORR).This work used a dual template method to prepare the amorphous rare earth-bas...The development of an e fficacious and easily prepared no nprecious metal electrocatalyst is crucial for the oxygen reduction reaction(ORR).This work used a dual template method to prepare the amorphous rare earth-based catalyst PrO_(x)-NC,and optimized the calcination temperature and proportion.The PrO_(x)-NC-900 catalyst has high durability and activity and exhibits superior ORR performance in alkaline electrolytes with an onset potential(E_(0))of 0.96 V and a half-wave potential(E_(1/2))of 0.85 V.The research results indicate that the ORR performance of rare earth oxide composite carbon catalysts can be improved by adjusting oxygen vacancies(Ov).In addition,high specific surface area,N rich defect carbon.increased oxygen vacancies,and the synergistic effect of oxygen vacancies and N-doped carbon interfacial layer play a significant part in the enhancement of ORR.The performance of the zinc air battery assembled with PrO_(x)-NC-900 is significantly improved,and rare earth oxides and carbon frameworks originating from metal organic frameworks(MOFs)contribute to the oxygen electrocatalyst and electron transfer rate of the zinc air battery.This catalyst provides promising information for the development of rare earth metal oxide nanostructures as potential candidate materials for ORR in alkaline media.展开更多
A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for ...A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.展开更多
In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-dept...In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-depth exploration of photocatalytic reaction systems with fewer constraints imposed by surface chemistry.Typically,the isotropy of a specific facet provides a perfect support for studying heteroatom doping.Herein,this work delves into the intrinsic catalytic sites for photocatalytic nitrogen fixation in iron-doped lithium tantalate single crystals.The presence of iron not only modifies the electronic structure of lithium tantalate,improving its light absorption capacity,but also functions as an active site for the nitrogen adsorption and activation.The photocatalytic ammonia production rate of the iron-doped lithium tantalate in pure water is maximum 26.95μg cm^(−2)h^(−1),which is three times higher than that of undoped lithium tantalate.The combination of first-principles simulations with in situ characterizations confirms that iron doping promotes the rate-determining step and changes the pathway of hydrogenation to associative alternating.This study provides a new perspective on in-depth investigation of intrinsic catalytic active sites in photocatalysis and other catalytic processes.展开更多
The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of den...The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of dendritic solidification structures.Combining scanning electron microscopy and energy-dispersive scanning analysis and ANSYS simulation,the high-precision image processing software Mimics Research was utilized to conduct the extraction of dendritic morphologies.Reverse engineering software NX Imageware was employed for the 3D reconstruction of two-dimensional dendritic morphologies,restoring the dendritic characteristics in three-dimensional space.The results demonstrate that in a two-dimensional plane,dendrites connect with each other to form irregularly shaped“ring-like”structures.These dendrites have a thickness greater than 0.1 mm along the Z-axis direction,leading to the envelopment of molten steel by dendrites in a 3D space of at least 0.1 mm.This results in obstructed flow,confirming the“bridging”of dendrites in three-dimensional space,resulting in a tendency for central segregation.Dense and dispersed tiny dendrites,under the influence of heat flow direction,interconnect and continuously grow,gradually forming primary and secondary dendrites in three-dimensional space.After the completion of dendritic solidification and growth,these microdendrites appear dense and dispersed on the two-dimensional plane,providing the nuclei for the formation of new dendrites.When reduction occurs at a solid fraction of 0.46,there is a noticeable decrease in dendritic spacing,resulting in improved central segregation.展开更多
Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles in...Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles incorporated on nitrogen-doped porous carbon (CuO@NC) catalyst for NO_(3)-RR.Part of Cu(Ⅱ) is reduced to Cu(Ⅰ) during the NO_(3)-RR process to construct Cu(Ⅰ)-Cu(Ⅱ) pairs,confirmed by in situ X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.Density functional theory (DFT) calculations indicated that the formation of Cu(Ⅰ) could provide a reaction path with smaller energy barrier for NO_(3)-RR,while Cu(Ⅱ) effectively suppressed the competition of hydrogen evolution reaction (HER).As a result,CuO@NC catalyst achieved a Faradaic efficiency of 84.2% at -0.49 V versus reversible hydrogen electrode (RHE),and a NH_(3)yield rate of 17.2 mg h^(-1)mg^(-1)cat.at -0.79 V vs.RHE,higher than the HaberBosch process (<3.4 g h^(-1)g^(-1)cat.).This work may open a new avenue for effective NO_(3)-RR by modulating oxidation states.展开更多
Ultra-low emission of nitrogen oxide(NO_(x))is an irreversible trend for the development of waste-to-energy industry.But traditional approaches to remove NO_(x) face significant challenge s,such as low denitration eff...Ultra-low emission of nitrogen oxide(NO_(x))is an irreversible trend for the development of waste-to-energy industry.But traditional approaches to remove NO_(x) face significant challenge s,such as low denitration efficiency,complex denitration system,and high investment and operating cost.Here we put forward a novel polymer non-catalytic reduction(PNCR)technology that utilized a new type of polymer agent to remove NO_(x),and the proposed PNCR technology was applied to the existing waste-to-energy plant to test the denitration performance.The PNCR technology demonstrated excellent denitration performance with a NO_(x) emission concentration of<100 mg/Nm^(3) and high denitration efficiency of>75%at the temperature range of 800-900℃,which showed the application feasibility even on the complex and unstable industrial operating conditions.In addition,PNCR and hybrid polymer/selective non-catalytic reduction(PNCR/SNCR)technology possessed remarkable economic advantages including low investment fee and low operating cost of<10 CNY per ton of municipal solid waste(MSW)compared with selective catalytic reduction(SCR)technology.The excellent denitration performance of PNCR technology forebodes a broad industrial application prospect in the field of flue gas cleaning for waste-to-energy plants.展开更多
