This paper focuses on the Korla-Ruoqiang desert railway line,utilizing ERAS(ERA5 is the fifth generation of ECMWF(European Centre for Medium-Range Weather Forecasts)atmospheric reanalysis global climate data)wind data...This paper focuses on the Korla-Ruoqiang desert railway line,utilizing ERAS(ERA5 is the fifth generation of ECMWF(European Centre for Medium-Range Weather Forecasts)atmospheric reanalysis global climate data)wind data to conduct a comprehensive analysis of the wind energy environment along the line in all aspects,reveals the characteristics of wind-sand transport,and puts forward the countermeasures to prevent and control wind-sand disasters.The results of the study indicate that:(1)the wind-sand along the line mainly occurs in the spring and summer seasons,and the dominant sand-moving directions are easterly(ENE,E and NNE)and northeasterly(NE).(2)The average annual sand-moving wind speed ranges from 5.80 m/s to 7.25 m/s,and the annual frequency of sand-moving ranges from 11.99%to 37.26%.(3)The annual sand drift potential(DP)along the line ranges from 69.20 VU to 607.24 VU,with three types of wind energy environments:low,medium and high.The resultant drift potential(RDP)ranges from 45.52 VU to 547.49 VU,and the wind variability index(RDP/DP)is between 0.54 and 0.90.(4)The average sand transport quantity along the line ranges from 2.92 m^(3)/m/a to 9.09 m3/m/a.Based on these results,we optimize the sand blocking,sand fixing and wind erosion prevention measures for different types of wind-sand environments,establish a scientific and efficient wind-sand protection and control system to solve the wind-sand problems and provide a scientific foundation for the prevention and control of wind-sand disasters along the line.展开更多
Sub-3 nm aluminum(Al)nanocrystal is an emerging class of nanomaterial with properties distinct to noble metal nanoclusters.The complete solution synthesis of aluminum nanoclusters was recently reported,and their photo...Sub-3 nm aluminum(Al)nanocrystal is an emerging class of nanomaterial with properties distinct to noble metal nanoclusters.The complete solution synthesis of aluminum nanoclusters was recently reported,and their photoluminescence(PL)was observed for the first time.At the moment,there exists no method to tune the size of ultrasmall aluminum nanocrystals in solution thus no knowledge on the boundary state between aluminum nanoclusters to plasmonic nanoparticles.In this work,it is demonstrated a study of size-controlled solution synthesis of ultrasmall aluminum nanocrystals with size controlled between -2.2 and -3.8 nm.Increasing the size results in three sets of spectral responses:(1)absorption due to nascent plasmons generated at -340 nm for larger particles,confirmed by Mie theory calculations;(2)significant decreased quantum yield of PL from -7.8%to -2.4%,indicating reduced quantum confinement effects and increased metallicity;(3)drop of fluorescence lifetime was observed,especially when the diameter of aluminum nanoparticles was changed from -3.0 to -3.8 nm.This study provides experimental evidence and insights to the transitional state between aluminum nanoclusters and plasmonic nanoparticles,which seems to occur at size larger than gold nanoclusters.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.52168065)。
文摘This paper focuses on the Korla-Ruoqiang desert railway line,utilizing ERAS(ERA5 is the fifth generation of ECMWF(European Centre for Medium-Range Weather Forecasts)atmospheric reanalysis global climate data)wind data to conduct a comprehensive analysis of the wind energy environment along the line in all aspects,reveals the characteristics of wind-sand transport,and puts forward the countermeasures to prevent and control wind-sand disasters.The results of the study indicate that:(1)the wind-sand along the line mainly occurs in the spring and summer seasons,and the dominant sand-moving directions are easterly(ENE,E and NNE)and northeasterly(NE).(2)The average annual sand-moving wind speed ranges from 5.80 m/s to 7.25 m/s,and the annual frequency of sand-moving ranges from 11.99%to 37.26%.(3)The annual sand drift potential(DP)along the line ranges from 69.20 VU to 607.24 VU,with three types of wind energy environments:low,medium and high.The resultant drift potential(RDP)ranges from 45.52 VU to 547.49 VU,and the wind variability index(RDP/DP)is between 0.54 and 0.90.(4)The average sand transport quantity along the line ranges from 2.92 m^(3)/m/a to 9.09 m3/m/a.Based on these results,we optimize the sand blocking,sand fixing and wind erosion prevention measures for different types of wind-sand environments,establish a scientific and efficient wind-sand protection and control system to solve the wind-sand problems and provide a scientific foundation for the prevention and control of wind-sand disasters along the line.
基金the National Natural Science Foundation of China(Nos.61905211,91833303,11621101,and 61774131)the National Key Research and Development Program of China(No.2017YFA0205700)+2 种基金Science Foundation of Zhejiang Province(No.Y21B050009)the Fundamental Research Funds for the Central Universities(Nos.511308*172210191 and 2019FZA5002)Ningbo Science and Technology Project(No.2018B10093)。
文摘Sub-3 nm aluminum(Al)nanocrystal is an emerging class of nanomaterial with properties distinct to noble metal nanoclusters.The complete solution synthesis of aluminum nanoclusters was recently reported,and their photoluminescence(PL)was observed for the first time.At the moment,there exists no method to tune the size of ultrasmall aluminum nanocrystals in solution thus no knowledge on the boundary state between aluminum nanoclusters to plasmonic nanoparticles.In this work,it is demonstrated a study of size-controlled solution synthesis of ultrasmall aluminum nanocrystals with size controlled between -2.2 and -3.8 nm.Increasing the size results in three sets of spectral responses:(1)absorption due to nascent plasmons generated at -340 nm for larger particles,confirmed by Mie theory calculations;(2)significant decreased quantum yield of PL from -7.8%to -2.4%,indicating reduced quantum confinement effects and increased metallicity;(3)drop of fluorescence lifetime was observed,especially when the diameter of aluminum nanoparticles was changed from -3.0 to -3.8 nm.This study provides experimental evidence and insights to the transitional state between aluminum nanoclusters and plasmonic nanoparticles,which seems to occur at size larger than gold nanoclusters.
