The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor ...The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion.展开更多
Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems cons...Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems consisting of two insulators.Here,motivated by the emergence of an insulator-metal transition in type-Ⅲ heterostructures and the superconductivity in some“special”two-dimensional(2D)semiconductors via electron doping,we predict that the 2D heterostructure SnSe_(2)/PtTe_(2) is a model system for realizing IS by using firstprinciples calculations.Our results show that due to slight but crucial interlayer charge transfer,SnSe_(2)/PtTe_(2) turns to be a type-Ⅲ heterostructure with metallic properties and shows a superconducting transition with the critical temperature(T_(c))of 3.73 K.Similar to the enhanced electron–phonon coupling(EPC)in the electrondoped SnSe_(2) monolayer,the IS in the SnSe_(2)/PtTe_(2) heterostructure mainly originates from the metallized SnSe_(2) layer.Furthermore,we find that its superconductivity is sensitive to tensile lattice strain,forming a domeshaped superconducting phase diagram.Remarkably,at 7%biaxial tensile strain,the superconducting T_(c) can increase more than twofold(8.80 K),resulting from softened acoustic phonons at the𝑀point and enhanced EPC strength.Our study provides a concrete example for realizing IS in type-Ⅲ heterostructures,which waits for future experimental verification.展开更多
The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter per...The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.展开更多
Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The ...Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The Co−30Ni−10Al−3V−6Ti−2Ta alloy,designed based onγʹphase dissolution temperature and phase fraction,was synthesized via arc melting and heat treatment.Phase transition temperatures,microstructure evolution,and hightemperature mechanical properties were characterized by differential scanning calorimetry,scanning electron microscopy,dual-beam TEM,and compression tests.Results show that the alloy has low density(8.15 g/cm^(3))and highγʹdissolution temperature(1234℃),along with unique yield strength retention from room temperature to 650℃.The yield strength anomaly(YSA)is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism,contributing to superior high-temperature stability of the alloy.The yield strength of this alloy outperforms other lowdensity Co-based superalloys in the temperature range of 23−650℃.展开更多
The exploration of efficient photocatalytic materials for CO_(2)conversion into hydrocarbon energy fuel is of paramount significance.However,problems,such as rapid charge recombination,low quantum efficiency,and poor ...The exploration of efficient photocatalytic materials for CO_(2)conversion into hydrocarbon energy fuel is of paramount significance.However,problems,such as rapid charge recombination,low quantum efficiency,and poor product selectivity,still limit the efficiency of photocatalytic CO_(2)reduction.Here,this study reports a Sscheme heterostructure of MnFe_(2)O_(4)/Bi_(2)WO_(6),formed by loading MnFe_(2)O_(4)nanoparticles onto Bi_(2)WO_(6) microflowers with oxygen-rich vacancies,enabling photocatalytic CO_(2)reduction.Notably,the developed MnFe_(2)O_(4)/Bi_(2)WO_(6) heterostructure improved the photocatalytic CO_(2)reduction ability,achieving a maximum CO generation rate of 32.7μmol·h^(-1)·g^(-1),which is 3.7 and 14.3 times higher than that of Bi_(2)WO_(6) and MnFe_(2)O_(4),respectively.Additionally,the CO production mechanism by CO_(2)photocatalytic reduction was proposed based on detailed characterization and density functional theory(DFT)calculation.The findings of this study suggest that introducing oxygen vacancies and constructing heterojunctions can significantly improve the photocatalytic CO_(2)reduction performance of Bi_(2)WO_(6).展开更多
Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon ...Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon dioxide upon electron-impact.Through fragment ions and electron coincidence momentum imaging,we unambiguously determine the ionization mechanism by measuring the projectile energy loss in association with the C^(+) +O_(2)^(+) channel.Further potential energy and trajectory calculations enable us to elucidate the dynamical details of this fragmentation process,in which a bond rearrangement pathway is found to proceed via the structural deformation to a triangular intermediate.Moreover,we demonstrate a further roaming pathway for the formation of O_(2)^(+) from CO_(2)^(+) 2,in which a frustrated C-O bond cleavage leaves the O atom without sufficient energy to escape.The O atom then wanders around varied configuration spaces of the flat potential energy regions and forms a C-O-O_(2)^(+) intermediate prior to the final products C^(+) +O_(2)^(+).Considering the large quantities of free electrons in interstellar space,the processes revealed here are expected to be significant and should be incorporated into atmospheric evolution models.展开更多
We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X...We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X represents transition metal elements.Systematic analysis of electronic band structures,phonon dispersions,and electron-phonon coupling reveals that substitution of MA binary metal combinations and X metal atoms can create favorable conditions for superconductivity.Mapping of superconducting critical temperatures,combined with dynamical stability analysis through phonon calculations,identifies ten superconducting candidates at ambient pressure.Among these,LiNaAgH_(6) exhibits nearly-free-electron behavior reminiscent of monovalent electron superconductors.It demonstrates exceptional superconducting properties with electron–phonon coupling λ=2.707,which yields a superconducting transition temperature T_(c) of 206.4 K using the Allen–Dynes formula.Its structural analogs MgNaPdH_(6),LiMgPdH_(6),LiMgAgH_(6),LiMgAuH_(6) all exhibit superconducting transition temperatures above 110 K.These findings advance our fundamental understanding of superconductivity in quaternary hydrides and provide guidance for rational design of new high-temperature superconducting materials.展开更多
Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-depo...Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication(EBF3).Finer and short-range ordering structures were observed in the remelted sample,whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases.High-temperature cyclic and isothermal oxidation tests at 1000℃ were carried out.The total weight gain after 60 h of cyclic oxidation decreased by 17.49%and 30.46%for the remelted and deposited samples,respectively,compared to the as-cast state.Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples.A multilayer oxide consisting of TiO_(2)+Al_(2)O_(3)+SiO_(2)+AlNbO_(4) was studied for its excellent oxidation resistance.The oxidation behavior of rutile,corundum and other oxides was analyzed using first principles calculations and chemical defect analysis.Overall,this research,which introduces novel treatments,offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.展开更多
The defect regulation and p-n heterojunction of composites have gained significant attention due to their potential applications.Nitrogen(N)as doping heteroatoms and perylene-3,4,9,10-tetracarboximide(PDINH)as an appr...The defect regulation and p-n heterojunction of composites have gained significant attention due to their potential applications.Nitrogen(N)as doping heteroatoms and perylene-3,4,9,10-tetracarboximide(PDINH)as an appropriate n-type semiconductor were innovatively and reasonably selected to enhance the photocatalytic performance of pristine p-type cuprous oxide(Cu_(2)O).In this study,the defect regula-tion of N doping(1)achieved the small-size effect of Cu_(2)O,(2)optimized the electron features,and(3)improved the kinetics of reactive oxygen species.The p-n heterojunction with PDINH was developed to sharply improve the light utilization of Cu_(2)O,from the UV region to the near-infrared region.As expected,the optimized Cu_(2)N_(x)O_(1–x)/PDINH(x=0.02)exhibited excellent long-term photocatalytic antibacterial ac-tivities,with antibacterial rates exceeding 91%against Staphylococcus aureus and Pseudomonas aeruginosa.Defect regulation and p-n heterojunction of Cu_(2)O-based composites thus provide a great deal of potential for future advancements in photocatalysis.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
The quest for high-energy-density magnesium-air batteries is hindered by the efficiency-voltage trade-off,ultimately leading to an unsatisfactory energy density.Here,we effectively mitigate the inherent efficiency-vol...The quest for high-energy-density magnesium-air batteries is hindered by the efficiency-voltage trade-off,ultimately leading to an unsatisfactory energy density.Here,we effectively mitigate the inherent efficiency-voltage trade-off by introducing a novel anode material,specifically,Mg-0.5Sn-0.5In-0.5Ga.This anode demonstrates exceptional anodic efficiency,achieving 60.5±2.5%at 1 mA cm^(-2),65.3±2.7%at 10 mA cm^(-2),and 71.4±1.2%at 20 mA cm^(-2).Furthermore,the discharge voltage is significantly enhanced,reaching 1.76±0.01 V at 1 mA cm^(-2),1.44±0.02 V at 10 mA cm^(-2),and 1.21±0.08 V at 20 mA cm^(-2).Consequently,our newly developed anode exhibits a remarkable energy density of 2312±98 W h kg^(-1),placing it among the top-performing magnesium anodes documented in the literature.Density functional theory calculations and experimental investigations have unveiled that the exceptional performance can be attributed to the inhibition of water reduction,facilitated by the hybridization between solute atoms and neighboring Mg atoms.Furthermore,the activation of the second phase,introducing additional galvanic couples,significantly contributes to this performance.This study presents valuable insights that can guide the design of novel anodes,contributing to the advancement of high-performance magnesium-air batteries.展开更多
In this study,supported Pd catalysts were prepared and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)which successfully degrade bisphenol F(BPF).Among the supported catalysts(i.e.,Pd/SiO_...In this study,supported Pd catalysts were prepared and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)which successfully degrade bisphenol F(BPF).Among the supported catalysts(i.e.,Pd/SiO_(2),Pd/CeO_(2),Pd/TiO_(2)and Pd/Al2O3),Pd/TiO_(2)exhibited the highest catalytic activity due to the high isoelectric point and high Pd0 content.Pd/TiO_(2)prepared by the deposition method leads to high Pd dispersion,which are the key factors for efficient BPF degradation.The influencing factors were investigated during the reaction process and two possible degradation pathways were proposed.Density functional theory(DFT)calculations demonstrate that stronger BPF adsorption and BPF degradation with lower reaction barrier occurs on smaller Pd particles.The catalytic activities are strongly dependent on the structural features of the catalysts.Both experiments and theoretical calculations prove that the reaction is actuated by electron transfer rather than radicals.展开更多
As a means of quantitative interpretation,forward calculations of the global lithospheric magnetic field in the Spherical Harmonic(SH)domain have been widely used to reveal geophysical,lithological,and geothermal vari...As a means of quantitative interpretation,forward calculations of the global lithospheric magnetic field in the Spherical Harmonic(SH)domain have been widely used to reveal geophysical,lithological,and geothermal variations in the lithosphere.Traditional approaches either do not consider the non-axial dipolar terms of the inducing field and its radial variation or do so by means of complicated formulae.Moreover,existing methods treat the magnetic lithosphere either as an infinitesimally thin layer or as a radially uniform spherical shell of constant thickness.Here,we present alternative forward formulae that account for an arbitrarily high maximum degree of the inducing field and for a magnetic lithosphere of variable thickness.Our simulations based on these formulae suggest that the satellite magnetic anomaly field is sensitive to the non-axial dipolar terms of the inducing field but not to its radial variation.Therefore,in forward and inverse calculations of satellite magnetic anomaly data,the non-axial dipolar terms of the inducing field should not be ignored.Furthermore,our results show that the satellite magnetic anomaly field is sensitive to variability in the lateral thickness of the magnetized shell.In particular,we show that for a given vertically integrated susceptibility distribution,underestimating the thickness of the magnetic layer overestimates the induced magnetic field.This discovery bridges the greatest part of the alleged gap between the susceptibility values measured from rock samples and the susceptibility values required to match the observed magnetic field signal.We expect the formulae and conclusions of this study to be a valuable tool for the quantitative interpretation of the Earth's global lithospheric magnetic field,through an inverse or forward modelling approach.展开更多
