cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Spectrally Localized Strichartz Estimates and Nonlinear Schrödinger Equations
Creators: name: Bolleyer, Andreas
Publisher: name: Karlsruhe
Year: 2015
Subjects: Strichartzabschätzung
nichtlineare Schrödingergleichung

description: We investigate the nonlinear Schrödinger equation in an abstract setting and derive a local existence theorem, which allows to reproduce and in some cases extend known results. We furthermore derive a new global existence theorem for the nonlinear Schrödinger equation on certain 2-dimensional product manifolds.
Abrasion of flat rotating shapes
Creators: name: Roth, A. E.
name: Marques, C. M.
name: Durian, D. J.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We report on the erosion of flat linoleum "pebbles" under steady rotation in a slurry of abrasive grit. To quantify shape as a function of time, we develop a general method in which the pebble is photographed from multiple angles with respect to the grid of pixels in a digital camera. This reduces digitization noise, and allows the local curvature of the contour to be computed with a controllable degree of uncertainty. Several shape descriptors are then employed to follow the evolution of different initial shapes toward a circle, where abrasion halts. The results are in good quantitative agreement with a simple model, where we propose that points along the contour move radially inward in proportion to the product of the radius and the derivative of radius with respect to angle.
Methods for image recovery in computational imaging
Creators: name: Xiao, Lei
Publisher: name: University of British Columbia
Year: 2017

description: As a classic topic that has been studied for decades, image restoration is still a very active research area. Developing more effective and efficient methods are highly desirable. This thesis addresses image restoration problems for applications in computational imaging including Time-of-Flight (ToF) imaging and digital photography. While ToF cameras have shown great promise at low-cost depth imaging, they suffer from limited depth-of-field and low spatial-resolution. We develop a computational method to remove lens blur and increase image resolution of off-the-shelf ToF cameras. The method solves latent images directly from the raw sensor data as an inverse problem, and supports for future ToF cameras that use multiple frequencies, phases and exposures. Photographs taken by hand-held cameras are likely to suffer from blur caused by camera shake during exposure. Removing such blur and recovering sharp images as a post-process is therefore critical. We develop a blind deblurring method that is purely based on stochastic random-walk optimization. This simple framework in combination with different priors produces comparable results to the much more complex state-of-the-art deblurring algorithms. Blur causes even more serious issues for document photographs as slight blur can make Optical Character Recognition (OCR) techniques fail. We address the blind deblurring problem specifically for common document photographs. Observing that the latter are mostly composed of high-order structures, our method captures such domain property by a series of high-order filters as well as customized response functions. These parameters are trained from data by discriminative learning approach and form an end-to-end network that can efficiently and jointly estimate blur kernels and legible images. Discriminative learning approaches achieve convincing trade-off between image quality and computational efficiency, however, they require separate training for each restoration task and problem condition, making it time-consuming and difficult to encompass all tasks and conditions during training. We combine discriminative learning and formal optimization techniques to learn image priors that require a single-pass training and share across various tasks and conditions while keeping the efficiency as previous discriminative methods. After being trained, our method can be combined with other likelihood or priors to address unseen restoration tasks or further improve the image quality.
Anisotropic flow far from equilibrium
Creators: name: Borghini, Nicolas
name: Gombeaud, Clement
Publisher: name: arXiv
Year: 2010
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: We compute analytically the anisotropic flow in an expanding mixture of several species of relativistic massive particles. We find that a single collision per particle in average already leads to sizable elliptic flow, with mass ordering between the species.
description: 13 pages, 7 figures. v2: journal version (a few typos corrected, extra acknowledgments added)
Ring-Opening 1,3-Aminochalcogenation of Donor–Acceptor Cyclopropanes: A Three-Component Approach
Creators: name: Augustin, André U.
name: Jones, Peter G.
name: Werz, Daniel B.
Publisher: name: FID GEO
Year: 2019

description: Abstract A 1,3-aminothiolation was realized by reacting 2-substituted cyclopropane 1,1-dicarboxylates with sulfonamides and N-(arylthio)succinimides. Under Sn(OTf)2 catalysis the transformation proceeded smoothly to the corresponding ring-opened products bearing the sulfonamide in the 1-position next to the donor and the arylthio residue in the 3-position next to the acceptor. The procedure was extended to the corresponding selenium analogues by employing N-(phenylseleno)succinimides as an electrophilic selenium source.
Transmissionselektronenmikroskopie mit elektrostatischen Zach-Phasenplatten
Creators: name: Hettler, Simon Josef
Publisher: name: Karlsruhe
Year: 2015
Subjects: Transmissionselektronenmikroskopie
Elektrostatische Phasenplatten
Phasenkontrast
Objektwellenrekonstruktion
Inelastische Elektronenstreuung

description: Elektrostatische Zach-Phasenplatten (PP) erlauben die Kontrastverstärkung von transparenten Objekten in der Transmissionselektronenmikroskopie. In der vorliegenden Arbeit wurde die Herstellung von Zach-PP optimiert und deren Auswirkung auf die Bildentstehung durch Simulationen und Experimente mit verschiedenen Proben analysiert. Die Möglichkeit der Verwendung einer Zach-PP in der Hochauflösung, der Objektwellenrekonstruktion und in Verbindung mit inelastischer Streuung wird aufgezeigt.
The Protein-Coding Human Genome: Annotating High-Hanging Fruits
Creators: name: Hatje, Klas
name: Mühlhausen, Stefanie
name: Simm, Dominic
name: Kollmar, Martin
Publisher: name: FID GEO
Year: 2019

