bluuebunny/crossref_metadata_2025_split huggingface dataset:
Analysis of Formation of the Suppression Effect of Nuclear Reaction Inelastic Channels in the Presence of Hyperfine Splitting
Authors: Kagan Yu. , Afanas'ev A. M. 
Published: February 2015

The analysis, carried out in the work, of the emergence of the effect of suppression of the nuclear reaction (ES) during resonance Bragg scattering of Mössbauer gamma-quanto from nuclei under conditions of a hyperfine splitting allows to clearly reveal the fundamental features characteristic of this phenomenon. An is shown in sections 3 and 4, in a general case of realization of ES neither electric nor magnetic vectors of the wave field in the crystal turn to zero at the points of equilibrium positions of the nuclei. For the reaction to be suppressed, it is necessary that the total amplitude of the excited nucleus formation be zero. In this case, a rather peculiar picture of the electromagnetic field within the crystal sets in which depends on the character of the hyperfine splitting and on the multiplicity of the transition.
In this work, conditions have been found of the coexistence of ES for both polarizations, and with these conditions being fulfilled, the strongly resonantly absorbing crystal becomes transparent for the whole of radiation. Special attention has been paid to the proof that lattice vibrations do not restore the nuclear absorption of gamma-quanta. It is interesting that all this takes place during resonant interaction with a separate nucleus when the cross-section of the inelastic process may be large as compared with the elastic scattering cross-section. Although all these features (and a number of others discussed in detail in the text) essentially distinguish ES from the Borrmann effect for X-rays, there is a circumstance which makes them related. In both cases it is necessary to produce a coherent superposition of waves within the crystal owning to the Bragg diffraction of the incident quanta, and in the both cases the crystal becomes more transparent for the radiation that comes through.
Das Rotationsspektrum des JF/ Rotational Spectrum of IF
Authors: Tiemann E. , Hoeft J. , Törring T. 
Published: February 2015

IF was produced by microwave discharge of l2 and C6F10(CFa)2. The rotational transitions J=0→1 and 1→2 in the vibrational states ν = 0, 1, 2 were observed. The analysis of the hyperfine structure yields the following hfs constants:

127I: e qv Q = (-3440.89+5.47 (ν+½) ±0.20) MHz,
cI = ( + 90 ±10) kHz.
Zur geometrischen Struktur von CF5
−, — eine wellenmechanische Untersuchung / The Geometrical Structure of CF0
− , a Wave Mechanical Investigation
Authors: Wang S.-J. 
Published: February 2015

The geometrical structure of CF5
− has been ab initio investigated, taking all 52 electrons into account, using the MOLPRO-Programm/SCF-MO-LC-(LCGO)-Method. After approximating the core by means of the energy variation method and varying the ηp-values and the C - F-distance a total energy of - 517,7008 a. u. with a C - F4,5-distance of 2.78 a. u. and a C - F1,2,3 -distance of 2.74 a. u. for the CF5
−-system of the trigonal bipyramidal structure was found.
Likewise a total energy of -517.7036 a. u. with a C - F -distance of 2.58 a. u. in the tetraedral CF4 and a CF4 - F−-distance of 5.80 a. u. for the CF4 -F−-system was found. The best C-F-distance of the tetraedral CF4 was given at a distance of 2.51 a. u.
According to this investigation it can be concluded that the structure of the system CF4 - F− is the most stable one. An interesting result through the analysis of the electrondistribution is that the carbon atom is almost in all structure systems nearly unchanged.
Begleitbanden der Null-Phononenlinien des Phosphoreszenzüberganges dotierter Cr3+: Alha6J3-Kristalle. Teil I. Lumineszenz / The Sidebands of the zero Phonon band of the Phosphorescence Transition in Cr3+ : Alha6J3 Single Crystals. I. Luminescence
Authors: Koglin E. , Krasser W. , Wolff G. , Nürnberg H. W. 
Published: February 2015

