bluuebunny/crossref_metadata_2025 huggingface dataset:
Heat-Flow Birefringence in Gases
Authors: Hess S.
Published: February 2015

Heat-flow birefringence is described by a constitutive law which links the anisotropic part of the dielectric tensor with the gradient of the heat flux or the 2nd spatial derivative of the temperature field. For a gas of linear molecules, this relation is derived from transport-relaxation equations which, in turn, were obtained from the Waldmann-Snider equation. The magnitude of the heat-flow birefringence can be inferred from the Senftleben-Beenakker effect of the viscosity and of the heat conductivity. It is found to be of measurable size.
Nonreciprocal Propagation of Guided Waves in Sliding Laminae of Isotropic Dielectrics
Authors: Gehre O. , Mayer H. M. , Tutter M.
Published: February 2015

The well-known relation of Fresnel and Lorentz for the effect of material motion on the propagation of light is extended to guided waves propagating in a system of dielectric layers differing in refractive index as well as in the magnitude of their velocities. The analysis is based only on the existence of a transverse dispersion (determinantal equation) which is invariant with respect to sliding motion at least to first order in β. A one-to-one correspondence ("transmodification") of wave vectors in the moving and in the quiescent state is used to demonstrate that nonuniform motion can lead to (convectively) unstable modes. The theory is applied to a moving parallel-plate waveguide and to the model of a glow discharge enclosed in a circular waveguide.
The Possibility of Micro-fission Chain-reactions and their Application to the Controlled Release of Thermonuclear Energy
Authors: Winterberg F.
Published: February 2015

It had been shown 1,
2 recently that it may be possible to reach densities up to 103 g/cm3 by imploding a solid hydrogen pellet with the aid of a symmetric arrangement of multiple laser beams irradiating the pellet simultaneously from all sides. The purpose of this proposed scheme was to reduce the energy input requirements for the controlled release of thermonuclear energy delivered by laser ignited T - D micro-explosion systems.

It is shown in this paper that by applying the foregoing concept of high density compression to a pellet consisting of fissionable material such as U235, Pu239, or U223, the critical mass for the initiation of a fission chain reaction in these materials can be reduced by many orders of magnitude raising the possibility of micro-fission-explosions with laser energy inputs for compression within the expected reach of laser technology. Alternatively, the pellet compression may be also achieved by the employment of intense relativistic electron beams. In addition, by surrounding the fis­sionable pellet with a layer of dense T - D material to be compressed together with the pellet, the minimum pellet size can be furthermore reduced by neutron reflection from the high neutron albedo T - D shell. For fissionable pellets without a reflector the critical mass can be as small as ∼ 0.3 g requiring a laser energy input for compression of several megajoule. For a pellet surrounded by a T - D reflector the critical mass can be reducel down to ∼10-3g with a laser energy input for compression of several 105 joule.

In addition to the neutron albedo effect of the T - D shell there is a bootstrap mechanism where­by the T - D mantle achieves thermonuclear temperatures resulting in the emission of thermo­nuclear reaction neutrons into the fissionable pellet causing more fission reactions and thereby raising the temperature of the pellet. This then in turn will lead to an additional heating of the T - D blanket resulting in an increased flux of thermonuclear neutrons raising the fission rate even further. Because of the greatly increased material density, a fission chain reaction initiated in it will grow in proportion much faster than in uncompressed fissionable material as it is being used in conventional fission bombs.

The system described may have important usefulness as a small fission power plant especially for space propulsion applications but also for a more effective burn in a thermonuclear micro-bomb reactor as a fission supported fusion reaction.
Strain Effects in the Paraelectric Resonance of KCl: Li
Authors: Dischler B.
Published: February 2015

The effects of random internal strains on the paraelectric resonance spectra for off-center Li in KCl are investigated quantitatively. Diagrams giving the theoretical line positions and relative intensities are presented for the principal orientations 〈100〉, 〈110〉, and 〈111〉. Where the model for an ideal host crystal predicts only one line, up to six lines are obtained in the present calcula­tion. A direct comparison with the published experimental spectra, taken at 9, 24, 29, 35, 63 and 74 GHz is performed. Very good agreement is found and the magnitude of internal strain has been inferred, yielding values between 18 and 42 bar for different samples. Random internal electric fields are found to be of the order 3kV/cm. For the halfwidth of the main signal, the orientation and frequency dependence is examined and explained by the calculations. The possible use of paraelectric Li as a microprobe for internal strains and internal electric fields in KCl is discussed. The electric dipole moment of Li7 is found to be 5.9±0.3 Debye in agreement with previous deter­minations. The “cube edge” tunneling model with equidistant zero field levels, separated by 22.2 GHz for Li7, is fully confirmed.
Photoreactions of Small Organic Molecules
Authors: Reinke D. , Kraessig R. , Baumgärtel H.
Published: February 2015

The photoionization curves and the threshold energies for the molecules vinylchloride, vinylfluoride, 1,1-difluoroethylene and their abundant fragment ions have been measured with synchrotron radiation in the photon energy range from 10 - 23 eV. Appearance potentials were used to calculate heats of formation, bond energies and ionization potentials. The structure of ion efficiency curves is discussed in terms of different ionization processes.
Zur Besdireibung von Atonirümpfen init kleinen Basissätzen im Rahmen des SCF-MO-LCGO-Verfahrens / Describing of the core with small basis sets of the SCF-MO-LCGO-method
Authors: Wang S.-J.
Published: February 2015

