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1983 (221)
1Author    J. Brokx, G. Vertogen, E.W C Van GroesenRequires cookie*
 Title    On the Field-Induced Cholesteric-Nematic Transition in Cholesteric Liquid Crystals with Homeotropic Boundary Conditions  
 Abstract    The influence of homeotropic boundary conditions on the cholesteric-nematic transition is discussed, starting from the assumption that the director field consists of only components perpendicular to the helix axis, which is directed parallel to the boundary planes. Attention is paid to the solution of Cladis and Kleman for the simpler case without magnetic field. Their solution, consisting of regularly spaced line signularities, is derived in another more transparent way. Besides it is shown that even director fields without singularities are possible. The presence of a magnetic field complicates the solution considerably. Now the relevant Euler-Lagrange equation is solved in an approximate way by partly resorting to the difference method. The usefulness of the method is demonstrated by applying this technique to the nematic-cholesteric transition and the Freedericksz transition in nematics. 
  Reference    Z. Naturforsch. 38a, 1 (1983); received August 28 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0001.pdf 
 Identifier    ZNA-1983-38a-0001 
 Volume    38 
2Author    W. EckhardtRequires cookie*
 Title    Surface Polariton Mode Densities  
 Abstract    Starting from the Green functions of the electromagnetic (EM) field in two adjacent dielectric half-spaces, the surface and bulk contributions to the EM-density of states are discussed. The mode densities determine the thermodynamic properties of the radiation field. 
  Reference    Z. Naturforsch. 38a, 10—15 (1983); received September 10 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0010.pdf 
 Identifier    ZNA-1983-38a-0010 
 Volume    38 
3Author    ManfredH. Kluckner-, B.Sesh RaoRequires cookie*
 Title      
 Abstract    Vibration-rotation wave functions for HF and HI are computed by solving the radial Schroedinger wave equation numerically using an anharmonic potential function with seven adjustable parameters. With these wave functions the matrix elements of [(r — r e)/r e ] n are computed. These are then applied in a least squares fit to experimentally measured values of the electric dipole matrix elements to yield the dipole moment coefficients Af 0 , M\ ,..., M 5 . 
  Reference    Z. Naturforsch. 38a, 16—19 (1983); received August 10. 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0016.pdf 
 Identifier    ZNA-1983-38a-0016 
 Volume    38 
4Author    R. Gerling, K. DrägerRequires cookie*
 Title    Evidence for Different Ferromagnetic Phases in Amorphous Fe 4 oNi4oB 2 o Detected by EPR  
 Abstract    Amorphous ferromagnetic Fe^Ni^I^o (T C = 662 K) has been investigated by EPR in the tem-perature range from 110 to 510 K. From the temperature dependence of the magnetic field at res-onance, the saturation magnetization could be evaluated. Around 470 K the line width of the resonance signal exhibits a pronounced minimum, and the EPR-intensity deviates at this temperature from pure ferromagnetic behaviour. Both effects can be explained by assuming the presence of a second ferromagnetic phase with a Curie temperature of r c '=470 K. Upon annealing of Fe4 0 Ni 40 B 2 o at temperatures slightly higher than 77 changes in physical properties, such as Curie temperature, density and relative strain at fracture are observable. It is proposed that the onset of the low temperature relaxation which is responsible for these changes in physical properties is related to the transition of the second ferromagnetic phase to the paramagnetic state. 
  Reference    Z. Naturforsch. 38a, 20—26 (1983); received November 6 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0020.pdf 
 Identifier    ZNA-1983-38a-0020 
 Volume    38 
5Author    Ulrich Pätzmann, Wolfgang BrocknerRequires cookie*
 Title    Schwingungsspektren von Ag 3 PS 4 und Cu 3 PS 4  
 Abstract    eingeg. am 27. Oktober 1982 Vibrational Spectra of AgjPS 4 and Cu } PS 4 The infrared and Raman spectra of silver thiophosphate Ag^PS 4 have been recorded. The ob-served frequencies are assigned on the basis of tetrahedral units by considering a splitting of the F 2 modes by the crystal field. The vibrational frequencies of copper thiophosphate Cu 3 PS 4 are completed for the far infrared region. For both title compounds DTA-data have been determined and interpreted. 
