bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pure Rotational Spectroscopy of Sodium Chloride, NaCl, up to 930 GHz
Authors: Caris M. , Lewen F. , Winnewisser G. 
Published: February 2015

The pure rotational spectra of both isotopomers of NaCl, i. e. 23Na35Cl and 23Na37Cl, have been recorded in high resolution with the Cologne terahertz spectrometer. A total of 189 new rotational lines have been measured in the frequency region between 200 and 930 GHz. Twenty nine of these transitions are assigned for Na35Cl to the vibrational ground state with J < 72, and 102 lines arise from vibrationally excited states up to the 5th vibrational state: ν = 5̅. For Na37Cl a total of 58 rotational lines with J ≤ 76 and ν ≤ 4 could be detected. The newly measured lines were fitted together with the published microwave and millimeter-wave transitions to obtain a refined and extended set of molecular parameters: Na35Cl: B0 = 6513.04908(41) MHz, D0 = 9.338978(141) kHz, H0 = -1.0433(144) mHz and Na37Cl: B0 = 6373.74158(66) MHz, D0 = 8.943327(185) kHz, H0 = -0.9623(162) mHz.
From the experimental data the equilibrium constants Be, α, γ, De, β, δ, He and ε are calculated as well. The refined parameters for both isotopomers allow precise frequency predictions to be made far into the terahertz region. Thus this new and highly precise data set for NaCl is intended to support future astrophysical observations.
Entangled Quantum States and the Kronecker Product
Authors: Steeb Willi-Hans , Hardy Yorick 
Published: February 2015

C
Entangled quantum states are an important component of quantum computing techniques such as quantum error-correction, dense coding and quantum teleportation. We determine the requirements for a state in the Hilbert space ⊗ Cn
for m, n ∈ N to be entangled and a solution to the corresponding “factorization” problem if this is not the case.We consider the implications of these criteria for computer algebra applications.
Bromine and Antimony NQR of 4-Aminopyridinium Tetrabromoantimonate(III)
Authors: Niki Haruo , Yogi Mamoru , Tamanaha Mikako , Seto Urara , Hashimoto Masao , Terao Hiromitsu 
Published: February 2015

The temperature dependences of T1 and T2 of 81Br and 121Sb NQR have been measured in order to study the phase transition at Tc = 224 K as well as the crystal dynamics in 4-aminopyridinium tetrabromoantimonate(III) (4-NH2PyHSbBr4). The temperature dependence of T1 of 81Br and 121Sb NQR follows the usual T2 law in the range from 80 to 120 K. T1 is dominated by fluctuations of the EFG at the Br and Sb nuclei due to lattice vibrations.
The T1 vs. 1/T curves in the region between about 120 and 140 K can be described by exponential curves. The activation energies of motions obtained from these curves are similar to those from proton NMR. The exponential changes of T1 of Br and Sb NQR are attributable to fluctuations caused by the thermal motion of 4-NH2PyH cations.
Echo signals of Br and SbNQRin the lowtemperature phase could not be detected at temperatures higher than 145 and 150 K, respectively, because the S/N ratios became poor owing to the very short T2. The echo signals could also not be detected at temperatures above Tc because of the short T2
Preliminary Studies of the Obtaining of Solid Metallic Cerium from Fluoride Melts
Authors: Constantin Virgil , Popescu Ana-Maria , Zuca Stefania 
Published: February 2015

The present study deals with the obtaining of solid cerium by molten salt electrolysis of a 46.74 - 48.26 - 5wt% LiF-NaF-NaCeF4 mixture, in the temperature range 700 - 730 °C and with a current efficiency of ~ 75%.
For this purpose NaCeF4 was obtained, characterized and it’s cubic form was identified. The solubility and decomposition potential of this compound in the molten electrolyte 49.2 - 50.8% LiF-NaF was also studied.
Structure and Properties of [(CH2OH)3CNH3]H2AsO4
Authors: Waśkowska A. , Dacko S. , Czapla Z. 
Published: February 2015

Crystals of [(CH2OH)3CNH3]H2AsO4 have been grown, and X-ray diffraction analysis has shown them to be monoclinic, with space group P21. A three-dimensional network of hydrogen bonds of the type O-H. . . O and N-H. . . O forms strong cation-cation and cation-anion linkages. Stabilizing the structure, they create favourable conditions in the crystal to be polar. The temperature dependent behaviour of the dielectric permittivity, measured along three crystal axes in the range 100 - 300 K, did not show any evidence for a phase transition, while the pyroelectric properties of the crystal confirmed the lack of a centre of symmetry.
These polar features locate [(CH2OH)3CNH3]H2AsO4 among the materials applicable to electrooptics and for the second harmonic generation.
The Rotational Spectrum of Ketene Isotopomers with 18O and 13C Revisited
Authors: Guarnieri A. , Huckaufa A. 
Published: February 2015

