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1988 (183)
101Author    D. Mauer, G. Winnewisser, KoichiM T Yamada, J. Hahn, K. ReinartzRequires cookie*
 Title      
 Abstract    The rotational spectrum of gas phase HSSSH has been recorded for the first time in absorption with the Cologne free-space-cell millimeterwave spectrometer. In the frequency region between 80 and 300 GHz a prominent series of Q-branches has been observed and assigned. The hitherto identified rotational lines unambigously arise from a perpendicular-type spectrum. In addition, successive J lines of the compact Q-branches show no indication of the easily detectable intensity alternation which arises when the molecule possesses an axis of symmetry due to nuclear spin statistical weights. Therefore the geometrical structure of the molecule does not have a C2 axis of symmetry. The present data are not complete enough for a unique structure determination. However on the basis of the present data we can definitely rule out conformations with C2 or C2v symmetry to be responsible for the strongest observed transitions of the spectrum. The molecule is not floppy as predicted from semi empirical MO calculations. On the contrary the conformation observed is rather rigidly locked into one position with no sign of possible internal rotation. We consider a sulfur triangle with the two hydrogen atoms sticking out symmetrically to the same side of the SSS-plane to be the most likely structure. D e te c tio n o f G a s -P h a s e H y d r o g e n tr is u lf id e , H S S S H 
  Reference    Z. Naturforsch. 43a, 617—620 (1988); received May 11 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0617.pdf 
 Identifier    ZNA-1988-43a-0617 
 Volume    43 
102Author    Zenon Polacki, Janusz Rak, Anna TempczykRequires cookie*
 Title     
 Abstract    h e o r e tic a l A p p ro a c h in E x p la n a tio n o f E n e r g y D o n o r P r o p e r tie s o f 1 ,4 -D io x a n e a n d 1 ,4 -D io x a n e -W a te r C o m p le x e s The CNDO/2 CI method was used for the examination of 1,4-dioxane and 1,4-dioxane-water complexes (2:1), taking into account various conformations of the dioxane molecule. The energies of the molecules in the ground and excited states, the energies of hydrogen bond formation, the dipole moments, the transition moments, and the oscillator strengths for both the complexed and isolated 1,4-dioxane molecules were evaluated. The results of these studies are used to reveal the influence of water on the features of energy transfer from excited, by y-radiation, 1,4-dioxane or dioxane-water complexes to the luminophor. 
  Reference    Z. Naturforsch. 43a, 621—626 (1988); received March 23 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0621.pdf 
 Identifier    ZNA-1988-43a-0621 
 Volume    43 
103Author    R. Twardowski, J. KuśbaRequires cookie*
 Title      
 Abstract    The article deals with the influence of reversible excitation energy transfer on the fluorescence decay in systems with random distribution of molecules. On the basis of a hopping model, we have obtained an expression for the Laplace transform of the decay function and an expression for the average decay time. The case of dipole-dipole interaction is discussed in detail. 
  Reference    Z. Naturforsch. 43a, 627—632 (1988); received April 19 1988* 
  Published    1988 
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 Identifier    ZNA-1988-43a-0627 
 Volume    43 
104Author    O. Awadelkarim, A. Claesson, LundRequires cookie*
 Title     
 Abstract    ESR experiments aiming at clarifying the structure of radicals present in X-irradiated crystals of ethylene glycol and other diols are reported. By comparison with data for the corresponding glasses it is concluded that a major source of free radicals is the decomposition of trapped electrons. The radical structure is identified. F r e e R a d ic a ls in X -I r r a d ia te d E th y le n e G ly c o l C r y s ta ls 
  Reference    Z. Naturforsch. 43a, 633—637 (1988); received April 27 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0633.pdf 
 Identifier    ZNA-1988-43a-0633 
 Volume    43 
105Author    Akira Endoh, Isao OkadaRequires cookie*
 Title     
 Abstract    n te r n a l C a tio n M o b ilitie s in th e M o lte n T e r n a r y S y s te m (L i, N a , K)C1 o f th e E u te c tic C o m p o s itio n For molten (Li, Na, K)C1 of the eutectic composition (53.5-8.6-37.9 mol%), in the temperature range from 773 K to 973 K the relative differences in the internal cation mobilities have been measured by the Klemm method, and the conductivity by a direct current method. From these data and the molar volumes, evaluated from those of the pure salts on the assumption of additivity, internal mobilities of the cations, bu , fcN a and bK, have been calculated. Below ca. 873 K t>u< bK< bNa, and above bu < bNa< bK. These orders are interpreted in terms of the potential profiles for cations located between two CP ions. bLi and bK in the present ternary system can be fairly well expressed by function of the number density of CP ions presented previously for the binary system (Li, K)C1. 