The sidebands of the zero phonon band of the phosphorescence transition

are investigated in Cr3+:Alha6J3 single crystals for several Cr (III)-concentrations. At low Cr (III)-concentrations of 2 mol-% the electronic transitions can be assigned to the zero phonon transition of the phosphorescence and the corresponding phonon sidebands with the aid of polarisation measurements, the temperature behaviour of the bands and the isotope effect. Under the influence of a trigonal field D3 combined with spin-orbit coupling, both transitions

and

are observed. The phonon sidebands and the internal vibrational sidebands of the

transition are compared with infrared and Raman vibrational bands.
At a Chromium (III) concentration of 26 mol-%, some additional bands are measured nearby the

transition, which cannot be explained in the single ion crystal field model. There exists a super exchange interaction between the Cr3+-ions across the urea ligands. The interaction can be described by a Hamiltonian Hex = -JS1 · S2, which splits the 4A2-ground level into four levels | 4A2 ·
4A2〉 S = 0,1,2,3 with energy differences |J|; 2|J| and 3 |J|. In the phosphorescence spectrum the four transitions |2E · 4A2)〉S' = 1 → |4A2·4A2〉s = 0,1,2,3 are observed and the value of the exchange integral is calculated.
Kinetics of Formation of SrWO4 in the Solid State Reaction Between WO3 and SrCO3
Authors: Flor Giorgio , Massarotti Vincenzo , Riccardi Riccardo 
Published: February 2015

The solid state reaction WO3 + SrCO3 → SrWO4 + CO2 was studied with the reactants in form both of separate pellets and of powder mixtures.
As for pellets, by an application of Wagner’s method it was possible to state that the governing process is the cation counterdiffusion involving W6+ and Sr2+.
Thermogravimetric measurements in the temperature range 663° - 755 °C on equimolar powder mixtures and with SrCO3 in a specially prepared spherulitic form were interpreted using Dünwald- Wagner’s equation
Electromagnetic Transitions in 177Hf
Authors: El-Nesr M. S. , Bashandy E. , Mousa M. G. 
Published: February 2015

The gamma transitions in 177Hf have been measured using a 50cm radius iron-free double focusing beta-ray spectrometer. The decay scheme is investigated and the K-conversion coefficients of the 208 and 321 keV transitions have been determined.
Comparison with theoretical conversion coefficients for pure El radiation calculated by Sliv and Band indicates that the K-conversion process of the 208 keV transition is normal while the large anomaly observed in the K-conversion process of the 32l keV E1 transition is compatible with a large M2 admixture or more probable with the presence of penetration matrix elements. From comparison with theoretical conversion coefficients the 113 keV M1+E2 transition has been found to be (95.12+0.6)% E2 corresponding to |δ| = 4.38±0.33. The decay scheme of 177Lu is discussed in terms of nuclear models.
Zur Variation von Lumineszenz-Lebensdauern durch eine dielektrische Grenzfläche
Authors: Tews K. H. 
Published: February 2015

Abstract
A theory of the luminescence lifetime of a radiation-damped classical electrical point dipole near a plane interface to a medium with different optical constants is given. The influence of the interface on the lifetime of the dipole is calculated in first approximation with the methods of molecular optics. Theoretical and experimental results for a purely dielectric interface are compared.
Spektroskopische Bestimmung der Dissoziationsenergie von AlO aus Gleichgewichtsmessungen in Flammen
Authors: Frank P. , Krauss L. 
Published: February 2015

Abstract
Measurements of particle concentrations of Al and AlO are performed in premixed laminar H2/O2-flames with additives of organic aluminium compounds. Using the oscillator strengths in electronic-vibronic transitions of AlO published by Michels 1, absolute number densities for different equilibria in the range 2750 - 2980 K are determined. By means of second law and third law plots a dissociation energy for AlO of 5.06 ± 0.08 eV is achieved. This value is in agreement with recent results obtained from mass spectroscopic techniques by Hildenbrand 2.
Appearance Potentials of Field Ions
Authors: Heinen H. J. , Röllgen F. W. , Beckey H. D. 
Published: February 2015