The pure rotational spectra of [18O]ketene, H2C=C18O, [1-13C]ketene, H2C=13CO, and [2-13C]ketene, H2
13C=CO, have been revisited in the frequency region 200 - 350 GHz in the ground vibrational state.
From more than 100 R-branch transitions for each isotopomer a set of rotational and centrifugal distortion constants could be derived using the Watson S-reduction formalism. The values obtained for the rotational constants B and C agree very well with results of former investigations. The agreement is worse with respect to the A constants, but our newly determined A values agree well with the corresponding values of the main species and the 17O isotopomer.
EPR Study of Cu2+ and VO2+ Ions in [NH4H3(C2O4)2] ·2H2O Single Crystals
Authors: Biyik R. , Tapramaz R. , Karabulut B. 
Published: February 2015

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The EPR spectra of Cu2+ and VO2+ ions in [NH4H3(C2O4)2]·2H2O single crystals were recorded at room temperature in three orthogonal planes. The spectra indicate that the Cu2+ and VO2+ ions substitute NH+4 ions. The principal values of the and A tensors were determined. The ground state wave function of the Cu2+ ion in the lattice has been calculated and the covalancy and Fermi contact terms of the VO2+ ions were evaluated.
Anomalous Inhomogeneous Broadening of Electronic Spectra of Molecules with Internal Charge Transfer
Authors: Tomin V. I. , Hubisz K. , Mudryka Z. 
Published: February 2015

Excited states with internal charge transfer of some molecules show an anomalously strong inhomogeneous broadening of their electronic spectra. Here such an inhomogeneous broadening for N, N-dimethylaminobenzonithrile (DMABN) was studied. The spectral inhomogeneity for DMABN in some polar solvents reaches 140 - 150 nm.
The interpretation of the obtained results is based on treating a solution as a set of chemically identical solvates with a luminophor molecule in the centre, having different energies of the pure electronic transitions. The inhomogeneity arises due to an intermolecular effect of the luminophors environment on its spectra in polar solvents, as well as a process of intramolecular movement of the twisting fragments relative to the main moiety of DMABN.
Single Crystal ESR of Copper Doped KHCO3
Authors: Lötz Albert 
Published: February 2015

A
The principal components of the g- and -tensor of 63Cu2+ obtained from single crystal ESR spectra of copper doped KHCO3 are gzz = 2.2347(1), gyy = 2.0474(1), gxx = 2.0468(1), Azz = 20.43(2) mT, Ayy = 3.22(1) mT, Axx = 2.63(2) mT. The unique axes of both tensors are parallel and lie in the mirror plane of the point group of the crystal (2/m). The direction of this axis conforms with the expectation from the structure of the first coordination shell of the K+ ions. This provides strong evidence for copper entering the K+ positions without major lattice disturbance. Several of the results presented here are at variance with those of an earlier report on the same subject.
Local Spacetime Dynamics, the Einstein-Straus Vacuole and the PIONEER Anomaly: A New Access to these Problems
Authors: Fahr Hans-Jörg , Siewert Mark 
Published: February 2015

