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241.
U.M. Leloglu E. Kocaoglan 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2008
Although it is generally agreed that the outer space should be used for the benefit of all mankind, only a fraction of the countries have the necessary technological base for accessing space. Space technology, with its implications on science, economy and well-being of citizens, is mostly chosen as one of the priority areas for technological development by developing countries. However, there is already an over-capacity in global space industry and there are doubts on necessity of additional capacity establishment by developing countries. In this study, the importance and benefits of capacity-building in these countries are emphasized and the advantages and disadvantages that developing countries have in the framework of space technology acquisition are briefly presented. The feasibility of certain levels of space technology is discussed and the necessity of combining existing indigenous capabilities with technology obtained from foreign sources in the optimal way is stressed. We have also mentioned various general mechanisms of technology transfer and argued the importance of licensing in catching-up developed countries. After considering the necessary conditions of efficiency of technology, such as establishment of regional centers of space science and technology education by United Nations, joint development of space systems, complete technology transfer packages, cooperative space projects within regional organizations, coordinated constellations and special agreements with large space agencies, which are specific mechanisms already in use, are reviewed. Some typical examples of mechanisms are also given with special emphasize on small satellite technology that makes access to space affordable for many countries. Through sharing and analyzing the experience of developing countries in their odyssey of space capacity-building, the difficulties can be negotiated and the vicious circles can be broken. This study, in our view, is a step to incite a general discussion of obstacles and opportunities for developing countries, that could help them in using their limited resources effectively, hence, enable them to offer better conditions to their citizens and to contribute space science to a larger extend. 相似文献
242.
Space Science Reviews - 相似文献
243.
Beginning in the early 1950s, data from neutron monitors placed the taxonomy of cosmic ray temporal variations on a firm footing,
extended the observations of the Sun as a transient source of high energy particles and laid the foundation of our early concepts
of a heliosphere. The first major impact of the arrival of the Space Age in 1957 on our understanding of cosmic rays came
from spacecraft operating beyond the confines of our magnetosphere. These new observations showed that Forbush decreases were
caused by interplanetary disturbances and not by changes in the geomagnetic field; the existence of both the predicted solar
wind and interplanetary magnetic field was confirmed; the Sun was revealed as a frequent source of energetic ions and electrons
in the 10–100 MeV range; and a number of new, low-energy particle populations was discovered. Neutron monitor data were of
great value in interpreting many of these new results.
With the launch of IMP 6 in 1971, followed by a number of other spacecraft, long-term monitoring of low and medium energy
galactic and anomalous cosmic rays and solar and interplanetary energetic particles, and the interplanetary medium were available
on a continuous basis. Many synoptic studies have been carried out using both neutron monitor and space observations. The
data from the Pioneer 10/11 and Voyagers 1/2 deep space missions and the journey of Ulysses over the region of the solar poles have significantly extended our knowledge of the heliosphere and have provided enhanced
understanding of many effects that were first identified in the neutron monitor data.
Solar observations are a special area of space studies that has had great impact on interpreting results from neutron monitors,
in particular the identification of coronal holes as the source of high-speed solar wind streams and the recognition of the
importance of coronal mass ejections in producing interplanetary disturbances and accelerating solar energetic particles.
In the future, with the new emphasis on carefully intercalibrated networks of neutron monitors and the improved instrumentation
for space studies, these symbionic relations should prove to be even more productive in extending our understanding of the
acceleration and transport of energetic particles in our heliosphere.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
244.
W H Thiemann H Rosenbauer U J Meierhenrich 《Advances in Space Research (includes Cospar's Information Bulletin, Space Research Today)》2001,27(2):323-328
In the last years extraterrestrial scenarios for the origin of homochirality in biological structures received considerable attention in the topical literature: Rubenstein and Bonner postulated a rapidly rotating neutron star emitting circularly polarised synchrotron radiation responsible for the first asymmetric synthesis; the group of Bailey published the observation of circular polarisation caused by Mie scattering from aligned dust grains in the Orion OMC-1 star-formation region that might provide an enantioselective effect on prochiral or racemic organic molecules. Rikken and Raupach observed a magnetochiral effect and considered extraterrestrial magnetic fields of sufficient strengths to introduce biomoleculars parity violation. With the aim to investigate these hypotheses among other theories describing the origin of biological asymmetry, our laboratory participates in the conception and development of ROSETTA's COSAC Experiment, that is designed to identify organic molecules in the cometary matter in situ. Within COSAC's 'Chirality Module' enantiomers will be separated gas chromatographically with the help of capillary columns coated with chirally active liquid films. This technique will allow the separation of specific chiral organic compounds out of the analysed cometary matter into their enantiomeric constituents. Both thermo conductivity and mass spectrometric detectors will be used to determine each enantiomer's amount and therefore the corresponding enantiomeric excesses. As a consequence of COSAC's 'Chirality-Experiment' far-reaching results are expected to investigate the various hypotheses about the first asymmetric synthesis. 相似文献
245.
