bluuebunny/crossref_metadata_2025 huggingface dataset:
Modellrechnungen über Platzwechselenergien in Kristalliten mit Zinkblendegitter
Authors: Bresch A. , Matossi F.
Published: March 2015

With a simplified force system (COULOMB and BORN forces), the activation energies for several site exchanges in a small crystallite of cubic ZnS are computed. They depend strongly on the specific configuration of the crystallite.
Zur Theorie des Wärmestrompotentials in angeströmten Lichtbögen
Authors: Koller A.
Published: March 2015

In einem stationären Lichtbogen läßt sich die Abhängigkeit des Wärmestrompotentials von einem radialen oder axialen Massenstrom durch analytische Lösungen der ELENBAAS–HELLERSchen Differentialgleichung beschreiben. Die angegebene Lösung enthält im Falle des axial angeströmten Lichtbogens die bekannte Theorie von STINE und WATSON als eine erste Näherung. Die Isothermen des stationären Lichtbogens werden in dimensionslosen Variablen berechnet, so daß die Darstellung die Größen Massenstrom, Bogenradius und Stromstärke sowie die Materialkonstanten elektrische Leitfähigkeit, Wärmeleitfähigkeit und spezifische Wärme nicht mehr enthält. Transformationen leisten den Übergang zu einem speziellen Bogentyp. Die Bedingungen für den Anschluß der stromlosen Zone an den leitfähigen Kern lassen sich erfüllen. Die Lösung zeigt Beziehungen zwischen den Isothermen in einem Lichtbogen und in einer Flamme auf. Es werden ferner Ausdrücke für die Bogenspannung und die Bogenleistung angegeben.
Das Diffusionsverhalten des Wasserstoffes in der Legierung Pd : Ag = 77 : 23 in Abhängigkeit von seiner Konzentration
Authors: Küssner A.
Published: March 2015

Es wird eine Methode zur Bestimmung des Wasserstoff-Diffusionskoeffizienten in Metallfolien in Abhängigkeit von der Wasserstoffkonzentration beschrieben. Die Legierung Pd : Ag = 77 : 23 wurde bei 30, 50 und 75 °C bei Wasserstoffkonzentrationen zwischen 0 und 0,4 H/Me untersucht. Entsprechende Ergebnisse werden mitgeteilt. Der in der homogenen Metallphase absorbierte Wasserstoff zeigt eine starke Konzentrationsabhängigkeit des Diffusionskoeffizienten.

Ferner wird über Potentialmessungen an zugbelasteten PdAg-Folien berichtet. Es wird der experimentelle Beweis für die Hypothese geliefert, die Druckhysterese sei auf mechanische Spannungen zurückzuführen.

Die experimentellen Ergebnisse sprechen gegen die Annahme, der absorbierte Wasserstoff sei in Protonen und Elektronen dissoziiert.
Magnetische, elektrische und thermische Eigenschaften von FeGa1,3
Authors: Wagini H.
Published: March 2015

An der ferromagnetischen Verbindung FeGal,3 wurde die Sättigungsmagnetisierung, der elektrische Widerstand, die absolute differentielle Thermospannung und die Wärmeleitfähigkeit oberhalb Zimmertemperatur gemessen. Es ergaben sich zwei CURIE-Punkte bei 483 °K und 697 °K, die verschiedenen, gleichzeitig vorhandenen ferromagnetischen Strukturen zuzuordnen sind.
Der gerichtete Einbau von Schwermetallphasen in GaAs
Authors: Reiss B. , Renner Th.
Published: March 2015

Arsenide mehrerer Schwermetalle geben mit GaAs Legierungen, in denen die Schwermetallphase eutektischer Gefügebestandteil ist. Durch gerichtetes Erstarren der Schmelzen kann der Einbau dieser Phasen häufig in Form von parallel orientierten Nadeln erzwungen werden. Einige dieser Systeme werden beschrieben.
Interferometrische Untersuchung der Deformation von Laserstäben während des Pumpvorganges
Authors: Bayer E. , Schaack G.
Published: March 2015

