cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Evolution of Electronic Structure in Atomically Thin Sheets of WS2 and WSe2
Creators: name: Zhao, Weijie
name: Ghorannevis, Zohreh
name: Chua, Leiqiang
name: Toh, Minglin
name: Kloc, Christian
name: Tan, Ping-Heng
name: Eda, Goki
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Geometrical confinement effect in exfoliated sheets of layered materials leads to significant evolution of energy dispersion with decreasing layer thickness. Molybdenum disulphide (MoS2) was recently found to exhibit indirect to direct gap transition when the thickness is reduced to a single monolayer. This leads to remarkable enhancement in the photoluminescence efficiency, which opens up new opportunities for the optoelectronic applications of the material. Here we report differential reflectance and photoluminescence (PL) spectra of mono- to few-layer WS2 and WSe2 that indicate that the band structure of these materials undergoes similar indirect to direct transition when thinned to a single monolayer. Strong enhancement in PL quantum yield is observed for monoayer WS2 and WSe2 due to exciton recombination at the direct band edge. In contrast to natural MoS2 crystals extensively used in recent studies, few-layer WS2 and WSe2 show comparatively strong indirect gap emission along with distinct direct gap hot electron emission, suggesting high quality of synthetic crystals prepared by chemical vapor transport method. Fine absorption and emission features and their thickness dependence suggest strong effect of Se p-orbitals on the d electron band structure as well as interlayer coupling in WSe2.
description: to be published in ACS Nano
Surface structure and reactivity of platinum in the oxidation of ammonia
Creators: name: Zeng, Yingfeng
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2008
Subjects: subject: Platinum
subject: ammonia-oxidation
subject: catalysts
subject: Pt(533)
subject: Pt(443)
subject: Pt(865)
subject: Pt(100)
subject: Pt foil
subject: hysteresis
subject: ammonia
subject: NO
subject: nitrogen
subject: phase transition
subject: structure sensitivity
subject: restructuring
subject: pressure gap
subject: material gap
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: [no abstract]
Jasminum fruticans Jacq.
Creators: name: Becherer
Publisher: name: Zenodo
Year: 1956
Subjects: Biodiversity
Taxonomy

description: V. fruticans Jacq. (V. saxatilis Scop.) Cat. 274und429. Bis 3130m. l: Sex du Coeur (J.); Linleux (J.). - 3: Penninische Kette verbreitet; hohe Stellen: Oberrothorn bei Zermatt, 3000 m (Gilomen 1938); Gornergrat bei Zermatt, 3130 m (Braun-Blanquet 1919). - 4: Binntal (Binz); Rappental (B. C. W.). Forma stenophylla Briq. (f. angusta Vierhapper) - 3: Riffelberg bei Zermatt (Vierhapper). Mit rosa Blüten: Bielen bei Saas-Fee (Hirschmann); mit weissen Blüten: Hohnegg bei Saas-Fee (idem).
description: Published as part of Becherer, 1956, Florae Vallesiacae Supplementum, pp. 1-556 in Denkschriften der Schweizerischen Naturforschenden Gesellschaft 71 on pages 1-556
Synthesis and characterisation of alkali metal tungsten bronzes, Lix WO3 and Mx M'y W1-y O3 (M = Li, Na, Cs and M' = Nb, Mo) systems
Creators: name: Dey, Kalpana Rani
Publisher: name: Hannover : Universität
Year: 2004
Subjects: subject: Tungsten bronze systems: Li-Nb-PTB/Cs-Nb-HTB
subject: optical properties
subject: phase stability range
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: [no abstract]
Inhalt I. Quartal 2017/Aktuelle Ausstellungen/Impressum
Creators: name: Redaktion, Die
Publisher: name: KulturGut : aus der Forschung des Germanischen Nationalmuseums
Year: 2016

description: KulturGut : aus der Forschung des Germanischen Nationalmuseums, Nr. 52 (2017): KulturGut: aus der Forschung des Germanischen Nationalmuseums
Synthesis and characterization of one-dimensional oxide nanotubes encapsulated with platinum metal nanoparticles
Creators: name: Aresipathi, Catherine
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2009
Subjects: subject: Oxide nanotubes
subject: templating structures
subject: nanofibers
subject: magnus salt
subject: sol-gel process
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: [no abstract]
Combining heavy quark spin and local hidden gauge symmetries in the dynamical generation of hidden charm baryons
Creators: name: Xiao, C. W.
name: Nieves, J.
name: Oset, E.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present a coupled channel unitary approach to obtain states dynamically generated from the meson baryon interaction with hidden charm, using constraints of heavy quark spin symmetry. We use as basis of states, $\bar D B$, $\bar D^* B$ states, with $B$ baryon charmed states belonging to the 20 representations of SU(4) with $J^P=1/2^+,~3/2^+$. In addition we also include the $η_c N$ and $J/ψN$ states. The inclusion of these coupled channels is demanded by heavy quark spin symmetry, since in the large $m_Q$ limit the $D$ and $D^*$ states are degenerate and are obtained from each other by means of a spin rotation, under which QCD is invariant. The novelty in the work is that we use dynamics from the extrapolation of the local hidden gauge model to SU(4) and we show that this dynamics fully respects the constraints of heavy quark spin symmetry. With the full space of states demanded by the heavy quark spin symmetry and the dynamics of the local hidden gauge we look for states dynamically generated and find four basic states which are bound, corresponding to $\bar D Σ_c$, $\bar D Σ_c^*$, $\bar D^* Σ_c$ and $\bar D^* Σ_c^*$, decaying mostly into $η_c N$ and $J/ψN$. All the states appear in isospin $I=1/2$ and we find no bound states or resonances in $I=3/2$. The $\bar D Σ_c$ state appears in $J=1/2$, the $\bar D Σ_c^*$ in $J=3/2$, the $\bar D^* Σ_c$ appears nearly degenerate in $J=1/2, ~3/2$ and the $\bar D^* Σ_c^*$ appears nearly degenerate in $J=1/2, ~3/2, ~5/2$, with the peculiarity that in $J=5/2$ the state has zero width in the space of states chosen. All the states are bound with about 50 MeV with respect to the corresponding $\bar D B$ thresholds and the width, except for the $J=5/2$ state, is also of the same order of magnitude.
Synthesis of new dioxatricyclic oxetanes and aza-analogues of the marine natural product dictyoxetane
Creators: name: Martínez Lamenca, Carolina
Publisher: name: Hannover : Universität
Year: 2004
Subjects: subject: Dioxatricyclic segments
subject: oxetane
subject: azetidine
subject: tandem reactions
subject: azaglycosides
subject: Dewey Decimal Classification::500 | Naturwissenschaften::540 | Chemie