Financial pressures are forcing organizations to minimize operations costs. Although the easiest way to achieve this goal is simply to reduce operational requirements, often this is not possible. Therefore, automation must be employed. This paper discusses the system trade-offs that must be performed to maximize the impact of automation efforts. The discussion begins with the development of generic automation guidelines. Since many automation issues are program-specific, the paper addresses the application of these principles to operation of the ORBCOMM satellite constellation. This example demonstrates how automation can be used to produce a highly efficient satellite operations system. 相似文献
246.
Kallenbach R. Robert F. Geiss J. Herbst E. Lammer H. Marty B. Millar T.J. Ott U. Pepin R.O. 《Space Science Reviews》2003,106(1-4):319-376
Volatile isotope abundances are tracers for the evolutionary processes of the solar system. At the same time they carry information
on the galactic nucleosynthetic sources, from which solar matter originates. This working group report summarizes the present
knowledge and addresses unresolved issues regarding fractionation of isotopes of volatile elements in the solar system.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
247.
Michael W. Liemohn Yingjuan Ma Rudy A. Frahm Xiaohua Fang Janet U. Kozyra Andrew F. Nagy J. David Winningham James R. Sharber Stas Barabash Rickard Lundin 《Space Science Reviews》2006,126(1-4):63-76
Atmospheric photoelectrons have been observed well above the ionosphere of Mars by the ASPERA-3 ELS instrument on Mars Express.
To systematically interpret these observations, field lines from two global MHD simulations were analyzed for connectivity
to the dayside ionosphere (allowing photoelectron escape). It is found that there is a hollow cylinder behind the planet from
1–2 R
M away from the Mars-Sun line that has a high probability of containing magnetic field lines with connectivity to the dayside
ionosphere. These results are in complete agreement with the ELS statistics. It is concluded that the high-altitude photoelectrons
are the result of direct magnetic connectivity to the dayside at the moment of the measurement, and no extra trapping or bouncing
mechanisms are needed to explain the data. 相似文献
248.
Dartnell LR Storrie-Lombardi MC Mullineaux CW Ruban AV Wright G Griffiths AD Muller JP Ward JM 《Astrobiology》2011,11(10):997-1016
Primitive photosynthetic microorganisms, either dormant or dead, may remain today on the martian surface, akin to terrestrial cyanobacteria surviving endolithically in martian analog sites on Earth such as the Antarctic Dry Valleys and the Atacama Desert. Potential markers of martian photoautotrophs include the red edge of chlorophyll reflectance spectra or fluorescence emission from systems of light-harvesting pigments. Such biosignatures, however, would be modified and degraded by long-term exposure to ionizing radiation from the unshielded cosmic ray flux onto the martian surface. In this initial study into this issue, three analytical techniques--absorbance, reflectance, and fluorescence spectroscopy--were employed to determine the progression of the radiolytic destruction of cyanobacteria. The pattern of signal loss for chlorophyll reflection and fluorescence from several biomolecules is characterized and quantified after increasing exposures to ionizing gamma radiation. This allows estimation of the degradation rates of cyanobacterial biosignatures on the martian surface and the identification of promising detectable fluorescent break-down products. 相似文献
249.
Andrew S. Rivkin Jian-Yang Li Ralph E. Milliken Lucy F. Lim Amy J. Lovell Britney E. Schmidt Lucy A. McFadden Barbara A. Cohen 《Space Science Reviews》2011,163(1-4):95-116
Our understanding of the composition of Ceres is driven by remote sensing of its surface. We review spectral observations of Ceres over wavelengths from the ultraviolet to the radio, as well as non-spectral data such as thermal inertia, photometric properties, radar experiments, and surface variability. We also discuss the closest likely meteorite analogs to Ceres and consider the likelihood that material from Ceres could be delivered to Earth. 相似文献
250.