The elongation of neodymium-glass laser-rods (LG 52 and LG 55 of Schott u. Gen., Mainz), the curvature and the tilting of their end surfaces have been measured by means of a MICHELSON-interferometer, a rotating-drum-camera and a laser illuminating the interferometer with short, isolated “spikes” during the pumping pulse of the rod. The pumping arrangements used for the tested rods are an elliptical cylinder and a rotational ellipsoid. A linear dependence of the observed deformation from the absorbed pumping energy is observed for this four-level material, so that the elongation of the rod and the curvature and the tilting angle of the surfaces can be expressed in terms of the pumping energy.

The deformation measured in the elliptical cylinder pumping arrangement is compared with the calculated density of the absorbed energy within a laser rod illuminated by such an elliptical mirror. The main features of the observations are represented by this calculation.
Zu de Gennes’ Methode der Korrelationsfunktion in der Theorie der Supraleitung
Authors: Lüders Gerhart
Published: March 2015

At a second order transition, gap function and transition temperature of a superconductor can be determined from a linear integral equation. According to DE GENNES, the kernel of this integral equation may be obtained from a correlation function. This relation between correlation function and kernel is critically discussed. It is shown that the quantum mechanical correlation function is to be replaced by its slowly varying part, and it is suggested that the latter may be calculated from classical mechanics. The classical correlation function can be expressed as a momentum integral over a distribution in phase space developing with time according to the laws of classical mechanics. In the presence of statistically distributed impurities, the distribution function obeys the BOLTZMANN equation. Finally, the mathematical formulation of reflection properties of surfaces is discussed.
Die Druckverbreiterung der diffusen Heliumlinien, Vergleich zwischen Messung und Theorie im quasistatischen Bereich
Authors: Pfennig H. , Trefftz E.
Published: March 2015

It is difficult to discriminate between theories of pressure broadening of spectral lines through comparison with experiments. Line profiles are insensitive with respect to details of the theory, and it is difficult to keep experimental conditions clear and certain enough to make the comparison relevant. We used measurements of VIDAL 1 which are satisfactory from the experimental point of view. The wings of the diffuse He-lines 2P — nD are compared with those calculated by quasistatic theory. Part B deals with STARK effect splitting of the upper level. Part C describes the quasistatic theory of the line wings, and discusses the probability function of the so called micro field strength. In part D the results of the calculation are compared with the measurements. The comparison is relevant only for the violet wings of the triplet series. The red wing of the triplet lines and the violet wing of the singlet lines are disturbed by the forbidden component 2P — nP. The red wing of singlet lines is experimentally too inexact because of disturbing wings of neighboring triplet lines. The slope of the violet side of the triplet wings shows good agreement between theory and measurement for the far wing (large Δv). For decreasing Δv the experimental curve stays below the theoretical curve. For comparison of wing intensities it proves to be important to normalize the line profiles. It is seen that the measured height of the wings increases less with increasing main quantum number than the theoretical height.
Über die Wechselwirkung eines Plasmastrahls mit einem achsensymmetrischen Magnetfeld
Authors: Ragaller K.
Published: March 2015

The interaction of a plasma jet with an axisymmetric magnetic field, is calculated in linear approximation for a periodic and for a convergent or divergent field configuration.

The solution depends on the MACH number, the magnetic pressure number, and the magnetic REYNOLDS number.

In the convergent field, the plasma is decelerated. If the flow is supersonic, this is connected with a contraction of the jet leading beyond equilibrium and therefore being followed by an expansion. In the subsonic case, the stopping is accompanied by a broadening of the jet.