Guangdong’s carbon emissions have surpassed the world’s 11th largest emitter.It is indispensable for this province to find a robust cost-effective strategy for reducing carbon emissions.This study employed the Low E...Guangdong’s carbon emissions have surpassed the world’s 11th largest emitter.It is indispensable for this province to find a robust cost-effective strategy for reducing carbon emissions.This study employed the Low Emissions Analysis Platform model,marginal cost curves,and Monte Carlo methods to simulate the energy consumption,carbon emissions,and economic benefits of emission reduction in Guangdong Province from 2020 to 2030 under the application of various structural optimization policies and energy-saving technologies.The main findings are as follows:In 2030,Guangdong Province is projected to achieve a carbon emission reduction of 273.6 to 304.6million t CO_(2eq),with a total reduction cost ranging from 1030.9 to 1452.2 billion yuan.Increasing the share of renewable energy,which still has significant growth potential,can lead to a 1.4 times greater reduction in carbon emissions compared to the application of energy-saving technologies,despite the latter yielding 2.3 times more energy savings.The emission reduction measures with net-cost can contribute 71.4%to the total carbon reduction of the province,being much larger than those with net benefits.The power sector plays a critical role in carbon emission reduction within Guangdong Province,with its various measures exerting the most substantial impact on emission reduction quantity and cost,contributing cumulative variance contributions of 90.1%and 84.3%,respectively.It has relatively large potential for emission reduction and relatively low cost of structural adjustment.展开更多
Against the background of“carbon peak and carbon neutrality,”it is of great practical significance to develop non-blast furnace ironmaking technology for the sustainable development of steel industry.Carbon-bearing ...Against the background of“carbon peak and carbon neutrality,”it is of great practical significance to develop non-blast furnace ironmaking technology for the sustainable development of steel industry.Carbon-bearing iron ore pellet is an innovative burden of direct reduction ironmaking due to its excellent self-reducing property,and the thermal strength of pellet is a crucial metallurgical property that affects its wide application.The carbon-bearing iron ore pellet without binders(CIPWB)was prepared using iron concentrate and anthracite,and the effects of reducing agent addition amount,size of pellet,reduction temperature and time on the thermal compressive strength of CIPWB during the reduction process were studied.Simultaneously,the mechanism of the thermal strength evolution of CIPWB was revealed.The results showed that during the low-temperature reduction process(300-500℃),the thermal compressive strength of CIPWB linearly increases with increasing the size of pellet,while it gradually decreases with increasing the anthracite ratio.When the CIPWB with 8%anthracite is reduced at 300℃for 60 min,the thermal strength of pellet is enhanced from 13.24 to 31.88 N as the size of pellet increases from 8.04 to 12.78 mm.Meanwhile,as the temperature is 500℃,with increasing the anthracite ratio from 2%to 8%,the thermal compressive strength of pellet under reduction for 60 min remarkably decreases from 41.47 to 8.94 N.Furthermore,in the high-temperature reduction process(600-1150℃),the thermal compressive strength of CIPWB firstly increases and then reduces with increasing the temperature,while it as well as the temperature corresponding to the maximum strength decreases with increasing the anthracite ratio.With adding 18%anthracite,the thermal compressive strength of pellet reaches the maximum value at 800℃,namely 35.00 N,and obtains the minimum value at 1050℃,namely 8.60 N.The thermal compressive strength of CIPWB significantly depends on the temperature,reducing agent dosage,and pellet size.展开更多
Magnesium and magnesium alloys,serving as crucial lightweight structural materials and hydrogen storage elements,find extensive applications in space technology,aviation,automotive,and magnesium-based hydrogen industr...Magnesium and magnesium alloys,serving as crucial lightweight structural materials and hydrogen storage elements,find extensive applications in space technology,aviation,automotive,and magnesium-based hydrogen industries.The global production of primary magnesium has reached approximately 1.2 million tons per year,with anticipated diversification in future applications and significant market demand.Nevertheless,approximately 80%of the world’s primary magnesium is still manufactured through the Pidgeon process,grappling with formidable issues including high energy consumption,massive carbon emission,significant resource depletion,and environmental pollution.The implementation of the relative vacuum method shows potential in breaking through technological challenges in the Pidgeon process,facilitating clean,low-carbon continuous magnesium smelting.This paper begins by introducing the principles of the relative vacuum method.Subsequently,it elucidates various innovative process routes,including relative vacuum ferrosilicon reduction,aluminum thermal reduction co-production of spinel,and aluminum thermal reduction co-production of calcium aluminate.Finally,and thermodynamic foundations of the relative vacuum,a quantitative analysis of the material,energy flows,carbon emission,and production cost for several new processes is conducted,comparing and analyzing them against the Pidgeon process.The study findings reveal that,with identical raw materials,the relative vacuum silicon thermal reduction process significantly decreases raw material consumption,energy consumption,and carbon dioxide emissions by 15.86%,30.89%,and 26.27%,respectively,compared to the Pidgeon process.The relative vacuum process,using magnesite as the raw material and aluminum as the reducing agent,has the lowest magnesium-to-feed ratio,at only 3.385.Additionally,its energy consumption and carbon dioxide emissions are the lowest,at 1.817 tce/t Mg and 7.782 t CO_(2)/t Mg,respectively.The energy consumption and carbon emissions of the relative vacuum magnesium smelting process co-producing calcium aluminate(12CaO·7Al_(2)O_(3),3CaO·Al_(2)O_(3),and CaO·Al_(2)O_(3))are highly correlated with the consumption of dolomite in the raw materials.When the reduction temperature is around 1473.15 K,the critical volume fraction of magnesium vapor for different processes varies within the range of 5%–40%.Production cost analysis shows that the relative vacuum primary magnesium smelting process has significant economic benefits.This paper offers essential data support and theoretical guidance for achieving energy efficiency,carbon reduction in magnesium smelting,and the industrial adoption of innovative processes.展开更多
