The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclus...The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclusively observed in thin films under atmospheric pressure,underscoring the critical role of the heterointerface.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
Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storag...Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.展开更多
Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research...Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research used chemical co-precipitation within an automated experimental device to synthesize RETaO_(4)(RE=Nd,Sm,Gd,Ho,Er)powders.The device automatically monitored and controlled the solutions'pH,improving the chemical co-precipitation efficiency.The crystal structure and microstructure of the RETaO_(4)powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase transition.The m'-RETaO_(4)powders exhibit nano-size grains,while m-RETaO_(4)powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis es-timates the reversive ferroelastic tetragonal-monoclinic phase transition temperatures.Overall,this research focuses on the synthesis,crystal structures,microstructures,and phase transition of the fabricated RETaO_(4)powders.展开更多
Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Her...Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.展开更多
The development of high-performance structural and functional materials is vital in many industrial fields.High-and medium-entropy alloys(H/MEAs)with superior comprehensive properties owing to their specific microstru...The development of high-performance structural and functional materials is vital in many industrial fields.High-and medium-entropy alloys(H/MEAs)with superior comprehensive properties owing to their specific microstructures are promising candidates for structural materials.More importantly,multitudinous efforts have been made to regulate the microstructures and the properties of H/MEAs to further expand their industrial applications.The various heterostructures have enormous potential for the development of H/MEAs with outstanding performance.Herein,multiple heterogeneous structures with single and hierarchical heterogeneities were discussed in detail.Moreover,preparation methods for compositional inhomogeneity,bimodal structures,dualphase structures,lamella/layered structures,harmonic structures(core-shell),multiscale precipitates and heterostructures coupled with specific microstructures in H/MEAs were also systematically reviewed.The deformation mechanisms induced by the different heterostructures were thoroughly discussed to explore the relationship between the heterostructures and the optimized properties of H/MEAs.The contributions of the heterostructures and advanced microstructures to the H/MEAs were comprehensively elucidated to further improve the properties of the alloys.Finally,this review discussed the future challenges of high-performance H/MEAs for industrial applications and provides feasible methods for optimizing heterostructures to enhance the comprehensive properties of H/MEAs.展开更多
Due to the lack of the three-dimensional structure of the Zhaoji Salt Basin,the salt mining enterprises have obvious clustering when choosing sites.Production capacity declines rapidly as mining deepens,and the enterp...Due to the lack of the three-dimensional structure of the Zhaoji Salt Basin,the salt mining enterprises have obvious clustering when choosing sites.Production capacity declines rapidly as mining deepens,and the enterprises are entering a stage of stagnation in production.In this study,a dense seismic array of 125 short-period stations was deployed around the core mining area and its vicinity of the salt mine industry,we used the ambient noise tomography(ANT)method to image the three-dimensional shear wave velocity structure at the depth shallower than 3 km.The results indicate:(1)The overall shear wave velocity in the study area is relatively lower,ranging from 0.8 to 1.8 km/s,which could be related to the loose and thick deposition of the Zhaoji sub-depression.(2)The three-dimensional shear wave velocity structure reveals that the sedimentary thickness of the Zhaoji sub-depression is deeper in the southeast and shallower in the northwest,with the sedimentary center located around Heping Town and Dahuangzhuang Town.(3)The Zhaoji salt mine is a low-velocity anomalous zone in the shear wave velocity structure with an inverse‘C'character spreading along Nanchenji Town and Zhaoji Town,with a depth ranging from approximately 1.2 to 2.8 km,it may be caused by the development of rock fissures due to water extraction and injection.The surrounding rock exhibits relatively high velocity,which reflects the morphological characteristics of the Zhaoji Salt Basin.The three-dimensional shear wave velocity model obtained in this study provides scientific guidance for the industrial exploitation of the Zhaoji salt mine and reference for salt exploration of the Hongze Salt Basin.It also provides an important basis for the seismic risk assessment of the salt basins.Simultaneously,it holds significant implications for exploring the application of ambient noise tomography method in spatial detection of salt mine belt.展开更多
The discovery of high-temperature superconductivity in bilayer nickelate La_(3)Ni_(2)O_(7)under high-pressure conditions has spurred extensive efforts to stabilize superconductivity at ambient pressure.Recently,the re...The discovery of high-temperature superconductivity in bilayer nickelate La_(3)Ni_(2)O_(7)under high-pressure conditions has spurred extensive efforts to stabilize superconductivity at ambient pressure.Recently,the realization of superconductivity in compressively strained La_(3)Ni_(2)O_(7)thin films grown on the SrLaAlO_(4)substrates,with a T_(c)exceeding 40 K,represents a significant step toward this goal.Here,we investigate the influence of film thickness and carrier doping on the electronic structure of La_(3)Ni_(2)O_(7)thin films,ranging from 0.5 to 3 unit cells,using first-principles calculations.For a 2 unit-cell film with an optimal doping concentration of 0.3 hole per formula unit(0.15 hole/Ni),the Ni-d_(z^(2))interlayer bonding state crosses the Fermi level,resulting in the formation ofγpockets at the Fermi surface.These findings align with angle-resolved photoemission spectroscopy experimental data.Our results provide theoretical validation for the recent experimental discovery of ambient-pressure superconductivity in La_(3)Ni_(2)O_(7)thin films and underscore the significant impact of film thickness and carrier doping on electronic property modulation.展开更多