description: [no abstract]
Program Verification in the presence of complex numbers, functions with branch cuts etc
Creators: name: Davenport, James H.
name: Bradford, Russell
name: England, Matthew
name: Wilson, David
Publisher: name: arXiv
Year: 2012
Subjects: subject: Symbolic Computation (cs.SC)
subject: FOS: Computer and information sciences

description: In considering the reliability of numerical programs, it is normal to "limit our study to the semantics dealing with numerical precision" (Martel, 2005). On the other hand, there is a great deal of work on the reliability of programs that essentially ignores the numerics. The thesis of this paper is that there is a class of problems that fall between these two, which could be described as "does the low-level arithmetic implement the high-level mathematics". Many of these problems arise because mathematics, particularly the mathematics of the complex numbers, is more difficult than expected: for example the complex function log is not continuous, writing down a program to compute an inverse function is more complicated than just solving an equation, and many algebraic simplification rules are not universally valid. The good news is that these problems are theoretically capable of being solved, and are practically close to being solved, but not yet solved, in several real-world examples. However, there is still a long way to go before implementations match the theoretical possibilities.
A possible evolutionary scenario of highly magnetized super-Chandrasekhar white dwarfs: progenitors of peculiar type Ia supernovae
Creators: name: Das, Upasana
name: Mukhopadhyay, Banibrata
name: Rao, A. R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Several recently discovered peculiar type Ia supernovae seem to demand an altogether new formation theory that might help explain the puzzling dissimilarities between them and the standard type Ia supernovae. The most striking aspect of the observational analysis is the necessity of invoking super-Chandrasekhar white dwarfs having masses ~ 2.1-2.8M_sun, M_sun being the mass of Sun, as their most probable progenitors. Strongly magnetized white dwarfs having super-Chandrasekhar masses were already established to be potential candidates for the progenitors of peculiar type Ia supernovae. Owing to the Landau quantization of the underlying electron degenerate gas, theoretical results yielded the observationally inferred mass range. Here we sketch a possible evolutionary scenario by which super-Chandrasekhar white dwarfs could be formed by accretion on to a commonly observed magnetized white dwarf, invoking the phenomenon of flux freezing. This opens the multiple possible evolutions ending in supernova explosions of super-Chandrasekhar white dwarfs having masses within the range stated above. We point out that our proposal has observational support, like, the recent discovery of a large number of magnetized white dwarfs by SDSS.
description: 5 pages including 3 figures; to appear in The Astrophysical Journal Letters
Two questions on polynomial decomposition
Creators: name: Wyman, Brian
name: Zieve, Michael
Publisher: name: arXiv
Year: 2013
Subjects: subject: Commutative Algebra (math.AC)
subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 13B25, 11C08

description: Given a univariate polynomial f(x) over a ring R, we examine when we can write f(x) as g(h(x)) where g and h are polynomials of degree at least 2. We answer two questions of Gusic regarding when the existence of such g and h over an extension of R implies the existence of such g and h over R. We also pose two new questions along these lines.
description: 7 pages
Transverse single spin asymmetries of charged hadrons at forward and backward rapidity in p+p, p+Al and p+Au collisions in PHENIX
Creators: name: Bok, Jeongsu
Publisher: name: Zenodo
Year: 2023
Subjects: dis23
phenix
p+p
p+al
p+au
transverse spin asymmetry
hadron
forward-rapidity
backward-rapidity
muon arms

description: Talk presented at the Deep Inelastic Scattering 2023 conference
Performance Analysis of Parallel Pollard's Rho Algorithm
Creators: name: Koundinya, Anjan K.
name: G., Harish
name: K., Srinath N.
name: E., Raghavendra G.
name: V., Pramod Y.
name: R., Sandeep
name: G, Punith Kumar
Publisher: name: arXiv
Year: 2013
Subjects: subject: Distributed, Parallel, and Cluster Computing (cs.DC)
subject: FOS: Computer and information sciences

