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1989 (196)
181Author    B. P. Koch, B. BruhnRequires cookie*
 Title      
 Abstract    The spinning motion of aspherical satellites whose center of mass moves in a given elliptic polar orbit around an oblate central body is investigated using analytical and numerical methods. In the case of a magnetic satellite, dipole-dipole interaction with the central body is included. For small eccentricity, oblateness and magnetic interaction, the Melnikov method is used to study chaotic and perodic motions. The parameter dependence of the width of the chaotic layer and of the periodic resonances is discussed. For some selected parameter values the theoretical predictions are checked by numerical methods. C h a o tic a n d P e r io d ic M o tio n s o f S a te llite s in E llip tic O r b its 
  Reference    Z. Naturforsch. 44a, 1155 (1989); received August 2 1989 
  Published    1989 
  Keywords    Satellite motion, subharmonics, homoclinic points, Melnikov method, chaos 
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 TEI-XML for    default:Reihe_A/44/ZNA-1989-44a-1155.pdf 
 Identifier    ZNA-1989-44a-1155 
 Volume    44 
182Author    *. A. Kawski, A. Kubicki, J. CzajkoRequires cookie*
 Title     
 Abstract    h e E ffe c t o f S u b s titu e n ts o n th e P o la r ity in th e F ir s t E x c ite d S in g le t S t a te o f S o m e tr a n s -S ty r y l-M e th y l-S u lf o n e s The effect of substituents R (R = N(CH3)2, OCH3, CH3, H, CI, Br, CN) on the polarity of trans-styryl-methyl-sulfones in the first excited singlet state is investigated. Linear relations are found between the dipole moment in the excited state, /ie, and the Hammett constant, a* , and also between /ze and the dipole moment in the ground state, ;zg. On increasing the electron-donor power of R, l-ie grows faster than 
  Reference    Z. Naturforsch. 44a, 1163 (1989); received August 8 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1163 
 Volume    44 
183Author    G. Chiodelli, G. Campari-Viganò, G. FlorRequires cookie*
 Title    Y B a 2C  
 Abstract    u 30 7 _ x : T r a n s p o r t P r o p e r tie s an d D e fe c ts a t H ig h T e m p e r a tu r e Electrical resistivity measurements were carried out on polycrystalline YBa2Cu,07_ v at temper­ atures 300 < T < 1023 K and oxygen partial pressures 5 ■ 10"7 < p0l < 1 atm. The samples, equili­ brated in the range from 5 10~4 to 1 atm, show metallic behaviour, the one equilibrated at p0, = 2 • 10"5 shows a transition between metallic and semiconducting behaviour at 920 K, and that equilibrated at p0i — 5-10" shows semiconducting behaviour: for the latter the relevant resistivity is due to the oxygen-ion migration. The isotherms log a vs. log (in the temperature range from 723 to 1023 K) show slopes of about 1/6 at 723 K (orthorhombic phase) and about 1/2 at 1023 K (tetragonal phase). These results are discussed in terms of appropriate defect models. 
  Reference    Z. Naturforsch. 44a, 1167—1171 (1989); received September 28 1989 
  Published    1989 
  Keywords    Superconductors, electrical properties, defects 
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 TEI-XML for    default:Reihe_A/44/ZNA-1989-44a-1167.pdf 
 Identifier    ZNA-1989-44a-1167 
 Volume    44 
184Author    Karl Hensen, Michael DräbingRequires cookie*
 Title    E in e  
 Abstract    A u s w e rtm e th o d e fü r D S C -K u rv e n b in ä r e r G e m isc h e sow ie d ie P h a s e n d ia g r a m m e e in ig e r M e th y lc h lo r s ila n e m it L u tid in A New Evaluation of DSC-curves of Binary Mixtures and the Phase Diagrams of Some Methylchlorosilanes with Lutidine A new evaluation of DSC-curvcs of binary mixtures is given. By analyzing the phase diagrams of methyltrichlorosilane and dimethyldichlorosilane with some lutidines the existence of the incongruently melting addition compounds MeSiCl3-(2.3-Lutidine2 ■ 3.4-Lutidine* Me2SiCl2 • (3.5-Lutidine)2, Me2SiCl2 • 3.5-Lutidine, and the congruently melting compound MeSiCl3-(3.4-Lutidine)2 was proven. 
