Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Ruffling in a Series of Nickel(II) meso-Tetrasubstituted Porphyrins as a Model for the Conserved Ruffling of the Heme of Cytochromes c (1995)
    s.l. : American Chemical Society
    Journal of the American Chemical Society 117 (1995), S. 11085-11097 
    Details
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/ja00150a008
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    On the Sum Coloring Problem on Interval Graphs (1999)
    Springer
    Algorithmica 23 (1999), S. 109-126 
    Details
    ISSN: 1432-0541
    Keywords: Key words. Coloring, Interval graphs, Approximation algorithms, VLSI-design, Over-the-cell routing.
    Source: Springer Online Journal Archives 1860-2000
    Topics: Computer Science , Mathematics
    Notes: Abstract. In this paper we study the following NP-complete problem: given an interval graph G = (V,E) , find a node p -coloring $ \langle V_1, V_2, . . ., V_p\rangle $ such that the cost $ \xi (\langle V_1, V_2, . . ., V_p \rangle ) = \sum^p_{i=1} i|V_i| $ is minimal, where $ \langle V_1, V_2, . . ., V_p \rangle $ denotes a partition of V whose subsets are ordered by nonincreasing cardinality. We present an O(m χ (G) + n log n) time ε -approximate algorithm (ε 〈 2) to solve the problem, where n , m , and χ #(G) are the number of nodes of the interval graph, its number of cliques, and its chromatic number, respectively. The algorithm is shown to solve the problem exactly on some classes of interval graphs, namely, the proper and the containment interval graphs, and the intersection graphs of sets of ``short'' intervals. The problem of determining the minimum number of colors needed to achieve the minimum $\xi (\langle V_1, V_2, . . ., V_p \rangle )$ over all p -colorings of G is also addressed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00009252
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Conceptual model of the evolution of groundwater quality at the wet zone in Sri Lanka (1999)
    Springer
    Environmental geology 39 (1999), S. 149-164 
    Details
    ISSN: 1432-0495
    Keywords: Key words Water cycle ; Groundwater flow ; Water quality ; Isotopic composition ; Evolution of groundwater quality
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences
    Notes: Abstract  The evolution of groundwater quality at a wet zone in Sri Lanka was made clear using field investigation, chemical and isotopic analyses methods. In the wet zone, the concentrations of major ions and electrical conductivity (EC) in the groundwater are low with small seasonal change. Except for sodium, silica and chloride, the EC and other major ion concentrations increase along the groundwater flow direction. The contributions of bicarbonate and calcium ions to the increase in EC are the largest among the major ions. The groundwater quality shows calcium-bicarbonate type, the initial stage of the Chebotarev series. There is a seasonal change in isotopic composition. The isotopically lighter groundwater was found at the valley bottom in the rainy season. Under the very heavy precipitation conditions, the slope of the regression line between δD and δ18O and deuterium excess for groundwater are close to 8 and 10, respectively. In other cases, the slopes of the regression lines and deuterium excess are, less than 8 and 10, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002540050445
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Nonlinear oscillations and chaotic behavior due to impact lonization of shallow donors in InSb (1989)
    Springer
    Applied physics 48 (1989), S. 137-141 
    Details
    ISSN: 1432-0630
    Keywords: 72.20H ; 72.80E ; 72.20M
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract Both nonlinear oscillations and chaotic behavior in n-InSb are experimentally investigated for the case of impact ionization of shallow donors at low temperatures. Complex behavior including a simple periodic oscillation, a period-doubling route to chaos, and quasiperiodic behavior are observed with increasing electric field as the parameter. For the first time, a type of pitchfork bifurcation (period halving) is seen.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01141275
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Cooperative interaction among the various regulatory sites within the NMDA receptor-channel complex in modulating the evoked responses to noxious thermal stimuli of spinal dorsal horn neurons in the cat (1998)
    Springer
    Experimental brain research 120 (1998), S. 257-262 
    Details
    ISSN: 1432-1106
    Keywords: Key words NMDA receptor ; Spinal dorsal horn ; Nociceptive response ; Noxious heating
