TY  - JOUR
A1  - Lorenz, Bernd
A1  - Spatz, J. P.
A1  - Hochheimer, H. D.
A1  - Menon, V.
A1  - Parthasarathy, R.
A1  - Martin, C. R.
A1  - Bechthold, Jeff
A1  - Hor, P.-H.
T1  - Dimensional crossover of the temperature dependence of the electrical conductivity of template synthesized polyaniline and polypyrrole
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Lorenz, Bernd
A1  - Tozer, S. W.
A1  - Hochheimer, H. D.
A1  - Menon, V.
A1  - Parthasarathy, R.
A1  - Martin, C. R.
T1  - Magnetoresistance of conducting polymers
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Lorenz, Bernd
A1  - Spatz, J. P.
A1  - Weishaupt, K.
A1  - Hochheimer, H. D.
A1  - Menon, V.
A1  - Parthasarathy, R.
A1  - Martin, C. R.
A1  - Bechthold, Jeff
A1  - Hor, P.-H.
T1  - Observation of crossover from three to two dimensional variable range hopping in template synthesized polypyrrole and polyaniline
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Werner, Klaus
A1  - Barstow, Martin A.
A1  - Holberg, J. B.
A1  - Koester, D.
A1  - Nousek, J. A.
T1  - Extreme ultraviolet spectroscopy of white dwarfs
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Beeger, Helmut
A1  - Bricks, Wolfgang
A1  - Broscheit, Frank
A1  - Bütow, Heike
A1  - Bütow, Martin
A1  - Englert, Wolfgang
A1  - Gehrke, Albrecht
A1  - Hallermann, Sigrun
A1  - Jahn, Gert
A1  - Kirsch, H.
A1  - Klohn, Werner
A1  - Markert, Wolfgang
A1  - Meißgeier, Jürgen
A1  - Mülders, Wolfgang
A1  - Nicklaus, W.
A1  - Reinhardt, Karl Heinz
A1  - Robel, B.
A1  - Schmidtke, Kurt-Dietmar
A1  - Werner-Tokarski, D.
T1  - Seydlitz Erdkunde 3 : Ausgabe Saarland
Y1  - 1996
PB  - Schroedel
CY  - Hannover
ER  - 
TY  - JOUR
A1  - Laucht, Manfred
A1  - Esser, Günter
A1  - Schmidt, Martin H.
A1  - Stöhr, R.-M.
A1  - Weindrich, D.
A1  - Ihle, Wolfgang
A1  - Marcus, A.
T1  - Viereinhalb Jahre danach : Mannheimer Risikokinder im Vorschulalter
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Reichstein, Markus
A1  - Bahn, Michael
A1  - Ciais, Philippe
A1  - Frank, Dorothea
A1  - Mahecha, Miguel D.
A1  - Seneviratne, Sonia I.
A1  - Zscheischler, Jakob
A1  - Beer, Christian
A1  - Buchmann, Nina
A1  - Frank, David C.
A1  - Papale, Dario
A1  - Rammig, Anja
A1  - Smith, Pete
A1  - Thonicke, Kirsten
A1  - van der Velde, Marijn
A1  - Vicca, Sara
A1  - Walz, Ariane
A1  - Wattenbach, Martin
T1  - Climate extremes and the carbon cycle
JF  - Nature : the international weekly journal of science
N2  - The terrestrial biosphere is a key component of the global carbon cycle and its carbon balance is strongly influenced by climate. Continuing environmental changes are thought to increase global terrestrial carbon uptake. But evidence is mounting that climate extremes such as droughts or storms can lead to a decrease in regional ecosystem carbon stocks and therefore have the potential to negate an expected increase in terrestrial carbon uptake. Here we explore the mechanisms and impacts of climate extremes on the terrestrial carbon cycle, and propose a pathway to improve our understanding of present and future impacts of climate extremes on the terrestrial carbon budget.
