TY  - JOUR
A1  - Pollatos, Olga
A1  - Yeldesbay, Azamat
A1  - Pikovskij, Arkadij
A1  - Rosenblum, Michael
T1  - How much time has passed? Ask your heart
JF  - Frontiers in neurorobotics
N2  - Internal signals like one's heartbeats are centrally processed via specific pathways and both their neural representations as well as their conscious perception (interoception) provide key information for many cognitive processes. Recent empirical findings propose that neural processes in the insular cortex, which are related to bodily signals, might constitute a neurophysiological mechanism for the encoding of duration. Nevertheless, the exact nature of such a proposed relationship remains unclear. We aimed to address this question by searching for the effects of cardiac rhythm on time perception by the use of a duration reproduction paradigm. Time intervals used were of 0.5, 2, 3, 7, 10, 14, 25, and 40s length. In a framework of synchronization hypothesis, measures of phase locking between the cardiac cycle and start/stop signals of the reproduction task were calculated to quantify this relationship. The main result is that marginally significant synchronization indices (Sls) between the heart cycle and the time reproduction responses for the time intervals of 2, 3, 10, 14, and 25s length were obtained, while results were not significant for durations of 0.5, 7, and 40s length. On the single participant level, several subjects exhibited some synchrony between the heart cycle and the time reproduction responses, most pronounced for the time interval of 25s (8 out of 23 participants for 20% quantile). Better time reproduction accuracy was not related with larger degree of phase locking, but with greater vagal control of the heart. A higher interoceptive sensitivity (IS) was associated with a higher synchronization index (SI) for the 2s time interval only. We conclude that information obtained from the cardiac cycle is relevant for the encoding and reproduction of time in the time span of 2-25s. Sympathovagal tone as well as interoceptive processes mediate the accuracy of time estimation.
KW  - time interval reproduction
KW  - synchronization
KW  - heart cycle
KW  - interoception
KW  - interoceptive sensitivity
Y1  - 2014
U6  - https://doi.org/10.3389/fnbot.2014.00015
SN  - 1662-5218
VL  - 8
SP  - 1
EP  - 9
PB  - Frontiers Research Foundation
CY  - Lausanne
ER  - 
TY  - JOUR
A1  - Mengel, Matthias
A1  - Levermann, Anders
T1  - Ice plug prevents irreversible discharge from East Antarctica
JF  - Nature climate change
N2  - Changes in ice discharge from Antarctica constitute the largest uncertainty in future sea-level projections, mainly because of the unknown response of its marine basins(1). Most of West Antarctica's marine ice sheet lies on an inland-sloping bed(2) and is thereby prone to a marine ice sheet instability(3-5). A similar topographic configuration is found in large parts of East Antarctica, which holds marine ice equivalent to 19 m of global sea-level rise(6), that is, more than five times that of West Antarctica. Within East Antarctica, the Wilkes Basin holds the largest volume of marine ice that is fully connected by subglacial troughs. This ice body was significantly reduced during the Pliocene epoch(7). Strong melting underneath adjacent ice shelves with similar bathymetry(8) indicates the ice sheet's sensitivity to climatic perturbations. The stability of the Wilkes marine ice sheet has not been the subject of any comprehensive assessment of future sea level. Using recently improved topographic data(6) in combination with ice-dynamic simulations, we show here that the removal of a specific coastal ice volume equivalent to less than 80 mm of global sea-level rise at the margin of the Wilkes Basin destabilizes the regional ice flow and leads to a self-sustained discharge of the entire basin and a global sea-level rise of 3-4 m. Our results are robust with respect to variation in ice parameters, forcing details and model resolution as well as increased surface mass balance, indicating that East Antarctica may become a large contributor to future sea-level rise on timescales beyond a century.
Y1  - 2014
U6  - https://doi.org/10.1038/NCLIMATE2226
SN  - 1758-678X
SN  - 1758-6798
VL  - 4
IS  - 6
SP  - 451
EP  - 455
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Shalom, Menny
A1  - Guttentag, Miguel
A1  - Fettkenhauer, Christian
A1  - Inal, Sahika
A1  - Neher, Dieter
A1  - Llobet, Antoni
A1  - Antonietti, Markus
T1  - In situ formation of heterojunctions in modified graphitic carbon nitride: synthesis and noble metal free photocatalysis
JF  - Chemistry of materials : a publication of the American Chemical Society
N2  - Herein, we report the facile synthesis of an efficient roll-like carbon nitride (C3N4) photocatalyst for hydrogen production using a supramolecular complex composed of cyanuric acid, melamine, and barbituric acid as the starting monomers. Optical and photocatalytic investigations show, along with the known red shift of absorption into the visible region, that the insertion of barbituric acid results in the in situ formation of in-plane heterojuctions, which enhance the charge separation process under illumination. Moreover, platinum as the standard cocatalyst in photocatalysis could be successfully replaced with first row transition metal salts and complexes under retention of 50% of the catalytic activity. Their mode of deposition and interaction with the semiconductor was studied in detail. Utilization of the supramolecular approach opens new opportunities to manipulate the charge transfer process within carbon nitride with respect to the design of a more efficient carbon nitride photocatalyst with controlled morphology and optical properties.
Y1  - 2014
U6  - https://doi.org/10.1021/cm503258z
SN  - 0897-4756
SN  - 1520-5002
VL  - 26
IS  - 19
SP  - 5812
EP  - 5818
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Saleem, H.
A1  - Thunga, M.
A1  - Kollosche, Matthias
A1  - Kessler, M. R.
A1  - Laflamme, S.
T1  - Interfacial treatment effects on behavior of soft nano-composites for highly stretchable dielectrics
JF  - Polymer : the international journal for the science and technology of polymers
N2  - We investigate the influence of interfacial treatment on the matrix filler interaction using a melt mixing process to fabricate robust and highly stretchable dielectrics. Silicone oil and silane coupling agent are studied as possible solutions to enhance the compatibility between the inorganic fillers and polymer matrix. Morphology, thermomechanical and dielectric behavior of the prepared specimens are studied. Results show that specimens filled with silicone oil coated particles have promising dielectric and thermal properties. The mechanical properties reveal a stiffness enhancement by 67% with a high strain at break of 900%. The relative permittivity of the specimens prepared with silicone oil increased by 45% as observed from the dielectric analysis. (C) 2014 Elsevier Ltd. All rights reserved.
