@article{XuCaoBrenneretal.2015, author = {Xu, Jingsan and Cao, Shaowen and Brenner, Thomas J. K. and Yang, Xiaofei and Yu, Jiaguo and Antonietti, Markus and Shalom, Menny}, title = {Supramolecular Chemistry in Molten Sulfur: Preorganization Effects Leading to Marked Enhancement of Carbon Nitride Photoelectrochemistry}, series = {Advanced functional materials}, volume = {25}, journal = {Advanced functional materials}, number = {39}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {1616-301X}, doi = {10.1002/adfm.201502843}, pages = {6265 -- 6271}, year = {2015}, abstract = {Here, a new method for enhancing the photoelectrochemical properties of carbon nitride thin films by in situ supramolecular-driven preorganization of phenyl-contained monomers in molten sulfur is reported. A detailed analysis of the chemical and photophysical properties suggests that the molten sulfur can texture the growth and induce more effective integration of phenyl groups into the carbon nitride electrodes, resulting in extended light absorption alongside with improved conductivity and better charge transfer. Furthermore, photophysical measurements indicate the formation of sub-bands in the optical bandgap which is beneficial for exciton splitting. Moreover, the new bands can mediate hole transfer to the electrolyte, thus improving the photooxidation activity. The utilization of high temperature solvent as the polymerization medium opens new opportunities for the significant improvement of carbon nitride films toward an efficient photoactive material for various applications.}, language = {en} } @article{XinLaRueObergetal.2015, author = {Xin, Hong and LaRue, Jerry and Oberg, Henrik and Beye, Martin and Turner, J. J. and Gladh, J{\"o}rgen and Ng, May L. and Sellberg, Jonas A. and Kaya, Sarp and Mercurio, G. and Hieke, F. and Nordlund, Dennis and Schlotter, William F. and Dakovski, Georgi L. and Minitti, Michael P. and F{\"o}hlisch, Alexander and Wolf, Martin and Wurth, Wilfried and Ogasawara, Hirohito and Norskov, Jens K. and Ostrom, Henrik and Pettersson, Lars G. M. and Nilsson, Anders and Abild-Pedersen, Frank}, title = {Strong Influence of Coadsorbate Interaction on CO Desorption Dynamics on Ru(0001) Probed by Ultrafast X-Ray Spectroscopy and Ab Initio Simulations}, series = {Physical review letters}, volume = {114}, journal = {Physical review letters}, number = {15}, publisher = {American Physical Society}, address = {College Park}, issn = {0031-9007}, doi = {10.1103/PhysRevLett.114.156101}, pages = {6}, year = {2015}, abstract = {We show that coadsorbed oxygen atoms have a dramatic influence on the CO desorption dynamics from Ru(0001). In contrast to the precursor-mediated desorption mechanism on Ru(0001), the presence of surface oxygen modifies the electronic structure of Ru atoms such that CO desorption occurs predominantly via the direct pathway. This phenomenon is directly observed in an ultrafast pump-probe experiment using a soft x-ray free-electron laser to monitor the dynamic evolution of the valence electronic structure of the surface species. This is supported with the potential of mean force along the CO desorption path obtained from density-functional theory calculations. Charge density distribution and frozen-orbital analysis suggest that the oxygen-induced reduction of the Pauli repulsion, and consequent increase of the dative interaction between the CO 5 sigma and the charged Ru atom, is the electronic origin of the distinct desorption dynamics. Ab initio molecular dynamics simulations of CO desorption from Ru(0001) and oxygen-coadsorbed Ru(0001) provide further insights into the surface bond-breaking process.}, language = {en} } @misc{XiangHofreiterZhao2015, author = {Xiang, Hai and Hofreiter, Michael and Zhao, Xingbo}, title = {Reply to Peng et al.: Archaeological contexts should not be ignored for early chicken domestication}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {16}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1502207112}, pages = {E1972 -- E1973}, year = {2015}, language = {en} } @misc{XiangGaoYuetal.2015, author = {Xiang, Hai and Gao, Jianqiang and Yu, Baoquan and Hofreiter, Michael and Zhao, Xingbo}, title = {Reply to Peters et al.: Further discussions confirm early Holocene chicken domestication in northern China}, series = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {112}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, number = {19}, publisher = {National Acad. of Sciences}, address = {Washington}, issn = {0027-8424}, doi = {10.1073/pnas.1503956112}, pages = {E2416 -- E2416}, year = {2015}, language = {en} } @article{WuerfelNeherSpiesetal.2015, author = {W{\"u}rfel, Uli and Neher, Dieter and Spies, Annika and Albrecht, Steve}, title = {Impact of charge transport on current-voltage characteristics and power-conversion efficiency of organic solar cells}, series = {Nature Communications}, volume = {6}, journal = {Nature Communications}, publisher = {Nature Publ. Group}, address = {London}, issn = {2041-1723}, doi = {10.1038/ncomms7951}, pages = {9}, year = {2015}, abstract = {This work elucidates the impact of charge transport on the photovoltaic properties of organic solar cells. Here we show that the analysis of current-voltage curves of organic solar cells under illumination with the Shockley equation results in values for ideality factor, photo-current and parallel resistance, which lack physical meaning. Drift-diffusion simulations for a wide range of charge-carrier mobilities and illumination intensities reveal significant carrier accumulation caused by poor transport properties, which is not included in the Shockley equation. As a consequence, the separation of the quasi Fermi levels in the organic photoactive layer (internal voltage) differs substantially from the external voltage for almost all conditions. We present a new analytical model, which considers carrier transport explicitly. The model shows excellent agreement with full drift-diffusion simulations over a wide range of mobilities and illumination intensities, making it suitable for realistic efficiency predictions for organic solar cells.}, language = {en} } @phdthesis{Wust2015, author = {Wust, Johannes}, title = {Mixed workload managment for in-memory databases}, pages = {VIII, 167}, year = {2015}, language = {en} } @misc{WuGlebeBoeker2015, author = {Wu, Lei and Glebe, Ulrich and B{\"o}ker, Alexander}, title = {Surface-initiated controlled radical polymerizations from silica nanoparticles, gold nanocrystals, and bionanoparticles}, series = {Polymer Chemistry}, volume = {6}, journal = {Polymer Chemistry}, number = {29}, publisher = {Royal Society of Chemistry}, address = {Cambridge}, issn = {1759-9954}, doi = {10.1039/c5py00525f}, pages = {5143 -- 5184}, year = {2015}, abstract = {In recent years, core/shell nanohybrids containing a nanoparticle core and a distinct surrounding shell of polymer brushes have received extensive attention in nanoelectronics, nanophotonics, catalysis, nanopatterning, drug delivery, biosensing, and many others. From the large variety of existing polymerization methods on the one hand and strategies for grafting onto nanoparticle surfaces on the other hand, the combination of grafting-from with controlled radical polymerization (CRP) techniques has turned out to be the best suited for synthesizing these well-defined core/shell nanohybrids and is known as surface-initiated CRP. Most common among these are surface-initiated atom transfer radical polymerization (ATRP), surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization, and surface-initiated nitroxide-mediated polymerization (NMP). This review highlights the state of the art of growing polymers from nanoparticles using surface-initiated CRP techniques. We focus on mechanistic aspects, synthetic procedures, and the formation of complex architectures as well as novel properties. From the vast number of examples of nanoparticle/polymer hybrids formed by surface-initiated CRP techniques, we present nanohybrid formation from the particularly important and most studied silica nanoparticles, gold nanocrystals, and proteins which can be regarded as bionanoparticles.}, language = {en} } @article{WolffSchindlerBrand2015, author = {Wolff, Wanja and Schindler, Sebastian and Brand, Ralf}, title = {The Effect of Implicitly Incentivized Faking on Explicit and Implicit Measures of Doping Attitude: When Athletes Want to Pretend an Even More Negative Attitude to Doping}, series = {PLoS one}, volume = {10}, journal = {PLoS one}, number = {4}, publisher = {PLoS}, address = {San Fransisco}, issn = {1932-6203}, doi = {10.1371/journal.pone.0118507}, pages = {10}, year = {2015}, abstract = {The Implicit Association Test (IAT) aims to measure participants' automatic evaluation of an attitude object and is useful especially for the measurement of attitudes related to socially sensitive subjects, e.g. doping in sports. Several studies indicate that IAT scores can be faked on instruction. But fully or semi-instructed research scenarios might not properly reflect what happens in more realistic situations, when participants secretly decide to try faking the test. The present study is