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1986[X]
101Author    B. N. Cyvin, S. J. Cyvin, M. Somer, W. BrocknerRequires cookie*
 Title    Schwingungsberechnungen der käfigstrukturierten Molekülionen P7 -, AS7 " und Sbv"  
 Abstract    Normal coordinate analyses for the cage-like molecule ions P3-, As3-and Sb3-with C 3 symmetry were performed, based on a very simple initial force field with three numerical param eters transferred from P4S3. FIR frequencies of Sb3-have been recorded. The force field was refined by adjusting the symmetry force constants to fit the observed frequencies. The final force fields were used to calculate the potential energy distribution terms (PED), the mean amplitudes of vibration and the first-order Coriolis coupling constants for the title molecule ions. 
  Reference    Z. Naturforsch. 41a, 549 (1986); eingegangen am 24. Dezem ber 1985 
  Published    1986 
  Keywords    Vibration Spectra, Cage Compounds, P7-, As3-, Sb^~ 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0549.pdf 
 Identifier    ZNA-1986-41a-0549 
 Volume    41 
102Author    H. Boysen, R. ForstRequires cookie*
 Title    Determination of Approximate Superstructures in the Urea-Hexadecane Inclusion Compound by Representation Analysis  
 Abstract    The inclusion compound of urea with hexadecane has a superstructure o f an ideal hexagonal structure found in other members of the series o f urea-n-paraffin adducts consisting essentially of honeycomb-like channels formed by the host into which the long chain molecules are embedded. In order to elucidate the nature of the superstructure, which manifests itself by addiditonal weaker reflexions (h k ll2) and (0 0 /) (all / = integer), it is expanded into basis functions trans­ forming as the irreducible representations (IR's) of the average space group P6|22. Most o f the IR 's can be ruled out by exploiting the symmetry of the diffraction pattern. For the rem aining sets of basis functions a least squares fit to the measured intensities is perform ed separately for each IR. Those yielding reliable agreements are then taken as key IR 's describing the prevalent modulations. In this way it is possible to obtain valuable inform ation about the main character­ istics of the superstructure, even if the true structure cannot be fully determined. In the present case a strong modulation belonging to the A3 IR was found to produce rotations o f the urea molecules around axes parallel to the channels as well as slight lateral translations. An additional contribution from r 5 results in a superposition of individual orthorhom bic domains with slightly different hydrogen bond angles. A phase transition below 147 K can be attributed to M2 and is connected with an ordering of the guest molecules and a simultaneous orthorhom bic deform ation of the channels. 
  Reference    Z. Naturforsch. 41a, 553—559 (1986); received D ecember 14 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0553.pdf 
 Identifier    ZNA-1986-41a-0553 
 Volume    41 
103Author    OskarE. PolanskyRequires cookie*
 Title    Über topologische Räume, welche kovalenten Verbindungen zugeordnet werden können, und ihre Bedeutung für die Chemie On Topological Spaces Associated with Covalent Compounds and Their Meaning for Chemistry  
 Abstract    Using H ausdorffs neighbourhood axioms, topological spaces associated with molecular graphs are derived. Their meaning for chemistry is illustrated by topological charge stabilization and the topological effect on MO (TEMO). Finally the role of molecular topology with regard to chemical structure is discussed. K ey w o rd s : Topological Spaces of Molecules, Topological Effect on MO (TEMO), Molecular Graphs, Molecular Topology. 
  Reference    Z. Naturforsch. 41a, 560—566 (1986); eingegangen am 16. Dezember 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0560.pdf 
 Identifier    ZNA-1986-41a-0560 
 Volume    41 
104Author    Claus KahlertRequires cookie*
 Title    Existence and Uniqueness of Solutions of Piecewise-Defined Continuous Dynamical Systems  
 Abstract    The question of existence and uniqueness of trajectories in piecewise-defined autonom ous dynamical systems is investigated. Examples o f prototype equations violating existence and/or uniqueness are presented as well as criteria testing these properties. 
  Reference    Z. Naturforsch. 41a, 567 (1986); received November 13 1986 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0567_n.pdf 
 Identifier    ZNA-1986-41a-0567_n 
 Volume    41 
105Author    R. Anion, D. Caminiti, P. Atzei, F. Cucca, G. Squintu, BongiovanniRequires cookie*
 Title    Coordination o f Rhodium (III) in D ilute Aqueous Solutions in Presence o f Chloride  
  Reference    Z. Naturforsch. 41a, 569 (1986) 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0569_e.pdf 
 Identifier    ZNA-1986-41a-0569_e 
 Volume    41 
106Author    R. Brucker, M. SorgRequires cookie*
 Title    Geometry of the SU (2) Di-Meron Solution  
 Abstract    The geometric properties of the di-m eron solution to the SU (2) Yang-Mills equations are studied in detail. The essential geometric structure of this solution is that of a locally symmetric space endowed with a R iem annian structure which is conformally flat. The di-meron solution is representable by an integrable 3-distribution over Euclidean 4-space. The corresponding integral surfaces are obtained in analytic form. 
