bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the Problem of Closure Conditions in Particular for Vlasov Turbulence
Authors: Max-Planck-Institut für Physik und Astrophysik, München Pitter 
Published: February 2015

Abstract
In turbulence-theory, the equations for the dynamics of statistical quantities usually form an infinite system. The coupled momentum equations are the best known example. Such relations can also be derived for the n-point-distribution functions which describe the stochastic state of a tur bulent medium at every instant. This will be shown for the case of Vlasov turbulence. In order to obtatin a solution, it is a common procedure, to terminate such infinite systems of equations by closure-conditions. Often this is considered as an approximation. In the case of Vlasov-turbulence it can be shown that a wide variety of closure conditions, all of which are exactly admissible, exists.
Über linear passive Transformationen stochastischer Prozesse. II.
Authors: Keller J. 
Published: February 2015

Abstract
In this paper some further results in the theory of Linear Passive Transformations (LPT) of stochastic Processes will be given, among them a theorem on the LPT of the characteristic functional of the input-process which allows one under certain conditions to get the probability -distributions of the output-process. The theory is generalized to vector-valued stochastic processes and to processes defined by means of distributions.
Höhere Bornsche Näherungen für die elastische Streuung von Elektronen an Atomen Higher Born Approximations for Elastic Electron Scattering from Atoms
Authors: Dudenhausen Wolf-Dieter 
Published: February 2015

Higher Born Approximations for Elastic Electron Scattering from Atoms. A theorem analogous to the unitarity relation by Glauber and Schomaker is derived for Born’s approximations. For a given potential Φ (r) =μ (ħ2/2 m) V (r) of the scattering atom the n-th approximation fn for the scattering amplitude is defined as the function resulting from the n-th iterative step of Born’s approximation.| If | fn |2 is expanded into a series of powers of the parameter μ, this series up to terms in μn+1 is defined as the n-th approximation for the differential cross section dσn/dΩ, and not |fn|2 itself. In this case an extension of the optical theorem Im fn+1 (0) = (k/4π) σn can be derived.
For a potential Φ(r)=-(Z e2/4π ε0 r)·exp(-r/R) ∑ airi exact analytic expressions for the scattering amplitude fn and the differential cross section dσn/dΩ can be given in first and second Born approximations.
An important example is the hydrogen-like atomic potential in which, in contradistinction to Wentzel’s model, the electron density σ(r) is limited even for r → 0. For this model, the differential scattering cross section in second Born approximation exceeds the values of the first approximation for all scattering angles, while experimental data indicate a correction of the opposite sign. An estimate of the cross sections in third approximation shows that they are again below’ the first approximation. These results indicate that the Born’s first approximation is not only less complicated but even more accurate than the second one. The absolute values of the scattering amplitudes in first and second approximations diverge considerably even at high energies, mainly due to the imaginary part Im f2(ϑ) of /2(ϑ). Therefore, conclusions on the phase η(ϑ) from Im f2(ϑ) do not seem to be reliable.
Notizen: Über die Ursache der Supraleitung; II
Authors: Krebs H. 
Published: February 2015

Abstract
The assumption that superconductivity can occur if the electrons can move without crossing atomic nodal surfaces is confirmed by some more examples. In compounds as CuRh2S4 (spinel structure) and CuS2 (pyrite structure) per formula unit one s electron is missing to a stabtle electron configura­ tion. The high pressure modifications of Se and Te possess one 5s resp. one 6s electron per atom.
InC8K, LiBi, and NaBi pz orbitals of C resp. Bi and s or­bitals of the alkali atoms form layers without nodal surfaces.
In the hexagonal and tetragonal tungsten bronzes there exist channels containing molecular orbitals without nodal surfaces. In the cases mentioned last the superconductivity is expected to be highly anisotropic.
Root Mean Square Charge Radii of 12C, 14N and 16O
Authors: Bentz Hans Alfred 
Published: February 2015

