Based on the study of the harmonic suppression on DC side of the multi-pulse rectification system,a software platform is established in Matlab environment.The phase-shift angle is studied from the aspects of system st...Based on the study of the harmonic suppression on DC side of the multi-pulse rectification system,a software platform is established in Matlab environment.The phase-shift angle is studied from the aspects of system stability and economy,analyzing the effects of phase-shift angle on the input-side line current,the output-side voltage ripple,the equivalent capacity of autotransformer and other auxiliary devices in 12-pulse rectifier system.The software platform can complete the analysis only by inputting the initial conditions,eliminating the derivation of the intermediate formula and reducing the complexity of the system analysis,and have good scalability.The simulation results show that the system can effectively analyze the influence of phase angle on 12-pulse star-connected transformer.展开更多
目的:探讨75%乙醇加维生素B_(12)外敷联合特定电磁波(TDP)照射预防肿瘤病人经外周静脉置入中心静脉导管(PICC)相关静脉血栓的效果。方法:选择PICC置管后血栓风险评估≥19分的肿瘤病人182例,随机分为两组各91例,对照组给予常规护理,观察...目的:探讨75%乙醇加维生素B_(12)外敷联合特定电磁波(TDP)照射预防肿瘤病人经外周静脉置入中心静脉导管(PICC)相关静脉血栓的效果。方法:选择PICC置管后血栓风险评估≥19分的肿瘤病人182例,随机分为两组各91例,对照组给予常规护理,观察组在常规护理基础上给予75%乙醇加维生素B12外敷置管静脉,同时给予特定电磁波照射,连续14 d,每日2次,比较两组病人血浆纤维蛋白原(FIB)、D-二聚体(D-D)、凝血酶原时间(PT)、静脉血栓发生率、发生时间、不良反应、满意度。结果:两组病人置管后14 d FIB、D-D、PT比较差异均有统计学意义(P<0.05);两组静脉血栓发生率比较差异有统计学意义(P<0.05),观察组静脉血栓发生时间较对照组后移。结论:75%乙醇加维生素B12外敷联合TDP照射有助于预防肿瘤病人PICC相关静脉血栓。展开更多
根据南方电网实际需要,研制了12脉波直流融冰兼SVC系统。基于电力电子整流技术的直流融冰装置,兼具静止无功补偿(Static Var Compensation,简称SVC)功能,应用前景广阔。以贵州电网500kV变电站直流融冰兼SVC工程为例,对系统功能、切换方...根据南方电网实际需要,研制了12脉波直流融冰兼SVC系统。基于电力电子整流技术的直流融冰装置,兼具静止无功补偿(Static Var Compensation,简称SVC)功能,应用前景广阔。以贵州电网500kV变电站直流融冰兼SVC工程为例,对系统功能、切换方案、控制系统、晶闸管阀组和现场应用进行了分析,论证了采用12脉波直流融冰兼SVC系统的必要性和优点。展开更多
基金National Natural Science Foundation of China(Nos.51367010,51867012)Lanzhou City Talent Innovation and Entrepreneurship Science and Technology Program Subsidy(No.2017-RC-51)。
文摘Based on the study of the harmonic suppression on DC side of the multi-pulse rectification system,a software platform is established in Matlab environment.The phase-shift angle is studied from the aspects of system stability and economy,analyzing the effects of phase-shift angle on the input-side line current,the output-side voltage ripple,the equivalent capacity of autotransformer and other auxiliary devices in 12-pulse rectifier system.The software platform can complete the analysis only by inputting the initial conditions,eliminating the derivation of the intermediate formula and reducing the complexity of the system analysis,and have good scalability.The simulation results show that the system can effectively analyze the influence of phase angle on 12-pulse star-connected transformer.
文摘目的:探讨75%乙醇加维生素B_(12)外敷联合特定电磁波(TDP)照射预防肿瘤病人经外周静脉置入中心静脉导管(PICC)相关静脉血栓的效果。方法:选择PICC置管后血栓风险评估≥19分的肿瘤病人182例,随机分为两组各91例,对照组给予常规护理,观察组在常规护理基础上给予75%乙醇加维生素B12外敷置管静脉,同时给予特定电磁波照射,连续14 d,每日2次,比较两组病人血浆纤维蛋白原(FIB)、D-二聚体(D-D)、凝血酶原时间(PT)、静脉血栓发生率、发生时间、不良反应、满意度。结果:两组病人置管后14 d FIB、D-D、PT比较差异均有统计学意义(P<0.05);两组静脉血栓发生率比较差异有统计学意义(P<0.05),观察组静脉血栓发生时间较对照组后移。结论:75%乙醇加维生素B12外敷联合TDP照射有助于预防肿瘤病人PICC相关静脉血栓。
文摘根据南方电网实际需要,研制了12脉波直流融冰兼SVC系统。基于电力电子整流技术的直流融冰装置,兼具静止无功补偿(Static Var Compensation,简称SVC)功能,应用前景广阔。以贵州电网500kV变电站直流融冰兼SVC工程为例,对系统功能、切换方案、控制系统、晶闸管阀组和现场应用进行了分析,论证了采用12脉波直流融冰兼SVC系统的必要性和优点。