description: Abstract The major transcript variants of human protein-coding genes are annotated to a certain degree of accuracy combining manual curation, transcript data, and proteomics evidence. However, there is considerable disagreement on the annotation of about 2000 genes—they can be protein-coding, noncoding, or pseudogenes—and on the annotation of most of the predicted alternative transcripts. Pure transcriptome mapping approaches seem to be limited in discriminating functional expression from noise. These limitations have partially been overcome by dedicated algorithms to detect alternative spliced micro-exons and wobble splice variants. Recently, knowledge about splice mechanism and protein structure are incorporated into an algorithm to predict neighboring homologous exons, often spliced in a mutually exclusive manner. Predicted exons are evaluated by transcript data, structural compatibility, and evolutionary conservation, revealing hundreds of novel coding exons and splice mechanism re-assignments. The emerging human pan-genome is necessitating distinctive annotations incorporating differences between individuals and between populations.
Human gestational N-methyl-d-aspartate receptor autoantibodies impair neonatal murine brain function
Creators: name: Jurek, Betty
name: Chayka, Mariya
name: Kreye, Jakob
name: Lang, Katharina
name: Kraus, Larissa
name: Fidzinski, Pawel
name: Kornau, Hans-Christian
name: Dao, Le-Minh
name: Wenke, Nina K.
name: Long, Melissa
name: Rivalan, Marion
name: Winter, York
name: Leubner, Jonas
name: Herken, Julia
name: Mayer, Simone
name: Mueller, Susanne
name: Boehm-Sturm, Philipp
name: Dirnagl, Ulrich
name: Schmitz, Dietmar
name: Kölch, Michael
name: Prüss, Harald
Publisher: name: FID GEO
Year: 2019

description: Objective Maternal autoantibodies are a risk factor for impaired brain development in offspring. Antibodies (ABs) against the NR1 (GluN1) subunit of the N-methyl-d-aspartate receptor (NMDAR) are among the most frequently diagnosed anti-neuronal surface ABs, yet little is known about effects on fetal development during pregnancy. Methods We established a murine model of in utero exposure to human recombinant NR1 and isotype-matched nonreactive control ABs. Pregnant C57BL/6J mice were intraperitoneally injected on embryonic days 13 and 17 each with 240μg of human monoclonal ABs. Offspring were investigated for acute and chronic effects on NMDAR function, brain development, and behavior. Results Transferred NR1 ABs enriched in the fetus and bound to synaptic structures in the fetal brain. Density of NMDAR was considerably reduced (up to −49.2%) and electrophysiological properties were altered, reflected by decreased amplitudes of spontaneous excitatory postsynaptic currents in young neonates (−34.4%). NR1 AB-treated animals displayed increased early postnatal mortality (+27.2%), impaired neurodevelopmental reflexes, altered blood pH, and reduced bodyweight. During adolescence and adulthood, animals showed hyperactivity (+27.8% median activity over 14 days), lower anxiety, and impaired sensorimotor gating. NR1 ABs caused long-lasting neuropathological effects also in aged mice (10 months), such as reduced volumes of cerebellum, midbrain, and brainstem. Interpretation The data collectively support a model in which asymptomatic mothers can harbor low-level pathogenic human NR1 ABs that are diaplacentally transferred, causing neurotoxic effects on neonatal development. Thus, AB-mediated network changes may represent a potentially treatable neurodevelopmental congenital brain disorder contributing to lifelong neuropsychiatric morbidity in affected children. ANN NEUROL 2019;86:656–670
Neutrinos Meet Supersymmetry - Quantum Aspects of Neutrinophysics in Supersymmetric Theories
Creators: name: Hollik, Wolfgang Gregor
Publisher: name: Karlsruhe
Year: 2015

description: We address the influence of quantum corrections to neutrino masses and mixings and discuss the possibilities to completely generate the flavor mixing irrespective of any tree-level flavor model.Furthermore, we describe a new class of vacua with a new minimum appearing in the standard Higgs direction. The results hint towards a charge and color breaking global minimum and therefore extend existing bounds at tree-level.
Wilson Loops in N=2 Super-Yang-Mills from Matrix Model
Creators: name: Passerini, F.
name: Zarembo, K.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We compute the expectation value of the circular Wilson loop in N=2 supersymmetric Yang-Mills theory with N_f=2N hypermultiplets. Our results indicate that the string tension in the dual string theory scales as the logarithm of the 't Hooft coupling.
description: 37 pages, 9 figures; v2: Numerical factors corrected, simple derivation of Wilson loop and discussion of continuation to complex lambda added; v3: instanton partition function re-analyzed in order to take into account a contribution of the hypermultiplets
Riccati equation and the problem of decoherence II: Symmetry and the solution of the Riccati equation
Creators: name: Gardas, Bartlomiej
Publisher: name: arXiv
Year: 2010
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In this paper we revisit the problem of decoherence applying the block operator matrices analysis. Riccati algebraic equation associated with the Hamiltonian describing the process of decoherence is studied. We prove that if the environment responsible for decoherence is invariant with respect to the antylinear transformation then the antylinear operator solves Riccati equation in question. We also argue that this solution leads to neither linear nor antilinear operator similarity matrix. This fact deprives us the standard procedure for solving linear differential equation (e.g, Schrodinger equation). Furthermore, the explicit solution of the Riccati equation is found for the case where the environment operators commute with each other. We discuss the connection between our results and the standard description of decoherence (one that uses the Kraus representation). We show that reduced dynamics we obtain does not have the Kraus representation if the initial correlations between the system and its environment are present. However, for any initial state of the system (even when the correlations occur) reduced dynamics can be written in a manageable way.
description: 17 pages, 0 figures, The quality of English used in the paper has been improved
Syntheseanwendungen der oxidativen aromatischen Kupplung – von Biphenolen zu Nanographenen
Creators: name: Grzybowski, Marek
name: Sadowski, Bart?Omiej
name: Butenschön, Holger
name: Gryko, Daniel T.
Publisher: name: FID GEO
Year: 2019