Abstract
From elastic electron scattering between 30 and 60 MeV, the following essentially model independent rms charge radii (fm) have been deduced: 2.395 + 0.028 (12C) ; 2.492 + 0.033 (14N) ;2.666± 0.033 (16O). An improved value for 9Be is (2.43 ±0.08) fm.
The Temperature Dependence of the Isotope Effect for Electromigration of Lithium Ions in Molten Lithium Nitrate
Authors: Lundén Arnold , Ekhed Alf 
Published: February 2015

The relative difference (Δb/b) between the internal electromigration mobilities of 6Li and 7Li in molten LiNO3 has been measured over the range 313° to 488 0C. The mass effect,μ =(Δb/b) /(Δm/m), is found to be
μ = 0.0845+ (0.00002 ±0.00002) (t-300) where t is the temperature in °C and the quoted error is the standard deviation. There is thus in this case no significant influence of the temperature upon the mass effect. Some previous investiga­tions of molten LiNO3 gave smaller values for the mass effect. The reasons for these apparent dis­crepancies are discussed. A slight, but significant, anomalous enrichment of the light isotope is ob­tained in the middle of the cell, as has been previously observed in experiments with KNO3 .
The mass effects have now been measured for all five alkali ions in the pure molten nitrates. For a corresponding temperature chosen 5% above the melting point none of the experimental values differ more than 14% from the relation
μ+ =-0.0848 (1+m +/46) -1.
The obtained relations are interpreted in terms of cooperative motion of the ions in a molten salt.
Magnetische Widerstandsänderung von Kupfer-und Silber-Einkristallen
Authors: Neubert W. , Neubert W. 
Published: February 2015

Abstract
Magnetoresistance measurements of Copper and Silver single crystals in weak magnetic fields at 4.2 K are reported. In addition, the magnetosresistance has been calculated. The model used is based on ROAF's analytical representation of the Fermi surface. In view of the simplifying as­ sumptions made about bandstructure and scattering mechanism, the experimental data are found to agree reasonably well with the results of the numerical calculations.
Messung der Oszillatorenstärken von SiI-, SiII-und SiIII-Linien im Wellenlangenbereich 1100 — 2600 Å und Vergleich des Vakuum-UV-Strahlungsnormals mit dem Kohlebogen
Authors: Hofmann W. 
Published: February 2015

The oscillator strengths of 72 Si I-, Si II- and Si III-lines and multiplets in the wavelength region 1100 -2600 Å were measured in emission. The light source was a wall-stabilized arc burning in argon at atmopheric pressure into which small amounts of silicon tetrafluoride and fluorine were introduced. All oscillator strengths were measured relatively and then put on an absolute scale by using the value Anm = 1,64 · 108 sec-1 for the transition probability of the Si I-multiplet 2506 Å to 2528 Å.
The vacuum-UV intensity calibration method using the central intensities of optically thick lines in the cascade arc was extended up to the wavelength 2516 Å. In this wavelength region it could be directly compared with the radiation of the anode crater of the carbon arc. Full agreement between these two intensity standards was found.
Bestimmung der optischen Konstanten von Halbleitern an Proben mit nichtidealen Oberflächen
Authors: Jaumann J. , Werheit H. 
Published: February 2015

Abstract
Am Beispiel GaAs wird gezeigt, daß es möglich ist, die bei Durchlässigkeits-und Reflexions-messungen an planparallelen Proben durch Oberflächenstreuung auftretenden Intensitätsverluste näherungsweise aus den Meßwerten selbst zu bestimmen und bei der Berechnung der optischen Konstanten zu berücksichtigen.
Kernmagnetische Relaxation in Chloroform
Authors: Dietrich W , Kosfeld R 
Published: February 2015