Y1  - 2013
U6  - https://doi.org/10.1038/nature12350
SN  - 0028-0836
VL  - 500
IS  - 7462
SP  - 287
EP  - 295
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Kissling, W. D.
A1  - Dormann, Carsten F.
A1  - Groeneveld, Juergen
A1  - Hickler, Thomas
A1  - Kühn, Ingolf
A1  - McInerny, Greg J.
A1  - Montoya, Jose M.
A1  - Römermann, Christine
A1  - Schiffers, Katja
A1  - Schurr, Frank Martin
A1  - Singer, Alexander
A1  - Svenning, Jens-Christian
A1  - Zimmermann, Niklaus E.
A1  - O'Hara, Robert B.
T1  - Towards novel approaches to modelling biotic interactions in multispecies assemblages at large spatial extents
JF  - Journal of biogeography
N2  - Aim Biotic interactions within guilds or across trophic levels have widely been ignored in species distribution models (SDMs). This synthesis outlines the development of species interaction distribution models (SIDMs), which aim to incorporate multispecies interactions at large spatial extents using interaction matrices. Location Local to global. Methods We review recent approaches for extending classical SDMs to incorporate biotic interactions, and identify some methodological and conceptual limitations. To illustrate possible directions for conceptual advancement we explore three principal ways of modelling multispecies interactions using interaction matrices: simple qualitative linkages between species, quantitative interaction coefficients reflecting interaction strengths, and interactions mediated by interaction currencies. We explain methodological advancements for static interaction data and multispecies time series, and outline methods to reduce complexity when modelling multispecies interactions. Results Classical SDMs ignore biotic interactions and recent SDM extensions only include the unidirectional influence of one or a few species. However, novel methods using error matrices in multivariate regression models allow interactions between multiple species to be modelled explicitly with spatial co-occurrence data. If time series are available, multivariate versions of population dynamic models can be applied that account for the effects and relative importance of species interactions and environmental drivers. These methods need to be extended by incorporating the non-stationarity in interaction coefficients across space and time, and are challenged by the limited empirical knowledge on spatio-temporal variation in the existence and strength of species interactions. Model complexity may be reduced by: (1) using prior ecological knowledge to set a subset of interaction coefficients to zero, (2) modelling guilds and functional groups rather than individual species, and (3) modelling interaction currencies and species effect and response traits. Main conclusions There is great potential for developing novel approaches that incorporate multispecies interactions into the projection of species distributions and community structure at large spatial extents. Progress can be made by: (1) developing statistical models with interaction matrices for multispecies co-occurrence datasets across large-scale environmental gradients, (2) testing the potential and limitations of methods for complexity reduction, and (3) sampling and monitoring comprehensive spatio-temporal data on biotic interactions in multispecies communities.
KW  - Community ecology
KW  - ecological networks
KW  - global change
KW  - guild assembly
KW  - multidimensional complexity
KW  - niche theory
KW  - prediction
KW  - species distribution model
KW  - species interactions
KW  - trait-based community modules
Y1  - 2012
U6  - https://doi.org/10.1111/j.1365-2699.2011.02663.x
SN  - 0305-0270
VL  - 39
IS  - 12
SP  - 2163
EP  - 2178
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Leifso, A.
A1  - MacDougall, A. S.
A1  - Husband, B.
A1  - Hierro, J. L.
A1  - Köchy, Martin
A1  - Pärtel, M.
A1  - Peltzer, D. A.
