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1988 (183)
121Author    M.C S Im, La Tio, Lte, C. Margheritis, C. SinistriRequires cookie*
 Title    In te rio n ic P o te n tia ls a n  
 Abstract    Monte Carlo simulations on molten AgCl were carried out in order to test the applicability of the interionic potentials recently proposed for this salt in the solid phase. None of the literature potentials can be used as such: in all cases pairs of like ions reach too short distances of approach causing the collapse of the system. It was proved that, in order to obtain equilibration of the system, the pair potentials of like ions must be recalculated. On the basis of these modified potentials, MC simulations of molten AgCl were carried out at 728 (m.p.), 1000 and 1500 K. The polarization energy effect was also analyzed with the use of a soft ion model. 
  Reference    Z. Naturforsch. 43a, 751—754 (1988); received July 1 1988 
  Published    1988 
  Keywords    Interionic potentials, Monte Carlo simulation, molten AgCl 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0751.pdf 
 Identifier    ZNA-1988-43a-0751 
 Volume    43 
122Author    N. Heineking, M. Andolfatto, C. Kruse, W. Eberstein, H. DreizlerRequires cookie*
 Title      
 Abstract    Employing the high resolution of microwave Fourier transform spectroscopy, we investigated the lowest rotational transitions of fluoro-, bromo-, and iodoacetylene-d. Along with the rotational, centrifugal distortion, halogen nuclear quadrupole, and halogen spin-rotation coupling constants, we determined the deuterium quadrupole coupling constants of bromo-and iodoacetylene-d. For fluoroacetylene-d, we redetermined the deuterium nuclear quadrupole coupling constants with higher accuracy. D e u te riu m Q u a d r u p o le C o u p lin g C o n s ta n ts o f D e u te ro h a lo g e n o a c e ty le n e s 
  Reference    Z. Naturforsch. 43a, 755—757 (1988); received July 9 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0755.pdf 
 Identifier    ZNA-1988-43a-0755 
 Volume    43 
123Author    G. T. Stauf, D.La Graffe, P. A. Dowben, K. Emrich, S. Barfuss, W. Hirschwald, N. M. BoagRequires cookie*
 Title      
 Abstract    The ionic decomposition of gaseous bridge-bonded dimanganese silyl carbonyl [Mn(CO)5]2(ju-SiH2) has been investigated via photon and electron induced ionization mass spectroscopy, as well as gas-phase photoabsorption measurements. The thermodynamic cycle incorporating ionic fragments has been constructed from these results. The thermodynamic cycle illuminates the decomposition process of this organometallic compound. This has potential application in the production of silicide Mn,Si coatings by both pyrolysis and by patterned photolysis using an UV laser. T h e S ta b ility a n d D e c o m p o sitio n o f G a s e o u s |M n (C O) 5l2(^ -S i H 2) 
  Reference    Z. Naturforsch. 43a, 758—764 (1988); received May 18 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0758.pdf 
 Identifier    ZNA-1988-43a-0758 
 Volume    43 
124Author    H. L. Krätzschmar, E. W. Selzle, SchlagRequires cookie*
 Title     
 Abstract    Optical transitions between excited vibrational states in the electronic ground and excited state of benzene were measured with ion dip spectroscopy in a supersonic jet. The observed spectra show clear rotational structure, dependent on the wavelength of the excitation laser and could be simulat­ ed by computer calculations. Ion dip spectroscopy is known to be a powerful method for the analysis of highly excited vibrational states in the electronic ground state, which are not accessible to absorption spectroscopy in supersonic jets. R o ta tio n a lly R e so lv ed Io n D ip S p e c tro s c o p y o f B e n z e n e 
  Reference    Z. Naturforsch. 43a, 765—768 (1988); received June 18 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0765.pdf 
 Identifier    ZNA-1988-43a-0765 
 Volume    43 
125Author    Z. NaturforschRequires cookie*
 Title     
 Abstract    c e to n itrile -W a te r S o lu tio n s o f S o d iu m H a lid e s : V isc o sity a n d S e lf-D iffu s io n o f C H 3C N a n d H 20 Measurements of the viscosity of solutions of NaCl and Nal in acetonitrile-water mixtures at 25 °C, and of the self-diffusion coefficients of CH3CN and H20 in these liquids, using 14C and 3H as tracers, are reported. The results confirm the previously postulated preferential solvation of the ions by acetonitrile. 
