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1998[X]
21Author    H. BaurRequires cookie*
 Title    The Glass Transition Within the Thermodynamics of Irreversible Processes  
 Abstract    The glass transition caused by a finite cooling rate is a continuous non-linear dissipative process whose description requires a clear distinction between equilibrium and non-equilibrium quantities. The so-called Davies or Prigogine-Defay relations (in form of an equation as well as in form of an inequality) are not relevant in such a process. The determining quantities of the glass transition are -from a macroscopic phenomenological point of view -the fluidity of the melt and the partial free enthalpy of the microscopic vacancies in the melt. All of the characteristics of the dynamics of the glass transition are essentially due to these two quantities. 
  Reference    Z. Naturforsch. 53a, 157—170 (1998); received December 29 1997 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0157.pdf 
 Identifier    ZNA-1998-53a-0157 
 Volume    53 
22Author    Hsing-Ya LiRequires cookie*
 Title    Zero Eigenvalue Analysis for the Determination of Multiple Steady States in Reaction Networks  
 Abstract    A chemical reaction network can admit multiple positive steady states if and only if there exists a pos-itive steady state having a zero eigenvalue with its eigenvector in the stoichiometric subspace. A zero eigenvalue analysis is proposed which provides a necessary and sufficient condition to determine the possibility of the existence of such a steady state. The condition forms a system of inequalities and equa-tions. If a set of solutions for the system is found, then the network under study is able to admit multi-ple positive steady states for some positive rate constants. Otherwise, the network can exhibit at most one steady state, no matter what positive rate constants the system might have. The construction of a zero-eigenvalue positive steady state and a set of positive rate constants is also presented. The analysis is demonstrated by two examples. 
  Reference    Z. Naturforsch. 53a, 171—177 (1998); received December 31 1997 
  Published    1998 
  Keywords    Reaction Network, Multiple Steady States, Zero Eigenvalue Analysis 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0171.pdf 
 Identifier    ZNA-1998-53a-0171 
 Volume    53 
23Author    S. R. LoganRequires cookie*
 Title    The Trouton-Hildebrand-Everett Rule  
 Abstract    Fundamental scientific reasons are advanced for preferring the formulation of the THE Rule offered in a Note of 1996 to that employed by Rooney in a Note of 1997. These illustrate that, whereas Transition State theory has been of considerable service to the development of chemical kinetics, it has not been of any utility in regard to issues of thermodynamics 
  Reference    Z. Naturforsch. 53a, 178 (1998); received February 27 1998 
  Published    1998 
  Keywords    Trouton-Hildebrand-Everett Rule, Entropy of Vaporisation, Transition State Theory 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0178_n.pdf 
 Identifier    ZNA-1998-53a-0178_n 
 Volume    53 
24Author    T. Gerisch, A. Rieckers, H.-J VolkertRequires cookie*
 Title    Thermodynamic Formalism and Phase Transitions of Generalized Mean-Field Quantum Lattice Models  
 Abstract    The general structure of thermodynamic equilibrium states for a class of quantum mechanical (multi-lattice) systems is elaborated, combining quantum statistical and thermodynamical methods. The quantum statistical formulation is performed in terms of recent operator algebraic concepts emphasizing the role of the permutation symmetry due to homogeneous coarse graining and employing the internal symmetries. The variational principle of the free energy functional is derived, which determines together with the symmetries the general form of the limiting Gibbs states in terms of their central decomposition. The limiting minimal free energy density and its possible equilibrium states are analyzed on various levels of the description by means of convex analysis, where the Fenchel transforms of the free energies provide entropy like potentials. On the thermodynamic level a modified entropy surface is obtained, which specifies only in combination with its concave envelope the regions of pure and mixed phase states. The symmetry properties of a certain model allow to specify the (non-) differentiability of the minimal free energy density. A characterization and classification of phase transitions in terms of quantum statistical equilibrium states is proposed, and the connection to the Landau theory is established demonstrating that the latter implies a (continuous) deformation of the sets of equilibrium states along a canonically given curve. 
