bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Microwave Spectrum of Isopropyl Iodide: The Iodine Hyperfine Structure and a Centrifugal Distortion Analysis
Authors: Gripp Joachim , Dreizler Helmut 
Published: February 2015

Abstract
The ground stafe microwave spectrum of isopropyl iodide has been investigated by microwave Fourier transform (MWFT) spectroscopy. 212 hyperfine components of 39 mainly a-type transitions have been assigned from the measured spectra in the frequency range between 4 and 30 GHz. With a MWFT double resonance modulation (MWFTDR) spectrometer a weak c-type transition and a "forbidden" ΔJ = 2 line could be observed. The spectra were analysed using a diagonalization procedure of the complete Hamiltonian matrix and a simultaneous least squares fit of the rotational, quartic centrifugal distortion and the iodine quadrupole and spin rotation coupling constants directly to the measured frequencies. A set of 14 constants could be obtained with high accuracy. The rotational constant A and some of the centrifugal distortion constants could be improved using some large higher order quadrupole perturbations and the results of the MWFTDR measurements for the analysis.
Covariant Electrodynamics in Vacuum
Authors: Wilhelm H. E. 
Published: February 2015

Abstract
The generalized Galilei covariant Maxwell equations and their EM field transformations are applied to the vacuum electrodynamics of a charged particle moving with an arbitrary velocity v in an inertial frame with EM carrier (ether) of velocity w. In accordance with the Galilean relativity principle, all velocities have absolute meaning (relative to the ether frame with isotropic light propagation), and the relative velocity of two bodies is defined by the linear relation uG = v1 - v2. It is shown that the electric equipotential surfaces of a charged particle are compressed in the direction parallel to its relative velocity v - w (mechanism for physical length contraction of bodies). The magnetic field H(r, t) excited in the ether by a charge e moving uniformly with velocity v is related to its electric field E(r, t) by the equation H=ε0(v - w)xE/[ 1 +w • (t>- w)/c2
0], which shows that (i) a magnetic field is excited only if the charge moves relative to the ether, and (ii) the magnetic field is weak if v - w is not comparable to the velocity of light c0 . It is remarkable that a charged particle can excite EM shock waves in the ether if |i> - w\ > c0. This condition is realizable for anti-parallel charge and ether velocities if |v-w| > c0- | w|, i.e., even if |v| is subluminal. The possibility of this Cerenkov effect in the ether is discussed for terrestrial and galactic situations
Does Cold Fusion Exist and is it Measurable?
Authors: Komarov V. V. , Melsheimer O. , Popova A. 
Published: February 2015

Abstract
The dynamical nature of the cold fusion problem is considered. A general model of two slow charged particles interacting in a metal crystal is developed. It is shown that there exists a resonance state of this system. The value of the positive real resonance energy depends on the properties of the metal crystal. An estimate of the probability of cold nuclear fusion in condensed matter is given
Luminescence Properties of Transition-Metal Ions in Double Complex Salts
Authors: Schmidtke Hans-Herbert , Mink Hans J. 
Published: February 2015

Abstract
The luminescence spectra and radiative lifetimes of a series of d3 and d6 double complex compounds with bipyridine (bip), phenanthroline (phen), ammonia and ethylenediamine (en) ligands in the cations and chloride, cyanide, thiocyanide and oxalate (ox) ligands in the anions have been investigated at temperatures down to 2 K. Although energy transfer between the component ions is predicted from the Förster and Dexter theory to be effective due to the finite overlap of the donor emission and the acceptor absorption spectra, no emission could be detected for most of the double complexes. Only [Ru(bip)3]tr-[Cr(NH3)2(NCS)4]2, [Ru(bip)3][PtCl6] and [Cr(d4-en)3] [Rh(SCN)6] exhibit characteristic luminescence spectra which in part are enhanced compared to their component emissions. For rationalizing the results, radiationless deactivation by various decay channels which compete with the energy transfer mechanism must be considered.
RKR Potential, FCF and Mixing Coefficients of the A1 Σu
+ and b3Πu States of Na2
Authors: Babaky O. , Hussein K. 
Published: February 2015

