| | 101 | Author
| Sean Bohaty | Requires cookie* | | | Title
| Theoretical Determination of the Mass of a Roton  | | | | Abstract
| For 56 years, researchers have sought, with varied success, to determine the mass of a roton. However, with the recent emergence of the author's theory of superfluid 4 He, the time may soon be at hand when the roton's mass is determined unequivocally. This letter reports the first quantitative results of the new theory of helium II. Using data from a neutron scattering experiment, the mass of a roton was calculated. It was found that the roton mass is 2.12 x 10 -* 7 kg or approximately 0.32 m He , where m He is the mass of a helium atom. | | | |
Reference
| Z. Naturforsch. 52a, 561—563 (1997); received May 13 1997 | | | |
Published
| 1997 | | | |
Keywords
| Rotons, Special relativity, Superfluid helium-4 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0561.pdf | | | | Identifier
| ZNA-1997-52a-0561 | | | | Volume
| 52 | |
| 102 | Author
| George Maroulis | Requires cookie* | | | Title
| Linear and Non-linear Polarizabilities for P2CX 1 £ g + ) | | | | Abstract
| Electric polarizabilities and hyperpolarizabilities were calculated from accurate self-consistent field wavefunctions for P 2 . The following values are reported, using the experimental bond length of 1.8934 Ä: dipole polarizability a zz = 69.83 and <x xx = 41.20 e 2 al £ h _1 , second dipole hyperpolariz-ability 7zzzz = 17 040, 7^ = 11581 and y XXZ2 = 4724 e*a*E~ 3 , quadrupole polarizability, C zz " = 276.14, C xzxz = 232.64 and C xxxx = 151.25 e 2 a^ £ h -1 , dipole-octopole polarizability, E, , z , — 331.00 and E x xxx — — 154.66 e 2 £ h ~ 1 and for the dipole-dipole-quadrupole hyperpolariz-ability, ß zz . zz = -2441, B xz _ xz = -1442, B xxzz = 866 and B xx xx = -1411 e'atE' 2 . | | | |
Reference
| Z. Naturforsch. 52a, 564—566 (1997); received September 2 1992 | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0564.pdf | | | | Identifier
| ZNA-1997-52a-0564 | | | | Volume
| 52 | |
| 104 | Author
| Markus Abel, Arkady Pikovsky | Requires cookie* | | | Title
| Parametric Excitation of Breathers in a Nonlinear Lattice | | | | Abstract
| We investigate localized periodic solutions (breathers) in a lattice of parametrically driven, nonlin-ear dissipative oscillators. These breathers are demonstrated to be exponentially localized, with two characteristic localization lengths. The crossover between the two lengths is shown to be related to the transition in the phase of the lattice oscillations. | | | |
Reference
| Z. Naturforsch. 52a, 570—572 (1997); received | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0570.pdf | | | | Identifier
| ZNA-1997-52a-0570 | | | | Volume
| 52 | |
| 105 | Author
| M. J. Bünner, Th Meyer, A. Kittel, J. Parisi | Requires cookie* | | | Title
| On the Correspondence of Time-Delay and Spatially Extended Systems | | | | Abstract
| We establish a straightforward connection between spatially extended systems, the dynamics of which are modeled with the help of partial differential equations and time-delay systems. To this end, we give a linear partial differential equation with a nonlinear boundary condition whose solutions are equivalent to the solutions of a time-delay differential equation. We observe that the phase space of these systems exhibits a pronounced structure. In this paper, we express the structure of the phase space of time-delay systems and the corresponding spatially extended system by distinguishing between a 'linear subsystem' and a 'localized nonlinearity'. We find that the high-dimensional chaotic dynamics observed in time-delay systems is fundamentally different from the spatio-temporal chaos observed in homogeneous spatially extended systems, the dynamics of which is modeled with the help of nonlinear partial differential equations. To this end, we investigate the space-time correlation function and the 'thermodynamic limit'. | | | |
Reference
| Z. Naturforsch. 52a, 573—577 (1997); received | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0573.pdf | | | | Identifier
| ZNA-1997-52a-0573 | | | | Volume
| 52 | |
| 106 | Author
| Thomas Kirner, OttoE. Rössler | Requires cookie* | | | Title
| Frequency Clustering in a Chain of Weakly Coupled Oscillators | | | | Abstract