description: Abstract Die oxidative aromatische Kupplung nimmt einen grundlegenden Platz in der modernen Arenchemie ein. Sie ist das Mittel der Wahl für den Aufbau großer, komplizierter Molekülarchitekturen. Auch die Scholl-Reaktion und ihre Anwendungen in der Synthese chiraler Biphenole und Naturstoffe sind stark beforscht. Die Möglichkeit, Biarylverknüpfungen ohne Vorfunktionalisierung herzustellen, bietet einen effizienten Weg zu vielen komplexen Strukturen. Obwohl die Chemie hinter diesem Prozess erst jetzt nach und nach voll verstanden wird, ist er weiterhin eine Quelle der Inspiration. Dies trifft besonders auf Heterokupplungen zu, d. h. oxidative, aromatische Kupplungen unter chemoselektiver C-C-Bindungsbildung zwischen zwei verschiedenen Arenen. Eine Analyse der Fortschritte in diesem Feld seit 2013 zeigt, dass zahlreiche Gruppen hierzu beigetragen haben – durch die Entdeckung neuer struktureller Möglichkeiten, die Erweiterung zu oberflächengestützten (Cyclo)dehydrierungen und die Entwicklung neuer Reagenzien.
Rephasing invariance and the neutrino mu-tau symmetry
Creators: name: Chiu, S. H.
name: Kuo, T. K.
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: The vacuum neutrino mixing is known to exhibit an approximate $μ-τ$ symmetry, which was shown to be preserved for neutrino propagating in matter. This symmetry reduces the neutrino transition probabilities to very simple forms when expressed in a rephasing invariant parametrization introduced earlier. Applications to long baseline experiments are discussed.
description: 12 pages, 4 figures
Communication, Awareness and Acceptance of Digital Banking Amidst Cash Crunch in Southeast and South-South, Nigeria
Creators: name: Onuegbu, Okechukwu Christopher
name: Agbamu, Bettina Oboakore
name: Anyakoha, Belinda Uju
name: Anunike, Ogonna Wilson
Publisher: name: arXiv
Year: 2025
Subjects: subject: General Economics (econ.GN)
subject: FOS: Economics and business

description: Digital banking is among the technological innovations currently reverberating the cyber wave. this study seeks to assess communication, awareness and acceptance of it among the residents of south-east and south-south, nigeria. the survey objectives were to ascertain awareness level of the south-east and south-south residents towards digital banking during the cash crunch, determine the acceptance level of digital banking among the south-east and south-south residents, find out the role of communication in awareness and acceptance of digital banking during the cash crunch in south-east and south-south nigeria, and assess the usage of digital banking amidst cash crunch in south-east and south nigeria. the study methodology is a sample survey which allowed researchers to administer questionnaires on 385 respondents out of the 50,166,807 study population. the findings showed that awareness level of digital banking was good (36%) in south-east and south-south nigeria during the cash crunch but it level of acceptance and usage improved more (37%) after the cash crunch. the study also ascertained that communication contribute significantly (59%) towards the usage and acceptance of digital banking in the two zones. it further showed that usage of digital banking in south-east and south-south has improved due to significant contributions of communication.
description: Pages 3043-5463, Volume 2, Issues 1
Location Planning for the Production of CO2-Based Chemicals Using the Example of Olefin Production†
Creators: name: Thonemann, Nils
name: Stießel, Sebastian
name: Maga, Daniel
name: Dresen, Boris
name: Hiebel, Markus
name: Hunstock, Björn
name: Deerberg, Görge
name: Weidner, Eckhard
Publisher: name: FID GEO
Year: 2020

description: Abstract A methodology for identifying suitable locations for the CO2-based production of olefins in Germany is presented. Based on electricity and CO2 requirements, locations are identified that can provide sufficient CO2 and renewable energy for the conversion of CO2 to olefins. In addition, the use of existing infrastructures is taken into account. The regional, technical renewable energy potential in Germany is sufficient to produce ∼ 800 kt of olefins from CO2-based methanol per year in one plant. But the currently available CO2 point sources with high CO2 concentrations of around 100 % are not sufficient to meet the CO2 requirement of an 800 kt a−1 methanol-to-olefins plant. If existing refineries are preferred due to existing infrastructure services, locations in the north of Cologne, in Lower Saxony, and in Brandenburg are particularly suitable. A full substitution of fossil olefins by CO2-based olefins is possible in Germany. The challenge is to provide sufficient renewable electricity for the production of H2 with a low CO2 intensity.
2540 km: Bimagic baseline for neutrino oscillation parameters
Creators: name: Dighe, Amol
name: Goswami, Srubabati
name: Ray, Shamayita
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show that a source-to-detector distance of 2540 km offers multiple advantages for a low energy neutrino factory with a detector that can identify muon charge. At this baseline, for any neutrino hierarchy, the wrong-sign muon signal is almost independent of CP violation and $θ_{13}$ in certain energy ranges. This reduces the uncertainties due to these parameters and allows the identification of the hierarchy in a clean way. In addition, part of the muon spectrum is also sensitive to the CP violating phase and $θ_{13}$, so that the same setup can be used to probe these parameters as well.
description: 4 pages, 4 figures, Revtex4. Text modified. Version to appear in PRL
Observation of Robust Néel Skyrmions in Metallic PtMnGa
Creators: name: Srivastava, Abhay K.
name: Devi, Parul
name: Sharma, Ankit K.
name: Ma, Tianping
name: Deniz, Hakan
name: Meyerheim, Holger L.
name: Felser, Claudia
name: Parkin, Stuart S. P.
Publisher: name: FID GEO
Year: 2019

