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超导透镜及其聚焦行为(英文)
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作者 石金水 林郁正 +1 位作者 丁伯南 罗达十 《强激光与粒子束》 EI CAS CSCD 北大核心 2002年第2期307-311,共5页
理论上分析了利用高温超导体作为透镜聚焦强流相对论电子束的机理。实验研究中 ,研制出的YBa2 Cu3 O7-δ高温超导体作为透镜的传输和聚焦性能得到验证。结果表明 ,超导透镜具有明显的聚焦效果 ,并可有效控制束流强度分布 ,使被聚焦电子... 理论上分析了利用高温超导体作为透镜聚焦强流相对论电子束的机理。实验研究中 ,研制出的YBa2 Cu3 O7-δ高温超导体作为透镜的传输和聚焦性能得到验证。结果表明 ,超导透镜具有明显的聚焦效果 ,并可有效控制束流强度分布 ,使被聚焦电子在束横截面上的分布更为均匀。 展开更多
关键词 超导透镜 强流相对论电子束 聚焦 高温超导 束流强度分布
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Endoscopic ultrasound-guided biliary drainage 被引量:7
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作者 Disaya Chavalitdhamrong Peter V Draganov 《World Journal of Gastroenterology》 SCIE CAS CSCD 2012年第6期491-497,共7页
Endoscopic ultrasound(EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde ... Endoscopic ultrasound(EUS)-guided biliary drainage has emerged as a minimally invasive alternative to percutaneous and surgical interventions for patients with biliary obstruction who had failed endoscopic retrograde cholangiopancreatography(ERCP).EUSguided biliary drainage has become feasible due to the development of large channel curvilinear therapeutic echo-endoscopes and the use of real-time ultrasound and fluoroscopy imaging in addition to standard ERCP devices and techniques.EUS-guided biliary drainage is an attractive option because of its minimally invasive,single step procedure which provides internal biliary decompression.Multiple investigators have reported high success and low complication rates.Unfortunately,high quality prospective data are still lacking.We provide detailed review of the use of EUS for biliary drainage from the perspective of practicing endoscopists with specific focus on the technical aspects of the procedure. 展开更多
关键词 Bile duct Biliary obstruction Biliary drainage Endoscopic ultrasound Endoscopic ultrasound-guidedbiliary drainage
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Dual-lens beam compression for optical coupling in superconducting nanowire single-photon detectors 被引量:6
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作者 Labao Zhang Chao Wan +5 位作者 Min Gu Ruiying Xu Sen Zhang Lin Kang Jian Chen Peiheng Wu 《Science Bulletin》 SCIE EI CAS CSCD 2015年第16期1434-1438,共5页
The optical coupling of superconducting nanowire single-photon detectors (SNSPDs) has always been restricted to a single-mode fiber for a limited detection area. In this study, for enhancing photon coupling, a dual-... The optical coupling of superconducting nanowire single-photon detectors (SNSPDs) has always been restricted to a single-mode fiber for a limited detection area. In this study, for enhancing photon coupling, a dual-lens system operating at 2.2 K was used to compress the beam size on the basis of the Gaussian beam theory and geometric approximation. A magnification of approximately 0.3 was obtained, and a focused spot with diameter of approximately 10 ~m was measured from a multimode fiber. Assisted with the compressed beam, a system efficiency of 55 % (1550 nm) was achieved for a SNSPD with a detection area of 10 μm × 10 μm and 62.5 pm multimode fiber coupling. At the same time, a high speed of 106 MHz was measured with the proposed system. The realization of a highly compressed optical beam reduced the optical coupling requirement and helped maintain a high speed for the SNSPD. 展开更多
关键词 Superconducting nanowire SINGLE-PHOTON Infrared detector Large detection area
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