The approximation of the stable core has been investigated, using small basis sets of the SCF -MO -LCGO-method. The results of the calculated three Gauss-functions and the total energies for the configuration (1s)2 (2s)2 of B+, C2+, N3+, O4+ and F5+ are given and compared with the basis sets of five Gauss-functions. A discussion on the quality of these basis sets for molecular calculations is given.
Eigenvektoren und Intensitäten der Raman- Linien von Polaritonen in ein- und zweiachsigen Ionenkristallen / Eigenvectors and Intensities of Raman Lines of Polaritons in Uniaxial and Biaxial Ionic Crystals
Authors: Borstel G. , Merten L.
Published: February 2015

Explicit formulas are derived for the eigenvectors of polaritons (quasi-normal coordinates and electric field). With these eigenvectors Raman scattering cross sections can be calculated directly.
Beobachtung von Inversionswänden in einer nematischen Flüssigkeit / Observation of inversion walls in nematic liquid, crystals
Authors: Heppke G. , Schneider F.
Published: February 2015

The magnetic field induced deformations of a homeotropic nematic liquid crystal layer are studied by means of the electric conductance. Its time dependence observed after rotating the magnetic field direction by 180° is explained by the formation of alignment inversion walls.
Einfluß von Kohärenzeffekten auf die Linienformen im ENDOR-Spektrum des Perinaphthenyl-Radikals / Influence of Coherence Effects On Line Shapes in the ENDOR Spectrum of the Perinaphthenyl Radical
Authors: Dinse K.-P.
Published: February 2015

A cw high-power ENDOR spectrometer is described. Freed's theory of coherence effects on ENDOR line shapes of free radicals in solution was tested with cw NMR fields up to 30 Gauss. The neutral radical Perinaphthenyl (PNT) with groups of three and six equivalent protons served as example. A satisfactory agreement with the theory was found, even in quantitative terms. Very reasonable values for relaxation times T1e , T2e and T1n of the PNT could be determined by fitting Te-1/We, Wn/We and using measured values for BMW, BNMR and the EPR line width.
Struktur amorpher Aufdampfschichten der Legierung (Ag+50 At.-Proz. Cu) / Structure of the Amorphous Alloy (Ag + 50 at.-% Cu)
Authors: Breitling G. , Mader S. , Richter H.
Published: February 2015

A discussion of the atomic distribution curves obtained by Fourier-analysis of electron diffraction patterns shows that thin films of the alloy (Ag + 50 at.-% Cu) are liquid-like amorphous. The amorphous alloy (Ag + 50 at.% Cu) is composed of the 3 regions Cu, (Ag + 50 at.-% Cu) alloy and Ag. Further investigations yield two different degrees of order. At lesser order only the distances of the 3 zigzag chains of the amorphous regions show up in the atomic distribution curve, while at more extended order the three (r1) Cu, alloy,

-distances of the hexagonal close packing are also observed. Finally, in the case of lesser order it is shown that the atomic distribution curve calculated from the 3 zigzag chains of the amorphous alloy (Ag + 50 at.-% Cu) is in good agreement with the experimental one.
Über die Fluoreszenzfähigkeit von Triphenylcarboniumderivaten / Fluorescence Yields of Triphenylcarbonium Derivatives
Authors: Hoffmann G. , Schönbucher A. , Steidl H.
Published: February 2015

The absolute fluorescence yields of triphenylcarbonium derivatives are correlated with the change of bond order between central-C-atom and phenyl group during the electronic transition. The fluo rescence yield is reduced by a rotation of the phenyl group only if the π-electron system of the phenyl group is sufficiently strong coupled to the other part of the molecule. The change of bond order can be assumed as a measure for the coupling.
On the Green's Function Approach and the Parametric Study of Force Constants
Authors: Alix A. , Mohan N. , Müller A.
Published: February 2015

A detailed study of the Green's function analysis of the vibrations of substituted and perturbed molecules is made. The similarity in approach of this procedure with the parametric study of force constants is pointed out. The significance of the signs of the different parameters entering the '"mixing parameter matrix" is discussed for any nth order case, using the definition of potential energy distribution.
Zur Torsions-Schwingungs-Rotationswechselwirkung in Rotationsspektren. II. / Overall Rotation Interaction in Rotation Spectra II
Authors: Mäder H. , Andresen U. , Dreizier H.
Published: February 2015

A molecular model with five degrees of freedom, three for the overall rotation, one for the internal rotation and one for another vibration, is discussed. The treatment is restricted to C3-symmetric internal rotors. Regarding this special symmetry the classical kinetic energy is formulated. Two possible sets of molecule orientated coordinate systems, one the instantaneous principal axis system, the other an axis system in which the vibrational angular momentum disappears, and the transformation between them are discussed. A general expansion for the potential energy is given. The Hamiltonian is derived for the special case of a molecule with a symmetry plane restricting the vibrational motion to an in-plane vibration. The numerical methods to evaluate the coefficients of the kinetic part of this Hamiltonian and the possibilities to solve the eigenvalue problem, including a remark to the Van-Vleck perturbation treatment, are discussed.
The High Resolution Far Infrared Spectrum of Diacetylene,Obtained with a Michelson Interferometer
Authors: Winther F.
Published: February 2015

A commercial interferometer has been modified for high resolution gas phase work by addition of a variable temperature cell of 3 m path length. The data reduction method is described, and examples of the performance are given. Two rotation-vibration bands of diacetylene, ν9 and ν7-ν9, have been analyzed to yield ν9=220.139(5), ν7=482.13(1), and B0 = 0.14649(7) cm-1.
Bestimmung der Röntgen-Debye-Temperatur aus dem Borrmann-Effekt in Germanium / Determination of the X-ray Debye Temperature in Germanium by Means of the Borrmann Effect
Authors: Ludewig J.
Published: February 2015