T1  - Expansion of a globally pervasive grass occurs without substantial trait differences between home and away populations
JF  - Oecologia
N2  - The global expansion of species beyond their ancestral ranges can derive from mechanisms that are trait-based (e.g., post-establishment evolved differences compared to home populations) or circumstantial (e.g., propagule pressure, with no trait-based differences). These mechanisms can be difficult to distinguish following establishment, but each makes unique predictions regarding trait similarity between ancestral ('home') and introduced ('away') populations. Here, we tested for trait-based population differences across four continents for the globally distributed grass Dactylis glomerata, to assess the possible role of trait evolution in its worldwide expansion. We used a common-environment glasshouse experiment to quantify trait differences among home and away populations, and the potential relevance of these differences for competitive interactions. Few significant trait differences were found among continents, suggesting minimal change during global expansion. All populations were polyploids, with similar foliar carbon:nitrogen ratios (a proxy for defense), chlorophyll content, and biomass. Emergence time and growth rate favored home populations, resulting in their competitive superiority over away populations. Small but significant trait differences among away populations suggest different introductory histories or local adaptive responses following establishment. In summary, the worldwide distribution of this species appears to have arisen from its pre-adapted traits promoting growth, and its repeated introduction with cultivation and intense propagule pressure. Global expansion can thus occur without substantial shifts in growth, reproduction, or defense. Rather than focusing strictly on the invader, invasion success may also derive from the traits found (or lacking) in the recipient community and from environmental context including human disturbance.
KW  - Invasion ecology
KW  - Common-environment trial
KW  - Competition
KW  - Plant functional traits
KW  - Orchard grass
Y1  - 2012
U6  - https://doi.org/10.1007/s00442-012-2370-4
SN  - 0029-8549
VL  - 170
IS  - 4
SP  - 1123
EP  - 1132
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Pereira, Fernanda S.
A1  - Nascimento, Heliara D. L.
A1  - Magalhaes, Alvicler
A1  - Peter, Martin G.
A1  - Bataglion, Giovana Anceski
A1  - Eberlin, Marcos N.
A1  - Gonzalez, Eduardo R. P.
T1  - ESI(+)-MS and GC-MS study of the hydrolysis of N-azobenzyl derivatives of chitosan
JF  - Molecules
N2  - New N-p-chloro-, N-p-bromo-, and N-p-nitrophenylazobenzylchitosan derivatives, as well as the corresponding azophenyl and azophenyl-p-sulfonic acids, were synthesized by coupling N-benzylvchitosan with aryl diazonium salts. The synthesized molecules were analyzed by UV-Vis, FT-IR, H-1-NMR and N-15-NMR spectroscopy. The capacity of copper chelation by these materials was studied by AAS. Chitosan and the derivatives were subjected to hydrolysis and the products were analyzed by ESI(+)-MS and GC-MS, confirming the formation of N-benzyl chitosan. Furthermore, the MS results indicate that a nucleophilic aromatic substitution (SnAr) reaction occurs under hydrolysis conditions, yielding chloroaniline from N-p-bromo-, and N-p-nitrophenylazo-benzylchitosan as well as bromoaniline from N-p-chloro-, and N-p-nitrophenylazobenzyl-chitosan.
KW  - chitosan
KW  - N-azobenzylchitosan
KW  - ESI-MS
KW  - GC-MS
KW  - SnAr reaction
Y1  - 2014
U6  - https://doi.org/10.3390/molecules191117604
SN  - 1420-3049
VL  - 19
IS  - 11
SP  - 17604
EP  - 17618
PB  - MDPI
CY  - Basel
ER  - 
TY  - JOUR
A1  - Bland-Hawthorn, Joss
A1  - Ellis, S. C.
A1  - Leon-Saval, S. G.
A1  - Haynes, R.
A1  - Roth, Martin M.
A1  - Löhmannsröben, Hans-Gerd
A1  - Horton, A. J.
A1  - Cuby, J. -G.
A1  - Birks, T. A.
A1  - Lawrence, J. S.
A1  - Gillingham, P.
A1  - Ryder, S. D.
A1  - Trinh, C.