  Reference    Z. Naturforsch. 41a, 571—584 (1986); received D ecem ber 2 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0571.pdf 
 Identifier    ZNA-1986-41a-0571 
 Volume    41 
107Author    J.M M J Vogels, L.U E Konings, D. C. SchramRequires cookie*
 Title    Source Properties of a Hollow Cathode Arc Plasma  
 Abstract    Experiments have been carried out on the properties of a hollow cathode as an ion-source. The measured electron density, ion and neutral tem peratures and drift velocities have been compared with predictions from the conservation laws for m atter, momentum and energy. Very large exit drift velocities of ions and neutrals are observed. The magnitude and direction, against the electric field, can be explained on the basis of the momentum balance. At weak magnetic field strengths even supersonic drift velocities are found. The charge flux carried by the ions is about five percent o f the net arc current. For small flows, the ionized fraction of the gas supply approaches 100%. The neutral particle density outside the cathode consist of a fraction drifting with a large velocity out of the cathode and a fraction of cool background atoms. The change of the ratio of these fractions with increasing distance to the cathode causes the average neutral particle drift to decrease very rapidly. Finally, an analysis o f the overall cathode power balance is given. 
  Reference    Z. Naturforsch. 41a, 585 (1986); received November 19 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0585.pdf 
 Identifier    ZNA-1986-41a-0585 
 Volume    41 
108Author    R. K. Roychoudhury, Sikha BhattacharryaRequires cookie*
 Title    Spatially Inhomogeneous Plasma with Negative Ions and Modified KdV Equation with x Dependent Term  
 Abstract    We have derived a modified KdV equation with x dependent term in the case o f a spatially inhomogeneous plasma using the stretched co-ordinate system by Asano. Exact and perturbation solutions derived from inverse scattering method are discussed. 
  Reference    Z. Naturforsch. 41a, 601—6 (1986); revised version received Decem ber 9 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0601.pdf 
 Identifier    ZNA-1986-41a-0601 
 Volume    41 
109Author    Ulrich Parlitz, W. Erner LauterbornRequires cookie*
 Title    Resonances and Torsion Numbers of Driven Dissipative Nonlinear Oscillators  
 Abstract    The torsion of the local flow around closed orbits and its relation to the superstructure in the bifurcation set of strictly dissipative nonlinear oscillators is investigated. The torsion num ber describing the twisting behaviour of the flow turns out to be a suitable invariant for the classifi­ cation of local bifurcations and resonances in those systems. Furtherm ore, the notions of winding num ber and resonance are generalized to arbitrary one-dimensional dissipative oscillators. 
  Reference    Z. Naturforsch. 41a, 605 (1986); received December 23 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0605.pdf 
 Identifier    ZNA-1986-41a-0605 
 Volume    41 
110Author    S. J. Cyvin3, B.N C Yvin3, M.-AE. Inarsrudb, J. Brunvoll3, G. D. Íaz, Flem Ing0Requires cookie*
 Title    Tetrahedral XY4 Molecules: Application of the Keating Bendings to the Degenerate Vibrations  
 Abstract    The Keating force field o f tetrahedral XY4 molecules is defined in analogy with valence and central force fields. The applicability o f the Keating coordinates versus valence and central coordinates is tested by different approaches. The general conclusion goes in favour of the Keating coordinates. 
  Reference    Z. Naturforsch. 41a, 615—618 (1986); received January 29 1986 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0615.pdf 
 Identifier    ZNA-1986-41a-0615 
 Volume    41 
111Author    S. Remme, G. Lehmann, K. Recker, F. W. AllrafenRequires cookie*
 Title    Electron Paramagnetic Resonance of N i2+ in BaZnF4 Single Crystals  
 Abstract    X-band EPR measurements of N i-doped BaZnF4 crystals revealed presence of three centers. Well-resolved hyperfine structure from nuclei at suitable orientations allowed assignment of the most intense spectrum to single ions on Ba sites. The occupation of Zn sites is considerably lower. The third spectrum is assigned to pairs of N i2+ ions on adjacent Ba sites. Attempts to correlate the zero-field splitting (ZFS) patterns of the single ion spectra with the distortions of the first coordination spheres of Ba and Zn resp. with a single intrinsic ZFS parameter for both bridging and nonbridging ligands were equally unsuccessful as in the case of M n2+. 
