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651.
Elisabeth Abbe Thomas Renger Maciej Sznajder Benjamin Klemmed Elisa Sachse René Hübner Tilman Schüler Yves Bärtling Benjamin Muchow Martin Tajmar Tino Schmiel 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(7):2312-2321
Over the last years, Carbon Nanotubes (CNT) drew interdisciplinary attention. Regarding space technologies a variety of potential applications were proposed and investigated. However, no complex data on the behaviour and degradation process of carbon nanotubes under space environment exist. Therefore, it is necessary to investigate the performance of these new materials in space environment and to revaluate the application potential of CNTs in space technologies.Hence, CiREX (Carbon Nanotubes – Resistance Experiment) was developed as a part of a student project. It is a small and compact experiment, which is designed for CubeSat class space satellites. These are a class of nanosatellites with a standardized size and shape. The CiREX design, electrical measurements and the satellites interfaces will be discussed in detail. CiREX is the first in-situ space material experiment for CNTs.To evaluate the data obtained from CiREX, ground validation tests are mandatory. As part of an extensive test series the behaviour of CNTs under solar ultra violet light (UV) and vacuum ultraviolet light (VUV) was examined. Single-walled carbon nanotubes (SWNT), multi-walled carbon nanotubes (MWNT) and MWNT/resin composite (ME) were exposed to different light sources. After the exposure, the defect density was investigated with Raman spectroscopy. There is a clear indication that UV and VUV light can increase the defect density of untreated CNTs and influence the electrical behaviour. 相似文献
652.
653.
刘菁 《西安航空技术高等专科学校学报》2008,26(4):34-36
近来,因物业管理方与业主之间的暴力事件在一些地方屡屡发生,其所表现的物业纠纷类型是多方面的,有的是物业管理的不作为,有的是合同违约,有的是业主利益难以维护。导致纠纷的原因一类为物业管理本身所存在的问题,一类则可归结为外部环境所存在的问题,而解决问题的关键是建立新型的物业管理体制。 相似文献
654.
张海波 《长沙航空职业技术学院学报》2009,9(3):62-65
运用先进的物资管理理念和新近飞速发展的物流新技术,结合航空修理企业对物资管理的特殊需求,设计了一个基于B/S架构的航修企业物资管理信息系统。 相似文献
655.
航空电子系统对飞行控制系统的性能及精度要求越来越高,采用DSP和PCI实现数据的处理和传输成为一种发展趋势,并广泛应用于飞行控制领域。介绍了一种采用F2812及PCI9054实现数据处理和传输的电路,给出了基于F2812及PCI9054的PCI主模式的设计,也给出了一种16位局部数据总线做主模式的解决方案,实现了DSP到PCI的主模式访问,为飞行控制系统提供了高性能的解决方案。 相似文献
656.
657.
Richa Trivedi Sudhir Jain Amit Jain A.K. Gwal 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
The ionospheric Total Electron Content (TECs), derived by dual frequency signals from the Global Positioning System (GPS) recorded near the Indian equatorial anomaly region, Bhopal (23.2°N, 77.4°E, Geomagnetic 14.2°N) were analyzed for the period of January, 2005 to February, 2008. The work deals with monthly, diurnal, solar and magnetic activity variations on night-time enhancement in TEC. From a total of 157 night-time enhancements, 75 occur during pre-midnight and 82 post-midnight hours. The occurrence of night-time enhancement in TEC is utmost during summer months, followed by equinox and winter months. The occurrence of night-time enhancement in TEC decreases with increase in solar and magnetic activities. We observed that peak size and half amplitude duration are positively correlated, while time of occurrence of night-time enhancement in TEC and time of peak enhancement are negatively correlated with solar activity. The peak size, half amplitude duration, time of peak enhancement and time of occurrence of night-time enhancement in TEC shows negative correlation with magnetic activity. The results have been compared with the earlier ones and discussed in terms of possible source mechanism responsible for the enhancement at anomaly crest region. 相似文献
658.
Hongwei Liu Zhaokui Wang Yulin Zhang 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2013
The Earth’s gravity field can be measured with high precision by constructing the purely gravitational orbit of the inner-satellite in Inner-formation Flying System (IFS), which is independently proposed by Chinese scholars and offers a new way to carry out gravity field measurement by satellite without accelerometers. In IFS, for the purpose of quickly evaluating the highest degree of recovered gravity field model and geoid error as well as analyzing the influence of system parameters on gravity field measurement, an analytical formula was established by spectral analysis method. The formula can reflect the analytical relationship between gravity field measurement performance and system parameters such as orbit altitude, the inner-satellite orbit determination error, the inner-satellite residual disturbances, data sampling interval and total measurement time. This analytical formula was then corrected by four factors introduced from numerical simulation of IFS gravity field measurement. By comparing computation results from corrected analytical formula and the actual gravity field measurement performance by CHAMP, the correctness and rationality of this analytical formula were verified. Based on this analytical formula, the influences of system parameters on IFS gravity field measurement were analyzed. It is known that gravity field measurement performance is a monotone decreasing function of orbit altitude, the inner-satellite orbit determination error, the inner-satellite residual disturbances, data sampling interval and the reciprocal of total measurement time. There is a match relationship between the inner-satellite orbit determination error and residual disturbances, in other words, the change rate of gravity field measurement performance with one of them is seriously restricted by their relative size. The analytical formula can be used to quantitatively evaluate gravity field measurement performance fast and design IFS parameters optimally. It is noted that the analytical formula and corresponding conclusions are applied to any gravity satellite which measures gravity field by satellite perturbation orbit. 相似文献
659.
Government organizations have to justify high expenditure during periods of financial crisis such as the one we are experiencing today. Space agencies have attempted to increase the returns on their investments in space missions by encouraging the commercial use of advanced technologies. This paper describes two technology transfer (TT) cases promoted by JAXA, in order to identify the organizational models and determinants of TT. The development of a TT process from space to Earth not only benefits the aerospace industry but also the network of national companies. The aim of the paper is to investigate who the actors are and the nature of their role, as well as the determinants of the TT process in the Japanese space sector. The case studies confirm the typical path of transfer as ‘Earth–space–Earth’. 相似文献
660.
用中国传统文化建构当代大学生思想政治教育体系 总被引:2,自引:0,他引:2
中国传统化是中华民族在生息繁衍中形成的理论化和非理论化的,并转而影响整个社会的,具有稳定的共同精神、心理状态、思维方式和价值取向等精神成果的浓缩;它对于建构当代大学生思想政治教育体系具有重要的指向价值。 相似文献