Cognitive radar is a concept proposed by Simon Haykin in 2006 as a new generation of radar system that imitates human cognitive features.Different from the adaptive signal processing at the receiver in adaptive radar,...Cognitive radar is a concept proposed by Simon Haykin in 2006 as a new generation of radar system that imitates human cognitive features.Different from the adaptive signal processing at the receiver in adaptive radar,the cognitive radar realizes closedloop adaptive policy adjustment of both transmitter and receiver in the continuous interaction with the environment.As a networked radar may significantly enhance the flexibility and robustness than its monostatic counterpart,the wireless networked cognitive radar(WNCR)attracts increasing research.This article firstly reviews the concept and development of cognitive radar,especially the related researches of networked cognitive radar.Then,the co-design of cognitive radar and communication is investigated.Although the communication quality between radar sensing nodes is the premise of detection,tracking,imaging and anti-jamming performance of the WNCR,the latest researches seldom consider the communication architecture design for WNCR.Therefore,this article mainly focuses on the proposal of WNCR concept based on the researches of cognitive radar and analyzes research challenges of WNCR system in practical application,and the corresponding guidelines are proposed to inspire future research.展开更多
作为钠离子电池正极材料,锰基层状氧化物具有理论储钠容量高、成本低和热稳定性高等优点,但也存在因结构畸变、Na^(+)/空位有序以及过渡金属空位等带来的循环稳定性问题。研究表明,抑制过渡金属空位可有效提升锰基层状氧化物正极的电化...作为钠离子电池正极材料,锰基层状氧化物具有理论储钠容量高、成本低和热稳定性高等优点,但也存在因结构畸变、Na^(+)/空位有序以及过渡金属空位等带来的循环稳定性问题。研究表明,抑制过渡金属空位可有效提升锰基层状氧化物正极的电化学性能。为此,本工作对比研究了溶胶凝胶制备过程中高温淬火对Na_(0.67)Fe1/3Co_(1/3)Mn_(1/3)O_(2)(NFCMO)结构和性能的影响。结果表明,相比于未经高温淬火处理的NFCMO,高温液氮淬火合成的NFCMO-LN具有更高的比容量和倍率性能。NFCMO和NFCMO-LN在0.1C下的初始放电比容量分别为91.1 m Ah/g和129.8 m Ah/g;1C倍率下循环100周后的容量保留率分别为100%和90%。即使在10C的高倍率下,NFCMO-LN仍能提供56.2 m Ah/g的放电比容量。结构分析表明,高温液氮淬火能有效抑制过渡金属空位的产生,提升了材料的结构稳定性。研究结果为钠离子电池正极材料的结构设计和电化学性能优化提供了一种可行的技术途径。展开更多
目的:阐述证据质量评价方法在临床药学实践工作中的应用,促进临床合理用药。方法:介绍我院(怀化市第一人民医院)临床药师以循证医学为基础制订的药物使用的证据质量评价标准化流程[以GRADE(Grades of Recommendations Assessment,Develo...目的:阐述证据质量评价方法在临床药学实践工作中的应用,促进临床合理用药。方法:介绍我院(怀化市第一人民医院)临床药师以循证医学为基础制订的药物使用的证据质量评价标准化流程[以GRADE(Grades of Recommendations Assessment,Development and Evaluation)系统为主],并通过医嘱点评、新药申请和用药咨询三项临床药学实践案例描述该流程的使用方法。结果与结论:我院制订的证据质量评价标准化流程为首先查找权威指南及参考书、药品说明书和相关研究文献等,当查找后在无高级别证据的情况下应用GRADE系统对现有证据进行评分、定级等来量化其质量,以及时、准确地给出用药建议。在3个实践案例中,使用GRADE系统评分结果分别为≤-3分、=-2分、≤-3分,证据级别分别为D级(极低级证据)、C级(低级证据)、D级,推荐强度分别为无推荐、弱推荐、强烈反对推荐。临床药师在工作中利用上述标准化的证据质量评价方法可为临床提供合理的用药建议。展开更多
基金This work was supported by the National Natural Science Foundation of China under Grant No.91948303.
文摘Cognitive radar is a concept proposed by Simon Haykin in 2006 as a new generation of radar system that imitates human cognitive features.Different from the adaptive signal processing at the receiver in adaptive radar,the cognitive radar realizes closedloop adaptive policy adjustment of both transmitter and receiver in the continuous interaction with the environment.As a networked radar may significantly enhance the flexibility and robustness than its monostatic counterpart,the wireless networked cognitive radar(WNCR)attracts increasing research.This article firstly reviews the concept and development of cognitive radar,especially the related researches of networked cognitive radar.Then,the co-design of cognitive radar and communication is investigated.Although the communication quality between radar sensing nodes is the premise of detection,tracking,imaging and anti-jamming performance of the WNCR,the latest researches seldom consider the communication architecture design for WNCR.Therefore,this article mainly focuses on the proposal of WNCR concept based on the researches of cognitive radar and analyzes research challenges of WNCR system in practical application,and the corresponding guidelines are proposed to inspire future research.
文摘作为钠离子电池正极材料,锰基层状氧化物具有理论储钠容量高、成本低和热稳定性高等优点,但也存在因结构畸变、Na^(+)/空位有序以及过渡金属空位等带来的循环稳定性问题。研究表明,抑制过渡金属空位可有效提升锰基层状氧化物正极的电化学性能。为此,本工作对比研究了溶胶凝胶制备过程中高温淬火对Na_(0.67)Fe1/3Co_(1/3)Mn_(1/3)O_(2)(NFCMO)结构和性能的影响。结果表明,相比于未经高温淬火处理的NFCMO,高温液氮淬火合成的NFCMO-LN具有更高的比容量和倍率性能。NFCMO和NFCMO-LN在0.1C下的初始放电比容量分别为91.1 m Ah/g和129.8 m Ah/g;1C倍率下循环100周后的容量保留率分别为100%和90%。即使在10C的高倍率下,NFCMO-LN仍能提供56.2 m Ah/g的放电比容量。结构分析表明,高温液氮淬火能有效抑制过渡金属空位的产生,提升了材料的结构稳定性。研究结果为钠离子电池正极材料的结构设计和电化学性能优化提供了一种可行的技术途径。
文摘目的:阐述证据质量评价方法在临床药学实践工作中的应用,促进临床合理用药。方法:介绍我院(怀化市第一人民医院)临床药师以循证医学为基础制订的药物使用的证据质量评价标准化流程[以GRADE(Grades of Recommendations Assessment,Development and Evaluation)系统为主],并通过医嘱点评、新药申请和用药咨询三项临床药学实践案例描述该流程的使用方法。结果与结论:我院制订的证据质量评价标准化流程为首先查找权威指南及参考书、药品说明书和相关研究文献等,当查找后在无高级别证据的情况下应用GRADE系统对现有证据进行评分、定级等来量化其质量,以及时、准确地给出用药建议。在3个实践案例中,使用GRADE系统评分结果分别为≤-3分、=-2分、≤-3分,证据级别分别为D级(极低级证据)、C级(低级证据)、D级,推荐强度分别为无推荐、弱推荐、强烈反对推荐。临床药师在工作中利用上述标准化的证据质量评价方法可为临床提供合理的用药建议。