description: Integer factorization is one of the vital algorithms discussed as a part of analysis of any black-box cipher suites where the cipher algorithm is based on number theory. The origin of the problem is from Discrete Logarithmic Problem which appears under the analysis of the crypto-graphic algorithms as seen by a crypt-analyst. The integer factorization algorithm poses a potential in computational science too, obtaining the factors of a very large number is challenging with a limited computing infrastructure. This paper analyses the Pollards Rho heuristic with a varying input size to evaluate the performance under a multi-core environment and also to estimate the threshold for each computing infrastructure.
description: 8 pages, 4 figures, Journal
Sustainability assessment of land use systems
Creators: name: Walter, Christof
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2006
Subjects: subject: Sustainable agriculture
subject: sustainability assessment
subject: land use systems
subject: Dewey Decimal Classification::600 | Technik::630 | Landwirtschaft, Veterinärmedizin

description: [no abstract]
Veronica dillenii Crantz
Creators: name: Becherer
Publisher: name: Zenodo
Year: 1956
Subjects: Biodiversity
Taxonomy

description: V. Dillenii Crantz (V. succulenta All., V. verna var. longistyla Ces., Pass. et Gib.) Trockenrasen, Äcker. Hierher vermutlich die Angaben des Cat. 273 unter V. verna var. succulenta: Tourbillon bei Sitten, St-Martin (Hörens) und Wirbel nördlich Fiescherthal.- Bis2120m:bei Zermatt. l: Les Oranges, 1050 m (Oberson); Chemin des Messieurs bei Salvan, 1150 m (idem). - 2: Fully (Garns);obHohtenn(Zwicky);Leiggern(idem); Ausserberg-Baltschieder (Huber); westlich der Seilbahn Naters-Birgisch, Steilhang ob der Lötschbergbahn (Seitter); südlich Hegdorn (Kunz); nördlichMassaeggen (idem). - 3: Bei Bourg-St-Pierre, 1600m (Heinis); Bagnes (Garns); Iserables, 1100m (Oberson); Chandolin, 1800-1930 m (Bernoulli); Törbel (Stebler); Findelen bei Zermatt, bis in die letzten Roggenfelder, 2120 m (Thellung 1922); Saastal: Gspon (Gyhr), Heimischgarten, Tälwaldji, Bodmen, Bidermatten-Tamatten (alles: Becherer und Thommen), zwischen Unter-dem-Berg und Grund, FUSS des Grundberges (beides: Becherer), mehrfach ferner bei Fee: nördlich der «Wildi» (Tschopp), bei den Bielen (Tschopp und Schatzmann) und bei Hohnegg (Bührer); Birch bei Visperterminen (Gams). - 3a: Simplon-Dorf (v. Tavel); Gabi (Dinter). - 4: ZwischenBrig und Termen (B.B.T.Z.); Bitsch (Koch); Z'Matt-Mörel (Däniker; Becherer und Zwicky); Binneggen (H. Frey); Binn (nach Schinzund Keller); Ulrichen (Baur).
description: Published as part of Becherer, 1956, Florae Vallesiacae Supplementum, pp. 1-556 in Denkschriften der Schweizerischen Naturforschenden Gesellschaft 71 on pages 1-556
TcdE: the silent member in the pathogenicity locus of Clostridium difficile?
Creators: name: Olling, Alexandra
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2009
Subjects: subject: Clostridium difficile
subject: TcdE
subject: bacterial lysis
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit

description: [no abstract]
Temporal and spatial analyses of citrus variegated chlorosis and coffee leaf scorch, caused by Xylella fastidiosa
Creators: name: Denecke, Andrea
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2006
Subjects: subject: Xylella fastidiosa
subject: citrus variegated chlorosis
subject: coffee leaf scorch
subject: temporal progress
subject: spatial spread
subject: Dewey Decimal Classification::600 | Technik::630 | Landwirtschaft, Veterinärmedizin