  Reference    Z. Naturforsch. 43a, 769—773 (1988); received May 17 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0769.pdf 
 Identifier    ZNA-1988-43a-0769 
 Volume    43 
126Author    Masato Kakihana, Minoru Akiyama, Tadashi Nagumo, Makoto OkamotoRequires cookie*
 Title     
 Abstract    e riv e d fro m I n f r a r e d S p e c tro s c o p ic D a t a o f D -, I3 C -, 15N -, a n d 180 -L a b e l e d S p e c ie s The infrared spectra (4000-100 cm " 1) of the a-form crystal of glycine (NH 3 -CH, -COO ") and of thirteen isotopic modifications comprising D, 13C, 1SN, and O were measured at 80 and 290 K. Excellent resolution was reached at the low temperature. In the low temperature spectra the fine structure of the nearly degenerate NH3 and ND3 antisymmetric deformational modes and the C02-torsional bands in the vicinity of 200 cm-1 for each of the isotopic molecules, which in the low-frequency region are strongly overlapped by a number of lattice modes, clearly showed up. Based upon the frequency data of the 14 isotopic analogs and the precisely known structure of the molecule, a normal coordinate analysis was carried out. 307 observed frequencies were utilized to derive a new empirical valence force field reduced to a set of 50 force constants by a number of restrictive assumptions. The resulting force field reproduced the 307 frequencies with a root-mean-square deviation of 3.32 cm-1. This force field emphasizes the importance of interaction force constants of the in-plane C 02-rocking and C 02-deformational coordinates with the CH2-twisting coordinate, which can come form a significant deviation of this molecule from an ideal Cs-symmetry. The composition of normal vibrations from generally accepted local-symmetry coordinates is given in terms of the potential energy distribution (PED). The PED results indicate that almost all the normal modes below 1600 cm' 1 are extensively intermixed group modes, thus precluding a simple normal vibrational decription. Interestingly the PED description for several vibrations associated with the NHj —CH2 —C fragment exhibits strong mixing between quasi-,4' symmetric and -A" antisymmetric coordinates with respect to a pseudo molecular symmetry (CCN) plane in this molecule. A n E m p ir ic a l P o te n tia l F u n c tio n o f a -G ly c in e 
  Reference    Z. Naturforsch. 43a, 774—792 (1988); received June 16 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0774.pdf 
 Identifier    ZNA-1988-43a-0774 
 Volume    43 
127Author    P. Nikolov, T. Deligeorgiev, N. Tyutyulkov, I. KanevRequires cookie*
 Title     
 Abstract    y n th e s is , S tr u c tu r e , a n d S p e c tr a l P r o p e r tie s o f P y ry liu m S a lts a n d T h e ir D e riv a tiv e s . I I.5 -(B e n z y lid e n)-a n d 5 -(C in n a m y lid e n)-5 ,6 ,7 ,8 -T e tr a h y d r o -1,3 -D ip h e n y l-2 -B e n z o p y ry liu m S a lts The synthesis, structure and spectral properties of a group of dyes with a pyrylium ring are described. Quantumchemical calculations indicate that the chromophore system has a structure corresponding to that of the polymethine dyes. 