Emergency department nurses face severe occupational stress leading to anxiety,depression,and burnout,which significantly impair their well-being and patientcare quality.This narrative review examined the role of mind...Emergency department nurses face severe occupational stress leading to anxiety,depression,and burnout,which significantly impair their well-being and patientcare quality.This narrative review examined the role of mindfulness-based stress reduction(MBSR)in addressing these challenges.Rooted in nonjudgmental present-moment awareness,MBSR enhances emotional regulation and reduces psychological distress by fostering adaptive coping strategies.Studies have demonstrated its efficacy in lowering anxiety,depressive symptoms,and emotional exhaustion,while improving workplace well-being,empathy,and job satisfaction.Mechanistically,MBSR improves interoceptive awareness and autonomic balance,as evidenced by physiological markers such as heart rate variability.However,gaps remain in long-term efficacy assessments,personalized interventions,and integration with multidisciplinary approaches.Future research should prioritize tailored biomarker-driven programs,longitudinal studies,and scalable implementation strategies in high-stress clinical settings.This review underscores MBSR’s potential as a sustainable,evidence-based tool to enhance emergency department nurses’mental health and professional performance,advocating for broader adoption and further refinement of its practical applications.展开更多
The electrochemical reduction of carbon dioxide(CO_(2))into value-added chemicals and fuels has been extensively studied as a promising strategy for mitigating environmental issues and achieving sustainable energy con...The electrochemical reduction of carbon dioxide(CO_(2))into value-added chemicals and fuels has been extensively studied as a promising strategy for mitigating environmental issues and achieving sustainable energy conversion.Substantial efforts have been made to improve the understanding of CO_(2)reduction reaction(CO_(2)RR)mechanisms by computational and spectroscopic studies.An in-depth understanding of CO_(2)RR mechanism can provide the guidance and criteria for designing high-efficiency catalysts,and hence,steering CO_(2)RR to desired products.This review systematically discusses the formation mechanisms and reaction pathways of various CO_(2)RR products,including C_(1)products(CO,HCOOH,and CH_(4)),C_(2)products(C_(2)H_(4),C_(2)H_(5)OH,and CH_(3)COOH),and C_(3+)products(C_(3)H_(6),C_(3)H_(7)OH,and others).The reaction pathways are elucidated by analyzing the adsorption behavior,energy barriers,and intermediate coupling steps involved in the generation of each product.Particular emphasis is placed on the key intermediates,such as^(*)OCHO,^(*)COOH,^(*)CO,^(*)OCCOH,and^(*)CCO,which play crucial roles in determining the product selectivity.The effects of catalyst composition,morphology,and electronic structure on the adsorption and activation of these intermediates are also discussed.Moreover,advanced characterization techniques,including in-situ spectroscopy and isotopic labeling experiments,are highlighted for their contributions to unraveling the reaction mechanisms.The review aims to provide critical insights to reveal the activity-determining para meters and underlying CO_(2)RR mechanisms,which will guide the rational design of next-generation electrocatalysts for selective CO^(2)RR towards high-value products.展开更多
基金supports from the National Natural Science Foundation of China(Grant Nos.12305372 and 22376217)the National Key Research&Development Program of China(Grant Nos.2022YFA1603802 and 2022YFB3504100)+1 种基金the projects of the key laboratory of advanced energy materials chemistry,ministry of education(Nankai University)key laboratory of Jiangxi Province for persistent pollutants prevention control and resource reuse(2023SSY02061)are gratefully acknowledged.
文摘Using photoelectrocatalytic CO_(2) reduction reaction(CO_(2)RR)to produce valuable fuels is a fascinating way to alleviate environmental issues and energy crises.Bismuth-based(Bi-based)catalysts have attracted widespread attention for CO_(2)RR due to their high catalytic activity,selectivity,excellent stability,and low cost.However,they still need to be further improved to meet the needs of industrial applications.This review article comprehensively summarizes the recent advances in regulation strategies of Bi-based catalysts and can be divided into six categories:(1)defect engineering,(2)atomic doping engineering,(3)organic framework engineering,(4)inorganic heterojunction engineering,(5)crystal face engineering,and(6)alloying and polarization engineering.Meanwhile,the corresponding catalytic mechanisms of each regulation strategy will also be discussed in detail,aiming to enable researchers to understand the structure-property relationship of the improved Bibased catalysts fundamentally.Finally,the challenges and future opportunities of the Bi-based catalysts in the photoelectrocatalytic CO_(2)RR application field will also be featured from the perspectives of the(1)combination or synergy of multiple regulatory strategies,(2)revealing formation mechanism and realizing controllable synthesis,and(3)in situ multiscale investigation of activation pathways and uncovering the catalytic mechanisms.On the one hand,through the comparative analysis and mechanism explanation of the six major regulatory strategies,a multidimensional knowledge framework of the structure-activity relationship of Bi-based catalysts can be constructed for researchers,which not only deepens the atomic-level understanding of catalytic active sites,charge transport paths,and the adsorption behavior of intermediate products,but also provides theoretical guiding principles for the controllable design of new catalysts;on the other hand,the promising collaborative regulation strategies,controllable synthetic paths,and the in situ multiscale characterization techniques presented in this work provides a paradigm reference for shortening the research and development cycle of high-performance catalysts,conducive to facilitating the transition of photoelectrocatalytic CO_(2)RR technology from the laboratory routes to industrial application.
