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21.
Pavel Vysko
il 《Journal of Geodynamics》1987,8(2-4)
The border area between the Bohemian Massif and the Carpathians arc is covered by dense networks of repeated levellings as well as horizontal (triangulation, trilateration) measurements. The results were adjusted in separate vertical or horizontal networks respectively. Derived rates of vertical and horizontal movements are presented. The properties of these movements are discussed as a background to the tectonic development of the area under study. 相似文献
22.
au am nu¶rt;, nuau ¶rt;u¶rt;aum ¶rt;ua, a u ¶rt; ma aum u¶rt;uu aam ma¶rt;am . a a au ¶rt; uuauu u nm nmu a u m muna, mm m¶rt; ma a anma n u. uunua muau u m¶rt; nua [4, 5]. n¶rt; am nuam m¶rt; u, u¶rt;u u m¶rt;a a u a nm nu nu¶rt;um au m u m¶rt;. 相似文献
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Milan Rieder Miroslav Huka Dagmar Kučerová Luděk Minařík Jiří Obermajer Pavel Povondra 《Contributions to Mineralogy and Petrology》1970,27(2):131-158
Compositions of natural lithium-iron micas are approximated best by the sidero-phyllite-polylithionite join. These micas contain little or no magnesium and manganese. Their octahedral sheets contain close to two trivalent cations (mainly aluminum) in small crystallographic sites and a variable quantity of lithium and R+2 (mainly iron) in large sites. Octahedral vacancies are situated mostly in large sites. Lithium and R+2 approach a 44 replacement relationship in micas with octahedral occupancy close to six. Lithium and fluorine show a good positive correlation (small excess of fluorine over lithium), which indicates a crystallochemical association between them. There is a less distinct positive correlation between lithium and R+4.Based on simplifications, a calculation shows that about two-thirds of octahedral vacancies are caused by substitutions within the octahedral sheet, one-third, by tetrahedral substitutions. Different methods of calculating the crystallochemical formula yield slightly different numbers of octahedral vacancies, but do not affect the mica's position in plots of physical parameters against composition. If a crystallochemical formula is calculated from analysis of a mica contaminated with quartz, topaz, or feldspar, the apparent number of octahedral vacancies increases; such a formula exhibits unusual behavior in composition plots. 相似文献
26.
František Jiříček Pavel Tříska Jaroslav Vojta Ya. I. Likhter V. V. Korobovkin Reviewer V. Bumba 《Studia Geophysica et Geodaetica》1973,17(1):49-58
Summary The Interkosmos5 VLF experiment consisted of a spectrum analyser with twelve narrow-band channels and broadband measurements between0.07 and20 kHz using an analogue telemetry with a tape recorder on board. The apparatus used in the experiment is shortly described, some examples ofVLF phenomena observed are given and a review of all analogue data recorded is shown in a graphical calendar. 相似文献
27.
The distribution of controlling pressure formations, occurring in the Northern Hemisphere during the winters (January and February) of the years 1952 – 1996, has been analysed. It was found that the deepening of the Icelandic and Aleutian pressure lows is connected not only with a particular QBO phase and level of geomagnetic activity (Bochníek et al., 1999) but also with a particular level of solar activity. 相似文献
28.
Huth Radan Mládek Richard Metelka Ladislav Sedlák Pavel Huthová Zuzana Kliegrová Stanislava Kyselý Jan Pokorná Lucie Halenka Tomáš Janoušek Martin 《Studia Geophysica et Geodaetica》2003,47(4):863-873
This note summarizes results of the first integration of regional numerical weather prediction model ALADIN in a climate mode. The ALADIN model, developed in an international cooperation led by Météo France, is operationally used for weather prediction. The grid step of the model is 12 km; the integration domain covers a major part of Europe. A one-month-long run has been performed with this model on observed boundary conditions (represented by assimilations by the global model ARPEGE). It is demonstrated that no excessive error is generated and accumulated in the model during the integration; hence the model is integrable for extended time periods and may serve a basis for a development towards a regional climate model. 相似文献
29.
Pavel Ya. Groisman Richard W. Knight 《地球科学进展》2007,22(11):1191-1207
A disproportionate increase in precipitation coming from intense rain events, in the situation of general warming (thus, an extension of the vegetation period with intensive transpiration) and an insignificant change in total precipitation could lead to an increase in the frequency of potentially serious type of extreme events: prolonged periods without precipitation (even when the mean seasonal rainfall totals increase). This paper investigates whether this development is already occurring during the past several decades over North America south of 55°N, for the same period when changes in frequency of intense precipitation events are being observed. Lengthy strings of “dry” days without sizeable (>1.0 mm) precipitation were assessed only during the warm season (defined as a period when mean daily temperature is above the 5℃ threshold) when water is intensively used for transpiration and prolonged periods without sizable rainfall represent a hazard for terrestrial ecosystem's health and agriculture. During the past four decades, the mean duration of prolonged dry episodes (20 days or longer in southeastern Canada, 1 month or longer in the Eastern United States and along the Gulf Coast of Mexico and 2 months or longer in the Southwestern United States and Northern Mexico) has significantly increased. As a consequence, the return period of 1 month long dry episodes over the Eastern U.S. has been reduced more than twofold from 15 to 6~7 years. The longer average duration of dry episodes has occurred during a relatively wet period around most of the continent south of 55°N but is not observed over the Northwestern U.S. and adjacent regions of Southern Canada. 相似文献
30.
~~2006年国家自然科学基金批准项目一览表(地球科学部分)~~ 相似文献