Equivalence between love waves propagating in double layer and single layer medium     

Oldřich Novotný  Karel Pěč 《Studia Geophysica et Geodaetica》1964,8(1):24-33

Физическое объяснение частотного уравнения волн Лява для двухслойной среды, покрывающей полупространство, с точки зрения интерференции пространственныхSH-волн дало возможность определить параметры эквивалентной среды с одним слоем, покрывающим долупространство. Под эквивалентностью здесь подразумевается совпадение кривой дисперсии волн Лява. Оказывается, что за исключением нескольких весьма простых случаев двухслсйную среду обобщенно нельзя заменить эквивалентной однослойной моделью таким образом, чтобы как слой, так и полупространство были однородными. Полупространство эквивалентной модели в общих случаях, учитывая наличие пространственныхSH-волн, обладает дисперсионными свойствами и является анизотропным. С помощью принципа эквивалентности частотное увавнение волн Лява в двухслойной среде были установлены дальнейшие волны, сушествуюшие не во всем частотном спектре. Существование и число этих ветвей зависит от отношения мощностьй слоев и от порядкового номера обертона волн Лява.  相似文献   

Some pressure test phenomena of worden and CG-2 (sharpe) gravimeters     

Karel Diviš  Viktor Höschl  Stanislav Hrách  Reviewer M. Pick 《Studia Geophysica et Geodaetica》1981,25(1):14-23

Summary The results of pressure tests of gravimeters Worden No. 961, CG-2 Nos 174 G, 323 and 374 in a pressure chamber are presented. Apart from deriving the barometric correction, the authors have also studied accompanying phenomena, which occur during pressure tests of gravimeters — the barometric after-effect and hysteresis. The processing of the results in two ways differing in the method of eliminating the drift of the gravimeter, yields nearly identical results. The hysteresis was investigated for atmospheric pressures of 720±150 Torr (1 Torr=0.133322 kPa), a rate of change of 30 Torr/min and a temperature of 22°C. The barometric after-effect was investigated in greater detail for the CG-2 gravimeter No. 174 G at a pressure difference of 225 Torr, rate of change of 30, 15 and 7.5 Torr/min and a gravimeter heating temperature of 35 °C. It was also found that the barometric correction can be determined, using the method given, with sufficient accuracy. As a result of the existence of hysteresis, however, the derived results must be applied carefully in field gravity measurements with some gravimeters.  相似文献   

Reliability of focal mechanism determination     

Karel Klíma  Libuše Ruprechtová  Reviewer V. Červený 《Studia Geophysica et Geodaetica》1981,25(3):224-230

Summary The fault plane solution determined by means of a computer algorithm, correlating the radiation pattern with the distribution of observations, was investigated from the point of view of its reliability. The maximum of the correlation function R corresponds to the optimum solution found by the computer. If the families of nodal lines fitting the decreased correlation function R —dR retain the character of the optimum solution even whendR increases, we assume that the solution has been determined with a sufficient accuracy.  相似文献   

Wolf-Rayet binaries: Evolutionary causes for their distribution in the Galaxy     

Bambang Hidayat  A. Gunawan Admiranto  Karel A. Van Der Hucht 《Astrophysics and Space Science》1984,99(1-2):175-190

On the basis of the most recent data, the fraction of known Wolf-Rayet binaries is 0.22. In the solar neighbourhood (d<2.5 kpc) this fraction is 0.34In order to assess the relative importance of massive binary evolution as one of the ways to produce WR stars, the galactic distribution of WR binaries is compared with that of single WR stars using improved intrinsic parameters and new data for the fainter WR stars.In the galactic plane the increase of the binary frequency with galactocentric distance is confirmed.In a direction perpendicular to the galactic plane it is demonstrated at all distances from the Sun that the single-line spectroscopic WR binaries with small mass functions have definitely larger -distances than the single WR stars and the WR binaries with massive companions. This is consistent with the evolutionary scenario for massive binaries summarized by van den Heuvel (1976). Among the single WR stars the fraction of those with large |z|-distances is increasing with galactocentric distance, like the fraction of the known binaries. This implies that among the high-|z| single WR stars as well as among the WR stars with lower |z|-values many binaries are still to be discovered.The total WR binary frequency in the Galaxy could be well above 50%.Contribution from the Bosscha Observatory No. 79.Invited paper presented at the Lembang-Bamberg IAU Colloquium No. 80 on Double Stars: Physical Properties and Generic Relations, held at Bandung, Indonesia, 3–7 June, 1983.  相似文献   