Abstract
The appearance potentials (AP) of various ions, which are produced by field ionization at platinum tip emitters have been measured by a retarding potential energy analyzer coupled to the output of a single-focusing magnetic mass spectrometer. Adsorption layers of water and organic molecules on the emitter surface were found to have no significant influence on the AP measurements. The APs of the H3O+ and (H2O)2H+ ions in the water spectrum and the CH3OH2
+ and (CH3OH)2H+ ions in the methanol spectrum suggest that the emitter surface is involved in the protonation reactions. The APs of the other ions in the water and methanol spectra have also been studied. The APs of the molecular ions of the paraffins allow conclusions to be drawn about the energy deposition function for field ionization. The fragment ions of n-heptane were found to have surprisingly low APs, up to 2.4-eV less than the molecular ion. The AP of the CH3
+ ion in the methane spectrum indicates that it arises from a surface reaction.
Die Abhängigkeit der Fluoreszenzquantenausbeute von der Anregungswellenlänge bei Carbonylverbindungen des Pyrens
Authors: Kröning P. 
Published: February 2015

Abstract
Pyrene-3-aldehyde, 3-acetylpyrene and 3-benzoylpyrene show almost no fluorescence in dilute solution in non-polar solvents. In more concentrated solutions, however, a long wave fluorescence is observed, showing the existence of weak intermolecular forces, even in the ground state. In polar solvents, pyrene-3-aldehyde and 3-acetylpyrene exhibit short wave monomer fluorescence whilst 3-benzoylpyrene does not fluoresce. The intensity for both long and short wave fluorescence is dependent upon the excitation wave length and is a maximum for excitation in the weak long wave tail of the first absorption band. Molecules are thought to have a greater absorption in this region if they interact strongly with their polar or polarizable surroundings. Due to the very short singlet lifetime of isolated monomers (τ<C10-10 sec), such molecules have a greater probability of forming a fluorescence state than more weakly interacting ones.
Measurements of C2 Radicals in Flames with a Tunable Dye-Laser
Authors: Becker K. H. , Haaks D. , Tatarczyk T. 
Published: February 2015

Abstract
By laser excited fluorescence using extra-cavity techniques the C2(a3πu) radical concentration in an acetylene oxygen atom flame was measured in comparison to the emission intensity from C2(d3πg) radicals which are produced by chemiluminescent reactions.
Viskosimetrische Untersuchungen zur Frage nach dem Aufbau flüssiger Quecksilber-Thallium-Legierungen / Viscometric Investigations on the Structure of Liquid Mercury Thallium Alloys
Authors: Predel Bruno , Arpshofen Ingo 
Published: February 2015

By means of a capillary tube viscometer we have investigated liquid Hg-Tl alloys in the temperature range from 20° to 90 °C.
On the basis of the experimental results it can be concluded that associations with the stoichiometric composition Hg3Tl are existing in the liquid Hg-Tl alloys. The percentage of these associations is dependent on the concentration, and furthermore, on temperature. The maximum percentage at 25 °C and 25 at % Tl is about 20 at %.
Thermoelectric Power and Electric Conductivity of the (Ag, Na) Cl and (Ag,Na)Br Solid Solutions
Authors: Magistris A. , Schiraldi A. , Chiodelli G. 
Published: February 2015

The electric conductivity and the initial thermoelectric power are determined for the solid solutions (Ag, Na)X (X = Cl, Br) over the whole composition range.
Data drawn from both kinds of measurements allow to approximately estimate the contributions of cation vacancies and interstitial Ag* to the transport process.
Two composition regions are distinguished: 0≦NNaX≦0.6 and 0.7<NNaX<1 where interstitial Ag+ and cation vacancies, respectively, are prevailing.
Classical Annihilation Radiation
Authors: Liboff Richard L. , Maresca Neal J. 
Published: February 2015