KW  - Dielectric materials
KW  - Permittivity
KW  - Surface treatment
Y1  - 2014
U6  - https://doi.org/10.1016/j.polymer.2014.06.054
SN  - 0032-3861
SN  - 1873-2291
VL  - 55
IS  - 17
SP  - 4531
EP  - 4537
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Pradhan, Basudev
A1  - Albrecht, Steve
A1  - Stiller, Burkhard
A1  - Neher, Dieter
T1  - Inverted organic solar cells comprising low-temperature-processed ZnO films
JF  - Applied physics : A, Materials science & processing
N2  - Inverted organic solar cells are fabricated using low-temperature-annealed ZnO film as an electron transport layer. Uniform ZnO films were prepared by spin coating a diethylzinc (DEZ) precursor solution in air, followed by annealing at 100 A degrees C. Organic solar cells prepared on these ZnO films with a 1:1 P3HT:PCBM blend as the active layer show a high power conversion efficiency of 4.03 %, which is more than 10 % higher than the PCE of solar cells comprising ZnO prepared via a high-temperature sol-gel route.
Y1  - 2014
U6  - https://doi.org/10.1007/s00339-014-8373-8
SN  - 0947-8396
SN  - 1432-0630
VL  - 115
IS  - 2
SP  - 365
EP  - 369
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Arlen, T.
A1  - Aune, T.
A1  - Barnacka, Anna
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Bouvier, A.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cerruti, M.
A1  - Chen, X.
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dumm, J.
A1  - Eisch, J. D.
A1  - Falcone, A.
A1  - Federici, S.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hakansson, N.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Hughes, Z.
A1  - Humensky, T. B.
A1  - Johnson, C. A.
A1  - Kaaret, P.
A1  - Kar, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Madhavan, A. S.
A1  - Majumdar, P.
A1  - McArthur, S.
A1  - McCann, A.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nelson, T.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, M.
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Sadun, A.
A1  - Santander, M.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Sheidaei, F.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Theiling, M.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weekes, T. C.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Wilhelm, Alina
A1  - Williams, D. A.
A1  - Zitzer, B.
A1  - Boettcher, Markus
A1  - Fumagalli, M.
T1  - Investigating broadband variability of the TeV blazar 1ES 1959+650
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We summarize broadband observations of the TeV-emitting blazar 1ES 1959+650, including optical R-band observations by the robotic telescopes Super-LOTIS and iTelescope, UV observations by Swift Ultraviolet and Optical Telescope, X-ray observations by the Swift X-ray Telescope, high-energy gamma-ray observations with the Fermi Large Area Telescope, and very-high-energy (VHE) gamma-ray observations by VERITAS above 315 GeV, all taken between 2012 April 17 and 2012 June 1 (MJD 56034 and 56079). The contemporaneous variability of the broadband spectral energy distribution is explored in the context of a simple synchrotron self Compton (SSC) model. In the SSC emission scenario, we find that the parameters required to represent the high state are significantly different than those in the low state. Motivated by possible evidence of gas in the vicinity of the blazar, we also investigate a reflected emission model to describe the observed variability pattern. This model assumes that the non-thermal emission from the jet is reflected by a nearby cloud of gas, allowing the reflected emission to re-enter the blob and produce an elevated gamma-ray state with no simultaneous elevated synchrotron flux. The model applied here, although not required to explain the observed variability pattern, represents one possible scenario which can describe the observations. As applied to an elevated VHE state of 66% of the Crab Nebula flux, observed on a single night during the observation period, the reflected emission scenario does not support a purely leptonic non-thermal emission mechanism. The reflected emission model does, however, predict a reflected photon field with sufficient energy to enable elevated gamma-ray emission via pion production with protons of energies between 10 and 100 TeV.
KW  - BL Lacertae objects: individual (1ES 1959+650)
KW  - gamma rays: galaxies
Y1  - 2014
U6  - https://doi.org/10.1088/0004-637X/797/2/89
SN  - 0004-637X
SN  - 1538-4357
VL  - 797
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Aune, T.
A1  - Behera, B.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Cardenzana, J. V.
A1  - Cerruti, M.
A1  - Chen, Xuhui
A1  - Ciupik, L.
A1  - Collins-Hughes, E.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Dumm, J.
A1  - Dwarkadas, Vikram V.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, Simone
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fleischhack, H.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gall, D.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krennrich, F.
A1  - Kumar, S.
A1  - Lang, M. J.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - McCann, A. J.
A1  - Meagher, K.
A1  - Millis, J.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Pandel, D.
A1  - Park, N.
A1  - Pohl, Martin
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Ratliff, G.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rousselle, J.
A1  - Sembroski, G. H.
A1  - Shahinyan, K.
A1  - Sheidaei, F.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Telezhinsky, Igor O.
A1  - Tsurusaki, K.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vassiliev, V. V.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Ward, J. E.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Wilhelm, Alina
T1  - Investigating the TeV morpholoy of MGRO J1908+06 with veritas
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We report on deep observations of the extended TeV gamma-ray source MGRO J1908+06 made with the VERITAS very high energy gamma-ray observatory. Previously, the TeV emission has been attributed to the pulsar wind nebula (PWN) of the Fermi-LAT pulsar PSR J1907+0602. We detect MGRO J1908+06 at a significance level of 14 standard deviations (14 sigma) and measure a photon index of 2.20 +/- 0.10(stat) +/- 0.20(sys). The TeV emission is extended, covering the region near PSR J1907+0602 and also extending toward SNR G40.5-0.5. When fitted with a two-dimensional Gaussian, the intrinsic extension has a standard deviation of sigma(src) = 0 degrees.44 +/- 0 degrees.02. In contrast to other TeV PWNe of similar age in which the TeV spectrum softens with distance from the pulsar, the TeV spectrum measured near the pulsar location is consistent with that measured at a position near the rim of G40.5-0.5, 0 degrees.33 away.
