The inferior structure/electrochemistry stability due to the volume expansion and the less lithium storage active sites of transition metal oxide (TMO) are critical issue hindering their commercialization.The rational...The inferior structure/electrochemistry stability due to the volume expansion and the less lithium storage active sites of transition metal oxide (TMO) are critical issue hindering their commercialization.The rational design to utilize the combined advantages of both structure and composition is a key strategy to address these challenges.Here,the (FeCoNiMnCrMg)_(2)O_(3)high entropy oxide(HEO) with different morphologic structures are developed through integrating molecule and microstructure engineering.The morphologic structure of high entropy oxide transforms from solid spheres to multishelled core-shell spheres,and then to hollow spheres,which is governed by a thermally induced non-uniform shrinkage process coupled with Kirkendall effect diffusion due to the different calcination temperature.Even with the incorporation of various metallic ions,the high entropy oxide with a homogeneous single-phase solid solution maintained their shape and uniformity in size due to the ability of metal ions to coexist on the same lattice point.Benefiting from the meticulous control of both compositional and geometric factors,the hollow high entropy oxide exhibited a significantly high specific capacity (1722.1 mAh g^(-1)after 200cycles at 1 A g^(-1)) and long-life span for lithium storage(2158.7 mAh g^(-1)over 900 cycles at 4 A g^(-1)).The collaborative lattice and consistent volume demonstrated in this study offer significant potential in directing the development of materials for advanced energy storage solutions.展开更多
Supercapacitors(SCs)stand out among various energy storage devices owing to their high power density and long-term cyc-ling stability.As new two-dimensional material,MXenes have become a research hotspot in recent yea...Supercapacitors(SCs)stand out among various energy storage devices owing to their high power density and long-term cyc-ling stability.As new two-dimensional material,MXenes have become a research hotspot in recent years owing to their unique structure and rich surface functional groups.Compared with other materials,MXenes are more promising for SCs owing to their tunable precurs-ors,structural stability,and excellent electrical conductivity.However,the rate performance and electrochemical reaction activity of MXene materials are poor,and stacking severely limits their application.Therefore,various modification strategies are employed to im-prove the electrochemical performance of MXene materials.As the modification strategy of MXene electrode materials often involves in-creasing the number of ion transport channels to expose more active sites,the packing density is also affected to different degrees.There-fore,achieving a balance between high volumetric capacitance and rapid ion transport has become a key issue for the application of MXene-based SCs in wearable devices and microdevices.In this paper,the latest progress in the preparation methods and modification strategies of MXenes in recent years is reviewed with the aim of achieving both high volumetric capacitance and high ion transport for ex-panding the application of MXene-based SCs in microdevices and wearable devices.展开更多
Surface structural engineering is desirable in modifying the surface performance of carbonyl iron powder(CIP)to enhance microwave absorption(MA)and anti-oxidation performance.Herein,the surface shape-dependent CIP abs...Surface structural engineering is desirable in modifying the surface performance of carbonyl iron powder(CIP)to enhance microwave absorption(MA)and anti-oxidation performance.Herein,the surface shape-dependent CIP absorbers are designed via surface coating with zinc oxide(ZnO)nanoparticles and then a thermal annealing treatment.The morphology of ZnO nanoparticles which can be easily regulated by controlling the annealing temperature ultimately affects the MA performance of CIP coating with ZnO nanoparticles(CIP@ZnO).The core-shell CIP@ZnO particles with cubic cone ZnO nanoparticles exhibit ex-cellent MA performance and thermal stability in comparison to the original CIP.Specifically,the CIP@ZnO annealed at 350 ℃(CIP@ZnO-350)samples which have the cubic cone ZnO nanoparticles exhibit a min-imum reflection loss(RLmin)of-55.35 dB at a thickness of 2.1 mm and a maximum effective absorp-tion bandwidth(EAB)of 7.09 GHz at a thickness of 2.0 mm.In addition,the antioxidant property of the CIP@ZnO composite particles is abruptly enhanced,which breaks the restriction of the application of CIP at high temperatures.The superior MA performance of CIP@ZnO particles with cubic cone ZnO nanoparti-cles comes from the enhancement in surface shape-dependent multiple microwave scattering,interfacial polarization,and electromagnetic-dielectric synergism between ZnO and CIP.展开更多
Antimony(Sb)is recognized as a potential electrode material for sodium-ion batteries(SIBs)due to its huge reserves,affordability,and high theoretical capacity(660 mAh·g^(-1)).However,Sb-based materials experience...Antimony(Sb)is recognized as a potential electrode material for sodium-ion batteries(SIBs)due to its huge reserves,affordability,and high theoretical capacity(660 mAh·g^(-1)).However,Sb-based materials experience significant volume expansion during cycling,leading to comminution of the active substance and limiting their practical use in SIBs.Therefore,the volume expansion issue of Sb-based materials during charging/discharging must be solved to create high-performance SIBs.This paper presents a detailed review of structural engineering of Sb-based electrode materials,focusing on the performance effects of different kinds of structures on advanced performance SIBs.Finally,the future development and the challenges of Sb-based materials are prospected.This paper can provide specific perspectives on the structure construction and optimization of Sb-based anode materials so as to promote the rapid development and practical applications of SIBs.展开更多
Fe-N-C catalysts are widely considered as promising non-precious-metal candidates for electrocatalytic oxygen reduction reaction(ORR),Yet despite their high catalytic activity through rational modulation,challenges re...Fe-N-C catalysts are widely considered as promising non-precious-metal candidates for electrocatalytic oxygen reduction reaction(ORR),Yet despite their high catalytic activity through rational modulation,challenges remain in their low site density and unsatisfactory mass transfer structure.Herein,we present a structural engineering approach employing a soft-template coating strategy to fabricate a hollow and hierarchically porous N-doped carbon framework anchored with atomically dispersed Fe sites(FeNCh) as an efficient ORR catalyst.The combination of hierarchical porosity and high exterior surface area is proven crucial for exposing more active sites,which gives rise to a remarkable ORR performance with a half-wave potential of 0.902 V in 0.1 m KOH and 0.814 V in 0.1 m HClO_(4),significantly outperforming its counterpart with solid structure and dominance of micropores(FeNC-s).The mass transfer property is revealed by in-situ electrochemical impedance spectroscopy(EIS) measurement.The distribution of relaxation time(DRT) analysis is further introduced to deconvolve the kinetic and mass transport processes,which demonstrates an alleviated mass transport resistance for FeNC-h,validating the effectiveness of structural engineering.This work not only provides an effective structural engineering approach but also contributes to the comprehensive mass transfer evaluation on advanced electrocatalyst for energy conversion applications.展开更多