Abstract
An expression for the total energy £r of radiation associated with the classical annihilation of two uniformly moving massless charge distributions which are identical except for sign is obtained. The energy is found to be generated by the processes of bremsstrahlung, pair interaction, and static field cancellation whose contributions give the result εR = 2 γ β2 ε0 where ε0 is the charge distribution self-energy. Application of the results to several sample charge distributions supports the conjecture that infinite acceleration of charge does not necessitate infinite radiated energy. A criterion for the finiteness of total emission is established with respect to the self-energies of the charge distributions. For the case of non-zero mass distributions, a formula for the total energy of annihilation is developed, suggesting an annihilation event to be interpretable in terms of the separate annihilation of electromagnetic and inertial mass.
Messung der Kontinuumstrahlung von Krypton und Xenon in einem durch Stoßwellen aufgeheizten Plasma
Authors: Carls Hans-H. 
Published: February 2015

Abstract
We report on the measurement of the Recombination Continuum of Krypton in the wavelength region between 2300 Å and 3600 Å. The plasma behind a reflected shock has been used as a light source. Good agreement was found between measured absorption coefficients and theoretical ones if the electron density was measured from the broadening of the Balmer line Hβ, while the measurements show departures by a factor 5 to 9 from Rankine-Hugoniot predicted values. Possible deviations from ideal shock behaviour are discussed.
Ein Modell zur verzögerten Fluoreszenz von Anthracen/Tetracen Kristallen
Authors: Wolff H. 
Published: February 2015

Abstract
Spectra and decay-times of delayed fluorescence in anthracene single crystals doped with tetracene at concentrations ranging between 3·10-10 to 3·10-5 were measured (T = 300°K). The dependence of the relative intensities and the decay-times on the concentration is explained by a simple model: The triplet-excitons of the host-lattice are captured by triplet traps localized in the nearest neighbourhood of the guest molecules. Than, the energy either goes to the tetracene, or thermally stimulated back into the triplet exciton band. The energy transfer of singlet excitons is taken into the considerations. The differential-equations describing the model are approximative^ solved. The solutions are compared with the experimental results. From the measurements a transfer rate K= (1.1 ± 0.4) · 104 for singlet excitons is derived, corresponding to a velocity constant of ks = 5.5 · 1011 s-1 (at p = 0.7 ± 0.07). The transfer of triplet excitons is governt by the constant k = 2 · 1011 s-1 . This corresponds a diffusion constant of triplet excitons D= (1.25 ± 0.2) · 104 cm2 s-1 . The lifetime of the tetracene triplet state within the antracene lattice is found to be τ = ( 1.09 ± 0.1) · 10-3 s.
55Mn NMR Studies in Aqueous Permanganate Solutions
Authors: Lutz O. , Steinkilberg W. 
Published: February 2015

Abstract
The NMR signals of the nuclei 55Mn and 2H have been investigated in aqueous solutions of permanganates. The concentration dependence of the NMR signals of 55Mn has been determined in potassium permanganate solutions in H2O and D2O and a large solvent isotope effect on the chemical shift of 55Mn has been established. The ratio of the Larmor frequencies of 55Mn relative to 2H has been measured with high accuracy. Using the concentration dependence, the ratio of the Larmor frequencies of 55Mn for infinite dilution relative to 2H in pure D2O is given. From this ratio a magnetic moment for 55Mn in the permanganate ion has been derived.
Gravimetrie Interdiffusion Measurements in Molten Halides at Temperatures up to 1000 °C
Authors: Behn Anders , Sjöblom Carl-Axel 
Published: February 2015