T1  - A complex multi-notch astronomical filter to suppress the bright infrared sky
JF  - Nature Communications
N2  - A long-standing and profound problem in astronomy is the difficulty in obtaining deep near-infrared observations due to the extreme brightness and variability of the night sky at these wavelengths. A solution to this problem is crucial if we are to obtain the deepest possible observations of the early Universe, as redshifted starlight from distant galaxies appears at these wavelengths. The atmospheric emission between 1,000 and 1,800 nm arises almost entirely from a forest of extremely bright, very narrow hydroxyl emission lines that varies on timescales of minutes. The astronomical community has long envisaged the prospect of selectively removing these lines, while retaining high throughput between them. Here we demonstrate such a filter for the first time, presenting results from the first on-sky tests. Its use on current 8 m telescopes and future 30 m telescopes will open up many new research avenues in the years to come.
Y1  - 2011
U6  - https://doi.org/10.1038/ncomms1584
SN  - 2041-1723
VL  - 2
IS  - 50
PB  - Nature Publ. Group
CY  - London
ER  - 
TY  - JOUR
A1  - Svenning, Jens-Christian
A1  - Gravel, Dominique
A1  - Holt, Robert D.
A1  - Schurr, Frank Martin
A1  - Thuiller, Wilfried
A1  - Muenkemueller, Tamara
A1  - Schiffers, Katja H.
A1  - Dullinger, Stefan
A1  - Edwards, Thomas C.
A1  - Hickler, Thomas
A1  - Higgins, Steven I.
A1  - Nabel, Julia E. M. S.
A1  - Pagel, Jörn
A1  - Normand, Signe
T1  - The influence of interspecific interactions on species range expansion rates
JF  - Ecography : pattern and diversity in ecology ; research papers forum
Y1  - 2014
U6  - https://doi.org/10.1111/j.1600-0587.2013.00574.x
SN  - 0906-7590
SN  - 1600-0587
VL  - 37
IS  - 12
SP  - 1198
EP  - 1209
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Maslin, Mark A.
A1  - Pancost, Richard D.
A1  - Wilson, Katy E.
A1  - Lewis, Jonathan
A1  - Trauth, Martin H.
T1  - Three and half million year history of moisture availability of South West Africa evidence from ODP site 1085 biomarker records
JF  - Palaeogeography, palaeoclimatology, palaeoecology : an international journal for the geo-sciences
N2  - Ocean Drilling Program Site 1085 provides a continuous marine sediment record off southern South West Africa for at least the last three and half million years. The n-alkane partial derivative(13) C record from this site records changes in past vegetation and provides an indication of the moisture availability of SW Africa during this time period. Very little variation, and no apparent trend, is observed in the n-alkane delta C-13 record, suggesting stable long-term conditions despite significant changes in East African tectonics and global climate. Slightly higher n-alkane delta C-13 values occur between 3.5 and 2.7 Ma suggesting slightly drier conditions than today. Between 2.5 and 2.7 Ma there is a shift to more negative n-alkane delta C-13 values suggesting slightly wetter conditions during a similar to 0.2 Ma episode that coincides with the intensification of Northern Hemisphere Glaciation (iNHG). From 2.5 to 0.4 Ma the n-alkane delta C-13 values are very consistent, varying by less than +/- 0.5 parts per thousand and suggesting little or no long-term change in the moisture availability of South West Africa over the last 2.5 million years. This is in contrast to the long-term drying trend observed further north offshore from the Namib Desert and in East Africa. A comparison of the climate history of these regions suggests that Southern Africa may have been an area of long-term stability over the last 3.5 Myrs.
KW  - Plio-Pleistocene
KW  - Aridity
KW  - SW Africa
KW  - Biomarkers
KW  - Palaeoclimate
KW  - Human evolution
Y1  - 2012
U6  - https://doi.org/10.1016/j.palaeo.2011.12.009
SN  - 0031-0182
VL  - 317
SP  - 41
EP  - 47
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Frank, Dorothe A.
A1  - Reichstein, Markus
A1  - Bahn, Michael
A1  - Thonicke, Kirsten
A1  - Frank, David
A1  - Mahecha, Miguel D.
