bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characteristics of Photoelectrochemical Cells Based on n/n+-Si and p/n+-Si Photoanodes Modified by Metal Films
Authors: Wang S. , Li G. , Li H. , Getoff N. 
Published: February 2015

Abstract
Photoelectrochemical cells (PECs), composed of different epitaxial n-Si photoanodes coated with evaporated metal film of Ni, Pt, Ni/Pt and immersed in solution with redox couple Br2/Br- or Fe(NC)3
6Fe(CN)4
6
- were investigated. The open circuit photovoltage and short circuit curent density of these PECs under optimum conditions by illuminating with a bromine-tungsten lamp (65 mW/cm2), are 0.494 V and 45.8 mA/cm2, respectively. By using a p/n+ junction for the epitaxial silicon and the Schottky barrier effect formed at the silicon-metal interface, a much higher conversion efficiency of optical to electrical energy up to 12.3% could be achieved
Triple Resonance Experiments in Microwave Fourier Transform Spectroscopy
Authors: Vogelsanger B. 
Published: February 2015

Abstract
Two-dimensional (2 D) correlation techniques in microwave Fourier transform spectroscopy have been extended to study triple resonance phenomena. Dipole-forbidden double- and triple-quantum transitions have been observed with a five-pulse sequence. The introduction of a phase cycle acting as a triple-quantum filter has simplified the recorded spectra. Experimental results on trifluoromethylacetylene are given as an example
Improved Version of a Microwave Fourier Transform Spectrometer in the Frequency Band from 26 to 40 GHz
Authors: Keussen Ch. , Schwarz R. , Andresen U. , Dreizler H. 
Published: February 2015

Abstract
We report the design and performance of an improved version of a microwave Fourier transform spectrometer in the frequency region between 26 and 40 GHz for the investigation of rotational spectra. The performance is illustrated by rotational transitions of allene-d4 and isotopomers of carbonyl sulfide in natural abundance. The high sensitivity of the spectrometer allows the measurement of very weak lines in only a few minutes
1H - 17O Nuclear Quadrupole Double Resonance in DL-Proline
Authors: Seliger J. , Žagar V. , Blinc R. , Kadaba P. K. , Fiat D. 
Published: February 2015

Abstract

17O nuclear quadrupole resonance spectra have been measured in an 17O enriched polycristalline sample of DL-proline with the help of 1H - 17O nuclear quadrupole double resonance technique. The results show the presence of eight chemically inequivalent oxygen sites corresponding to four inequivalent proline molecules in the unit cell. The oxygen sites may be grouped into two sets of four sites. One set with the short proton-oxygen distances belongs to the C - O • • • H groups whereas the other with the long proton-oxygen distances to the C = O groups
Possible Participation of Lithium in Fleischmann-Pons Reaction is Testable
Authors: Frodl P. , Rössler O. E. , Hoffmann M. , Wah F. 
Published: February 2015

Abstract
If the amount of heat reported by Fleischmann and Pons to occur in their electrochemical "fusion" experiment is assumed to be produced entirely by the "clean" nuclear reaction 6Li + 2D → 2dHe (22.4 MeV), then the concentration of 6Li in the reaction fluid should during a period of 120 hours go down by a measurable amount, namely between 3.4 and 0.25 percent dependent on whether the natural isotopic mixture of (less likely) pure 6 Li was used in the experiment
Access to Primary Charge Separation Mechanism in Photosynthetic Reaction Centers: Anisotropic Excitation Spectra of Electric Field Modulated Fluorescence Yields
Authors: Eberl U. 
Published: February 2015

Abstract
Two-step sequential and unistep, superexchange primary electron transfer form primary radical pair states which differ in the direction and magnitude of their dipole moments as revealed in the X-ray structure analysis. The direction can be measured by the excitation anisotropy of electric field induced changes of the fluorescence yield. This method determines angles between the dipole of the primary radical pair and photoselected transition moments (in absorption and emission) of cofactors in the reaction centers. Transitions particularly favourable for discrimination between the two models of primary electron transfer are discussed.
Gaussian Approach to (1 + 1) Dimensional φ6 Solitons at Finite Temperature
Authors: Roychoudhury Rajkumar , Sengupta Manasi 
Published: February 2015

