Here we fabricate LA103Z Mg-Li alloy via wire-arc directed energy deposition(WA-DED),and subsequent aging treatment is employed to improve its mechanical property.Results show that a typical dual-phase microstructure ...Here we fabricate LA103Z Mg-Li alloy via wire-arc directed energy deposition(WA-DED),and subsequent aging treatment is employed to improve its mechanical property.Results show that a typical dual-phase microstructure is formed upon WA-DED,consisting of α-Mg,β-Li,AlLi and Li_(2)MgAl,with negligible porosity,and the core-shell Li_(2)MgAl/AlLi composite particles are also generated.After aging treatment,the microstructure is slightly coarsened,together with the precipitation of nano-sized D0_(3)-Mg_(3)Al particles,as well as the dissolution and the mergence of α-Mg phases.Negligible strength and ductility anisotropies are found for the as-deposited alloy.Significant strength increment is achieved via aging treatment,and the ultimate strength increases by~20%(~34 MPa),reaching 200±1 MPa.Both as-deposited and aged alloys show acceptable uniform elongation,with a transgranular fracture mode.Precipitation strengthening enabled by nano-sized D0_(3)-Mg_(3)Al precipitates is primarily responsible for the strength increment mediated by aging treatment.Grain refinement strengthening and solid solution strengthening provide additional contributions to the improved strength.Our work thus offers an applicable additive manufacturing pathway for the efficient and safety-guaranteed fabrication of Mg-Li alloy components with decent mechanical property.展开更多
MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significant...MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significantly inhibit its electrochemical performance and further wide application.Herein,a physicochemical double protection strategy is proposed to stabilize MXene in the hydrothermal process effectively.Polyvinylpyrrolidone(PVP),with the structure of a long chain and abundant O/N function groups,provides physical protection against agglomeration(steric effect)and chemical protection against oxidation(electron transfer)at the same time,contributing to the synthesis of MXene-based hybrids with high conductivity and fully exposed active sites.As proof of the concept,2D MXene/Co_(9)S_(8) nanohybrids with a scaly surface are fabricated and present impressive performance,especially rate performance for hybrid supercapacitor(HSC)with MoS_(2) as the counter electrode.The HSC demonstrates a high energy density of 111 Wh kg^(-1) at 845 W kg^(-1) and an excellent rate performance of 61 Wh kg^(-1) at 16.9 kW kg^(-1).展开更多
Due to their high mechanical compliance and excellent biocompatibility,conductive hydrogels exhibit significant potential for applications in flexible electronics.However,as the demand for high sensitivity,superior me...Due to their high mechanical compliance and excellent biocompatibility,conductive hydrogels exhibit significant potential for applications in flexible electronics.However,as the demand for high sensitivity,superior mechanical properties,and strong adhesion performance continues to grow,many conventional fabrication methods remain complex and costly.Herein,we propose a simple and efficient strategy to construct an entangled network hydrogel through a liquid-metal-induced cross-linking reaction,hydrogel demonstrates outstanding properties,including exceptional stretchability(1643%),high tensile strength(366.54 kPa),toughness(350.2 kJ m^(−3)),and relatively low mechanical hysteresis.The hydrogel exhibits long-term stable reusable adhesion(104 kPa),enabling conformal and stable adhesion to human skin.This capability allows it to effectively capture high-quality epidermal electrophysiological signals with high signal-to-noise ratio(25.2 dB)and low impedance(310 ohms).Furthermore,by integrating advanced machine learning algorithms,achieving an attention classification accuracy of 91.38%,which will significantly impact fields like education,healthcare,and artificial intelligence.展开更多
Nickel(II)as one of the primary categories of heavy metals can lead to serious health problems if achieving the critical levels in the water.Thus,it is vital to propose a stable,reliable,and economical approach for de...Nickel(II)as one of the primary categories of heavy metals can lead to serious health problems if achieving the critical levels in the water.Thus,it is vital to propose a stable,reliable,and economical approach for detecting Ni ions.The microfluidic paper-based analytical devices(µPADs)are potential candidates for the detection of water quality parameters including pH,heavy ions,nitrite and so on.However,it suffers from a huge error caused by the environment and artificial mistakes.In this study,we proposed an improved technique route to increase the stability and reliability of microfluidic paper-based analytical devices.The main technique points include a stable light source,a matched camera,improved reliability of the devices,and effective calculated methods.Finally,we established 15 standard curves that could be used to detect nickel ions and obtained uniform colorimetric results with reliability and repeatability.With those improvements,the relative errors for the five types of real water samples from the Zhongshan industrial parks were reduced to 0.26%,14.78%,24.20%,50.29%and 3.53%,respectively.These results were conducive to exploring this technique for the detection of nickel ions in wastewater from the Zhongshan industrial parks.The results demonstrated that the above technique route is promising for the detection of other heavy metal ions in industrial effluent.展开更多
MnO_(2)has emerged as one of the favored cathode materials for aqueous zinc ion batteries(AZIBs)due to its high theoretical capacity and abundant crystalline structures.However,MnO_(2)cathode generally suffers from po...MnO_(2)has emerged as one of the favored cathode materials for aqueous zinc ion batteries(AZIBs)due to its high theoretical capacity and abundant crystalline structures.However,MnO_(2)cathode generally suffers from poor electrical conductivity and rapid capacity degradation due to unavoidable manganese dissolution during cycling,limiting their further utilization.In this study,we modify the d-band center of Mn by introducing non-precious metal Bi atoms into the MnO_(2)system,thereby strengthening the Mn-O bonding to inhibit manganese dissolution.Theoretical calculations reveal that the d-band center of Mn in Bi-MnO_(2)shifts upward,promoting electron transfer from O 2p orbitals to Mn-O bonding orbitals.This enhances the Mn-O bond strength,stabilizing Mn atoms in the crystal lattice and reducing manganese solvation loss.As a result,the conductivity and cyclic stability of Bi-MnO_(2)are significantly improved.The results demonstrate that Bi-MnO_(2)exhibits outstanding electrochemical properties,with a capacity of 392.3 mAh g^(-1)after 100 cycles at 0.2 A g^(-1)and a capacity retention of 83.25%after 5000 cycles at 1.0 A g^(-1).This study presents a new approach to address the manganese dissolution issue,which could further advance the application of d-band center theory in MnO_(2)materials.展开更多
