Characteristics of road landscaping were analyzed,as a kind of "linear" landscaping,it could be classified into urban street landscaping,urban ring road and expressway landscaping.Differences between road la...Characteristics of road landscaping were analyzed,as a kind of "linear" landscaping,it could be classified into urban street landscaping,urban ring road and expressway landscaping.Differences between road landscaping projects and other garden landscaping projects or construction projects were analyzed.Landscaping project for the South 3rd Ring Road of Xi'an City(in Yanta District)was taken for an example to summarize construction experience,discuss present conditions and features of garden landscaping supervision in China.The artistic and physiological properties of garden landscaping,as well as the supervision during maintenance period were stressed,but it was also pointed out that garden landscaping supervision in China was actually not given sufficient attention.On this basis,key points in the supervision of road landscaping project were proposed:understanding design ideas,selection of landscape plants,quality control of concealed works,prevention and control of diseases and insects,construction safety management and overall image;only by effectively implementing these key points,a high-quality road landscaping project could be realized to improve the image of a city and beautify its environment.展开更多
This paper proposed through systematic analysis that road tail gas is an important source of PM2.5,and elaborated the infl uence of urban road space forms and road landscapes on urban microclimate,on the basis of whic...This paper proposed through systematic analysis that road tail gas is an important source of PM2.5,and elaborated the infl uence of urban road space forms and road landscapes on urban microclimate,on the basis of which gave corresponding landscape design suggestions for PM2.5 control.展开更多
Achieving high-quality perovskite films with uniform morphology and homogeneous crystallinity is challenging owing to the coffee ring effect(CRE) in the spray-coating technologies. In this study, an evaporation/spray-...Achieving high-quality perovskite films with uniform morphology and homogeneous crystallinity is challenging owing to the coffee ring effect(CRE) in the spray-coating technologies. In this study, an evaporation/spray-coating two-step deposition method is used to fabricate Cs_(0.19)FA_(0.81)PbI_(2.5)Br_(0.5)light harvesters for perovskite solar cells(PSCs). Considering the solid–liquid reaction, we establish a reaction-dependent regulating strategy that inhibits CRE successfully and prepare a high-quality perovskite layer, wherein the solvent for the FAI/Br solution during the spraying process is changed from isopropanol to n-butyl alcohol(NBA). The retarded-drying-enhanced spreading of the NBA solution inhibits contact line pinning to suppress the capillary flows and increases the reaction between metal halides(CsI/PbI_(2)) and organic salts(FAI/Br), which result in a reduction in the accumulation of solutes in the periphery effectively inhibiting CRE. Consequently, we obtain a high performance Cs_(0.19)FA_(0.81)PbI_(2.5)Br_(0.5) PSC with a power conversion efficiency(PCE) of 19.17%. An enlarged perovskite film(10 × 10 cm^(2)) containing 40 sub-cells is prepared. The average PCE of these devices is 18.33 ± 0.56%, proving the reliability of the "coffee ring" regulating strategy. This study provides an effective approach for CRE controlment in spraying technology to achieve high repeatability devices with good performance.展开更多
文摘Characteristics of road landscaping were analyzed,as a kind of "linear" landscaping,it could be classified into urban street landscaping,urban ring road and expressway landscaping.Differences between road landscaping projects and other garden landscaping projects or construction projects were analyzed.Landscaping project for the South 3rd Ring Road of Xi'an City(in Yanta District)was taken for an example to summarize construction experience,discuss present conditions and features of garden landscaping supervision in China.The artistic and physiological properties of garden landscaping,as well as the supervision during maintenance period were stressed,but it was also pointed out that garden landscaping supervision in China was actually not given sufficient attention.On this basis,key points in the supervision of road landscaping project were proposed:understanding design ideas,selection of landscape plants,quality control of concealed works,prevention and control of diseases and insects,construction safety management and overall image;only by effectively implementing these key points,a high-quality road landscaping project could be realized to improve the image of a city and beautify its environment.
文摘This paper proposed through systematic analysis that road tail gas is an important source of PM2.5,and elaborated the infl uence of urban road space forms and road landscapes on urban microclimate,on the basis of which gave corresponding landscape design suggestions for PM2.5 control.
基金supported by the National Key Research and Development Program of China(2018YFB1500104)the Technological Innovation Key Project of Guangdong Province(skjtdzxrwqd2018005)the National Natural Science Foundation of China(U20A20245)。
文摘Achieving high-quality perovskite films with uniform morphology and homogeneous crystallinity is challenging owing to the coffee ring effect(CRE) in the spray-coating technologies. In this study, an evaporation/spray-coating two-step deposition method is used to fabricate Cs_(0.19)FA_(0.81)PbI_(2.5)Br_(0.5)light harvesters for perovskite solar cells(PSCs). Considering the solid–liquid reaction, we establish a reaction-dependent regulating strategy that inhibits CRE successfully and prepare a high-quality perovskite layer, wherein the solvent for the FAI/Br solution during the spraying process is changed from isopropanol to n-butyl alcohol(NBA). The retarded-drying-enhanced spreading of the NBA solution inhibits contact line pinning to suppress the capillary flows and increases the reaction between metal halides(CsI/PbI_(2)) and organic salts(FAI/Br), which result in a reduction in the accumulation of solutes in the periphery effectively inhibiting CRE. Consequently, we obtain a high performance Cs_(0.19)FA_(0.81)PbI_(2.5)Br_(0.5) PSC with a power conversion efficiency(PCE) of 19.17%. An enlarged perovskite film(10 × 10 cm^(2)) containing 40 sub-cells is prepared. The average PCE of these devices is 18.33 ± 0.56%, proving the reliability of the "coffee ring" regulating strategy. This study provides an effective approach for CRE controlment in spraying technology to achieve high repeatability devices with good performance.
