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1978 (218)
1Author    HerbertRainer Petry, Mikolaj SawickiRequires cookie*
 Title    The V-V Sector of the Lee Model  
 Abstract    The Schrödinger-equation in the V-V sector of the Lee model is investigated. We obtain a three-body Lippmann-Schwinger equation, with a new type of disconnectedness, and construct the resolvent operator by means of a modified Faddeev technique. 
  Reference    Z. Naturforsch. 33a, 1 (1978); received September 28 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0001.pdf 
 Identifier    ZNA-1978-33a-0001 
 Volume    33 
2Author    Jukka Jokisaari, Juha Kuonanoja, Anna-Maija HäkkinenRequires cookie*
 Title    3 C NMR Spectra of Trimethylene Oxide and Sulphide  
 Abstract    The 13 C NMR spectra of trimethylene oxide and trimethylene sulphide have been recorded and analysed as second-order spectra. The values of all the C—H coupling constants with their signs are reported. The signs of the C—H coupling constants in trimethylene oxide were determined by selective irradiation experiments and theoretical calculations, while in trimethylene sulphide the signs were obtained directly from the analysis. The one-bond C—H coupling constants are approximately 3 Hz greater in trimethylene oxide than in trimethylene sulphide, while the absolute values of the two-bond and three-bond coupling constants, 2 Jcvh and 3 JcaH, are about 1 Hz greater in the latter molecule. Experimental The samples used were 70 ± 1 mole per cent solutions in CDCI3. They were degassed with the freeze-pump-thaw method. All the spectra were recorded with a JNM-FX-100 FT NMR instrument operating at the DQD (Digital Quadrature Detec-tion) mode using a frequency range of either 500 Hz or 400 Hz and collecting 16 k data points. The spectra were Fourier-transformed without apodiz-ing. The single resonance spectra were analysed with the program LAOCN3, while in the calculations of theoretical double resonance spectra the program HETERO [1] was used. The power used in selective double resonance experiments was adjusted by measuring the residual coupling, 1 JcH' an< ^ ^y comparing it with the value obtained from the calculated spectrum. 
  Reference    Z. Naturforsch. 33a, 7—10 (1978); received October 25 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0007.pdf 
 Identifier    ZNA-1978-33a-0007 
 Volume    33 
3Author    C. Goldbaeh, G. Nollez, S. Popović, M. PopovićRequires cookie*
 Title    Electrical Conductivity of High Pressure Ionized Argon  
 Abstract    In order to investigate some properties of a medium with a low number of particles in a Debye sphere, the electrical conductivity of high-pressure ionized Argon has been measured. A special emphasis is laid on the so-called "non-ideality" effects in the collective behaviour of charged particles. A kind of threshold for these effects is observed at »d ^ 4. The observed asymptotic behaviour of the screening parameter indicates that heavy charged particles have the same influence on the screening mechanism as electrons. The experimental values of the electrical conductivity are in excellent agreement with similar recent measurements. 
  Reference    Z. Naturforsch. 33a, 11—17 (1978); received April 21 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0011.pdf 
 Identifier    ZNA-1978-33a-0011 
 Volume    33 
4Author    S.Noor MohammadRequires cookie*
 Title    Potential Energy Surfaces for Alkali-Trimers  
 Abstract    Semi-empirical potential energy surfaces for alkali-trimers are derived from the simplest form of London's approximation, by evaluating the Coulomb and exchange integrals as half of the sum and difference of two new interaction potential curves for the 1 2g + and 3 J?u + states of the cor-responding alkali dimers. The trimers attain maximum stability in their linear symmetric con-figuration. The force constants corresponding to stretching and bending deformations of the homo-nuclear trimers have been calculated for the linear symmetric configuration. Unlike the stretching, the bending deformation is seen to be very much insensitive to the ground state energy variation of the trimers. 
  Reference    Z. Naturforsch. 33a, 18—20 (1978); received May 16 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0018.pdf 
 Identifier    ZNA-1978-33a-0018 
 Volume    33 
5Author    K.-F Dössel, J. Wiese, D. H. SutterRequires cookie*
 Title    The Rotational Zeeman Effect of Formylchloride  
 Abstract    The rotational Zeeman effect of several low J transitions of Formylchloride was investigated at fields close to 25 kGauss. The results are compared to those for Formylfluoride. The larger values for the paramagnetic susceptibilities are indicative for low lying excited electronic states which together with the comparatively large molecular electric quadrupole moments may be the reason for the low stability of the molecule. 
