bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistence and Mobility of Imidacloprid and Abamectin Residues in Green House Soil
Authors: Haddad Marwan , Khalaf Osama , Jodeh Shehdeh
Published: February 2015

Two pesticides were selected, imidacloprid (Konfidor ®) and abamectin (Vertimec ®) which are widely used in controlling insects and pests in greenhouses in Palestine. Imidacloprid and Abamectin adsorption onto greenhouse soil surfaces was studied by batch experiments. Experiments were conducted in a set of 100 mL capped conical flasks. In each pesticide adsorption experiment, an aliquot (50 mL) of (10-50 mg/L) solutions was used. Pesticides concentration was analyzed at the end of each experiment. The results indicate that: (1) the degradation of Imidacloprid and Abamectin soils was fitted to the second-order reaction kinetics model and showed good performance for all treatments, (2) the GUS values obtained for Imidacloprid and Abamectin were ranging between 1.95 and 3.3 and 1.68 to 3.31, respectively which is rated moderate to slightly high leachable/transportable to groundwater [understanding], (3) the distribution coefficient for both tested pesticides exhibit increasing adsorption on soil surface with increasing concentration in solution, (4) the observed persistence, half-life for Imidacloprid and Abamectin was 61 and 41 days, respectively, and in good agreement with reported in literature values, (5) mobility rate constants (Kd of 2 to 11 and Koc of 142 to 817) obtained for both Imidacloprid and Abamectin were higher than those reported in literature revealing that the tested soil is higher in leaching capacity, (6) the risk of particle-bound pesticide transport through soil to groundwater was rated slightly high to high for both pesticides, and (7) mobility and persistence results of Imidacloprid and Abamectin on soil obtained in this study were highly influenced by soil composition of high silt and low organic matter content leading to lower sorption rates and higher leaching to groundwater.
Llamados a ser Protagonistas. Política Educativa, Movilización Juvenil y Participación de los Estudiantes Secundarios. Provincia de Buenos Aires, Argentina, 2009- 2014
Authors: Larrondo Marina
Published: February 2015

A partir de un conjunto de hallazgos empíricos y conceptuales—producto de una investigación finalizada—en este trabajo buscamos dar cuenta de las características que asume la participación política de los estudiantes secundarios en el ámbito escolar y en las organizaciones del movimiento estudiantil. Para ello, analizamos y ponemos en relación dichas características con los cambios recientes en la política educativa provincial, sus efectos y múltiples apropiaciones por parte de los actores involucrados: directivos, estudiantes y militantes. Sugerimos entonces que los cambios en la política tienen vínculos complejos y multidimensionales con las organizaciones políticas en un contexto de reconfiguraciones de la militancia juvenil; y arriesgamos que dicha confluencia ha impactado en una importante revitalización de la participación escolar y de la conformación de organizaciones estudiantiles, tanto partidarias como independientes. Consideramos que este trabajo puede enriquecer las reflexiones en torno a la relación entre políticas educativas, escuelas y acción colectiva. Por último, en un contexto regional donde la literatura enfatiza la movilización estudiantil a partir de características confrontativas con el Estado y las formas institucionales de representación política, el caso argentino nos permite mostrar y reflexionar sobre otras articulaciones posibles entre estas instancias y la participación política juvenil. ￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼￼
Melatonin counteracts changes in hypothalamic gene expression of signals regulating feeding behavior in high-fat fed rats
Authors: Ríos-Lugo María J. , Jiménez-Ortega Vanesa , Cano-Barquilla Pilar , Mateos Pilar Fernández , Spinedi Eduardo J. , Cardinali Daniel P. , Esquifino Ana I.
Published: February 2015

Background: Previous studies indicate that the administration of melatonin caused body weight and abdominal visceral fat reductions in rodent models of hyperadiposity. The objective of the present study performed in high-fat fed rats was to evaluate the activity of melatonin on gene expression of some medial basal hypothalamus (MBH) signals involved in feeding behavior regulation, including neuropeptide Y (NPY), proopiomelanocortin (POMC), prolactin-releasing peptide (PrRP), leptin- and insulin-receptors (R) and insulin-R substrate (IRS)-1 and -2. Blood levels of leptin and adiponectin were also measured.

Methods: Adult Wistar male rats were divided into four groups (n=16 per group): (i) control diet (3% fat); (ii) high-fat (35%) diet; (iii) high-fat diet+melatonin; (iv) control diet+melatonin. Rats had free access to high-fat or control chow and one of the following drinking solutions: (a) tap water; (b) 25 μg/mL of melatonin.

Results: After 10 weeks, the high-fat fed rats showed augmented MBH mRNA levels of NPY, leptin-R, PrRP, insulin-R, IRS-1 and IRS-2. The concomitant administration of melatonin counteracted this increase. Feeding of rats with a high-fat diet augmented expression of the MBH POMC gene through an effect insensitive to melatonin treatment. The augmented levels of circulating leptin and adiponectin seen in high-fat fed rats were counteracted by melatonin as was the augmented body weight: melatonin significantly attenuated a body weight increase in high-fat fed rats without affecting chow or water consumption. Melatonin augmented plasma leptin and adiponectin in control rats.

