7 research outputs found
Weak localization in ultrananocrystalline diamond
In this letter we present results of magnetotransport measurements, carried out on heavily nitrogen-doped ultrananocrystalline diamond films, prepared by plasma-enhanced chemical vapor deposition. This material having at room temperature appreciably high electric conductivity ( ∼ 4200 S m−1) revealed surprisingly at Kelvin temperatures a giant negative magnetoresistance reaching up to 22% at 1.28 K and at 8 T. The analysis of experimental data has borne evidence of the fact that the transport in this subsystem has a character of low-dimensional disordered metal and it is controlled by quantum interference effects of electrons resulting in their weak localization
On Expansion of a Spherical Enclosure Bathed in Zero-Point Radiation
Abstract: In the present contribution a simple thought experiment made with an idealized spherical enclosure bathed in zero-point (ZP) electromagnetic radiation and having walls made of a material with an upper frequency cut-off has been qualitatively analysed. As a result, a possible mechanism of filling real cavities with ZP radiation based on Doppler’s effect has been suggested and corresponding entropy changes have been discussed
Highly disordered two-dimensional electron system in a weak magnetic field
The highly disordered two-dimensional electron gas contained in multi-δ-layers was
experimentally investigated by a magnetotransport method to obtain information about the
nature of electron states in the range of weak magnetic fields. The data observed have been
found to be in conflict with the widely accepted floating of the extended states at vanishing
magnetic fields and we have suggested an alternative interpretation of the data as a direct
transition from an integral quantum Hall liquid to a two-dimensional disordered conductor
with the transport controlled by weakly localized states
Flooding ecology of voles, mice and shrews: the importance of geomorphological and vegetational heterogeneity in river floodplains
Contains fulltext :
32511.pdf (publisher's version ) (Closed access)Since voles, mice and shrews are important animals in food chains of river floodplains, there is a need for data on their spatial and temporal distribution in periodically flooded areas. During a live trapping study between two successive floods in an embanked river floodplain, the ’Afferdensche en Deestsche Waarden (ADW)’, six species were frequently observed, viz,Microtus arvalis (Pallas, 1778),Clethrionomys glareolus (Schreber, 1780),Sorex araneus (Linnaeus, 1758),Crocidura russula (Hermann, 1780),Micromys minutus (Pallas, 1771) andApodemus sylvaticus (Linnaeus, 1758). Ungrazed rough herbaceous vegetation appeared to be rich in numbers and species, whereas no spoors of small mammals were observed in large parts of the ADW floodplain (eg bare substrates and maize fields). Vegetation structure seemed to be very important in guiding the recolonisation process after flood events. Throughout the year the highest numbers of small mammals were captured on and near the non-flooded elevated parts functioning as refugia during inundation. Poor habitat connectivity, sparseness of non-flooded recolonisation sources and small numbers of survivors led to slow recolonisation. The time between two successive floods (eight months) was not long enough for entire recolonisation of ADW. Small mammal densities at more than 30 m from the non-flooded areas were always lower than in non-flooded areas