KW  - gamma rays: general
KW  - gamma-ray burst: individual (MGRO J1908+06, VER J1907+062)
KW  - pulsars: individual (PSR J1907+0602)
KW  - ISM: supernova remnants
Y1  - 2014
U6  - https://doi.org/10.1088/0004-637X/787/2/166
SN  - 0004-637X
SN  - 1538-4357
VL  - 787
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - THES
A1  - Steyrleuthner, Robert
T1  - Korrelation von Struktur, optischen Eigenschaften und Ladungstransport in einem konjugierten Naphthalindiimid-Bithiophen Copolymer mit herausragender Elektronenmobilität
T1  - Correlation of structure, optical properties and charge transport in a conjugated naphtalendiimide-bithiophene copolymer with outstanding electron mobility
N2  - Organische Halbleiter besitzen neue, bemerkenswerte Materialeigenschaften, die sie für die grundlegende Forschung wie auch aktuelle technologische Entwicklung (bsw. org. Leuchtdioden, org. Solarzellen) interessant werden lassen. Aufgrund der starken konformative Freiheit der konjugierten Polymerketten führt die Vielzahl der möglichen Anordnungen und die schwache intermolekulare Wechselwirkung für gewöhnlich zu geringer struktureller Ordnung im Festkörper. Die Morphologie hat gleichzeitig direkten Einfluss auf die elektronische Struktur der organischen Halbleiter, welches sich meistens in einer deutlichen Reduktion der Ladungsträgerbeweglichkeit gegenüber den anorganischen Verwandten zeigt. So stellt die Beweglichkeit der Ladungen im Halbleiter einen der limitierenden Faktoren für die Leistungsfähigkeit bzw. den Wirkungsgrad von funktionellen organischen Bauteilen dar. Im Jahr 2009 wurde ein neues auf Naphthalindiimid und Bithiophen basierendes Dornor/Akzeptor Copolymer vorgestellt [P(NDI2OD‑T2)], welches sich durch seine außergewöhnlich hohe Ladungsträgermobilität auszeichnet. In dieser Arbeit wird die Ladungsträgermobilität in P(NDI2OD‑T2) bestimmt, und der Transport durch eine geringe energetischer Unordnung charakterisiert. Obwohl dieses Material zunächst als amorph beschrieben wurde zeigt eine detaillierte Analyse der optischen Eigenschaften von P(NDI2OD‑T2), dass bereits in Lösung geordnete Vorstufen supramolekularer Strukturen (Aggregate) existieren. Quantenchemische Berechnungen belegen die beobachteten spektralen Änderungen. Mithilfe der NMR-Spektroskopie kann die Bildung der Aggregate unabhängig von optischer Spektroskopie bestätigt werden. Die Analytische Ultrazentrifugation an P(NDI2OD‑T2) Lösungen legt nahe, dass sich die Aggregation innerhalb der einzelnen Ketten unter Reduktion des hydrodynamischen Radius vollzieht. Die Ausbildung supramolekularen Strukturen nimmt auch eine signifikante Rolle bei der Filmbildung ein und verhindert gleichzeitig die Herstellung amorpher P(NDI2OD‑T2) Filme. Durch chemische Modifikation der P(NDI2OD‑T2)-Kette und verschiedener Prozessierungs-Methoden wurde eine Änderung des Kristallinitätsgrades und gleichzeitig der Orientierung der kristallinen Domänen erreicht und mittels Röntgenbeugung quantifiziert. In hochauflösenden Elektronenmikroskopie-Messungen werden die Netzebenen und deren Einbettung in die semikristallinen Strukturen direkt abgebildet. Aus der Kombination der verschiedenen Methoden erschließt sich ein Gesamtbild der Nah- und Fernordnung in P(NDI2OD‑T2). Über die Messung der Elektronenmobilität dieser Schichten wird die Anisotropie des Ladungstransports in den kristallographischen Raumrichtungen von P(NDI2OD‑T2) charakterisiert und die Bedeutung der intramolekularen Wechselwirkung für effizienten Ladungstransport herausgearbeitet. Gleichzeitig wird deutlich, wie die Verwendung von größeren und planaren funktionellen Gruppen zu höheren Ladungsträgermobilitäten führt, welche im Vergleich zu klassischen semikristallinen Polymeren weniger sensitiv auf die strukturelle Unordnung im Film sind.
N2  - Organic semiconductors are in the focus of recent research and technological development (eg. for organic light-emitting diodes and solar cells) due to their specific and outstanding material properties. The strong conformational freedom of conjugated polymer chains usually leads to a large number of possible geometric arrangements while weak intermolecular interactions additionally lead to poor structural order in the solid state. At the same time the morphology of those systems has direct influence on the electronic structure of the organic semiconductor which is accompanied by a significant reduction of the charge carrier mobility in contrast to their inorganic counterparts. In that way the transport of charges within the semiconductor represents one of the main limiting factors regarding the performance and efficiency of functional organic devices. In 2009 Facchetti and coworkers presented a novel conjugated donor/acceptor copolymer based on naphthalene diimide and bithiophene [P(NDI2OD‑T2)] which was characterized by an outstanding charge carrier mobility. In this work the mobility of electrons and holes in the bulk of P(NDI2OD‑T2) is determined by single carrier devices and the time-of-flight technique. The results imply a low energetic disorder in these polymer layers. While the material was initially expected to be mainly amorphous, a detailed study of the photophysical properties of P(NDI2OD‑T2) shows that precursors of supramolecular assemblies (aggregates) are already formed in polymer solution. Quantum-chemical calculations support the occurring optical changes. NMR spectroscopy was applied to independently prove the formation of chain aggregates in commonly used organic solvents. The investigation of P(NDI2OD‑T2) solutions by analytical ultracentrifugation implies that aggregation mainly proceeds within single polymer chains by reduction of the hydrodynamic radius. To understand the influence of the chemical structure, pre-aggregation and crystal packing of conventional regioregular P(NDI2OD-T2) on the charge transport, the corresponding regioirregular polymer RI-P(NDI2OD-T2) was synthesized. By combining optical, X-ray, and transmission electron microscopy data, a quantitatively characterization of the aggregation, crystallization, and backbone orientation of all of the polymer films was possible, which was then correlated to the electron mobilities in electron-only diodes. The anisotropy of the charge transport along the different crystallographic directions is demonstrated and how the mobility depends on π-stacking but is insensitive to the degree or coherence of lamellar stacking. The comparison between the regioregular and regioirregular polymers also shows how the use of large planar functional groups leads to improved charge transport, with mobilities that are less affected by chemical and structural disorder with respect to classic semicrystalline polymers such as poly(3-hexylthiophene).
KW  - organische Halbleiter
KW  - Ladungstransport
KW  - Solarzellen
KW  - Polymere
KW  - Photophysik
KW  - organic semiconductor
KW  - charge transport
KW  - solar cells
KW  - polymers
KW  - photo physics
Y1  - 2014
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus-71413
ER  - 
TY  - JOUR
A1  - Palyulin, Vladimir V.
A1  - Chechkin, Aleksei V.
A1  - Metzler, Ralf
T1  - Levy flights do not always optimize random blind search for sparse targets
JF  - Proceedings of the National Academy of Sciences of the United States of America
N2  - It is generally believed that random search processes based on scale-free, Levy stable jump length distributions (Levy flights) optimize the search for sparse targets. Here we show that this popular search advantage is less universal than commonly assumed. We study the efficiency of a minimalist search model based on Levy flights in the absence and presence of an external drift (underwater current, atmospheric wind, a preference of the walker owing to prior experience, or a general bias in an abstract search space) based on two different optimization criteria with respect to minimal search time and search reliability (cumulative arrival probability). Although Levy flights turn out to be efficient search processes when the target is far from the starting point, or when relative to the starting point the target is upstream, we show that for close targets and for downstream target positioning regular Brownian motion turns out to be the advantageous search strategy. Contrary to claims that Levy flights with a critical exponent alpha = 1 are optimal for the search of sparse targets in different settings, based on our optimization parameters the optimal a may range in the entire interval (1, 2) and especially include Brownian motion as the overall most efficient search strategy.
