In recent years,the depletion risk of fossil fuels has driven increasing interest in renewable energy.Among various technologies,proton exchange membrane fuel cells(PEMFCs)stand out due to their fast startup and high ...In recent years,the depletion risk of fossil fuels has driven increasing interest in renewable energy.Among various technologies,proton exchange membrane fuel cells(PEMFCs)stand out due to their fast startup and high power density.However,the commonly used Nafion membranes suffer from reduced proton conductivity under low humidity and high temperatures,limiting their practical application.Polyoxometalates(POMs),with their excellent proton conductivity and thermal stability,have emerged as promising alternatives.Yet,their high water solubility raises safety concerns,and their water-dependent conduction mechanisms and structure–function relationships remain insufficiently understood.These issues hinder the practical development of POM-based proton conductors.This paper presents a comprehensive review of the key properties and proton conduction mechanisms of POMs,with a particular focus on POM crystals and their composites exhibiting high proton conductivity.Representative studies are analyzed to elucidate design strategies,structure–function relationships,and recent research progress over the past five years.Finally,perspectives and recommendations are proposed to inform future research directions and promote practical applications in the field of proton-conducting materials.展开更多
Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and hi...Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.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
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
Mimicking the electric microenvironment of natural tissue is a promising strategy for developing biomedical implants. However, current research has not taken biomimetic electrical functional units into consideration w...Mimicking the electric microenvironment of natural tissue is a promising strategy for developing biomedical implants. However, current research has not taken biomimetic electrical functional units into consideration when designing biomedical implants. In this research, ordered structures with Schottky heterojunction functional unit (OSSH) were constructed on titanium implant surfaces for bone regeneration regulation. The Schottky heterojunction functional unit is composed of periodically distributed titanium microdomain and titanium oxide microdomain with different carrier densities and surface potentials. The OSSH regulates the M2-type polarization of macrophages to a regenerative immune response by activating the PI3K-AKT-mTOR signal pathway and further promotes osteogenic differentiation of rat bone marrow mesenchymal stem cells. This work provides fundamental insights into the biological effects driven by the Schottky heterojunction functional units that can electrically modulate osteogenesis.展开更多
Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and...Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.展开更多
Ganoderma polysaccharides(GPs),derived from various species of the Ganoderma genus,exhibit diverse bioactivities,including immune modulation,anti-tumor effects,and gut microbiota regulation.These properties position G...Ganoderma polysaccharides(GPs),derived from various species of the Ganoderma genus,exhibit diverse bioactivities,including immune modulation,anti-tumor effects,and gut microbiota regulation.These properties position GPs as dual-purpose agents for medicinal and functional food development.This review comprehensively explores the structural complexity of six key GPs and their specific mechanisms of action,such as TLR signaling in immune modulation,apoptosis pathways in anti-tumor activity,and their prebiotic effects on gut microbiota.Additionally,the structure-activity relationships(SARs)of GPs are highlighted to elucidate their biological efficacy.Advances in green extraction techniques,including ultrasonic-assisted and enzymatic methods,are discussed for their roles in enhancing yield and aligning with sustainable production principles.Furthermore,the review addresses biotechnological innovations in polysaccharide biosynthesis,improving production efficiency and making large-scale production feasible.These insights,combined with ongoing research into their bioactivity,provide a solid foundation for developing health-promoting functional food products that incorporate GPs.Furthermore,future research directions are suggested to optimize biosynthesis pathways and fully harness the health benefits of these polysaccharides.展开更多
Based on the observational data from 60 short-period stations deployed in the Jishishan M6.2 earthquake epicenter and adjacent regions(Gansu Province,2023),this study inverted the near-surface S-wave velocity structur...Based on the observational data from 60 short-period stations deployed in the Jishishan M6.2 earthquake epicenter and adjacent regions(Gansu Province,2023),this study inverted the near-surface S-wave velocity structure through teleseismic receiver function analysis by using the amplitude of direct P-wave.The results reveal that the epicentral area(Liugou Township and surroundings)exhibits markedly low S-wave velocities of 400-600 m/s,with a mean value of(500±50)m/s.In contrast,intermountain basins-Guanting Basin and Dahejia Basin-demonstrate significantly elevated velocities,exceeding the epicentral zone by 100-300 m/s,with values concentrated at 600-900 m/s.Notably,localized areas such as Jintian Village and Caotan Village maintain stable S-wave velocities of(700±30)m/s.The western margin tectonic belt of Jishishan displays distinctive velocity differentiation:A pronounced velocity gradient zone along the 35.8°N latitude boundary separates northern areas(<550 m/s)from southern regions(>750 m/s).These findings demonstrate significant spatial heterogeneity in shallow S-wave velocity structures,primarily controlled by three factors:(1)topographic-geomorphic units,(2)stratigraphic lithological contrasts,and(3)anthropogenic modifications.The persistent low-velocity anomalies(<600 m/s)in the epicentral zone and northern Yellow River T2 terrace likely correlate with Quaternary unconsolidated sediments,enhanced groundwater circulation,and bedrock weathering.These results provide critical geophysical constraints for understanding both the seismogenic environment of the Jishishan earthquake and its damage distribution patterns.Furthermore,they establish a foundational framework for regional seismic intensity evaluation,site amplification analysis,and secondary hazard risk assessment.展开更多