With increasing magnetic REYNOLDS number, “wakes” appear which extend upstream or downstream, depending on the values of the magnetic pressure number and the MACH number.
Field Ionisation Studies Using a Double Focussing Mass Spectrometer
Authors: Beynon J. H. , Fontaine A. E. , Job B. E.
Published: March 2015

Intense field ionisation mass spectra have been obtained with an A.E.I. M.S.7 mass spectrometer, used with very simple modifications to the ion source.

Some features of the spectra of a variety of compounds are given and the spectrum of acetone is discussed in detail. A special feature of this spectrum is the variety of ions with a mass greater than that of a single molecule.

The relatively small energy spread of the field ion source enabled resolving powers, higher than those possible with a spark source, to be obtained. Multiplets occurring in the spectra were easily resolved.
Die Oberflächenstruktur von epitaxial aufgewachsenen Indiumarsenidschichten
Authors: Nentwich Gerhard
Published: March 2015

Es wurden Epitaxieschichten von Indiumarsenid auf Galliumarsenid untersucht. Dabei wurde bei 755 °C Substrattemperatur das Auftreten von Pyramiden an der Probenfläche festgestellt. Aus den Elektronenbeugungsaufnahmen kann geschlossen werden, daß es sich um Pyramiden mit {311}· Flächen handelt.
Prüfung der Zeitdilatation mit Hilfe des Mößbauer-Effektes
Authors: Hönl H. , Bennewtz F.
Published: March 2015

A Lorenz-invariant treatment of the second order DOPPLER effect in rotational motions is given. The calculation is then performed in a generally covariant manner. Experimental consequences concerning the mechanical stability of clocks are discussed, and attention is drawn to a possible refinement of the rotational experiments.
Doorway States and Intermediate Structure Phenomena
Authors: Weidenmüller Hans A.
Published: March 2015

The phenomenon of the distribution of a doorway state over many complicated compound nuclear states, i. e. the formation and properties of a so-called micro-giant resonance, are investigated analytically and numerically by means of a simple model. The distribution of the poles in the complex plane and the distribution of the residues of the S-matrix are obtained numerically and used to calculate the average cross-section. It is shown that the LANE-THOMAS-WIGNER theory applies, except for a possible correction to the shape of the resonance occuring in the cross-section averaged over the energy. This shape need not be describable by a LORENTzian. Estimates of the “spreading width” W and the “total width” W0 are given for particular cases. It is noteworthy that the relationship W0=W+Γ need not be correct even as an order-of-magnitude estimate, where Γ is the decay width of the doorway state.
β ν- und β α-Winkelkorrelationen beim Zerfall von 8Li und 8B
Authors: Eichner H. , Lauterjung K. H. , Meinhardt H. , Schimmer B. , Schmidt-Rohr U.
Published: March 2015

The βv- and βα-angular correlations for the decay of 8Li→8Be*→2α previously studied have been remeasured with an improved experimental setup. In addition we have measured these correlations for the decay 8B→8Be→2 α.

For the coefficient b in the angular correlation between β-, ν- and α-particle for Gamow—Teller interaction W (b,,ϑ,φ)dΩ=[1+bv/c) cos ϑ·cos φ] dΩ

we got b(8Li) = —1,01 ± 0,07 and b (8B) =1,05 ± 0,12. Both results are in agreement with pure axial vector interaction.

For the coefficient B in the angular correlation between β- and α-particle W(Θ) dΩ= (1+A·cos Θ+B·cos2Θ) dΩ

we got B (8Li) = (+0.0031 ± 0.0003) · Wβ and B (8B) = (-0.0023 ±0.0003) ·Wβ . The experimental result

δ=B (8Li) —B (8B) = (0.0054 ± 0.0004) Wβ

is within the range predicted by the Conserved Vector Current theory.
Isobarisch analoge Zustände in 145Eu
Authors: Marouchian K. , Brentano P. Von , Wurm J. P. , Zaidi S. A. A.
Published: March 2015