Abstract
Die kernmagnetischen Relaxationszeiten T1 und T2 von Chloroform wurden im Temperaturbereich von - 35 °C bis +90 °C erneut gemessen. Die experimentellen Ergebnisse zeigen, daß in diesem Temperaturintervall keine Spin-Rotationswechselwirkung vorliegt. Aus der transversalen Relaxationszeit wird für jede Temperatur die Spin-Spin-Kopplungskonstante A/2 π zwischen Chlorkernen und Protonen ermittelt.
Gegenstromelektrolytische Gewinnung von reinem Calcium aus geologischem Material
Authors: Bilal B 
Published: February 2015

Abstract
Mit Hilfe der Gegenstromelektrolyse wurde das Calcium geologischer Proben von den sonst schwer zu entfernenden Spuren der Begleitelemente Sr, Ba, Na und Mn in einem ein-zigen Arbeitsgang derart getrennt, daß sie aktivierungsanaly-tisch nicht mehr nachweisbar waren.
Auf die Eignung der Methode zur Trennung und Reindarstellung von Substanzen für die Aktivierungsanalyse wird besonders hingewiesen.
Zur Darstellung der Elektronen-Gitter-Wechselwirkung
Authors: Charlé K.-P , Haug A. 
Published: February 2015

Abstract
Im Gegensatz zu bisherigen Formulierungen, die spezielle Modelle und erhebliche Vereinfachungen enthalten, wird der Kopplungsfaktor der Elektronen-Gitter-Wechselwirkung für langwellige Gitterschwingungen durch eine Taylor-Entwicklung gewonnen. Es wird gezeigt, daß dabei kein Unterschied zwischen Normal- und Umklappprozessen besteht und daß der Kopplungsfaktor auch bei letzteren außer vom Elektronenanfangszustand nur vom Ausbreitungsvektor der Gitterschwingungen abhängt. Der Vergleich mit anderen Kopplungsfaktoren gibt Aufschluß über deren Güte.
Light Induced Modulation of Absorption (LIMA) of CdS Crystals
Authors: Böer K.W. 
Published: February 2015

Abstract
With chopped high intensity optical excitation a modulation of the optical absorption in a wide wavelength-range in CdS was observed. This light induced modulation of absorption is attributed to a redistribution of carriers over levels in the band gap following the chopping frequency. With this method the energy spectrum of certain traps and recombination centers can be determined and their frequency factor and capture cross section obtained. This method permits also the analysis of fast recombination centers.
Abhängigkeit des optischen Bandabstandes von der molaren Zusammensetzung bei Zinksulfid-Kadmiumsulfid-Mischkristallen
Authors: Kotera Y. , Serine T. 
Published: February 2015

Abstract
The optical band gap was determined for powder samples of (ZnxCd1-x) S by absorption measurements using a microspectrophotometer. Whereas the lattice constants (measured by X-ray lattice analysis) are linear functions of the components, the band gap is smaller than expected from the molar composition. The relation between band gap and composition was found to be linear, with a break at the equimolar composition. Possible reasons of this phenomen are discussed.
Ligand Hyperfine Interaction in the Complex [Mn(H2O)6] ++ in La2(Mg,Mn)3(NO3)12·24H2O
Authors: Ormondt D. van , Beer R. de , Brouha M. , Groot F. de 
Published: February 2015

Abstract
The elements of the hyperfine interaction (h.f.i.) between the manganese ion and the protons in the complex [Mn(H2O)6]++ in one of the two possible sites in La2(Mg, Mn)3(NO3)12 · 24 H2O have been measured with ENDOR at 15 to 20 K. The six water molecules in the complex at the chosen site are equivalent for reasons of symmetry.
One principal direction of the h.f.i. tensor of each proton is found to be perpendicular to the Mn, O line. With the assumption that each proton is located in the plane of the other two principal directions of its interaction tensor the positions of the protons are evaluated from the anisotropic parts of the h.f.i. tensors. In this calculation the effect of covalency on the anisotropic h.f.i. is ac-counted for with the aid of a simple model.
The isotropic h.f.i.'s with the two protons of a water molecule appear to be very nearly equal (+ 0.890 MHz for both). This latter result is remarkable in view of the fact that one proton is distinctly nearer to the manganese ion than the other.
Untersuchung des Einflusses von Leitsalz auf die ESR-Spektren neutraler und geladener Radikale in flüssigen Kristallen
Authors: Haustein H. , Möbius K. , Dinse K. 
Published: February 2015