  Reference    Z. Naturforsch. 53a, 179—207 (1998); received March 2 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0179.pdf 
 Identifier    ZNA-1998-53a-0179 
 Volume    53 
25Author    Wiwat Sidhisoradej, Supot Hannongbua, David RuffoloRequires cookie*
 Title    Three-body Effects in Calcium(n)-ammonia Solutions: Molecular Dynamics Simulations  
 Abstract    Molecular dynamics simulations have been performed with and without three-body corrections at an average temperature of 240 K using a flexible ammonia model. The system consists of one calcium ion and 215 ammonia molecules. The calcium(II)-ammonia interactions were newly developed, based on ab initio calculations with a basis set of double zeta quality. The role of three-body interactions on the structural and dynamical properties of the solution has been investigated. The presence of three-body corrections leads to the reduction of the first shell coordination number of Ca(II) in liquid ammonia from 9 to 8, the increase of the size of the solvation shell by 0.33 A and the disappearance of the sec-ond solvation shell. 
  Reference    Z. Naturforsch. 53a, 208—216 (1998); received February 16 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0208.pdf 
 Identifier    ZNA-1998-53a-0208 
 Volume    53 
26Author    M. F. El-Sayed, D. K. CallebautRequires cookie*
 Title    Nonlinear Electrohydrodynamic Stability of Two Superposed Bounded Fluids in the Presence of Interfacial Surface Charges  
 Abstract    The method of multiple scales is used to analyse the nonlinear propagation of waves on the interface between two superposed dielectric fluids with uniform depths in the presence of a normal electric field, taking into account the interfacial surface charges. The evolution of the amplitude for travelling waves is governed by a nonlinear Schrödinger equation which gives the criterion for modulational instability. Numerical results are given in graphical form, and some limiting cases are recovered. Three cases, in the pure hydrodynamical case, depending on whether the depth of the lower fluid is equal to or greater than or smaller than the one of the upper fluid are considered, and the effect of the electric field on the stability regions is determined. It is found that the effect of the electric field is the same in all the cases for small values of the field, and there is a value of the electric field after which the effect differs from case to case. It is also found that the effect of the electric field is stronger in the case where the depth of the lower fluid is larger than the one of the upper fluid. On the other hand, the evolution of the am-plitude for standing waves near the cut-off wavenumber is governed by another type of nonlinear Schrödinger equation with the roles of time and space are interchanged. This equation makes it possible to determine the nonlinear dispersion relation, and the nonlinear effect on the cut-off wavenumber. 
  Reference    Z. Naturforsch. 53a, 217—232 (1998); received January 23 1998 
  Published    1998 
  Keywords    Hydrodynamic Stability, Electrohydrodynamics, Nonlinearity, Interfacial Instability, Dielectric Fluids, Surface Charges 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0217.pdf 
 Identifier    ZNA-1998-53a-0217 
 Volume    53 
27Author    M. Sandmann, A. WürflingerRequires cookie*
 Title    PVT Measurements on 4'-w-Hexyl-Biphenyl-4-Carbonitrile (6CB) and 4 -w-Heptyl-Biphenyl-4-Carbonitrile (7CB) up to 300 MPa  
 Abstract    P, V m , 7" data were established for 4'-n-hexyl-biphenyl-4-carbonitrile (6CB) and 4'-n-heptyl-biphen-yl-4-carbonitrile (7CB) between 300 and 370 K up to 300 MPa, and specific volumes were determined for the liquid crystalline, isotropic, and also partly for the crystal phases. Volume and enthalpy chang-es at the phase transitions are also presented. In the case of 6CB, a new crystal phase has been detect-ed, corresponding to a triple point at 338 K and 196 MPa. The p, V m , T data enabled us to separate the entropy change into a volume-dependent part and configurational part. From the molar volumes along the nematic-isotropic phase transition T Nl (p), the molecular field parameter y= 3lnT NI /3ln V NI was deter-mined. 
  Reference    Z. Naturforsch. 53a, 233—238 (1998); received March 11 1998 
  Published    1998 
  Keywords    6CB, 7CB, High Pressure, pVT, Phase transitions, Thermodynamics 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0233.pdf 
 Identifier    ZNA-1998-53a-0233 
 Volume    53 
28Author    Giorgio Concas, Anna Corrias, Enrico Manca, Giaime Marongiu, Giorgio Paschina, Giorgio SpanoRequires cookie*
 Title    An X-ray Diffraction and Mössbauer Spectroscopy Study of the Reaction between Hematite and Aluminum Activated by Ball Milling  
 Abstract    The reaction between hematite and aluminum in presence of allumina as diluent activated by Ball Milling powder mixtures in different energetic conditions has been investigated. To this purpose, the powders at different milling times have been characterized by X-ray Diffraction and Mössbauer Spec-troscopy. A self-substained combustion reaction was observed when the strongest energetic conditions of milling were adopted. The intermediate products of the reaction also depend on the energetic condi-tions: the formation of hercynite is favoured by the use of strong energetic conditions while the forma-tion of an Fe-Al alloy was observed when a low energy per single hit is transferred to the powders. 