基金funded by National Natural Science Foundation of China(Nos.12402142,11832013 and 11572134)Natural Science Foundation of Hubei Province(No.2024AFB235)+1 种基金Hubei Provincial Department of Education Science and Technology Research Project(No.Q20221714)the Opening Foundation of Hubei Key Laboratory of Digital Textile Equipment(Nos.DTL2023019 and DTL2022012).
文摘Owing to their global search capabilities and gradient-free operation,metaheuristic algorithms are widely applied to a wide range of optimization problems.However,their computational demands become prohibitive when tackling high-dimensional optimization challenges.To effectively address these challenges,this study introduces cooperative metaheuristics integrating dynamic dimension reduction(DR).Building upon particle swarm optimization(PSO)and differential evolution(DE),the proposed cooperative methods C-PSO and C-DE are developed.In the proposed methods,the modified principal components analysis(PCA)is utilized to reduce the dimension of design variables,thereby decreasing computational costs.The dynamic DR strategy implements periodic execution of modified PCA after a fixed number of iterations,resulting in the important dimensions being dynamically identified.Compared with the static one,the dynamic DR strategy can achieve precise identification of important dimensions,thereby enabling accelerated convergence toward optimal solutions.Furthermore,the influence of cumulative contribution rate thresholds on optimization problems with different dimensions is investigated.Metaheuristic algorithms(PSO,DE)and cooperative metaheuristics(C-PSO,C-DE)are examined by 15 benchmark functions and two engineering design problems(speed reducer and composite pressure vessel).Comparative results demonstrate that the cooperative methods achieve significantly superior performance compared to standard methods in both solution accuracy and computational efficiency.Compared to standard metaheuristic algorithms,cooperative metaheuristics achieve a reduction in computational cost of at least 40%.The cooperative metaheuristics can be effectively used to tackle both high-dimensional unconstrained and constrained optimization problems.
文摘In this paper,we report the design of ultrafine ordered PtFeZn ternary intermetallics uniformly supported on ZIF-8-derived Zn,N-codoped graphitic carbon(ZnNC)via a green aqueous impregnation method followed by a two-step annealing protocol(H_(2)/Ar,600 and 800℃)to circumvent the sintering issues imposed by conventional thermodynamics.Physical characterizations(X-ray diffraction,high-angle annular dark-field scanning transmission electron microscopy,X-ray absorption spectroscopy)and theoretical calculations reveal that low-temperature annealing at 600℃stabilizes sub-nano disordered PtFe alloys via the strong metal-support interactions(SMSI)between Zn in ZnNC and Pt precursors,while high-temperature treatment at 800℃promotes Zn diffusion from the support into the alloy bulk and simultaneously triggers the disorder-to-order phase transition.The as-prepared ZnNC-15PtFeZn exhibits an initial mass activity of 0.769 mA/μgPt and retains 61.7%of its activity after 30000 cycles of accelerated stress testing(AST).Notably,when used as a cathode catalyst in MEA,ZnNC-15PtFeZn achieves superior power density(2.018 W/cm^(2)under H_(2)-O_(2))at half the Pt loading(0.05 mg/cm^(2))of state-of-the-art commercial Pt/C,highlighting its potential for low-Pt PEMFCs.Density functional theory confirms that Fe enhances ORR activity via ligand effects,while Zn strengthens Pt-Fe/Zn bonding(elevating vacancy formation energies),thereby improving structural stability.This mild,scalable aqueous impregnation strategy offers a general approach for synthesizing multi-component ordered alloys in electrocatalysis.
基金supported by the National Natural Science Foundation of China(Grants 21573222,21622607,91545202 and U1532117)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB17020200)+1 种基金CAS Youth Innovation PromotionK.C.Wong Education Foundation in Ningbo University
文摘Zeolitic imidazolate frameworks（ZIFs） are widely employed in catalyst synthesis as parental materials for electrochemical energy storage and conversion. Herein, we have demonstrated a facile synthesis of highly efficient catalyst for oxygen reduction reaction in both alkaline and acidic medium, which is derived from ZIF-8 functionalized with ammonium ferric citrate via two-step pyrolysis in Ar and NHatmosphere.The results reveal that the catalytic activity improvement after NH3 pyrolysis benefits from mesoporedominated morphology and high utilization of Fe-containing active sites. The optimum catalyst shows excellent performance in zinc-air battery and polymer electrolyte membrane fuel cell tests.
基金supported by the National Natural Science Foundation of China(No.52474355)the Liaoning Province Science and Technology Plan Joint Program(Key Research and Development Program Project),China(Nos.2022JH25/10200003 and 2023JH2/101800058).
文摘The application of liquid core reduction(LCR)technology in thin slab continuous casting can refine the internal microstruc-tures of slabs and improve their production efficiency.To avoid crack risks caused by large deformation during the LCR process and to minimize the thickness of the slab in bending segments,the maximum theoretical reduction amount and the corresponding reduction scheme for the LCR process must be determined.With SPA-H weathering steel as a specific research steel grade,the distributions of tem-perature and deformation fields of a slab with the LCR process were analyzed using a three-dimensional thermal-mechanical finite ele-ment model.High-temperature tensile tests were designed to determine the critical strain of corner crack propagation and intermediate crack initiation with various strain rates and temperatures,and a prediction model of the critical strain for two typical cracks,combining the effects of strain rate and temperature,was proposed by incorporating the Zener-Hollomon parameter.The crack risks with different LCR schemes were calculated using the crack risk prediction model,and the maximum theoretical reduction amount for the SPA-H slab with a transverse section of 145 mm×1600 mm was 41.8 mm,with corresponding reduction amounts for Segment 0 to Segment 4 of 15.8,7.3,6.5,6.4,and 5.8 mm,respectively.
