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1.
It has been found that ammonium ions belong together with potassium and sodium ions to the main cationic species in algal cells. The intracellular concentration of ammonium ions, which changes from 4 to 160 μmol. g?1 wet weight, strongly influences the influx and reflux of different ions. Algal cells containing 4… 6 μmol of ammonium ions per gram cumulate ammonium ions in the light with a very high initial rate of 40… 80 pmol. cm?2. s?1, whereas the influx of nitrite or nitrate ions is slower by more than one order. Whereas ammonium ions simply displace potassium ions from the cell, the uptake of nitrite and nitrate ions is more complicated. These ions are rapidly reduced inside the cell into ammonium ions, which is connected with the reflux of potassium and hydroxyl ions. Ammonium ions formed take part in metabolic reactions releasing hydrogen ions. 相似文献
2.
A. Zeman 《Journal of Geodynamics》1988,9(2-4)
Comparison of the results of height adjustments on the International Repeated Levelling Network in Czechoslovakia with the normal heights from the first international adjustment affords information about general trends of height changes in the period of approx. 1943–1976 (mean epochs of both levelling). Negative changes of the heights (subsidences) occured over practically the whole county, amounting to about 70 mm in south Moravia and south-west Slovakia.Also the height changes determined from independent adjustments of the network in Czechoslovakia at the same epoch was studied. This was based on the premise of unchanging height of the Lišv fundamental levelling benchmark in south Bohemia. As the result, we got practically the same courses of the isolines of identical height changes, only systematically shifted by about 60 mm.The data of comparison should be the subject of interpretation from the point of view of structural geology for which they can serve as a basis for studying fundamental tendencies of the dynamics of the Earth's crust in the investigated region and for given time period. 相似文献
3.
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).
¶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–).相似文献
4.
The cumulation of chromium(III) and (VI) has been studied in batch cultures of planktonic algae Microcystis incerta, Scedenesmus obliquus, Chlorella kessleri and Chlamydomonas geitleri at different chromium and algal cells concentrations. It has been found that chromium(VI) is practically not cumulated in algae, whereas chromium(III) is very rapidly cumulated in all types of algae investigated. The cumulation factor increases with the decrease of the radius of algae cells and it reaches the value of 106 for Microcystis incerta even after a few hours of contact. The kinetics, the cumulation factors and the capacity of algae to cumulate chromium(III) is practically the same for living as well as for dead cells and therefore it can be concluded that the cumulation of chromium(III) is due predominantly to the chemical sorption on the surface of algal cells. 相似文献
5.
甘肃灵台黄土剖面记录地球磁场长期变化的可靠性探析 总被引：11，自引：4，他引：7
对甘肃灵台黄土／古土壤序列黄土层Ｌ１以及古土壤层ＳＯ和Ｓ１进行的较为详细的古地磁和岩石磁学研究表明：该剖面黄土剩余磁性在锁定过程中受到的平滑作用不大,因此能够记录百年尺度的地球磁场长期变化;而古土壤剩余磁性则受到强烈的平滑作用,不能记录百年尺度的地球磁场长期变化．在此基础上,对黄土层Ｌ１记录的地球磁场长期变化特征进行了分析,进一步证实了Ｍｏｎｏ Ｌａｋｅ和Ｌａｓｃｈａｍｐ漂移是两个独立的事件。 相似文献
6.
Abstact The results are summarized of the correlation between the detailed geomorphological analysis and the geodynamic interpretation of the twelve high-precision levelling measurements of the Earth's recent surface movements (1983–1989) in the hazardous area of Jezeí Castle in the Kruné hory Mts. Indicated are the types and régime of these movements (Tab 1, Fig 3) which are climatic, tectonic and anthropogenous in origin. Both slightly and strongly deformed zones in the near-surface part of crystalline rocks massif were formed (Fig 1). The landform patterns (Fig 2), as well as the present-day activity of geological processes are described. 相似文献
7.
