The idea of an inductive teaching method based on perceptual modalities in a flipped-classroom concept, to be applied to the teaching of Structural Geology and Tectonics and the Earth Sciences in general, came from th...The idea of an inductive teaching method based on perceptual modalities in a flipped-classroom concept, to be applied to the teaching of Structural Geology and Tectonics and the Earth Sciences in general, came from the need to appraise new forms of interaction/teaching in today＇s globalized context. Even if sporadic and carried out in a far from systematic way, the type of teaching examined in this study was tested on secondary school students specializing in science in a heterogeneous sample of children aged 15 to 18 years. The educational experiment was divided into six phases, each characterized by the prevalent use of perceptual modalities. The initial phase, characterized by creative writing, aimed to develop the kinaesthetic modality. The second stood as an ＂anchor＂ for the objectives to be achieved through a form of dramatization. The third emphasized individual investigation, in accordance with criteria typical of the flipped-classroom method. The fourth consisted of fieldwork to stimulate visual and tactile modalities. In the fifth, the teacher operated as a ＂scientific mediator＂, favouring the auditory capacity. And, finally, the sixth, with its body of knowledge and the finalization of the goal to be achieved, lay within the scope of the issues addressed by Structural Geology and Tectonics.展开更多
Electrorheological(ER)and magnetorheological(MR)dampers,which are active damping devices,stand out for their exceptional performance in mitigating vibrations in mechanical systems and construction engineering.Their pr...Electrorheological(ER)and magnetorheological(MR)dampers,which are active damping devices,stand out for their exceptional performance in mitigating vibrations in mechanical systems and construction engineering.Their prowess lies in the inherent ability of ER/MR fluids to change their mechanical properties,particularly viscosity and shear stress,in response to the influence of electric or magnetic fields.In this study,a damper filled with Giant-ER(GER)fluid,a modified product of ER fluid,is employed in the rotor system for vibration suppression.This damper operates in a Cut submode derived from the conventional working modes.This mode results in an effective enhancement of the damping performance by integrating the advantages of these modes,thereby achieving a damping force density of 1.2×10^(4) N/m^(2) and a modulation coefficient of 15 within a multilayered cylindrical damper.Whereafter,the dynamics of the rotor system are modeled and analyzed based on the Jeffcott rotor model,which incorporates a parallelogram-structured motion decoupling mechanism equipped with the proposed Cut submode dampers that are introduced to reduce the vibration of the transmission shaft in the rotor system.Furthermore,to evaluate the damping effect,a vibration-damping performance validation testbed is constructed.The results are noteworthy,demonstrating that by leveraging the superior properties of the GER fluid,the Cut submode damper effectively suppresses the vibrations of the transmission shaft,particularly at the resonant frequencies,achieving an impressive 88.9%reduction when subjected to an electric field of 3 kV/mm compared to the action of 0 kV/mm.This performance highlights the exceptional effectiveness of the proposed Cut submode,underscoring its vast potential for various engineering applications.展开更多
文摘The idea of an inductive teaching method based on perceptual modalities in a flipped-classroom concept, to be applied to the teaching of Structural Geology and Tectonics and the Earth Sciences in general, came from the need to appraise new forms of interaction/teaching in today＇s globalized context. Even if sporadic and carried out in a far from systematic way, the type of teaching examined in this study was tested on secondary school students specializing in science in a heterogeneous sample of children aged 15 to 18 years. The educational experiment was divided into six phases, each characterized by the prevalent use of perceptual modalities. The initial phase, characterized by creative writing, aimed to develop the kinaesthetic modality. The second stood as an ＂anchor＂ for the objectives to be achieved through a form of dramatization. The third emphasized individual investigation, in accordance with criteria typical of the flipped-classroom method. The fourth consisted of fieldwork to stimulate visual and tactile modalities. In the fifth, the teacher operated as a ＂scientific mediator＂, favouring the auditory capacity. And, finally, the sixth, with its body of knowledge and the finalization of the goal to be achieved, lay within the scope of the issues addressed by Structural Geology and Tectonics.
基金supported by the National Natural Science Foundation of China(Grant Nos.62325302,U2013202,62203076)the Natural Science Foundation of Chongqing,China(Grant No.CSTB2024NSCQ-MSX0472)+1 种基金the Fundamental Research Funds for the Central Universities(Grant Nos.2024CDJCGJ-006,2024CDJGF-043,2024CDJZDQT-001,2023CDJXY-014)the Sichuan Provincial Science and Technology Program(Grant No.2023JDRC0069).
文摘Electrorheological(ER)and magnetorheological(MR)dampers,which are active damping devices,stand out for their exceptional performance in mitigating vibrations in mechanical systems and construction engineering.Their prowess lies in the inherent ability of ER/MR fluids to change their mechanical properties,particularly viscosity and shear stress,in response to the influence of electric or magnetic fields.In this study,a damper filled with Giant-ER(GER)fluid,a modified product of ER fluid,is employed in the rotor system for vibration suppression.This damper operates in a Cut submode derived from the conventional working modes.This mode results in an effective enhancement of the damping performance by integrating the advantages of these modes,thereby achieving a damping force density of 1.2×10^(4) N/m^(2) and a modulation coefficient of 15 within a multilayered cylindrical damper.Whereafter,the dynamics of the rotor system are modeled and analyzed based on the Jeffcott rotor model,which incorporates a parallelogram-structured motion decoupling mechanism equipped with the proposed Cut submode dampers that are introduced to reduce the vibration of the transmission shaft in the rotor system.Furthermore,to evaluate the damping effect,a vibration-damping performance validation testbed is constructed.The results are noteworthy,demonstrating that by leveraging the superior properties of the GER fluid,the Cut submode damper effectively suppresses the vibrations of the transmission shaft,particularly at the resonant frequencies,achieving an impressive 88.9%reduction when subjected to an electric field of 3 kV/mm compared to the action of 0 kV/mm.This performance highlights the exceptional effectiveness of the proposed Cut submode,underscoring its vast potential for various engineering applications.