Seeking for extremely active and durable bifunctional electrocatalysts towards the overall water splitting possesses a strategic significance on the development of sustainable and clean energy for the replacement of f...Seeking for extremely active and durable bifunctional electrocatalysts towards the overall water splitting possesses a strategic significance on the development of sustainable and clean energy for the replacement of fossil fuels.Ir-based nanomaterials are deemed as one of the most highefficiency oxygen evolution reaction electrocatalysts while the hydrogen evolution reaction performance is unfavorable.In this work,we report a one-pot hydrothermal synthesis of N-doped graphene anchored Ir nanoparticles(Ir/N-rGO) with ultrasmall particle size(~2.0 nm).Apart from the predictably superior OER performance,the resultant Ir/N-rGO also displays excellent hydrogen evolution reaction(HER) performance,requiring merely 76 and 260 mV overpotentials to achieve the current density of 10 mA cm^(-2) towards HER and OER,respectively.When applied as the bifunctional electrodes for overall water splitting,Ir/N-rGO needs a lower overpotential(1.74 V) to achieve a current density of50 mA cm^(-2) in alkaline solution,exceeding that of Pt/C and RuO_(2) couple(1.85 V).Thus,the as-fabricated Ir/N-rGO has a commendable prospect in the practical application of alkaline water electrocatalysis.展开更多
The development of potential transition-metal carbide/nitride heterojunctions is hindered by overall understanding and precise modulation for heterointerface effects.Herein,we demonstrate that Mo_(2)C/Mo_(2)N heteroju...The development of potential transition-metal carbide/nitride heterojunctions is hindered by overall understanding and precise modulation for heterointerface effects.Herein,we demonstrate that Mo_(2)C/Mo_(2)N heterojunction with the precisely regulated high-quality interface can achieve marvelous rate performance and energy output via enlarging the interface-effect range and maximizing "accelerated charge" amount The heterointerface mechanism improving properties is synergistically revealed from kinetics and thermodynamics perspectives.Kinetics analysis confirms that the self-built electric field affords a robust force to drive rapid interface electrons/ions migration.The small adsorption energy,high density of states and quite low diffusion barrier thermodynamically enhance the electrochemical reaction dynamics on heterointerface.Consequently,the almost optimal performance of ultrahigh capacitance retention(85.6% even at 10 A g^(-1)) and pronounced energy output(96.4 Wh kg^(-1))in hybridsupercapacitors than other Mo_(2)C/Mo_(2)N-based materials is presented.This work gives new insight into the energy storage mechanism of heterojunction and guides the design of advanced electrodes.展开更多
Considering the importance and complexity of benzene oxidation on mineral oxide aerosol surfaces in the atmosphere,gas-phase 3 d-transition metal oxide cations were used as models of active sites on mineral oxide aero...Considering the importance and complexity of benzene oxidation on mineral oxide aerosol surfaces in the atmosphere,gas-phase 3 d-transition metal oxide cations were used as models of active sites on mineral oxide aerosols to mimic the corresponding reactions.The various cations have been prepared by laser ablation and reacted with benzene in a linear ion trap reactor.Of the 103 systematically investigated cations,39 clusters can oxidize benzene at room temperature.In addition to the adsorption channel,other five types of reaction channels were observed,including dehydrogenation of C6H6,charge exchange,hydrogen atom transfer,oxygen atom transfer,and the formation of C6H5O^+radical,among which the first two pathways are prevale nt and the formation of C6H6O^+cations has not been reported in literature.The insight into the benzene oxidation reactions derived from the gas-phase model systems is helpful to build a detailed picture of oxidative mechanisms of C6H6 and its derivatives over corresponding mineral oxide aerosols.展开更多
Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo...Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo anatomical and functional information.This technology has great application potential in microscopic imaging and endoscope system.In recent years,the devel-opment of micro electro mechanical system(MEMS)technology has promoted the improvement and miniaturization of the photoacoustic imaging system,as well as its preclinical and clinical appli-cations.This paper introduces the research progress of MEMS technology in photoacoustic micro-scope systems and the miniaturization of photoacoustic endoscope ultrasonic transducers,and points out the shortcomings of existing technology and the direction of future development.展开更多
The space-confined synthesis method has been an efficient way for the preparation of linear carbon chains.However,the large-scale preparation of linear carbon chains still faces many challenges due to the lack of meth...The space-confined synthesis method has been an efficient way for the preparation of linear carbon chains.However,the large-scale preparation of linear carbon chains still faces many challenges due to the lack of methods for the large-scale synthesis of precursors,such as short carbon chains(polyynes),and regulation technology for the transport of reactants in one-dimensional space.Here,we report a facile method for the rapid preparation of polyynes in large quantities using a commercial laser marking machine.Spectroscopic characterizations show that a large number of polyynes,such as C_(8)H_(2),C_(10)H_(2),C_(12)H_(2),and C_(14)H_(2),can be produced by ablating the graphite plate immersed in the organic liquid using a laser marking machine.The results of in situ Raman spectroscopy investigation of C_(2n)H_(2)-filled single-walled carbon nanotubes further confirm that a variety of polyyne molecules are synthesized.Meanwhile,in situ Raman spectroscopy also shows that the local heating treatment can accelerate the filling process of C_(2n)H_(2)into one-dimensional channels.This work provides new insights into the study of linear carbon chains and space-confined synthesis methods.展开更多
The sulfide-based solid-state electrolytes(SEs)reactivity toward moisture and Li-metal are huge barriers that impede their large-scale manufactu ring and applications in all-solid-state lithium batteries(ASSLBs).Herei...The sulfide-based solid-state electrolytes(SEs)reactivity toward moisture and Li-metal are huge barriers that impede their large-scale manufactu ring and applications in all-solid-state lithium batteries(ASSLBs).Herein,we proposed an Al and O dual-doped strategy for Li_(3)PS_(4)SE to regulate the chemical/electrochemical stability of anionic PS_(4)^(3-)tetrahedra to mitigate structural hydrolysis and parasitic reactions at the SE/Li interface.The optimized Li_(3.08)A_(10.04)P_(0.96)S_(3.92)O_(0.08)SE presents the highestσLi+of 3.27 mS cm^(-1),which is~6.8 times higher than the pristine Li_(3)PS_(4)and excellently inhibits the structural hydrolysis for~25 min@25%humidity at RT.DFT calculations confirmed that the enhanced chemical stability was revealed to the intrinsically stable entities,e.g.,POS33-units.Moreover,Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)SE cycled stably in Li//Li symmetric cell over 1000 h@0.1 mA cm^(-2)/0.1 mA h cm^(-2),could be revealed to Li-Al alloy and Li_(2)Oat SE/Li interface impeding the growth of Li-dendrites during cycling.Resultantly,LNO@LCO/Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)/Li-In cell delivered initial discharge capacities of 129.8 mA h g^(-1)and 83.74%capacity retention over 300 cycles@0.2 C at RT.Moreover,the Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)SE presented>90%capacity retention over 200 and 300 cycles when the cell was tested with LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA)cathode material vs.5 and 10 mg cm^(-2)@RT.展开更多
Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron sp...Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron spectroscopy(APXPS)emerges as an emerging photon-in-electron-out technique in in-situ/operando analysis by bridging the pressure-gap between conventional ultra-high vacuum(UHV)and near ambient or even close to operating conditions,rendering the advancement of XPS from a UHV-based technique to a versatile and powerful tool that enables the specific probe of numerous events taking place at the gas–solid,liquid–solid and liquid–gas nanoscale interfaces which are critical to nanocatalysis research.For example,APXPS probes information on catalytically active phase and reaction kinetics in nanocatalytic processes;details inside the electric double-layer at an electrolyte/electrode interface can now be accessed;more efficient nanocatalyst design can be achieved and energy transfer venues can be optimized.Here,we aim to critically review the recent advances in instrumentation and the probe of the gas–solid,liquid–solid,and gas–liquid nanoscale interfaces using APXPS-based methodologies,followed by putting forward an outlook of development of APXPS as a rising in-situ/operando analytical means in surface science,nanocatalysis,nanoscience materials science.展开更多
The electrochemical conversion of CO_(2) into value-added chemicals presents an environmentally sustainable alternative to conventional fossil-derived processes,yet achieving high selectivity remains challenging due t...The electrochemical conversion of CO_(2) into value-added chemicals presents an environmentally sustainable alternative to conventional fossil-derived processes,yet achieving high selectivity remains challenging due to competing reaction pathways.Here,we demonstrate precise tuning of CO_(2) electroreduction pathways through femtosecond laser-driven surface doping of Cu with targeted metals,achieving Faradaic efficiencies of 58.9%for CO,67.9%for formate,and 37.8%for ethylene.This spatially shaping laser technique enables nanoscale deposition of any metal(including Sb,Sn,Re,La,In,Co,Ni,Ag,and Pt)onto Cu foil,forming compositionally graded Cu-based bimetallic surfaces with controlled atomic ratios.Systematic electronic structure analysis reveals that secondary metals induce d-band center shifts spanning−0.21 to+0.78 eV,governing intermediate adsorption energetics-upward shifts strengthen*CO binding via enhanced back-donation,while downward shifts generally weaken adsorbate interactions.Through precise control of Cu/Sn and Cu/Sb atomic ratios,we manipulate electronic structures of CuSn and CuSb catalysts and consequently demonstrate continuous tuning of formate(19.0%-67.9%)and CO(18.8%-58.9%)selectivity.In-situ Raman spectroscopy and valence band X-ray photoelectron spectroscopy(XPS)elucidate dual modulation mechanisms.Sn enhances CO desorption by weakening*CO adsorption,whereas La promotes ethylene formation through optimized CO absorption and dimerization.The tunability of the reaction pathways aligns with metal-dependent stabilization of critical intermediates(CO and*OCHO).This work introduces a nanoscale-depth and trace-level multi-elemental loading strategy with tunable ratios on copper electrodes,enabling precise electronic structure manipulation of Cu-based electrocatalysts to mechanistically elucidate the correlation between surface electronic states and product selectivity,offering a roadmap to design and modulate Cu-based catalysts for selective CO_(2)-to-chemical conversion and beyond via low-cost laser processing techniques.展开更多
Due to the strong magneto-elastic coupling in ferromagnetic/ferroelectric heterostructures and the potential applications in lowpower magnetoelectric nanodevices,ferroelastic domains and the corresponding dynamic evol...Due to the strong magneto-elastic coupling in ferromagnetic/ferroelectric heterostructures and the potential applications in lowpower magnetoelectric nanodevices,ferroelastic domains and the corresponding dynamic evolution under external stimuli have attracted intense research interest.Using pulsed laser deposition method,we have successfully grown layered-perovskite Bi_(2)WO_(6)thin films on SrTiO_(3)(001)substrates.Interestingly,for the as-grown thin films with step-flow morphology,the relationship between ferroelastic domain number and size shows a normal distribution,which is similar to the Boltzman distribution for confined gas molecules at equilibrium.In addition,with post-annealing,the thin films with as-grown island-like morphology can be optimized for layered morphology,and the initial small ferroelastic domains can grow into large domains.This study provides an effective strategy for ferroelastic domain engineering,which can be applied for the design of multiferroic heterostructures and low-power nanodevices.展开更多
Bi_(4)Br_(4)is a material rich in intriguing topological properties.Monolayer Bi_(4)Br_(4)film exhibits helical edge states characteristic of a quantum spin Hall insulator,while bulk Bi_(4)Br_(4)represents a higher-or...Bi_(4)Br_(4)is a material rich in intriguing topological properties.Monolayer Bi_(4)Br_(4)film exhibits helical edge states characteristic of a quantum spin Hall insulator,while bulk Bi_(4)Br_(4)represents a higher-order topological insulator with hinge states.However,direct exfoliation from single crystal can only obtain thin nanowires due to the weak van der Waals forces between Bi_(4)Br_(4)chains,which limits its optical analysis and application,while the growth of Bi_(4)Br_(4)thin films is also full of challenges due to the extremely narrow growth temperature range and the accurate control of the BiBr_(3)flux.Here,we reported the controlled growth ofα-Bi_(4)Br_(4)thin films on intrinsic silicon substrates using molecular beam epitaxy.The growth temperature,BiBr_(3)flux,and the flux ratio of Bi and BiBr_(3)were accurately controlled.Then,the morphology,composition,and bonding of the prepared films were investigated using atomic force microscopy,X-ray photoelectron spectroscopy and Raman spectroscopy.The growth of large,uniform thin films provides an ideal material platform for studying the physical properties of Bi_(4)Br_(4).Additionally,we utilized Fourier-transform infrared spectroscopy to explore the film’s infrared characteristics,revealing strong absorption in the low frequency range due to the high proportion of one-dimensional topological edge states and laying the groundwork for further exploration of its potential applications in the optoelectronic field.展开更多
Developing facile methods to construct hierarchical-structured transition metal phosphides is beneficial for achieving high-efficiency hydrogen evolution catalysts.Herein,a self-template strategy of hydrothermal treat...Developing facile methods to construct hierarchical-structured transition metal phosphides is beneficial for achieving high-efficiency hydrogen evolution catalysts.Herein,a self-template strategy of hydrothermal treatment of solid Ni-Co glycerate nanospheres followed by phosphorization is delivered to synthesize hierarchical Ni Co P hollow nanoflowers with ultrathin nanosheet assembly.The microstructure of Ni Co P can be availably tailored by adjusting the hydrothermal treatment temperature through affecting the hydrolysis process of Ni-Co glycerate nanospheres and the occurred Kirkendall effect.Benefitting from the promoted exposure of active sites and affluent mass diffusion routes,the HER performance of the Ni Co P hollow nanoflowers has been obviously enhanced in contrast with the solid Ni Co P nanospheres.The fabricated Ni Co P hollow nanoflowers yield the current density of 10 m A cmà2at small overpotentials of 95 and 127 m V in 0.5 mol Là1H2SO4and 1.0 mol Là1KOH solution,respectively.Moreover,the two-electrode alkaline cell assembled with the Ni Co P and Ir/C catalysts exhibits sustainable stability for overall water splitting.The work provides a simple but efficient method to regulate the microstructure of transition metal phosphides,which is helpful for achieving high-performance hydrogen evolution catalysts based on solid-state metal alkoxides.展开更多