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract  Interactions among antagonists acting at different regulatory sites within the N-methyl-D-aspartate (NMDA) receptor-channel complex on the evoked responses to noxious thermal stimuli of wide dynamic range (WDR) neurons in spinal dorsal horn were studied on 21 adult anesthetized and spinalized cats. The responses of nociceptive spinal dorsal horn neurons to noxious heating (45–55°C) of the glabrous skin of the unilateral hind paw were reduced markedly by iontophoretically applied antagonists. The specific recognition site antagonist, DL-2-amino-5-phosphonovaleratic acid (APV), the strychnine-insensitive glycine site antagonist 7-chlorokynurenic acid (7CKA), the polyamine site antagonist ifenprodil (IFEN), and the phencyclidine (PCP) site antagonists ketamine (KET) and MK-801 (40–100 nA) significantly reduced (t-tests, P 〈 0.01) the noxious thermal stimulus-evoked responses in about 70% of the neurons by (mean ± SE) 54.1±5.8% (n=19), 80.8 ± 4.7% (n = 16), 51.1 ± 6.4% (n = 10), 77 ± 4.9% (n = 16) and 81.2 ± 8.1% (n = 5), respectively. APV and IFEN were less effective in blocking noxious thermal stimuli-evoked responses than 7CKA, KET and MK-801 (ANOVA, P 〈 0.05). The responses were completely inhibited in some neurons. After co-administration of the antagonists, APV + 7CKA, APV + IFEN, 7CKA + IFEN, APV + KET and APV + MK-801, all at the subthreshold ejection current, the responses were reduced markedly in 13 of 16, 7 of 10, 5 of 10, 3 of 6 and 3 of 5 neurons, respectively. The present study suggests that blockage of any component of the NMDA receptor-channel complex antagonizes the NMDA receptor-mediated response, and that there are the cooperative interactions among the various regulatory sites within the NMDA receptor-channel complex in the transmission or modulation of spinal nociceptive thermal information.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002210050399
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Elastic-Plastic Finite Element Analysis of the Effect of the Compressive Loading on the Crack Tip Plasticity (2006)
    s.l. ; Stafa-Zurich, Switzerland
    Key engineering materials Vol. 324-325 (Nov. 2006), p. 73-76 
    Details
    ISSN: 1013-9826
    Source: Scientific.Net: Materials Science & Technology / Trans Tech Publications Archiv 1984-2008
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: An elastic-plastic finite element analysis of the effect of the compressive loading oncrack tip plasticity is presented. Two center-cracked panel specimens with different crack lengthsare analysed under tension-compression loading. The size and shape of the crack tip reverse plasticzone, the crack opening profiles of the crack tip for short (0.1 mm) and long crack (2 mm) havebeen studied. The analysis shows that the compressive loading has a significant contributiontowards the crack tip plasticity
    Type of Medium: Electronic Resource
    URL: http://www.tib-hannover.de/fulltexts/2011/0528/01/52/transtech_doi~10.4028%252Fwww.scientific.net%252FKEM.324-325.73.pdf
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Experimental and molecular dynamics study of the pressure dependence of Raman spectra of oxygen (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 660-672 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The pressure dependence of Raman spectra of gaseous O2 at 300 K has been studied experimentally and by molecular dynamics (MD) simulation. Experimental spectra are reported for the pressure range of 40–3000 bar and MD spectra for four thermodynamic states in the pressure range of 130–3000 bar. The MD trajectories are calculated using the Lennard-Jones atom–atom intermolecular potential. The interaction-induced effects on the system polarizability are evaluated using the first order dipole–induced dipole (DID) approximation. In the case of depolarized Raman scattering, the experimental line shapes and time correlation functions agree very well with the MD results. The density dependence of the experimental second spectral moment is also in excellent agreement with the MD predictions. The MD results indicate that the relative contribution of the interaction-induced polarizability to the depolarized spectrum increases with increasing density, but remains small within the density range considered, and that the spectrum is dominated by orientational relaxation of the molecular polarizability. The experimental depolarized Raman and MD orientational time correlation functions are compared to the results of J-diffusion and Steele models of relaxation. We find that neither of these models can account for single molecule reorientation in oxygen gas over the entire range of pressures. At high pressures, the experimental results for the frequency-dependent depolarization ratio η differ significantly from the "classical'' value of 3/4 over most of the accessible frequency range. Similar behavior is found for the corresponding Rayleigh depolarization ratios. The MD calculations predict a much smaller deviation of η from the value of 3/4, suggesting that induction mechanisms other than DID are needed to explain the experimental data. The experimentally observed pressure dependence of the Q branch of the Raman spectrum is explained using the motional narrowing model of Brueck.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.455241
