From cardinal spline wavelet bases to highly coherent dictionaries

Wavelet families arise by scaling and translations of a prototype function, called the mother wavelet. The construction of wavelet bases for cardinal spline spaces is generally carried out within the multi-resolution analysis scheme. Thus, the usual way of increasing the dimension of the multi-resolution subspaces is by augmenting the scaling factor. We show here that, when working on a compact interval, the identical effect can be achieved without changing the wavelet scale but reducing the translation parameter. By such a procedure we generate a redundant frame, called a dictionary, spanning the same spaces as a wavelet basis but with wavelets of broader support. We characterize the correlation of the dictionary elements by measuring their 'coherence' and produce examples illustrating the relevance of highly coherent dictionaries to problems of sparse signal representation

Highly Crystalline and Semiconducting Imine-Based Two-Dimensional Polymers Enabled by Interfacial Synthesis

Single-layer and multi-layer 2D polyimine films have been achieved through interfacial synthesis methods. However, it remains a great challenge to achieve the maximum degree of crystallinity in the 2D polyimines, which largely limits the long-range transport properties. Here we employ a surfactant-monolayer-assisted interfacial synthesis (SMAIS) method for the successful preparation of porphyrin and triazine containing polyimine-based 2D polymer (PI-2DP) films with square and hexagonal lattices, respectively. The synthetic PI-2DP films are featured with polycrystalline multilayers with tunable thickness from 6 to 200 nm and large crystalline domains (100–150 nm in size). Intrigued by high crystallinity and the presence of electroactive porphyrin moieties, the optoelectronic properties of PI-2DP are investigated by time-resolved terahertz spectroscopy. Typically, the porphyrin-based PI-2DP 1 film exhibits a p-type semiconductor behavior with a band gap of 1.38 eV and hole mobility as high as 0.01 cm2 V−1 s−1, superior to the previously reported polyimine based materials. © 2020 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA

A Cu3BHT-Graphene van der Waals Heterostructure with Strong Interlayer Coupling for Highly Efficient Photoinduced Charge Separation

Two-dimensional van der Waals heterostructures (2D vdWhs) are of significant interest due to their intriguing physical properties critically defined by the constituent monolayers and their interlayer coupling. Synthetic access to 2D vdWhs based on chemically tunable monolayer organic 2D materials remains challenging. Herein, the fabrication of a novel organic–inorganic bilayer vdWh by combining π-conjugated 2D coordination polymer (2DCP, i.e., Cu3BHT, BHT = benzenehexathiol) with graphene is reported. Monolayer Cu3BHT with detectable µm2-scale uniformity and atomic flatness is synthesized using on-water surface chemistry. A combination of diffraction and imaging techniques enables the determination of the crystal structure of monolayer Cu3BHT with atomic precision. Leveraging the strong interlayer coupling, Cu3BHT-graphene vdWh exhibits highly efficient photoinduced interlayer charge separation with a net electron transfer efficiency of up to 34% from Cu3BHT to graphene, superior to those of reported bilayer 2D vdWhs and molecular-graphene vdWhs. This study unveils the potential for developing novel 2DCP-based vdWhs with intriguing physical properties

název v anglickém jazyce není uveden

Výsledky charakterizují vypracovaný animální model psychózy založený na krátkodobé neonatální ischémii mozku a dokládají jistou míru jak konstrukční, fenomenologické tak i predikční validity. Vzniklé ischemicko-hypoxické poškození, které jsme navodili dočasným uzávěrem obou společných krkavic potkana 12. PND, lze s přihlédnutím k rozdílnému stupni zralosti funkcí přirovnat k situaci způsobené perinatální hypoxií lidského plodu a novorozence. Přes dílčí rozdíly ve vybraných biochemických ukazatelích (napětí krevních plynů, aktivita GGT, hladiny druhých poslů), jsme pozorovali změny v chování potkana v období jeho pohlavního dospívání, které podporují původní předpoklad, že perinatální hypoxie lidského plodu a novorozence je etiopatogenetickým faktorem pro vznik schizofrenie, a to především u jedinců s genetickým rizikem jaké představují jednonukleotidové polymorfizmy kandidátních genůAlthough the cause of schizophrenia is not fully elucidated, there is increasing evidence that this severe psychiatric illness may result from a disturbance early in development. Evidence for this so called "neuro- developmental hypothesis" comes from a variety of sources, including epidemiological, gynecological, psychological and pathological data. Fetal and perinatal hypoxia-ischemia belongs to obstetric complications which can increase the risk of schizophrenia. These complications such as premature rupture of fetal membranes, low birth weight, newborn immaturity, forceps delivery and resuscitation at birth are frequently accompanied by hypoxic-ischemic brain damage during delivery. We assume that perinatal hypoxia together with genetic factors influence a susceptibility to schizophrenia and represent significant risk factors of this disease. We used a heuristic model in our study to determine if brain hypoxic-ischemic episode can actually cause not only changes of biochemical markers but also behavioral changes resembling those seen in schizophrenia. Neurodevelopmental processes in neonatal rats continue during the first three weeks of postnatal life and reach the level of those observed in human newborns at the end of the second postnatal week. Therefore, rat pups at postnatal day 12 (PND12) were used...nezařazení_neaktivníFirst Faculty of Medicine1. lékařská fakult

Mikropohon pohonu kolesa

Import 20/04/2006Prezenční výpůjčkaKatedra hornických strojů (343) FS VŠB (Ostrava

Vývoj konstrukčního provedení strojních uzlů na základě výsledků zjištěné provozní spolehlivosti u strojního zařízení hnědouhelných povrchových dolů

Import 20/04/2006Prezenční výpůjčkaVŠB - Technická univerzita Ostrava. Fakulta strojní. Katedra (340) výrobních strojů a konstruován