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381.
H. H. Koelle 《Space Policy》1986,2(1)
It appears virtually certain that humans will return to the lunar surface to stay and exploit the lunar resources. The only remaining question is who, when and how humankind will go there to establish a permanent lunar base. This article describes the decision-making process of determining the parameters of a lunar base. It offers modelling options as a frame of reference for planning the lunar base and its logistic support, and gives the reasons why a detailed analysis of the options and forward planning should have a high priority now. 相似文献
382.
试论高等数学教学与 CAI 总被引:2,自引:0,他引:2
吴光旭 《中国民航学院学报》1997,(3)
阐述了CAI在数学教学中的重要作用,以实例说明了在CAI实验课教学中应注意的几个方面,并对目前数学CAI教学所面临的问题进行了探讨 相似文献
383.
384.
Dynamicloadisoneoftheimportantoriginalparametersinstructuraldynamicanalysis.Ithasobviousinfluencestodynamicsdesign,vibrationcontrols,activecontroltechnologyandsoon.Sincel97O,manyresearchitemsinthisfieldhavebeenaccomplishedintheworld-Sometheoriesandexperimentalmethodsofdynamicloadidentificationhadbeencreatedinfrequencydomain[l'2J-Howeverftherearesomedisadvantagesthattheycouldbeadaptedonlytoidenti-fythesteady-stateloadandnottoidentifythetransientload,suchasshockloadwithshortsampling.Forvarious… 相似文献
385.
Astronauts are often on a voluntarily reduced energy intake during space missions, possibly caused by a metabolic or emotional stress response with involvement of the central serotonergic system (SES). We investigated 24 h urinary excretion (24 h-E) of serotonin (5-HT) and 5-hydroxyindol acidic acid as indicators of the SES in healthy males under two different normocaloric conditions: normal physical activity (NPA) and -6 degree head-down-tilt (HDT). HDT or NPA were randomly arranged with a recovery period of 6 months in between. 24 h-E of hormones varied widely among individuals. Values were higher in HDT compared to NPA. Assuming that the 24 h-E values are, beside being indicators for alterations in the number and metabolism of platelets. Also indicators of central SES, HDT condition seems to activate central SES in a higher degree compared to NPA. Therefore, changes in central SES might be involved in the mechanisms associated with space flight or microgravity, including possible maladaptations such as voluntary undernutrition. 相似文献
386.
空间微波交会雷达总体构想 总被引:1,自引:0,他引:1
结合我国载人航天工程未来发展的需要,分析了国外微波交会雷达技术的发展方向,提出了我国微波交会雷达的总体实施方案构想。 相似文献
387.
388.
随着科技的发展,空间天气对电力系统、通信导航系统和航天资产等遍布全球的技术基础设施的影响越来越深.需要加强对空间天气事件过程的理解,提升空间天气的预报能力,优化基础设施设计,从而减缓空间天气对社会造成的影响.基于这些需求,国际空间研究委员会(COSPAR)联合国际与日共存计划(ILWS)共同成立专家组,研究制定了全球2015-2025空间天气发展路线图.本文对该路线图进行介绍和解读,讨论该路线图对中国空间天气发展的启示. 相似文献
389.
Alberto Buzzoni Giuseppe Altavilla Siwei Fan Carolin Frueh Italo Foppiani Marco Micheli Jaime Nomen Noelia Sánchez-Ortiz 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(1):371-393
We report on extensive photometry and low-resolution () spectroscopy of the deep-space debris WT1190F, which impacted Earth offshore from Sri Lanka, on 2015 November 13. In spite of its likely artificial origin (as a relic of some past lunar mission), the case offered important points of discussion for its suggestive connection with the envisaged scenario for a (potentially far more dangerous) natural impactor, like an asteroid or a comet.Our observations indicate for WT1190F an absolute magnitude , with a flat dependence of reflectance on the phase angle, such as ?mag?deg?1. The detected short-timescale variability suggests that the body was likely spinning with a period twice the nominal figure of , as from the observed lightcurve. In the color domain, WT1190F closely resembled the Planck deep-space probe. This match, together with a depressed reflectance around 4000 and 8500 Å may be suggestive of a “grey” (aluminized) surface texture.The spinning pattern remained in place also along the object fiery entry in the atmosphere, a feature that may have partly shielded the body along its fireball phase perhaps leading a large fraction of its mass to survive intact, now lying underwater along a tight (?km) strip of sea, at a depth of 1500?m or less.Under the assumption of Lambertian scatter, an inferred size of ?cm is obtained for WT1190F. By accounting for non-gravitational dynamical perturbations, the Area-to-Mass ratio of the body was in the range ?m2?kg?1.Both these figures resulted compatible with the two prevailing candidates to WT1190F’s identity, namely the Athena II Trans-Lunar Injection Stage of the Lunar Prospector mission, and the ascent stage of the Apollo 10 lunar module, callsign “Snoopy”. Both candidates have been analyzed in some detail here through accurate 3D CAD design mockup modelling and BRDF reflectance rendering to derive the inherent photometric properties to be compared with the observations. 相似文献
390.
Will Furnell Abhishek Shenoy Elliot Fox Peter Hatfield 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2019,63(5):1523-1540
The Langton Ultimate Cosmic ray Intensity Detector (LUCID) is a payload onboard the satellite TechDemoSat-1, used to study the radiation environment in Low Earth Orbit (635?km). LUCID operated from 2014 to 2017, collecting over 2.1 million frames of radiation data from its five Timepix detectors on board. LUCID is one of the first uses of the Timepix detector technology in open space, with the data providing useful insight into the performance of this technology in new environments. It provides high-sensitivity imaging measurements of the mixed radiation field, with a wide dynamic range in terms of spectral response, particle type and direction. The data has been analysed using computing resources provided by GridPP, with a new machine learning algorithm that uses the Tensorflow framework. This algorithm provides a new approach to processing Medipix data, using a training set of human labelled tracks, providing greater particle classification accuracy than other algorithms. For managing the LUCID data, we have developed an online platform called Timepix Analysis Platform at School (TAPAS). This provides a swift and simple way for users to analyse data that they collect using Timepix detectors from both LUCID and other experiments. We also present some possible future uses of the LUCID data and Medipix detectors in space. 相似文献