The question concerning the extent of the local spacetime has often been raised. At what circumsolar distance the well known Robertson-Walker spacetime of our expanding universe may become a valid approximation? Inside of that distance a local Schwarzschild metric, which permits to explain the Keplerian motions of planets within the frame of general relativity, must be applicable.We briefly analyze the historical answer to that question given by Einstein, Straus and their followers and show that till now this answer is unsatisfactory in many respects.
We revisit the problem of local spacetime geometries in the light of their effects on local photon propagation in view of the radiopropagation phenomena detected with the NASA spaceprobes PIONEER-10/11, waiting for a satisfying answer for several decades now. Comparing radiosignals outgoing from the earth to the probe and ingoing again from the probe to the receiver on earth do show anomalous frequency shifts which presently find no explanation by anomalous non-Newtonian decelerations of these probes. Therefore we study cosmological conditions for the transfer of radiosignals between the earth and these distant probes based on time dependent local spacetime geometries. First we study the cosmological redshift of radiophotons during their propagation to the spaceprobe and show that this shift in fact explains the registered PIONEER phenomenon under the assumption that the full cosmological expansion of the universe also takes place locally. Though yielding the right magnitude, one finds that this assumption leads to a redshift instead of the observed blueshift. We then, however, show that theoretically motivated forms of time dependent local spacetime metrices in fact lead to a blueshift of the needed magnitude. The appropriate local space vacuole is characterized by a Schwarzschild metric of a central mass increasing with cosmic time. Though it is clear that further studies of this effect have to be carried out to give more credit and verification to this hypothetical result, nevertheless more careful hightech radiotracking of freely flying spaceprobes may do a usefull job in confirming a completely unexpected, but cosmologically highly relevant phenomenon.
A Gated Four Probe Technique for Field Effect Measurements on Disordered Organic Semiconductors
Authors: von Hauff Elizabeth , Spethmann Nicolas , Parisi Jürgen 
Published: February 2015

A gated four probe measurement technique to isolate contact resistances in field effect measurements
on disordered organic semiconductors was investigated. Organic field effect transistors (OFETs) were prepared with two additional electrodes in the contact geometry protruding into the source-drain channel to monitor the variation in potential across the channel. Two high impedance electrometers were used to determine the potential at the contacts. This technique allows to directly determine the magnitude of the parasitic contact resistances between metal contact and organic semiconductor from the drop in potential at the contact regions. The effects of contact resistances, which can falsify measurements on bulk transport parameters such as the field effect mobility, can be then eliminated during material characterization. Additionally, the temperature and electric field dependence of the contact resistances offers valuable information about the charge injection and extraction processes between metal and organic semiconductor. The effects of the four probe geometry, specifically the effect of the channel electrodes on the current-voltage characteristics, of hole transport in a polythiophene (P3HT) OFET with Au contacts were investigated and found not to influence device performance, except at currents « 1 nA. The IV characteristics were shown to follow the expected FET behaviour. From the variation in potential along the channel it was found that contact resistances at the source contact (charge injecting contact) are minimal while contact resistances at the
drain contact (charge extracting contact) are significant, resulting in a much lower effective sourcedrain voltage than that applied to the device.
Error Analysis of the Oscillating Cup Method for Viscosity Measurements of Molten Salts
Authors: Tolbaru Dumitru , Popescu Ana-Maria , Zuca Stefania 
Published: February 2015

The errors in viscosity measurements by the oscillating cup method were calculated as a function of the limit of accuracy imposed by the uncertainty in determining the constants of the oscillating system R, I, T0, δ0 and the limit of precision resulting from errors in determining the experimental parameters δ , T , h, ρ.
Thus, by evaluating the fractional error of each of the parameters and implicitly its distinct contribution to the total standard error, it was established that the “meniscus error” Δh, which is difficult to be controlled or avoided, represents the major source of imprecision of oscillating cup viscometers.
Phase Behaviour and FTIR Spectra of Ionic Liquids: The Mixtures of 1-Butyl-1-methylpyrrolidinium Chloride and TaCl5
Authors: Babushkina Olga B 
Published: February 2015

A series of ionic liquids consisting of 1-butyl-1-methylpyrrolidinium chloride (Pyr14Cl) and TaCl5 at molar ratios of Pyr14Cl in the range of 0.85 - 0.20 was synthesized. They exhibit potential application as electrolytes for the electrochemical deposition of tantalum. The thermal behaviour of the Pyr14Cl-TaCl5 mixtures was investigated, using differential scanning calorimetry (DSC) to estimate the range of thermal stability and to determine the optimal compositions for electrochemical trials. The Pyr14Cl-TaCl5 mixtures formed stoichiometric 3 : 2 and 2 : 3 crystalline phases with melting points of 70 °C and 130 °C, respectively, characterized by entropies of fusion of 13.6 JK−1 mol−1 and 10.1 JK−1 mol−1. The mixtures with molar fractions of Pyr14Cl equal to 0.60 and 0.40 were clear and transparent liquids and had the lowest viscosity; they were the most suitable for electrochemical applications.
FTIR spectra of the Pyr14Cl-TaCl5 mixtures allowed to get insight into inter-ionic interactions and the nature of formation of these ionic liquids as a function of the molar ratio of the components.
Spectroscopy and Electrochemistry of Tantalum(V) in 1-Butyl-1-methylpyrrolidinium Trifluoromethanesulfonate
Authors: Babushkina Olga B. , Ekres Silvia , Nauer Gerhard E. 
Published: February 2015