Conclusions: The results indicate that an effect on gene expression of feeding behavior signals at the central nervous system (CNS) may complement a peripheral rise of the energy expenditure produced by melatonin to decrease body weight in high-fat fed rats.
Thermodynamic Functions at Isobaric Process of van der Waals Gases
Authors: Matsumoto Akira
Published: February 2015

The thermodynamic functions for the van der Waals equation are investigated at isobaric process. The Gibbs free energy is expressed as the sum of the Helmholtz free energy and PV, and the volume in this case is described as the implicit function of the cubic equation for V in the van der Waals equation. Furthermore, the Gibbs free energy is given as a function of the reduced temperature, pressure and volume, introducing a reduced equation of state. Volume, enthalpy, entropy, heat capacity, thermal expansivity, and isothermal compressibility are given as functions of the reduced temperature, pressure and volume, respectively. Some thermodynamic quantities are calculated numerically and drawn graphically. The heat capacity, thermal expansivity, and isothermal compressibility diverge to infinity at the critical point. This suggests that a second-order phase transition may occur at the critical point.
Studies of the Local Phase-transition Behaviour for Ni+ -II Centers in RbCaF3 Crystal from EPR Data
Authors: Zheng Wen-Chen , Wu Shao-Yi
Published: February 2015

By fitting the calculated EPR gi(i = x, y, z) factors to the observed values, the local release factor kl which is introduced to characterize the release (or elongation) effect of impurity-ligand bonds along the rotational axis in the cubic-to-tetragonal phase transition of ABX3 perovskites, is obtained for the Ni+- II center in RbCaF3 crystal. The result shows that, similar to the local rotational angle (or order parameter) Φ, the local release factor is unlike that of the host crystal. It suggests that in the doped crystal the impurity can affect the local phase transition behaviour in the vicinity of impurity ions.
X-ray Investigations of Liquid Bismuth-Copper Alloys
Authors: Nzali J. Nomssi , Hoyer W.
Published: February 2015

Liquid copper, bismuth, and eleven bismuth-copper alloys were investigated at temperatures above the liquidus with X-ray diffraction. The experimental procedure was adjusted to reduce the effects of evaporation. The Faber-Ziman total structure factors S(Q) feature a splitting of the first maximum and negative values for Q around 1 Å -1 in a large concentration range. The results are compared to previous neutron diffraction results by Zaiss and Steeb, to square-well potential model calculations by Gopala Rao and Satpathy and to a simple segregation model. The segregation model reproduces the features qualitatively. Partial structure factors are assessed by fitting both neutron and X-ray scattering results with reverse Monte-Carlo simulation
Non-Kinematicity of the Dilation-of-time Relation of Einstein for Time-intervals
Authors: Golden Sidney
Published: February 2015

Light-pulses that are reflected recurrently to one another by two kinematically equivalent dynamically identical inertial systems moving collinearly and irrotationally with uniform relative velocity generate sequences of contiguous time-intervals in both. By means of clocks stationed in the two systems, each time-interval is both measurable locally and calculable non-locally in accord with basic requirements of special relativity theory. Their ratio yields the velocity dependent dilation-of-time relation of Einstein, but an equivalent spatially dependent version of it is obtained as well, because the time-intervals involved are actually determined by the distances that exist between the systems when the reflections occur. As a result, the Einstein relation involves no time-rates of clocks that are actually affected kinematically by the systems containing them.
Properties of Nanocrystalline Nickel Particles in Ni-Si0 2 Composites
Authors: Ennas G. , Falquri A. , Piccaluga G. , Solinas S. , Gatteschi D. , Sangregoriob C. , Benedettic A.
Published: February 2015

Nickel-Silica nanocomposites with a nickel content equal to 10, 15, 20 wt% have been prepared by a sol-gel method starting from ethanolic solutions of tetraethoxysilane and nickel nitrate hexahydrate. After selation the samples were reduced in H-> flow at selected temperature (450 °C < T < 600 °C). The morphological, structural and magnetic properties were investigated by transmission electron microscopy (TEM), wide and small angle X-ray scattering (WAXS, SAXS), magnetic susceptibility in zero field cooled and field cooled mode (ZFC and FC), and magnetic hysteresis loop. Nanometric nickel particles are observed in all the investigated samples. TEM, WAXS and SAXS techniques indicate that the average nickel particle size grows slightly but almost regularly with the nickel concentration. TEM results moreover indicate that also the width of the particle size distribution, which can be simulated by log-normal functions, follows this trend. All the sample treated in hydrogen show superparamagnetic behaviour. The magnetisation falls to reach saturation up to highest measuring field of 70 kOe even at 3 K, while the observed coercivity Hc is much higher than the theoretical bulk one. Some uncertainty in the complete interpretation of the sequence of magnetic measurements is attributed to a progressive oxidation of the samples when these are air exposed.
Orthogonal Smectic Layers Favour Nucleation through Diffusioncontrolled Transformations: A Systematic Crystallization Kinetics Study
Authors: Kumar P. A. , Swathi Pisupati , Pisipati V. G. K. M.
Published: February 2015

Systematic investigations of the crystallization kinetics of two representative compounds of p-phenylbenzylidene-p´ -alkylanilines are performed, using differential scanning calorimetry, to study the influence of the kinetophase (occurs prior to the crystal phase) on the nucleation process. The dimensionality of the crystal growth and the related crystallization process are discussed in terms of the Avrami parameters n and b. The trend in the magnitude of the Avrami exponent n supports the occurrence of temperature-dependent transformations in the orthorhombic molecular array.
Pair Densities in a Two-dimensional Electron Gas (Jellium) at Strong Coupling from Scattering Theory with Kukkonen-Overhauser Effective Interactions
Authors: Capurro F. , Asgari R. , Davoudi B. , Polini M. , Tosi P.
Published: February 2015

