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1981 (245)
1Author    W. Jaspers, SchattkeRequires cookie*
 Title     
 Abstract    Starting from a master equation for a discrete order parameter a dynamical model is set up via mean-field approximation in the Fokker-Planck equation. The time evolution of some mean values is calculated numerically, showing two transitions with characteristic slowing down of the relaxation time. 
  Reference    Z. Naturforsch. 36a, 1 (1981); received October 31 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0001.pdf 
 Identifier    ZNA-1981-36a-0001 
 Volume    36 
2Author    -J Bohn, G. SimonRequires cookie*
 Title     
 Abstract    Influence of Phonon Drag on the Eledromigration in Metals For the driving force of electromigration on an impurity atom in a metal usually one takes into consideration only the direct influence of the electrical field and the collisions with electrons. It is shown that the contribution of the phonon drag to the driving force may in some cases exceed the contribution of the electrons considerably. A system of Boltzmann transport equations for the distribution functions of electrons, phonons and impurity atoms is set up and solved in linear approximation. As a result of the theory the "effective" charge of the impurity atoms — that is that quantity, which is usually obtained by experimental investigations — can be split up into two additive contributions from electron and phonon collisions. The effective charge can be expressed through microscopic quantities. The magnitude of the effective charges agrees rather well with experiment, but not their dependence on temperature. D e r E in flu ß d e r P h o n o n e n m itf ü h r u n g a u f d e n E le k tr o tr a n s p o r t in M e ta lle n 
  Reference    Z. Naturforsch. 36a, 10 (1981); eingegangen am 20. November 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0010.pdf 
 Identifier    ZNA-1981-36a-0010 
 Volume    36 
3Author    Turky, M. Čerček, R. Tavzes, J. StefanRequires cookie*
 Title     
 Abstract    The modification of the ion-acoustic wave dispersion under the action of a high frequency electric field was studied experimentally, the wave propagating along and against the plasma stream. The frequency of the field amounted to approximately half the electron plasma frequency. It was found that the phase velocity of the ion wave and the plasma drift velocity decrease as the effective high frequency field power increases. In flu e n c e o f H ig h F re q u e n c y E le c tric F ield o n th e D is p e rs io n o f I o n -A c o u s tic W a v es in P lasm a 
  Reference    Z. Naturforsch. 36a, 17—22 (1981); received September 18 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0017.pdf 
 Identifier    ZNA-1981-36a-0017 
 Volume    36 
4Author    Koichi Yamada, Gisbert WinnewisserRequires cookie*
 Title    The Hot Band  
 Abstract    Two hot bands associated with the vs vibration-rotation band of cyanoacetylene, HC3N, have been measured with a diode laser spectrometer in the 2060— 2100 cm-1 range. Since the width of the observed lines is essentially determined by Doppler broadening, the splitting of the hot band rovibrational transitions due to /-type doubling could be resolved and was assigned. Improved spectral parameters were obtained, including the anharmonicity parameters. 
  Reference    Z. Naturforsch. 36a, 23—29 (1981); received November 26 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0023.pdf 
 Identifier    ZNA-1981-36a-0023 
 Volume    36 
5Author    J. Bendig, D. Kreysig, A. KawskiRequires cookie*
 Title     
 Abstract    n te r p r e ta t io n d e r A b s o r p tio n s s p e k tr e n v o n A z a -u n d A z in iu m -s u b s titu ie r te n A n th r a c e n e n The Interpretation of Absorption Spectra of Aza-and Azinium-Substituted Anthracenes The absorption spectra of the 3 isomeric aza-and the 4 isomeric azinium-anthracenes are dis­ cussed on the basis of the absorption anisotropy, the oscillator strenght and the fluorescence decay times. The influence of endocyclic substitution depends on the position of the aza-and aziniumgroup, respectively. In the case of acridine, acridinium, benzo[g]quinolinium and benzo[f]-isoquinolinium the So -> ^-transition is observable. The spectra of benzo[g]quinoline, benzo[f]-isoquinoline and acridizinium are similar to those of anthracene. 