Currently,the link prediction algorithms primarily focus on studying the interaction between nodes based on chain structure and star structure,which predominantly rely on low-order structural information and do not ex...Currently,the link prediction algorithms primarily focus on studying the interaction between nodes based on chain structure and star structure,which predominantly rely on low-order structural information and do not explore the multivariate interactions between nodes from the perspective of higher-order structural information present in the network.The cycle structure is a higher-order structure that lies between the star and clique structures,where all nodes within the same cycle can interact with each other,even in the absence of direct edges.If a node is encompassed by multiple cycles,it indicates that the node interacts and associates with a greater number of nodes in the network,and it means the node is more important in the network to some extent.Furthermore,if two nodes are included in multiple cycles,it signifies the two nodes are more likely to be connected.Therefore,firstly,a multi-information fusion node importance algorithm based on the cycle structure information is proposed,which integrates both high-order and low-order structural information.Secondly,the obtained integrated structure information and node feature information is regarded as the input features,a two-channel graph neural network model is designed to learn the cycle structure information.Then,the cycle structure information is utilised for the task of link prediction,and a graph neural link predictor with multi-information interactions based on the cycle structure is developed.Finally,extensive experimental validation and analysis show that the node ranking result of the proposed node importance index is more consistent with the actual situation,the proposed graph neural network model can effectively learn the cycle structure information,and using higher-order structural information—cycle information proves to significantly enhance the overall link prediction performance.展开更多
Coal pore parameters are closely related to macrolithotypes and coal structures,having a large influence over the gas potential and productivity of coalbed methane(CBM).The Middle Jurassic Xishanyao Formation,located ...Coal pore parameters are closely related to macrolithotypes and coal structures,having a large influence over the gas potential and productivity of coalbed methane(CBM).The Middle Jurassic Xishanyao Formation,located in the southern Junggar Basin of northwestern China,has geological conditions with rich CBM resources.The 46 Xishanyao coal samples gathered from the drilling cores and coal mines cover 4 types of macrolithotypes(bright coal 1,semi-bright coal 2,semi-dull coal 3,and dull coal 4)and 2 types of coal structures(primary coal I and cataclastic coal II).Based on a range of pore testing experiments and analytical methods,the dual effects of different macrolithotypes and coal structures on pore structures were intensely studied.The results showed that the specific surface area(SSA)and total pore volume(TPV)of coal samples increased gradually from bright to dull coals.For the same macrolithotypes,the SSA and TPV of the primary coals were lower than those of the cataclastic coals.Generally,the pore structures of bright and semi-bright coals are simpler when compared to semi-dull and dull coals with the same coal structure,whereas cataclastic coals have more complicated pore structure systems than primary coals with the same macrolithotypes.The bright and semi-bright coals have higher vitrinite contents and more endogenous fractures,whereas well-developed structural fractures were identified in cataclastic coals.Therefore,bright and semi-bright coals have better pore connectivity than semi-dull and dull coals with the same coal structure,the pore connectivity of cataclastic coals being slightly better than that of primary coals under the same macrolithotypes.In terms of the CBM adsorption conditions,the eight type samples formed a descending order:Ⅱ-4>I-4>Ⅱ-3>Ⅰ-3>Ⅱ-2>Ⅰ-2>Ⅱ-1>Ⅰ-1,while they ranked as follows when consideration was given to the CBM seepage capacities:II-2>Ⅱ-1>Ⅰ-2>Ⅰ-1>Ⅰ-3>Ⅰ-4>Ⅱ-3>Ⅱ-4.As a result,it could be determined that the bright and semi-bright coals had stronger adsorption capacities,whereas the cataclastic coals had better pore connectivity and seepage capacities.Pore structure characteristics should be analysed under the dual control of different macrolithotypes and coal structures,so that they can provide greater value for guiding CBM exploration and exploitation,as along for preventing underground gas accidents.展开更多
Photoelectrocatalytic(PEC)seawater splitting as a green and sustainable route to harvest hydrogen is attractive yet hampered by low activity of photoanodes and unexpected high selectivity to the corrosive and toxic ch...Photoelectrocatalytic(PEC)seawater splitting as a green and sustainable route to harvest hydrogen is attractive yet hampered by low activity of photoanodes and unexpected high selectivity to the corrosive and toxic chlorine.Especially,it is full of challenges to unveil the key factors influencing the selectivity of such complex PEC processes.Herein,by regulating the energy band and surface structure of the anatase TiO_(2) nanotube array photoanode via nitrogen-doping,the seawater PEC oxidation shifts from Cl^(-)oxidation reaction(ClOR)dominant on the TiO_(2) photoanode(61.6%)to oxygen evolution reaction(OER)dominant on the N-TiO_(2) photoanode(62.9%).Comprehensive investigations including operando photoelectrochemical FTIR and DFT calculations unveil that the asymmetric hydrogen-bonding water at the N-TiO_(2) electrode/electrolyte interface enriches under illumination,facilitating proton transfer and moderate adsorption strength of oxygen-intermediates,which lowers the energy barrier for the OER yet elevates the energy barrier for the ClOR,resulting to a promoted selectivity towards the OER.The work sheds light on the underlying mechanism of the PEC water oxidation processes,and highlights the crucial role of interfacial water on the PEC selectivity,which could be regulated by controlling the energy band and the surface structure of semiconductors.展开更多
Rare earth elements(REEs) are associated with phosphorite,which is an important strategic reserve resource.During sorting process of phosphorite,REEs may move with specific host minerals,however,occurrence state and m...Rare earth elements(REEs) are associated with phosphorite,which is an important strategic reserve resource.During sorting process of phosphorite,REEs may move with specific host minerals,however,occurrence state and moving pattern of REEs from rock to products are still unclear,which limits separation and enrichment of REEs from phosphorite.Mappings of scanning electron microscope(SEM) and electron probe X-ray micro-analyzer(EPMA) of REEs are highly consistent with those of calcium and phosphorus,and complementary with that of magnesium,which indicates that fluorapatite(Fap) is the main host mineral of REEs.The results of flotation and leaching experiments further indicate that REEs are enriched along with Fap from phosphorite to products.Occupied sites and occupation number of REEs were obtained by X-ray diffraction(XRD) refinement based on the Rietveld method.La,Ce,Nd,and Y can occupy both Ca1 and Ca2 sites.The ratios of La,Ce,Nd,and Y at Ca2 and Cal sites are 4.20,3.70,3.00,and 1.33,showing a decreasing trend,indicating that La,Ce,and Nd tend to occupy Ca2 sites,while Y tends to occupy Ca1 sites.X-ray absorption fine structure(XAFS) shows that REEs mainly form coordinate structures with oxygen and fluorine,which is a direct evidence that REEs replace calcium(Ⅱ) in phosphorite in an isomorphism form.Coordination structure and polyhedral configuration analysis indicate that substitution degree of La,Ce,Nd,and Y is Y> La> Ce≈Nd from easy to difficult at Cal and Ca2 sites.The research enriches the mineralization theory of REEs-bearing phosphorite and provides certain theoretical guidance for selective enrichment of REEs from phosphorite.展开更多
Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clus...Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clusters stabilized by cyclohexanethiol(HSC_(6)H_(11))ligands.Using electrospray ionization mass spectrometry(ESI-MS)and single-crystal X-ray diffraction(SXRD),structures of the Pd clusters ranging from Pd4(SC_(6)H_(11))8 to Pd18(SC_(6)H_(11))36 were determined.This analysis revealed a structure evolution from polygonal to elliptical geometries of the PdnS2n frameworks as the cluster size increased.UV-Vis-NIR spectroscopy,combined with quantum chemical calculations,elucidated changes in the electronic structure of the clusters.Catalytic studies on the Sonogashira cross-coupling reactions demonstrated a size-dependent decline in activity attributed to variations in structural arrangements and electronic properties.Mechanistic insights proposed a distinctive Pd(Ⅱ)-Pd(Ⅳ)catalytic cycle.This research underscores how ligands and cluster size influence the structures and properties of Pd clusters,offering valuable insights for the future design and application of Pd clusters in advanced catalysis and beyond.展开更多
Pyrochlore oxide(Y_(2)Ru_(2)O_(7))has been identified as a promising catalyst for the oxygen evolution reaction(OER)in advanced green energy strategies.However,its electrochemical inertness necessitates the exploratio...Pyrochlore oxide(Y_(2)Ru_(2)O_(7))has been identified as a promising catalyst for the oxygen evolution reaction(OER)in advanced green energy strategies.However,its electrochemical inertness necessitates the exploration of an effective strategy to facilitate electronic modulation.This study proposes a surface modification approach involving the integration of defective NiFe(D-NiFe)nanoparticles onto a Y_(2)Ru_(2)O_(7)(YRO)support(YRO@D-NiFeP/Ru)using a Prussian blue analog(PBA).Numerous cyanide(CN)vacancies are generated through the oxidation treatment of the NiFe PBA grown on the YRO support,yielding a defective PBA precursor(YRO@D-PBA).Subsequent annealing facilitates the transformation to the D-NiFe nanoparticles on the YRO support(YRO@D-NiFeP/Ru),which augments the exposure of Ni3+active sites beneficial for the OER.Moreover,the reduction of Ru cations from YRO results in the exsolution of Ru nanoparticles,which promotes synergistic charge transfer from the nanoparticles to the interior of Y_(2)Ru_(2)O_(7).Consequently,YRO@D-NiFeP/Ru exhibits a remarkable voltage of 1.49 V at 10 mA·cm^(−2) and the lowest Tafel slope of 42.4 mV·dec^(−1).In addition,a Zn–air battery constructed with YRO@D-NiFeP/Ru exhibits an outstanding power density of 136.2 mW·cm^(−2) and high charge–discharge stability,confirming the applicability of YRO@D-NiFeP/Ru in metal-air batteries.展开更多
One-dimensional nanomaterials with hollow structures could provide large space for ion storage and charge accumulation.Herein,TiO_(2)/MoSe_(2)-Carbon nanotube composite(NT)materials were designed and fabricated by the...One-dimensional nanomaterials with hollow structures could provide large space for ion storage and charge accumulation.Herein,TiO_(2)/MoSe_(2)-Carbon nanotube composite(NT)materials were designed and fabricated by the template method and the chelation coordination reaction.The stability and conductivity were improved by the presence of titanium and hollow tubular-architecture carbon in the whole structure.As a result,the as-prepared TiO_(2)/MoSe_(2)-Carbon hybrid achieved a high-rate performance of 760.0 mAh·g^(−1) at a current density of 0.1 A·g^(−1),while still obtaining stability after 300 charge/discharge cycles.The enhancement of the lithium storage capacity mainly contributed to the acceleration of the electron conductivity and the storage kinetics.Moreover,the hollow structure reduced the volume strain and stress caused by the rapid insertion and removal of lithium ions,which ensured the favorable stability of lithium storage.The experiment shows that the kinetic of the TiO_(2)/MoSe_(2)-carbon hybrid during the lithium storage process is dominated by the pseudocapacitance mechanism.This work provides a new idea and scheme for the design and preparation of hierarchical nanotube composite electrode materials.展开更多
Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet s...Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet static supporting stability and dynamic terrain adaptability through the utilization of the Rigid-Elastic Hybrid(REH)dynamics model.First,a bionic foot model,named the Hinge Tension Elastic Complex(HTEC)model,was developed by extracting key features from human feet.Furthermore,the kinematics and REH dynamics of the HTEC model were established.Based on the foot dynamics,a nonlinear optimization method for stiffness matching(NOSM)was designed.Finally,the HTEC-based foot was constructed and applied onto BHR-B2 humanoid robot.The foot static stability is achieved.The enhanced adaptability is observed as the robot traverses square steel,lawn,and cobblestone terrains.Through proposed design method and structure,the mobility of the humanoid robot is improved.展开更多
Microbial corrosion of hydraulic concrete structures(HCSs)has received increasing research concerns.However,knowledge on the morphology of attached biofilms,as well as the community structures and functions cultivated...Microbial corrosion of hydraulic concrete structures(HCSs)has received increasing research concerns.However,knowledge on the morphology of attached biofilms,as well as the community structures and functions cultivated under variable nutrient levels is lacking.Here,biofilm colonization patterns and community structures responding to variable levels of ammonia and sulfate were explored.From field sampling,NH_(4)^(+)-N was proven key factor governing community structure in attached biofilms,verifying the reliability of selecting target nutrient species in batch experiments.Biofilms exhibited significant compositional differences in field sampling and incubation experiments.As the nutrient increased in batch experiments,the growth of biofilms gradually slowed down and uneven distribution was detected.The proportions of proteins and β-d-glucose polysaccharides in biofilms experienced a decrease in response to elevated levels of nutrients.With the increased of nutrients,themass losses of concretes exhibited an increase,reaching a highest value of 2.37%in the presence of 20 mg/L of ammonia.Microbial communities underwent a significant transition in structure and metabolic functions to ammonia gradient.The highest activity of nitrification was observed in biofilms colonized in the presence of 20 mg/L of ammonia.While the communities and their functions remained relativelymore stable responding to sulfate gradient.Our research provides novel insights into the structures of biofilms attached on HCSs and the metabolic functions in the presence of high level of nutrients,which is of significance for the operation and maintenance of hydraulic engineering structures.展开更多
Weak interactions prevent the magnetic particles from achieving excellent electromagnetic wave absorp-tion(EMA)at a low filler loading(FL).The construction of one-dimensional magnetic metal fibers(1D-MMFs)contributes ...Weak interactions prevent the magnetic particles from achieving excellent electromagnetic wave absorp-tion(EMA)at a low filler loading(FL).The construction of one-dimensional magnetic metal fibers(1D-MMFs)contributes to the formation of an electromagnetic(EM)coupling network,enhancing EM properties at a low FL.However,precisely controlling the length of 1D-MMFs to regulate permittivity at low FL poses a challenge.Herein,a novel magnetic field-assisted growth strategy was used to fabricate Co-based fibers with adjustable permittivity and aspect ratios.With a variety of FL changes,centimeter-level Co long fibers(Co-lf)consistently exhibited higher permittivity than Co particles and Co short fibers due to the enhancement of the effective EM coupling.The Co-lf exhibits excellent EMA performance(-54.85 dB,5.8 GHz)at 10 wt.%FL.Meanwhile,heterogeneous interfaces were introduced to increase the interfacial polarization through a fine phosphorylation design,resulting in elevated EMA performances(-51.50 dB,6.6 GHz)at 10 wt.%FL for Co_(2)P/Co long fibers.This study improves the orderliness of the particle arrangement by regulating the length of 1D-MMFs,which affects the behavior of electrons inside the fibers,providing a new perspective for improving the EMA properties of magnetic materials at a low FL.展开更多