  Reference    Z. Naturforsch. 44a, 1172—1176 (1989); received September 18 1989 
  Published    1989 
  Keywords    DSC-Curves Melting Point, Phase Diagrams, Addition Compounds, Methylchlorosi­ lanes, Lutidine 
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 TEI-XML for    default:Reihe_A/44/ZNA-1989-44a-1172.pdf 
 Identifier    ZNA-1989-44a-1172 
 Volume    44 
185Author    Martin Körfer, Raymond Kind, Hartmut Fuess, Fachgebiet StrukturforschungRequires cookie*
 Title      
 Abstract    Deuteron magnetic resonance (DMR) spectroscopic was performed on a single crystal of CD3NH3HgCl3. The electric field gradient tensors of the independent CD3NH3 -groups were determined by quadrupole perturbed NMR. NMR-NQR-rotation patterns were recorded in the ferro-(T = 295 K) and paraelectric (F = 342 K) phases. In the ferroelectric phase a precessional motion of the CD3NH3-group was detected. The angle y(T) between the axis of the molcculc and the precession-axis increases with temperature. In the paraelectric phase the precession of methyl­ ammonium is superimposed by an anisotropic 90 -flipping motion. The flipping planes are parallel to the polar axis. 
  Reference    Z. Naturforsch. 44a, 1177—1182 (1989); received September 23 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1177 
 Volume    44 
186Author    W.-I Jung, O. LutzRequires cookie*
 Title     
 Abstract    o u b le S p in E ch o V olum e S e le c tiv e N M R S p e c tro s c o p y w ith a 1.5 T W h o le B o d y I m a g e r For volume selective nuclear magnetic resonance spectroscopy with protons a modified version of the double spin echo method has been implemented on a 1.5 T whole body imager. The high performance of the localization sequence has been verified with phantoms and tissue. A spectral resolution of about 2 • 10"8 was obtained. The volume elements are well shaped and positioned, the minimal size was 2.2 cm3. Spectra of porcine leg muscle tissue with different echo times are presented. 
  Reference    Z. Naturforsch. 44a, 1183—1186 (1989); received October 12 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1183 
 Volume    44 
187Author    M.C L Gerry, S. J. Howard, N. Heineking, H. DreizlerRequires cookie*
 Title      
 Abstract    The microwave spectrum of HNC1 O is reported for the first time. The measurements were made with both Stark modulated and microwave Fourier transform spectrometers. The 170 and 14N quadrupole hyperfine structure has been resolved and rotational, centrifugal distortion and 170 and 14N quadrupole coupling constants have been evaluated. The 1 O coupling constants are compared with those from an ab initio prediction. T h e M ic ro w a v e S p e c tru m a n d N u c le a r Q u a d r u p o le C o u p lin g C o n s ta n ts o f H N C 170 
  Reference    Z. Naturforsch. 44a, 1187—1190 (1989); received September 29. 1989 
  Published    1989 
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 TEI-XML for    default:Reihe_A/44/ZNA-1989-44a-1187.pdf 
 Identifier    ZNA-1989-44a-1187 
 Volume    44 
188Author    Kirsten Vormann, Helmut DreizlerRequires cookie*
 Title      
 Abstract    The n B quadrupole hyperfine structure in the rotational spectra of three isotopic species of hydroxydifluoroborane, BF2OH, BF2OD, and BF,18OH has been investigated and the quadrupole coupling constants of these species have been determined. Using the variation of the 11B quadrupole coupling constants with isotopic substitution, it has been possible to evaluate the complete quadru­ pole coupling tensor, including the off-diagonal element yah, for each isotopic species. 11 B o ro n Q u a d r u p o le H y p e r fin e S t r u c t u r e in th e R o ta tio n a l S p e c tr u m o f H y d r o x y d iflu o ro b o r a n e 
  Reference    Z. Naturforsch. 44a, 1191—1195 (1989); received October 12 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1191 
 Volume    44 
189Author    N. Heineking, H. Dreizler, K. Endo, Y. KamuraRequires cookie*
 Title     
 Abstract    ig h R e s o lu tio n M ic ro w a v e S p e c tr a o f P y r id in e -N -o x id e a n d a -P ic o lin e -N -o x id e The rotational spectra of pyridine-N-oxide and x-picoline-N-oxide (= 2-methvlpyridine-N-oxide) have been observed by means of pulsed microwave spectroscopy. For both molecules, the 14N quadrupole coupling constants have been obtained. For x-picoline-N-oxide. in addition the parame­ ters of the internal rotation motion and the centrifugal distortion constants have been determined. 