  Reference    Z. Naturforsch. 43a, 793—796 (1988); received March 16 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0793.pdf 
 Identifier    ZNA-1988-43a-0793 
 Volume    43 
128Author    VithayaW. Ruangpornvisuti, BerndM. RodeRequires cookie*
 Title      
 Abstract    A Monte Carlo simulation has been performed to study the hydration of the magnesium complex of 1,4,7,10-tetraazacyclododecane (cyclen). An intermolecular potential function for magnesium cyclen complex and water, derived from ab initio calculations was used. The first hydration shell results to consist of 18 water molecules. A M o n te C a r lo S tu d y o n a M a g n e s iu m C y c le n C o m p le x 
  Reference    Z. Naturforsch. 43a, 797—800 (1988); received June 13 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0797.pdf 
 Identifier    ZNA-1988-43a-0797 
 Volume    43 
129Author    SalimM. KhalilRequires cookie*
 Title    M I N D  
 Abstract    O -F o r c e s C a lc u la tio n s o f 1 -S u b s titu te d C y c lo p ro p y l C a tio n s a n d A n io n s MINDO-Forces calculations are reported, after complete optimization of geometry, for 1-X-sub-stituted cyclopropyl cations and anions, where X is H. All the substituents are stabilizing. It was found that the 7r-donating groups interact strongly with the cyclopropyl cations, whereas the ^-withdrawing groups interact strongly with cyclopropyl anion depending on the electron demand. 
  Reference    Z. Naturforsch. 43a, 801—805 (1988); received May 9 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0801.pdf 
 Identifier    ZNA-1988-43a-0801 
 Volume    43 
130Author    C. J. Timmermans, G.M W Kroesen, P. M. Vallinga, D. C. SchramRequires cookie*
 Title    o f a H  
 Abstract    ig h D e n s ity , S u p e r-A tm o s p h e ric 2 k A C a s c a d e A rc in A rg o n Experimental results are reported for simultaneous pressure and current pulses up to 14 bar and 2200 A superimposed on an atmospheric pressure 60 A dc cascade arc. A current density over 108 A/m2, previously 107A/m2 (power density 1012W/m3, previously 1010W/m3) has been ob­ tained. The electron temperature of the thermal plasma was deduced from the end-on measured radiance of argon lines, and the electron density from the absolute continuum emission. The values found for the quantities mentioned during the quasi-stationary phase of the current pulse, lasting ~ 1 ms, were 27 000 K and 3 • 1023 m"3, respectively, at a pressure of ~ 1.5 bar (ionization degree 100%), and 18 000 K and > 1024m-3, respectively, for a pressure of 14 bar (ionization degree 60%). These values satisfy the LTE relation. Deviations from the Spitzer conductivity have been observed in this weakly non-ideal plasma. In general, the high ionized thermal plasma studied with its composition of neutral, singly ionized and doubly ionized argon atoms can serve as a useful medium for spectroscopic studies of highly ionized systems and as a valuable source of radiation in the visible a well as in the near and far ultraviolet parts of the spectrum. P la s m a P a r a m e te r s a n d W e a k ly N o n -I d e a l B e h a v io u r 
  Reference    Z. Naturforsch. 43a, 806—818 (1988); received April 301988 
  Published    1988 
  Keywords    High density, cascade arc, weakly non-ideal, super-atmospheric, argon 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0806.pdf 
 Identifier    ZNA-1988-43a-0806 
 Volume    43 
131Author    Michael KleinRequires cookie*
 Title      
 Abstract    Mandelbrot Set in a Non-Analytic M ap A 2-dimensional non-analytic map is presented which gen­ erates a Mandelbrot set (as well as Julia sets) not different from those obtained of the complex-analytic logistic map itself. For the complex logistic map: = z2 n +c (1) 
  Reference    Z. Naturforsch. 43a, 819—820 (1988); received July 25 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0819_n 
 Volume    43 
132Author    S. E. MassenRequires cookie*
 Title    A Modification of the Skyrme Single Particle Potenital and the RM S Radii of Nuclei  
 Abstract    The Skyrme single particle potential is modified by adding a new term which is taken to be the derivative of the central part of the Skyrme interaction. It is seen that, when this term is added to the original Skyrme interaction, there is a better agreement with experiment regarding the various moments of the charge densities of nuclei with 48 < A < 208. 
