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腔镜辅助手术与开放手术治疗cN0期甲状腺乳头状癌的对比 被引量:16
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作者 王宇 李崔伟 +7 位作者 史潇 史荣亮 渠宁 马奔 徐伟博 王玉龙 朱永学 嵇庆海 《中国肿瘤临床》 CAS CSCD 北大核心 2019年第20期1051-1055,共5页
目的:比较胸骨切迹入路腔镜辅助下甲状腺手术(minimally invasive video-assisted thyroidectomy,MIVAT)与传统开放手术(open thyroid surgery,OTS)治疗临床淋巴结阴性(clinically node-negative,cN0)甲状腺乳头状癌(papillary thyroid ... 目的:比较胸骨切迹入路腔镜辅助下甲状腺手术(minimally invasive video-assisted thyroidectomy,MIVAT)与传统开放手术(open thyroid surgery,OTS)治疗临床淋巴结阴性(clinically node-negative,cN0)甲状腺乳头状癌(papillary thyroid carcinoma,PTC)的彻底性、安全性以及术后美容效果的差异。方法:收集2012年1月至2017年12月间复旦大学附属肿瘤医院行胸骨切迹入路MIVAT的80例cN0期PTC患者,并根据1:2比例使用随机数法抽取160例同期行OTS的PTC患者。患者手术方式为腺叶切除/全甲切除术+预防性中央区淋巴结清扫术。采用χ~2检验、Kaplan-Meier生存分析与Log-rank检验对比两种手术方式的差异。结果:MIVAT组的平均手术时间长于OTS组(P=0.003),但住院时间明显缩短(P<0.001)。手术疗效方面,MIVAT组与OTS组患者的术后复发率、淋巴结清扫数目以及淋巴结转移数目的差异均无统计学意义(均P>0.05)。手术安全性方面,两种术式术后发生喉返神经损伤、术后血肿和感染等并发症的发生率相近(均P>0.05)。两组患者术后的改良版温哥华瘢痕量表(Vancouver scar scale,VSS)评分亦无显著性差异(P=0.288),但MIVAT组相比OTS组可以显著缩短颈部瘢痕长度(P<0.001)。结论:对于cN0期PTC而言,MIVAT在手术的疗效、安全性上与OTS无明显区别,尽管MIVAT的改良VSS瘢痕评分与OTS类似,但胸骨切迹入路MIVAT可以显著减少颈部切口长度,具有一定的美容效果,同时由于切口位置更低,容易遮盖,美容效果更好。因此,经胸骨切迹入路MI-VAT可在临床实践中进一步推广。 展开更多
关键词 甲状腺乳头状癌 腔镜辅助下甲状腺手术 疗效 安全性 美容效果
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Improved Strategy of Grid-Forming Virtual Synchronous Generator Based on Transient Damping
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作者 Lei Zhang rongliang shi +2 位作者 Junhui Li Yannan Yu Yu Zhang 《Energy Engineering》 EI 2024年第11期3181-3197,共17页
The grid-forming virtual synchronous generator(GFVSG)not only employs a first-order low-pass filter for virtual inertia control but also introduces grid-connected active power(GCAP)dynamic oscillation issues,akin to t... The grid-forming virtual synchronous generator(GFVSG)not only employs a first-order low-pass filter for virtual inertia control but also introduces grid-connected active power(GCAP)dynamic oscillation issues,akin to those observed in traditional synchronous generators.In response to this,an improved strategy for lead-lag filter based GFVSG(LLF-GFVSG)is presented in this article.Firstly,the grid-connected circuit structure and control principle of typical GFVSG are described,and a closed-loop small-signal model for GCAP in GFVSG is established.The causes of GCAP dynamic oscillation of GFVSG under the disturbances of active power command as well as grid frequency are analyzed.On this basis,the LLF-GFVSG improvement strategy and its parameter design method are given.Finally,the efficiency of the proposed control strategy in damping GCAP dynamic oscillations under various disturbances is verified using MATLAB simulations and experimental comparison results. 展开更多
关键词 Grid-forming virtual synchronous generator first-order low-pass filter lead-lag filter small-signal model parameter design
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Self-tuning virtual synchronous generator control for improving frequency stability in autonomous photovoltaic-diesel microgrids 被引量:30
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作者 rongliang shi Xing ZHANG +3 位作者 Chao HU Haizhen XU Jun GU Wei CAO 《Journal of Modern Power Systems and Clean Energy》 SCIE EI 2018年第3期482-494,共13页
This paper investigates the use of a virtual synchronous generator(VSG) to improve frequency stability in an autonomous photovoltaic-diesel microgrid with energy storage. VSG control is designed to emulate inertial re... This paper investigates the use of a virtual synchronous generator(VSG) to improve frequency stability in an autonomous photovoltaic-diesel microgrid with energy storage. VSG control is designed to emulate inertial response and damping power via power injection from/to the energy storage system. The effect of a VSG with constant parameters(CP-VSG) on the system frequency is analyzed. Based on the case study, self-tuning algorithms are used to search for optimal parameters during the operation of the VSG in order to minimize the amplitude and rate of change of the frequency variations. The performances of the proposed self-tuning(ST)-VSG, the frequency droop method, and the CP-VSG are evaluated by comparing their effects on attenuating frequency variationsunder load variations. For both simulated and experimental cases, the ST-VSG was found to be more efficient than the other two methods in improving frequency stability. 展开更多
关键词 Virtual SYNCHRONOUS generator(VSG) Frequency stability AUTONOMOUS MICROGRID SELF-TUNING algorithm Energy storage system
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