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1984[X]
141Author    GrauelRequires cookie*
 Title     
 Abstract    It is demonstrated that the sinh-Gordon equation can be written as covariant exterior derivatives of Lie algebra valued differential forms and, moreover, that these nonlinear differential equations represent a com­ pletely integrable system. Soliton Connection of the sinh-Gordon Equation 
  Reference    Z. Naturforsch. 39a, 917—918 (1984); received August 8 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0917_n.pdf 
 Identifier    ZNA-1984-39a-0917_n 
 Volume    39 
142Author    A.M K MüllerRequires cookie*
 Title     
 Abstract    a ria tio n a lly D e te rm in e d O c c u p a ti o n " N u m b e r s " in a n E x te n d e d T h o m a s -F e r m i S c h e m e Thomas-Fermi theory is generalized by the introduction of an occupation distribution func­ tion/(s). The ansatz f(s) = 9(sx -s) of the conventional TF theory is derived from a variational principle. The implications with respect to the density functional theory are discussed. Future work is intended to include interaction, leading to deviations from the step function, which will account for correlation effects. 
  Reference    Z. Naturforsch. 39a, 919—923 (1984); received March 28 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0919.pdf 
 Identifier    ZNA-1984-39a-0919 
 Volume    39 
143Author    T. Rose, G. L. Borchert, O.W B SchultRequires cookie*
 Title      
 Abstract    The x-ray intensities of the Kß and KO lines relative to the Ka, transition were measured with high accuracy for the pairs La20 3-La, SmS-Sm, Sm20 3-Sm and Ta20 5-Ta. The K/?13 and K /?->4 lines do not show significant intensity shifts. However, the intensity of the KO line is in La20 3 (15.0 ±4.7)% higher, in SmS (6.9 ± 2.7)% lower and in Ta20 5 (12.5 ± 8.7)% higher than that emitted from the corresponding metal. These results can be reproduced by Dirac-Fock-calculations, where the KO-intensities show a typical dependence on the quantum numbers of the valence electrons. The observed shifts indicate a 4f-5d hybridization or promotion in metallic Lanthanum and suggest the missing of a 4f electron in metallic Samarium compared to the free atom. T h e In flu e n c e o f th e C h e m ic a l S t a t e o n K x -R a y I n te n s it ie s * 
  Reference    Z. Naturforsch. 39a, 924—929 (1984); received August 10 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0924.pdf 
 Identifier    ZNA-1984-39a-0924 
 Volume    39 
144Author    M. S. Dimitrijević, P. V. GrujićRequires cookie*
 Title      
 Abstract    Classical two-electron configurations, proposed by Langmuir in the days of Old Quantum Theory as models for helium-like atoms, have been examined making use of modern semi-classical theory for the periodic orbits quantization. Combining both analytical and numerical investigations, energy spectra for the rotor-like and oscillator-like models have been evaluated, for the nuclear charges Z = 1, 2, 3, 6. No essential improvement of the original result (for Z = 2) is obtained, signifying that either configuration turns out to be inferior to the simple Bohr's planetary model. Stability of these systems with respect to small perturbations has been examined and a general criterion for selecting classical models as candidates for atomic orbitals within the semiclassical theory is discussed. 
  Reference    Z. Naturforsch. 39a, 930—938 (1984); received June 25. 1984 
  Published    1984 
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 Identifier    ZNA-1984-39a-0930 
 Volume    39 
145Author    K.R K Chhajlani, P. Sanghvi, PurohitRequires cookie*
 Title     
 Abstract    a y le ig h -T a y lo r I n s ta b ility o f a S t r a t if ie d M a g n e t i z e d M e d iu m in th e P r e s e n c e o f S u s p e n d e d P a r ti c le s R. The hydromagnetric Rayleigh-Taylor instability of a composite medium has been studied in the presence of suspended particles for an exponentially varying density distribution. The prevalent horizontal magnetic field and viscosity of the medium are assumed to be variable. The dispersion relation is derived for such a medium. It is found that the stability criterion is independent of both viscosity and suspended particles. The system can be stabilized for an appropriate value of the magnetic field. It is found that the suspended particles can suppress as well as enhance the growth rate of the instability in certain regions. The growth rates are obtained for a viscid medium with the inclusion of suspended particles and without it. It has been shown analytically that the growth rate is modified by the inclusion of the relaxation frequency parameter of the suspended particles. 
  Reference    Z. Naturforsch. 39a, 939—944 (1984); received June 5. 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0939.pdf 
 Identifier    ZNA-1984-39a-0939 
 Volume    39 
146Author    German Arenas, Jürgen GeigerRequires cookie*
 Title      
 Abstract    Streaks were found in the electron diffraction diagrams of ion-etched single-crystalline SrTi03 for beam incidence parallel to the [111] direction. The streaks correspond to intensity walls perpendicular to the [COO] directions in agreement with the theoretical prediction. The soft phonons seem not to contribute significantly to the streaks. 