Protein Kinase G(PKG)is an important intracellular signal transduction enzyme,and its activity is modulated by cyclic guanosine monophosphate(cGMP).PKG plays a pivotal role in various significant physiological process...Protein Kinase G(PKG)is an important intracellular signal transduction enzyme,and its activity is modulated by cyclic guanosine monophosphate(cGMP).PKG plays a pivotal role in various significant physiological processes,including vascular smooth muscle relaxation,myocardial cell function regulation,neuron growth,and synaptic plasticity,et al.In recent years,the role of PKG in diseases has gradually attracted attention,and the abnormalities in its signaling pathway are closely related to the occurrence and development of cardiovascular and neurological diseases.Although PKG has been widely studied,its complex functions in different physiological systems and potential innovative applications still need to be further explored.This article reviews the purification techniques for PKG,discusses the advantages and disadvantages of different extraction methods,summarizes the structure and activation mechanism of each domain of PKG,and analyzes the physiological functions of PKG in organisms,especially the well-established roles in the cardiovascular system,nervous system,and endocrine system.The emerging therapeutic applications of PKG are also reviewed.In addition,the challenges of this field are proposed at the end.展开更多
Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy depositio...Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy deposition(EB-DED)technique,including three samples with composition mutation of 100%,composition change rate of 10%and 30%.Results show that the composition-change rate significantly affects the microstructure and mechanical properties of the samples.In the sample with abrupt change of composition,the sharp shift in composition between 304 stainless steel and Mo leads to a great difference in the microstructure and hardness near the interface between the two materials.With the increase in the number of gradient layers,the composition changes continuously along the direction of deposition height,and the microstructure morphology shows a smooth transition from 304 stainless steel to Mo,which is gradually transformed from columnar crystal to dendritic crystal.Elements Fe,Mo,and other major elements transform linearly along the gradient direction,with sufficient interlayer diffusion between the deposited layers,leading to good metallurgical bonding.The smaller the change in composition gradient,the greater the microhardness value along the deposition direction.When the composition gradient is 10%,the gradient layer exhibits higher hardness(940 HV)and excellent resistance to surface abrasion,and the overall compressive properties of the samples are better,with the compressive fracture stress in the top region reaching 750.05±14 MPa.展开更多
This review explores multi-directional functionally graded(MDFG)nanostructures,focusing on their material characteristics,modeling approaches,and mechanical behavior.It starts by classifying different types of functio...This review explores multi-directional functionally graded(MDFG)nanostructures,focusing on their material characteristics,modeling approaches,and mechanical behavior.It starts by classifying different types of functionally graded(FG)materials such as conventional,axial,bi-directional,and tri-directional,and the material distribution models like power-law,exponential,trigonometric,polynomial functions,etc.It also discusses the application of advanced size-dependent theories like Eringen’s nonlocal elasticity,nonlocal strain gradient,modified couple stress,and consistent couple stress theories,which are essential to predict the behavior of structures at small scales.The review covers the mechanical analysis of MDFG nanostructures in nanobeams,nanopipes,nanoplates,and nanoshells and their dynamic and static responses under different loading conditions.The effect of multi-directional material gradation on stiffness,stability and vibration is discussed.Moreover,the review highlights the need for more advanced analytical,semi-analytical,and numerical methods to solve the complex vibration problems ofMDFG nanostructures.It is evident that the continued development of these methods is crucial for the design,optimization,and real-world application of MDFG nanostructures in advanced engineering fields like aerospace,biomedicine,and micro/nanoelectromechanical systems(MEMS/NEMS).This study is a reference for researchers and engineers working in the domain of MDFG nanostructures.展开更多
Magnetically responsive microstructured functional surface(MRMFS),capable of dynamically and reversibly switching the surface topography under magnetic actuation,provides a wireless,noninvasive,and instantaneous way t...Magnetically responsive microstructured functional surface(MRMFS),capable of dynamically and reversibly switching the surface topography under magnetic actuation,provides a wireless,noninvasive,and instantaneous way to accurately control the microscale engineered surface.In the last decade,many studies have been conducted to design and optimize MRMFSs for diverse applications,and significant progress has been accomplished.This review comprehensively presents recent advancements and the potential prospects in MRMFSs.We first classify MRMFSs into one-dimensional linear array MRMFSs,two-dimensional planar array MRMFSs,and dynamic self-assembly MRMFSs based on their morphology.Subsequently,an overview of three deformation mechanisms,including magnetically actuated bending deformation,magnetically driven rotational deformation,and magnetically induced self-assembly deformation,are provided.Four main fabrication strategies employed to create MRMFSs are summarized,including replica molding,magnetization-induced self-assembly,laser cutting,and ferrofluid-infused method.Furthermore,the applications of MRMFS in droplet manipulation,solid transport,information encryption,light manipulation,triboelectric nanogenerators,and soft robotics are presented.Finally,the challenges that limit the practical applications of MRMFSs are discussed,and the future development of MRMFSs is proposed.展开更多
This paper proposes a new step-by-step Chebyshev space-time spectral method to analyze the force vibration of functionally graded material structures.Although traditional space-time spectral methods can reduce the acc...This paper proposes a new step-by-step Chebyshev space-time spectral method to analyze the force vibration of functionally graded material structures.Although traditional space-time spectral methods can reduce the accuracy mismatch between tem-poral low-order finite difference and spatial high-order discre tization,the ir time collocation points must increase dramatically to solve highly oscillatory solutions of structural vibration,which results in a surge in computing time and a decrease in accuracy.To address this problem,we introduced the step-by-step idea in the space-time spectral method.The Chebyshev polynomials and Lagrange's equation were applied to derive discrete spatial goverming equations,and a matrix projection method was used to map the calculation results of prev ious steps as the initial conditions of the subsequent steps.A series of numerical experiments were carried out.The results of the proposed method were compared with those obtained by traditional space-time spectral methods,which showed that higher accuracy could be achieved in a shorter computation time than the latter in highly oscillatory cases.展开更多