Abstract
Using the Gaussian effective potential approach, φ6 soliton solutions at finite temperature are studied for both the general case and the particular case λ2 = 2ξm2. A critical temperature is found at which soliton solutions cease to exist. The effective potential together with the mass-gap equation are studied in detail, and comparison with existing work on this subject is made
Internal Mobilities in Molten (Li, Pb(II))Cl as Remeasured by the Klemm Method
Authors: Haibara Teruo , Okada Isao 
Published: February 2015

Abstract
Internal cation mobility ratios in molten (Li, Pb(II))Cl at 650 °C have been remeasured by Klemm's column method. From these and available data on the densities and conductivities, the internal mobilities bLi and bPb have been calculated. It was found that at low LiCl content bu is surprisingly high, while at low PbCl2 content bPb is surprisingly low. The former trend agrees with that found by Klemm and Monse with the migrating boundary method and disagrees with that found by Behl and Egan with the EMF method. The latter trend agrees with that resulting from a neglected point given by Behl and Egan and disagrees with that tentatively reported by Klemm and Monse. The peculiar mobility behaviour of (Li, Pb(II))Cl is compared with that of similar Cd(II), Sr, and Ba systems
Temperatur- und Konzentrationsabhängigkeit der 115In-Knightshift im flüssigen In-Mn-System
Authors: Senel I. , Quitmann D. 
Published: February 2015

Abstract
NMR measurements of the 115In-Knightshift and the linewidth in liquid In-Mn are reported. They were carried out in an external magnetic field of about 4.0 T at concentrations 0, 3, and 6 at.% Mn at temperatures from 400 K to 1300 K. According to our experimental results there are no localized magnetic moments in the liquid In-Mn-system. The experimental results are discussed in the framework of theories on metallic alloys.
On the Effective Interaction of two Hydrogen Centres in Niobium
Authors: Frodl P. , Sommer F. T. , Hau K. , Wahl F. 
Published: February 2015

Abstract
We derive an effective interaction between hydrogen impurities in Niobium using a microscopic theory of hydrogen in metals. Our model consists of an infinite bcc-crystal with two hydrogen centres occupying tetrahedral interstitial sites, neighbouring on the first to the fourth coordination shell. The elastic interactions are assumed to obey the classical harmonic approximation. The electronic interactions due to both the coulomb potentials and the overlap of the impurity induced electron densities in the vicinity of the interstitials also play an important role. These latter interactions are treated as two-body interactions in a zeroth order approximation of the New Tamm-Dancoffmethod. A separation ansatz results in an effective interaction which depends on the distance between the interstitials and upon the spin states of their excess electrons. We propose some improvements on our model, and to test our calculations, we construct the grand partition function of an appropriate lattice gas model.
Kinetic Derivation of Gauss's Law and Its Thermodynamic Significance
Authors: Dunning-Davies J. , Lavenda B. H. 
Published: February 2015

Abstract
Gauss's error law for generalized jump processes in which the average value is also the most probable value is derived from the maximum likelihood path for the growth of a fluctuation. Evolution towards equilibrium and the spontaneous growth of a fluctuation from equilibrium are analyzed and compared in the continuous, diffusion limit.
Quantum Features of Microwave Propagation in a Rectangular Waveguide
Authors: Marinescu Nicolae , Nistor Rudolf 
Published: February 2015

Abstract
The formal analogy between the distribution of the electromagnetic field in waveguides and microwave cavities and quantum mechanical probability distributions is put into evidence. A waveguide of a cut-off frequency ωc acts on an electromagnetic wave as a quantum potential barrier Ug = hωc
. A non-habitual time independent Schrödinger equation, describing guided wave propagation, is established
Ideal Gas Approximation for an Ion Cloud in a Penning Trap
Authors: Kretzschmar Martin 
Published: February 2015