  Reference    Z. Naturforsch. 41a, 619 (1986); received February 3 1986 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0619.pdf 
 Identifier    ZNA-1986-41a-0619 
 Volume    41 
112Author    Eckhard Fliege, Helm Ut Dreizler, Michael Meyer, Khalid Iqbal, John SheridanRequires cookie*
 Title    4N Nuclear Quadrupole Coupling and Methyl Internal Rotation of 2-, 4-, and 5-Methyl Oxazole  
 Abstract    In the following we give an outline of 14N nuclear quadrupole, internal axis method (IAM) methyl internal rotation, and fourth order centrifugal distortion -only needed for extrapolating transition frequencies to higher J values — analyses performed for 2-, 4-, and 5-methyl oxazole. The results are discussed, the three methyl oxazoles being com pared with one another and with their common parent, oxazole. 
  Reference    Z. Naturforsch. 41a, 623 (1986); received December 16 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0623.pdf 
 Identifier    ZNA-1986-41a-0623 
 Volume    41 
113Author    W. Kasten, H. DreizlerRequires cookie*
 Title    Investigation of the 14N Quadrupole Hyperfine Structure and the Stark Effect of Methyl Isocyanate and Methyl Isothiocyanate by Microwave Fourier Transform Spectroscopy  
 Abstract    The nitrogen 14N quadrupole hyperfine structure and the Stark effect in the rotational spectra of methyl isocyanate and methyl isothiocyanate were investigated by high resolution microwave Fourier transform spectroscopy. The components of the coupling tensor in the principal inertia axis system and the n a com­ ponents of the dipole moments have been determined. 
  Reference    Z. Naturforsch. 41a, 637 (1986); received February 1 1986 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0637.pdf 
 Identifier    ZNA-1986-41a-0637 
 Volume    41 
114Author    O. L. StiefvaterRequires cookie*
 Title    Substitution Structures of Gauche and Trans Isobutyraldehyde by Double Resonance Modulation Microwave Spectroscopy  
 Abstract    Nine isotopic species of gauche- and seven isotopic forms of rra«.s-isobutyraldehyde, (CH3)2CHCHO, have been studied by DRM microwave spectroscopy to determine dihedral angles within and between the two rotameric conformations. In the gauche conformation one methyl group (subscript 3) eclipses the oxygen atom exactly, and best compatibility with the isotopic data is obtained when the two carbon-to-m ethyl bonds are assumed to be of equal length. The isotopic data for the less stable trans rotam er do not allow unequivocal determination of the bondlengths in the isobutyl skeleton, but bond angles and dihedral angles are determined satisfactorily. 
  Reference    Z. Naturforsch. 41a, 641 (1986); received Decem ber 11 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0641.pdf 
 Identifier    ZNA-1986-41a-0641 
 Volume    41 
115Author    Wolfgang Von Gentzkow, Erwin Knapek, Isolde Dietrich, Helmut FormanekRequires cookie*
 Title    Three Dimensional Structure of the Copper Complex of N,N'-Bis-salicyloyl-hydrazine  
 Abstract    N,N'-Bis-salicyloyl-hydrazine (BSH) is a very efficient copper deactivator. In this study the three dimensional structure of the copper-BSH complex was investigated with a cryotrans-mission-electron microscope and sterical and energetic calculations. The neat copper-BSH complex forms a nearly am orphous polymer. By absorption of e.g. gaseous am m onia a hexagonal structure shows up without fundam entally transform ing the conformation of the complex. The most dom inant lattice periodicities are 0.9 and 1.1 nm as obtained by electron microscopical imaging, electron diffraction and sterical calculations. The model shows that copper is very well shielded in the complex by the surrounding BSH-molecules. D ue to this, copper is perfectly deactivated. 
  Reference    Z. Naturforsch. 41a, 653—6 (1986); received D ecember 11 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0653.pdf 
 Identifier    ZNA-1986-41a-0653 
 Volume    41 
116Author    J. Koput, B. Marciniak, S. PaszycRequires cookie*
 Title    Protonation of the Trimethylated Pyrichrominium Ion  
 Abstract    Spectroscopic manifestations o f protonation of the trim ethylated pyrichrom inium ion studied previously experimentally [1] are investigated using a semiempirical IN D O /S Cl method. Singlet and triplet energy levels o f the free ion and several protonated species are calculated, and transition energies and oscillator strengths are compared with experimental spectra. Calculated charge densities on nitrogen atoms are correlated with experimental pKa values for the ground and lowest excited singlet and triplet states. The possibility o f the proton transfer reaction (phototautom erization) in the lowest excited singlet state of monoprotonated species is discussed on the basis o f IN D O /S Cl calculations, fluorescence and absorption spectroscopy. 
