bluuebunny/crossref_metadata_2025_split huggingface dataset:
Notizen: Inviscid Burgers Equation, Painleve Analysis and a Bäcklund Transformation
Authors: Steeb W.-H. , Euler N. 
Published: February 2015

Abstract
The inviscid Burgers equation is studied with the Painleve analysis. A Bäcklund transformation is constructed. Then we give the symmetry generators. A two-dimensional case is also investigated.
The Quantum Statistical Free Energy Minimum Principle for Multi-Lattice Mean Field Theories
Authors: Gerisch Th. , Rieckers A. 
Published: February 2015

Abstract
The quantum statistical frame for infinite multi-lattice spin systems is introduced. The thermodynamic functionals specific internal energy, entropy and free energy are shown to exist on the set of permutation invariant states for polynomial mean field interactions by direct estimation methods. Their dependence on the relative sizes of the sublattice systems is made explicit. The set of homogeneous minimal free energy states is shown to be a Bauer simplex which contains all limiting Gibbs states. For the extremal minimal free energy states the self-consistency equations are derived.
Improved Molecular Constants of Acetylene Obtained from the v5 Band System
Authors: Moravec A. , Winnewisser G. , Yamada K. M. T. , Blom C. E. 
Published: February 2015

Abstract
A vibration-rotation band system of acetylene of the /Πu bending vibration v5 has been recorded with high resolution by a Bruker IFS 120 HR Michelson spectrometer. From the analysis of the hot band of the normal isotopic species, v4 + v5 - v4, and the fundamental band of HC13CH in natural abundance an improved set of constants has been derived. The intensity perturbation due to the l-type resonance has been clearly observed in the band system v4 + v5 -v4
A Theory of Anharmonic Perturbations in a Penning Trap
Authors: Kretzschmar Martin 
Published: February 2015

Abstract
Classical hamiltonian perturbation theory formulated in terms of action-angle variables is applied to develop a general and systematic method for calculating the influence of anharmonic perturbations on the motion of a charged particle in a Penning trap. Action-angle variables are ideally suited to determine the shifts of the characteristic frequencies in a perturbed orbit. The application of the method is demonstrated by several case studies
Variation of the Dielectric Relaxation Behaviour of Water by Added Alcohols
Authors: Lux A. , Stockhausen M. 
Published: February 2015

Abstract
The dielectric relaxation of water rich aqueous solutions of ethanol, ehtylene glycol, glycerol, diethylene glycol, 1,2-butanediol, 1,3-butanediol and 1,4-butanediol has been measured at 20 °C. In all cases the fitting of the data by a sum of Debye type spectral components allows for two description modes which can be interpreted as a collective alteration of the water relaxation or, on the other hand, as formation of a microheterogenous solution where "affected" and "unaffected" water becomes discernible
Lattice Vibrations, MIR and FIR Optical Properties of Boron and Icosahedral Boron-Rich Borides II. β-Rhombohedral Structure Group
Authors: Werheit H. , Haupt H. , Higashi I. 
Published: February 2015

Abstract
The lattice vibrations of the ß-rhombohedral boron structure group are investigated in detail by group theory. IR spectra of pure ß-rhombohedral boron as well as of B: Mn, B: Fe, B: Cu, and B: Cu/Al are presented and discussed. In comparison with boron carbide most of the absorption bands can be associated with certain vibrations. The vibration frequencies are determined by application of the phenomenological theory of Waser and Pauling, which thus yields a reliable estimation of the restoring forces ion these solides
Hydrogen in Electrodynamics. V. Dirac-Hydrogen by Means of New Operators
Authors: Sallhofer Hans 
Published: February 2015

Abstract
After a discussion of the one-component Schrödinger (1926) and the four-component Dirac (1928) representation of hydrogen it is shown that the six-component electrodynamic picture is considerably simpler and clearer. The computational effort is reduced to a fraction
Report: Nonequilibrium Phase Transitions of Impact Ionization Breakdown in Extrinsic Semiconductors
Authors: Parisi J. , Peinke , J. , Rau U. , Clauß W. 
Published: February 2015