| A numerical simulation of a chain of diffusively coupled nonlinear oscillators with a linear param-eter gradient exhibits clusters of frequencies. The intention was to investigate the frequency-gradient in the stimulus conduction system of the heart. The phenomenon generalizes earlier findings on "frequency plateaus" described in the 1960's by Nicholas Diamant as a model of small-intestine transport. This "waxing and waining" phenomenon is a version of chaos. Thus, subtle chaos in the heart and waxing and waining type chaos in the intestine may be related. | | | |
Reference
| Z. Naturforsch. 52a, 578—580 (1997); received June 10 1997 | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0578.pdf | | | | Identifier
| ZNA-1997-52a-0578 | | | | Volume
| 52 | |
| 108 | Author
| Walter Nadler, HansH. Diebner, OttoE. Rössler | Requires cookie* | | | Title
| Space-Discretized Verlet-Algorithm from a Variational Principle | | | | Abstract
| A form of the Verlet-algorithm for the integration of Newton's equations of motion is derived from Hamilton's principle in discretized space and time. It allows the computation of exactly time-reversible trajectories on a digital computer, offers the possibility of systematically investigating the effects of space discretization, and provides a criterion as to when a trajectory ceases to be physical. | | | |
Reference
| Z. Naturforsch. 52a, 585—587 (1997); received June 10 1997 | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0585.pdf | | | | Identifier
| ZNA-1997-52a-0585 | | | | Volume
| 52 | |
| 109 | Author
| J. Peinke, R. Friedrich, A. Naert | Requires cookie* | | | Title
| A New Approach to Characterize Disordered Structures | | | | Abstract
| A new application of the theory of Markov processes to the characterization of fractal scaling behavior is presented. We show under which condition distinct stochastic processes of a cascade lead to multifractal scaling behavior. We apply our method to the analysis of the statistical properties of the energy in turbulent fluid flow. | | | |
Reference
| Z. Naturforsch. 52a, 588—592 (1997); received June 10 1997 | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0588.pdf | | | | Identifier
| ZNA-1997-52a-0588 | | | | Volume
| 52 | |
| 110 | Author
| OttoE. Rössler, HansH. Diebner, Werner Pabst | Requires cookie* | | | Title
| Micro Relativity | | | | Abstract
| A new synthesis based on microscopic classical thinking is attempted in the spirit of the molecular-dynamics-simulation (MDS) paradigm. Leibniz's idea that joint scale transformations cancel out is invoked. Boltzmann discovered that a time reversal in the whole universe is undetectable from the inside. As a corollary, objective micro time reversals occur in the interface between a subsystem and the rest of the universe, whenever the former undergoes a time reversal. This is shown to occur in a generic class of Hamiltonian systems. The "microinterface" arrived at generalizes the macro frame of relativity to the micro realm. Micro relativity comprises Bohr's idea of an observer-relative complementarity and Everett's idea of an observer-relative state. As in relativity proper, a multiplicity of worlds (cuts) exist. For the inhabitants of an artificial MDS universe, therefore a radically new option is available: world change technology. | | | |
Reference
| Z. Naturforsch. 52a, 593—599 (1997); received June 10 1997 | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0593.pdf | | | | Identifier
| ZNA-1997-52a-0593 | | | | Volume
| 52 | |
| 111 | Author
| Peter Wagner, Joachim Peinke | Requires cookie* | | | Title
| Scaling Properties of Traffic-flow Data | | | | Abstract
| By computing the probability distributions of the velocity difference between cars a time-delay r apart, the scaling properties of traffic flow can be analysed. These data display scaling behaviour thus confirming earlier results that have found 1// Q -noise in traffic flow. Furthermore, the applicability of the scaling analysis for describing the two-point statistics of traffic flow is demonstrated, leading to an additional test for the dynamical properties of microscopic and macroscopic traffic flow models. | | | |
Reference
| Z. Naturforsch. 52a, 600—604 (1997); received June 10 1997 | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0600.pdf | | | | Identifier
| ZNA-1997-52a-0600 | | | | Volume
| 52 | |
| 113 | Author
| Roman Goc, JanW. Wąsicki | Requires cookie* | | | Title
| Computer Simulation of the Order-Disorder Transition in Ammonium Chloride | | | | Abstract
