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1984[X]
21Author    R. Rünger, D. PloumbidisRequires cookie*
 Title      
 Abstract    Measurements of both the 5IV and 195Pt Knight shift in the V3Pt compound are reported for temperatures ranging from 300 K to about 1300 K. The temperature coefficients of the Knight shift and the NMR linewidth have been determined. An interpretation of the observations is given in the frame of a model which is based on the temperature dependence of the core polar­ ization contribution to the total Knight shift. 
  Reference    Z. Naturforsch. 39a, 145—147 (1984); received December 11983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0145.pdf 
 Identifier    ZNA-1984-39a-0145 
 Volume    39 
22Author    V. Hinkel, D. PloumbidisRequires cookie*
 Title     
 Abstract    u c le a r M a g n e tic R e s o n a n c e S tu d ie s o f L iq u id S e m ic o n d u c tin g S b -T e A llo y s Nuclear magnetic resonance studies of ,23Sb and 121Sb in the Sb^Te^,. liquid alloy system are described. Interest is focussed on the concentration dependence of the Knight shift and the NMR linewidth. Measurements of the Knight shift and linewidth have been carried out over the entire concentration range at elevated temperatures (900-1100) K. Knight shifts of ,23Sb and 12lSb, measured to high precision, show hyperfine structure anomaly. Both. Knight shift and linewidth show strong dependence on the alloy concentration and extreme behavior at the concentrations 40 at.% Sb and 50 at.% Sb. respectively. The experimental results are discussed in terms of modes concerning the electronic structure of liquid semiconductors. 
  Reference    Z. Naturforsch. 39a, 148—151 (1984); received November 28. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0148.pdf 
 Identifier    ZNA-1984-39a-0148 
 Volume    39 
23Author    Ivan GutmanRequires cookie*
 Title    Topological Studies on H eteroconjugated M olecules. A New Pairing Theorem  
 Abstract    It is shown that the pairing property of Hückel molecular orbital energy levels holds also in the case of certain conjugated molecules containing heteroatoms. 
  Reference    Z. Naturforsch. 39a, 152—154 (1984); received December 6. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0152.pdf 
 Identifier    ZNA-1984-39a-0152 
 Volume    39 
24Author    MartinaHans Betzel, Petra Bürger, SchulzRequires cookie*
 Title     
 Abstract    ib ra tio n a l S p e c tr a a n d F o r c e C o n s t a n t s o f S y m m e tr ic T o p s , X X X v n |11. H ig h R e s o lu tio n I n f r a r e d I n v e s t ig a t io n o f U n s ta b le H 3S n C l in th e v , / v 4 R e g io n N e a r 1 9 0 0 c m " 1 The infrared spectra in the v,/v4 region near 1900 cm-1 of natural H3SnCl and monoisotopic H3ll6Sn35Cl have been recorded with a resolution of 0.04 cm-1. Isotopic and rotational fine structure has been resolved, and a rotational analysis based on 472 lines, o(J, K) — 4.3x 10_3cm_1, has been performed, v, and v4 (v0 = 1917.1932(7) and 1924.6790(4) cm-1 respectively in H3116Sn35Cl) interact weakly by Coriolis .y, y resonance, Ci,4 ~ 0.019. No further perturbations of v, and v4 were observed. The tin isotopic shift of v4 is significant, Av4 relative to ll6Sn being -0.170(6) and -0.326(6) cm-1 respectively for ll8Sn and l20Sn. The hot band (v3 + v4) -v3 has been observed, = + 0.423(5) cm"1. 
  Reference    Z. Naturforsch. 39a, 155—161 (1984); received November 2 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0155.pdf 
 Identifier    ZNA-1984-39a-0155 
 Volume    39 
25Author    F. Lantelme, P. TurqRequires cookie*
 Title     
 Abstract    tu d y by N u m e ric a l S im u la tio n o f th e S t r u c t u r a l a n d D y n a m ic a l P r o p e rtie s o f th e F u s e d L iC l-K C l E u te c tic The ionic properties of the eutectic LiCl-KCl melt are examined in a large range of tempera­ ture and density. The radial distribution functions are calculated. It is shown that, although the contribution of the Coulomb energy to the thermodynamic properties decreases at high tempera­ tures it remains always predominant and explains the temperature dependence of the specific heat at constant volume. The diffusion coefficients of Li+, K+ and CF are determined. The mechanism of the ionic motion is studied through the memory function formalism. Two types of motion are detected, which arise from binary collisions and from dynamical events which involve a large number of ions. Temperature and volume changes show that the lithium ions remain always surrounded by a more structured atmosphere which hinders their motion. This effect becomes more apparent at high temperature and low density. 
