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951.
952.
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{{/each}} 《气候与环境研究》1999,4(1):127-127
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{{if article.graphicalAbstractinfoCn && article.graphicalAbstractinfoCn != ""}}{{@ article.graphicalAbstractinfoCn}}{{/if}} 相似文献
953.
{{each article.authors author i}}
{{if author.authorNameCn && author.authorNameCn != ''}}
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{{/each}} 《气候与环境研究》1999,4(1):128-128
{{@ convertAbstractHtml(article.abstractinfoCn, "cn")}}
{{if article.graphicalAbstractinfoCn && article.graphicalAbstractinfoCn != ""}}{{@ article.graphicalAbstractinfoCn}}{{/if}} 相似文献
954.
Špičák A. Horálek J. Boušková A. Tomek Č. Vaněk J. 《Studia Geophysica et Geodaetica》1999,43(1):87-106
We are proposing a hypothesis that earthquake swarms in the West Bohemia/Vogtland seismoactive region are generated by magmatic activity currently transported to the upper crustal layers. We assume that the injection of magma and/or related fluids and gases causes hydraulic fracturing which is manifested as an earthquake swarm at the surface. Our statements are supported by three spheres of evidence coming from the western part of the Bohemian Massif: characteristic manifestations of recent geodynamic activity, the information from the neighbouring KTB deep drilling project and from the 9HR seismic reflection profile, and the detailed analysis of local seismological data. (1) Recent manifestations of geodynamic activity include Quaternary volcanism, rich CO
2
emissions, anomalies of mantle-derived
3
He, mineral springs, moffets, etc. (2) The fluid injection experiment in the neighbouring KTB deep borehole at a depth of 9 km induced hundreds of micro-earthquakes. This indicates that the Earth's crust is near frictional failure in the western part of the Bohemian Massif and an addition of a small amount of energy to the tectonic stress is enough to induce an earthquake. Some pronounced reflections in the closely passing 9HR seismic reflection profile are interpreted as being caused by recent magmatic sills in the crust. (3) The local broadband seismological network WEBNET provides high quality data that enable precise localization of seismic events. The events of the January 1997 earthquake swarm are confined to an extremely narrow volume at depths of about 9 km. Their seismograms display pronounced reflections of P- and S-waves in the upper crust. The analysis of the process of faulting has disclosed a considerable variability of the source mechanism during the swarm.
We conclude that the mechanism of intraplate earthquake swarms generated by magma intrusions is similar to that of induced seismicity. As the recent tectonic processes and manifestations of geodynamic activity are similar in European areas with repeated earthquake swarm occurrence (Bohemian Massif, French Massif Central, Rhine Graben), we assume that magma intrusions and related fluid and gas release at depths of about 10 km are the universal cause of intraplate earthquake swarm generation 相似文献
955.
Vršnak B. Roša D. Božić H. Brajša R. Ruždjak V. Schroll A. Wöhl H. 《Solar physics》1999,185(2):207-225
Two large stable solar filaments were used as test tracers to determine the apparent synodic rotation rate as a function of the central meridian distance for several filaments' segments at different heights. An analytic fitting procedure was applied to determine simultaneously the real synodic rotation rate and the height of the traced filament segments. The determined heights were compared with the values obtained from the widths of filament contours on the solar disk and with the values obtained by direct measurements at the solar limb. Furthermore, the obtained rotation rates and heights of the filaments' segments close to the filaments' pivot points were compared with the values obtained using two successive central meridian passages. Finally, sources and scales of errors were investigated and possible implications on the previous studies of the solar differential rotation were considered. 相似文献
956.
A study of inorganic iodine speciation in the water column of a naturally eutrophicated anchialine pond (Rogoznica Lake, East Adriatic Coast) was conducted in a period between April and July 2004 to obtain information how close the inorganic iodine system is to that of inorganic nutrients during spring, when phytoplankton activity is at maximum, and how the system changes up to summer, when highly reducible redox-conditions prevail in deep water. 相似文献
957.
958.
J. Klačka 《Earth, Moon, and Planets》1993,60(1):17-21
Abrupt or gradual disintegration of the interplanetary dust particle causes increase of its distance from the Sun due to the solar radiation pressure. The problem of the orbital evolution of the interplanetary dust particles under such disintegration processes is discussed. The process of gradual disintegration due to the solar wind particles is calculated in detail. Obtained results represent corrections to the changes of orbital elements for the Poynting-Robertson effect and effect of the solar wind. 相似文献
959.
Arūnas Kučinskas Audrius Bridžius Vladas Vansevičius 《Astrophysics and Space Science》2002,280(1-2):159-163
The goal of this work is to assess the expected scientific output from the photometric studies of globular clusters in the
Large Magellanic Cloud with ESA's astrometric space mission GAIA. For this purpose we simulate GAIA photometry of individual
stars in synthetic cluster populations, covering a large range of cluster ages and metallicities. We find that accurate effective
temperatures (Δ T
eff<10%) can be obtained from GAIA photometry down to V ∼ 18 for stars in populations within the studied metallicity range ([M/H] = -0.4 ... -1.7). GAIA will also provide photometric
metallicities (Δ [M/H] ≲ 0.3 dex) for the cluster giants brighter than V ∼ 17.5. The knowledge of the effective temperature sand metallicities will allow to obtain accurate ages of stellar populations
younger than about 1 Gyr using the usual procedure of main sequence turn-off point fitting. Ages of older stellar populations
(≳ 1 Gyr) may be constrained from the isochrone fits to the giant branches in the observed CMDs. We conclude that GAIA will
provide excellent opportunities for studying star formation histories far beyond the Milky Way, providing means for better
understanding of stellar and galactic evolution in different astrophysical environments.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
960.
We calculate the effective mass of a spherical star-like object under the assumption that the mass of an object represents a function of the gravitational potential in which it occurs. We show that due to this mass-dependence on the gravitational potential, it is not possible that a star of a larger mass than that of a neutron star shrinks to a point singularity. We present the value of the upper limits to the mass of spherical mass bodies as a function of their radii in a large range of their mass densities. 相似文献