  Reference    Z. Naturforsch. 33a, 21 (1978); received November 2 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0021.pdf 
 Identifier    ZNA-1978-33a-0021 
 Volume    33 
6Author    G. K. Pandey, D. H. SutterRequires cookie*
 Title    Molecular g-Values, Magnetic Susceptibility Anisotropics, Second Moments of the Charge Distribution, and Molecular Electric Quadrupole Moments in trans-and cis-Thioformic Acid  
 Abstract    The rotational Zeeman effect in the microwave spectrum of trans-and cis-Thioformic Acid has been investigated at field strengths upto 25.6 kG. Measurements were done for both AM = 0 and AM = ± 1 selection rules for the trans species and for AM = ^ 1 for the eis species. From the observed splittings the following parameters were obtained for the diagonal elements of the molecular g tensor and the susceptibility anisotropics. trans HCOSH -0.4091 ± 0.0009 -0.0703 ± 0.0003 -0.0345 4-0.0003 [2 Xaa — Xbb — Xcc] j Xaa] j [2 Xbb -Xcc Gaa gbb Gcc 10~ 6 erg G 2 mole 10~ 6 erg G 2 mole eis HCOSH -0.4017 ± 0.0012 -0.0711 ± 0.0004 -0.0318 ± 0.0004 -0.67 ± 0.8 11.37 ±0.5 7.32 ± 1.2 16.48 ± 0.8 (all experimental uncertinties are single standard deviations). The molecular electric quadrupole moments derived from the Zeeman data indicate that there is no significant covalent bonding in the O ... H region of the trans species. 
  Reference    Z. Naturforsch. 33a, 29—37 (1978); received November 17 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0029.pdf 
 Identifier    ZNA-1978-33a-0029 
 Volume    33 
7Author    Chiara Margheritis, Cesare SinistriRequires cookie*
 Title    Monte Carlo Calculations on Molten Silver Bromide  
 Abstract    Using crystal data in the range 20—300 °C, the AgBr interionic pair potentials were calculated-By means of these potentials the melt was computer simulated with the Monte Carlo method at three different temperatures (694, 1000 and 1778 K). The system thus obtained is relaxed and it behaves as if an important cohesive force, like the homopolar one, would be lacking. It was empirically proved that if the interionic repulsive potentials are reduced by about 40% the experimental values of the density and of the internal energy are reproduced. 
  Reference    Z. Naturforsch. 33a, 38—41 (1978); received November 15 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0038.pdf 
 Identifier    ZNA-1978-33a-0038 
 Volume    33 
8Author    Alberto Schiraldi, Elisabetta PezzatiRequires cookie*
 Title    Thermoelectric Power of the Molten Systems (Cu, Ag) X (X = C1, Br, I)  
 Abstract    Initial thermoelectric power determinations were carried out on the molten systems (Cu, Ag)X, (X=C1, Br, I) at 1000 K. As for the employing of either cooper or silver electrodes thermocells, the choice was based on literature thermodynamic data. Comparison between ideal and actual behaviour allowed to discover negative excess partial ionic entropies. 
  Reference    Z. Naturforsch. 33a, 42 (1978); received November 21 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0042.pdf 
 Identifier    ZNA-1978-33a-0042 
 Volume    33 
9Author    J. C. Whitmer, S. J. Cyvin, B. N. CyvinRequires cookie*
 Title    Harmonie Force Fields and Bond Orders for Naphthalene, Anthracene, Biphenylene and Perylene with Mean Amplitudes for Perylene  
 Abstract    Complete normal coordinate analyses were performed for naphthalene, anthracene, biphenylene and perylene, starting from a simple force field with seven adjustable force constants. A rela-tionship between bond orders and carbon-carbon stretching force constants was deduced from: (a) bond distances as a function of bond orders, (b) a version of Badger's rule relating stretching force constants to the bond distances. The relationship was used to modify the initial seven-parameter force field, and the vibrational frequencies calculated from both the initial and modi-fied force fields are discussed. In general the simple force field approximation produces sets of frequencies in remarkably good agreement with experimental assignments. The force field ap-proximation failed badly when applied to benzene. No obvious explanation was found for this unexpected feature, which makes it worth while to continue the investigations. The mean ampli-tudes of vibration were calculated. For perylene an account of the complete set of mean ampli-tudes is given for the first time. 
  Reference    Z. Naturforsch. 33a, 45—54 (1978); received October 25 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0045.pdf 
 Identifier    ZNA-1978-33a-0045 
 Volume    33 
10Author    Mareen Mammo, Muthana ShanshalRequires cookie*
 Title    Interaction of Antimalarials with Coenzyme Q10  
 Abstract    Assuming face to face (JI—JT) complexation of the antimalarials, quinine, primaquine and chloroquine, with CoQ and applying Hiickel MOs for their quinoline skelet and for the dimethoxy-benzoquinone ring of CoQ the interaction energies are calculated using 2nd order perturbation. The perturbation treatment yielded an increase in the LUMO energy of CoQ suggesting an increase in its reduction potential due to complexation. This increase is confirmed expermentally by Polaro-graphie measurements of the EV2 values for the corresponding 1:1 mixtures. Similar increase is observed for the 1: 1 mixture with aniline but not with cyclohexylamine. It is expected that such an increase in the reduction potential of CoQ should hinder its functioning as electron carrier in the respiratory chain. 