  Reference    Z. Naturforsch. 43a, 821—822 (1988); received May 21 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0821_n.pdf 
 Identifier    ZNA-1988-43a-0821_n 
 Volume    43 
133Author    Ewa Broclawik, Malgorzata WitkoRequires cookie*
 Title    Quantum Chemical Calculations for some Toluene Derivatives  
 Abstract    Heterogeneous catalytic oxidation of p-substituted tolu­ enes is of interest [1] for the production of derivatives of benzaldehyde, some of which (e.g. anisic aldehyde and p-tert-butylbenzaldehyde) being valuable components of fra­ grances. The mode of the adsorption depends on the type of the hydrocarbon and the active center on the catalyst surface. In order to elucidate the mechanism of the reaction it is necessary to know the electronic and geometrical properties of the molecule to be adsorbed, since the geometry of the adsorption complex should decide about which of the many possible routes of transformation of the complex during the oxidation predominates, and hence about the selectivity of the reaction. 
  Reference    Z. Naturforsch. 43a, 823—824 (1988); received May 3 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0823_n.pdf 
 Identifier    ZNA-1988-43a-0823_n 
 Volume    43 
134Author    G. Schmitz, H. Klein, D. WoermannRequires cookie*
 Title    Spinodal Decomposition in a Polystyren/ Cyclohexane Solution of Critical Composition  
 Abstract    Results of experiments are reported demonstrating spi-noidal decomposition in a critical mixture of polystyrene and cyclohexane. If time and length are properly scaled using data obtained from static and dynamic light scattering exper­ iments, the time evolution of the "spinodal ring" is repre­ sented to a good approximation by an empirical equation proposed by Snyder and Meakin which describes spinodal decomposition for various types of systems. 
  Reference    Z. Naturforsch. 43a, 825—827 (1988); received June 24 1988 
  Published    1988 
  Keywords    Phase transition, spinodal decomposition, criti­ cal phenomena, polymer solution 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0825_n.pdf 
 Identifier    ZNA-1988-43a-0825_n 
 Volume    43 
135Author    H. WallschlägerRequires cookie*
 Title     
 Abstract    o n lin e a r T h e r m o d y n a m ic s o f M o v in g M a te r ia l S u r fa c e s in E le c tric F ie ld s A continuum-mechanical formalism is presented for the phenomenological description of moving, curvilinear, material surfaces in electric fields in interaction with volume-phases. In addition to conventional equations (balance and constitutive laws) the explicit use of relations for the surface geometry is introduced. A method to establish nonlinear constitutive equations by tensorial and thermodynamical considerations is proved to be applicable to two-dimensional continua. The resulting equations for boundaries interacting with adjacent volumes are of practical importance for the selfconsistent calculation of boundary values. The physical meaning of the different relations is discussed. 
  Reference    Z. Naturforsch. 43a, 829—846 (1988); received April 13 1988 
  Published    1988 
  Keywords    A0340, A4700, A8265 Key words: Nonlinear irreversible thermodynamics, volume-surface-interaction, moving boundary, electric field 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0829.pdf 
 Identifier    ZNA-1988-43a-0829 
 Volume    43 
136Author    L. J. Gallego, J. A. Somoza, M. C. BlancoRequires cookie*
 Title      
 Abstract    We have computed the concentration fluctuations, Scc (0), in a binary mixture of hard spheres on the basis of the Percus-Yevick compressibility (PYC), Percus-Yevick virial (PYV) and Mansoori-Carnahan-Starling (MCS) equations of state. We have also used the Flory-Huggins (FH) model for an athermal solution as a first approximation to the hard sphere description. At fluid packing fraction values, the PYC and MCS theories give similar Scc(0) results, whereas the differences between these and those derived from the PYV equation are more significant. The FH model appears to give rather bad results, which is consistent with the studies of other authors on the entropy of mixing of a binary mixture of hard spheres. The impossibility of a fluid-fluid phase transition in this kind of system is clearly shown by the behaviour of Scc (0) in any of the theories studied. 
