目的探讨慢性病患者自我损耗概念的定义及其内涵,为开展自我损耗相关研究提供参考。方法系统检索1998年—2022年发表在CINAHL、PubMed、Cochrane Library、Web of Science、Embase、知网、中国生物医学文献服务系统、万方数据库中的关...目的探讨慢性病患者自我损耗概念的定义及其内涵,为开展自我损耗相关研究提供参考。方法系统检索1998年—2022年发表在CINAHL、PubMed、Cochrane Library、Web of Science、Embase、知网、中国生物医学文献服务系统、万方数据库中的关于自我损耗的文献。采用Walker和Avant的概念分析法对纳入文献进行分析。结果共纳入39篇文献。慢性病患者自我损耗的定义属性为心理资源消耗、自我控制能力下降,且两者交互影响;其前因为疾病相关因素、人口学特征、睡眠因素、认知因素、心理社会因素;后果为不良健康行为、心理负担加重及生活质量下降。测量工具包括自我调节疲劳量表、自我损耗后效量表和自我损耗源量表。结论该研究明晰了慢性病患者自我损耗的定义属性、前因及后果,可为以后开展慢性病自我损耗评估工具开发、理论模型构建及干预研究等提供参考。展开更多
Three design methods for wireless power transmission(WPT)systems using antenna arrays have been investigated.The three methods,corresponding to three common application scenarios of WPT systems,are based on the method...Three design methods for wireless power transmission(WPT)systems using antenna arrays have been investigated.The three methods,corresponding to three common application scenarios of WPT systems,are based on the method of maximum power transmission efficiency(MMPTE)between two antenna arrays.They are unconstrained MMPTE,weighted MMPTE,and constrained MMPTE.To demonstrate the optimal design process with the three methods,a WPT system operating at 2.45 GHz is designed,simulated,and fabricated,in which the transmitting(Tx)array,consisting of 36 microstrip patch elements,is configured as a square and the receiving(Rx)array,consisting of 5 patch elements,is configured as an L shape.The power transmission efficiency(PTE)is then maximized for the three application scenarios,which yields the maximum possible PTEs and the optimized distributions of excitations for both Tx and Rx arrays.The feeding networks are then built based on the optimized distributions of excitations.Simulations and experiments reveal that the unconstrained MMPTE,which corresponds to the application scenario where no radiation pattern shaping is involved,yields the highest PTE.The next highest PTE belongs to the weighted MMPTE,where the power levels at all the receiving elements are imposed to be equal.The constrained MMPTE has the lowest PTE,corresponding to the scenario in which the radiated power pattern is assumed to be flat along with the Rx array.展开更多
文摘目的探讨慢性病患者自我损耗概念的定义及其内涵,为开展自我损耗相关研究提供参考。方法系统检索1998年—2022年发表在CINAHL、PubMed、Cochrane Library、Web of Science、Embase、知网、中国生物医学文献服务系统、万方数据库中的关于自我损耗的文献。采用Walker和Avant的概念分析法对纳入文献进行分析。结果共纳入39篇文献。慢性病患者自我损耗的定义属性为心理资源消耗、自我控制能力下降,且两者交互影响;其前因为疾病相关因素、人口学特征、睡眠因素、认知因素、心理社会因素;后果为不良健康行为、心理负担加重及生活质量下降。测量工具包括自我调节疲劳量表、自我损耗后效量表和自我损耗源量表。结论该研究明晰了慢性病患者自我损耗的定义属性、前因及后果,可为以后开展慢性病自我损耗评估工具开发、理论模型构建及干预研究等提供参考。
基金the National Natural Science Foundation of China under Grant No.61971231.
文摘Three design methods for wireless power transmission(WPT)systems using antenna arrays have been investigated.The three methods,corresponding to three common application scenarios of WPT systems,are based on the method of maximum power transmission efficiency(MMPTE)between two antenna arrays.They are unconstrained MMPTE,weighted MMPTE,and constrained MMPTE.To demonstrate the optimal design process with the three methods,a WPT system operating at 2.45 GHz is designed,simulated,and fabricated,in which the transmitting(Tx)array,consisting of 36 microstrip patch elements,is configured as a square and the receiving(Rx)array,consisting of 5 patch elements,is configured as an L shape.The power transmission efficiency(PTE)is then maximized for the three application scenarios,which yields the maximum possible PTEs and the optimized distributions of excitations for both Tx and Rx arrays.The feeding networks are then built based on the optimized distributions of excitations.Simulations and experiments reveal that the unconstrained MMPTE,which corresponds to the application scenario where no radiation pattern shaping is involved,yields the highest PTE.The next highest PTE belongs to the weighted MMPTE,where the power levels at all the receiving elements are imposed to be equal.The constrained MMPTE has the lowest PTE,corresponding to the scenario in which the radiated power pattern is assumed to be flat along with the Rx array.
