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1978[X]
101Author    A. Lodding, S. J. Larsson, H. OdeliusRequires cookie*
 Title    Secondary Ion Mass Spectra of Apatites  
 Abstract    The detection sensitivities and the possibilities of quantification in the ion probe analysis of microelements in tooth and bone mineralized tissue are limited partly by selective ionization yields, partly by the complicated intrinsic mass spectra of the apatite matrix. Such intrinsic spectra have been recorded for hydroxy-, fluor-and chlorapatite. The limits of analysis have been examined for most of the elements in the periodic table. With a routine SIMS technique developed for the study of mineralized tissues, the lowest concentrations for semi-quantitative measurement have been assessed to lie below 10 wt ppm for at least 20 elements and below 100 wt ppm for another 25 to 30 trace elements in apatites. 
  Reference    Z. Naturforsch. 33a, 697—708 (1978); received April 7 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0697.pdf 
 Identifier    ZNA-1978-33a-0697 
 Volume    33 
102Author    Wolfgang Brockner, BjergN. Cyvin, SvenJ. CyvinRequires cookie*
 Title    Normalkoordinatenanalyse und mittlere Schwingungsamplituden für Cl5SbOPCl3, Cl5NbOPCl3 und Cl5TaOPCl3  
 Abstract    Normal Coordinate Analysis and Mean Amplitudes of Vibration for ClsSbOPCl3 , Cl5NbOPCl3 and ClJaOPCl3 A normal coordinate analysis was performed for some C15M0PC1S molecules (M = Sb, Nb, Ta). The final force field in terms of a described set of symmetry coordinates is reported for Cl5SbOPCls. The initial force field for Cl5SbOPCl3 was applied to calculate the vibrational frequencies of the Cl5NbOPCls and Cl5TaOPCls adducts. An assignment of the vibrational frequencies of the title compounds and the corresponding potential energy distribution terms are given for Cl5SbOPCls . For the Cl5SbOPCl3 molecule the final force field was also used to calculate the mean amplitudes of vibration. 
  Reference    Z. Naturforsch. 33a, 709—713 (1978); eingegangen am 25. März 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0709.pdf 
 Identifier    ZNA-1978-33a-0709 
 Volume    33 
103Author    S. J. Cyvin, B. N. Cyvin, W. Brockner, A. F. DemirayRequires cookie*
 Title    Molecular Vibration Analysis of the TeCl4 Tetramer and Monomer and the SeCl4 Tetramer for teoretisk kjemi, Universitetet i Trondheim  
 Abstract    The molecular vibrations of (TeCl^ and (SeCl4)4 are studied on the basis of a cubane-like Ta model. Symmetry coordinates are produced by using the theory developed for tetrahedral com-plexes with trigonal ligands. Approximate vibrational frequencies are calculated from very simple four-parameter force fields and used as an aid in tentative assignments of observed fre-quencies from literature. Next the force fields are refined by adjustments to the observed fre-quencies assigned as fundamentals. Potential energy distribution terms and mean amplitudes of vibration are calculated. Finally the monomeric form of TeCl4 is analysed, mainly in order to show the frequency shifts on passing from the monomer to tetramer. 