We present a calculation of the spin-averaged and spin-resolved pair distribution functions for a homogeneous gas of electrons moving in a plane with e2/r interactions at coupling strength rs = 10. The calculation is based on the solution of a two-electron scattering problem for both parallelspin- and antiparallel-spin-pairs interacting via effective spin-dependent many-body potentials. The scattering potentials are modeled within the approach proposed by Kukkonen and Overhauser to treat exchange and correlations under close constraints imposed by sum rules. We find very good agreement with quantum MonteCarlo data for the spin-averaged pair density. We also find that short-range pairing between parallel-spin electrons is beginning to emerge in the paramagnetic fluid at this coupling strength, as a precursor of a transition to a fully spin-polarized fluid state occurring at stronger coupling.
Resonant IR Photon Induced Dissociation in Organic Molecules with Chain-like Substructures
Authors: Jungclas H. , Schmidt L. , Komarov V. V. , Popova A. M. , Stureikoa I. O.
Published: February 2015

A nonstatistical model for the resonant IR photon induced dissociation of organic molecules by IR photons is suggested. The model is based on the excimol theory for molecules which contain chains of identical diatomic dipole groups. IR photon radiation can induce resonantly collective vibrational excitations (excimols) in these molecular substructures. The accumulation of several excimols in the molecular chain causes a local heating of the molecule and its fragmentation on a time scale of several hundreds of femtoseconds. An analytical expression for the fragmentation probability is derived and analysed.
The Determination of Mobility and Immobility of Water Adsorbed in Type 5A and 13X Zeolites by IR and DTA
Authors: Ucun F.
Published: February 2015

In this study, infrared (IR) and differential thermal analysis (DTA) data were used to investigate the mobility of water adsorbed in synthetic zeolites of type 5A and 13X with pore diameters of 5 and 10 Å, respectively. The results indicate that there are at least two types of water, mobile and immobile ones, in the narrow pore zeolite, while there is only mobile water in the wide pore zeolite.
Photoswitching of the Optical and Electrical Properties of One-dimensional π-Electron Systems
Authors: Tyutyulkov Nikolai , Dietz Fritz
Published: February 2015

The photoswitching of the energy gap width of the isomeric forms of photoresponsive polymers with homomiclear photochrome diaryletheue elementary units is investigated theoretically, taking into account the correlation correction. It is shown that a real switching of electrical conductivity (insulator ⇔ semiconductor or conductor) can not be realized with polymers with alternant homomiclear π -electron systems within the elementary unit. A change and tuning-in of the light absorption is possible in most cases.
The Investigation of Phase Diagrams of Erbium Pnictides
Authors: Abdusalyamova M. N. , Rachmatov O. I.
Published: February 2015

The phase diagrams of Er-Sb and Er-Bi have been obtained. Erbium forms three compounds with antimony as well as bismuth. The antimonides and bismuthides Er5Sb3 (1640°C), Er5Bi3 (1427°C), ErSb2 (650°C) and ErBi2 (595°C) are formed by peritectic reactions. ErSb (2040°C) and ErBi (1860°C) melt congruently
Phase-space Symmetry and the Action Function of the Pendulum Problem
Authors: Olszewski S. , Roliński T. , Baszczak M. , Kozak R.
Published: February 2015

An approach to the pendulum problem, which is an alternative to the well-known traditional treatment of that problem, has been formulated. An advantage of the new approach is provided by a full symmetry in the position and momentum variables of the Hamiltonian expression for the energy of the system. A similar symmetry holds for the Hamilton equations describing the motion of a pendulum-like point mass. Calculations of the action function forthe two kinds of pendulum Hamiltonians - the traditional one and the new one - are presented.
The Thermal Conductivity of Molten KHF2
Authors: Slavíček Pavel , Matal Oldřich , Žmij Bronislav , Nejedlý Milan , Žaloudek Josef
Published: February 2015

The thermal conductivity of the molten KHF2 has been determined by means of a specially developed experimental facility at 250 to 450°C.
Mean Amplitudes of Vibration of F3ClO
Authors: Baran E. J.
Published: February 2015

Mean amplitudes of vibration of F3ClO have been calculated from vibrational spectroscopic data in the temperature range between 0 and 1000 K. Its bond properties are discussed on the basis of the obtained results and by comparison with known data for related species. Mean amplitudes of vibration for the related F3BrO molecule are also estimated and briefly discussed
NQR Study of Piperazinium Tetrahalogenometalates(II) [C4H12N2]MX4 (M = Zn, Cd, Hg; X = Br, I)
Authors: Ishihara Hideta , Hatano Naoko , Horiuchi Keizo , Terao Hiromitsu
Published: February 2015

1

The 81Brand127INQR (V1: m =±1/2 ↔ m =±3/2 transition) frequencies in the title compounds were measured as functions of temperature. Four NQR lines were observed for each bromide or iodide in the temperature range investigated. Piperaziniumtetrabromocadmate(II)was obtained as a monohydrate () containing isolated CdBr4
2− anions, piperazinium dications, and water molecules (monoclinic, P21/c at 293 K). The crystal structure of piperazinium tetraiodocadmate(II) (2) was found to consist of isolated CdI4
2− anions and dications (orthorhombic, P212121 at 293 K). The structures of others seem to be similar to that of (2). The DSC measurement of (1) showed heat anomalies at ca. 363, 386 and 556 K, that of the anhydrous sample only at 556 K, which suggests that the former two heat anomalies are due to dehydration. All the other compounds exhibited also a phase transition around 550 K and decomposed above 600 K. Disappearance (or remarkable weakening in intensity) of the NQR lines was observed at 330 - 350 K in all compounds, indicating the pronounced excitation of librational motions of anions and/or cations. The NQR results indicate that the covalent character of M-X bond is in the order Zn-X < Cd-X ≪ Hg-X.
35Cl Quadrupole Relaxation Study on Cs2[Au(I)Cl2][Au(III)Cl4] and Cs2[Ag(I)Cl2][Au(III)Cl4]
Authors: Ishikawa A. , Kurasawa M. , Kurasawa K. , Sasane A. , Ikeda R. , Kojima N.
Published: February 2015