Excitation functions for the elastic proton scattering from the target nucleus 144Sm have been measured in the energy-range from 8.600 to 11.600 MeV at six different scattering angles. Strong resonances were observed in the highly excited compound nucleus 145Eu, which are the isobaric analogues to the low-lying states of 145Sm. The resonances have been interpreted as BREIT-WIGNER resonances, superimposed on a smoothly varying background. The analysis was carried out in terms of a single level approximation. Energies, l-values, and widths of these resonances have been determined, and are compared with corresponding results of (d, p) -experiments.
Anomaly in the Energy Dependence of the Angular Distributions for Deuterons Scattered from Mg24 in the Energy Range from 6 to 13 MeV
Authors: Mayer-Böricke C. , Siemssen R. H.
Published: March 2015

Angular distributions for elastic and 2+ inelastic deuteron scattering from Mg24 have been obtained at various energies in the range from 6 to 13 MeV. Yield functions have been measured in 50 keV steps at 90° and 150°. In the region from 10 to 13 MeV, the elastic angular distributions show an anomalous behavior : instead of moving in from 180°, a new maximum is created by the breakup of a broad maximum at about 100° into two maxima. The inelastic angular distributions do not show such an anomalous energy dependence. Therefore the Blair phase rule between the elastic and the 2+ inelastic angular distributions breaks down in the energy region of the anomaly in the elastic scattering, but it holds outside this energy region. In spite of fluctuations in the excitation functions, an optical-model analysis of the elastic angular distributions yields parameters which, with the exception of W, vary smoothly with energy.
Anregung von 2+-Zuständen gerader Kerne durch unelastische Deuteronenstreuung
Authors: Jahr R. , Santo R.
Published: March 2015

Some regularities in the experimental angular distributions of inelastically scattered deuterons (Ed ∼ 11.8 MeV) corresponding to the lowest 2+ states of the even nuclei 12C, 20Ne, 22Ne, 24Mg, 26Mg, 28Si, 32S, 40A, Ti, 52Cr, Fe, 58Ni, Zn, Kr, Sr and Zr are discussed. BLAIR’S phase rule is approximately valid for strongly deformed nuclei in the region of 24Mg, whereas it is not valid for the other nuclei. The latter also results from DWBA calculations which have been carried out for nuclei with mass number A ≧ 40, using a real coupling potential. Several different sets of optical parameters have been used for the calculations and it is found that the extracted deformation parameters depend considerably on the choice of the optical potential.
Der Spinabschneideparameter für einige mittelschwere Kerne aus Neutronenreaktionen
Authors: Bormann M. , Dreyer F. , Seebeck U. , Voigts W.
Published: March 2015

In der Kernniveaudichte nach dem FERMI-Gas-Modell wird die Abhängigkeit der Dichte der Kernniveaus vom Drehimpuls des Kerns wesentlich durch den Spinabschneideparameter σ bestimmt. Dieser kann unter anderem aus den Winkelverteilungen der emittierten Teilchen und aus dem Verhältnis isomerer Wirkungsquerschnitte für Compoundkernreaktionen erhalten werden, die sich nach der statistischen Theorie der Kernreaktionen beschreiben lassen. Für einige Kernreaktionen schneller Neutronen wurden derartige Meßdaten ermittelt und daraus Spinabschneideparameter σ für die Kerne Ar37, Co58, Ni61, Ge75 und Se73 abgeleitet. Die Ergebnisse werden verglichen mit entsprechenden Angaben anderer Arbeiten für mittelschwere Kerne und mit den Voraussagen des FERMI-Gas-Modells.
Untersuchung von Hoch-β-Plasmen in toroidalen Magnetfeldern
Authors: Remy E.
Published: March 2015