Abstract
Assuming a sufficiently low density of the trapped particles the methods of equilibrium statistical mechanics for non-interacting particles are used to find expectation values and distribution functions for the most interesting 1-particle observables. The results are applied in a perturbation calculation to estimate space charge effects at low particle densities
The influence of solvent on the UV-visible absorption and luminescence spectra of some highly fluorescent vitamin derivatives, the products of the reaction of N-methylated vitamin Bj with cytidine (I), adenosine (II) and 2-amino-4-methylpyridine (III) is studied. Spectroscopic manifestations of protonation of I and II are also investigated using a semiempirical INDO/S CI method. Singlet and triplet energy levels of the free ion and several protonated species are calculated, and transition energies and oscillator strengths are compared with the experimental spectra. Calculated charge densities on heteroatoms in the ground and excited singlet and triplet states are correlated with changes of the experimental pKa values with excitation. The results for I and II are compared with those for the trimethylated pyrichrominium ion (III) previously studied
Authors: Muralimohan Rao D. , Kalidas C. 
Published: February 2015

Abstract
The conductance of HCl and HBr in water-dimethylformamide (DMF) mixtures of 10-80 wt % DMF at 25 ºC has been measured and discussed, using the three parameter conductance equation suggested by Fuoss et al. in 1965. The ionic conductances and Waiden products of the H + , C - and Br- ions have been determined and explained. No appreciable ion-association of these acids in these media has been found
Monte Carlo Simulation of Muscarine in Water Solution
Authors: Margheritis Chiara 
Published: February 2015

Abstract
Monte Carlo simulations of muscarine water solution were carried out using ab-initio SCFLCAO- MO interaction potentials. The overall results indicate that in water solution the preferred conformation, on the basis of enthalpic considerations, should be the one having the dihedral angle H02-02-C4-H4, τ, equal to 180°. The molecule shows a first hydration shell with about 35 water molecules: of these only about 25 are constantly present, 18 are at a distance equal to lower than 2.5 A and only 5 have an interaction energy larger than -21 kJ/mole. The results do not support the hypothesis that the role of Ol in muscarinic activity is that of increasing hydrophylic bonds
Onset of Buoyancy and Surface-Tension Driven Instabilities in Presence of Random Vibrations
Authors: Dandapat B. S. 
Published: February 2015

Abstract
Onset of thermal convection in an incompressible fluid layer bounded between a perfectly heat conducting lower rigid plate and an upper free surface is analysed when the layer is subject to random vibrations. It is shown that when the vibrations are characterized by a white noise process, they hasten the onset of convection. Further it is shown that the stability zone is demarcated by an inverted parabola in the (R, M) plane.
An EPR Investigation of Cr3+ and Ni2 + in Synthetic Pyrite Crystals
Authors: Siebert D. , Miller R. , Fiechter S. , Dulski P. , Hartmann A. 
Published: February 2015

Abstract
In many synthetic pyrite single crystals of high quality and purity we could detect Cr3 + and Ni2 + by EPR at 78 K as unwanted impurities. The assignment was possible by means of the isotopes Cr53 and Ni61, occurring in natural abundance. The paramagnetic centers exhibit unusual g-values. In case of Ni2 + a ligand hyperfine interaction could be observed beside the normal hyperfine interaction with the Ni61 nucleus. For some crystals the Cr 3 + signal intensity could be increased up to ten times by temperature increasement from 78 K to about 100 K. At 78 K the Cr3 + intensity was quenched by IR irradiation.
A High Pressure Pulsed Expansion Valve for Gases, Liquids, and Supercritical Fluids
Authors: Köster C. , Grotemeyer J. , Schlag E. W. 
Published: February 2015