  Reference    Z. Naturforsch. 43a, 638—642 (1988); received April 26 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0638.pdf 
 Identifier    ZNA-1988-43a-0638 
 Volume    43 
106Author    Dirk Borchers, PeterC. Schmidt, Alarich WeissRequires cookie*
 Title     
 Abstract    h e o r e tic a l S tu d ie s o f th e E le c tric F ie ld G r a d ie n t in H e x a c h lo r o m e ta lla te s The electric field gradient (EFG) at the chlorine site is calculated for cubic compounds of the K2PtCl6-type (space group Fm3m), M'2M'vClg, where M1 is an alkali metal and MeIV a tetravalent element. In the calculations the total EFG is subdivided into the contribution of the complex [MivC16]2~, EFGcomplex, and the contribution of the ions outside the complex, EFGlattice. EFGcom pl?x is calculated by the local electron density formalism using the MS-Xa-method, and EFG,atlice is determined by the point charge model. It is found that EFGC lex is positive whereas EFGlaltjce is negative. Including antishielding effects, the magnitude of EFGlattice is about one fourth of EFGcomplex. The trends in the EFG for the various compounds found theoretically are the same as the trends in the experimental nuclear quadrupole coupling constants e2 Q q/h. However, the absolute values of EFGlheo are smaller than the values EFGexp deduced from e2 Q q/h. For a fixed central atom MIV the (positive) EFGexp is increasing with increasing radii of the cations (and increasing lattice constant). This increase can be understood by an increase of EFGlaltice-, ^ . . On the other hand, for fixed cations and different tetravalent metal atoms, the EFG is increasing with increasing electronegativity of the central atom. This can be understood by an increase of EFGcomplex. For distorted octahedra it is found that the change in the EFG due to the distortion is also due to a change in EFGcomplex. 
  Reference    Z. Naturforsch. 43a, 643—650 (1988); received April 16 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0643 
 Volume    43 
107Author    M. Andolfatto, H. Krause, D. H. Sutter, M. H. PalmerRequires cookie*
 Title     
 Abstract    h e I n tr a m o le c u la r E le c tric F ie ld G r a d ie n t a t th e 14N -N u c le u s in M o n o flu o r o a c e to n itrile a n d a n Im p ro v e d P a r t i a l ^ -S t r u c t u r e o f th e M o le c u le The 14N quadrupole coupling tensor in CH2FCN and CD2FCN was determined from the hyperfine splittings of low J rotational transitions to give indirect structural information on the geometry of the CCN chain. The CCN chain turns out to be slightly bent (2° away from F), in excellent agreement with the result of an earlier ab initio calculation. 
  Reference    Z. Naturforsch. 43a, 651—656 (1988); received May 4 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0651.pdf 
 Identifier    ZNA-1988-43a-0651 
 Volume    43 
108Author    N. Heineking, H. DreizlerRequires cookie*
 Title     
 Abstract    u c le a r Q u a d r u p o le H y p e r fin e S tr u c tu r e in th e R o ta tio n a l S p e c tr u m o f 3 -C h lo ro p y rid in e . A n A p p lic a tio n o f M ic ro w a v e -M ic ro w a v e D o u b le R e s o n a n c e F o u r ie r T r a n s f o r m S p e c tro s c o p y We redetermined the rotational and the chlorine-35 and nitrogen-14 nuclear quadrupole coupling constants of 3-chloropyridine. The values are A = 5839.5330(12) MHz, B = 1604.1875(6) MHz, and C= 1258.3121 (5) MHz for the rotational constants, and xaa(C\) = — 72.255(19) MHz, *W(C1) = + 38.500(13) MHz, Zec(Cl) = + 33.755(23) MHz and Za(1(N) = -0.009(13) MHz, xbfc(N) = -3.473 (10) MHz, 2C C (N) — + 3.482(16) MHz for the chlorine-35 and nitrogen-14 nuclear quadrupole coup­ ling constants, respectively. Application of double resonance modulation technique is shown to greatly simplify the assign­ ment of hyperfine structure components even of weak rotational transitions. 
  Reference    Z. Naturforsch. 43a, 657—661 (1988); received May 11 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0657 
 Volume    43 
109Author    D. Baalss, S. HessRequires cookie*
 Title     
 Abstract    h e V is c o sity C o e ffic ie n ts o f O r ie n te d N e m a tic a n d N e m a tic D is c o tic L iq u id C r y s ta ls ; A ffin e T r a n s f o r m a tio n M o d e l General expressions are derived for the anisotropy of the viscosity and for the Leslie coefficients governing the flow alignment subject to the assumption that the equipotential surfaces for the interaction of oriented nonspherical molecules in the nematic or nematic discotic phase of a liquid crystal are related to a spherical interaction potential by an affine transformation. In particular, for uniaxial particles, the seven independent viscosity coefficients of a nematic are given in terms of the two viscosity coefficients of a reference fluid of spherical particles and the axes ratio of the nonsphe­ rical molecules. The theory is compared with results from nonequilibrium molecular dynamics computer simulations and with experimental data. 
