Bearing support position is one of main factors affecting vibration characteristics of rotor systems. To optimize the bearing support positions in a high-speed flexible rotor system (HSFRS) based on the vibration char...Bearing support position is one of main factors affecting vibration characteristics of rotor systems. To optimize the bearing support positions in a high-speed flexible rotor system (HSFRS) based on the vibration characteristics, an optimization method of bearing support positions in the HSFRS is proposed. In this method, a finite element (FE) model of a high-speed flexible rotor (HSFR) was established. The natural frequencies and mode shapes of the HSFRS were used to obtain the initial design scheme of the bearing support positions. A frequency characteristic equation of the HSFRS was established to obtain the critical speeds of the HSFRS. And a dynamic model of the HSFRS was established to analyze the vibration characteristics for different bearing support position cases. The problem of optimizing bearing support positions in the HSFRS was solved by the developed method. The results showed that vibration amplitudes of the HSFRS were more stable when the bearing support positions were optimized. This study can provide a new method for optimizing bearing support positions of rotor systems.展开更多
The use of coercion to alter behavior in persons with intellectual and other developmental disabilities has a long history. Despite the work of leaders in the development of Positive Behaviour Support (PBS), the use o...The use of coercion to alter behavior in persons with intellectual and other developmental disabilities has a long history. Despite the work of leaders in the development of Positive Behaviour Support (PBS), the use of chemical, mechanical, physical or personal, and environmental restraints continues, resulting in traumatization, physical and emotional harm, and in some instances, death. When coercion is used, the trust between people breaks down, and the lack of trust is reinforced by the power differentials present when coercion occurs. Social justice provides an avenue for rebalancing power and regaining trust, but people affected by disabilities have historically been excluded from theories of social justice and, in some cases, do not fall within the definition of what it means to be a person in the paradigms put forth by a number of different authors. The term non-coercive has been used in an attempt to reframe behavior change theories and practices, but this term describes the absence of negative circumstances and interventions, rather than the presence of positive and affirming interactions which improve the quality of life of all stakeholders.展开更多
Objectives We evaluated the feasibility, tolerability, and efficacy of a strategy for percutaneous pump （IABP） placement through the left axillary-subelavian artery to provide mechanical in patients with end-stage ...Objectives We evaluated the feasibility, tolerability, and efficacy of a strategy for percutaneous pump （IABP） placement through the left axillary-subelavian artery to provide mechanical in patients with end-stage heart failure as a bridge to heart transplantation. intra-aortic balloon circulatory support展开更多
基金National Natural Science Foundation of China (No. 51975068)。
文摘Bearing support position is one of main factors affecting vibration characteristics of rotor systems. To optimize the bearing support positions in a high-speed flexible rotor system (HSFRS) based on the vibration characteristics, an optimization method of bearing support positions in the HSFRS is proposed. In this method, a finite element (FE) model of a high-speed flexible rotor (HSFR) was established. The natural frequencies and mode shapes of the HSFRS were used to obtain the initial design scheme of the bearing support positions. A frequency characteristic equation of the HSFRS was established to obtain the critical speeds of the HSFRS. And a dynamic model of the HSFRS was established to analyze the vibration characteristics for different bearing support position cases. The problem of optimizing bearing support positions in the HSFRS was solved by the developed method. The results showed that vibration amplitudes of the HSFRS were more stable when the bearing support positions were optimized. This study can provide a new method for optimizing bearing support positions of rotor systems.
文摘The use of coercion to alter behavior in persons with intellectual and other developmental disabilities has a long history. Despite the work of leaders in the development of Positive Behaviour Support (PBS), the use of chemical, mechanical, physical or personal, and environmental restraints continues, resulting in traumatization, physical and emotional harm, and in some instances, death. When coercion is used, the trust between people breaks down, and the lack of trust is reinforced by the power differentials present when coercion occurs. Social justice provides an avenue for rebalancing power and regaining trust, but people affected by disabilities have historically been excluded from theories of social justice and, in some cases, do not fall within the definition of what it means to be a person in the paradigms put forth by a number of different authors. The term non-coercive has been used in an attempt to reframe behavior change theories and practices, but this term describes the absence of negative circumstances and interventions, rather than the presence of positive and affirming interactions which improve the quality of life of all stakeholders.
文摘Objectives We evaluated the feasibility, tolerability, and efficacy of a strategy for percutaneous pump （IABP） placement through the left axillary-subelavian artery to provide mechanical in patients with end-stage heart failure as a bridge to heart transplantation. intra-aortic balloon circulatory support
