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1983[X]
41Author    S. V. MentusRequires cookie*
 Title    Glassy Carbon/KCl-Solution Interface Impedance. Mechanical Surface Treatment Effect  
 Abstract    The dependence of complex impedance behaviour on mechanical surface treatment of glassy carbon electrodes in standard water KCl solutions at room temperature was investigated. A considerable frequency dependence of both the real and the imaginary term of the impedance was observed in the entire 1 -50 kHz range of frequencies used for electrodes of different surface roughness. The results are discussed in the light of the Levie theory. 
  Reference    Z. Naturforsch. 38a, 252—255 (1983); received October 7 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0252.pdf 
 Identifier    ZNA-1983-38a-0252 
 Volume    38 
42Author    AlbrechtW. Hofmann, WilliamM. WhiteRequires cookie*
 Title    Ba, Rb and Cs in the Earth's Mantle  
 Abstract    In 166 isotope dilution analyses of Ba, Rb, Cs on fresh basalts from mid-ocean ridges and oceanic islands, Ba/Rb and Cs/Rb ratios are nearly constant. From this, we conclude that Ba/Rb and Cs/Rb ratios are essentially constant in the present-day mantle in spite of large differences in the degree of source depletion or enrichment. As it appears improbable that these ratios could be both constant and non-primitive, we propose that they are representative of the primitive mantle and of the present-day crust-mantle system. We explain this uniformity of relative abundances as follows: the mantle is depleted by subtraction of a mobile phase such as a partial melt or an aqueous fluid. In either case, a significant amount of the mobile phase remains in the residue. Ba, Rb and Cs are among the most highly incompatible elements. Therefore the mobile phase cannot fractionate these elements relative to one another but retains the source ratios of Ba/Rb and Cs/Rb. Also, the amount of mobile phase remaining in the residue is enough to dominate the Ba, Rb and Cs concentrations in the residue. Consequently, neither the mobile phase nor the residue, nor any other portion of the mantle that may be enriched by addition of the mobile phase, will be changed in their relative abundances of Ba, Rb and Cs, even though the absolute abundances of these elements may change by orders of magnitude. The primitive Ba/Rb = 11.3 and Cs/Rb = 12.6 x 10~ 3 lead to the following estimates for the primitive mantle: Ba = 6.9 ppm (taken from Jagoutz et al. [1]). Rb = 0.61 ppm and Cs = 7.7 ppb. Assuming the earth has a chondritic Sr/Ba ratio of 3.08, we calculate a Rb/Sr ratio of 0.029 for the earth. This corresponds to a present-day 87 Sr/ 86 Sr of 0.7045. This value lies near the lower limit of the ratios estimated from the correlation of Nd and Sr isotopic abundances in oceanic basalts. The Cs/Rb ratios is about a factor of ten lower than the CI-chondritic ratio and a factor of three lower than the lunar ratio. This low terrestrial Cs/Rb ratio should be matched by similar values in the continental crust. However, the large range of Cs/Rb ratios found in the crust prevent us from obtaining a meaningful mass balance. 
  Reference    Z. Naturforsch. 38a, 256—266 (1983); received November 12 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0256.pdf 
 Identifier    ZNA-1983-38a-0256 
 Volume    38 
43Author    H. W. Weber, O. Braun, L. Schultz, F. BegemannRequires cookie*
 Title    The Noble Gas Record in Antarctic and Other Meteorites  
 Abstract    Data are reported for the concentration and isotopic composition of He, Ne, and Ar in 11 Antarctic and 8 other stone meteorites. Cosmic ray exposure ages and whole rock gas retention model ages are given. The noble gas record suggests that all three ALLAN HILLS eucrites analysed so far belong to the same meteorite fall while the three eucrites from the ELEPHANT MORAINE area appear to be three independent individual falls. 
