The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporat...The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was reported.Outstanding hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mV at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) samples.In the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co sites.It was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 V at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting voltage.It was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation.展开更多
Developing dynamic color-tunable ultra-long room temperature phosphorescence(URTP)polymers with afterglow of over 1 s,photo-chromism,and multi-stimuli response for practical anti-counterfeiting and information securit...Developing dynamic color-tunable ultra-long room temperature phosphorescence(URTP)polymers with afterglow of over 1 s,photo-chromism,and multi-stimuli response for practical anti-counterfeiting and information security applications is attractive but very challenging.Herein,by doping multicolor phosphorescence pyri-dinium bromide L block or viologen-based photo-chromic V block into polyvinyl alcohol matrixes,the water-stimuli-responsive color-tunable URTP polymerfilms with afterglow of up to 8 s and the reversible viologen-based photochromic polymerfilms have been developed.More significantly,a series of dynamic color-tunable URTP polymerfilms with ultra-long afterglow of over 6 s,photo-chromism,and water-stimuli response have been successfully exploited by integrating L and V blocks into one polymer system.Mechanistic investigations have revealed that their photo-chromism mainly comes from the photo-generated viologen free radicals.Furthermore,their dynamic multilevel anti-counterfeiting applications have been demonstrated.These results pave the way to develop smarter multifunctional URTP materials for anti-counterfeiting and optical sensing.展开更多
A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the mai...A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs.In this work,we adopted a solid-liquid two-step film formation technique,which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films.This method possesses the advantages of integrating vapor deposition and solution methods,which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform,large-area perovskite film.Furthermore,modification of the NiO_(x)/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization.As a result,a large-area perovskite film possessing larger grains,fewer pinholes,and reduced defects could be achieved.The inverted PSM with an active area of 61.56 cm^(2)(10×10 cm^(2)substrate)achieved a champion power conversion efficiency of 20.56%and significantly improved stability.This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.展开更多
In the present work,multi walled carbon nanotubes(MWCNT)reinforced magnesium(Mg)matrix composite was fabricated by friction stir processing(FSP)with an aim to explore its mechanical and electrochemical behavior.Micros...In the present work,multi walled carbon nanotubes(MWCNT)reinforced magnesium(Mg)matrix composite was fabricated by friction stir processing(FSP)with an aim to explore its mechanical and electrochemical behavior.Microstructural observations showed that the thickness of the produced composite layer was in the range of 2500μm.FSP resulted uniform distribution of CNT near the surface while agglomerated layers in the subsurface.Grain refinement of Mg achieved by FSP improved the hardness but significant enhancement in the hardness value was observed for FSPed MWCNT/Mg composites.Potentiodynamic polarization studies revealed that the increase in corrosion current density was observed for MWCNT/Mg composite compared with grain refined Mg and pure Mg,implying the significance of secondary phase(MWCNT)in decreasing the corrosion resistance of the composite.展开更多
Electrocatalytic water splitting for hydrogen production is hampered by the sluggish oxygen evolution reaction(OER)and large power consumption and replacing the OER with thermodynamically favourable reactions can impr...Electrocatalytic water splitting for hydrogen production is hampered by the sluggish oxygen evolution reaction(OER)and large power consumption and replacing the OER with thermodynamically favourable reactions can improve the energy conversion efficiency.Since iron corrodes easily and even self-corrodes to form magnetic iron oxide species and generate corrosion currents,a novel strategy to integrate the hydrogen evolution reaction(HER)with waste Fe upgrading reaction(FUR)is proposed and demonstrated for energy-efficient hydrogen production in neutral media.The heterostructured MoSe_(2)/MoO_(2) grown on carbon cloth(MSM/CC)shows superior HER performance to that of commercial Pt/C at high current densities.By replacing conventional OER with FUR,the potential required to afford the anodic current density of 10 m A cm^(-2)decreases by 95%.The HER/FUR overall reaction shows an ultralow voltage of 0.68 V for 10 m A cm^(-2)with a power equivalent of 2.69 k Wh per m^(3)H_(2).Additionally,the Fe species formed at the anode extract the Rhodamine B(Rh B)pollutant by flocculation and also produce nanosized magnetic powder and beneficiated Rh B for value-adding applications.This work demonstrates both energy-saving hydrogen production and pollutant recycling without carbon emission by a single system and reveals a new direction to integrate hydrogen production with environmental recovery to achieve carbon neutrality.展开更多
Facile deposition of a water-splitting catalyst on low-cost electrode materials could be attractive for hydrogen production from water and solar energy conversion. Herein we describe fast electrodeposition of cobalt-b...Facile deposition of a water-splitting catalyst on low-cost electrode materials could be attractive for hydrogen production from water and solar energy conversion. Herein we describe fast electrodeposition of cobalt-based water oxidation catalyst （Co-WOC） on simple graphite electrode for water splitting, The deposition process is quite fast, which reaches a plateau in less than 75 min and the final ctLrrent density is -1.8 mA/cm2 under the applied potential of 1.31 V at pH --7.0. The scanning electron microscopy （SEM） study shows the formation of nanometer-sized particles （10-100 nm） on the surface of the electrode after only 2 min and micrometer-sized particles （2-5/zm） after 90 rain of electrolysis. X-ray photoelectron spectroscopy （XPS） data demonstrate the as-synthesized ex-situ catalyst mainly contains Co2＋ and Co3＋ species incorporating a substantial amount of phosphate anions. These experiments suggest that cost-efficient cobalt oxide materials on graphite exhibit alluring ability for water splitting, which might provide a novel method to fabricate low-cost devices for electrochemical energy storage.展开更多
Developing an efficient freshwater and electricity co-generation device(FECGD)can solve the shortage of freshwater and electricity.However,the poor salt resistance and refrigeration properties of the materials for FEC...Developing an efficient freshwater and electricity co-generation device(FECGD)can solve the shortage of freshwater and electricity.However,the poor salt resistance and refrigeration properties of the materials for FECGD put big challenges in the efficient and stable operation of these devices.To address these issues,we propose the covalent organic framework(COF)confined co-polymerization strategy to prepare COF-modified acrylamide cationic hydrogels(ACH-COF),where hydrogen bonding interlocking between negatively charged polymer chains and COF pores can form a salt resistant hydrogel for stabilizing tunable passive interfacial cooling(TPIC).The FECPDs based on the TPIC and salt resistance of ACH-COF display a maximum output power density of 2.28 W m-2,which is 4.3 times higher than that of a commercial thermoelec-tric generator under one solar radiation.The production rate of freshwater can reach 2.74 kg m-2 h-1.Our results suggest that the high efficiency and scala-bility of the FECGD can hold the promise of alleviating freshwater and power shortages.展开更多