An efficient and eco-friendly carbon nitride nanosheet(NM-g-C3N4)-catalyzed decarboxylative coupling reaction of imidazo-fused heterocycles(i.e.,imidazo[1,2-a]pyridines,benzo[d]imidazo[2,1-b]thiazole)with N-phenylglyc...An efficient and eco-friendly carbon nitride nanosheet(NM-g-C3N4)-catalyzed decarboxylative coupling reaction of imidazo-fused heterocycles(i.e.,imidazo[1,2-a]pyridines,benzo[d]imidazo[2,1-b]thiazole)with N-phenylglycines in dimethyl carbonate(DMC)has been developed.The toxic solvents,external oxidants,and restricted reaction conditions could be effectively avoided in this powerful and sustainable protocol.Remarkably,NM-g-C3N4 could be straightforwardly recovered by simple centrifugation and recycled and reused at least 7 times without an obvious decrease in catalytic activity.展开更多
Mimicking the nitric oxide(NO)-release and glycocalyx functions of native vascular endothelium on cardiovascular stent surfaces has been demonstrated to reduce in-stent restenosis(ISR)effectively.However,the practical...Mimicking the nitric oxide(NO)-release and glycocalyx functions of native vascular endothelium on cardiovascular stent surfaces has been demonstrated to reduce in-stent restenosis(ISR)effectively.However,the practical performance of such an endothelium-mimicking surfaces is strictly limited by the durability of both NO release and bioactivity of the glycocalyx component.Herein,we present a mussel-inspired amine-bearing adhesive coating able to firmly tether the NO-generating species(e.g.,Cu-DOTA coordination complex)and glycocalyx-like component(e.g.,heparin)to create a durable endothelium-mimicking surface.The stent surface was firstly coated with polydopamine(pDA),followed by a surface chemical cross-link with polyamine(pAM)to form a durable pAMDA coating.Using a stepwise grafting strategy,Cu-DOTA and heparin were covalently grafted on the pAMDA-coated stent based on carbodiimide chemistry.Owing to both the high chemical stability of the pAMDA coating and covalent immobilization manner of the molecules,this proposed strategy could provide 62.4%bioactivity retention ratio of heparin,meanwhile persistently generate NO at physiological level from 5.9±0.3 to 4.8±0.4×10^(-10) mol cm^(-2) min^(-1) in 1 month.As a result,the functionalized vascular stent showed long-term endothelium-mimicking physiological effects on inhibition of thrombosis,inflammation,and intimal hyperplasia,enhanced re-endothelialization,and hence efficiently reduced ISR.展开更多
Carbon-based nanomaterials,including carbon nanotubes,carbon nanospheres,and carbon nanofibers,are becoming a research hotspot due to their unique structure and good mechanical,thermal,electrical,optical,and chemical ...Carbon-based nanomaterials,including carbon nanotubes,carbon nanospheres,and carbon nanofibers,are becoming a research hotspot due to their unique structure and good mechanical,thermal,electrical,optical,and chemical properties.With the development of material synthesis technology,they can be functionalized and used in various fields such as energy,environment,and biomedicine.In particular,stimuli-responsive carbon-based nanomaterials have stood out in recent years because of their smart behavior.Researchers have applied carbon-based nanomaterials to different disease treatments based on their stimulus-response properties.In this paper,based on stimuli-responsive carbon-based nanomaterials’morphology,we categorize them into carbon nanotubes,carbon nanospheres,and carbon nanofibers according to their morphology.Then,their applications in probes,bioimaging,tumor therapy,and other fields are discussed.Finally,we address the advantages and disadvantages of carbon-based stimuliresponsive nanomaterials and discuss their future perspective.展开更多
InGaN nanowires (NWs) are grown on pyramid textured Si substrates by stationary plasma-assisted molecular beam epitaxy (PA-MBE). The incidence angles of the highly directional source beams vary for different pyramid f...InGaN nanowires (NWs) are grown on pyramid textured Si substrates by stationary plasma-assisted molecular beam epitaxy (PA-MBE). The incidence angles of the highly directional source beams vary for different pyramid facets, inducing a distinct inter-facet modulation of the In content of the InGaN NWs, which is verified by spatial element distribution analysis. The resulting multi-wavelength emission is confirmed by photoluminescence (PL) and cathodoluminescence (CL). Pure GaN phase formation dominates on certain facets, which is attributed to extreme local growth conditions, such as low active N flux. On the same facets, InGaN NWs exhibit a morphology change close to the pyramid ridge, indicating inter-facet atom migration. This cross-talk effect due to inter-facet atom migration is verified by a decrease of the inter-facet In content modulation amplitude with shrinking pyramid size. A detailed analysis of the In content variation across individual pyramid facets and element distribution line profiles reveals that the cross-talk effect originates mainly from the inter-facet atom migration over the convex pyramid ridge facet boundaries rather than the concave base line facet boundaries. This is understood by first-principles calculations showing that the pyramid baseline facet boundary acts as an energy barrier for atom migration, which is much higher than that of the ridge facet boundary. The influence of the growth temperature on the inter-facet In content modulation is also presented. This work gives deep insight into the composition modulation for the realization of multi-color light-emitting devices based on the monolithic growth of InGaN NWs on pyramid textured Si substrates.展开更多
基金supported by the National Natural Science Foundation of China(52475320).
文摘Here we fabricate LA103Z Mg-Li alloy via wire-arc directed energy deposition(WA-DED),and subsequent aging treatment is employed to improve its mechanical property.Results show that a typical dual-phase microstructure is formed upon WA-DED,consisting of α-Mg,β-Li,AlLi and Li_(2)MgAl,with negligible porosity,and the core-shell Li_(2)MgAl/AlLi composite particles are also generated.After aging treatment,the microstructure is slightly coarsened,together with the precipitation of nano-sized D0_(3)-Mg_(3)Al particles,as well as the dissolution and the mergence of α-Mg phases.Negligible strength and ductility anisotropies are found for the as-deposited alloy.Significant strength increment is achieved via aging treatment,and the ultimate strength increases by~20%(~34 MPa),reaching 200±1 MPa.Both as-deposited and aged alloys show acceptable uniform elongation,with a transgranular fracture mode.Precipitation strengthening enabled by nano-sized D0_(3)-Mg_(3)Al precipitates is primarily responsible for the strength increment mediated by aging treatment.Grain refinement strengthening and solid solution strengthening provide additional contributions to the improved strength.Our work thus offers an applicable additive manufacturing pathway for the efficient and safety-guaranteed fabrication of Mg-Li alloy components with decent mechanical property.