  Reference    Z. Naturforsch. 53a, 239—244 (1998); received February 28 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0239.pdf 
 Identifier    ZNA-1998-53a-0239 
 Volume    53 
29Author    T.Lakshmi Kasturi, V. G. KrishnanRequires cookie*
 Title    Electron Paramagnetic Resonance and DTA Investigation of Cr 3+ in Tris(guanidinium) Hexafluoroaluminate Single Crystals  
 Abstract    Electron Paramagnetic Resonance (EPR) studies of Cr 3+ in single crystals of tris(guanidinium) hexa-fluoroaluminate, [C(NH 2) 3 ] 3 A1F 6 , have been carried out in the X-band region. A temperature depen-dent study of the zero-field splitting parameter D in the range 77-398 K shows the presence of a phase transition, which is supported by Differential Thermal Analysis. In addition, 19 F superhyperfine struc-ture has been observed in the 9.3% naturally abundant 53 Cr isotope hyperfine structure. D shows a large decrease with increasing temperature. The phase transition brings about a chemical inequivalence in the two chemically equivalent but magnetically inequivalent room temperature (CrF 6) 3 " species. Compar-ison is made with the alums A1C1 3 • 6H 2 0, as well as other guanidinium aluminum salts. 
  Reference    Z. Naturforsch. 53a, 245—250 (1998); received December 16 1997 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0245.pdf 
 Identifier    ZNA-1998-53a-0245 
 Volume    53 
30Author    Sen-Yue LouRequires cookie*
 Title    Extended Painleve Expansion, Nonstandard Truncation and Special Reductions of Nonlinear Evolution Equations  
 Abstract    To study a nonlinear partial differential equation (PDE), the Painleve expansion developed by Weiss, Tabor and Carnevale (WTC) is one of the most powerful methods. In this paper, using any singular manifold, the expansion series in the usual Painleve analysis is shown to be resummable in some different ways. A simple nonstandard truncated expansion with a quite universal reduction function is used for many nonlinear integrable and nonintegrable PDEs such as the Burgers, Korteweg de-Vries (KdV), Kadomtsev-Petviashvli (KP), Caudrey-Dodd-Gibbon-Sawada-Kortera (CDGSK), Nonlinear Schrödinger (NLS), Davey-Stewartson (DS), Broer-Kaup (BK), KdV-Burgers (KdVB), A0 4 , sine-Gordon (sG) etc. 
  Reference    Z. Naturforsch. 53a, 251—258 (1998); received February 4 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0251.pdf 
 Identifier    ZNA-1998-53a-0251 
 Volume    53 
31Author    H. Uhlig, M.-J Hoffmann, P. Lamparter, S. SteebRequires cookie*
 Title    Atomic Structure of Rare Earth Si-Al-O-N Glasses  
 Abstract    In this paper the results of X-ray diffraction experiments of Ln-Si-Al-O-N (Ln = La, Gd, Yb) glasses are presented. Total structure factors and pair correlation functions allow the determination of the first coordination sphere of Ln atoms. The bond lengths observed correspond to the ionic radii of the Ln-ions surrounded by oxygen and nitrogen atoms. The presence of non-bridging nitrogen is discussed together with results of neutron diffraction, NMR-experiments and XPS-studies of other authors. 