Abstract
The interdiffusion coefficient of bromide ions at low concentration in molten silver chloride has been measured with the gravimetric technique, and it can be "least-squares" fitted into the equation D23 = 6.58 x 10-4 exp { - (4280 ± 110) / RT) (503-820 °C) where D23 is expressed in cm2 s-1 and RT in cal equiv-1 . Friction coefficients as defined by Klemm do not indicate association between the chloride and bromide ions. The interdiffusion coefficients of potassium ions in molten sodium chloride at 900 °C and of sodium ions in molten potassium chloride at 995 °C, both at low concentration, have been found to be approximately 2 x 10-4 cm2 s-1
Zur innermolekularen elektronischen Relaxation des freien Benzols nach Elektronenstoßanregung
Authors: Hartfuß Hans J. 
Published: February 2015

Abstract
A crossed-beam-experiment was built up, which allows to determine spectra and decay-times of the target-molecules. The energy of the exciting electrons is 200 eV. The maximum density in forward direction of the molecular beam equals a pressure of 6·10-4 Torr, much below the lowest pressure, where pressure-induced relaxation is observed. The following target-molecules were used:
C6H6 , C6D6 , C6H5F, C6H5Cl . The measured decay-times are evaluated with the quantum-yield-data of other authors, to determine the relaxation-times for the Intersystem-Crossing-process 1B2u →
3B1u of Benzene. A comparison with theory gives the interaction-energies between singlet- and triplet-BO-states. The energies are of the order of 10-9 eV.
Microwave Spectrum and Dipole Moment of Methylenecyclobutenone
Authors: Czieslik W. , Carpentier L. , Sutter D. H. 
Published: February 2015

Abstract
The microwave spectrum of Methylenecyclobutenone has been investigated in the vibrational ground state in the range of 8 to 26.5 GHz. From a least square fit of 12 lines with J ≦ 4 the rotational constants have been calculated as A =5.775664±0.000009 GHz, B = 4.312314 ± 0.000007 GHz, C = 2.467814±0.000008 GHz. The inertia defect Δ = - 0.09 amuÅ2 indicates that the molecule is planar. From Stark-effect measurements the components of the molecular electric dipole moment were obtaied as |μa| = 2.04 ± 0.02 D, |μb| = 2.70±0.03 D, |μtotal| = 3.39 ± 0.05 D.
Precision Measurements of Magnetic Moments of Nuclei with weak NMR Signals
Authors: Sahm W. , Schwenk A. 
Published: February 2015

Two NMR spectrometers were combined and a special probe assembly was constructed in order to enable a simultaneous measurement of the signals of 2H and any nucleus, the gyromagnetic ratio of which is <1.4·107T-1sec-1. The Larmor frequencies of 39K, 73Ge, and 109Ag in well defined samples were referred very accurately to the resonance of 2H in D2O. It was possible now, to refer the Lamor frequencies of the nuclei 41K, 57Fe, 87Sr, 107Ag, 183W, 187Os, which were previously referred to the resonance of one of the nuclei mentioned above, to the Larmor frequencies of the deuteron and the proton in D2O or H2O.
The magnetic moments of all these nuclei are given.
Molecular g-Values, Magnetic Susceptibility Anisotropics and Molecular Electric Quadrupole Moment of Methylenecyclobutenone
Authors: Czieslik W. , Sutter D. H. 
Published: February 2015

The rotational Zeeman-effect of methylenecyclobutenone has been investigated giving the molecular (g-values: gaa = -0.0925 ± 0.0003, gbb = -0.0729 ±0.0003, gcc = -0.0086 ± 0.0003 and the magnetic susceptibility anisotropies:
2χaa-χbb-χcc= (23.0 ± 0.5) · 10-6 erg/G2 mole and
2χbb-χcc-χaa= (25.5 ± 0.5) · 10-6 erg/G2 mole.
These values correspond to the following molecular electric quadrupole moments given in units of 10-28 esu cm2: Qaa = 1.0±0.6, Qbb= 2.8±0.6 and Qcc = 3.8± 1.0. The experimental data of methylenecyclobutenone and similar strained ring molecules are compared with the results of INDO-calculations and values obtained from additivity rules for bond contributions.
INDO- and CNDO-Approximated Molecular Orbital Calculations on the Spin-Spin Coupling Constants in Some 2-Substituted Oxetanes
Authors: Jokisaari Jukka 
Published: February 2015