Photocatalysis has been a research hotspot in recent years,and the design and modification of photocat-alysts have been the key points.Common methods for designing photocatalysts,including constructing heterojunctions...Photocatalysis has been a research hotspot in recent years,and the design and modification of photocat-alysts have been the key points.Common methods for designing photocatalysts,including constructing heterojunctions and homojunctions,have been developed on the basis of heterojunctions.In this study,two homojunctions of manganese dioxide(MnO_(2)),including a high-index crystal plane homojunction and a general homojunction,are prepared using a stepwise hydrothermal method.Using a capping agent,the high-index crystal surface of the MnO_(2)is exposed.It is found that the electron transport efficiency be-tween the two components of the homojunction with high-index planes is higher and the adsorption capacity of the oxygen is stronger,which leads to higher photocatalytic efficiency.In addition,the newly designed high-index homojunction is used for the treatment of bacterial infections,and it kills Staphy-lococcus aureus(S.aureus)and Escherichia coli(E.coli)at rates of 99.95%±0.04%and 99.31%±0.25%,respectively.It also has excellent therapeutic effects on mouse wounds,which implies superb practical application value.This work provides a new strategy for the improved design of homojunctions and the application of photocatalytic materials.展开更多
Different forms of construction materials(e.g.,paints,foams,and boards)dramatically improve the quality of life.With the increasing environmental requirements for buildings,it is necessary to develop a comprehensive s...Different forms of construction materials(e.g.,paints,foams,and boards)dramatically improve the quality of life.With the increasing environmental requirements for buildings,it is necessary to develop a comprehensive sustainable construction material that is flexible in application and exhibits excellent performance,such as fireproofing and thermal insulation.Herein,an adjustable multiform material strategy by water regulation is proposed to meet the needs of comprehensive applications and reduce environmental costs.Multiform gels are constructed based on multiscale cellulose fibers and hollow glass microspheres,with fireproofing and thermal insulation.Unlike traditional materials,this multiscale cellulose-based gel can change forms from dispersion to paste to dough by adjusting its water content,which can realize various construction forms,including paints,foams,and low-density boards according to different scenarios and corresponding needs.展开更多
A 3D structured composite of carbon nanofibers @ MnO2 on copper foil is reported here as a binder free anode of lithium ion batteries, with high capacity, fast charge/discharge rate and good stability. Carbon nanofibe...A 3D structured composite of carbon nanofibers @ MnO2 on copper foil is reported here as a binder free anode of lithium ion batteries, with high capacity, fast charge/discharge rate and good stability. Carbon nanofiber yarns were synthesized directly over copper foil through a floating catalyst method. The growth of carbon nanofiber yarns was significantly enhanced by mechanical polishing of the copper foils, which can be attributed to the increased surface roughness and surface area of the copper foils. MnO2 was then grown over carbon nanofibers through spontaneous reduction of potassium permanganate by the carbon nanofibers. The obtained composites of carbon nanofibers@MnO2 over copper foil were tested as an anode in lithium ion batteries and they show superior electrochemical performance. The initial reversible capacity of carbon nanofibers@MnO2 reaches up to around 998 mAh.g-1 at a rate of 60 mmA.g-l based on the mass of carbon nanofibers and MnO2. The carbon nanofibers @ MnO2 electrodes could deliver a capacity of 630 mAh.g-1 at the beginning and maintain a capacity of 440 mmAh.g-1 after 105 cycles at a rate of 600 mA.g-~. The high initial capacity can be attributed to the presence of porous carbon nanofiber yarns which have good electrical conductivity and the MnO2 thin film which makes the entire materials electrochemically active. The high cyclic stability of carbon nanofibers@MnO2 can be ascribed to the MnO2 thin film which can accommodate the volume expansion and shrinking during charge and discharge and the good contact of carbon nanofibers with MnO2 and copper foil.展开更多
Internal friction of nanocrystalline nickel is investigated by mechanical spectroscopy from 360 K to 120 K. Two relaxation peaks are found when nanocrystalline nickel is bent up to 10% strain at room temperature and f...Internal friction of nanocrystalline nickel is investigated by mechanical spectroscopy from 360 K to 120 K. Two relaxation peaks are found when nanocrystalline nickel is bent up to 10% strain at room temperature and fast cooling. However, these two peaks disappear when the sample is annealed at room temperature in vacuum for ten days. The occurrence and disappearance of the two relaxation peaks can be explained by the interactions of partial dislocations and point defects in nanocrystalline materials.展开更多
The synchronous construction of metal phosphate and phosphorus-doped carbon structures is of great significance to innovate the design,synthesis,and application of catalysts,as these phosphoruscontaining composite mat...The synchronous construction of metal phosphate and phosphorus-doped carbon structures is of great significance to innovate the design,synthesis,and application of catalysts,as these phosphoruscontaining composite materials have shown a remarkable contribution to electrocatalysts.However,their preparation procedure generally involves using large amounts of excess phosphorus sources for phosphorization,which inevitably release poisonous PH_(3) or dangerous phosphorus vapor.Here,a strategy for in-situ formation of FePO_(4) embedded in P-doped carbon 2D nano film(FePO_(4)/PdC)is developed using a highly integrated precursor,which is a small molecular organophosphine ligand,1,1’bis(diphenylphosphine)ferrocene(DPPF).The multi-source precursor DPPF that contains Fe,P,and C is molecular-vapor-deposited on the nickel foam(NF)supported ZIF-67 nanosheets to obtain the composite catalyst,namely DPPF-500/ZIF-67/NF.FePO_(4)/PdC encapsulated the ZIF-67 derived Co/N-doped carbon matrix(Co NC)to form a sandwich structure FePO_(4)/PdC@CoNC.The constructed catalyst shows good performance for OER,requiring an overpotential of only 297 m V to deliver 600 m A/cm^(2) with a Tafel slope of 42.7 m V dec^(-1).DFT calculations demonstrate that the synergistic effects between the metal active center and P-doped carbon film reduce the energy barriers and improve electron transport.This method of constructing P-containing catalysts overcomes the demand for additional P sources to realize eco-friendly fabrication and yields a unique structure with good catalytic activity.展开更多