A1  - Smith, Pete
A1  - Van der Velde, Marijn
A1  - Vicca, Sara
A1  - Babst, Flurin
A1  - Beer, Christian
A1  - Buchmann, Nina
A1  - Canadell, Josep G.
A1  - Ciais, Philippe
A1  - Cramer, Wolfgang
A1  - Ibrom, Andreas
A1  - Miglietta, Franco
A1  - Poulter, Ben
A1  - Rammig, Anja
A1  - Seneviratne, Sonia I.
A1  - Walz, Ariane
A1  - Wattenbach, Martin
A1  - Zavala, Miguel A.
A1  - Zscheischler, Jakob
T1  - Effects of climate extremes on the terrestrial carbon cycle: concepts, processes and potential future impacts
JF  - Global change biology
N2  - Extreme droughts, heat waves, frosts, precipitation, wind storms and other climate extremes may impact the structure, composition and functioning of terrestrial ecosystems, and thus carbon cycling and its feedbacks to the climate system. Yet, the interconnected avenues through which climate extremes drive ecological and physiological processes and alter the carbon balance are poorly understood. Here, we review the literature on carbon cycle relevant responses of ecosystems to extreme climatic events. Given that impacts of climate extremes are considered disturbances, we assume the respective general disturbance-induced mechanisms and processes to also operate in an extreme context. The paucity of well-defined studies currently renders a quantitative meta-analysis impossible, but permits us to develop a deductive framework for identifying the main mechanisms (and coupling thereof) through which climate extremes may act on the carbon cycle. We find that ecosystem responses can exceed the duration of the climate impacts via lagged effects on the carbon cycle. The expected regional impacts of future climate extremes will depend on changes in the probability and severity of their occurrence, on the compound effects and timing of different climate extremes, and on the vulnerability of each land-cover type modulated by management. Although processes and sensitivities differ among biomes, based on expert opinion, we expect forests to exhibit the largest net effect of extremes due to their large carbon pools and fluxes, potentially large indirect and lagged impacts, and long recovery time to regain previous stocks. At the global scale, we presume that droughts have the strongest and most widespread effects on terrestrial carbon cycling. Comparing impacts of climate extremes identified via remote sensing vs. ground-based observational case studies reveals that many regions in the (sub-)tropics are understudied. Hence, regional investigations are needed to allow a global upscaling of the impacts of climate extremes on global carbon-climate feedbacks.
KW  - carbon cycle
KW  - climate change
KW  - climate extremes
KW  - climate variability
KW  - disturbance
KW  - terrestrial ecosystems
Y1  - 2015
U6  - https://doi.org/10.1111/gcb.12916
SN  - 1354-1013
SN  - 1365-2486
VL  - 21
IS  - 8
SP  - 2861
EP  - 2880
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Janssen, Annette B. G.
A1  - Arhonditsis, George B.
A1  - Beusen, Arthur
A1  - Bolding, Karsten
A1  - Bruce, Louise
A1  - Bruggeman, Jorn
A1  - Couture, Raoul-Marie
A1  - Downing, Andrea S.
A1  - Elliott, J. Alex
A1  - Frassl, Marieke A.
A1  - Gal, Gideon
A1  - Gerla, Daan J.
A1  - Hipsey, Matthew R.
A1  - Hu, Fenjuan
A1  - Ives, Stephen C.
A1  - Janse, Jan H.
A1  - Jeppesen, Erik
A1  - Joehnk, Klaus D.
A1  - Kneis, David
A1  - Kong, Xiangzhen
A1  - Kuiper, Jan J.
A1  - Lehmann, Moritz K.
A1  - Lemmen, Carsten
A1  - Oezkundakci, Deniz
A1  - Petzoldt, Thomas
A1  - Rinke, Karsten
A1  - Robson, Barbara J.
A1  - Sachse, Rene
A1  - Schep, Sebastiaan A.