Silicon(Si)-based anodes have emerged as promising candidates for the next-generation lithium-ion batteries(LIBs)due to their high theoretical capacity(4200 mAh g^(-1)).However,their further application is hindered by...Silicon(Si)-based anodes have emerged as promising candidates for the next-generation lithium-ion batteries(LIBs)due to their high theoretical capacity(4200 mAh g^(-1)).However,their further application is hindered by critical challenges,including severe volume expansion(~300%),formation of unstable solid electrolyte interphase(SEI),and inherently low conductivity.While extensive research has sought to alleviate the substantial internal stress caused by volume expansion through the rational design of Si-based anode structures,the underlying mechanisms that govern these improvements remain insufficiently understood,leaving significant gaps in mechanical and interface electrical failure.To build a comprehensive understanding relationship between structural design and performance enhancement of Si-based anodes,this review first analyzes the characteristics of various Sibased anode structures and their associated internal stresses.Subsequently,it summarizes effective strategies to optimize the performance of Si-based anodes,including doping design,novel electrolyte design,and fu nctional binder design.Additionally,we assess emerging technologies with high commercial potential for structural design and interfacial modification,such as porous carbon carriers,chemical vapor deposition(CVD),spray granulation,and pre-lithiation.Finally,this work provides perspectives on the structural design of Si-based anodes.Overall,this review systematically summarizes modification strategies for Si-based anodes through structural regulation and interface engineering,thereby providing a foundation for advanced structural and interfacial design.展开更多
Host-vip engineering of donor-acceptor(D-A)coordination polymer(CP)materials has been proved to be a promising emission modulation strategy for the fabrication of highly tunable luminophores.Herein,it is shown that ...Host-vip engineering of donor-acceptor(D-A)coordination polymer(CP)materials has been proved to be a promising emission modulation strategy for the fabrication of highly tunable luminophores.Herein,it is shown that the fluorescence modulation of host-vip D-A CPs could be achieved through subtle structural engineering.Two isoreticular CPs,{M_(3)(μ_(3)-F)(BDC)_(3)(TPT)(solvents)}_(n)(M=Cd^(2+)for 1 and Zn^(2+)for 2,TPT=2,4,6-tri(4-pyridyl)-1,3,5-triazine,H_(2)BDC=1,4-benzenedicarboxylic acid),were selected as porous host CPs for investigation.By introducing different polyaromatic hydrocarbon(PAH)vips(anthracene;phenanthrene;pyrene;triphenylene;perylene;and coronene)into the host framework,two series of host-vip D-A CPs(PAHs@1 and PAHs@2)were obtained.Detailed investigation indicates that the subtle structural differences originated from the metal center affected D-A interactions between the PAH and TPT ligand,which result in distinct emission properties of PAHs@1 and PAHs@2.These results suggest the potential of structural modulation in the property tuning of the D-A CPs.展开更多
Metal‒organic framework(MOF)derivatives employed as electromagnetic wave(EMW)absorption materials have gained considerable attention because of their plentiful coordination components and diverse nanomicrostructures.H...Metal‒organic framework(MOF)derivatives employed as electromagnetic wave(EMW)absorption materials have gained considerable attention because of their plentiful coordination components and diverse nanomicrostructures.However,achieving broadband EMW absorption solely through nanoscale structural design remains challenging.Herein,a cross-scale structural engineering strategy is proposed to address this limitation.At the nanomicroscale,MOF-derived Co_(x)Ni_(y)@C nanorods were fabricated via a solvothermal and pyrolysis process.Systematic manipulation of the built-in electric field(BIEF)heterointerface achieved through adjusting the Co/Ni atomic ratio significantly promotes electron-directed migration,alters the spatial charge distribution,and ultimately enhances the polarization relaxation and magnetic resonance effects,resulting in superior EMW absorption performance(the effective absorption bandwidth of Co_(2)Ni@C is 4.9 GHz at 1.75 mm).The geometric configuration of the electromagnetic metastructures was subsequently optimized via CST software.Through cross-scale structural design,the simulated gradient honeycomb structure metamaterial composed of Co_(2)Ni@C achieves multiband compatibility,and the EAB reaches 38 GHz(covering 2-40 GHz)with a total thickness of 15 mm.This research elucidates the BIEF loss mechanism of MOF-derived Co_(x)Ni_(y)@C composites by rationally controlling the Co/Ni atomic ratio and provides novel insights into the structural design of electromagnetic nanomaterials.展开更多
The two-dimensional van der Waals layered semiconductor In_(2)Se_(3) has emerged as a promising candidate for non-volatile ferroelectric memory,optoelectronic devices,and polymorphic phase engineering.Polymorphic In_(...The two-dimensional van der Waals layered semiconductor In_(2)Se_(3) has emerged as a promising candidate for non-volatile ferroelectric memory,optoelectronic devices,and polymorphic phase engineering.Polymorphic In_(2)Se_(3) typically stabilizes in three distinct phases:α-,β′-,and β^(*)-In_(2)Se_(3),each dominant within specific temperature ranges.Although the crystal structures and ferroelectric properties of these phases have been widely studied,the unambiguous assignment of their in-plane and out-of-plane ferroelectric behaviors,as well as the mechanisms governing their phase transitions,remains a subject of active debate.In this study,we investigate the evolution of atomic and electronic structures in molecular beam epitaxy-grown ultrathin In_(2)Se_(3) films through correlated microstructural and macroscopic physical property analysis.By employing scanning tunneling microscopy/spectroscopy,temperature-dependent Raman spectroscopy,and piezoresponse force microscopy,we demonstrate a reversible temperature-induced phase transition between the in-plane ferroelectric β^(*)and antiferroelectric β′phases.Furthermore,we confirm robust out-of-plane ferroelectric polarization in the as-grown films and achieve an electric-field-driven transition from the β^(*)to β′phase.Our findings not only advance the fundamental understanding of phase transitions and polarization evolution in two-dimensional semiconductors but also open new avenues for the design of tunable,non-volatile ferroelectric memory devices.展开更多
Lithium metal batteries(LMBs)offer high energy densities but face challenges including poor reversibility and Li dendrite growth.Herein,we evaluate two flexible composite current collectors composed of reduced graphen...Lithium metal batteries(LMBs)offer high energy densities but face challenges including poor reversibility and Li dendrite growth.Herein,we evaluate two flexible composite current collectors composed of reduced graphene oxide and carbon nanotubes(rGO/CNT)to investigate how Li storage mechanisms influence electrochemical performance.By modulating the number of layers in rGO,the few-layered rGO/CNT collector(FL-CC)stores Li through a pure plating mechanism,whereas the multi-layered rGO/CNT collector(ML-CC)stores lithium via a hybrid intercalation/plating mechanism.The hybrid mechanism in ML-CC promotes reversible Li-ion storage,reduces active Li-ion loss,and suppresses dendrite formation.As a result,ML-CC achieves superior cycling stability compared to FLCC in both LMBs and anode-free LMB tests paired with LiFePO_(4)cathodes at a practical areal capacity of 4.5 mAh cm^(-2).This study highlights the importance of structural design in current collectors and demonstrates that incorporating lithiatable materials can significantly enhance the electrochemical stability of anode-free LMBs.展开更多
The conversion of carbon dioxide(CO_(2))into hydrocarbons through electrochemical CO_(2)reduction reaction(eCO_(2)RR)shows a promising method to reduce CO_(2)levels and decrease reliance on fossil fuels in the years t...The conversion of carbon dioxide(CO_(2))into hydrocarbons through electrochemical CO_(2)reduction reaction(eCO_(2)RR)shows a promising method to reduce CO_(2)levels and decrease reliance on fossil fuels in the years to come.Copper-based electrocatalysts exhibit a pronounced inclination for C-C coupling,drawing considerable interest as a favored metal catalyst for generating C_(2+)products through CO_(2)RR.However,CO_(2)RR still has some obstacles including product selectivity,higher overpotential,low Faradic efficiency(FE),stability,and current density(CD).Therefore,advancement in this field enables us to comprehend the complex multi-proton electron transfer during C-C coupling and engineering strategies to improve FE and CD.Herein,this review presents some key features of Cu-based catalysts as an electrocatalyst for C_(2) product formation while addressing the industrial challenges that hinder commercialization of CO_(2)RR.In addition,recent strategies on Cu-based catalysts,synthesis strategies,advanced characterizations,and mechanistic investigations via theoretical simulations have been presented.Furthermore,recent approaches towards the composition,oxidation states,and active facets have been presented.Thus,the most favorable mechanism and possible pathways to synthesize C_(2+)products have been explained using theoretical calculations.展开更多