  Reference    Z. Naturforsch. 39a, 162—168 (1984); received November 12. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0162.pdf 
 Identifier    ZNA-1984-39a-0162 
 Volume    39 
26Author    N., O. H., C. I. Minh, Tho NguyenRequires cookie*
 Title     
 Abstract    b I n itio C a lc u la tio n s o f th e M o le c u la r S t r u c t u r e s a n d th e E le c tro n ic P r o p e r tie s o f P h o s p h a -A lk y n e s R -C = P (R = H , A/O Calculations. Molecular Structures, Electronic Properties, Phospha-Alkynes Results of ab initio SCF calculations on phospha-alkynes R -C = P with R = H. CH3, NH2, OH. F and CI are reported. The geometries were optimized by the force method with analytical gradient employing double zeta (DZ) basis sets. Various molecular and one-electron properties are calculated with double zeta plus polarization functions (DZ + P) and compared with experi­ mental ones. The effect of substituents is analysed in terms of computed properties. 
  Reference    Z. Naturforsch. 39a, 169—174 (1984); received May 20. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0169.pdf 
 Identifier    ZNA-1984-39a-0169 
 Volume    39 
27Author    Tae-Kyu Ha, MinhTho NguyenRequires cookie*
 Title     
 Abstract    b in itio C I S tu d y o f th e G r o u n d a n d E x c ite d S t a t e s o f C u F 2 a n d C u C l? Ab initio configuration interaction (CI) calculations of the ground, electronically excited and the ionized states (cations) are reported for CuF2 and CuCl2. The calculated results are compared with available experimental values of the UV spectrum of CuCL and the ionization potentials obtained from the photoelectron spectrum of CuF2. 
  Reference    Z. Naturforsch. 39a, 175—178 (1984); received December 13 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0175.pdf 
 Identifier    ZNA-1984-39a-0175 
 Volume    39 
28Author    G. Pálinkás, P. Bopp, G. Jancsó, K. HeinzingerRequires cookie*
 Title      
 Abstract    The results of molecular dynamics simulations of low and high pressure liquid water using a modified central force potential have been analyzed in order to study the effect of pressure on the hydrogen bond structure of water. The properties investigated and discussed include the hydrogen bond angle distribution, the O — O distance distribution between the neighbour molecules, the structure of the first coordination sphere in the high density liquid and the average number of hydrogen bonds. 
  Reference    Z. Naturforsch. 39a, 179—185 (1984); received December 16 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0179.pdf 
 Identifier    ZNA-1984-39a-0179 
 Volume    39 
29Author    Takaya Iida, Kaname ItoRequires cookie*
 Title     
 Abstract    o m e C o n s id e r a tio n s o n th e R o le o f W a te r in T h in L a y e r C h r o m a to g r a p h y o f I n o r g a n ic A n io n s The volume ratios of the mobile and stationary phases in thin layer chromatography, and the partition coefficients of halide and halate anions and some other anions between these phases were obtained by developing the ions simultaneously with a series of metaphosphates. The water contents of the developing solvents influenced the volume ratios very much, but not so much the partition coefficients. The logarithm of the partition coefficient of the halide anions is pro­ portional to the reciprocal of their ionic radius, and that of the halate anions and oxoanions to the partial charge on the oxygens of them. 