A1  - Schmid, Martin
A1  - Scholten, Huub
A1  - Teurlincx, Sven
A1  - Trolle, Dennis
A1  - Troost, Tineke A.
A1  - Van Dam, Anne A.
A1  - Van Gerven, Luuk P. A.
A1  - Weijerman, Mariska
A1  - Wells, Scott A.
A1  - Mooij, Wolf M.
T1  - Exploring, exploiting and evolving diversity of aquatic ecosystem models: a community perspective
JF  - Aquatic ecology : the international forum covering research in freshwater and marine environments
N2  - Here, we present a community perspective on how to explore, exploit and evolve the diversity in aquatic ecosystem models. These models play an important role in understanding the functioning of aquatic ecosystems, filling in observation gaps and developing effective strategies for water quality management. In this spirit, numerous models have been developed since the 1970s. We set off to explore model diversity by making an inventory among 42 aquatic ecosystem modellers, by categorizing the resulting set of models and by analysing them for diversity. We then focus on how to exploit model diversity by comparing and combining different aspects of existing models. Finally, we discuss how model diversity came about in the past and could evolve in the future. Throughout our study, we use analogies from biodiversity research to analyse and interpret model diversity. We recommend to make models publicly available through open-source policies, to standardize documentation and technical implementation of models, and to compare models through ensemble modelling and interdisciplinary approaches. We end with our perspective on how the field of aquatic ecosystem modelling might develop in the next 5-10 years. To strive for clarity and to improve readability for non-modellers, we include a glossary.
KW  - Water quality
KW  - Ecology
KW  - Geochemistry
KW  - Hydrology
KW  - Hydraulics
KW  - Hydrodynamics
KW  - Physical environment
KW  - Socio-economics
KW  - Model availability
KW  - Standardization
KW  - Linking
Y1  - 2015
U6  - https://doi.org/10.1007/s10452-015-9544-1
SN  - 1386-2588
SN  - 1573-5125
VL  - 49
IS  - 4
SP  - 513
EP  - 548
PB  - Springer
CY  - Dordrecht
ER  - 
TY  - JOUR
A1  - Pagel, Jörn
A1  - Anderson, Barbara J.
A1  - Cramer, Wolfgang
A1  - Fox, Richard
A1  - Jeltsch, Florian
A1  - Roy, David B.
A1  - Thomas, Chris D.
A1  - Schurr, Frank Martin
T1  - Quantifying range-wide variation in population trends from local abundance surveys and widespread opportunistic occurrence records
JF  - Methods in ecology and evolution : an official journal of the British Ecological Society
N2  - 2. We present a hierarchical model that integrates observations from multiple sources to estimate spatio-temporal abundance trends. The model links annual population densities on a spatial grid to both long-term count data and to opportunistic occurrence records from a citizen science programme. Specific observation models for both data types explicitly account for differences in data structure and quality.
 3. We test this novel method in a virtual study with simulated data and apply it to the estimation of abundance dynamics across the range of a butterfly species (Pyronia tithonus) in Great Britain between 1985 and 2004. The application to simulated and real data demonstrates how the hierarchical model structure accommodates various sources of uncertainty which occur at different stages of the link between observational data and the modelled abundance, thereby it accounts for these uncertainties in the inference of abundance variations.
 4. We show that by using hierarchical observation models that integrate different types of commonly available data sources, we can improve the estimates of variation in species abundances across space and time. This will improve our ability to detect regional trends and can also enhance the empirical basis for understanding range dynamics.
KW  - atlas data
KW  - Bayesian statistics
KW  - biogeography
KW  - butterflies
KW  - citizen science programme
KW  - conservation biology
KW  - count data
KW  - macroecology
KW  - state-space model
Y1  - 2014
U6  - https://doi.org/10.1111/2041-210X.12221
SN  - 2041-210X
SN  - 2041-2096
VL  - 5
IS  - 8
SP  - 751
EP  - 760
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - GEN
A1  - Voropaev, S.
