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191.
Theoretical studies have shown the possibility of high-temperature ('high enthalpy') geothermal reservoirs in the pre-Tertiary rocks at 4–5 km depth range within the Pannonian Basin. This expectation was proven by the hotwater/steam blowout of Fábiánsebestyén-4 borehole (16.12.85–31.1.86). Exploration efforts carried out during 1987–88 in the broad vicinity of the borehole proved that reservoirs of this type can be found with the combination of seismic reflection, silica-thermometry and magnetotelluric sounding methods. Deliberate prospection should be continued in all suitable areas within the basin, since high enthalpy reservoirs promise profitable operation of geothermal power stations. 相似文献
192.
In this paper, two factors — the redistribution of the density and the variation in the angular velocity of the Earth rotation, that affect the adopted value of the flattening for equidensity surface within the Earth, are discussed. The computational results show that the contribution of the redistribution of the density in the Earth interior (especially in the core) on the change of the flattening at the core-mantle boundary (CMB) is marginal, and that the calculated value of the flattening at the CMB can be in good agreement with the VLBI observed value so long as the fact that the angular velocity of the Earth rotation has undergone the tidal evolution is taken into account. As a result, this paper presents a set of recommended values of the dynamical parameters of the Earth (see Table III) for computing Earth's forced nutation series. 相似文献
193.
C. Jordan S.A. Sim A.D. McMurry M. Aruvel 《Monthly notices of the Royal Astronomical Society》2001,326(1):303-312
Observations of ε Eri (K2 V) have been made with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope . The spectra obtained show a number of emission lines which can be used to determine, or place limits on, the electron density and pressure. Values of the electron pressure are required in order to make quantitative models of the transition region and inner corona from absolute line fluxes, and to constrain semi-empirical models of the chromosphere. Using line flux ratios in Si iii and O iv a mean electron pressure of P e = N e T e =4.8×1015 cm−3 K is derived. This value is compatible with the lower and upper limits to P e found from flux ratios in C iii , O v and Fe xii . Some inconsistencies which may be because of small uncertainties in the atomic data used are discussed. 相似文献
194.
Michael Mendillo Johan Warell Sanjay S. Limaye Jeffrey Baumgardner Ann Sprague Jody K. Wilson 《Planetary and Space Science》2001,49(14-15)
We describe and compare two methods of short-exposure, high-definition ground-based imaging of the planet Mercury. Two teams have recorded images of Mercury on different dates, from different locations, and with different observational and data reduction techniques. Both groups have achieved spatial resolutions of <250 km, and the same albedo features and contrast levels appear where the two datasets overlap (longitudes 270–360°). Dark albedo regions appear as mare and correlate well with smooth terrain radar signatures. Bright albedo features agree optically, but less well with radar data. Such confirmations of state-of-the-art optical techniques introduce a new era of ground-based exploration of Mercury's surface and its atmosphere. They offer opportunities for synergistic, cooperative observations before and during the upcoming Messenger and BepiColombo missions to Mercury. 相似文献
195.
A recently developed near infrared high speed photometer intended for lunar oc-cultation studies is described. The primary scientific objective is to reach milli arc second levels of angular resolution so that circumstellar structure of the occulted sources can be resolved. Near infrared sky brightness close to the lunar limb is also studied. Angular diameter derived from the observed occultation of IRC +20169 is presented and system performance discussed. 相似文献
196.
197.
198.
A. R. King K. Schenker U. Kolb M. B. Davies 《Monthly notices of the Royal Astronomical Society》2001,321(2):327-332
We show that the usual picture of supersoft X-ray binary evolution as driven by conservative thermal time-scale mass transfer cannot explain the short orbital periods of RX J0537.7–7034 (3.5 h) and 1E 0035.4–7230 (4.1 h). Non-conservative evolution may produce such periods, but requires very significant mass loss, and is highly constrained. 相似文献
199.
Matthias R. Aellig Alan J. Lazarus Justin C. Kasper Keith W. Ogilvie 《Astrophysics and Space Science》2001,277(1-2):305-307
The Triana PlasMag Faraday Cup (FC) will be able to determine speed, flow angles, temperature, and density of the main solar
wind ion species with a time resolution of better than one second. Thus, the Triana PlasMag FC will enable resolution of spatial
structures as small as a few hundred kilometers as the structures convect past the spacecraft. Under typical solar wind conditions,
that size is comparable to a few proton gyroradii.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
200.
Dryer M. Fry C.D. Sun W. Deehr C. Smith Z. Akasofu S.-I. Andrews M.D. 《Solar physics》2001,204(1-2):265-284
Prediction of solar-generated disturbances and their three-dimensional propagation through interplanetary space continues
to present a vitally important operational space weather forecasting objective. This paper presents the first successful real-time
prediction of a series of major heliospheric shock waves at Earth, including the one from the 14 July 2000 (`Bastille Day')
flare. An ensemble of three models and their predictions were distributed to a world-wide group of interested scientists as
part of an informal Internet space weather forecast research program. Two of the models, STOA (Shock Time of Arrival) and
ISPM (Interplanetary Shock Propagation Model), presently in operation by the US Air Force Weather Agency, provided predictions
of shock arrival time (SAT) that were, respectively, 0.5 hours after and 3.7 hours before the observed arrival. The third
model, HAFv.2 (Hakamada–Akasofu–Fry version 2.0) predicted a time 0.3 hours after the observed shock arrival time (14:37 UT,
15 July 2000). Of primary interest to this study is the third model, firstly in terms of its capability of propagating shocks
through non-uniform solar wind conditions, and secondly, in terms of its ability to integrate multiple solar events and display
them graphically along with the background solar wind. This latter capability was brought to bear on ten real-time-reported
flares, some with CMEs (coronal mass ejections) that took place as companions to the Bastille flare during the period 7–15
July 2000. Some limited statistics are given regarding the three models' shock arrival prediction capability at Earth, as
an extension of our earlier studies with this three model ensemble in the prediction of SAT. HAFv.2, however, was able to
describe not only the ten events and their interaction as measured at Earth, but also at the spacecraft NEAR (orbiting the
asteroid, Eros, at 1.8 AU), and CASSINI (en route, at 4.0 AU, to Saturn). Several important points are noted: (1) this epoch
represents a small statistical sample that should be expanded; and (2) the three models, based on theory, empiricism, and
simulations represent the state of the art that should presage a similar community process. This paper was presented earlier
as an Invited Talk at the American Geophysical Union Fall Meeting, December 14–19, 2000, in San Francisco, CA, U.S.A.toward
space weather objectives in the Sun-Earth domain.
Supplementary material to this paper is available in electronic form at http://dx.doi.org/10.1023/A:1014200719867 相似文献