Diversity of soil microorganisms in different habitats of arid and semi-arid areas plays an important role in the soil texture and nutrient,promoting the growth of vegetation in those areas.To clarify the response of ...Diversity of soil microorganisms in different habitats of arid and semi-arid areas plays an important role in the soil texture and nutrient,promoting the growth of vegetation in those areas.To clarify the response of soil bacterial community diversity to the changes of environmental factors in different habitats,this study collected soil samples under the canopies of Tamarix ramosissima Ledeb.in oasis,transition zone,and desert habitats in the upper reaches of the Tarim River,Northwest China.High-throughput sequencing technology and PICRUSt2 software were used to explore the composition and function of soil bacterial communities in different habitats of T.ramosissima.The results showed that:(1)soil environmental factors under the canopy of T.ramosissima in the three habitats differed significantly,with soil moisture and nutrient conditions being better in the oasis;(2)Proteobacteria,Bacteroidetes,Firmicutes,Actinobacteria,and Gemmatimonadetes were the major bacterial communities in the three habitats;(3)soil bacterial community composition under the canopy of T.ramosissima varied greatly,and the richness was significantly different among the three habitats;(4)redundancy analysis indicated that soil water content and available phosphorous were the most important environmental factors influencing the composition of soil bacterial community;and(5)6 primary functions and 21 secondary functions were obtained by PICRUSt2 function prediction,with metabolism being the most dominant function.This study revealed the response of soil bacterial community composition to habitat changes and their driving factors in the upper reaches of the Tarim River,which could improve the understanding of ecological sensitivity of soil microorganisms in arid and semi-arid areas,and provide a theoretical foundation for improving soil quality and ecological protection.展开更多
Enhancing the lubricating properties and antibacterial adhesion resistance of implantable medical materials is critical to prevent soft tissue injury during implantation and the formation of bacterial biofilms.Prior s...Enhancing the lubricating properties and antibacterial adhesion resistance of implantable medical materials is critical to prevent soft tissue injury during implantation and the formation of bacterial biofilms.Prior studies may have exhibited limitations in the preparation methodologies and long-term stability of coatings for implantable medical materials.In this study,we developed a multilayered hybrid hydrogel coating method based on the rate difference of polymerization initiation on the material surface.The acquired coating with persistent lubrication capability retained its functionality after 2×10^(4) cycles of friction and 21 days of PBS immersion.A quaternary ammonium salt coating with antibacterial properties was introduced to further functionalize the coating.Animal experiments demonstrated that this coating exhibited remarkable effects on delaying encrustation and bacterial colonization.These studies indicate that this simple method of introducing lubricating and antibacterial coatings on catheters is likely to enhance the biocompatibility of medical devices and has broad application prospects in this field of medical devices.展开更多
With the continuously increasing awareness of energy conservation and the intensifying impacts of global warming, Personal Thermal Management (PTM) technologies are increasingly recognized for their potential to ensur...With the continuously increasing awareness of energy conservation and the intensifying impacts of global warming, Personal Thermal Management (PTM) technologies are increasingly recognized for their potential to ensure human thermal comfort in extreme environments. Biomimetic structures have emerged as a novel source of inspiration for PTM applications. This review systematically summarizes the biomimetic structures, phase change materials, manufacturing methods, and the performance of multifunctional PTM wearables. Firstly, it analyzes the biomimetic structures with thermal regulation and encapsulated phase change material functionalities from different dimensions, highlighting their applications in PTM. Subsequently, it outlines the conventional manufacturing methods incorporating various biomimetic structures, offering strategies for the production of PTM wearables. The review also discusses the typical performance characteristics of multifunctional PTM wearables, addressing the current demands in thermal management. Finally, opportunities and challenges in PTM field are proposed, proposing new directions for future research.展开更多
The construction of carbon nanocoil(CNC)-based chiral-dielectric-magnetic trinity composites is considered as a promising approach to achieve excellent low-frequency microwave absorption.However,it is still challengin...The construction of carbon nanocoil(CNC)-based chiral-dielectric-magnetic trinity composites is considered as a promising approach to achieve excellent low-frequency microwave absorption.However,it is still challenging to further enhance the low frequency microwave absorption and elucidate the related loss mechanisms.Herein,the chiral CNCs are first synthesized on a threedimensional(3D)carbon foam and then combined with the FeNi/NiFe_(2)O_(4) nanoparticles to form a novel chiral-dielectric-magnetic trinity foam.The 3D porous CNC-carbon foam network provides excellent impedance matching and strong conduction loss.The formation of the FeNi-carbon interfaces induces interfacial polarization loss,which is confirmed by the density functional theory calculations.Further permeability analysis and the micromagnetic simulation indicate that the nanoscale chiral magnetic heterostructures achieve magnetic pinning and coupling effects,which enhance the magnetic anisotropy and magnetic loss capability.Owing to the synergistic effect between dielectricity,chirality,and magnetism,the trinity composite foam exhibits excellent microwave absorption performance with an ultrabroad effective absorption bandwidth(EAB)of 14 GHz and a minimum reflection of loss less than-50 dB.More importantly,the C-band EAB of the foam is extended to 4 GHz,achieving the full C-band coverage.This study provides further guidelines for the microstructure design of the chiral-dielectric-magnetic trinity composites to achieve broadband microwave absorption.展开更多