  Reference    Z. Naturforsch. 38a, 27—30 (1983) 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0027.pdf 
 Identifier    ZNA-1983-38a-0027 
 Volume    38 
6Author    F. Fischer, R. FuhrichRequires cookie*
 Title    IR Studies of Crystalline Methanol Films with Textures  
 Abstract    When amorphous methanol films, deposited at 78 K on a substrate already covered by a thin crystalline methanol layer, are crystallized above 104 K they obtain a growth texture. This can be seen from relative intensity alterations of IR bands related to the hydrogen bondings. Another growth texture is obtained by depositing the film at 145 K. Large spherulites are seen between crossed polarizers. Other alterations of IR bands are observed. From the interpretation of this dichroism we learn about the growth mechanism. The relations of polymer chains with hydrogen bonds to those with covalent bonds are discussed. Isothermal sublimation can be studied from the linear decrease of a single IR band. This allows to determine the heat of sublimation. 
  Reference    Z. Naturforsch. 38a, 31—36 (1983); received October 15 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0031.pdf 
 Identifier    ZNA-1983-38a-0031 
 Volume    38 
7Author    A. Piel, H. RichterRequires cookie*
 Title    Experimental Study of Ion Dynamic Effects in Overlapping Helium Lines at Low Densities  
 Abstract    The line profiles of the overlapping helium lines 447.1 nm and 492.2 nm have been investigated in an improved plasma source of high purity at electron densities of 1 x 10 21 m -3 and 3x 10 2 ' m~ 3 . The plasma parameters N E , T E and T 0 were determined carefully by independent diagnostics, which enables a critical comparison with existing theories (BCS II and MMM). We observed ion dynamic effects which considerably modify the line shape of the forbidden components. Our experiments extend the existing observations towards higher ion temperatures. Systematic trends observed earlier are critically discussed. 
  Reference    Z. Naturforsch. 38a, 37—46 (1983); received September 29 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0037.pdf 
 Identifier    ZNA-1983-38a-0037 
 Volume    38 
8Author    Janina Legendziewicz, Grazyna Oczko, Wieslaw StrękRequires cookie*
 Title    Intensity Analysis and Luminescence Spectra of Non-Aqueous Solutions of Europium Compounds  
 Abstract    The oscillator strengths of the f-f transitions as well the fluorescence spectra for europium Perchlorate, chloride and nitrate in mono-and disubstituted amides have been measured. The Judd-Ofelt parameters are calculated. The formation of inner-sphere europium complexes is dis-cussed on the basis of intensity analysis of the absorption and luminescence spectra. In mono-and disubstituted amides solutions the f-f transitions of Eu +3 have been analysed and the three parameters fitted with satisfactory accuracy. Among all f-f transitions the hypersensitive ones in absorption 7 F" 5 D 0 and fluorescence 5 D n —> 7 F 2 varied most markedly. From an analysis of the data it was concluded that only Eu(N0 3) 3 and EUC1 3 in DMF form inner-sphere complexes. At low concentration of EUC1 3 in DMF the predominant form is [EuCl(DMF) > _i] +2 , whereas at high concentration the predominant form is [EUC1 2 (DMF) > ,_2] +i . The intensity of the hypersensi-tive bands decreases with increasing EUC1 3 concentration, contrary to the common opinion that complexation increases the intensity of hypersensitive bands. 
  Reference    Z. Naturforsch. 38a, 47—55 (1983); received September 28. 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0047.pdf 
 Identifier    ZNA-1983-38a-0047 
 Volume    38 
9Author    Shukri Lepaja, Henry Strub, Daniel-Joseph LougnotRequires cookie*
 Title    Photophysical Study of a Series of Cyanines Part III. The direct photooxidation reaction [1|  
 Abstract    The main degradative pathway of tricarbocyanine dyes in aerated solutions is demonstrated to be a photooxidation; using sensitization techniques and specific quenchers, this reaction is estab-lished to proceed via singlet oxygen for a part, and the site at which this species attacks the polymethinic skeleton is unambiguously determined. The major photoproduct is identified as being 1,3,3-trimethyl-2-indolinone. Direct Photooxidation of Tricarbocyanine Dyes 
  Reference    Z. Naturforsch. 38a, 56—60 (1983); received October 1. 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0056.pdf 
 Identifier    ZNA-1983-38a-0056 
 Volume    38 
10Author    A. H. Jubert, C. O. Della Védova, E. L. Varetti, O. E. Piro, P. J. AymoninoRequires cookie*
 Title    Semiempirical Calculation of the Rotational Barrier and Valence Force Constants in Fluorocarbonylsulfenyl Chloride  
 Abstract    The rotational barrier about the C-S bond in fluorocarbonylsulfenyl chloride [FC(0)SC1] is investigated using the CNDO method. The results confirm the existence of planar eis and trans conformers and the higher stability of the latter, as suggested by previous vibrational results. The valence force constants in FC(0)SC1 were also calculated and the values obtained compare favourably with results from a previous normal coordinate calculation and with those of related compounds. 
