Although the five-degree-of-freedom magnetic levitation system composed of two conical bearingless switched reluctance motors(CBSRMs)owns the simplest structure,the torque and levitation forces are coupled greatly.The...Although the five-degree-of-freedom magnetic levitation system composed of two conical bearingless switched reluctance motors(CBSRMs)owns the simplest structure,the torque and levitation forces are coupled greatly.Therefore,it is difficult to make the rotor rotate and be fully levitated simultaneously.To solve this problem,two different role division control strategies are proposed in this paper,i.e.individual role division and mutual role division control strategies.The difference between them is the selection of motor which controls the torque or the axial force.In order to understand the characteristics of control variables,the principle and mathematical model of CBSRM are introduced.After that,two control strategies are explained in detail.To verify the demonstrated performance,the simulations are completed with MATLAB/Simulink.展开更多
This paper examines the decline of tuberculosis and the faltering of TB in China. Specifically, I examine how institutional change--the construction and dismantling of the work-unit system--has affected TB control. Th...This paper examines the decline of tuberculosis and the faltering of TB in China. Specifically, I examine how institutional change--the construction and dismantling of the work-unit system--has affected TB control. The work-unit system was an employment system under which the vast majority of the population, in both urban and rural areas, had guaranteed employment and a host of benefits, including health insurance and access to the public health and health care systems. This system was created in the 1950s, which coincided with the decline of TB mortality and morbidity. The 1990s dismantling of the work-unit system has coincided with resurgent TB. This comparative historical sociological work examines TB control in Shanghai at three critical junctures: before the work-unit system was constructed, while it was in place, and since it has been dismantled. I examine both Shanghai's urban districts and rural counties, based on data gathered from archival sources and in-depth interviews during 17 months of field research. I argue that the work-unit system provided an effective basic-level infrastructure for the provision of public health and health care services that reached the entire population. This infrastructure was critical to the success of TB control efforts during the work-unit era, and its dismantling has been a key cause of the faltering of TB control in recent years.展开更多
基金supported by the National Natural Science Foundations of China (Nos. 51877107,51577087,51477074)
文摘Although the five-degree-of-freedom magnetic levitation system composed of two conical bearingless switched reluctance motors(CBSRMs)owns the simplest structure,the torque and levitation forces are coupled greatly.Therefore,it is difficult to make the rotor rotate and be fully levitated simultaneously.To solve this problem,two different role division control strategies are proposed in this paper,i.e.individual role division and mutual role division control strategies.The difference between them is the selection of motor which controls the torque or the axial force.In order to understand the characteristics of control variables,the principle and mathematical model of CBSRM are introduced.After that,two control strategies are explained in detail.To verify the demonstrated performance,the simulations are completed with MATLAB/Simulink.
文摘This paper examines the decline of tuberculosis and the faltering of TB in China. Specifically, I examine how institutional change--the construction and dismantling of the work-unit system--has affected TB control. The work-unit system was an employment system under which the vast majority of the population, in both urban and rural areas, had guaranteed employment and a host of benefits, including health insurance and access to the public health and health care systems. This system was created in the 1950s, which coincided with the decline of TB mortality and morbidity. The 1990s dismantling of the work-unit system has coincided with resurgent TB. This comparative historical sociological work examines TB control in Shanghai at three critical junctures: before the work-unit system was constructed, while it was in place, and since it has been dismantled. I examine both Shanghai's urban districts and rural counties, based on data gathered from archival sources and in-depth interviews during 17 months of field research. I argue that the work-unit system provided an effective basic-level infrastructure for the provision of public health and health care services that reached the entire population. This infrastructure was critical to the success of TB control efforts during the work-unit era, and its dismantling has been a key cause of the faltering of TB control in recent years.