KW  - search optimization
KW  - stochastic processes
KW  - Levy foraging hypothesis
Y1  - 2014
U6  - https://doi.org/10.1073/pnas.1320424111
SN  - 0027-8424
VL  - 111
IS  - 8
SP  - 2931
EP  - 2936
PB  - National Acad. of Sciences
CY  - Washington
ER  - 
TY  - JOUR
A1  - Goychuk, Igor
T1  - Life and death of stationary linear response in anomalous continuous time random walk dynamics
JF  - Communications in theoretical physics : a series journal of the Chinese Physical Society (A)
N2  - Linear theory of stationary response in systems at thermal equilibrium requires to find equilibrium correlation function of unperturbed responding system. Studies of the response of the systems exhibiting anomalously slow dynamics are often based on the continuous time random walk description (CTRW) with divergent mean waiting times. The bulk of the literature on anomalous response contains linear response functions like one by Cole-Cole calculated from such a CTRW theory and applied to systems at thermal equilibrium. Here we show within a fairly simple and general model that for the systems with divergent mean waiting times the stationary response at thermal equilibrium is absent, in accordance with some recent studies. The absence of such stationary response (or dying to zero non-stationary response in aging experiments) would confirm CTRW with divergent mean waiting times as underlying physical relaxation mechanism, but reject it otherwise. We show that the absence of stationary response is closely related to the breaking of ergodicity of the corresponding dynamical variable. As an important new result, we derive a generalized Cole-Cole response within ergodic CTRW dynamics with finite waiting time. Moreover, we provide a physically reasonable explanation of the origin and wide presence of 1/f noise in condensed matter for ergodic dynamics close to normal, rather than strongly deviating.
KW  - random walks
KW  - anomalous response and relaxation
KW  - stationarity
KW  - aging
KW  - 1/f noise
Y1  - 2014
SN  - 0253-6102
SN  - 1572-9494
VL  - 62
IS  - 4
SP  - 497
EP  - 504
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Xu, Jingsan
A1  - Brenner, Thomas J. K.
A1  - Chabanne, Laurent
A1  - Neher, Dieter
A1  - Antonietti, Markus
A1  - Shalom, Menny
T1  - Liquid-Based growth of polymeric carbon nitride layers and their use in a mesostructured polymer solar cell with V-oc exceeding 1 V
JF  - Journal of the American Chemical Society
N2  - Herein we report a general liquid-mediated pathway for the growth of continuous polymeric carbon nitride (C3N4) thin films. The deposition method consists of the use of supramolecular complexes that transform to the liquid state before direct thermal condensation into C3N4 solid films. The resulting films exhibit continuous porous C3N4 networks on various substrates. Moreover, the optical absorption can be easily tuned to cover the solar spectrum by the insertion of an additional molecule into the starting complex. The strength of the deposition method is demonstrated by the use of the C3N4 layer as the electron acceptor in a polymer solar cell that exhibits a remarkable open-circuit voltage exceeding 1 V. The easy, safe, and direct synthesis of carbon nitride in a continuous layered architecture on different functional substrates opens new possibilities for the fabrication of many energy-related devices.
Y1  - 2014
U6  - https://doi.org/10.1021/ja508329c
SN  - 0002-7863
VL  - 136
IS  - 39
SP  - 13486
EP  - 13489
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Godec, Aljaz
A1  - Chechkin, Aleksei V.
A1  - Barkai, Eli
A1  - Kantz, Holger
A1  - Metzler, Ralf
T1  - Localisation and universal fluctuations in ultraslow diffusion processes
JF  - Journal of physics : A, Mathematical and theoretical
N2  - We study ultraslow diffusion processes with logarithmic mean squared displacement (MSD) < x(2)(t)> similar or equal to log(gamma)t. Comparison of annealed (renewal) continuous time random walks (CTRWs) with logarithmic waiting time distribution psi(tau) similar or equal to 1/(tau log(1+gamma)tau) and Sinai diffusion in quenched random landscapes reveals striking similarities, despite the great differences in their physical nature. In particular, they exhibit a weakly non-ergodic disparity of the time-averaged and ensemble-averaged MSDs. Remarkably, for the CTRW we observe that the fluctuations of time averages become universal, with an exponential suppression of mobile trajectories. We discuss the fundamental connection between the Golosov localization effect and non-ergodicity in the sense of the disparity between ensemble-averaged MSD and time-averaged MSD.
KW  - Sinai diffusion
KW  - anomalous diffusion
KW  - quenched energy landscape
Y1  - 2014
U6  - https://doi.org/10.1088/1751-8113/47/49/492002
SN  - 1751-8113
SN  - 1751-8121
VL  - 47
IS  - 49
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Schick, Daniel
A1  - Herzog, Marc
A1  - Wen, Haidan
A1  - Chen, Pice
A1  - Adamo, Carolina
A1  - Gaal, Peter
A1  - Schlom, Darrell G.
A1  - Evans, Paul G.
A1  - Li, Yuelin
A1  - Bargheer, Matias
T1  - Localized excited charge carriers generate ultrafast inhomogeneous strain in the multiferroic BiFeO3
JF  - Physical review letters
N2  - We apply ultrafast x-ray diffraction with femtosecond temporal resolution to monitor the lattice dynamics in a thin film of multiferroic BiFeO3 after above-band-gap photoexcitation. The sound-velocity limited evolution of the observed lattice strains indicates a quasi-instantaneous photoinduced stress which decays on a nanosecond time scale. This stress exhibits an inhomogeneous spatial profile evidenced by the broadening of the Bragg peak. These new data require substantial modification of existing models of photogenerated stresses in BiFeO3: the relevant excited charge carriers must remain localized to be consistent with the data.
Y1  - 2014
U6  - https://doi.org/10.1103/PhysRevLett.112.097602
SN  - 0031-9007
SN  - 1079-7114
VL  - 112
IS  - 9
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Abramowski, Attila
A1  - Aharonian, Felix A.
A1  - Benkhali, Faical  Ait
A1  - Akhperjanian, A. G.
A1  - Angüner, Ekrem Oǧuzhan
A1  - Backes, Michael
A1  - Balenderan, Shangkari
A1  - Balzer, Arnim
A1  - Barnacka, Anna
A1  - Becherini, Yvonne
A1  - Tjus, J. Becker
A1  - Berge, David
A1  - Bernhard, Sabrina
A1  - Bernlöhr, K.