Abstract
In the study of semiconductor electronic breakdown we observe the self-generated formation of spatio-temporal dissipative structures, when a bias voltage is applied at liquid-helium temperature. The underlying nonlinear physics of impurity impact ionization reveals critical phase transition behavior by varying the temperature at constant voltage
The 14N Nuclear Quadrupole Coupling Tensors, the Tensors of the Molecular Magnetic Susceptibility and the Molecular Electric Quadrupole Moment in Pyrazole: A High Resolution Rotational Zeeman Effect Study
Authors: Böttcher O. , Sutter D. H. 
Published: February 2015

Abstract
High resolution zero field and Zeeman rotational spectra of 1 D-pyrazole have been studied by microwave Fourier-transform spectroscopy. The zero field hfs patterns allowed to improve the quadrupole coupling constants for both 14N nuclei. From the high field Zeeman multiplets the diagonal elements of the g-tensor were obtained as gaa= -0.1178(2),.gbb=-0.0762(2) and gcc = 0.0608 (2). The two independent components of the molecular magnetic susceptibility anisotropy in units of 10-6 erg G-2 mole- 1 are 2 ξaa - ξbb - ξcc= 52.69(32) and 2 ξbb - ξcc - ξaa = 39.32(29) were, a, b, c denote the molecular principal inertia axes. From these values the components of the molecular electric quadrupole moment tensor in units of 10-26 esu cm2 follow as Qaa = 5.84(22), Qbb= -0.58 (21) and Qcc= -5.27(38). Comparison with corresponding values for the undeuterated species leads to the complete tensors including their orientation with respect to the nuclear frame.
Franck-Condon States of Coumarins in Alcoholic Solutions
Authors: Bączyński A. , Targowski P. , Ziętek B. , Radomska D. 
Published: February 2015

Abstract
The temperature dependence of the fluorescence spectra of coumarin 2, coumarin 10 and coumarin 120 in ethyl alcohol is investigated. A blue-shift of the spectra with increase of temperature is observed. The blue-shift is explained by means of excited and ground Franck-Condon state parameters obtained by the adjustment of analytical shape factors to experimental spectra.
Maxwell's Equations and Shear Waves in the Vortex Sponge
Authors: Kelly Edward M. 
Published: February 2015

Abstract
The vortex sponge is a fluid substratum which is criss-crossed by innumerable fine hollow vortex tubes. Bending of tubes causes them to drift; the combination of drift and bending turns out to have effects mathematically identical to those of electric and magnetic fields. Thus, electromagnetism can be viewed mechanically, with Maxwell's curl equations governing the translation and rotation of the substratum. Shear and shear waves are illustrated by a plane shear wave.
A New Intracrystalline Isotope Effect: 18O under the Faces of Amethyst
Authors: Klemm A. , Banerjee A. , Hoernes S. 
Published: February 2015

Abstract
The concentration of 18O within well formed crystals of amethyst was found to vary beneath the different growth faces, increasing in the order z→ r→m. The 18O/16O fractionation factor between the faces m and z was measured as 1.0007.
Existence of Nowhere Differentiable Boundaries in a Realistic Map
Authors: Kittel A. , Peinke J. , Klein M. , Baier G. , Parisi J. , Rössler O. E. 
Published: February 2015

Abstract
A generic 3-dimensional diffeomorphic map, with constant Jacobian determinant, is proposed and looked at numerically. It contains a lower-dimensional basin boundary along which a chaotic motion takes place. This boundary is nowhere differentiable in one direction. Therefore, nowhere differentiable limit sets exist generically in nature.
Notizen: Non-coincidence of Isotropic and Anisotropic Raman Spectra of the v3 Mode of the CH3F/CD3F System
Authors: Schiel D. , Richter W. , Döge G. 
Published: February 2015

Abstract
It has been proved with the aid of CH3F/CD3F mixtures that the remarkably large non-coincidence effect in the Raman scattering spectrum of the v3 mode of liquid methyl fluoride is due to intermolecular vibrational coupling mediated mainly by transition dipole interaction. The amount of the effect and its temperature and mole fraction dependence are - at least qualitatively - in agreement with Logan's theoretical concept. The rather different behaviour of the isotopic species and the asymmetry and narrow width of the isotropic band, however, raise new questions which require further investigations.
Correlation of NQR and Chemical Bond Parameters
Authors: Weiss Alarich , Wigand Silvia 
Published: February 2015

Abstract
Nuclear quadrupole resonance is an effective spectroscopic method to investigate the charge density distribution in solids. The range of compounds which may be investigated is wide, reaching from a crystal lattice built up by an ordered arrangement of neutral molecules in the crystalline material to ionic crystals and to metallic solids.
First the correlations between NQR quantities and bond parameters which become apparent from the molecular orbital picture will be discussed, e.g. Hammett a, x-parameter, ionic character i, s-character, ionicity, electronegativity in their connection to NQR. Then, the correlations of NQR frequencies, respectively nuclear quadrupole coupling constants, with bond lengths and bond angles are considered.
Cross correlations, e.g. of NQR frequencies with bond distances, bond distances with vibrational frequencies, and vibrational frequencies with NQR frequencies are discussed as are pK A dependencies of NQR parameters. The connection of e
The Structure of Tetrachlorostannate Complexes with Ketones from 35Cl NQR Data
Authors: Feshin Valentin P. , Dolgushin Gennadii V. , Lazarev Igor M. , Voronkov Mikhail, G. 
Published: February 2015

Abstract

35Cl NQR spectra (77 K) of 1:1 and 2:1 RR'CO-SnCl 4 are recorded and discussed. These spectra change in the course of time. At low temperatures either octahedral or trigonal-bipyramidal complexes (depending on the ratio of components and the nature of ligands) are formed. Frequently these systems contain a mixture of steric isomers or a mixture of complexes having different coordination numbers of the tin atom. In the solid state some complexes show a transition from one to another configuration.
NQR Study of AlBr3 Complexes with Donor-Acceptor O-Al Bond
Authors: Ishihara Hideta , Nakashima Shouko , Yamada Koji , Okuda Tsutomu , Weiss Alarich 
Published: February 2015

Abstract

81Br and 27Al NQR were observed in AlBr 3 complexes with 4-XC6H4 NO,(X = H, CI, Br, I, CH3 , and C2H5), C6H5COBr, (C6H5)2CO, and (C2H5)2O. In the 4-XC6H4 NO2 complexes, the 27Al quadrupole coupling constants (QCC's) were well correlated with the Hammett er p 's of the para-substituents, i.e., electron-withdrawing groups caused reduction of the charge density of O-Al bonds which resulted in large 27Al QCC's and vice versa. The temperature dependences of the 81Br NQR frequencies and quadrupolar spin-lattice relaxation times showed that the 4-C2H5C6H4NO2 and C6H5 COBr complexes undergo phase transitions at 154 K and around 200 K, respectively, and show hindered rotation of the AlBr3 groups at higher temperatures, and that the (C2H5) 2O complex reorients above ca. 120 K.
Multinuclear Quadrupole Resonance Studies of Biological Systems
Authors: Hiyama Yukio 
Published: February 2015

Abstract
We have employed multinuclear quadrupole resonance, using the field cycling technique, to study the structure of heterocyclic biomolecules. The electron density at nitrogen was investigated by the Townes-Dailey model of 14N NQR. Large substituent effects were evident especially on the n orbitals. Electron transfer through H-bonds also affects the 14 N quadrupole interaction. Deuterium quadrupole resonance at exchangeable sites was also utilized. Since the deuterium quadrupole correlation coefficient is sensitive to the geometry of H-bonds, the intermolecular distance of the pyrrole-pyridine complex could be determined. The field cycling technique is sensitive enough to detect 14 N ··· 14 N double transitions in parabanic acid thanks to the long spin-lattice relaxation time. However in many biological systems, such as hydrates, the technique is hardly applicable because of the short proton relaxation times. In such cases the solid state NMR technique was utilized. The 2H NMR spectrum of thymidine reveals interesting static and dynamical features of deuterium quadrupole interaction.
Temperature Dependence Studies of 35Cl NQR Frequencies in Magnesium and Nickel Hexachlorotellurate(IV) Hexahydrates and Nickel Hexachloroiridate(IV) Hexahydrate
Authors: Sasane A. , Fukumitsu S. , Mori Y. , Nakamura D. 
Published: February 2015