  Reference    Z. Naturforsch. 43a, 662—670 (1988); received May 13 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0662 
 Volume    43 
110Author    Z. NaturforschRequires cookie*
 Title      
 Abstract    We present an explicit construction of minimal deterministic automata which accept the languages of L-R symbolic sequences of unimodal maps resp. arbitrarily close approximations thereof. They are used to study a recently introduced complexity measure of this language which we conjecture to be a new invariant under diffeomorphisms. On each graph corresponding to such an automaton, the evolution is a topological Markov chain which does not seem to correspond to a partition of the interval into a countable number of intervals. O n S y m b o lic D y n a m ic s o f O n e -H u m p e d M a p s o f th e In te rv a l 
  Reference    Z. Naturforsch. 43a, 671—680 (1988); received May 16 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0671.pdf 
 Identifier    ZNA-1988-43a-0671 
 Volume    43 
111Author    MercedesN. LakhtakiaRequires cookie*
 Title    Akhlesh Lakhtakia Department of Engineering Science and Mechanics  
 Abstract    The Julia set of Ramanujan's iterated exponential map, Fr+1 (z) = exp {Fr(z)} —1, is investigated for positive integral r. Connection with Devaney's work on the map zr+1 = / exp[zr] is also made. R a m a n u ja n a n d th e J u l i a S e t o f th e I te r a t e d E x p o n e n tia l M a p 
  Reference    Z. Naturforsch. 43a, 681—683 (1988); received April 30 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0681.pdf 
 Identifier    ZNA-1988-43a-0681 
 Volume    43 
112Author    Pierre GuéretRequires cookie*
 Title      
 Abstract    A set of fully symmetric maxwellian equations is proposed, with a quantum mechanical coupling term between matter and fields. Its relativistic transformation properties and conservation laws are presented. Dual, monopole4ike solutions are described, which have properties consistent with those of the Dirac electron and magnetic monopole. The spatial extent of the monopole fields is proposed to be bound within two extreme radial limits rp and R0 such that a In (R0/rp) = 1, where a ~ 1/137 is the electromagnetic fine structure constant, yielding for the ratio R0/rp a very large number in the order of the ratio of the so-called universe radius to the Planck length. 
  Reference    Z. Naturforsch. 43a, 684—686 (1988); received March 12 1988 
  Published    1988 
  Keywords    Dirac Electron, Magnetic Monopole, Maxwell's Equations 
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 Identifier    ZNA-1988-43a-0684 
 Volume    43 
113Author    S. Oehler, R. Stannarius, H. SchmiedelRequires cookie*
 Title      
 Abstract    In v e s tig a tio n s o f th e P itc h D e p e n d e n c e o f S e lf-d iffu sio n in C h o le s te ric L iq u id C r y s ta ls Self-diffusion in the isotropic and twisted nematic phases of mesogenic substances has been studied by means of 'H-and 13C-NMR. From the line shape analysis of the recorded 13C-NMR spectra we obtained the diffussion coefficient DL along the helical pitch. Various concentrations of a chiral additive changed the pitch P0 of a nematic mixture of phenyl-benzoates from 4.7 |am to 7.8 |am. The measured values of D± were in the range from 2.4 • 10" 12 m2 s"1 to 1.9 • 10"11 m2 s ~ W e found an Arrhenius behaviour with an activation energy of about 55 kJ/mole nearly independent of the pitch. The obtained data for DL seem to have a lower than quadratic dependence on P0. 
  Reference    Z. Naturforsch. 43a, 687—692 (1988); received April 9 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0687 
 Volume    43 
114Author    He Wenjie, J. Brunvoll, S. J. CyvinRequires cookie*
 Title    Supplements to Enumeration of Benzenoid and Coronoid Hydrocarbons  
 Abstract    The previous report on enumeration and classification of benzenoids and coronoids is supplemented. Perhaps the most significant contribution is the enumeration of benze­ noids with 12 hexagons. 
  Reference    Z. Naturforsch. 43a, 693—694 (1988); received April 30 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0693_n 
 Volume    43 
115Author    WarrenH. InskeepRequires cookie*
 Title    On Electromagnetic Spinors and Quantum Theory  
 Abstract    The Maxwell theory is related to the Dirac theory by two heuristic arguments based on electromagnetic spinors. First, given the condition to have spinors, if the free field Maxwell's equations are satisfied, then the spinors satisfy the Weyl equations. Second, a sufficient condition for electromagnetic spinors directly gives the Weyl equations with the usual sub­ stitutions for momentum and energy. It is proposed that the heuristic nature of the first argument is related to the idea of a point having a more general symmetry than a sphere. 
