滚动摩擦沉积增材(Additive Friction Rolling Deposition,AFRD)是一种新兴的金属固态增材制造技术,特别适用于基于熔合增材制造方法易产生凝固缺陷的高强度铝合金。采用AFRD方法进行2024-O铝合金增材,获得全致密无缺陷的四层增材试件,...滚动摩擦沉积增材(Additive Friction Rolling Deposition,AFRD)是一种新兴的金属固态增材制造技术,特别适用于基于熔合增材制造方法易产生凝固缺陷的高强度铝合金。采用AFRD方法进行2024-O铝合金增材,获得全致密无缺陷的四层增材试件,利用金相显微镜、扫描电子显微镜对不同旋转速度增材试件宏观形貌、微观组织进行了表征。结果表明:(1)沉积层组织致密,无夹杂、裂纹等缺陷、相邻两沉积层之间形成良好的冶金结合。(2)沉积层呈现细小的轴晶粒组织,随着旋转速度升高,晶粒尺寸呈下降趋势。(3)沉积层第二相粒子呈现点片状分布于Al基体上,随着转速增大,第二相粒子趋向于细化与均匀。展开更多
初中物理实验是物理课程的基础,是物理学习过程中的重要环节,是培养学生认真的科研态度及锻炼学生动手能力的重要手段。但目前许多初中存在着实验场地不足、实验设备不全等现象,部分学校更是由于实验仪器经费不足或考虑到实验危险性等原...初中物理实验是物理课程的基础,是物理学习过程中的重要环节,是培养学生认真的科研态度及锻炼学生动手能力的重要手段。但目前许多初中存在着实验场地不足、实验设备不全等现象,部分学校更是由于实验仪器经费不足或考虑到实验危险性等原因,将物理实验的次数和时长减少甚至直接由教师演示或讲授而非学生动手操作,导致学生的物理实验教学效果不理想。虚拟仿真实验在成本效益、实验安全性、实验效果、实验资源的丰富性、个性化学习、学习数据分析和实践能力训练等方面都有一定的优势,因此越来越多的教育机构和学校选择引入虚拟仿真实验来辅助教学。文章基于NOBOOK实验平台,通过设计并实施一系列实验,我们深入分析了接触面粗糙程度、压力大小以及速度等因素对滑动摩擦力的影响,丰富了物理实验教学的内容,通过NOBOOK实验平台的有效应用,提升了学生对滑动摩擦力概念的理解与实验操作能力,为初中物理实验教学的创新与发展提供了有益的探索。Physics experiments in junior high schools are the foundation of physics curricula and an essential part of the physics learning process. They are crucial in cultivating students’ serious scientific research attitudes and exercising their hands-on skills. However, many junior high schools face issues such as insufficient experimental venues and incomplete equipment. Some schools, due to insufficient funding for experimental instruments or concerns about experimental safety, have reduced the number and duration of physics experiments or even resorted to teachers demonstrating or lecturing instead of allowing students to operate hands-on, resulting in unsatisfactory outcomes for physics experimental teaching. Virtual simulation experiments have advantages in terms of cost-effectiveness, experimental safety, experimental results, richness of experimental resources, personalized learning, learning data analysis, and practical ability training. Therefore, an increasing number of educational institutions and schools are choosing to introduce virtual simulation experiments to assist teaching. This article, based on the NOBOOK experimental platform, has designed and implemented a series of experiments to deeply analyze the influence of factors such as the roughness of the contact surface, the magnitude of pressure, and the speed of sliding friction. This has enriched the content of physics experimental teaching. Through the effective application of the NOBOOK experimental platform, students’ understanding of the concept of sliding friction and their experimental operation skills have been improved, providing beneficial exploration for the innovation and development of junior high school physics experimental teaching.展开更多
文摘滚动摩擦沉积增材(Additive Friction Rolling Deposition,AFRD)是一种新兴的金属固态增材制造技术,特别适用于基于熔合增材制造方法易产生凝固缺陷的高强度铝合金。采用AFRD方法进行2024-O铝合金增材,获得全致密无缺陷的四层增材试件,利用金相显微镜、扫描电子显微镜对不同旋转速度增材试件宏观形貌、微观组织进行了表征。结果表明:(1)沉积层组织致密,无夹杂、裂纹等缺陷、相邻两沉积层之间形成良好的冶金结合。(2)沉积层呈现细小的轴晶粒组织,随着旋转速度升高,晶粒尺寸呈下降趋势。(3)沉积层第二相粒子呈现点片状分布于Al基体上,随着转速增大,第二相粒子趋向于细化与均匀。
文摘初中物理实验是物理课程的基础,是物理学习过程中的重要环节,是培养学生认真的科研态度及锻炼学生动手能力的重要手段。但目前许多初中存在着实验场地不足、实验设备不全等现象,部分学校更是由于实验仪器经费不足或考虑到实验危险性等原因,将物理实验的次数和时长减少甚至直接由教师演示或讲授而非学生动手操作,导致学生的物理实验教学效果不理想。虚拟仿真实验在成本效益、实验安全性、实验效果、实验资源的丰富性、个性化学习、学习数据分析和实践能力训练等方面都有一定的优势,因此越来越多的教育机构和学校选择引入虚拟仿真实验来辅助教学。文章基于NOBOOK实验平台,通过设计并实施一系列实验,我们深入分析了接触面粗糙程度、压力大小以及速度等因素对滑动摩擦力的影响,丰富了物理实验教学的内容,通过NOBOOK实验平台的有效应用,提升了学生对滑动摩擦力概念的理解与实验操作能力,为初中物理实验教学的创新与发展提供了有益的探索。Physics experiments in junior high schools are the foundation of physics curricula and an essential part of the physics learning process. They are crucial in cultivating students’ serious scientific research attitudes and exercising their hands-on skills. However, many junior high schools face issues such as insufficient experimental venues and incomplete equipment. Some schools, due to insufficient funding for experimental instruments or concerns about experimental safety, have reduced the number and duration of physics experiments or even resorted to teachers demonstrating or lecturing instead of allowing students to operate hands-on, resulting in unsatisfactory outcomes for physics experimental teaching. Virtual simulation experiments have advantages in terms of cost-effectiveness, experimental safety, experimental results, richness of experimental resources, personalized learning, learning data analysis, and practical ability training. Therefore, an increasing number of educational institutions and schools are choosing to introduce virtual simulation experiments to assist teaching. This article, based on the NOBOOK experimental platform, has designed and implemented a series of experiments to deeply analyze the influence of factors such as the roughness of the contact surface, the magnitude of pressure, and the speed of sliding friction. This has enriched the content of physics experimental teaching. Through the effective application of the NOBOOK experimental platform, students’ understanding of the concept of sliding friction and their experimental operation skills have been improved, providing beneficial exploration for the innovation and development of junior high school physics experimental teaching.