In den letzten Jahren sind bei der Erzeugung von dichten und heißen Plasmen mit den sog. linearen Theta-Pinch-Apparaturen große Fortschritte erzielt worden. Die Einschlußzeiten bleiben jedoch begrenzt auf einige Mikrosekunden, da bei den linearen Apparaturen das Plasma entlang der Feldlinien an den Enden der Spule ausströmen kann. Daher wurden Untersuchungen an toroidalen Theta-Pinchen durchgeführt, die hier zusammenfassend dargestellt werden. Im rein kreisförmigen toroidalen Magnetfeld driftet das Plasma in Richtung wachsenden Radius des Torus, ist also nicht im Gleichgewicht. Mit zwei speziellen toroidalen Feldkonfigurationen, dem sog. M+S und dem toroidalen Theta-Pinch mit überlagertem Hexapolfeld, konnte experimentell ein Gleichgewicht angenähert bzw. erreicht werden. Die M+S-Konfiguration gehört zur Klasse der geschlossenen Konfigurationen, bei denen besonders die Stabilitätsfrage untersucht wird. Der toroidale Theta-Pinch mit überlagertem Hexapol gehört zur Klasse der offenen Konfigurationen. Er zeigt in Übereinstimmung mit den theoretischen Erwartungen ein stabiles Verhalten. Die sog. Cusp-Verluste an den offenen Stellen dieser Konfiguration wurden experimentell bestimmt und mit den Verlusten verglichen die aus verschiedenen Modellen folgen. Die theoretischen Erwartungen lassen für die Verlustraten einen Spielraum von zwei Größenordnungen. Die vorläufigen experimentellen Ergebnisse deuten auf die theoretisch günstigeren Möglichkeiten hin.
Die Lithiumhäufigkeit und die Struktur der äußeren Konvektionszone in sonnenähnlichen Sternen
Authors: Böhm K.-H.
Published: March 2015

The observations of the Lithium abundance and the isotope ratio Li6/Li7 in stars are briefly reviewed and some simple conclusions are drawn. It is emphasized that — in addition to the mechanism proposed by BODENHEIMER — a slow (timescale ≈ 109 years) mixing process in main sequence F and G stars is necessary to account for the observations.

The present state of the theory of convective overshooting is reviewed in this context. Two new models of the outer solar convection zone are presented. The temperature at their lower boundaries are 2.04 x 106 °K and 2.27 x 106 °K, showing that only a rather small convective overshoot may be sufficient for mixing the matter in the convection zone with the layers, in which Li7 is burnt.

Our models differ from earlier ones, because (when calculating the mean stratification) we take into account the condition that the mixing length can nowhere be larger than the distance from the nearest boundary of the convection zone. It is shown that this approach also leads to a slight change of the numerical factors in the formulae usually used.
Neutron Exposure Ages of Meteorites
Authors: Fireman E. L.
Published: March 2015

Co60 and Ar39 were measured in a number of recently fallen meteorites. From these data the amount of shielding surrounding the samples in space was estimated. In the carbonaceous chondrite, Murray, the Co60 activity was very large compared to the Co60 activities in the other chondrites even though the Ar39 activities were almost identical. In the iron meteorites there was an inverse relationship between the Co60 and Ar39 activities; shielding material increased the Co60 activity and decreased the Ar39 activity.

In the cases of Abee and Bruderheim, neutron exposure ages were obtained from the Kr80/Co80, Kr82/Co60, and Xe128/Co60 ratios because the Co60 was measured in large samples from the interior of the same fragment in which krypton, xenon, bromine, and iodine had previously been measured. The neutron exposure ages were approximately an order of magnitude larger than the spallation exposure ages. The order-of-magnitude differences in the exposure ages could be attributed to space erosion or to an ancient neutron irradiation.
Ein hochauflösendes γ-Spektrometer mit Ge(Li)-Detektor und Feldeffekttransistor-Vorverstärker
Authors: Kalbitzer S. , Melzer W. , Kemmer J. , Walther P.
Published: March 2015

Die vorliegende Arbeit beschreibt die Herstellung hochauflösender Ge (Li) -Detektoren nach verschiedenen Driftmethoden und den Entwurf eines schnellen Vorverstärkers mit einem Feldeffekt-Transistor in der Eingangsstufe.