Establishing an energy-saving and affordable hydrogen production route from infinite seawater presents a promising strategy for achieving carbon neutrality and low-carbon development.Compared with the kinetically slug...Establishing an energy-saving and affordable hydrogen production route from infinite seawater presents a promising strategy for achieving carbon neutrality and low-carbon development.Compared with the kinetically sluggish oxygen evolution reaction(OER),the thermodynamically advantageous sulfion oxidation reaction(SOR)enables the S^(2-)pollutants recovery while reducing the energy input of water electrolysis.Here,a nanoporous NiMo alloy ligament(np-NiMo)with AlNi_(3)/Al_(5)Mo heterostructure was prepared for hydrogen evolution reaction(HER,-0.134V versus reversible hydrogen electrode(vs.RHE)at 50mA/cm^(2)),which needs an Al_(89)Ni_(10)Mo_(1)as a precursor and dealloying operation.Further,the np-NiMo alloy was thermal-treated with S powder to generate Mo-doped NiS_(2)(np-NiMo-S)for OER(1.544V vs.RHE at 50mA/cm^(2))and SOR(0.364 V vs.RHE at 50mA/cm^(2)),while still maintaining the nanostructuring advantages.Moreover,for a two-electrode electrolyzer system with np-NiMo cathode(1M KOH+seawater)coupling np-NiMo-S anode(1mol/L KOH+seawater+1 mol/L Na_(2)S),a remarkably ultra-low cell potential of 0.532 V is acquired at 50mA/cm^(2),which is about 1.015 V below that of normal alkaline seawater splitting.The theory calculations confirmed that the AlNi_(3)/Al_(5)Mo heterostructure within np-NiMo promotes H_(2)O dissociation for excellent HER,while the Mo-dopant of np-NiMo-S lowers energy barriers for the rate-determining step from^(*)S_(4)to^(*)S_(8).This work develops two kinds of NiMo alloy with tremendous prominence for achieving energy-efficient hydrogen production from alkaline seawater and sulfur recycling from sulfion-rich sewage.展开更多
Developing cost-effective and high-activity catalysts for the methanolysis of ammonia borane(AB)has attracted great attention in the field of hydrogen energy recently.Besides the modification of the electronic structu...Developing cost-effective and high-activity catalysts for the methanolysis of ammonia borane(AB)has attracted great attention in the field of hydrogen energy recently.Besides the modification of the electronic structure of the catalysts,external factors such as visible light irradiation can improve the efficiency of hydrogen production as well.In the present study,a Z-scheme heterostructured VO-Cu_(0.5)Ni_(0.5)O catalysts were constructed by introducing a plenteous phase interface and oxygen vacancy(Vo).The catalytic activity of as-prepared VO-Cu_(0.5)Ni_(0.5)O toward AB methanolysis has been improved dramatically with the assistance of visible light irradiation.The turnover frequency(TOF)under visible light irradiation was measured to be 29_(mol)H_(2)·mol_(cat.)^(-1)·min^(-1),which is 1.4 times larger than the TOF in the absence of visible light.Systematic characterization experiments and density functional theory(DFT)calculations were conducted to unveil the causation of enhanced catalytic activity.The results demonstrated that the enhancement of the catalytic activity of VO-Cu_(0.5)Ni_(0.5)O originated from the electronic structure modification induced by the formation of heterojunctions,the introduction of oxygen vacancies,and the assistance of visible light cooperatively.The formation of heterojunction and the introduction of oxygen vacancies provoked the upshift of the d-band center;while the visible light irradiation induced the photogenerated electrons to transfer from Cu to Ni sites at the interface.Such electron structure modulation is beneficial for the construction of abundant active sites,thereby enhancing the adsorption of methanol on the Ni sites,which is considered as the rate-determine step for the methanolysis of AB.The strong interaction between Ni and O weakened the O-H bond of methanol,accelerating the methanolysis of AB.These results demonstrate the utilization of combined heterojunction,oxygen vacancy,and visible light to explore highly active AB methanolysis catalysts,which should shed light on the exploration of more effective catalysts for AB methanolysis.展开更多
The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-...The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.展开更多
To obtain the precise calculation method for the peak energy density and energy evolution properties of rocks subjected to uniaxial compression(UC)before the post-peak stage,particularly at s0.9sc(s denotes stress and...To obtain the precise calculation method for the peak energy density and energy evolution properties of rocks subjected to uniaxial compression(UC)before the post-peak stage,particularly at s0.9sc(s denotes stress and sc is the peak strength),extensive UC and uniaxial graded cyclical loading-unloading(GCLU)tests were performed on four rock types.In the GCLU tests,four unloading stress levels were designated when σ<0.9σc and six unloading stress levels were designated forσ≥0.9σc.The variations in the elastic energy density(ue),dissipative energy density(ud),and energy storage efficiency(C)for the four rock types under GCLU tests were analyzed.Based on the variation of ue whenσ≥0:9σc,a method for calculating the peak energy density was proposed.The energy evolution in rock under UC condition before the post-peak stage was examined.The relationship between C0.9(C atσ≥0:9σc)and mechanical behavior of rocks was explored,and the damage evolution of rock was analyzed in view of energy.Compared with that of the three existing methods,the accuracy of the calculation method of peak energy density proposed in this study is higher.These findings could provide a theoretical foundation for more accurately revealing the failure behavior of rock from an energy perspective.展开更多