  Reference    Z. Naturforsch. 33a, 714—721 (1978); received March 6 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0714.pdf 
 Identifier    ZNA-1978-33a-0714 
 Volume    33 
104Author    SalimM. Khalil, Muthana ShanshalRequires cookie*
 Title    MINDO-FORCES Calculation of the Benzyl and Vinyl Radicals and the Reactions ^K.+H^CH* and CH4 + ^CH3 + +H  
 Abstract    The MIND0/3-F0RCES method is applied for the calculation of the 1 CH2-1-H2 CH4 reaction. The variation of geometry is carried out in such a manner as to allow for the deviation from the Csv symmetry along the H 7 —CH, reaction coordinate. The changes in the geometric parameters of the system during the reaction are followed. It is found that the transition state of the reaction corresponds to ß = 1.8Ä and has a geometry closer to the reactants than the products. The cal-culated activation energy is 13.57 kcal/mol and the calculated reaction enthalpy 106.36 kcal/mol (118.9 kcal/mol exp.). Similar calculations for the CH4 ,+ yield a D2d structure and a AH[ value of 269.68 kcal/mol (274.0 kcal/mol exp.). The activation energy of the decomposition reaction CH4 + -> CH3 + + H -is 84.54 kcal/mol, the reaction enthalpy is 42.83 kcal/mol (38.10 kcal/mol exp.). Using both MINDO/2-and MIND0/3.F0RCES a Q>v geometry is calculated for the benzyl radical. The AHf values are 48.40 and 67.93 kcal/mol respectively. The latter calculation shows that the rotated perpendicular conformation of the methylene group is by 2 kcal/mol less stable than the planar one. The rotation transition state corresponds to the rotation angle 50°. The change in ithe geometric parameters during the rotation is followed. For he vinyl radical the MINDO/3-FORCES calculation yields a CCH angle of 151.1° and a H{ value of 69.8 kcal/mol (65 kcal/mol exp.). 
  Reference    Z. Naturforsch. 33a, 722—730 (1978); received February 17 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0722.pdf 
 Identifier    ZNA-1978-33a-0722 
 Volume    33 
105Author    P. Baluk, A. KawskiRequires cookie*
 Title    some 1,3,4-Oxadiazole Derivatives in n-Paraffins at 77 K  
 Abstract    The quasilinear absorption and fluorescence spectra of 2-(1-naphthyl) -5-phenyl 1,3,4 oxadiazole, 2-(2-naphthyl)-5-phenyl 1,3,4 oxadiazole, 2-(1-naphthyl) -5-(4-biphenylyl) -1,3,4 oxadiazole and 2-(2-naphthyl)-5-(4-biphenylyl)-1,3,4 oxadiazole have been studied in n-hexane, decane and nonane at 77 K. An analysis of the vibrational structure in the first electronic excited singlet state (Sj) and in the ground state (S0) is given. Internal oscillations in the in-vestigated molecules found from the quasilinear spectra are in agreement with those found in the infrared spectra. 
  Reference    Z. Naturforsch. 33a, 731—735 (1978); received January 10 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0731_n.pdf 
 Identifier    ZNA-1978-33a-0731_n 
 Volume    33 
106Author    H. Langer, H. VersmoldRequires cookie*
 Title    Signal to Noise Improvement in Simple Spectro- scopic Line Shape Studies  
 Abstract    Often in spectroscopic line shape experiments one is interested in the line width of a Gaussian or Lorentzian profile. We want to call attention to a simple numerical procedure which allows a significant signal to noise improve-ment in such studies. 
  Reference    Z. Naturforsch. 33a, 738—739 (1978); received April 21 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0738_n.pdf 
 Identifier    ZNA-1978-33a-0738_n 
 Volume    33 
107Author    W.-H SteebRequires cookie*
 Title    The Lie Derivative, Invariance Conditions, and Physical Laws  
 Abstract    The properties of the Lie derivative of a differential form with respect to a vector field are applied to some physical problems. In particular we study balance equations. 
  Reference    Z. Naturforsch. 33a, 742—748 (1978); received March 4 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0742.pdf 
 Identifier    ZNA-1978-33a-0742 
 Volume    33 
108Author    G.E J Eggermont, P. W. Hermans, L.J F Hermans, H.F P Knaap, J.J M BeenakkerRequires cookie*
 Title    Viscomagnetic Heat Flux Experiments as a Test of Gas Kinetic Theory in the Burnett Regime  
 Abstract    In a rarefied polyatom ic gas stream ing through a rectangular channel, an external m agnetic field produces a heat flux perpendicular to the flow direction. Experim ents on this "viscom agnetic heat flux" have been performed for CO, N 2 , CH4 and H D at room temperature, w ith different orientations o f the magnetic field. Such m easurem ents enable one to separate the boundary layer contribution from the purely bulk contribution by means o f the theory recently developed by Vestner. Very good agreem ent is found between the experim entally determined bulk contribution and the theoretical Burnett value for CO, N 2 and CH4 , y e t the behavior o f H D is found to be anomalous. 
