Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

Wyszukujesz frazę "Neumann, F." wg kryterium: Autor


Wyświetlanie 1-5 z 5
Tytuł:
Identifying the oldest larva of a myrmeleontiformian lacewing-a morphometric approach
Autorzy:
Herrera-Florez, A.F.
Braig, F.
Haug, C.
Neumann, C.
Wunderlich, J.
Hornig, M.K.
Haug, J.T.
Powiązania:
https://bibliotekanauki.pl/articles/2082151.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Insecta
Myrmeleontidae
Ascalaphidae
compression fossil
fossil larva
Cretaceous
Crato Formation
Brazil
Opis:
Neuroptera is one of the smaller ingroups of Holometabola, the ingroup of Insecta characterised by “complete” metamorphosis. Neuroptera comprises about 6000 species in the modern fauna, but appears to have been more diverse in the past. While adults distantly resemble certain moths or damselflies, the larval forms of Neuroptera are mostly fierce predators with prominent venom-injecting stylets. The most well-known of these larvae are probably those of antlions. Antlions and their closer relatives (silky lacewings, split-footed lacewings, ribbon-winged lacewings, spoon-winged lacewings, and owlflies) form a distinct monophyletic ingroup of Neuroptera, Myrmeleontiformia, hence the antlion-like forms. The fossil record of antlion-like larvae dates back far into the Cretaceous; many forms are known by exceptionally wellpreserved specimens entrapped in amber. The oldest fossil record of a neuropteran larva (not an antlion-like form) comes from Lebanese amber. Interestingly, the supposedly oldest record of an antlion-like larva is preserved in rock and comes from the famous Lower Cretaceous Crato Formation. We re-evaluate this fossil based on high-resolution composite photography. Due to the non-availability of many key characters, standard procedures for identifying the specimen to a more narrow ingroup remains challenging. Therefore, we used a morphometric approach. A combination of non-metric multidimensional scaling (NMDS), parallel coordinate plots and discriminant function analysis indicates that the fossil is a representative of the group Ascalaphidae (owlflies) + Myrmeleontidae (antlions). We discuss implications of this result for the fossil record of neuropteran larvae. These include the rather derived morphology of the oldest fossil larva of Myrmeleontiformia in contrast to previous expectations. Furthermore, fossils from soil dwellers can not only be expected to be found in amber, but also as compression fossils.
Źródło:
Acta Palaeontologica Polonica; 2020, 65, 2; 235-250
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Facies architecture of the fluvial Missão Velha Formation (Late Jurassic-Early Cretaceous), Araripe Basin, Northeast Brazil : paleogeographic and tectonic implications
Autorzy:
Fambrini, G. L.
Neumann, V. H. M. L.
Menezes-Filho, J. A. B
da Silva-Filho, W. F.
de Oliveira, É. V.
Powiązania:
https://bibliotekanauki.pl/articles/139001.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Araripe Basin
Missão Velha Formation
fluvial facies
architectural element
rift basins
basen Araripe
Missão Velha
facje rzeczne
element architektoniczny
rów tektoniczny
Opis:
Sedimentological analysis of the Missão Velha Formation (Araripe Basin, northeast Brazil) is the aim of this paper through detailed facies analysis, architectural elements, depositional systems and paleocurrent data. The main facies recognized were: (i) coarse-grained conglomeratic sandstones, locally pebbly conglomerates, with abundant silicified fossil trunks and several large-to-medium trough cross-stratifications and predominantly lenticular geometry; (ii) lenticular coarse-to-medium sandstones with some granules, abundant silicified fossil wood, and large-to-medium trough cross-stratifications, cut-and fill features and mud drapes on the foresets of cross-strata, (iii) poorly sorted medium-grained sandstones with sparse pebbles and with horizontal stratification, (iv) fine to very fine silty sandstones, laminated, interlayered with (v) decimetric muddy layers with horizontal lamination and climbing-ripple cross-lamination. Nine architectural elements were recognized: CH: Channels, GB: Gravel bars and bed forms, SB: Sand bars and bedforms, SB (p): sand bedform with planar cross-stratification, OF: Overbank flow, DA: Downstream-accretion macroforms, LS: Laminated sandsheet, LA: Lateral-accretion macroforms and FF: Floodplain fines. The lithofacies types and facies associations were interpreted as having been generated by alluvial systems characterized by (i) high energy perennial braided river systems and (ii) ephemeral river systems. Aeolian sand dunes and sand sheets generated by the reworking of braided alluvial deposits can also occur. The paleocurrent measurements show a main dispersion pattern to S, SE and SW, and another to NE/E. These features imply a paleodrainage flowing into the basins of the Recôncavo-Tucano-Jatobá.