description: [no abstract]
Innocent Bystanders: Carbon Stars from the Sloan Digital Sky Survey
Creators: name: Green, Paul J.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Among stars showing carbon molecular bands (C stars), the main sequence dwarfs, likely in post-mass transfer binaries, are numerically dominant in the Galaxy. Via spectroscopic selection from the Sloan Digital Sky Survey, we retrieve 1220 C stars, ~5 times more than previously known, including a wider variety than past techniques such as color or grism selection have netted, and additionally yielding 167 DQ white dwarfs. Of the C stars with proper motion measurements, we identify 69% as clearly dwarfs (dCs), while ~7% are giants. The dCs likely span absolute magnitudes M_i from ~6.5 to 10.5. "G-type" dC stars with weak CN and relatively blue colors are probably the most massive dCs still cool enough to show C_2 bands. We report Balmer emission in 22 dCs, none of which are G-types. We find 8 new DA/dC stars in composite spectrum binaries, quadrupling the total sample of these "smoking guns" for AGB binary mass transfer. Eleven very red C stars with strong red CN bands appear to be "N"-type AGB stars at large Galactocentric distances, one likely a new discovery in the dIrr galaxy Leo A. Two such stars within 30arcmin of each other may trace a previously unidentified dwarf galaxy or tidal stream at ~40 kpc. We explore the multiwavelength properties of the sample and report the first X-ray detection of a dC star, which shows strong Balmer emission. Our own spectroscopic survey additionally provides the dC surface density from a complete sample of dwarfs limited by magnitude, color, and proper-motion.
description: 42 pages, 11pt preprint; accepted for ApJ January 15, 2013. Full data tables for main sample and DQ sample included
A High Rate Tension Device for Characterizing Brain Tissue
Creators: name: Rashid, Badar
name: Destrade, Michel
name: Gilchrist, Michael
Publisher: name: arXiv
Year: 2013
Subjects: subject: Biological Physics (physics.bio-ph)
subject: Medical Physics (physics.med-ph)
subject: Tissues and Organs (q-bio.TO)
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The mechanical characterization of brain tissue at high loading velocities is vital for understanding and modeling Traumatic Brain Injury (TBI). The most severe form of TBI is diffuse axonal injury (DAI) which involves damage to individual nerve cells (neurons). DAI in animals and humans occurs at strains > 10% and strain rates > 10/s. The mechanical properties of brain tissues at these strains and strain rates are of particular significance, as they can be used in finite element human head models to accurately predict brain injuries under different impact conditions. Existing conventional tensile testing machines can only achieve maximum loading velocities of 500 mm/min, whereas the Kolsky bar apparatus is more suitable for strain rates > 100/s. In this study, a custom-designed high rate tension device is developed and calibrated to estimate the mechanical properties of brain tissue in tension at strain rates < 90/s, while maintaining a uniform velocity. The range of strain can also be extended to 100% depending on the thickness of a sample. The same apparatus can be used to characterize the dynamic behavior of skin and other soft biological tissues by using appropriately sized load cells with a capacity of 10 N and above.
description: 10 pages
Type-I X-ray bursts reveal a fast co-evolving behavior of the corona in an X-ray binary
Creators: name: Chen, Yu-Peng
name: Zhang, Shu
name: Zhang, Shuang-Nan
name: Li, Jian
name: Wang, Jian-Min
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The coronae in X-ray binaries (XRBs) still remain poorly understood, although they have been believed for a long time to play a key role in modeling the characteristic outbursts of XRBs. Type-I X-ray bursts, the thermonuclear flashes happening on the surface of a neutron star (NS), can be used as a probe to the innermost region of a NS XRB, where the corona is believed to be located very close to the NS. We report the discovery of a tiny life cycle of the corona that is promptly co-evolved with the type-I bursts superimposed on the outburst of the NS XRB IGR J17473$-$2721. This finding may serve as the first evidence of directly seeing the rapid disappearance and formation of a corona in an XRB with a cooling/heating timescale of less than a second, which can strongly constrain the accretion models in XRBs at work.
description: The Astrophysical Journal, 2012, 752, L34
Ulrike Müssemeier, Die merowingerzeitlichen Funde aus der Stadt Bonn und ihrem Umland
Creators: name: Theuws, Frans
Publisher: name: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts
Year: 2016

description: Rezension zu: Ulrike Müssemeier, Die merowingerzeitlichen Funde aus der Stadt Bonn und ihrem Umland. Rheinische Ausgrabungen volume 67. Philipp von Zabern, Darmstadt 2012. € 98.50. ISBN 978-3-8053-4794-5. 548 pages, 233 plates, 9 maps, 2 supplements.
description: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts, Bd. 93 (2015)
Tryptophan scanning of barttin identifies molecular determinants of its function on CIC-K chloride channels
Creators: name: Wojciechowski, Daniel
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2013
Subjects: subject: Mutagenese Scan
subject: CIC-K Chlorid Kanäle
subject: Barttin
subject: mutagenesis scan
subject: CIC-K chloride channels
subject: Dewey Decimal Classification::500 | Naturwissenschaften::570 | Biowissenschaften, Biologie

description: [no abstract]
Transparent self-cleaning coatings on polycarbonate surfaces
Creators: name: Fateh, Razan
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2014
Subjects: subject: Self-cleaning
subject: adhesion
subject: mechanical stability
subject: thin film
subject: photocatalysis
subject: superhydrophilicity
subject: Selbstreinigung
subject: Haftfestigkeit
subject: mechanische Festigkeit
subject: Dünnschicht
subject: Photokatalyse
subject: Superhydrophilie
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: [no abstract]
Symmetry protected topological phases from decorated domain walls
Creators: name: Chen, Xie
name: Lu, Yuan-Ming
name: Vishwanath, Ashvin
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Symmetry protected topological (SPT) phases with unusual edge excitations can emerge in strongly interacting bosonic systems and are classified in terms of the cohomology of their symmetry groups. Here we provide a physical picture that leads to an intuitive understanding and wavefunctions for several SPT phases in d=1,2,3 dimensions. We consider symmetries which include a Z_2 subgroup, that allows us to define domain walls. While the usual disordered phase is obtained by proliferating domain walls, we show that SPT phases are realized when these proliferated domain walls are `decorated', i.e. are themselves SPT phases in one lower dimension. For example a d=2 SPT phase with Z_2 and time reversal symmetry is realized when the domain walls that proliferate are themselves in a d=1 Haldane/AKLT state. Similarly, d=3 SPT phases with Z_2 * Z_2 symmetry emerges when domain walls in a d=2 SPT with Z_2 symmetry are proliferated. The resulting ground states are shown to be equivalent to that obtained from group cohomology and field theoretical techniques. The result of gauging the Z_2 symmetry in these phases is also discussed. An extension of this construction where time reversal plays the role of Z_2 symmetry allows for a discussion of several d=3 SPT phases. This construction also leads to a new perspective on some well known d=1 SPT phases, from which exactly soluble parent Hamiltonians may be derived.
description: 17 pages, 8 figures
Trust-aware agents for self-organising computing systems
Creators: name: Bernard, Yvonne
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2014
Subjects: subject: Organic computing
subject: social organic computing
subject: multi-agent systems
subject: open distributed systems
subject: Trust
subject: reputation
subject: Desktop Grids
subject: Vertrauen
subject: Multiagentensysteme
subject: offene verteilte Systeme
subject: Dewey Decimal Classification::000 | Allgemeines, Wissenschaft::000 | Informatik, Wissen, Systeme::004 | Informatik