  Reference    Z. Naturforsch. 39a, 186—189 (1984); received November 22. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0186.pdf 
 Identifier    ZNA-1984-39a-0186 
 Volume    39 
30Author    Claus Wibbelmann, Wolfgang Brockner, Brigitte Eisenmann, Herbert SchäferRequires cookie*
 Title     
 Abstract    r is ta lls tr u k tu r u n d S c h w in g u n g s s p e k tr u m d es P r a s e o d y m -o r th o -T h io p h o s p h a te s P r P S 4* Crystal Structure and Vibrational Spectrum of PrPS4 PrPS4 crystallizes in the tetragonal system, space group I4|/acd with the lattice constants u= 1091.4(5) pm. c = 1936.1(8) pm. In the structure there are slightly distorted PS^_ tetrahedra as discrete structural units, placed along the 6-axis. Far infrared, infrared and Raman spectra of this compound have been recorded. The observed frequencies are assigned rangewise by factor group analysis and the Td-D 4h-correlation. The Raman data of rare-earth ortho thiophosphates LnPS4 with Ln = La. Ce. Pr. Nd. Sm. Tb and Tm are given in a line diagram. 
  Reference    Z. Naturforsch. 39a, 190—194 (1984); eingegangen am 26. November 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0190.pdf 
 Identifier    ZNA-1984-39a-0190 
 Volume    39 
31Author    J. Biedrzycki, J.Błażejowski, J. Szychliński, A. LedòchowskiRequires cookie*
 Title     
 Abstract    h o to c h e m is try o f N itr a c r in e a n d its A n a lo g u e s : A c rid in e D e riv a tiv e s a s E le c tro n D o n o r s Studies on the electron transfer in the excited state from electron donors: acridine, 9-aminoacridine and its derivatives, including nitracrine and its isomers, to CC14 as a suitable electron acceptor, were undertaken. UV radiation (/. = 366 nm), absorbed only by acridine bases, generates CI" ions. The fluorescence quenching measurements indicate that no interaction appears between molecules of acridine bases in the excited singlet state and CC14 molecule. A scheme of photochemical processes is proposed which assumes that the triplet state of the base molecule is the reactive one. 
  Reference    Z. Naturforsch. 39a, 195—200 (1984); received July 30. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0195.pdf 
 Identifier    ZNA-1984-39a-0195 
 Volume    39 
32Author    R. Rünger, D. PloumbidisRequires cookie*
 Title    Knight Shift in the V3Ga Compound at High Temperatures  
 Abstract    The temperature dependence of the Knight shift of both ?IV and 7lGa in the V3Ga compound has been measured over the entire range from 300 K to 1300 K. The results are discussed using a model based on the assumption that the core polarization contribution to the total Knight shift is the temperature dependent term. 
  Reference    Z. Naturforsch. 39a, 201—202 (1984); received November 21 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0201_n.pdf 
 Identifier    ZNA-1984-39a-0201_n 
 Volume    39 
33Author    I. Senel, D. PloumbidisRequires cookie*
 Title    Nuclear Magnetic Resonance Investigations in Liquid In-Ni Alloys  
 Abstract    Measurements of the ll5In Knight shift and the NMR linewidth in liquid In-Ni have been carried out over the concentration range (0—50) at.% Ni at high temperatures. With changes of the Ni concentration important changes occur in the hyperfine interactions referring to 115In. The experimental results for higher Ni concentrations are in good agreement with a model involving a significant d-d exchange interaction. 
  Reference    Z. Naturforsch. 39a, 203—204 (1984); received November 23. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0203_n.pdf 
 Identifier    ZNA-1984-39a-0203_n 
 Volume    39 
34Author    Fritz BoppRequires cookie*
 Title     
 Abstract    u a n te n p h y s ik a lis c h e r Z u s t a n d s r a u m im K o n tin u u m Quantum physical state space in continua As previously shown, quantum physics for single pairs of creation and annihilation processes may be derived from first principles. Quantum physics at all can be therefore considered as an interplay of such elementary processes. This is easily possible if the number of pairs of processes is finite. Difficulties arise only for infinite numbers. The difficulties are similar to those occurring in the derivation of the equation for an oscillating string from that for an oscillator chain. It is true that the spectra of both systems are not continuously connected. However, a weaker theorem is more important: The chain eigen­ value of each order converges to the string one of the same order for an infinitely growing number of oscillators of a certain kind. Therefore both systems are continuously connected in the sense of semiconvergency. Exhausting the space continuum with a sequence of lattices equably becomming infinitely large and fine, the infinitely dimensional Hilbertspace is steadily connected with the finitely dimensional one in the sense of semiconvergency. It will be shown that the Hilbert spaces in the sequence of lattices yield the suitable tool for quantum physics as an interplay in the mentioned sense. This kind of Hilbert space, the so-called rational one, must be preferred in physics rather than the real one introduced by Hilbert, since all theories in physics are based on a finite number of data. In particular, we formulate Dirac's equation in the rational Hilbert space. It is shown that, even in quantum physics, a theorem of classical physics remains true, according to which relativity results from certain principles formulating most obvious experiences. We obtain the Lorentz invariant Dirac equation mainly from a modification of Newtons definition II according to which p = Hv/c2 (instead of p = m v). 