African swine fever virus(ASFV)pB318L is an important protein for viral replication that acts as a membrane-bound trans-geranylgeranyl-diphosphate synthase(GGPPS)catalyzing the condensation of isopentenyl diphosphate(...African swine fever virus(ASFV)pB318L is an important protein for viral replication that acts as a membrane-bound trans-geranylgeranyl-diphosphate synthase(GGPPS)catalyzing the condensation of isopentenyl diphosphate(IPP)with allylic diphosphates.Recently we solved the crystal structure pB318L lacking N-terminal transmembrane region and performed a preliminary structural analysis.In this study,structure-based mutagenesis study and geranylgeranyl pyrophosphate(GGPP)production assay further revealed the key residues for the GGPPS activity.Structural comparison showed pB318L displays a strong similarity to typical GGPPSs instead of protein prenyltransferases.The phylogenetic analysis indicated pB318L may share a common ancestor with the GGPPSs from Brassicaceae plants rather than from its natural host.The subcellular localization analysis showed pB318L is localized in both nucleus and cytoplasm(including the endoplasmic reticulum membrane and mitochondria outer membrane).A unique N-terminal nuclear localization signal(NLS)following the transmembrane region was discovered in pB318L and the NLS was confirmed to be required for the nuclear import.We further revealed the NLS plays an essential role in the interaction with nuclear transporter karyopherin subunit alpha 1(KPNA1).Their interaction may suppress signal transducers and activators of transcription 1(STAT1)translocation and subsequently competitively inhibit nuclear import of IFNstimulated gene factor 3(ISGF3)complex.Our biochemical,structural and cellular analyses provide novel insights to pB318L that acts as an essential GGPPS that promotes viral replication and as a nuclear import protein that may be involved in immune evasion of ASFV.展开更多
Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on...Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina ores.The results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO concentration.Fourier transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO substitution.Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents increased.Structural analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO substitution.However,bond strength is another important factor affecting the slag viscosity.The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.展开更多
With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite h...With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity.The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene nanoplates.The unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric synergy.Therefore,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 mm.Besides,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.展开更多
基金supported by the National Natural Science Foundation of China(Nos.22203027 and U22A20107)the Henan Province Science and Technology Attack Plan Project(No.242102230020)+6 种基金the Students Innovative Pilot Plan of Henan University(Nos.202510475004 and XJ2025182)“Grassland Talents”of Inner Mongolia Autonomous Region,Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(No.NJYT23030)Technology Breakthrough Engineering Hydrogen Energy Field“Unveiling and Leading”Project(No.2024KJTW0018)“Steed plan High level Talents”of Inner Mongolia University,Carbon neutralization research project(No.STZX202218)Inner Mongolia Autonomous Region Natural Science Foundation(No.2023MS02002)Guangdong Provincial Key Laboratory of Materials and Technologies for Energy Conversion(No.MATEC2024KF011)National Key R&D Program of China(No.2022YFA1205201).
文摘In recent years,the depletion risk of fossil fuels has driven increasing interest in renewable energy.Among various technologies,proton exchange membrane fuel cells(PEMFCs)stand out due to their fast startup and high power density.However,the commonly used Nafion membranes suffer from reduced proton conductivity under low humidity and high temperatures,limiting their practical application.Polyoxometalates(POMs),with their excellent proton conductivity and thermal stability,have emerged as promising alternatives.Yet,their high water solubility raises safety concerns,and their water-dependent conduction mechanisms and structure–function relationships remain insufficiently understood.These issues hinder the practical development of POM-based proton conductors.This paper presents a comprehensive review of the key properties and proton conduction mechanisms of POMs,with a particular focus on POM crystals and their composites exhibiting high proton conductivity.Representative studies are analyzed to elucidate design strategies,structure–function relationships,and recent research progress over the past five years.Finally,perspectives and recommendations are proposed to inform future research directions and promote practical applications in the field of proton-conducting materials.
基金supported by the Innovative Research Group Project of the National Natural Science Foundation of China(T2121004)Key Programme(52235007)National Outstanding Youth Foundation of China(52325504).
文摘Hydrogel scaffolds have numerous potential applications in the tissue engineering field.However,tough hydrogel scaffolds implanted in vivo are seldom reported because it is difficult to balance biocompatibility and high mechanical properties.Inspired by Chinese ramen,we propose a universal fabricating method(printing-P,training-T,cross-linking-C,PTC&PCT)for tough hydrogel scaffolds to fill this gap.First,3D printing fabricates a hydrogel scaffold with desired structures(P).Then,the scaffold could have extraordinarily high mechanical properties and functional surface structure by cycle mechanical training with salting-out assistance(T).Finally,the training results are fixed by photo-cross-linking processing(C).The tough gelatin hydrogel scaffolds exhibit excellent tensile strength of 6.66 MPa(622-fold untreated)and have excellent biocompatibility.Furthermore,this scaffold possesses functional surface structures from nanometer to micron to millimeter,which can efficiently induce directional cell growth.Interestingly,this strategy can produce bionic human tissue with mechanical properties of 10 kPa-10 MPa by changing the type of salt,and many hydrogels,such as gelatin and silk,could be improved with PTC or PCT strategies.Animal experiments show that this scaffold can effectively promote the new generation of muscle fibers,blood vessels,and nerves within 4 weeks,prompting the rapid regeneration of large-volume muscle loss injuries.
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 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 Natural Science Foundation of China(Nos.52072127,52201297,U21A2055,and U22A20160)the China Postdoctoral Science Foundation(No.2022M711200)the Royal Society(No.IEC/NSFC/191344)(UK).