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Experimental and molecular dynamics study of depolarized Rayleigh scattering by O2 (1987)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 87 (1987), S. 840-851 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Collision-induced effects on depolarized Rayleigh scattering (DRS) in gaseous oxygen at 300 K in the pressure range from 10 to 3000 bar have been studied experimentally. DRS spectra for four thermodynamic states at this temperature and in the pressure range from 130 to 3000 bar have also been obtained from molecular dynamics (MD) simulation. Molecular trajectories were calculated using the Lennard-Jones atom–atom potential and the system polarizability was modeled using the first order dipole–induced dipole approximation. The frequency dependence of DRS band shapes is well reproduced by the MD results, which predict that the orientational contribution dominates the overall band shape. The agreement between experimental and calculated second, fourth, and sixth spectral moments is very good. The observed density dependence of the spectral moments is analyzed in terms of contributions from the collision-induced (CI) polarizability component and orientational pair correlations. The second spectral moment, M2, is found to decrease with increasing density at low densities and to increase at higher densities. The MD results indicate that the initial decrease in M2 is due primarily to slow relaxation of the CI polarizability at low densities. The increase in M2 at higher densities is found to be mainly due to the contribution from orientational-CI cross correlations. MD results as well as analytical calculations, carried out for the low density limit, predict that the CI contribution to the total DRS intensity remains relatively small (≤4%) throughout the entire density range. The observed density dependence of the intensity is not consistent with these calculations. Possible sources of this disagreement are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.453291
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Synchrony and the emergence of chaos in oscillations on supported catalysts (1990)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 92 (1990), S. 745-756 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Complex behavior of an oscillating reaction on an array of catalytic regions was modeled using a distributed model consisting of a 10×10 matrix with ten randomly placed oscillators coupled via heat transfer. Each single oscillator was described by a very simple system of two differential equations chosen to model the CO/NO reaction on supported Pd. However, the coupled system exhibited very complex behavior with periodic oscillations, period multiplications, beat structures and chaos. All of these complex features predicted by the model have also been found in experiments. In addition, the model was able to predict the experimentally observed tendencies in the development of complex behavior with changing reaction conditions. Changing distributions of the cells or introducing small differences in the description of the single oscillators did not change the principal features of the system. However, the transition to chaos could be changed in that for one distribution of active cells a Feigenbaum sequence to chaos was found but not in another. With one oscillator twice as active as the rest of the cells, the high activity cell was dominant and entrained the whole system, leading to completely synchronized behavior. Also in this situation, however, chaotic responses were found, when the high activity oscillator was in a stable ignited state. Possible generalizations of this treatment to other oscillating systems are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.458428
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Density effects on collision induced Raman scattering in CO2–Ar and CO2–Xe mixtures (1988)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 89 (1988), S. 156-159 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The density dependence of the intensity of the CO2 Raman forbidden ν2 band (667.3 cm−1 ) has been studied in the CO2 –Ar and CO2 –Xe mixtures at 40 and 80 °C. The experimental results show that the band intensity increases linearly with density from 0.057 to 0.166 mol/cm3 which indicates that two-particle collisions dominate the scattering process. The intensity of the ν2 band is higher in the CO2 –Xe mixture than that in the CO2 –Ar mixture, and the experimental intensity ratio for the two mixtures is 2.2±0.2. The very good agreement between the experimental intensity ratio and the ratio calculated theoretically for the dipole–quadrupole (Aα) contribution to the collision induced scattering indicates that the Aα mechanism is responsible for the appearance of the forbidden band.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.455498
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...