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111.
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Douglas A. Simons Paola Amico Dietrich Baade Sam Barden Randall Campbell Gert Finger Kirk Gilmore Roland Gredel Paul Hickson Steve Howell Norbert Hubin Andreas Kaufer Ralf Kohley Philip MacQueen Sergej Markelov Mike Merrill Satoshi Miyazaki Hidehiko Nakaya Darragh O'Donoghue Tino Oliva Andrea Richichi Derrick Salmon Ricardo Schmidt Hongjun Su Simon Tulloch Maria Luisa García Vargas R. Mark Wagner Olivier Wiecha Binxun Ye 《Experimental Astronomy》2005,19(1-3):15-44
Results of a survey of instrumentation and detector systems, either currently deployed or planned for use at telescopes larger than 3.5 m, in ground based observatories world-wide, are presented. This survey revealed a number of instrumentation design trends at optical, near, and mid-infrared wavelengths. Some of the most prominent trends include the development of vastly larger optical detector systems (> 109 pixels) than anything built to date, and the frequent use of mosaics of near-infrared detectors – something that was quite rare only a decade ago in astronomy. Some future science applications for detectors are then explored, in an attempt to build a bridge between current detectors and what will be needed to support the research ambitions of astronomers in the future. 相似文献
114.
J. L. Bertaux E. Quémerais R. Lallement E. Kyrölä W. Schmidt T. Summanen J. P. Goutail M. Berthé J. Costa T. Holzer 《Solar physics》1997,175(2):737-770
After one year of almost flawless operation on board the SOHO spacecraft poised at L1 Lagrange point, we report the main features
of SWAN observations. SWAN is mainly dedicated to the monitoring of the latitude distribution of the solar wind by the Lα
method. Maps of sky Lα emissions were recorded througout the year. The region of maximum emission, located in the upwind hemisphere,
deviates strongly from the pattern that could be expected from a solar wind constant with latitude. It is divided into two
lobes by a depression aligned with the solar equatorial plane called the Lyα groove already noted in 1976 Prognoz data. The
north lobe is much brighter than the south lobe. These two characteristics can be explained qualitatively by an enhanced ionization
along the neutral sheet where the slow solar wind is concentrated, which results from the higher low-latitude solar wind mass
flux as measured by Ulysses. The groove is the direct imprint on the sky of the enhanced carving by the slow solar wind, at
this time of solar minimum, when the tilt angle of the neutral sheet is small. The question is still pending to predict what
will happen with the ascending phase of the solar cycle. Observations of comets are briefly mentioned, with the ability of
SWAN to monitor the H2O production of many comets. Operations of the instrument are briefly described, including some instrumental problems which
could be solved by software modifications sent to the instrument.
Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1004979605559 相似文献
115.
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H. Schleicher H. Balthasar M. Knölker W. Schmidt K. Jockers 《Earth, Moon, and Planets》1994,66(1):13-17
Filtergrams of high spatial and temporal resolution were obtained in the methane band centred at 892 nm during the impact of fragment L of comet Shoemaker-Levy 9 on Jupiter. The light curve shows two maxima of an emission ball observed above the limb shortly after the impact. The second maximum was the brightest and had a short life time of about 90 seconds. During it's life, the apparent height of the emission ball declined towards the surface of Jupiter; the amount of displacement is larger than the expected effect caused by Jupiter's rotation. About half an hour after the impact, a domelike feature became visible when the location of the impact rotated into the illuminated hemisphere of Jupiter. 相似文献
117.
Dieter S. Schmidt 《Celestial Mechanics and Dynamical Astronomy》1979,19(3):279-289
A computer program for the manipulation of power series in several variables is used to find the first order solution to Hill's lunar problem. The ratiom of the mean motion of the Sun to that of the Moon is kept as a formal parameter. The series inm are known to converge very poorly. It is shown how efficient algorithms among them the Lie transformation allow us to compute the series inm as far as they are needed. When the series are evaluated at Brown's numerical value form the results achieve or exceed his accuracy. 相似文献
118.
This paper describes an uncomplicated sampling technique for ultratrace element analysis of coastal and surface seawaters (maximum depth 100 m). The sampler system is very easy to operate. To prevent contamination problems, interchangeable 500-ml Teflon bottles are used as both sampling and storage vessels. The seawater samples are stabilized in situ by preacidifying the sampling bottles. For the determination of mercury in seawater the desired system has been developed: sampling bottle = storage bottle = reaction vessel. 相似文献
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120.
D. S. Schmidt 《Celestial Mechanics and Dynamical Astronomy》1988,45(1-3):201-206
The Hamiltonian function of the restricted problem of three bodies near the triangular Lagrangian point is normalized through sixth order terms with the help of MACSYMA. The same calculations were done previously with an algebraic processor in order to establish the stability at a critical value of the mass ratio. 相似文献