Laying the under-sleeper pad(USP)is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload.To explore the impact of application of the USP on the dynamic and static me...Laying the under-sleeper pad(USP)is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload.To explore the impact of application of the USP on the dynamic and static mechanical behavior of the ballast track in the heavy-haul railway system,numerical simulation models of the ballast bed with USP and without USP are presented in this paper by using the discrete element method(DEM)-multi-flexible body dynamic(MFBD)coupling analysis method.The ballast bed support stiffness test and dynamic displacement tests were carried out on the actual operation of a heavy-haul railway line to verify the validity of the models.The results show that using the USP results in a 43.01%reduction in the ballast bed support stiffness and achieves a more uniform distribution of track loads on the sleepers.It effectively reduces the load borne by the sleeper directly under the wheel load,with a 7.89%reduction in the pressure on the sleeper.Furthermore,the laying of the USP changes the lateral resistance sharing ratio of the ballast bed,significantly reducing the stress level of the ballast bed under train loads,with an average stress reduction of 42.19 kPa.It also reduces the plastic displacement of ballast particles and lowers the peak value of rotational angular velocity by about 50%to 70%,which is conducive to slowing down ballast bed settlement deformation and reducing maintenance costs.In summary,laying the USP has a potential value in enhancing the stability and extending the lifespan of the ballast bed in heavy-haul railway systems.展开更多
在高校教学改革中,如何将BOPPPS与PAD有效融合创新课堂混合式教学模式已成为研究重点。本研究通过构建BOPPPS与PAD相融合的多元课堂混合教学模式,并应用于“统计学”课堂改革。BOPPPS + PAD课堂混合式教学模式不仅优化了教学结构,提升...在高校教学改革中,如何将BOPPPS与PAD有效融合创新课堂混合式教学模式已成为研究重点。本研究通过构建BOPPPS与PAD相融合的多元课堂混合教学模式,并应用于“统计学”课堂改革。BOPPPS + PAD课堂混合式教学模式不仅优化了教学结构,提升了教学效率,还显著增强了学生参与度和学习兴趣。实践证明,该混合式教学模式能有效促进“高品质”课堂的构建,为人才培养的高质量发展提供了有力支撑。In the teaching reform of colleges and universities, how to effectively integrate BOPPPS and PAD to innovate the classroom blended teaching mode has become the focus of research. In this study, we constructed a multi-classroom hybrid teaching model that integrates BOPPPS and PAD, and applied it to the “statistics” classroom reform. The BOPPPS + PAD classroom blended teaching mode not only optimizes the teaching structure, improves the teaching efficiency, but also significantly enhances students’ participation and interest in learning. Practice has proved that this blended teaching model can effectively promote the construction of “high-quality” classrooms and provide strong support for the high-quality development of talent training.展开更多
传统的时间序列分析课程教学模式,考核方式只关注于学生对基本知识点的掌握情况,导致对于学生综合能力培养的教学效果不好。基于此,提出融合OBE (Outcome-Based Education)与PAD (Participation, Access and Diversity)理念的时间序列...传统的时间序列分析课程教学模式,考核方式只关注于学生对基本知识点的掌握情况,导致对于学生综合能力培养的教学效果不好。基于此,提出融合OBE (Outcome-Based Education)与PAD (Participation, Access and Diversity)理念的时间序列分析课程教学模式研究。根据时间序列分析课程教学的培养方案,按照逆向教学设计法,确定教学目标,在PAD理念下,以学生为教学主体,以培养综合能力为本位,根据教学目标设计教学环节,在考虑设计的教学环节基础上,基于OBE理念,使用综合评价方式设计教学综合评价方案。通过实践证明,使用融合OBE与PAD理念的时间序列分析课程教学模式进行教学,有效促进了学生综合能力的发展。The traditional teaching mode of time series analysis focuses solely on the students’ mastery of fundamental knowledge points, which results in a general lack of comprehensive ability among students. Therefore, the research on teaching mode of time series analysis course integrating OBE and PAD concepts is proposed. Based on the training plan for the time series analysis course, according to the reverse teaching design method, teaching objectives are determined. Under the PAD concept, students are regarded as the main body of teaching, with the training of comprehensive ability serving as the standard. The teaching process is designed according to the teaching objectives. Based on considering the designed teaching process, a comprehensive evaluation method is used to design a teaching comprehensive evaluation scheme based on the OBE concept. Through practice, it has been proven that the teaching mode of time series analysis courses integrating OBE and PAD concepts has effectively promoted the development of students’ comprehensive ability.展开更多
基金the project supported by the National Natural Science Foundation of China(Grant No.52372425)the Fundamental Research Funds for the Central Universities(Science and technology leading talent team project)(Grant No.2022JBXT010).