description: Abstract Over the past decade the family of chiral noncollinear spin textures has continued to expand with the observation in metallic compounds of Bloch-like skyrmions in several B20 compounds, and antiskyrmions in a tetragonal inverse Heusler. Néel like skyrmions in bulk crystals with broken inversion symmetry have recently been seen in two distinct nonmetallic compounds, GaV4S8 and VOSe2O5 at low temperatures (below ≈13 K) only. Here, the first observation of bulk Néel skyrmions in a metallic compound PtMnGa and, moreover, at high temperatures up to ≈220 K is reported. Lorentz transmission electron microscopy reveals the chiral Néel character of the skyrmions. A strong variation is reported of the size of the skyrmions on the thickness of the lamella in which they are confined, varying by a factor of 7 as the thickness is varied from ≈90 nm to ≈4 µm. Moreover, the skyrmions are highly robust to in-plane magnetic fields and can be stabilized in a zero magnetic field using suitable field-cooling protocols over a very broad temperature range to as low as 5 K. These properties, together with the possibility of manipulating skyrmions in metallic PtMnGa via current induced spin–orbit torques, make them extremely exciting for future spintronic applications.
Self-Assembled Flexible and Integratable 3D Microtubular Asymmetric Supercapacitors
Creators: name: Li, Fei
name: Wang, Jinhui
name: Liu, Lixiang
name: Qu, Jiang
name: Li, Yang
name: Bandari, Vineeth Kumar
name: Karnaushenko, Daniil
name: Becker, Christian
name: Faghih, Maryam
name: Kang, Tong
name: Baunack, Stefan
name: Zhu, Minshen
name: Zhu, Feng
name: Schmidt, Oliver G.
Publisher: name: FID GEO
Year: 2019

description: Abstract The rapid development of microelectronics has equally rapidly increased the demand for miniaturized energy storage devices. On-chip microsupercapacitors (MSCs), as promising power candidates, possess great potential to complement or replace electrolytic capacitors and microbatteries in various applications. However, the areal capacities and energy densities of the planar MSCs are commonly limited by the low voltage window, the thin layer of the electrode materials and complex fabrication processes. Here, a new-type three-dimensional (3D) tubular asymmetric MSC with small footprint area, high potential window, ultrahigh areal energy density, and long-term cycling stability is fabricated with shapeable materials and photolithographic technologies, which are compatible with modern microelectronic fabrication procedures widely used in industry. Benefiting from the novel architecture, the 3D asymmetric MSC displays an ultrahigh areal capacitance of 88.6 mF cm−2 and areal energy density of 28.69 mW h cm−2, superior to most reported interdigitated MSCs. Furthermore, the 3D tubular MSCs demonstrate remarkable cycling stability and the capacitance retention is up to 91.8% over 12 000 cycles. It is believed that the efficient fabrication methodology can be used to construct various integratable microscale tubular energy storage devices with small footprint area and high performance for miniaturized electronics.
Dynamics of particle flips in two-dimensional quasicrystals
Creators: name: Engel, Michael
name: Umezaki, Masahiro
name: Trebin, Hans-Rainer
name: Odagaki, Takashi
Publisher: name: arXiv
Year: 2010
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The dynamics of quasicrystals is more complicated than the dynamics of periodic solids and difficult to study in experiments. Here, we investigate a decagonal and a dodecagonal quasicrystal using molecular dynamics simulations of the Lennard-Jones-Gauss interaction system. We observe that the short time dynamics is dominated by stochastic particle motion, so-called phason flips, which can be either single-particle jumps or correlated ring-like multi-particle moves. Over long times, the flip mechanism is efficient in reordering the quasicrystals and can generate diffusion. The temperature dependence of diffusion is described by an Arrhenius law. We also study the spatial distribution and correlation of mobile particles by analyzing the dynamic propensity.
description: 10 pages, 14 figures
Enzymatic Formation of Rufoschweinitzin, a Binaphthalene from the Basidiomycete Cortinarius rufoolivaceus
Creators: name: Thiele, Wiebke
name: Froede, Rita
name: Steglich, Wolfgang
name: Müller, Michael
Publisher: name: FID GEO
Year: 2020