  Reference    Z. Naturforsch. 38a, 267—272 (1983); received November 29 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0267.pdf 
 Identifier    ZNA-1983-38a-0267 
 Volume    38 
44Author    H. Voshage, H. Feldmann, O. BraunRequires cookie*
 Title    Investigations of Cosmic-Ray-Produced Nuclides in Iron Meteorites: 5. More Data on the Nuclides of Potassium and Noble Gases, on Exposure Ages and Meteoroid Sizes  
 Abstract    The concentrations of the cosmic-ray-produced He-, Ne-, and Ar-nuclides in samples of 31 iron meteorites have been determined by mass spectrometry. Thereby, the number of samples analyzed in this laboratory has grown to 83. A critical examination of all these results was performed. The data of at least 52 samples prove to be useful to describe the "normal" abundance patterns of cosmogenic noble gases in iron meteorites; the description is accom-plished by a new system of equations that correlate some properly selected abundance ratios with one another. The correlations serve as an instrument to recognize and diagnose certain abundance anomalies (3 He-or 38 Ar-deficiencies) which occur in about 25% of all samples analyzed. They allow to select those data which may unhesitatingly be applied in calculations concerning the irradiation histories of the respective meteorites. Another matter of concern for establishing these histories are the cosmic-ray-exposure ages. Mass spectrometric abundance analyses on meteoritic potassium have provided new data on the 4I K/ 40 K exposure ages of about 10 iron meteorites as well as on meteoroid sizes and sample depths. For two meteorites of the chemical group IIIAB, Joe Wright Mountains and Picacho, the age values obtained are 685 and 635 Ma, respectively. The results confirm our previous conclusion that the IIIAB-irons resided originally within a more or less contiguous partial volume (metallic core?) of their parent body and were ejected in consequence of a single impact event that happened about 670 Ma ago. Another motive for the present investigation was to measure the exposure ages for meteorites of the chemical groups IIICD and HIE. However, the new information obtained on their age distributions is still inadequate to answer some old questions concerning a possible relationship to the event that produced the IIIAB-meteoroids 670 Ma ago. 
  Reference    Z. Naturforsch. 38a, 273—280 (1983); received November 2 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0273.pdf 
 Identifier    ZNA-1983-38a-0273 
 Volume    38 
45Author    R. Haase, W. EngelsRequires cookie*
 Title    Diffusion in Non-ideal Liquid Mixtures  
 Abstract    An equation proposed recently (Haase and Jansen, 1980) relates to the dependence on composition and temperature of the diffusion coefficient D and of the kinematic diffu-sion coefficient D* in a binary nonelectrolyte solution. This equation is now applied to our own measurements of the activity coefficients and of the diffusion coefficient in the non-ideal liquid system carbon tetrachloride + acetone at 20 °C and 40 °C over the entire range of compositions. (For 0 °C only values of D are available.) It turns out that the function D (.v), where .v denotes the mole fraction of one of the components, exhibits a minimum at each tem-perature, while D* (x) nearly represents a straight line. We establish a correlation between the deviations from Raoult's Law and the sign of the difference D — D*. 
  Reference    Z. Naturforsch. 38a, 281—283 (1983); received November 10 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0281_n.pdf 
 Identifier    ZNA-1983-38a-0281_n 
 Volume    38 
46Author    G.-J Ni, W. WonnebergerRequires cookie*
 Title    Tunneling Through the Opaque Inverted Parabola  
 Abstract    The inverted parabola remains an exactly solvable tunneling barrier when imaginary parts are added to the potential. They represent the effect of particle absorption. In the limit of strong absorption ("opaque barrier") convenient limiting forms for the tunneling probability are derived using asymptotic expansions of the exact scattering solution. An application to Zener tunneling is made and the result is compared to the case of tunneling under viscous dissipation. Significant differences are found between these two approaches to tunneling under dissipation. 
  Reference    Z. Naturforsch. 38a, 285—288 (1983); received November 18 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0285.pdf 
 Identifier    ZNA-1983-38a-0285 
 Volume    38 
47Author    D. C. Schräm, I.J A M V D Mullen, B.F M Pots, C. J. TimmermansRequires cookie*
 Title    On the Pressure Balance and Plasma Transport in Cylindrical Magnetized Arcs  
 Abstract    Magnetized current-carrying plasmas exhibit usually significant Ex B rotation velocities which often approach the ion thermal velocity. It is shown both experimentally and theoretically that this rotation in combination with inertia, viscosity and friction leads to an important reduction of the radial transport. If the radial electric field component is directed inward an inwardly directed force on the ions is set up. On the other hand, turbulence leads to enhanced transport especially at higher values of the electron Hall parameter. Also this effect is observed in this experiment and is shown to be in accordance with measured turbulence levels. 
