Search results for "Function"
showing 10 items of 14432 documents
Airy-function approach to binary black hole merger waveforms: The fold-caustic diffraction model
2022
From numerical simulations of the Einstein equations, and also from gravitational wave observations, the gravitational wave signal from a binary black hole merger is seen to be simple and to possess certain universal features. The simplicity is somewhat surprising given that non-linearities of general relativity are thought to play an important role at the merger. The universal features include an increasing amplitude as we approach the merger, where transition from an oscillatory to a damped regime occurs in a pattern apparently oblivious to the initial conditions. We propose an Airy-function pattern to model the binary black hole (BBH) merger waveform, focusing on accounting for its simpl…
Variability of the Level of Development of Functopnal Urban Areas
2018
Miejskie obszary funkcjonalne mają istotne znaczenie w realizacji zarówno Krajowej Polityki Miejskiej 2023, jak i terytorialnej polityki rozwoju. Celem badania jest określenie poziomu rozwoju obszarów funkcjonalnych miast wojewódzkich Polski. Badania przeprowadzono z wykorzystaniem metody taksonomicznej w ujęciu dynamicznym obejmującym okres 2005-2015. Podstawę wyznaczenia wielkości taksonomicznych stanowił zestaw wskaźników diagnostycznych ujętych w trzech wymiarach rozwoju: społecznym, gospodarczym i środowiskowym. W ramach badania została podjęta ocena poziomu rozwoju miast centralnych MOF oraz oddzielnie miast i gmin ich otoczenia. Dodatkowo określono poziom rozwoju każdego z wymiarów r…
L-karnitīna biosintēzes inhibitora mildronāta neirotropo efektu pētījumi eksperimentālajos modeļos
2014
Elektroniskā versija nesatur pielikumus
Reversible self-assembly of metal chalcogenide/metal oxide nanostructures based on Pearson hardness.
2010
Nanotechnology has reached a stage of development where not individual nanoparticles but rather systems of greater complexity are the focus of concern. These complex structures incorporate two or more types of materials, an example of which is the formation of metal–semiconductor hybrids, which effectively combine the properties of both materials. The assembly of multicomponent nanoparticles from constituents with different optical, electrical, magnetic, and chemical properties can lead to novel functionalities that are independent of the individual components and may be tailored to fit a specific application. These applications include such far-reaching challenges as solar energy conversio…
Zum Spannungsverhältnis zwischen ästhetischen und linguistischen Qualitätskriterien literarischer Übersetzungen
2017
Today, literary translation occupies a special place in the translation theory, despite the fact that some researchers consider the dichotomous division within the discipline into literary and non-literary texts as resolved and unjustified. This article is an attempt to present a breakdown of selected aesthetic and linguistic criteria for the quality assessment of literary translations in order to consider, on this basis, the validity of the interdisciplinary approach to the criticism of translation of literary texts. The analysis is focused in particular on the translation quality parameters established by Sigrid Kupsch-Losereit. It is then followed by the reflection on the possibilities t…
Basic Mechanisms of Diffusive and Diffusion-Related Oxygen Transport in Biological Systems: A Review
1992
In mammals, energy metabolism of active tissues requires permanent availability of oxygen. Because cessation of O 2 supply results in loss of organ function within seconds or minutes, continual feed of adequate amounts of O 2 to tissue is the most vital task for living organisms. For many years, it therefore has been one of the greatest challenges to physiologists to understand the mechanisms provided by nature to satisfy this need for oxygen.
Recent Developments in the Chiral Brønsted Acid-catalyzed Allylboration Reaction with Polyfunctionalized Substrates
2016
Asymmetric allylboration has played a central role in organic synthesis ever since the pioneering work by Hoffman and Brown, having found applications in the total synthesis of many natural products. A new dawn for this 40 year-old reaction occurred with the beginning of the new century when the first catalytic asymmetric methods came into play. In less than one decade, several methodologies, able to achieve the desired homoallylic alcohols with ee ranges in the high 90s, were developed. Among them, in the present account, we will disclose our contribution to the development of the chiral binolphosphoric-derived BrOnsted acid-catalyzed allylboration of aldehydes originally reported by Antil…
Lithium Cation-Catalyzed Benzene Diels-Alder Reaction: Insights on the Molecular Mechanism Within the Molecular Electron Density Theory.
2020
The lithium cation Li+-catalyzed Diels-Alder (DA) reactions of benzene toward a series of acetylenes of improved nucleophilicity can be described within the context of the molecular electron density theory (MEDT) at the ωB97XD/6-311G(d,p) level. Conceptual density functional theory indices characterize the crown ether solvated complex benzene-lithium Bz-Li-Cro as a superelectrophile. Coordination of a lithium cation to benzene does not change substantially the electron localization function electronic structure of benzene. The DA reaction of Bz-Li-Cro with acetylene shows a reduction of the energy of activation of 6.9 kcal·mol-1, which is not sufficient for the reaction to take place, thus …
Theoretical Studies of the Reactivity of Cyclopentadienyl Nitrosyl Alkyl Species of Molybdenum and Tungsten
2000
International audience; The reactivity differences observed experimentally for Cp*W(NO)(CH2CMe3)2 and CpMo(NO)(CH2CMe3)2 have been investigated using density functional theory (DFT) techniques. The reactions of the CpW(NO)(CH2) model complex with NH3 and CH4 are more exothermic and have lower activation barriers than the corresponding processes for CpMo(NO)(CH2). The η2(C,H) methane complex CpM(NO)(CH2)(CH4) (M = Mo, W) can undergo two competitive processes: C−H activation to afford CpM(NO)(CH3)2 or loss of methane. The relative barrier heights are almost identical for M = W, whereas the formation of CpM(NO)(CH3)2 is significantly disfavored for M = Mo. The activation of C−H and N−H bonds …
Influence of structural elements on iron(III) chelating properties in a new series of amino acid-derived monohydroxamates
2018
Abstract A series of amino acid-derived monohydroxamate compounds A1 – A7 was synthesized and characterized for their coordination properties of Fe(III). The series varies in their skeletal lengths and compositions; some compounds lack external substituents, others are substituted with external functional amino or carboxylic groups, or alternatively inert methyl. Undertaken investigations allowed the determination of stoichiometry, stability constants and spectroscopic parameters of formed ferric complexes. Incorporation of an external functional group with a dissociable proton affects the coordination behavior; the presence of carboxylic or amino groups hampers the formation of mono-, di- …