| The phase transition at T c = 243 K in ammonium chloride is well established to be of the order-disorder type. The ammonium chloride has a CsCl-type cubic structure with hydrogen atoms pointing toward four of the eight chloride ions at the corners of the unit cell. This means that there are two possible orientations of ammonium tetrahedron; a and b. In the ordered phase below the T c temperature all ammonium ions have the same, let it be a, orientation. Above the T c temperature ions are randomly distributed among the two possible orientations a and b. An attempt was made to correlate such structural transition with the second moment of the proton NMR absorption line. This approach was chosen because the second moment is the parameter of the NMR line for which the exact theoretical formula exist, and which is mainly a function of the structure and the reorien-tational state of the studied material. It was found that the NMR second moments calculated for the described above model of the structural transition properly reflect the changes of the experimental NMR second moments measured at temperatures below and above this transition. | | | |
Reference
| Z. Naturforsch. 52a, 609—613 (1997); received June 18 1997 | | | |
Published
| 1997 | | | |
Keywords
| NMR, Ammonium chloride, Phase transition, Simulation | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0609.pdf | | | | Identifier
| ZNA-1997-52a-0609 | | | | Volume
| 52 | |
| 114 | Author
| P. K. Babu, J. Ramakrishna | Requires cookie* | | | Title
| C1 NQR Studies of Bismuth Trichloride | | | | Abstract
| The temperature dependence of the 35 C1 nuclear quadrupole resonance (NQR) frequency and spin lattice relaxation time (Ti) are studied in crystalline BiCl 3 , in the range 40 -300 K. The positive temperature coefficient observed for one of the 35 C1 resonances is explained in terms of the strong intermolecular interactions that exist in this compound. Variation of with temperature is found to be similar at the chemically inequivalent halogen sites. Semiclassical descriptions based on torsional oscillator dynamics are found to be inadequate for explaining the spin lattice relaxation. Tj (T) data follow an AT 2 + BT 3 type behaviour, indicating that the anharmonic nature of the lattice vibrations plays a significant role in determining the temperature dependence of 7i at high temperatures. | | | |
Reference
| Z. Naturforsch. 52a, 614—620 (1997); received April 4 1997 | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0614.pdf | | | | Identifier
| ZNA-1997-52a-0614 | | | | Volume
| 52 | |
| 115 | Author
| W. Osak | Requires cookie* | | | Title
| Charge Transport and Relaxation in Triglycine Sulphate (TGS) | | | | Abstract
| Charging currents, J-V characteristics and electron conductivity have been measured in triglycine sulphate along three crystallographic directions: a, b and c. The measurements have been taken in a wide temperature range between — 196°C and 80 °C. It is found that the charging currents have short relaxation times in the directions: a and c and a long relaxation time along the ferroelec-tric b axis. The J-V characteristics in the direction of the a and c axes have the shapes characteristic for linear dielectrics with space charge limited currents. The J-V characteristic for the b axis depends on the temperature: In the region of the phase transition the Fridkin-Kreher formula (J cc F 4/3) is satisfied; for low temperatures characteristic agrees with SCLC theory for linear dielectrics with Gaussian traps energy distribution. The d.c. conductivity along the c axis is much higher than along the a and b axes. In the investigated temperature range, the electrical conductivity has an activation character. For — 100°C < T < -193°C there is: <roc(l/T) exp(-E/kT). The activation energy depends both on the crystallographic direction and on the temperature-range. For low temperatures, T < — 100 °C, the activation energies are very small (of the order of a few hundreds eV). Subject classification: 72 (Electronic transport in condensed matter); 77 (Dielectrics, piezoelectrics and ferroelectrics and their properties). | | | |
Reference
| Z. Naturforsch. 52a, 621—628 (1997); received February 17 1997 | | | |
Published
| 1997 | | | |
Keywords
| Ferroelectrics, J-V characteristics, Electrical conductivity | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0621.pdf | | | | Identifier