INTERNAL DOSE RESEARCH PAPERS INTDOSKIT:An R-Code for Calculation of Dose Coefficients and Studying Their Uncertainties Bastian Breustedt 1,Niranjan Chavan 2,Thomas Makumbi 2(1.Karlsruhe Institute of Technology,Instit...INTERNAL DOSE RESEARCH PAPERS INTDOSKIT:An R-Code for Calculation of Dose Coefficients and Studying Their Uncertainties Bastian Breustedt 1,Niranjan Chavan 2,Thomas Makumbi 2(1.Karlsruhe Institute of Technology,Institute of Biomedical Engineering(IBT),Fritz-Haber-Weg 1,D-76131 Karlsruhe,Germany;2.Karlsruhe Institute of Technology,Institute for Thermal Energy Technology and Safety(ITES),Hermann-von-Helmholtz-Platz 1,76344 EggensteinLeopoldshafen,Germany)Abstract:An R-code,which allows the calculation of the time dependent activity distribution based on ICRP reference models,the number of decays in a commitment period,and the dose coefficients for tissues and organs of the human body,has been developed.R Language was chosen due to its powerful mathematical and statistical modeling features,as well as its graphical capabilities.展开更多
文摘The efficiency and stability of catalysts for photocatalytic hydrogen evolution(PHE)are largely governed by the charge transfer behaviors across the heterojunction interfaces.In this study,CuO,a typical semiconductor featuring a broad spectral absorption range,is successfully employed as the electron acceptor to combine with CdS for constructing a S-scheme heterojunction.The optimized photocatalyst(CdSCuO2∶1)delivers an exceptional hydrogen evolution rate of 18.89 mmol/(g·h),4.15-fold higher compared with bare CdS.X-ray photoelectron spectroscopy(XPS)and ultraviolet-visible diffuse reflection absorption spectroscopy(UV-vis DRS)confirmed the S-scheme band structure of the composites.Moreover,the surface photovoltage(SPV)and electron paramagnetic resonance(EPR)indicated that the photogenerated electrons and photogenerated holes of CdS-CuO2∶1 were respectively transferred to the conduction band(CB)of CdS with a higher reduction potential and the valence band(VB)of CuO with a higher oxidation potential under illumination,as expected for the S-scheme mechanism.Density-functional-theory calculations of the electron density difference(EDD)disclose an interfacial electric field oriented from CdS to CuO.This built-in field suppresses charge recombination and accelerates carrier migration,rationalizing the markedly enhanced PHE activity.This study offers a novel strategy for designing S-scheme heterojunctions with high light harvesting and charge utilization toward sustainable solar-tohydrogen conversion.
基金supported by the National Key R&D Program of China (Grant Nos.2022YFA1403103 and 2019YFA0308603)the National Natural Science Foundation of China (Grant No.12304167)the Shandong Provincial Natural Science Foundation of China (Grant No.ZR2023QA020)。
文摘Interfacial superconductivity(IS)has been a topic of intense interest in condensed matter physics,due to its unique properties and exotic photoelectrical performance.However,there are few reports about IS systems consisting of two insulators.Here,motivated by the emergence of an insulator-metal transition in type-Ⅲ heterostructures and the superconductivity in some“special”two-dimensional(2D)semiconductors via electron doping,we predict that the 2D heterostructure SnSe_(2)/PtTe_(2) is a model system for realizing IS by using firstprinciples calculations.Our results show that due to slight but crucial interlayer charge transfer,SnSe_(2)/PtTe_(2) turns to be a type-Ⅲ heterostructure with metallic properties and shows a superconducting transition with the critical temperature(T_(c))of 3.73 K.Similar to the enhanced electron–phonon coupling(EPC)in the electrondoped SnSe_(2) monolayer,the IS in the SnSe_(2)/PtTe_(2) heterostructure mainly originates from the metallized SnSe_(2) layer.Furthermore,we find that its superconductivity is sensitive to tensile lattice strain,forming a domeshaped superconducting phase diagram.Remarkably,at 7%biaxial tensile strain,the superconducting T_(c) can increase more than twofold(8.80 K),resulting from softened acoustic phonons at the𝑀point and enhanced EPC strength.Our study provides a concrete example for realizing IS in type-Ⅲ heterostructures,which waits for future experimental verification.
基金supported by the National Natural Science Foundation of China(52471240)the Natural Science Foundation of Zhejiang Province(LZ23B030003)+2 种基金the Fundamental Research Funds for the Central Universities(226-2024-00075)support from the Engineering and Physical Sciences Research Council(EPSRC,UK)RiR grant-RIR18221018-1EU COST CA23155。
文摘The electric double layer(EDL)at the electrochemical interface is crucial for ion transport,charge transfer,and surface reactions in aqueous rechargeable zinc batteries(ARZBs).However,Zn anodes routinely encounter persistent dendrite growth and parasitic reactions,driven by the inhomogeneous charge distribution and water-dominated environment within the EDL.Compounding this,classical EDL theory,rooted in meanfield approximations,further fails to resolve molecular-scale interfacial dynamics under battery-operating conditions,limiting mechanistic insights.Herein,we established a multiscale theoretical calculation framework from single molecular characteristics to interfacial ion distribution,revealing the EDL’s structure and interactions between different ions and molecules,which helps us understand the parasitic processes in depth.Simulations demonstrate that water dipole and sulfate ion adsorption at the inner Helmholtz plane drives severe hydrogen evolution and by-product formation.Guided by these insights,we engineered a“water-poor and anion-expelled”EDL using 4,1’,6’-trichlorogalactosucrose(TGS)as an electrolyte additive.As a result,Zn||Zn symmetric cells with TGS exhibited stable cycling for over 4700 h under a current density of 1 mA cm^(−2),while NaV_(3)O_(8)·1.5H_(2)O-based full cells kept 90.4%of the initial specific capacity after 800 cycles at 5 A g^(−1).This work highlights the power of multiscale theoretical frameworks to unravel EDL complexities and guide high-performance ARZB design through integrated theory-experiment approaches.
