The fatigue damage behavior of the nanocrystalline Au films on polyimide substrates was investigated.It was found that the very high-cycle fatigue damage resistance of the Au film was significantly enhanced by at leas...The fatigue damage behavior of the nanocrystalline Au films on polyimide substrates was investigated.It was found that the very high-cycle fatigue damage resistance of the Au film was significantly enhanced by at least a factor of~2 in supported loading through adding an ultrathin Ti interlayer at the Au film/polyimide interface.Such a better fatigue damage resistance is mainly ascribed to the effective suppression of voiding at the Au film/polyimide interface through modulation of the Au/Ti interface,and thus the propensity of the cyclic strain localization and grain boundary cracking is reduced.The finding may provide a potential strategy for the design of flexible devices with ultra-long fatigue life.展开更多
The Yelapa-Chimo Metamorphic Complex forms part of the Jalisco Block in western Mexico and exposes a wide range of Early Cretaceous metamorphic rocks;such as paragneiss,orthogneiss,amphibolites,and migmatites.However,...The Yelapa-Chimo Metamorphic Complex forms part of the Jalisco Block in western Mexico and exposes a wide range of Early Cretaceous metamorphic rocks;such as paragneiss,orthogneiss,amphibolites,and migmatites.However,the pressure-temperature(P-T)conditions of metamorphism and partial melting remain poorly studied in the region.To elucidate metamorphic P-T conditions,phase equilibrium modelling was applied to two sillimanite-garnet paragneisses,one amphibole-orthogneiss,and one amphibolite.Sillimanite-garnet paragneisses exhibit a lepidoblastic texture with a biotite+sillimanite+kyanite+garnet+quartz+plagioclase+K-feldspar mineral assemblage.Amphibole-orthogneiss and amphibolite display a nematoblastic texture with an amphibole+(1)plagioclase+quartz+(1)titanite assemblage and an amphibole+(2)plagioclase+(2)titanite+ilmenite retrograde mineral assemblage.Pseudosections calculated for the two sillimanite-garnet paragneiss samples show P-T peak conditions at~6-7.5 kbar and~725-740℃.The results for amphibole-orthogneiss and the amphibolite yield P-T peak conditions at~8.5-10 kbar and~690-710℃.The mode models imply that metasedimentary and metaigneous units can produce up to~20 vol%and~10 vol%of melt,respectively.Modelling within a closed system during isobaric heating suggests that melt compositions of metasedimentary and metaigneous units are likely to have direct implications for the petrogenesis of the Puerto Vallarta Batholith.Our new data indicate that the Yelapa-Chimo Metamorphic Complex evolved through a metamorphic gradient between~23-33℃km^-1and the metamorphic rocks formed at depths between~22 km and~30 km with a burial rate of~2.0 km Ma^-1.Finally,the P-T data for both metasedimentary and metaigneous rocks provide new constraints on an accretionary framework,which is responsible for generating metamorphism and partial melting in the YelapaChimo Metamorphic Complex during the Early Cretaceous.展开更多
Understanding the oceanographic and environmental changes experienced on the South American Pacific coast during the Plio-Pleistocene transition and the influence of these variations on the evolution of marine ecosyst...Understanding the oceanographic and environmental changes experienced on the South American Pacific coast during the Plio-Pleistocene transition and the influence of these variations on the evolution of marine ecosystems is particularly interesting to assess the effects of current global climate projections.We present a stratigraphic model of the marine sedimentary successions exposed in Coquimbo(∼30°S),northern Chile,supported by 22 numerical ages from the last 6 Ma obtained through^(87)Sr/^(86)Sr dating of fossil mollusk shells.This stratigraphic model,and paleoecological and sedimentary facies analyses allow us to interpret the paleoenvironmental evolution and depositional dynamics in the basin.The marine successions accumulated in four sedimentation episodes:the first two on the shoreface during Messinian-Zanclean(∼6-5.10 Ma)and Zanclean-Piacenzian(∼4.23-3 Ma)ages,whereas the last two occurred mainly on the foreshore during middle Calabrian(∼1.15 Ma)and late Calabrian-Chibanian(∼0.83-0.25 Ma).The most significant taxonomic changes are observed in the transition between the Pliocene and Pleistocene deposits(∼3-1.15 Ma),reflecting the shift from faunal associations typical of warm-temperate waters to others of cool-temperate water preferences.The faunal turnover identified in this study correlates well with two climatic transition pulses out of three previously recognized in the southeastern Pacific Ocean for the Plio-Pleistocene:one during the Piacenzian-Gelasian(3-2.4 Ma),marked by a decrease in water temperature and an expansion of upwelling zones in the Humboldt Current System;and the other during the Gelasian-Calabrian(2-1.5 Ma),which has been linked to the establishment of the current El Niño Southern Oscillation(ENSO)climate system.展开更多