Two 35ClNQR spin echo signals, VQ1 = 17.28MHz (Au(I)-Cl) and VQ2 = 27.10MHz (Au(III)-Cl), have been observed at 77 K from two samples of Cs2[Au(I)Cl2][Au(III)Cl4] prepared differently. The resonances resulted at the same frequencies but with different line widths. Cs2[Ag(I)Cl2]- [Au(III)Cl4] yielded a singlet, VQ2 = 27.96 MHz, at 77 K. The three samples gave rise to ESR signals indicating the presence of paramagnetic Au(II) or Ag(II) sites with low concentration. 35ClNQR spin-lattice relaxation time T
1Q measurements revealed that only the reorientational motions of the anions [Au(III)Cl4]− are exited at high temperatures.
Confirmation of the Existence of Modulation Wave Motion in Incommensurate Rb2ZnCl4 by Hahn Echo and 2D NMR
Authors: Muntean Ligia , Mikac Ursa , Subramanian R. K. , Ailion David C.
Published: February 2015

87Rb Hahn echo nuclear magnetic resonance (NMR) and 35Cl Hahn echo nuclear quadrupole resonance (NQR) measurements were performed at 293 - 302 K in the incommensurate (I) phase of Rb2ZnCl4. The existence of a Hahn echo decay that is shorter than the true T2 and one that has an exponential dependence on the cube of the echo time indicates the presence of slow motions. The diffusion coefficient D can be obtained from the rate of decay of the Hahn echo. Similar values for D were obtained from the two different measurements, indicating that both the Rb and the Cl atoms are experiencing the same motional mechanism. This mechanism must be due to simultaneous motions of each and can not be due to individual motions of only one type of atom. Further confirmation of the presence of modulation wave motion was obtained from 87Rb two-dimensional (2D) exchange-difference NMR measurements.
Study of Structural Phase Transitions in [Mg(H2O)6][SiF6] by Means of Single Crystal 2H NMR
Authors: Iijima Takahiro , Mizuno Motohiro , Suhara Masahiko , Endo Kazunaka
Published: February 2015

The temperature and angular dependences of 2H NMR spectra were measured for single crystal of [Mg(H2O)6][SiF6]. At 283 K, (e2Qq/h,η) of 2H, averaged by fast 180° flip of water molecules, were obtained as (128 kHz, 0.72), (123 kHz, 0.82) and (106 kHz, 0.80), corresponding to three unequal water molecules in [Mg(H2O)6]2+. At 338 K, (e2Qq/h,η) averaged further by the fast reorientation of [Mg(H2O)6]2+ around the 3 axis was obtained as (57 kHz, 0.01). In phase II, the jumping rate for the reorientation ( ) and the amplitude of the rotational modulation (Δ ) of [Mg(H2O)6]2+ about the C3 axis were obtained from the simulation of 2H NMR spectra. The jumping rate at infinite temperature and the activation energy were estimated from the temperature dependence of k as k0 = 9 1017 s-1 and a = 78 kJmol-1, respectively. The II-III phase transition was found to be related with the freeze of this motion
NQR and DSC Studies on Structural Phase Transitions and Lattice Stability in Some Tetrabromozincate(II) Compounds A2ZnBr4
Authors: Horiuchi Keizo , Ishihara Hideta , Hatano Naoko , Okamoto Syuntaroh , Gushiken Tohru
Published: February 2015

The temperature dependence of 81Br NQR frequencies in some tetrabromozincate(II) compounds, pyridinium tetrabromozincate(II) (pyH)2ZnBr4, 4-picolinium tetrabromozincate(II) (4- piH)2ZnBr4, 2,6-lutidinium tetrabromozincate(II) (2,6-luH)2ZnBr4 and guanidinium tetrabromozincate( II) (guH)2ZnBr4,weremeasured between 77Kand temperatureswhere signals faded out.All compounds exhibited four NQR signals over the whole temperature range investigated. Moreover, DSC was measured between about 130 K and melting points. (4-piH)2ZnBr4 and (guH)2ZnBr4 showed no structural phase transition, while (pyH)2ZnBr4 and (2,6-luH)2ZnBr4 showed a single phase transition. The values of transition entropies obtained suggest that these transitions are of the order-disorder type. The nature of these transitions and the lattice stability in the present compounds were discussed
Theory of Nuclear Quadrupole Interactions of 14N, 17O, and 35Cl Nuclei in p-Cl-Ph-CH-N=TEMPO
Authors: Jeong Junho , Briere Tina M. , Sahoo N. , Das T. P. , Ohira S. , Nishiyama K. , Nagamine K.
Published: February 2015

The nuclear quadrupole coupling constants and asymmetry parameters have been studied for the 35Cl, 17O, and 14N nuclei in the molecular ferromagnet 4-(p-chlorobenzylideneamino)-TEMPO (2,2,6,6-tetramethyl- piperidin-1-yloxyl) using elctronic stuctures obtained by the Hartree-Fock procedure for the bare system and systems with trapped muon and muonium. Trends in the sizes of the coupling constants and asymmetry parameters for the various nuclei have been studied, and possible physical explanations have been proposed. For the systems with trapped muon or muonium, very substantial influences of the muon and muonium on the coupling constants and asymmetry parameters for the nuclei close to the trapping sites have been observed. The coupling constants and asymmetry parameters are found to be very different for the various nuclei, for the two cases where muon is trapped near chlorine and muonium near oxygen, indicating that, if experimental data were available to compare with theory, one could make conclusions about which of these two centers is responsible for the observed muon spin rotation frequency associated with the muon magnetic hyperfine interactions in these two trapped systems
Mössbauer Spectroscopic Studies of (Me2NH2)2SnX6 (X = Cl or Br) and Their Related Complexes
Authors: Katada Motomi , Afroj Dilara , Yamauchi Takashi , Kawata Satoshi
Published: February 2015