  Reference    Z. Naturforsch. 36a, 30 (1981); eingegangen am 4. November 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0030.pdf 
 Identifier    ZNA-1981-36a-0030 
 Volume    36 
6Author    MichaelH. Palmer, Isobel Simpson, (. In, Part, RobertH. FindlayRequires cookie*
 Title    4N  
 Abstract    N u c le a r Q u a d r u p o le C o u p lin g in H e te r o c y c lic C o m p o u n d s , P a r t 2. A C o m p a ris o n o f a b in itio C a lc u la tio n s a n d E x p e r im e n ta l R e s u lts f o r th e A z o le s a n d A z in e s Ab initio calculations of double zeta quality have been reported for the conjugated 5-and 6-membered ring heterocycles containing NH and NMe groups. The electric field gradients were calculated and the derived nuclear quadrupole coupling constants (NQCC) compared, both in magnitude and direction, with those obtained by microwave spectroscopy and by nuclear quadru­ pole resonance. A comparison of the results with those of the corresponding 0-and S-heterocycles, and with acyclic compounds has been given, and it was shown that aromaticity considerations were of no relevance to the NQCC values at pyridine-like N ; planarity of the N atom at N-1 in the systems 2 c—9 c is responsible for the very low magnitude of Xn, and this is clearly associated with the level of 7r-donation from N-l; this is a function of position of the other ring N atoms, and appears to become saturated as the ring positions become predominantly N. In particular three contiguous N atoms seem to have less effect than two N atoms. 
  Reference    Z. Naturforsch. 36a, 34—50 (1981); received November 11 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0034.pdf 
 Identifier    ZNA-1981-36a-0034 
 Volume    36 
7Author    K. J. Hartig, J. Lichtscheidl, N. Getoff, Ludwig BoltzmannRequires cookie*
 Title     
 Abstract    r o d u c tio n o f P o ly c ry s ta llin e « -T i 0 2-L a y e rs f o r P h o to e le c tro c h e m ic a l P u rp o s e The preparation of highly photoactive, polycrystalline n-Ti02-semiconductors by thermo-chemical oxidation of Titanium metal sheets was investigated systematically. The optimum temperature in an oxygen atmosphere was found to be between 550 °C and 650 °C for a period of 10—30 min. Careful etching of the Titanium surface prior to oxidation is a decisive step in the production process. The growth, adhesion on the substrate and photoefficiency of the Ti02-crystals were studied under various experimental conditions. Ti02-layers prepared under optimum conditions showed a photocurrent higher than 2 mA • cm-2 in 0.1 mol • dm-3 KCl as electrolyte and about 6 mA • cm-2 in 1 mol • dm-3 KOH, respectively. The overall energy conversion was = 3.5%. 
  Reference    Z. Naturforsch. 36a, 51—56 (1981); received September 18 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0051.pdf 
 Identifier    ZNA-1981-36a-0051 
 Volume    36 
8Author    R. Frank, G. GauglitzRequires cookie*
 Title     
 Abstract    e s tim m u n g p a rtie lle r p h o to c h e m is c h e r Q u a n te n a u s b e u te n ü b e r k o m b in ie r te A b s o r p tio n s -u n d F lu o re s z e n z m e ss u n g On the Determination of Partial Photochemical Quantum Yields by Combined Absorbance and Fluorescence Measurement A combined automatic set up for the measurement of fluorescence and absorbance is described. The absorbance at irradiation wavelength E' and a fluorescence reaction spectrum are measured continously and simultaneously. Even for solutions with high concentrations up to E '> 1, the fluorescence intensity can be corrected for. By this method the photodegradation of fluorescent dyes was examined. Because only a few of the degradation products fluoresce, the determination of kinetic parameters is easier than from absorbance measurements. The method gave good results for laser dyes using even high concentrations (E' > 1), with less calculatory expenditure and smaller standard deviation in comparison to the evaluation of absorbance measurements only. 