To optimize secondary air nozzle structure in purifying burner,this study focused on the comparison of purification,combustion and NO_(x)emission characteristics of pulverized coal preheated by a 30 kW purifying burne...To optimize secondary air nozzle structure in purifying burner,this study focused on the comparison of purification,combustion and NO_(x)emission characteristics of pulverized coal preheated by a 30 kW purifying burner with coaxial and centrosymmetric structures.Centrosymmetric structure shifted the position of main burning region down in high-temperature reduction unit(HTRU),and the number of branches differently influenced the temperature in different regions with this structure.For reductive gas components,CO concentration with centrosymmetric structure was higher compared to coaxial structure,while the differences in H_(2)and CH_(4)concentrations were smaller.Centrosymmetric structure was more disadvantageous to improve physicochemical properties of pulverized coal compared to coaxial structure,and this structure with four branches further deteriorated its properties compared to two branches.In mild combustion unit(MCU),the temperature at top was lower with centrosymmetric structure,while was higher in the rest.Centrosymmetric structure more effectively reduced NO_(x)emission compared to coaxial structure,but with slight sacrifice of combustion efficiency(η).Moreover,both two-branch and four-branch centrosymmetric structures realized ultra-low NO_(x)emission(<50 mg·m^(-3))with high η of over 98.50%,and the former was more advantageous.With this optimal structure,η and NO_(x)emission were 99.25%and 40.42 mg·m^(-3).展开更多
We considered adding different amounts(1%,2%,3%,and 4%)of EMR to prepare manganese residue polymer magnesium phosphate cement composite(EMR-PMPC).The influence mechanism of EMR doping on the early macroscopic and micr...We considered adding different amounts(1%,2%,3%,and 4%)of EMR to prepare manganese residue polymer magnesium phosphate cement composite(EMR-PMPC).The influence mechanism of EMR doping on the early macroscopic and microscopic pore structure properties of composites was studied by combining macroscopic and microscopic testing methods.The experimental results show that the addition of EMR can improve the working performance of the slurry and enhance the strength in the later stage,the 28 d compressive strength value of the slurry doped with EMR can reach 49.5 MPa.The Mn element and NH4_(+)^(-)N in EMR react with MgO in the raw material to produce Struvite and Mn(OH)_(2)and Mn_(3)(PO_(4))·6H_(2)O gel,the hydration products coexist with each other and lap each other to form a dense microfine structure and effectively refine the pores.The hydration process consists of five stages,mainly concentrated in the first 10 h or less to exothermic mainly,infrared spectral absorption band is mainly composed of O-H bond,H-O-H bond,PO_(4)bond and metal oxygen bond 3 parts,EMR makes the wave number of the absorption band from the ground wave number to the high wave number.EMR doping T_(2)spectral relaxation time will lag behind,the pore size distribution changes.The total porosity and bound fluid saturation decrease with increasing,the free fluid saturation shows the opposite trend,the permeability decreases and then increases.展开更多
基金supported by the National Natural Science Foundation of China[52125307(to P.G.),12404192(to R.C.S),12274061(to L.Q.)]Key Research and Development Program from the Ministry of Science and Technology(2023YFA1406301)the support from the New Cornerstone Science Foundation through the XPLORER PRIZE。
文摘The infinite-layer nickelates,proposed as analogs to superconducting cuprates,provide a promising platform for exploring the mechanisms of unconventional superconductivity.However,the superconductivity has been exclusively observed in thin films under atmospheric pressure,underscoring the critical role of the heterointerface.
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supported by the National Natural Science Foundation of China(Nos.22171102 and 22090044)the National Key R&D Program of China(Nos.2021YFF0500502 and 2023YFA1506304)+2 种基金the Jilin Province Science and Technology Development Plan(No.20230101024JC)the"Medicine+X"crossinnovation team of Bethune Medical Department of Jilin University"Leading the Charge with Open Competition"construction project(No.2022JBGS04)the Jilin University Graduate Training Office(Nos.2021JGZ08 and 2022YJSJIP20).
文摘Solid-state electrolytes(SSEs),as the core component within the next generation of key energy storage technologies-solid-state lithium batteries(SSLBs)-are significantly leading the development of future energy storage systems.Among the numerous types of SSEs,inorganic oxide garnet-structured superionic conductors Li7La3Zr2O12(LLZO)crystallized with the cubic Iaˉ3d space group have received considerable attention owing to their highly advantageous intrinsic properties encompassing reasonable lithium-ion conductivity,wide electrochemical voltage window,high shear modulus,and excellent chemical stability with electrodes.However,no SSEs possess all the properties necessary for SSLBs,thus both the ionic conductivity at room temperature and stability in ambient air regarding cubic garnet-based electrolytes are still subject to further improvement.Hence,this review comprehensively covers the nine key structural factors affecting the ion conductivity of garnet-based electrolytes comprising Li concentration,Li vacancy concentration,Li carrier concentration and mobility,Li occupancy at available sites,lattice constant,triangle bottleneck size,oxygen vacancy defects,and Li-O bonding interactions.Furthermore,the general illustration of structures and fundamental features being crucial to chemical stability is examined,including Li concentration,Li-site occupation behavior,and Li-O bonding interactions.Insights into the composition-structure-property relations among cubic garnet-based oxide ionic conductors from the perspective of their crystal structures,revealing the potential compatibility conflicts between ionic transportation and chemical stability resulting from Li-O bonding interactions.We believe that this review will lay the foundation for future reasonable structural design of oxide-based or even other types of superionic conductors,thus assisting in promoting the rapid development of alternative green and sustainable technologies.
基金the Rare and Precious Metals Material Genetic Engineering Project of Yunnan Province(202102AB080019-1)National Key Research and Development Program of China(2022YFB3708600)the National Natural Science Foundation of China(91960103).
文摘Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research used chemical co-precipitation within an automated experimental device to synthesize RETaO_(4)(RE=Nd,Sm,Gd,Ho,Er)powders.The device automatically monitored and controlled the solutions'pH,improving the chemical co-precipitation efficiency.The crystal structure and microstructure of the RETaO_(4)powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase transition.The m'-RETaO_(4)powders exhibit nano-size grains,while m-RETaO_(4)powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis es-timates the reversive ferroelastic tetragonal-monoclinic phase transition temperatures.Overall,this research focuses on the synthesis,crystal structures,microstructures,and phase transition of the fabricated RETaO_(4)powders.