The temperature dependence in the 119Sn Mössbauer spectral area for {(CH3)2NH2}2SnCl6 was found to be almost linear, although a phase transition of the complex has been suggested by IR, 35Cl NQR and NMRstudies, while an anomaly in the temperature dependence for {(CH3)2NH2}2SnBr6 was found at 235 K, which is close to the phase transition temperature 253 K determined by 89Br NQR. These differences are attributable to molecular motion of the dimethylammonium ion in the complexes. The X-ray powder diffraction pattern of {(CH3)2NH2}2SnCl6 did not change near the phase transition point, but that of {(CH3)2NH2}2SnBr6 changed at 108 - 123 K and 233 - 253 K
Light Scattering from Glass-forming Molten Salts
Authors: Kalampounias A. G. , Papatheodorou G. N. , Yannopoulos S. N.
Published: February 2015

Raman scattering has been employed to study the temperature and polarization dependence of the vibrational modes for the glass-forming halide salt mixtures xZnCl2-(1 - x)AlCl3, with x = 0.8 and 0.6. The analysis has shown that the vibrational modes of the mixtures arise from a contribution of the vibrational modes of the pure components salts. Emphasis has also been given to the low-frequency modes (3 - 80 cm-1), and particular points related to the glass transition phenomenology are discussed in view of the experimental findings.
Rotational Spectra of Fluorodiacetylene and Fluorotriacetylene Produced by Electrical Discharge
Authors: Dreizler Helmut , Mata Santiago , Lesarri Alberto , López Juan C. , Blanco Susana , Alonso José L.
Published: February 2015

The rotational spectra of discharge produced13C isotopomers of fluorodiacetylene were recorded with high sensitivity to improve the centrifugal distortion analysis. Stimulated by the sensitivity attained by the spectrometer the investigation was extended to detect the hitherto unknown fluorotriacetylene. The spectrum of a linear molecule was found, which with high probability belongs to fluorotriacetylene.
Influence of Second Coordination Sphere on the Kinetics of Electrode Reactions in Molten Salts
Authors: Kuznetsov S. A. , Gaune-Escarda M.
Published: February 2015

The influence of the second coordination sphere on the electroreduction of hafnium complexes to hafnium metal, and the redox reaction Eu(III) + e⇔ ,Eu(II) in alkali halide melts was studied. It is shown that the large caesium cations in the melt reduce the transfer and the diffusion coefficients as well as the heterogeneous rate constants for charge transfer of hafnium complexes. The standard rate constants for the europium redox reaction increase when going from NaCl-KCl to CsCl. The different influence of the second coordination sphere on the electrode reactions is explained by different limitation stages for electron transfer.
Simple Two-pulse Time-reversal Sequence for Quadrupole-coupled Spin System
Authors: Sergeev N. A. , Panich A. M.
Published: February 2015

We demonstrate both theoretically and experimentally that the two-pulse sequence (2n+1)· 90ᵒY- 90ᵒX-Acq(t )without delay between the pulses yields the reverse of the time evolution of spin systems with quadrupole interactions. This process results in refocusing of the spin magnetization into a magic echo at te = t1/2 after the second pulse, where t1 is the length of the first pulse. 33.25.+k; 76.20.+q; 76.60.-k; 76.60.Lz
Speedup in Quantum Adiabatic Evolution Algorithm
Authors: Bae Joonwoo , Kwon Younghun
Published: February 2015

The quantum adiabatic evolution algorithm suggested by Farhi et al. was effective in solving NPcomplete problems. The algorithm is governed by the adiabatic theorem. Therefore, in order to reduce the running time, it is essential to examine the minimum energy gap between the ground level and the next one in the evolution. In this paper we show a way of speedup in the quantum adiabatic evolution algorithm, using an extended Hamiltonian. We present the exact relation between the energy gap and the elements of the extended Hamiltonian, which provides a new point of view to reduce the running time.
On the Restricted and Combined Use of Rüdenberg’s Approximations in Molecular Orbital Theories of Hartree-Fock Type
Authors: Koch Wolfhard , Freyb Bastian , Ruiza Juan Francisco Sánchez , Scior Thomas
Published: February 2015

Rüdenberg’s well-known letter of 1951 entitled “On the Three- and Four-Center Integrals in Molecular Quantum Mechanics” explicitly presents two approximation formulas for four-center repulsion integrals, only. When applied to some types of three-center repulsion integrals, however, these two recipes still imply considerable oversimplifications. Using both one-electron and two-electron routes of Rüdenberg’s truncated expansion, on the other hand, such shortcomings can be avoided strictly. Starting from four simple “Unrestricted and Combined” (U&C) approximation schemes introduced elsewhere, an improved “Restricted and Combined” (R&C) approximation picture for Fock-matrix elements now will be outlined, which does not tolerate any unnecessary oversimplifications. Although the simplicity of the U&C scheme is lost in this case, R&C-approximated Fock-matrix elements still can be constructed from one- and two-center integrals alone in an effective way. Moreover, due to their dependence on a single geometric parameter, all types of two-center integrals can be calculated in advance for about one hundred fixed interatomic distances at the desired level of sophistication and stored once and for all. A cubic spline algorithm may be taken to interpolate the actual integral value from each precomputed list.
Synthesis and Characterization of Smectic Polymorphism in Higher Homologues of N-(p-n-Alkoxybenzylidene)-p-n-(Alkylanilines)
Authors: Pisipati Venkata G. K. M. , George A. K. , Srinivasu Ch. , Murty P. N.
Published: February 2015