基金supported by the National Natural Science Foundation of China(Nos.51831007,52101135)the Shenzhen Science and Technology Program,China(No.SGDX20210823104002016)the Guangdong Basic and Applied Basic Research Foundation,China(Nos.2021B1515120071,JCYJ20220531095217039)。
文摘Low-density superalloys often exhibit low yield strength in the intermediate temperature range(300−650℃).To enhance yield performance in this range,the CALPHAD method was used to design a new Co-based superalloy.The Co−30Ni−10Al−3V−6Ti−2Ta alloy,designed based onγʹphase dissolution temperature and phase fraction,was synthesized via arc melting and heat treatment.Phase transition temperatures,microstructure evolution,and hightemperature mechanical properties were characterized by differential scanning calorimetry,scanning electron microscopy,dual-beam TEM,and compression tests.Results show that the alloy has low density(8.15 g/cm^(3))and highγʹdissolution temperature(1234℃),along with unique yield strength retention from room temperature to 650℃.The yield strength anomaly(YSA)is attributed to high stacking fault energy and activation of the Kear−Wilsdorf locking mechanism,contributing to superior high-temperature stability of the alloy.The yield strength of this alloy outperforms other lowdensity Co-based superalloys in the temperature range of 23−650℃.
基金supported by the National Natural Science Foundation of China(No.11974152)the Liaoning Provincial Natural Science Foundation Program,the Doctoral Research Initiation Project(No.2024-BS-003)the Liaoning University 2024 Basic Research Projects in Science and Technology(No.LJ212410140026).
文摘The exploration of efficient photocatalytic materials for CO_(2)conversion into hydrocarbon energy fuel is of paramount significance.However,problems,such as rapid charge recombination,low quantum efficiency,and poor product selectivity,still limit the efficiency of photocatalytic CO_(2)reduction.Here,this study reports a Sscheme heterostructure of MnFe_(2)O_(4)/Bi_(2)WO_(6),formed by loading MnFe_(2)O_(4)nanoparticles onto Bi_(2)WO_(6) microflowers with oxygen-rich vacancies,enabling photocatalytic CO_(2)reduction.Notably,the developed MnFe_(2)O_(4)/Bi_(2)WO_(6) heterostructure improved the photocatalytic CO_(2)reduction ability,achieving a maximum CO generation rate of 32.7μmol·h^(-1)·g^(-1),which is 3.7 and 14.3 times higher than that of Bi_(2)WO_(6) and MnFe_(2)O_(4),respectively.Additionally,the CO production mechanism by CO_(2)photocatalytic reduction was proposed based on detailed characterization and density functional theory(DFT)calculation.The findings of this study suggest that introducing oxygen vacancies and constructing heterojunctions can significantly improve the photocatalytic CO_(2)reduction performance of Bi_(2)WO_(6).
基金supported by the National Natural Science Foundation of China (Grant Nos.12325406,92261201,12404305,and W2512072)the Shaanxi Province Natural Science Fundamental Research Project (Grant Nos.2023JC-XJ-03 and23JSQ013)the China Postdoctoral Science Foundation (Grant Nos.BX20240286 and 2024M7625)。
文摘Abiotic oxygen formation predates photosynthesis,sustaining early chemical evolution,yet its elementary mechanisms remain contested.Here,we show the production pathways for molecular oxygen from doubly ionized carbon dioxide upon electron-impact.Through fragment ions and electron coincidence momentum imaging,we unambiguously determine the ionization mechanism by measuring the projectile energy loss in association with the C^(+) +O_(2)^(+) channel.Further potential energy and trajectory calculations enable us to elucidate the dynamical details of this fragmentation process,in which a bond rearrangement pathway is found to proceed via the structural deformation to a triangular intermediate.Moreover,we demonstrate a further roaming pathway for the formation of O_(2)^(+) from CO_(2)^(+) 2,in which a frustrated C-O bond cleavage leaves the O atom without sufficient energy to escape.The O atom then wanders around varied configuration spaces of the flat potential energy regions and forms a C-O-O_(2)^(+) intermediate prior to the final products C^(+) +O_(2)^(+).Considering the large quantities of free electrons in interstellar space,the processes revealed here are expected to be significant and should be incorporated into atmospheric evolution models.