Electrospun nanofibers(NFs)have shown excellent properties including high porosity,abundant active sites,controllable diameter,uniform and designable structure,high mechanical strength,and superior resistance to exter...Electrospun nanofibers(NFs)have shown excellent properties including high porosity,abundant active sites,controllable diameter,uniform and designable structure,high mechanical strength,and superior resistance to external destruction,which are ideal nanoreactors for in situ characterizations.Among various techniques,in situ transmission electron microscopy(TEM)has enabled operando observation at the atomic level due to its high temporal and spatial resolution combined with excellent sensitivity,which is of great importance for rational materials design and performance improvement.In this review,the basic knowledge of in situ TEM techniques and the advantages of electrospun nanoreactors for in situ TEM characterization are first introduced.The recent development in electrospun nanoreactors for studying the physical properties,structural evolution,phase transition,and formation mechanisms of materials using in situ TEM is then summarized.The electrochemical behaviors of carbon nanofibers(CNFs),metal/metal oxide NFs,and solidelectrolyte interphase for different rechargeable batteries are highlighted.Finally,challenges faced by electrospun nanoreactors for in situ TEM characterization are discussed and potential solutions are proposed to advance this field.展开更多
The controlled introduction of elastic strains is an appealing strategy for modulating the physical properties of semiconductor materials.With the recent discovery of large elastic deformation in nanoscale specimens a...The controlled introduction of elastic strains is an appealing strategy for modulating the physical properties of semiconductor materials.With the recent discovery of large elastic deformation in nanoscale specimens as diverse as silicon and diamond,employing this strategy to improve device performance necessitates first-principles computations of the fundamental electronic band structure and target figures-of-merit,through the design of an optimal straining pathway.Such simulations,however,call for approaches that combine deep learning algorithms and physics of deformation with band structure calculations to custom-design electronic and optical properties.Motivated by this challenge,we present here details of a machine learning framework involving convolutional neural networks to represent the topology and curvature of band structures in k-space.These calculations enable us to identify ways in which the physical properties can be altered through“deep”elastic strain engineering up to a large fraction of the ideal strain.Algorithms capable of active learning and informed by the underlying physics were presented here for predicting the bandgap and the band structure.By training a surrogate model with ab initio computational data,our method can identify the most efficient strain energy pathway to realize physical property changes.The power of this method is further demonstrated with results from the prediction of strain states that influence the effective electron mass.We illustrate the applications of the method with specific results for diamonds,although the general deep learning technique presented here is potentially useful for optimizing the physical properties of a wide variety of semiconductor materials。展开更多
As a renewable,biocompatible,biodegradable soft material,chitin hydrogels have better advantages in stability,antibacterial activity,antifouling,cost,immunogenicity,and so on than most polymer hydrogels.However,compar...As a renewable,biocompatible,biodegradable soft material,chitin hydrogels have better advantages in stability,antibacterial activity,antifouling,cost,immunogenicity,and so on than most polymer hydrogels.However,compared with other widely used polymer hydrogels with high strength and toughness,the practical applications of chitin-based hydrogels have been limited by their weak mechanical properties,such as cartilage repair and meniscus replacement.Here,we present the design and fabrication of chitin hydrogels with excellent mechanical strength and toughness by a dehydration and rehydration strategy.By sequential dehydration and rehydration processes,the crystalline domains in the chitin hydrogels can be properly controlled.With optimized crystallinity,the elastic modulus of the chitin hydrogels exceeds all previously reported values,and the fracture toughness is even comparable to some synthetic polymer hydrogels,while maintaining a high-water-content of about 80 wt.%.At the same water content,the mechanical properties of the chitin hydrogels are positively correlated with the hydrogel crystallinity,which proves that the change of mechanical properties of hydrogels is not simply dependent on weight concentration.The hydrogels can be further strengthened by incorporating other biopolymers that are intrinsically weak,which makes the hydrogels promising for applications in fields such as cartilage repair and meniscus replacement.Moreover,the hydrogels enable loading and release of water-soluble and poorly water-soluble drugs.This highly extendable strengthening and toughening strategy of chitin and chitin-based biopolymer hydrogels paves the way for their widely applications.展开更多
Although Ni-Ti-O nanopores(NPs) can be fabricated by anodization of mechanically polished NiTi alloys, the top disordered layer is difficult to remove thus hindering the functionality of the Ni-Ti-O NPs. In this work,...Although Ni-Ti-O nanopores(NPs) can be fabricated by anodization of mechanically polished NiTi alloys, the top disordered layer is difficult to remove thus hindering the functionality of the Ni-Ti-O NPs. In this work, an electropolishing(EP) pretreatment was performed on the NiTi substrate prior to anodization to thoroughly expose the NPs. Our results show that the EP pretreatment for 5 min perfectly removes the top disordered layer on the Ni-Ti-O NPs to expose the underlying NPs and consequently, the corrosion resistance and antibacterial ability are enhanced. The exposed NPs can elongate bone marrow mesenchymal stem cells, which may be responsible for the upregulated alkaline phosphatase activity, secretion of Type I collagen, and extracellular matrix mineralization. These results suggest that EP is a desirable pretreatment before anodization of the NiTi alloys because the irregular surface layer on the Ni-Ti-O NPs can be removed to enhance the corrosion resistance and biological functions.展开更多
Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large sur...Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors.Herein,we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes(Co3O4/NCNTs)hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air.The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions.As sensor electrode,the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40μA(mmol/L)^-1 cm^-2,a linear range of 5.00μmol/L-11.00 mmol/L,and a detection limitation of 1μmol/L in H2O2 detection,and a good glucose detection performance with 5μmol/L.These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.展开更多