Abstract
The 35Cl NQR frequencies in MgTeCl6 · 6H2O, NiTeCl6
· 6H2O, and NiIrCl6 · 6H2O have been determined at various temperatures. These compounds form rhombohedral crystals with the space group R3̄ ,showing a single resonance line. The 35Cl NQR frequencies of the Te(IV) complexes exhibit an unusual positive temperature coefficient. The deuterated analogs of the Te(IV) complexes show a small frequency shift at 77 K. These results are interpreted by the presene of O-H ··· CI type weak H-bonds. The resonance frequency of the Ir(IV) complex versus temperature curve shows a minimum and a maximum. This unusual temperature dependence is mainly explained by the same type of the H-bond as existing in the Te(IV) complexes. The π-bond formation between Ir and CI atoms is also partly responsible for the unusual temperature dependence.
Theoretical Study of the Indirect Quadrupole-Quadrupole Interactions in Metals and Alloys
Authors: Fazleyev N. G. 
Published: February 2015

Abstract
The indirect multipole interactions of nuclei and impurity paramagnetic ions in metals and alloys via conduction electrons are investigated by means of the dielectric function method. The Hamiltonian of the indirect quadrupole-quadrupole interaction of impurity paramagnetic ions and nuclei is constructed selfconsistently, taking into account the exchange interactions and correlations of the conduction electrons as well as the antishielding effects. It is shown that the energy of these indirect quadrupole interactions of the nuclei and the paramagnetic ions decreases with the distance as R ~ 3 , oscillating with a period which is determined by the wave vector on the Fermi surface and the distance R. The influence of these indirect quadrupole-quadrupole interactions on the width and shape of the NMR lines is studied.
Radio-Spectroscopic Studies of Magnetic Properties of High Temperature Superconductors
Authors: Lippmaa E. , Joon E. , Heinmaa I. , Miidel V. , Miller A. , Stern R. 
Published: February 2015

Abstract
We have performed 17O and 63Cu NMR measurements in YBa2Cu3O7-δ (δ ≈ 0.15) oriented powder samples at CuO2 plane sites Cu(2) and 0(2, 3) in the temperature range 10-300 K. The temperature dependent Knight shift K(T) and spin lattice relaxation rate T1
-1-(T) of O(2, 3) yield K2T1T = const in accordance with the presence of free carriers at plane oxygen sites. A sharp decrease of T1
-1 of Cu(2) below 120 K is associated with the opening of a gap in the spectrum of antiferromagnetic spin fluctuations of localized copper 3 d9 electrons. The comparison of different temperature dependences of spin densities at the Cu and O sites shows the presence of two nearly independent spin systems. A close similarity of YBa2Cu3O7-δ a with heavy fermion superconductors is discussed.
NQR and Zeeman Split NQR Investigations on Oriented YBa2Cu3O7-δ and Non-Oriented Bi-Ca-Sr-Cu-O Powder
Authors: Riesemeier H. , Kamphausen H. , Pattloch J. , Stadermann G. , Lüders K. 
Published: February 2015

Abstract
Powder samples of YBa2Cu3O7-δ a were oriented by mechanically vibrating the powder at 2.4 K in a magnetic field of 1.2 T. Zeeman split NQR spectra of 63,65 Cu were obtained for the two different Cu sites. The data confirm the orientations of the principal axis system: x ∥ c for the Cu (1) site and z ∥ c for the Cu (2) site. Asymmetry parameters were determined for the two Cu sites yielding η̄1 = 0.95 ±0.2 and η̄2 = 0.008 ± 0.002. At the Cu(l) site local variations of the symmetry of the EFG tensor were observed. For the Cu sites (CuO2 -layers) in the Bi2Ca2Sr2Cu3Oy phase a nearly axially symmetric EFG tensor was found.
Studies of 139La and 63/65Cu-NQR in La 2-xMxCuO4 (M = Ba, Sr)
Authors: Kumagai K. , Nakamura Y. , Watanabe I. , Nakajima H. 
Published: February 2015

