6-（5-Carboxyl-2-methoxyphenyl）-apigenin （1）, a new flavonoid, was isolated from the 60% ethanol extract of Selaginella uncinata （Desv.） Spring. Its structure was established by spectroscopic methods. Compound 1 ...6-（5-Carboxyl-2-methoxyphenyl）-apigenin （1）, a new flavonoid, was isolated from the 60% ethanol extract of Selaginella uncinata （Desv.） Spring. Its structure was established by spectroscopic methods. Compound 1 represents the first example of the flavonoids possessing a benzoic acid substituent at C-6.展开更多
The effect of cerium content on the corrosion behavior of Al-Co-Ce amorphous alloys in 0.6 M NaCl solution was investigated by cyclic polarization, Mott-Schottky and X-ray photoelectron spectroscopy techniques. Result...The effect of cerium content on the corrosion behavior of Al-Co-Ce amorphous alloys in 0.6 M NaCl solution was investigated by cyclic polarization, Mott-Schottky and X-ray photoelectron spectroscopy techniques. Results indicated that the open circuit potential of Al-Co-Ce amorphous alloys displayed a decreased tendency with the increase in Ce content, and the amorphous alloy with 4 at.% Ce presented both the lowest passive current density and donor density indicating the best corrosion resistance, while adding excess Ce led to the reduced corrosion resistance of Al-Co-Ce alloys, Furthermore, it was found that a low Ce content is beneficial to the formation of a more protective passive film on Al-Co-Ce amorphous alloys, and the corrosion inhibition reactions of Al-Co-Ce alloys in 0.6 M NaCl solution were changed with the increase in Ce content and the detailed reasons were discussed.展开更多
Notes on 113 fungal taxa are compiled in this paper,including 11 new genera,89 new species,one new subspecies,three new combinations and seven reference specimens.Awide geographic and taxonomic range of fungal taxa ar...Notes on 113 fungal taxa are compiled in this paper,including 11 new genera,89 new species,one new subspecies,three new combinations and seven reference specimens.Awide geographic and taxonomic range of fungal taxa are detailed.In the Ascomycota the new genera Angustospora(Testudinaceae),Camporesia(Xylariaceae),Clematidis,Crassiparies(Pleosporales genera incertae sedis),Farasanispora,Longiostiolum(Pleosporales genera incertae sedis),Multilocularia(Parabambusicolaceae),Neophaeocryptopus(Dothideaceae),Parameliola(Pleosporales genera incertae sedis),and Towyspora(Lentitheciaceae)are introduced.Newly introduced species are Angustospora nilensis,Aniptodera aquibella,Annulohypoxylon albidiscum,Astrocystis thailandica,Camporesia sambuci,Clematidis italica,Colletotrichum menispermi,C.quinquefoliae,Comoclathris pimpinellae,Crassiparies quadrisporus,Cytospora salicicola,Diatrype thailandica,Dothiorella rhamni,Durotheca macrostroma,Farasanispora avicenniae,Halorosellinia rhizophorae,Humicola koreana,Hypoxylon lilloi,Kirschsteiniothelia tectonae,Lindgomyces okinawaensis,Longiostiolum tectonae,Lophiostoma pseudoarmatisporum,Moelleriella phukhiaoensis,M.pongdueatensis,Mucoharknessia anthoxanthi,Multilocularia bambusae,Multiseptospora thysanolaenae,Neophaeocryptopus cytisi,Ocellularia arachchigei,O.ratnapurensis,Ochronectria thailandica,Ophiocordyceps karstii,Parameliola acaciae,P.dimocarpi,Parastagonospora cumpignensis,Pseudodidymosphaeria phlei,Polyplosphaeria thailandica,Pseudolachnella brevifusiformis,Psiloglonium macrosporum,Rhabdodiscus albodenticulatus,Rosellinia chiangmaiensis,Saccothecium rubi,Seimatosporium pseudocornii,S.pseudorosae,Sigarispora ononidis and Towyspora aestuari.New combinations are provided for Eutiarosporella dactylidis(sexual morph described and illus trated)and Pseudocamarosporium pini.Descriptions,illustrations and/or reference specimens are designated for Aposphaeria corallinolutea,Cryptovalsa ampelina,Dothiorella vidmadera,Ophiocordyceps formosana,Petrakia echinata,Phragmoporthe conformis and Pse展开更多
Superhydrophobic coatings are increasingly being evaluated as anticorrosion interventions in exceedingly hydrated environments.However,concerns about their long-term durability and amenability to large-area applicatio...Superhydrophobic coatings are increasingly being evaluated as anticorrosion interventions in exceedingly hydrated environments.However,concerns about their long-term durability and amenability to large-area applications in marine environments are still hindering commercial-scale deployment.This study is focused on development of easy-to-apply superhydrophobic coatings,with multifunctional capabilities,in order to extend the integrity and durability of the coatings in harsh marine environments.Here,a set of facile methods involving selective chemical etching using concentrated Na OH,as well as fluorination with perfluoropolyether methyl ester were adopted to fabricate a superhydrophobic surface on basalt scales,having the required rough hierarchical micro-nanotextured and low surface energy.The superhydrophobic basalt scales were subsequently aligned atop a fluorocarbon resin,pre-deposited on a metal substrate,to yield a multifunctional superhydrophobic coating(3μL water droplet;contact angle=165.1°,rolling angle=0.7°),easily amenable to large surface area application and having excellent wear resistance,UV-aging resistance,salt spray resistance,corrosion resistance and antibacterial capabilities.展开更多
The low-cycle fatigue behavior of solutionized(T4)and aged(T6)WE43 magnesium alloys was studied at room temperature.The total strain amplitudes(△ε_(t)/2)were 0.4%,0.5%,0.6%,0.7%and 1.0%.Detailed microstructure evolu...The low-cycle fatigue behavior of solutionized(T4)and aged(T6)WE43 magnesium alloys was studied at room temperature.The total strain amplitudes(△ε_(t)/2)were 0.4%,0.5%,0.6%,0.7%and 1.0%.Detailed microstructure evolution was characterized by scanning electron microscope(SEM),electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM).The results showed that plastic strain amplitude decreased with the increasing cycle number in T4 alloy,which is due to the dense persistent slip bands(PSBs)and dynamic precipitates hinderingdislocation slip.In contrast,the plastic strain amplitude increases gradually in T6 alloy,which is attributed to the enhanced activation of pyramidal slip.The low-cycle fatigue life of T6 alloy with larger fatigue ductility coefficient is longer than that of T4 alloy.The Coffin-Manson model can accurately predict the fatigue life of T4 and T6 alloys compared to Jahed-Varvani(JV)energy model.For T4 alloy,the fatigue damage mechanism was dominated by basal slip.For T6 alloy,the enhanced pyramidal slip plays an important role to accommodate plastic deformation.展开更多