  Reference    Z. Naturforsch. 38a, 61—63 (1983); received August 23 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0061.pdf 
 Identifier    ZNA-1983-38a-0061 
 Volume    38 
11Author    M. Bester, M. Tanimoto, B. Vowinkel, G. Winnewisser, Koichi YamadaRequires cookie*
 Title    Rotational Spectrum of Methylcyanoacetylene A New Millimeter Wave Spectrometer  
 Abstract    The ground state rotational spectrum of methylcyanoacetylene, CH 3 CCCN, has been observed between 8 and 90 GHz, yielding precise rotational constants and a determination of the nuclear hyperfine costant eqQ = -4.0 ±0.2 MHz. The millimeter wave spectra (70 -90 GHz) were ob-tained with a newly constructed spectrometer, employing a synthesizer -controlled reflex klystron as source. 
  Reference    Z. Naturforsch. 38a, 64—67 (1983); received October 28 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0064.pdf 
 Identifier    ZNA-1983-38a-0064 
 Volume    38 
12Author    Volker Fischer, Klaus SchefflerRequires cookie*
 Title      
 Abstract    di-tert.butyl-phenol by 'H-DNMR Parts of the 'H-NMR spectra of the title substance show typical coalescence behaviour, which is analysed by line shape simulation. N-inversion is accounted for the dynamic process and rate constants and activation energies are given. 
  Reference    Z. Naturforsch. 38a, 68—73 (1983); eingegangen am 30. September 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0068.pdf 
 Identifier    ZNA-1983-38a-0068 
 Volume    38 
13Author    MichaelH. PalmerRequires cookie*
 Title    The Electronic Spectrum and Structure of Tetrasulfur Dinitride  
 Abstract    Ab initio configuration interaction calculations of the ground and singlet A' and A" excited states have been performed, with all possible single and double excitations from the 10 highest occupied orbitals to the lowest 17 virtual Orbitals being included, the previous C s symmetry molecular structure being used. Some of the states can be identified with excitation from individ-ual occupied (SCF) orbitals to members of the virtual set, but some are not well represented by single configuration concepts. The results suggest that the three broad UV-spectral maxima ob-served in solution are not single excitations, but groups of excited states, with a total of 8 states. The closeness of some of these states makes positive assignment difficult. The most probable as-signment is 455 nm (1 A"), 377 nm (2A" + 1 A' + 2A'), ~ 277 nm (3A" + 3A'), 232 nm (4A' + 4A"). 
  Reference    Z. Naturforsch. 38a, 74—77 (1983); received August 9 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0074.pdf 
 Identifier    ZNA-1983-38a-0074 
 Volume    38 
14Author    MichaelH. Palmer, In Part, RobertH. FindlayRequires cookie*
 Title    The Electronic Structure of Tetraphosphorus-and Tetraarsenic- Trisulphides; Interpretation of their Photoelectron Spectra  
 Abstract    Ab initio SCF calculations of the X'A, ground states of P 4 S 3 and As 4 S 3 are reported, together with configuration interaction studies of the 2 A 15 2 A 15 2 A 2 and 2 E states ofP 4 S 3 . A re-interpretation of the UV-photoelectron spectrum of the P 4 S 3 molecule, and As 4 S 3 by analogy, is presented and it is noted that Koopmans' theorem yields a very similar order and spacing between groups to the doublet states computed by configuration interaction. 
  Reference    Z. Naturforsch. 38a, 78—85 (1983); received October 7 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0078.pdf 
 Identifier    ZNA-1983-38a-0078 
 Volume    38 
15Author    W.-H Steeb, W. OevelRequires cookie*
 Title    Bäcklund Transformation Groups of Non-Linear Evolution Equations and the Painleve Property  
 Abstract    We show that the group theoretical reduction of evolu-tion equations which admit Lie-Bäcklund transformation groups does not lead in general to ordinary differential equations with the Painleve property. 
  Reference    Z. Naturforsch. 38a, 86—87 (1983); received October 23 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0086_n.pdf 
 Identifier    ZNA-1983-38a-0086_n 
 Volume    38 
16Author    Z. Giazitzoglou, H. Engels, U. SchillerRequires cookie*
 Title    Excess Free Energies in Molten CuCl-KCl-LiCl by EMF Measurements  
 Abstract    The ternary liquid system CuCl-KCl-LiCl has been investigated by means of emf measurements at about 450 up to 700 °C. Excess free energies and activity coefficients for molten CuCl in the KCl-LiCl eutectic are calculated by a best fit to the obtained data and from literature data for the corresponding binary systems employing the Redlich-Kister equation. 