Ceramic-based microwave absorption(MWA)materials have demonstrated significant application potential in cutting-edge fields,including aerospace and advanced weaponry,owing to their superior mechanical strength,excelle...Ceramic-based microwave absorption(MWA)materials have demonstrated significant application potential in cutting-edge fields,including aerospace and advanced weaponry,owing to their superior mechanical strength,excellent chemical and thermal stability,remarkable oxidation and corrosion resistance,outstanding electromagnetic wave(EMW)absorption performance,low density,and high-temperature durability.To further improve the performance of these materials,structural optimization has emerged as a widely adopted strategy.This review systematically summarizes recent advances in ceramic-based MWA materials across multiple scales,from the nanoscale and microscale to the macroscale,and establishes interconnections among synthesis techniques,structural design,and electromagnetic(EM)behavior.The effects of structural engineering,defect modulation,and hierarchical porosity on the dielectric and magnetic loss mechanisms are discussed,along with how morphology influences impedance matching and attenuation efficiency.Finally,the challenges and future prospects of developing lightweight,broadband,and high-temperature-resistant ceramic absorbers are outlined,providing insights for the intelligent design of next-generation EMW absorption systems.展开更多
As a two-dimensional(2D) material, polymeric carbon nitride(g-C_3N_4) nanosheet holds great potentials in environmental purification and solar energy conversion. In this review, we summarized latest progress in the op...As a two-dimensional(2D) material, polymeric carbon nitride(g-C_3N_4) nanosheet holds great potentials in environmental purification and solar energy conversion. In this review, we summarized latest progress in the optimization of photocatalytic performance in 2D g-C_3N_4. Some of the latest structural engineering methods were summed up, where the relevant influences on the behaviors of photoinduced species were emphasized. Furthermore, the construction strategies for band structure modulation and charge separation promotion were then discussed in detail. A brief discussion on the opportunity and challenge of 2D g-C_3N_4-based photocatalysis are presented as the conclusion of this review.展开更多
Owing to the high theoretical capacity,metal sulfides have emerged as promising anode materials for potassium-ion batteries(PIBs).However,sluggish kinetics,drastic volume expansion,and polysulfide dissolution during c...Owing to the high theoretical capacity,metal sulfides have emerged as promising anode materials for potassium-ion batteries(PIBs).However,sluggish kinetics,drastic volume expansion,and polysulfide dissolution during charge/discharge result in unsatisfactory electrochemical performance.Herein,we design a core-shell structure consisting of an active bismuth sulfide core and a highly conductive sulfur-doped carbon shell(Bi2S3@SC)as a novel anode material for PIBs.Benefiting from its unique core-shell structure,this Bi2S3@SC is endowed with outstanding potassium storage performance with high specific capacity(626 mAh·g^(-1)under 50 mA·g^(-1))and excellent rate capability(268.9 mAh·g^(-1)at 1 A·g^(-1)).More importantly,a Bi2S3@SC//KFe[Fe(CN)6]full cell is successfully fabricated,which achieves a high reversible capacity of 257 mAh·g^(-1)at 50 mA·g^(-1)over 50 cycles,holding great potentials in practical applications.Density functional theory(DFT)calculations reveal that potassium ions have a low diffusion barrier of 0.54 eV in Bi2S3 due to the weak van der Waals interactions between layers.This work heralds a promising strategy in the structural design of high-performance anode materials for PIBs.展开更多
Carbon nitride(C_(3)N_(4))holds great promise for photocatalytic H_(2)O_(2)production from oxygen reduction.In spite of great research efforts,they still suffer from low catalytic efficiency primarily limited by the f...Carbon nitride(C_(3)N_(4))holds great promise for photocatalytic H_(2)O_(2)production from oxygen reduction.In spite of great research efforts,they still suffer from low catalytic efficiency primarily limited by the fast recombination of photogenerated charge carriers.In this work,we report the multiscale structural engineering of C_(3)N_(4)to significantly improve its optoelectronic properties and consequently photocatalytic performance.The product consists of porous spheres with high surface areas,abundant nitrogen defects,and alkali metal doping.Under visible light irradiation,our catalyst shows a remarkable H_(2)O_(2)production rate of 3,080μmol·g^(−1)·h^(−1),which is more than 10 times higher than that of bulk C_(3)N_(4)and exceeds those of most other C_(3)N_(4)-based photocatalysts.Moreover,the catalyst exhibits great stability,and can continuously work for 15 h without obvious activity decay under visible light irradiation,eventually giving rise to a high H_(2)O_(2)concentration of ca.45 mM.展开更多
Noble-metal-free surface-enhanced Raman scattering(SERS)substrates have attracted great attention for their abundant sources,good signal uniformity,superior biocompatibility,and high chemical stability.However,the lac...Noble-metal-free surface-enhanced Raman scattering(SERS)substrates have attracted great attention for their abundant sources,good signal uniformity,superior biocompatibility,and high chemical stability.However,the lack of controllable synthesis and fabrication of noble-metal-free substrates with high SERS activity impedes their practical applications.Herein,we propose a general strategy to fabricate a series of planar transition-metal nitride(TMN)SERS chips via an ambient temperature sputtering deposition route.For the first time,tungsten nitride(WN)and tantalum nitride(TaN)are used as SERS materials.These planar TMN chips show remarkable Raman enhancement factors(EFs)with~105 owing to efficient photoinduced charge transfer process between TMN chips and probe molecules.Further,structural engineering of these TMN chips is used to improve their SERS activity.Benefiting from the synergistic effect of charge transfer process and electric field enhancement by constructing a nanocavity structure,the Raman EF of WN nanocavity chips could be greatly improved to~1.29×10^(7),which is an order of magnitude higher than that of planar chips.Moreover,we also design the WN/monolayer MoS2 heterostructure chips.With the increase of surface electron density on the upper WN and more exciton resonance transitions in the heterostructure,a~1.94×10^(7)level EF and a 5×10^(-10)M level detection limit could be achieved.Our results provide important guidance for the structural design of ultrasensitive noble-metal-free SERS chips.展开更多
Causality is the science of cause and effect.It is through causality that explanations can be derived,theories can be formed,and new knowledge can be discovered.This paper presents a modern look into establishing caus...Causality is the science of cause and effect.It is through causality that explanations can be derived,theories can be formed,and new knowledge can be discovered.This paper presents a modern look into establishing causality within structural engineering systems.In this pursuit,this paper starts with a gentle introduction to causality.Then,this paper pivots to contrast commonly adopted methods for inferring causes and effects,i.e.,induction(empiricism)and deduc-tion(rationalism),and outlines how these methods continue to shape our structural engineering philosophy and,by extension,our domain.The bulk of this paper is dedicated to establishing an approach and criteria to tie principles of induction and deduction to derive causal laws(i.e.,mapping functions)through explainable artificial intelligence(XAI)capable of describing new knowledge pertaining to structural engineering phenomena.The proposed approach and criteria are then examined via a case study.展开更多