description: Abstract Dimeric polyketides are widespread fungal secondary metabolites. They occur in both ascomycetes and basidiomycetes and, therefore, across fungal phyla. Here we report the isolation of a new binaphthalene, named rufoschweinitzin, from the basidiomycete Cortinarius rufoolivaceus. Rufoschweinitzin consists of two symmetrically 4,4′-coupled torachrysone-8-O-methyl ether moieties. Furthermore, we have identified a binaphthalene biosynthetic gene cluster in an unrelated fungus, the ascomycete Xylaria schweinitzii. Heterologous expression of the encoded cytochrome P450 enzyme verified its coupling activity: dimerization of torachrysone-8-O-methyl ether led to the formation of rufoschweinitzin alongside a hitherto unknown regioisomer, now named alloschweinitzin. We have thus demonstrated enzymatic formation of the basidiomycete's metabolite rufoschweinitzin and made the regiochemistry of alloschweinitzin accessible with an ascomycete-derived enzyme.
Spin-Orbit Symmetries of Conduction Electrons in Silicon
Creators: name: Li, Pengke
name: Dery, Hanan
Publisher: name: arXiv
Year: 2011
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: We derive a spin-dependent Hamiltonian that captures the symmetry of the zone edge states in silicon. We present analytical expressions of the spin-dependent states and of spin relaxation due to electron-phonon interactions in the multivalley conduction band. We find excellent agreement with experimental results. Similar to the usage of the Kane Hamiltonian in direct band-gap semiconductors, the new Hamiltonian can be used to study spin properties of electrons in silicon.
description: 4 pages, 1 figure, 1 table
Kontextsensitive Erkennung und Interpretation fahrrelevanter statischer Verkehrselemente
Creators: name: Nienhüser, Dennis
Publisher: name: Karlsruhe
Year: 2014

description: In dieser Arbeit werden Methoden und Verfahren zur Umwelterkennung und Situationsinterpretation entwickelt, mit denen statische Verkehrselemente (Verkehrszeichen und Ampeln) erkannt und im Kontext der Verkehrssituation interpretiert werden. Die Praxistauglichkeit der entwickelten Methoden und Verfahren wird durch umfangreiche Experimente demonstriert, bei denen auf die Verwendung realer Daten, kostengünstiger Sensorik und Echtzeitverarbeitung Wert gelegt wird.
Magnetocardiography with a modular spin-exchange relaxation free atomic magnetometer array
Creators: name: Wyllie, R
name: Kauer, M
name: Smetana, G
name: Wakai, R
name: Walker, T
Publisher: name: arXiv
Year: 2011
Subjects: subject: Medical Physics (physics.med-ph)
subject: Atomic Physics (physics.atom-ph)
subject: Instrumentation and Detectors (physics.ins-det)
subject: FOS: Physical sciences

description: We present a portable four-channel atomic magnetometer array operating in the spin exchange relaxation-free regime. The magnetometer array has several design features intended to maximize its suitability for biomagnetic measurement, specifically foetal magnetocardiography, such as a compact modular design, and fibre coupled lasers. The modular design allows the independent positioning and orientation of each magnetometer, in principle allowing for non-planar array geometries. Using this array in a magnetically shielded room, we acquire adult magnetocadiograms. These measurements were taken with a 6-11 fT Hz^(-1/2) single-channel baseline sensitivity that is consistent with the independently measured noise level of the magnetically shielded room.
description: 15 pages, 5 figures
The Black Hole Mass in Brightest Cluster Galaxy NGC 6086
Creators: name: McConnell, Nicholas J.
name: Ma, Chung-Pei
name: Graham, James R.
name: Gebhardt, Karl
name: Lauer, Tod R.
name: Wright, Shelley A.
name: Richstone, Douglas O.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We present the first direct measurement of the central black hole mass, M_BH, in NGC 6086, the Brightest Cluster Galaxy (BCG) in Abell 2162. Our investigation demonstrates for the first time that stellar dynamical measurements of M_BH in BCGs are possible beyond the nearest few galaxy clusters. We observed NGC 6086 with laser guide star adaptive optics and the integral-field spectrograph (IFS) OSIRIS at the W.M. Keck Observatory, and with the seeing-limited IFS GMOS-N at Gemini Observatory North. We combined the two IFS data sets with existing major-axis kinematics, and used axisymmetric stellar orbit models to determine M_BH and the R-band stellar mass-to-light ratio, M*/L_R. We find M_BH = 3.6(+1.7)(-1.1) x 10^9 M_Sun and M*/L_R = 4.6(+0.3)(-0.7) M_Sun/L_Sun (68% confidence), from models using the most massive dark matter halo allowed within the gravitational potential of the host cluster. Models fitting only IFS data confirm M_BH ~ 3 x 10^9 M_Sun and M*/L_R ~ 4 M_Sun/L_Sun, with weak dependence on the dark matter halo structure. When data out to 19 kpc are included, the unrealistic omission of dark matter causes the best-fit black hole mass to decrease dramatically, to 0.6 x 10^9 M_Sun, and the best-fit stellar mass-to-light ratio to increase to 6.7 M_Sun/L_Sun. The latter value is at further odds with stellar population studies favoring M*/L ~ 2 M_Sun/L_Sun,R. Biases from dark matter omission could extend to dynamical models of other galaxies with central stellar cores, and new measurements of M_BH from models with dark matter could steepen the empirical scaling relationships between black holes and their host galaxies.
description: 22 pages, 19 figures; accepted for publication in ApJ
The Magnetoviscous-thermal Instability
Creators: name: Islam, Tanim
Publisher: name: arXiv
Year: 2011
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: Plasma Physics (physics.plasm-ph)
subject: FOS: Physical sciences