基金supported by the National Key R&D Program of China (Grant No.2022YFA1403201)the National Natural Science Foundation of China (Grant Nos.12125404,T2495231,123B2049,and 12204138)+9 种基金the Advanced MaterialsNational Science and Technology Major Project (Grant No.2024ZD0607000)the Natural Science Foundation of Jiangsu Province (Grant Nos.BK20233001 and BK20253009)the Jiangsu Funding Program for Excellent Postdoctoral Talent (Grant No.2024ZB002)the China Postdoctoral Science Foundation (Grant No.2025M773331)the Fundamental and Interdisciplinary Disciplines Breakthrough Plan of the Ministry of Education of Chinathe AI&AI for Science program of Nanjing UniversityArtificial Intelligence and Quantum physics (AIQ) program of Nanjing Universitythe Fundamental Research Funds for the Central Universitiesthe Natural Science Foundation of Nanjing University of Posts and Telecommunications(Grant Nos.NY224165,NY220038,and NY219087)the Hua Li Talents Program of Nanjing University of Posts and Telecommunications。
文摘We report a theoretical investigation into superconductivity within the MAXH_(6) quaternary hydride system using first-principles calculations,where M and A denote alkali and alkaline earth elements,respectively,and X represents transition metal elements.Systematic analysis of electronic band structures,phonon dispersions,and electron-phonon coupling reveals that substitution of MA binary metal combinations and X metal atoms can create favorable conditions for superconductivity.Mapping of superconducting critical temperatures,combined with dynamical stability analysis through phonon calculations,identifies ten superconducting candidates at ambient pressure.Among these,LiNaAgH_(6) exhibits nearly-free-electron behavior reminiscent of monovalent electron superconductors.It demonstrates exceptional superconducting properties with electron–phonon coupling λ=2.707,which yields a superconducting transition temperature T_(c) of 206.4 K using the Allen–Dynes formula.Its structural analogs MgNaPdH_(6),LiMgPdH_(6),LiMgAgH_(6),LiMgAuH_(6) all exhibit superconducting transition temperatures above 110 K.These findings advance our fundamental understanding of superconductivity in quaternary hydrides and provide guidance for rational design of new high-temperature superconducting materials.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0609000)National Natural Science Foundation of China(Grant Nos.52171034 and 52101037)Postdoctoral Fellowship Program of CPSFara(No.GZB20230944).
文摘Up-and-coming high-temperature materials,refractory high entropy alloys,are suffering from lower oxidation resistance,restricting their applications in the aerospace field.In this study,two novel treatments of Al-deposited and remelted were developed to refine the microstructure and enhance the oxidation resistance of refractory high entropy alloy using electron beam freeform fabrication(EBF3).Finer and short-range ordering structures were observed in the remelted sample,whereas the Al-deposited sample showcased the formation of silicide and intermetallic phases.High-temperature cyclic and isothermal oxidation tests at 1000℃ were carried out.The total weight gain after 60 h of cyclic oxidation decreased by 17.49%and 30.46%for the remelted and deposited samples,respectively,compared to the as-cast state.Oxidation kinetics reveal an evident lower mass gain and oxidation rate in the treated samples.A multilayer oxide consisting of TiO_(2)+Al_(2)O_(3)+SiO_(2)+AlNbO_(4) was studied for its excellent oxidation resistance.The oxidation behavior of rutile,corundum and other oxides was analyzed using first principles calculations and chemical defect analysis.Overall,this research,which introduces novel treatments,offers promising insights for enhancing the inherent oxidation resistance of refractory high entropy alloys.
基金supported by the National Natural Science Foundation Joint Fund(Nos.U1806223 and U2106226)the National Natural Science Foundation of China(No.52371081)the Key Technology Research and Development Program of Shandong Province(No.2020CXGC010703).
文摘The defect regulation and p-n heterojunction of composites have gained significant attention due to their potential applications.Nitrogen(N)as doping heteroatoms and perylene-3,4,9,10-tetracarboximide(PDINH)as an appropriate n-type semiconductor were innovatively and reasonably selected to enhance the photocatalytic performance of pristine p-type cuprous oxide(Cu_(2)O).In this study,the defect regula-tion of N doping(1)achieved the small-size effect of Cu_(2)O,(2)optimized the electron features,and(3)improved the kinetics of reactive oxygen species.The p-n heterojunction with PDINH was developed to sharply improve the light utilization of Cu_(2)O,from the UV region to the near-infrared region.As expected,the optimized Cu_(2)N_(x)O_(1–x)/PDINH(x=0.02)exhibited excellent long-term photocatalytic antibacterial ac-tivities,with antibacterial rates exceeding 91%against Staphylococcus aureus and Pseudomonas aeruginosa.Defect regulation and p-n heterojunction of Cu_(2)O-based composites thus provide a great deal of potential for future advancements in photocatalysis.
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the R&D Program of Beijing Municipal Education Commission(No.KM202310005010)the National Natural Science Foundation of China(No.52001015)for their financial support.
文摘The quest for high-energy-density magnesium-air batteries is hindered by the efficiency-voltage trade-off,ultimately leading to an unsatisfactory energy density.Here,we effectively mitigate the inherent efficiency-voltage trade-off by introducing a novel anode material,specifically,Mg-0.5Sn-0.5In-0.5Ga.This anode demonstrates exceptional anodic efficiency,achieving 60.5±2.5%at 1 mA cm^(-2),65.3±2.7%at 10 mA cm^(-2),and 71.4±1.2%at 20 mA cm^(-2).Furthermore,the discharge voltage is significantly enhanced,reaching 1.76±0.01 V at 1 mA cm^(-2),1.44±0.02 V at 10 mA cm^(-2),and 1.21±0.08 V at 20 mA cm^(-2).Consequently,our newly developed anode exhibits a remarkable energy density of 2312±98 W h kg^(-1),placing it among the top-performing magnesium anodes documented in the literature.Density functional theory calculations and experimental investigations have unveiled that the exceptional performance can be attributed to the inhibition of water reduction,facilitated by the hybridization between solute atoms and neighboring Mg atoms.Furthermore,the activation of the second phase,introducing additional galvanic couples,significantly contributes to this performance.This study presents valuable insights that can guide the design of novel anodes,contributing to the advancement of high-performance magnesium-air batteries.
基金supported by the National Natural Science Foundation of China(NSFC)(No.21978137).
