Utilization of urban underground space has become a vital approach to alleviate the strain on urban land resources,and to optimize the structure and pattem of the city.It is also very important to improve the city env...Utilization of urban underground space has become a vital approach to alleviate the strain on urban land resources,and to optimize the structure and pattem of the city.It is also very important to improve the city environment,build livable city and increase the capacity of the city.Based on the analysis of existing evaluation methods and their problems,a method for evaluating underground space resources based on a negative list of adverse factors affecting underground space development is proposed,to be primarily used in urban planning stages.A list of the adverse factors is established,including limiting factors,constraining factors and influencing factors.Taking Xi'an as an example,using a geographical information system platform,a negative list of adverse factors for the underground space resources in Xi'an City are evaluated,and preventive measures are proposed.Natural resources,exploitable resources,and the potential growth of exploitable underground space resources are evaluated.Underground space assessment in the different development stages of the city,collaborative utilization and safety evaluation for multiple subsurface resources,environmental impact and assessment,as well as evaluation methods based on big data and intelligent optimization algorithms are all discussed with the aim of serving city planning and construction.展开更多
High-performance gas sensing materials operated at room temperature(RT) are attractive for a variety of real-time gas monitoring applications,especially with the excellent durability and flexibility of wearable sensor...High-performance gas sensing materials operated at room temperature(RT) are attractive for a variety of real-time gas monitoring applications,especially with the excellent durability and flexibility of wearable sensor.The constructing heterostructure is one of the significant approaches in design strategies of sensing materials.This heterostructure effectively increases the active site for improving sensing performance and decreasing energy consumption.Herein,the heterostructure of Au nanoparticles modified CeO_(2)@carbon-quantum-dots(Au/CeO_(2)@CQDs) with a three-dimensional(3D) scaffold structure are successfully synthesized by an effective strategy,which can apply for preparing flexible gas sensor.The gas sensing properties of Au/CeO_(2)@CQDs based on flexible substrate are obtained under long-term repeated NO_(2) exposure at RT.Meanwhile,the long-term mechanical stability of this gas sensing device is also detected after different bending cycles.The Au/CeO_(2)@CQDs based on flexible substrate sensor exhibits excellent performance,including higher sensitivity(47.2),faster response(18 s)and recovery time(22 s) as well as longer-term stability than performance of pure materials.The obtained sensor also reveals outstanding mechanical flexibility,which is only a tiny response fluctuation(8.1%) after 500 bending/relaxing cycles.Therefore,our study demonstrates the enormous potential of this sensing materials for hazardous gas monitoring in future portable and wearable sensing platform.展开更多
This paper shows a detailed methodology for creating 2D and 3D visual facility map of the campus. The purpose of this study work is to develop an interactive interface containing the 2 and 3-Dimensional features of al...This paper shows a detailed methodology for creating 2D and 3D visual facility map of the campus. The purpose of this study work is to develop an interactive interface containing the 2 and 3-Dimensional features of all the facilities within the University of Lagos. The spatial attributes of the facilities were collected with the aid of total stations. The most recent Google earth software was used as source of data to produce 2-dimensional facilities of the study area through digitization process. SRTM Digital elevation model image was downloaded from United State Geological Survey website to give the elevation data required for the 3-dimensional representation. All these data were processed with ArcGIS 10.2.1.展开更多
基金This research is supported by National Key Research and Development Project,Ministry of Science and Technology of the People’s Republic of China(2018YFC1504700).
文摘Utilization of urban underground space has become a vital approach to alleviate the strain on urban land resources,and to optimize the structure and pattem of the city.It is also very important to improve the city environment,build livable city and increase the capacity of the city.Based on the analysis of existing evaluation methods and their problems,a method for evaluating underground space resources based on a negative list of adverse factors affecting underground space development is proposed,to be primarily used in urban planning stages.A list of the adverse factors is established,including limiting factors,constraining factors and influencing factors.Taking Xi'an as an example,using a geographical information system platform,a negative list of adverse factors for the underground space resources in Xi'an City are evaluated,and preventive measures are proposed.Natural resources,exploitable resources,and the potential growth of exploitable underground space resources are evaluated.Underground space assessment in the different development stages of the city,collaborative utilization and safety evaluation for multiple subsurface resources,environmental impact and assessment,as well as evaluation methods based on big data and intelligent optimization algorithms are all discussed with the aim of serving city planning and construction.
基金financially supported by the Natural Science Foundation of Shandong Province (Nos. ZR2021QB136 and ZR2022MH091)the Innovation and Entrepreneurship Training Program for Undergraduates of Shandong Province (No.S202110439100)+2 种基金Tai'an Science and Technology Innovation Development Project (No.2021GX068)the Academic Promotion Program of Shandong First Medical University (No. 2019QL008)the Chinese Academy of Sciences。
文摘High-performance gas sensing materials operated at room temperature(RT) are attractive for a variety of real-time gas monitoring applications,especially with the excellent durability and flexibility of wearable sensor.The constructing heterostructure is one of the significant approaches in design strategies of sensing materials.This heterostructure effectively increases the active site for improving sensing performance and decreasing energy consumption.Herein,the heterostructure of Au nanoparticles modified CeO_(2)@carbon-quantum-dots(Au/CeO_(2)@CQDs) with a three-dimensional(3D) scaffold structure are successfully synthesized by an effective strategy,which can apply for preparing flexible gas sensor.The gas sensing properties of Au/CeO_(2)@CQDs based on flexible substrate are obtained under long-term repeated NO_(2) exposure at RT.Meanwhile,the long-term mechanical stability of this gas sensing device is also detected after different bending cycles.The Au/CeO_(2)@CQDs based on flexible substrate sensor exhibits excellent performance,including higher sensitivity(47.2),faster response(18 s)and recovery time(22 s) as well as longer-term stability than performance of pure materials.The obtained sensor also reveals outstanding mechanical flexibility,which is only a tiny response fluctuation(8.1%) after 500 bending/relaxing cycles.Therefore,our study demonstrates the enormous potential of this sensing materials for hazardous gas monitoring in future portable and wearable sensing platform.
文摘This paper shows a detailed methodology for creating 2D and 3D visual facility map of the campus. The purpose of this study work is to develop an interactive interface containing the 2 and 3-Dimensional features of all the facilities within the University of Lagos. The spatial attributes of the facilities were collected with the aid of total stations. The most recent Google earth software was used as source of data to produce 2-dimensional facilities of the study area through digitization process. SRTM Digital elevation model image was downloaded from United State Geological Survey website to give the elevation data required for the 3-dimensional representation. All these data were processed with ArcGIS 10.2.1.