  Reference    Z. Naturforsch. 36a, 57—61 (1981); eingegangen am 30. September 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0057.pdf 
 Identifier    ZNA-1981-36a-0057 
 Volume    36 
9Author    F. Schneider, N. K. SharmaRequires cookie*
 Title      
 Abstract    d u c e d S m e c tic P h ases I. P o ly m o r p h is m in B in a ry M ix tu r e s o f A lk y lo x y b e n z y lid e n e -a lk y la n ilin e s w ith A lk y l-a n d A lk y lo x y -c y a n o b ip h e n y ls The diagrams of state of mixtures of 4-n-alkyloxybenzylidene-4'-n-butylanilines with 4-»-alkyl-and 4-n-alkyloxy-4'-cyanobiphenyls are studied. The mixtures form induced smectic phases of type Sa, Sb and Se. In all three smectic phases the thickness of the smectic layers agrees with the mean values of the molecular lengths. In most cases the induced Sa phases do not show uninterrupted miscibility with the Sa phases of the pure components. For instance, the system 40 • 4/8 CBP exhibits three separate Sa phase areas. The maximum transition tempera­ tures of the induced smectic phases increase with increasing chain length of the azomethines, but remain constant in case of the Sa and Sb phases or even decrease in case of the Se phases with increasing chain length of the cyanobiphenyls. 
  Reference    Z. Naturforsch. 36a, 62—67 (1981); received October 30 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0062.pdf 
 Identifier    ZNA-1981-36a-0062 
 Volume    36 
10Author    Lucilla Alagna, Carla Cauletti, Laboratorio Tsecs-Cnr, RomaMarco Andreocci, Claudio Furlani, Gerhard HageleRequires cookie*
 Title     
 Abstract    tu d y o f S u lfu r-S u lfu r N o n b o n d e d I n te r a c tio n s in S u b s titu te d D ip h o s p h in e D isu lfid es b y G a s-P h a se U V P h o to e le c tr o n S p e c tro s c o p y Herrn Professor Hermann Hartmann zum 65. Geburtstag gewidmet Ultraviolet photoelectron spectra (UPS) of tetrasubstituted diphosphine disulfides RR'P(S)-P(S)RR' exhibit peculiar 1:2:1 splitting patterns in the region 7.5—9.5 eV for which a through-bond coupling mechanism between the sulfur lone pairs lying in the PPS planes is proposed. Further bond orbitals are related to bands at higher I. E. in the UP spectra. 
  Reference    Z. Naturforsch. 36a, 68—71 (1981); received October 1 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0068.pdf 
 Identifier    ZNA-1981-36a-0068 
 Volume    36 
11Author    Okan GurelRequires cookie*
 Title    Exploded Points  
 Abstract    A new concept of a mathematical object of zero dimension, an exploded point, is introduced. The dimension used is defined on the basis of the functional characteristics of the system, thus it may be referred to as /-dimension. A stability index is also defined for the mathematical objects including exploded points, which can be related to the /-dimension. It is shown that the mathe­ matical object exhibited by the Lorenz system after the second bifurcation is such a point. A recursive formula based on the definition of the exploded point. E x p lo d e d P o in ts 
  Reference    Z. Naturforsch. 36a, 72 (1981); received November 24 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0072.pdf 
 Identifier    ZNA-1981-36a-0072 
 Volume    36 
12Author    I. A. Gryczyński, S. Kawski, T. Paszyc, SkowyraRequires cookie*
 Title    Quenching of the Yt-Base Fluorescence by Heavy-Atom Induced Intermolecular Singlet-Triplet Energy Transfer  
 Abstract    Quenching of the Ft-base fluorescence by a series of halogen derivatives of benzene and naphthalene was mea­ sured in dioxane. For the naphthalene derivatives, the presence of the heavy atom in the acceptor molecule was found to affect strongly the fluorescence quenching rate constant, whereas no such effect was observed for the benzene derivatives. The fact is explained with the as­ sumption of a singlet-triplet energy transfer from the Ft-base molecules to the naphthalene derivatives. 