Spin-spin coupling constants between the methine proton in the oxetane ring and the phenyl protons and carbon nuclei have been calculated in different conformations in the INDO approximation for 2-phenyloxetane and 2-(4-fluorophenyl) oxetane, and in the CNDO approximation for 2-(2- chlorophenyl) oxetane and 2-(3-chlorophenyl) oxetane. In each case the finite perturbation method has been used.
In the case of 2-(2-chlorophenyl) oxetane a fairly high energy barrier for the rotation around the C-C bond between the rings is obtained, while in the other three cases the barrier is much lower. The calculations predict an equilibrium conformation in which the oxygen atom lies almost in the plane of the aromatic ring.
The calculated dipole moments of 2-(2-chlorophenyl) oxetane and 2-(3-chlorophenyl) oxetane vary significantly with conformation.
Energy Levels of Pt197
Authors: Alves S. Calzavara , Barros S. de , Gonçalves A. 
Published: February 2015

Spectra of γ rays (higher than 0.3 MeV) following the β decay of Ir197 are measured with a Ge-Li detector (30 cm3). The existence of four new brandies to the Pt197 levels at 877.6 ± 0.3; 939.7±0.3; 1049.6±0.3; 1341.8±0.3 keV is proposed and lower limit log f t values are determined. Spin and parity (1/2, 3/2)+ are assigned to the ground state of Ir197.
A new transition of 299.5 ± 0.2 keV was observed following the Pt197 (80 min) decay.
Energieübertragung zwischen gleich- und ungleichartigen Molekülen in LösungII. Experimente über Konzentrationsdepolarisation der Fluoreszenz / Energy Transfer Among Like and Unlike Molecules in Solution.II. Study of Concentration Depolarization of Fluorescence
Authors: Kawski A. , Kamiński J. 
Published: February 2015

Abstract
Radiationless energy transfer between like molecules (homotransfer) in thin rigid cellulose acetate films was studied by the concentration depolarization of the photoluminescence. The investigated substances are rhodamine B, 9-methylanthracene and 5-methyl-2-phenylindole. The experimental results have been compared with the “multi-shell model” of a luminescent centre. Good agreement was found with the equation which takes into account the excitation energy remigration. Concentration -depolarization measurements show that the critical distances R1, at which the probability of transfer of the excitation equals that of emission, are dependend on the excited wavelength. This is due to the failure of thermal relaxation of the exciting molecules with their environment.
Thermodynamic and Physical Behaviour of Binary Mixtures Involving Sulfolane Viscosity, Dielectric Constant and Solid + Liquid Phase Diagram of Mixtures of Dioxane + Sulfolane
Authors: Jannelli Liliana , Inglese Americo , Sacco Antonio , Ciani Pietro 
Published: February 2015

Abstract
Excess functions, H≠E, S≠E, G≠E for activation of viscous flow, as well as the dielectric constants of dioxane (1) - sulfolane (2) mixtures were determined: slight negative deviations from ideality were observed in both cases, with a minimum at x ≈ 0.5.
Solid-liquid equilibrium temperatures were also measured over the entire composition range. Solid solutions were observed in the region in which mesomorphic sulfolane is in equilibrium with the liquid.
Two phase diagrams may be drawn, in the region 0.33 ≦ x2 ≦ 0.98: one is of the simple eutectic type and the other exhibits two eutectis and a flat maximum corresponding to a 1:2 molecular compound, the occurrence of which is supposed to be caused by weak electrostatic attractions in a system of favorable crystal geometry rather than by bonding. A lessening of these interactions, with increasing temperature, would result in the liquid solution regular behaviour.