Difficulties in obtaining component characteristics in the sub-idle state of rotor constrain the simulation capabilities of ground and windmill start-up processes for turbofan engines.This paper proposes a backbone fe...Difficulties in obtaining component characteristics in the sub-idle state of rotor constrain the simulation capabilities of ground and windmill start-up processes for turbofan engines.This paper proposes a backbone feature method based on conventional characteristics parameters to derive the full-state characteristics of fan.The application of the fan’s full-state characteristics in component-level model of turbofan engine enables zero-speed iterative simulation for ground start-up process and windmill simulation for windmill start-up process,thereby improving the simulation capability of sub-idle state during turbofan engine start-up.展开更多
目的基于真实世界数据(Real World Data,RWD)对注射泵的主要有效性评价功能进行研究,最大程度反映其临床实践中的真实性能表现,以建立科学有效的评价方法。方法选取本院重症医学科3种品牌(M、F、L)注射泵共计37台次作为研究对象,根据建...目的基于真实世界数据(Real World Data,RWD)对注射泵的主要有效性评价功能进行研究,最大程度反映其临床实践中的真实性能表现,以建立科学有效的评价方法。方法选取本院重症医学科3种品牌(M、F、L)注射泵共计37台次作为研究对象,根据建立的临床使用评价指标,分别在5、25和50 mL/h 3种流速下,获得注射泵出第1滴液的时间和响应时间来测试注射泵快速启动的性能差异,计算流速平均值、相对示值误差和示值重复性来测试注射泵注射精度的性能差异;分别在5、10和15 mL/h 3种流速下,获得注射泵的流速波动下限和间歇时间来测试注射泵联机中继的性能差异。结果在快速启动功能方面,设定流速越大,注射泵出第1滴液的时间和响应时间越短,且在3种流速下,M品牌注射泵出第1滴液的时间和响应时间都最短(P<0.05)。在注射精度功能方面,在3种流速下,M和L品牌的流速控制性能和示值稳定性都显著优于F品牌(P<0.05)。在联机中继功能方面,人工模拟联机中继功能导致的流速波动下限和间歇时间差异显著(P<0.05),且设定流速越大,实时流速从下降到恢复设定值需要的间歇时间就越短。另外,M品牌的自动联机中继功能可有效解决前序泵与后序泵中继过程中产生的药物流量抖动或间断,但有瞬时流速上升,相对能够保证药物流量的稳定性和连续性。结论使用正确的基于RWD的注射泵临床使用评价方法不仅能够规范临床应用行为,还能够为注射泵的评价、准入/淘汰和集中采购/价格谈判提供数据支撑。展开更多
The oil film clutch, which is superior in speed adjustment, is capable of being used in the belt conveyor to carry out soft start operation. According to running properties of both belt conveyor and oil film clutch...The oil film clutch, which is superior in speed adjustment, is capable of being used in the belt conveyor to carry out soft start operation. According to running properties of both belt conveyor and oil film clutch, equations that are used to decide the lubricating oil flow and the number of oil films (i.e. the number of rotating and stationary plates) are deduced theoretically. Also key parameters are provided for the design of the hydraulic system. All these together provide the theoretical basis for the soft start design of the belt conveyor and references for the application of the oil film clutch in similar fields.展开更多
文摘Difficulties in obtaining component characteristics in the sub-idle state of rotor constrain the simulation capabilities of ground and windmill start-up processes for turbofan engines.This paper proposes a backbone feature method based on conventional characteristics parameters to derive the full-state characteristics of fan.The application of the fan’s full-state characteristics in component-level model of turbofan engine enables zero-speed iterative simulation for ground start-up process and windmill simulation for windmill start-up process,thereby improving the simulation capability of sub-idle state during turbofan engine start-up.
文摘The oil film clutch, which is superior in speed adjustment, is capable of being used in the belt conveyor to carry out soft start operation. According to running properties of both belt conveyor and oil film clutch, equations that are used to decide the lubricating oil flow and the number of oil films (i.e. the number of rotating and stationary plates) are deduced theoretically. Also key parameters are provided for the design of the hydraulic system. All these together provide the theoretical basis for the soft start design of the belt conveyor and references for the application of the oil film clutch in similar fields.
