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1984[X]
101Author    H. Fliege, DreizlerRequires cookie*
 Title     
 Abstract    In this paper we present the determination of the deuterium quadrupole tensor of nitric acid D15N03, performed with microwave Fourier transform spectroscopy applied to a gas sample in thermodynamic equilibrium. Hitherto molecular beam methods had to be used for similar investigations. 
  Reference    Z. Naturforsch. 39a, 630—632 (1984); received April 15 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0630.pdf 
 Identifier    ZNA-1984-39a-0630 
 Volume    39 
102Author    S. C. Mehrotra, G. Bestmann, H. Dreizler, H. MäderRequires cookie*
 Title      
 Abstract    With use of a Fourier transform microwave spectrometer in the range of 4 GHz to 18 GHz, the pressure dependence of collisional coherence dephasing times T2 at room temperature has been determined for (a) the transition 7 = 0-»7= 1 of OCS, 18OCS, and OC3^S, (b) nine transitions of S02 in ground state having 13 ^ 7 ^ 59, and (c) eight transitions of S02 having 12^7^55 in the first excited bending vibrational state, where 7 is the rotational quantum number of the lower state. 
  Reference    Z. Naturforsch. 39a, 633—636 (1984); received May 21 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0633.pdf 
 Identifier    ZNA-1984-39a-0633 
 Volume    39 
103Author    E. Fliege, H. DreizlerRequires cookie*
 Title     
 Abstract    n te r n a l R o ta tio n A n a ly s is o f th e G r o u n d S t a t e M ic r o w a v e S p e c tru m o f 2 -B ro m o p ro p e n e The microwave spectrum of 2-bromopropene was reinvestigated with the use of microwave Fourier transform spectroscopy. For the two isotopic species CH3C79Br=CH2 and CH3C8lBr=CH2 the bromine quadrupole coupling was determined with higher accuracy. The barrier hindering internal methyl rotation was obtained from the ground state. 
  Reference    Z. Naturforsch. 39a, 637—645 (1984); received May 21 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0637.pdf 
 Identifier    ZNA-1984-39a-0637 
 Volume    39 
104Author    M. Stockhausen, E. DachwitzRequires cookie*
 Title      
 Abstract    The complex permittivity of methanol + acetonitrile at 20 °C was measured over the whole composition range at frequencies up to 36 GHz. It can be described by superposition of two Debye type components, one of them being due to associated methanol. This component is discussed with respect to two simple models, considering relaxation as governed by rotational tumbling of associates or by fluctuation of hydrogen bonds. The latter description appears to be the more suitable one. 
  Reference    Z. Naturforsch. 39a, 646—650 (1984); received April 2 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0646.pdf 
 Identifier    ZNA-1984-39a-0646 
 Volume    39 
105Author    A., St Limmer, M. FindeisenRequires cookie*
 Title     
 Abstract    r o to n N M R S tu d ie s o f th e S m e c tic -G P h a s e o f T e re p h th a ly lid e n e -B is -4 -n -p r o p y la n ilin e (Proton NMR studies and lineshape simulations of the smectic-G phase of TBPrA are pre­ sented. From them a model for the layer arrangement in smectic-G is suggested. It postulates a freezing-in of the layer structure at the smectic-C — G phase transition. The layer normals are inclined at a fixed angle to the polarizing magnetic field corresponding to the tilt angle at the end of the C phase. The tilt of the molecular directors in the G phase is much greater (because of a relatively large negative jump in the layer thickness at the C— G-transition) and grows with decreasing temperature. Moreover a distribution of the molecular directors on the fictive tilt cone (in smectic-G there is no possibility for the directors to reorient about the layer normal as in smectic-C) has to be employed to get a good fit to the experimental data. 