  Reference    Z. Naturforsch. 33a, 749 (1978); received March 22 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0749.pdf 
 Identifier    ZNA-1978-33a-0749 
 Volume    33 
109Author    W. E. Köhler, H.F P Knaap, G.E J Eggermont, T. HooftRequires cookie*
 Title    Kinetic Theory of Nonequilibrium Alignment Phenomena in Dilute Polyatomic Gases in External Magnetic and Electric Fields  
 Abstract    The inverse operator technique for the solution o f the linearized W aldm ann-Snider equation in first order Chapman-Enskog-approximation is used to calculate non-equilibrium rotational angular m om entum polarizations caused by a temperature-or a velocity gradient. The presence o f an external homogeneous m agnetic or electric field is taken into account. In particular, the viscom agnetic vector-and tensor polarization for linear m olecules and the therm oelectric vector-and tensor polarization for polar sym metric top molecules are treated. Detailed expressions are given in term s o f W aldmann-Snider collision cross sections. W hile for the tensor polarizations the self-adjoint part o f the collision operator gives the major contribution, the vector polariza­ tions occur due to the existence o f a non-selfadjoint part. 
  Reference    Z. Naturforsch. 33a, 761—777 (1978); received June 7 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0761.pdf 
 Identifier    ZNA-1978-33a-0761 
 Volume    33 
110Author    A. KlemmRequires cookie*
 Title    The Evaluation of Partial Pressures from MD-Simulations of Liquids  
 Abstract    In the simulation of liquids by the periodic cube model the pressure can be evaluated by adding up the forces exerted by the particles on one side of a plane on the particles on the other side of the plane, or by an application of the virial theorem. The pressure also occurs in some relations between velocity-velocity-and force-position-autocorrelation functions. 
  Reference    Z. Naturforsch. 33a, 778 (1978); received May 3 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0778.pdf 
 Identifier    ZNA-1978-33a-0778 
 Volume    33 
111Author    W. KernerRequires cookie*
 Title    M HD Stability for a Class of Tokamak Equilibria with Fixed Boundaries  
 Abstract    The stability behavior w ith respect to internal m odes is discussed for a class o f tokamak equilibria with non-circular cross-sections and essentially flat current profiles. The stability analysis is done by com puter both sym bolically and num erically w ith the help o f a normal mode code, which extrem izes the Lagrangian o f the system . I t is found th a t the stability lim it agrees well w ith that o f the Mercier criterion. There are stable high-beta equilibria in this model. 
  Reference    Z. Naturforsch. 33a, 792—798 (1978); received May 3 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0792.pdf 
 Identifier    ZNA-1978-33a-0792 
 Volume    33 
112Author    Michael Weber, Siegfried SteebRequires cookie*
 Title    Nahordnung in Fe-C-Schmelzen mittels Neutronenstreuung  
 Abstract    Neutron diffraction m easurem ents were done w ith Fe-C-m elts (5; 13; and 17 at % C) using the m ethod o f isotopic substitution. The neutron sm all angle scattering effect observed could be explained by m agnetic scattering, caused by spin-fluctuations still existing in the m olten state far away from the Curie temperature. Total structure factors were calculated from observed intensities taking into account the correction for m agnetic scattering. For each carbon concen­ tration tw o alloys were investigated, one using iron o f natural isotopic abundance and the other using enriched 5 7Fe. From a comparison o f the (/-region below the first m axim um o f the total structure factor as obtained using F enat or 5 7F e, respectively, a tendency to the preference o f unlike nearest neighbours is concluded, the distance betw een Fe-C-pairs being 2.2 Ä. 