The effects of dual Zr and O plasma immersion ion implantation(Zr&O PIII)on antibacterial properties of ZK60 Mg alloys are systematically investigated.The results show that a hydrophobic,smooth,and ZrO_(2)-contain...The effects of dual Zr and O plasma immersion ion implantation(Zr&O PIII)on antibacterial properties of ZK60 Mg alloys are systematically investigated.The results show that a hydrophobic,smooth,and ZrO_(2)-containing graded film is formed.Electrochemical assessment shows that the corrosion rate of the plasma-treated Mg alloy decreases and the decreased degradation rate is attributed to the protection rendered by the surface oxide.In vitro and in vivo antibacterial tests reveal Zr&O PIII ZK60 presents higher antibacterial rate compared to Zr PIII ZK60 and untreated control.The hydrophobic and smooth surface suppresses bacterial adhesion.High concentration of oxygen vacancies in the surface films are determined by X-ray photoelectron spectroscopy(XPS),UV-vis diffuse reflectance spectra(UV-vis DRS)and electron paramagnetic resonance(EPR)and involved in the production of reactive oxygen species(ROS).The higher level of ROS expression inhibits biofilm formation by down-regulating the expression of icaADBC genes but up-regulating the expression of icaR gene.In addition,Zr&O PIII improves cell viability and initial cell adhesion confirming good cytocompatibility.Dual Zr&O PIII is a simple and practical means to expedite clinical acceptance of biodegradable magnesium alloys.展开更多
An investigation on the oxidation mechanism of the graphite in the MgO-C refractory materials is helpful to improving both the quality of these materials and to preventing and/or lowering of the adverse effects of the...An investigation on the oxidation mechanism of the graphite in the MgO-C refractory materials is helpful to improving both the quality of these materials and to preventing and/or lowering of the adverse effects of the high-temperature oxidation. In this research, the oxidation behavior of the MgO-C refractories containing 5～20 wt% graphite was studied via weight-loss method. Atmospheric air was used for oxidation at temperatures ranging from 900℃ to 1300°C and the experimental data were compared with those obtained from the dimensionless kinetic equations of the shrinking core model, in order to determine the oxidation mechanisms of the refractories. The best fit was achieved with the porous layer diffusion control regime. Oxidation mechanism tends, however, to slightly deviate from pure pore diffusion control to pore diffusion-external gas transfer regime in the samples having more graphite contents (e.g. 20%).展开更多
It is often advantageous to display material properties relationships in the form of charts that highlight important correlations and thereby enhance our understanding of materials behavior and facilitate materials se...It is often advantageous to display material properties relationships in the form of charts that highlight important correlations and thereby enhance our understanding of materials behavior and facilitate materials selection.Unfortunately,in many cases,these correlations are highly multidimensional in nature,and one typically employs low-dimensional cross-sections of the property space to convey some aspects of these relationships.To overcome some of these difficulties,in this work we employ methods of data analytics in conjunction with a visualization strategy,known as parallel coordinates,to represent better multidimensional materials data and to extract useful relationships among properties.We illustrate the utility of this approach by the construction and systematic analysis of multidimensional materials properties charts for metallic and ceramic systems.These charts simplify the description of high-dimensional geometry,enable dimensional reduction and the identification of significant property correlations and underline distinctions among different materials classes.展开更多
基金the financial support of the Doctoral Research Initiation Foundation of Linyi University(LYDX2020BS016)the National Natural Science Foundation of Shandong Province(ZR2021QB208,ZR2022MB054)+4 种基金the National Natural Science Foundation of China(22305262)SIAT Innovation Program for Excellent Young Researchers(2022)Shenzhen Science and Technology Program Grant(RCJC20200714114435061,ZDSYS20220527171406014)the City University of Hong Kong Donation Research Grants(9220061 and 9229021)City University of Hong Kong Strategic Research Grant(SRG 7005505)。
文摘The earth-abundant and high-performance catalysts are crucial for commercial implementation of hydrogen evolution reaction(HER).Herein,a multifunctional site strategy to construct excellent HER catalysts by incorporating iridium(Ir)ions on the atomic scale into orthorhombic-CoSe2(Ir-CoSe_(2))was reported.Outstanding hydrogen evolution activity in alkaline media such as a low overpotential of 48.7 mV at a current density of 10 mA cm^(-2)and better performance than commercial Pt/C catalysts at high current densities were found in the Ir-CoSe_(2) samples.In the experiments and theoretical calculations,it was revealed that Ir enabled CoSe_(2)to form multifunctional sites to synergistically catalyze alkaline HER by promoting the adsorption and dissociation of H_(2)O(Ir sites)and optimizing the binding energy for H^(*)on Co sites.It was noticeable that the electrolytic system comprising the Ir-CoSe_(2)electrode not only produced hydrogen efficiently via HER,but also degraded organic pollutants(Methylene blue).The cell voltage of the dual-function electrolytic system was 1.58 V at the benchmark current density of 50 mA cm^(-2),which was significantly lower than the conventional water splitting voltage.It was indicated that this method was a novel strategy for designing advanced HER electrocatalysts by constructing multifunctional catalytic sites for hydrogen production and organic degradation.
基金Priority Academic Program Development of Jiangsu Higher Education InstitutionsApplied Basic Research Programs of Science and Technology Commission Foundation of Jiangsu Province,Grant/Award Number:BK20231340+4 种基金Changzhou Introduction Program of Innovative Leading Talents,Grant/Award Number:CQ20220111Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20170290Natural Science Foundation of the Higher Education Institutions of Jiangsu Province,Grant/Award Number:17KJB150002Opening Project of Zhejiang Engineering Research Center of Fat-soluble Vitamin,Grant/Award Number:202107National Natural Science Foundation of China,Grant/Award Numbers:51803143,。
文摘Developing dynamic color-tunable ultra-long room temperature phosphorescence(URTP)polymers with afterglow of over 1 s,photo-chromism,and multi-stimuli response for practical anti-counterfeiting and information security applications is attractive but very challenging.Herein,by doping multicolor phosphorescence pyri-dinium bromide L block or viologen-based photo-chromic V block into polyvinyl alcohol matrixes,the water-stimuli-responsive color-tunable URTP polymerfilms with afterglow of up to 8 s and the reversible viologen-based photochromic polymerfilms have been developed.More significantly,a series of dynamic color-tunable URTP polymerfilms with ultra-long afterglow of over 6 s,photo-chromism,and water-stimuli response have been successfully exploited by integrating L and V blocks into one polymer system.Mechanistic investigations have revealed that their photo-chromism mainly comes from the photo-generated viologen free radicals.Furthermore,their dynamic multilevel anti-counterfeiting applications have been demonstrated.These results pave the way to develop smarter multifunctional URTP materials for anti-counterfeiting and optical sensing.
