Experimental investigation of turbulent processes in a complex terrain     

Thomas Foken  Jan Pretel  Reviewer J. Bednář  Reviewer Z. Jaňour 《Studia Geophysica et Geodaetica》1988,32(3):318-328

In the present paper the first results of the international KOPEX-86 experiment are presented. The experiment took place at the Kopisty Atmospheric Observatory of the Institute of Physics of the Atmosphere in Prague as part of a special project of the Commission of the Academy of Sciences in Planetary Geophysics (KAPG) in June and July 1986. Using 4 ultrasonic anemometers at 4 levels up to 80 m, Doppler-SODAR and wind-, temperature- and radiation balance gradients from 2 to 80 m, a complex investigation of the atmospheric boundary layer in an industrial area was made. The authors present the first results of

–	the anthropogenic influence on the energy exchange in the atmospheric boundary layer.
–	the influence of a complex terrain on the turbulent characteristics and their vertical distribution.

am n mam ¶rt;a¶rt; numa -86. num n¶rt;u mu u u u 1986. a num mu amuu mumma uuu am aa nma . u nu 4 amuu am a 4 ma ¶rt; 80 , ¶rt;nn ¶rt;aa u uua¶rt;um mu ma, mnam u a¶rt;uauu 2 ¶rt; 80 n¶rt;uu n u¶rt;au nau am. m n¶rt;aam n mam, aau

–	u¶rt;au amn ¶rt;mu a muu na am,
–	uu n mmu a aamumuu mmmu u a u mua an¶rt;u.

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On the gravitation absorption hypothesis     

Zdeněk Šimon  Jan Kostelecký  Antonín Zeman  Reviewer L. Skalský 《Studia Geophysica et Geodaetica》1988,32(1):16-23

Summary It is recommended that the data from measurements with supraconducting gravity meters be also analysed with regard to verifying the gravitation absorption hypothesis. Based on theoretical data from a3-year period, the spectrum of the assumed effect of shielding the gravitational influence of the Sun by the Earth's body on the value of the acceleration of gravity has been calculated for the tidal station Brussels (Figs 2a–e).

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¶rt;aam aauuam ¶rt;a uu n¶rt;uaumau ma mu u nuunm n¶rt;auaumauu. a mmuu ¶rt;a a mmu nu¶rt; u nm n¶rt;naa ma auauaumau ¶rt;mu a m a uu u u mmu ¶rt; nuu mauu (u. 2a–).

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КРИТИКА     

Milan Burša  Jiří Vaněk  Oldřich Novotný  Ladislav Křivský  Petronela Ochabová  Jan Bednář 《Studia Geophysica et Geodaetica》1988,32(4):416-420

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Trends in planetary wave activity in the upper middle atmosphere inferred from the nighttime LF radio wave absorption measurements     

Jan Laštovička 《Studia Geophysica et Geodaetica》1994,38(2):206-212

Summary The nighttime LF radio wave absorption in the lower ionosphere measured at two frequencies in central Europe over 1963–1985 is used to infer planetary wave activity and its long-term trend in the upper middle atmosphere (∼90–100 km). The observed positive trend is roughly consistent with results based on daytime absorption. Nighttime results are less pronounced and less statistically significant probably due to perturbing effects of geomagnetic activity. The observed trends, which are probably of anthropogenic origin, are together with the daytime results [3,4] the first evidence of long-term trends in planetary wave activity in the upper middle atmosphere.  相似文献   

Memorial Dimitrij Alekseevich Rodionov 1931–1994     

Jan Harff 《Mathematical Geosciences》1995,27(6):811-812

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Surface-wave mode coupling for efficient forward modelling and inversion of body-wave phases     

Henk Marquering  Roel Snieder 《Geophysical Journal International》1995,120(1):186-208

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A geomagnetic event recorded in loess deposits of the Tönchesberg (Germany): identification of the Blake magnetic polarity episode     

Jan Reinders  Ulrich Hambach 《Geophysical Journal International》1995,122(2):407-418

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Nonlinear adaptive regression predictors based on singular decomposition     

Jan John  Josef Štekl 《Studia Geophysica et Geodaetica》1990,34(4):369-378

Summary The paper deals with a non-linear regression model, linear in parameters. The least-squares adaptation method has been used to determine the model parameters. The conditionality problem in solving equations, which follows from the dependent predictors, has been suppressed by singular decomposition. This model is especially suitable for treating meteorological problems because non-linear processes, e.g. changes of air masses, changes of circulation patterns, etc., can be treated. The model has been tested in connection with the forecast of daily maximum and minimum temperatures. The RMS error lies in the range of 1–2°C, if the principal PPM is supposed.