description: [no abstract]
Evolution of Protostellar Outflow around Low-mass Protostar
Creators: name: Machida, Masahiro N.
name: Hosokawa, Takashi
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The evolution of protostellar outflow is investigated with resistive magneto-hydrodynamic nested-grid simulations that cover a wide range of spatial scales (\sim 1AU - 1pc). We follow cloud evolution from the pre-stellar core stage until the infalling envelope dissipates long after the protostar formation. We also calculate protostellar evolution to derive protostellar luminosity with time-dependent mass accretion through a circumstellar disk. The protostellar outflow is driven by the first core prior to protostar formation and is directly driven by the circumstellar disk after protostar formation. The opening angle of the outflow is large in the Class 0 stage. A large fraction of the cloud mass is ejected in this stage, which reduces the star formation efficiency to \sim 50%. After the outflow breaks out from the natal cloud, the outflow collimation is gradually improved in the Class I stage. The head of the outflow travels more than \sim 10^5AU in \sim 10^5 yr. The outflow momentum, energy and mass derived in our calculations agree well with observations. In addition, our simulations show the same correlations among outflow momentum flux, protostellar luminosity and envelope mass as those in observations. These correlations differ between Class 0 and I stages, which is explained by different evolutionary stages of the outflow; in the Class 0 stage, the outflow is powered by the accreting mass and acquires its momentum from the infalling envelope; in the Class I stage, the outflow enters the momentum-driven snow-plough phase. Our results suggest that protostellar outflow should determine the final stellar mass and significantly affect the early evolution of low-mass protostars.
description: 35 pages, 17 figures, Accepted for publication in MNRAS. For high resolution figures see http://jupiter.geo.kyushu-u.ac.jp/machida/arxiv/outflow.pdf
X-ray bursts as a probe of the corona: the case of XRB 4U 1636-536
Creators: name: Ji, Long
name: Zhang, Shu
name: Chen, YuPeng
name: Zhang, Shuang-Nan
name: Torres, Diego F.
name: Kretschmar, Peter
name: Chernyakova, Masha
name: Li, Jian
name: Wang, Jian-Min
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: To investigate the possible cooling of the corona by soft X-rays bursts, we have studied 114 bursts embedded in the known X-ray evolution of 4U 1636-536. We have grouped these bursts according to the ratio of the flux in the 1.5--12 keV band with respect to that in the 15--50 keV band, as monitored by RXTE/ASM and Swift/BAT, respectively. We have detected a shortage at hard X-rays while bursting. This provides hints for a corona cooling process driven by soft X-rays fed by the bursts that occurred on the surface of neutron star. The flux shortage at 30--50 keV has a time lag of 2.4$\pm$1.5 seconds with respect to that at 2--10 keV, which is comparable to that of 0.7$\pm$0.5 seconds reported in bursts of IGR 17473-2721. We comment on the possible origin of these phenomena and on the implications for the models on the location of the corona.
description: 6 pages, 9 figures, accepted by MNRAS
Trusted community : a novel multiagent organisation for open distributed systems
Creators: name: Klejnowski, Lukas
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2014
Subjects: subject: Open distributed systems
subject: organic computing
subject: multiagent systems
subject: MAS organisations
subject: trust and reputation
subject: desktop grid systems
subject: Offene verteilte Systeme
subject: Multiagentensysteme
subject: Multiagentenorganisationen
subject: Vertrauen und Reputation
subject: Desktop Grid Systeme
subject: Dewey Decimal Classification::000 | Allgemeines, Wissenschaft::000 | Informatik, Wissen, Systeme::004 | Informatik

description: [no abstract]
Tumour-specific immune responses and tumour stroma analysis in a murine model for pancreatic adenocarcinoma
Creators: name: Vermeer, Benjamin
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2007
Subjects: subject: Pancreatic adenocarcinoma
subject: tumour-specific immune response
subject: tumour stroma
subject: Dewey Decimal Classification::600 | Technik::610 | Medizin, Gesundheit

description: [no abstract]
Veronica acinifolia L.
Creators: name: Becherer
Publisher: name: Zenodo
Year: 1956
Subjects: Biodiversity
Taxonomy