文摘Mimicking the electric microenvironment of natural tissue is a promising strategy for developing biomedical implants. However, current research has not taken biomimetic electrical functional units into consideration when designing biomedical implants. In this research, ordered structures with Schottky heterojunction functional unit (OSSH) were constructed on titanium implant surfaces for bone regeneration regulation. The Schottky heterojunction functional unit is composed of periodically distributed titanium microdomain and titanium oxide microdomain with different carrier densities and surface potentials. The OSSH regulates the M2-type polarization of macrophages to a regenerative immune response by activating the PI3K-AKT-mTOR signal pathway and further promotes osteogenic differentiation of rat bone marrow mesenchymal stem cells. This work provides fundamental insights into the biological effects driven by the Schottky heterojunction functional units that can electrically modulate osteogenesis.
基金National Natural Science Foundation of China(32201491)Young Elite Scientists Sponsorship Program by CAST(2023QNRC001)The authors extend their appreciation to the Deanship of Scientific Research at Northern Border University,Arar,KSA for funding this research work through the project number“NBU-FPEJ-2024-1101-02”.
文摘Research efforts on electromagnetic interference(EMI)shielding materials have begun to converge on green and sustainable biomass materials.These materials offer numerous advantages such as being lightweight,porous,and hierarchical.Due to their porous nature,interfacial compatibility,and electrical conductivity,biomass materials hold significant potential as EMI shielding materials.Despite concerted efforts on the EMI shielding of biomass materials have been reported,this research area is still relatively new compared to traditional EMI shielding materials.In particular,a more comprehensive study and summary of the factors influencing biomass EMI shielding materials including the pore structure adjustment,preparation process,and micro-control would be valuable.The preparation methods and characteristics of wood,bamboo,cellulose and lignin in EMI shielding field are critically discussed in this paper,and similar biomass EMI materials are summarized and analyzed.The composite methods and fillers of various biomass materials were reviewed.this paper also highlights the mechanism of EMI shielding as well as existing prospects and challenges for development trends in this field.
基金supported by the National Natural Science Foundation of China(Nos.82373762,31872675)Major Special Programe of science and technology of Yunnan(202402AA310032,202305AH340005)+1 种基金the Cooperation Project with DR PLANT Company(2023)the Foundation of the State Key Laboratory of Phytochemistry and Plant Resources in West China(Nos.P2020-KF02,P2022-KF10).
文摘Ganoderma polysaccharides(GPs),derived from various species of the Ganoderma genus,exhibit diverse bioactivities,including immune modulation,anti-tumor effects,and gut microbiota regulation.These properties position GPs as dual-purpose agents for medicinal and functional food development.This review comprehensively explores the structural complexity of six key GPs and their specific mechanisms of action,such as TLR signaling in immune modulation,apoptosis pathways in anti-tumor activity,and their prebiotic effects on gut microbiota.Additionally,the structure-activity relationships(SARs)of GPs are highlighted to elucidate their biological efficacy.Advances in green extraction techniques,including ultrasonic-assisted and enzymatic methods,are discussed for their roles in enhancing yield and aligning with sustainable production principles.Furthermore,the review addresses biotechnological innovations in polysaccharide biosynthesis,improving production efficiency and making large-scale production feasible.These insights,combined with ongoing research into their bioactivity,provide a solid foundation for developing health-promoting functional food products that incorporate GPs.Furthermore,future research directions are suggested to optimize biosynthesis pathways and fully harness the health benefits of these polysaccharides.
基金project is supported in part by Broadband Seismic 3D Array Detection(PhaseⅠ),Deep Earth Probe and Mineral Resources Exploration-National Science and Technology Major Project(Grant No.2024ZD1000300)National Natural Science Foundation of China(42204061)Gansu Jishishan 6.2 magnitude earthquake scientific investigation(DQJB23Y45)program。
文摘Based on the observational data from 60 short-period stations deployed in the Jishishan M6.2 earthquake epicenter and adjacent regions(Gansu Province,2023),this study inverted the near-surface S-wave velocity structure through teleseismic receiver function analysis by using the amplitude of direct P-wave.The results reveal that the epicentral area(Liugou Township and surroundings)exhibits markedly low S-wave velocities of 400-600 m/s,with a mean value of(500±50)m/s.In contrast,intermountain basins-Guanting Basin and Dahejia Basin-demonstrate significantly elevated velocities,exceeding the epicentral zone by 100-300 m/s,with values concentrated at 600-900 m/s.Notably,localized areas such as Jintian Village and Caotan Village maintain stable S-wave velocities of(700±30)m/s.The western margin tectonic belt of Jishishan displays distinctive velocity differentiation:A pronounced velocity gradient zone along the 35.8°N latitude boundary separates northern areas(<550 m/s)from southern regions(>750 m/s).These findings demonstrate significant spatial heterogeneity in shallow S-wave velocity structures,primarily controlled by three factors:(1)topographic-geomorphic units,(2)stratigraphic lithological contrasts,and(3)anthropogenic modifications.The persistent low-velocity anomalies(<600 m/s)in the epicentral zone and northern Yellow River T2 terrace likely correlate with Quaternary unconsolidated sediments,enhanced groundwater circulation,and bedrock weathering.These results provide critical geophysical constraints for understanding both the seismogenic environment of the Jishishan earthquake and its damage distribution patterns.Furthermore,they establish a foundational framework for regional seismic intensity evaluation,site amplification analysis,and secondary hazard risk assessment.
基金supported by the National Natural Science Foundation of China(Nos.22374033,22174031,22407037)the Natural Science Foundation of Heilongjiang Province(No.ZD2022B001).