Abstract
A novel design of a pulsed valve for coupling chromatographic techniques with gaseous and liquid mobile phases to a time-of-flight mass spectrometer with multiphoton ionization (MUPI) is presented. The valve can be operated in low pressure regions ( <10 bar) up to temperatures of 350 °C and at higher pressures (300 bar) up to temperatures of 200 °C. Pulse widths lower than 100 μs could be measured. First results demonstrate the ability of interfacing of liquid chromatography to MUPI-mass spectrometry. Additional coupling of CO2-laser desorption to the valve allows the interface to be used for mass spectrometric measurements of nonvolatile biomolecules.
Kathodo- und Photolumineszenz der Seltenerd-aktivierten Granatsysteme Y3-xGdxM2GaGe2O12 (M = Mg, Zn)
Authors: Wiehl J. , Kemmler-Sack S. 
Published: February 2015

Abstract
The optical properties of the self-activated garnet systems Y3-x GdxM2GaGe2O12 (M = Mg, Zn) activated with Ce, Pr, Eu, Tb are strongly influenced by an energy transfer between defect centers of the host and the activator ions. The luminescence properties are studied as a function of the parameter x for M = Mg, Zn.
Tautomerism in Five-membered Nitrogen Heterocycles. A Test of the Reliability of Semiempirical (AMI, PM3, MNDO) Quantum Chemical Methods
Authors: Fabian Walter M. F. 
Published: February 2015

Abstract
The reliability of three popular semiempirical quantum chemical methods (AM1, PM3, MNDO) for the treatment of tautomeric equilibria is tested in a series of five-membered nitrogen heterocycles. The known flaw of MNDO to overestimate the stability of compounds with two or more adjacent pyridine-like lone pairs is also present in AM1 and to a somewhat lesser extent in PM3. Tautomeric species differing in the number of adjacent pyridine-like lone pairs, thus, cannot be adequately treated by these semiempirical methods. Both AM1 as well as PM3, however, represent major improvements over MNDO in the case of lactam-lactim tautomerism. The stability of N-oxides as compared to N-hydroxy tautomers seems to be overestimated by the PM3 method. All three semiempirical methods yield quite reliable ionization potentials and dipole moments.
The 63,65Cu NQR Spectra of Di-coordinated CuI Cations with 2-Substituted Pyridine Ligands
Authors: Habiyakare Augustin , Lücken Edwin A. C. 
Published: February 2015

Abstract
The NQR frequencies of the 63,65 Cu nuclei in di-coordinated complex cations of Cu 1 , having the general formula CuL 2X, where L is a substituted pyridine and X is a hard anion such as ClO4 , are reported and discussed in the light of the known crystal structures. A departure from a strictly linear geometry of the L 2 Cu cation has but little effect on the resonance frequency, but the donor-acceptor bond between the nitrate anion and the copper atom in bis(2,6-lutidine)cuprous nitrate, which was postulated on crystallographic grounds, is confirmed by the NQR results, which also indicate a similar interaction in bis(2,6-lutidine)cuprous trifluoroacetate. A number of the complexes discussed here have not been reported previously.
Investigation of the C-Cl Bonds in Trichloroacrylic Acid, Cl2C = CClCOOH, by Single Crystal Zeeman Split NQR
Authors: Wulfsberg Gary , Weiden Norbert , Weiss Alarich 
Published: February 2015

Abstract
The 35Cl NQR spectrum of trichloroacrylic acid, Cl2C = CClCOOH, was studied by single crystal Zeeman NQR spectroscopy at 303 K (high temperature phase I) and at 275 K (low temperature phase II). At 303 K for the = CCl2 group chlorines it was found eQΦzz h-1(35Cl(2)) = 76.179 MHz, η (35Cl) = 0.1597; eQΦzz h -1 (35Cl(3))= 74.693 MHz, η(35Cl) = 0.1868 and for the = CClC - group chlorine eQΦzz h -1(35Cl(1)) = 75.145 MHz, η (35Cl) = 0.1568. The difference in the electric field gradients at the stereochemically inequivalent chlorines Cl(2) and Cl(3) is rather large. The asymmetry parameter η (35Cl(1)) shows an unusual temperature dependence which probably originates from the change of the hydrogen dynamics and position within the dimeric H-bonded unit (Cl2C = CClCOOH)2 during the phase transition
Elementary Excitations in Order-Disorder Systems Studied by NQR
Authors: Milia F. , Papavassiliou G. , Giannakopoulos E. 
Published: February 2015