  Reference    Z. Naturforsch. 38a, 289—303 (1983); received June 11 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0289.pdf 
 Identifier    ZNA-1983-38a-0289 
 Volume    38 
48Author    Reinhild BöhmeRequires cookie*
 Title    Direkte Methoden bei Überstruktureffekten von höherem Index  
 Abstract    Direct Methods in the Case of Superstructure Effects of a Higher Index Superstructure effects take place with structures satisfying a pseudotranslation t. We discuss how to apply direct methods for the phase determination of the weak reflexions for structures where the index of t is larger than 2 and the atoms satisfy the pseudotranslation exactly or not at all. 
  Reference    Z. Naturforsch. 38a, 304—307 (1983); eingegangen am 21. September 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0304.pdf 
 Identifier    ZNA-1983-38a-0304 
 Volume    38 
49Author    Z. B. Maksić, K. RupnikRequires cookie*
 Title    On the Calculation of the Electrostatic Potentials at the Nuclei in the Point-charge Approximation  
 Abstract    It is shown that the concept of atomic charge in molecules is a useful tool in studying electro-static potentials at the nuclei which in turn are closely related to a number of molecular properties. Calculations executed on a selected set of widely different compounds provide extensive evidence that the semiempirical SCC-MO (self-consistent charge) atomic charges are equally successful in this respect as the ab initio DZ ones. 
  Reference    Z. Naturforsch. 38a, 308—312 (1983); received September 14 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0308.pdf 
 Identifier    ZNA-1983-38a-0308 
 Volume    38 
50Author    ZvonimirB. Maksić, Kresimir RupnikRequires cookie*
 Title    On the Approximate Relation Between the Sum of Semiempirical Molecular Orbital Energies and the Total Energy of a Molecule  
 Abstract    The Ruedenberg type formula relating the total molecular energy to the sum of orbital energies is examined by using SCC-MO and ab initio DZ MO eigenvalues. Comparison with rigorous ab initio DZ energy expectation values indicates that Ruedenberg's formula in its original form can not provide semiquantitative information on molecular energetics. Much more promissing in this respect is the electrostatic potential at the nuclei approach of Politzer and Parr. 
  Reference    Z. Naturforsch. 38a, 313—316 (1983); received September 14 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0313.pdf 
 Identifier    ZNA-1983-38a-0313 
 Volume    38 
51Author    E. Haid, D. Köhnlein, G. Kössler, O. Lutz, W. Messner, K. R. Mohn, G. Nothaft, B. Van Rickelen, W. Schich, N. SteinhauserRequires cookie*
 Title    Scandium NMR Investigations in Aqueous Solutions  
 Abstract    45 Sc NMR chemical shifts, linewidths, and longitudinal relaxation rates have been measured in aqueous solutions of scandium chloride and sulphate as a function of the appropriate acid. A common typical behaviour of these parameters without sudden changes has been observed. Also signals in the basic range have been obtained. H 2 0 —D 2 0 solvent isotope effects on Larmor frequency and relaxation rates are presented. 
  Reference    Z. Naturforsch. 38a, 317—321 (1983); received December 3 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0317.pdf 
 Identifier    ZNA-1983-38a-0317 
 Volume    38 
52Author    A. Kawski, M. Stoń, I. JanićRequires cookie*
 Title    On the Intensity Distribution within Photoluminescence Bands in Rigid and Liquid Solutions  
 Abstract    The effect of the excitation light frequency on the intensity distribution within the fluorescence band and the band position of non-polar and strongly polar luminescent substances is investigated in pure and mixed liquid and glassy solvents. An interpretation concerning the intensity distribu-tion in the emission band and the local temperatures determined by the method of Stepanov is given. 