FTIR spectroscopic and electrochemical characterizations of tantalum(V) in 1-butyl-1-methylpyrrolidinium trifluoromethanesulfonate (Pyr14TFMS)-TaCl5 ionic liquids are performed with 5, 15, and 35 mol% TaCl5 as the media for potential electrochemical application. On the basis of FTIR spectra the electrochemical active species are identified as follows: [TaOCl4]−, [TaOCl5]2−, [TaCl5F]−, and [TaCl5F2]2−. The dominant species are the oxochloride complexes of tantalum(V).
Cyclic voltammograms of Pyr14TFMS-TaCl5 mixtures at 80 °C exhibit three reduction peaks: at −0.8 V, −0.9 V, and −2.4 V. The first reduction peak corresponds to the reduction of the oxochloride species of tantalum(V), the second is assigned to the reduction of the mixed chloride-fluoride species of tantalum(V), and the third peak to the further reduction of tantalum.
The spectroscopic data confirm the suggestion that oxochloride complexes of tantalum(V) become the dominant species in ionic liquids with the oxygen-containing functional group [CF3SO3]−, possibly restricting the process of tantalum metal deposition from these ionic liquids.
Surface Magnetic Effects in an Alternating Superlattice
Authors: Xu Zhi , Kuang Xiao-Yu 
Published: February 2015

We investigate the surface magnetism of the alternating superlattice with localized spin-1/2. Using
the mean-field approximation method, we discuss not only the correlation between the critical value
j0C of the exchange constant in the surface layer and interlayer exchange constants, but also the connection
between j0C and the bulk exchange constant jA. The calculated results are in good agreement
with the former theoretical calculations. Based on the solutions, we show the relations between the
critical parameter c = JS/JA and the bulk exchange constants as well as the surface transition temperature.
JS is the exchange constant in the first two surface layers. Comparing with the earlier theoretical
works, our results show the effect of the surface modification more gradual.
The Dispersion Relation for the 1/sinh2 Potential in the Classical Limit
Authors: Campbell Joel 
Published: February 2015

Abstract
The dispersion relation for the inverse hyperbolic potential is calculated in the classical limit. This is shown for both the low amplitude phonon branch and the high amplitude soliton branch. It is shown that these results qualitatively follow the previously found ones for the inverse squared potential where explicit analytic solutions are known
Alignment of Buckingham Parameters to Generalized Lennard-Jones Potential Functions
Authors: Lim Teik-Cheng 
Published: February 2015

Abstract
The Lennard-Jones(12-6) and the Exponential-6 potential functions are commonly used in computational softwares for describing the van der Waals interaction energy. Some softwares allow switching between these two potentials under prescribed condition(s) that attempt to connect the parameter relationship between the two functions. Here we propose a technique by which the parameter relationship between both potentials is extracted by simultaneously imposing an equal force constant at the well depth’s minimum and an equal mean interatomic energy from the point of equilibrium to the point of total separation. The former imposition induces good agreement for the interatomic compression and a small change in the interatomic distance near the equilibrium while the latter enables good agreement for large interatomic separation. The excellent agreement exhibited by the plots validates the technique of combined criteria proposed herein
Metal Binding by Humic Substances – Characterization by High-Resolution Lanthanoide Ion Probe Spectroscopy (HR-LIPS)
Authors: Marmodée Bettina , Klerk Joost de , Ariese Freek , Gooijer Cees , Kumke Michael U. 
Published: February 2015

Abstract
In ultra-low-temperature experiments at 4.7 K the luminescence of Eu(III) bound to different hydroxy- and methoxybenzoic acids and to humic substances (HS) was investigated. The benzoic acid derivatives were used as simple model compounds for common metal-binding structures in HS. The Eu(III) luminescence was directly excited by means of a pulsed dye laser, scanning through the 5D0 ← 7F0 transition of Eu(III) and subsequently high-resolution total luminescence spectra (TLS) were recorded. Based on the thorough analysis of the high-resolution TLS conclusions were drawn with respect to the number of different complexes formed and to the symmetry of the complexes. The crystal-field strength parameter Nν (B2q) was dependent on the electrostatic forces induced by the ligands as well as on the symmetry of the complexes. The formation of thermodynamically stable complexes was found to be slow even for small model ligands such as 2-hydroxybenzoic acid. Comparison between the model compounds and HS clearly revealed that the carboxylate group is the dominant binding site in HS. Indices for the formation of chelates, e. g. similar to 2-hydroxybenzoic acid, were not found for HS
Defective BN Nanotubes: A Density Functional Theory Study of B-11 and N-14 NQR Parameters
Authors: Giahi Masoud , Mirzaei Mahmoud 
Published: February 2015

