射线实时成像检验技术在复合材料桨叶检测中的实践运用

采用射线实时成像检验技术对复合材料桨叶进行射线检测,与采用射线照相检测技术检测复合材料桨叶相比,采用实时成像检验技术检测复合材料桨叶缩短了检测时间,提高了工作效率。     

GE传感与检测科技在世界无损检测大会上展示创新技术

传感2与00检8测年科10技月在2世6界日无,G损E检测大会(WCNDT)1152号展台展出其在无损检测(NDT)解决方案领域最新的创新技术。本次GE展出的产品包括:(1)Phythm软件平台。Rhythm是一套集检测数据的采集、报告、检查以及存档功能于一身的软件平台。Rhythm的功能现已扩展到了超声波检测方面,     

聚丙烯腈基碳纤维高温处理过程中石墨微晶的生长

分别采用激光拉曼光谱法(Raman)、广角X一射线衍射法(WAXD)研究并比较了聚丙烯腈基碳纤维在高温处理过程中,石墨结构形成时微晶的生长,尤其是在宽度方向上的增长规律.结果表明,在所选取的高温处理温度范围内,随着处理温度的不断提高,在石墨层面间距不断减小的同时,微晶在宽度方向上的增长基本上呈线性.拉曼光谱和X-射线衍射两种分析手段均能有效表征石墨微晶及片层结构,但由于基本空间模型的不同,两者所反映的基本结构信息有一定差别.     

DC Characteristics of Gamma-ray Irradiated SiGe HBT in Comparison with Si BJT

The changes of DC characteristics of SiGe HBT after being submitted to γ-ray irradiation of 700 krad, 7 000 krad and 10 000 krad were compared to those of Si BJT. Generally speaking, Ib and Ib- Ib0 increase with the doses increasing. For SiGe HBT, with the doses increasing, Ic and Ic-Ic0 as well as the related changes of the current gain （β） will decrease at higher Vbe, while for Si BJT, with the doses increasing, after irradiation, Ib and Ic-Ic0 increase; ,8 and its related changes also decrease with their differences, however, tending to be very small at high doses of 7 000 krad and 10 000 krad. Moreover, given the same doses, the decreases of,a are much larger than SiGe HBT, which shows that SiGe HBT＇s anti-radiation performance proves to be better than Si BJT. Still, in SiGe HBT, some strange phenomena were observed： Ic-Ic0 will increase after the radiation of 7 000 krad in less than 0.65 V and as will ,8 in less than 0.75 V. The mechanism of radiation-induced change in DC characteristies was also discussed.     

DC Characteristics of Gamma-ray Irradiated SiGe HBT in Comparison with Si BJT

The changes of DC characteristics of SiGe HBT after being submitted to γ-ray irradiation of 700 krad, 7 000 krad and 10 000 krad were compared to those of Si BJT. Generally speaking, Ib and Ib–Ib0 increase with the doses increasing. For SiGe HBT, with the doses increasing, Ic and Ic–Ic0 as well as the related changes of the current gain (β) will decrease at higher Vbe, while for Si BJT, with the doses increasing, after irradiation, Ib and Ic–Ic0 increase; β and its related changes also decrease with their differences, however, tending to be very small at high doses of 7 000 krad and 10 000 krad. Moreover, given the same doses, the decreases of β are much larger than SiGe HBT, which shows that SiGe HBT’s anti-radiation performance proves to be better than Si BJT. Still, in SiGe HBT, some strange phe-nomena were observed: Ic–Ic0 will increase after the radiation of 7 000 krad in less than 0.65 V and as will β in less than 0.75 V. The mechanism of radiation-induced change in DC characteristics was also discussed.     

空间用功率MOSFET器件2N7266总剂量

文章针对空间用功率MOSFET器件2N7266进行了60Co源γ射线辐射试验研究。在辐射过程中,采用JT-1型晶体管特性图示仪和计算机控制的摄像机实时监测器件电参数随辐射剂量变化的特征,通过试验研究获得了被试器件阈值电压、漏电流和击穿电压随总剂量变化的特征,得出了被试器件抗总剂量辐射的指标。研究结果可为被试器件在航天器型号的使用提供技术参考依据。     

基于蒙特卡罗法辐射传递系数的统计分析

文章基于蒙特卡罗方法定义了表面热辐射换热辐射传递系数的表达式,确定其概率分布和置信度水平并进行统计分析.推导封闭腔内辐射传递系数的相对和绝对误差公式,为求解辐射传递系数所需追踪射线数量提供参考依据.     

“手术”后“哈勃”功能强大90倍

北京时间2009年5月12日,NASA派出STS-125任务组,实施哈勃空间望远镜第5次。也是最后一次大型“手术”。“手术”后的“哈勃”,功能比刚刚升空时强大90倍,人们不再为其2014年退役前的健康状况担忧。“哈勃”的“继任者”预计2013年送入运行轨道,而中国自主研制的首台空间望远镜——硬X射线调制望远镜,则计划于2011年左右发射升空。     

X射线脉冲星导航及其潜在应用

X射线脉冲星导航就是在航天器上安装X射线探测器,探测脉冲星辐射的X射线光子,测量脉冲到达时间（TOA）和提取脉冲星影像信息,经过相应的信号和数据处理,航天器自主高精度确定轨道、时间和姿态等导航参数的实现过程。本文在概述脉冲星导航技术发展历程和国外X射线脉冲星导航计划的基础上,分析国内开展X射线脉冲星导航技术研究的基础条件,并详细论述X射线脉冲星在导航卫星自主导航、深空探测与星际飞行、以及空间科学研究等领域的潜在应用价值。这表明X射线脉冲星导航是实现真正意义上的航天器高精度自主导航的一种有效模式和可行途径,对于国防和国民经济建设具有重要的战略研究意义。