  Reference    Z. Naturforsch. 38a, 322—324 (1983); received October 29 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0322.pdf 
 Identifier    ZNA-1983-38a-0322 
 Volume    38 
53Author    Ernst Noid, Georg Rainer-Harbach, Peter Lamparter, Siegfried SteebRequires cookie*
 Title    Untersuchung von Fe^B^-und Fe^n-Schmelzen mittels Röntgen-Beugung  
 Abstract    X-Ray investigation with Fe^B, 0 -and Fe^B ]7 -melts By means of X-ray diffraction the two molten alloys Fe^Bio and Fe 83 B 17 were investigated. The second maximum of the intensity curve shows in both cases a small shoulder which up to now never was observed with binary melts. The interatomic distances and the coordination numbers were evaluated. The normalized atomic distances taken from the pair correlation function of amorphous Fe 80 B 20 agree well with those reported in literature for a tetrahedral model, whereas the normalized distances obtained with the two melts show rather large devia-tions from this model. 
  Reference    Z. Naturforsch. 38a, 325—328 (1983); eingegangen am 27. November 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0325.pdf 
 Identifier    ZNA-1983-38a-0325 
 Volume    38 
54Author    P. Lamparter, W. Martin, S. Steeb, W. FreylandRequires cookie*
 Title    Neutron Diffraction Study on the Structure of Liquid Cs-Sb Alloys  
 Abstract    By neutron diffraction experiments the total structure factors and the total pair correlation functions of liquid Cs-Sb alloys containing 85, 75, 65, and 50 at% Cs, respectively, were deter-mined. The structural results confirm the non metallic properties of Cs-Sb melts. The correspondence of the nearest neighbour atomic arrangement in liquid Cs 75 Sb 2 5 and in the solid compound semiconductor Cs 3 Sb suggests a similar type of bonding, namely by valence bonds and ionic forces simultaneously. The stability of this compound in the molten state leads to a microsegregation tendency between compound forming regions and excess Cs in the concen-tration range from pure Cs up to 25 at% Sb, which is established by a small angle scattering effect. Proceeding from Cs 75 Sb 25 to Cs 5 oSb 5 o, a continuous change in the structure takes place. Covalently bonded Sb chains are formed just as found in the corresponding solid compounds ASb (A = alkali metal). An additional diffraction peak in front of the main peak of the structure factors within this composition range implies the formation of rather large molecular clusters in the alloys. 
  Reference    Z. Naturforsch. 38a, 329—335 (1983); received November 11 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0329.pdf 
 Identifier    ZNA-1983-38a-0329 
 Volume    38 
55Author    A. AsenbaumRequires cookie*
 Title    Brillouin-Streuung an dichten Fluiden  
 Abstract    On Brillouin Scattering in Dense Fluids It has been shown analytically that Mountain's theory of the spectral distribution of density fluctuations in fluids having an external degree of freedom (MOUXI) is equivalent to the translational hydrodynamics theory (TH) of Desai and Kapral at liquid state densities where selfdiffusion can be neglected. On the other hand, comparing TH and Mountain's second theory of Brillouin scattering on thermal relaxing fluids involving a frequency dependent volume vis-cosity (MOUETA), differences are found in several spectral components, especially the intensity of the Rayleigh line, of the Brillouin spectra of CC1 4 , C 6 H 12 and C 6 H 6 at large values of the wave vector k. This theoretical effect can be demonstrated experimentally by fitting TH and MOUETA to experimental Brillouin spectra of CC1 4 at high values of k, resulting in small changes of the corresponding relaxation times. 
  Reference    Z. Naturforsch. 38a, 336—349 (1983); received October 7 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0336.pdf 
 Identifier    ZNA-1983-38a-0336 
 Volume    38 
56Author    V., BerndPeter Schweiss, Hartmut Fuess, Gerhard Fecher, Alarich WeissRequires cookie*
 Title    On the Order-Disorder Phase Transformation of Anilinium Halides Inelastic Neutron Scattering on Anilinium Bromide, C 6 H 5 NHf Br®, and its Partially Deuterated Derivatives C 6 H 5 ND®Br® and C 6 D 5 NH® Br®  
 Abstract    The order-disorder phase transition which occurs at T c = 296.9 K in anilinium bromide, C 6 H 5 NH 3 Br, is studied by inelastic neutron time-of-flight measurements. Data are taken from hydrogenated and partially deuterated samples (C 6 D 5 NH 3 Br and C 6 H 5 ND 3 Br) below and above the transition temperature. From the inelastic scattering data the phonon frequency distribution in the range of the intermolecular vibrations is calculated. The assignment of bands is given and changes in the spectra with temperature are discussed. The analysis of the quasielastic line revealed substantial broadening due to rotational diffusion of the —NH® group. These jump diffusion processes were observed in the orthorhombic high temperature and — with markedly diminished rate — in the monoclinic phase below T Q . From the correlation times at different temperatures the activation energies are estimated for both phases. Comparison with calculated elastic incoherent structure factors suggests jumps of 60° for hindered rotation. 