  Reference    Z. Naturforsch. 36a, 76—77 (1981); received November 4 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0076_n.pdf 
 Identifier    ZNA-1981-36a-0076_n 
 Volume    36 
13Author    C. BojarskiRequires cookie*
 Title    Comments on the Mean Diffusion Length of Luminescent Molecules in Solutions  
 Abstract    The effect of concentration of donor and acceptor mol­ ecules on the mean diffusion length in solutions is dis­ cussed. 
  Reference    Z. Naturforsch. 36a, 78—79 (1981); received October 20 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0078_n.pdf 
 Identifier    ZNA-1981-36a-0078_n 
 Volume    36 
14Author    Robert ShawRequires cookie*
 Title    Relevance of Attractors to Dissipative Systems III. Informational Aspects of Nonconservative Flows IV. Maps on the Unit Interval V. Analogy with Phase-Transitions, Overview VI. Relation of One-Dimensional Maps to Dynamic Flows VII. Calculation of A for the Lorenz Attractor VIII. Experimental Verification IX. Determinism and Reversibility in Phase Space X. Steps Toward a Classification of Strange Attractors XI. Relation Between 3D Flows, 2D Maps, ID Maps XII. Strange Attractor Phenomenology XIII. Informational Aspects of Turbulence XIV. 1// Noise, Concluding Speculations Acknowledgements Appendix I Dynamical System as a Noise Amplifier Appendix II Evolution of Probability Densities References  
 Abstract    Simple system equations displaying turbulent behavior are reviewed in the light of information theory. It is argued that a physical implementation of such equations is capable of acting as an information source, bringing into the macroscopic variables information not implicit in initial conditions. The average rate of information production A is a system state function, and is given for simple cases by a "Liapunov characteristic exponent", developed by Oseledec. The transition of a system from laminar to turbulent behavior is understandable in terms of the change of A from negative to positive, corresponding to the change of the system from an information sink to a source. The new information of turbulent systems precludes predictability past a certain time; when new information accumulates to displace the initial data, the system is undetermined. The observed geometry of strange attractors is seen to arise naturally from a rule allowing joining but not splitting of trajectories in phase space. The phenomenology of strange attractors in three dimensions is discussed, and a basis for their classification suggested. A comment is made on the commonplace occurrence of information producing systems in the real world, and on their possible relation to 1// noise. S tra n g e A ttr a c to r s , C h a o tic B e h a v io r, a n d I n f o r m a t io n F lo w * 
  Reference    Z. Naturforsch. 36a, 80—112 (1981); received October 15 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0080.pdf 
 Identifier    ZNA-1981-36a-0080 
 Volume    36 
15Author    Ulrich WeinertRequires cookie*
 Title    On the Inversion of the Linearized Collision Operator  
 Abstract    Some features are discussed in connection with the representation of the linearized Boltzmann collision operator and its inversion. It is shown that under certain assumptions the inverse operator can be given explicitly as an integral kernel function. O n th e In v e rs io n o f th e L in e a riz e d C o llis io n O p e r a to r 
  Reference    Z. Naturforsch. 36a, 113—120 (1981); received December 15 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0113.pdf 
 Identifier    ZNA-1981-36a-0113 
 Volume    36 
16Author    Kunihiko MorimotoRequires cookie*
 Title      
 Abstract    In order to calculate the rotating frame spin-lattice relaxation time T\e for tunneling NH4-ion systems at low temperature, a model of relaxation, which is available when yH\,TT^> 1, is proposed, where Hl is the local dipolar field and rr the correlation time. The present model is useful especially in two cases: (1) when the NH4-ion is relatively magnetically isolated and the assumption of a common spin temperature cannot be used. (2) when the level crossing of the NH4-ion occurs in the rotating frame. In case (1), non-single exponential relaxation is predicted. In case (2), T\g is shown to be proportional to rr, while the prediction of the weak collision theory is T\e cc rr_1. The present model is compared with the strong collision theory of Slichter and Ailion. S tro n g C o llis io n I n d u c e d S p in -L a ttic e R e la x a tio n f o r T u n n e lin g N H 4-io n S y stem s in th e R o t a ti n g F ra m e 