the first to investigate IAT faking when there is only an implicit incentive to do so. Sixty-five athletes (22.83 years +/- 2.45; 25 women) were randomly assigned to an incentive-to-fake condition or a control condition. Participants in the incentive-to-fake condition were manipulated to believe that athletes with lenient doping attitudes would be referred to a tedious 45-minute anti-doping program. Attitudes were measured with the pictorial doping brief IAT (BIAT) and with the Performance Enhancement Attitude Scale (PEAS). A one-way MANOVA revealed significant differences between conditions after the manipulation in PEAS scores, but not in the doping BIAT. In the light of our hypothesis this suggests that participants successfully faked an exceedingly negative attitude to doping when completing the PEAS, but were unsuccessful in doing so on the reaction time-based test. This study assessed BIAT faking in a setting that aimed to resemble a situation in which participants want to hide their attempts to cheat. The two measures of attitude were differentially affected by the implicit incentive. Our findings provide evidence that the pictorial doping BIAT is relatively robust against spontaneous and naive faking attempts. (B) IATs might be less prone to faking than implied by previous studies.}, language = {en} } @misc{WitzelNeugartRuppeletal.2015, author = {Witzel, Katja and Neugart, Susanne and Ruppel, Silke and Schreiner, Monika and Wiesner, Melanie and Baldermann, Susanne}, title = {Recent progress in the use of 'omics technologies in brassicaceous vegetables}, series = {Frontiers in plant science}, volume = {6}, journal = {Frontiers in plant science}, publisher = {Frontiers Research Foundation}, address = {Lausanne}, issn = {1664-462X}, doi = {10.3389/fpls.2015.00244}, pages = {14}, year = {2015}, abstract = {Continuing advances in 'omics methodologies and instrumentation is enhancing the understanding of how plants cope with the dynamic nature of their growing environment. 'Omics platforms have been only recently extended to cover horticultural crop species. Many of the most widely cultivated vegetable crops belong to the genus Brassica: these include plants grown for their root (turnip, rutabaga/swede), their swollen stem base (kohlrabi), their leaves (cabbage, kale, pak choi) and their inflorescence (cauliflower, broccoli). Characterization at the genome, transcript, protein and metabolite levels has illustrated the complexity of the cellular response to a whole series of environmental stresses, including nutrient deficiency, pathogen attack, heavy metal toxicity, cold acclimation, and excessive and sub optimal irradiation. This review covers recent applications of omics technologies to the brassicaceous vegetables, and discusses future scenarios in achieving improvements in crop end-use quality.}, language = {en} } @article{WirthHatterDrostetal.2015, author = {Wirth, Jonas and Hatter, Nino and Drost, Robert and Umbach, Tobias R. and Barja, Sara and Zastrow, Matthias and R{\"u}ck-Braun, Karola and Pascual, Jose Ignacio and Saalfrank, Peter and Franke, Katharina J.}, title = {Diarylethene Molecules on a Ag(111) Surface: Stability and Electron-Induced Switching}, series = {The journal of physical chemistry : C, Nanomaterials and interfaces}, volume = {119}, journal = {The journal of physical chemistry : C, Nanomaterials and interfaces}, number = {9}, publisher = {American Chemical Society}, address = {Washington}, issn = {1932-7447}, doi = {10.1021/jp5122036}, pages = {4874 -- 4883}, year = {2015}, abstract = {Diarylethene derivatives are photochromic molecular switches, undergoing a ring-opening/-closing reaction by illumination with light. The symmetry of the closed form is determined by the WoodWard Hoffinann rules according to which the reaction proceeds by corirotatory rotation -in that case. Here, we show by a cOrnbined approach of scanning tunneling microscopy (STM) and density functional theory (DFT) calculations that the Open isomer of 4,4'-(4,4'-(perfluorocydopent-1-ene-1,2-diyl)bis(5-methyl-thiophent-4,2,4-dipyridine) (PDTE) retains its open form upon adsorption on a Ag(111) surface. It caribe switched into a closed form, which we identify as the digrotatOly cydization product, by controlled manipulation 'With the STM tip, Evidence of an electric-field dependent switching-process 'is interpreted on the basis of a Simple electroStatic Model, which suggests that the reaction proceedS via an "upright" intermediate state. This pathway thus strongly differs from the switching reaction in solution.}, language = {en} }