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1.
Constanze La Dous 《Space Science Reviews》1963,1(4):203-706
A catalogue is presented of all the low-resolution IUE spectra of dwarf novae and nova-like stars that were recorded until the end of 1987. All spectra have been reduced, and are displayed, in a homogeneous way. In addition to details about these data, to the extent available, their position in the outburst light curves is given, physical information about each system, and a comprehensive list of references for published observations in all wavelength ranges.In collaboration with Janet A. Mattei, American Association of Variable Star Observers, 25 Birch Street, Cambridge, MA 02138-1205, U.S.A. 相似文献
2.
V. Zaconte M. Casolino C. De Santis L. Di Fino C. La Tessa M. Larosa L. Narici P. Picozza 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2010
We present here the energy spectra relative to different geomagnetic regions as measured by the ALTEA (Anomalous Long Term Effects on Astronauts) detector in the International Space Station – USLab from August 2006 to July 2007. 相似文献
3.
8月一直以来都是旅游的旺季,各国各地的商家都鼓足了劲呐喊摇旗,希望能够吸引到更多的客人。作为一个游客,很幸运地、你可以在本月享受法国的狂欢节、日本的夏日祭典、美国的商场减价促销……当然,你也可以选择避开熙熙攘攘的人群,寻找一处优美的景色,依山傍水,自然地留下,冥冥之中,命运就这样引导了你,寻找那处传说中的美景,然后,尽情享受大自然的恩赐吧。本月,推荐给你的是人间天堂的西溪湿地,享受静谧之美;海上的梦幻乐园,享受蔚蓝之魅。 相似文献
4.
火爆全中国的纪录片《舌尖上的中国》终于有了图书版The hometown of each tongue constitute the wholeof China,and forming a parr of something calledculture,inherited from generation to generation.With wisdom,Chincse got the delicous food fromnature,all this has been able to achieve,duc totheir fear of God and food as well as love of the 相似文献
5.
6.
We describe work that has recently been completed on deriving the fundamental parameters of eight WR stars through the photoionization modelling of their surrounding nebulae using non-LTE WR flux distributions. The resulting effective temperatures range from 57 000–71 000 K for the WN4-5 stars and <30 000–42 000 K for the WN6-8 stars. The derived stellar parameters are compared with those obtained from stellar emission line modelling. We find good agreement for the hot early WN stars, indicating that the non-LTE WR flux distributions have essentially the correct shape in the crucial far-UV region. We find lower temperatures for the four cooler late WN stars, particularly for the two WN6 stars. For the nebulae surrounding these stars, we find that the model flux distributions produce too much nebular ionization. We suggest that these discrepancies arise because of the lack of line-blanketing in the WR atmospheres. For the WO1 central star of G2.4+1.4, with strong nebular He II 4686 A emission, we derive a temperature of 105 000 K, somewhat less than previous estimates. The positions of our eight WR stars on the H-R diagram are compared with the evolutionary tracks of Maeder (1990) for solar metallicity. In common with previous workers, we find that our derived luminosities are too low, giving an initial mass range of 25–40 M, below that expected for the majority of WR stars. 相似文献
7.
Crider Dana H. Brain David A. Acuña Mario H. Vignes Didier Mazelle Christian Bertucci Cesar 《Space Science Reviews》2004,111(1-2):203-221
We examine the magnetic field in the martian magnetosheath due to solar wind draping. Mars Global Surveyor provided 3-D vector magnetic field measurements at a large range of altitudes, local times, and solar zenith angles as the spacecraft orbit evolved. We choose orbits with very clean signatures of draping to establish the nominal morphology of the magnetic field lines at local times of near-subsolar and near-terminator. Next, using a compilation of data from Mars Global Surveyor, we determine the average magnetic field morphology in the martian magnetosheath due to the solar wind interaction. The topology of the field is as expected from previous observations and predictions. The magnetic field magnitude peaks at low altitude and noon magnetic local time and decreases away from that point. The magnetic field has an inclination from the local horizontal of 5.6° on average in the dayside magnetosheath and 12.5° on the nightside. The inclination angle is closest to zero at noon magnetic local time and low altitude. It increases both upward and to later local times. The magnetic field in the induced magnetotail flares out from the Mars—Sun direction by 21°. Finally, we compare the observations to gasdynamic model predictions and find that the shocked solar wind flow in the martian magnetosheath can be treated as a gasdynamic flow with the magnetic pileup boundary as the inner boundary to the flow. 相似文献
8.
Rebecca La Norcia Dario Spiller Fabio Curti Christian Circi 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2021,67(11):3409-3425
A study on reconfiguration manoevres applied to a tetrahedral formation in highly elliptical orbits is proposed, by using a propellantless solution. The manoeuvring strategy consists in exploiting certain environmental forces, specifically those provided by solar radiation pressure and atmospheric drag, by actively controlling the satellites’ attitudes. Through inverse dynamics particle swarm optimization the optimal attitudes required for the manoeuvres are evaluated, whereas the configuration’s evolution is simulated by a high-fidelity orbital simulator. The goal of the reconfiguration problem is to find an optimal control in order for the four spacecraft to reach a desired configuration in a specified portion of orbit, where the desired configuration is evaluated by a shape and size geometric parameter. By increasing the manoeuvring time and the satellites’ area to mass ratio, all the case studies considered are successfully verified. 相似文献
9.
AlliedSignal Commercial Avionics Systems (ASCAS) and its partners have established the following business objectives: short term (forward-fit and retrofit with off-the-shelf products; co-development of integrated systems); mid term (co-production of avionics products in the CIS); long term (become an integrated element of CIS aerospace industry in partnership with local firms and to maintain the necessary focus to achieve these goals). ASCAS has formed a strategic business enterprise which is dedicated to developing the avionics market within the CIS. ASCAS was fortunate to find a joint venture partner who possesses skills that complement its present core competencies. The advantage of this business arrangement is that, while expanding their experience and expertise in the area of systems integration, they can directly benefit from the expertise and capabilities of indigenous airframe and equipment manufacturers (customer knowledge, simulation and integration experience, capable/skilled manpower) 相似文献
10.
Hassanali Akbari Asti Bhatt Cesar La Hoz Joshua L. Semeter 《Space Science Reviews》2017,212(1-2):249-294
Space plasmas are host to the electrostatic Langmuir waves and a rich range of processes associated with them. Many of such processes that are of interest in micro-scale plasma physics and magnetosphere-ionosphere physics are open to investigation via incoherent scatter plasma lines—i.e., a pair of resonant peaks in the incoherent scatter radar (ISR) spectrum, symmetrically displaced from the radar transmitting frequency by about the plasma frequency, as the signature of Langmuir waves in the ISR spectrum. There now exists a large body of literature devoted to the investigation of a number of topics in ionospheric physics via plasma line theory and observation. It is the goal of this work to provide a comprehensive review of this literature, from the early theoretical works on oscillations in magnetized plasma to the recent advances in plasma line measurements and applications. This review includes detailed theoretical discussions on the intensity and frequency displacement of plasma lines. It reviews the experimental observations of plasma lines enhanced by various sources of energy and discusses the implications of the observations in the context of ionospheric physics. The review also covers the practical aspects of plasma line measurements, from measurement techniques to the applications of plasma lines in estimating the bulk parameters of the ionosphere. 相似文献