  Reference    Z. Naturforsch. 39a, 651—657 (1984); received March 19 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0651.pdf 
 Identifier    ZNA-1984-39a-0651 
 Volume    39 
106Author    H. Onusseit, H. StegemeyerRequires cookie*
 Title     
 Abstract    b s e rv a tio n o f D ir e c t P h a s e T r a n s i t i o n S m e c tic A B lu e P h a s e in a L iq u id C r y s ta llin e M ix e d S y s te m Hithertoo, for all liquid-crystalline samples exhibiting Blue Phases (BP) it has been found that these phases occur between the cholesteric and the isotropic state. In the mixed system of cholesteryl myristate and an azoxybenzene derivative a phase transition from the smectic A phase directly to the BP has been observed. The phase diagram has been obtained by differential scanning calorimetry and is discussed together with the helical pitch behaviour. 
  Reference    Z. Naturforsch. 39a, 658—661 (1984); received April 16. 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0658.pdf 
 Identifier    ZNA-1984-39a-0658 
 Volume    39 
107Author    R. Bär, G. Gauglitz, R. Benz, J. Polster, P. Spang, H. DürrRequires cookie*
 Title     
 Abstract    h o to k in e tis c h e U n te r s u c h u n g e n a n d e n p h o t o c h r o m e n S y s te m e n d e r D ih y d ro in d o liz in e Herrn Prof. Dr. H. Mauser zum 65. Geburtstag gewidmet Photokinetic examinations of photochromic systems as dihydroindolizines The dependence of partial photochemical quantum yields on temperature and light intensity was examined with two dihydroindolizines. Some nonlinear optimization procedures and least squares methods are used to solve the system of differential equations. The distinct influence of the competitive thermal reaction can be demonstrated for both photochromic systems by deter­ mination of thermodynamic and kinetic parameters. 
  Reference    Z. Naturforsch. 39a, 662—667 (1984); eingegangen am 16. April 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0662.pdf 
 Identifier    ZNA-1984-39a-0662 
 Volume    39 
108Author    ZahidH. KhanRequires cookie*
 Title     
 Abstract    le c tro n ic S p e c tr a o f R a d ic a l C a t io n s a n d T h e i r C o r r e l a ti o n w ith P h o to e le c tr o n S p e c tr a I. Dibenzochrysene and Dibenzanthracenes Electronic absorption spectra of the radical cations of 1.2,7.8-dibenzochrysene, 1.2,3.4-dibenz-anthracene, 1.2,5.6-dibenzanthracene and 1.2,7.8-dibenzanthracene in boric acid are measured. The transition energies of the cations are calculated using the Longuet-Higgins-Pople and Wasilewski type Open-Shell-SCF-MO methods with limited CI. A comprehensive discussion of the absorption bands is given in the light of the calculations and the photoelectron spectral data for the hydrocarbons. The correspondence between the optical and photoelectron spectra is found to be extremely good with almost negligible matrix shifts, thus highlighting the role of photo­ electron spectroscopy in understanding the optical spectra of the radical cations and vice versa. Finally, a correlation diagram for the observed electronic transitions for the radical cations of anthracene and its benzologs is presented from which it is inferred that the optical A-transitions have some sort of correlation with the first IP's of the respective hydrocarbons. 
  Reference    Z. Naturforsch. 39a, 668—677 (1984); received February 7 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0668.pdf 
 Identifier    ZNA-1984-39a-0668 
 Volume    39 
109Author    Gerhard Raabe, Eberhard Heyne, Wolfgang Schleker, Jörg FleischhauerRequires cookie*
 Title      
 Abstract    Quantumchemical Calculations on Borine (Borabenzene) Although many Borinato-transition metal-complexes have been isolated after the first synthesis and characterisation of such a molecule in 1970, nobody succeeded so far in isolating the unsub-stituted neutral ligand Borine (Borabenzene) C5H5B. It is the aim of this theoretical investigation to find at least a partial answer to the question why the free borine should be a highly reactive molecule. The results of semiempirical and ab-initio-calculations presented here show that the LUMO of the free and unsubstituted borine in contrast to benzene and pyridine should be a er*-molecular orbital which causes pronounced a-acceptor properties. 