  Reference    Z. Naturforsch. 38a, 88—89 (1983); received October 9 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0088_n.pdf 
 Identifier    ZNA-1983-38a-0088_n 
 Volume    38 
17Author    D. Carbone, A. Chisari, E. Montoneri, G. C. Pappalardo, G. ScarlataRequires cookie*
 Title    Dipole Moments and Configurations of Triaryl Acrilonitriles  
 Abstract    The electric dipole moments of trans-1,2 diaryl acrilo-nitrile 1 and of a series of triaryl acrilonitriles 2-14 were measured in benzene solution at 25 °C. A mesomeric moment of 0.4 D was found to act between the phenyl-and the nitrile groups through the vinylic bond in triaryl acrilo-nitrile 2. For this molecule the direction of action of the total molecular moment was calculated and used to evalu-ate theoretical moments for the possible E and Z configu-rations of some unsymmetrical derivative compounds of the series. The configuration was settled for each com-pound on the basis of comparison between experimental and calculated dipole moment values. 
  Reference    Z. Naturforsch. 38a, 90—91 (1983); received May 29 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0090_n.pdf 
 Identifier    ZNA-1983-38a-0090_n 
 Volume    38 
18Author    Wolfgang Brockner, Ulrich PätzmannRequires cookie*
 Title    Raman-Spektren von gelöstem Na^Se -6H 2 0  
 Abstract    Raman Spectra of dissolved Na 4 P 2 S 6 • 6 H 2 0 Raman spectra with polarization measurements of a saturated Na 4 P 2 S 6 • 6 H 2 0 solution are recorded. Especially the polarization data prove the assignment of the vibra-tional frequencies of the hexathiohypodiphosphate anion P 2 Sr with D 3d symmetry. A reliable assignment of the P 2 Sg~ frequencies is important for the interpretation of the vibration spectra of crystalline metal phosphorus trisulfides containing P 2 S 6 groups. 
  Reference    Z. Naturforsch. 38a, 92—93 (1983); eingegangen am 8. Dezember 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0092_n.pdf 
 Identifier    ZNA-1983-38a-0092_n 
 Volume    38 
19Author    Isao Okada, Arnold LundénRequires cookie*
 Title    On the Distribution of Isotopes in a Separation Column in Countercurrent Electromigration of Molten Binary Mixtures  
 Abstract    In countercurrent electromigration of molten binary mixtures with a common anion in which each cation is composed of two isotopes, the less mobile cation is enriched toward the anode, and, at the same time, the isotopes of this cation become distributed in a complicated way. Thus, the zone next to the anode where the heavy isotope is enriched is immediately followed by a region where a slight enrichment of the light isotope occurs, while for the more mobile cation the heavy isotope is enriched in both these regions. This phenomenon has been observed in experi-ments with the systems (Li-K)N0 3 and (Li-K)Cl and it has also been reproduced by analyzing the flow equations for the constituent components numerically with a computer. It is verified that the existing formulation for the calculation of the elementary separation factor holds independent of whether there is such an anomaly in the isotope distribution for the less mobile cation. 
  Reference    Z. Naturforsch. 38a, 97—105 (1983); received September 29 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0097.pdf 
 Identifier    ZNA-1983-38a-0097 
 Volume    38 
20Author    F. Lantelme, M. ChemlaRequires cookie*
 Title    Chronoamperometric Determination of Solid State Diffusion Coefficients in Copper-Gold Alloys Using a Molten Salt Electrolyte  
 Abstract    The intermetallic diffusion coefficient in Cu-Au alloy between 400 °C and 550 °C is measured by chronoamperometry using a Cu-Au electrode in a molten LiCl-KCl electrolyte containing small amounts of Cu + ions. The current response to a defined constant potential step is controlled by the rate of diffusion in the alloy electrode. The mathematical treatment developed by introducing the Boltzman transformation shows that the current density is a linear function of the reciprocal square root of time whatever the dependence of D versus concentration is. The method is applied to cathodic as well as anodic potential pulses which correspond to surface alloying or dissolution i.e. diffusion "in" or "out" the sample. The shift of the interface due to the copper deposition or dissolution is considered according to the Oldham and Raleigh's method. By studying the electrochemical response at very short times the diffusion can be examined in the first atomic layers of the electrode interface. 
  Reference    Z. Naturforsch. 38a, 106—115 (1983); received October 15 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0106.pdf 
 Identifier    ZNA-1983-38a-0106 
 Volume    38 
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