文摘Laying the under-sleeper pad(USP)is one of the effective measures commonly used to delay ballast degradation and reduce maintenance workload.To explore the impact of application of the USP on the dynamic and static mechanical behavior of the ballast track in the heavy-haul railway system,numerical simulation models of the ballast bed with USP and without USP are presented in this paper by using the discrete element method(DEM)-multi-flexible body dynamic(MFBD)coupling analysis method.The ballast bed support stiffness test and dynamic displacement tests were carried out on the actual operation of a heavy-haul railway line to verify the validity of the models.The results show that using the USP results in a 43.01%reduction in the ballast bed support stiffness and achieves a more uniform distribution of track loads on the sleepers.It effectively reduces the load borne by the sleeper directly under the wheel load,with a 7.89%reduction in the pressure on the sleeper.Furthermore,the laying of the USP changes the lateral resistance sharing ratio of the ballast bed,significantly reducing the stress level of the ballast bed under train loads,with an average stress reduction of 42.19 kPa.It also reduces the plastic displacement of ballast particles and lowers the peak value of rotational angular velocity by about 50%to 70%,which is conducive to slowing down ballast bed settlement deformation and reducing maintenance costs.In summary,laying the USP has a potential value in enhancing the stability and extending the lifespan of the ballast bed in heavy-haul railway systems.
文摘在高校教学改革中,如何将BOPPPS与PAD有效融合创新课堂混合式教学模式已成为研究重点。本研究通过构建BOPPPS与PAD相融合的多元课堂混合教学模式,并应用于“统计学”课堂改革。BOPPPS + PAD课堂混合式教学模式不仅优化了教学结构,提升了教学效率,还显著增强了学生参与度和学习兴趣。实践证明,该混合式教学模式能有效促进“高品质”课堂的构建,为人才培养的高质量发展提供了有力支撑。In the teaching reform of colleges and universities, how to effectively integrate BOPPPS and PAD to innovate the classroom blended teaching mode has become the focus of research. In this study, we constructed a multi-classroom hybrid teaching model that integrates BOPPPS and PAD, and applied it to the “statistics” classroom reform. The BOPPPS + PAD classroom blended teaching mode not only optimizes the teaching structure, improves the teaching efficiency, but also significantly enhances students’ participation and interest in learning. Practice has proved that this blended teaching model can effectively promote the construction of “high-quality” classrooms and provide strong support for the high-quality development of talent training.
文摘传统的时间序列分析课程教学模式,考核方式只关注于学生对基本知识点的掌握情况,导致对于学生综合能力培养的教学效果不好。基于此,提出融合OBE (Outcome-Based Education)与PAD (Participation, Access and Diversity)理念的时间序列分析课程教学模式研究。根据时间序列分析课程教学的培养方案,按照逆向教学设计法,确定教学目标,在PAD理念下,以学生为教学主体,以培养综合能力为本位,根据教学目标设计教学环节,在考虑设计的教学环节基础上,基于OBE理念,使用综合评价方式设计教学综合评价方案。通过实践证明,使用融合OBE与PAD理念的时间序列分析课程教学模式进行教学,有效促进了学生综合能力的发展。The traditional teaching mode of time series analysis focuses solely on the students’ mastery of fundamental knowledge points, which results in a general lack of comprehensive ability among students. Therefore, the research on teaching mode of time series analysis course integrating OBE and PAD concepts is proposed. Based on the training plan for the time series analysis course, according to the reverse teaching design method, teaching objectives are determined. Under the PAD concept, students are regarded as the main body of teaching, with the training of comprehensive ability serving as the standard. The teaching process is designed according to the teaching objectives. Based on considering the designed teaching process, a comprehensive evaluation method is used to design a teaching comprehensive evaluation scheme based on the OBE concept. Through practice, it has been proven that the teaching mode of time series analysis courses integrating OBE and PAD concepts has effectively promoted the development of students’ comprehensive ability.