Kostelecký J. Kostelecký J. Pešek I. Šimek J. Švábenský O. Weigel J. Zeman A. 《Studia Geophysica et Geodaetica》2004,48(3):503-518
Several quasigeoid models for the Czech Republic have been developed for different purposes since mid-seventies using different data sources: gravimetric, astronomical and GPS/levelling observations, as well as data gained from the territories of neighbouring countries. Two of the recent solutions, namely the VUGTK96 quasigeoid obtained from heterogeneous data and gravimetric quasigeoid CR2000 are described and compared. Accuracies of the models were estimated with the help of accuracy characteristics resulting from the processing, by comparison with GPS/levelling results available for most of the territory, and, finally, tested on a special GPS/levelling profile across the steepest slope of the quasigeoid surface in the south-eastern part of the territory. It is shown that the CR2000 gravimetric quasigeoid is suitable for transformation of ellipsoidal GPS heights to the gravity related heights with an accuracy of 3 cm. 相似文献
8.
Antonín Zeman Reviewer M. Burša Reviewer M. Pick 《Studia Geophysica et Geodaetica》1981,25(3):284-288
Summary Simple expressions for the deformation of equipotential surfaces and changes of the deflections of the vertical are derived at points of the Earth's surface, which are due to the variations of the rotational component of the gravity potential under free nutation of the Earth's axis of rotation (pole wandering). The results of the solution of this problem given in[1] are discussed. The values of the tilts and the changes of geoid heights for extreme deviations of the poles are considered from the point of view of the effect on measuring tilts and on levelling. An elastically deformable Earth is assumed. It is concluded that reductions with respect to the mean Earth's pole are not realistic at the present degree of accuracy of levelling. The necessity to reduce long-term tilt observations, or the possibility of determining the time variations of the rotational axis from the analysis of these observations is pointed out. 相似文献
9.
Summary Simple linear representation of the components of an approximate plane solution of point mass loading of the Earth's surface in a conveniently chosen coordinate system leads to selection of a 2nd-degree curve which is the best fit of the spherical solution for the given Earth model. The new approximate solution, which, analogously to the plane solution, can be called a parabolic solution, enables the simple input parameters of the plane solution to be used also for substantially larger angular distances. The comparison with the spherical solution is carried out by computing the effects of the M2-wave of ocean tides. The results of the computations for the tidal station Brussels prove the two solutions to be in sufficient agreement for global problems as well.
m nu uau aa nuuum nm u m m au nmu u n¶rt;¶rt; um ¶rt;uam ¶rt;m ma u m mnu, ma auu a n¶rt;¶rt;um u u ¶rt; ¶rt;a ¶rt;u u. nuuum u, m n aauu nm u aam naauu u, nm unam nm ¶rt; ¶rt;a nm u ¶rt;a ¶rt; m u amu. au uu u m uu uu 2 u nuu. mam uu ¶rt; nuu mauu ¶rt;aam ¶rt;mum au u u ¶rt;a ¶rt;a a¶rt;a.相似文献
10.
The study of supergene processes (i.e., secondary processes running in ore deposits and driven by thermodynamic nonequilibrium between ore-and rock-forming minerals and natural waters, gasses, etc.) is important in order to understand the migration of heavy metals from ore into their adjacent surroundings. The contamination of the local environment can be characterized by the composition of pore waters. The Pb-Zn-Cu ore deposits of Zlaté Hory (Czech Republic) have been chosen for a detailed study of pore solutions. A simple model has been created to describe the evolution of supergene processes in the ore deposits. This model is based on the determination of chemical composition of pore solutions. The dilution of pore solutions of such mineral deposits results in acid mine drainage. Pore solutions can have, during specific stages of their evolution, relatively high concentrations of Cu (0.09 mol/kg), Zn (0.1 mol/kg), SO4 (0.8 mol/kg) and an extremely low pH (1.38). The supergene alteration of pyrite is the most important process determining the character of pore water. This reaction causes significant acidification and is a leading source of acid mine drainage. The leached zone originates from the interaction of pyrite and limonite. Increased concentrations of heavy metals and sulfates occur in pore waters. The dynamic composition of pore waters within ore deposits undergoing the supergene process can be used to distinguish: (1) three main zoneslimonite, transition, and primary zone and (2) two areas—an area with the highest intensity of weathering processes and an area of weathering initiation. In these areas the rate of sulfide oxidation is higher as a result of low pH. From the study of these zones and areas we can further our knowledge of ore body, pore solution, acid mine drainage, and contamination of the local environment. 相似文献