  Reference    Z. Naturforsch. 39a, 945—947 (1984); received July 11 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0945.pdf 
 Identifier    ZNA-1984-39a-0945 
 Volume    39 
147Author    C. BojarskiRequires cookie*
 Title      
 Abstract    flu e n c e o f th e R e v e rsib le E n e rg y T r a n s f e r o n th e D o n o r F lu o re s c e n c e Q u a n t u m Y ie ld in D o n o r -A c c e p to r S y s te m s * In mixed systems of donor and acceptor molecules having closely located Sx levels a reversible nonradiative energy transfer should occur. It influences remarkably the dependence of the donor quantum yield rjp on the acceptor concentration in the range of high acceptor concentrations of systems with high donor-to-acceptor reduced concentration ratios. 
  Reference    Z. Naturforsch. 39a, 948—951 (1984); received December 10. 1983 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0948.pdf 
 Identifier    ZNA-1984-39a-0948 
 Volume    39 
148Author    JaninaR. HeidtRequires cookie*
 Title      
 Abstract    flu e n c e o f I n te r n a l H e a v y A to m s o n th e S p e c tr o s c o p ic P r o p e rtie s o f 9 -A c e to x y -1 0 -P h e n y la n th r a c e n e D e r iv a tiv e s Absorption and fluorescence spectra, fluorescence quantum yields and decay times have been measured for new derivatives of 9-acetoxy-10-acetoxyhalogenophenylanthracene in dioxane. It is found that the strength of the absorption transition decreases with increases atomic number Z of the halogen substituent whereas the strength of the fluorescence transition is constant with the exception for the fluoro-substituted derivatives. The loss of mirror symmetry between the absorption and fluorescence spectra is more evident for the 10-(4-acetoxy-3'-halogenophenyl)an-thracene derivatives than for the remaining compounds. The determined nonradiative electronic relaxation rate constant and "dark reactions" quantum yield increases with increasing Z value. These findings are explained on the basis of the spin-orbit coupling enlarged by the heavy substituent and through perturbation of the functional groups, which causes different changes of the molecular geometries in the S0 and S* states, respectively. 
  Reference    Z. Naturforsch. 39a, 952—959 (1984); received February 7 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0952.pdf 
 Identifier    ZNA-1984-39a-0952 
 Volume    39 
149Author    Requires cookie*
 Title     
 Abstract    u m in escen ce o f 5 -P h e n y lte tr a z o le a n d its D e riv a tiv e s P a r t III. Q u a n tu m Y ie ld s a n d M e a n L ife tim e s o f F lu o r e s c e n c e 
  Reference    Z. Naturforsch. 39a, 960 (1984) 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0960.pdf 
 Identifier    ZNA-1984-39a-0960 
 Volume    39 
150Author    J.Chr Buhl, A. WillgallisRequires cookie*
 Title    K in e tic s a n  
 Abstract    d M e c h a n is m o f H iib n e r ite (M n W 0 4) a n d F e rb e rite (F e W 0 4) C r y s ta lliz a tio n u n d e r H y d r o th e r m a l C o n d itio n s The kinetics of the crystallization of hiibnerite (MnWOa) and ferberite (FeW04) was studied by hydrothermally reacting the metal (Il)-chlorides and sodium tungstate in a special autoclave at two temperatures (300 °C. 400 °C) and a pressure of 1 kbar. The rates of crystallization were determined by continual removal of the reactants from the autoclave. At both temperatures, the decrease of tungstate concentration in solution followed at first order reaction. The rate constants of the reactions were calculated and the Jerofejev-equation was used to describe the kinetics. The rate of hiibnerite formation was larger and increased faster with temperature. This should affect the formation of mixed crystals by initiating a shift of the composition towards higher MnW04/FeW04 ratios and might well account for a zonation or inhomogeneity of natural wolframites. 