Abstract
A study of the spin-orbit interaction between the A1Σu
+ and b3Πu states of Na2 , based on the collision-induced transitions (2) 1Σ g →A
1
Σu
+ recorded with a high resolution Fourier transform spectrometer, had led to the determination of the deperturbed constants of the A1Σu
+ and b3Πu states [1]. From these constants the Rydberg-Klein-Rees (RKR) potential curves for the A1Σu
+ (0≦v≦ 15) and b3Πu (0 ≦ v ≦ 25) states and the Franck-Condon factors (FCF) within the range of vibrational levels involved in the interaction of these two states are calculated, together with the mixing coefficients for the pair (A1Σu
+)v=4 - (b3Πu)v=10.
Investigation of the Microwave Spectrum of Perchlorylfluoride by Microwave Fourier Transform Spectroscopy
Authors: Heldmann C. , Dreizler H. 
Published: February 2015

Abstract
We reinvestigated the rotational spectrum of perchlorylfluoride-35Cl and -37Cl by microwave Fourier transform spectroscopy and determined the rotational, centrifugal and quadrupole coupling constants and the dipole moment with higher precision and the spin-rotation constants for the first time.
High Resolution Study of the Rotational Spectrum of Formaldoxime, Combined with Quantum Chemical Calculations, Its 14N Spin-Rotation Coupling, 14N Nuclear Quadrupole hfs, and Its Rotational Zeeman-Effect
Authors: Klesing A. , Sutter D. H. 
Published: February 2015

Abstract
A high resolution study of the rotational spectrum of formaldoxime was carried out with the aim to resolve a discrepancy between early microwave results and recent ab initio calculations. Accurate 14N quadrupole coupling constants and spin-rotation coupling constants could be derived from zero field hfs multiplets. From the Zeeman-splittings in external magnetic fields up to 18kGauss the diagonal elements of the molecular g-tensor and the anisotropics in the diagonal elements of the molecular magnetic susceptibility tensor were obtained and were used to derive the diagonal elements of the molecular electric quadrupole moment tensor. For comparison, Hartree Fock SCF calculations were carried out with a basis of TZVP quality. As it turned out such calculations are able to reproduce the molecular electric quadrupole moment tensor but fail to reproduce the 14N nuclear qudrupole coupling constants to better than 0.3 MHz. A revised formula to predict spinrotation coupling constants of first row elements such as nitrogen is also proposed.
Pure Rotation Spectrum of NNO in the Far Infrared Region
Authors: Yamada Koichi M. T. 
Published: February 2015

Abstract
The pure rotational spectrum of NNO has been observed as an impurity in the NO spectrum which has been recorded with a high resolution Fourier transform spectrometer. The observed high-J transitions in the ground vibrational state were analyzed by a least-squares fit together with the available millimeter and submillimeter wave data. It has been proved that the highly precise data of Maki et al. [3] can be used as a wavenumber standard for the far infrared.
Chaos Near Structural Phase Transition
Authors: Beige H. , Diestelhorst M. , Forster R. , Albers J. , Petersson J. 
Published: February 2015

Abstract
An experimental model of a Duffing oscillator is presented. It consists of a linear inductance, a resistance and a ferroelectric nonlinear capacitance. A computer controlled measuring system recorded quantitatively the phase portrait of this series-resonance circuit. The comparison of experimentally observed phase portraits with those calculated by a computer allows to check different assumptions about the nature of the nonlinear properties
Methyl Internal Rotation Fine Structure in the Ground State Rotational Spectrum of Gauche Butane
Authors: Vormann Kirsten , Dreizler Helmut , Hübner Hans , Hüttner Wolfgang 
Published: February 2015

Abstract
The methyl torsional fine structure in the rotational spectrum of gauche butane in the vibrational ground state was investigated in the frequency range between 10 and 141 GHz. Using the internal axis method (IAM) in the formulation of Woods, all internal rotation parameters were determined with high accuracy. The barrier height of the methyl internal rotation was determined to 11.34 (29) kJ/mol (2.710 (69) kcal/mol)
Notizen: A Pulsed Molecular Beam Microwave Fourier Transform Spectrometer with Parallel Molecular Beam and Resonator Axes
Authors: Grabow J.-U , Stahl W. 
Published: February 2015