  Reference    Z. Naturforsch. 53a, 259—26470 (1998); received March 26 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0259.pdf 
 Identifier    ZNA-1998-53a-0259 
 Volume    53 
32Author    Normann Kleiner, Sebastian Fischer, Dieter FröhlichRequires cookie*
 Title    A New Type of Chaotic Attractor  
 Abstract    An experimentally discovered inverted spiral-type chaotic attractor is reproduced by a model equation. Does there exist a simple equation for the attractor re-cently found both in an electronic and a hydrodynamical system [1]? After a first, unpublished attempt by Sven Sahle to mirror a classical spiral-type attractor using a tube put into the middle, which yielded "messy" equa-tions, a fairly simple ordinary differential equation (ODE) was found and will be presented in the following. An experimental result is reproduced in Figure 1. It Deviation Fig. 1. Experimental attractor obtained with a hydrodynami-cal system, cf. [1] 
  Reference    Z. Naturforsch. 53a, 265 (1998); received February 24 1998 
  Published    1998 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0265_n.pdf 
 Identifier    ZNA-1998-53a-0265_n 
 Volume    53 
33Author    Dmitri Ivanov, Alfred RedfieldRequires cookie*
 Title    Development of a Field Cycling NMR System for PQR Detection in Biopolymers  
 Abstract    Our goal is to extend the sensitivity of field cycling pure quadrupole resonance (PQR) methods to be of use in biological systems. The nuclei of interest are 25 Mg, 67 Zn, 43 Ca, n B and 17 0. The experiment is based on a field cycling double resonance technique, in which the quadrupole reso-nance of a rare nucleus is found through its effect on the magnetic order of the abundant nucleus to which the rare nucleus is coupled through dipole-dipole interaction. A field-cycling NMR spectrometer has been developed, based on our existing 500 MHz high resolution spectrometer. The sample can be shuttled pneumatically from the high field of a commercial 500 MHz magnet to the magnet's top, where the residual field and its gradient is canceled out by a pair of Helmholtz coils. Low field homogeneity is within 0.5 gauss. The X H signal is observed at high field as a free induction decay (FID) after a 90° pulse. At low field the sample can be irradiated by a digitally tuned RF coil in the 300 kHz-7 MHz range. The sample has to be maintained at low temperature (~30 K) to avoid relaxation via thermal motion of methyl groups in biomolecules. For this purpose field cycling equipment is placed in a variable temperature dewar (4-300 K). We plan to use solutions of biomolecules in standard cryoprotective buffer, containing ~ 30% glycerol. Preliminary results on the quadrupole resonance of natural abundance 17 0 in the cryoprotective buffer and of natural abundance n B in a protease inhibitor at 50 mM are presented. 
  Reference    Z. Naturforsch. 53a, 269—272 (1998); received October 31 1997 
  Published    1998 
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 Identifier    ZNA-1998-53a-0269 
 Volume    53 
34Author    PhilipJ. Bray, GaryL. PetersenRequires cookie*
 Title    NMR and NQR Studies of Borate Glasses  
 Abstract    Nuclear magnetic resonance (NMR) has been used for some 40 years to study atomic arrange-ments, chemical bonding, and structural groupings in borate glasses and crystalline compounds, and nuclear quadrupole resonance (NQR) has more recently increased the resolution and accuracy of the measurements. Examples are presented of the use of first-order and second-order quadrupo-lar effects in "B NMR spectra to obtain structural information, and n B and 10 B NQR spectra to obtain the quadrupolar parameters Q cc (the coupling constant) and 77 (the asymmetry parameter) with accuracies of 5 or 6 significant figures, and 3 figures, respectively. Q cc and 77 are extremely sensitive to changes in atomic rearrangements and chemical bonds, so they are excellent monitors and provide identification of bonding configurations and structural groupings in borates: Examples are also presented in which combinations of NMR and NQR data are used to extract the desired information. NQR detection of resonances at frequencies as low as 276 kHz is discussed. 
  Reference    Z. Naturforsch. 53a, 273—284 (1998); received December 30 1997 
  Published    1998 
  Keywords    NMR, NQR, Borates, Quadrupolar Interactions 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0273.pdf 
 Identifier    ZNA-1998-53a-0273 
 Volume    53 
35Author    Mariusz Maćkowiak, Piotr KątowskiRequires cookie*
 Title    2D Off-Resonance Nutation NQR Spectroscopy of Spin 3/2 Nuclei  
 Abstract    The effects of off-resonance irradiation in nutation NQR experiments are demonstrated both experimentally and theoretically. The theoretical description of the off-resonance effects in 2D nutation NQR spectroscopy is given, and general exact formulas for the asymmetry parameter are obtained. It is shown that the outcome of the off-resonance nutation experiments depends on the data acquisition procedure, leading to one-or three-line nutation spectra. To explain this fact and to describe the off-resonance nutation experiment properly, the transient response theory of a quadrupolar spin system to an RF pulse was modified using the wave-function approach. The 2D separation of interactions technique has been applied to separate a static and a randomly time-fluctuating dynamic part of the quadrupole interaction in the antiferroelectric phase of poly-crystalline ammonium dihydrogen arsenate. Two-dimensional off-resonance nutation NQR spectroscopy has been used to determine the full quadrupolar tensor of spin-3/2 nuclei in several molecular crystals containing the 35 C1 and 75 As nuclei. The off-resonance phenomena in 2D NQR are very important from the practical point of view (determination of r\ in multiple or broad-line spectrum) and also provide interesting information on the dynamic properties of a quadrupolar spin system. 