Lithium-sulfur batteries(LSBs)boasting remarkable energy density have garnered significant attention within academic and industrial spheres.Nevertheless,the progression of LSBs remains constrained by the languid redox...Lithium-sulfur batteries(LSBs)boasting remarkable energy density have garnered significant attention within academic and industrial spheres.Nevertheless,the progression of LSBs remains constrained by the languid redox kinetics intrinsic to sulfur and the pronounced shuttle effect induced by lithium polysulfides(Li PSs),which seriously affecting the energy density,cycling life and rate capacity.The conceptualization and implementation of catalytic materials stand acknowledged as a propitious stratagem for orchestrating kinetic modulation,particularly in excavating the conversion of LiPSs and has evolved into a focal point for disposing.Among them,chalcogenide catalytic materials(CCMs)have shown satisfactory catalytic effects ascribe to the unique physicochemical properties,and have been extensively developed in recent years.Considering the lack of systematic summary regarding the development of CCMs and corresponding performance optimization strategies,herein,we initiate a comprehensive review regarding the recent progress of CCMs for effective collaborative immobilization and accelerated transformation kinetics of Li PSs.Following that,the modulation strategies to improve the catalytic activity of CCMs are summarized,including structural engineering(morphology engineering,surface/interface engineering,crystal engineering)and electronic engineering(doping and vacancy,etc.).Finally,the application prospect of CCMs in LSBs is clarified,and some enlightenment is provided for the reasonable design of CCMs serving practical LSBs.展开更多
Herein,we report three novel electron-deficient aromatics,ethenylene-bridged bisisoindigos 3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-2-oxoind-oline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-d...Herein,we report three novel electron-deficient aromatics,ethenylene-bridged bisisoindigos 3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-2-oxoind-oline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one)(NCCN),3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-7-fluoro-2-oxoindoline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one)(NFFN),and(3E,3″E)-6,6″-((E)-ethene-1,2-diyl)bis(1,1′-bis(4-decyltetradecyl)-[3,3′-bipyrrolo[2,3-b]pyridinylidene]-2,2′(1H,1′H)-dione)(NNNN),and their derived donor–acceptor(D–A)copolymers,namely poly[3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-2-oxoindoline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one-6-yl)]-alt-[5,6-difluoro-4,7-di[(thiophen-2-yl)-5-yl)]benzo[c][1,2,5]thiadiazole](PNCCN-FBT),poly[3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-7-fluoro-2-oxoindoline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one-6-yl)]-alt-[5,6-difluoro-4,7-di[(thiophen-2-yl)-5-yl)]benzo[c][1,2,5]thiadiazole](PNFFNFBT),and poly[(3E,3″E)-6′,6‴-((E)-ethene-1,2-diyl)bis(1,1′-bis(4-decyltetradecyl)-[3,3′-bipyrrolo[2,3-b]pyridinylidene]-2,2′(1H,1′H)-dione-6-yl)]-alt-[5,6-difluoro-4,7-di[(thiophen-2-yl)-5-yl)]benzo[c][1,2,5]thiadiazole](PNNNN-FBT),in which 5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole(FBT)acts as the electron-donating units.The ethenylene-bridging unit reduces the steric hindrance of the three bisisoindigos.Incorporation of heteroatoms,such as fluorine and sp2-nitrogen atoms,endows them with multiple CH···F,CH···N,and N···S intramolecular hydrogen bonds/nonbinding interactions,resulting in increasing backbone planarity from NCCN,NFFN,to NNNN,and thus from PNCCN-FBT,PNFFN-FBT,to PNNNN-FBT.We found that all copolymers formed an improved molecular packing in the 1-chloronaphthalene(CN)-processed thin film compared with the 1,2-dichlorobenzene-processed one.The CN-processed PNCCN-FBT-based polymer field-effect transistors showed ambipolar transport characteristics with the electron mobility(μe)and hole mobility of 1.20 and 0.46 cm^(2)V^(−1)^s(−1),respectively,while the PNFFN-FBT-and PNNNN-FBT-based ones afforded unique n-type transport characteristics with impressively highμe up to 3.28 cm^(2)V^(−1)^s(−1).The lower frontier molecular orbital energy levels of PNFFN-FBT are the key reason for its higherμe.This study demonstrated that heteroatom structural engineering on ethenylene-bridged bisisoindigos is an effective way to construct high-performance n-type polymer semiconductors.展开更多
Kinked rebar is a special type of steel material,which is installed in beam column nodes and frame beams.It effectively enhances the blast resilience,seismic collapse resistance,and progressive collapse resistance of ...Kinked rebar is a special type of steel material,which is installed in beam column nodes and frame beams.It effectively enhances the blast resilience,seismic collapse resistance,and progressive collapse resistance of reinforced concrete(RC)structures without imposing substantial cost burdens,thereby emerging as a focal point of recent research endeavors.On the basis of explaining the working principle of kinked rebars,this paper reviews the research status of kinked rebars at home and abroad from three core domains:the tensile mechanical properties of kinked rebars,beam column nodes with kinked rebars,and concrete frame structures with kinked rebars.The analysis underscores that the straightening process of kinked rebars does not compromise their ultimate strength but significantly bolsters structural ductility and enhances energy dissipation capabilities.In beam-column joints,the incorporation of kinked rebars facilitates the seamless transfer of plastic hinges,adhering to the design principle of“strong columns and weak beams.”In addition,kinked rebars can greatly improve the resistance of the beam;The seismic resistance,internal explosion resistance,and progressive collapse resistance of reinforced concrete frame structures with kinked rebar have significantly improved.Beyond its primary application,the principle of kinked rebar was extended to other applications of kinked materials such as corrugated steel plates and origami structures,and the stress characteristics of related components and structures were studied.Intriguingly,this paper also proposes the application of kinked rebars in bridge engineering,aiming to address the challenges of localized damage concentration and excessive residual displacement in RC bridge piers.The introduction of kinked rebars in piers is envisioned to mitigate these issues,with the paper outlining its advantages and feasibility,thereby offering valuable insights for future research on kinked reinforcement and seismic design strategies for bridges.展开更多
基金financially supported by the Central Guidance on Local Science and Technology Development Fund of Sichuan Province(No.2023ZYDF044)LingYan Project(No.2024C01090)
文摘The inferior structure/electrochemistry stability due to the volume expansion and the less lithium storage active sites of transition metal oxide (TMO) are critical issue hindering their commercialization.The rational design to utilize the combined advantages of both structure and composition is a key strategy to address these challenges.Here,the (FeCoNiMnCrMg)_(2)O_(3)high entropy oxide(HEO) with different morphologic structures are developed through integrating molecule and microstructure engineering.The morphologic structure of high entropy oxide transforms from solid spheres to multishelled core-shell spheres,and then to hollow spheres,which is governed by a thermally induced non-uniform shrinkage process coupled with Kirkendall effect diffusion due to the different calcination temperature.Even with the incorporation of various metallic ions,the high entropy oxide with a homogeneous single-phase solid solution maintained their shape and uniformity in size due to the ability of metal ions to coexist on the same lattice point.Benefiting from the meticulous control of both compositional and geometric factors,the hollow high entropy oxide exhibited a significantly high specific capacity (1722.1 mAh g^(-1)after 200cycles at 1 A g^(-1)) and long-life span for lithium storage(2158.7 mAh g^(-1)over 900 cycles at 4 A g^(-1)).The collaborative lattice and consistent volume demonstrated in this study offer significant potential in directing the development of materials for advanced energy storage solutions.