Die γ-Strahlung von 60Co wurde mit 3 keV HWB aufgelöst. Für den Fano-Faktor ergab sich ein Wert von 0,20-0,25 im Energiebereich von 300-2750 keV.
Induktive Ortung von Funken in einer Funkenkammer
Authors: Poelz G. , Springer K.
Published: March 2015

A spark chamber is described, for use of particle-path location in a magnetic spectrometer. The spark is localized electronically by inducing pulses in wire windings with co-ordinate-depending amplitudes. The method was proved in a spark chamber with 15 × 15 cm2 electrodes of stainless steel meshes, with 13 wires per mm, 0.036 mm thick. A nearly linear slope for the calibration curve has been obtained with artificial sparks. Sparks at the same spot gave a pulse-height distribution with a half-width corresponding to 0.2—0.3 mm and a total spread of 0.4—0.7 mm. Results obtained with a Ce144 β source showed, that a similar behaviour can be expected for natural sparks. This method renders possible a simple and compact set-up, without any restriction in respect to the material used for the electrodes of the chamber.
S. C. F. Study of the OH3
+ Ion
Authors: Rajagopal P.
Published: March 2015

Λ convergent self consistent field calculation for the OH3
+ ion is reported. The results indicate that the isolated ion is planar, with an OH distance of 1.9007 a. u. ( = 1.006 Å nearly), self consistent field energy of —76.3722 a. u., and force constants of k1= 6.84 × 105 dynes/cm and kΔ/l2=2.39 × 105 dynes/cm.

The correlation contribution to the binding energy for several ten electron systems are analysed in the Appendix.
Neue Forderungen für die Epitaxie: Die Reliefbedingungen
Authors: Menzel-Kopp Chr.
Published: March 2015

The epitaxy of Cu2O grown on copper crystal spheres by thermal oxidation is well known. Allways one pair of 〈110〉 directions in the metal and the oxide are parallel. The complicate epitaxial situation of the antiparallel orientation on the 〈110〉 great circles is now established by two principles: The atomic relievo of a {hhl} plane consists of {111}, {001} or {110} facets. Adjacent facets of metal and oxide must contain the same number of 〈110〉 rows of metal atoms and the distance between 〈110〉 rows in adjacent facets must not deviate more than 20%. An older rule was concerned with the distance of 〈110〉 rows in the {hhl} planes. This rule is a consequence of the two principles but solely it is not sufficient.
Erklärung stellarer und planetarer Magnetfelder durch einen turbulenzbedingten Dynamomechanismus
Authors: Steenbeck M. , Krause F.
Published: March 2015

In a foregoing paper 1 the effects of a turbulent motion on magnetic fields were investigated. Especially turbulence was treated under the influence of CORIOLiS-forces and gradients of density and/or turbulence intensity. It was shown that on these conditions the average cross-product of velocity and magnetic field has a non-vanishing component parallel to the average magnetic field. Here we give the consequences of this effect for rotating, electrically conducting spheres.

At first a sphere rotating with constant angular velocity is investigated. The quadratic effect provides for dynamo maintainance of the magnetic fields. A field of dipol-type has the weakest condition for maintainance. Applications to the magnetic field of the earth show a good agreement with the conceptions of the physical state of the earth’s core.

For a second model differential rotation is included. We have also dynamo maintainance. Since we have to assume that generally the angular velocity is a function decreasing with the distance from the centre of the sphere, the calculations show that we have a preferred self-excited build-up of a quadrupol-type field. This model may be applicable to magnetic stars.