Abstract
The 35Cl spin-lattice and spin-spin relaxation times T1 and T2 as functions of temperature and impurity concentration were analytically calculated and experimentally verified for the incommen-surate phase of [Rb1-x (NH 4)x]2 ZnCl4 . The results agree with the theoretical predictions for both the amplitude and Goldstone modes of fluctuations.
81Br and 127I NQR and Phase Transitions in CH3NH3 HgBr3 and CH3NH3 HgI3
Authors: Terao Hiromitsu , Okuda Tsutomu 
Published: February 2015

Abstract
The 81Br and 127I NQR spectra were recorded in CH3NH3 HgBr3 and CH3NH HgI3 , respectively. In addition to a phase transition at 338 K, successive phase transitions take place at 127 ± 1, 184±1 and 243±5 K in CH3NH3 HgBr3. On heating, the resonance lines of CH3NH3HgI3 disappear near a phase transition at 328 K and one line appears above this temperature. The temperature variations of the resonance frequencies of the terminal halogen atoms in both crystals are extraordinarily steep. This indicates the large amplitude molecular motions expected for the CH3NH3 cations which are linked to the terminal halogen atoms through N-H ··· X type H-bonding.
N Nuclear Quadrupole Resonance Study of the Phase Transitions of Ba[Fe(CN)5NO]·3H2O
Authors: Murgich Juan , Bonalde Ismardo , Abanero Jose A. 
Published: February 2015

Abstract
The 14N nuclear quadrupole resonance (NQR) of the cyanides in Ba[Fe(CN) s NO] · 3H2O (BNP) was observed between 77 and 293 K. Phase transitions exist at 118,131 (both weakly first order) and 233 K (second order). Most of the cyanides were perturbed by the structural changes except for one of the trans cyanides that was only affected by the transition at 131 K. The mechanism of the phase transitions is interpreted in terms of soft modes resulting from the ion rearrangement produced by the slowing down of the water molecules upon cooling. A comparison of the NQR spectrum of BNP with that of Na2[Fe(CN)5NO] · 3H2O showed that the substitution of Na+ by Ba2+ produced only minor changes in the charge distribution of the nitroprusside ion.
The ab initio Calculation of Nuclear Quadrupole Coupling Constants and their Comparison with Experiment
Authors: Palmer Michael H. 
Published: February 2015

Abstract
Ab initio calculations of electric field gradients (EFG) and conversion to nuclear quadrupole coupling constants (NQCC) are described, with particular reference to 14 N and 10,11B. The correlation of EFG and NQCC for a series of boranes leads to the value 8.32 MHz/a.u. (0.0354 barn) for Q(11B).
The structural variations of these microwave and single molecule calculations of 10,11 B NQCC are discussed.
A Study of High Tc Oxide Superconductors by NQR and NMR Measurements
Authors: Asayama K. , Kitaoka Y. 
Published: February 2015

Abstract
Results of NQR, NMR and nuclear relaxation measurements in normal and superconducting states of high Tc superconductors, (La1-x Sr(Ba)x)2 CuO4 , YBa2Cu3O7, (Bi - Pb)2Sr2Ca2Cu3O10 , Tl2Ba2Ca2Cu3O10 and (Nd1-xCex)2 CuO4 are reviewed.
Fade-Out of 35Cl NQR in Chloral n-Butylhemiacetal
Authors: Hashimoto Masao , Isono Takahiro , Niki Haruo , Higa Takuya 
Published: February 2015