  Reference    Z. Naturforsch. 33a, 55—58 (1978); received August 11 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0055.pdf 
 Identifier    ZNA-1978-33a-0055 
 Volume    33 
11Author    Vi, Milan Remko, Jan PolčinRequires cookie*
 Title    LCAO MO Investigations on Lignin Model Compounds CNDO/CI Calculations of Electronic Spectra of Cinnamaldehyde Structures  
 Abstract    The electronic absorption spectra of cinnamaldehyde, o-, m-, p-hydroxycinnamaldehyde and 3-methoxy-4-hydroxy cinnamaldehyde were theoretically and experimentally studied, by means of the semiempirical CNDO/CI method. The calculated and observed transition energies were in good agreement. 
  Reference    Z. Naturforsch. 33a, 59—65 (1978); received August 9 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0059.pdf 
 Identifier    ZNA-1978-33a-0059 
 Volume    33 
12Author    Kin-Ichi MasudaRequires cookie*
 Title    Changes in Density of States Caused by Chemisorption: Monolayer of Adatoms on a Model Transition Metal  
 Abstract    The effect of chemisorption of a monolayer of atoms on the (001) surface of a model transition metal is investigated using the Green's function formalism and the phase shift technique. The electronic structure of the surface is obtained by the application of the Kalkstein and Soven method. For comparison, both a single and two peaked model of the surface density of states (DOS) are used. The change in the DOS upon chemisorption as well as the adatom DÖS are cal-culated within the Newns-Anderson model for chemisorption. It is shown that the two peaked substrate DOS model can qualitatively account for the strong coverage dependence of the photo-emission spectra observed in the H/W(100) system. In addition, it is shown that the direct inter-action between the adatoms plays an important role in the monolayer chemisorption. 
  Reference    Z. Naturforsch. 33a, 66—73 (1978); received October 26 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0066.pdf 
 Identifier    ZNA-1978-33a-0066 
 Volume    33 
13Author    Helmut RagerRequires cookie*
 Title    35 C1 and 37 C1 Pure Quadrupole Resonance in a-CH2ClCOOH: Hydrogen Bonding and Chlorine Isotope Effect  
 Abstract    The temperature dependence of the pure nuclear quadrupole resonance of 35 C1 and 37 C1 in solid a-CH2ClCOOH has been measured from 77 K to 298 K. The NQR spectrum consists of a doublet arising from the two nonequivalent chlorine atoms in the unit cell. The temperature dependence was calculated using the Bayer-Kushida theory which gives a satisfactory fit to the NQR spectra in the temperature range investigated. From the NQR data evidence of an isotope effect was found for both nonequivalent chlorine atoms. The isotope effect depends on the C-Cl bond length and its direction probably on the state of binding of the chlorine atoms. The NQR results and their interpretation are consistent with the crystal structure of a-CH2C1C00H. 
  Reference    Z. Naturforsch. 33a, 74—77 (1978); received October 30 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0074.pdf 
 Identifier    ZNA-1978-33a-0074 
 Volume    33 
14Author    J. Bendig, D. KreysigRequires cookie*
 Title    Strahlungslose Energieübertragung von angeregten N-Heteroareniumkationen zu Rhodamin B  
 Abstract    Non-Radiative Energy Transfer from Excited N-Heteroarenium Cations to Rhodamin B. The systems acridizinium-and N-methylacridinium ion, respectively, as energy donors and rhodamin B (tetrafluoroborate) as energy acceptor show in solutions of low viscosity (solvent : methanol) energy transfer by resonance, in which a multi-step mechanism is participating. The experimental results of the detected singlet-singlet transfer are in good agreement with the predictable values of Förster's theory, if the spectroscopic parameters of the donor and the accep-tor are corrected by assumption of their dependence upon concentration. 
  Reference    Z. Naturforsch. 33a, 78—82 (1978); eingegangen am 9. November 1977. 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0078.pdf 
 Identifier    ZNA-1978-33a-0078 
 Volume    33 
15Author    W. Hagele, D. Schmid, H. C. WolfRequires cookie*
 Title    Triplet-State Electron Spin Resonance of Chlorophyll a and b Molecules and Complexes in PMMA and MTHF I: Experimental Determination of Fine-Structure and Rate Constants  
 Abstract    The triplet state zero-field splittings and the rate constants for the population and depopulation of the triplet spin sublevels have been investigated for chlorophyll a and chlorophyll b in poly-methylmethacrylate (PMMA) and methyltetrahydrofurane (MTHF) as a function of the con-centration. In PMMA both chlorophyll a and chlorophyll b yielded only one ESR spectrum in the entire range of concentration which could be covered (1.5 X 10 -5 — 1 X 10 -3 mole/1). In MTHF the results were more complicated. At low concentrations (up to 10 3 mole/1) only one spectrum was observed, at higher concentrations additional spectra were detectable (all together two for chlorophyll a and five for chlorophyll b at 10 -1 mole/1). The assignment of these spectra was facilitated by observing the "triplet resonance-field identity" which connects the resonance-field strengths for the canonical orientations of one particular species. Furthermore, the rate constants for some of these species could be determined. 