基金supported by National Natural Science Foundation of China(No.523B2070,No.52225606).
文摘Polymeric perylene diimide(PDI)has been evidenced as a good candidate for photocatalytic water oxidation,yet the origin of the photocatalytic oxygen evolution activity remains unclear and needs further exploration.Herein,with crystal and atomic structures of the self-assembled PDI revealed from the X-ray diffraction pattern,the electronic structure is theoretically illustrated by the first-principles density functional theory calculations,suggesting the suitable band structure and the direct electronic transition for efficient photocatalytic oxygen evolution over PDI.It is confirmed that the carbonyl O atoms on the conjugation structure serve as the active sites for oxygen evolution reaction by the crystal orbital Hamiltonian group analysis.The calculations of reaction free energy changes indicate that the oxygen evolution reaction should follow the reaction pathway of H_(2)O→^(*)OH→^(*)O→^(*)OOH→^(*)O_(2)with an overpotential of 0.81 V.Through an in-depth theoretical computational analysis in the atomic and electronic structures,the origin of photocatalytic oxygen evolution activity for PDI is well illustrated,which would help the rational design and modification of polymeric photocatalysts for efficient oxygen evolution.
基金National Natural Science Foundation of China(52261032,51861021,51661016)Science and Technology Plan of Gansu Province(21YF5GA074)+2 种基金Public Welfare Project of Zhejiang Natural Science Foundation(LGG22E010008)Wenzhou Basic Public Welfare Scientific Research Project(G2023020)Incubation Program of Excellent Doctoral Dissertation-Lanzhou University of Technology。
文摘The development of high-performance structural and functional materials is vital in many industrial fields.High-and medium-entropy alloys(H/MEAs)with superior comprehensive properties owing to their specific microstructures are promising candidates for structural materials.More importantly,multitudinous efforts have been made to regulate the microstructures and the properties of H/MEAs to further expand their industrial applications.The various heterostructures have enormous potential for the development of H/MEAs with outstanding performance.Herein,multiple heterogeneous structures with single and hierarchical heterogeneities were discussed in detail.Moreover,preparation methods for compositional inhomogeneity,bimodal structures,dualphase structures,lamella/layered structures,harmonic structures(core-shell),multiscale precipitates and heterostructures coupled with specific microstructures in H/MEAs were also systematically reviewed.The deformation mechanisms induced by the different heterostructures were thoroughly discussed to explore the relationship between the heterostructures and the optimized properties of H/MEAs.The contributions of the heterostructures and advanced microstructures to the H/MEAs were comprehensively elucidated to further improve the properties of the alloys.Finally,this review discussed the future challenges of high-performance H/MEAs for industrial applications and provides feasible methods for optimizing heterostructures to enhance the comprehensive properties of H/MEAs.
基金supported by the National Key R&D Program of China(No.2024YFC3012902)the National Natural Science Foundation of China(No.42074070)supported by the Huai’an Earthquake Prevention and Disaster Reduction Service Center“Salt Cavern Exploration Project”(No.HAZC-2021050155-001)。
文摘Due to the lack of the three-dimensional structure of the Zhaoji Salt Basin,the salt mining enterprises have obvious clustering when choosing sites.Production capacity declines rapidly as mining deepens,and the enterprises are entering a stage of stagnation in production.In this study,a dense seismic array of 125 short-period stations was deployed around the core mining area and its vicinity of the salt mine industry,we used the ambient noise tomography(ANT)method to image the three-dimensional shear wave velocity structure at the depth shallower than 3 km.The results indicate:(1)The overall shear wave velocity in the study area is relatively lower,ranging from 0.8 to 1.8 km/s,which could be related to the loose and thick deposition of the Zhaoji sub-depression.(2)The three-dimensional shear wave velocity structure reveals that the sedimentary thickness of the Zhaoji sub-depression is deeper in the southeast and shallower in the northwest,with the sedimentary center located around Heping Town and Dahuangzhuang Town.(3)The Zhaoji salt mine is a low-velocity anomalous zone in the shear wave velocity structure with an inverse‘C'character spreading along Nanchenji Town and Zhaoji Town,with a depth ranging from approximately 1.2 to 2.8 km,it may be caused by the development of rock fissures due to water extraction and injection.The surrounding rock exhibits relatively high velocity,which reflects the morphological characteristics of the Zhaoji Salt Basin.The three-dimensional shear wave velocity model obtained in this study provides scientific guidance for the industrial exploitation of the Zhaoji salt mine and reference for salt exploration of the Hongze Salt Basin.It also provides an important basis for the seismic risk assessment of the salt basins.Simultaneously,it holds significant implications for exploring the application of ambient noise tomography method in spatial detection of salt mine belt.
基金supported by the National Key R&D Program of China(Gran Nos.2022YFA1402304 and 2022YFA1402802)the National Natural Science Foundation of China(Grant Nos.12494591,12122405,12274169,and 92165204)+4 种基金Program for Science and Technology Innovation Team in Zhejiang(Grant No.2021R01004)Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices(Grant No.2022B1212010008)Guangdong Fundamental Research Center for Magnetoelectric Physics(2024B0303390001)Guangdong Provincial Quantum Science Strategic Initiative(Grant No.GDZX2401010)the Fundamental Research Funds for the Central Universities。
文摘The discovery of high-temperature superconductivity in bilayer nickelate La_(3)Ni_(2)O_(7)under high-pressure conditions has spurred extensive efforts to stabilize superconductivity at ambient pressure.Recently,the realization of superconductivity in compressively strained La_(3)Ni_(2)O_(7)thin films grown on the SrLaAlO_(4)substrates,with a T_(c)exceeding 40 K,represents a significant step toward this goal.Here,we investigate the influence of film thickness and carrier doping on the electronic structure of La_(3)Ni_(2)O_(7)thin films,ranging from 0.5 to 3 unit cells,using first-principles calculations.For a 2 unit-cell film with an optimal doping concentration of 0.3 hole per formula unit(0.15 hole/Ni),the Ni-d_(z^(2))interlayer bonding state crosses the Fermi level,resulting in the formation ofγpockets at the Fermi surface.These findings align with angle-resolved photoemission spectroscopy experimental data.Our results provide theoretical validation for the recent experimental discovery of ambient-pressure superconductivity in La_(3)Ni_(2)O_(7)thin films and underscore the significant impact of film thickness and carrier doping on electronic property modulation.