  Reference    Z. Naturforsch. 43a, 695—696 (1988); received April 24 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0695_n 
 Volume    43 
116Author    U. Böberg, BrösaRequires cookie*
 Title     
 Abstract    Turbulence in a pipe is derived directly from the Navier-Stokes equation. Analysis of numerical simulations revealed that small disturbances called 'mothers' induce other much stronger distur­ bances called 'daughters'. Daughters determine the look of turbulence, while mothers control the transfer of energy from the basic flow to the turbulent motion. From a practical point of view, ruling mothers means ruling turbulence. For theory, the mother-daughter process represents a mechanism permitting chaotic motion in a linearly stable system. The mechanism relies on a property of the linearized problem according to which the eigenfunctions become more and more collinear as the Reynolds number increases. The mathematical methods are described, comparisons with experi­ ments are made, mothers and daughters are analyzed, also graphically, with full particulars, and the systematic construction of small systems of differential equations to mimic the non-linear process by means as simple as possible is explained. We suggest that more then 20 but less than 180 essential degrees of freedom take part in the onset of turbulence. PACS number: 47.25. Ae O n s e t o f T u rb u le n c e in a P ip e 1. Even the Most Ordinary Things are not Understood 
  Reference    Z. Naturforsch. 43a, 697—726 (1988); received June 15 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0697 
 Volume    43 
117Author    B. M. Herbst, W.-H SteebRequires cookie*
 Title      
 Abstract    The chaotic behaviour of the parametrically driven one-dimensional sine-Gordon equation with periodic boundary conditions is studied. The initial condition is u (x, 0) = / (x), u, (x, 0) = 0 where/ is the breather solution of the one-dimensional sine-Gordon equation at t = 0. We vary the amplitude of the driving force, the frequency of the driving force and the damping constant. For appropriate values of the driving force, frequency and damping constant chaotic behaviour with respect to the time-evolution of u(x = fixed, f) can be found. The space structure u(t = fixed, .x) changes with increasing driving force from a zero mode structure to a breather-like structure consisting of a few modes. 
  Reference    Z. Naturforsch. 43a, 727—733 (1988); received January 2 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0727.pdf 
 Identifier    ZNA-1988-43a-0727 
 Volume    43 
118Author    I. R. YukhnovskiiRequires cookie*
 Title      
 Abstract    It is shown that the events occuring in the vicinity of the critical point can be described in full by means of the collective variables with the appropriate reference system. The partition function containing the explicit form for the quartic measure density is obtained and integrated. Expressions for the critical temperature, critical density and critical chemical potential surfaces are calculated. 
  Reference    Z. Naturforsch. 43a, 734—740 (1988); received January 6 1988 
  Published    1988 
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 TEI-XML for    default:Reihe_A/43/ZNA-1988-43a-0734.pdf 
 Identifier    ZNA-1988-43a-0734 
 Volume    43 
119Author    S.Sreehari Sastry, V. Venkata, Rao, G. Satyanandam, T. F. Sundar, RajRequires cookie*
 Title      
 Abstract    The dielectric properties of HgCl2 :2 KCl crystals have been measured as a function of frequency (102 — 105 Hz) and temperature (304-415 K), along with the d.c. conductivity, in two mutually perpendicular (X and Y) directions. Along the X direction a simple Debye type relaxation mecha­ nism is observed at 304 K. A large dielectric anisotropy has been noticed at all frequencies and temperatures. Phase transitions of ferroelectric and order-disorder type are observed along the X and 7 direction, respectively. D ie le c tric S tu d ie s on H g C l 2 : 2 K C l C r y s ta ls 
  Reference    Z. Naturforsch. 43a, 741—744 (1988); received January 15 1988 
  Published    1988 
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 Identifier    ZNA-1988-43a-0741 
 Volume    43 
120Author    E. Yurtsever, Kimya Bölümii, Orta Dogu, Teknik Üniversitesi, Ankara, TurkeyRequires cookie*
 Title     
 Abstract    C o m p a ra tiv e S tu d y o f V a r ia tio n a l T e c h n iq u e s fo r S c h r ö d in g e r E q u a tio n s . P o in tw is e Q u a lity C r ite r ia Different variational schemes for solving the Schrödinger equation are tested for the model potential of Kratzer-Fues. Wavefunctions are analyzed in terms of their global (expectation values) and local properties which are expressed as functions of coordinates. The Rayleigh-Ritz variation almost uniformly produces the most accurate expectation values. However the point properties show qualitatively different behaviour for different regions of the coordinate space. To define the local quality, a set of criteria is proposed. 
  Reference    Z. Naturforsch. 43a, 745—750 (1988); received April 12 1988 
  Published    1988 
  Keywords    Eigenvalue problem, quality of solution, local properties 
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 Identifier    ZNA-1988-43a-0745 
 Volume    43 
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