Źródło:
Acta Geologica Polonica; 2017, 67, 4; 515-545
0001-5709
Pojawia się w:
Acta Geologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Early Power Estimation of Mixed-Signal Design
Autorzy:
Kotynia, Ł.
Sathyamurthy, M.
Neumann, F.
Hennig, E.
Powiązania:
https://bibliotekanauki.pl/articles/397912.pdf
Data publikacji:
2012
Wydawca:
Politechnika Łódzka. Wydział Mikroelektroniki i Informatyki
Tematy:
Universal Verification Methodology
sygnał mieszany
power profiling
mixed-signal design
Opis:
In this paper, we present the idea of using dynamic power estimation during the system-level design. A mixed-signal wireless IC with energy harvesting is used as an example of a device where power exploration and optimization plays a key role during the architecture planning. The novelty of this approach lies in introducing the activity profile for the mixed-signal chip as an important indicator of the power consumption that can drive the design phase. The method presented in this paper is based on modeling of the complete chip in order to apply it with a mixed-language Universal Verification Methodology (UVM) environment. It was decided to use the Verilog-D, SystemVerilog and Verilog-AMS languages to represent behavior of the digital and analog/mixed-signal parts of the chip.
Źródło:
International Journal of Microelectronics and Computer Science; 2012, 3, 4; 138-145
2080-8755
2353-9607
Pojawia się w:
International Journal of Microelectronics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Growth and Properties of ZnMnTe Nanowires
Autorzy:
Zaleszczyk, W.
Janik, E.
Presz, A.
Szuszkiewicz, W.
Morhange, J. F.
Dłużewski, P.
Kret, S.
Kirmse, H.
Neumann, W.
Dynowska, E.
Domagała, J. Z.
Caliebe, W.
Aleszkiewicz, M.
Pacuski, W.
Golnik, A.
Kossacki, P.
Baczewski, L. T.
Petroutchik, A.
Karczewski, G.
Wojtowicz, T.
Powiązania:
https://bibliotekanauki.pl/articles/2047697.pdf
Data publikacji:
2007-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.46.Df
68.65.La
78.55.Et
78.67.Bf
81.15.Hi
Opis:
Catalytically enhanced growth of ZnMnTe diluted magnetic semiconductor nanowires by molecular beam epitaxy is reported. The growth is based on the vapor-liquid-solid mechanism and was performed on (001) and (011)-oriented GaAs substrates from elemental sources. X-ray diffractometry, scanning and transmission electron microscopy, atomic force microscopy, photoluminescence spectroscopy, and Raman scattering were performed to determine the structure of nanowires, their chemical composition, and morphology. These studies revealed that the obtained ZnMnTe nanowires possess zinc-blende structure, have an average diameter of about 30 nm, typical length between 1 and 2μm and that Mn$\text{}^{2+}$ ions were incorporated into substitutional sites of the ZnTe crystal lattice.
Źródło:
Acta Physica Polonica A; 2007, 112, 2; 351-356
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stochastic Carrier Dynamics in Semiconductor Superlattices
Autorzy:
Fromhold, T. M.
Bujkiewicz, S.
Patanè, A.
Stapleton, S. P.
Sherwood, D.
Fowler, D.
Cooper, J.
Eaves, L.
Belyaev, A. E.
Krokhin, A. A.
Neumann, A.
Wilkinson, P. B.
Sankeshwar, N. S.
Henini, M.
Sheard, F. W.
Powiązania:
https://bibliotekanauki.pl/articles/2044604.pdf
Data publikacji:
2006-01
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
73.20.At
73.21.Cd
Opis:
We explore a new regime of hot carrier dynamics, in which electrons in a superlattice miniband exhibit a unique type of stochastic motion when a magnetic field is tilted at an angle θ to the superlattice axis. Remarkably, the dynamics of a miniband electron in a tilted magnetic field reduce to a one-dimensional simple harmonic oscillator, of angular frequency ω$\text{}_{C}$ cos θ, where ω$\text{}_{C}$ is the cyclotron frequency, driven by a time-dependent plane wave whose angular frequency equals the Bloch frequency ω$\text{}_{B}$. At bias voltages for which ω$\text{}_{B}$=nω$\text{}_{C}$ cos θ, where n is an integer, the electron orbits change from localised Bloch-like trajectories to unbounded stochastic orbits, which diffuse rapidly through intricate web patterns in phase space. To quantify how these webs affect electron transport, we make drift-diffusion calculations of the current-voltage curves including the effects of space-charge build up. When the magnetic field is tilted, our simulations reveal a large resonant peak, which originates from stochastic delocalisation of the electron orbits. We show that the corresponding quantised eigenstates change discontinuously from a highly localised character when the system is off resonance to a fully delocalised form when the resonance condition is satisfied.
Źródło:
Acta Physica Polonica A; 2006, 109, 1; 43-52
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-5 z 5

    Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies