This paper presents a three-dimensional time-dependent nonlinear theory of helix traveling wave tubes for beam- wave interaction. The radio frequency electromagnetic fields are represented as the superposition of azim...This paper presents a three-dimensional time-dependent nonlinear theory of helix traveling wave tubes for beam- wave interaction. The radio frequency electromagnetic fields are represented as the superposition of azimuthally sym- metric waves in a vacuum sheath helix. Coupling impedance is introduced to the electromagnetic field equations＇ stimulating sources, which makes the theory easier and more flexible to realize. The space charge fields are calculated by electron beam space-charge waves expressed as the superposition solutions of Helmholtz equations. The focusing forces due to either a solenoidal field or a periodic permanent magnetic field is also included. The dynamical equations of electrons are Lorentz equations associating with electromagnetic fields, focusing fields and space-charge fields. The numerically simulated results of a tube are presented.展开更多
目的:探讨在鞘管保护下经T管窦道采用硬镜联合钬激光治疗肝内外胆道残余结石的临床价值。方法:2015年8月~2018年8月,将62例肝内外胆管残余结石病人,随机将分为硬镜组和纤维胆道镜组(软镜组),各31例,硬镜组在鞘管保护下经T管窦道采用硬...目的:探讨在鞘管保护下经T管窦道采用硬镜联合钬激光治疗肝内外胆道残余结石的临床价值。方法:2015年8月~2018年8月,将62例肝内外胆管残余结石病人,随机将分为硬镜组和纤维胆道镜组(软镜组),各31例,硬镜组在鞘管保护下经T管窦道采用硬镜联合钬激光碎石取石治疗,软镜组则经T管窦道采用纤维胆道镜联合钬激光碎石取石,分析比较两组手术时间、术后住院时间、结石取净率,以及相关主要并发症。结果:硬镜组结石取净率优于软镜组(90.3%vs64.5%,P=0.033),硬镜组手术时间少于软镜组(63±58min vs 130±44min,P<0.01);两组术后住院时间、并发症发生率等比较无统计学差异(P>0.05)。结论:对于术后肝内外胆管残余结石,采用经T管窦道硬镜联合钬激光进行碎石取石是安全、可行、高效的,手术时间短,术后恢复快,是治疗胆道外科术后残余结石可优选的微创治疗策略。展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 60601004,60801029,10876005,and60931001)
文摘This paper presents a three-dimensional time-dependent nonlinear theory of helix traveling wave tubes for beam- wave interaction. The radio frequency electromagnetic fields are represented as the superposition of azimuthally sym- metric waves in a vacuum sheath helix. Coupling impedance is introduced to the electromagnetic field equations＇ stimulating sources, which makes the theory easier and more flexible to realize. The space charge fields are calculated by electron beam space-charge waves expressed as the superposition solutions of Helmholtz equations. The focusing forces due to either a solenoidal field or a periodic permanent magnetic field is also included. The dynamical equations of electrons are Lorentz equations associating with electromagnetic fields, focusing fields and space-charge fields. The numerically simulated results of a tube are presented.
文摘目的:探讨在鞘管保护下经T管窦道采用硬镜联合钬激光治疗肝内外胆道残余结石的临床价值。方法:2015年8月~2018年8月,将62例肝内外胆管残余结石病人,随机将分为硬镜组和纤维胆道镜组(软镜组),各31例,硬镜组在鞘管保护下经T管窦道采用硬镜联合钬激光碎石取石治疗,软镜组则经T管窦道采用纤维胆道镜联合钬激光碎石取石,分析比较两组手术时间、术后住院时间、结石取净率,以及相关主要并发症。结果:硬镜组结石取净率优于软镜组(90.3%vs64.5%,P=0.033),硬镜组手术时间少于软镜组(63±58min vs 130±44min,P<0.01);两组术后住院时间、并发症发生率等比较无统计学差异(P>0.05)。结论:对于术后肝内外胆管残余结石,采用经T管窦道硬镜联合钬激光进行碎石取石是安全、可行、高效的,手术时间短,术后恢复快,是治疗胆道外科术后残余结石可优选的微创治疗策略。