A1  - Birsin, E.
A1  - Biteau, Jonathan
A1  - Böttcher, Markus
A1  - Boisson, Catherine
A1  - Bolmont, J.
A1  - Bordas, Pol
A1  - Bregeon, Johan
A1  - Brun, Francois
A1  - Brun, Pierre
A1  - Bryan, Mark
A1  - Bulik, Tomasz
A1  - Carrigan, Svenja
A1  - Casanova, Sabrina
A1  - Chadwick, Paula M.
A1  - Chakraborty, N.
A1  - Chalme-Calvet, R.
A1  - Chaves, Ryan C. G.
A1  - Chretien, M.
A1  - Colafrancesco, Sergio
A1  - Cologna, Gabriele
A1  - Conrad, Jan
A1  - Couturier, C.
A1  - Cui, Y.
A1  - Dalton, M.
A1  - Davids, I. D.
A1  - Degrange, B.
A1  - Deil, C.
A1  - dewilt, P.
A1  - Djannati-Ataï, A.
A1  - Domainko, W.
A1  - Donath, A.
A1  - Dubus, G.
A1  - Dutson, K.
A1  - Dyks, J.
A1  - Dyrda, M.
A1  - Edwards, T.
A1  - Egberts, Kathrin
A1  - Eger, P.
A1  - Espigat, P.
A1  - Farnier, C.
A1  - Fegan, S.
A1  - Feinstein, F.
A1  - Fernandes, M. V.
A1  - Fernandez, D.
A1  - Fiasson, A.
A1  - Fontaine, G.
A1  - Forster, A.
A1  - Fuling, M.
A1  - Gabici, S.
A1  - Gajdus, M.
A1  - Gallant, Y. A.
A1  - Garrigoux, T.
A1  - Giavitto, G.
A1  - Giebels, B.
A1  - Glicenstein, J. F.
A1  - Gottschall, D.
A1  - Grondin, M. -H.
A1  - Grudzinska, M.
A1  - Hadsch, D.
A1  - Haeffner, S.
A1  - Hahn, J.
A1  - Harris, J.
A1  - Heinzelmann, G.
A1  - Henri, G.
A1  - Hermann, G.
A1  - Hervet, O.
A1  - Hillert, A.
A1  - Hinton, James Anthony
A1  - Hofmann, W.
A1  - Hofverberg, P.
A1  - Holler, Markus
A1  - Horns, D.
A1  - Ivascenko, A.
A1  - Jacholkowska, A.
A1  - Jahn, C.
A1  - Jamrozy, M.
A1  - Janiak, M.
A1  - Jankowsky, F.
A1  - Jung, I.
A1  - Kastendieck, M. A.
A1  - Katarzynski, K.
A1  - Katz, U.
A1  - Kaufmann, S.
A1  - Khelifi, B.
A1  - Kiefeer, M.
A1  - Klepser, S.
A1  - Klochkov, D.
A1  - Kluzniak, W.
A1  - Kolitzus, D.
A1  - Komin, Nu.
A1  - Kosack, K.
A1  - Krakau, S.
A1  - Krayzel, F.
A1  - Kruger, P. P.
A1  - Laffon, H.
A1  - Lamanna, G.
A1  - Lefaucheur, J.
A1  - Lefranc, V.
A1  - Lemiere, A.
A1  - Lemoine-Goumard, M.
A1  - Lenain, J. -P.
A1  - Lohse, T.
A1  - Lopatin, A.
A1  - Lu, C. -C.
A1  - Marandon, V.
A1  - Marcowith, Alexandre
A1  - Marx, R.
A1  - Maurin, G.
A1  - Maxted, N.
A1  - Mayer, M.
A1  - McComb, T. J. L.
A1  - Mehault, J.
A1  - Meintjes, P. J.
A1  - Menzler, U.
A1  - Meyer, M.
A1  - Mitchell, A. M. W.
A1  - Moderski, R.
A1  - Mohamed, M.
A1  - Mora, K.
A1  - Moulin, Emmanuel
A1  - Murach, T.
A1  - de Naurois, M.
A1  - Niemiec, J.
A1  - Nolan, S. J.
A1  - Oakes, L.
A1  - Odaka, H.
A1  - Ohm, S.
A1  - Opitz, B.
A1  - Ostrowski, M.
A1  - Oya, I.
A1  - Panter, M.
A1  - Parsons, R. D.
A1  - Arribas, M. Paz
A1  - Pekeur, N. W.
A1  - Pelletier, G.
A1  - Perez, J.
A1  - Petrucci, P. -O.
A1  - Peyaud, B.
A1  - Pita, S.
A1  - Poon, H.
A1  - Puhlhofer, G.
A1  - Punch, M.
A1  - Quirrenbach, A.
A1  - Raab, S.
A1  - Reichardt, I.
A1  - Reimer, A.
A1  - Reimer, O.
A1  - Renaud, M.
A1  - de los Reyes, R.
A1  - Rieger, F.
A1  - Rob, L.
A1  - Romoli, C.
A1  - Rosier-Lees, S.
A1  - Rowell, G.
A1  - Rudak, B.
A1  - Rulten, C. B.
A1  - Sahakian, V.
A1  - Salek, D.
A1  - Sanchez, David M.
A1  - Santangelo, Andrea
A1  - Schlickeiser, R.
A1  - Schussler, F.
A1  - Schulz, A.
A1  - Schwanke, U.
A1  - Schwarzburg, S.
A1  - Schwemmer, S.
A1  - Sol, H.
A1  - Spanier, F.
A1  - Spengler, G.
A1  - Spies, F.
A1  - Stawarz, L.
A1  - Steenkamp, R.
A1  - Stegmann, Christian
A1  - Stinzing, F.
A1  - Stycz, K.
A1  - Sushch, Iurii
A1  - Tavernet, J. -P.
A1  - Tavernier, T.
A1  - Taylor, A. M.
A1  - Terrier, R.
A1  - Tluczykont, M.
A1  - Trichard, C.
A1  - Valerius, K.
A1  - Van Eldik, C.
A1  - Van Soelen, B.
A1  - Vasileiadis, G.
A1  - Veh, J.
A1  - Venter, C.
A1  - Viana, A.
A1  - Vincent, P.
A1  - Vink, J.
A1  - Volk, H. J.
A1  - Volpe, F.
A1  - Vorster, M.
A1  - Vuillaume, T.
A1  - Wagner, S. J.
A1  - Wagner, P.
A1  - Wagner, R. M.
A1  - Ward, M.