Recently,the eutectic high-entropy alloy(EHEA),AlCoCrFeNi_(2.1),can reach a good balance of strength and ductility.The dual-phase alloy exhibits a eutectic lamellar microstructure with large numbers of interfaces.Howe...Recently,the eutectic high-entropy alloy(EHEA),AlCoCrFeNi_(2.1),can reach a good balance of strength and ductility.The dual-phase alloy exhibits a eutectic lamellar microstructure with large numbers of interfaces.However,the role of the interfaces in plastic deformation have not been revealed deeply.In the present work,the orientation relationship(OR)of the interfaces has been clarified as the Kurdjumov-Sachs(KS)interfaces presenting〈111〉_(B2) 〈110〉_(FCC)and {110} _(B2){111}_(FCC) independent of their morphologies.There exist three kinds of interfaces in the EHEA,namely,The dominating interface and the secondary interface are both non-slip planes and atomistic-scale faceted,facilitating the nucleation and slip transmission of the dislocations.The formation mechanism of the preferred interfaces is revealed using the atomistic geometrical analysis according to the criteria of the low interfacial energy based on the coincidence-site lattice(CSL)theory.In particular,the ductility of the dual-phase alloy originates from the KS interface-induced slip continuity across interfaces,which provides a high slip-transfer geometric factor.Moreover,the strengthening effect can be attributed to the interface resistance for the dislocation transmission due to the mismatches of the moduli and lattice parameters at the interfaces.展开更多
Implant-related infection and early bone integration are the main risk factors of implants for long-term service,to overcome these difficulties,SLA-TiCu surface was prepared by sandblasting and large-grits etching(SLA...Implant-related infection and early bone integration are the main risk factors of implants for long-term service,to overcome these difficulties,SLA-TiCu surface was prepared by sandblasting and large-grits etching(SLA)treatment on a novel antibacterial titanium-copper alloy(TiCu),which is the most prevalent surface treatment with micro/submicron hierarchical structures to titanium-based implants.Effects of SLA-TiCu surface on the adhesion,proliferation,apoptosis and differentiation of MC3T3-E1 cells as well as the antibacterial activity against a common orthopedic pathogen(Staphylococcus aureus)were studied.Compared to the following surfaces:sandblasting and large-grits etched pure titanium(SLATi),mechanically ground pure titanium and TiCu alloy(M-Ti and M-TiCu),these results indicated that SLA-TiCu surface obviously enhanced the bone-related gene expressions(alkaline phosphates(ALP),collagen typeⅠ(COLⅠ),Runt-related transcription factor 2(RUN x 2),and osteopontin(OPN)).Moreover,SLA-TiCu surface could maintain a sustainable release of Cu2+ions and effectively inhibited the viability of bacteria.This study demonstrated that SLA-TiCu surface possessed multifunctional characteristics of improved osteogenic ability and antibacterial activity,making it promising as a novel implant material for hard tissue repairs such as orthopedics and dental implants.展开更多
Background Global connectivity and environmental change pose continuous threats to dengue invasions from worldwide to China.However,the intrinsic relationship on introduction and outbreak risks of dengue driven by the...Background Global connectivity and environmental change pose continuous threats to dengue invasions from worldwide to China.However,the intrinsic relationship on introduction and outbreak risks of dengue driven by the landscape features are still unknown.This study aimed to map the patterns on source-sink relation of dengue cases and assess the driving forces for dengue invasions in China.Methods We identified the local and imported cases(2006–2020)and assembled the datasets on environmental conditions.The vector auto-regression model was applied to detect the cross-relations of source-sink patterns.We selected the major environmental drivers via the Boruta algorithm to assess the driving forces in dengue outbreak dynamics by applying generalized additive models.We reconstructed the internal connections among imported cases,local cases,and external environmental drivers using the structural equation modeling.Results From 2006 to 2020,81,652 local dengue cases and 12,701 imported dengue cases in China were reported.The hotspots of dengue introductions and outbreaks were in southeast and southwest China,originating from South and Southeast Asia.Oversea-imported dengue cases,as the Granger-cause,were the initial driver of the dengue dynamic;the suitable local bio-socioecological environment is the fundamental factor for dengue epidemics.The Bio8[odds ratio(OR)=2.11,95%confidence interval(CI):1.67–2.68],Bio9(OR=291.62,95%CI:125.63–676.89),Bio15(OR=4.15,95%CI:3.30–5.24),normalized difference vegetation index in March(OR=1.27,95%CI:1.06–1.51)and July(OR=1.04,95%CI:1.00–1.07),and the imported cases are the major drivers of dengue local transmissions(OR=4.79,95%CI:4.34–5.28).The intermediary effect of an index on population and economic development to local cases via the path of imported cases was detected in the dengue dynamic system.Conclusions Dengue outbreaks in China are triggered by introductions of imported cases and boosted by landscape features and connectivity.Our research will contribute to devel展开更多
Designing and synthesis of cost effective bulk metallic glasses （BMGs） has been of considerable interest during the last decade so that they can be made commercially viable. Among these, Zr-based BMGs have been repo...Designing and synthesis of cost effective bulk metallic glasses （BMGs） has been of considerable interest during the last decade so that they can be made commercially viable. Among these, Zr-based BMGs have been reported extensively due to their attractive properties, An alloy having composition Zr65Cu18Ni9A18 was designed and synthesized using 2-3 N pure materials by Cu mould casting. The alloy was characterized by X- ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS） and high temperature differential scanning calorimetry （DSC）. Thermal parameters like supercooled liquid region △Tx, reduced glass transition temperature Trg, γ and δ parameters were evaluated. Mechanical properties like microhardness, nanohardness, elastic modulus and fracture strength were measured. The alloy showed wide supercooled liquid region of 129＋1 K with improved thermal stability. The alloy has considerable fracture strength along with fair amount of ductility.展开更多
This work was focused on study of anti-infection ability and its underlying mechanism of a novel dental implant made of titanium-copper(TiCu)alloy.In general,most studies on antibacterial implants have used a single p...This work was focused on study of anti-infection ability and its underlying mechanism of a novel dental implant made of titanium-copper(TiCu)alloy.In general,most studies on antibacterial implants have used a single pathogen to test their anti-infection ability using infectious animal models.However,dental implant-associated infections are polymicrobial diseases.We innovatively combine the classic ligature model in dogs with sucrose-rich diets to induce oral infections via the canine native oral bacteria.The anti-infection ability,biocompatibility and underlying mechanism of TiCu implant were systematically investigated in comparison with pure Ti implant via general inspection,hematology,imageology(micro-CT),microbiology(16S rDNA and metagenome),histology,and Cu ion detections.Compared with Ti implant,TiCu implant demonstrated remarkable anti-infection potentials with excellent biocompatibility.Additionally,the underlying anti-infection mechanism of TiCu implant was considered to involve maintaining the oral microbiota homeostasis.It was found that the carbohydrates in the plaques formed on the surface of TiCu implant were metabolized through the tricarboxylic acid cycle(TCA)cycles,which prevented the formation of an acidic microenvironment and inhibited the accumulation of acidogens and pathogens,thereby maintaining the microflora balance between aerobic and anaerobic bacteria.展开更多