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Резюме Оnuсывеamся мamемamuческuŭ annaрam нелuнеŭноŭ ре?rt;рессuонноŭ мо?rt;елu, лuнеŭноŭ оmнос umельно naрaмеmров. Для оnре?rt;еленuя naрaмеmров мо?rt;елu uсnользуеmся меmо?rt; нauменьщuх квa?rt;рamов. Плохaя обусловленносmь сuсmемы нauменьщuх квa?rt;рamов, коmорaя вызвaнa взauмноŭ зaвuсuмосmью nре?rt;uкmоров, всmрaняеmся nрu nомощu сuн?rt;улярноŭ ?rt;екомnозuцuu. Эma мо?rt;ель nо?rt;хо?rt;um ?rt;ля nрuмененuя в меmеороло?rt;uu, maк кaк онa nозволяеm рaбоmamь с нелuнеŭносmямu, кaк нanрuмер uзмененuе воз?rt;ущных мaсс, uзмененuе хaрaкmерa цuркуляцuu u m. n. Мо?rt;ель nроверяеmся нa nро?rt;нозе ?rt;невных мuнuмaльных u мaксuмaльных mемnерamур. Сре?rt;няя квa?rt;рamuческaя ошuбкa нaхо?rt;umся в uнmе?rt;рaле оm 1 ?rt;о 2° (uсnользовaн nрuнцun РРМ).

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Compositional changes of minerals associated with dynamic recrystallizatin     

Richard A. Yund  Jan Tullis 《Contributions to Mineralogy and Petrology》1991,108(3):346-355

The rate of compositional and isotopic exchange between minerals may be enhanced significantly if the rock is deformed simultaneously. The enhanced exchange rate may result from a reduction in grain size (shorter distance for volume diffusion), dissolution and growth of grains by diffusion creep (pressure solution), or the movement of high-angle grain boundaries through strained grains during recrystallization in the dislocation creep regime. The migration of high-angle grain boundaries provides high diffusivity paths for the rapid exchange of components during recrystallization. The operation of the latter process has been demonstrated by deforming aggregates consisting of two plagioclases (An₁ and An₇₉) at 900°C, 1 GPa confining pressure, and a strain rate of ∼2x10^-6s^-1. The polygonal, recrystallized grains were analyzed using an analytical transmission electron microscope and have a variable but often intermediate composition. At the conditions of these experiments, the volume interdiffusion rate of NaSi/CaAl is too slow to produce any observable chemical change, and microstructural-chemical relations indicate that the contribution from diffusion creep was insignificant except for initially fine-grained (2–10 μm) aggregates. These results indicate that strain-induced recrystallization can be an effective mechanism for enhancing the kinetics of metamorphic reactions and for resetting the isotope systematics of minerals such as feldspars, pyroxenes, and amphiboles.  相似文献   

Effects of the IMF pro- and anti-sectors in the winter midlatitude ionosphere     

Jan Laštovička  Reviewer L. Křívský 《Studia Geophysica et Geodaetica》1985,29(1):101-104

Summary On the basis of the 1966–73 data, the effect of the difference between pro- and anti-sectors of the IMF is found to be negligible in the winter midlatitude (Central Europe) ionosphere contrary to the dominant effect of this difference in the high-latitude ionosphere found earlier.

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a ¶rt;a a 1966–73. u¶rt;m u m amu ¶rt; pro- u anti- mau . na a u ¶rt;um (¶rt; na) u, , a naa a, naum um u.

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