Institution
University of Paderborn
Education•Paderborn, Nordrhein-Westfalen, Germany•
About: University of Paderborn is a education organization based out in Paderborn, Nordrhein-Westfalen, Germany. It is known for research contribution in the topics: Computer science & Context (language use). The organization has 6684 authors who have published 16929 publications receiving 323154 citations.
Topics: Computer science, Context (language use), Software, Control reconfiguration, Nonlinear system
Papers published on a yearly basis
Papers
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TL;DR: The realization of a bright ultrafast type II parametric down-conversion source of twin beams free of any spatiotemporal correlations in a periodically poled KTiOPO4 (PP-KTP) waveguide is reported.
Abstract: We report the realization of a bright ultrafast type II parametric down-conversion source of twin beams free of any spatiotemporal correlations in a periodically poled KTiOPO4 (PP-KTP) waveguide. From a robust, single-pass setup it emits pulsed two-mode squeezed vacuum states: photon-number entangled pairs of single-mode pulses or, in terms of continuous variables quantum optics, pulsed Einstein-Podolsky-Rosen states in the telecom wavelength regime. We verify the single-mode character of our source by measuring Glauber correlation functions g(2) and demonstrate with a pump energy as low as 75 pJ per pump pulse a mean photon number of 2.5.
243 citations
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TL;DR: In this article, new functional forms have been developed for multiparameter equations of state for non-and weakly polar fluids and for polar fluids, which were established with an optimization algorithm which considers data sets for different fluids simultaneously.
Abstract: New functional forms have been developed for multiparameter equations of state for non- and weakly polar fluids and for polar fluids. The resulting functional forms, which were established with an optimization algorithm which considers data sets for different fluids simultaneously, are suitable as a basis for equations of state for a broad variety of fluids. The functional forms were designed to fulfil typical demands of advanced technical application with regard to the achieved accuracy. They are numerically very stable and their substance-specific coefficients can easily be fitted to restricted data sets. In this way, a fast extension of the group of fluids for which accurate empirical equations of state are available is now possible. This article deals with the results found for the polar fluids CFC-11 (trichlorofluoromethane), CFC-12 (dichlorodifluoromethane), HCFC-22 (chlorodifluoromethane), HFC-32 (difluoromethane), CFC-113 (1,1,2-trichlorotrifluoroethane), HCFC-123 (2,2-dichloro-1,1,1-trifluoroethane), HFC-125 (pentafluoroethane), HFC-134a (1,1,1,2-tetrafluoroethane), HFC-143a (1,1,1-trifluoroethane), HFC-152a (1,1-difluoroethane), carbon dioxide, and ammonia. The substance-specific parameters of the new equations of state are given as well as statistical and graphical comparisons with experimental data. General features of the new class of equations of state such as their extrapolation behavior or their numerical stability and results for non- and weakly polar fluids have been discussed in preceding articles.
242 citations
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TL;DR: A selective classified bibliography of symbolic computation in some areas of chemistry is provided together with some examples of computer algebra algorithms and techniques to facilitate future joint work of chemists and computer scientists.
Abstract: A selective classified bibliography of symbolic computation in some areas of chemistry is provided together with some examples of computer algebra algorithms and techniques to facilitate future joint work of chemists and computer scientists. © 2004 Wiley Periodicals, Inc. Int J Quantum Chem, 2004
240 citations
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TL;DR: This study investigates the accuracy of computational approaches for modeling changes in absorption energies with respect to changes in geometry and applied external electric fields and proposes a procedure which combines structure optimization or molecular dynamics simulation using DFT methods with a semiempirical or ab initio multireference configuration interaction treatment of the excitation energies.
Abstract: Rhodopsins can modulate the optical properties of their chromophores over a wide range of wavelengths. The mechanism for this spectral tuning is based on the response of the retinal chromophore to external stress and the interaction with the charged, polar, and polarizable amino acids of the protein environment and is connected to its large change in dipole moment upon excitation, its large electronic polarizability, and its structural flexibility. In this work, we investigate the accuracy of computational approaches for modeling changes in absorption energies with respect to changes in geometry and applied external electric fields. We illustrate the high sensitivity of absorption energies on the ground-state structure of retinal, which varies significantly with the computational method used for geometry optimization. The response to external fields, in particular to point charges which model the protein environment in combined quantum mechanical/molecular mechanical (QM/MM) applications, is a crucial feature, which is not properly represented by previously used methods, such as time-dependent density functional theory (TDDFT), complete active space self-consistent field (CASSCF), and Hartree-Fock (HF) or semiempirical configuration interaction singles (CIS). This is discussed in detail for bacteriorhodopsin (bR), a protein which blue-shifts retinal gas-phase excitation energy by about 0.5 eV. As a result of this study, we propose a procedure which combines structure optimization or molecular dynamics simulation using DFT methods with a semiempirical or ab initio multireference configuration interaction treatment of the excitation energies. Using a conventional QM/MM point charge representation of the protein environment, we obtain an absorption energy for bR of 2.34 eV. This result is already close to the experimental value of 2.18 eV, even without considering the effects of protein polarization, differential dispersion, and conformational sampling.
240 citations
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TL;DR: In this article, it was shown that the unique nontrivial spatially homogeneous equilibrium given by u = v ≡ 1 μ is globally asymptotically stable in the sense that for any choice of suitably regular nonnegative initial data (u 0, v 0 ) such that u 0 ≢ 0, the above problem possesses a uniquely determined global classical solution ( u, v ) with ( u, v ) | t = 0 = ( u 0, v 0) which satisfies ∞ ∞ as t → ∞.
239 citations
Authors
Showing all 6872 results
Name | H-index | Papers | Citations |
---|---|---|---|
Martin Karplus | 163 | 831 | 138492 |
Marco Dorigo | 105 | 657 | 91418 |
Robert W. Boyd | 98 | 1161 | 37321 |
Thomas Heine | 84 | 423 | 24210 |
Satoru Miyano | 84 | 811 | 38723 |
Wen-Xiu Ma | 83 | 420 | 20702 |
Jörg Neugebauer | 81 | 491 | 30909 |
Thomas Lengauer | 80 | 477 | 34430 |
Gotthard Seifert | 80 | 445 | 26136 |
Reshef Tenne | 74 | 529 | 24717 |
Tim Meyer | 74 | 548 | 24784 |
Qiang Cui | 71 | 292 | 20655 |
Thomas Frauenheim | 70 | 451 | 17887 |
Walter Richtering | 67 | 332 | 14866 |
Marcus Elstner | 67 | 209 | 18960 |