Gaoya dianqi高频电流的趋肤效应使等效导体中电流产生的热损耗增大，为输电线路融冰提供了一种新的技术方法。文中提出了一种基于LC振荡放电的高频融冰方法，利用RLC串联电路从某一稳态向另一稳态转换时由电容充放电引起电流变化的特性，通过控制电压方波来获得高频的电流。该方法可以有效降低IGBT的开关频率，减少开关损耗。根据功率器件的性能设计了一台融冰电源，仿真实验表明，对长度分别为40 km和35 km的LGJ-400/50导线、LGJ-240/40导线、LGJ-120/25导线和LGJ-70/10导线可获得1 ...
李颖许 +4 more
doaj
Gaoya dianqi, 2019 风对雨雪冰冻气候下输变电设备表面覆冰有重要的影响,是研究设备覆冰机理、导线融冰的重要参数之一,但在人工环境下获得均匀稳定风的难度很大。文中介绍了具有均匀风功能的人工覆冰气候室的基本情况,基于自由射流理论,通过仿真计算、冰风洞缩比试验和人工覆冰气候室实际测试,试验表明:采用吹风方式比吹—吸风方式和吸风方式在风机功率和风的均匀性方面更有优势;通过优化设计风洞结构,可以在人工覆冰气候室内实现稳定的均匀风;均匀风对人工气候室内温度分布影响较小 ...
孙利朋 +5 more
doaj
Dianci bileiqi, 2018 在寒冷地区,绝缘子上的覆冰会严重影响绝缘性能,对电网的安全运行造成危害。雪作为一种大气覆冰类型,会降低输电线路外绝缘性能,严重时可能引发绝缘子闪络事故。造成绝缘子绝缘性能下降的一个重要因素是雪中的盐分。在雪融化时,较高的盐分会导致融雪水电导率增加,极易引发绝缘子闪络。在人工气候室内对玻璃板以及玻璃绝缘子进行覆雪试验,并在覆雪期、储雪期以及融雪期内进行分层测量,关注不同覆雪时期内的盐分迁移现象以及对环境温度造成的影响。试验表明,在覆雪期内湿雪会发生少量的盐分迁移,在储雪期内盐分迁移很难发生 ...
李隆基 +7 more
doaj
[Clinical strategies and indication expansion of interventional ultrasonography ablative therapy for hepatic tumors]. [PDF]
Zhonghua Gan Zang Bing Za ZhiLiang YG, Wang HY, Zhao QY, Jiang TA.
europepmc +1 more source
[Deep learning-driven high-frequency ultrasound method for skin aging assessment]. [PDF]
Sheng Wu Yi Xue Gong Cheng Xue Za ZhiZhang X +5 more
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[Multi-modal tumor boundary clustering recognition based on artificial intelligence virtual cells and near-infrared surgical field]. [PDF]
Sheng Wu Yi Xue Gong Cheng Xue Za ZhiLi W, Wang T, Yang X, Zhou F.
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[DOT1L controls neuronal amyloid precursor protein expres-sion via the p38 MAPK-mediated mitochondrial dynamics homeostasis axis]. [PDF]
Zhejiang Da Xue Xue Bao Yi Xue BanZhang Y +6 more
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[Current status and challenges of artificial intelligence and organoid technologies in precision diagnosis and treatment of gastrointestinal stromal tumors]. [PDF]
Zhong Nan Da Xue Xue Bao Yi Xue BanYou J +7 more
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[Expert Consensus on Shared Decision-making in the Diagnosis and Treatment of Ground-glass Opacity-featured Lung Adenocarcinoma]. [PDF]
Zhongguo Fei Ai Za ZhiZhao X +4 more
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