The territory of the Polar Urals is characterized by significant forecast resources of natural zeolites. In case of their successful development, the resources of the zeolite deposits can provide a positive impact on the development of a number of industries in the adjacent regions of the Urals and Western Siberia. At the same time, the available data about the zeolite-bearing rocks of the Polar Urals present in published research paper and materials of geological funds is rather contradictory. The results of research performed by different scientific groups often contain opposed conclusions on the mineralogical composition, the content of the commercial component in the ore, as well as on the ore reserves calculation and the potential of commercial exploitation for the same mineral occurrences. In many respects, this situation can be explained by the complexity of the geological and geomorphological conditions of the territory under consideration, the remoteness of the promising mineral occurrences from large scientific and industrial centers, and the variety of ore occurrences. This work presents the study results of lithological–petrographic features and the material composition of the eluvial debris of the Middle–Late (Givetian–Frasnian) Devonian zeolite-bearing rocks of the volcanogenic-sedimentary origin within the Naunpe area of the Polar Urals., The main objective of the proposed research was to evaluate the economic feasibility of their development and possible directions for commercial exploitation of this type of ores. Research methods included petrographic study of samples of zeolite-bearing rocks in thin sections, SEM-EDS, determination of the total mineral composition by XRD and the chemical composition by XRF. Within the Naunpe area, the outcrops of zeolite-bearing rocks on the surface are represented by blankets and debris of small lumpy–gravel eluvial deposits with indistinct outlines. Macroscopically, zeolite-bearing eluvial deposits are represented by reddish or pinkish in color, massive and relatively homogenous rocks. The ore occurrences are well interpreted based on the remote sensing data. According to the results of petrographic, lithological, and mineralogical studies, three main rock types were distinguished among the eluvial debris deposits: zeolite-bearing crystallo–lithoclastic tuffs of the mafic, intermediate, and felsic composition, and also tuffoargillites, and siliceous rocks., and Crystallo–lithoclastic tuffs and tuffoargillites contain Ca-zeolites, represented mainly by laumontite (13.8–18.9 %), which fill small open spaces between crystallites and lithoclasts. Volcanic glass fragments and feldspars from tuffoargillites are replaced partially or completely by zeolites. The content of zeolites in these rocks is even lower (less than 10 %). The characteristic features of the studied zeolite-bearing rocks from the ores of the known deposits of the Polar and Subpolar Urals have higher contents of Fe2O3, CaO и Na2O and lower content of K2O. The obtained results show that the studied rocks are quite complex, diverse, and polygenetic, as well as their formation is a result of several stages of post-volcanic authigenic mineral formation. The rather low content of zeolite minerals in these rocks and high variability of the material composition decrease the industrial potential of that eluvial debris deposits as an object of mineral raw material base. At this, they can be considered as prospecting indicator for prospecting the areas with a similar geological structure.
This paper is inspired by recent results [15, 16] which have shown that a multiplicative generator of a strict triangular norm can be reconstructed from the first partial derivatives of the triangular norm on the segment {0} x [0,1]. The strict triangular norms to which this method is applicable have been called zero-reconstructible triangular norms. This paper shows that every continuous triangular norm can be approximated (with an arbitrary precision) by a zero-reconstructible one, and thus substantiates the significance of this subclass of strict triangular norms.
Zero-term rank of a matrix is the minimum number of lines (rows or columns) needed to cover all the zero entries of the given matrix. We characterize the linear operators that preserve zero-term rank of the
$m \times n$ real matrices. We also obtain combinatorial equivalent condition for the zero-term rank of a real matrix.
Metoda zesilování rozmítnutých pulzů vyvinutá Donnou Stricklandovou a Gérardem Mourouem v roce 1985 a oceněná letošní Nobelovou cenou za fyziku způsobila doslova revoluci v konstrukci laserových systémů s vysokým špičkovým výkonem. Maximální intenzita dnešních laserů je až milionkrát vyšší než před 30 lety a jejich využití je celosvětové. Petawattové laserové systémy se uplatňují v celé řadě experimentů z oblasti biologie, fyziky materiálů, urychlování částic či laboratorní astrofyziky. Českou republiku v této oblasti úspěšně reprezentují laboratoře ELI Beamlines v Dolních Břežanech u Prahy, kde jsou v současnosti v provozu dva unikátní laserové systémy terrawatové a petawattové třídy L1 Allegra a L3 HAPLS., The Chirped Pulse Amplification method, developed by Donna Strickland and Gérard Mourou in 1985, which was awarded this year's Nobel Prize in Physics, has revolutionized the field of high peak power laser systems. The maximum intensity of today's lasers is almost a million times higher than it was 30 years ago and their application is worldwide. Experiments using petawatt laser systems range from biology, material physics, and particle acceleration to laboratory astrophysics. The Czech Republic is successfully represented in this field by the ELI Beamlines facility located in Dolní Břežany near Prague, which houses two unique terawatt and petawatt class laser systems L1 Allegra and L3 HAPLS., Lucia Koubíková., and Obsahuje bibliografické odkazy
Zévy (Tridacnidae) jsou mezi mořskými mlži výjimečné velikostí i způsobem získávání potravy. V jejich plášti se vyskytují mikroskopické řasy zooxantely, které fotosyntézou produkují sacharidy, o něž se dělí s hostitelem. Za nápadné zbarvení pláště vděčí zévy zooxantelám a specializovaným buňkám iridocytům., Giant clams (Tridacnidae) are exceptional among sea clams for their size and the way they acquire food. On their shells microscopic zooxanthella algae occur, producing saccharides through photosynthesis, which they share with the host. The conspicuous coloring of the shells is due to the clams’ zooxanthellae and specialized iridocyte cells., and Nicole Černohorská.