Accuracy of Normal Heights Determined Using Improved Geopotential Models     

Raděj  Karel 《Studia Geophysica et Geodaetica》1997,41(3):217-220

The accuracy of determining the Molodensky normal heights using geopotential models has been investigated. On the basis of geopotential model JGM-3/OSU91A the Molodensky normal heights can be computed with an accuracy of about ±35 cm at the GPS sites in the central part of Europe. On the basis of JGM-3/OSU91A improved the accuracy becomes higher, about ±14 cm.  相似文献   

Space-time variations of the frequency-energy relation for mining-induced seismicity in the Ostrava-Karviná mining district     

Karel Holub 《Pure and Applied Geophysics》1996,146(2):265-280

The values of parameters of the relation logN=a–b logE characterize in general the level of seismicity of individual regions. In the present paper, a detailed analysis ofb values of the frequency-energy distributions was carried out with the aid of a database of seismic events recorded by the seismological networks in the Ostrava-Karviná Coal Mine District (Czech Republic), using the least squares regression and maximum likelihood method, as well. The determination ofb value was performed for a relatively large number of regions investigated and for different time series of observations. Special attention has been paid to induced seismic events statistics for the vicinity of one of the coalfaces in the Lazy Mine. It could be generally stated that lowerb values correspond to a higher level of induced seismic activity, while the higher ones correspond to a low and a moderate seismic activity.  相似文献   

Coordinated Simultaneous Freja Satellite and Niemegk Observatory ULF Measurements     

Prikner  Karel 《Studia Geophysica et Geodaetica》1997,41(3):247-263

The standard FFT analysis was applied to thirteen pulsation events selected from the March–April 1993 simultaneous measurements in space (Freja satellite) and on the ground (Niemegk Observatory). The spectral processing of the six-minute sections of record in two coordinate components perpendicular to the magnetic field lines had two principal subjects in view: a) Frequency-amplitude satellite-ground relations. The average values of smoothed spectral amplitude transmission coefficients in the total Pc4-3 and, separately, in Pc4 and Pc3 bands were 0.60, 0.48 and 0.70, respectively. The maximum values were observed within the Pc3 band, near f 30 mHz. b) Estimation of frequency bands of field line resonances (FLRs) recorded on Freja. Freja's motion in a broad latitude range (±5° around Niemegk) during the measurements enabled two frequency bands of FLRs with a width of 10's of mHz to be identified on Freja. The weighted frequencies of the FLRs bands on Freja were f _wA 36 mHz and f _wB 18 mHz with fine structure separations of about 5 mHz and 4 mHz, respectively. The second band with f _wB 18 mHz was mostly not observed at Niemegk, and this could be the consequence of the satellite moving partly through regions of L greater than that of Niemegk.  相似文献   

Abschätzung der Geometrischen-und Genauigkeitsparameter eines Dreiecknetzes     

Karel Kučera 《Studia Geophysica et Geodaetica》1970,14(4):382-388

Summary Approximate formulae (2,4) were derived for estimating the geometric parameters of a national triangular net, if its area P, in a certain way determined circumference O, and intended average length of the triangle side d are given. The formulae are given for n_Δ triangles, n_b points, n_d sides, and for r_g conditions with a trigonometrical net the bearings of which are measured, or r_l conditions with a trilateral net. Other approximate formulae (7–10) serve for estimating the mean errors M_g and M_l of adjusted observations and the positional errors M_x,y,g and M_x,y,l of the points of the net. Equation (11) gives the relation between the mean errors of observations m_g and m_l, which leads to the same positional accuracy with both bearing and distance measuring methods. The effect of the relative error R_d of the estimate of distance d is only observed with the geometric parameters and it is given by equations (6).

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Anschrift: Politickych vězňů 12, Praha 1-Nové Město.  相似文献   

Die Lage Der Nordatlantisch-Europäischen Hochdruckgebiete Während des IGJ     

Karel Bayer 《Studia Geophysica et Geodaetica》1962,6(3):297-308

Резюме Предлагается метод картографической обработки частоты положений отчетливых антициклонов. Метод применяется для приземного поля давления. Для отдельных времен времен года в течение МГГ определялось наиболее частое положение в североатлантичеокой и европей областях. На основании полученных результатов можно сделать основной вывод о существовании высокой устойчивости Азорското дентра, который на протяжении МГГ не изменялся своему пояожению практически ни даже в речение отдеиьиых времен года, однако же были обнаружены отчетливые сезонные изменения направления антициклональиых отрогов из Азорской области высокото давления.

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Herrn Univ. Prof. Dr Alois Gregor zum 70-sten Geburtstage gewidmet

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Anschrift: Boční II, Praha 4—Spoiřilov.  相似文献   

PhasesLg etRg observées à Praha     

Karel Pěč 《Studia Geophysica et Geodaetica》1961,5(3):219-226

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