Abstract
We report on first experiences with a pulsed molecular beam microwave Fourier transform spectrometer with parallel molecular beam and resonator axes. This setup shows up a high resolution and sensitivity.
The Effect of ω-Substituted Acceptors in 4-Dimethylamino-trans-Styrenes on the Polarity in the Ground and Excited Singlet State
Authors: Kawski A. , Gloyna D. , Bojarski P. , Czajko J. , Gadomska-Lichacz J. 
Published: February 2015

ABSTRACT
The electric dipole moment in the ground (μg) and in the first excited singlet state (μe) of co-substituted acceptors in 4-dimethylamino-trans-styrenes (Z = P(S)Ph2 , P(O)Ph2 , SO2CH3 ) were determined by solvatochromic and thermochromic methods. The obtained values of μe and μg and the values for Z = CN and Z = NO 2 known from the literature [2] fulfill the linear relation between the dipole moments (μe or μg and the Hammett constants σp of the substituents. On pincreasing the electron-acceptor power of Z, μe grows faster than μg
Contribution of Malonyl Radical Control in the Classical Belousov-Zhabotinsky Reaction
Authors: Försterling Horst-Dieter , Murányi Szilvia 
Published: February 2015

Abstract
In the original theory of the Belousov-Zhabotinsky reaction it is assumed that the oscillations are exclusively controlled by bromide ions. From uv/vls and ESR experiments on BZ systems started with Ce4 + we conclude that malonyl radicals play an important role as additional intermediates. The experiments are in agreement with calculations based on the Radicalator model.
Temperature and Pressure Dependence of Self Diffusion in Octamethylcyclotetrasiloxane and Hexamethylcyclotrisilazane
Authors: Greiner-Schmid A. , Has M. , Lüdemann H.-D. 
Published: February 2015

Abstract
The pressure dependence of the self diffusion coefficient D for octamethylcyclotetrasiloxane and hexamethylcyclotrisilazane has been determined by the NMR spin echo technique with pulsed magnetic field gradients at pressures up to 200 MPa and at temperatures between 490 K and 290 K.
The data extend partially into the deeply supercooled range. The isobaric temperature dependence of these data is quantitatively described by the empirical Vogel-Fulcher-Tammann equation. For both substances the melting pressure curves were determined in addition.
Intermolecular Potential Function Including Anisotropie Terms for Ammonia/Cu2+ Based on ab-initio Calculations
Authors: Kroemer R. T. , Michopoulos Y. , Rode B. M. 
Published: February 2015

Abstract
An intermolecular pair potential function for Cu2+-NH3 has been derived based on ab-initio calculations with a ECP-DZV basis set. For copper the original ECP-DZV basis set was modified in order to avoid unwanted charge-transfer effects. The final potential function including anisotropic terms was constructed from a total of 679 configurations.
Dissipative Structures in Demixing Binary Liquid Systems
Authors: Zander Roland , Dittmann Michael , Schneider Gerhard M. 
Published: February 2015

Abstract
The demixing of a horizontal fluid layer of far-critical composition in the presence of a vertical temperature gradient can cause the formation of dissipative structures and thereby lead to a regular distribution of the precipitate. The occurrence of these convective structures is explained with the model of a Rayleigh-Benard instability (RBI) which is driven by parallel gradients of temperature and concentration. The distribution of the precipitate is a synergetic effect of the macroscopic convective pattern and the local action of the Marangoni flow at the surfaces of the drops. If boundary conditions prohibit an RBI, the distribution of the precipitate also becomes inhomogeneous in course of time; however, in this case no regular pattern is observable and the inhomogeneities develop mainly due to the Marangoni convection near the surfaces of the larger drops that have settled at the boundary of the sample volume
ENDOR Spectra of Pyrene Excited Triplet State in Naphthalene-TCNB Crystals
Authors: Corvaja Carlo , Lodolo Andrea , Maniero Anna Lisa 
Published: February 2015