This paper proposes a novel power management strategy for plug-in hybrid electric vehicles based on deep reinforcement learning algorithm.Three parallel soft actor-critic(SAC)networks are trained for high speed,medium...This paper proposes a novel power management strategy for plug-in hybrid electric vehicles based on deep reinforcement learning algorithm.Three parallel soft actor-critic(SAC)networks are trained for high speed,medium speed,and low-speed conditions respectively;the reward function is designed as minimizing the cost of energy cost and battery aging.During operation,the driving condition is recognized at each moment for the algorithm invoking based on the learning vector quantization(LVQ)neural network.On top of that,a driving cycle reconstruction algorithm is proposed.The historical speed segments that were recorded during the operation are reconstructed into the three categories of high speed,medium speed,and low speed,based on which the algorithms are online updated.The SAC-based control strategy is evaluated based on the standard driving cycles and Shenyang practical data.The results indicate the presented method can obtain the effect close to dynamic programming and can be further improved by up to 6.38%after the online update for uncertain driving conditions.展开更多
Graphene oxide（GO） membranes play an important role in various nanofiltration applications including desalination, water purification, gas separation, and pervaporation. However, it is still very challenging to achi...Graphene oxide（GO） membranes play an important role in various nanofiltration applications including desalination, water purification, gas separation, and pervaporation. However, it is still very challenging to achieve both high separation efficiency and good water permeance at the same time. Here, we synthesized two kinds of GO-based composite membranes i.e. reduced GO（rGO）@MoO2 and rGO@WO3 by in-situ growth of metal nanoparticles on the surface of GO sheets. They show a high separation efficiency of ～100% for various organic dyes such as rhodamine B, methylene blue and evans blue, along with a water permeance over 125 Lm（-2） h（-1） bar（-1）. The high water permeance and rejection efficiency open up the possibility for the real applications of our GO composite membranes in water purification and wastewater treatment. Furthermore, this composite strategy can be readily extended to the fabrication of other ultrathin molecular sieving membranes for a wide range of molecular separation applications.展开更多
High-energy ball milling(HEBM)combined with powder metallurgy route was used to fabricate carbon nanotube(CNT)reinforced 7055 Al composites.Two powder morphology evolution processes(HEBM-1 and HEBM-2)were designed to ...High-energy ball milling(HEBM)combined with powder metallurgy route was used to fabricate carbon nanotube(CNT)reinforced 7055 Al composites.Two powder morphology evolution processes(HEBM-1 and HEBM-2)were designed to investigate the dispersion and damage of CNTs during HEBM process.HEBM-1 evolution process involved powder fl attening,cold-welding and fracture,while HEBM-2 evolution process consisted of powder fl attening and fracture.For HEBM-1,the repetitive fracture and cold-welding process was effective for dispersing CNTs.However,the powder fl attening process in HEBM-2 was unsuccessful in dispersing CNTs due to two reasons:(1)the thickness of fl aky Al powders exceeded the critical value,and(2)the clustered CNTs embedded in fl aky Al powders could not be unravelled.Because of the broadening of D band and the appearance of a new defect-related D’band,product of I D/I G and full width half maximum of D band,rather than I D/I G,was used to evaluate the actual damage of CNTs.It indicates that the damage of CNTs was severe in powder fl attening and fracture stages,while the damage of CNTs was small in powder cold-welding stage.展开更多
In-situ incorporation of layered double hydroxides(LDH)nanocontainers into plasma electrolytic oxidation(PEO)coatings on AZ91 Mg alloy has been achieved in the present study.Fumarate was selected as Mg corrosion inhib...In-situ incorporation of layered double hydroxides(LDH)nanocontainers into plasma electrolytic oxidation(PEO)coatings on AZ91 Mg alloy has been achieved in the present study.Fumarate was selected as Mg corrosion inhibitor for exchange and intercalation into the nanocontainers,which were subsequently incorporated into the coating.It was found that the thickness and compactness of the coatings were increased in the presence of LDH nanocontainers.The corrosion protection performance of the blank PEO,LDH containing PEO and inhibitor loaded coatings was evaluated by means of polarization test and electrochemical impedance spectroscopy(EIS).The degradation process and corrosion resistance of PEO coating were found to be greatly affected by the loaded inhibitor and nanocontainers by means of ion-exchange when corrosion occurs,leading to enhanced and stable corrosion resistance of the substrate.展开更多
Aims One major goal of modern community ecology is to understand how deterministic and stochastic processes combine to drive community assembly.However,little empirical knowledge is known about how their relative impo...Aims One major goal of modern community ecology is to understand how deterministic and stochastic processes combine to drive community assembly.However,little empirical knowledge is known about how their relative importance varies between common and rare species.Methods We exploited two 30-year data sets of plant communities in a temperate steppe using two different methods.One is a null model method,and the other is a recently developed direct-calculation method.Important Findings We found that stochastic processes tended to be more important in influencing rare than common species.This finding suggests that stochastic forces may play a more important role in structuring communities with more rare species,providing a possible solution to the debate on the varied importance of deterministic and stochastic processes among different communities.展开更多
In this investigation,time-released monolithic osmotic pump(TMOP)tablets containing diltiazem hydrochloride(DIL)were prepared on the basis of osmotic pumping mechanism.The developed dosage forms were coated by Kollido...In this investigation,time-released monolithic osmotic pump(TMOP)tablets containing diltiazem hydrochloride(DIL)were prepared on the basis of osmotic pumping mechanism.The developed dosage forms were coated by Kollidon®SR-Polyethylene Glycol(PEG)mixtures via compression-coated technology instead of spray-coating method to form the outer membrane.For more efficient formulation screening,a three-factor five-level central composite design(CCD)was introduced to explore the optimal TMOP formulation during the experiments.The in vitro tests showed that the optimized formulation of DIL-loaded TMOP had a lag time of 4 h and a following 20-h drug release at an approximate zero-order rate.Moreover,the releasemechanismwas proven based on osmotic pressure and its profile could be well simulated by a dynamic equation.After oral administration by beagle dogs,the comparison of parameters with the TMOP tablets and reference preparations show no significant differences for C_(max)(111.56±20.42,128.38±29.46 ng/ml)and AUC_(0-48 h)(1654.97±283.77,1625.10±313.58 ng h/ml)but show significant differences for T_(max)(13.00±1.16,4.00±0.82 h).These pharmacokinetic parameters were consistent with the dissolution tests that the TMOP tablets had turned out to prolong the lag time of DIL release.展开更多