  Reference    Z. Naturforsch. 53a, 285—292 (1998); received January 26 1998 
  Published    1998 
  Keywords    Nuclear Quadrupole Resonance, 2D Nutation Spectroscopy, Off-resonance Irradiation, Electric Field Gradient Tensor 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0285.pdf 
 Identifier    ZNA-1998-53a-0285 
 Volume    53 
36Author    T. Minamisono, K. Sato, H. Akai, S. Takeda, Y. Maruyama, K. Matsuta, M. Fukuda, T. Miyake, A. Morishita, T. Izumikawa, Y. NojirrRequires cookie*
 Title    Electric Quadrupole Interactions of the Short-Lived ß-Emitter 12 N in Insulator Crystals ( 12 N Implanted in Single Crystal Ti0 2 )  
 Abstract    The electronic structure of nitrogen atoms as impurities in an ionic Ti0 2 crystal has been investigat-ed by analyzing electric field gradients (EFGs) measured by use of short-lived /3-emitting 12 N implant-ed following nuclear reactions. Conventional ß-NMR and its modification, suitable for the detection of quadrupole effects in the NMR spectra, were used for the investigation of hyperfine interactions of 12 N located in substitutional sites of O atoms and interstitial sites in the crystal. In order to deduce absolute values of the EFGs from the obtained eqQ/h, the quadrupole moment of 12 N has been determined from the NMR detection of 12 N implanted in BN(hexagonal) crystal. Here the EFG at the N atom in BN was measured by detecting the FT-NMR of l4 N in the crystal. The EFGs in Ti0 2 are compared with the theoretical predictions based on the ab initio band-structure calculation in the framework of the KKR method. 
  Reference    Z. Naturforsch. 53a, 293—300 (1998); received December 30 1997 
  Published    1998 
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 Identifier    ZNA-1998-53a-0293 
 Volume    53 
37Author    David Stephenson, JohnA S Smith, St Augustine, Tobago TrinidadRequires cookie*
 Title    Double Resonance Detection Using Zero Field Level Crossing  
 Abstract    Double resonance level crossing detection cannot normally be used to record transitions between the quadrupole Zeeman levels. Neither can it be used if the quadrupole resonance frequency is larger than the proton NMR frequency in high field. A simple variation of the level crossing experiment is demonstrated which allows energy to be efficiently transferred from quadrupole to proton system and hence lead to detection in these two cases. In the case of the quadrupole Zeeman levels it allows transitions between the ±\ levels to be detected in a small magnetic field, allowing measurement of the asymmetry parameter (r\) for spin 3/2 systems. This is demonstrated for the 1X B nucleus in triethanolamine borate. Detection of high frequency quadrupole transitions is demonstrated from which relaxation information is obtained. 
  Reference    Z. Naturforsch. 53a, 301—304 (1998); received October 31 1997 
  Published    1998 
  Keywords    NQR, Asymmetry Parameter, Relaxation, n B, 35 C1 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0301.pdf 
 Identifier    ZNA-1998-53a-0301 
 Volume    53 
38Author    M. Tanigaki, S. Takeda, K. Matsuta, Y. Matsumoto, T. Minamisono, H. Akai, K. Sato, T. Miyake, Y. Maruyama, A. Morishita, M. Fukuda, Y. NojiriRequires cookie*
 Title    NMR Detection of Oxygen Isotopes in Ti0 2 Single Crystal  
 Abstract    We studied the electric quadrupole interactions of Oxygen isotopes in a Ti0 2 single crystal. For l 3 0 and 19 0 nuclei, quadrupole coupling constants were measured by the /3-NMR technique, and for the 17 0 nucleus the FT-NMR technique was utilized. We synthesized a Ti0 2 single crystal which was enriched in 17 0 up to 5 atom % to observe NMR signals without any perturbations from impurities. Using the known quadrupole moment of l7 0, EFGs at an O site in Ti0 2 and the quadrupole moments of 13 0 and l9 0 were determined. 