The anomal transmission of CuK radiation through "thick"' perfect crystal slices of Germanium is strongly temperature dependent. This temperature dependence was measured between 293 and 6 K in the (220) symmetric Laue case and used to evaluate the Debye temperature θM . The wellknown uncorrected value θ′M = 290K was obtained near room temperature. Taking into account TDS and Compton scattering in addition to the photoelectric absorption the corrected value θM = 294 or 296 K was found, depending on the source of data. With decreasing temperature the corrected θM increases slightly up to a maximum at very low temperatures, as predicted by Batterman and Chipman and by Salter.
Zur Untersuchung von Gleichgewichten instabiler Komplexe und die Bestimmung der Beweglichkeiten der einzelnen Spezies mittels Gegenstrom-Ionenwanderung / Investigation of the Equilibrium of Unstable Complexes and the Determination of their Mobility by Means of Countercurrent Ion Migration
Authors: Bilal B. A.
Published: February 2015

In a countercurrent ion migration process the ion of an element (e. g. a metal cation) can form various unstable complexes with the anion of the countercurrent electrolyte. The total concentration of such an element in its stationary and locally constant distribution in a countercurrent ion migration column is then determined by the average mobility of all equilibrated species containing this element. From stationary distributions in their dependence on concentration the mobilities of the various species can be determined if the constants of the different equilibrium stages are known and vice versa.
d2 and d8 Trigonal Energy Levels
Authors: Perumareddi J. R.
Published: February 2015

The trigonal d2 and d8 symmetry adapted eigenvectors and energy determinants have been obtained in two different representations, with and without cubic orientation. Spin-orbit perturbation was applied last in both the representations. The complete theory developed here is necessary in a definitive and a meaningful study of the interpretation of the spectral and magnetic properties of trigonally distorted or substituted cubic systems and of trigonal systems in which the axial part of the ligand field is of such a magnitude that the cubic parentage has no meaning.
Die physikalischen Grundlagen der Uran235-Anreicherung nach dem Trenndüsenverfahren / The Physics of Uranium235-Enrichment in the Separation Nozzle Process
Authors: Bley P. , Dürr R. , Ehrfeld W. , Eisenbeiß G.
Published: February 2015

The energy consumption of the separation nozzle process for enrichment of U235 is discussed in terms of the entropy production in the separation system. Experimental results obtained from measurements with Pitot type pressure probes and a numerical Navier-Stokes analysis of the nozzle flow show that ordinary viscous dissipation is the most important entropy production mechanism. The relatively large amount of kinetic energy observed at the end of the nozzle indicates some possibilities of lowering the specific energy consumption of the process.
Conversion Electrons of 116In following Neutron Capture
Authors: Schreckenbach K. , Suarez A. A. , Egidy T. von
Published: February 2015

The reaction 115In (n,e)116In has been measured with the beta spectrometer at the FRM reactor in Munich. Multipolarities of 44 transitions up to 600 keV have been determined. The spin and parity assignments in the level scheme of Rabenstein et al. are verified by this measurement. New spins and parities could be assigned to 6 levels.
Thermoelectric Power of the Molten Systems (Ag + Me)I and (Cu + Me) I (Me = Na, K, Rb, Cs)
Authors: Pezzati Elisabetta , Schiraldi Alberto , Magistris Aldo
Published: February 2015

The systems (Ag+Me)I and (Cu+Me)I were investigated by measuring their initial thermoelectric power; mixtures containing AgI show a behaviour much closer to the ideality than mixtures containing CuI. Interesting conclusions are suggested about the heats of transport of silver and copper ions in the pure molten iodides.
Effect of Compton Scattering on the Borrmann Effect of X-Rays in Silicon Crystals
Authors: Giardina M. D. , Merlini A.
Published: February 2015

The absolute integrated intensities diffracted in anomalous transmission through thick, nearly perfect crystals of silicon were measured for AgKα and MoKα wavelengths and for the {220} reflection, at room and liquid nitrogen temperatures. There is good agreement between experimental values and those calculated by using the formulas of the dynamical theory of diffraction, provided the contribution of Compton scattering μC* is included in the effective absorption coefficient μ*. μC* is a considerable fraction of μ* (from 23 to 55 per cent) for the two wavelengths and temperatures used in the present work. The experimental values of μC* agree well with those calculated by using the theory of the Compton contribution to the dynamical absorption coefficient of X-rays. A simple formula which is a good approximation of the rigorous expression of μC* is also given. The Debye temperature Θ of Si was derived from the experimental dependence of the intensities on crystal thickness for the {220} reflection at room and liquid nitrogen temperatures by using CuKα radiation. It was found that Θ = 521+5 and 543 + 5 °K at 295 and 77 °K, respectively, in agreement with the results of other authors.
Interdiffusion of Silver Ions in Molten Thallous Nitrate
Authors: Behn Anders , Sjöblom Carl-Axel
Published: February 2015

The interdiffusion coefficient of silver ions in molten thallous nitrate has been determined with the gravimetric technique. The observed data can be "least-squares" fitted into an Arrhenius equation

D12 = 1.07 × 10-3 exp-(4130 ± 400)/R T

where D12 is expressed in cm2s-1, R in calories equivalent-1, and T in degrees K. Friction coefficients rAgTl calculated according to the Klemm 1 model indicate association between the cations, as has been indicated in mixtures of silver nitrate with heavy alkali nitrates also.
Rate Constant for the Reaction of OH with n-C4H10
Authors: Stuhl F.
Published: February 2015