基金supported by the National Natural Science Foundation of China(No.21571062)the Program for Professor of Special Appointment(Eastern Scholar)at the Shanghai Institutions of Higher Learning to JGL,and the Fundamental Research Funds for the Central Universities(No.222201717003)。
文摘Exploiting non-precious metal catalysts with excellent oxygen reduction reaction(ORR)performance for energy devices is paramount essential for the green and sustainable society development.Herein,low-cost,high-performance biomass-derived ORR catalysts with an asymmetric Fe-N_(3)P configuration was prepared by a simple pyrolysis-etching technique,where carboxymethyl cellulose(CMC)was used as the carbon source,urea and 1,10-phenanthroline iron complex(FePhen)as additives,and Na_(3)PO_(4)as the phosphorus dopant and a pore-forming agent.The CMC-derived FeNPC catalyst displayed a large specific area(BET:1235 m^(2)g^(-1))with atomically dispersed Fe-N_(3)P active sites,which exhibited superior ORR activity and stability in alkaline solution(E_(1/2)=0.90 V vs.RHE)and Zn-air batteries(P_(max)=149 mW cm^(-2))to commercial Pt/C catalyst(E_(1/2)=0.87 V,P_(max)=118 mW cm^(-2))under similar experimental conditions.This work provides a feasible and costeffective route toward highly efficient ORR catalysts and their application to Zn-air batteries for energy conversion.
基金supported by the National Natural Science Foundation of China(No.41977029).
文摘Mining and tailings deposition can cause serious heavy metal(loids)pollution to the surrounding soil environment.Soil microorganisms adapt their metabolism to such conditions,driving alterations in soil function.This study aims to elucidate the response patterns of nitrogen-cycling microorganisms under long-term heavy metal(loids)exposure.The results showed that the diversity and abundance of nitrogen-cyclingmicroorganisms showed negative feedback to heavy metal(loids)concentrations.Denitrifying microorganisms were shown to be the dominant microorganisms with over 60%of relative abundance and a complex community structure including 27 phyla.Further,the key bacterial species in the denitrification process were calculated using a random forest model,where the top three key species(Pseudomonas stutzei,Sphingobium japonicum and Leifsonia rubra)were found to play a prominent role in nitrite reduction.Functional gene analysis and qPCR revealed that nirK,which is involved in nitrite reduction,significantly accumulated in the most metal-rich soil with the increase of absolute abundance of 63.86%.The experimental results confirmed that the activity of nitrite reductase(Nir)encoded by nirK in the soil was increased at high concentrations of heavy metal(loids).Partial least squares-path model identified three potential modes of nitrite reduction processes being stimulated by heavy metal(loids),the most prominent of which contributed to enhanced nirK abundance and soil Nir activity through positive stimulation of key species.The results provide new insights and preliminary evidence on the stimulation of nitrite reduction processes by heavy metal(loids).
基金supported by the National Natural Science Foundation of China(Nos.22272105 and 22002110)Natural Science Foundation of Shanghai(No.23ZR1423900)。
文摘Nitrogen-doping of carbon support(N-C)for platinum(Pt)nanoparticles to form Pt/N-C catalyst represents an effective strategy to promote the electrocatalysis of cathodic oxygen reduction reaction(ORR)in proton exchange membrane fuel cells.For fundamental understanding,clearly identifying the metalsupport effect on enhancement mechanisms of ORR electrocatalysis is definitely needed.In this work,the impact of Pt-support interaction via interfacial Pt-N coordination on electrocatalytic ORR activity and stability in Pt/N-C catalyst is deeply studied through structural/compositional characterizations,electrochemical measurements and theoretical DFT-calculations/AIMD-simulations.The resulting Pt/N-C catalyst exhibits a superior electrocatalytic performance compared to the commercial Pt/C catalyst in both half-cell and H_(2)-O_(2)fuel cell.Experimental and theoretical results reveal that the interfacial Pt-N coordination enables electron transfer from N-C support to Pt nanoparticles,which can weaken the adsorption strength of oxygen intermediates on Pt surface to improve ORR activity and induce the strong Pt-support interaction to enhance electrochemical stability.
基金supported by the National Natural Science Foundation of China(Nos.22106105 and 22201180)the Innovation Program of Shanghai Municipal Education Commission(No.2019-01-07-00-E00015)+2 种基金Shanghai Science and Technology Innovation Program(No.21DZ1206300)the Central Local Science and Technology Development Guidance Fund(No.YDZX20213100003002)Shanghai Science and Technology Commission Program(No.20060502200).
文摘Photocatalytic conversion of CO_(2) is pivotal for mitigating the global greenhouse effect and fostering sustainable energy development.Nowadays,polymeric carbon nitride(PCN)has gained widespread application in CO_(2) solar reduction due to its excellent visible light response,suitable conduction band position,and good cost-effectiveness.However,the amorphous nature and low conductivity of PCN limit its photocatalytic efficiency by leading to low carrier concentrations and facile electron–hole recombination during photocatalysis.Addressing this bottleneck,in this study,potassium-doped PCN(KPCN)/copper(Ⅱ)-complexed bipyridine hydroxyquinoline carboxylic acid(Cu(Ⅱ)(bpy)(H_(2)hqc))composite catalysts were synthesized through a multistep microwave heating process.In the composite,the formation of an S-scheme junction facilitates the enrichment of more negative electrons on the conduction band of KPCN via intermolecular electron–hole recombination between Cu(Ⅱ)(bpy)(H_(2)hqc)(CuPyQc)and KPCN,thereby promoting efficient photoreduction of CO_(2) to CO.Microwave heating enhances the amidation reaction between these two components,achieving the immobilization of homogeneous molecular catalysts and forming amidation chemical bonds that serve as key channels for the S-scheme charge transfer.This work not only presents a new PCN-based catalytic system for CO_(2) reduction applications,but also offers a novel microwave-practical approach for immobilizing homogeneous catalysts.