  Reference    Z. Naturforsch. 38a, 350—358 (1983); received October 13 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0350.pdf 
 Identifier    ZNA-1983-38a-0350 
 Volume    38 
57Author    I. Einheitliche, ReaktionenHeinz MauserRequires cookie*
 Title    Zur spektroskopischen Analyse von Reaktionen zweiter Ordnung  
 Abstract    On the Spectrophotometric Analysis of Second Order Reactions The following questions are investigated: Is it possible to analyse chemical reactions with spec-trophotometric means only, without knowledge of molar absorptivities? What kind of informa-tions are necessary to distinguish between two or more chemical reactions? This investigation is restricted on simple reactions of first and second order. The differential equation is solved for the general case. Difference Equations for the kinetic analysis are expressed. For a number of selected reactions the characteristic parameters are listed. More complicated reactions will be investigated in a following paper. 
  Reference    Z. Naturforsch. 38a, 359—367 (1983); eingegangen am 10. Juli 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0359.pdf 
 Identifier    ZNA-1983-38a-0359 
 Volume    38 
58Author    Günter WermuthRequires cookie*
 Title    Elektronenspektren /7-donator-substituierter Benzonitrile und Benzoesäureäthylester  
 Abstract    The positions of 'L a and 'L b type absorption bands as well as the fluorescence polarization and natural lifetime show that p-donor substituted benzonitriles emit from a 'L b -state. On the other hand, the nature of the lowest excited state of ^-substituted ethylbenzoates depends upon the kind of the donor. In case of a dialkylamino group as donor substituent the emission occurs from the 'L a -state, in case of weeker donors, like methoxy, from the 'L b -state. In the intermediate case of p-aminoethylbenzoate the excited state depends upon the polarity of the solvent. The 'L b <-'A transition occurs at higher wave numbers for the donor substituent ethyl-benzoates than for the correspondingly substituted benzonitriles, although the ester group represents the stronger acceptor substituent than the nitrile group in spectroscopic respect. This effect is interpreted using perturbation theory according to Petruska. 
  Reference    Z. Naturforsch. 38a, 368—377 (1983); eingegangen am 26. November 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0368.pdf 
 Identifier    ZNA-1983-38a-0368 
 Volume    38 
59Author    M. H. PalmerRequires cookie*
 Title    Assignment of the UV-Photoelectron Spectrum of Tetrasulfur Tetranitride  
 Abstract    Ab initio configuration interaction calculations of the ground and doublet states of S 4 N 4 show changes in the order of states relative to a large basis set Koopmans' Theorem order. Conse-quential changes in the assignment of the UV-photoelectron spectrum are reported. 
  Reference    Z. Naturforsch. 38a, 378—382 (1983); received December 7 1982 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0378.pdf 
 Identifier    ZNA-1983-38a-0378 
 Volume    38 
60Author    Requires cookie*
 Title      
 Abstract    o6 o'ixJ 8 8 8 8 05 <X5 8 8 8 8 28 36 a? oo o o9 20 20 28 20 O OO Ca Q 8 2U 48 7U a Q 32 20 0340-4811 / 83 / 0300-0383 $ 01.3 0/0. -Please order a reprint rather than making your own copy. 384 Notizen 
  Reference    Z. Naturforsch. 38a, 383 (1983) 
  Published    1983 
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 TEI-XML for    default:Reihe_A/38/ZNA-1983-38a-0383_n.pdf 
 Identifier    ZNA-1983-38a-0383_n 
 Volume    38 
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