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题名基于三维可视图的地区电网电压凹陷评估
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作者
郑斌
陈铁敏
魏琼
林思海
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机构
上海市电力公司检修公司变电运维中心
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出处
《电力与能源》
2013年第1期51-55,共5页
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文摘
针对用电压凹陷矩阵来表示电网发生故障时产生的电压凹陷不够直观的问题,提出了在改进故障点法基础上用三维可视图来表示电压凹陷的方法,实现在多节点电网中可以直观地看出电网发生电压凹陷的节点及电压凹陷的深度。根据电压凹陷深度和故障距离的关系曲线对传输线分区,在每条传输线上设置有限个故障点,计算每个故障点上发生短路故障时,每个节点的电压凹陷深度,并通过每个故障点的故障概率分布来评估不同电压凹陷深度区间的凹陷频次,绘制电压凹陷的三维可视图。提出的方法应用于IEEE 30节点标准测试系统,验证了该方法的正确性和实用性。
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关键词
电压凹陷矩阵
三维可视图
电压凹陷深度
IEEE30节点标准测试系统
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Keywords
Voltage sag matrix
3D visual chart
Voltage sag depth
ieee-30 node test system
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分类号
TM711
[电气工程—电力系统及自动化]
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题名颈淋巴结阴性鼻咽癌颈部的放射治疗
被引量：7
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作者
李茵
曹卡加
陈秋燕
谢国丰
黄培钰
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机构
中山大学肿瘤防治中心鼻咽科
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出处
《癌症》
SCIE
CAS
CSCD
北大核心
2005年第5期627-630,共4页
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文摘
背景与目的:颈淋巴结阴性鼻咽癌(简称N0鼻咽癌)约占全部鼻咽癌病例的20%～30%,对这部分患者,治疗规范是在照射鼻咽病灶的同时预防照射双上颈部。但有些研究者主张行全颈预防照射。本研究分析和比较上颈部预防照射和全颈预防照射的颈部复发率和生存率的影响,以探讨N0鼻咽癌颈部的放射治疗。方法:选取178例经病理组织学确诊的N0鼻咽癌患者,其中88例接受上颈预防照射(上颈照射组),90例接受全颈预防照射(全颈照射组)。用Kaplan-M eier和log-rank法计算和比较两组生存率,用Cox模型分析影响预后的因素。结果:上颈照射组和全颈照射组的1、3、5年生存率分别为98.9%、90.9%、80.7%和97.8%、80.0%、71.1%(P=0.224);1、3、5年无瘤生存率分别是93.2%、80.7%、77.3%和85.6%、68.9%、64.4%(P=0.163);颈部复发率分别是1.14%和1.08%(P>0.05)。多因素分析显示:性别、T分期和近期疗效是影响N0鼻咽癌预后的独立因素。结论:对于颈淋巴结阴性鼻咽癌患者只需作上颈预防性照射。
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关键词
鼻咽肿瘤
放射治疗
预后
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Keywords
Nasopharyngeal neoplasms
Radiotherapy
PrognosisAbstract BACKGROUND & OBJECTIVE: Nasopharyngeal carcinoma (NPC) patients with negative cervical lymph node (N0-NPC) account for 20% -30% of all NPC patients. Prophylactic irradiation to the upper neck is a criterion of treatment for these patients. But some authors suggest to prophylactically irradiate the the whole neck. This study was to analyze and compare long-term outcomes of the N0-NPC patients treated by prophylactic irradiation to the upper neck and to the whole neck, and explore radiotherapy on neck for N0-NPC patients. METHODS: A total of 178 N0-NPC patients, proved by pathology, were treated in our hospital from Jul. 1998 to Dec. 1999. Of the 178 patients, 88 received prophylactic irradiation to the upper neck (upper neck group), 90 received prophylactic irradiation to the whole neck (whole neck group). Kaplan-Meier method and log-rank test were used to analyze and compare survival rate of the 2 groups. Cox model was used to study prognostic factors of N0-NPC. RESULTS: The 1-, 3-, and 5-year overall survival rates were 98.9%, 90.9%, and 80.7% in upper neck group, and 97.8%, 80.0%, and 71.1% in whole neck group (P = 0.224). The 1-, 3-, and 5-year disease-free survival rates were 93.2%, 80.7%, and 77.3% in upper neck group, and 85.6%, 68.9%, and 64.4% in whole neck group (P = 0.163). The incidence of cervical lymph nodes recurrence was 1.14% in upper neck group, and 1.09% in whole neck group (P> 0.05). Multivariate analysis showed that gender, T stage, and short-term outcome were independent prognostic factors of N0-NPC. CONCLUSION: Prophylactic irradiation to upper neck is recommended for N0-NPC patients.KEYWORDS: Nasopharyngeal neoplasms
Radiotherapy
Prognosis
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分类号
R739.63
[医药卫生—肿瘤]
R730.55
[医药卫生—肿瘤]
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