基金Project supported by the National Natural Science Foundation of China(22062019)the Natural Science Foundation of Inner Mongolia of China(2022QN02002)Science and Technology Program of Inner Mongolia Autonomous Region,China(2020PT0003)。
文摘The development of an e fficacious and easily prepared no nprecious metal electrocatalyst is crucial for the oxygen reduction reaction(ORR).This work used a dual template method to prepare the amorphous rare earth-based catalyst PrO_(x)-NC,and optimized the calcination temperature and proportion.The PrO_(x)-NC-900 catalyst has high durability and activity and exhibits superior ORR performance in alkaline electrolytes with an onset potential(E_(0))of 0.96 V and a half-wave potential(E_(1/2))of 0.85 V.The research results indicate that the ORR performance of rare earth oxide composite carbon catalysts can be improved by adjusting oxygen vacancies(Ov).In addition,high specific surface area,N rich defect carbon.increased oxygen vacancies,and the synergistic effect of oxygen vacancies and N-doped carbon interfacial layer play a significant part in the enhancement of ORR.The performance of the zinc air battery assembled with PrO_(x)-NC-900 is significantly improved,and rare earth oxides and carbon frameworks originating from metal organic frameworks(MOFs)contribute to the oxygen electrocatalyst and electron transfer rate of the zinc air battery.This catalyst provides promising information for the development of rare earth metal oxide nanostructures as potential candidate materials for ORR in alkaline media.
基金supported by the National Natural Science Foundation of China(No.U2067212)the National Science Fund for Distinguished Young Scholars(No.21925603).
文摘A sp^(2) carbon-conjugated covalent organic framework (BDATN) was modified through γ-ray radiation reduction and subsequent acidification with hydrochloric acid to yield a novel functional COF (named rBDATN-HCl) for Cr(Ⅵ) removal.The morphology and structure of rBDATN-HCl were analyzed and identified by SEM,FTIR,XRD and solid-state13C NMR.It is found that the active functional groups,such as hydroxyl and amide,were introduced into BDATN after radiation reduction and acidification.The prepared rBDATN-HCl demonstrates a photocatalytic reduction removal rate of Cr(Ⅵ) above 99%after 60min of illumination with a solid-liquid ratio of 0.5 mg/mL,showing outstanding performance,which is attributed to the increase of dispersibility and adsorption sites of r BDATN-HCl.In comparison to the cBDATN-HCl synthesized with chemical reduction,rBDATN-HCl exhibits a better photoreduction performance for Cr(Ⅵ),demonstrating the advantages of radiation preparation of rBDATN-HCl.It is expected that more functionalized sp^(2) carbon-conjugated COFs could be obtained by this radiation-induced reduction strategy.
基金supported by Natural Science Foundation of Shandong Province(Nos.ZR2022YQ42,ZR2021JQ15,ZR2021QE011,ZR2021ZD20,2022GJJLJRC-01)Innovative Team Project of Jinan(No.2021GXRC019)the National Natural Science Foundation of China(Nos.52022037,52202366).
文摘In contrast to research on active sites in nanomaterials,lithium tantalate single crystals,known for their exceptional optical properties and long-range ordered lattice structure,present a promising avenue for in-depth exploration of photocatalytic reaction systems with fewer constraints imposed by surface chemistry.Typically,the isotropy of a specific facet provides a perfect support for studying heteroatom doping.Herein,this work delves into the intrinsic catalytic sites for photocatalytic nitrogen fixation in iron-doped lithium tantalate single crystals.The presence of iron not only modifies the electronic structure of lithium tantalate,improving its light absorption capacity,but also functions as an active site for the nitrogen adsorption and activation.The photocatalytic ammonia production rate of the iron-doped lithium tantalate in pure water is maximum 26.95μg cm^(−2)h^(−1),which is three times higher than that of undoped lithium tantalate.The combination of first-principles simulations with in situ characterizations confirms that iron doping promotes the rate-determining step and changes the pathway of hydrogenation to associative alternating.This study provides a new perspective on in-depth investigation of intrinsic catalytic active sites in photocatalysis and other catalytic processes.
基金supported by Open Foundation of the State Key Laboratory of Refractories and Metallurgy(No.G201711)the National Natural Science Foundation of China(Nos.52104317 and 51874001).
文摘The impact of heavy reduction on dendritic morphology was explored by combining experimental research and numerical simulation in metallurgy,including a detailed three-dimensional(3D)analysis and reconstruction of dendritic solidification structures.Combining scanning electron microscopy and energy-dispersive scanning analysis and ANSYS simulation,the high-precision image processing software Mimics Research was utilized to conduct the extraction of dendritic morphologies.Reverse engineering software NX Imageware was employed for the 3D reconstruction of two-dimensional dendritic morphologies,restoring the dendritic characteristics in three-dimensional space.The results demonstrate that in a two-dimensional plane,dendrites connect with each other to form irregularly shaped“ring-like”structures.These dendrites have a thickness greater than 0.1 mm along the Z-axis direction,leading to the envelopment of molten steel by dendrites in a 3D space of at least 0.1 mm.This results in obstructed flow,confirming the“bridging”of dendrites in three-dimensional space,resulting in a tendency for central segregation.Dense and dispersed tiny dendrites,under the influence of heat flow direction,interconnect and continuously grow,gradually forming primary and secondary dendrites in three-dimensional space.After the completion of dendritic solidification and growth,these microdendrites appear dense and dispersed on the two-dimensional plane,providing the nuclei for the formation of new dendrites.When reduction occurs at a solid fraction of 0.46,there is a noticeable decrease in dendritic spacing,resulting in improved central segregation.