The kinetic behavior of OH radicals was studied in the presence of a large excess of n-butane. Hydroxyl radicals were produced by pulsed vacuum-uv photolysis of H2O and were monitored directly by a resonance fluorescence method. The rate constant for the reaction OH + n-butane was determined to be 2.35 (±0.35) × 10-12 cm3 molecule-1 sec-1 at 298 °K.
Nichtgleichgewichtscffekte im Argonkaskadenbogen im Druckbereich von 0,2 atm bis 5,0 atm / Non-LTE Effects in an Argon Cascade Arc in the Pressure Range from 0.2 atm to 5.0 atm
Authors: Garz D.
Published: February 2015

An analysis of the plasma state was performed by determination of the electron temperature and the distribution temperature from end -on intensity measurements in the arc axis and by determination of the heavy particle temperature from measurements of the electrical field strength. The electrical current of the arc was varied between 1.5 amp and 60 amp and the argon pressure was varied from 0.2 atm to 5.0 atm. It turned out that not the electron density but the mean free path of the electrons is the essential parameter for the adjustment of LTE. Moreover radial end-on intensity measurements of Ar-I lines with different upper energy levels revealed significant intensity anomalies spreading from the axis of the arc to the walls. These effects could be explained assuming that a diffusion of Ar atoms, which are excited to 4s-levels, takes place out of the arc axis. The diffusion equation and its solution led to a satisfying explanation of the observed radial non-LTE effects.
Absorptions- und Fluoreszenzuntersuchungen in kompcnsierbaren cholesterischen Mesophasen Teil II: Elektroncnübergänge mit unterschiedlicher Polarisationsriehtung / Absorption and Fluorescence Measurements in Compensated Cholesteric Mesophases. Part II: Electronic Transitions of Different Polarization
Authors: Mainusch K.-J. , Pollmann P. , Stegemeyer H.
Published: February 2015

Mixtures of cholesterogenic compounds of opposite helical twisting power at a definite temperature Tn behave like a nematic liquid crystal (compensated mixtures). Using lecithin treated quartz plates nematic mesophases form a homeotropic texture with the optical axes perpendicular to the quartz surface. Thus, in compensated cholesteric mixtures the long axes of the molecules at Tn switch by an angle of 90°. The orientation of the cholesteric solvent molecules is transferred to rodlike solute chromophores also switching at Tn . By measurements of the change of absorptivity or fluorescence intensity of the solute chromophores at Tn one can determine the direction of the transition moment with respect to the molecular axes. This effect has been tested in the case of chromophores with transitions of different polarization.
Valence Effect in the Electromigration of Impurities in Paramagnetic Nickel
Authors: Turban L. , Guilmin P. , Gerl M.
Published: February 2015

The apparent effective diarge Z** of 125Sb, 113Sn, 110Ag, 58Co, 59Fe and 54Mn has been measured in polycristalline paramagnetic nickel, using the thindayer technique. The atom transport appears to be directed toward the cathode for all the investigated solutes. For left-hand impurities, this effect is interpreted as due to predominant d-hole scattering on the impurity; for right-hand impurities both the direct field effect and d-hole scattering have an influence on the direction of the transport.
Bericht: On the Logic of Quantum Mechanics
Authors: Beltrametti E. G. , Cassinelli G.
Published: February 2015

We are concerned with the formulation of the essential features of quantum theory in an abstract way, utilizing the mathematical language of proposition lattice theory. We review this approach giving a set of consistent axioms which enables to achieve the relevant results: the formulation and the essential role of the superposition principle is particularly examined.
MO-theoretische Behandlung des F5SO--Ions und der korrespondierenden Saure F5SOH / The F5SO--Ion and the Corresponding Acid F5SOH
Authors: Rode Bernd M.
Published: February 2015

The bonding in the F5SO--ion is discussed by comparing the results of CNDO MO calculations on this and some related compounds with data obtained from IR- and RAMAN-spectra. Theoretical and experimental results are found to be in good agreement. The-yet not prepared -acid F5SOH is discussed with respect to its stabilization and acidity.
Determination of Interatomic Potentials from the Far Wings of Spectral Lines Perturbed by Neutral Atoms
Authors: Losen J. , Behmenburg W.
Published: February 2015

An indirect method for the determination of interatomic potentials from measurements of the far wings of atomic absorption lines perturbed by neutral atoms is described. In this method the potential parameters are derived by optimum adjustment of line shapes calculated on the basis of the PHQSB-theory (binary approximation of the quasistatic theory of line broadening), assuming Lennard- Jones interaction, to measured profiles of an atomic absorption line perturbed by neutral atoms. The method is applied to measurements of the Hg-absorption line λ 2537 Å, perturbed by Ar and Hg at an Ar number density of 1.26 × 1019 cm-3 and Hg number densities between 7.4 × 1016 and 3.36 × 1018 cm-3, corresponding to temperatures between 427 and 563.5 °K. The reliability of the resulting L.-J.-parameters is discussed by considering the validity criteria of the PHQSB-theory and by comparison with potential curves obtained from other spectroscopic data.
Zum Mechanismus der kollinearen Abstrahlung der 2. Stokes-Linie bei der stimulierten Raman-Streuung / On the collinear Emission of 2nd Order Stokes Radiation in Stimulated Raman Scattering
Authors: Aussenegg F. , Deserno U. , Scherr D.
Published: February 2015

