Common-track constellation is a special kind of constellation, all ground tracks of satellites are in one track. With recursive orbit or quasi-recursive orbit, the ground track of the constellation is a closed loop wi...Common-track constellation is a special kind of constellation, all ground tracks of satellites are in one track. With recursive orbit or quasi-recursive orbit, the ground track of the constellation is a closed loop with a repeating track. In particular, if the constellation is in one orbit plane, the constellation can meet the requirement for a multi-satellite launch mission and fast satellite-satellite link establishment. The characteristics and coverage properties of a common-track constellation in one orbit plane are studied in this paper. The simulation results show that a common-track constellation in one orbit plane can provide favorable coverage to a target station in the polar areas.展开更多
目的探讨高血压病患者药物治疗前后不同降压幅度对颈总动脉弹性改善程度的影响。方法选取187例高血压病患者进行降压治疗,血压降至140/90 mm Hg以下后持续维持3个月,应用血管回声跟踪(ET)技术检测高血压病患者治疗前后颈总动脉弹性参数...目的探讨高血压病患者药物治疗前后不同降压幅度对颈总动脉弹性改善程度的影响。方法选取187例高血压病患者进行降压治疗,血压降至140/90 mm Hg以下后持续维持3个月,应用血管回声跟踪(ET)技术检测高血压病患者治疗前后颈总动脉弹性参数即僵硬度(β)、压力应变弹性系数(Ep)、顺应性(AC)、增大指数(AI)及脉搏波传导速度(PWVβ)。结果 1收缩压控制为不同水平各弹性参数比较差异均有统计学意义(P<0.05);2舒张压控制为不同水平AC值比较差异具有统计学意义(P<0.05)。结论 1药物治疗能有效改善高血压病患者颈总动脉弹性;2高血压病患者降压达标后,血压控制水平不同各弹性参数改善程度也不同。展开更多
文摘Common-track constellation is a special kind of constellation, all ground tracks of satellites are in one track. With recursive orbit or quasi-recursive orbit, the ground track of the constellation is a closed loop with a repeating track. In particular, if the constellation is in one orbit plane, the constellation can meet the requirement for a multi-satellite launch mission and fast satellite-satellite link establishment. The characteristics and coverage properties of a common-track constellation in one orbit plane are studied in this paper. The simulation results show that a common-track constellation in one orbit plane can provide favorable coverage to a target station in the polar areas.
文摘目的探讨高血压病患者药物治疗前后不同降压幅度对颈总动脉弹性改善程度的影响。方法选取187例高血压病患者进行降压治疗,血压降至140/90 mm Hg以下后持续维持3个月,应用血管回声跟踪(ET)技术检测高血压病患者治疗前后颈总动脉弹性参数即僵硬度(β)、压力应变弹性系数(Ep)、顺应性(AC)、增大指数(AI)及脉搏波传导速度(PWVβ)。结果 1收缩压控制为不同水平各弹性参数比较差异均有统计学意义(P<0.05);2舒张压控制为不同水平AC值比较差异具有统计学意义(P<0.05)。结论 1药物治疗能有效改善高血压病患者颈总动脉弹性;2高血压病患者降压达标后,血压控制水平不同各弹性参数改善程度也不同。