基金National Natural Science Foundation of China (52371228, 52402045)fund of Key Laboratory of Advanced Materials of Ministry of Education(Advmat-2414)。
文摘Electrocatalytic nitrate reduction reaction (NO_(3)-RR) to ammonia under ambient conditions is expected to be a green process for ammonia synthesis and alleviate water pollution issues.We report a CuO nanoparticles incorporated on nitrogen-doped porous carbon (CuO@NC) catalyst for NO_(3)-RR.Part of Cu(Ⅱ) is reduced to Cu(Ⅰ) during the NO_(3)-RR process to construct Cu(Ⅰ)-Cu(Ⅱ) pairs,confirmed by in situ X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy.Density functional theory (DFT) calculations indicated that the formation of Cu(Ⅰ) could provide a reaction path with smaller energy barrier for NO_(3)-RR,while Cu(Ⅱ) effectively suppressed the competition of hydrogen evolution reaction (HER).As a result,CuO@NC catalyst achieved a Faradaic efficiency of 84.2% at -0.49 V versus reversible hydrogen electrode (RHE),and a NH_(3)yield rate of 17.2 mg h^(-1)mg^(-1)cat.at -0.79 V vs.RHE,higher than the HaberBosch process (<3.4 g h^(-1)g^(-1)cat.).This work may open a new avenue for effective NO_(3)-RR by modulating oxidation states.
基金supported by the National Natural Science Foundation of China(No.92367107)。
文摘Ultra-low emission of nitrogen oxide(NO_(x))is an irreversible trend for the development of waste-to-energy industry.But traditional approaches to remove NO_(x) face significant challenge s,such as low denitration efficiency,complex denitration system,and high investment and operating cost.Here we put forward a novel polymer non-catalytic reduction(PNCR)technology that utilized a new type of polymer agent to remove NO_(x),and the proposed PNCR technology was applied to the existing waste-to-energy plant to test the denitration performance.The PNCR technology demonstrated excellent denitration performance with a NO_(x) emission concentration of<100 mg/Nm^(3) and high denitration efficiency of>75%at the temperature range of 800-900℃,which showed the application feasibility even on the complex and unstable industrial operating conditions.In addition,PNCR and hybrid polymer/selective non-catalytic reduction(PNCR/SNCR)technology possessed remarkable economic advantages including low investment fee and low operating cost of<10 CNY per ton of municipal solid waste(MSW)compared with selective catalytic reduction(SCR)technology.The excellent denitration performance of PNCR technology forebodes a broad industrial application prospect in the field of flue gas cleaning for waste-to-energy plants.
基金supported by Hainan Provincial Natural Science Foundation of China(No.721RC525).
文摘Guangdong’s carbon emissions have surpassed the world’s 11th largest emitter.It is indispensable for this province to find a robust cost-effective strategy for reducing carbon emissions.This study employed the Low Emissions Analysis Platform model,marginal cost curves,and Monte Carlo methods to simulate the energy consumption,carbon emissions,and economic benefits of emission reduction in Guangdong Province from 2020 to 2030 under the application of various structural optimization policies and energy-saving technologies.The main findings are as follows:In 2030,Guangdong Province is projected to achieve a carbon emission reduction of 273.6 to 304.6million t CO_(2eq),with a total reduction cost ranging from 1030.9 to 1452.2 billion yuan.Increasing the share of renewable energy,which still has significant growth potential,can lead to a 1.4 times greater reduction in carbon emissions compared to the application of energy-saving technologies,despite the latter yielding 2.3 times more energy savings.The emission reduction measures with net-cost can contribute 71.4%to the total carbon reduction of the province,being much larger than those with net benefits.The power sector plays a critical role in carbon emission reduction within Guangdong Province,with its various measures exerting the most substantial impact on emission reduction quantity and cost,contributing cumulative variance contributions of 90.1%and 84.3%,respectively.It has relatively large potential for emission reduction and relatively low cost of structural adjustment.
基金support of the National Natural Science Foundation of China(52074080,52004001,and 51574002).
文摘Against the background of“carbon peak and carbon neutrality,”it is of great practical significance to develop non-blast furnace ironmaking technology for the sustainable development of steel industry.Carbon-bearing iron ore pellet is an innovative burden of direct reduction ironmaking due to its excellent self-reducing property,and the thermal strength of pellet is a crucial metallurgical property that affects its wide application.The carbon-bearing iron ore pellet without binders(CIPWB)was prepared using iron concentrate and anthracite,and the effects of reducing agent addition amount,size of pellet,reduction temperature and time on the thermal compressive strength of CIPWB during the reduction process were studied.Simultaneously,the mechanism of the thermal strength evolution of CIPWB was revealed.The results showed that during the low-temperature reduction process(300-500℃),the thermal compressive strength of CIPWB linearly increases with increasing the size of pellet,while it gradually decreases with increasing the anthracite ratio.When the CIPWB with 8%anthracite is reduced at 300℃for 60 min,the thermal strength of pellet is enhanced from 13.24 to 31.88 N as the size of pellet increases from 8.04 to 12.78 mm.Meanwhile,as the temperature is 500℃,with increasing the anthracite ratio from 2%to 8%,the thermal compressive strength of pellet under reduction for 60 min remarkably decreases from 41.47 to 8.94 N.Furthermore,in the high-temperature reduction process(600-1150℃),the thermal compressive strength of CIPWB firstly increases and then reduces with increasing the temperature,while it as well as the temperature corresponding to the maximum strength decreases with increasing the anthracite ratio.With adding 18%anthracite,the thermal compressive strength of pellet reaches the maximum value at 800℃,namely 35.00 N,and obtains the minimum value at 1050℃,namely 8.60 N.The thermal compressive strength of CIPWB significantly depends on the temperature,reducing agent dosage,and pellet size.
基金supported by the China Postdoctoral Science Foundation(No.2023T160088)the Youth Fund of the National Natural Science Foundation of China(No.52304324).
