We theoretically investigate the high-order-harmonic generation from the H2^＋ molecular ion exposed to the combi- nation of an intense trapezoidal laser and a static field. The results show that the harmonic spectrum...We theoretically investigate the high-order-harmonic generation from the H2^＋ molecular ion exposed to the combi- nation of an intense trapezoidal laser and a static field. The results show that the harmonic spectrum is obviously extended and the short quantum path is selected to contribute to the spectrum, because the corresponding long path is seriously suppressed. Then the combined Coulomb and laser field potentials and the time-dependent electron wave packet distributions are applied to illustrate the physical mechanism of high-order harmonic gen- eration. Finally, by adjusting the intensity of the static field and superposing a properly selected range of the HHG spectrum, a 90-as isolated attosecond pulse is straightforwardly obtained.展开更多
This paper is concerned with the robust control synthesis of autonomous underwater vehicle （AUV） for general path following maneuvers. First, we present maneuvering kinematics and vehicle dynamics in a unified frame...This paper is concerned with the robust control synthesis of autonomous underwater vehicle （AUV） for general path following maneuvers. First, we present maneuvering kinematics and vehicle dynamics in a unified framework. Based on H∞ loop-shaping procedure, the 2-DOF autopilot controller has been presented to enhance stability and path tracking. By use of model reduction, the high-order control system is reduced to one with reasonable order, and further the scaled low-order controller has been analyzed in both the frequency and the time domains. Finally, it is shown that the autopilot control system provides robust performance and stability against prescribed levels of uncertainty.展开更多
目的:探讨路径式护理在H型高血压合并射血分数保留的心力衰竭(hear t failure with preserved ejection fraction,HFPEF)治疗中的应用效果。方法:选取秦皇岛市第一医院心血管内科于2015年1月至2016年8月收治的100例H型高血压合并HFPEF...目的:探讨路径式护理在H型高血压合并射血分数保留的心力衰竭(hear t failure with preserved ejection fraction,HFPEF)治疗中的应用效果。方法:选取秦皇岛市第一医院心血管内科于2015年1月至2016年8月收治的100例H型高血压合并HFPEF患者为对照组,采用常规护理。选取2016年9月至2019年1月收治的100例H型高血压合并HFPEF患者为观察组,采用路径式护理。比较两组的健康知识掌握情况、血压、左房容积/体表面积(left atrial volume index,LAVI)等指标。结果:观察组的健康知识知晓率、去除高危因素重要性知晓率高于对照组,差异有统计学意义(P<0.05)。观察组干预后的收缩压、舒张压低于对照组,LAVI小于对照组,差异有统计学意义(P<0.05)。观察组干预后的同型半胱氨酸(homocysteine,Hcy)低于对照组,氨基末端脑肽钠前体(N-terminal pro-brain natriuretic peptide,NT-proBNP)低于对照组,差异有统计学意义(P<0.05)。结论:路径式护理能提高H型高血压合并HFPEF患者对自身疾病的认识,提高血压控制水平,改善左房泵血功能。展开更多
Ewa·Wojcicka [1] has proved that the connected 3 γ critical graphs has a H path and has put forward to such a conjecture: Connected 3 γ critical graphs without endpoints are H graphs. In this paper,we prove tha...Ewa·Wojcicka [1] has proved that the connected 3 γ critical graphs has a H path and has put forward to such a conjecture: Connected 3 γ critical graphs without endpoints are H graphs. In this paper,we prove that if G is a connected 3 γ critical graph without endpoints and has a H paht ap →a such that d(a,b)=3, then G is a H graph. The result partially solves Ewa. Wojcickas conjecture.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No 11404204the Key Project of the Ministry of Education of China under Grant No 211025+1 种基金the Research Fund for the Doctoral Program of Higher Education of China under Grant No 20111404120004the Natural Science Foundation for Young Scientists of Shanxi Province of China under Grant No2009021005
文摘We theoretically investigate the high-order-harmonic generation from the H2^＋ molecular ion exposed to the combi- nation of an intense trapezoidal laser and a static field. The results show that the harmonic spectrum is obviously extended and the short quantum path is selected to contribute to the spectrum, because the corresponding long path is seriously suppressed. Then the combined Coulomb and laser field potentials and the time-dependent electron wave packet distributions are applied to illustrate the physical mechanism of high-order harmonic gen- eration. Finally, by adjusting the intensity of the static field and superposing a properly selected range of the HHG spectrum, a 90-as isolated attosecond pulse is straightforwardly obtained.
基金a part of the project titled "Development of Key Marine Equipments for Enhancement of Ocean Industry-Development of Underwater Manipulator and Thrusting System Driven by Electric Motor" funded by the Ministry of Land, Transport and Maritime Affairs, Korea
文摘This paper is concerned with the robust control synthesis of autonomous underwater vehicle （AUV） for general path following maneuvers. First, we present maneuvering kinematics and vehicle dynamics in a unified framework. Based on H∞ loop-shaping procedure, the 2-DOF autopilot controller has been presented to enhance stability and path tracking. By use of model reduction, the high-order control system is reduced to one with reasonable order, and further the scaled low-order controller has been analyzed in both the frequency and the time domains. Finally, it is shown that the autopilot control system provides robust performance and stability against prescribed levels of uncertainty.
文摘Ewa·Wojcicka [1] has proved that the connected 3 γ critical graphs has a H path and has put forward to such a conjecture: Connected 3 γ critical graphs without endpoints are H graphs. In this paper,we prove that if G is a connected 3 γ critical graph without endpoints and has a H paht ap →a such that d(a,b)=3, then G is a H graph. The result partially solves Ewa. Wojcickas conjecture.
