The optoelectronic oscillator(OEO)is a typical time-delay system with rich nonlinear dynamical characteristics.Most of the previous research on OEOs has been focused on analyzing the properties of OEOs with a long tim...The optoelectronic oscillator(OEO)is a typical time-delay system with rich nonlinear dynamical characteristics.Most of the previous research on OEOs has been focused on analyzing the properties of OEOs with a long time delay,which makes it difficult to realize mode locking without additional phaselocking mechanisms.We have achieved,for the first time to our knowledge,a self-mode-locking OEO and generated stable microwave frequency combs by analyzing the characteristics of OEOs with an ultrashort time scale.In the experiment,the self-mode-locking OEOs with fundamental mode,second-order harmonic,and sixth-order harmonic were realized by adjusting the system parameters,all of which produced uniform square wave signals with tunable duty cycles,steep rising and falling edges,and periods of less than 20 ns.The self-fundamental-mode-locking OEOs with different time delays were also implemented and experimentally realized.Furthermore,the experiment revealed the self-hybrid mode-locking OEO,which is the coexistence and synchronization of the three measured self-locking modes in one OEO cavity,demonstrating the complex nonlinear dynamical behaviors of the OEO system and enabling the generation of periodic nonuniform hybrid square wave signals.The realization of the self-mode-locking OEO and the generation of flexible and stable square wave signals at ultrashort time scales enrich the study of OEO nonlinear dynamics in the realm of complex microwave waveform generation,offering promising applications in areas such as atomic clocks,radars,communications,and optoelectronic neural networks.展开更多
The high peak power of picosecond pulses produced by a self-mode-locked semiconductor disk laser can effectively improve the efficiency of nonlinear frequency conversion.This paper presents the intracavity frequency t...The high peak power of picosecond pulses produced by a self-mode-locked semiconductor disk laser can effectively improve the efficiency of nonlinear frequency conversion.This paper presents the intracavity frequency tripling in a self-mode-locked semiconductor disk laser,and a picosecond pulse train at 327 nm wavelength is achieved.The pulse repetition rate is 0.49 GHz,and the pulse width is 5.0 ps.The obtained maximum ultraviolet output power under mode locking is 30.5 m W,and the corresponding conversion efficiency is obviously larger than that of continuous-wave operation.These ultraviolet picosecond pulses have high spatial and temporal resolution and can be applied in some emerging fields.展开更多
目的观察知信行模式护理对输尿管结石手术患者疾病认知、自护能力及预后的影响。方法选取2022年2月至2023年3月于安徽中医药大学附属六安市中医院的70例行输尿管结石手术患者为研究对象,按照随机数字表法将其分为对照组(35例)与观察组(3...目的观察知信行模式护理对输尿管结石手术患者疾病认知、自护能力及预后的影响。方法选取2022年2月至2023年3月于安徽中医药大学附属六安市中医院的70例行输尿管结石手术患者为研究对象,按照随机数字表法将其分为对照组(35例)与观察组(35例)。对照组实施常规护理,观察组实施知信行模式护理干预,两组均干预至患者出院。比较两组患者疾病认知、疼痛数字评分法(NRS)、一般自我效能感量表(GSES)、自我护理能力测定量表(ESCA)和术后并发症发生情况。结果观察组患者出院前1 d疾病认知评分高于较对照组,差异有统计学意义(P<0.05);观察组术后12、24、48 h NRS评分低于对照组,差异有统计学意义(P<0.05);观察组出院前1 d GSES评分和ESCA评分高于对照组,差异有统计学意义(P<0.05);两组术后并发症总发生率比较,差异无统计学意义(P>0.05)。结论知信行模式护理可有效增强输尿管结石手术患者的疾病认知,提升患者的自我效能与自护能力,利于缓解术后疼痛,对促进患者康复具有积极意义。展开更多
基金supported by the National Natural Science Foundation of China(Grant No.62301495)the Project of the National Key Laboratory of Microwave Photonics(Nanjing University of Aeronautics and Astronautics),Ministry of Education(Grant No.NJ20220007).
文摘The optoelectronic oscillator(OEO)is a typical time-delay system with rich nonlinear dynamical characteristics.Most of the previous research on OEOs has been focused on analyzing the properties of OEOs with a long time delay,which makes it difficult to realize mode locking without additional phaselocking mechanisms.We have achieved,for the first time to our knowledge,a self-mode-locking OEO and generated stable microwave frequency combs by analyzing the characteristics of OEOs with an ultrashort time scale.In the experiment,the self-mode-locking OEOs with fundamental mode,second-order harmonic,and sixth-order harmonic were realized by adjusting the system parameters,all of which produced uniform square wave signals with tunable duty cycles,steep rising and falling edges,and periods of less than 20 ns.The self-fundamental-mode-locking OEOs with different time delays were also implemented and experimentally realized.Furthermore,the experiment revealed the self-hybrid mode-locking OEO,which is the coexistence and synchronization of the three measured self-locking modes in one OEO cavity,demonstrating the complex nonlinear dynamical behaviors of the OEO system and enabling the generation of periodic nonuniform hybrid square wave signals.The realization of the self-mode-locking OEO and the generation of flexible and stable square wave signals at ultrashort time scales enrich the study of OEO nonlinear dynamics in the realm of complex microwave waveform generation,offering promising applications in areas such as atomic clocks,radars,communications,and optoelectronic neural networks.
基金supported by the Cooperation Project between Chongqing Local Universities and Institutions of Chinese Academy of Sciences,Chongqing Municipal Education Commission(No.HZ2021007)the National Natural Science Foundation of China(Nos.61904024,61975003,61790584,and 62025506)the Science and Technology Research Program of Chongqing Municipal Education Commission(No.KJZD-M201900502)。
文摘The high peak power of picosecond pulses produced by a self-mode-locked semiconductor disk laser can effectively improve the efficiency of nonlinear frequency conversion.This paper presents the intracavity frequency tripling in a self-mode-locked semiconductor disk laser,and a picosecond pulse train at 327 nm wavelength is achieved.The pulse repetition rate is 0.49 GHz,and the pulse width is 5.0 ps.The obtained maximum ultraviolet output power under mode locking is 30.5 m W,and the corresponding conversion efficiency is obviously larger than that of continuous-wave operation.These ultraviolet picosecond pulses have high spatial and temporal resolution and can be applied in some emerging fields.
文摘目的观察知信行模式护理对输尿管结石手术患者疾病认知、自护能力及预后的影响。方法选取2022年2月至2023年3月于安徽中医药大学附属六安市中医院的70例行输尿管结石手术患者为研究对象,按照随机数字表法将其分为对照组(35例)与观察组(35例)。对照组实施常规护理,观察组实施知信行模式护理干预,两组均干预至患者出院。比较两组患者疾病认知、疼痛数字评分法(NRS)、一般自我效能感量表(GSES)、自我护理能力测定量表(ESCA)和术后并发症发生情况。结果观察组患者出院前1 d疾病认知评分高于较对照组,差异有统计学意义(P<0.05);观察组术后12、24、48 h NRS评分低于对照组,差异有统计学意义(P<0.05);观察组出院前1 d GSES评分和ESCA评分高于对照组,差异有统计学意义(P<0.05);两组术后并发症总发生率比较,差异无统计学意义(P>0.05)。结论知信行模式护理可有效增强输尿管结石手术患者的疾病认知,提升患者的自我效能与自护能力,利于缓解术后疼痛,对促进患者康复具有积极意义。
