Systematic studies on the genesis,properties,and distribution of natural nanoparticles(NNPs)in soil remain scarce.This study examined a soil chronosequence of continuous paddy field land use for periods ranging from 0...Systematic studies on the genesis,properties,and distribution of natural nanoparticles(NNPs)in soil remain scarce.This study examined a soil chronosequence of continuous paddy field land use for periods ranging from 0 to 1000 years to determine how NNPs in soil changed at the early stages of soil genesis in eastern China.Soil samples were collected from coastal reclaimed paddy fields that were cultivated for 0,50,100,300,700,and 1000 years.Natural nanoparticles were isolated and characterized along with bulk soil samples(<2-mm fraction)for selected physical and chemical properties.The NNP content increased with increasing soil cultivation age at 60 g m^(-2) year-1,which was related to decreasing soil electrical conductivity(172-1297μS cm^(-1))and NNP zeta potentials(from -22 to -36 mV)with increasing soil cultivation age.Changes in several NNP properties,such as pedogenic iron oxide and total organic carbon contents,were consistent with those of the bulk soils across the soil chronosequence.Notably,changes in NNP iron oxide content were obvious and illustrated active chemical weathering,pedogenesis,and potential impacts on the microbial community.Redundancy analysis demonstrated that the soil cultivation age was the most important factor affecting NNP properties,contributing 60.7% of the total variation.Cluster and principal component analysis(PCA)revealed splitting of NNP samples into age groups of 50-300 and 700-1000 years,indicating rapid evolution of NNP properties,after an initial period of desalinization(approximately 50 years).Overall,this study provides new insights into NNP evolution in soil during pedogenesis and predicting their influences on agriculture and ecological risks over millennial-scale rice cultivation.展开更多
We investigate the superposition properties of the dipole and quadrupole plasmon modes in the near field both experimentally, by using photoemission electron microscopy(PEEM), and theoretically. In particular, the asy...We investigate the superposition properties of the dipole and quadrupole plasmon modes in the near field both experimentally, by using photoemission electron microscopy(PEEM), and theoretically. In particular, the asymmetric near-field distributions on gold(Au) nanodisks and nanoblocks under oblique incidence with different polarizations are investigated in detail. The results of PEEM measurements show that the evolutions of the asymmetric near-field distributions are different between the excitation with s-polarized and p-polarized light.The experimental results can be reproduced very well by numerical simulations and interpreted as the superposition of the dipole and quadrupole modes with the help of analytic calculations. Moreover, we hypothesize that the electrons collected by PEEM are mainly from the plasmonic hot spots located at the plane in the interface between the Au particles and the substrate in the PEEM experiments.展开更多
A nanoplasmonic hydrogen-sensing system based on palladium/silver nanosheets （Pd/Ag NSs） was developed and used for sensitive assessment of the hydrogen evolution reaction （HER） in colloid solutions. As a model HE...A nanoplasmonic hydrogen-sensing system based on palladium/silver nanosheets （Pd/Ag NSs） was developed and used for sensitive assessment of the hydrogen evolution reaction （HER） in colloid solutions. As a model HER system, the semiconductor CdS/CdSe core/shell quantum dot （QD）-based hydrogen-producing colloidal system was used, and the HER performances of QDs with two different surface coatings were assessed in this study. In the sensing system, the photocatalytically generated hydrogen reacts with Pd/Ag NSs, resulting in a gradual red-shift of localized surface plasmon resonance, which to a certain degree is almost linearly proportional to the amount of hydrogen generated. Such a nanoplasmonic hydrogen sensing platform would be useful as an alternative for optical assessment and fast selection of a highly efficient and cost-effective solar hydrogen generation system for practical applications.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41721001 and 41130532)。
文摘Systematic studies on the genesis,properties,and distribution of natural nanoparticles(NNPs)in soil remain scarce.This study examined a soil chronosequence of continuous paddy field land use for periods ranging from 0 to 1000 years to determine how NNPs in soil changed at the early stages of soil genesis in eastern China.Soil samples were collected from coastal reclaimed paddy fields that were cultivated for 0,50,100,300,700,and 1000 years.Natural nanoparticles were isolated and characterized along with bulk soil samples(<2-mm fraction)for selected physical and chemical properties.The NNP content increased with increasing soil cultivation age at 60 g m^(-2) year-1,which was related to decreasing soil electrical conductivity(172-1297μS cm^(-1))and NNP zeta potentials(from -22 to -36 mV)with increasing soil cultivation age.Changes in several NNP properties,such as pedogenic iron oxide and total organic carbon contents,were consistent with those of the bulk soils across the soil chronosequence.Notably,changes in NNP iron oxide content were obvious and illustrated active chemical weathering,pedogenesis,and potential impacts on the microbial community.Redundancy analysis demonstrated that the soil cultivation age was the most important factor affecting NNP properties,contributing 60.7% of the total variation.Cluster and principal component analysis(PCA)revealed splitting of NNP samples into age groups of 50-300 and 700-1000 years,indicating rapid evolution of NNP properties,after an initial period of desalinization(approximately 50 years).Overall,this study provides new insights into NNP evolution in soil during pedogenesis and predicting their influences on agriculture and ecological risks over millennial-scale rice cultivation.
基金Japan Society for the Promotion of Science(JSPS)(JP15H00856,JP15H01073,JP15K04589,JP23225006,JP26870014)National Natural Science Foundation of China(NSFC)(11527901)
文摘We investigate the superposition properties of the dipole and quadrupole plasmon modes in the near field both experimentally, by using photoemission electron microscopy(PEEM), and theoretically. In particular, the asymmetric near-field distributions on gold(Au) nanodisks and nanoblocks under oblique incidence with different polarizations are investigated in detail. The results of PEEM measurements show that the evolutions of the asymmetric near-field distributions are different between the excitation with s-polarized and p-polarized light.The experimental results can be reproduced very well by numerical simulations and interpreted as the superposition of the dipole and quadrupole modes with the help of analytic calculations. Moreover, we hypothesize that the electrons collected by PEEM are mainly from the plasmonic hot spots located at the plane in the interface between the Au particles and the substrate in the PEEM experiments.
基金This work was financially supported by the National Natural Science Foundation of China （Nos. 21475125 and 21175125）, the Hundred Talents Program of the Chinese Academy of Sciences, and the State Key Laboratory of Electroanalytical Chemistry （No. 110000R387）.
文摘A nanoplasmonic hydrogen-sensing system based on palladium/silver nanosheets （Pd/Ag NSs） was developed and used for sensitive assessment of the hydrogen evolution reaction （HER） in colloid solutions. As a model HER system, the semiconductor CdS/CdSe core/shell quantum dot （QD）-based hydrogen-producing colloidal system was used, and the HER performances of QDs with two different surface coatings were assessed in this study. In the sensing system, the photocatalytically generated hydrogen reacts with Pd/Ag NSs, resulting in a gradual red-shift of localized surface plasmon resonance, which to a certain degree is almost linearly proportional to the amount of hydrogen generated. Such a nanoplasmonic hydrogen sensing platform would be useful as an alternative for optical assessment and fast selection of a highly efficient and cost-effective solar hydrogen generation system for practical applications.