基金supported by the National Natural Science Foundation of China(No.52272242)the Provisional Key Research and Development Program of Henan Province,China(No.231111240600)+1 种基金the Natural Science Foundation of Henan Province,China(No.242300421428)the Start-up Funding for Scientific Research of Zhengzhou University,China(No.32310221).
文摘Supercapacitors(SCs)stand out among various energy storage devices owing to their high power density and long-term cyc-ling stability.As new two-dimensional material,MXenes have become a research hotspot in recent years owing to their unique structure and rich surface functional groups.Compared with other materials,MXenes are more promising for SCs owing to their tunable precurs-ors,structural stability,and excellent electrical conductivity.However,the rate performance and electrochemical reaction activity of MXene materials are poor,and stacking severely limits their application.Therefore,various modification strategies are employed to im-prove the electrochemical performance of MXene materials.As the modification strategy of MXene electrode materials often involves in-creasing the number of ion transport channels to expose more active sites,the packing density is also affected to different degrees.There-fore,achieving a balance between high volumetric capacitance and rapid ion transport has become a key issue for the application of MXene-based SCs in wearable devices and microdevices.In this paper,the latest progress in the preparation methods and modification strategies of MXenes in recent years is reviewed with the aim of achieving both high volumetric capacitance and high ion transport for ex-panding the application of MXene-based SCs in microdevices and wearable devices.
基金National Natural Science Foundation of China(No.52173264).
文摘Surface structural engineering is desirable in modifying the surface performance of carbonyl iron powder(CIP)to enhance microwave absorption(MA)and anti-oxidation performance.Herein,the surface shape-dependent CIP absorbers are designed via surface coating with zinc oxide(ZnO)nanoparticles and then a thermal annealing treatment.The morphology of ZnO nanoparticles which can be easily regulated by controlling the annealing temperature ultimately affects the MA performance of CIP coating with ZnO nanoparticles(CIP@ZnO).The core-shell CIP@ZnO particles with cubic cone ZnO nanoparticles exhibit ex-cellent MA performance and thermal stability in comparison to the original CIP.Specifically,the CIP@ZnO annealed at 350 ℃(CIP@ZnO-350)samples which have the cubic cone ZnO nanoparticles exhibit a min-imum reflection loss(RLmin)of-55.35 dB at a thickness of 2.1 mm and a maximum effective absorp-tion bandwidth(EAB)of 7.09 GHz at a thickness of 2.0 mm.In addition,the antioxidant property of the CIP@ZnO composite particles is abruptly enhanced,which breaks the restriction of the application of CIP at high temperatures.The superior MA performance of CIP@ZnO particles with cubic cone ZnO nanoparti-cles comes from the enhancement in surface shape-dependent multiple microwave scattering,interfacial polarization,and electromagnetic-dielectric synergism between ZnO and CIP.
基金financially supported by Zhejiang Province Postdoctoral Research Project(No.ZJ 2023146)the Municipal Key R&D Program of Ningbo(No.2023Z064)。
文摘Antimony(Sb)is recognized as a potential electrode material for sodium-ion batteries(SIBs)due to its huge reserves,affordability,and high theoretical capacity(660 mAh·g^(-1)).However,Sb-based materials experience significant volume expansion during cycling,leading to comminution of the active substance and limiting their practical use in SIBs.Therefore,the volume expansion issue of Sb-based materials during charging/discharging must be solved to create high-performance SIBs.This paper presents a detailed review of structural engineering of Sb-based electrode materials,focusing on the performance effects of different kinds of structures on advanced performance SIBs.Finally,the future development and the challenges of Sb-based materials are prospected.This paper can provide specific perspectives on the structure construction and optimization of Sb-based anode materials so as to promote the rapid development and practical applications of SIBs.
基金National Natural Science Foundation of China (Nos. 22078242 and U20A20153)Applied Basic Research Program of Yunnan Province (Nos. 202101BE070001-032 and 202101BH070002)。
文摘Fe-N-C catalysts are widely considered as promising non-precious-metal candidates for electrocatalytic oxygen reduction reaction(ORR),Yet despite their high catalytic activity through rational modulation,challenges remain in their low site density and unsatisfactory mass transfer structure.Herein,we present a structural engineering approach employing a soft-template coating strategy to fabricate a hollow and hierarchically porous N-doped carbon framework anchored with atomically dispersed Fe sites(FeNCh) as an efficient ORR catalyst.The combination of hierarchical porosity and high exterior surface area is proven crucial for exposing more active sites,which gives rise to a remarkable ORR performance with a half-wave potential of 0.902 V in 0.1 m KOH and 0.814 V in 0.1 m HClO_(4),significantly outperforming its counterpart with solid structure and dominance of micropores(FeNC-s).The mass transfer property is revealed by in-situ electrochemical impedance spectroscopy(EIS) measurement.The distribution of relaxation time(DRT) analysis is further introduced to deconvolve the kinetic and mass transport processes,which demonstrates an alleviated mass transport resistance for FeNC-h,validating the effectiveness of structural engineering.This work not only provides an effective structural engineering approach but also contributes to the comprehensive mass transfer evaluation on advanced electrocatalyst for energy conversion applications.
基金supported by the Science and Technology Plan of Fujian Provincial,China(2022G02020 and 2022H6002)the Collaborative Innovation Platform Project for Advanced Electrochemical Energy Storage Technology,Fuxiaquan National Independent Innovation Demonstration Zone,China(3502ZCQXT2022001)+1 种基金the Significant Science and Technology Project of Xiamen(the Future Industrial Area),China(3502Z20231058)the Scientific Research Startup Funding for Special Professor of Minjiang Scholars。
文摘Silicon(Si)-based anodes have emerged as promising candidates for the next-generation lithium-ion batteries(LIBs)due to their high theoretical capacity(4200 mAh g^(-1)).However,their further application is hindered by critical challenges,including severe volume expansion(~300%),formation of unstable solid electrolyte interphase(SEI),and inherently low conductivity.While extensive research has sought to alleviate the substantial internal stress caused by volume expansion through the rational design of Si-based anode structures,the underlying mechanisms that govern these improvements remain insufficiently understood,leaving significant gaps in mechanical and interface electrical failure.To build a comprehensive understanding relationship between structural design and performance enhancement of Si-based anodes,this review first analyzes the characteristics of various Sibased anode structures and their associated internal stresses.Subsequently,it summarizes effective strategies to optimize the performance of Si-based anodes,including doping design,novel electrolyte design,and fu nctional binder design.Additionally,we assess emerging technologies with high commercial potential for structural design and interfacial modification,such as porous carbon carriers,chemical vapor deposition(CVD),spray granulation,and pre-lithiation.Finally,this work provides perspectives on the structural design of Si-based anodes.Overall,this review systematically summarizes modification strategies for Si-based anodes through structural regulation and interface engineering,thereby providing a foundation for advanced structural and interfacial design.