基金financially supported by the Beijing Natural Science Founding(No.2202050)the National Natural Science Foundation of China(No.21111120074).
文摘MXene,with metallic conductivity,strong hydrophilicity,and rich chemistries,has been widely used as electrode material for energy storage.However,the notorious issues of aggregation and oxidation for MXene significantly inhibit its electrochemical performance and further wide application.Herein,a physicochemical double protection strategy is proposed to stabilize MXene in the hydrothermal process effectively.Polyvinylpyrrolidone(PVP),with the structure of a long chain and abundant O/N function groups,provides physical protection against agglomeration(steric effect)and chemical protection against oxidation(electron transfer)at the same time,contributing to the synthesis of MXene-based hybrids with high conductivity and fully exposed active sites.As proof of the concept,2D MXene/Co_(9)S_(8) nanohybrids with a scaly surface are fabricated and present impressive performance,especially rate performance for hybrid supercapacitor(HSC)with MoS_(2) as the counter electrode.The HSC demonstrates a high energy density of 111 Wh kg^(-1) at 845 W kg^(-1) and an excellent rate performance of 61 Wh kg^(-1) at 16.9 kW kg^(-1).
基金supported by the National Key Research&Development Program of China(grant no.2022YFC3500503)the National Natural Science Foundation of China(grant nos.62227807,12374171,12004034,62402041)+2 种基金the Beijing Institute of Technology Research Fund Program for Young Scholars,Chinathe Fundamental Research Funds for the Central Universities(grant nos.2024CX06060)Beijing Youth Talent Lifting Project.
文摘Due to their high mechanical compliance and excellent biocompatibility,conductive hydrogels exhibit significant potential for applications in flexible electronics.However,as the demand for high sensitivity,superior mechanical properties,and strong adhesion performance continues to grow,many conventional fabrication methods remain complex and costly.Herein,we propose a simple and efficient strategy to construct an entangled network hydrogel through a liquid-metal-induced cross-linking reaction,hydrogel demonstrates outstanding properties,including exceptional stretchability(1643%),high tensile strength(366.54 kPa),toughness(350.2 kJ m^(−3)),and relatively low mechanical hysteresis.The hydrogel exhibits long-term stable reusable adhesion(104 kPa),enabling conformal and stable adhesion to human skin.This capability allows it to effectively capture high-quality epidermal electrophysiological signals with high signal-to-noise ratio(25.2 dB)and low impedance(310 ohms).Furthermore,by integrating advanced machine learning algorithms,achieving an attention classification accuracy of 91.38%,which will significantly impact fields like education,healthcare,and artificial intelligence.
基金funded by the Beijing Natural Science Foundation[Grant No.Z210006]the National Natural Science Foundation of China[Grant No.62275061].
文摘Nickel(II)as one of the primary categories of heavy metals can lead to serious health problems if achieving the critical levels in the water.Thus,it is vital to propose a stable,reliable,and economical approach for detecting Ni ions.The microfluidic paper-based analytical devices(µPADs)are potential candidates for the detection of water quality parameters including pH,heavy ions,nitrite and so on.However,it suffers from a huge error caused by the environment and artificial mistakes.In this study,we proposed an improved technique route to increase the stability and reliability of microfluidic paper-based analytical devices.The main technique points include a stable light source,a matched camera,improved reliability of the devices,and effective calculated methods.Finally,we established 15 standard curves that could be used to detect nickel ions and obtained uniform colorimetric results with reliability and repeatability.With those improvements,the relative errors for the five types of real water samples from the Zhongshan industrial parks were reduced to 0.26%,14.78%,24.20%,50.29%and 3.53%,respectively.These results were conducive to exploring this technique for the detection of nickel ions in wastewater from the Zhongshan industrial parks.The results demonstrated that the above technique route is promising for the detection of other heavy metal ions in industrial effluent.
基金supported by the Beijing Natural Science Foundation(No.2202050).
文摘MnO_(2)has emerged as one of the favored cathode materials for aqueous zinc ion batteries(AZIBs)due to its high theoretical capacity and abundant crystalline structures.However,MnO_(2)cathode generally suffers from poor electrical conductivity and rapid capacity degradation due to unavoidable manganese dissolution during cycling,limiting their further utilization.In this study,we modify the d-band center of Mn by introducing non-precious metal Bi atoms into the MnO_(2)system,thereby strengthening the Mn-O bonding to inhibit manganese dissolution.Theoretical calculations reveal that the d-band center of Mn in Bi-MnO_(2)shifts upward,promoting electron transfer from O 2p orbitals to Mn-O bonding orbitals.This enhances the Mn-O bond strength,stabilizing Mn atoms in the crystal lattice and reducing manganese solvation loss.As a result,the conductivity and cyclic stability of Bi-MnO_(2)are significantly improved.The results demonstrate that Bi-MnO_(2)exhibits outstanding electrochemical properties,with a capacity of 392.3 mAh g^(-1)after 100 cycles at 0.2 A g^(-1)and a capacity retention of 83.25%after 5000 cycles at 1.0 A g^(-1).This study presents a new approach to address the manganese dissolution issue,which could further advance the application of d-band center theory in MnO_(2)materials.
基金financially supported by the National Natural Science Foundation of China (21875112)the Natural Science Foundation of Jiangsu Province (BK20171473)+1 种基金support from the National and Local Joint Engineering Research Center of Biomedical Functional Materialsa project sponsored by the Priority Academic Program Development of Jiangsu Higher Education Institutions。
文摘Seeking for extremely active and durable bifunctional electrocatalysts towards the overall water splitting possesses a strategic significance on the development of sustainable and clean energy for the replacement of fossil fuels.Ir-based nanomaterials are deemed as one of the most highefficiency oxygen evolution reaction electrocatalysts while the hydrogen evolution reaction performance is unfavorable.In this work,we report a one-pot hydrothermal synthesis of N-doped graphene anchored Ir nanoparticles(Ir/N-rGO) with ultrasmall particle size(~2.0 nm).Apart from the predictably superior OER performance,the resultant Ir/N-rGO also displays excellent hydrogen evolution reaction(HER) performance,requiring merely 76 and 260 mV overpotentials to achieve the current density of 10 mA cm^(-2) towards HER and OER,respectively.When applied as the bifunctional electrodes for overall water splitting,Ir/N-rGO needs a lower overpotential(1.74 V) to achieve a current density of50 mA cm^(-2) in alkaline solution,exceeding that of Pt/C and RuO_(2) couple(1.85 V).Thus,the as-fabricated Ir/N-rGO has a commendable prospect in the practical application of alkaline water electrocatalysis.