Higher homologues of N-(p-n-alkoxybenzylidene)-p-n-alkylanilines (nO.m) compounds with n = 15 and 18 and m = 4 to 10, 12, 14, and 16 have been synthesized and the smectic polymesomorphism is studied. The transition temperatures were obtained both from thermal polarizing microscopy and differential scanning calorimetry. The compounds exhibit a smectic-F phase from the isotropic melt, their amount increasing with the number of the alkoxy chain. This implies that with the alkoxy chain number the manifestation of smectic-F occurs with shorter alkyl chain. The phase variants were confirmed with miscibility studies
A Theoretical Application of 3D J-Resolved NMR Spectroscopy for ISnKm (I = 1/2, S = 1/2 and 1, K = 3/2) Spin Systems
Authors: Şaka I. , Tezel Ö. , Gençten A.
Published: February 2015

In 3D J-resolved NMR spectroscopy, the chemical shift along one axis and the spin-spin coupling parameters along the two other different axes are resolved. Product operator theory is used for the analytical description of multi-dimensional NMR experiments on weakly coupled spin systems. In this study, the product operator description of heteronuclear 3D J-resolved NMR spectroscopy of weakly coupled ISn Km (I = 1/2, S = 1/2 and 1, K = 3/2) spin systems is presented.
Note: External Influences, Sexuality, and Chirality
Authors: Klemm Alfred
Published: February 2015

It is shown that the sexual proliferation of a chiral population leads much faster than exponentially to monochirality.
Relation between Magnetic, Spectroscopic and Structural Properties of Binuclear Copper(II) Complexes of Pentadentate Schiff-base Ligand, Semi-empirical and ab-initio Calculations
Authors: Elerman Y. , Kara H. , Elmali A.
Published: February 2015

The synthesis and characterization of [Cu2(L1)(3,5 prz)] (L1=1,3-Bis(2-hydroxy-3,5-chlorosalicylideneamino) propan-2-ol) 1 and of [Cu2(L2)(3,5 prz)] (L2=1,3-Bis(2-hydroxy-bromosalicylideneamino) propan-2-ol) 2 are reported. The compounds were studied by elemental analysis, infrared and electronic spectra. The structure of the Cu2(L1)(3,5 prz)] complex was determined by x-ray diffraction. The magnetochemical characteristics of these compounds were determined by temperaturedependent magnetic susceptibility measurements, revealing their antiferromagnetic coupling. The superexchange coupling constants are 210 cm−1 for 1 and 440 cm−1 for 2. The difference in the magnitude of the coupling constants was explained by the metal-ligand orbital overlaps and confirmed by ab-initio restricted Hartree-Fock (RHF) calculations. In order to determine the nature of the frontier orbitals, Extended Hückel Molecular Orbital (EHMO) calculations are also reported.
Theoretical Investigations Of The Epr G Factors For Er3+ In Pr2cuo4 Superconductor
Authors: Wu Shao-Yi , Dong Hui-Ning , Li Peng
Published: February 2015

The electron paramagnetic resonance g factors g|| and g⊥ for Er3+ in the superconductor Pr2CuO4 are investigated by using the perturbation formulas of g factors for a 4f11 ion in tetragonal symmetry. In these formulas, the contributions to the g factors due to the second-order perturbation terms and the admixture of different states are considered. The crystal field parameters used in the calculations are obtained from the superposition model and the local structural parameters of the impurity Er3+ located on the host Pr3+ site. The superposition model parameters adopted in this paper are comparable with those for similar tetragonal Er3+ centers in some zircon compounds in previous work. The above investigations may be helpful to understand the electronic and magnetic properties and hence the superconductivity of the Er3+ doped Pr2CuO4.
(E)-4-Methyl-1-tributylstannyl-oct-1-en-6-yn-3-ol: Circular Dichroism Measurement and Determination of the Absolute Configuration by Quantum-chemical CD Calculations
Authors: Voloshina E. N. , Raabe G. , Fleischhauer J. , Kramp G. J. , Gais H.-J.
Published: February 2015

3

The chiroptical properties of the diastereomeric alcohols (E)-(3S,4S)-4-methyl-1-tributylstannyloct- 1-en-6-yn-3-ol ((S,S)-) and (E)-(3R,4S)-4-methyl-1-tributylstannyl-oct-1-en-6-yn-3-ols ((R,S)- 3) have been studied experimentally as well as by quantum-chemical calculations. The structures of 20 conformers of each isomer, which were found to represent local minima at the MNDO level, have been optimized with density functional theory (DFT). Based on these geometries the excitation energies and oscillator as well as rotational strengths have been calculated using a time-dependent DFT (TDDFT) method. The CD spectra of the compounds were then obtained as superposition of Boltzmann-weighted spectra for each of the structures. By comparison of the calculated and the experimental CD spectra the absolute configurations have been assigned to the investigated compounds.
A Study for Obtaining more Compacton Solutions of the Modified Form of Fifth-order Korteweg-De Vries-like Equations
Authors: Inc Mustafa
Published: February 2015

In this paper we investigate exact solutions of a modified form of fifth-order Korteweg-de Vrieslike equations by using two direct methods. Thus we get new compacton solutions having infinite wings or tails. In addition, new periodic and singular periodic wave solutions are obtained.
Controlled and Secure Direct Communication Using GHZ State and Teleportation
Authors: Gao T.
Published: February 2015