  Reference    Z. Naturforsch. 44a, 1196 (1989); received October 12 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1196 
 Volume    44 
190Author    A. Utz, Brunsch, S. P. Lamparter, SteebRequires cookie*
 Title     
 Abstract    We present structural investigations using the energy dispersive X-ray diffraction (EDXD)-method on amorphous Fe-Tb-and Fe-Co-Tb-alloys over an extended concentration range. Atomic-distances. partial coordination numbers, and chemical short range order parameters are reported. The short range order is characterized by a compound forming tendency. In an amorphous Fe-Co-Tb-alloy, doping with hydrogen affects the short range order and gives rise to an in-plane magne­ tization direction. A to m ic S tr u c tu r e o f A m o rp h o u s F e -T b -a n d A m o rp h o u s F e -C o -T b -A llo y s by M e a n s o f E D X D 
  Reference    Z. Naturforsch. 44a, 1201 (1989); received September 23 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1201 
 Volume    44 
191Author    H.-D Has, LüdemannRequires cookie*
 Title     
 Abstract    Self diffusion coefficients of CF3Br and CF3C1 are given for the temperature range 140 430 K at pressures up to 200 MPa. The are analysed by the interacting sphere model. S e lf D iffu sio n in C o m p re s s e d F lu id C F 3B r a n d C F 3C1 
  Reference    Z. Naturforsch. 44a, 1210—1214 (1989); received September 5 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1210 
 Volume    44 
192Author    H. Bader, O. Krätzschmar, H. L. Selzle, E. W. SchlagRequires cookie*
 Title    Io  
 Abstract    n D ip S p e c tru m o f th e F lu o ro b e n z e n e -A rg o n v a n d e r W a a ls C o m p le x in a S u p e rs o n ic J e t The ion dip spectrum of the fluorobenzene-Argon van der Waals complex has been measured and the complex shift in the ground state is determined. The observed dips then could be assigned by comparison with the ion dip spectra and hotband spectra of the fluorobenzene molecule. 