基金the financial support from Shanxi Province Science and Technology Department(20201101012,202101060301016)the support from the APRC Grant of the City University of Hong Kong(9380086)+5 种基金the TCFS Grant(GHP/018/20SZ)MRP Grant(MRP/040/21X)from the Innovation and Technology Commission of Hong Kongthe Green Tech Fund(202020164)from the Environment and Ecology Bureau of Hong Kongthe GRF grants(11307621,11316422)from the Research Grants Council of Hong KongGuangdong Major Project of Basic and Applied Basic Research(2019B030302007)Guangdong-Hong Kong-Macao Joint Laboratory of Optoelectronic and Magnetic Functional Materials(2019B121205002).
文摘A considerable efficiency gap exists between large-area perovskite solar modules and small-area perovskite solar cells.The control of forming uniform and large-area film and perovskite crystallization is still the main obstacle restricting the efficiency of PSMs.In this work,we adopted a solid-liquid two-step film formation technique,which involved the evaporation of a lead iodide film and blade coating of an organic ammonium halide solution to prepare perovskite films.This method possesses the advantages of integrating vapor deposition and solution methods,which could apply to substrates with different roughness and avoid using toxic solvents to achieve a more uniform,large-area perovskite film.Furthermore,modification of the NiO_(x)/perovskite buried interface and introduction of Urea additives were utilized to reduce interface recombination and regulate perovskite crystallization.As a result,a large-area perovskite film possessing larger grains,fewer pinholes,and reduced defects could be achieved.The inverted PSM with an active area of 61.56 cm^(2)(10×10 cm^(2)substrate)achieved a champion power conversion efficiency of 20.56%and significantly improved stability.This method suggests an innovative approach to resolving the uniformity issue associated with large-area film fabrication.
文摘In the present work,multi walled carbon nanotubes(MWCNT)reinforced magnesium(Mg)matrix composite was fabricated by friction stir processing(FSP)with an aim to explore its mechanical and electrochemical behavior.Microstructural observations showed that the thickness of the produced composite layer was in the range of 2500μm.FSP resulted uniform distribution of CNT near the surface while agglomerated layers in the subsurface.Grain refinement of Mg achieved by FSP improved the hardness but significant enhancement in the hardness value was observed for FSPed MWCNT/Mg composites.Potentiodynamic polarization studies revealed that the increase in corrosion current density was observed for MWCNT/Mg composite compared with grain refined Mg and pure Mg,implying the significance of secondary phase(MWCNT)in decreasing the corrosion resistance of the composite.
基金financially supported by the Key Research and Development Program of Hubei Province (2021BAA208)the National Natural Science Foundation of China (52002294,51974208 and U2003130)+3 种基金the Young Top-notch Talent Cultivation Program of Hubei ProvinceKnowledge Innovation Program of Wuhan-Shuguang Project (2022010801020364)the City University of Hong Kong Strategic Research Grant (SRG) (7005505)the City University of Hong Kong Donation Research Grant (DONRMG 9229021)。
文摘Electrocatalytic water splitting for hydrogen production is hampered by the sluggish oxygen evolution reaction(OER)and large power consumption and replacing the OER with thermodynamically favourable reactions can improve the energy conversion efficiency.Since iron corrodes easily and even self-corrodes to form magnetic iron oxide species and generate corrosion currents,a novel strategy to integrate the hydrogen evolution reaction(HER)with waste Fe upgrading reaction(FUR)is proposed and demonstrated for energy-efficient hydrogen production in neutral media.The heterostructured MoSe_(2)/MoO_(2) grown on carbon cloth(MSM/CC)shows superior HER performance to that of commercial Pt/C at high current densities.By replacing conventional OER with FUR,the potential required to afford the anodic current density of 10 m A cm^(-2)decreases by 95%.The HER/FUR overall reaction shows an ultralow voltage of 0.68 V for 10 m A cm^(-2)with a power equivalent of 2.69 k Wh per m^(3)H_(2).Additionally,the Fe species formed at the anode extract the Rhodamine B(Rh B)pollutant by flocculation and also produce nanosized magnetic powder and beneficiated Rh B for value-adding applications.This work demonstrates both energy-saving hydrogen production and pollutant recycling without carbon emission by a single system and reveals a new direction to integrate hydrogen production with environmental recovery to achieve carbon neutrality.
基金supported by the National Natural Science Foundation of China(21271166)the Fundamental Research Funds for the Central Universities+1 种基金Program for New Century Excellent Talents in University(NCET)Young Thousand Talented Program
文摘Facile deposition of a water-splitting catalyst on low-cost electrode materials could be attractive for hydrogen production from water and solar energy conversion. Herein we describe fast electrodeposition of cobalt-based water oxidation catalyst （Co-WOC） on simple graphite electrode for water splitting, The deposition process is quite fast, which reaches a plateau in less than 75 min and the final ctLrrent density is -1.8 mA/cm2 under the applied potential of 1.31 V at pH --7.0. The scanning electron microscopy （SEM） study shows the formation of nanometer-sized particles （10-100 nm） on the surface of the electrode after only 2 min and micrometer-sized particles （2-5/zm） after 90 rain of electrolysis. X-ray photoelectron spectroscopy （XPS） data demonstrate the as-synthesized ex-situ catalyst mainly contains Co2＋ and Co3＋ species incorporating a substantial amount of phosphate anions. These experiments suggest that cost-efficient cobalt oxide materials on graphite exhibit alluring ability for water splitting, which might provide a novel method to fabricate low-cost devices for electrochemical energy storage.