Abstract
Continuous wave and pulsed NQR, dielectric absorption and infrared (IR) measurements were carried out to investigate the origin of the peculiar temperature dependence of the S/N ratio of the 35Cl NQR in the title compound. The dielectric and IR experiments evidenced a thermally activated jumping motion of the H atom participating in O-H O H-bonds. As T1 and T2 below 120 K were much longer than T*2 of about 10 μs, the line broadening in this temperature region was attributed to static lattice defects. A random freezing of the jumping motion may be the origin of the defects. In the range 120-170 K, S/N was extremely low and T2 was less than 10 μs, probably having a minimum in between. The short T2 is considered to be responsible for the low S/N. A minimum of S/N at about 240 K is attributed to a T1 minimum (less than 10 (μs) at that temperature.
Chlorine Nuclear Quadrupole Relaxation due to the Motion of Pyridinium Cations in Pyridinium Hexachlorometallates(IV): (pyH)2 MCl6 (M = Sn, Pb, Te)
Authors: Tai Yutaka , Asaji Tetsuo , Nakamura Daiyu 
Published: February 2015

Abstract
The temperature dependence of the chlorine quadrupole spin-lattice relaxation time T1Q was observed for one of the three 35Cl NQR lines of (pyH)2 MCl6(M = Sn, Pb, Te). Each T1Q curve can be devided into three temperature regions. In the low-and high-temperature regions, T1Q is dominantly determined by the relaxation mechanism due to the libration and reorientation of [MCl6]2- , respectively. In the intermediate temperature region, T1Q results from the modulation of the electric field gradient by the motion of the neighboring pyridinium cations. This way the reorientational motion of the cation between potential wells with nonequivalent depths is precisely characterized.
Lattice Imperfections and Relaxation of Cl NQR in Chloral Iso-Butylhemiacetal
Authors: Niki Haruo , Igei Ryokan , Higa Takuya , Hashimoto Masao , Isono Takahiro 
Published: February 2015

Abstract
The temperature dependence of the S/N ratios of three 35Cl NQR lines (v1, v2 , v3) in chloral iso-butylhemiacetal shows interesting features in the range 77-300 K. 35Cl T1 indicates that above 220 K reorientation of CCl 3 is excited, and this results in a gradual decrease in S/N. The activation energy calculated from 35Cl NQR T1 results is 30 kJ mol-1 for v1 and v2 but 25 kJ mol -1 for v 3 . The difference seems to be attributable to the motion of H in the OH group. A minimum of 35Cl NQR T2 is found around 180 K but 35Cl T1 shows no anomaly. 35Cl T2 determines the S/N ratios in the range between 130-220 K. The line broadening below 130 K is attributable to an inhomogeneity of the electric field gradient at resonant nuclei produced by lattice defects.
Nuclear Quadrupole Coupling Tensors of 2H in the a-Alum RbAl(SO4)2 · 12D2O and the Dynamical Behaviour of the D2O Molecules. An Investigation by NMR and IR
Authors: Ramakrishna J. , Weiden Norbert , Weiss Alarich 
Published: February 2015

Abstract
By single crystal NMR the nuclear quadrupole coupling constants eQΦzz h-1 (2H), the asymmetry parameters η(2H) and the direction cosines of the principal axes of the electric field gradient tensors of the 2H atoms of the two kinds of D2O molecules have been determined at 295 K in RbAl(SO4)2 · 12D2O. The results show that the D2O molecules surrounding the ion Al3+ are “static” within the time scale of the 2H nuclear quadrupole interaction while the D2O belonging to the octahedron around the Rb+ undergoes fast reorientations around the twofold molecular axis. For the two kinds of D2O in the alum we found: eQΦzz
(1)h-1 (2H) = 186.5 kHz, η(1),(2H) = 0.1234; eQΦzz
(2)h-1 (2H) = 169.7 kHz,η (2)(2H) = 0.1297; eQΦzz
(3)h-1(2H) = 122.1 kHz, (2H) = 0.8087. eQΦzz
(1) and eQΦzz
(2) belong to the "static" D2O molecules and an assignment to the two different 2H atoms has been performed. The IR spectra of RbAl(SO4)2 · 12(H1-xDx)2O have been investigated, and for the O - D stretching frequencies values of 2145 cm-1 , 2235 cm-1 , 2470 cm-1 and 2525 cm -1 have been obtained. They agree well with the relations between ṽOD and eQΦzz h-1(2H) given in the literature.