  Reference    Z. Naturforsch. 36a, 121—127 (1981); received December 4 1980* 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0121.pdf 
 Identifier    ZNA-1981-36a-0121 
 Volume    36 
17Author    Ivan GutmanRequires cookie*
 Title    Topological Resonance Energy of V ery Large Benzenoid Hydrocarbons  
 Abstract    An approximate expression is obtained for the resonance energy of benzenoid hydrocarbons. The resonance energy is shown to depend in a simple manner on the number of six-membered cycles and on the number of Kekule structural formulae of the molecule. By this approach, the resonance energies of very large benzenoid hydrocarbons can be determined. T o p o lo g ic a l R e s o n a n c e E n e rg y o f V e r y L a rg e B e n z e n o id H y d r o c a r b o n s 
  Reference    Z. Naturforsch. 36a, 128—131 (1981); received September 22 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0128.pdf 
 Identifier    ZNA-1981-36a-0128 
 Volume    36 
18Author    D. Koledin, P. GrujićRequires cookie*
 Title    Low-Energy e-He(21L) Scattering Calculations  
 Abstract    Cross sections for e-He(21L) scattering have been calculated in the energy range 1 ^ E eV. For I > 0 partial cross sections a simple analytical method, proposed by the authors before, which is essentially an extension of Seaton's exact resonance method, has been applied. In the case 1 = 0, when a complex "angular momentum quantum number" in the rotated space appears, a matching procedure has been adopted, making use of a more realistic model potential. The results for Q(21S-21S), ^ (2 1S-21P) and Q(21 P-2*P) cross sections are compared with other theoretical calculations and in the case of the elastic Q(21S-21S) cross section with the available experimental data as well. The applicability of the analytical method used in the electron-atom scattering calculations is discussed, in particular for those processes which play a dominant role in the Stark broaden­ ing of spectral lines from plasmas. Finally, the relevance of the present method to searching for an eventual resonant (or virtual) state near 2X S threshold has been discussed. 
  Reference    Z. Naturforsch. 36a, 132 (1981); received December 8 1979 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0132.pdf 
 Identifier    ZNA-1981-36a-0132 
 Volume    36 
19Author    M. Mintas, G. W. FilbyRequires cookie*
 Title     
 Abstract    a r b o n C o n ta m in a n t B u ild u p a n d S p u tte r in g B e h a v io u r o n Z in c O x id e D u r in g X P S E x a m in a tio n The effect of argon and oxygen sputtering on carbon contaminant buildup on ZnO during XPS (X-ray photoelectron spectroscopy) analysis has been examined. Argon and oxygen sputtering cause a rapid decline in hydroxyl oxygen and contaminant carbon content at the surface. Reduc­ tion to metallic zinc is not observed. In a carefully baked instrument after sputtering a stable clean surface could be maintained over several hours of analysis. 
  Reference    Z. Naturforsch. 36a, 140—143 (1981); received December 11 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0140.pdf 
 Identifier    ZNA-1981-36a-0140 
 Volume    36 
20Author    D. Lortz, W. Lötz, J. Nührenberg, F. CapRequires cookie*
 Title      
 Abstract    Three-dimensional analytical force-free magnetohydrostatic equilibria may be obtained by separation of variables with respect to cylindrical coordinates. These equilibria are then used to study numerically flux surfaces of various three-dimensional configurations. 
  Reference    Z. Naturforsch. 36a, 144—149 (1981); received December 12 1980 
  Published    1981 
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 TEI-XML for    default:Reihe_A/36/ZNA-1981-36a-0144.pdf 
 Identifier    ZNA-1981-36a-0144 
 Volume    36 
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