基金National Key Research and Development Program of China,Grant/Award Number:2020YFC1523300Construction of Innovation Platform Program of Qinghai Province of China,Grant/Award Number:2022-ZJ-T02。
文摘Currently,the link prediction algorithms primarily focus on studying the interaction between nodes based on chain structure and star structure,which predominantly rely on low-order structural information and do not explore the multivariate interactions between nodes from the perspective of higher-order structural information present in the network.The cycle structure is a higher-order structure that lies between the star and clique structures,where all nodes within the same cycle can interact with each other,even in the absence of direct edges.If a node is encompassed by multiple cycles,it indicates that the node interacts and associates with a greater number of nodes in the network,and it means the node is more important in the network to some extent.Furthermore,if two nodes are included in multiple cycles,it signifies the two nodes are more likely to be connected.Therefore,firstly,a multi-information fusion node importance algorithm based on the cycle structure information is proposed,which integrates both high-order and low-order structural information.Secondly,the obtained integrated structure information and node feature information is regarded as the input features,a two-channel graph neural network model is designed to learn the cycle structure information.Then,the cycle structure information is utilised for the task of link prediction,and a graph neural link predictor with multi-information interactions based on the cycle structure is developed.Finally,extensive experimental validation and analysis show that the node ranking result of the proposed node importance index is more consistent with the actual situation,the proposed graph neural network model can effectively learn the cycle structure information,and using higher-order structural information—cycle information proves to significantly enhance the overall link prediction performance.
基金supported by the National Natural Science Foundation of China(Grant No.42102223)the Chinese Postdoctoral Science Foundation(Grant Nos.2021M693844,2022T150284)+1 种基金the Chinese Geological Survey Project(Grant No.DD20160204-3)the discipline innovation team of Liaoning Technical University(Grant Nos.LNTU20TD-14,LNTU20TD-30)。
文摘Coal pore parameters are closely related to macrolithotypes and coal structures,having a large influence over the gas potential and productivity of coalbed methane(CBM).The Middle Jurassic Xishanyao Formation,located in the southern Junggar Basin of northwestern China,has geological conditions with rich CBM resources.The 46 Xishanyao coal samples gathered from the drilling cores and coal mines cover 4 types of macrolithotypes(bright coal 1,semi-bright coal 2,semi-dull coal 3,and dull coal 4)and 2 types of coal structures(primary coal I and cataclastic coal II).Based on a range of pore testing experiments and analytical methods,the dual effects of different macrolithotypes and coal structures on pore structures were intensely studied.The results showed that the specific surface area(SSA)and total pore volume(TPV)of coal samples increased gradually from bright to dull coals.For the same macrolithotypes,the SSA and TPV of the primary coals were lower than those of the cataclastic coals.Generally,the pore structures of bright and semi-bright coals are simpler when compared to semi-dull and dull coals with the same coal structure,whereas cataclastic coals have more complicated pore structure systems than primary coals with the same macrolithotypes.The bright and semi-bright coals have higher vitrinite contents and more endogenous fractures,whereas well-developed structural fractures were identified in cataclastic coals.Therefore,bright and semi-bright coals have better pore connectivity than semi-dull and dull coals with the same coal structure,the pore connectivity of cataclastic coals being slightly better than that of primary coals under the same macrolithotypes.In terms of the CBM adsorption conditions,the eight type samples formed a descending order:Ⅱ-4>I-4>Ⅱ-3>Ⅰ-3>Ⅱ-2>Ⅰ-2>Ⅱ-1>Ⅰ-1,while they ranked as follows when consideration was given to the CBM seepage capacities:II-2>Ⅱ-1>Ⅰ-2>Ⅰ-1>Ⅰ-3>Ⅰ-4>Ⅱ-3>Ⅱ-4.As a result,it could be determined that the bright and semi-bright coals had stronger adsorption capacities,whereas the cataclastic coals had better pore connectivity and seepage capacities.Pore structure characteristics should be analysed under the dual control of different macrolithotypes and coal structures,so that they can provide greater value for guiding CBM exploration and exploitation,as along for preventing underground gas accidents.
文摘Photoelectrocatalytic(PEC)seawater splitting as a green and sustainable route to harvest hydrogen is attractive yet hampered by low activity of photoanodes and unexpected high selectivity to the corrosive and toxic chlorine.Especially,it is full of challenges to unveil the key factors influencing the selectivity of such complex PEC processes.Herein,by regulating the energy band and surface structure of the anatase TiO_(2) nanotube array photoanode via nitrogen-doping,the seawater PEC oxidation shifts from Cl^(-)oxidation reaction(ClOR)dominant on the TiO_(2) photoanode(61.6%)to oxygen evolution reaction(OER)dominant on the N-TiO_(2) photoanode(62.9%).Comprehensive investigations including operando photoelectrochemical FTIR and DFT calculations unveil that the asymmetric hydrogen-bonding water at the N-TiO_(2) electrode/electrolyte interface enriches under illumination,facilitating proton transfer and moderate adsorption strength of oxygen-intermediates,which lowers the energy barrier for the OER yet elevates the energy barrier for the ClOR,resulting to a promoted selectivity towards the OER.The work sheds light on the underlying mechanism of the PEC water oxidation processes,and highlights the crucial role of interfacial water on the PEC selectivity,which could be regulated by controlling the energy band and the surface structure of semiconductors.
基金Project supported by Guizhou Provincial Basic Research Program (Natural Science)(Qian Ke He Basic-ZK 2024 General 626)National Natural Science Foundation of China (52164018)Scientific Research Foundation for High-level Talents of Anhui University of Science and Technology (13210025)。
文摘Rare earth elements(REEs) are associated with phosphorite,which is an important strategic reserve resource.During sorting process of phosphorite,REEs may move with specific host minerals,however,occurrence state and moving pattern of REEs from rock to products are still unclear,which limits separation and enrichment of REEs from phosphorite.Mappings of scanning electron microscope(SEM) and electron probe X-ray micro-analyzer(EPMA) of REEs are highly consistent with those of calcium and phosphorus,and complementary with that of magnesium,which indicates that fluorapatite(Fap) is the main host mineral of REEs.The results of flotation and leaching experiments further indicate that REEs are enriched along with Fap from phosphorite to products.Occupied sites and occupation number of REEs were obtained by X-ray diffraction(XRD) refinement based on the Rietveld method.La,Ce,Nd,and Y can occupy both Ca1 and Ca2 sites.The ratios of La,Ce,Nd,and Y at Ca2 and Cal sites are 4.20,3.70,3.00,and 1.33,showing a decreasing trend,indicating that La,Ce,and Nd tend to occupy Ca2 sites,while Y tends to occupy Ca1 sites.X-ray absorption fine structure(XAFS) shows that REEs mainly form coordinate structures with oxygen and fluorine,which is a direct evidence that REEs replace calcium(Ⅱ) in phosphorite in an isomorphism form.Coordination structure and polyhedral configuration analysis indicate that substitution degree of La,Ce,Nd,and Y is Y> La> Ce≈Nd from easy to difficult at Cal and Ca2 sites.The research enriches the mineralization theory of REEs-bearing phosphorite and provides certain theoretical guidance for selective enrichment of REEs from phosphorite.