  Reference    Z. Naturforsch. 39a, 963—965 (1984); received July 13 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0963.pdf 
 Identifier    ZNA-1984-39a-0963 
 Volume    39 
151Author    W. Preetz, D. TensfeldtRequires cookie*
 Title     
 Abstract    le k tr o n e n s p e k tre n d e r F l u o r o -C h l o r o -I r i d a te (I V) , [IrF " C l6 _ n]2 , / i = 1 -5 Electronic Spectra of Fluoro-Chloro-Iridates(IV), [IrFnCl6_n]2~, n = 1-5 The electronic absorption spectra of the solid tetramethylammonium salts of [IrF"C 6_"]2~, «=1-5, including the stereoisomers for n = 2, 3, 4, were measured in KCl pellets at 10 K, the electronic Raman spectra (ER) on rotating samples of the pure complex salts at 80 K. The strong bands in the UV/VIS region are assigned as charge-transfer transitions from cr(tlu), 7r(t|g, tlu, t2u) Cl orbitals into the n (t3g) Ir(IV) level. The observed splittings and shifts are interpreted by qualitative MO treatment "according to the point groups D4h, C4v, C3v and C2v of the mixed ligand complexes. Two week bands in the NIR region between 1650 and 2000 nm are assigned to intraconfigurational transitions within the 2T2g(Oh) ground term, split by spin-orbit coupling (5000-6000 cm-1) and lowered symmetry (30-110 cm-1) into three Kramers doubletts. The assignment of the O-O transitions is confirmed by stronger bands at the same frequencies in the ER spectra. They are coupling preferably with odd vibration modes in the absorption and with even modes in the ER spectra. The hypsochromic shift of the d-d-bands corresponds with the increase of the relativistic nephelauxetic ratio ß* from 0.75 to 0.90 and indicates the loss of covalency with increasing number of F ligands. 
  Reference    Z. Naturforsch. 39a, 966—974 (1984); eingegangen am 10. August 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0966.pdf 
 Identifier    ZNA-1984-39a-0966 
 Volume    39 
152Author    G. Spinolo, U.Anselmi TamburiniRequires cookie*
 Title     
 Abstract    o lo m ite D e c o m p o s itio n to (C a , M g) 0 S o lid S o lu tio n s : A n X -R a y D if f r a c tio n S tu d y , P a r t I. Dolomite [CaMg(C03)2] full decomposition has been studied by in situ powder X-ray diffraction. The primary products are Ca-rich and Mg-rich (Ca.Mg)O solid solutions with compositions different from equilibrium values. In some cases a strained form of calcite is also produced. The experimental results show that the oxides are formed in a direct process with a shear mechanism, whereas calcite formation is due to CaO recarbonation. 
  Reference    Z. Naturforsch. 39a, 975—980 (1984); received July 24 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0975.pdf 
 Identifier    ZNA-1984-39a-0975 
 Volume    39 
153Author    G. Spinolo, U.Anselmi TamburiniRequires cookie*
 Title     
 Abstract    o lo m ite D e c o m p o s itio n to (C a , M g) 0 S o lid S o lu ti o n s : A n X -R a y D if fr a c tio n S tu d y . P a r t II. The full decomposition of dolomites with low and high iron content at low temperatures and low pressures is discussed with reference to the free energy of mixing of the ternary system Ca. Fe, Mg/O. The actual products of the primary step are a couple of rock salt structured oxides close to the spinodal compositions and with very small particle sizes. A subsequent diffusional process can produce large crystallites with equilibrium compositions, but it is effective only when either a low-iron dolomite is used as starting material or higher temperatures are employed. 
  Reference    Z. Naturforsch. 39a, 981—985 (1984); received July 30. 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0981.pdf 
 Identifier    ZNA-1984-39a-0981 
 Volume    39 
154Author    Gunnar Albrecht, Georg ZundelRequires cookie*
 Title    C a rb  
 Abstract    o x y lic A c id -N B a s e H y d r o g e n B o n d s w ith L a r g e P r o t o n P o la riz a b ility in A c e to n itr ile a s a F u n c t i o n o f t h e B a s ic ity o f th e H y d ro g e n B o n d A c c e p to r s Carboxylic acid-N base systems are studied in acetonitrile. The association equilibrium constants K.d and the proton transfer equilibrium constants KpT in the OH • • • N ^ CT- • • H+N bonds formed, are determined from IR spectra. The association constants Ka increase in proportion to the basicity of the hydrogen bond acceptors. The same is true with regard to the proton transfer constants. The OH-■ N ^ O-- • • H+N equilibria are shifted with increasing basicity to the right hand side. It is discussed that this shift is caused by an intrinsic effect as well as by an extrinsic one (interaction of the dipole of the hydrogen bond with its environment). A linear relation exists between log A ^PT and ApK.A (pKa of the protonated base minus pK.A of the acid). 50% transfer of the protons to the N base is found at ApK,d = 2.6. As indicated by intense continua. these hydrogen bonds show large proton polarizability if the degree of asymmetry of their proton potentials is not too large. 