  Reference    Z. Naturforsch. 33a, 799—807 (1978); eingegangen am 14. April 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0799.pdf 
 Identifier    ZNA-1978-33a-0799 
 Volume    33 
113Author    C. H. Tillmanns, L. Merten, G. BörstelRequires cookie*
 Title    Mikroskopisches Modell eines Ionenkristalles mit einem Brown'schen Untergitter I. Allgemeine Theorie  
 Abstract    The rigid ion model is extended to ionic crystals w ith a Brownian sublattice. This sublattice is form ed b y particles which have the possibility to assum e at least two positions along a direction overcom ing a potential barrier. Such a D ebye relaxation process is connected w ith a spontane­ ous dipole m om ent. Taking into account this additional dipole m om ent in the equation o f m otion for ionic crystals w e get the corresponding equation for ionic crystals w ith a Brownian sublattice. In part I I o f this paper this com plex system o f equations, which depends on temperature, is solved for a simple model o f a diatom ic ionic crystal. 
  Reference    Z. Naturforsch. 33a, 808 (1978); eingegangen 8. März 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0808.pdf 
 Identifier    ZNA-1978-33a-0808 
 Volume    33 
114Author    C. S. SunandanaRequires cookie*
 Title    Phonon-Assisted Indirect Transitions in Cadmium Sulfate Crystals  
 Abstract    The fundamental absorption edge of "suprapur" cadmium sulphate (3 CdSC>4 • 8 H2O) crystal occurs in the region below 200 nm. The power-law dependence of the optical density on photon energy suggests indirect electronic transitions made possible by the emission or absorption of 0.067 eV phonons. The indirect band gap (Eg) at 300 K is 6.09 eV. The phonon energy of 0.067 eV is found to arise from one of the Raman-active modes (E) of the sulphate ion. The band edge is found to shift monotonically towards higher energies at a rate of — 2.3 meV per K between 300 and 77 K. The laser Raman spectrum of the 3 CdSC>4 • 8 H 2O is also reported. 
  Reference    Z. Naturforsch. 33a, 815 (1978); received January 26 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0815.pdf 
 Identifier    ZNA-1978-33a-0815 
 Volume    33 
115Author    H. K. IllesreiterRequires cookie*
 Title    Temperature Dependence of Sensitized Photocurrents between 200 and 293 K  
 Abstract    With an oxacarbocyanine dye monolayer on the surface of a p-chloranil single crystal and sandwiched between metal electrodes the temperature dependence of sensitized photocurrents has been measured with this "dry" electrochemical cell in the temperature range from 200—293 K. The activation energy of 0.26 i 0.02 eV is discussed in terms of a reaction scheme that involves a thermalization distance within the coulomb well of an intermediate state. 
  Reference    Z. Naturforsch. 33a, 822 (1978); received April 25 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0822.pdf 
 Identifier    ZNA-1978-33a-0822 
 Volume    33 
116Author    K.-D Willamowski, 0. E. RösslerRequires cookie*
 Title    Contributions to the Theory of Mass Action Kinetics I. Enumeration of Second Order Mass Action Kinetics  
 Abstract    By investigating the reaction diagram in its own right, it is possible to solve the problem of enumerating all the different types of mass action kinetics up to second order. The amount of non isomorphic complex sets for a given number of species and of non isomorphic reaction networks and reversible reaction networks which can be derived from a given number of complexes is given. 