  Reference    Z. Naturforsch. 39a, 678—681 (1984); eingegangen am 19. April 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0678.pdf 
 Identifier    ZNA-1984-39a-0678 
 Volume    39 
110Author    Alberto Schiraldi, Primo BaldiniRequires cookie*
 Title     
 Abstract    o la r H e a t C a p a c ity o f A g l: E v a lu a tio n o f th e C a t io n i c a n d A n io n ic C o n tr ib u tio n s fro m T h e r m o e le c tr ic P o w e r D a t a Thermoelectric power data provide a useful tool for the evaluation of the thermodynamic properties of ionic species of both solid and molten electrolytes in equilibrium with electrodes of thermocells; however a previous evaluation of the heat of transport of the mobile ions is necessary. This is the case of Agl. whose standard modifications have been investigated with silver electrode thermocells some years ago. The interpretation of the thermoelectric power change at the melting point allows one to recognize that the heat of transport of the silver ions in the high conductivity bcc modification is practically the same as in molten Agl. This result has been used to evaluate the molar heat of the silver ions in the bcc phase from the corresponding thermoelectric power data reported in the literature. The analysis of the thermoelectric power change at the transition point, from the wurtzitic to the bcc phase, as well as a more speculative interpretation of thermoelectric power data obtained with iodine electrode thermocells, allows one to evaluate the molar heat of the iodide ions in the bcc modification of Agl. The summation of the ionic contributions so computed reproduces rather satisfactorily the trend of Agl molar heat data obtained with adiabatic calorimetry. 
  Reference    Z. Naturforsch. 39a, 682—685 (1984); received April 16 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0682.pdf 
 Identifier    ZNA-1984-39a-0682 
 Volume    39 
111Author    KritsanaP. Sagarik, BerndM. RodeRequires cookie*
 Title     
 Abstract    n th e H y d ro g e n B o n d s o f M e ta l I o n / W a t e r / A m i d e C o m p le x e s The effect of N-substitution on the hydrogen bonds of metal ion/water/amide complexes is studied on Li+/N-methylformamide-water as an example. Using the energies and Mulliken atomic populations derived from ab initio calculations with minimal GLO basis set, the Li+/N-methyl formamide-water and Li+/formamide-water complexes are compared. The transference of the effect of metal ions along the molecular structure seems to have a profound relationship to the bond polarizabilities of the backbone atoms. This can be discussed qualitatively in terms of changes in the Mulliken atomic publications. T h e o re tic a l S tu d ie s o n th e E f fe c t o f N -S u b s t i t u t i o n 
  Reference    Z. Naturforsch. 39a, 686—691 (1984); received May 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0686.pdf 
 Identifier    ZNA-1984-39a-0686 
 Volume    39 
112Author    Hans SallhoferRequires cookie*
 Title      
 Abstract    The transversality in the electrodynamic hydrogen field is discussed. In [1] it has been shown that the system of differential equations of electrodynamics and that of relativistic wave mechanics are isomorphic: Rel. WM = Electrodyn. (1) 
  Reference    Z. Naturforsch. 39a, 692—695 (1984); received April 17 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0692.pdf 
 Identifier    ZNA-1984-39a-0692 
 Volume    39 
113Author    A., B.V G K M Pisipati, N.V S RaoRequires cookie*
 Title    P h a s e T r a n s itio n S tu d ie s in  
 Abstract    The variation of density and ultrasonic velocity with temperature in N-(p-methoxyben-zylidene)-p-aminobenzonitrile (PMBAB) and N-(p-ethoxybenzylidene)-p-aminobenzonitrile (PEBAB) are presented. The density jumps and thermal expansion coefficients suggest the nematic-isotropic transition of both compounds to be of first order. The adiabatic compressibil­ ity ßäd, molar sound velocity Rn and molar compressibility Aw are computed. The contribution of a methylene unit to the molar volume is found to be higher than literature values. The anomalous ultrasonic velocity dip at the nematic-isotropic transition for both compounds is found to be high; the value is many times those found for other nematic-isotropic or nematic-smectic A transitions. 
