A new method is developed for removing the nickel coating on ITER superconducting cables by mechanical polishing.The obvious advantage of the mechanical method,which uses a nylon brush,is that there is no chemical res...A new method is developed for removing the nickel coating on ITER superconducting cables by mechanical polishing.The obvious advantage of the mechanical method,which uses a nylon brush,is that there is no chemical residual left in the cable,which would otherwise result in passive effects on the joint resistance.The coating resistance test results of this newly developed method are compared with those of the two other methods that can meet the requirements of ITER.An automatic polishing machine is designed and manufactured for the procedure to provide quality under precise control.This new technique can replace the conventional manual method due to its improved efficiency.展开更多
针对自动文摘处理,提出一种新颖的自动文摘句子加权方法.该方法采用基于互增强关系(MRP)的迭代算法模拟句子和词之间的循环加权关系,计算句子权重.实验结果表明,基于MRP的迭代算法收敛速度快;与传统的自动文摘方法和MS Word Summarizer...针对自动文摘处理,提出一种新颖的自动文摘句子加权方法.该方法采用基于互增强关系(MRP)的迭代算法模拟句子和词之间的循环加权关系,计算句子权重.实验结果表明,基于MRP的迭代算法收敛速度快;与传统的自动文摘方法和MS Word Summarizer相比,所提出的基于MRP的句子加权方法可以使自动文摘系统具有更好的性能.展开更多
基金supported by ITER Research Project of China Matched Program(No.2008GB102000)
文摘A new method is developed for removing the nickel coating on ITER superconducting cables by mechanical polishing.The obvious advantage of the mechanical method,which uses a nylon brush,is that there is no chemical residual left in the cable,which would otherwise result in passive effects on the joint resistance.The coating resistance test results of this newly developed method are compared with those of the two other methods that can meet the requirements of ITER.An automatic polishing machine is designed and manufactured for the procedure to provide quality under precise control.This new technique can replace the conventional manual method due to its improved efficiency.
文摘目的研究自动管电流调制扫描及50%权重自适应性统计迭代重建算法（adaptive statistical iterative reconstruction,ASIR）重建时,不同噪声指数（noise index,NI）的设定对胸部CT扫描图像质量的影响,探索合适的NI以降低辐射剂量。方法前瞻性地连续纳入193例行胸部CT扫描的患者,随机分为6组,各组NI预设为15、18、21、24、27、30,并进一步根据患者的体质量指数（Body Mass Index,BMI）分为三个亚组：偏瘦及正常组（BMI≤23.9）、超重组（24≤BMI≤27.9）、肥胖组（BMI≥28）。所有患者均采用自动管电流调制技术扫描,50%权重的ASIR重建。由2位放射科医师采用盲法分别对图像质量进行主观评分（〈13分,良好;13~15分,临界;〉15分,不能接受）,测量肺重建及纵隔重建图像的噪声（脂肪）、信噪比（大血管-脂肪）、对比噪声比（大血管-脂肪）。记录各患者CT容积剂量指数（CT does index volume,CTDIvol）、剂量长度乘积（dose length product,DLP）、有效剂量（effective dose,ED）。另外记录每位患者纵隔重建图像管电流小于50m A的层面占所有层面的百分比。结果随着NI的升高,图像主观评分增高（质量下降）,信噪比及对比噪声比降低。各NI预设条件下胸部CT图像主观评分均≤15分,仅NI=30时,4例（4/34）患者图像主观评分为13~15分。NI=30时图像主观评分显著高于、信噪比低于NI为15~27图像（P〈0.05）。NI为24~30的辐射剂量显著低于NI为15~21（P〈0.05）。NI为27及30时,随着BMI增加,出现电流低于50m A层面百分比降低（P〈0.05）。在NI为30时,随着BMI增加,辐射剂量显著增加（P〈0.05）。结论自动管电流调制扫描及50%ASIR重建下,胸部CT扫描可以预设NI为30,在大幅降低辐射剂量的同时,图像质量也能满足诊断要求。
文摘针对自动文摘处理,提出一种新颖的自动文摘句子加权方法.该方法采用基于互增强关系(MRP)的迭代算法模拟句子和词之间的循环加权关系,计算句子权重.实验结果表明,基于MRP的迭代算法收敛速度快;与传统的自动文摘方法和MS Word Summarizer相比,所提出的基于MRP的句子加权方法可以使自动文摘系统具有更好的性能.