description: Accretion flows onto underluminous black holes, such as Sagittarius A* at the center of our galaxy, are dilute (mildly collisional to highly collisionless), optically thin, and radiatively inefficient. Therefore, the accretion properties of such dilute flows are expected to be modified by their large viscosities and thermal conductivities. Second, turbulence within these systems needs to transport angular momentum as well as thermal energy generated through gravitational infall outwards in order to allow accretion to occur. This is in contrast to classical accretion flows, in which the energy generated through accretion down a gravitational well is locally radiated. In this paper, using an incompressible fluid treatment of an ionized gas, we expand on previous research by considering the stability properties of a magnetized rotating plasma wherein the thermal conductivity and viscosity are not negligible and may be dynamically important. We find a class of MHD instabilities that can transport angular momentum and thermal energy outwards. They are plausible candidates to describe accretion in radiatively inefficient accretion flows (RIAFs). We finish by discussing the implications for analytic models and numerical MHD simulations of mildly dilute or collisionless astrophysical plasmas, and immediate directions for further research.
description: submitted to the Astrophysical Journal, Revision 1
Spectrum of the Wilson Dirac Operator at Finite Lattice Spacings
Creators: name: Akemann, G.
name: Damgaard, P. H.
name: Splittorff, K.
name: Verbaarschot, J. J. M.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We consider the effect of discretization errors on the microscopic spectrum of the Wilson Dirac operator using both chiral Perturbation Theory and chiral Random Matrix Theory. A graded chiral Lagrangian is used to evaluate the microscopic spectral density of the Hermitian Wilson Dirac operator as well as the distribution of the chirality over the real eigenvalues of the Wilson Dirac operator. It is shown that a chiral Random Matrix Theory for the Wilson Dirac operator reproduces the leading zero-momentum terms of Wilson chiral Perturbation Theory. All results are obtained for fixed index of the Wilson Dirac operator. The low-energy constants of Wilson chiral Perturbation theory are shown to be constrained by the Hermiticity properties of the Wilson Dirac operator.
description: 48 pages, 8 figures,v2 minor corrections same version as published in PRD
Katalytische Difunktionalisierung von nichtaktivierten Alkenen mit reaktionsträgem Hexamethyldisilan durch Neubildung von Silyliumionen
Creators: name: Wu, Qian
name: Roy, Avijit
name: Irran, Elisabeth
name: Qu, Zheng-Wang
name: Grimme, Stefan
name: Klare, Hendrik F. T.
name: Oestreich, Martin
Publisher: name: FID GEO
Year: 2019

description: Abstract Es wird über eine metallfreie, intermolekulare syn-Addition von Hexamethyldisilan an einfache Alkene berichtet. Der Katalysezyklus wird durch die Übertragung einer Methylgruppe des Disilans auf eine Silyliumion-artige Zwischenstufe eingeleitet und aufrechterhalten, was der (Neu)bildung des Silyliumion-Katalysators gleichkommt. Das Hauptmerkmal der Reaktionssequenz ist die Spaltung der Si-Si-Bindung im Zuge einer 1,3-Silylwanderung von Silicium nach Kohlenstoff. Eine zentrale Zwischenstufe der Katalyse wurde durch Röntgenbeugung strukturell charakterisiert, und der berechnete Reaktionsmechanismus steht in vollständigem Einklang mit den experimentellen Befunden.
Superconducting Vortices induced Periodic Magnetoresistance Oscillations in Single Crystal Au Nanowires
Creators: name: He, Lin
name: Wang, Jian
Publisher: name: arXiv
Year: 2011
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We show in this paper that it is possible to induce superconducting vortices in a gold nanowire connected to superconducting electrodes. The gold nanowire acquires superconductivity by the proximity effect. The differential magnetoresistance of the nanowire beyond a critical magnetic field shows uniform oscillations with increasing field with a period of \phi0/(2\pir^2) (\phi0 = h/2e is the superconducting flux quantum, r = 35 nm is the radius of the nanowire). We demonstrate that these periodic oscillations are the signatures of the sequential generation and moving of vortices across the gold nanowire.
Background Reduction Methods and Vacuum Technology at the KATRIN Spectrometers
Creators: name: Görhardt, Stefan
Publisher: name: Karlsruhe
Year: 2014
Subjects: KATRIN
vacuum
bake-out
NEG
LN2 cooled baffle

description: The goal of KATRIN is to measure the absolute mass of the electron-antineutrino with a sensitivity of 200 meV by analyzing the shape of the tritium-beta-decay energy spectrum. To minimize the background due to residual gas ionization, a pressure in the lower 10E-11 mbar region is required. This work focuses on the applied vacuum technology. In addition a system of LN2 cooled baffles was designed that eliminates radon-induced background, which is essential for a neutrino mass measurement.
Solid-State and Gas-Phase Structures and Energetic Properties of the Dangerous Methyl and Fluoromethyl Nitrates
Creators: name: Reichel, Marco
name: Krumm, Burkhard
name: Vishnevskiy, Yury V.
name: Blomeyer, Sebastian
name: Schwabedissen, Jan
name: Stammler, Hans-Georg
name: Karaghiosoff, Konstantin
name: Mitzel, Norbert W.
Publisher: name: FID GEO
Year: 2019

