目的:考察中美青少年学生卷入度及各维度的异同。方法:采用特拉华学生卷入度量表(DSES-S)对2951名中国青少年和3016名美国青少年的学生卷入度进行跨文化比较。结果:中美青少年在学生卷入度总分上的差异无统计学意义[(29.1 ±4.7...目的:考察中美青少年学生卷入度及各维度的异同。方法:采用特拉华学生卷入度量表(DSES-S)对2951名中国青少年和3016名美国青少年的学生卷入度进行跨文化比较。结果:中美青少年在学生卷入度总分上的差异无统计学意义[(29.1 ±4.7) vs. (29.4 ±5.2), P 】0.05],但中国青少年的情感卷入度得分高于美国[(14.3 ±2.9) vs. (13.6 ±3.4), P 0.05]。结论:中美青少年在认知–行为卷入度和情感卷入度上存在差异。展开更多
In the wireless power transfer system for freely moving biomedical implants,the receiving unit was generally inefficient for the reason that its design parameters including the receiving coil's dimension and recei...In the wireless power transfer system for freely moving biomedical implants,the receiving unit was generally inefficient for the reason that its design parameters including the receiving coil's dimension and receiving circuits' topology were always determined by experiments.In order to build the relationship between these parameters and the total transfer efficiency,this paper developed a novel efficiency model based on the impedance model of the coil and the circuit model of the receiving circuits.According to the design constraints,the optimal design parameters in the worst case were derived.The results indicate that the combination of the two-layered receiving coil and half-bridge rectifier has more advantages in size,efficiency and safety,which is preferred in the receiving unit.Additionally,when the load resistance increases,the optimal turn number of the receiving coil basically keeps constant and the corresponding transmitting current and total efficiency decrease.For 100 Ω load,the transmitting current and total efficiency in the worst case were measured to be 5.30 A and 1.45% respectively,which are much better than the published results.In general,our work provides an efficient method to determine the design parameters of the wireless power transfer system for freely moving biomedical implants.展开更多
文摘目的:考察中美青少年学生卷入度及各维度的异同。方法:采用特拉华学生卷入度量表(DSES-S)对2951名中国青少年和3016名美国青少年的学生卷入度进行跨文化比较。结果:中美青少年在学生卷入度总分上的差异无统计学意义[(29.1 ±4.7) vs. (29.4 ±5.2), P 】0.05],但中国青少年的情感卷入度得分高于美国[(14.3 ±2.9) vs. (13.6 ±3.4), P 0.05]。结论:中美青少年在认知–行为卷入度和情感卷入度上存在差异。
基金supported by the National Natural Science Foundation of China(Grant No.61473281)the National Sciences and Technology Support Project(Grant No.2015BAI01B13)State Key Laboratory of Robotics Self-plan Project(Grant No.2016-Z06)
文摘In the wireless power transfer system for freely moving biomedical implants,the receiving unit was generally inefficient for the reason that its design parameters including the receiving coil's dimension and receiving circuits' topology were always determined by experiments.In order to build the relationship between these parameters and the total transfer efficiency,this paper developed a novel efficiency model based on the impedance model of the coil and the circuit model of the receiving circuits.According to the design constraints,the optimal design parameters in the worst case were derived.The results indicate that the combination of the two-layered receiving coil and half-bridge rectifier has more advantages in size,efficiency and safety,which is preferred in the receiving unit.Additionally,when the load resistance increases,the optimal turn number of the receiving coil basically keeps constant and the corresponding transmitting current and total efficiency decrease.For 100 Ω load,the transmitting current and total efficiency in the worst case were measured to be 5.30 A and 1.45% respectively,which are much better than the published results.In general,our work provides an efficient method to determine the design parameters of the wireless power transfer system for freely moving biomedical implants.