  Reference    Z. Naturforsch. 39a, 205—217 (1984); received November 2 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0205.pdf 
 Identifier    ZNA-1984-39a-0205 
 Volume    39 
35Author    St Limmer, M. FindeisenRequires cookie*
 Title     
 Abstract    r o to n N M R S tu d ie s a n d L in e s h a p e S im u l a ti o n s o f th e M e s o p h a s e s o f T e r e p h th a ly lid e n e -B is -4 -n -p r o p y la n ilin e (T B P R A) — E v id e n c e f o r C o n f o r m a t io n a l C h a n g e s From comparison of simulated and experimental spectra in the nematic, smectic-A, and smectic-C phases of TBPrA it can be concluded that there are conformational changes of the molecule giving obviously rise to a continuous variation of the direction of the long molecular axis with respect to a frame of reference connected with a conformation of the molecule that was derived from the crystal conformation of TBBA. 
  Reference    Z. Naturforsch. 39a, 218—222 (1984); received December 3 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0218.pdf 
 Identifier    ZNA-1984-39a-0218 
 Volume    39 
36Author    MichaelC. BöhmRequires cookie*
 Title     
 Abstract    o d e l C a lc u la tio n s o n O n e -D im e n s io n a l (I D) P o ly -D e c k e r S a n d w ic h C o m p o u n d s . A C r y s ta l O r b i t a l I n v e s tig a tio n B ased o n th e T ig h t-B in d in g F o r m a lis m The band structures of 11 one-dimensional (ID) poly-decker sandwich compounds with dif­ ferent transition metal centers M (M = Mn, Fe, Co, Ni, Cu, Zn) and a variety of fivemembered n ligands L from the cyclopentadienyl moiety (C5H5) to the pure boron ring B5H5 have been studied by means of a semiempirical crystal orbital procedure based on the INDO approxima­ tion in order to allow a priori predictions on possible semiconducting or conducting low-dimen­ sional materials composed by ML fragments. To determine the (numerically) different self-energy corrections (i.e. long-range and short-range "correlations") in the transition metal 3d spines and the ligand backbones approximate quasi-particle shifts have been employed for the correction of the Hartree-Fock (HF) band energies. The band structure properties (e.g., dispersion curves, density of states distributions, effective mass parameters, propagation times of charge carriers) are discussed in the light of the semiempirical tight-binding approach. It is shown that the forbidden band gaps are reduced with an increasing number of B atoms in the n ligands. The gap in the Mn(C5H5) stack amounts to 8.27 eV, while overlapping dispersion curves are predicted in the Zn(B5H5) derivative. This model polymer is the only intrinsic conductor in the series of the studied ID metallocenes; all other compounds require injected charge carriers (electrons or holes) in order to achieve partially filled bands. Injected holes in the Mn or Fe backbones lead to ID materials with conducting 3d spines; the charge transfer in this regime is best described as some type of hopping motion. The remaining poly-decker strands belong to the class of organic metals (injected carriers) with conductive pathways that are formed by diffuse ligand states leading to transfer processes that can be rationalized in terms of a band picture. The rotational profiles and the magnitudes of intracell and intercell interactions are also studied. The band structure properties (band gaps, characters of the valence and conduction bands) depend critically on the mutual orientations between neighbouring unit cells in the case of ligands with low spatial symmetries. General rules and strategies for synthetic approaches to organometallic ID materials containing 3d centers with small or vanishing band gaps are formulated. 