A1  - Korochantsev, A.
A1  - Petukhov, D.
A1  - Kocherov, A.
A1  - Kaeter, David
A1  - Ziemann, Martin Andreas
A1  - Boettger, Ute
T1  - Ordinary chondrites of Chelyabinsk meteorite and comparison with asteroid 25143 (Itokawa)
T2  - PLoS one
Y1  - 2016
SN  - 1086-9379
SN  - 1945-5100
VL  - 51
SP  - A644
EP  - A644
PB  - Wiley-Blackwell
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Kunnus, Kristjan
A1  - Josefsson, I.
A1  - Rajkovic, Ivan
A1  - Schreck, Simon
A1  - Quevedo, Wilson
A1  - Beye, Martin
A1  - Weniger, C.
A1  - Gruebel, S.
A1  - Scholz, M.
A1  - Nordlund, D.
A1  - Zhang, W.
A1  - Hartsock, R. W.
A1  - Gaffney, K. J.
A1  - Schlotter, W. F.
A1  - Turner, J. J.
A1  - Kennedy, B.
A1  - Hennies, F.
A1  - de Groot, F. M. F.
A1  - Techert, S.
A1  - Odelius, Michael
A1  - Wernet, Ph.
A1  - Föhlisch, Alexander
T1  - Identification of the dominant photochemical pathways and mechanistic insights to the ultrafast ligand exchange of Fe(CO)(5) to Fe(CO)(4)EtOH
JF  - Structural dynamics
N2  - We utilized femtosecond time-resolved resonant inelastic X-ray scattering and ab initio theory to study the transient electronic structure and the photoinduced molecular dynamics of a model metal carbonyl photocatalyst Fe(CO)(5) in ethanol solution. We propose mechanistic explanation for the parallel ultrafast intra-molecular spin crossover and ligation of the Fe(CO)(4) which are observed following a charge transfer photoexcitation of Fe(CO)(5) as reported in our previous study [ Wernet et al., Nature 520, 78 (2015)]. We find that branching of the reaction pathway likely happens in the (1)A(1) state of Fe(CO)(4). A sub-picosecond time constant of the spin crossover from B-1(2) to B-3(2) is rationalized by the proposed B-1(2) -> (1)A(1) -> B-3(2) mechanism. Ultrafast ligation of the B-1(2) Fe(CO)(4) state is significantly faster than the spin-forbidden and diffusion limited ligation process occurring from the B-3(2) Fe(CO)(4) ground state that has been observed in the previous studies. We propose that the ultrafast ligation occurs via B-1(2) -> (1)A(1) -> (1)A'Fe(CO)(4)EtOH pathway and the time scale of the (1)A(1) Fe(CO)(4) state ligation is governed by the solute-solvent collision frequency. Our study emphasizes the importance of understanding the interaction of molecular excited states with the surrounding environment to explain the relaxation pathways of photoexcited metal carbonyls in solution. (C) 2016 Author(s).
Y1  - 2016
U6  - https://doi.org/10.1063/1.4941602
SN  - 2329-7778
VL  - 3
PB  - American Institute of Physics
CY  - Washington
ER  - 
TY  - JOUR
A1  - Kamann, S.
A1  - Husser, T. -O.
A1  - Brinchmann, Jarle
A1  - Emsellem, E.
A1  - Weilbacher, Peter Michael
A1  - Wisotzki, Lutz
A1  - Wendt, Martin
A1  - Krajnovic, D.
A1  - Roth, M. M.
A1  - Bacon, Roland
A1  - Dreizler, S.
