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复合材料壳体磁场固化技术 总被引:1,自引:0,他引:1
环氧树脂基复合材料及缠绕壳体在磁场中缠绕和固化的技术为前苏联独有,美国只作了一些验证研究。这种技术使得复合材料加工过程中树脂基体发生物理和化学变化,固化后力学性能显著改善,而且质量更加稳定。实现该技术的设备已在前苏联应用。磁场中固化还适用于树脂涂层和粘接层。 相似文献
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本文用遍布全球的52个电离层垂测台站资料,研究1958年7月8日磁暴期间全球电离层扰动的发展变化;各扇区的响应特性;扰动的传播轨迹及速度等。获得以下结果:1.几大扇区的电离层扰动始于南北两极,美洲扇区除具这一特征外,其赤道地区在磁暴急始后不久,出现一个扰动中心,邻近区域的扰动受其控制。2.扰动由高纬向低纬发展,由扰动中心向外传播。3.扰动峰面几乎与地磁力线垂直,即扰动沿磁力线方向发展,其传播速度大约在150—600m/s范围。 相似文献
4.
对1978年8月27至28日期间观测到的磁云与尾随高速流的相互作用进行数值模拟,基本拟合了1AU处的观测剖面。模拟结果表明,磁云-高速流系统将导致前向快,慢激波和后向快激波的形成。 相似文献
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Large amounts of coronal material are propelled outward into interplanetary space by Coronal Mass Ejections (CMEs). Thus one might expect to find evidence for expanding flux ropes in the solar wind as well. To prove this assumption magnetic clouds were analyzed and correlated with H-observations of disappearing filaments. When clouds were found to be directly associated with a disappearing filament, the magnetic structure of the cloud was compared with that of the associated filament. Additionally the expansion of magnetic clouds was examined over a wide range of the heliosphere and compared with the expansion observed for erupting prominences. 相似文献
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Keith T. Strong 《Space Science Reviews》1994,70(1-2):133-142
We review recent observations by the Yohkoh-SXT in collaboration with other spacecraft and ground-based observatories of coronal loops and prominences. These new results point to problems that SoHO will be able to address. With a unique combination of rapid-cadence digital imaging (32 s full-disk and 2 s partial-frame images), high spatial resolution (2.5 arcsec pixels), high sensitivity (EM 1042 cm–3), a low-scatter mirror, and large dynamic range, SXT can observe a vast range of targets on the Sun. Over the first 21 months of Yohkoh operations, SXT has taken over one million images of the corona and so is building up an invaluable long-term database on the large-scale corona and loop geometry. The most striking thing about the SXT images is the range of loop sizes and shapes. The active regions are a bright tangle of magnetic field lines, surrounded by a network of large-scale quiet-Sun loops stretching over distances in excess of 105 km. The cross-section of most loops seems to be constant. Loops displaying significant increase in the ratio of the footpoint to loop-top diameter () are the exception, not the rule, implying the presence of widespread currents in the corona.All magnetic structures show changes. Time scales range from seconds to months. The question of how these structures are formed, become filled with hot plasma, and are maintained is still open. While we see the propagation of brightenings along the length of active-region loops and in X-ray jets with velocities of several hundred km/s, much higher velocities are seen in the quiet Sun. In XBP flares, for example, velocities of over 1000 km/s are common. Active-region loops seem to be in constant motion, moving slowly outward, carrying plasma with them. During flares, loops often produce localized brightenings at the base and later at the apex of the loop. Quiescent filaments and prominences have been observed regularly. Their coronal manifestation seems to be an extended arcade of loops overlying the filament. Reliable alignment of the ground-based data with the X-ray images make it possible to make a detailed intercomparison of the hot and cold plasma structures over extended periods. Hence we are able to follow the long-term evolution of these structures and see how they become destabilized and erupt. 相似文献
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V. Yurchyshyn Q. Hu R.P. Lepping B.J. Lynch J. Krall 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2007,40(12):1821-1826
Coronal mass ejections (CMEs) observed near the Sun via LASCO coronographic imaging are the most important solar drivers of geomagnetic storms. ICMEs, their interplanetary, near-Earth counterparts, can be detected in situ, for example, by the Wind and ACE spacecraft. An ICME usually exhibits a complex structure that very often includes a magnetic cloud (MC). They can be commonly modelled as magnetic flux ropes and there is observational evidence to expect that the orientation of a halo CME elongation corresponds to the orientation of the flux rope. In this study, we compare orientations of elongated CME halos and the corresponding MCs, measured by Wind and ACE spacecraft. We characterize the MC structures by using the Grad–Shafranov reconstruction technique and three MC fitting methods to obtain their axis directions. The CME tilt angles and MC fitted axis angles were compared without taking into account handedness of the underlying flux rope field and the polarity of its axial field. We report that for about 64% of CME–MC events, we found a good correspondence between the orientation angles implying that for the majority of interplanetary ejecta their orientations do not change significantly (less than 45 deg rotation) while travelling from the Sun to the near-Earth environment. 相似文献
8.
统计第23个太阳活动周内中等及以上强度(Dstmin<-50nT)的磁暴事件,线性拟合分析磁暴主相DDstmin和达到DDstmin前一个表征太阳极紫外辐射强度的F10.7之间的相关性.结果表明:随着太阳极紫外辐射增强,DDstmin<-50nT的磁暴出现的总数增多,在弱、中等和强太阳极紫外辐射条件下,其数量分别为56,84和85;随着太阳极紫外辐射增强,强磁暴(-200nT ≤ Dstmin<-100nT)和大磁暴(Dstmin<-200nT)发生的数量和相对发生率呈增长趋势,尤其是大磁暴数目(1,4,12)和相对发生率(1.79%,4.76%,14.12%)明显呈增长趋势;大磁暴(|Dstmin|)与太阳极紫外辐射(F10.7)之间存在中度正相关关系,其相关系数为0.532,并且主要体现在大磁暴(|Dstmin|)与强太阳极紫外辐射(F10.7)之间的中度正相关性,其相关系数为0.582.大磁暴与强太阳极紫外辐射之间的相关性可为空间天气预报提供参考依据. 相似文献
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介绍了边缘计算的基本概念及与云计算的对比。针对电机远程运维需求,介绍了电机远程运维系统的架构及主要功能。在描述边缘侧设备与远程运维平台的数据交互过程的基础上,详细阐述了边缘计算在电机远程运维系统中的应用。 相似文献