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1.
Elastic properties of eclogite rocks from the Bohemian massif   总被引:1,自引:0,他引:1  
Summary Compressional velocity anistropy has been studied in detail at atmospheric pressure for 78 specimens of 23 types of eclogite rocks from the Bohemian massif. For nine of these rock types, compressional and shear velocities were measured as a function of pressure to750 MPa at room temperature. The velocity anisotropy for both compressional and shear waves is less than4% at high pressure. The velocities increase with increasing garnet content and decrease with increasing symplectitization. The Moldanubian eclogites have significantly higher velocities, on the average, than the eclogites from the Kruné hory crystalline complex, although the densities of both groups are comparable.  相似文献   
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u¶rt;m ¶rt; anum¶rt;-amm aamumu maum a aa nu mummu (). ma¶rt;am aamumu uu mau auma uu am auu a uu aaa aa.  相似文献   
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Summary The level of microseismic noise is studied at locations in the Western Carpathians where, apart from the vertical component of the noise, also its horizontal component was recorded by a broad-band seismograph. The amplitudes of the permanent noise in the horizontal component ranged from 10 to 83 nm and, at most locations, the predominant periods T>0.45 s, although the predominant periods of the vertical component in the Carpathian region are mostly within the interval T 0.24–0.37 s.  相似文献   
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Summary The maximum changes of magnification were determined for electrodynamic seismographs with standard characteristics and for some experimental long-period seismographs, the constants of which are given in Tab. 1, when the period of the seismometer or galvanometer has a deviation of not more than 5% from the standard value. Under the assumption of control of the other constants of the seismograph, identical amplitude and phase responses with a small change of the absolute magnification of the seismograph may be achieved with characteristicsAII ( 2 >0.2), AIV ( 2 0.4), B ( 2 >0.3) Nos28, 32 and33. This deviation can also be compensated by adjusting the optical distance. The procedure of adjusting the identical characteristics is suitable for systems with which an accurate setting of the period is difficult and for systems with an uncontrollable period, provided their values are within the limits of allowed deviations from the standard constants.  相似文献   
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Summary Three quantities M, E 1/2 and E 2/3 are used for studying the Balkan earthquake provinces. Most of them show a regular trend of activity, for some of them the observation period of 70 years is too short. Some graphs give evidence of the coincidence or migration of activity.  相似文献   
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Zusammenfassung Es wurde versucht, mit Hilfe der piezophotographischen Methode das Druckfeld in der Nähe einer Untergrundsprengung zu untersuchen. Kugelförmige Ladungen von 5 kg TNT wurden 3 m unter die Oberfläche im konsolidierten Sandboden angebracht. Piezophotographische Druckaufnehmer mit Messbereich 1,5–250 bar und 15–2500 bar wurden sowohl statisch, als auch dynamisch geeicht und ihre Richtungscharakteristik bestimmt. Es wurden insgesamt 5 Druckfelduntersuchungen vorgenommen, wobei die Druckmessungen in einem orthogonalen Netz von Messpunkten, das sich bis in die Entfernung von 40 Ladungshalbmessern ausdehnte, durchgeführt wurden. Die entwickelte Messtechnik wird eingehend beschrieben. Auf Grund der erhaltenen Ergebnisse konnte unmittelbar für jeden Versuch die Druckverteilung in vertikalen und horizontalen Netzprofilen festgelegt werden. Das Druckfeld wurde danach durch den Isobarenverlauf in der untersuchten Ebene abgebildet.  相似文献   
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Summary The amplitude and phase responses of electromagnetic seismographs with an arbitrary number of galvanometers, used to increase the dynamic range of the seismograph or to filter perturbing oscillations, are derived. The fundamental parameters of the system, i.e. the partial periods and the partial constants of damping of the seismometer and of the individual galvanometers, together with the coupling terms, are replaced by other constants. These enable the responses of each channel to be computed with the aid of a combination of elementary responses of the systems of the set with zero couplings between the galvanometers and a zero effect of the motion of the galvanometers on the motion of the seismometer. The elementary responses are defined by 2 types of substitute constants: equivalent constants, determined by the roots of the characteristic equation, or by the partial periods, and reduced damping constants. The possibilities of analysing a system with equivalent constants are demonstrated on the case of a seismograph with 2 galvanometers.  相似文献   
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