基金supported by the Beijing Natural Science Founding (2202050)the Beijing Institute of Technology scientific cooperation project (BITBLR2020010)+1 种基金the National Nature Science Foundation of China (21111120074)the National Nature Science Foundation of China (20806008)。
文摘The development of potential transition-metal carbide/nitride heterojunctions is hindered by overall understanding and precise modulation for heterointerface effects.Herein,we demonstrate that Mo_(2)C/Mo_(2)N heterojunction with the precisely regulated high-quality interface can achieve marvelous rate performance and energy output via enlarging the interface-effect range and maximizing "accelerated charge" amount The heterointerface mechanism improving properties is synergistically revealed from kinetics and thermodynamics perspectives.Kinetics analysis confirms that the self-built electric field affords a robust force to drive rapid interface electrons/ions migration.The small adsorption energy,high density of states and quite low diffusion barrier thermodynamically enhance the electrochemical reaction dynamics on heterointerface.Consequently,the almost optimal performance of ultrahigh capacitance retention(85.6% even at 10 A g^(-1)) and pronounced energy output(96.4 Wh kg^(-1))in hybridsupercapacitors than other Mo_(2)C/Mo_(2)N-based materials is presented.This work gives new insight into the energy storage mechanism of heterojunction and guides the design of advanced electrodes.
基金supported by National Key R&D Program of China(No.2016YFC0203000)the National Natural Science Foundation of China(No.21503015)the Fundamental Research Funds for the Central Universities(Nos.22050205,2017CX01008)。
文摘Considering the importance and complexity of benzene oxidation on mineral oxide aerosol surfaces in the atmosphere,gas-phase 3 d-transition metal oxide cations were used as models of active sites on mineral oxide aerosols to mimic the corresponding reactions.The various cations have been prepared by laser ablation and reacted with benzene in a linear ion trap reactor.Of the 103 systematically investigated cations,39 clusters can oxidize benzene at room temperature.In addition to the adsorption channel,other five types of reaction channels were observed,including dehydrogenation of C6H6,charge exchange,hydrogen atom transfer,oxygen atom transfer,and the formation of C6H5O^+radical,among which the first two pathways are prevale nt and the formation of C6H6O^+cations has not been reported in literature.The insight into the benzene oxidation reactions derived from the gas-phase model systems is helpful to build a detailed picture of oxidative mechanisms of C6H6 and its derivatives over corresponding mineral oxide aerosols.
基金supported by the National Natural Science Foundation of China(No.32101153)the Fundamental Research Funds for the Central Universities(No.2021CX11018).
文摘Photoacoustic imaging(PAI)is a new biomedical imaging technology that provides a mixed contrast mechanism and excellent spatial resolution in biological tissues.It is a non-invasive technology that can provide in vivo anatomical and functional information.This technology has great application potential in microscopic imaging and endoscope system.In recent years,the devel-opment of micro electro mechanical system(MEMS)technology has promoted the improvement and miniaturization of the photoacoustic imaging system,as well as its preclinical and clinical appli-cations.This paper introduces the research progress of MEMS technology in photoacoustic micro-scope systems and the miniaturization of photoacoustic endoscope ultrasonic transducers,and points out the shortcomings of existing technology and the direction of future development.
基金Project supported by the Nanhu Scholars Program for Young Scholars of Xinyang Normal University
文摘The space-confined synthesis method has been an efficient way for the preparation of linear carbon chains.However,the large-scale preparation of linear carbon chains still faces many challenges due to the lack of methods for the large-scale synthesis of precursors,such as short carbon chains(polyynes),and regulation technology for the transport of reactants in one-dimensional space.Here,we report a facile method for the rapid preparation of polyynes in large quantities using a commercial laser marking machine.Spectroscopic characterizations show that a large number of polyynes,such as C_(8)H_(2),C_(10)H_(2),C_(12)H_(2),and C_(14)H_(2),can be produced by ablating the graphite plate immersed in the organic liquid using a laser marking machine.The results of in situ Raman spectroscopy investigation of C_(2n)H_(2)-filled single-walled carbon nanotubes further confirm that a variety of polyyne molecules are synthesized.Meanwhile,in situ Raman spectroscopy also shows that the local heating treatment can accelerate the filling process of C_(2n)H_(2)into one-dimensional channels.This work provides new insights into the study of linear carbon chains and space-confined synthesis methods.
基金supported by the National Natural Science Foundation of China(Nos.21203008,21975025,12274025)the Hainan Province Science and Technology Special Fund(Nos.ZDYF2021SHFZ232,ZDYF2023GXJS022)the Hainan Province Postdoctoral Science Foundation(No.300333)。
文摘The sulfide-based solid-state electrolytes(SEs)reactivity toward moisture and Li-metal are huge barriers that impede their large-scale manufactu ring and applications in all-solid-state lithium batteries(ASSLBs).Herein,we proposed an Al and O dual-doped strategy for Li_(3)PS_(4)SE to regulate the chemical/electrochemical stability of anionic PS_(4)^(3-)tetrahedra to mitigate structural hydrolysis and parasitic reactions at the SE/Li interface.The optimized Li_(3.08)A_(10.04)P_(0.96)S_(3.92)O_(0.08)SE presents the highestσLi+of 3.27 mS cm^(-1),which is~6.8 times higher than the pristine Li_(3)PS_(4)and excellently inhibits the structural hydrolysis for~25 min@25%humidity at RT.DFT calculations confirmed that the enhanced chemical stability was revealed to the intrinsically stable entities,e.g.,POS33-units.Moreover,Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)SE cycled stably in Li//Li symmetric cell over 1000 h@0.1 mA cm^(-2)/0.1 mA h cm^(-2),could be revealed to Li-Al alloy and Li_(2)Oat SE/Li interface impeding the growth of Li-dendrites during cycling.Resultantly,LNO@LCO/Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)/Li-In cell delivered initial discharge capacities of 129.8 mA h g^(-1)and 83.74%capacity retention over 300 cycles@0.2 C at RT.Moreover,the Li_(3.08)Al_(0.04)P_(0.96)S_(3.92)O_(0.08)SE presented>90%capacity retention over 200 and 300 cycles when the cell was tested with LiNi_(0.8)Co_(0.15)Al_(0.05)O_(2)(NCA)cathode material vs.5 and 10 mg cm^(-2)@RT.