文摘Protein Kinase G(PKG)is an important intracellular signal transduction enzyme,and its activity is modulated by cyclic guanosine monophosphate(cGMP).PKG plays a pivotal role in various significant physiological processes,including vascular smooth muscle relaxation,myocardial cell function regulation,neuron growth,and synaptic plasticity,et al.In recent years,the role of PKG in diseases has gradually attracted attention,and the abnormalities in its signaling pathway are closely related to the occurrence and development of cardiovascular and neurological diseases.Although PKG has been widely studied,its complex functions in different physiological systems and potential innovative applications still need to be further explored.This article reviews the purification techniques for PKG,discusses the advantages and disadvantages of different extraction methods,summarizes the structure and activation mechanism of each domain of PKG,and analyzes the physiological functions of PKG in organisms,especially the well-established roles in the cardiovascular system,nervous system,and endocrine system.The emerging therapeutic applications of PKG are also reviewed.In addition,the challenges of this field are proposed at the end.
基金National Natural Science Foundation of China(51975286)。
文摘Fe-Mo functionally graded materials(FGMs)with different composition-change rates from 100%304 stainless steel to 100%Mo along the composition gradient direction were prepared by electron beam-directed energy deposition(EB-DED)technique,including three samples with composition mutation of 100%,composition change rate of 10%and 30%.Results show that the composition-change rate significantly affects the microstructure and mechanical properties of the samples.In the sample with abrupt change of composition,the sharp shift in composition between 304 stainless steel and Mo leads to a great difference in the microstructure and hardness near the interface between the two materials.With the increase in the number of gradient layers,the composition changes continuously along the direction of deposition height,and the microstructure morphology shows a smooth transition from 304 stainless steel to Mo,which is gradually transformed from columnar crystal to dendritic crystal.Elements Fe,Mo,and other major elements transform linearly along the gradient direction,with sufficient interlayer diffusion between the deposited layers,leading to good metallurgical bonding.The smaller the change in composition gradient,the greater the microhardness value along the deposition direction.When the composition gradient is 10%,the gradient layer exhibits higher hardness(940 HV)and excellent resistance to surface abrasion,and the overall compressive properties of the samples are better,with the compressive fracture stress in the top region reaching 750.05±14 MPa.
文摘This review explores multi-directional functionally graded(MDFG)nanostructures,focusing on their material characteristics,modeling approaches,and mechanical behavior.It starts by classifying different types of functionally graded(FG)materials such as conventional,axial,bi-directional,and tri-directional,and the material distribution models like power-law,exponential,trigonometric,polynomial functions,etc.It also discusses the application of advanced size-dependent theories like Eringen’s nonlocal elasticity,nonlocal strain gradient,modified couple stress,and consistent couple stress theories,which are essential to predict the behavior of structures at small scales.The review covers the mechanical analysis of MDFG nanostructures in nanobeams,nanopipes,nanoplates,and nanoshells and their dynamic and static responses under different loading conditions.The effect of multi-directional material gradation on stiffness,stability and vibration is discussed.Moreover,the review highlights the need for more advanced analytical,semi-analytical,and numerical methods to solve the complex vibration problems ofMDFG nanostructures.It is evident that the continued development of these methods is crucial for the design,optimization,and real-world application of MDFG nanostructures in advanced engineering fields like aerospace,biomedicine,and micro/nanoelectromechanical systems(MEMS/NEMS).This study is a reference for researchers and engineers working in the domain of MDFG nanostructures.
基金financially supported by the Shenzhen Science and Technology Project(Project Nos.JCYJ20220818102201003,JCYJ20220818100001002)the Shenzhen Sustainable Development Special Project(Project No.KCXFZ20230731094500001)+1 种基金the National Natural Science Foundation of China(Project Nos.51975597,52175446)the Natural Science Foundation of Guangdong Province(Project No.2022B1515020011)。
文摘Magnetically responsive microstructured functional surface(MRMFS),capable of dynamically and reversibly switching the surface topography under magnetic actuation,provides a wireless,noninvasive,and instantaneous way to accurately control the microscale engineered surface.In the last decade,many studies have been conducted to design and optimize MRMFSs for diverse applications,and significant progress has been accomplished.This review comprehensively presents recent advancements and the potential prospects in MRMFSs.We first classify MRMFSs into one-dimensional linear array MRMFSs,two-dimensional planar array MRMFSs,and dynamic self-assembly MRMFSs based on their morphology.Subsequently,an overview of three deformation mechanisms,including magnetically actuated bending deformation,magnetically driven rotational deformation,and magnetically induced self-assembly deformation,are provided.Four main fabrication strategies employed to create MRMFSs are summarized,including replica molding,magnetization-induced self-assembly,laser cutting,and ferrofluid-infused method.Furthermore,the applications of MRMFS in droplet manipulation,solid transport,information encryption,light manipulation,triboelectric nanogenerators,and soft robotics are presented.Finally,the challenges that limit the practical applications of MRMFSs are discussed,and the future development of MRMFSs is proposed.
基金supported by the Advance Research Project of Civil Aerospace Technology(Grant No.D020304)National Nat-ural Science Foundation of China(Grant Nos.52205257 and U22B2083).
文摘This paper proposes a new step-by-step Chebyshev space-time spectral method to analyze the force vibration of functionally graded material structures.Although traditional space-time spectral methods can reduce the accuracy mismatch between tem-poral low-order finite difference and spatial high-order discre tization,the ir time collocation points must increase dramatically to solve highly oscillatory solutions of structural vibration,which results in a surge in computing time and a decrease in accuracy.To address this problem,we introduced the step-by-step idea in the space-time spectral method.The Chebyshev polynomials and Lagrange's equation were applied to derive discrete spatial goverming equations,and a matrix projection method was used to map the calculation results of prev ious steps as the initial conditions of the subsequent steps.A series of numerical experiments were carried out.The results of the proposed method were compared with those obtained by traditional space-time spectral methods,which showed that higher accuracy could be achieved in a shorter computation time than the latter in highly oscillatory cases.