基金supported by the Start-Up Research Funding of Fujian Normal University(No.Y0720326K13)the National Natural Science Foundation of China(Nos.22103035 and 22033005)+2 种基金the National Key R&D Program of China(No.2022YFA1503900)Shenzhen Science and Technology Program(No.RCYX20231211090357078)Guangdong Provincial Key Laboratory of Catalysis(No.2020B121201002).
文摘Atomically precise palladium(Pd)clusters are emerging as versatile nanomaterials with applications in catalysis and biomedicine.This study explores the synthesis,structure evolution,and catalytic properties of Pd clusters stabilized by cyclohexanethiol(HSC_(6)H_(11))ligands.Using electrospray ionization mass spectrometry(ESI-MS)and single-crystal X-ray diffraction(SXRD),structures of the Pd clusters ranging from Pd4(SC_(6)H_(11))8 to Pd18(SC_(6)H_(11))36 were determined.This analysis revealed a structure evolution from polygonal to elliptical geometries of the PdnS2n frameworks as the cluster size increased.UV-Vis-NIR spectroscopy,combined with quantum chemical calculations,elucidated changes in the electronic structure of the clusters.Catalytic studies on the Sonogashira cross-coupling reactions demonstrated a size-dependent decline in activity attributed to variations in structural arrangements and electronic properties.Mechanistic insights proposed a distinctive Pd(Ⅱ)-Pd(Ⅳ)catalytic cycle.This research underscores how ligands and cluster size influence the structures and properties of Pd clusters,offering valuable insights for the future design and application of Pd clusters in advanced catalysis and beyond.
基金supported by Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korea government(MOTIE)(No.RS-2024-00398346,ESS BigData-Based O&M and Asset Management Technical Manpower Training)the National Research Foundation of Korea(NRF)grant funded by the Korea government(MSIT)(No.RS-2024-00350658).
文摘Pyrochlore oxide(Y_(2)Ru_(2)O_(7))has been identified as a promising catalyst for the oxygen evolution reaction(OER)in advanced green energy strategies.However,its electrochemical inertness necessitates the exploration of an effective strategy to facilitate electronic modulation.This study proposes a surface modification approach involving the integration of defective NiFe(D-NiFe)nanoparticles onto a Y_(2)Ru_(2)O_(7)(YRO)support(YRO@D-NiFeP/Ru)using a Prussian blue analog(PBA).Numerous cyanide(CN)vacancies are generated through the oxidation treatment of the NiFe PBA grown on the YRO support,yielding a defective PBA precursor(YRO@D-PBA).Subsequent annealing facilitates the transformation to the D-NiFe nanoparticles on the YRO support(YRO@D-NiFeP/Ru),which augments the exposure of Ni3+active sites beneficial for the OER.Moreover,the reduction of Ru cations from YRO results in the exsolution of Ru nanoparticles,which promotes synergistic charge transfer from the nanoparticles to the interior of Y_(2)Ru_(2)O_(7).Consequently,YRO@D-NiFeP/Ru exhibits a remarkable voltage of 1.49 V at 10 mA·cm^(−2) and the lowest Tafel slope of 42.4 mV·dec^(−1).In addition,a Zn–air battery constructed with YRO@D-NiFeP/Ru exhibits an outstanding power density of 136.2 mW·cm^(−2) and high charge–discharge stability,confirming the applicability of YRO@D-NiFeP/Ru in metal-air batteries.
基金supported by the Research Fund of the State Key Laboratory of Solidification Processing(NPU)China(No.2022-QZ-03)+2 种基金the Open Research Fund of National Key Laboratory of Special Vehicle Design,Manufacturing Integration Technology(No.GZ2022KF001).Shenzhen Science and Technology Program(No.JCYJ20210324142805014)Shaanxi Province Youth Science,Technology New Star(No.2022KJXX-20)the Opening Project of State Key Laboratory of Polymer Materials Engineering(Sichuan University)(No.sklpme2022-4-05).
文摘One-dimensional nanomaterials with hollow structures could provide large space for ion storage and charge accumulation.Herein,TiO_(2)/MoSe_(2)-Carbon nanotube composite(NT)materials were designed and fabricated by the template method and the chelation coordination reaction.The stability and conductivity were improved by the presence of titanium and hollow tubular-architecture carbon in the whole structure.As a result,the as-prepared TiO_(2)/MoSe_(2)-Carbon hybrid achieved a high-rate performance of 760.0 mAh·g^(−1) at a current density of 0.1 A·g^(−1),while still obtaining stability after 300 charge/discharge cycles.The enhancement of the lithium storage capacity mainly contributed to the acceleration of the electron conductivity and the storage kinetics.Moreover,the hollow structure reduced the volume strain and stress caused by the rapid insertion and removal of lithium ions,which ensured the favorable stability of lithium storage.The experiment shows that the kinetic of the TiO_(2)/MoSe_(2)-carbon hybrid during the lithium storage process is dominated by the pseudocapacitance mechanism.This work provides a new idea and scheme for the design and preparation of hierarchical nanotube composite electrode materials.
基金supported by the National Natural Science Foundation of China(Grant No.62073041)the Open Fund of Laboratory of Aerospace Servo Actuation and Transmission(Grant No.LASAT-2023A04)the Fundamental Research Funds for the Central Universities(Grant Nos.2024CX06011,2024CX06079)。
文摘Passive bionic feet,known for their human-like compliance,have garnered attention for their potential to achieve notable environmental adaptability.In this paper,a method was proposed to unifying passive bionic feet static supporting stability and dynamic terrain adaptability through the utilization of the Rigid-Elastic Hybrid(REH)dynamics model.First,a bionic foot model,named the Hinge Tension Elastic Complex(HTEC)model,was developed by extracting key features from human feet.Furthermore,the kinematics and REH dynamics of the HTEC model were established.Based on the foot dynamics,a nonlinear optimization method for stiffness matching(NOSM)was designed.Finally,the HTEC-based foot was constructed and applied onto BHR-B2 humanoid robot.The foot static stability is achieved.The enhanced adaptability is observed as the robot traverses square steel,lawn,and cobblestone terrains.Through proposed design method and structure,the mobility of the humanoid robot is improved.