An attempt is made to check by experiment the assumption that the 2nd order Stokes radiation in collinear direction is generated from the primary light by the same mechanism as the 1st order radiation. If is found that the 1st order Stokes beam does not have a sufficiently high intensity over a sufficiently long interaction lenght to explain the generation of the observed 2nd order Stokes radiation as exclusively attributable to this mechanism. An alternative theory is advanced according to which the molecular vibrations generated in the 1st order Stokes process contribute to this effect in the small-signal range. This allows a more plausible explanation of the experimental results. The experiments were performed with benzene at λ = 0.53 μm because this substance exhibits strong stimulated Raman scattering without selffocusing at this wavelenght.
Bestimmung von Elastizitätskoeffizienten einer nematischen Flüssigkeit durch elektrische Leitfähigkeitsmessungen / Elastic constants of a nematic liquid crystal determined by electric conductivity measurements
Authors: Schneider F.
Published: February 2015

The influence of a magnetic field of variable strength and direction on the deformations and the electric conductivity of a nematic liquid crystal is treated theoretically. The results are in good agreement with measurements of the electric conductivity of MBBA, doped with tetrabutylammonium picrate. The bend and the splay elastic constants of MBBA are found to be k33 = 8.62 · 10-7 dyn and k11 = 6.38 · 10-7 dyn at 22.1 °C.
Infrared-Microwave Double Resonance Experiments with NH3
Authors: Kreiner W. A. , Römheld M. , Rudolph H. D.
Published: February 2015

Infrared-microwave double resonance experiments have been performed with ammonia. The experimental equipment consists of a microwave spectrometer and an N2O-laser. First results are in general agreement with previous experiments of other authors. Higher resolution reveals more details of the IR-pumped ν2[aqQ(8, 7)] transition. Several four-level systems were observed.
Elektronenbeugungsmessungen zur Struktur des Methoximethylphosphorylfluorids / Electron Diffraction Investigations of the Structure of Methoxi-methyl-phosphoryl-fluoride
Authors: Zeil Werner , Kratz Helmuth , Haase Joachim , Oberhammer Heinz
Published: February 2015

The structure of Methoxi-methyl-phosphoryl-fluoride has been investigated by electron diffraction on gases. The bond distance of the P-F bond (1.536 Å) corresponds with the value given by Kuchitsu for OPF3 (1.523 ±0.003 Å). The P = O distance is remarkable longer than the value given by Kuchitsu, but corresponds to a value given by Oberhammer for the molecule OP (OCH3)3.
Partial r8-and r0-Structure, Direction of the Dipole Moment and Quadrupole Coupling Tensor in Methanesulfenyl Chloride(CH3SCl)
Authors: Guarnieri A. , Charpentier L. , Kück B.
Published: February 2015

The microwave spectra of three further isotopic species of methanesulfenyl chloride have been investigated. These results together with the results of investigations of isotopic species previously studied enable the calculation of a more accurate r0-structure.

The rs-distance of the S-Cl bond has been determined. Orientation and direction of the dipole moment and the total quadrupole coupling tensor have also been obtained.
The Future Burden of Industrial CO2 on the Atmosphere and the Oceans
Authors: Zimen K. E. , Altenhein F. K.
Published: February 2015

The cumulated input of industrial CO2 into the atmosphere during the next 100 years or so will be about 10 times the natural C02 content if the present rate of increase is restricted only by the finiteness of fossil fuel resources. The resulting surplus of CO2 in the atmosphere and the oceans as a function of time is calculated using the equations for the exchange kinetics between the reservoirs and the logistic function. The results indicate a transient maximum level of roughly 300% over pre-industrial figures in the atmosphere as well as in the mixed ocean surface. This level would be reached during the second half of the next century, if fossil fuels are not going to be replaced by other energy sources much faster than can be anticipated at the present time. Long before the maxi- mum level is reached the increase will probably have serious consequences for the ecological systems in the sea.
Vibrational Analysis of Polymeric Hydrogen Fluoride: Cyclic (HF)6
Authors: Cyvin S. J. , Devarajan V. , Brunvoll J. , Ra Ø .
Published: February 2015

The molecular vibrations of cyclic (HF)6 are studied. The consequences of complex characters for irreducible representations of the appropriate point group (C6h) are elucidated. The secular equation of the vibrational problem is solved in terms of real coordinates. Those of the degenerate species were obtained by a transformation of the complex symmetry coordinates. The force constants were taken from solid HF data. Mean amplitudes of vibration were calculated and compared with electron diffraction results.
The Chemiluminescent Reaction of HCO with O2(1⊿g)
Authors: Becker K. H. , Fink E. H. , Langen P. , Schurath U.
Published: February 2015

A chemiluminescence spectrum above 1 μ is observed when olefins or formaldehyde are reacted with active oxygen. Part of the bands are quenched by water vapor and shifted upon deuteration of the fuel, while others are unaffected. The latter bands are attributed to the (2A′-2A″) electronic transition of HO2 radicals produced by the reaction of HCO radicals with O2(1⊿g) metastable molecules. The quenchable bands are probably overtone transitions of vibrationally excited HO2 radicals in the 2A″ ground state.
The Molecular Zeeman Effect in 2-Methylfuran
Authors: Czieslik W. , Andresen U. , Dreizler H.
Published: February 2015

The rotational Zeeman effect in 2-methylfuran has been measured and the results are compared with those of furan. The Zeeman parameters for the torsional A-species are gaa = -0.0704 ± 0.0005, gbb = -0.0335 ± 0.0004, gcc = +0.0253 ± 0.0005, 2 χaa - χbb - χcc = (23.6 ±0.9) · 10-6 erg/(G2 mole), 2 χbb - χaa - χcc = (44.2 ± 0.7) · 10-6 erg/(G2mole). The corresponding values of the torsional E-species agree with those of the A-species within twice the standard deviation.

