观察和比较单次低强度骑车和跑步对健康男生动脉硬度的短时影响,并探索跑步坡度的可能作用。方法:采用随机均衡交叉自身对照设计,16名健康男生的年龄为(21.8±0.4)岁,按空白对照方案(non-exercise control trial,CON)、骑车方案(cyc...观察和比较单次低强度骑车和跑步对健康男生动脉硬度的短时影响,并探索跑步坡度的可能作用。方法:采用随机均衡交叉自身对照设计,16名健康男生的年龄为(21.8±0.4)岁,按空白对照方案(non-exercise control trial,CON)、骑车方案(cycle trial,CYC)、0坡度跑步方案(treadmill trial at 0,TM0)和18%坡度跑步方案(treadmill trial at 18%,TM18)进行实验。受试者均在运动前进行基线(baseline,BL)动脉硬度测定,然后进行持续30min的单次运动,强度均控制在35%心率储备。运动结束后即刻(0min)和结束后40min对动脉硬度进行重复测定。动脉硬度用心-踝血管指数(cardio-ankle vascular index,CAVI)来评价,用每个方案中CAVI相对于其基线的变化(ΔCAVI)进行统计分析。结果:CON方案中ΔCAVI在BL、0min和40min时分别为(0.0±0.0)(0.1±0.1)和(0.0±0.1),变化未见显著性。CYC方案中运动后即刻ΔCAVI从基线(0.0±0.0)明显下降至(-1.1±0.1),休息40min基本恢复至基线(-0.2±0.1)。虽然TM0和TM18方案中运动结束后即刻ΔCAVI出现幅度类似于CYC的下降,但在休息40 min后ΔCAVI仍均维持在较低水平(-0.6±0.1,P<0.05vs.CON和CYC)。TM0和TM18方案之间则无明显差别。结论:在相同靶心率的前提下,骑车和跑步均能明显降低动脉硬度,但跑步对动脉硬度的影响优于骑车。相同靶心率跑步中,改变坡度对动脉硬度无影响。展开更多
A novel 50 kW fast charger was proposed for electric vehicles. The proposed fast charger is divided into two main sections an AC-DC converter performing a PFC function and a DC-DC converter performing a charging funct...A novel 50 kW fast charger was proposed for electric vehicles. The proposed fast charger is divided into two main sections an AC-DC converter performing a PFC function and a DC-DC converter performing a charging function. A transformer including leakage inductances was used in the AC-DC converter in order to obtain isolation and inductance. A series-connection topology was used in the DC-DC converter between the DC-bus and outlet. This topology enables high power conversion efficiency up to 95% for the DC-DC converter. In order to reduce the impact of the 50 kW charging on the AC grid, the proposed fast charger system includes a buffering battery unit between the two main power conversion units. This leads to reductions in the power installation costs of power companies and to improvements in the power quality were verified through simulations and experimental results. on the AC grid. The performances of the proposed fast charger system展开更多
文摘观察和比较单次低强度骑车和跑步对健康男生动脉硬度的短时影响,并探索跑步坡度的可能作用。方法:采用随机均衡交叉自身对照设计,16名健康男生的年龄为(21.8±0.4)岁,按空白对照方案(non-exercise control trial,CON)、骑车方案(cycle trial,CYC)、0坡度跑步方案(treadmill trial at 0,TM0)和18%坡度跑步方案(treadmill trial at 18%,TM18)进行实验。受试者均在运动前进行基线(baseline,BL)动脉硬度测定,然后进行持续30min的单次运动,强度均控制在35%心率储备。运动结束后即刻(0min)和结束后40min对动脉硬度进行重复测定。动脉硬度用心-踝血管指数(cardio-ankle vascular index,CAVI)来评价,用每个方案中CAVI相对于其基线的变化(ΔCAVI)进行统计分析。结果:CON方案中ΔCAVI在BL、0min和40min时分别为(0.0±0.0)(0.1±0.1)和(0.0±0.1),变化未见显著性。CYC方案中运动后即刻ΔCAVI从基线(0.0±0.0)明显下降至(-1.1±0.1),休息40min基本恢复至基线(-0.2±0.1)。虽然TM0和TM18方案中运动结束后即刻ΔCAVI出现幅度类似于CYC的下降,但在休息40 min后ΔCAVI仍均维持在较低水平(-0.6±0.1,P<0.05vs.CON和CYC)。TM0和TM18方案之间则无明显差别。结论:在相同靶心率的前提下,骑车和跑步均能明显降低动脉硬度,但跑步对动脉硬度的影响优于骑车。相同靶心率跑步中,改变坡度对动脉硬度无影响。
基金Project supported by Changwon National University in 2011-2012
文摘A novel 50 kW fast charger was proposed for electric vehicles. The proposed fast charger is divided into two main sections an AC-DC converter performing a PFC function and a DC-DC converter performing a charging function. A transformer including leakage inductances was used in the AC-DC converter in order to obtain isolation and inductance. A series-connection topology was used in the DC-DC converter between the DC-bus and outlet. This topology enables high power conversion efficiency up to 95% for the DC-DC converter. In order to reduce the impact of the 50 kW charging on the AC grid, the proposed fast charger system includes a buffering battery unit between the two main power conversion units. This leads to reductions in the power installation costs of power companies and to improvements in the power quality were verified through simulations and experimental results. on the AC grid. The performances of the proposed fast charger system
