In this article, authors describe how to use the project-based learning （PBL） pedagogy to enhance students＇ Calculus learning based on the first author＇s experimental teaching experience. The ＂2014 BMCC Polar Art...In this article, authors describe how to use the project-based learning （PBL） pedagogy to enhance students＇ Calculus learning based on the first author＇s experimental teaching experience. The ＂2014 BMCC Polar Art Calendar＂ project was completed by Calculus students at Borough of Manhattan Community College （BMCC） during the fall 2013 semester. Students were requested to apply graphs of polar equations to create computer-generated images with a variety of flower patterns by using the Maple technology in a math lab. At the end of this project, students were requested to submit and present their written reports to express their mathematical thinking. Authors also explain in details how to create projects compatible with textbook knowledge learning objectives, how to prepare scaffolding materials for students to use, how to utilize a math lab and to work with lab technicians in Maple Software, and how to design a rubric for project evaluations. Students＇ artwork created in the Polar Art Calendar are presented. Students＇ positive outcomes have proven a success of this project design as well as its execution as an example of PBL. Benefits to students and challenges to teachers on the use of PBL approach have been discussed at the end of this article.展开更多
In the process of unconventional natural gas development practice,the"extreme utilization"concept that focuses on"continuously breaking through the limit of development technology"is gradually form...In the process of unconventional natural gas development practice,the"extreme utilization"concept that focuses on"continuously breaking through the limit of development technology"is gradually formed,and supports the scale benefit exploration of unconventional gas in China.On this basis,the development theory of"extreme utilization"is proposed,its theoretical connotation together with development technologies of unconventional natural gas are clarified.The theoretical connotation is that,aiming at"extreme gas reservoirs","extreme techniques"are utilized to build subsurface connected bodies,expand the discharge area,and enlarge the production range,to obtain the maximum single-well production,extreme recovery,and eventually achieve the"extreme effect"of production.The series of development technologies include micro/nano-scale reservoir evaluation,"sweet spot"prediction,unconventional percolation theory and production capacity evaluation,optimization of grid well pattern,optimal-fast drilling and volume fracturing,and working regulation optimization and"integrated"organizing system.The"extreme utilization"development theory has been successfully applied in the development of unconventional gas reservoirs such as Sulige tight gas,South Sichuan shale gas,and Qinshui coalbed methane.Such practices demonstrate that,the"extreme utilization"development theory has effectively promoted the development of unconventional gas industry in China,and can provide theoretical guidance for effective development of other potential unconventional and difficult-to-recovery resources.展开更多
Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis （e...Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis （e. g. the pushover analysis）, and the structural damage is considered via plastic hinges. Simultaneously, a practical approach is developed to obtain the relationships between the proposed index and earthquake intensities based on the capacity spectrum method. The proposed index is then illustrated through two low-rise reinforced concrete frames, and it is also compared with some other indices. The results indicate that the proposed index is on the safe side and not sensitive to the lateral load pattern. The storey index is helpful to reflect the storey damage and to uncover the position of the weak storey. Finally, the relationship between performance levels and damage index values is also proposed through statistical analysis for the performance-based seismic evaluation.展开更多
文摘In this article, authors describe how to use the project-based learning （PBL） pedagogy to enhance students＇ Calculus learning based on the first author＇s experimental teaching experience. The ＂2014 BMCC Polar Art Calendar＂ project was completed by Calculus students at Borough of Manhattan Community College （BMCC） during the fall 2013 semester. Students were requested to apply graphs of polar equations to create computer-generated images with a variety of flower patterns by using the Maple technology in a math lab. At the end of this project, students were requested to submit and present their written reports to express their mathematical thinking. Authors also explain in details how to create projects compatible with textbook knowledge learning objectives, how to prepare scaffolding materials for students to use, how to utilize a math lab and to work with lab technicians in Maple Software, and how to design a rubric for project evaluations. Students＇ artwork created in the Polar Art Calendar are presented. Students＇ positive outcomes have proven a success of this project design as well as its execution as an example of PBL. Benefits to students and challenges to teachers on the use of PBL approach have been discussed at the end of this article.
基金Supported by the China National Science and Technology Major Project(2017ZX05035,2016ZX05037)。
文摘In the process of unconventional natural gas development practice,the"extreme utilization"concept that focuses on"continuously breaking through the limit of development technology"is gradually formed,and supports the scale benefit exploration of unconventional gas in China.On this basis,the development theory of"extreme utilization"is proposed,its theoretical connotation together with development technologies of unconventional natural gas are clarified.The theoretical connotation is that,aiming at"extreme gas reservoirs","extreme techniques"are utilized to build subsurface connected bodies,expand the discharge area,and enlarge the production range,to obtain the maximum single-well production,extreme recovery,and eventually achieve the"extreme effect"of production.The series of development technologies include micro/nano-scale reservoir evaluation,"sweet spot"prediction,unconventional percolation theory and production capacity evaluation,optimization of grid well pattern,optimal-fast drilling and volume fracturing,and working regulation optimization and"integrated"organizing system.The"extreme utilization"development theory has been successfully applied in the development of unconventional gas reservoirs such as Sulige tight gas,South Sichuan shale gas,and Qinshui coalbed methane.Such practices demonstrate that,the"extreme utilization"development theory has effectively promoted the development of unconventional gas industry in China,and can provide theoretical guidance for effective development of other potential unconventional and difficult-to-recovery resources.
基金The National Basic Research Program of China(973 Program)(No.2007CB714200)
文摘Based on the concept of stiffness degradation, a damage index of the whole frame and the storey is proposed for the frame seismic performance evaluation. The index is compatible with the non-linear static analysis （e. g. the pushover analysis）, and the structural damage is considered via plastic hinges. Simultaneously, a practical approach is developed to obtain the relationships between the proposed index and earthquake intensities based on the capacity spectrum method. The proposed index is then illustrated through two low-rise reinforced concrete frames, and it is also compared with some other indices. The results indicate that the proposed index is on the safe side and not sensitive to the lateral load pattern. The storey index is helpful to reflect the storey damage and to uncover the position of the weak storey. Finally, the relationship between performance levels and damage index values is also proposed through statistical analysis for the performance-based seismic evaluation.