基金National Natural Science Foundation of China,Grant/Award Numbers:22108125,22175094Natural Science Foundation of Jiangsu Province,Grant/Award Number:BK20210627+1 种基金China Postdoctoral Science Foundation,Grant/Award Number:2023M730484Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX23_1173。
文摘Developing an efficient freshwater and electricity co-generation device(FECGD)can solve the shortage of freshwater and electricity.However,the poor salt resistance and refrigeration properties of the materials for FECGD put big challenges in the efficient and stable operation of these devices.To address these issues,we propose the covalent organic framework(COF)confined co-polymerization strategy to prepare COF-modified acrylamide cationic hydrogels(ACH-COF),where hydrogen bonding interlocking between negatively charged polymer chains and COF pores can form a salt resistant hydrogel for stabilizing tunable passive interfacial cooling(TPIC).The FECPDs based on the TPIC and salt resistance of ACH-COF display a maximum output power density of 2.28 W m-2,which is 4.3 times higher than that of a commercial thermoelec-tric generator under one solar radiation.The production rate of freshwater can reach 2.74 kg m-2 h-1.Our results suggest that the high efficiency and scala-bility of the FECGD can hold the promise of alleviating freshwater and power shortages.
基金supported by the National Natural Science Foundation of China(No.52173251)the China National Funds for Distinguished Young Scientists(No.51925104)+1 种基金NSFC-Guangdong Province Joint Program(Key program No.U21A2084)the Cen-tral Guidance on Local Science and Technology Development Fund of Hebei Province(No.226Z1303G).
文摘Photocatalysis has been a research hotspot in recent years,and the design and modification of photocat-alysts have been the key points.Common methods for designing photocatalysts,including constructing heterojunctions and homojunctions,have been developed on the basis of heterojunctions.In this study,two homojunctions of manganese dioxide(MnO_(2)),including a high-index crystal plane homojunction and a general homojunction,are prepared using a stepwise hydrothermal method.Using a capping agent,the high-index crystal surface of the MnO_(2)is exposed.It is found that the electron transport efficiency be-tween the two components of the homojunction with high-index planes is higher and the adsorption capacity of the oxygen is stronger,which leads to higher photocatalytic efficiency.In addition,the newly designed high-index homojunction is used for the treatment of bacterial infections,and it kills Staphy-lococcus aureus(S.aureus)and Escherichia coli(E.coli)at rates of 99.95%±0.04%and 99.31%±0.25%,respectively.It also has excellent therapeutic effects on mouse wounds,which implies superb practical application value.This work provides a new strategy for the improved design of homojunctions and the application of photocatalytic materials.
基金supported by the National Natural Science Foundation of China(Nos.51732011,U1932213,22105194,and 92163130)the National Key Research and Development Program of China(Nos.2021YFA0715700 and 2018YFE0202201)+3 种基金the University Synergy Innovation Program of Anhui Province(No.GXXT-2019-028)Science and Technology Major Project of Anhui Province(No.201903a05020003)the Fundamental Research Funds for the Central Universities(No.WK2090050043)Anhui Provincial Key R&D Programs(No.202104a05020013).
文摘Different forms of construction materials(e.g.,paints,foams,and boards)dramatically improve the quality of life.With the increasing environmental requirements for buildings,it is necessary to develop a comprehensive sustainable construction material that is flexible in application and exhibits excellent performance,such as fireproofing and thermal insulation.Herein,an adjustable multiform material strategy by water regulation is proposed to meet the needs of comprehensive applications and reduce environmental costs.Multiform gels are constructed based on multiscale cellulose fibers and hollow glass microspheres,with fireproofing and thermal insulation.Unlike traditional materials,this multiscale cellulose-based gel can change forms from dispersion to paste to dough by adjusting its water content,which can realize various construction forms,including paints,foams,and low-density boards according to different scenarios and corresponding needs.
基金VISTA-a basic research program funded by Statoil,conducted in close collaboration with The Norwegian Academy of Science and Letters which is gratefully acknowledged
文摘A 3D structured composite of carbon nanofibers @ MnO2 on copper foil is reported here as a binder free anode of lithium ion batteries, with high capacity, fast charge/discharge rate and good stability. Carbon nanofiber yarns were synthesized directly over copper foil through a floating catalyst method. The growth of carbon nanofiber yarns was significantly enhanced by mechanical polishing of the copper foils, which can be attributed to the increased surface roughness and surface area of the copper foils. MnO2 was then grown over carbon nanofibers through spontaneous reduction of potassium permanganate by the carbon nanofibers. The obtained composites of carbon nanofibers@MnO2 over copper foil were tested as an anode in lithium ion batteries and they show superior electrochemical performance. The initial reversible capacity of carbon nanofibers@MnO2 reaches up to around 998 mAh.g-1 at a rate of 60 mmA.g-l based on the mass of carbon nanofibers and MnO2. The carbon nanofibers @ MnO2 electrodes could deliver a capacity of 630 mAh.g-1 at the beginning and maintain a capacity of 440 mmAh.g-1 after 105 cycles at a rate of 600 mA.g-~. The high initial capacity can be attributed to the presence of porous carbon nanofiber yarns which have good electrical conductivity and the MnO2 thin film which makes the entire materials electrochemically active. The high cyclic stability of carbon nanofibers@MnO2 can be ascribed to the MnO2 thin film which can accommodate the volume expansion and shrinking during charge and discharge and the good contact of carbon nanofibers with MnO2 and copper foil.
基金Supported by the National Basic Research Programme of China under Grant No 2004CB619305, the Natural Science Foundation of China under Grant Nos 50461001 and 50831004/E01081, and the Natural Science Foundation of Jiangsu Province （BK2006716）.
文摘Internal friction of nanocrystalline nickel is investigated by mechanical spectroscopy from 360 K to 120 K. Two relaxation peaks are found when nanocrystalline nickel is bent up to 10% strain at room temperature and fast cooling. However, these two peaks disappear when the sample is annealed at room temperature in vacuum for ten days. The occurrence and disappearance of the two relaxation peaks can be explained by the interactions of partial dislocations and point defects in nanocrystalline materials.