Abstract
The nuclear quadrupole resonance of 139La and 63/65Cu in La2-x CMxCuO4 (M = Ba, Sr) is investigated for x up to unity. The shift of the resonance frequency of 139La-NQR for 0.01 < x <0.05 indicates an anomalous change of the quadrupole interactions at T*c, where the frustrated magnetic phase appears. The Cu-NQR reveals clear changes of T1
-1 and T2
-1 and also of the profile of the Cu-NQR spectra with increasing x beyond x = 0.3~0.4, suggesting a suppression of antiferromagnetic fluctuations by hole-doping, and also a change of the electronic state of the La-system around x = 0.3 ~0.4.
14N and 39K Nuclear Quadrupole Coupüng in KNO3
Authors: Bastow T. J. , Stuart S. N. 
Published: February 2015

Abstract
The nuclear quadrupole interaction tensors of 14N and 39K in potassium nitrate at room temperature have been determined from nuclear magnetic resonance (NMR) rotation studies of single crystals at 9.4 T. Values for the coupling constants and asymmetry parameters at 296 K are:

14N: e2 qQ/h = 751 kHz, η = 0.022;

39K: e2 qQ/h = 1326kHz, η = 0.171.
The temperature dependence, on approaching the order-disorder phase transition near 401 K, is linear.
On the Nature of the “Bleaching out” Process of the 35Cl NQR Signals in 1,2,3-Trichlorobenzene
Authors: Wigand Silvia , Weiden Norbert , Weiss Alarich 
Published: February 2015

Abstract
The 35Cl NQR frequencies, linewidths, and spin-lattice relaxation times T1(35Cl) of 1,2,3-trichlorotrideuterobenzene were measured at various temperatures. The deuterated compound shows the same bleaching out phenomenon as 1,2,3-trichlorobenzene. Single crystal 2H NMR measurements were carried out at 295 and 193 K. The nuclear quadrupole coupling constants at room temperature are in the range of 175.8 ≦ e2qQh-1 (2H)/kHz ≦ 179.5, and the asymmetry parameters η in the range of 0.060 ≦ η (2H) ≦ 0.073. As for the principal axes of the electric field gradient tensor, it was found that Φzz(2H) is parallel to the C - D bond, Φyy (2H) is perpendicular to the benzene ring plane and Φxx(2H) lies in the ring plane. The linewidths of the 2H NMR satellites are idependent of temperature. For the undeuterated compound, the temperature dependence of T1(1H) was also measured. The mechanism leading to the bleaching out of the 35Cl NQR signals is discussed.
Influence of Thermoactivated Molecular Motions on the 35Cl Quadrupole Relaxation
Authors: Kjuntsel I.A. , Mokeeva V. A. , Shaposhnikov I. G. , Soifer G. B. 
Published: February 2015

Abstract
The effect on the 35Cl quadrupole relaxation of modulations of the electric field gradient by thermally activated motions of nearby nonbonding symmetric and asymmetric atomic groups has been investigated. This way the activation energy of the motions has been determined and the fraction of the electric field gradient influenced by the motions has been estimated. This fraction can be taken as a measure of the intensity of nonbonding interactions in solids.
Antimony NQR and Nuclear Magnetic Relaxation in Hexaammonium Dodecafluorotrisulfatotetraantimonate (III), (NH4)6 Sb4(SO4)3F12
Authors: Chihara Hideaki , Nakamura Nobuo 
Published: February 2015