The out-of-plane minus the average in-plane components of the magnetic susceptibility, ⊿χ = χcc - 1/2 (χaa + χbb), for 2-methylfuran and furan are compared. The substitution of a methyl group for a proton in the 2-position of furan changes ⊿χ by + (4.8 ± 1.0) · 10-6 erg/(G2mole).
On the d-Orbital Influence in INDO Calculations of NMR and ESR Parameters of Sulphur Heterocyclics
Authors: Galasso V.
Published: February 2015

Comparative calculations by the self-consistent perturbed INDO method on thiophene and by the unrestricted HF INDO method on the 2-thenyl radical show that satisfactory reproduction of nuclear spin coupling constants and hyperfine coupling constants for sulphur heterocyclics can be obtained by considering the sp interaction only.
Unified Analysis of the Metal Vapour Arc
Authors: Ecker G.
Published: February 2015

for given values of the total current density j and the cathode spot surface temperature T a unified and consistent calculation of the cathode drop, Uc , the electron temperature in the ionization region T _- the electron emission current density je , the ion current density j+ , and the extension of the space charge region lsp are presented.

We find that the counter diffusion of plasma electrons into the space charge region plays a decisive role. It causes an effective space charge region extension lsp of a few plasma electron Debey lengths which in general is much less than the ion mean-free-path commonly used. Without the effect of the counter diffusing electrons, the theoretical results deviate from the experimental data by orders of magnitude.

For the example of a Cu metal vapour-or vacuum arc the cathode drop is found to be approximately Uc = 15 [V], the electron temperature about T- =25000 [°K] and the ratio j+/j= 0.5.

Since the analysis allows for multiple ionization the presence of multiply charged ions in the spot area can be calculated.

The results of this investigation justify within the E-areas the approximations used in the analysis for the copper arc in an earlier investigation 1. Outside these E-areas a recalculation with the new results derived here may cause markable changes.
Konversionselektronen von 156Gd nach Neutroneneinfang / The Conversion Electron Spectrum of the Reaction 155Gd(n,e)156Gd
Authors: Schreckenbach K.
Published: February 2015

The conversion electron spectrum of the reaction 155Gd (n, e) 156Gd has been measured up to 8.5 MeV. The results below 4.5 MeV are presented and multipolarities are determined with these results. E0 admixtures of the Δ I = 0 transitions from the 0 + β-vibrational band to the ground state band were determined with 15% accuracy. 156Gd level schemes are discussed and extended by new spin and parity assignments.
The Equation of State for a one-component System
Authors: Neumann H. P.
Published: February 2015

The cooperative problem for a lattice gas on a plane, square lattice and on a simple cubic lattice is solved by a system of two coupled, transcendental equations, derived by a combinatorial method, which describes a homogeneous or periodical particle density on the lattice as a function of the temperature and the chemical potential of the lattice-gas.

For the particle interaction a Hard-Core potential (nearest neighbour exclusion) with a soft long-range tail is assumed. The zero-component of the Fourier-transform of this long-range interaction part can be positive or negative.

The system of transcendental equations is solved by a graphic method. As a result, the complete pressure-density state diagram and the pressure-temperature phase diagram can be drawn.

The lattice-gas exists in three stable phases: gas, liquid and solid. Three phase changes are possible: condensation, crystallization and sublimation.

Critical points of condensation and freezing are examined. The number of possible phases and phase changes at a fixed temperature depends on the geometric structure of the particle interaction.
Resonator-verstärkte Absorptionsspektroskopie in einem Farbstofflaser / Intracavity Enhancement of Absorption Spectra in a Dye Laser
Authors: Weyssenhoff H. v. , Rehling U.
Published: February 2015

When a weak absorber is placed inside the cavity of a broadband untuned dye laser a strong enhancement of the extinction is observed. This effect is investigated quantitatively for the absorption of the Na-D1 line by sodium atoms dispersed in a flame. A set of laser rate equations containing the known stimulated emission cross sections as well as the absorption cross sections for both the ground and the triplet state, is used to determine the spectral and temporal behavior of the laser action and of the enhancement effect. Theoretical and experimental results are in agreement within the limits of error. This intracavity absorption enhancement technique offers particular advantages for the detection of short-lived intermediate species. Its sensitivity is not likely to be matched by other absorption methods.
Messung des 3H-Betaspektrums und Bestimmung der Obergrenze für die Ruhemasse des elektronischen Antineutrinos / Measurement of the H3-Betaspectrum and Determination of an Upper Limit for the Electronic Antineutrino Rest Mass
Authors: Röde B.
Published: February 2015

The β-spectrum of tritium has been measured with the Heidelberg (π/2)√13 high resolution magnetic spectrometer. A new almost backscatter free source technique and a special proportional counter were developed. Special attention is paid to the problem of energy losses of the electrons in the source layer to get a theoretical expression for correcting the measured spectra in a physically meaningful way. On the basis of the Wilcoxon ranktest an upper limit of 8 6 eV at 90 per cent confidence was obtained for the antineutrino rest mass.
Method for the Rapid Interruption of Large Electric Currents
Authors: Winterberg F.
Published: February 2015