Abstract
In the course of an investigation of electrolytically generated radical ions in the nematic mesophase of liquid crystals, we studied the influence of supporting electrolyte on the degree of molecular ordering. In the case of the radical anion of tetracyanoethylene (TCNE-) electrolytic generation results in a lower degree of ordering than chemical generation with sodium iodide. By using the neutral radical perinaphthenyl as a probe it was assured that the degree of ordering of the solvent is not disturbed by adding 0.1-m. tetrapropylammoniumperchlorate. A pronounced linewidth variation is observed for the chemically generated TCNE- which is attributed to spin density modulation by dynamic interaction with the Na+ counter ion.
EPR-Untersuchung an elektrolytisch erzeugten Semichinonen in flüssigen Kristallen
Authors: Haustein H. , Möbius K. , Dinse K. 
Published: February 2015

Abstract
Electrolytically generated semiquinone radical ions have been studied in the nematic mesophase of p-azoxyanisole by EPR methods. The degree of molecular ordering of benzo-, naphtho-, and anthrasemiquinones varied from 0.085, 0.18 to 0.20, respectively. The observed shifts of the hfs splitting constants and the g factors are in reasonable agreement with theoretical predictions. The negative sign of the C1
13 splitting constant of benzosemiquinone has been confirmed.
Isotopenaustausch-Untersuchungen an Silicat-Ionenaustauschern
Authors: Hoinkis E. , Levi H. 
Published: February 2015

Abstract
The isotopic exchange in Ba-and Sr-Zeolite X has been investigated over the entire range of the process. A special solution of the diffusion equation for the relevant case has been applied to evaluate self-diffusion measurements.
The diffusion process was found to be non-uniform. It has been shown that 80% of the ex-changeable Ba-ions and 65% of the Sr-ions diffuse with a high diffusion coefficient and the remainder with a low one. They differ by four to five orders of magnitude at room temperature. In the temperature range 120° to 0 °C the activation enthalpy for the slow process is about twice as high as for the fast process.
This behaviour is explaned in terms of cation location in the zeolite X lattice. The cations are accommodated in two types of channel systems which are assumed to be separated from each other at least with respect to alkaline earth ions. The cation position within the channel systems are discussed.
Gegenstromelektrolytische Stofftrennung in dünnen Flüssigkeitsschichten
Authors: Bilal B. A. 
Published: February 2015

Abstract
Es wird eine Anordnung beschrieben, in der die gegenstromelektrolytische Stofftrennung in einer dünnen Elektrolytschicht stattfindet. Die Eigenschaften der Anordnung hinsichtlich der Trennschärfe und Trennleistung, sowie die Verwendungsmöglichkeiten insbesondere für Anreicherungen im Bereich hoher Salzkonzentration werden mitgeteilt.
Excimerenbildung in organischen Flüssigkeiten bei Elektronenanregung
Authors: Joneleit D. 
Published: February 2015

Abstract
Emission-spectra and decay-times of benzene and some of its derivatives and of α-methylnaphthalene have been measured under electron-excitation. In most cases the spectra show a strong emission of excimers. The results can be interpreted self-consistently with a reaction-scheme used also for uv-excitation. However, this interpretation gives reaction-constants remarkably different from those measured for uv-excitation.
Notizen: A Superconducting Bolometer as a High Sensitivity Detector for Molecular Beams
Authors: Cavallini M. , Gallinaro G. , Scoles G. 
Published: February 2015

Abstract
The construction, operation and calibration of a superconducting bolometer is reported. Operated as a molecular beam detector the bolometer has, for Argon, a maximum sensitivity of 7 · 106 molecules sec -1 corresponding to a N.E.P. of 3 · 10-13 Watt Hz-½.
Über den Zusammenhang zwischen Selbstenergiefunktional und Ansprechfunktion eines wechselwirkenden Elektronengases
Authors: Kessel W 
Published: February 2015

