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1Author    G. J. Hill, J. M. Keartland, M.J R HochRequires cookie*
 Title    Pressure Dependence of the EFG in Semimetallic Arsenic and Antimony  
 Abstract    The pressure variation of the axial EFG at the ion sites in semimetallic arsenic and antimony, at am-bient temperature, has been investigated using pulsed NQR. A weakly nonlinear decrease of the EFG is observed in both systems. The data are analyzed in terms of the lattice contribution to the EFG, which involves a lattice of point monopoles immersed in a uniform, compensating, background charge. The pressure dependence of the EFG obtained from the present measurements is far weaker than the pres-sure dependence of the calculated lattice contribution. Our results support previous suggestions that va-lence effects are important in determining the EFG in these semimetals. 
  Reference    Z. Naturforsch. 53a, 501—503 (1998); received March 24 1998 
  Published    1998 
  Keywords    EFG, NQR, Arsenic, Antimony, Pressure 
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 TEI-XML for    default:Reihe_A/53/ZNA-1998-53a-0501.pdf 
 Identifier    ZNA-1998-53a-0501 
 Volume    53 
2Author    Liuping Chen, Thomas Gross, Hans-Dietrich LüdemannRequires cookie*
 Title    The T, /7-Dependence of the Chemical Shift of the Hydroxyl Protons in Deeply Supercooled Methanol and Water  
 Abstract    The hydroxyl proton chemical shifts 6 (H-O) of supercooled methanol (7" min = 149 K) and water have been determined (7" min = 183 K), and the pressure dependence of these shifts was measured up to 200 MPa. In both compounds the downfield shift of <5 (H-O) continues down to the lowest tempera-tures reached. This result disagrees with the two state models for the hydrogen bond formation in both liquids. The isotherms ö (H 2 0) show for T< 273 K an upfield shift that becomes more pronounced with decreasing temperature. For 6 (H-O-CH^), increasingp causes at all temperatures a downshift. 
  Reference    Z. Naturforsch. 55a, 473—477 (2000); received November 11 1999 
  Published    2000 
  Keywords    NMR, Supercooling, Pressure, Methanol, Water 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0473.pdf 
 Identifier    ZNA-2000-55a-0473 
 Volume    55 
3Author    Mitsuru Matsumoto, Toshiyasu Tarumi, Isao Takahashi, Shigenobu Funahashi, Toshiaki Noda, HideoD. TakagiRequires cookie*
 Title    Pressure Dependence of the Electrode Potentials of Some Iron(III/II), Cobalt(III/II), and Ni(III/II) Couples in Aqueous Solution: Estimation of the Reaction Volumes for M(III)/M(II) Couples  
 Abstract    Pressure dependence of the electrode potentials for various M 3+/2+ couples (M = Fe, Co, and Ni with o-phenanthroline, bipyridine, terpyridine, 1,4,7-triazacyclononane, and 1,4,7-tri-thiacyclononane) was measured by cyclic voltammetry in aqueous solution vs. a Ag/AgCl reference electrode. The reaction volume of the Ag/AgCl reference electrode was estimated from the change in the partial molar volumes of Feaq3+/2+ and Co(terpyridine)23+/2+ couples, and the volumes for the formation of M 2+ from M 3+ were determined. The electrostrictive component for the change in the oxidation state for the M 3+/2+ couple was calculated on the basis of the Drude-Nernst equation and by the mean spherical approximation (MSA). The isolated volumes for the formation of M 2+ from M 3+ were compared with the values predicted by theory. 
  Reference    Z. Naturforsch. 52b, 1087—1093 (1997); received June 16 1997 
  Published    1997 
  Keywords    Pressure, Electrode Potential, Reaction Volumes 
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 TEI-XML for    default:Reihe_B/52/ZNB-1997-52b-1087.pdf 
 Identifier    ZNB-1997-52b-1087 
 Volume    52 
4Author    H.G L Coster, U. ZimmermannRequires cookie*
 Title    Transduction of Turgor Pressure by Cell Membrane Compression  
 Abstract    It is suggested that turgor pressure sensing in plant cells occurs via compression of the cell membranes; either at the plasmalemma where a pressure gradient exists, or the tonoplast due to the pressure developed inside the cell. Considerations of electro-mechanical forces in electrical breakdown of cells suggests that significant changes in the thickness of som e regions of the mem­ brane can indeed occur. It is readily envisaged how such changes in membrane thickness can be coupled to changes in active transport processes. 