description: V. acinifolia L. Cat. 275. Sehr selten; eine einzige, leider nicht genaue und nicht datierte Angabe aus neuerer Zeit: 3:Martigny (F.).
description: Published as part of Becherer, 1956, Florae Vallesiacae Supplementum, pp. 1-556 in Denkschriften der Schweizerischen Naturforschenden Gesellschaft 71 on pages 1-556
Transcript analysis of apple scab susceptible and resistant Malus domestica Borkh. cultivars and establishment of a mannose selection transformation system for apple
Creators: name: Degenhardt, Juliana
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2006
Subjects: subject: Suppression substractive hybridization
subject: metallothionein
subject: pathogenesis-related proteins
subject: Agrobacterium tumefaciens
subject: mannose
subject: chlorophenol red assay
subject: GUS assay
subject: positive selection system
subject: Dewey Decimal Classification::600 | Technik::630 | Landwirtschaft, Veterinärmedizin

description: [no abstract]
Study of a general growth model
Creators: name: Albano, G.
name: Giorno, V.
name: Román-Román, P.
name: Torres-Ruiz, F.
Publisher: name: arXiv
Year: 2024
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Probability (math.PR)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: 34A05

description: We discuss a general growth curve including several parameters, whose choice leads to a variety of models including the classical cases of Malthusian, Richards, Gompertz, Logistic and some their generalizations. The advantage is to obtain a single mathematically tractable equation from which the main characteristics of the considered curves can be deduced. We focus on the effects of the involved parameters through both analytical results and computational evaluations.
description: 25 pages, 32 figures
Die Wirkungsmacht der Kopie: Zur Wahrnehmung von Metallobjekten am Beginn der Bronzezeit
Creators: name: Stockhammer, Philipp W.
Publisher: name: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts
Year: 2016

description: ...
description: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts, Bd. 93 (2015)
Patrick Jung, Die römischen Beinartefakte aus dem Gebiet der Colonia Ulpia Traiana (Xanten)
Creators: name: Deschler-Erb, Sabine
Publisher: name: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts
Year: 2016

description: Rezension zu: Patrick Jung, Die römischen Beinartefakte aus dem Gebiet der Colonia Ulpia Traiana (Xanten). Unter Mitwirkung von Hubert Berke und Astrid Dingeldey, mit einem Beitrag von Ina Vanden Berghe und Marina Van Bos. Xantener Berichte Band 26. Philipp von Zabern, Darmstadt, Mainz 2013. € 75,—. ISBN 978-3-8053-4790-7. 314 Seiten, 109 Tafeln.
description: Germania : Anzeiger der Römisch-Germanischen Kommission des Deutschen Archäologischen Instituts, Bd. 93 (2015)
Tunable decoupling and matching concepts for compact mobile terminal antennas
Creators: name: Chen, Yi
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2017
Subjects: subject: Mobile terminal antennas
subject: frequency reconfigurability
subject: decoupling and matching networks
subject: Antennen für mobile Endgeräte
subject: Rekonfigurierbarkeit
subject: Entkopplungs- und Anpassnetzwerke
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: [no abstract]
Translocation of watermelon chlorotic stunt virus (WmCSV) in its insect vector Bemisia tabaci (Genn.)
Creators: name: Fahmy Elwazzan, Inas Farouk
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2006
Subjects: subject: Bemisia tabaci
subject: virus transmission
subject: begomoviruses
subject: Watermelon chlorotic stunt virus
subject: translocation pathway
subject: immunolocalization
subject: Dewey Decimal Classification::600 | Technik::630 | Landwirtschaft, Veterinärmedizin

description: [no abstract]
Effect of partial ionization on wave propagation in solar magnetic flux tubes
Creators: name: Soler, R.
name: Diaz, A. J.
name: Ballester, J. L.
name: Goossens, M.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Observations show that waves are ubiquitous in the solar atmosphere and may play an important role for plasma heating. The study of waves in the solar corona is usually based on linear ideal magnetohydrodynamics (MHD) for a fully ionized plasma. However, the plasma in the photosphere and the chromosphere is only partially ionized. Here we investigate theoretically the impact of partial ionization on MHD wave propagation in cylindrical flux tubes in the two-fluid model. We derive the general dispersion relation that takes into account the effects of neutral-ion collisions and the neutral gas pressure. We take the neutral-ion collision frequency as an arbitrary parameter. Particular results for transverse kink modes and slow magnetoacoustic modes are shown. We find that the wave frequencies only depend on the properties of the ionized fluid when the neutral-ion collision frequency is much lower that the wave frequency. For high collision frequencies realistic of the solar atmosphere ions and neutrals behave as a single fluid with an effective density corresponding to the sum of densities of both fluids and an effective sound velocity computed as the average of the sound velocities of ions and neutrals. The MHD wave frequencies are modified accordingly. The neutral gas pressure can be neglected when studying transverse kink waves but it has to be taken into account for a consistent description of slow magnetoacoustic waves. The MHD waves are damped due to neutral-ion collisions. The damping is most efficient when the wave frequency and the collision frequency are of the same order of magnitude. For high collision frequencies slow magnetoacoustic waves are more efficiently damped than transverse kink waves. In addition, we find the presence of cut-offs for certain combinations of parameters that cause the waves to become non-propagating.
description: Accepted for publication in A&A
Impediments of Green Supply Chain Management Implementation in Addis Ababa Tannery Companies
Creators: name: Amha Zewdu
Publisher: name: Zenodo
Year: 2019

