Academic literature on the topic 'Šťovík'

We consider the magnetic Schrödinger operator on R2. The magnetic field is the sum of a homogeneous magnetic field and periodically varying pointlike magnetic fields on a lattice. We shall give a sufficient condition for each Landau level to be an infinitely degenerated eigenvalue. This condition is also necessary for the lowest Landau level. In the threshold case, we see that the spectrum near the lowest Landau level is purely absolutely continuous. Moreover, we shall give an estimate for the density of states for Landau levels and their gaps. The proof is based on the method of Geyler and Šťovíček, the magnetic Bloch theory, and canonical commutation relations.

AbstractWe classify all tilting classes over an arbitrary commutative ring via certain sequences of Thomason subsets of the spectrum, generalizing the classification for noetherian commutative rings by Angeleri, Pospíšil, ŠÅ¥ovíček and Trlifaj (2014). We show that the n-tilting classes can equivalently be expressed as classes of all modules vanishing in the first n degrees of one of the following homology theories arising from a finitely generated ideal: {\operatorname{Tor}_{*}(R/I,-)}, Koszul homology, Čech homology, or local homology (even though in general none of those theories coincide). Cofinite-type n-cotilting classes are described by vanishing of the corresponding cohomology theories. For any cotilting class of cofinite type, we also construct a corresponding cotilting module, generalizing the construction of Šťovíček, Trlifaj and Herbera (2014). Finally, we characterize cotilting classes of cofinite type amongst the general ones, and construct new examples of n-cotilting classes not of cofinite type, which are in a sense hard to tell apart from those of cofinite type.

Abstract Inspired by work of Ladkani and Groth–Šťovíček, we explain how to construct generalisations of the classical reflection functors of Bernšteĭn, Gel′fand, and Ponomarev by means of the Grothendieck construction.

Abstract Let $R$ be a commutative noetherian ring. The notion of $n$-wide subcategories of ${\operatorname{\mathsf{Mod}}}\ R$ is introduced and studied in Matsui–Nam–Takahashi–Tri–Yen in relation to the cohomological dimension of a specialization-closed subset of ${\operatorname{Spec}}\ R$. In this paper, we introduce the notions of $n$-coherent subsets of ${\operatorname{Spec}}\ R$ and $n$-uniform subcategories of $\mathsf{D}({\operatorname{\mathsf{Mod}}}\ R)$ and explore their interactions with $n$-wide subcategories of ${\operatorname{\mathsf{Mod}}}\ R$. We obtain a commutative diagram that yields filtrations of subcategories of ${\operatorname{\mathsf{Mod}}}\ R$, $\mathsf{D}({\operatorname{\mathsf{Mod}}}\ R)$ and subsets of ${\operatorname{Spec}}\ R$ and complements classification theorems of subcategories due to Gabriel, Krause, Neeman, Takahashi, and Angeleri Hügel–Marks–Šťovíček–Takahashi–Vitória.

Technical-economical study of biofuel cultivation is the topic of this diploma thesis. This is a study that includes the technology of growing biomass and its subsequent treatment. Part of the work is an economic and sensitivity analysis, which aims to determine the price of produced biomass. This work focuses on herbal biofuels and their comparison with other types of fuels.

Energy sorrel (Rumex patientia L. x Rumex tianschanicus A. Los.) is a plant with a high yield of above-ground biomass. Because of this, it is grown as energy crop, but in Ukraine it is also important forage crop. Mycobiota has not been examined, even though energy sorrel is grown in the Czech Republic experimentally since 1992 (in agricultural operations since 2001). The aims of this thesis were: to determine the composition of mycobiota of healthy plants and of mycobiota associated with leaf and stem spots, to verify whether fungi isolated from spots can cause these spots and if previously isolated fungus Phomopsis sp. can cause spots. Fungi were cultivated on 2% malt extract agar and then morphologically determined. From representative strains were isolated DNA and sequences of the ITS region were compared with the GenBank databases, this verified the morphological determination and the sterile species were determined. In total 24 morphotypes of endophytic fungi were cultivated from healthy plants. The most common species were: Clonostachys rosea f. rosea, Cladosporium cladosporioides, Rhizopus arrhizus var. arrhizus, Alternaria alternata and Acremonium strictum. From the spots were isolated in total 29 morphotypes, the dominant species were: A. strictum, Aureobasidium pullulans, C....

Energy sorrel (Rumex patientia L. x Rumex tianschanicus A. Los.) is a plant with a high yield of above-ground biomass. Because of this, it is grown as energy crop, but in Ukraine it is also important forage crop. Mycobiota has not been examined, even though energy sorrel is grown in the Czech Republic experimentally since 1992 (in agricultural operations since 2001). The aims of this thesis were: to determine the composition of mycobiota of healthy plants and of mycobiota associated with leaf and stem spots, to verify whether fungi isolated from spots can cause these spots and if previously isolated fungus Phomopsis sp. can cause spots. Samples were colected from 4 sites in Czech republic, in three samplings during the vegetation season. Endophytes were isolated from root, stem and leaf. Fungi asociated with spots were isolated from stem and leaf. Fungi were cultivated on 2% malt extract agar and then morphologically determined. From representative strains were isolated DNA and sequences of the ITS region were compared with the GenBank databases, this verified the morphological determination and the sterile species were determined. The most common endophytes were Clonostachys rosea f. rosea, Cladosporium cladosporioides, Rhizopus arrhizus var. arrhizus, Alternaria alternata a Acremonium strictum...

The problem of the Rumex alpinus invasion in the region of the Giant Mountains (Krkonoše) has been watched closely for many years. This species expels indigenous plants of this region and therefore threatens the balance of the ecosystem. The aim of this thesis is the identification of the factors responsible for spreading of the species on a selected area. The initial hypothesis expected that the disturbances of various species increased the sprouting of the species from the seed plants. Moreover, general knowledge was presented which introduced the importance of the characteristics of the environment during the spreading of Rumex alpinus. It was expected that the main factors would include the just distributed places connected to potential corridors (pathways, brooks, etc.). It was possible to prove that the higher the disturbance the higher the number of the new Rumex alpinus seedlings. It is therefore not surprising that this species can be found mostly along brooks, pathways and on meadows close to settlements and villages. Part of the results was the information that Rumex alpinus spreads faster on the local pastures. This could affect further spreading of the species in the region as the number of pastures grows. Key words: Rumex alpinus, disturbance, invasive plants, Giant Mountains...