Abstract
By linearizing the Dyson equation of the electron gas in an externally applied force field an integral equation for the adiabatic response function is derived. Its relation to the electron self-energy is considered which leads to certain approximations in the response function if the self-energy functional is given. This is illustrated for the case that the self-energy is a linear functional of the electron Green's function.
Wirkungsquerschnitte der Photoabsorption und Photoionisation des N2-Moleküls
Authors: Comes F.J. , Weber K.W. 
Published: February 2015

Abstract
The cross sections of photoabsorption and photoionization of the nitrogen molecule have been determined with high resolution (Δλ: 0.08 Å). The experiments demonstrate that the continuous absorption is overlapped by strong bands which are diffuse due to radiationless transitions. The competition of autoionization and predissociation leads to a strong variation of the ionization probability. Arguments are given to explain this behaviour of the nitrogen bands.
Messung kleiner Atomkonzentrationen in der Gasphase mittels Resonanzfluoreszenz im Vakuum-UV
Authors: Becker K.H. , Groth W , Jud W 
Published: February 2015

Abstract
The resonance fluorescence of atomic oxygen, nitrogen, krypton, and argon was measured in the vacuum-uv region as a function of the atom concentration. In a model the calculated fluorescence intensity is approximated to the experimental dependences by variation of a single parameter k0 . The best fit to the experimental data defines k0 as effective absorption coefficient in the central part of the resonance lines. The application of the resonance fluorescence as an analytical tool for atom reactions at low pressures is discussed.
Metastable Dissociation of CH5
+ Ions in the Methane Mass Spectrum
Authors: Mastan I , Mercea V 
Published: February 2015

Abstract
The main dissociation channels of the CH5
+ ion, i. e.

have been investigated by a mass spectrometric method. The pressure dependences of the ratios I14,90/I17 and I13,26/I17, in the range from 4,4·10-4 to 1·10-4 Torr, were plotted. The two ratios depend linearly on the pressure in the mass spectrometer analyzer. Since the two straight lines do not pass through the origine the conclusion is drawn that, for both dissociation channels of the CH5
+ ion, besides the collision-induced transitions, spontaneous transitions, i. e. pure metastable transitions, take place.
The spontaneous dissociations constants (λ1 = 7,5·105 sec-1 , λ2 = 5,2·104 sec-1) and collision-induced dissociation cross-sections (σ1 = 5,25 · 10-16 cm2 , σ2 = 3,2·10-16 cm2) have been estimated.
These results are discussed and compared with those reported by other authors.
Rotation-Vibration Interaction in the Microwave Spectrum of Fulminic Acid, HCNO
Authors: Bodenseh Hans Karl , Winnewisser Manfred 
Published: February 2015

Abstract
Rotational transitions in the microwave spectrum (20 - 46 GHz) of HCNO have been measured and assigned to seven excited vibrational states. The direct l-type doubling transitions of the II-component of the vibrational levels ν5 = 3 have been measured and analyzed, yielding the following values:
q(0)
3×5 = 27.0920 ± 1.8·10-4 MHz
EII - EΦ = Δ≅ 65 cm-1.
Fluorine Hyperfine Interaction in Aromatic Anion Radicals
Authors: Colpa J.P. , Fischer P. H. H. 
Published: February 2015

The relation between the fluorine hyperfine splittings in about 20 fluorine substituted aromatic radicals and the π spin densities calculated according to McLachlans method is analysed with an expression of the type
aF = QF
FF ρπ
FF + QF
CC ρπ
CC + (QF
FC + QF
FC) ρπ
FC .

