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941.
S.D. Kogan 《Physics of the Earth and Planetary Interiors》1984,34(3):150-158
This paper deals with the construction procedure for regional travel-time curves and the new average global curve for P times. This paper also presents new average global values for PcP times constructed from observed travel times. 相似文献
942.
943.
Recently the method of flotation is used as a simple step within a number of procedures of chemical analysis for enrichment of waters or industrial lyes to be investigated by ions. By the example of tin analysis all the possible variants are compared with regard to their efficiency. The advantages result from the using conventional methods of chemical analysis in connection with coprecipitation of traces and their flotation at trace levels of ng/ml. The flotation is a fast method of enrichment, it is easily to handle and sufficiently exact. As a proof example the chemical analysis of Sn, Au and Ag is described. 相似文献
944.
M. Bouchon S. Gaffet C. Cornou M. Dietrich J.P. Glot F. Courboulex A. Caserta G. Cultrera F. Marra R. Guiguet 《Journal of Seismology》2000,4(4):517-523
We found extensive evidence that the vertical ground accelerations produced during the largest shock (M = 6.0) of the 1997 Umbria-Marche earthquake sequence exceeded 1g in two areas close to the heavily-damaged villages of Annifo and Colle Croce. This evidence comes from the striking observation of thousands of freshly fractured and broken rocks and stones in these areas. Some of the broken stones lie isolated on soft detritic soil while others had been previously piled up, probably a long time agoto clear the fields for farming. The freshness of the cuts and fractures and the consistency of the observations for thousands of rocks and stones in these areas indicate that these rocks were thrown upwards during the earthquake, with breakage occurring at the time of impact. Ground motion calculations consistent with the static deformation inferred from GPS and interferometry data, show that the broken stones and rocks are found in the zone where the strongest shaking took place during the earthquake and that most of the shaking there was vertical. 相似文献
945.
Summary An entirely new procedure is proposed in this paper for interpreting anomalies of dykes. This reduces the ambiguity in magnetic interpretation. Measurements of the first vertical derivative simplifies the problem of interpretation and also supplies additional information concerning the parameters of a dyke. The first vertical derivative profile cuts the distance axis at two points whose separation is related to the depth and direction of magnetisation of a dyke. 相似文献
946.
A simple and general technique to obtain a six-component earthquake input motion of a rigid foundation using three-linear-components earthquake record is presented. Using the multicomponent input, the maximum structural response to an arbitrarily oriented earthquake is derived. The method is applied to determine the response spectrum for a two-d.o.f. laterally and torsionally coupled linear system. The effects of foundation geometry, structural properties and apparent wave velocity on the structural response are investigated. It is found that increasing the foundation size reduces the peak values of the input motion; this reduction is more pronounced for a square foundation than for a circular one. 相似文献
947.
D. J. Stom S. S. Timofeeva N. F. Kashina L. J. Bielykh S. N. Souslov V. V. Boutorov M. S. Apartzin 《洁净——土壤、空气、水》1980,8(3):203-211
By the example of some phenols and qninones, in aqueous solutions possibilities for the quantitative determination are tested separately and in the mixture. Methods for thin-layer chromatography and spectrophotometry were developed. There can be chromatographically deteeted between 5 and 80 μg of substance. Phenol and quinone concentrations of 1.5 · 10?3 … 0.5 · 10?4 M were spectrophotometrically investigated. 相似文献
948.
Scattering of antiplane shear waves (SH) in two dimensions by surface and near-surface defects in a homogeneous, isotropic elastic semi-infinite medium has been studied. Attention has been focused here in the range of medium to long wavelengths. A combined finite element and analytical technique has been used to study the problems of scattering by semi-circular and triangular canyons. The results for the former case are compared with the known exact solution and those for the latter case are compared with some available approximate solutions. Finally a problem of multiple scattering by a triangular canyon and a nearby circular tunnel is studied. Numerical results are presented showing the effects of multiple scattering and different angles of incidence. These results are of interest in earthquake engineering. 相似文献
949.
S. E. HJELT 《Geophysical Prospecting》1976,24(1):1-18
By using two components of anomalous magnetic fields and a formulation including complex numbers it is possible to calculate the position parameters of thick plates and both magnetization and position of thin plates directly from any two or three points of anomaly profiles. The formulae (interpretation operators) allow automatic topographic corrections to be made. The new two-component operators give more reliable results than the conventional methods of interpretation. The variance of the parameter values obtained with subsequent points of an anomaly measures directly, the total error of interpretation. The application of infinite thin plate operators to a long profile results in characteristic patterns, from which the estimation of the number of plates and their approximate position is possible. 相似文献
950.