A theoretical scheme for controlled and secure direct communication is proposed. The communication is based on GHZ state and controlled quantum teleportation. After insuring the security of the quantum channel (a set of qubits in the GHZ state), Alice encodes the secret message directly on a sequence of particle states in the GHZ state and transmits them to Bob, supervised by Charlie using controlled quantum teleportation. Bob can read out the encoded messages directly by the measurement on his qubits. In this scheme, the controlled quantum teleportation transmits Alice’s message without revealing any information to a potential eavesdropper. Because there is not a transmission of the qubit carrying the secret messages between Alice and Bob in the public channel, it is completely secure for controlled and direct secret communication if a perfect quantum channel is used. The feature of this scheme is that the communication between two sides depends on the agreement of a third side.
A NMR Spin-Echo Study of Diffusion in Molten Salts
Authors: Palmer Günter , Richter Joachim , Zeidler Manfred D.
Published: February 2015

Pressure-dependent measurements of the cationic self-diffusion coefficients of molten (Na, Li)NO3 were carried out at 613 K. The pressure range lies between ambient pressure and 200 MPa. A new high-pressure probe, operating with heating coils, was constructed from titanium alloy. The temperature difference across the probe could be confined to 2.5 K. By use of a switchable high-frequency coil the nuclei lithium and sodium could be measured in succession within the same sample. The activation volumes are composition-dependent and range from 5 to 9 cm3mol−1.
On Structure Descriptors Related with Intramolecular Energy of Alkanes
Authors: Gutman Ivan , Furtula Boris , Arsić Biljana
Published: February 2015

In an earlier work it was demonstrated that the Zenkevich index U provides a measure of the intramolecular energy of an organic molecule, and that - in the case of alkanes - it is related to the Wiener index. We now show that U is much closer related to the recently introduced variable Wiener index Wλ : Within sets of isomeric alkanes, the relation between U and Wλ is linear, the (U,Wλ )-points forming several, mutually parallel, lines. Each such line pertains to a group of isomers possessing a fixed number of methyl groups. There exists a critical value of the parameter λ for which all the (U,Wλ )-lines coalesce, in which case the relation between U and Wλ becomes independent of the number of methyl groups. Approximate analytical expressions for the (U,Wλ )-dependence are deduced.
EPR Parameters and Local Atom-position Parameters for Co2+ Ions in CdS and CdSe Semiconductors
Authors: Zheng Wen-Chen , Wu Xiao-Xuan , Mei Yang , Zi Jian
Published: February 2015

The EPR parameters (zero-field splitting D and g factors gII, g⊥) of Co2+ ions in CdS and CdSe semiconductors are calculated from the high-order perturbation formulas based on the cluster approach for a 3d7 ion in trigonal symmetry. These formulas include the contribution to the EPR parameters from both the spin-orbit coupling parameter of the 3d7 ion and that of the ligand. From the calculations, the local atom-position parameters u (which are different from the corresponding values in the host crystals) for the Co2+ impurity centers in both semiconductors are estimated. The results are discussed
Crystal Field Analysis and Electron-phonon Coupling in Sc2O3:Cr3+
Authors: Brik M. G. , Avram N. M.
Published: February 2015

Crystal field analysis of the energy level structure of the Cr3+ ion in the Sc2O3 crystal is performed, using the exchange charge model of the crystal field theory. The crystal field parameters acting on the optical electrons of the Cr3+ ion at the sites with C2 and C3i symmetry are calculated from the crystal structure data. On the basis of the comparison between experimental absorption and emission spectra and theoretically calculated energy levels of Sc2O3:Cr3+, the conclusion is made that the spectroscopic properties of the title host are determined by the Cr3+ ion at the positions of C2 local symmetry. The Stokes shift S = 4.32 and the energy of the phonons effectively interacting with an impurity center h̅ω = 499 cm−1 are derived from the experimental spectra of absorption and emission
Hydromagnetic Instability Criteria for Stratified Viscoelastic Dusty Finitely Conducting Plasmas
Authors: El-Sayed M. F.
Published: February 2015

The instability of a stratified, viscoelastic (Walters B’ or Rivlin-Ericksen) magnetoplasma, including the effects of finite resistivity and suspended particles, is investigated using linear analysis. The horizontal applied magnetic field and the viscosity, as well as the viscoelasticity of the medium are assumed to be variable. The dispersion relation, which is obtained for the general case on employing boundary conditions appropriate to the case of two free boundaries, is then specialized for the two models. The hydromagnetic instability conditions are obtained and discussed analytically, and the results are numerically confirmed. The variation of the growth rate of the unstable modes with the different parameters has been evaluated analytically. All the physical parameters are found to have stabilizing as well as destabilizing effects on the considered system. For the Walters B’ viscoelastic model it was found that the kinematic viscoelasticity, fluid resistivity, and stratification parameter have a stabilizing effect, while the mass concentration (or relaxation frequency) of the suspended particles, kinematic viscosity, and Alfvén velocity have a destabilizing effect on the considered system. Also, for the case of the Rivlin-Ericksen viscoelastic model we found that the mass concentration of the suspended particles, Alfvén velocity, and kinematic viscosity have a stabilizing effect, while both the finite resistivity and stratification parameter have a destabilizing effect; the relaxation frequency of the suspended particles has no effect on the stability of the system. The case of a dusty plasma with infinite conductivity and presence (or absence) of a magnetic field is also considered. Its stability conditions are obtained, from which it is concluded that the presence of dust always reduces the growth rate of the unstable Rayleigh-Taylor perturbations. The limiting case of a viscid (and inviscid) finitely conducting dusty plasma is considered, and the stability conditions are discussed, from which we found that the magnetic field has a stabilizing effect in the absence of both viscosity and finite resistivity, the stability of the system ocurrs for values of the Alfvén velocity greater than a critical value. -PACS: 47.20.-k; 47.50+d; 47.65.+a.
Exact Soliton Solutions To An Averaged Dispersion-Managed Fiber System Equation
Authors: Li Biao
Published: February 2015