基金financially supported by the National Natural Science Foundation of China(21872020)the 1226 Engineering Health Major Project(BWS17J028,AWS16J018)the Fundamental Research Funds for the Central Universities(N180705004)。
文摘The synchronous construction of metal phosphate and phosphorus-doped carbon structures is of great significance to innovate the design,synthesis,and application of catalysts,as these phosphoruscontaining composite materials have shown a remarkable contribution to electrocatalysts.However,their preparation procedure generally involves using large amounts of excess phosphorus sources for phosphorization,which inevitably release poisonous PH_(3) or dangerous phosphorus vapor.Here,a strategy for in-situ formation of FePO_(4) embedded in P-doped carbon 2D nano film(FePO_(4)/PdC)is developed using a highly integrated precursor,which is a small molecular organophosphine ligand,1,1’bis(diphenylphosphine)ferrocene(DPPF).The multi-source precursor DPPF that contains Fe,P,and C is molecular-vapor-deposited on the nickel foam(NF)supported ZIF-67 nanosheets to obtain the composite catalyst,namely DPPF-500/ZIF-67/NF.FePO_(4)/PdC encapsulated the ZIF-67 derived Co/N-doped carbon matrix(Co NC)to form a sandwich structure FePO_(4)/PdC@CoNC.The constructed catalyst shows good performance for OER,requiring an overpotential of only 297 m V to deliver 600 m A/cm^(2) with a Tafel slope of 42.7 m V dec^(-1).DFT calculations demonstrate that the synergistic effects between the metal active center and P-doped carbon film reduce the energy barriers and improve electron transport.This method of constructing P-containing catalysts overcomes the demand for additional P sources to realize eco-friendly fabrication and yields a unique structure with good catalytic activity.
基金the National Natural Science Foundation of China,Grant/Award Numbers:22179022,22109023,22209027,22209097the Industry-University-Research Joint Innovation Project of Fujian Province,Grant/Award Number:2021H6006+2 种基金the FuXiaQuan National Independent Innovation Demonstration Zone Collaborative Innovation Platform,Grant/Award Number:2022-P-027the Youth Innovation Fund of Fujian Province,Grant/Award Numbers:2021J05043,2022J05046the Award Program for Fujian Minjiang Scholar Professorship,the Talent Fund Program of Fujian Normal University and Shenzhen Science and Technology Program,Grant/Award Numbers:JCYJ20220530142806015,JCYJ20220818101008018。
文摘Electrospun nanofibers(NFs)have shown excellent properties including high porosity,abundant active sites,controllable diameter,uniform and designable structure,high mechanical strength,and superior resistance to external destruction,which are ideal nanoreactors for in situ characterizations.Among various techniques,in situ transmission electron microscopy(TEM)has enabled operando observation at the atomic level due to its high temporal and spatial resolution combined with excellent sensitivity,which is of great importance for rational materials design and performance improvement.In this review,the basic knowledge of in situ TEM techniques and the advantages of electrospun nanoreactors for in situ TEM characterization are first introduced.The recent development in electrospun nanoreactors for studying the physical properties,structural evolution,phase transition,and formation mechanisms of materials using in situ TEM is then summarized.The electrochemical behaviors of carbon nanofibers(CNFs),metal/metal oxide NFs,and solidelectrolyte interphase for different rechargeable batteries are highlighted.Finally,challenges faced by electrospun nanoreactors for in situ TEM characterization are discussed and potential solutions are proposed to advance this field.
基金The computations involved in this work were conducted on the computer cluster at Skolkovo Institute of Science and Technology(Skoltech)CEST Multiscale Molecular Modelling group and Massachusetts Institute of Technology(MIT)Nuclear Science Engineering department.E.T.,Z.S.,A.S.,and J.L.acknowledge support by the Skoltech-MIT Next Generation Program 2016-7/NGPE.T.and A.S.acknowledge support by the Center for Integrated Nanotechnologies,an Office of Science User Facility operated for the U.S.Department of Energy Office of Science by Los Alamos National Laboratory(Contract 89233218CNA000001)+1 种基金Sandia National Laboratories(Contract DE-NA-0003525)M.D.acknowledges support from MIT J-Clinic for Machine Learning and Health.S.S.acknowledges support from Nanyang Technological University through the Distinguished University Professorship.
文摘The controlled introduction of elastic strains is an appealing strategy for modulating the physical properties of semiconductor materials.With the recent discovery of large elastic deformation in nanoscale specimens as diverse as silicon and diamond,employing this strategy to improve device performance necessitates first-principles computations of the fundamental electronic band structure and target figures-of-merit,through the design of an optimal straining pathway.Such simulations,however,call for approaches that combine deep learning algorithms and physics of deformation with band structure calculations to custom-design electronic and optical properties.Motivated by this challenge,we present here details of a machine learning framework involving convolutional neural networks to represent the topology and curvature of band structures in k-space.These calculations enable us to identify ways in which the physical properties can be altered through“deep”elastic strain engineering up to a large fraction of the ideal strain.Algorithms capable of active learning and informed by the underlying physics were presented here for predicting the bandgap and the band structure.By training a surrogate model with ab initio computational data,our method can identify the most efficient strain energy pathway to realize physical property changes.The power of this method is further demonstrated with results from the prediction of strain states that influence the effective electron mass.We illustrate the applications of the method with specific results for diamonds,although the general deep learning technique presented here is potentially useful for optimizing the physical properties of a wide variety of semiconductor materials。
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Nos.XDB0470303 and XDB0450402)the National Key Research and Development Program of China(Nos.2018YFE0202201 and 2021YFA0715700)+1 种基金the National Natural Science Foundation of China(No.22293044)the Major Basic Research Project of Anhui Province(No.2023z04020009).
文摘As a renewable,biocompatible,biodegradable soft material,chitin hydrogels have better advantages in stability,antibacterial activity,antifouling,cost,immunogenicity,and so on than most polymer hydrogels.However,compared with other widely used polymer hydrogels with high strength and toughness,the practical applications of chitin-based hydrogels have been limited by their weak mechanical properties,such as cartilage repair and meniscus replacement.Here,we present the design and fabrication of chitin hydrogels with excellent mechanical strength and toughness by a dehydration and rehydration strategy.By sequential dehydration and rehydration processes,the crystalline domains in the chitin hydrogels can be properly controlled.With optimized crystallinity,the elastic modulus of the chitin hydrogels exceeds all previously reported values,and the fracture toughness is even comparable to some synthetic polymer hydrogels,while maintaining a high-water-content of about 80 wt.%.At the same water content,the mechanical properties of the chitin hydrogels are positively correlated with the hydrogel crystallinity,which proves that the change of mechanical properties of hydrogels is not simply dependent on weight concentration.The hydrogels can be further strengthened by incorporating other biopolymers that are intrinsically weak,which makes the hydrogels promising for applications in fields such as cartilage repair and meniscus replacement.Moreover,the hydrogels enable loading and release of water-soluble and poorly water-soluble drugs.This highly extendable strengthening and toughening strategy of chitin and chitin-based biopolymer hydrogels paves the way for their widely applications.