  Reference    Z. Naturforsch. 39a, 696—699 (1984); received April 4 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0696.pdf 
 Identifier    ZNA-1984-39a-0696 
 Volume    39 
114Author    N.V S Rao, V.G K M Pisipati, P. V. Datta, Prasad, D. SaranRequires cookie*
 Title    ESR Study of M olecular Ordering in PEBAB and PMBAB  
 Abstract    An ESR study of the nematic liquid crystals PEBAB and PMBAB has been carried out using a nitroxide radical as paramagnetic probe. The order parameter (5) deter­ mined this way are in close agreement with those deter­ mined by NMR. For EBAB our S values differ from those determined by ESR with a different probe (VAAC). 
  Reference    Z. Naturforsch. 39a, 700—701 (1984); received March 21 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0700_n.pdf 
 Identifier    ZNA-1984-39a-0700_n 
 Volume    39 
115Author    Wolfgang Fleischer, Gerhard SoffRequires cookie*
 Title     
 Abstract    o u n d S t a te S o lu tio n s o f th e K le in -G o r d o n E q u a t io n fo r S tro n g P o t e n ti a l s We explicitly construct normalized solutions of the Klein-Gordon equation for various types of attractive potentials. Our computed binding energies of several short-and long-range poten­ tials are compared with results published by different authors. Special emphasis is laid on the determination of critical potential strengths, i.e. the onset of spontaneous pair creation of spin-0 particles. In the vicinity of these critical values the single-particle interpretation breaks down. The phenomenon of simultaneous particle and antiparticle binding in a short-range potential is investigated. 
  Reference    Z. Naturforsch. 39a, 703—719 (1984); received January 28 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0703.pdf 
 Identifier    ZNA-1984-39a-0703 
 Volume    39 
116Author    Z. NaturforschRequires cookie*
 Title      
 Abstract    Relativistic generalisation of the Lenz vector (I) The non-relativistic motion of a particle in a central field with Mr potential, e.g. the motion of an electron in the Coulomb field of a charged nucleus at rest, is described by the equation of motion (non-relativistic Kepler problem) m x" = x • x /r\ with a = ez e (product of the charges of the central body ez and the electron e). From this equation of motion, three statements of con­ servation can be derived: in respect of the energy E, of the angular momentum L and of the Lenz vector A = m {jc' x L + x • x/r). The geometric meaning of A is that of a vector pointing in the direction of the perihelion of the particle orbits (conic sections). It will be demonstrated that also at the relativistic Kepler problem, which is based on the equation of motion m (jc'/|/T — (jc7c)2)' = x ■ x/r3 an analogous Lenz vector exists. It represents a quantity of conservation — in the same way as the relativistic energy and the relativistic angular momentum. For the transitional case — ► oo, where the relativistic problem turns into the non-relativistic problem, the relativistic Lenz vector also turns into the non-relativistic Lenz vector. The generalised (relativistic) Lenz vector has also a geometric meaning. Its direction coincides with the oriented axis of symmetry of the orbits (rosettes, spirals, hyperbola-type curves etc.). The quantity of conservation A occupies a special position in respect of the quantities of con­ servation energy and angular momentum. Whereas the energy and the angular momentum cor­ respond with a symmetry of time and space, the Lenz quantity of conservation corresponds with a symmetry of the orbits. The fact that the Lenz vector can relativistically be generalised touches thereby on principal aspects. R e la tiv is tis c h e V e r a llg e m e in e ru n g d e s L e n z s c h e n V e k to r s (I) 
  Reference    Z. Naturforsch. 39a, 720—732 (1984); eingegangen 17. April 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0720.pdf 
 Identifier    ZNA-1984-39a-0720 
 Volume    39 
117Author    Z. NaturforschRequires cookie*
 Title      