文摘In this study,supported Pd catalysts were prepared and used as heterogeneous catalysts for the activation of peroxymonosulfate(PMS)which successfully degrade bisphenol F(BPF).Among the supported catalysts(i.e.,Pd/SiO_(2),Pd/CeO_(2),Pd/TiO_(2)and Pd/Al2O3),Pd/TiO_(2)exhibited the highest catalytic activity due to the high isoelectric point and high Pd0 content.Pd/TiO_(2)prepared by the deposition method leads to high Pd dispersion,which are the key factors for efficient BPF degradation.The influencing factors were investigated during the reaction process and two possible degradation pathways were proposed.Density functional theory(DFT)calculations demonstrate that stronger BPF adsorption and BPF degradation with lower reaction barrier occurs on smaller Pd particles.The catalytic activities are strongly dependent on the structural features of the catalysts.Both experiments and theoretical calculations prove that the reaction is actuated by electron transfer rather than radicals.
基金supported by the National Natural Science Foundation of China(Grant Nos.42250103 and 42174090)the Opening Fund of Key Laboratory of Geological Survey and Evaluation of Ministry of Education(Grant No.GLAB2023ZR02)the Ministry of Science and Technology(MOST)Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources(Grant No.MSFGPMR2022-4)。
文摘As a means of quantitative interpretation,forward calculations of the global lithospheric magnetic field in the Spherical Harmonic(SH)domain have been widely used to reveal geophysical,lithological,and geothermal variations in the lithosphere.Traditional approaches either do not consider the non-axial dipolar terms of the inducing field and its radial variation or do so by means of complicated formulae.Moreover,existing methods treat the magnetic lithosphere either as an infinitesimally thin layer or as a radially uniform spherical shell of constant thickness.Here,we present alternative forward formulae that account for an arbitrarily high maximum degree of the inducing field and for a magnetic lithosphere of variable thickness.Our simulations based on these formulae suggest that the satellite magnetic anomaly field is sensitive to the non-axial dipolar terms of the inducing field but not to its radial variation.Therefore,in forward and inverse calculations of satellite magnetic anomaly data,the non-axial dipolar terms of the inducing field should not be ignored.Furthermore,our results show that the satellite magnetic anomaly field is sensitive to variability in the lateral thickness of the magnetized shell.In particular,we show that for a given vertically integrated susceptibility distribution,underestimating the thickness of the magnetic layer overestimates the induced magnetic field.This discovery bridges the greatest part of the alleged gap between the susceptibility values measured from rock samples and the susceptibility values required to match the observed magnetic field signal.We expect the formulae and conclusions of this study to be a valuable tool for the quantitative interpretation of the Earth's global lithospheric magnetic field,through an inverse or forward modelling approach.
基金financially supported by the Guangxi Natural Science Fund for Distinguished Young Scholars(No.2024GXNSFFA010008)the Natural Science Foundation of Jilin Province of China(No.20240101098JC)the National Natural Science Foundation of China(No.22469002)。
文摘Establishing an energy-saving and affordable hydrogen production route from infinite seawater presents a promising strategy for achieving carbon neutrality and low-carbon development.Compared with the kinetically sluggish oxygen evolution reaction(OER),the thermodynamically advantageous sulfion oxidation reaction(SOR)enables the S^(2-)pollutants recovery while reducing the energy input of water electrolysis.Here,a nanoporous NiMo alloy ligament(np-NiMo)with AlNi_(3)/Al_(5)Mo heterostructure was prepared for hydrogen evolution reaction(HER,-0.134V versus reversible hydrogen electrode(vs.RHE)at 50mA/cm^(2)),which needs an Al_(89)Ni_(10)Mo_(1)as a precursor and dealloying operation.Further,the np-NiMo alloy was thermal-treated with S powder to generate Mo-doped NiS_(2)(np-NiMo-S)for OER(1.544V vs.RHE at 50mA/cm^(2))and SOR(0.364 V vs.RHE at 50mA/cm^(2)),while still maintaining the nanostructuring advantages.Moreover,for a two-electrode electrolyzer system with np-NiMo cathode(1M KOH+seawater)coupling np-NiMo-S anode(1mol/L KOH+seawater+1 mol/L Na_(2)S),a remarkably ultra-low cell potential of 0.532 V is acquired at 50mA/cm^(2),which is about 1.015 V below that of normal alkaline seawater splitting.The theory calculations confirmed that the AlNi_(3)/Al_(5)Mo heterostructure within np-NiMo promotes H_(2)O dissociation for excellent HER,while the Mo-dopant of np-NiMo-S lowers energy barriers for the rate-determining step from^(*)S_(4)to^(*)S_(8).This work develops two kinds of NiMo alloy with tremendous prominence for achieving energy-efficient hydrogen production from alkaline seawater and sulfur recycling from sulfion-rich sewage.
基金supported the Natural Science Foundation of Guangdong Province(Nos.2022A1515140085,2022A1515111022 and 2022A1515110275)the Major and Special Project in the Field of Intelligent Manufacturing of the Universities in Guangdong Province(No.2020ZDZX2067)+2 种基金the Natural Science Foundation of Huizhou University(No.HZU202004)the Professorial and Doctoral Scientific Research Foundation of Huizhou University(No.2020JB046)the Open Project Program of Guangdong Provincial Key Laboratory of Electronic Functional Materials and Devices,Huizhou University(No.EFMDN2021004M).