基金supported by the National Natural Science Foundation of China(22005153)Haihe Laboratory of Sustainable Chemical Transformations(No.YYJC202101).
文摘Host-vip engineering of donor-acceptor(D-A)coordination polymer(CP)materials has been proved to be a promising emission modulation strategy for the fabrication of highly tunable luminophores.Herein,it is shown that the fluorescence modulation of host-vip D-A CPs could be achieved through subtle structural engineering.Two isoreticular CPs,{M_(3)(μ_(3)-F)(BDC)_(3)(TPT)(solvents)}_(n)(M=Cd^(2+)for 1 and Zn^(2+)for 2,TPT=2,4,6-tri(4-pyridyl)-1,3,5-triazine,H_(2)BDC=1,4-benzenedicarboxylic acid),were selected as porous host CPs for investigation.By introducing different polyaromatic hydrocarbon(PAH)vips(anthracene;phenanthrene;pyrene;triphenylene;perylene;and coronene)into the host framework,two series of host-vip D-A CPs(PAHs@1 and PAHs@2)were obtained.Detailed investigation indicates that the subtle structural differences originated from the metal center affected D-A interactions between the PAH and TPT ligand,which result in distinct emission properties of PAHs@1 and PAHs@2.These results suggest the potential of structural modulation in the property tuning of the D-A CPs.
基金supported by the National Natural Science Foundation of China(Grant Nos.52572051,52231007,52172103,and 52222204)the Jiangsu Provincial Program of Science and Technology(Grant No.BE2023044)the Natural Science Basic Research Program in Shaanxi(Grant No.2022JC-25).
文摘Metal‒organic framework(MOF)derivatives employed as electromagnetic wave(EMW)absorption materials have gained considerable attention because of their plentiful coordination components and diverse nanomicrostructures.However,achieving broadband EMW absorption solely through nanoscale structural design remains challenging.Herein,a cross-scale structural engineering strategy is proposed to address this limitation.At the nanomicroscale,MOF-derived Co_(x)Ni_(y)@C nanorods were fabricated via a solvothermal and pyrolysis process.Systematic manipulation of the built-in electric field(BIEF)heterointerface achieved through adjusting the Co/Ni atomic ratio significantly promotes electron-directed migration,alters the spatial charge distribution,and ultimately enhances the polarization relaxation and magnetic resonance effects,resulting in superior EMW absorption performance(the effective absorption bandwidth of Co_(2)Ni@C is 4.9 GHz at 1.75 mm).The geometric configuration of the electromagnetic metastructures was subsequently optimized via CST software.Through cross-scale structural design,the simulated gradient honeycomb structure metamaterial composed of Co_(2)Ni@C achieves multiband compatibility,and the EAB reaches 38 GHz(covering 2-40 GHz)with a total thickness of 15 mm.This research elucidates the BIEF loss mechanism of MOF-derived Co_(x)Ni_(y)@C composites by rationally controlling the Co/Ni atomic ratio and provides novel insights into the structural design of electromagnetic nanomaterials.
基金supported by the National Natural Science Foundation of China(Grant Nos.92365203,12534013,12174096,and 12474167)the Hunan Provincial Science Fund for Distinguished Young Scholars(Grant No.2022JJ10060)+1 种基金the Science and Technology Innovation Program of Hunan Province(Grant Nos.2025ZYJ001 and 2021RC4026)the Science Fund for Self-initiated Innovation of NUDT。
文摘The two-dimensional van der Waals layered semiconductor In_(2)Se_(3) has emerged as a promising candidate for non-volatile ferroelectric memory,optoelectronic devices,and polymorphic phase engineering.Polymorphic In_(2)Se_(3) typically stabilizes in three distinct phases:α-,β′-,and β^(*)-In_(2)Se_(3),each dominant within specific temperature ranges.Although the crystal structures and ferroelectric properties of these phases have been widely studied,the unambiguous assignment of their in-plane and out-of-plane ferroelectric behaviors,as well as the mechanisms governing their phase transitions,remains a subject of active debate.In this study,we investigate the evolution of atomic and electronic structures in molecular beam epitaxy-grown ultrathin In_(2)Se_(3) films through correlated microstructural and macroscopic physical property analysis.By employing scanning tunneling microscopy/spectroscopy,temperature-dependent Raman spectroscopy,and piezoresponse force microscopy,we demonstrate a reversible temperature-induced phase transition between the in-plane ferroelectric β^(*)and antiferroelectric β′phases.Furthermore,we confirm robust out-of-plane ferroelectric polarization in the as-grown films and achieve an electric-field-driven transition from the β^(*)to β′phase.Our findings not only advance the fundamental understanding of phase transitions and polarization evolution in two-dimensional semiconductors but also open new avenues for the design of tunable,non-volatile ferroelectric memory devices.
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea goverment(MSIT)(RS-2025-02218301)supported by the Nano&Material Technology Development Program through the National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(No.RS-2024-00412289).
文摘Lithium metal batteries(LMBs)offer high energy densities but face challenges including poor reversibility and Li dendrite growth.Herein,we evaluate two flexible composite current collectors composed of reduced graphene oxide and carbon nanotubes(rGO/CNT)to investigate how Li storage mechanisms influence electrochemical performance.By modulating the number of layers in rGO,the few-layered rGO/CNT collector(FL-CC)stores Li through a pure plating mechanism,whereas the multi-layered rGO/CNT collector(ML-CC)stores lithium via a hybrid intercalation/plating mechanism.The hybrid mechanism in ML-CC promotes reversible Li-ion storage,reduces active Li-ion loss,and suppresses dendrite formation.As a result,ML-CC achieves superior cycling stability compared to FLCC in both LMBs and anode-free LMB tests paired with LiFePO_(4)cathodes at a practical areal capacity of 4.5 mAh cm^(-2).This study highlights the importance of structural design in current collectors and demonstrates that incorporating lithiatable materials can significantly enhance the electrochemical stability of anode-free LMBs.
基金the financial support from International Society of Engineering Science and Technology(ISEST)UK。
文摘The conversion of carbon dioxide(CO_(2))into hydrocarbons through electrochemical CO_(2)reduction reaction(eCO_(2)RR)shows a promising method to reduce CO_(2)levels and decrease reliance on fossil fuels in the years to come.Copper-based electrocatalysts exhibit a pronounced inclination for C-C coupling,drawing considerable interest as a favored metal catalyst for generating C_(2+)products through CO_(2)RR.However,CO_(2)RR still has some obstacles including product selectivity,higher overpotential,low Faradic efficiency(FE),stability,and current density(CD).Therefore,advancement in this field enables us to comprehend the complex multi-proton electron transfer during C-C coupling and engineering strategies to improve FE and CD.Herein,this review presents some key features of Cu-based catalysts as an electrocatalyst for C_(2) product formation while addressing the industrial challenges that hinder commercialization of CO_(2)RR.In addition,recent strategies on Cu-based catalysts,synthesis strategies,advanced characterizations,and mechanistic investigations via theoretical simulations have been presented.Furthermore,recent approaches towards the composition,oxidation states,and active facets have been presented.Thus,the most favorable mechanism and possible pathways to synthesize C_(2+)products have been explained using theoretical calculations.