description: Green supply Chain Management has emerged as a trending topic of discussion for the Organization development, enhanced competitive advantages, increase customer satisfaction, improved brand image, and of course minimum adverse impacts on the environment. However, Green business practices are not easy to adopt and implement, due to the presence of many barriers. Identification of essential barriers for Green Supply Chain Management implementation is also difficult because of its numerous characteristics. The purpose of this study was to examine the main impediments of green supply chain management implementation in Addis Ababa Tannery Companies. In order to attain the objectives of the study, mixed approach was entertained. As a means of data collection instrument; questionnaire and structured interview questions were applied. The population of the study were 49 employees of 7 tannery companies in Addis Ababa, mainly those at managerial position and responsible either directly or indirectly for the supply chain activities of the company. All the population taken as a sample; from a total of 49 questionnaires distributed, only 42 of them were correctly filled and applied in the study, and this revealed a response rate of 85.71%. The interviews were conducted with Environmental Technology Directorate, Director of Leather Industry Development Institute ( LIDI) and Deputy Manager of City Government of Addis Ababa Environmental Protection Authority. In order to analyze, interpret and present the data captured via questionnaire, Statistical Package for the Social Science (SPSS) were used. The quantitative data were analyzed using mean, mode, standard deviation, correlation and regression analysis. The findings of the study revealed that; the existence of statistically significant negative association between the impediments and implementation of green supply chain management
Ultrashort laser pulses from optical parametric amplifiers and oscillators
Creators: name: Lang, Tino
Publisher: name: Hannover : Gottfried Wilhelm Leibniz Universität Hannover
Year: 2014
Subjects: subject: Optical parametric amplifier and oscillator
subject: ultra-broad non-collinear phase-matching
subject: (2+1)D simulation
subject: chi2D
subject: parasitic and spatiotemporal effects
subject: Optisch parametrische Verstärker und Oszillatoren
subject: nichtkollineare Phasenanpassung
subject: parasitäre und raum-zeitliche Effekte
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: [no abstract]
Two-qubit microwave quantum logic gate with 9Be+ ions in scalable surface-electrode ion traps
Creators: name: Hahn, Henning
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2019
Subjects: subject: trapped ions
subject: quantum information processing
subject: near-ﬁeld microwaves
subject: two-qubit gates
subject: Gefangene Ionen
subject: Quanteninformationsverarbeitung
subject: Nahfeld-Mikrowellen
subject: Zwei-Qubit Gatter
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: Towards the goal of a large-scale quantum computer based on trapped ions, near-ﬁeld microwaves represent a promising approach to perform the techni- cally challenging key operation of a two-qubit entangling gate. In this thesis we present the ﬁrst microwave-driven two-qubit gate in 9Be+ ions employing a ﬁrst-order ﬁeld-independent qubit transition and a scalable surface-electrode ion trap at room temperature. We test the quality of the gate operation by producing a maximally entangled state and measuring the resulting state preparation ﬁdelity in a reduced tomography procedure. For the best two- qubit gate achieved in the system we ﬁnd this ﬁdelity to be F = 98.2 ± 1.2 %. Following a comprehensive error analysis based on numerical simulations and experimentally determined input parameters, we identify current inﬁdelity con- tributions of the apparatus. Here, the natural error source of the microwave near-ﬁeld approach, namely ﬂuctuating AC Zeeman shifts, could be reduced to the 10^−4 level due to the optimized design of the employed microwave con- ductor. As we ﬁnd that the three largest errors can all be reduced upon purely technical improvements, higher ﬁdelities are feasible in the future. Besides the gate realization, the thesis also comprises the initial characterization of the employed ion trap as well as the design and construction of a Raman laser at ∼ 313 nm which is utilized to perform near ground state cooling of radial modes of a single- and two-ion crystal. Here, ensuing heating rate measure- ments on a single-ion’s radial modes show good agreement with the electric- ﬁeld noise spectral density expected from literature given the chosen mode frequency and nearest ion-to-electrode distance of 70 µm. Finally, we present the operation of a ﬁrst multi-layer ion trap whose electrode layout features a 3-dimensional microwave conductor intended for performing microwave-driven two-qubit gates. Following a characterization of the resulting near-ﬁeld pat- tern using a single ion as a local ﬁeld probe, we ﬁnd the multi-layer conductor to have signiﬁcantly better ﬁeld properties when compared to an equivalent single-layer design. Given these promising results, future work will focus on the integration of similar microwave circuitry in a multi-zone trap array as envisioned by the QCCD architecture.
New exact solutions of the Dirac equation of a charged particle interacting with an electromagnetic plane wave in a medium
Creators: name: Varro, Sandor
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Exact solutions are presented of the Dirac equation of a charged particle moving in a classical monochromatic electromagnetic plane wave in a medium of index of refraction n < 1. The found solutions are expressed in terms of new complex trigonometric polynomials, which form a doubly infinite set labeled by two integer quantum numbers. These quantum numbers represent quantized spectra of the energy-momentum components of the charged particle along the polarization vector and along the propagation direction of the applied electromagnetic plane wave field (which is considered as a laser field of arbitrary high intensity, propagating in an underdense plasma). These new solutions may serve as a basis for the description of possible quantum features of mechanisms of acceleration of electrons by high-intensity laser fields.
description: 20 pages, 3 figures
Luminosity of young Jupiters revisited. Massive cores make hot planets
Creators: name: Mordasini, Christoph
Publisher: name: arXiv
Year: 2013
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The intrinsic luminosity of young Jupiters is of high interest for planet formation theory. It is an observable quantity that is determined by important physical mechanisms during formation, namely the accretion shock structure, and even more fundamentally, the basic formation mechanism (core accretion or gravitational instability). We study the impact of the core mass on the post-formation entropy and luminosity of young giant planets forming via core accretion with a supercritical shock (cold accretion). For this, we conduct self-consistently coupled formation and evolution calculations of giant planets with masses between 1 and 12 Jovian masses and core masses between 20 and 120 Earth masses. We find that the post-formation luminosity of massive giant planets is very sensitive to the core mass. An increase of the core mass by a factor 6 results in an increase of the post-formation luminosity of a 10 Jovian mass planet by a factor 120. Due to this dependency, there is no single well defined post-formation luminosity for core accretion, but a wide range. For massive cores (~100 Earth masses), the post-formation luminosities of core accretion planets become so high that they approach those in the hot start scenario that is often associated with gravitational instability. For the mechanism to work, it is necessary that the solids are accreted before or during gas runaway accretion, and that they sink deep into the planet. We make no claims whether or not such massive cores can actually form in giant planets. But if yes, it becomes difficult to rule out core accretion as formation mechanism based solely on luminosity for directly imaged planets that are more luminous than predicted for low core masses. Instead of invoking gravitational instability as the consequently necessary formation mode, the high luminosity could also be caused simply by a more massive core.
description: 11 pages, 6 figures. A&A accepted
Über System- und Regelungsdynamiken von Windenergieanlagen und deren Einfluss auf die Umrichterlebensdauer
Creators: name: Morisse, Marcel
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2020
Subjects: subject: wind energy
subject: lifetime
subject: power cycling
subject: system dynamics
subject: DFIG control
subject: individual pitch control
subject: Windenergie
subject: Lebensdauer
subject: Lastwechselzyklen
subject: Systemdynamiken
subject: DFIG-Regelung
subject: Einzelblattverstellregelung
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: Zuverlässige und kostengünstige Energiegewinnung aus regenerativen Quellen ist die Basis für eine erfolgreiche Transformation des zu einem großen Bestandteil auf fossilen Brennstoffen basierenden Energieversorgungssystems. Häufige Frühausfälle der leistungselektronischen Umrichtersysteme in Windenergieanlagen stehen aufgrund der resultierenden Stillstandzeiten der Windenergieanlagen diesem Ziel entgegen. Die vorliegende Dissertation liefert einen Beitrag zur Bewertung solcher Frühausfälle, indem es die Einflüsse dynamischer Systemgrößen und -wechselwirkungen auf die Umrichterlebensdauer betrachtet. Im Fokus steht hierbei die Lebensdauer der leistungselektronischen Halbleitermodule im Hinblick auf thermomechanische Wechselzyklenbelastung.
Uncertainty relations in quantum theory
Creators: name: Schwonnek, René
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2018
Subjects: subject: Preparation uncertainty
subject: measurement uncertainty
subject: entropic uncertainty
subject: joint measurements
subject: multicriterial convex optimization
subject: Preparationsunschärfe
subject: Messunschärfe
subject: entropische Unschärfe
subject: gemeinsame Messungen
subject: multikriterielle konvexe Optimierung
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik

description: Uncertainty relations are commonly praised as one of the central pillars of quantum theory. Usually, they are taught in the first weeks of a beginners lecture, and introduced in the ?rst chapters of a textbook. However, their precise operational meaning and a formulation in a general context, i.e. beyond the example of position and momentum observables, are often left out. The reasoning for this is twofold: On one hand, an exact operational definition of uncertainty, indeterminacy and a corresponding uncertainty principle has been the content of many debates since the early days of quantum mechanics until today. From a modern perspective, we have the consent that there are at least the two notions of preparation and measurement uncertainty: the first notion prohibits the existence of dissipation free states and the latter one the existence of error free joint measurements. On the other hand, we have that, the mathematical tools, which are needed for comprehensive treatment of uncertainty relations in a general context, are still under development and usually go far beyond the mathematical level of an introductory course. In this thesis we will investigate these two notions of uncertainty, their corre- sponding uncertainty relations, such as their interplay. The aim of this thesis is to give answers to the central questions: (1.) Which quantities should be used to formulate uncertainty? (2.) How can we compute uncertainty relations for those? (3.) Are there connections between the two notions of uncertainty? We will do this, whenever possible, in a most general context and with a focus on relevant examples, otherwise. Therefore, we will consider constructions of mea- surement errors and deviation measures that quantify uncertainty, based on, so called, cost functions. Commonly used uncertainty measures like variances, en- tropies, and the Hamming distance are examples for these. We will investigate the structure of the corresponding uncertainty relations and provide several methods that enable us to compute them. The third question is addressed by a theorem that shows, for sharp observables, that measurement uncertainty relations can be lower bounded by preparation uncertainty relations, whenever the same cost function is used.