  Reference    Z. Naturforsch. 41a, 661—664 (1986); received Novem ber 2 1985 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0661.pdf 
 Identifier    ZNA-1986-41a-0661 
 Volume    41 
117Author    R. Anton, K. Häupl, P. Rudolf, P. WißmannRequires cookie*
 Title    Electrical and Structural Properties of Thin Palladium Films  
 Abstract    The electrical resistivity of thin palladium films deposited on amorphous substrates is measured in dependence on film thickness. The data are interpreted with the help of a statistical model taking into account structural inform ation obtained from AES, TEM and x-ray diffraction texture analysis. The steep decrease of resistivity in the ultra-thin thickness region can be immediately correlated with the formation of coherent areas in the films. A more flattened course is reached at about 8 nm thickness where a continuous film structure develops. 
  Reference    Z. Naturforsch. 41a, 665 (1986); received January 25 1986 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0665.pdf 
 Identifier    ZNA-1986-41a-0665 
 Volume    41 
118Author    Herbert Niephaus, Gerhard Raabe, Jörg FleischhauerRequires cookie*
 Title    Quantenchemische Rechnungen an Stickstoffbasen. Teil 4*: Zur Berechnung der Polarisierbarkeiten aliphatischer Amine mit der M IN D O /3-FP-M ethode Quantumchemical Calculations on Nitrogen Bases. Part 4 *. On the Calculation of the Polarizabilities of Aliphatic Amines with the MIN DO/3-FP-Method  
 Abstract    The polarizabilities of some primary, secondary, and tertiary amines have been calculated with the M INDO/3-FP-m ethod. The calculated values are found to correlate with the experimental polarizabilities and with those determ ined by the m ethod o f M iller and Savchik in a satisfying manner. In addition atom ic polarizabilities have been calculated according to the method of Metzger. Averaging over the calculated mean atom ic polarizabilities o f hydrogen, carbon, and nitrogen yields increments which, when used to recalculate molecular polarizabilities, lead to values which correlate in an excellent m anner with those determ ined from densities and re­ fraction indices by means o f the Lorenz-Lorentz-equation. Because different nitrogen increments have been determ ined for primary, secondary and tertiary amines, the param eters presented here m ake it possible to distinguish between con­ stitutional isomers as long as they belong to different groups (i.e. primary, secondary, and tertiary amines), something which cannot be done using the m ethod o f Miller and Savchik. The increments derived do not only allow to predict the polarizabilities o f primary, secondary and tertiary amines but can be used to calculate the corresponding values for hydrazines and poly­ functional amines with equal success. 
  Reference    Z. Naturforsch. 41a, 671—677 (1986); eingegangen am 1. F ebruar 1986 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0671.pdf 
 Identifier    ZNA-1986-41a-0671 
 Volume    41 
119Author    Michael Dittmann, GerhardM. SchneiderRequires cookie*
 Title    Convective Instabilities and Dynamic Structures in Phase-Separation Processes of Binary Liquid Mixtures  
 Abstract    In pressure jum p experiments on the phase separation of binary liquid mixtures o f cyclo-hexane + methanol, an organisation o f the finely dispersed precipitate could be observed to give a macroscopic dissipative structure during the early stages of the ageing process of the newly formed phase. Prelim inary phenomenological investigations suggest a mechanism similar to the Rayleigh-Benard instability (RBI) and the Soret-driven instability (SDI). 
  Reference    Z. Naturforsch. 41a, 678—6 (1986); received January 25 1986 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0678.pdf 
 Identifier    ZNA-1986-41a-0678 
 Volume    41 
120Author    H. KjeykampRequires cookie*
 Title    Die Wellenlängen der L-Serie des Röntgen-Spektrums von Technetium  
 Abstract    The wavelengths of the of Technetium L Series of the X-ray spectrum The L series of the X-ray spectrum of technetium was measured between 400 and 600 pm using the linear spec­ trom eter of an X-ray microanalyzer. The wavelengths and relative intensities of ten identified lines are given. 
  Reference    Z. Naturforsch. 41a, 681—682 (1986); eingegangen am 13. F ebruar 1986 
  Published    1986 
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 TEI-XML for    default:Reihe_A/41/ZNA-1986-41a-0681_n.pdf 
 Identifier    ZNA-1986-41a-0681_n 
 Volume    41 
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