基金supported by the Sciences Foundation of Xinjiang Uygur Autonomous Region(2024D01C32)the Xinjiang Uygur Autonomous Region Education Department Basic Scientific Project(XJEDU2023P005)+1 种基金the National Natural Science Foundation of China(32001145)the 2024 Xinjiang Uygur Autonomous Region Postdoctoral Funding Project.
文摘Diversity of soil microorganisms in different habitats of arid and semi-arid areas plays an important role in the soil texture and nutrient,promoting the growth of vegetation in those areas.To clarify the response of soil bacterial community diversity to the changes of environmental factors in different habitats,this study collected soil samples under the canopies of Tamarix ramosissima Ledeb.in oasis,transition zone,and desert habitats in the upper reaches of the Tarim River,Northwest China.High-throughput sequencing technology and PICRUSt2 software were used to explore the composition and function of soil bacterial communities in different habitats of T.ramosissima.The results showed that:(1)soil environmental factors under the canopy of T.ramosissima in the three habitats differed significantly,with soil moisture and nutrient conditions being better in the oasis;(2)Proteobacteria,Bacteroidetes,Firmicutes,Actinobacteria,and Gemmatimonadetes were the major bacterial communities in the three habitats;(3)soil bacterial community composition under the canopy of T.ramosissima varied greatly,and the richness was significantly different among the three habitats;(4)redundancy analysis indicated that soil water content and available phosphorous were the most important environmental factors influencing the composition of soil bacterial community;and(5)6 primary functions and 21 secondary functions were obtained by PICRUSt2 function prediction,with metabolism being the most dominant function.This study revealed the response of soil bacterial community composition to habitat changes and their driving factors in the upper reaches of the Tarim River,which could improve the understanding of ecological sensitivity of soil microorganisms in arid and semi-arid areas,and provide a theoretical foundation for improving soil quality and ecological protection.
基金financially supported by the National Natural Science Foundation of China(Nos.52373296 and 52173287)。
文摘Enhancing the lubricating properties and antibacterial adhesion resistance of implantable medical materials is critical to prevent soft tissue injury during implantation and the formation of bacterial biofilms.Prior studies may have exhibited limitations in the preparation methodologies and long-term stability of coatings for implantable medical materials.In this study,we developed a multilayered hybrid hydrogel coating method based on the rate difference of polymerization initiation on the material surface.The acquired coating with persistent lubrication capability retained its functionality after 2×10^(4) cycles of friction and 21 days of PBS immersion.A quaternary ammonium salt coating with antibacterial properties was introduced to further functionalize the coating.Animal experiments demonstrated that this coating exhibited remarkable effects on delaying encrustation and bacterial colonization.These studies indicate that this simple method of introducing lubricating and antibacterial coatings on catheters is likely to enhance the biocompatibility of medical devices and has broad application prospects in this field of medical devices.
基金supported by Basic and Applied Basic Research Foundation of Guangdong Province(No.2024A1515010772)State Key Laboratory of Massive Personalized Customization System and Technology,No.H&C-MPC-2023-02-06(Q)+2 种基金“CUG scholar”Scientific Research Funds at China University of Geosciences,Wuhan(No.CUG2022185)Guangzhou Youth Top Talent ProgramChina College Student Innovation and Entrepreneurship Training Program(No.S202410491063).
文摘With the continuously increasing awareness of energy conservation and the intensifying impacts of global warming, Personal Thermal Management (PTM) technologies are increasingly recognized for their potential to ensure human thermal comfort in extreme environments. Biomimetic structures have emerged as a novel source of inspiration for PTM applications. This review systematically summarizes the biomimetic structures, phase change materials, manufacturing methods, and the performance of multifunctional PTM wearables. Firstly, it analyzes the biomimetic structures with thermal regulation and encapsulated phase change material functionalities from different dimensions, highlighting their applications in PTM. Subsequently, it outlines the conventional manufacturing methods incorporating various biomimetic structures, offering strategies for the production of PTM wearables. The review also discusses the typical performance characteristics of multifunctional PTM wearables, addressing the current demands in thermal management. Finally, opportunities and challenges in PTM field are proposed, proposing new directions for future research.
基金supported by the National Natural Science Foundation of China[Grant Nos.52272288 and 51972039]the China Postdoctoral Science Foundation[No.2021M700658].
文摘The construction of carbon nanocoil(CNC)-based chiral-dielectric-magnetic trinity composites is considered as a promising approach to achieve excellent low-frequency microwave absorption.However,it is still challenging to further enhance the low frequency microwave absorption and elucidate the related loss mechanisms.Herein,the chiral CNCs are first synthesized on a threedimensional(3D)carbon foam and then combined with the FeNi/NiFe_(2)O_(4) nanoparticles to form a novel chiral-dielectric-magnetic trinity foam.The 3D porous CNC-carbon foam network provides excellent impedance matching and strong conduction loss.The formation of the FeNi-carbon interfaces induces interfacial polarization loss,which is confirmed by the density functional theory calculations.Further permeability analysis and the micromagnetic simulation indicate that the nanoscale chiral magnetic heterostructures achieve magnetic pinning and coupling effects,which enhance the magnetic anisotropy and magnetic loss capability.Owing to the synergistic effect between dielectricity,chirality,and magnetism,the trinity composite foam exhibits excellent microwave absorption performance with an ultrabroad effective absorption bandwidth(EAB)of 14 GHz and a minimum reflection of loss less than-50 dB.More importantly,the C-band EAB of the foam is extended to 4 GHz,achieving the full C-band coverage.This study provides further guidelines for the microstructure design of the chiral-dielectric-magnetic trinity composites to achieve broadband microwave absorption.