A method is described which promises the rapid interruption of large electric currents in very short times. The method is based upon the electrostatic interruption of a Brilloin flow in ultrahigh vacuum. The method may turn out to be very important for inductive energy storage devices.
Die Anwendbarkeit verschiedener Näherungsmethoden zur Berechnung von Kraftkonstanten bei Säkulargleichungen der Ordnung n > 2 / The Applicability of Different Approximation Methods for the Calculation of Force Constants in Secular Equations of Order n > 2
Authors: Eysel Hans Hermann , Lehmann Walter J. , Lucas Kai , Müller Achim , Schmidt Karlheinz
Published: February 2015

Force constants for molecules with secular equations of order n > 2 have been determined with the help of various approximation methods based on the General Valence Force Field. The applicability of the approximations have been tested empirically. It cannot be predicted with certainty whether any approximation method yields reliable force constants. Some methods have been found to be inapplicable. The calculation of off-diagonal force constants with any approximation method is impossible. The principle of the quasi-determination of off-diagonal force constant matrix elements from the form of the G matrix on which most approximation methods are based, is critically discussed. It is shown that diagonal force constants calculated with approximation methods are more reliable if the coupling between the vibrations in the same species is low. The application of approximation methods for the determination of force constants without critical consideration is not meaningful.
Kriterium für spezifische zwischenmolekulare Effekte in Nichtelektrolyt-Flüssigkeiten: die Oberflächenspannung / Criterion for Specific Intermolecular Forces in Nonelectrolyte Fluids: The Surface Tension
Authors: Ulbrich Raimund
Published: February 2015

The surface tension of fluid nonelectrolytes is calculated using an approximation which refers to the intermolecular dispersion forces solely. In the cases of coincidence of calculated (σ*
20) and experimental (σ20
exp) values there are no specific intermolecular forces (owing to H-Bonds, Multipoles) . In the cases σ*
20 ≠ σ20
exp the existence of specific intermolecular forces must be supposed. An index A ≡ 10 · log (σ20
exp/σ*
20) is proposed to characterize the intensity of specific intermolecular forces in fluid nonelectrolytes.
Zeeman-Effekt im Mikrowellenrotationsspektrum der AlF-Molekel / Zeeman Effect in the Microwave Rotational Spectrum of the AIF Molecule
Authors: Honerjäger R. , Tischer R.
Published: February 2015

The Zeeman effect in the microwave rotational spectrum of 27Al19F has been measured in the ground vibrational state υ = 0 in order to determine the gJ-factor and the molecular magnetic susceptibility anisotropy ξT :

gJ=-0.08051(8) ; ξT/h=434(38)Hz/(kG)2 .

The molecular quadrupole moment and its electronic part are derived from the values of g j ,ξT , and the rotational constant B0 . - The spectrum obtained in the magnetic field exhibits resolvable hyperfine structure from the 27Al nucleus with spin l = 5/2 and enabled us to determine the magnetic shielding anisotropy of this nucleus:

σT=-224(71)·10-6.

This value agrees reasonably well with an estimated one obtained from an interrelation with the spin-rotation interaction constant cl .
Heat of Formation of the HCO Radical
Authors: Warneck P.
Published: February 2015

From the threshold of OH+ formation in the photoionisation of formic acid the heat of formation of the HCO radical is determined as 10.2 Kcal/mole, in agreement with the earlier value derived from photoionisation of formaldehyde
Das Absorptionsspektrum von kristallinem Hexacen / The Absorptionspectrum of Crystalline Hexagene
Authors: Preuß J. , Zänker Y.
Published: February 2015

The vis-uv-spectrum of crystals of hexacene measured with two perpendicular polarisation-directions is descripted and compared with the crystal-spectra of other acenes.
Atomic and Molecular Properties of Metals from Artificial Cloud Experiments in the Upper Atmosphere
Authors: Drapatz S. , Haser L. , Michel K.-W.
Published: February 2015

Time and frequency resolved observations of metal vapor clouds in the upper atmosphere can be used to obtain information on atomic and molecular properties of the metals involved, e. g. atomic transition probabilities, photoionization cross sections, chemical reactivity of atoms in the ground state and in excited states. Experimental techniques of evaporation, the methods of obser­vation and some of the more important results are discussed for Sr, Ba and Eu, in particular those which cannot be derived by laboratory experiment, namely, radiative transitions and oxidation pro­cesses which involve metastable states. Especially one finds that the photoionization and oxidation processes of Eu and Ba are significantly different in contrast to theoretical predictions
Ligand-Field Spin-Orbit Energy Levels in the d5 Electron Configuration of Octahedral and Tetrahedral Symmetry
Authors: König E. , Schnakig R. , Kremer S.
Published: February 2015

The complete ligand-field, Coulomb interelectronic repulsion, and spin-orbit interaction matrices have been derived for the d5 electron configuration within octahedral (Oh) and tetrahedral (Td) symmetry. The calculations were performed in both the weak-field and strong-field coupling schemes and complete agreement of the results was achieved. The energy matrices are parametrically dependent on ligand field (Dq), Coulomb repulsion (B, C), and spin-orbit interaction (ζ). Correct energy diagrams are presented which display the splittings by spin-orbit perturbation as well as the effect of configuration mixing. Applications to the interpretation of electronic spectra, and to complete studies in magnetism are pointed out. The detailed behavior at the crossover of ground terms is considered
Energieübertragung zwischen gleich- und ungleichartigen Molekülen in Lösung. I. Theorie / Energy Transfer Among Like and Unlike Molekules in Solution
Authors: Kawski A. , Kamiński J.
Published: February 2015