A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic s...A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic sensor that can continuously detect two kinds of parameters was achieved.By controlling the temperature from high to low,the function of fiber sulfide sensor and fiber DCP sensor can be realized,so as to realize the continuous detection of dual-parameter.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions,the response curves,linear detection ranges,detection limits and response times of the dual-parameter sensor for testing sulfide and DCP were obtained,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing sulfide and DCP concentration of practical water samples.展开更多
Pharmacokinetic analyses were performed using 20 pigs for 120-days implantation,while one sirolimus-eluting stent was implanted into one of their coronary artery.At different time points,the residual sirolimus on the ...Pharmacokinetic analyses were performed using 20 pigs for 120-days implantation,while one sirolimus-eluting stent was implanted into one of their coronary artery.At different time points,the residual sirolimus on the stent,delivered locally(to artery wall),regionally(to adjacent and downstream muscle)and systemically(to plasma and visceral organs),was detected throughout 120 days.Preclinical safety evaluation was performed using 32 pigs for 180-days implantation to study the safety of metal platform material and the effectiveness of sirolimus eluting coating on the HNS stent.The neointima area,restenosis rate and inflammatory grade for HNS and control group stents were detected and analyzed.Approximately 80%sirolimus was eluted from the sirolimuseluting stents after 30-days implantation in vivo.Additionally,there was sustained sirolimus in the artery wall,cardiac muscle and heart throughout 120-days implantation,and sirolimus accumulated to the peak at 90-days implantation.It was inferred that the sirolimus eluting stent in this study was covered by neointima before 90-days implantation,indicating that the sirolimus eluting coating on the HNS stent was safe and effective.Very little sirolimus was distributed in visceral organs after 14-days implantation.HNS sirolimus-eluting stent exhibited lower restenosis rate and lower inflammatory grade than control group,which verified that the sirolimus-eluting coating design in this study was reasonable and practical.In addition,there were no significant difference in restenosis rate and inflammatory score between HNS bare-metal stent and drug-eluting stents,illustrating that HNS has good bio-compatibility and is suitable to use as coronary artery stent material.展开更多
Amorphous Al2 O3-reinforced Al composite(am-Al2 O3/Al) compacted from ultrafine Al powders for high-temperature usages confronts with drawbacks because crystallization of am-Al2 O3 at high temperatures will result in ...Amorphous Al2 O3-reinforced Al composite(am-Al2 O3/Al) compacted from ultrafine Al powders for high-temperature usages confronts with drawbacks because crystallization of am-Al2 O3 at high temperatures will result in serious strength loss.Aiming at this unsolved problem,in this study,high-temperature Al materials with enhanced thermal stability were developed through introducing more thermally stable nano-sized particles via high-temperature pre-treatment of ultrafine A1 powders.It was found that the pre-treatment at ≤550℃ could introduce a few Al2 O3 in the Al matrix and increase the strength of the composites,but the strength was still below that of am-Al2 O3/Al because without being pinned firmly,grain boundaries(GBs) were softened at high temperature and intergranular fracture happened.When the pre-treatment was carried out at 600℃,nitridation and oxidation processes happened simultaneously,producing large numbers of intergranular(AlN+γ-Al2 O3) particles.GB sliding and intergranular fracture were suppressed;therefore,higher strength than that of am-Al2 O3/Al was realized.Furthermore,the(AIN+γ-Al2 O3)/Al exhibited more superior thermal stability compared to amAl2 O3/Al for annealing treatment at 580℃ for 8 h.Therefore,an effective way to fabricate high-temperature Al composite with enhanced thermal stability was developed in this study.展开更多
The development of high-efficiency photocatalysts is the primary goal in the field of photocatalytic antibacterial research.In this work,the Ga N:Zn O solid solution nanoparticles(NPs)photocatalyst with strong visible...The development of high-efficiency photocatalysts is the primary goal in the field of photocatalytic antibacterial research.In this work,the Ga N:Zn O solid solution nanoparticles(NPs)photocatalyst with strong visible absorption and large specific surface area was synthesized via the sol-gel and nitridation reaction process.Also,we systematically investigated the removal efficiency of the organic pollutant and antibacterial activity on E.coli and S.aureus.Notably,methylene blue solution could be completely degraded after 100 min of visible light illumination using 2 mg/m L Ga N:Zn O catalyst.Moreover,~94%of the E.coli were inactivated within 120 min,whereas 100%antibacterial activity against S.aureus was achieved after 90 min of visible light illumination mediated by Ga N:Zn O NPs.We further explore the potential mechanism of visible light photocatalytic antibacterial activity enhanced by Ga N:Zn O NPs photocatalyst.The current work not only provides a new and efficient photocatalytic antibacterial nanomaterial but also demonstrates its promising applications in environmental and biological fields.展开更多
基金the National Basic Research Program of China(No.2006CB504100).
文摘6-（5-Carboxyl-2-methoxyphenyl）-apigenin （1）, a new flavonoid, was isolated from the 60% ethanol extract of Selaginella uncinata （Desv.） Spring. Its structure was established by spectroscopic methods. Compound 1 represents the first example of the flavonoids possessing a benzoic acid substituent at C-6.
基金supported with National Key Research and Development Program of China (2018YFC0808500)National Natural Science Foundation of China (Nos. 51771195)
文摘The effect of cerium content on the corrosion behavior of Al-Co-Ce amorphous alloys in 0.6 M NaCl solution was investigated by cyclic polarization, Mott-Schottky and X-ray photoelectron spectroscopy techniques. Results indicated that the open circuit potential of Al-Co-Ce amorphous alloys displayed a decreased tendency with the increase in Ce content, and the amorphous alloy with 4 at.% Ce presented both the lowest passive current density and donor density indicating the best corrosion resistance, while adding excess Ce led to the reduced corrosion resistance of Al-Co-Ce alloys, Furthermore, it was found that a low Ce content is beneficial to the formation of a more protective passive film on Al-Co-Ce amorphous alloys, and the corrosion inhibition reactions of Al-Co-Ce alloys in 0.6 M NaCl solution were changed with the increase in Ce content and the detailed reasons were discussed.