基金supported by the grants from the National Natural Science Foundation of China to Heng Zhang(31970152)the Strategic Priority Research Program of CAS to Yu-Hui Dong(XDB37040302)the CAS Emergency Research Project on African Swine Fever to Yu-Hui Dong(Grant KJZDSW-L06-01).
文摘African swine fever virus(ASFV)pB318L is an important protein for viral replication that acts as a membrane-bound trans-geranylgeranyl-diphosphate synthase(GGPPS)catalyzing the condensation of isopentenyl diphosphate(IPP)with allylic diphosphates.Recently we solved the crystal structure pB318L lacking N-terminal transmembrane region and performed a preliminary structural analysis.In this study,structure-based mutagenesis study and geranylgeranyl pyrophosphate(GGPP)production assay further revealed the key residues for the GGPPS activity.Structural comparison showed pB318L displays a strong similarity to typical GGPPSs instead of protein prenyltransferases.The phylogenetic analysis indicated pB318L may share a common ancestor with the GGPPSs from Brassicaceae plants rather than from its natural host.The subcellular localization analysis showed pB318L is localized in both nucleus and cytoplasm(including the endoplasmic reticulum membrane and mitochondria outer membrane).A unique N-terminal nuclear localization signal(NLS)following the transmembrane region was discovered in pB318L and the NLS was confirmed to be required for the nuclear import.We further revealed the NLS plays an essential role in the interaction with nuclear transporter karyopherin subunit alpha 1(KPNA1).Their interaction may suppress signal transducers and activators of transcription 1(STAT1)translocation and subsequently competitively inhibit nuclear import of IFNstimulated gene factor 3(ISGF3)complex.Our biochemical,structural and cellular analyses provide novel insights to pB318L that acts as an essential GGPPS that promotes viral replication and as a nuclear import protein that may be involved in immune evasion of ASFV.
基金financially supported by the National Natural Science Foundation of China(Nos.52425408 and 52304345)the Fundamental Research Funds for the Central Universities,China(No.2023CDJXY-016)the Postdoctoral Science Foundation of Chongqing(No.CSTB2023NSCQ-BHX0174)。
文摘Currently,the Al_(2)O_(3)content in the high-alumina slag systems within blast furnaces is generally limited to 16wt%–18.5wt%,making it challenging to overcome this limitation.Unlike most studies that concentrated on managing the MgO/Al_(2)O_(3)ratio or basicity,this paper explored the effect of equimolar substitution of MgO for CaO on the viscosity and structure of a high-alumina CaO-MgO-Al_(2)O_(3)-SiO_(2)slag system,providing theoretical guidance and data to facilitate the application of high-alumina ores.The results revealed that the viscosity first decreased and then increased with higher MgO substitution,reaching a minimum at 15mol%MgO concentration.Fourier transform infrared spectroscopy(FTIR)results found that the depths of the troughs representing[SiO_(4)]tetrahedra,[AlO_(4)]tetrahedra,and Si-O-Al bending became progressively deeper with increased MgO substitution.Deconvolution of the Raman spectra showed that the average number of bridging oxygens per Si atom and the X_(Q^(3))/X_(Q^(2))(X_(Q^(i))is the molar fraction of Q^(i) unit,and i is the number of bridging oxygens in a[SiO_(4)]tetrahedral unit)ratio increased from 2.30 and 1.02 to 2.52 and 2.14,respectively,indicating a progressive polymerization of the silicate structure.X-ray photoelectron spectroscopy(XPS)results highlighted that non-bridging oxygen content decreased from 77.97mol% to 63.41mol% with increasing MgO concentration,whereas bridging oxygen and free oxygen contents increased.Structural analysis demonstrated a gradual increase in the polymerization degree of the tetrahedral structure with the increase in MgO substitution.However,bond strength is another important factor affecting the slag viscosity.The occurrence of a viscosity minimum can be attributed to the complex evolution of bond strengths of non-bridging oxygens generated during depolymerization of the[SiO_(4)]and[AlO_(4)]tetrahedral structures by CaO and MgO.
基金sponsored by National Natural Science Foundation of China(No.52302121,No.52203386)Shanghai Sailing Program(No.23YF1454700)+1 种基金Shanghai Natural Science Foundation(No.23ZR1472700)Shanghai Post-doctoral Excellent Program(No.2022664).
文摘With vigorous developments in nanotechnology,the elaborate regulation of microstructure shows attractive potential in the design of electromagnetic wave absorbers.Herein,a hierarchical porous structure and composite heterogeneous interface are constructed successfully to optimize the electromagnetic loss capacity.The macro–micro-synergistic graphene aerogel formed by the ice template‑assisted 3D printing strategy is cut by silicon carbide nanowires(SiC_(nws))grown in situ,while boron nitride(BN)interfacial structure is introduced on graphene nanoplates.The unique composite structure forces multiple scattering of incident EMWs,ensuring the combined effects of interfacial polarization,conduction networks,and magnetic-dielectric synergy.Therefore,the as-prepared composites present a minimum reflection loss value of−37.8 dB and a wide effective absorption bandwidth(EAB)of 9.2 GHz(from 8.8 to 18.0 GHz)at 2.5 mm.Besides,relying on the intrinsic high-temperature resistance of SiC_(nws) and BN,the EAB also remains above 5.0 GHz after annealing in air environment at 600℃ for 10 h.