  Reference    Z. Naturforsch. 39a, 223—246 (1984); received December 2 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0223.pdf 
 Identifier    ZNA-1984-39a-0223 
 Volume    39 
37Author    F. Van Der Graaf, J.A A KetelaarRequires cookie*
 Title     
 Abstract    iffu sio n M e a s u r e m e n ts w ith th e G r a v im e tr ic M e th o d in S o l u ti o n s a n d in M o lte n A lk a li N i t r a t e s The gravimetric method of interdiffusion measurement from a quartz frit is developped into an accurate general method. It is applied to a number of electrolyte solutions; for iodides and bromides a correction for the adsorption is applied. For the molten alkali nitrate systems (K-Cs)N03 at the molar fractions .xCs = 0.0 and -vCs = 0.1, (Na-Cs)N03 at .yCs = 0.0 and a-C s = 0.1. (Na-Rb)NO, at -yrb = 0.0 and .vRb = 0.1 and (Na-K)N03 at ,vna = 0.0, .vNa = 0.3 and .\'Na = 1.0 the interdiffusion coefficient is determined over the temperature range of 600-723 K. The values obtained here are discussed in comparison to those from literature. 
  Reference    Z. Naturforsch. 39a, 247—253 (1984); received December 23 1982 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0247.pdf 
 Identifier    ZNA-1984-39a-0247 
 Volume    39 
38Author    Z. NaturforschRequires cookie*
 Title      
 Abstract    A static magnetic field parallel to the direction of propagation of an incident light beam causes a small shift in the value of the refractive index and, correspondingly, of the absorption coeffi­ cient of a chiral molecule. This shift is opposite for enantiomers. However, it occurs for arbitrari­ ly polarized light and is therefore not a circular differential effect. T h e In flu e n c e o f a S t a ti c M a g n e tic F ie ld o n t h e O p t i c a l P ro p e rtie s o f C h ir a l M o le c u le s 
  Reference    Z. Naturforsch. 39a, 254—261 (1984); received October 19 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0254.pdf 
 Identifier    ZNA-1984-39a-0254 
 Volume    39 
39Author    Jan Jurga, Przemysfaw Hruszka, Bozena Hilczer, Jan KułRequires cookie*
 Title     
 Abstract    ig h T e m p e r a tu r e S tu d y o f M o le c u l a r M o ti o n in P o ly p h e n y le n e S u lfid e by T h e r m a lly S tim u la te d C u r r e n ts Thermally stimulated currents (TSC) in polyphenylene sulfide were measured in unpolarized and polarized samples. The TSC thermograms show a rapid increase in current at about 200 °C with an activation energy of about 1.6 eV. Additionally, in polarized samples a peak at about 150 °C related with the reorientational motions of the chain was found. 
  Reference    Z. Naturforsch. 39a, 262—266 (1984); received October 13. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0262.pdf 
 Identifier    ZNA-1984-39a-0262 
 Volume    39 
40Author    O. S. Tu D, Mirjana Eckert-MaksićRequires cookie*
 Title     
 Abstract    r o to n a tio n o f 4 H -P y r a n ^ l -o n e a n d i ts S u lf u r A n a lo g u e s . The molecular and electronic structure of 4H-pyran-4-one and its mono-and disubstituted sulfur analogues (1-4) are studied by the MNDO method. The salient structural features are qualitatively reproduced and the trend of changes of geometric parameters is in good agreement with experiment. The charge distributions exhibit strong polarization due to the large 7r-electron drift toward the exo-heteroatom. The protonated conjugated acids are considered too. It is found that exo-heteroatom protonation is favoured by 60-80 kcal/mol over the attachment of the proton to the intraring heteroatom. This is in accordance with experimental evidence. It is rationalized by the higher electron density centered on the exo-heteroatom and the appreciable increase in aromatic cyclic conjugation taking place upon the exo-protonation. 
  Reference    Z. Naturforsch. 39a, 267—275 (1984); received November 11 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0267.pdf 
 Identifier    ZNA-1984-39a-0267 
 Volume    39 
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