基金supported by the National Natural Science Foundation of China(NSFC),Basic Sciences Center Program(Extreme Light Field Manufacturing,No.52488301)and NSFC General Program(No.52475425)the National Key R&D Program of China(No.2022YFB4601300)Aeronautical Science Fund(No.3030021252404).
文摘Elucidation of a physicochemical process on nanocatalysts,especially under continuously evolving conditions,is often heavily tool-driven because of technical challenges.Recently,ambient pressure X-ray photoelectron spectroscopy(APXPS)emerges as an emerging photon-in-electron-out technique in in-situ/operando analysis by bridging the pressure-gap between conventional ultra-high vacuum(UHV)and near ambient or even close to operating conditions,rendering the advancement of XPS from a UHV-based technique to a versatile and powerful tool that enables the specific probe of numerous events taking place at the gas–solid,liquid–solid and liquid–gas nanoscale interfaces which are critical to nanocatalysis research.For example,APXPS probes information on catalytically active phase and reaction kinetics in nanocatalytic processes;details inside the electric double-layer at an electrolyte/electrode interface can now be accessed;more efficient nanocatalyst design can be achieved and energy transfer venues can be optimized.Here,we aim to critically review the recent advances in instrumentation and the probe of the gas–solid,liquid–solid,and gas–liquid nanoscale interfaces using APXPS-based methodologies,followed by putting forward an outlook of development of APXPS as a rising in-situ/operando analytical means in surface science,nanocatalysis,nanoscience materials science.
基金supported by the National Key R&D Program of China(No.2022YFB4601300)Aeronautical Science Fund(No.3030021252404)+2 种基金the National Natural Science Foundation of China(NSFC,No.52475425)the NSFC Basic Sciences Center Program(Extreme Light Field Manufacturing,No.52488301)We thank the Analytical&Testing Center of Beijing Institute of Technology for providing XPS and valence band measurements.We thank the BL02B01 and BL01B Beamlines at Shanghai Synchrotron Radiation Facility(SSRF),supported by the NSFC(No.11227902),for photoelectron spectroscopy and vibrational spectroscopy studies.We thank the support from beamline BL11U and BL10B at the National Synchrotron Radiation Laboratory(NSRL)in Hefei,China,for the synchrotron radiation and X-ray spectroscopic measurements.
文摘The electrochemical conversion of CO_(2) into value-added chemicals presents an environmentally sustainable alternative to conventional fossil-derived processes,yet achieving high selectivity remains challenging due to competing reaction pathways.Here,we demonstrate precise tuning of CO_(2) electroreduction pathways through femtosecond laser-driven surface doping of Cu with targeted metals,achieving Faradaic efficiencies of 58.9%for CO,67.9%for formate,and 37.8%for ethylene.This spatially shaping laser technique enables nanoscale deposition of any metal(including Sb,Sn,Re,La,In,Co,Ni,Ag,and Pt)onto Cu foil,forming compositionally graded Cu-based bimetallic surfaces with controlled atomic ratios.Systematic electronic structure analysis reveals that secondary metals induce d-band center shifts spanning−0.21 to+0.78 eV,governing intermediate adsorption energetics-upward shifts strengthen*CO binding via enhanced back-donation,while downward shifts generally weaken adsorbate interactions.Through precise control of Cu/Sn and Cu/Sb atomic ratios,we manipulate electronic structures of CuSn and CuSb catalysts and consequently demonstrate continuous tuning of formate(19.0%-67.9%)and CO(18.8%-58.9%)selectivity.In-situ Raman spectroscopy and valence band X-ray photoelectron spectroscopy(XPS)elucidate dual modulation mechanisms.Sn enhances CO desorption by weakening*CO adsorption,whereas La promotes ethylene formation through optimized CO absorption and dimerization.The tunability of the reaction pathways aligns with metal-dependent stabilization of critical intermediates(CO and*OCHO).This work introduces a nanoscale-depth and trace-level multi-elemental loading strategy with tunable ratios on copper electrodes,enabling precise electronic structure manipulation of Cu-based electrocatalysts to mechanistically elucidate the correlation between surface electronic states and product selectivity,offering a roadmap to design and modulate Cu-based catalysts for selective CO_(2)-to-chemical conversion and beyond via low-cost laser processing techniques.
基金supported by the NSF of China(Grant No.12004036)State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KFZD202201).
文摘Due to the strong magneto-elastic coupling in ferromagnetic/ferroelectric heterostructures and the potential applications in lowpower magnetoelectric nanodevices,ferroelastic domains and the corresponding dynamic evolution under external stimuli have attracted intense research interest.Using pulsed laser deposition method,we have successfully grown layered-perovskite Bi_(2)WO_(6)thin films on SrTiO_(3)(001)substrates.Interestingly,for the as-grown thin films with step-flow morphology,the relationship between ferroelastic domain number and size shows a normal distribution,which is similar to the Boltzman distribution for confined gas molecules at equilibrium.In addition,with post-annealing,the thin films with as-grown island-like morphology can be optimized for layered morphology,and the initial small ferroelastic domains can grow into large domains.This study provides an effective strategy for ferroelastic domain engineering,which can be applied for the design of multiferroic heterostructures and low-power nanodevices.
基金supported by the National Natural Science Foundation of China(Grant No.62275061,12321004,12274030,11704075)the Beijing Natural Science Foundation(Grant No.Z210006)the National Key Research and Development Program of China(Grant No.2020YFA0308800,2022YFA1403400).
文摘Bi_(4)Br_(4)is a material rich in intriguing topological properties.Monolayer Bi_(4)Br_(4)film exhibits helical edge states characteristic of a quantum spin Hall insulator,while bulk Bi_(4)Br_(4)represents a higher-order topological insulator with hinge states.However,direct exfoliation from single crystal can only obtain thin nanowires due to the weak van der Waals forces between Bi_(4)Br_(4)chains,which limits its optical analysis and application,while the growth of Bi_(4)Br_(4)thin films is also full of challenges due to the extremely narrow growth temperature range and the accurate control of the BiBr_(3)flux.Here,we reported the controlled growth ofα-Bi_(4)Br_(4)thin films on intrinsic silicon substrates using molecular beam epitaxy.The growth temperature,BiBr_(3)flux,and the flux ratio of Bi and BiBr_(3)were accurately controlled.Then,the morphology,composition,and bonding of the prepared films were investigated using atomic force microscopy,X-ray photoelectron spectroscopy and Raman spectroscopy.The growth of large,uniform thin films provides an ideal material platform for studying the physical properties of Bi_(4)Br_(4).Additionally,we utilized Fourier-transform infrared spectroscopy to explore the film’s infrared characteristics,revealing strong absorption in the low frequency range due to the high proportion of one-dimensional topological edge states and laying the groundwork for further exploration of its potential applications in the optoelectronic field.