Abstract
Triplet state traps, observed on optically excited single crystals of Naphthalene-TCNB doped with Pyrene, have been studied by EPR and ENDOR spectroscopy. The magnetic resonance lines recorded at low temperature (20 K) are shown to be due to triplet excitations localized almost completely on a Pyrene molecule. The complete hyperfine tensors of all the protons have been determined. The spin distribution is shown to be distorted in such a way that the triplet Pyrene molecule lacks the in-plane symmetry axes of the ground state molecule. The orientation of the triplet molecule in the crystal lattice and the relative orientation of Pyrene and TCNB are also discussed.
The Local Ordering of Molten LiNbO3 by X-ray Diffraction
Authors: Sugiyama K. , Nomura K. , Waseda Y. , Andonov P. , Kimura S. , Shigematsu K. 
Published: February 2015

Abstract
The structure of molten LiNbO3 has been studied in the range 1550-1600 K by high temperature X-ray diffraction. Octahedrally coordinated niobium is suggested to exist in the melt as a fundamental local structure.
The EFG Asymmetry Parameters at 35 Cl Nuclei and the Electronic Effects in Chlorine-Containing Organic and Complex Compounds of Group IVA and VA Elements
Authors: Feshin Valentin P. , Voronkov Mikhail G. 
Published: February 2015

Abstract
The 35 CL NQR method and, in particular, the EFG asymmetry parameters at 35 Cl nuclei were used for the solution of a number of principal problems of theoretical organic and organometallic chemistry, such as the mechanism of non-induction influence of the heteroatom M on the atom Y in the non-linear Y-Z-M or Y-Z = M group, M-Cl bond multiplicity in planar molecular fragments and the asymmetry of halogen atom electron distribution in organic and organometallic molecules. In tetrahedral molecules this distribution is nearly axially symmetric for different M. This symmetry is also characteristic for axial chlorine atoms in trigonal-bipyramidal and octahedral molecules, independently of M. The deviation of the electron distribution of equatorial chlorine atoms from axial symmetry in the two latter cases depends essentially upon M and does not depend much on the peculiarity of the formation of these polyhedra and the character and number of substituents.
Single Crystal 35Cl NQR of 2,3,4,4-Tetrachloro-1-oxo-1,4-dihydronaphthaline and of 2,2,3,4-Tetrachloro-1 -oxo-1,2-dihy dronaphthaline
Authors: Brummer Stefanie , Weiden Norbert , Weiss Alarich 
Published: February 2015

Abstract
2,3,4,4-Tetrachloro-1-oxo-1,4-dihydronaphthaline, ß-TKN, crystallizes in the orthorhombic space group D1 6
2 h - Pnma with Z = 4, and the 35Cl NQR spectrum consists of three lines with an intensity ratio of 2:1:1. The crystal structure of 2,2,3,4-tetrachloro-1-oxo-1,2-dihydronaphthaline, α-TKN, is described in literature as belonging to the polar space group C2
2 - P 21 with Z = 2. In contradiction to the reported space group and Z, we observed a three line 35Cl NQR spectrum with an intensity ratio of 2:1:1. Therefore, the crystal structure of α-TKN was redetermined at 7 = 296 K: space group C2
2h-P21/m, Z = 2, a = 888.4 (2) pm, b = 692.3 (2) pm, c = 869.6 (2) pm, β = 91.483 (5)°. The nuclear quadrupole coupling tensors have been investigated using a 4 π Zeeman NQR goniometer and FT NQR for tracing the zero splitting cones.
According to the crystal structure of β-TKN, two symmetry related zero splitting cones have been found for Cl(2), two for Cl(3), and four for Cl(4) ( T = 297 K). From the single crystal Zeeman split NQR measurements of α-TKN one zero splitting cone has been found for Cl(3), one for Cl(4), and two for CI(2) (T=290 K).
The asymmetry parameters η and the direction cosines of the principal axes Φxx, and Φyy, and Φzz of the nuclear quadrupole coupling tensors have been determined. The results are: Cl(j), v (35Cl(j)), e2 Q q h -1 (35Cl(j)), η(35Cl(j)) for β-TKN (at T = 297 K): Cl(2), 37.442 MHz, 74.469 MHz, 0.184; Cl(3), 36.854 MHz, 73.083 MHz, 0.160; Cl(4) , Cl(4'), 38.685 MHz, 77.307 MHz, 0.070 and for α-TKN (at T = 290 K): Cl(2), CI(2'), 38.297 MHz, 76.501 MHz, 0.086; Cl(3), 36.943 MHz, 73.700 MHz, 0.123; Cl(4), 36.311 MHz, 72.314 MHz, 0.160. By comparing the crystal structures and the 35Cl NQR results, the C-Cl bonds in the title compounds are discussed.
35Cl NQR Studies of Hexachlorometallates(IV) with Organic Cations, A2 [MCl6] and A'[MCl6], M=Sn, Te, Pb and A+, A'2+ = Organic Cation
Authors: Borchers Dirk , Weiss Alarich 
Published: February 2015