A1  - Weidinger, M.
A1  - Weitzel, Q.
A1  - White, R.
A1  - Wierzcholska, A.
A1  - Willmann, P.
A1  - Wornlein, A.
A1  - Wouters, D.
A1  - Yang, R.
A1  - Zabalza, V.
A1  - Zaborov, D.
A1  - Zacharias, M.
A1  - Zdziarski, A. A.
A1  - Zech, Alraune
A1  - Zechlin, H. -S.
T1  - Long-term monitoring of PKS2155-304 with ATOM and HESS:investigation of optical/gamma-ray correlations in different spectral states
JF  - Astronomy and astrophysics : an international weekly journal
N2  - In this paper we report on the analysis of all the available optical and very high-energy gamma-ray (> 200 GeV) data for the BL Lac object PKS 2155-304, collected simultaneously with the ATOM and H.E.S.S. telescopes from 2007 until 2009. This study also includes X-ray (RXTE, Swift) and high-energy gamma-ray (Fermi-LAT) data. During the period analysed, the source was transitioning from its flaring to quiescent optical states, and was characterized by only moderate flux changes at different wavelengths on the timescales of days and months. A flattening of the optical continuum with an increasing optical flux can be noted in the collected dataset, but only occasionally and only at higher flux levels. We did not find any universal relation between the very high-energy gamma-ray and optical flux changes on the timescales from days and weeks up to several years. On the other hand, we noted that at higher flux levels the source can follow two distinct tracks in the optical flux-colour diagrams, which seem to be related to distinct gamma-ray states of the blazar. The obtained results therefore indicate a complex scaling between the optical and gamma-ray emission of PKS 2155 304, with different correlation patterns holding at different epochs, and a gamma-ray flux depending on the combination of an optical flux and colour rather than a flux alone.
KW  - radiation mechanisms: non-thermal
KW  - galaxies: active
KW  - black hole physics
KW  - BL Lacertae objects: individual: PKS 2155-304
KW  - galaxies: jets
KW  - gamma rays: galaxies
Y1  - 2014
U6  - https://doi.org/10.1051/0004-6361/201424142
SN  - 0004-6361
SN  - 1432-0746
VL  - 571
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Aliu, E.
A1  - Archambault, S.
A1  - Aune, T.
A1  - Behera, B.
A1  - Beilicke, M.
A1  - Benbow, W.
A1  - Berger, K.
A1  - Bird, R.
A1  - Bouvier, A.
A1  - Buckley, J. H.
A1  - Bugaev, V.
A1  - Byrum, K.
A1  - Cerruti, M.
A1  - Chen, X.
A1  - Ciupik, L.
A1  - Connolly, M. P.
A1  - Cui, W.
A1  - Duke, C.
A1  - Dumm, J.
A1  - Errando, M.
A1  - Falcone, A.
A1  - Federici, S.
A1  - Feng, Q.
A1  - Finley, J. P.
A1  - Fortin, P.
A1  - Fortson, L.
A1  - Furniss, A.
A1  - Galante, N.
A1  - Gillanders, G. H.
A1  - Griffin, S.
A1  - Griffiths, S. T.
A1  - Grube, J.
A1  - Gyuk, G.
A1  - Hanna, D.
A1  - Holder, J.
A1  - Hughes, G.
A1  - Humensky, T. B.
A1  - Kaaret, P.
A1  - Kertzman, M.
A1  - Khassen, Y.
A1  - Kieda, D.
A1  - Krawczynski, H.
A1  - Krennrich, F.
A1  - Lang, M. J.
A1  - Madhavan, A. S.
A1  - Maier, G.
A1  - Majumdar, P.
A1  - McCann, A.
A1  - Moriarty, P.
A1  - Mukherjee, R.
A1  - Nieto, D.
A1  - Ong, R. A.
A1  - Otte, A. N.
A1  - Park, N.
A1  - Perkins, J. S.
A1  - Pohl, M.
A1  - Popkow, A.
A1  - Prokoph, H.
A1  - Quinn, J.
A1  - Ragan, K.
A1  - Rajotte, J.
A1  - Reyes, L. C.
A1  - Reynolds, P. T.
A1  - Richards, G. T.
A1  - Roache, E.
A1  - Rousselle, J.
A1  - Sembroski, G. H.
A1  - Sheidaei, F.
A1  - Skole, C.
A1  - Smith, A. W.
A1  - Staszak, D.
A1  - Stroh, M.
A1  - Telezhinsky, Igor O.
A1  - Theiling, M.
A1  - Tucci, J. V.
A1  - Tyler, J.
A1  - Varlotta, A.
A1  - Vincent, S.
A1  - Wakely, S. P.
A1  - Weinstein, A.
A1  - Welsing, R.
A1  - Williams, D. A.
A1  - Zajczyk, A.
A1  - Zitzer, B.
A1  - Abramowski, Attila
A1  - Aharonian, Felix A.
A1  - Benkhali, Faical  Ait
A1  - Akhperjanian, A. G.
A1  - Angüner, Ekrem Oǧuzhan
A1  - Anton, Gisela
A1  - Balenderan, Shangkari
A1  - Balzer, Arnim
A1  - Barnacka, Anna
A1  - Becherini, Yvonne
A1  - Tjus, J. Becker
A1  - Bernlöhr, K.
A1  - Birsin, E.
A1  - Bissaldi, E.
A1  - Biteau, Jonathan
A1  - Boettcher, Markus
A1  - Boisson, Catherine
A1  - Bolmont, J.
A1  - Bordas, Pol
A1  - Brucker, J.
A1  - Brun, Francois
A1  - Brun, Pierre
A1  - Bulik, Tomasz
A1  - Carrigan, Svenja
A1  - Casanova, Sabrina
A1  - Cerruti, M.
A1  - Chadwick, Paula M.
A1  - Chalme-Calvet, R.
A1  - Chaves, Ryan C. G.
A1  - Cheesebrough, A.
A1  - Chretien, M.
A1  - Colafrancesco, Sergio
A1  - Cologna, Gabriele
A1  - Conrad, Jan
A1  - Couturier, C.
A1  - Dalton, M.
A1  - Daniel, M. K.
A1  - Davids, I. D.
A1  - Degrange, B.
A1  - Deil, C.
A1  - deWilt, P.
A1  - Dickinson, H. J.
A1  - Djannati-Ataï, A.
A1  - Domainko, W.
A1  - Dubus, G.
A1  - Dutson, K.
A1  - Dyks, J.
A1  - Dyrda, M.
A1  - Edwards, T.
A1  - Egberts, Kathrin
A1  - Eger, P.
A1  - Espigat, P.
A1  - Farnier, C.