Abstract
A density functional theory (DFT) study is performed to investigate the influence of structural defects on the electronic structure properties of perfect boron nitride nanotubes (BNNTs). To this aim, as representative models, the single-walled (6,0) BNNT consisting of 36 boron, 36 nitrogen, and 12 hydrogen atoms and the single-walled (4,4) BNNT consisting of 36 boron, 36 nitrogen, and 16 hydrogen atoms are considered. The nuclear quadrupole resonance (NQR) parameters are calculated and compared in two perfect and defective models of the considered BNNTs. The results indicate that due to formation of non-hexagonal rings in the defective model because of removing a B-N bond, the NQR parameters at the sites of first neighbouring nuclei are significantly influenced by imposed perturbation, however, the sites of other nuclei, farther from perturbation, remain almost unchanged. The calculations are performed at the level of the BLYP method and 6-31G* standard basis set using the GAUSSIAN 98 package
Existence, Asymptotic Behaviour, and Blow up of Solutions for a Class of Nonlinear Wave Equations with Dissipative and Dispersive Terms
Authors: Polat Necat , Kaya Doğan 
Published: February 2015

Abstract
We consider the existence, both locally and globally in time, the asymptotic behaviour, and the blow up of solutions to the initial boundary value problem for a class of nonlinear wave equations with dissipative and dispersive terms. Under rather mild conditions on the nonlinear term and the initial data we prove that the above-mentioned problem admits a unique local solution, which can be continued to a global solution, and the solution decays exponentially to zero as t →+∞. Finally, under a suitable condition on the nonlinear term, we prove that the local solutions with negative and nonnegative initial energy blow up in finite time.
Novel Asymptotic SolitonWaves for the Nonlinear Schrödinger Equation with Varying Gain/Loss and Frequency Chirping
Authors: Lai Xian-Jing , Zhang Jie-Fang 
Published: February 2015

Abstract
This paper analysis spatial asymptotic waves propagation in nonuniform optical fiber. It finds an appropriate transformation such that the nonlinear variable-coefficient Schr¨odinger equation transform into the nonlinear Schr¨odinger equation with varying gain/loss and frequency chirping. It obtains solitonlike and periodic self-similar asymptotic waves by using the transformation. We analyze the evolution properties of some novel self-similar solutions. In addition, the nature of our self-similar asymptotic wave hints to the possibility of designing optical amplifier and focusing of spatial waves to overcome inevitable energy losses while performing in the optical nonlinear media.
The Solution of the Variable Coefficients Fourth-Order Parabolic Partial Differential Equations by the Homotopy Perturbation Method
Authors: Dehghan Mehdi , Manafian Jalil 
Published: February 2015

Abstract
In this work, the homotopy perturbation method proposed by Ji-Huan He [1] is applied to solve both linear and nonlinear boundary value problems for fourth-order partial differential equations. The numerical results obtained with minimum amount of computation are compared with the exact solution to show the efficiency of the method. The results show that the homotopy perturbation method is of high accuracy and efficient for solving the fourth-order parabolic partial differential equation with variable coefficients. The results show also that the introduced method is a powerful tool for solving the fourth-order parabolic partial differential equations.
Optimum Path of a Flying Object with Exponentially Decaying Density Medium
Authors: Abbasbandy Said , Pakdemirli Mehmet , Shivanian Elyas 
Published: February 2015

Abstract
In this paper, a differential equation describing the optimum path of a flying object is derived. The density of the fluid is assumed to be exponentially decaying with altitude. The equation is cast in to a dimensionless form and the exact solution is given. This equation is then analyzed by homotopy analysis method (HAM). The results showed in the figures reveal that this method is very effective and convenient.
Application of Variational Iteration Method for nth-Order Integro-Differential Equations
Authors: Abbasbandy Said , Shivanian Elyas 
Published: February 2015

Abstract
In this paper, the variational iteration method is proposed to solve Fredholm’s nth-order integrodifferential equations. The initial approximation is selected wisely which satisfies the initial conditions. The results reveal that this method is very effective and convenient in comparison with other methods.