Abstract

35Cl NQR spectra of eleven hexachlorometallates (IV) A1 [MCl6] and A'[MCl6], M = Sn, Te, Pb, and A+ =ethylammonium, 4-picolinium, anilinium, triethylammonium, chinoxalinium, and piperi-dinium ions, and A'2+ = 1.3-propylenediammonium ion, have been observed as a function of tem-perature. The ethylammonium hexachlorometallates(IV) (C2H5 NH3)2 [MCl6], M = Sn, Te, show a phase transition at 128.8 K and 204 K, respectively. Both compounds yield a single resonance line in their high temperature phases. In case of the stannate this single 35Cl resonance line splits up into two lines at Tc = 128.8 K, whereas for the tellurate no 35Cl NQR signals could be found in the low temperature phase. A phase transition was also found for the 1.3-propylenediammonium hexa-chlorostannate(IV) at 287 K where the six line NQR spectrum of the low temperature phase changes into a four line spectrum. In contrast, the corresponding plumbate shows no transition. All other compounds studied contain distorted [MCl6]2- octahedra, and therefore they yield more than one 35Cl resonance line. The complexes have been investigated in the temperature range temperature where the lines fade out. In case of the hexachlorostannates(IV) with the ethylammonium, the 1.3-propylenediammonium and the triethylammonium ions, the crystal structures of the compounds are known and compared with the results of the 35Cl NQR spectroscopy.
Augmented Plane Wave Study of Electric Field Gradients in Non-cubic Metals
Authors: Leiberich R. , Schmidt P. C. , Sahoo N. , Das T. P. 
Published: February 2015

Abstract
The electric field gradient (EFG) in body-centered tetragonal Indium metal and hexagonal closed packed Beryllium metal is calculated on the basis of a full potential scalar relativistic augmented plane wave procedure. The various contributions to the EFG in simple metals are discussed. The total EFG in In metal found theoretically is equal to qtheor = 2.67 x 1021 Vm-2 . This value agrees well with the experimental data. Using the quadrupole moment Q deduced from the hyperfine splitting of the muon X-ray spectra one gets g exp = 2.46 x 1021 Vm-2 . The valence electrons of Indium give a direct contribution of qel = 2.72 x 1021 Vm-2 , whereas the direct ionic contribution q ion is much smaller and has opposite sign: qion = -0.01 x 1021 Vm-2 . There is a small net shielding contribution of qsh = -0.03 x 1021 Vm-2 to the EFG composed of the ionic contribution gsh. ion = -0.39 x 1021 Vm- 2 and the valence electron contribution qsh,ve = 0.36 x 10 21 Vm-2 .
Temperature Dependence of the NQR Frequency and Linewidth of the High-J c Superconductor YBa 2 Cu 3 0 7 _ 5
Authors: Riesemeier H. , Pattloch J. , Scheidt E.W. , Schaefer M. , Lüders K. 
Published: February 2015

Abstract
For YBa2Cu3O7-δ a powder samples of different average grain sizes the temperature dependences of 63Cu NQR frequencies and signal intensities are reported for the Cu (1) site in a temperature range of 4 300 K. Both quantities show a non-monotonic behaviour in the vicinity of the superconduction transition temperature Tc . In the superconducting state the line shape of the NQR signal in zero-field depends on the strength of the dc magnetic field applied during the cooling-procedure. The resulting linewidth yields information about the internal trapped magnetic field.
63/65Cu- NQR Study of impurity-lnduced Magnetic Order in YBa2(Cu1-xMx)3O7 (M = Fe, Co)
Authors: Nakamichi Y. , Kumagai K. , Nakajima H. , Fujita T. 
Published: February 2015

Abstract
We have studied 63/65 Cu NQR at the Cu(l)-chain and Cu(2)-plane site of YBa2(Cu1-x Mx)3O7 (M = Fe, Co). The spin-lattice relaxation rate, T1
-1 , is enhanced at low temperatures and has in the Fe-system a peak at 2 and 4 K for x = 0.005 and 0.015, respectively. Below the peak temperatures the intensity of the Cu-NQR signal decreases rapidly. The results suggest that magnetic ordering of either Fe or Cu moments occurs without destroying the superconductivity below Tc on substituting Cu by magnetic ions.
The 181Ta Nuclear Quadrupole Interaction in the Charge Density Wave Phases of 1T-TaS2
Authors: Ganal P. , Butz T. , Lerf A. , Naito M. , Nishihara H. 
Published: February 2015

Abstract
With a high resolution time differential perturbed angular correlation spectrometer we investigated the nuclear quadrupole interaction of Ta in 1T-TaS2 . The results obtained for the commensurate charge density wave phase lead to a revised assignment of the previously observed 181Ta NQR resonances. Differences in the intracluster architecture of the 13-atom Star of David cluster between 1T-TaS2 and 1T-TaSe2 could be responsible for the metal to semiconductor transition which occurs in lT-TaS2 but not in lT-TaSe2 .
Activation Energies for Fluxional Behavior in Aryl(pentachlorocyclopentadienyl)mercurials, η1 -C5Cl5 HgR, from 35Cl NQR Relaxation Times
Authors: Weiden Norbert , Weiss Alarich , Wulfsberg Gary , Ilsley William , Ilsley William , Benner Kevin , Wourster William 
Published: February 2015

Abstract
Solid-state activation energies for fluxional behavior in three aryl-subsituted (pentachlorocyclo-pentadienyl)phenylmercury compounds RHgC5 Cl5 : (pentachlorocyclopentadienyl)(pentamethyl-phenyl)mercury (I, R = C6 (CH3)5 , Eact = 19.3 kJ mol-1); (pentachlorocyclopentadienyl)(2,4,6-tris-(terf-butyl)phenyl)mercury (II, R = 2,4,6-C 6 H 2 (C(CH3)3)3 , Eact = 59.5 kJ mol-1); and (pentachloro-cyclopentadienyl)(phenyl)mercury (III, R = C6H5 , E act = 62.8 kJ mol-1) have beeb obtained from 35Cl NQR spin-lattice relaxation-time measurements. II has also been shown to be fluxional in solution by 13C NMR spectra. II was prepared by an exchange reaction between Hg(C5Cl5)2 and Hg(2,4,6-C6H2(C(CH3)3)3)2 , which reacted readily despite the great steric hindrance present in the latter reagent.
35Cl NQR Study of Guest Dynamics in Thiourea-CCl4 Inclusion Complex
Authors: Matsuo Takasuke , Sekii Masako , Suga Hiroshi , Nakamura Nobuo , Chihara Hideaki 
Published: February 2015

Abstract

35Cl nuclear quadrupole resonance measurements on thiourea-CCl4 inclusion complex yielded two resonance lines with intensity ratio 1:3. This indicates that the guest CCl4 molecule occupies the three-fold symmetry site in the channel formed by the thiourea framework. The resonance frequencies closely follow Bayer's equation between 4.2 K and 27 K. At higher temperatures the resonance lines faded out. This is attributed to the onset of reorientation of the CCl4 molecule. The activation energy for this motion was estimated to be 6 kJ mol-1 .