We report long-lived,highly spatially localized plasmon states on the surface of nanoporous gold nanoparticles—nanosponges—with high excitation efficiency.It is well known that disorder on the nanometer scale,partic...We report long-lived,highly spatially localized plasmon states on the surface of nanoporous gold nanoparticles—nanosponges—with high excitation efficiency.It is well known that disorder on the nanometer scale,particularly in two-dimensional systems,can lead to plasmon localization and large field enhancements,which can,in turn,be used to enhance nonlinear optical effects and to study and exploit quantum optical processes.Here,we introduce promising,three-dimensional model systems for light capture and plasmon localization as gold nanosponges that are formed by the dewetting of gold/silver bilayers and dealloying.We study light-induced electron emission from single nanosponges,a nonlinear process with exponents of n≈5...7,using ultrashort laser pulse excitation to achieve femtosecond time resolution.The long-lived electron emission process proves,in combination with optical extinction measurements and finite-difference time-domain calculations,the existence of localized modes with lifetimes of more than 20 fs.These electrons couple efficiently to the dipole antenna mode of each individual nanosponge,which in turn couples to the far-field.Thus,individual gold nanosponges are cheap and robust disordered nanoantennas with strong local resonances,and an ensemble of nanosponges constitutes a meta material with a strong polarization independent,nonlinear response over a wide frequency range.展开更多
基金supported by the National Natural Science Foundation of China(NSFC,Grant Nos.52071319,51601198 and 51771207)Foundation for Outstanding Young Scholar sponsored by Institute of Metal Research(IMR),Natural Science Foundation of Liaoning Province of China(20180510025)Foundation for Outstanding Young Scholar sponsored by the Shenyang National Laboratory for Materials Science(L2019F23)。
文摘The fatigue damage behavior of the nanocrystalline Au films on polyimide substrates was investigated.It was found that the very high-cycle fatigue damage resistance of the Au film was significantly enhanced by at least a factor of~2 in supported loading through adding an ultrathin Ti interlayer at the Au film/polyimide interface.Such a better fatigue damage resistance is mainly ascribed to the effective suppression of voiding at the Au film/polyimide interface through modulation of the Au/Ti interface,and thus the propensity of the cyclic strain localization and grain boundary cracking is reduced.The finding may provide a potential strategy for the design of flexible devices with ultra-long fatigue life.
基金funded by Programa de Apoyo a Proyectos de Investigacion e Innovacion Tecnologica(PAPIIT)grant IN112314。
文摘The Yelapa-Chimo Metamorphic Complex forms part of the Jalisco Block in western Mexico and exposes a wide range of Early Cretaceous metamorphic rocks;such as paragneiss,orthogneiss,amphibolites,and migmatites.However,the pressure-temperature(P-T)conditions of metamorphism and partial melting remain poorly studied in the region.To elucidate metamorphic P-T conditions,phase equilibrium modelling was applied to two sillimanite-garnet paragneisses,one amphibole-orthogneiss,and one amphibolite.Sillimanite-garnet paragneisses exhibit a lepidoblastic texture with a biotite+sillimanite+kyanite+garnet+quartz+plagioclase+K-feldspar mineral assemblage.Amphibole-orthogneiss and amphibolite display a nematoblastic texture with an amphibole+(1)plagioclase+quartz+(1)titanite assemblage and an amphibole+(2)plagioclase+(2)titanite+ilmenite retrograde mineral assemblage.Pseudosections calculated for the two sillimanite-garnet paragneiss samples show P-T peak conditions at~6-7.5 kbar and~725-740℃.The results for amphibole-orthogneiss and the amphibolite yield P-T peak conditions at~8.5-10 kbar and~690-710℃.The mode models imply that metasedimentary and metaigneous units can produce up to~20 vol%and~10 vol%of melt,respectively.Modelling within a closed system during isobaric heating suggests that melt compositions of metasedimentary and metaigneous units are likely to have direct implications for the petrogenesis of the Puerto Vallarta Batholith.Our new data indicate that the Yelapa-Chimo Metamorphic Complex evolved through a metamorphic gradient between~23-33℃km^-1and the metamorphic rocks formed at depths between~22 km and~30 km with a burial rate of~2.0 km Ma^-1.Finally,the P-T data for both metasedimentary and metaigneous rocks provide new constraints on an accretionary framework,which is responsible for generating metamorphism and partial melting in the YelapaChimo Metamorphic Complex during the Early Cretaceous.
基金funded by ANID(Agencia Nacional de Investigación y Desarrollo de Chile)through the CONICYT-PFCHA/Doctorado Nacional/2015-21151267 Grant(D.Partarrieu)the projects ANID/FONDECYT 1200843,1251475(M.Rivadeneira)+2 种基金ANID/Centros Regionales R20F0008(CLAP)(M.Rivadeneira)LUGIS-UNAMUniversidad de Chile through the partial coverage of the costs of laboratory analysis
文摘Understanding the oceanographic and environmental changes experienced on the South American Pacific coast during the Plio-Pleistocene transition and the influence of these variations on the evolution of marine ecosystems is particularly interesting to assess the effects of current global climate projections.We present a stratigraphic model of the marine sedimentary successions exposed in Coquimbo(∼30°S),northern Chile,supported by 22 numerical ages from the last 6 Ma obtained through^(87)Sr/^(86)Sr dating of fossil mollusk shells.This stratigraphic model,and paleoecological and sedimentary facies analyses allow us to interpret the paleoenvironmental evolution and depositional dynamics in the basin.The marine successions accumulated in four sedimentation episodes:the first two on the shoreface during Messinian-Zanclean(∼6-5.10 Ma)and Zanclean-Piacenzian(∼4.23-3 Ma)ages,whereas the last two occurred mainly on the foreshore during middle Calabrian(∼1.15 Ma)and late Calabrian-Chibanian(∼0.83-0.25 Ma).The most significant taxonomic changes are observed in the transition between the Pliocene and Pleistocene deposits(∼3-1.15 Ma),reflecting the shift from faunal associations typical of warm-temperate waters to others of cool-temperate water preferences.The faunal turnover identified in this study correlates well with two climatic transition pulses out of three previously recognized in the southeastern Pacific Ocean for the Plio-Pleistocene:one during the Piacenzian-Gelasian(3-2.4 Ma),marked by a decrease in water temperature and an expansion of upwelling zones in the Humboldt Current System;and the other during the Gelasian-Calabrian(2-1.5 Ma),which has been linked to the establishment of the current El Niño Southern Oscillation(ENSO)climate system.
基金support by the Deutsche Forschungsgemeinschaft(SPP1839‘Tailored Disorder’,grants LI 580/12,RU 1383/5,SCHA 632/24)the Korea Foundation for the International Cooperation of Science and Technology(Global Research Laboratory project,K20815000003)+1 种基金the German-Israeli Foundation(GIF Grant No.1256)is gratefully acknowledgeda personal grant from the Studienstiftung des Deutschen Volkes.
文摘We report long-lived,highly spatially localized plasmon states on the surface of nanoporous gold nanoparticles—nanosponges—with high excitation efficiency.It is well known that disorder on the nanometer scale,particularly in two-dimensional systems,can lead to plasmon localization and large field enhancements,which can,in turn,be used to enhance nonlinear optical effects and to study and exploit quantum optical processes.Here,we introduce promising,three-dimensional model systems for light capture and plasmon localization as gold nanosponges that are formed by the dewetting of gold/silver bilayers and dealloying.We study light-induced electron emission from single nanosponges,a nonlinear process with exponents of n≈5...7,using ultrashort laser pulse excitation to achieve femtosecond time resolution.The long-lived electron emission process proves,in combination with optical extinction measurements and finite-difference time-domain calculations,the existence of localized modes with lifetimes of more than 20 fs.These electrons couple efficiently to the dipole antenna mode of each individual nanosponge,which in turn couples to the far-field.Thus,individual gold nanosponges are cheap and robust disordered nanoantennas with strong local resonances,and an ensemble of nanosponges constitutes a meta material with a strong polarization independent,nonlinear response over a wide frequency range.