基金supported by the National Key Research and Development Project of China(No.2021YFB2600200)the National Natural Science Foundation of China(Nos.52470185 and 52170159)the Open Research Fund of National Engineering Research Center of Water Resources Efficient Utilization and Engineering Safety,the Fund of National Key Laboratory of Water Disaster Prevention and Key Research and Development Program of Jiangsu Province(No.BE2022601).
文摘Microbial corrosion of hydraulic concrete structures(HCSs)has received increasing research concerns.However,knowledge on the morphology of attached biofilms,as well as the community structures and functions cultivated under variable nutrient levels is lacking.Here,biofilm colonization patterns and community structures responding to variable levels of ammonia and sulfate were explored.From field sampling,NH_(4)^(+)-N was proven key factor governing community structure in attached biofilms,verifying the reliability of selecting target nutrient species in batch experiments.Biofilms exhibited significant compositional differences in field sampling and incubation experiments.As the nutrient increased in batch experiments,the growth of biofilms gradually slowed down and uneven distribution was detected.The proportions of proteins and β-d-glucose polysaccharides in biofilms experienced a decrease in response to elevated levels of nutrients.With the increased of nutrients,themass losses of concretes exhibited an increase,reaching a highest value of 2.37%in the presence of 20 mg/L of ammonia.Microbial communities underwent a significant transition in structure and metabolic functions to ammonia gradient.The highest activity of nitrification was observed in biofilms colonized in the presence of 20 mg/L of ammonia.While the communities and their functions remained relativelymore stable responding to sulfate gradient.Our research provides novel insights into the structures of biofilms attached on HCSs and the metabolic functions in the presence of high level of nutrients,which is of significance for the operation and maintenance of hydraulic engineering structures.
基金supported by the National Key Research and Development Program of China(No.2024YFE0100600)the National Natural Science Foundation of China(No.52373303)+1 种基金the Shanghai Municipal Science and Technology Major Project(No.2021SHZDZX0100)the Fundamental Research Funds for the Central Universities and the Interdisciplinary Joint Research and Development Project of Tongji University(No.2022-4-ZD-01).
文摘Weak interactions prevent the magnetic particles from achieving excellent electromagnetic wave absorp-tion(EMA)at a low filler loading(FL).The construction of one-dimensional magnetic metal fibers(1D-MMFs)contributes to the formation of an electromagnetic(EM)coupling network,enhancing EM properties at a low FL.However,precisely controlling the length of 1D-MMFs to regulate permittivity at low FL poses a challenge.Herein,a novel magnetic field-assisted growth strategy was used to fabricate Co-based fibers with adjustable permittivity and aspect ratios.With a variety of FL changes,centimeter-level Co long fibers(Co-lf)consistently exhibited higher permittivity than Co particles and Co short fibers due to the enhancement of the effective EM coupling.The Co-lf exhibits excellent EMA performance(-54.85 dB,5.8 GHz)at 10 wt.%FL.Meanwhile,heterogeneous interfaces were introduced to increase the interfacial polarization through a fine phosphorylation design,resulting in elevated EMA performances(-51.50 dB,6.6 GHz)at 10 wt.%FL for Co_(2)P/Co long fibers.This study improves the orderliness of the particle arrangement by regulating the length of 1D-MMFs,which affects the behavior of electrons inside the fibers,providing a new perspective for improving the EMA properties of magnetic materials at a low FL.
基金Postdoctoral Fellowship Program of CPSF(GZC20232672)CAS Project for Young Scientists in Basic Research(YSBR-028)the Strategic Priority Research Program(XDA29010200)are gratefully acknowledged.
文摘To optimize secondary air nozzle structure in purifying burner,this study focused on the comparison of purification,combustion and NO_(x)emission characteristics of pulverized coal preheated by a 30 kW purifying burner with coaxial and centrosymmetric structures.Centrosymmetric structure shifted the position of main burning region down in high-temperature reduction unit(HTRU),and the number of branches differently influenced the temperature in different regions with this structure.For reductive gas components,CO concentration with centrosymmetric structure was higher compared to coaxial structure,while the differences in H_(2)and CH_(4)concentrations were smaller.Centrosymmetric structure was more disadvantageous to improve physicochemical properties of pulverized coal compared to coaxial structure,and this structure with four branches further deteriorated its properties compared to two branches.In mild combustion unit(MCU),the temperature at top was lower with centrosymmetric structure,while was higher in the rest.Centrosymmetric structure more effectively reduced NO_(x)emission compared to coaxial structure,but with slight sacrifice of combustion efficiency(η).Moreover,both two-branch and four-branch centrosymmetric structures realized ultra-low NO_(x)emission(<50 mg·m^(-3))with high η of over 98.50%,and the former was more advantageous.With this optimal structure,η and NO_(x)emission were 99.25%and 40.42 mg·m^(-3).
基金Funden by the National Natural Science Foundation of China(Nos.51868044 and 52178216)the Basic Research Program of Qinghai Province(No.2022-ZJ-921)+2 种基金the Innovation Star”Project for Excellent Postgraduates in Gansu Province(No.2022-CXZX-450)the Hongliu First-class Discipline Construction Program of Lanzhou University of TechnologyScience and Technology Project of Gansu Provincial Department of Transportation(No.2022-23)。
文摘We considered adding different amounts(1%,2%,3%,and 4%)of EMR to prepare manganese residue polymer magnesium phosphate cement composite(EMR-PMPC).The influence mechanism of EMR doping on the early macroscopic and microscopic pore structure properties of composites was studied by combining macroscopic and microscopic testing methods.The experimental results show that the addition of EMR can improve the working performance of the slurry and enhance the strength in the later stage,the 28 d compressive strength value of the slurry doped with EMR can reach 49.5 MPa.The Mn element and NH4_(+)^(-)N in EMR react with MgO in the raw material to produce Struvite and Mn(OH)_(2)and Mn_(3)(PO_(4))·6H_(2)O gel,the hydration products coexist with each other and lap each other to form a dense microfine structure and effectively refine the pores.The hydration process consists of five stages,mainly concentrated in the first 10 h or less to exothermic mainly,infrared spectral absorption band is mainly composed of O-H bond,H-O-H bond,PO_(4)bond and metal oxygen bond 3 parts,EMR makes the wave number of the absorption band from the ground wave number to the high wave number.EMR doping T_(2)spectral relaxation time will lag behind,the pore size distribution changes.The total porosity and bound fluid saturation decrease with increasing,the free fluid saturation shows the opposite trend,the permeability decreases and then increases.