基金supported by the National Natural Science Foundation of China (21573083)the Fundamental Research Funds for the Central Universities (2019kfy RCPY100)
文摘Developing facile methods to construct hierarchical-structured transition metal phosphides is beneficial for achieving high-efficiency hydrogen evolution catalysts.Herein,a self-template strategy of hydrothermal treatment of solid Ni-Co glycerate nanospheres followed by phosphorization is delivered to synthesize hierarchical Ni Co P hollow nanoflowers with ultrathin nanosheet assembly.The microstructure of Ni Co P can be availably tailored by adjusting the hydrothermal treatment temperature through affecting the hydrolysis process of Ni-Co glycerate nanospheres and the occurred Kirkendall effect.Benefitting from the promoted exposure of active sites and affluent mass diffusion routes,the HER performance of the Ni Co P hollow nanoflowers has been obviously enhanced in contrast with the solid Ni Co P nanospheres.The fabricated Ni Co P hollow nanoflowers yield the current density of 10 m A cmà2at small overpotentials of 95 and 127 m V in 0.5 mol Là1H2SO4and 1.0 mol Là1KOH solution,respectively.Moreover,the two-electrode alkaline cell assembled with the Ni Co P and Ir/C catalysts exhibits sustainable stability for overall water splitting.The work provides a simple but efficient method to regulate the microstructure of transition metal phosphides,which is helpful for achieving high-performance hydrogen evolution catalysts based on solid-state metal alkoxides.
基金the financial support from the National Natural Science Foundation of China(Nos.21971224,22171249)the Natural Science Foundation of Henan Provinee,China(No.202300410375)the College Students'Innovation and Entre-preneurship Training Program of Zhengzhou University(No.2021cxcy197).
文摘An efficient and eco-friendly carbon nitride nanosheet(NM-g-C3N4)-catalyzed decarboxylative coupling reaction of imidazo-fused heterocycles(i.e.,imidazo[1,2-a]pyridines,benzo[d]imidazo[2,1-b]thiazole)with N-phenylglycines in dimethyl carbonate(DMC)has been developed.The toxic solvents,external oxidants,and restricted reaction conditions could be effectively avoided in this powerful and sustainable protocol.Remarkably,NM-g-C3N4 could be straightforwardly recovered by simple centrifugation and recycled and reused at least 7 times without an obvious decrease in catalytic activity.
基金This work was supported by the National Natural Science Foundation of China(Project 82072072)International Cooperation Project by Science and Technology Department of Sichuan Province(2021YFH0056,2019YFH0103)the Fundamental Research Funds for the Central Universities(2682020ZT82,2682020ZT76).
文摘Mimicking the nitric oxide(NO)-release and glycocalyx functions of native vascular endothelium on cardiovascular stent surfaces has been demonstrated to reduce in-stent restenosis(ISR)effectively.However,the practical performance of such an endothelium-mimicking surfaces is strictly limited by the durability of both NO release and bioactivity of the glycocalyx component.Herein,we present a mussel-inspired amine-bearing adhesive coating able to firmly tether the NO-generating species(e.g.,Cu-DOTA coordination complex)and glycocalyx-like component(e.g.,heparin)to create a durable endothelium-mimicking surface.The stent surface was firstly coated with polydopamine(pDA),followed by a surface chemical cross-link with polyamine(pAM)to form a durable pAMDA coating.Using a stepwise grafting strategy,Cu-DOTA and heparin were covalently grafted on the pAMDA-coated stent based on carbodiimide chemistry.Owing to both the high chemical stability of the pAMDA coating and covalent immobilization manner of the molecules,this proposed strategy could provide 62.4%bioactivity retention ratio of heparin,meanwhile persistently generate NO at physiological level from 5.9±0.3 to 4.8±0.4×10^(-10) mol cm^(-2) min^(-1) in 1 month.As a result,the functionalized vascular stent showed long-term endothelium-mimicking physiological effects on inhibition of thrombosis,inflammation,and intimal hyperplasia,enhanced re-endothelialization,and hence efficiently reduced ISR.
基金the National Natural Science Foundation of China(32101153).
文摘Carbon-based nanomaterials,including carbon nanotubes,carbon nanospheres,and carbon nanofibers,are becoming a research hotspot due to their unique structure and good mechanical,thermal,electrical,optical,and chemical properties.With the development of material synthesis technology,they can be functionalized and used in various fields such as energy,environment,and biomedicine.In particular,stimuli-responsive carbon-based nanomaterials have stood out in recent years because of their smart behavior.Researchers have applied carbon-based nanomaterials to different disease treatments based on their stimulus-response properties.In this paper,based on stimuli-responsive carbon-based nanomaterials’morphology,we categorize them into carbon nanotubes,carbon nanospheres,and carbon nanofibers according to their morphology.Then,their applications in probes,bioimaging,tumor therapy,and other fields are discussed.Finally,we address the advantages and disadvantages of carbon-based stimuliresponsive nanomaterials and discuss their future perspective.
基金This work was supported by the Program for Chang Jiang Scholars and Innovative Research Teams in Universities(No.IRT_17R40)Science and Technology Program of Guangzhou(No.2019050001)+1 种基金the Guangdong Provincial Key Laboratory of Optical Information Materials and Technology(No.2017B030301007)MOE International Laboratory for Optical Information Technologies,the 111 Project,and the National Natural Science Foundation of China(No.51907171).
文摘InGaN nanowires (NWs) are grown on pyramid textured Si substrates by stationary plasma-assisted molecular beam epitaxy (PA-MBE). The incidence angles of the highly directional source beams vary for different pyramid facets, inducing a distinct inter-facet modulation of the In content of the InGaN NWs, which is verified by spatial element distribution analysis. The resulting multi-wavelength emission is confirmed by photoluminescence (PL) and cathodoluminescence (CL). Pure GaN phase formation dominates on certain facets, which is attributed to extreme local growth conditions, such as low active N flux. On the same facets, InGaN NWs exhibit a morphology change close to the pyramid ridge, indicating inter-facet atom migration. This cross-talk effect due to inter-facet atom migration is verified by a decrease of the inter-facet In content modulation amplitude with shrinking pyramid size. A detailed analysis of the In content variation across individual pyramid facets and element distribution line profiles reveals that the cross-talk effect originates mainly from the inter-facet atom migration over the convex pyramid ridge facet boundaries rather than the concave base line facet boundaries. This is understood by first-principles calculations showing that the pyramid baseline facet boundary acts as an energy barrier for atom migration, which is much higher than that of the ridge facet boundary. The influence of the growth temperature on the inter-facet In content modulation is also presented. This work gives deep insight into the composition modulation for the realization of multi-color light-emitting devices based on the monolithic growth of InGaN NWs on pyramid textured Si substrates.