description: Abstract An improved synthesis of the simplest nitric acid ester, methyl nitrate, and a new synthesis of fluoromethyl nitrate use the metathesis of the corresponding iodomethanes with silver nitrate. Both compounds were identified by spectroscopy and the structures determined for in situ grown crystals by X-ray diffraction as well as in the gas phase by electron diffraction. Fluorination leads to structures with shorter C−O and N−O bonds, has an energetically destabilizing effect and increases friction sensitivity, but decreases detonation performance.
Quantum fluctuations and strong mass renormalization in NiCl2-4SC(NH2)2
Creators: name: Kohama, Y.
name: Sologubenko, A.
name: Dilley, N. R.
name: Zapf, V. S.
name: Jaime, M.
name: Mydosh, J.
name: Paduan-Filho, A.
name: Al-Hassanieh, K.
name: Sengupta, P.
name: Gangadharaiah, S.
name: Chernyshev, A. L.
name: Batista, C. D.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: In a number of quantum paramagnets, magnetic field can induce a quantum phase transition to an antiferromagnetic state which exists for a range of fields Hc1 < H < Hc2. Generally, these compounds exhibit a significant asymmetry in their properties at low- and high-field transitions. Here we present detailed specific heat and thermal conductivity measurements in NiCl2-4SC(NH2)2 together with analytical and numerical results. We show that the asymmetry is caused by a strong renormalization of the effective mass of spin excitations due to quantum fluctuations for H
description: 4 pages, 3 figures. Acepted for publication in Phy. Rev. Lett
Threshold resummation for Drell-Yan production: theory and phenomenology
Creators: name: Bonvini, Marco
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a phenomenological study of Drell-Yan pair production at hadron colliders based on the NNLO fixed order calculation and on NNLL resummation of threshold logarithms. We give an argument to prove that resummation effects are relevant also for values of x=M^2/s far from threshold. We compare different prescriptions for the calculation of resummed quantities, emphasizing the differences coming from subleading terms, which are important when x is small. We present phenomenological predictions for Drell-Yan rapidity distributions at the LHC, we study the ambiguity related to the resummation prescription, and we compare it to that coming from scale variation.
description: 6 pages, 3 figures
Modellbasierter Ansatz zur probabilistischen Interpretation von Fahrsituationen
Creators: name: Schamm, Thomas
Publisher: name: Karlsruhe
Year: 2014
Subjects: Fahrerassistenz
Situationsinterpretation
Umfelderkennung

description: Diese Arbeit stellt ein methodisches Konzept vor, welches eine probabilistische Interpretation von Fahrsituationen auf Basis der Objekte im Fahrzeugumfeld ermöglicht. Wissen über Fahrsituationen wird in einer formalen Repräsentation abgelegt. Abhängig von den gemessenen Objektinformationen der Umfeldsensorik wird daraus ein graphisches Modell erzeugt. Aus diesem werden durch Inferenz Schlüsse über die Fahrsituation gezogen. Das Konzept wurde in Experimenten und realen Situationen erprobt.
Utilisation of trace element contents in benthic foraminifera for reconstructing sea water composition
Creators: name: Munsel, Dirk
Publisher: name: Karlsruhe
Year: 2014

description: Ausgewählte Spurenelemente wurden im Labor unter kontrollierten Umweltbedingungen in karbonatische Gehäuse benthischer Foraminiferen eingebaut. Die Konzentrationen aller verwandten Elemente wurden in neu gewachsenen Kammern mittels µ-Sy-RFA und LA-ICP-MS ermittelt. Die hieraus errechneten Verteilungskoeffizienten wurden zunächst für eine rezente Spezies, in einem zweiten Schritt dann für eine fossile Spezies benthischer Foraminiferen zur Rekonstruktion der Ozeanbedingungen angewandt.
Understanding the Structure and Properties of Sesqui-Chalcogenides (i.e., V2VI3 or Pn2Ch3 (Pn = Pnictogen, Ch = Chalcogen) Compounds) from a Bonding Perspective
Creators: name: Cheng, Yudong
name: Cojocaru-Mirédin, Oana
name: Keutgen, Jens
name: Yu, Yuan
name: Küpers, Michael
name: Schumacher, Mathias
name: Golub, Pavlo
name: Raty, Jean-Yves
name: Dronskowski, Richard
name: Wuttig, Matthias
Publisher: name: FID GEO
Year: 2019