Finally we look for dynamo maintainance of alternating fields. We consider the skin-depth to be small compared with the radius of the sphere, then we have plane geometry. The existence of periodical solutions is proved. Applications to the general magnetic field of the sun, which has a period of 22 years, are discussed.
Angular Dependence of Channelling in Gold Single Crystals
Authors: Schuckert R. D. , Lutz H. , Sizmann R.
Published: March 2015

The penetration profiles of 70 keV krypton-85 ions in gold single crystals were determined for different incident angles between the ion beam and the 〈110〉 or 〈111〉 crystal axis. Channelling is most pronounced in the 110 direction but it falls off at first steeply, then at angular deviations larger than 10° rather slowly by tilting to 〈111〉 or 〈100〉. A sharp aperture cannot be defined for the 110 channel; its half width is of the order of 2 ... 3°. In 〈111〉 no directional channel seems to be operative, although the long tail range distribution indicates a steering of the penetrating ions.
Isotope Thermotransport in Liquid Potassium, Rubidium, and Gallium
Authors: Lodding A. , Ott A.
Published: March 2015

Temperature differences ranging from 100°C to 500°C were maintained between the top and bottom ends of vertical capillaries containing liquid metal. The light isotope was found to be enriched at the hot end. The steady-sate isotope separation for different temperature ranges were between 1 and 3 per cent, corresponding to the thermal diffusion factors αK=3.1×10-2, αRb=3.1 × 10-2 and αGa=3.8 × 10 -2. According to a theoretical model, the results imply that the diffusing species is a “cluster” of several cooperating atoms, the mean diffusive displacement of which is considerably less than the effective cluster diameter. The clusters drift into voids given by the statistical fluctuations of free volume.
Numerische Lösung der 2- und 3-dimensionalen Schrödinger-Gleichung für beliebige Molekülpotentiale durch iterative Variation numerischer Testfunktionen mit einem Digitalrechner
Authors: Seelig Friedrich Franz
Published: March 2015

3-dimensional one-electron wave functions are evaluated on the basis of the well-known variational and orthogonality principles, but the test functions are described by the product of an anlytical factor, e-ϱ, ϱ = ΣK ZK rK, e with ZK = nuclear charge of the K-th atom and rK, e =distance of the K-th nucleus from the electron under consideration) that is common for all states and generates cusps at the loci of the nuclei, and a factor F that is individual for the different states and is submitted to variation. The product inserted into the original 3-dimensional SCHRÖDINGER equation yields several terms, one of which exactly compensates the potential due to the nuclei, thus rendering finally a pseudopotential which is generally discontinuous at the nuclei, but everywhere finite, whereas the true potential goes to - ∞ at the nuclei. The function F is defined in a 3-dimensional lattice with constant mesh and the expression for the expectation value of the energy and its variation are formulated for the test function e-ϱ F, F being numerical. As the final function thus gained is a molecular orbital that consists of a numerical and an exponential part, it may be called a NEMO (numerical exponential molecular orbital). A temporary program based on these special conditions and written in FORTRAN II is shortly described. As 4 large fields of the same size are stored in core storage (32 K) at the same time, only 20 × 16 × 16 meshpoints are available for the test function. Thus in this relatively coarse mesh excellent results are gained for the ground states of H and H2
+as test examples (error in energy less than 0.02%), but less good ones for some excited states (error in energy 0.2 to 2.3%, depending on the compactness of the wave function).
Berechnung kinetischer Isotopeneffekte für die Reaktion von Methyljodid mit Hydroxid-Ion
Authors: Willi A. V.
Published: March 2015

Kinetic carbon-13, deuterium, and oxygen-18 isotope effects are calculated from force constants for the SN2 reaction of CH3I with OH-. The secular equations for the vibrational frequencies of reactants and transition states are solved on an IBM 7094 computer. Values for 7 force constants of the planar CH3 moiety in the transition state (with an sp2 atom) are obtained by comparison with suitable stable molecules. The stretching force constants ƒCO = ƒ11, ƒCI = ƒ22, and ƒ12 in the transition state are chosen as linear functions of x, the degree of bond making and bond breaking, with the aid of eqs. (1) and (2).