| ZNA-1997-52a-0621 | | | | Volume
| 52 | |
| 116 | Author
| Giorgio Spinolo, Umberto Anselmi-Tamburini, Paolo Ghigna | Requires cookie* | | | Title
| An Exact and Simple Approach to log-log Plots for Defect and Ionic Equilibria | | | | Abstract
| An alternative approach to log-log plots for defect equilibria in the solid state and ionic equilibria in solution is presented. The method is based on the strictly monotone character of the functional dependence of an externally controlled thermodynamic variable (e.g. the oxygen partial pressure P(0 2) for the defect equilibria in a simple oxide, or a total concentration for the ionic equilibria in solution) on a chemically relevant compositional variable (such as the electron concentration n for defect equilibria, or [H 3 0 + ] or a free ligand concentration for solution equilibria). This functional dependency can be safely inverted. The concentration of all species and the externally controlled thermodynamic variable can be calculated as a function of the chemically relevant compositional variable. The appropriate plots are then obtained using naively a spreadsheet program. This method gives exact results in many more cases than the traditional approach. | | | |
Reference
| Z. Naturforsch. 52a, 629—636 (1997); received June 19 1997 | | | |
Published
| 1997 | | | |
Keywords
| Chemical equilibria, Point defects, log-log plots | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0629.pdf | | | | Identifier
| ZNA-1997-52a-0629 | | | | Volume
| 52 | |
| 117 | Author
| Hiroyuki Ishida, Masakazu Kato, Hiroshi Ono, Ryuichi Ikeda | Requires cookie* | | | Title
| Cationic Self-diffusion in Solid Choline Perchlorate Studied by NMR | | | | Abstract
| The 1 H spin-lattice and spin-spin relaxation times, and the second moment of the 1 H NMR linewidth of choline Perchlorate, [(Cff^NCfFCHiOHJClC^, were measured in its highest-temperature solid phase, i. e. above 275 K. X-ray powder patterns taken at ca. 380 K revealed that in this phase the crystal has a CsCl-type cubic structure (a = 6.326(4) A and Z = 1). From *H NMR experiments it was found that the cations in this phase undergo isotropic rotation and translational self-diffusion. From the 1 H T, measurements, the activation energies of the cationic rotation and self-diffusion were evaluated to be 21.4 ± 0.4 and 62 ± 3 kJ mol -1 , respectively. | | | |
Reference
| Z. Naturforsch. 52a, 637—639 (1997); received May 28 1997 | | | |
Published
| 1997 | | | |
Keywords
| Ionic plastic phase, Self-diffusion, Crystal structure, Nuclear magnetic resonance | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0637.pdf | | | | Identifier
| ZNA-1997-52a-0637 | | | | Volume
| 52 | |
| 119 | Author
| B. Sedelmeyer, P. Lamparter, S. Steeb | Requires cookie* | | | Title
| Structure of Molten Mn 74 Si 26 and Molten Mn 33 5 Si 66 5 by Neutron Diffraction | | | | Abstract
| Molten Mn 74 Si 26 and molten Mn 33 5 Si 66 5 were investigated by neutron diffraction. The pair correlation function yielded, together with the X-ray results from a former paper, the partial coordination numbers, atomic distances, and the short range order parameter with the result that the atomic distribution in molten Mn 33 5 Si 66 5 is statistical while the structure factor of molten Mn 74 Si 26 , as obtained with neutrons, shows a strong prepeak which means rather strong compound formation. | | | |
Reference
| Z. Naturforsch. 52a, 645—649 (1997); received May 7 1997 | | | |
Published
| 1997 | | | |
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| default:Reihe_A/52/ZNA-1997-52a-0645.pdf | | | | Identifier
| ZNA-1997-52a-0645 | | | | Volume
| 52 | |
| 120 | Author
| P. Adamčíková, Ševčík | Requires cookie* | | | Title
| The Blue Bottle Experiment and Pattern Formation in this System | | | | Abstract
| The methylene blue -saccharide -NaOH system, the so-called "Blue Bottle" experiment was investigated. When this system is poured into an open petri dish, spatial structures start to generate after an induction period. The induction period increases in the order of xylose < glucose < galac-tose < arabinose < mannose. | | | |
Reference
| Z. Naturforsch. 52a, 650—654 (1997); received April 21 1997 | | | |
Published
| 1997 | | | |
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| | | | | TEI-XML for
| default:Reihe_A/52/ZNA-1997-52a-0650.pdf | | | | Identifier
| ZNA-1997-52a-0650 | | | | Volume
| 52 | |
|