基金the National Natural Science Foundation of China(No.30770013,No.31500013,No.31000013,No.31360014,No.31470152)the Special Program of Basic Science of the Ministry of Science and Technology(No.2012FY111600)the Technology of and International Cooperation Program of the Ministry of Science and Technology(No.2009DFA31160)of the People’s Republic of China,and the opening funding of State key Laboratory of Mycology,Institute of Microbiology,Chinese Academy of Sciences for funding。
文摘Notes on 113 fungal taxa are compiled in this paper,including 11 new genera,89 new species,one new subspecies,three new combinations and seven reference specimens.Awide geographic and taxonomic range of fungal taxa are detailed.In the Ascomycota the new genera Angustospora(Testudinaceae),Camporesia(Xylariaceae),Clematidis,Crassiparies(Pleosporales genera incertae sedis),Farasanispora,Longiostiolum(Pleosporales genera incertae sedis),Multilocularia(Parabambusicolaceae),Neophaeocryptopus(Dothideaceae),Parameliola(Pleosporales genera incertae sedis),and Towyspora(Lentitheciaceae)are introduced.Newly introduced species are Angustospora nilensis,Aniptodera aquibella,Annulohypoxylon albidiscum,Astrocystis thailandica,Camporesia sambuci,Clematidis italica,Colletotrichum menispermi,C.quinquefoliae,Comoclathris pimpinellae,Crassiparies quadrisporus,Cytospora salicicola,Diatrype thailandica,Dothiorella rhamni,Durotheca macrostroma,Farasanispora avicenniae,Halorosellinia rhizophorae,Humicola koreana,Hypoxylon lilloi,Kirschsteiniothelia tectonae,Lindgomyces okinawaensis,Longiostiolum tectonae,Lophiostoma pseudoarmatisporum,Moelleriella phukhiaoensis,M.pongdueatensis,Mucoharknessia anthoxanthi,Multilocularia bambusae,Multiseptospora thysanolaenae,Neophaeocryptopus cytisi,Ocellularia arachchigei,O.ratnapurensis,Ochronectria thailandica,Ophiocordyceps karstii,Parameliola acaciae,P.dimocarpi,Parastagonospora cumpignensis,Pseudodidymosphaeria phlei,Polyplosphaeria thailandica,Pseudolachnella brevifusiformis,Psiloglonium macrosporum,Rhabdodiscus albodenticulatus,Rosellinia chiangmaiensis,Saccothecium rubi,Seimatosporium pseudocornii,S.pseudorosae,Sigarispora ononidis and Towyspora aestuari.New combinations are provided for Eutiarosporella dactylidis(sexual morph described and illus trated)and Pseudocamarosporium pini.Descriptions,illustrations and/or reference specimens are designated for Aposphaeria corallinolutea,Cryptovalsa ampelina,Dothiorella vidmadera,Ophiocordyceps formosana,Petrakia echinata,Phragmoporthe conformis and Pse
基金the financial supports of the National Natural Science Foundation of China under the contract No.51871049the Fundamental Research Funds for the Central Universities under the contract No.2017YFB0702303+1 种基金Liao Ning Revitalization Talents Program under the contract No.XLYC1807076the World Bank funded Africa Centers of Excellence for Development Impact(ACE Impact)Project。
文摘Superhydrophobic coatings are increasingly being evaluated as anticorrosion interventions in exceedingly hydrated environments.However,concerns about their long-term durability and amenability to large-area applications in marine environments are still hindering commercial-scale deployment.This study is focused on development of easy-to-apply superhydrophobic coatings,with multifunctional capabilities,in order to extend the integrity and durability of the coatings in harsh marine environments.Here,a set of facile methods involving selective chemical etching using concentrated Na OH,as well as fluorination with perfluoropolyether methyl ester were adopted to fabricate a superhydrophobic surface on basalt scales,having the required rough hierarchical micro-nanotextured and low surface energy.The superhydrophobic basalt scales were subsequently aligned atop a fluorocarbon resin,pre-deposited on a metal substrate,to yield a multifunctional superhydrophobic coating(3μL water droplet;contact angle=165.1°,rolling angle=0.7°),easily amenable to large surface area application and having excellent wear resistance,UV-aging resistance,salt spray resistance,corrosion resistance and antibacterial capabilities.
基金financially supported by the Natural Science Foundation of Liaoning Province(No.2020-MS-004)the Natural Science Foundation of Liaoning(ZR2021ME241)+1 种基金the National Natural Science Foundation of China(Nos.51601193 and 51701218)the National Key Research and Development Program of China(No.2016YFB0301104)。
文摘The low-cycle fatigue behavior of solutionized(T4)and aged(T6)WE43 magnesium alloys was studied at room temperature.The total strain amplitudes(△ε_(t)/2)were 0.4%,0.5%,0.6%,0.7%and 1.0%.Detailed microstructure evolution was characterized by scanning electron microscope(SEM),electron backscattered diffraction(EBSD)and transmission electron microscopy(TEM).The results showed that plastic strain amplitude decreased with the increasing cycle number in T4 alloy,which is due to the dense persistent slip bands(PSBs)and dynamic precipitates hinderingdislocation slip.In contrast,the plastic strain amplitude increases gradually in T6 alloy,which is attributed to the enhanced activation of pyramidal slip.The low-cycle fatigue life of T6 alloy with larger fatigue ductility coefficient is longer than that of T4 alloy.The Coffin-Manson model can accurately predict the fatigue life of T4 and T6 alloys compared to Jahed-Varvani(JV)energy model.For T4 alloy,the fatigue damage mechanism was dominated by basal slip.For T6 alloy,the enhanced pyramidal slip plays an important role to accommodate plastic deformation.