  Reference    Z. Naturforsch. 44a, 1215—1218 (1989); received November 13 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1215 
 Volume    44 
193Author    K. Weinkauf, C. Walter, U. Weickhardt, E. W. Boesl, SchlagRequires cookie*
 Title     
 Abstract    We present a new laser tandem mass spectrometry technique in a reflectron time of flight (TOF) instrument. A first pulsed laser performs the multiphoton ionization and the primary photodissoci-ation. A newly designed ion source permits a high mass resolution in the space focus of the 12 cm long first linear TOF, where then the secondary excitation can take place. For high resolution applications the pure secondary or pure metastable mass spectrum of a preselected precursor ion can be recorded using a new reflectron scanning technique. It is also possible to obtain the whole secondary mass spectrum with one cycle using a new postacceleration method. Several techniques for ejection of interfering ions are shown. The features of our techniques are demonstrated at various primary fragments of benzene. Key words: Mass spectrometry, Time of flight instruments, Laser excitation, Photodissociation. Multiphoton processes. L a s e r T a n d e m M a s s S p e c tr o m e try in a T im e o f F lig h t I n s tr u m e n t 
  Reference    Z. Naturforsch. 44a, 1219 (1989); received October 21 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1219 
 Volume    44 
194Author    Atsushi Ishikawa, Tetsuo Asaji, Daiyu NakamuraRequires cookie*
 Title     
 Abstract    tu d ie s o n M o le c u la r M o tio n s a n d P h a s e T ra n s itio n in P y rid in iu m T e tr a c h lo r o io d a te (I I I) C r y s ta ls by th e M e a s u r e m e n ts o f th e T e m p e r a tu r e D e p e n d e n c e s o f C h lo rin e N u c le a r Q u a d r u p o le . R e s o n a n c e F re q u e n c ie s a n d R e la x a tio n T im e s To elucidate the phase transition of pyridinium tetrachloroiodate(III) at Tc = 217 K, the temper­ ature dependences of the chlorine NQR frequencies and corresponding NQR spin-lattice and spin-spin relaxation times (T1Q and T2Q) have been measured in the range 77-370 K. Above ca. 370 K and between 206 and 223 K no chlorine NQR frequency could be observed, the chlorine relaxation times becoming extremely short (ca. 100 ps). Except for near Tc, the T10 values below ca. 310 K can be explained by fluctuations of the electric field gradient at the chlorine nuclei due to in-plane reorientations of the cations about their pseudohexad axis. The increase of T,q1 in the vicinity of Tc suggests a critical slowing down of the orientational fluctuations of the cations and a distortion of the complex anions. The decrease of T1Q above 310 K is considered to be mainly due to the in-plane reorientation of the complex anions. An activation energy of 64 kJ mol" 1 is evaluated for that motion. 
  Reference    Z. Naturforsch. 44a, 1226—1230 (1989); received July 31 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1226 
 Volume    44 
195Author    P. A. Svantesson, I. Albinsson, B.-E MellanderRequires cookie*
 Title    Io  
 Abstract    n ic C o n d u c tiv ity in th e p o ly (p ro p y le n e g ly c o l)-po ly (m e th y l m e th a c r y la te)-L iC F 3S 0 3 S y s te m The temperature dependence of the ionic conductivity in the PPG-rich part of the ternary system poly(propylene glycol)-poly(methyl methacrylate)-LiCF3S03 has been investigated. The highest conductivity values, 3 x 10"5 (ohm cm)"1 at 31 °C and 4 x 10"4 (ohm cm)" 1 at 77 C, were obtained for samples which had the properties of a pressure sensitive adhesive. The temperature dependence of the ionic conductivity could be well described by the Vogel-Tammann-Fulcher equation. Key words: Ionic conductivity, polymer electrolyte adhesive, poly (propylene glycol), poly (methyl methacrylate), LiCF3S03 
  Reference    Z. Naturforsch. 44a, 1231 (1989); received September 20 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1231 
 Volume    44 
196Author    C. G. KoutroulosRequires cookie*
 Title     
 Abstract    e la tiv is tic G ro u n d a n d E x c ite d S t a te E n e rg ie s o f a /1 -P a r tic le in H y p e rn u c le i U s in g W o o d s -S a x o n P o te n tia ls The relativistic Dirac equation with a scalar potential and the fourth component of a vector potential of the Woods-Saxon shape is solved numerically for potential parameters obtained by a last squares fitting procedure of the ground state binding energies of the A in a number of hypernu­ clei and its binding energies in the ground and excited states (as well as the relevant spacings) for various hypcrnuclei are determined. The results are in very good agreement with the preliminary experimental ones given by Chrien on the basis of the (7ix, K*) reaction on nuclei. 
  Reference    Z. Naturforsch. 44a, 1234 (1989); received July 24. 1989 
  Published    1989 
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 Identifier    ZNA-1989-44a-1234 
 Volume    44 
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