基金financially supported by the Fund for Shanxi ‘‘1331 Project’’ Key Innovative Research Team (No.PY201809)the Program for the Innovative Talents of Higher Education Institutions of Shanxi (PTIT)+1 种基金the Natural Science Foundation of Shanxi Province (No. 201801D121093)Hong Kong Research Grant Council (RGC) General Research Funds (GRF)(No. City U11205617)。
文摘Although Ni-Ti-O nanopores(NPs) can be fabricated by anodization of mechanically polished NiTi alloys, the top disordered layer is difficult to remove thus hindering the functionality of the Ni-Ti-O NPs. In this work, an electropolishing(EP) pretreatment was performed on the NiTi substrate prior to anodization to thoroughly expose the NPs. Our results show that the EP pretreatment for 5 min perfectly removes the top disordered layer on the Ni-Ti-O NPs to expose the underlying NPs and consequently, the corrosion resistance and antibacterial ability are enhanced. The exposed NPs can elongate bone marrow mesenchymal stem cells, which may be responsible for the upregulated alkaline phosphatase activity, secretion of Type I collagen, and extracellular matrix mineralization. These results suggest that EP is a desirable pretreatment before anodization of the NiTi alloys because the irregular surface layer on the Ni-Ti-O NPs can be removed to enhance the corrosion resistance and biological functions.
基金financially supported by the National Natural Science Foundation of China(NSFC)(Nos.51671003,21802003,21571112)Natural Science Foundation of Shandong Province(ZR2018BB031)+3 种基金the Shandong Taishan Scholar Program(H.W.)the China Postdoctoral Science Foundation(No.2017M610022)the start-up supports from Peking UniversityYoung Thousand Talented Program。
文摘Developing enzyme-free sensors with high sensitivity and selectivity for H2O2 and glucose is highly desirable for biological science.Especially,it is attractive to exploit noble-metal-free nanomaterials with large surface area and good conductivity as highly active and selective catalysts for molecular detection in enzyme-free sensors.Herein,we successfully fabricate hollow frameworks of Co3O4/N-doped carbon nanotubes(Co3O4/NCNTs)hybrids by the pyrolysis of metal-organic frameworks followed by calcination in the air.The as-prepared novel hollow Co3O4/NCNTs hybrids exhibit excellent electrochemical performance for H2O2 reduction in neutral solutions and glucose oxidation in alkaline solutions.As sensor electrode,the Co3O4/NCNTs show excellent non-enzymatic sensing ability towards H2O2 response with a sensitivity of 87.40μA(mmol/L)^-1 cm^-2,a linear range of 5.00μmol/L-11.00 mmol/L,and a detection limitation of 1μmol/L in H2O2 detection,and a good glucose detection performance with 5μmol/L.These excellent electrochemical performances endow the hollow Co3O4/NCNTs as promising alternative to enzymes in the biological applications.
基金The study was financially supported by the National Natural Science Foundation of China(51501218)Shenzhen Science and Technology Research Funding(JCYJ20160608153641020)Hong Kong Research Grants Council(RGC)General Research Funds(GRF)No.CityU 11301215.
文摘The effects of dual Zr and O plasma immersion ion implantation(Zr&O PIII)on antibacterial properties of ZK60 Mg alloys are systematically investigated.The results show that a hydrophobic,smooth,and ZrO_(2)-containing graded film is formed.Electrochemical assessment shows that the corrosion rate of the plasma-treated Mg alloy decreases and the decreased degradation rate is attributed to the protection rendered by the surface oxide.In vitro and in vivo antibacterial tests reveal Zr&O PIII ZK60 presents higher antibacterial rate compared to Zr PIII ZK60 and untreated control.The hydrophobic and smooth surface suppresses bacterial adhesion.High concentration of oxygen vacancies in the surface films are determined by X-ray photoelectron spectroscopy(XPS),UV-vis diffuse reflectance spectra(UV-vis DRS)and electron paramagnetic resonance(EPR)and involved in the production of reactive oxygen species(ROS).The higher level of ROS expression inhibits biofilm formation by down-regulating the expression of icaADBC genes but up-regulating the expression of icaR gene.In addition,Zr&O PIII improves cell viability and initial cell adhesion confirming good cytocompatibility.Dual Zr&O PIII is a simple and practical means to expedite clinical acceptance of biodegradable magnesium alloys.
文摘An investigation on the oxidation mechanism of the graphite in the MgO-C refractory materials is helpful to improving both the quality of these materials and to preventing and/or lowering of the adverse effects of the high-temperature oxidation. In this research, the oxidation behavior of the MgO-C refractories containing 5～20 wt% graphite was studied via weight-loss method. Atmospheric air was used for oxidation at temperatures ranging from 900℃ to 1300°C and the experimental data were compared with those obtained from the dimensionless kinetic equations of the shrinking core model, in order to determine the oxidation mechanisms of the refractories. The best fit was achieved with the porous layer diffusion control regime. Oxidation mechanism tends, however, to slightly deviate from pure pore diffusion control to pore diffusion-external gas transfer regime in the samples having more graphite contents (e.g. 20%).
文摘It is often advantageous to display material properties relationships in the form of charts that highlight important correlations and thereby enhance our understanding of materials behavior and facilitate materials selection.Unfortunately,in many cases,these correlations are highly multidimensional in nature,and one typically employs low-dimensional cross-sections of the property space to convey some aspects of these relationships.To overcome some of these difficulties,in this work we employ methods of data analytics in conjunction with a visualization strategy,known as parallel coordinates,to represent better multidimensional materials data and to extract useful relationships among properties.We illustrate the utility of this approach by the construction and systematic analysis of multidimensional materials properties charts for metallic and ceramic systems.These charts simplify the description of high-dimensional geometry,enable dimensional reduction and the identification of significant property correlations and underline distinctions among different materials classes.