Cílem studie je prozkoumat, zda lze tvrzení valenční teorie volebního chování ohledně motivací a důvodů volební účasti potvrdit na základě odpovědí na otevřenou otázku ohledně hlavního důvodu volební neúčasti. Konkrétně byla studována tvrzení, která se týkají konstrukce očekávaného užitku z volební účasti. K prozkoumání výše uvedených tvrzení valenční teorie ohledně motivací volební neúčasti byly využity otevřené otázky z pěti povolebních dotazníkových šetřeních konaných v Česku mezi lety 2004 a 2010. Výsledky ukazují, že nevoliči uvažují v dimenzích, které valenční teorie předpokládá. Ta totiž pro volební účast vyžaduje, aby jedinec očekával užitek z hlasování pro konkrétní stranu; tento užitek může být důsledkem jak pozičních, tak valenčních úvah. Analýza odpovědí na otevřené otázky ukázala, že hlavním důvodem neúčasti je to, že jedinci nenacházejí užitek z hlasování ve volbách a to za řady důvodů: malý význam politiky v jejich životě, jsou přesvědčení, že hlasováním nic neovlivní, nevědí pro koho hlasovat a nedůvěřují politikům., The aim of the study is to explore the valence theory’s account of voter turnout using open-ended questions which measured the main reason given by voters for electoral abstention. The focus was on the claim of the valence theory concerning the respondent’s expected benefit from participating in an election. Data from five post-election studies undertaken between 2004 and 2010 are analysed. The empirical results reveal that electoral abstention is explained by four key factors. Voters and non-voters differ as valence theory suggests because the latter exhibit less interest in politics, less trust in politicians and parties, less knowledge of who to vote for, and a feeling that voting does not change anything. These empirical results are consonant with the predictions made by valence theory and demonstrate that electoral participation is strongly determined by expected benefits., and Lukáš Linek.
The widely accepted cause of the collapse of the World Trade Center (WTC) towers in New York on Sept. 11, 2001, has been confirmed mathematically and firmly supported by mechanical analysis. Some lay critics, however, still question the conclusions of this analysis, even without presenting any meaningful calculations. They blame the collapse on a controlled demolition, implying a conspiracy by the republican government. many mass media outlets, including Czech ones, blindly gave this misinformation wide publicity. The present invited article summarizes why the collapse was a spontaneous and inevitable result of aircraft impact, and how this fact is explained and confirmed by mathematical analysis of the mechanics of collapse, and by numerous observed data., Zdeněk P. Bažant, Milan Jirásek., and Obsahuje bibliografii
This contribution gives a brief description of the characteristics of spectral lines formed in the solar chromosphere in the visual range and its continuum in the visual, millimetre, and sub-millimetre (mm-submm) spectral range. The contribution reviews processes responsible for continuum radiation of the limb in the visual range and continua in the mm-submm spectral range. The spectral lines of sodium doublet Na I D1 and D2 are not genuine chromospheric lines since their cores are formed predominately by resonant scattering of radiation from the upper photosphere. Therefore, the cores of Na I D1 and D2 provide information only about chromospheric velocities. An occurrence of the doublet Na I D1, D2 together with helium lines with large excitation and ionization potential indicates an intricate thermodynamic structure of the chromosphere. As numerical simulations indicate, the chromospheric internetwork comprises of cooler cavities surrounded with hotter sheets allowing the occurrence of spectral lines over a large range of excitation and ionization potentials. The contribution accentuates the large diagnostic potential of the mm-submm continua of the chromospheric spectrum. It will be fully exploited after finishing of the ALMA array for the study of the chromospheric fine structure with large angular and temporal resolution., Príspevok podáva stručnú charakteristiku čiarového spektra slnečnej chromosféry vo vizuálnej oblasti a jej spojitého spektra (kontinua) vo vizuálnej, milimetrovej a submilimetrovej (mm-submm) oblasti. Príspevok predstavuje procesy tvoriace vizuálne kontinuum pozorovatel'né na limbe a kontinuá v mm-submm oblasti. Čiary sodíkového dubletu NA I D1 a D2 nie sú v pravom slova zmysle chromosférické, pretože ich jadrá sú tvorené hlavne rezonančným rozptylom žiarenia hornej fotosféry, a preto poskytujú informáciu iba o rýchlostných poliach v chromosfére. Výskyt dubletu Na I D1 a D2 spolu s čiarami hélia s veľkou excitačnou a ionizačnou energiou naznačuje zložitú termodynamickú štruktúru chromosféry. Ako ukazujú numerické simulácie, chromosféra sa v oblastiach mimo magnetickej siete skládá z chladnejších oblastí obalených horúcou látkou, čo umožňuje vznik spektrálnych čiar vo vel'kom rozsahu excitačných a ionizačných energií. Príspevok poukazuje na vel'ký diagnostický potenciál kontinuí v mm-submm oblasti spektra chromosféry, ktorý bude naplno využitý po dokončení rádioteleskopu ALMA pri štúdiu jemnej štruktúry chromosféry s vel'mi vel'kým uhlovým a časovým rozlíšením., Július Koza., and Obsahuje bibliografii