By introducing a set of ordinary differential equations which possess q-deformed hyperbolic function solutions, and a new ansatz, a method is developed for constructing a series of exact analytical solutions of some nonlinear evolution equations. The proposed method is more powerful than various tanh methods, the secq-tanhq-method, generalized hyperbolic-function method, generalized Riccati equation expansion method, generalized projective Riccati equations method and other sophisticated methods. As an application of the method, an averaged dispersion-managed (DM) fiber system equation, which governs the dynamics of the core of the DM soliton, is chosen to illustrate the method. With the help of symbolic computation, rich new soliton solutions are obtained. From these solutions, some previously known solutions obtained by some authors can be recovered by means of some suitable choices of the arbitrary functions and arbitrary constants. Further, the soliton propagation and solitons interaction scenario are discussed and simulated by computer.
A Structural Model for Mixed-Nitrate Ionic Glasses
Authors: Akdeniz Z. , Tosi M. P.
Published: February 2015

We propose and evaluate a structural model for mixed K-Ca nitrate melts and glasses, which invokes the presence of strongly bound Ca2(NO3)7 groups surrounded by K ions that can transport charge by relatively free jumps. To this purpose we first construct ionic models for the pure ANO3 compounds (with A = alkali metal ion), by searching for suitable A+Z·(NO3)−Z interionic potentials in the space of interionic-law parameters with the help of known models for alkali chlorides. The available evidence mainly consists of infrared-active mode frequencies, and is compatible with two alternative types of interionic parameters. A choice between them is made on the basis of the fact that the NO3 group has a flat triangular shape and can execute torsional oscillations giving rise to a low-frequency Raman-active mode in the melt. This interionic force model is then combined with a similar model for Ca(NO3)2 to evaluate the structural properties of a 3KNO3·2Ca(NO3)2 unit, which is the constituent of the well-known glassformer CKN. We expect that the present model should be representative of other mixed alkali-divalent ion nitrate systems in the range of concentration where glass formation is observed.
Relaxation of Spin 1/2 in the Scalar Coupled Spin System AMX with Quadrupolar Nuclei in the Presence of Cross-correlation Effects
Authors: Kupriyanova G. S.
Published: February 2015

We present the formal theory of the nuclear magnetic relaxation of spin ½ A in a scalar coupled spin system AMX with quadrupolar nuclei of spin 1 (M, X) considering cross-correlation relaxation based on second order time-dependent perturbation theory and the product operator formalism. The expressions for longitudinal and transverse relaxation times and dynamic frequency shifts of each component of the spectral pattern are derived. Several experimental schemes for the selective determination of the cross-correlation rate between different spin orders are proposed.
Extended tanh-Function Method for Finding Travelling Wave Solutions of Some Nonlinear Partial Differential Equations
Authors: Inc Mustafa , Fan Engui G.
Published: February 2015

In this paper, we find travelling wave solutions of some nonlinear partial differential equations (PDEs) by using the extended tanh-function method. Some illustrative equations are investigated by this method and new travelling wave solutions are found. In addition, the properties of these nonlinear PDEs are shown with some figures.
Theoretical Studies of the EPR Parameters and the Local Structure of the Tetragonal Fe+ Center in KTaO3
Authors: Wu Shao-Yi , Dong Hui-Ning , Gao Xiu-Ying
Published: February 2015

The EPR parameters (zero-field splitting D and g factors g‖ and g⊥) and the local structure for the tetragonal Fe+ center in KTaO3 are theoretically studied by using the perturbation formulas of the EPR parameters for a 3d7 ion in tetragonally distorted dodecahedra. Based on these studies, we find that the impurity Fe+ may not locate on the regular dodecahedral K+ site but suffer a large off-center displacement ΔZ (≈ 0.43 Å) along one of the 100 〈or C4〉 axes, which is responsible for the large tetragonal distortion of the impurity center. The displacement ΔZ obtained in this work is comparable with that (≈ 0.46 Å ) of a similar monovalent Li+ on K+ site of KTaO3 obtained from the nuclear quadrupole shift and can be regarded as reasonable. The calculated g factors, particularly the anisotropy Δg (= Kg⊥ −g‖) based on the above displacement, agree with the observed values.
A Truncated Painlevé Expansion and Exact Analytical Solutions for the Nonlinear Schr¨Odinger Equation with Variable Coefficients
Authors: Li Biao , Chen Yong
Published: February 2015

By using the truncated Painlevé expansion analysis an auto-Bäcklund transformation is found for the nonlinear Schrödinger equation with varying dispersion, nonlinearity, and gain or absorption. Then, based on the obtained auto-Bäcklund transformation and symbolic computation, we explore some explicit exact solutions including soliton-like solutions, singular soliton-like solutions, which may be useful to explain the corresponding physical phenomena. Further, the formation and interaction of solitons are simulated by computer. - PACS Nos.: 05.45.Yv, 02.30.Jr, 42.65.Tg
Surface Wave Propagation in Thin Silver and Aluminium Films
Authors: Njeh Anouar , Abdelmoula Nabil , Fuess Hartmut , Ghozlen Mohamed Hédi Ben
Published: February 2015

Three kinds of acoustic waves are known: bulk waves, pseudo-surface waves and surface waves. A plane wave section of a constant-frequency surface of a film serves as a hint for the expected nature. Calculations based on slowness curves of films reveal frequency ranges where each type of acoustic waves is predominant. Dispersion curves and displacement acoustic waves are calculated and commented in each frequency interval for different coated materials. Both dispersion and sagittal elliptical displacement are sensitive and depend on diagrams mentioned above. Silver and aluminium thin films having different anisotropy ratios, namely 2.91 and 1.21, are retained for illustration.