For the Q factors the following values are obtained:
QF
FF =931 gauss; QF
CC =86.6 gauss and (QF
FC + QF
FC) =345 gauss.
Two simpler expressions with one and two parameters respectively are also tested.
A theoretical estimate is made for the values of the Q factors and the results are compared with the values obtained semi-empirically.
Thermotransport of Gold in Solid Lithium Metal
Authors: Thernquist Per 
Published: February 2015

Abstract
The thermotransport of Au in Li metal has been measured, using a steady state technique. The effective heat of transport, Q**/g, of the Au impurity was found to be +4.1 kcal/mole, whidi is less than half the activation energy for isothermal diffusion of Au in Li. The diffusion mechanism cannot be determined unambiguously, but the results support the notion of interstitial transport.
Kernmagnetische Relaxation und Selbstdiffusion in Benzol
Authors: Dietrich W. , Gross B. , Kosfeld R. 
Published: February 2015

Abstract
Es wurden erneut die longitudinale Relaxationszeit T1 und der Selbstdiffusionskoeffizient Ds des Benzols zwischen 0 °C und 100 °C gemessen. Besondere Sorgfalt galt hierbei der Temperierung der Probe. Nach der Relaxationstheorie von HUBBARD erfordert die Temperaturabhängigkeit des Spin-Rotations-Relaxationsprozesses ein starkes Anwachsen des Quotienten aus Selbstdiffusions-koeffizient und longitudinaler Relaxationszeit. Es wird jedoch mit steigender Temperatur eine Abnahme von Ds/T1 entsprechend der Dichteänderung des Benzols beobachtet.
Hieraus folgt, daß der Spin-Rotations-Prozeß bei Benzol zwischen 0 °C und 100 °C keinen wesentlichen Einfluß auf die longitudinale Relaxation besitzt. Dadurch lassen sich die inter-und intramolekularen Anteile des Relaxationsprozesses allein aus temperaturabhängigen Messungen von T1 DS und ρ in einfacher Weise bestimmen.
Molten Mixtures of K, Na Formates with Alkali Halides. Note II * Concerning the exchange reactions
Authors: Leonesi Dante , Piantoni Giammario , Franzosini Paolo 
Published: February 2015

Abstract
By employing a visual method, solid-liquid equilibria were studied in a wide series of molten mixtures in order to draw the maps of the reciprocal systems formed with K, Na formates and bromides or iodides. Within the accessible portion of each system, five crystallization regions, three ternary eutectics and two saddle points were identified. The interdependence between the areas of some crystallization regions and the sizes of the halogen ions was put into evidence.
Massenspektrometrisches Verfahren zur Bestimmung der Sauerstoff-Selbstdiffusion in Gläsern
Authors: Schaeffer H.A. , Oel H.J. 
Published: February 2015

Abstract
Mass spectrometric method for determining oxygen self-diffusion in glasses A mass spectrometric method has been developed employing 0 18 labelled oxides in order to study isotope exchange between two different glasses. The method provides self-diffusion coefficients for compact glass materials below the softening points without restrictions of the diffusion annealing time. Concentration profiles were obtained by grinding off thin layers and analysing the ratio of O18 /O16 for each layer. The extraction of oxygen from the glass is based on the reduction by mercuric cyanide at 400 °C to yield carbon dioxide. As an example diffusion profiles of O18 have been measured in samples of two lead glasses. Diffusion coefficients were calculated applying diffusion equations for two-phase systems. The temperature dependence fitted an Arrhenius plot, thus indicating the activation energies. It has been shown that the distribution of O18 is controlled by oxygen self-diffusion and is not affected by the difference in chemical composition of the two glasses nor by physical or chemical solubility of oxygen from air-atmosphere.
Abscheidung der intermetallischen Verbindung Nb3Sn aus der Gas-Phase
Authors: Kim Kyong-Min 
Published: February 2015

Abstract
Thermochemical calculations and experimental investigations were made for the vapor deposition of the superconducting intermetallic compound Nb3Sn through the reduction of the component halides with hydrogen. The standard free enthalpy ⊿GT
0, the equilibrium constant Kp and the yield a were calculated. The influence of the gas composition and of the temperature on the stoichiometry and the yield of the deposited Nb3Sn were investigated.