基金financially supported by the National Natural Science Foundation of China(Nos.52472305,52173265,52302087,and 52403049)the Science and Technology Planning Project of Sichuan Province(No.2023NSFSC1952)the Fundamental Research Funds for the Central Universities(Nos.2682021GF004,2682025CX057,and 2682024CX088)to freely explore basic research projects.
文摘Ceramic-based microwave absorption(MWA)materials have demonstrated significant application potential in cutting-edge fields,including aerospace and advanced weaponry,owing to their superior mechanical strength,excellent chemical and thermal stability,remarkable oxidation and corrosion resistance,outstanding electromagnetic wave(EMW)absorption performance,low density,and high-temperature durability.To further improve the performance of these materials,structural optimization has emerged as a widely adopted strategy.This review systematically summarizes recent advances in ceramic-based MWA materials across multiple scales,from the nanoscale and microscale to the macroscale,and establishes interconnections among synthesis techniques,structural design,and electromagnetic(EM)behavior.The effects of structural engineering,defect modulation,and hierarchical porosity on the dielectric and magnetic loss mechanisms are discussed,along with how morphology influences impedance matching and attenuation efficiency.Finally,the challenges and future prospects of developing lightweight,broadband,and high-temperature-resistant ceramic absorbers are outlined,providing insights for the intelligent design of next-generation EMW absorption systems.
基金supported by the National Natural Science Foundation of China (21437003, 21673126, 21621003, 21761142017)the Youth Innovation Promotion Association of CAS (2017493)Young Elite Scientist Sponsorship Program by CAST and Collaborative Innovation Center for Regional Environmental Quality
文摘As a two-dimensional(2D) material, polymeric carbon nitride(g-C_3N_4) nanosheet holds great potentials in environmental purification and solar energy conversion. In this review, we summarized latest progress in the optimization of photocatalytic performance in 2D g-C_3N_4. Some of the latest structural engineering methods were summed up, where the relevant influences on the behaviors of photoinduced species were emphasized. Furthermore, the construction strategies for band structure modulation and charge separation promotion were then discussed in detail. A brief discussion on the opportunity and challenge of 2D g-C_3N_4-based photocatalysis are presented as the conclusion of this review.
基金This study was supported by the Hong Kong Scholars Program(No.XJ2019022)the Fundamental Research Funds for the Central Universities(No.WK2060000032)+1 种基金the National Natural Science Foundation(Nos.51772283,21972145,and 51872249)General Research Fund(GRF,No.CityU 11307619).
文摘Owing to the high theoretical capacity,metal sulfides have emerged as promising anode materials for potassium-ion batteries(PIBs).However,sluggish kinetics,drastic volume expansion,and polysulfide dissolution during charge/discharge result in unsatisfactory electrochemical performance.Herein,we design a core-shell structure consisting of an active bismuth sulfide core and a highly conductive sulfur-doped carbon shell(Bi2S3@SC)as a novel anode material for PIBs.Benefiting from its unique core-shell structure,this Bi2S3@SC is endowed with outstanding potassium storage performance with high specific capacity(626 mAh·g^(-1)under 50 mA·g^(-1))and excellent rate capability(268.9 mAh·g^(-1)at 1 A·g^(-1)).More importantly,a Bi2S3@SC//KFe[Fe(CN)6]full cell is successfully fabricated,which achieves a high reversible capacity of 257 mAh·g^(-1)at 50 mA·g^(-1)over 50 cycles,holding great potentials in practical applications.Density functional theory(DFT)calculations reveal that potassium ions have a low diffusion barrier of 0.54 eV in Bi2S3 due to the weak van der Waals interactions between layers.This work heralds a promising strategy in the structural design of high-performance anode materials for PIBs.
基金the financial support from the National Key R&D Program of China(No.2017YFA0204800)the National Natural Science Foundation of China(No.22002100)the Collaborative Innovation Center of Suzhou Nano Science and Technology,and the 111 Project and Joint International Research Laboratory of Carbon-Based Functional Materials and Devices.
文摘Carbon nitride(C_(3)N_(4))holds great promise for photocatalytic H_(2)O_(2)production from oxygen reduction.In spite of great research efforts,they still suffer from low catalytic efficiency primarily limited by the fast recombination of photogenerated charge carriers.In this work,we report the multiscale structural engineering of C_(3)N_(4)to significantly improve its optoelectronic properties and consequently photocatalytic performance.The product consists of porous spheres with high surface areas,abundant nitrogen defects,and alkali metal doping.Under visible light irradiation,our catalyst shows a remarkable H_(2)O_(2)production rate of 3,080μmol·g^(−1)·h^(−1),which is more than 10 times higher than that of bulk C_(3)N_(4)and exceeds those of most other C_(3)N_(4)-based photocatalysts.Moreover,the catalyst exhibits great stability,and can continuously work for 15 h without obvious activity decay under visible light irradiation,eventually giving rise to a high H_(2)O_(2)concentration of ca.45 mM.
基金This work was supported by the National Natural Science Foundation of China(No.11874108).
文摘Noble-metal-free surface-enhanced Raman scattering(SERS)substrates have attracted great attention for their abundant sources,good signal uniformity,superior biocompatibility,and high chemical stability.However,the lack of controllable synthesis and fabrication of noble-metal-free substrates with high SERS activity impedes their practical applications.Herein,we propose a general strategy to fabricate a series of planar transition-metal nitride(TMN)SERS chips via an ambient temperature sputtering deposition route.For the first time,tungsten nitride(WN)and tantalum nitride(TaN)are used as SERS materials.These planar TMN chips show remarkable Raman enhancement factors(EFs)with~105 owing to efficient photoinduced charge transfer process between TMN chips and probe molecules.Further,structural engineering of these TMN chips is used to improve their SERS activity.Benefiting from the synergistic effect of charge transfer process and electric field enhancement by constructing a nanocavity structure,the Raman EF of WN nanocavity chips could be greatly improved to~1.29×10^(7),which is an order of magnitude higher than that of planar chips.Moreover,we also design the WN/monolayer MoS2 heterostructure chips.With the increase of surface electron density on the upper WN and more exciton resonance transitions in the heterostructure,a~1.94×10^(7)level EF and a 5×10^(-10)M level detection limit could be achieved.Our results provide important guidance for the structural design of ultrasensitive noble-metal-free SERS chips.