文摘Magnesium and magnesium alloys,serving as crucial lightweight structural materials and hydrogen storage elements,find extensive applications in space technology,aviation,automotive,and magnesium-based hydrogen industries.The global production of primary magnesium has reached approximately 1.2 million tons per year,with anticipated diversification in future applications and significant market demand.Nevertheless,approximately 80%of the world’s primary magnesium is still manufactured through the Pidgeon process,grappling with formidable issues including high energy consumption,massive carbon emission,significant resource depletion,and environmental pollution.The implementation of the relative vacuum method shows potential in breaking through technological challenges in the Pidgeon process,facilitating clean,low-carbon continuous magnesium smelting.This paper begins by introducing the principles of the relative vacuum method.Subsequently,it elucidates various innovative process routes,including relative vacuum ferrosilicon reduction,aluminum thermal reduction co-production of spinel,and aluminum thermal reduction co-production of calcium aluminate.Finally,and thermodynamic foundations of the relative vacuum,a quantitative analysis of the material,energy flows,carbon emission,and production cost for several new processes is conducted,comparing and analyzing them against the Pidgeon process.The study findings reveal that,with identical raw materials,the relative vacuum silicon thermal reduction process significantly decreases raw material consumption,energy consumption,and carbon dioxide emissions by 15.86%,30.89%,and 26.27%,respectively,compared to the Pidgeon process.The relative vacuum process,using magnesite as the raw material and aluminum as the reducing agent,has the lowest magnesium-to-feed ratio,at only 3.385.Additionally,its energy consumption and carbon dioxide emissions are the lowest,at 1.817 tce/t Mg and 7.782 t CO_(2)/t Mg,respectively.The energy consumption and carbon emissions of the relative vacuum magnesium smelting process co-producing calcium aluminate(12CaO·7Al_(2)O_(3),3CaO·Al_(2)O_(3),and CaO·Al_(2)O_(3))are highly correlated with the consumption of dolomite in the raw materials.When the reduction temperature is around 1473.15 K,the critical volume fraction of magnesium vapor for different processes varies within the range of 5%–40%.Production cost analysis shows that the relative vacuum primary magnesium smelting process has significant economic benefits.This paper offers essential data support and theoretical guidance for achieving energy efficiency,carbon reduction in magnesium smelting,and the industrial adoption of innovative processes.
文摘Emergency department nurses face severe occupational stress leading to anxiety,depression,and burnout,which significantly impair their well-being and patientcare quality.This narrative review examined the role of mindfulness-based stress reduction(MBSR)in addressing these challenges.Rooted in nonjudgmental present-moment awareness,MBSR enhances emotional regulation and reduces psychological distress by fostering adaptive coping strategies.Studies have demonstrated its efficacy in lowering anxiety,depressive symptoms,and emotional exhaustion,while improving workplace well-being,empathy,and job satisfaction.Mechanistically,MBSR improves interoceptive awareness and autonomic balance,as evidenced by physiological markers such as heart rate variability.However,gaps remain in long-term efficacy assessments,personalized interventions,and integration with multidisciplinary approaches.Future research should prioritize tailored biomarker-driven programs,longitudinal studies,and scalable implementation strategies in high-stress clinical settings.This review underscores MBSR’s potential as a sustainable,evidence-based tool to enhance emergency department nurses’mental health and professional performance,advocating for broader adoption and further refinement of its practical applications.
基金financially supported by the National Natural Science Foundation of China(Grants 22225901,21975237 and 51702312)the Fundamental Research Funds for the Central Universities(Grant WK2340000101)+5 种基金the USTC Research Funds of the Double First-Class Initiative(Grant YD2340002007 and YD9990002017)the Open Funds of the State Key Laboratory of Rare Earth Resource Utilization(Grant RERU2022007)the China Postdoctoral Science Foundation(Grants 2023M733371,2024M750006 and 2023T160617)Postdoctoral Fellowship Program(Grade C)of China Postdoctoral Science Foundation(GZC20230008)the Natural Science Foundation Youth Project of Anhui Province(2408085QB065)the Postdoctoral Research Funding Project of Anhui Province(2023B727)。
文摘The electrochemical reduction of carbon dioxide(CO_(2))into value-added chemicals and fuels has been extensively studied as a promising strategy for mitigating environmental issues and achieving sustainable energy conversion.Substantial efforts have been made to improve the understanding of CO_(2)reduction reaction(CO_(2)RR)mechanisms by computational and spectroscopic studies.An in-depth understanding of CO_(2)RR mechanism can provide the guidance and criteria for designing high-efficiency catalysts,and hence,steering CO_(2)RR to desired products.This review systematically discusses the formation mechanisms and reaction pathways of various CO_(2)RR products,including C_(1)products(CO,HCOOH,and CH_(4)),C_(2)products(C_(2)H_(4),C_(2)H_(5)OH,and CH_(3)COOH),and C_(3+)products(C_(3)H_(6),C_(3)H_(7)OH,and others).The reaction pathways are elucidated by analyzing the adsorption behavior,energy barriers,and intermediate coupling steps involved in the generation of each product.Particular emphasis is placed on the key intermediates,such as^(*)OCHO,^(*)COOH,^(*)CO,^(*)OCCOH,and^(*)CCO,which play crucial roles in determining the product selectivity.The effects of catalyst composition,morphology,and electronic structure on the adsorption and activation of these intermediates are also discussed.Moreover,advanced characterization techniques,including in-situ spectroscopy and isotopic labeling experiments,are highlighted for their contributions to unraveling the reaction mechanisms.The review aims to provide critical insights to reveal the activity-determining para meters and underlying CO_(2)RR mechanisms,which will guide the rational design of next-generation electrocatalysts for selective CO^(2)RR towards high-value products.