A theory presenting uniform description of the excitation energy transfer among like (concentration depolarization of photoluminescence) and unlike (quenching by foreign absorbing substances) molecules in solutions is given. Based on the shell model of a luminescent centre, expressions for the emission anisotropy as well as the quantum yield of photoluminescence have been obtained. The dependence of the probability of resonance excitation energy transfer on the mutual orientation of the transition moments of the interacting sensitizer and acceptor molecules, as well as the fluctuations of the concentration of the acceptor molecules have been taken into account
X-Ray Investigations of the Intermetallic Phases CaCd1-x Tlx and Caln1-x Tlx and Knight Shift Measurements of 205Tl- and 113Cd-NMR in the System CaCd1-x Tlx
Authors: Marcoll J. D. , Schmidt P. C. , Weiss Alarich
Published: February 2015

The quasibinary systems CaCd1-xTlx and CaIn1-xTlx- form continuous series of solid solutions for all concentrations x: 0 ≦ x ≦ 1. All alloys of both systems crystallize with space group Oh1-PmSm and one formula unit per unit cell (CsCl-type structure). Considerable deviations from Vegard’s law occur for CaCd1-x Tlx, while they are negligible for CaIn1-x Tlx. No sign for the appearance of superstructures was found in either system after equilibrating them at 300 °C for two hours. In the system CaCd1-xTlx the Knight shift Ks of the 205Tl- and 113Cd-NMR was measured at room temperature as a function of x. Saturated Tl(CH3CO2)- and Cd(NO3)2 solutions served as reference samples. The Knight shift of the 205Tl-resonance increases remarkably with increasing concentration x, whereas the Knight shift of the 113Cd-NMR decreases slightly with increasing x. No simple qualitative explanation is found for Ks(Tl) =f(x) and Ks(Cd) =f(x)
Band Structure of CaCd and CaTl and the Knight Shift of 113Cd- and 205Tl-NMR in the System CaCd1-x Tlx
Authors: Schmidt P. C. , Weiss Alarich
Published: February 2015

The energy bands of ordered CaCd and CaTl have been calculated by the nonrelativistic augmented plane wave (APW) method. The electron structure in the system CaCd1-xTlx is deduced from these calculations by using the rigid band model for the phases with 0<x<1. The band structures of CaCd and CaTl are similar to the valence bands of other phases of the CsCl-type. From the energy eigenvalues the electronic density of states curve, the partial densities of states curves, and the Fermi energy have been obtained. For states near the Fermi surface the spin density at the position of the Cd- and Tl-nuclei has been determined. The Knight shift Ks of the 113Cd-NMR and the 205Tl-NMR in the system CaCd1-xTlx has been calculated as a function of x. The slope of the curve Ks (x) for the Cd-NMR is equal for experimental and theoretical results. The absolute value of the calculated Knight shift is about a factor of 1.4 too small. Only the direct term to the Knight shift has been calculated. Relativistic effects have been included by a scale factor. It has not been possible to explain the shape of the function (2) for the Tl-NMR, since a full relativistic APW calculation is necessary for CaTl
Arrhenius-Parameter und kinetischer Isotopeneffekt für die Reaktion von Wasserstoffatomen mit Silan
Authors: Potzinger Peter , Glasgow Louis C. , Reimann Bruno
Published: February 2015

The Reaction of Hydrogen Atoms with Silane; Arrhenius Parameters and Kinetic Isotope Effect Relative rate constants were measured for the systems H + C2H4/SiD4 and D + C2D4/SiH4 over a wide temperature range. From the known arrheniusparameter for the reaction H + C2H4 the activation energy EA and the preexponential factor A of the abstraction reaction

H + SiD4 → HD + SiD3

may be calculated. Values of EA = 3.2 kcal/Mol and A = 4.92 • 1013 cm3 Mol-1 sec-1 were obtained. Upper limits for the kinetic isotope effects are given in the paper
Dissoziative Ionisation von Molekülen durch Alpha-Teilchen- und Elektronenstoß hei gleichen Stoßteilchen-Geschwindigkeiten / Dissociative Ionization of Molecules by Impact of a-Particles and Electrons at the same Velocities
Authors: Däublin F.
Published: February 2015

The mass spectra of CH4, C2H6, C3H8 and C2H4 produced by bombardment with a-particles and electrons show near agreement. This is approximately in accordance with the theoretical expectations. In contrast to the observations made by Melton and Rudolph, no essential stabilization by collision of excited ions was established
Über das Einstein-Podolsky-Rosen Paradoxon / On the Einstein-Podolsky-Rosen Paradox
Authors: Mittelstaedt P.
Published: February 2015

The EPR experiment is analysed in terms of ordinary quantum mechanics and shown to be compatible with the orthodox interpretation of this theory. There is no need to refer to Bohrs resolution of the EPR paradox, nor is it necessary to assume any further unusual properties of the quantum physical reality. In particular, it is shown that the EPR experiment does not contradict the fact that incommensurable properties cannot be objectivized simultaneously in a quantum mechanical system, and that the measuring process can be understood in terms of quantum theory as an interaction of the measuring apparatus and the object system.

From these results it follows that there is no reason to search for modifications of the quantum theory which might be more convenient for a realistic interpretation of the EPR experiment. Furthermore, the EPR experiment cannot be used as a motivation for introducing hidden variables into the quantum theory. Experimental investigations which try to test quantum mechanics in respect to the possibility of introducing local hidden variables can therefore not be justified by the EPR paradox.