A1  - Fegan, S.
A1  - Feinstein, F.
A1  - Fernandes, M. V.
A1  - Fernandez, D.
A1  - Fiasson, A.
A1  - Fontaine, G.
A1  - Foerster, A.
A1  - Fuessling, M.
A1  - Gajdus, M.
A1  - Gallant, Y. A.
A1  - Garrigoux, T.
A1  - Giavitto, G.
A1  - Giebels, B.
A1  - Glicenstein, J. F.
A1  - Grondin, M. -H.
A1  - Grudzinska, M.
A1  - Haeffner, S.
A1  - Hahn, J.
A1  - Harris, J.
A1  - Heinzelmann, G.
A1  - Henri, G.
A1  - Hermann, G.
A1  - Hervet, O.
A1  - Hillert, A.
A1  - Hinton, James Anthony
A1  - Hofmann, W.
A1  - Hofverberg, P.
A1  - Holler, M.
A1  - Horns, D.
A1  - Jacholkowska, A.
A1  - Jahn, C.
A1  - Jamrozy, M.
A1  - Janiak, M.
A1  - Jankowsky, F.
A1  - Jung, I.
A1  - Kastendieck, M. A.
A1  - Katarzynski, K.
A1  - Katz, U.
A1  - Kaufmann, S.
A1  - Khelifi, B.
A1  - Kieffer, M.
A1  - Klepser, S.
A1  - Klochkov, D.
A1  - Kluzniak, W.
A1  - Kneiske, T.
A1  - Kolitzus, D.
A1  - Komin, Nu.
A1  - Kosack, K.
A1  - Krakau, S.
A1  - Krayzel, F.
A1  - Krueger, P. P.
A1  - Laffon, H.
A1  - Lamanna, G.
A1  - Lefaucheur, J.
A1  - Lemiere, A.
A1  - Lemoine-Goumard, M.
A1  - Lenain, J. -P.
A1  - Lennarz, D.
A1  - Lohse, T.
A1  - Lopatin, A.
A1  - Lu, C. -C.
A1  - Marandon, V.
A1  - Marcowith, Alexandre
A1  - Marx, R.
A1  - Maurin, G.
A1  - Maxted, N.
A1  - Mayer, M.
A1  - McComb, T. J. L.
A1  - Mehault, J.
A1  - Menzler, U.
A1  - Meyer, M.
A1  - Moderski, R.
A1  - Mohamed, M.
A1  - Moulin, Emmanuel
A1  - Murach, T.
A1  - Naumann, C. L.
A1  - de Naurois, M.
A1  - Niemiec, J.
A1  - Nolan, S. J.
A1  - Oakes, L.
A1  - Ohm, S.
A1  - Wilhelmi, E. de Ona
A1  - Opitz, B.
A1  - Ostrowski, M.
A1  - Oya, I.
A1  - Panter, M.
A1  - Parsons, R. D.
A1  - Arribas, M. Paz
A1  - Pekeur, N. W.
A1  - Pelletier, G.
A1  - Perez, J.
A1  - Petrucci, P. -O.
A1  - Peyaud, B.
A1  - Pita, S.
A1  - Poon, H.
A1  - Puehlhofer, G.
A1  - Punch, M.
A1  - Quirrenbach, A.
A1  - Raab, S.
A1  - Raue, M.
A1  - Reimer, A.
A1  - Reimer, O.
A1  - Renaud, M.
A1  - de los Reyes, R.
A1  - Rieger, F.
A1  - Rob, L.
A1  - Romoli, C.
A1  - Rosier-Lees, S.
A1  - Rowell, G.
A1  - Rudak, B.
A1  - Rulten, C. B.
A1  - Sahakian, V.
A1  - Sanchez, David M.
A1  - Santangelo, Andrea
A1  - Schlickeiser, R.
A1  - Schuessler, F.
A1  - Schulz, A.
A1  - Schwanke, U.
A1  - Schwarzburg, S.
A1  - Schwemmer, S.
A1  - Sol, H.
A1  - Spengler, G.
A1  - Spies, F.
A1  - Stawarz, L.
A1  - Steenkamp, R.
A1  - Stegmann, Christian
A1  - Stinzing, F.
A1  - Stycz, K.
A1  - Sushch, Iurii
A1  - Szostek, A.
A1  - Tavernet, J. -P.
A1  - Tavernier, T.
A1  - Taylor, A. M.
A1  - Terrier, R.
A1  - Tluczykont, M.
A1  - Trichard, C.
A1  - Valerius, K.
A1  - van Eldik, C.
A1  - Vasileiadis, G.
A1  - Venter, C.
A1  - Viana, A.
A1  - Vincent, P.
A1  - Voelk, H. J.
A1  - Volpe, F.
A1  - Vorster, M.
A1  - Wagner, S. J.
A1  - Wagner, P.
A1  - Ward, M.
A1  - Weidinger, M.
A1  - Weitzel, Q.
A1  - White, R.
A1  - Wierzcholska, A.
A1  - Willmann, P.
A1  - Woernlein, A.
A1  - Wouters, D.
A1  - Zacharias, M.
A1  - Zajczyk, A.
A1  - Zdziarski, A. A.
A1  - Zech, Alraune
A1  - Zechlin, H. -S.
T1  - Long-term TeV and X-RAY observations of the GAMMA- RAY binary hess J0632+057
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
KW  - acceleration of particles
KW  - binaries: general
KW  - gamma rays: general(HESS J0632+057, VER J0633+057)
Y1  - 2014
U6  - https://doi.org/10.1088/0004-637X/780/2/168
SN  - 0004-637X
SN  - 1538-4357
VL  - 780
IS  - 2
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Marzeion, Ben
A1  - Levermann, Anders
T1  - Loss of cultural world heritage and currently inhabited places to sea-level rise
JF  - Environmental research letters
KW  - sea-level rise
KW  - cultural heritage
KW  - chlimate impacts
Y1  - 2014
U6  - https://doi.org/10.1088/1748-9326/9/3/034001
SN  - 1748-9326
VL  - 9
IS  - 3
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Zhang, Xiaoqing
A1  - Zhang, Xinwu
A1  - You, Qiong
A1  - Sessler, Gerhard M.
T1  - Low- cost, large- area, stretchable  piezoelectric films based on irradiation- crosslinked poly ( propylene)
JF  - Macromolecular materials and engineering
N2  - Low cost, large area, lightweight, stretchable piezoelectric films, based on space-charge electret with a foam structure (i.e., ferroelectrets or piezoelectrets), have been fabricated by using commercially available irradiation cross-linked poly(propylene) (IXPP) foam sheets. Piezoelectric d(33) coefficients are as high as 100pCN(-1). The piezoelectric performance in such IXPP films is well preserved for repeated strains of less than 10%. Piezoelectric d(33) coefficients are frequency independent in the range from 2 to 100Hz. Such new class materials may be applied in sensory skins, smart clothing, bio-inspired systems, microenergy harvesters, and so on.