基金supported financially by the National Natural Science Foundation of China(No.51771201 and No.51822402)the Key Project of Natural Science Foundation of Liaoning Province+4 种基金China(No.20180510059)the Shenyang National Laboratory for Materials Science(No.2017RP17)the State Key Laboratory of Solidification Processing in Northwestern Polytechnical University(No.SKLSP201902)support of the U.S.Army Research Office Project(W911NF-13-1-0438 and W911NF-19-2-0049)with the program managers,Drs.M.P.Bakas,S.N.Mathaudhu,D.M.Steppsupport from the National Science Foundation(DMR-1611180 and DMR-1809640)with the program directors,Drs.J.Yang,G.Shiflet,D.Farkas。
文摘Recently,the eutectic high-entropy alloy(EHEA),AlCoCrFeNi_(2.1),can reach a good balance of strength and ductility.The dual-phase alloy exhibits a eutectic lamellar microstructure with large numbers of interfaces.However,the role of the interfaces in plastic deformation have not been revealed deeply.In the present work,the orientation relationship(OR)of the interfaces has been clarified as the Kurdjumov-Sachs(KS)interfaces presenting〈111〉_(B2) 〈110〉_(FCC)and {110} _(B2){111}_(FCC) independent of their morphologies.There exist three kinds of interfaces in the EHEA,namely,The dominating interface and the secondary interface are both non-slip planes and atomistic-scale faceted,facilitating the nucleation and slip transmission of the dislocations.The formation mechanism of the preferred interfaces is revealed using the atomistic geometrical analysis according to the criteria of the low interfacial energy based on the coincidence-site lattice(CSL)theory.In particular,the ductility of the dual-phase alloy originates from the KS interface-induced slip continuity across interfaces,which provides a high slip-transfer geometric factor.Moreover,the strengthening effect can be attributed to the interface resistance for the dislocation transmission due to the mismatches of the moduli and lattice parameters at the interfaces.
基金financially supported by the National Key Research and Development Program of China(2018YFC1106601,2016YFC1100601)Liao Ning Revitalization Talents Program(XLYC1807069)+1 种基金National Natural Science Foundation(No.51631009,31870954)Key Projects for Foreign Cooperation of Bureau of International Cooperation Chinese Academy of Sciences(174321KYSB2018000)。
文摘Implant-related infection and early bone integration are the main risk factors of implants for long-term service,to overcome these difficulties,SLA-TiCu surface was prepared by sandblasting and large-grits etching(SLA)treatment on a novel antibacterial titanium-copper alloy(TiCu),which is the most prevalent surface treatment with micro/submicron hierarchical structures to titanium-based implants.Effects of SLA-TiCu surface on the adhesion,proliferation,apoptosis and differentiation of MC3T3-E1 cells as well as the antibacterial activity against a common orthopedic pathogen(Staphylococcus aureus)were studied.Compared to the following surfaces:sandblasting and large-grits etched pure titanium(SLATi),mechanically ground pure titanium and TiCu alloy(M-Ti and M-TiCu),these results indicated that SLA-TiCu surface obviously enhanced the bone-related gene expressions(alkaline phosphates(ALP),collagen typeⅠ(COLⅠ),Runt-related transcription factor 2(RUN x 2),and osteopontin(OPN)).Moreover,SLA-TiCu surface could maintain a sustainable release of Cu2+ions and effectively inhibited the viability of bacteria.This study demonstrated that SLA-TiCu surface possessed multifunctional characteristics of improved osteogenic ability and antibacterial activity,making it promising as a novel implant material for hard tissue repairs such as orthopedics and dental implants.
基金supported by the National Key Research and Development Program of China(2020YFC1200101)the National Natural Science Foundation of China(82073615,42041001).
文摘Background Global connectivity and environmental change pose continuous threats to dengue invasions from worldwide to China.However,the intrinsic relationship on introduction and outbreak risks of dengue driven by the landscape features are still unknown.This study aimed to map the patterns on source-sink relation of dengue cases and assess the driving forces for dengue invasions in China.Methods We identified the local and imported cases(2006–2020)and assembled the datasets on environmental conditions.The vector auto-regression model was applied to detect the cross-relations of source-sink patterns.We selected the major environmental drivers via the Boruta algorithm to assess the driving forces in dengue outbreak dynamics by applying generalized additive models.We reconstructed the internal connections among imported cases,local cases,and external environmental drivers using the structural equation modeling.Results From 2006 to 2020,81,652 local dengue cases and 12,701 imported dengue cases in China were reported.The hotspots of dengue introductions and outbreaks were in southeast and southwest China,originating from South and Southeast Asia.Oversea-imported dengue cases,as the Granger-cause,were the initial driver of the dengue dynamic;the suitable local bio-socioecological environment is the fundamental factor for dengue epidemics.The Bio8[odds ratio(OR)=2.11,95%confidence interval(CI):1.67–2.68],Bio9(OR=291.62,95%CI:125.63–676.89),Bio15(OR=4.15,95%CI:3.30–5.24),normalized difference vegetation index in March(OR=1.27,95%CI:1.06–1.51)and July(OR=1.04,95%CI:1.00–1.07),and the imported cases are the major drivers of dengue local transmissions(OR=4.79,95%CI:4.34–5.28).The intermediary effect of an index on population and economic development to local cases via the path of imported cases was detected in the dengue dynamic system.Conclusions Dengue outbreaks in China are triggered by introductions of imported cases and boosted by landscape features and connectivity.Our research will contribute to devel
基金The National Natural Science Foundation of China （50471077） the Ministry of Science and Technology of China （2006CB605201, 2005DFA50860） supported this work.
文摘Designing and synthesis of cost effective bulk metallic glasses （BMGs） has been of considerable interest during the last decade so that they can be made commercially viable. Among these, Zr-based BMGs have been reported extensively due to their attractive properties, An alloy having composition Zr65Cu18Ni9A18 was designed and synthesized using 2-3 N pure materials by Cu mould casting. The alloy was characterized by X- ray diffraction （XRD）, scanning electron microscopy （SEM）, energy dispersive X-ray spectroscopy （EDS） and high temperature differential scanning calorimetry （DSC）. Thermal parameters like supercooled liquid region △Tx, reduced glass transition temperature Trg, γ and δ parameters were evaluated. Mechanical properties like microhardness, nanohardness, elastic modulus and fracture strength were measured. The alloy showed wide supercooled liquid region of 129＋1 K with improved thermal stability. The alloy has considerable fracture strength along with fair amount of ductility.
基金supported by the Bureau of International Cooperation,Chinese Academy of Sciences[174321KYSB20180006]National Key Research and Development Program of China[2018YFC1106600,2016YFC1100600]+1 种基金Natural Science Foundation of China[51631009,31870954]Liaoning Revitalization Talents Program[XLYC1807069].