  Reference    (Z. Naturforsch. 31c, 461 [1976]; received April 13 1976) 
  Published    1976 
  Keywords    Turgor, Membrane, Pressure, Compression, Osmoregulation 
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 TEI-XML for    default:Reihe_C/31/ZNC-1976-31c-0461.pdf 
 Identifier    ZNC-1976-31c-0461 
 Volume    31 
5Author    S. Itoh, M. Konagai, K. TakahashiRequires cookie*
 Abstract    The structural and dynamic properties of molten lithium iodide are investigated at two pressures (334 MPa at 784 K and 1054 MPa at 915 K), using molecular dynamics simulations with Born-Mayer-Huggins type pair potentials. On increasing the pressure, the local packing of the ions changes from tetrahedral to octahedral, the self-exchange velocity in the coordination shells decreases by a factor of 0.031, Du by a factor of 0.033 and D, by a factor of 0.021. M o le c u la r D y n a m ic s S tu d y o f M o lte n L ith iu m Io d id e 
  Reference    Z. Naturforsch. 46a, 155 (1991); received February 15 1990 
  Published    1991 
  Keywords    Molecular dynamics, Liquid structure, Lil, Lithium iodide, Pressure 
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 TEI-XML for    default:Reihe_A/46/ZNA-1991-46a-0155.pdf 
 Identifier    ZNA-1991-46a-0155 
 Volume    46 
6Author    Rainer KimmichRequires cookie*
 Title    Multidimensional NQR: Imaging and Exchange Spectroscopy  
 Abstract    In this context a "dimension" can be of a spatial or of a spectroscopic nature. In the last two decades, multidimensional nuclear magnetic resonance and imaging have proven to be most useful tools for the investigation of materials. It turned out that some of these measuring principles can be applied to zero-field NQR as well. The purpose of this presentation is to elucidate two-dimensional exchange spectroscopy and imaging procedures suitable for NQR and to outline potential applications. 
  Reference    Z. Naturforsch. 51a, 330—336 (1996); received January 22 1996 
  Published    1996 
  Keywords    NQR, imaging, 2D exchange spectroscopy, pressure, temperature 
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 TEI-XML for    default:Reihe_A/51/ZNA-1996-51a-0330.pdf 
 Identifier    ZNA-1996-51a-0330 
 Volume    51 
7Author    Liuping Chen, Hans-Dietrich LüdemannRequires cookie*
 Title    Influence of Conformational Equilibria upon the Self-Diffusion of the Conformers in Neat Liquids  
 Abstract    The self-diffusion coefficients D of the isomers of liquid N-isopropyl-N-methylacetamide (IPMAA) and acetylacetone (AC AC) are studied as functions of temperature. For AC AC also pressure dependent studies were undertaken. In IPMAA the eis and trans conformers have almost identical D. In liquid ACAC, D Kclo is always smaller than D cnol , this difference being 15% around 300 K. 
  Reference    Z. Naturforsch. 55a, 605—608 (2000); received April 19 2000 
  Published    2000 
  Keywords    Conformers, Self Diffusion, Neat Liquids, Pressure 
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 TEI-XML for    default:Reihe_A/55/ZNA-2000-55a-0605.pdf 
 Identifier    ZNA-2000-55a-0605 
 Volume    55 
8Author    SeymourSteven Brody, Lisbeth StelzigRequires cookie*
 Title    Effect of Pressure on the Absorption Spectra of Phycobiliprotein and Porphyridium cruentum  
 Abstract    Changes in the absorption spectra o f P. cruentum and phycobiliprotein are observed as a function o f hydrostatic pressure. With phycobiliprotein both in solution and in algae, increasing hydrostatic pressure results in bathochrom ic shifts o f the absorption m axim a. In addition, there is a splitting o f the absorption band o f phycoerythrin. When P. cruentum is subjected to 250 bars there are increases in absorption by chlorophyll (at 700 and 698 nm), phycocyanin (at 640 nm) and phycoerythrin (at 580 and 550 nm). W hen a cell free solution o f phycobiliprotein is subjected to 300 bars there are increases in absorption by phycoerythrin (at 570 and 550 nm) and phycocyanin (at 634 nm). 
  Reference    Z. Naturforsch. 38c, 458—460 (1983); received January 21 1983 
  Published    1983 
  Keywords    Pressure, Phycobiliprotein, Algae, Pressure Induced Change in Absorption Spectra 
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 TEI-XML for    default:Reihe_C/38/ZNC-1983-38c-0458.pdf 
 Identifier    ZNC-1983-38c-0458 
 Volume    38