 Abstract    Relativistic generalisation of the Lenz vector (II) The Lenz vector A = m {*' x L + a • x/r} is a special integral of motion of the non-relativistic Kepler problem. Accordingly, there also exists a special integral of motion A (x, x') of the rela­ tivistic Kepler problem as pointed out in Part I of this paper. In the following Part II, the system of equations is compiled to the extent required for the relativistic generalisation of the Lenz vector and its interpretation. Starting point are the statements of conservation for the energy and the angular momentum. From these two quantities, it is possible to derive the complete system of solutions x(t) in accordance with standardised methods. Some details and some modifications of the approach are of special importance for the purposes of this paper. In the centre of the consideration are the construction and interpretation of the standardised polar angle Ö as a function of r, r'. The explicit time dependance of the functions r(t), 0(t) is not required for constructing the relativistic Lenz vector in the form A (x, x'). In the literature, one does Find only few, not sufficient for our purposes, data on the relativistic orbits (rosettes, spirals, hyperbola-type curves etc.). It is, therefore, necessary to discuss these orbits in detail. For this purpose, a series of relationships are derived which apparantly have not been published before. 
  Reference    Z. Naturforsch. 39a, 733—747 (1984); received April 17 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0733.pdf 
 Identifier    ZNA-1984-39a-0733 
 Volume    39 
118Author    D. S., X-R, S. Tu, G. Flor, V. Berbenni, A. Marini, V. Massarotti, R. RiccardiRequires cookie*
 Title      
 Abstract    Lattice parameters and thermal expansion of the three crystallographic modifications (a, ß and ß') of gadolinium molybdate have been determined. The y.-ß and ß'-ß transitions have also been investigated by means of DSC and DTA measurements. For the first one a transition enthalpy of 7.5 ± 0.5 kcal/mol was evaluated, while it was observed that factors such as the thermal history, the particle size and the heating/cooling rate affect the peak areas of the second one. The results can be explained on the basis of the model proposed by Jeitschko for the ß'-ß transition provided that the necessary kinetic aspects are taken into account. 
  Reference    Z. Naturforsch. 39a, 748—753 (1984); received May 24. 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0748.pdf 
 Identifier    ZNA-1984-39a-0748 
 Volume    39 
119Author    K. Igarashi, Y. Iwadate, J. Mochinaga, K. KawamuraRequires cookie*
 Title      
 Abstract    The refractive indexes of molten LaCl3-KCl, LaCl3-NaCl, and LaCl3-CaCl2 mixtures were measured goniometrically for nine wavelengths and represented by empirical formulas as func­ tions of both temperature and wavelength. According to the obtained formulas and the molar volume data, the molar refractivities and the electronic polarizabilities were estimated. 
  Reference    Z. Naturforsch. 39a, 754—758 (1984); received June 4 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0754.pdf 
 Identifier    ZNA-1984-39a-0754 
 Volume    39 
120Author    Kazutaka Takagi, Kawamura, Isao OkadaRequires cookie*
 Title    Ryuzo  
 Abstract    Internal mobility ratios in the molten binary system (Rb— Cs)N03 have been measured with the Klemm method. From these and the available data on the densities and conductivities, the internal mobilities of Rb+ and Cs+ have been calculated. Above (below) 420 °C, Cs+ is found to be more (less) mobile than Rb+. The internal mobilities of these ions in various binary alkali nitrates are compared. T h e I n te r n a l M o b ilitie s o f t h e M o lt e n B in a r y S y s te m (R b -C s) N 0 3 
  Reference    Z. Naturforsch. 39a, 759—763 (1984); received June 7 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0759.pdf 
 Identifier    ZNA-1984-39a-0759 
 Volume    39 
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