  Reference    Z. Naturforsch. 53a, 305—308 (1998); received December 31 1997 
  Published    1998 
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 Identifier    ZNA-1998-53a-0305 
 Volume    53 
39Author    H. Yoshida, H. Nishihara, S. Yokota, M. Ohyanagi, T. NakaokiRequires cookie*
 Title    Field-Swept NMR Spectra of n B in Pyrex Glass and 93 Nb in NbN Perturbed by Quadrupole Interaction  
 Abstract    NMR experiments of "B by both field-swept and high-resolution NMR are reported to probe the electric field gradient at boron sites and its distribution in Pyrex glass. Both spectra are successfully interpreted with the same set of parameters. It is stressed that field-swept NMR experiments to observe total powder spectrum can be helpful to get information on electric field gradients and asymmetry pa-rameters if there exist many nonequivalent sites of atoms, since satellite transitions are affected by the larger first-order quadrupole effect. Field-swept NMR of 93 Nb in superconducting NbN powder, pre-pared by self-propagating high-temperature synthesis, is also reported. A very broad field-swept spec-trum disturbed by quadrupole interaction has been observed. The spectrum is simulated by assuming distributions in electric field gradient and Knight shift at Nb sites. It is stressed that a combination of experiments at separated frequencies is important 
  Reference    Z. Naturforsch. 53a, 309—313 (1998); received January 26 1998 
  Published    1998 
  Keywords    NMR, Pyrex, Glass, n B, NbN, Superconductor, 93 Nb 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0309.pdf 
 Identifier    ZNA-1998-53a-0309 
 Volume    53 
40Author    O. Ege, S. Nishijima, E. Kimura, H. Akiyama, S. Hamai, H. NegitaRequires cookie*
 Title    Powder Zeeman NQR Study on the Absorption Forms for Nuclear Spin 5/2  
 Abstract    For nuclei which have a nuclear spin of 5/2 and exhibit a small asymmetry parameter of the electric field gradient (77) at the nuclear site, line shapes of the Powder Zeeman NQR (PZNQR) spectra based on the transition between the energy levels m x = ± 1/2 and ± 3/2 (the lower frequency line) were stud-ied by means of computer simulations and experiments, (i) When an 77 value is very small (type 1; 77 = 0), the line shape exhibits two shoulders like the style of the American football player, (ii) While an 77 value is small (type 2; 0< 77 < around 0.01) but not zero, the line shape has two small peaks which are symmetrically located on the shoulders, as in the case of the small 77 type of spin 3/2. (iii) When an 77 value is not small (type 3; around 0.01 <77), the line shape has two symmetrical dips in stead of the peaks, which are also similar to the case of not small 77 type of spin 3/2. As the 77 value increases from around 0.01, the two dips grow and reach the maximum at the 77 value of 0.349, and then become small-er and obscure in the range of 77 larger than 0.349. __ The observations of PZNQR spectra were performed for several compounds including the ,27 I and/or 12 'Sb nuclei to estimate the 77 values, and gave the results as follows: very small for I (207.683 and 209.133 MHz, at 77 K) in Snl 4 ; very small for 127 I (176.496 and 177.438 MHz, at 77 K) in Gal 3 ; small for 127 I (265.102 MHz, at 77 K) in CH 3 I; 0.33 for 127 I (247.69 MHz, at 77 K) in C 2 H 5 I; 0.27 for 121 Sb (58.23 MHz, at 290 K) in SbCl 3 . The estimated 77 values were compared to those obtained from the fre-quencies of two NQR lines for spin 5/2. They were in good agreement with each other for the small re-gion of 77, though somewhat large disagreements were seen in the cases of not small 77 values. 
  Reference    Z. Naturforsch. 53a, 314—317 (1998); received March 24 1998 
  Published    1998 
  Keywords    NQR, Nuclear Quadrupole Resonance, Zeeman effect, Powder Zeeman NQR, Spin 5/2 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0314.pdf 
 Identifier    ZNA-1998-53a-0314 
 Volume    53 
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