  Reference    Z. Naturforsch. 33a, 83 (1978); received November 4 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0083.pdf 
 Identifier    ZNA-1978-33a-0083 
 Volume    33 
16Author    W. Hagele, D. Schmid, H. C. WolfRequires cookie*
 Title    Triplet-State Electron Spin Resonance of Chlorophyll a and b Molecules and Complexes in PMMA and MTHF II: Interpretation of the Experimental Results  
 Abstract    ESR spectra of various triplet species, obtained with solutions of chlorophyll a or chlorophyll b in PMMA or MTHF, are attributed to isolated chlorophyll molecules, to chlorophyll-solvent complexes and to dimeric structures. The structure of the proposed dimer is determined using the experimental results for the fine-structure and the rate constants and by assuming an in-coherent triplet-energy exchange. Based on this model the structure of the reaction center in photosynthetic bacteria was also reevaluated using the experimental data which were published by various authors. 
  Reference    Z. Naturforsch. 33a, 94—97 (1978); received November 4 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0094.pdf 
 Identifier    ZNA-1978-33a-0094 
 Volume    33 
17Author    J. Knof, F.-J Theiss, J. WeberRequires cookie*
 Title    Influence of Aggregation on the Fluorescence Decay of Organic Laser Dyes  
 Abstract    Singlet decay times in dependence on temperature, concentration, solvent and detergent were measured in solutions of organic laser dyes. In the temperature range from 300 K to 115 K the reciprocal decay time obeys an Arrhenius relationship, the parameters of which were determined. Additional measurements were carried out on Acridinorange because a biexponential fluorescence decay due to monomers (r = 4.2 ns) and aggregated molecules (r — 14.7 ns) was found. 
  Reference    Z. Naturforsch. 33a, 98—103 (1978); received November 5 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0098.pdf 
 Identifier    ZNA-1978-33a-0098 
 Volume    33 
18Author    W. Gauß, J. Kronenbitter, 0. Lutz, A. Nolle, G. E. SieglochRequires cookie*
 Title    Quadrupole Splittings of Alkali NMR Signals in Decylammoniumchloride Mesophases  
 Abstract    In lyotropic mesophases of decylammoniumchloride the NMR signals of the alkali nuclei 6 Li, 7 Li, 23 Na, 39 K, 85 Rb, 87 Rb and 133 Cs solubilized in these mesophases have been observed. The linewidths of the signals are comparable with the linewidths in aqueous solutions. Apart from 6 Li and 39 K for all other alkali nuclei in the mesophases first-order quadrupole splitted spectra have been observed. For the rubidium isotopes 85 Rb and 87 Rb a ratio of the quadrupole splitting of 2.01 i 0.05 has been determined. Further the chemical shifts of the solubilized alkali nuclei relative to infinitely diluted aqueous solutions have been measured. 
  Reference    Z. Naturforsch. 33a, 105—109 (1978); received December 16 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0105.pdf 
 Identifier    ZNA-1978-33a-0105 
 Volume    33 
19Author    0. SeebergRequires cookie*
 Title    A Test of the Linear Response Theory for Irreversible Processes  
 Abstract    The temporal development of macroobservables is described within a correlation-function-formalism. The results are exact for a certain class of initial ensembles. The same problem is discussed with the help of the linear-response-formalism. The results agree under certain con-ditions which should be fulfilled for macroobservables. 
  Reference    Z. Naturforsch. 33a, 110—120 (1978); received August 10 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0110.pdf 
 Identifier    ZNA-1978-33a-0110 
 Volume    33 
20Author    I. Zhelyazkov, S. G. TagareRequires cookie*
 Title    Excitation of Low-Frequency Ion Acoustic Perturbations in the Presence of Stationary Lower Hybrid Turbulence  
 Abstract    We have shown that stationary turbulence consisting of an ensemble of randomly phased small-amplitude lower hybrid waves becomes modulationally unstable against the ion acoustic perturbations along the external magnetic field. The growth rate of this instability is calculated. 
  Reference    Z. Naturforsch. 33a, 121—123 (1978); received September 19 1977 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0121.pdf 
 Identifier    ZNA-1978-33a-0121 
 Volume    33 
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