文摘This work was focused on study of anti-infection ability and its underlying mechanism of a novel dental implant made of titanium-copper(TiCu)alloy.In general,most studies on antibacterial implants have used a single pathogen to test their anti-infection ability using infectious animal models.However,dental implant-associated infections are polymicrobial diseases.We innovatively combine the classic ligature model in dogs with sucrose-rich diets to induce oral infections via the canine native oral bacteria.The anti-infection ability,biocompatibility and underlying mechanism of TiCu implant were systematically investigated in comparison with pure Ti implant via general inspection,hematology,imageology(micro-CT),microbiology(16S rDNA and metagenome),histology,and Cu ion detections.Compared with Ti implant,TiCu implant demonstrated remarkable anti-infection potentials with excellent biocompatibility.Additionally,the underlying anti-infection mechanism of TiCu implant was considered to involve maintaining the oral microbiota homeostasis.It was found that the carbohydrates in the plaques formed on the surface of TiCu implant were metabolized through the tricarboxylic acid cycle(TCA)cycles,which prevented the formation of an acidic microenvironment and inhibited the accumulation of acidogens and pathogens,thereby maintaining the microflora balance between aerobic and anaerobic bacteria.
基金National Natural Science Foundation of China(51977029,52177210)Liaoning Provincial Science and Technology planned project(2021JH6/10500135)+1 种基金Fundamental Research Funds for the Central Universities(N2003002)Any opinions expressed in this paper are solely those of the authors and do not represent those of the sponsors.
文摘This paper proposes a novel power management strategy for plug-in hybrid electric vehicles based on deep reinforcement learning algorithm.Three parallel soft actor-critic(SAC)networks are trained for high speed,medium speed,and low-speed conditions respectively;the reward function is designed as minimizing the cost of energy cost and battery aging.During operation,the driving condition is recognized at each moment for the algorithm invoking based on the learning vector quantization(LVQ)neural network.On top of that,a driving cycle reconstruction algorithm is proposed.The historical speed segments that were recorded during the operation are reconstructed into the three categories of high speed,medium speed,and low speed,based on which the algorithms are online updated.The SAC-based control strategy is evaluated based on the standard driving cycles and Shenyang practical data.The results indicate the presented method can obtain the effect close to dynamic programming and can be further improved by up to 6.38%after the online update for uncertain driving conditions.
基金supported by the Ministry of Science and Technology of China (No. 2016YFA0200101)the National Natural Science Foundation of China (Nos. 51325205, 51290273, and 51521091)+1 种基金the Chinese Academy of Sciences (KGZD-EW-303-1, and KGZDEW-T06)the support of CAS-TWAS President Fellowship
文摘Graphene oxide（GO） membranes play an important role in various nanofiltration applications including desalination, water purification, gas separation, and pervaporation. However, it is still very challenging to achieve both high separation efficiency and good water permeance at the same time. Here, we synthesized two kinds of GO-based composite membranes i.e. reduced GO（rGO）@MoO2 and rGO@WO3 by in-situ growth of metal nanoparticles on the surface of GO sheets. They show a high separation efficiency of ～100% for various organic dyes such as rhodamine B, methylene blue and evans blue, along with a water permeance over 125 Lm（-2） h（-1） bar（-1）. The high water permeance and rejection efficiency open up the possibility for the real applications of our GO composite membranes in water purification and wastewater treatment. Furthermore, this composite strategy can be readily extended to the fabrication of other ultrathin molecular sieving membranes for a wide range of molecular separation applications.
基金supported by the Key Research Program of Frontier Sciences,CAS(No.QYZDJ-SSW-JSC015)the National Key R&D Program of China(No.2017YFB0703104)+2 种基金the Project of manned spaceflight(No.040103)the National Natural Science Foundation of China(Nos.51931009,51871215)the Youth Innovation Promotion Association CAS(No.2020197)。
文摘High-energy ball milling(HEBM)combined with powder metallurgy route was used to fabricate carbon nanotube(CNT)reinforced 7055 Al composites.Two powder morphology evolution processes(HEBM-1 and HEBM-2)were designed to investigate the dispersion and damage of CNTs during HEBM process.HEBM-1 evolution process involved powder fl attening,cold-welding and fracture,while HEBM-2 evolution process consisted of powder fl attening and fracture.For HEBM-1,the repetitive fracture and cold-welding process was effective for dispersing CNTs.However,the powder fl attening process in HEBM-2 was unsuccessful in dispersing CNTs due to two reasons:(1)the thickness of fl aky Al powders exceeded the critical value,and(2)the clustered CNTs embedded in fl aky Al powders could not be unravelled.Because of the broadening of D band and the appearance of a new defect-related D’band,product of I D/I G and full width half maximum of D band,rather than I D/I G,was used to evaluate the actual damage of CNTs.It indicates that the damage of CNTs was severe in powder fl attening and fracture stages,while the damage of CNTs was small in powder cold-welding stage.
基金support from National Natural Science Foundation of China(No.52071067 and U1737102)Mobility Programme of the Sino-German Center(M-0056)+1 种基金the Fundamental Research Funds for the Central Universities(N2002009)FUNCOAT project(H2020-MSCA-RISE-2018,Grant Agreement N 823942).
文摘In-situ incorporation of layered double hydroxides(LDH)nanocontainers into plasma electrolytic oxidation(PEO)coatings on AZ91 Mg alloy has been achieved in the present study.Fumarate was selected as Mg corrosion inhibitor for exchange and intercalation into the nanocontainers,which were subsequently incorporated into the coating.It was found that the thickness and compactness of the coatings were increased in the presence of LDH nanocontainers.The corrosion protection performance of the blank PEO,LDH containing PEO and inhibitor loaded coatings was evaluated by means of polarization test and electrochemical impedance spectroscopy(EIS).The degradation process and corrosion resistance of PEO coating were found to be greatly affected by the loaded inhibitor and nanocontainers by means of ion-exchange when corrosion occurs,leading to enhanced and stable corrosion resistance of the substrate.
基金National Natural Science Foundation(31300431)State Key Laboratory of Forest and Soil Ecology(LFSE2013-15)of ChinaChina Scholarship Council(CSC NO.201404910179).
文摘Aims One major goal of modern community ecology is to understand how deterministic and stochastic processes combine to drive community assembly.However,little empirical knowledge is known about how their relative importance varies between common and rare species.Methods We exploited two 30-year data sets of plant communities in a temperate steppe using two different methods.One is a null model method,and the other is a recently developed direct-calculation method.Important Findings We found that stochastic processes tended to be more important in influencing rare than common species.This finding suggests that stochastic forces may play a more important role in structuring communities with more rare species,providing a possible solution to the debate on the varied importance of deterministic and stochastic processes among different communities.
基金This work was supported by the State Key Laboratory(Longacting and Targeting Drug Delivery System)by the Special Construction Project(Taishan Scholar–Pharmacy Specially Recruited Experts).