T1  - MUSE crowded field 3D spectroscopy of over 12 000 stars in the globular cluster NGC 6397
JF  - Tectonophysics : international journal of geotectonics and the geology and physics of the interior of the earth
N2  - We present a detailed analysis of the kinematics of the Galactic globular cluster NGC 6397 based on more than similar to 18 000 spectra obtained with the novel integral field spectrograph MUSE. While NGC 6397 is often considered a core collapse cluster, our analysis suggests a flattening of the surface brightness profile at the smallest radii. Although it is among the nearest globular clusters, the low velocity dispersion of NGC 6397 of < 5 km s(-1) imposes heavy demands on the quality of the kinematical data. We show that despite its limited spectral resolution, MUSE reaches an accuracy of 1 km s(-1) in the analysis of stellar spectra. We find slight evidence for a rotational component in the cluster and the velocity dispersion profile that we obtain shows a mild central cusp. To investigate the nature of this feature, we calculate spherical Jeans models and compare these models to our kinematical data. This comparison shows that if a constant mass-to-light ratio is assumed, the addition of an intermediate-mass black hole with a mass of 600 M-circle dot brings the model predictions into agreement with our data, and therefore could be at the origin of the velocity dispersion profile. We further investigate cases with varying mass-to-light ratios and find that a compact dark stellar component can also explain our observations. However, such a component would closely resemble the black hole from the constant mass-to-light ratio models as this component must be confined to the central similar to 5 ' of the cluster and must have a similar mass. Independent constraints on the distribution of stellar remnants in the cluster or kinematic measurements at the highest possible spatial resolution should be able to distinguish the two alternatives.
KW  - globular clusters: individual: NGC 6397
KW  - stars: kinematics and dynamics
KW  - techniques: radial velocities
KW  - techniques: imaging spectroscopy
KW  - black hole physics
Y1  - 2016
U6  - https://doi.org/10.1051/0004-6361/201527065
SN  - 1432-0746
VL  - 588
PB  - EDP Sciences
CY  - Les Ulis
ER  - 
TY  - JOUR
A1  - Margold, Martin
A1  - Jansen, John D.
A1  - Gurinov, Artem L.
A1  - Codilean, Alexandru T.
A1  - Fink, David
A1  - Preusser, Frank
A1  - Reznichenko, Natalya V.
A1  - Mifsud, Charles
T1  - Extensive glaciation in Transbaikalia, Siberia, at the Last Glacial Maximum
JF  - Quaternary science reviews : the international multidisciplinary research and review journal
N2  - Successively smaller glacial extents have been proposed for continental Eurasia during the stadials of the last glacial period leading up to the Last Glacial Maximum (LGM). At the same time the large mountainous region east of Lake Baikal, Transbaikalia, has remained unexplored in terms of glacial chronology despite clear geomorphological evidence of substantial past glaciations. We have applied cosmogenic Be-10 exposure dating and optically stimulated luminescence to establish the first quantitative glacial chronology for this region. Based on eighteen exposure ages from five moraine complexes, we propose that large mountain ice fields existed in the Kodar and Udokan mountains during Oxygen Isotope Stage 2, commensurate with the global LGM. These ice fields fed valley glaciers (>100 km in length) reaching down to the Chara Depression between the Kodar and Udokan mountains and to the valley of the Vitim River northwest of the Kodar Mountains. Two of the investigated moraines date to the Late Glacial, but indications of incomplete exposure among some of the sampled boulders obscure the specific details of the post-LGM glacial history. In addition to the LGM ice fields in the highest mountains of Transbaikalia, we report geomorphological evidence of a much more extensive, ice-cap type glaciation at a time that is yet to be firmly resolved. (C) 2015 Elsevier Ltd. All rights reserved.
KW  - Glaciation
KW  - Transbaikalia
KW  - Last Glacial Maximum
KW  - Cosmogenic Be-10 exposure dating
KW  - Optically stimulated luminescence
Y1  - 2016
U6  - https://doi.org/10.1016/j.quascirev.2015.11.018
SN  - 0277-3791
VL  - 132
SP  - 161
EP  - 174
PB  - Elsevier
CY  - Oxford
ER  -