  Reference    Z. Naturforsch. 33a, 827 (1978); received April 19 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0827.pdf 
 Identifier    ZNA-1978-33a-0827 
 Volume    33 
117Author    Rt Paulsen, D. Ieter, R. Ehder, D. Etlef ThoennesRequires cookie*
 Title    Temperature and Solvent Dependence of Vanadium-51 Chemical Shifts and Line Widths of Vanadyl-triisopropylate  
 Abstract    Line widths Av 1/2 of 51V n.m.r. signals of vanadyl-triisopropylate V 0(0Pri)3 dissolved in tetrahydrofurane range from 10 to 610 Hz, increasing with decreasing temperature according to a theoretically proposed T-1''2 exj)(E/RT) law, indicating that the molecular correlation time rc is the main factor influencing line widths in this system. With lowering of temperature, 51V-shielding decreases (the temperature gradient of the chemical shift dy is about — 0.5 ppm/K over a temperature range of 300—180 K), suggesting a loss of molecular symmetry due to sol­ vation and association processes. In pentane, methylcyclohexane and diethylether, the dy/T and Avi/2/T correlations exhibit two inconsistencies at approximately 190 and 240 K which are attributed to the formation of clusters, and of oligomers {VO(OPri)3}re, respectively. The latter gives rise to a satellite line with an upfield shift relative to the monomeric species. Exchange inter­ actions are discussed as a second factor affecting line widths. 
  Reference    Z. Naturforsch. 33a, 834 (1978); received April 5 1978 
  Published    1978 
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 Identifier    ZNA-1978-33a-0834 
 Volume    33 
118Author    Iv An, G. Utm AnRequires cookie*
 Title    A Method for Calculation of Resonance Energy of Benzenoid Hydrocarbons  
 Abstract    A semiempirical topological formula (2) is derived, which reproduces Aihara's resonance energy [1] of benzenoid hydrocarbons with a chemically negligible error of 2 —3%. 
  Reference    Z. Naturforsch. 33a, 840 (1978); received March 4 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0840.pdf 
 Identifier    ZNA-1978-33a-0840 
 Volume    33 
119Author    V. T. YpkeRequires cookie*
 Title    Calculations on the ^-Structure of Dimethylsulfoxide  
 Abstract    On the basis of three different force fields the zero point average structure of dimethylsulfoxide has been calculated. Three different types of calculation were performed. It is found that the different force fields virtually do not affect the resulting parameters while the results from different types of calculation agree within three times the standard errors. The asymmetry of the methyl groups found with the calculation scheme of the rs-structure is also present in the average structure. 
  Reference    Z. Naturforsch. 33a, 842 (1978); received April 24 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0842.pdf 
 Identifier    ZNA-1978-33a-0842 
 Volume    33 
120Author    D.W E Ngelfriet, W. L. GroeneveldRequires cookie*
 Title    ,2,4-Triazole Complexes, IV* M agnetic properties of m anganese (II) (1 .2 ,4 -triazole)2 (NCS)2 , a two-dimensional H eisenberg antiferrom agnet  
 Abstract    Magnetic susceptibility measurements on single crystals of Mn(II)(trz)2(NCS)2 in the tempera­ ture range 1.8 — 300 K are reported. The compound has two-dimensional structural and magnetic properties. The data from susceptibility measurements are accounted for by considering the material to be a quadratic-layer, S = 5/2 Heisenberg antiferromagnet. From the comparison of the data with predictions from series expansions the intralayer exchange constant was found to be J /k = — 0.25 K. A transition to the antiferromagnetic state is observed at 7 ^ = 3.29 K with the b axis being the preferred axis. Magnetization measurements at 1.8 K along the b axis reveal a spin-flop transition at 10.8 kOe. The occurence of a second discontinuity in the magneti­ zation curve at 15.6 kOe is explained by assuming that the spin system goes to the spin-flop state via an intermediate spin arrangement, as is suggested by the presence of tilted MnN6 octahedra. From pulsed-field magnetization measurements at 1.17 K, a saturation field Hc = 74 kOe is found which also leads to J/k = —0.25 K. With the aid of neutron powder diffraction at 1.2 K the magnetic space group was determined to be Apb'a 2'! Preliminary results from heat capacity measurements on the corresponding Fe(II), Co(II), Ni(II) and Cu(II) compounds are reported. 
  Reference    Z. Naturforsch. 33a, 848 (1978); received March 31 1978 
  Published    1978 
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 TEI-XML for    default:Reihe_A/33/ZNA-1978-33a-0848.pdf 
 Identifier    ZNA-1978-33a-0848 
 Volume    33 
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