  Reference    Z. Naturforsch. 39a, 986—992 (1984); received June 28. 1984 
  Published    1984 
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 Identifier    ZNA-1984-39a-0986 
 Volume    39 
155Author    H.D H Försterling, R. Idstein, H. Pachl, SchreiberRequires cookie*
 Title    in th e B e lo u s o v -Z h a b o tin s k y -R e a c tio n  
 Abstract    The rate of formation of C02 in the BZ system is measured and compared to the predictions of the Field-Körös-Noyes (FKN)-theory. The experimental rate is found to be larger than the theoretical rate by a factor of about 100. This discrepancy cannot be easily explained without severe changes in the FKN model. Moreover, improved rate constants of the most important organic reactions in the BZ system are given. F o r m a tio n o f C a r b o n D io x id e 
  Reference    Z. Naturforsch. 39a, 993—997 (1984); received July 27 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0993.pdf 
 Identifier    ZNA-1984-39a-0993 
 Volume    39 
156Author    R. SchmidtRequires cookie*
 Title     
 Abstract    h e E n d o p e ro x id e o f T e t r a b e n z o p e n t a n c e n e . A N ew P h o to c h r o m ic E n d o p e r o x id e The thermal and the photochemical reactions of the endoperoxide of Tetrabenzo(bc,fg.lm,pq)-pentacene have been investigated with respect to its photochromic properties. The thermal yield of irreversible rearrangement reactions was determined to be Adec = 0.045. From the activation parameters of the thermal cycloreversion. forming the parent hydrocarbon and oxygen, a half life time of 114 years at 20 °C has been extrapolated. For the quantum yield of the irreversible photochemical rearrangement a value of (7dec = 0.03 was obtained. As can be seen from the wavelength dependence of the photocycloreversion quantum yield Qi, cycloreversion occurs not only from the thermalized S2(7rcc7r*c) but from higher excited states too. The maximum quantum yield was found at 302 nm to be (?i = 0.15. From our results it follows that this endoperoxide is of high quality in respect to the colour change colourless/blue and to thermal stability, whereas the reversibility is only moderate. 
  Reference    Z. Naturforsch. 39a, 998—1002 (1984); received July 31 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-0998.pdf 
 Identifier    ZNA-1984-39a-0998 
 Volume    39 
157Author    W. Kasten, H. DreizlerRequires cookie*
 Title     
 Abstract    e te rm in a tio n o f D ip o le M o m e n ts by M ic ro w a v e F o u r ie r T r a n s f o r m S p e c tr o s c o p y . T riflu o ro p ro p in e , T e r t.B u ty lis o c y a n id e , a n d C y a n o a c e ty le n e We report the measurements of dipole moments by Microwave Fourier Transform Spectro­ scopy. Hereby we indicate that it is worth to supplement this type of microwave spectroscopy to increase its capability. 
  Reference    Z. Naturforsch. 39a, 1003—1004 (1984); received August 9 1984 
  Published    1984 
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 Identifier    ZNA-1984-39a-1003 
 Volume    39 
158Author    Bärbel Maessen, Philippe Bopp, DonR. Mclaugh­, Lin, Max WolfsbergRequires cookie*
 Title    An Improved Variational Calculation of the Lower Vibrational Energy Levels of the Ammonia Molecule  
 Abstract    A new variational calculation of the inversion spectrum of ammonia is reported in which all six vibrational degrees of ammonia are employed. By fitting spectroscopic data, an inversion barrier of 1810 cm"1 is obtained. 
  Reference    Z. Naturforsch. 39a, 1005—1006 (1984); received August 8 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-1005_n.pdf 
 Identifier    ZNA-1984-39a-1005_n 
 Volume    39 
159Author    Sikha Bhattacharyya, RajkumarRoy ChoudhuryRequires cookie*
 Title    Weak Non Linearity and Magneto-Acoustic Waves  
 Abstract    We show that the property of a linear system viz, the fact that square of the amplitude propagates with the group velocity continues to be valid in the case of magneto acoustic waves in the presence of weak non linearity. 
  Reference    Z. Naturforsch. 39a, 1007—1008 (1984); received July 31. 1984 
  Published    1984 
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 Identifier    ZNA-1984-39a-1007_n 
 Volume    39 
160Author    M. ZanderRequires cookie*
 Title    Photoluminescence of |22|Paracyclophane and p-Xylene in the Presence of Silver Ions  
 Abstract    Phosphorescence spectra and phosphorescence lifetimes of [22]paracyclophane (I) and p-xylene have been mea­ sured in ethanol glass at 77 K in the presence of silver Perchlorate at various concentrations. From the results it is concluded that the ground state complex formed with AgC104 is much more stable in the case of the cyclophane than with /^-xylene. The results would indicate that under the conditions used [22]paracyclophane forms a 1:1 com­ plex with AgC104 with the silver ion being located within the cyclophane cage. Fluorescence quenching measure­ ments in fluid solution at room temperature using ethyl bromide and AgC104 as quenchers support this assump­ tion. 
  Reference    Z. Naturforsch. 39a, 1009—1010 (1984); received August 18. 1984 
  Published    1984 
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 TEI-XML for    default:Reihe_A/39/ZNA-1984-39a-1009_n.pdf 
 Identifier    ZNA-1984-39a-1009_n 
 Volume    39 
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