  Reference    Z. Naturforsch. 43a, 847—850 (1988); received May 28 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0847.pdf 
 Identifier    ZNA-1988-43a-0847 
 Volume    43 
137Author    Igor NovakRequires cookie*
 Title      
 Abstract    The electronic structure of mixed methylene dihalides CH2XY (X, Y = F, CI, Br, I) has been studied using extended Fenske-Hall LCAO MO method. The comparison with available photoelec-tron spectra confirmes previous assignments of all bands with binding energies <100eV. The electronic structure changes occurring upon varying the halogen substituents are discussed. 
  Reference    Z. Naturforsch. 43a, 851—854 (1988); received July 4 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0851.pdf 
 Identifier    ZNA-1988-43a-0851 
 Volume    43 
138Author    *. R. Brener, H. ShechterRequires cookie*
 Title    I n tr a  
 Abstract    m o le c u la r R o ta tio n a l P h a s e -T r a n s itio n in B u lk a n d A d s o rb e d F e (C O) 5 o n (0 0 0 1) G r a p h ite Mössbauer spectroscopy results on bulk iron pentacarbonyl Fe(CO)5 and as adsorbate on (0001) graphite display a sharp transition at ~ 110K related to intramolecular hindered rotations of CO-ligands, with no associated structural changes. The hysteresis in the temperature dependence of the quadrupole splitting and the abrupt change in the spectral intensity suggest a cooperative first-order phase transition. 
  Reference    Z. Naturforsch. 43a, 855—858 (1988); received July 20 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0855.pdf 
 Identifier    ZNA-1988-43a-0855 
 Volume    43 
139Author    H. E. WilhelmRequires cookie*
 Title     
 Abstract    o r e n tz T r a n s f o r m a tio n a s a G a lile i T r a n s f o r m a tio n w ith P h y s ic a l L e n g th a n d T im e C o n tr a c tio n s The Lorentz transformations between the space-time coordinates of a point in two inertial frames with arbitrary relative velocity, are reformulated as Galilei transformations with length and time contractions, by introducing the ether rest frame (in which light signals propagate isotropically with the vacuum speed of light). The generalized Galilei transformations for the (longitudinal) space coordinates (xt 2) and the time variables (f12) of a point in two inertial frames I 1 2 are not only of analogous structure, but have remarkable symmetry properties, too. The appearing length and time contractions are absolute effects in the sense of Lorentz-Fitzgerald, i.e., a rod has its largest length and a clock its fastest rate when at rest in the ether frame r 0. Thus, an analytical reformulation and a physical interpretation of the Lorentz transformations within Galilean relativity physics is achieved. 
  Reference    Z. Naturforsch. 43a, 859—864 (1988); received December 8 1987 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0859.pdf 
 Identifier    ZNA-1988-43a-0859 
 Volume    43 
140Author    EdwardM. KellyRequires cookie*
 Title     
 Abstract    e s o lu tio n o f th e E h r e n fe s t P a r a d o x b y N e w C o n tr a c tio n (E x p a n s io n) C r ite r ia If we assume that the integrity of an elastic solid is governed by exchanges of real and virtual photons, the solid becomes a seat of innumerable interconnected microscopic Kennedy-Thorndike experiments. The null result of that experiment leads to a deformation criterion having the Lorentz-Fitzgerald contraction as a special case. For a spinning disc the criterion, combined with an equation of compatibility, gives radial and tangential deformations which resolve the Ehrenfest paradox. 
  Reference    Z. Naturforsch. 43a, 865—867 (1988); received March 30 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0865.pdf 
 Identifier    ZNA-1988-43a-0865 
 Volume    43 
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