KW  - crosslinked poly(propylene)
KW  - ferroelectret
KW  - piezoelectricity
KW  - stretchability
Y1  - 2014
U6  - https://doi.org/10.1002/mame.201300161
SN  - 1438-7492
SN  - 1439-2054
VL  - 299
IS  - 3
SP  - 290
EP  - 295
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Nishikawa, Ken-Ichi
A1  - Hardee, P. E.
A1  - Dutan, I.
A1  - Niemiec, J.
A1  - Medvedev, M.
A1  - Mizuno, Y.
A1  - Meli, A.
A1  - Sol, H.
A1  - Zhang, B.
A1  - Pohl, Martin
A1  - Hartmann, D. H.
T1  - Magnetic agnetic field generation in core-sheath jets via the kinetic Kelvin-Helmholtz instability
JF  - The astrophysical journal : an international review of spectroscopy and astronomical physics
N2  - We have investigated magnetic field generation in velocity shears via the kinetic Kelvin-Helmholtz instability (kKHI) using a relativistic plasma jet core and stationary plasma sheath. Our three-dimensional particle-in-cell simulations consider plasma jet cores with Lorentz factors of 1.5, 5, and 15 for both electron-proton and electron-positron plasmas. For electron-proton plasmas, we find generation of strong large-scale DC currents and magnetic fields that extend over the entire shear surface and reach thicknesses of a few tens of electron skin depths. For electron-positron plasmas, we find generation of alternating currents and magnetic fields. Jet and sheath plasmas are accelerated across the shear surface in the strong magnetic fields generated by the kKHI. The mixing of jet and sheath plasmas generates a transverse structure similar to that produced by the Weibel instability.
KW  - acceleration of particles
KW  - magnetic fields
KW  - plasmas
KW  - radiation mechanisms: non-thermal
KW  - relativistic processes
KW  - stars: jets
Y1  - 2014
U6  - https://doi.org/10.1088/0004-637X/793/1/60
SN  - 0004-637X
SN  - 1538-4357
VL  - 793
IS  - 1
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Chen, Xuhui
A1  - Chatterjee, Ritaban
A1  - Zhang, Haocheng
A1  - Pohl, Martin
A1  - Fossati, Giovanni
A1  - Boettcher, Markus
A1  - Bailyn, Charles D.
A1  - Bonning, Erin W.
A1  - Buxton, Michelle
A1  - Coppi, Paolo
A1  - Isler, Jedidah
A1  - Maraschi, Laura
A1  - Urry, Meg
T1  - Magnetic field amplification and flat spectrum radio quasars
JF  - Monthly notices of the Royal Astronomical Society
N2  - We perform time-dependent, spatially resolved simulations of blazar emission to evaluate several flaring scenarios related to magnetic-field amplification and enhanced particle acceleration. The code explicitly accounts for light-travel-time effects and is applied to flares observed in the flat spectrum radio quasar (FSRQ) PKS 0208-512, which show optical/gamma-ray correlation at some times, but orphan optical flares at other times. Changes in both the magnetic field and the particle acceleration efficiency are explored as causes of flares. Generally, external Compton (EC) emission appears to describe the available data better than a synchrotron self-Compton (SSC) scenario, and in particular orphan optical flares are difficult to produce in the SSC framework. X-ray soft-excesses, gamma-ray spectral hardening, and the detections at very high energies of certain FSRQs during flares find natural explanations in the EC scenario with particle acceleration change. Likewise, optical flares with/without gamma-ray counterparts can be explained by different allocations of energy between the magnetization and particle acceleration, which may be related to the orientation of the magnetic field relative to the jet flow. We also calculate the degree of linear polarization and polarization angle as a function of time for a jet with helical magnetic field. Tightening of the magnetic helix immediately downstream of the jet perturbations, where flares occur, can be sufficient to explain the increases in the degree of polarization and a rotation by a parts per thousand yen180A degrees of the observed polarization angle, if light-travel-time effects are properly considered.
KW  - radiation mechanisms: non-thermal
KW  - galaxies: active
KW  - galaxies: jets
KW  - quasars: individual: PKS 0208-512
Y1  - 2014
U6  - https://doi.org/10.1093/mnras/stu713
SN  - 0035-8711
SN  - 1365-2966
VL  - 441
IS  - 3
SP  - 2188
EP  - 2199
PB  - Oxford Univ. Press
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Mizuno, Yosuke
A1  - Pohl, Martin
A1  - Niemiec, Jacek
A1  - Zhang, Bing
A1  - Nishikawa, Ken-Ichi
A1  - Hardee, Philip E.
T1  - Magnetic field amplification and saturation in turbulence behind a relativistic shock
JF  - Monthly notices of the Royal Astronomical Society
N2  - We have investigated via 2D relativistic magnetohydrodynamic simulations the long-term evolution of turbulence created by a relativistic shock propagating through an inhomogeneous medium. In the post-shock region, magnetic field is strongly amplified by turbulent motions triggered by pre-shock density inhomogeneities. Using a long-simulation box we have followed the magnetic field amplification until it is fully developed and saturated. The turbulent velocity is subrelativistic even for a strong shock. Magnetic field amplification is controlled by the turbulent motion and saturation occurs when the magnetic energy is comparable to the turbulent kinetic energy. Magnetic field amplification and saturation depend on the initial strength and direction of the magnetic field in the pre-shock medium, and on the shock strength. If the initial magnetic field is perpendicular to the shock normal, the magnetic field is first compressed at the shock and then can be amplified by turbulent motion in the post-shock region. Saturation occurs when the magnetic energy becomes comparable to the turbulent kinetic energy in the post-shock region. If the initial magnetic field in the pre-shock medium is strong, the post-shock region becomes turbulent but significant field amplification does not occur. If the magnetic energy after shock compression is larger than the turbulent kinetic energy in the post-shock region, significant field amplification does not occur. We discuss possible applications of our results to gamma-ray bursts and active galactic nuclei.
KW  - MHD
KW  - relativistic processes
KW  - shock waves
KW  - turbulence
KW  - methods: numerical
KW  - gamma-ray burst: general
Y1  - 2014
U6  - https://doi.org/10.1093/mnras/stu196
SN  - 0035-8711
SN  - 1365-2966
VL  - 439
IS  - 4
SP  - 3490
EP  - 3503
PB  - Oxford Univ. Press
CY  - Oxford
ER  -