description: Abstract A number of sesqui-chalcogenides show remarkable properties, which make them attractive for applications as thermoelectrics, topological insulators, and phase-change materials. To see if these properties can be related to a special bonding mechanism, seven sesqui-chalcogenides (Bi2Te3, Bi2Se3, Bi2S3, Sb2Te3, Sb2Se3, Sb2S3, and β-As2Te3) and GaSe are investigated. Atom probe tomography studies reveal that four of the seven sesqui-chalcogenides (Bi2Te3, Bi2Se3, Sb2Te3, and β-As2Te3) show an unconventional bond-breaking mechanism. The same four compounds evidence a remarkable property portfolio in density functional theory calculations including large Born effective charges, high optical dielectric constants, low Debye temperatures and an almost metal-like electrical conductivity. These results are indicative for unconventional bonding leading to physical properties distinctively different from those caused by covalent, metallic, or ionic bonding. The experiments reveal that this bonding mechanism prevails in four sesqui-chalcogenides, characterized by rather short interlayer distances at the van der Waals like gaps, suggestive of significant interlayer coupling. These conclusions are further supported by a subsequent quantum-chemistry-based bonding analysis employing charge partitioning, which reveals that the four sesqui-chalcogenides with unconventional properties are characterized by modest levels of charge transfer and sharing of about one electron between adjacent atoms. Finally, the 3D maps for different properties reveal discernible property trends and enable material design.
Ultrafast Internal Conversion in Ethylene I. The Excited State Lifetime
Creators: name: Tao, H.
name: Allison, T. K.
name: Wright, T. W.
name: Stooke, A. M.
name: Khurmi, C.
name: van Tilborg, J.
name: Liu, Y.
name: Falcone, R. W.
name: Belkacem, A.
name: Martinez, T. J.
Publisher: name: arXiv
Year: 2011
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Using a combined theoretical and experimental approach, we investigate the non-adiabatic dynamics of the prototypical ethylene (C2H4) molecule upon π \to π* excitation. In this first part of a two part series, we focus on the lifetime of the excited electronic state. The femtosecond Time-Resolved Photoelectron Spectrum (TRPES) of ethylene is simulated based on our recent molecular dynamics simulation using the ab initio multiple spawning method (AIMS) with Multi-State Second Order Perturbation Theory (Tao, et al. J. Phys. Chem. A 113 13656 2009). We find excellent agreement between the TRPES calculation and the photoion signal observed in a pump-probe experiment using femtosecond vacuum ultraviolet (hν = 7.7 eV) pulses for both pump and probe. These results explain the apparent discrepancy over the excited state lifetime between theory and experiment that has existed for ten years, with experiments (e.g., Farmanara, et al. Chem. Phys. Lett. 288 518 1998 and Kosma, et al. J. Phys. Chem. A 112 7514 2008) reporting much shorter lifetimes than predicted by theory. Investigation of the TRPES indicates that the fast decay of the photoion yield originates from both energetic and electronic factors, with the energetic factor playing a larger role in shaping the signal.
Structure Function Sum rules for Systems with Large Scattering Lengths
Creators: name: Goldberger, Walter D.
name: Rothstein, Ira Z.
Publisher: name: arXiv
Year: 2010
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Quantum Gases (cond-mat.quant-gas)
subject: High Energy Physics - Theory (hep-th)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We use a dispersion relation in conjunction with the operator product expansion (OPE) to derive model independent sum rules for the dynamic structure functions of systems with large scattering lengths. We present an explicit sum rule for the structure functions that control the density and spin response of the many-body ground state. Our methods are general, and apply to either fermions or bosons which interact through two-body contact interactions with large scattering lengths. By employing a Borel transform of the OPE, the relevant integrals are weighted towards infrared frequencies, thus allowing for greater overlap low energy data. Similar sum rules can be derived for other response functions. The sum rules can be used to extract the contact parameter introduced by Tan, including universality violating corrections at finite scattering lengths.
description: Added sum rule for polarized correlator which is dominated by the contact operator. Some typos fixed
Stability of Gieseker stable sheaves on K3 surfaces in the sense of Bridgeland and some applications
Creators: name: Kawatani, Kotaro
Publisher: name: arXiv
Year: 2011
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics

description: We show that some Gieseker stable sheaves on a projective K3 surface $X$ are stable with respect to a stability condition of Bridgeland on the derived category of $X$ if the stability condition is in explicit subsets of the space of stability conditions depending on the sheaves. Furthermore we shall give two applications of the result. As a part of these applications, we show that the fine moduli space of Gieseker stable torsion free sheaves on a K3 surface with Picard number one is the moduli space of $μ$-stable locally free sheaves if the rank of the sheaves is not a square number.
description: 34 pages, v2:we added one figure in page 23
Overload Capability of the Modular Multilevel Matrix Converter for Feeding High Torque Low Speed Drives
Creators: name: Kammerer, Felix
name: Gommeringer, Mario
name: Kolb, Johannes
name: Braun, Michael
Publisher: name: Karlsruhe
Year: 2014

description: In drive systems, the semiconductors of conventional converters must be dimensioned for the maximum torque. This results in a converter oversizing even for short time overload requirements near standstill, e.g. for mills in the mining industry. In contrast, the Modular Multilevel Matrix Converter (M3C) is characterized by the ability to share the installed switching power between the input and output side. Hence an overload capability up to 200% of the nominal value can be reached at low speeds without additional efforts. This paper explains how the overload capability is used and analyzes the overload torque limits in the whole speed range.
Polaronic signatures and spectral properties of graphene antidot lattices
Creators: name: Stojanovic, Vladimir M.
name: Vukmirovic, Nenad
name: Bruder, C.
Publisher: name: arXiv
Year: 2010
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Other Condensed Matter (cond-mat.other)
subject: FOS: Physical sciences

description: We explore the consequences of electron-phonon (e-ph) coupling in graphene antidot lattices (graphene nanomeshes), i.e., triangular superlattices of circular holes (antidots) in a graphene sheet. They display a direct band gap whose magnitude can be controlled via the antidot size and density. The relevant coupling mechanism in these semiconducting counterparts of graphene is the modulation of the nearest-neighbor electronic hopping integrals due to lattice distortions (Peierls-type e-ph coupling). We compute the full momentum dependence of the e-ph vertex functions for a number of representative antidot lattices. Based on the latter, we discuss the origins of the previously found large conduction-band quasiparticle spectral weight due to e-ph coupling. In addition, we study the nonzero-momentum quasiparticle properties with the aid of the self-consistent Born approximation, yielding results that can be compared with future angle-resolved photoemission spectroscopy measurements. Our principal finding is a significant e-ph mass enhancement, an indication of polaronic behavior. This can be ascribed to the peculiar momentum dependence of the e-ph interaction in these narrow-band systems, which favors small phonon momentum scattering. We also discuss implications of our study for recently fabricated large-period graphene antidot lattices.
description: published version