期刊文献+
共找到4篇文章
< 1 >
每页显示 20 50 100
太阳白光耀斑的射电辐射特征:运动Ⅳ型爆发和与耀斑后环共生的短周期脉动现象
1
作者 谢瑞祥 汪敏 《天文学报》 CSCD 北大核心 1999年第4期419-427,共9页
通过1991 年6 月6 日一个复杂的太阳活动事件( 包括宽带射电运动Ⅳ型爆发、脉冲相伴生的白光耀斑、耀斑后环及其伴生的射电多重短周期( 约1 - 4 秒) 脉动现象等) 的分析,探讨了白光耀斑产生的射电辐射特征,根据太阳白光... 通过1991 年6 月6 日一个复杂的太阳活动事件( 包括宽带射电运动Ⅳ型爆发、脉冲相伴生的白光耀斑、耀斑后环及其伴生的射电多重短周期( 约1 - 4 秒) 脉动现象等) 的分析,探讨了白光耀斑产生的射电辐射特征,根据太阳白光耀斑和射电运动Ⅳ型爆发产生的物理过程,着重讨论了射电运动Ⅳ型爆发、耀斑后环和短周期脉动现象。 展开更多
关键词 太阳白光耀斑 射电爆发 耀斑后环 射电脉动
下载PDF
对一颗快速脉动射电源的观测
2
作者 A.休伊什 S.J.贝尔 +3 位作者 J.D.H.皮尔金顿 P.F.司科特 R.A.科林斯 徐仁新 《北京大学学报(自然科学版)》 EI CAS CSCD 北大核心 2002年第B12期66-72,132-135,共11页
关键词 射电天文学 天文观测 辐射 中子星 白矮星 快速射电
下载PDF
The research of the staggered lamination linear pulse launcher
3
作者 宋立伟 张千帆 程树康 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2004年第6期601-604,共4页
This paper proposes a new type of pulse launcher that applies the principle of linear motors. The stator, viz. gun barrel, of the launcher has a new structure of one segment of iron core consisting of 3 staggered lami... This paper proposes a new type of pulse launcher that applies the principle of linear motors. The stator, viz. gun barrel, of the launcher has a new structure of one segment of iron core consisting of 3 staggered laminations. This structure is helpful in advancing the thrust force per volume. Based on introducing the structure and the working principles, this paper resolves the electromagnetic thrusting force and performs mechanical analysis and experiments on the sample launcher. The research shows that this launcher is simple and brushless structure with brief controlling. 展开更多
关键词 staggered lamination pulse launcher linear step motor
下载PDF
Molecular imaging of plaques in coronary arteries with PET and SPECT
4
作者 Zhong-Hua SUN Hairil Rashmizal Lei XU 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2014年第3期259-273,共15页
Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lu-men stenosis which is often used as an indicator for determining the severit... Coronary artery disease remains a major cause of mortality. Presence of atherosclerotic plaques in the coronary artery is responsible for lu-men stenosis which is often used as an indicator for determining the severity of coronary artery disease. However, the degree of coronary lumen stenosis is not often related to compromising myocardial blood flow, as most of the cardiac events that are caused by atherosclerotic plaques are the result of vulnerable plaques which are prone to rupture. Thus, identification of vulnerable plaques in coronary arteries has become increas-ingly important to assist identify patients with high cardiovascular risks. Molecular imaging with use of positron emission tomography (PET) and single photon emission computed tomography (SPECT) has fulfilled this goal by providing functional information about plaque activity which enables accurate assessment of plaque stability. This review article provides an overview of diagnostic applications of molecular imaging tech-niques in the detection of plaques in coronary arteries with PET and SPECT. New radiopharmaceuticals used in the molecular imaging of coro-nary plaques and diagnostic applications of integrated PET/CT and PET/MRI in coronary plaques are also discussed. 展开更多
关键词 Atherosclerotic plaque Coronary artery disease Single photon emission computed tomography Positron emission to-mography Vulnerability
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部