文摘In this investigation,time-released monolithic osmotic pump(TMOP)tablets containing diltiazem hydrochloride(DIL)were prepared on the basis of osmotic pumping mechanism.The developed dosage forms were coated by Kollidon®SR-Polyethylene Glycol(PEG)mixtures via compression-coated technology instead of spray-coating method to form the outer membrane.For more efficient formulation screening,a three-factor five-level central composite design(CCD)was introduced to explore the optimal TMOP formulation during the experiments.The in vitro tests showed that the optimized formulation of DIL-loaded TMOP had a lag time of 4 h and a following 20-h drug release at an approximate zero-order rate.Moreover,the releasemechanismwas proven based on osmotic pressure and its profile could be well simulated by a dynamic equation.After oral administration by beagle dogs,the comparison of parameters with the TMOP tablets and reference preparations show no significant differences for C_(max)(111.56±20.42,128.38±29.46 ng/ml)and AUC_(0-48 h)(1654.97±283.77,1625.10±313.58 ng h/ml)but show significant differences for T_(max)(13.00±1.16,4.00±0.82 h).These pharmacokinetic parameters were consistent with the dissolution tests that the TMOP tablets had turned out to prolong the lag time of DIL release.
基金Funded by the Natural Science Foundation of Hubei Province(No.2022CFB861)the Wenhua College Research and Innovation Team(No.2022T01)。
文摘A novel fiber optic sensor based on hydrogel-immobilized enzyme complex was developed for the simultaneous measurement of dual-parameter,the leap from a single parameter detecting fiber optic sensor to a fiber optic sensor that can continuously detect two kinds of parameters was achieved.By controlling the temperature from high to low,the function of fiber sulfide sensor and fiber DCP sensor can be realized,so as to realize the continuous detection of dual-parameter.The different variables affecting the sensor performance were evaluated and optimized.Under the optimal conditions,the response curves,linear detection ranges,detection limits and response times of the dual-parameter sensor for testing sulfide and DCP were obtained,respectively.The sensor displays high selectivity,good repeatability and stability,which have good potentials in analyzing sulfide and DCP concentration of practical water samples.
基金financially supported by National Key Research and Development Program of China(NO.2016YFC1102404 and NO.2016YFC1102405)Chinese Academy of Sciences President's International Fellowship Initiative(Grant No.2018FYE0005)National Natural Science Fund of China(81670319,81521001).
文摘Pharmacokinetic analyses were performed using 20 pigs for 120-days implantation,while one sirolimus-eluting stent was implanted into one of their coronary artery.At different time points,the residual sirolimus on the stent,delivered locally(to artery wall),regionally(to adjacent and downstream muscle)and systemically(to plasma and visceral organs),was detected throughout 120 days.Preclinical safety evaluation was performed using 32 pigs for 180-days implantation to study the safety of metal platform material and the effectiveness of sirolimus eluting coating on the HNS stent.The neointima area,restenosis rate and inflammatory grade for HNS and control group stents were detected and analyzed.Approximately 80%sirolimus was eluted from the sirolimuseluting stents after 30-days implantation in vivo.Additionally,there was sustained sirolimus in the artery wall,cardiac muscle and heart throughout 120-days implantation,and sirolimus accumulated to the peak at 90-days implantation.It was inferred that the sirolimus eluting stent in this study was covered by neointima before 90-days implantation,indicating that the sirolimus eluting coating on the HNS stent was safe and effective.Very little sirolimus was distributed in visceral organs after 14-days implantation.HNS sirolimus-eluting stent exhibited lower restenosis rate and lower inflammatory grade than control group,which verified that the sirolimus-eluting coating design in this study was reasonable and practical.In addition,there were no significant difference in restenosis rate and inflammatory score between HNS bare-metal stent and drug-eluting stents,illustrating that HNS has good bio-compatibility and is suitable to use as coronary artery stent material.
基金supported by the National Natural Science Foundation of China (Nos. U1508216 and 51771194)the Youth Innovation Promotion Association CAS (No. 2016179)the National Key R&D Program of China (No. 2017YFB0703104)。
文摘Amorphous Al2 O3-reinforced Al composite(am-Al2 O3/Al) compacted from ultrafine Al powders for high-temperature usages confronts with drawbacks because crystallization of am-Al2 O3 at high temperatures will result in serious strength loss.Aiming at this unsolved problem,in this study,high-temperature Al materials with enhanced thermal stability were developed through introducing more thermally stable nano-sized particles via high-temperature pre-treatment of ultrafine A1 powders.It was found that the pre-treatment at ≤550℃ could introduce a few Al2 O3 in the Al matrix and increase the strength of the composites,but the strength was still below that of am-Al2 O3/Al because without being pinned firmly,grain boundaries(GBs) were softened at high temperature and intergranular fracture happened.When the pre-treatment was carried out at 600℃,nitridation and oxidation processes happened simultaneously,producing large numbers of intergranular(AlN+γ-Al2 O3) particles.GB sliding and intergranular fracture were suppressed;therefore,higher strength than that of am-Al2 O3/Al was realized.Furthermore,the(AIN+γ-Al2 O3)/Al exhibited more superior thermal stability compared to amAl2 O3/Al for annealing treatment at 580℃ for 8 h.Therefore,an effective way to fabricate high-temperature Al composite with enhanced thermal stability was developed in this study.
基金supported by the National Natural Science Foundation of China(51702326,1872332,51901227)the Liaoning Province Natural Science Foundation(2019-MS-333)the National Key Research and Development Program of China(2018YFC1105504)。
文摘The development of high-efficiency photocatalysts is the primary goal in the field of photocatalytic antibacterial research.In this work,the Ga N:Zn O solid solution nanoparticles(NPs)photocatalyst with strong visible absorption and large specific surface area was synthesized via the sol-gel and nitridation reaction process.Also,we systematically investigated the removal efficiency of the organic pollutant and antibacterial activity on E.coli and S.aureus.Notably,methylene blue solution could be completely degraded after 100 min of visible light illumination using 2 mg/m L Ga N:Zn O catalyst.Moreover,~94%of the E.coli were inactivated within 120 min,whereas 100%antibacterial activity against S.aureus was achieved after 90 min of visible light illumination mediated by Ga N:Zn O NPs.We further explore the potential mechanism of visible light photocatalytic antibacterial activity enhanced by Ga N:Zn O NPs photocatalyst.The current work not only provides a new and efficient photocatalytic antibacterial nanomaterial but also demonstrates its promising applications in environmental and biological fields.