文摘Causality is the science of cause and effect.It is through causality that explanations can be derived,theories can be formed,and new knowledge can be discovered.This paper presents a modern look into establishing causality within structural engineering systems.In this pursuit,this paper starts with a gentle introduction to causality.Then,this paper pivots to contrast commonly adopted methods for inferring causes and effects,i.e.,induction(empiricism)and deduc-tion(rationalism),and outlines how these methods continue to shape our structural engineering philosophy and,by extension,our domain.The bulk of this paper is dedicated to establishing an approach and criteria to tie principles of induction and deduction to derive causal laws(i.e.,mapping functions)through explainable artificial intelligence(XAI)capable of describing new knowledge pertaining to structural engineering phenomena.The proposed approach and criteria are then examined via a case study.
基金financially supported by the National Natural Science Foundation of China(No.U21A2077)the Taishan Scholar Project Foundation of Shandong Province(No.ts20190908)+1 种基金the Natural Science Foundation of Shandong Province(No.ZR2021ZD05)the China Postdoctoral Science Foundation(Nos.2023TQ0192,2023M742065)。
文摘Lithium-sulfur batteries(LSBs)boasting remarkable energy density have garnered significant attention within academic and industrial spheres.Nevertheless,the progression of LSBs remains constrained by the languid redox kinetics intrinsic to sulfur and the pronounced shuttle effect induced by lithium polysulfides(Li PSs),which seriously affecting the energy density,cycling life and rate capacity.The conceptualization and implementation of catalytic materials stand acknowledged as a propitious stratagem for orchestrating kinetic modulation,particularly in excavating the conversion of LiPSs and has evolved into a focal point for disposing.Among them,chalcogenide catalytic materials(CCMs)have shown satisfactory catalytic effects ascribe to the unique physicochemical properties,and have been extensively developed in recent years.Considering the lack of systematic summary regarding the development of CCMs and corresponding performance optimization strategies,herein,we initiate a comprehensive review regarding the recent progress of CCMs for effective collaborative immobilization and accelerated transformation kinetics of Li PSs.Following that,the modulation strategies to improve the catalytic activity of CCMs are summarized,including structural engineering(morphology engineering,surface/interface engineering,crystal engineering)and electronic engineering(doping and vacancy,etc.).Finally,the application prospect of CCMs in LSBs is clarified,and some enlightenment is provided for the reasonable design of CCMs serving practical LSBs.
基金support from the Beijing Municipal Natural Science Foundation(grant no.2212054)the National Natural Science Foundation of China(grant nos.22075294,22175021,22275194,and 22021002)Beijing National Laboratory for Molecular Sciences(grant no.BNLMS-CXXM-202101).
文摘Herein,we report three novel electron-deficient aromatics,ethenylene-bridged bisisoindigos 3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-2-oxoind-oline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one)(NCCN),3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-7-fluoro-2-oxoindoline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one)(NFFN),and(3E,3″E)-6,6″-((E)-ethene-1,2-diyl)bis(1,1′-bis(4-decyltetradecyl)-[3,3′-bipyrrolo[2,3-b]pyridinylidene]-2,2′(1H,1′H)-dione)(NNNN),and their derived donor–acceptor(D–A)copolymers,namely poly[3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-2-oxoindoline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one-6-yl)]-alt-[5,6-difluoro-4,7-di[(thiophen-2-yl)-5-yl)]benzo[c][1,2,5]thiadiazole](PNCCN-FBT),poly[3,3′-((3E,3′E)-((E)-ethene-1,2-diyl)bis(1-(4-decyltetradecyl)-7-fluoro-2-oxoindoline-6-yl-3-ylidene))bis(1-(4-decyltetradecyl)-1,3-dihydro-2H-pyrrolo[2,3-b]pyridin-2-one-6-yl)]-alt-[5,6-difluoro-4,7-di[(thiophen-2-yl)-5-yl)]benzo[c][1,2,5]thiadiazole](PNFFNFBT),and poly[(3E,3″E)-6′,6‴-((E)-ethene-1,2-diyl)bis(1,1′-bis(4-decyltetradecyl)-[3,3′-bipyrrolo[2,3-b]pyridinylidene]-2,2′(1H,1′H)-dione-6-yl)]-alt-[5,6-difluoro-4,7-di[(thiophen-2-yl)-5-yl)]benzo[c][1,2,5]thiadiazole](PNNNN-FBT),in which 5,6-difluoro-4,7-di(thiophen-2-yl)benzo[c][1,2,5]thiadiazole(FBT)acts as the electron-donating units.The ethenylene-bridging unit reduces the steric hindrance of the three bisisoindigos.Incorporation of heteroatoms,such as fluorine and sp2-nitrogen atoms,endows them with multiple CH···F,CH···N,and N···S intramolecular hydrogen bonds/nonbinding interactions,resulting in increasing backbone planarity from NCCN,NFFN,to NNNN,and thus from PNCCN-FBT,PNFFN-FBT,to PNNNN-FBT.We found that all copolymers formed an improved molecular packing in the 1-chloronaphthalene(CN)-processed thin film compared with the 1,2-dichlorobenzene-processed one.The CN-processed PNCCN-FBT-based polymer field-effect transistors showed ambipolar transport characteristics with the electron mobility(μe)and hole mobility of 1.20 and 0.46 cm^(2)V^(−1)^s(−1),respectively,while the PNFFN-FBT-and PNNNN-FBT-based ones afforded unique n-type transport characteristics with impressively highμe up to 3.28 cm^(2)V^(−1)^s(−1).The lower frontier molecular orbital energy levels of PNFFN-FBT are the key reason for its higherμe.This study demonstrated that heteroatom structural engineering on ethenylene-bridged bisisoindigos is an effective way to construct high-performance n-type polymer semiconductors.
基金supported by the Zhejiang Provincial Natural Science Foundation of China under Grant No.LTGG23E080001Zhejiang Engineering Research Center of Intelligent Urban Infrastructure under Grant No.IUI2022-ZD-01.
文摘Kinked rebar is a special type of steel material,which is installed in beam column nodes and frame beams.It effectively enhances the blast resilience,seismic collapse resistance,and progressive collapse resistance of reinforced concrete(RC)structures without imposing substantial cost burdens,thereby emerging as a focal point of recent research endeavors.On the basis of explaining the working principle of kinked rebars,this paper reviews the research status of kinked rebars at home and abroad from three core domains:the tensile mechanical properties of kinked rebars,beam column nodes with kinked rebars,and concrete frame structures with kinked rebars.The analysis underscores that the straightening process of kinked rebars does not compromise their ultimate strength but significantly bolsters structural ductility and enhances energy dissipation capabilities.In beam-column joints,the incorporation of kinked rebars facilitates the seamless transfer of plastic hinges,adhering to the design principle of“strong columns and weak beams.”In addition,kinked rebars can greatly improve the resistance of the beam;The seismic resistance,internal explosion resistance,and progressive collapse resistance of reinforced concrete frame structures with kinked rebar have significantly improved.Beyond its primary application,the principle of kinked rebar was extended to other applications of kinked materials such as corrugated steel plates and origami structures,and the stress characteristics of related components and structures were studied.Intriguingly,this paper also proposes the application of kinked rebars in bridge engineering,aiming to address the challenges of localized damage concentration and excessive residual displacement in RC bridge piers.The introduction of kinked rebars in piers is envisioned to mitigate these issues,with the paper outlining its advantages and feasibility,thereby offering valuable insights for future research on kinked reinforcement and seismic design strategies for bridges.