文摘Developing cost-effective and high-activity catalysts for the methanolysis of ammonia borane(AB)has attracted great attention in the field of hydrogen energy recently.Besides the modification of the electronic structure of the catalysts,external factors such as visible light irradiation can improve the efficiency of hydrogen production as well.In the present study,a Z-scheme heterostructured VO-Cu_(0.5)Ni_(0.5)O catalysts were constructed by introducing a plenteous phase interface and oxygen vacancy(Vo).The catalytic activity of as-prepared VO-Cu_(0.5)Ni_(0.5)O toward AB methanolysis has been improved dramatically with the assistance of visible light irradiation.The turnover frequency(TOF)under visible light irradiation was measured to be 29_(mol)H_(2)·mol_(cat.)^(-1)·min^(-1),which is 1.4 times larger than the TOF in the absence of visible light.Systematic characterization experiments and density functional theory(DFT)calculations were conducted to unveil the causation of enhanced catalytic activity.The results demonstrated that the enhancement of the catalytic activity of VO-Cu_(0.5)Ni_(0.5)O originated from the electronic structure modification induced by the formation of heterojunctions,the introduction of oxygen vacancies,and the assistance of visible light cooperatively.The formation of heterojunction and the introduction of oxygen vacancies provoked the upshift of the d-band center;while the visible light irradiation induced the photogenerated electrons to transfer from Cu to Ni sites at the interface.Such electron structure modulation is beneficial for the construction of abundant active sites,thereby enhancing the adsorption of methanol on the Ni sites,which is considered as the rate-determine step for the methanolysis of AB.The strong interaction between Ni and O weakened the O-H bond of methanol,accelerating the methanolysis of AB.These results demonstrate the utilization of combined heterojunction,oxygen vacancy,and visible light to explore highly active AB methanolysis catalysts,which should shed light on the exploration of more effective catalysts for AB methanolysis.
基金sponsored by the National Natural Science Foundation of China(Nos.5210125 and 52375422)the Science Research Project of Hebei Education Department(No.BJK2023058)the Natural Science Foundation of Hebei Province(Nos.E2020208069,B2020208083 and E202320801).
文摘The stability and electrocatalytic efficiency of transition metal oxides for water splitting is determined by geometric and electronic structure,especially under high current densities.Herein,a newly designed lamella-heterostructured nanoporous CoFe/CoFe_(2)O_(4) and CeO_(2−x),in situ grown on nickel foam(NF),holds great promise as a high-efficient bifunctional electrocatalyst(named R-CoFe/Ce/NF)for water splitting.Experimental characterization verifies surface reconstruction from CoFe alloy/oxide to highly active CoFeOOH during in situ electrochemical polarization.By virtues of three-dimensional nanoporous architecture and abundant electroactive CoFeOOH/CeO_(2−x) heterostructure interfaces,the R-CoFe/Ce/NF electrode achieves low overpotentials for oxygen evolution(η_(10)=227 mV;η_(500)=450 mV)and hydrogen evolution(η_(10)=35 mV;η_(408)=560 mV)reactions with high normalized electrochemical active surface areas,respectively.Additionally,the alkaline full water splitting electrolyzer of R-CoFe/Ce/NF||R-CoFe/Ce/NF achieves a current density of 50 mA·cm^(−2) only at 1.75 V;the decline of activity is satisfactory after 100-h durability test at 300 mA·cm^(−2).Density functional theory also demonstrates that the electron can transfer from CeO_(2−x) by virtue of O atom to CoFeOOH at CoFeOOH/CeO_(2−x) heterointerfaces and enhancing the adsorption of reactant,thus optimizing electronic structure and Gibbs free energies for the improvement of the activity for water splitting.
基金the National Natural Science Foundation of China(Grant Nos.52104133 and 52304227)the Postdoctoral Foundation of Henan Province(Grant No.HN2022015)are appreciated.
文摘To obtain the precise calculation method for the peak energy density and energy evolution properties of rocks subjected to uniaxial compression(UC)before the post-peak stage,particularly at s0.9sc(s denotes stress and sc is the peak strength),extensive UC and uniaxial graded cyclical loading-unloading(GCLU)tests were performed on four rock types.In the GCLU tests,four unloading stress levels were designated when σ<0.9σc and six unloading stress levels were designated forσ≥0.9σc.The variations in the elastic energy density(ue),dissipative energy density(ud),and energy storage efficiency(C)for the four rock types under GCLU tests were analyzed.Based on the variation of ue whenσ≥0:9σc,a method for calculating the peak energy density was proposed.The energy evolution in rock under UC condition before the post-peak stage was examined.The relationship between C0.9(C atσ≥0:9σc)and mechanical behavior of rocks was explored,and the damage evolution of rock was analyzed in view of energy.Compared with that of the three existing methods,the accuracy of the calculation method of peak energy density proposed in this study is higher.These findings could provide a theoretical foundation for more accurately revealing the failure behavior of rock from an energy perspective.
文摘INTERNAL DOSE RESEARCH PAPERS INTDOSKIT:An R-Code for Calculation of Dose Coefficients and Studying Their Uncertainties Bastian Breustedt 1,Niranjan Chavan 2,Thomas Makumbi 2(1.Karlsruhe Institute of Technology,Institute of Biomedical Engineering(IBT),Fritz-Haber-Weg 1,D-76131 Karlsruhe,Germany;2.Karlsruhe Institute of Technology,Institute for Thermal Energy Technology and Safety(ITES),Hermann-von-Helmholtz-Platz 1,76344 EggensteinLeopoldshafen,Germany)Abstract:An R-code,which allows the calculation of the time dependent activity distribution based on ICRP reference models,the number of decays in a commitment period,and the dose coefficients for tissues and organs of the human body,has been developed.R Language was chosen due to its powerful mathematical and statistical modeling features,as well as its graphical capabilities.