Abstract
Antimony nuclear quadrupole resonance frequencies in (NH4)6Sb4 (SO4)3 F12 crystals were measured as a function of temperature, and no evidence of phase transition was detected between 77 K and room temperature. However, the resonance frequencies do not follow the Bayer type exactly. Such an anomaly is attributed to the effect of rotation of ammonium ions which form hydrogen bonds of types N -H ···F and N -H ···O. In fact, the spin-lattice relaxation time of 1H and 19F has a minimum which is ascribed to the reorientation of NH+
4 with an activation energy of 7.14 kJ mol -1. The switch model for the electric field gradient at Sb nuclei was examined.
Optimal Zeeman-NQR Powder Lineshape Calculations for 3/2≦I≦7/2
Authors: Varty Theresa , Julian R. , Brown C. , Temme Francis P. 
Published: February 2015

Abstract
The powder lineshapes, associated with Zeeman-NQR Δ|m|= ±1 transitions for half-integer spin from 3/2 and 7/2 are derived using an optimized (θ, ϕ) sampling algorithm for the intensity response. The I = 3/2 system is examined over the full asymmetry range, whereas the I >3/2 lineshapes are calculated for η ≦0.35. The algorithm adopted is modelled on the concepts in the earlier NMR lineshape calculations of Alderman, Solum, and Grant.
Strong Quadrupole Interaction in ENDOR Spectroscopy
Authors: Böttcher R. , Heinhold D. , Windsch W. 
Published: February 2015

Abstract
If the nuclear quadrupole interaction ĤQ of the ligands exceeds the magnetic hyperfine ĤHF and nuclear Zeeman ĤNZ interaction (ĤQ ≫ ĤHF +ĤNZ), ENDOR spectra show the same behaviour as Zeeman field perturbed NQR spectra. The angular dependence of the transition frequencies and the transition probabilities of such ENDOR spectra for axial symmetry are calculated and applied to analyze the 35, 37Cl distant ENDOR spectra of gamma-irradiated NaClO3 single crystals.
Line Narrowing in Nitrogen-14 NQR by Non-Resonant Irradiation
Authors: Zhuang Y. L. , Marino R. A. 
Published: February 2015

Abstract
The effect of non-resonant irradiation on the linewidth of 14N NQR lines has been investigated in three cases with zero asymmetry parameter. The characteristic time of the free induction decay (T2 *) in Trimethylamine (TMA), Triethylenediamine (TED) and Hexamethylenetetramine (HMT) was studied at 77 K. Circularly polarized non-resonant irradiations of 11 kHz were used with intensities of up to 24 G with a geometrical arrangement following Ito and Hashi. The largest effect, a 100% increase in T2*, is measured in TMA. No observable effect occurs in HMT. An intermediate result occurs in TED, where the considerable narrowing caused by the non-resonant field serves to provide a greater resolution of the fine structure first reported by Colligiani and Ambrosetti. This fine structure, presumably dipolar in origin, is not itself affected by the non-resonant irradiation. The degree to which the theory of dressing fields can account for these results is discussed.
Microwave Spectra of Furazan. IV. Rotation Spectra of Vibrationally Excited States of Perdeuterated Furazan
Authors: Stiefvater Otto L. 
Published: February 2015

Abstract
The pure rotation spectra of molecules in 25 vibrationally excited states of perdeuterated furazan, C2D2N2O, have been studied by double resonance modulation (DRM) microwave spectroscopy. Twelve of these spectra have been correlated, -on the basis of relative intensity measurements under DRM -, with fundamental vibrations as previously established by IR spectroscopy. Rotational parameters for these 12 fundamental levels are reported, and the contributions to the effective rotational constants and to the inertia defect of the ground state of d2 -furazan have been determined for 10 modes of vibration.
Thermodynamische Betrachtungen von Schmelzdiagrammen einiger Systeme aus Methylchlorsilanen und Lutidinen
Authors: Hensen Karl , Dräbing Michael 
Published: February 2015

Abstract
A thermodynamic interpretation of the liquidus curves of some methyltrichloro-respectively dimethyldichlorosilane/lutidine-systems is given. Based on certain approximations it was possible to fit thermodynamic functions to the experimental results to obtain the excess datas of binary systems. A comparison between the models of Redlich-Kister, Wilson and the NRTL-formalism for the free excess enthalpy of binary mixtures is given.