The carbon isotope effect as a function of x exhibits a flat maximum near x=0.6. If the bending force constants ƒHCO and ƒHCI are kept constant, k12/k13 is significantly lower than its maximum value only for values of x ≦ 0.3 and x ≧ 0.8. There is only a small influence of x on the deuterium isotope effect, kH/kD (compare rates of CH3I and CD3I). However, kH/kD) is strongly dependent on ƒHCO and ƒHCI . The oxygen-18 isotope effect decreases with increasing x. Experimental data of the D isotope effect — if they were available — could be used to adjust the bending force constants ƒHCO and ƒHCI (— or to adjust ƒHCO if ƒHCI is held constant). The degree of unsymmetry of the transition state could then be estimated with the aid of the C isotope effect. Experimental data of the O isotope effect would supply information on the direction of the unsymmetry — which is needed for a distinction between 2 possible values of x —. There is approximate agreement between the calculated and the experimental temperature dependence of the carbon-13 isotope effect.
Kernmagnetische Messungen von Selbstdiffusions-Koeffizienten in Wasser und Benzol bis zum kritischen Punkt
Authors: Hausser R. , Maier G. , Noack F.
Published: March 2015

The most commonly used nuclear magnetic resonance spin-echo methods for determining selfdiffusion coefficients D are described; some experimental data are presented for protons in water and in benzene from room temperature up to the critical point. The results are interpreted in terms of the free-volume rate theory of MACEDO and LITOVITZ. The D-value of benzene may be described by a single activation energy. Water, however, shows such behavior only at high temperatures, thus demonstrating the strong influence of hydrogen bonding. The STOKES-EINSTEIN relation between diffusion coefficient and viscosity is well satisfied over that part of the temperature range where viscosity values are available.
Zum Skin-Effekt zeitlich periodischer elektromagnetischer Felder unter Berücksichtigung der magnetischen Widerstandsänderung
Authors: Seebass Joachim
Published: March 2015

Magnetoresistance leads to a change of the normal skin-effect. The electromagnetic field, periodic in time, is calculated by a successive approximation method for a half-space, the electric conductivity of which is dependent quadratically on the magnetic field. As expected results show the existence of uneven harmonics. Compared with the case without magnetoresistance, the a-c-resist-ance of some part of the half-space is altered by additional terms, which are dependent on the intensity of the current. Analogous results are given for a planar conducting layer of constant thickness.
Quantenresonanzen der Ultraschallverstärkung in Wismut
Authors: Walther K.
Published: March 2015

Build-up of ultrasonic noise and ultrasonic amplification in a bismuth sample subjected simultaneously to an electric and a magnetic field are investigated. The ultrasonic noise is generated in the direction of carrier drift. Under conditions of ultrasonic amplification the quantum resonances of the magneto-acoustic attenuation in Bi are “inverted”, i. e. maxima of attenuation are converted into minima by the application of a suitable electric field. Estimated values of the de-attenuation caused by the electric drift field range around 100 db/cm, the gain referred to the attenuation at zero magnetic field being 22 db/cm for shear waves at 265 Mc/s. Optimum signal amplification corresponds to a minimum of generated ultrasonic noise.
The Electrical Conductivity of a Partially Ionized Argon-Potassium Plasma in a Magnetic Field
Authors: Feneberg W.
Published: March 2015

In the case of small deviations from thermal equilibrium the second ENSKOG approximation is used as a starting point for solving the BOLTZMANN equation of the electrons in a partially ionized plasma. The distribution function is expanded according to LAGUERRE polynomials up to the order of 3. In this order the electrical conductivity of a LORENTZ gas, which is known exactly, is obtained to an accuracy of roughly 5%. The approximation tested in this way was then used to calculate the conductivity of an argon-potassium mixture at electron temperatures between 2000°K and 3500°K.

If only he collisions between electrons and argon atoms were to be considered, the electrical conductivity in the absence of a magnetic field would, in view of the RAMSAUER effect, be greater by a factor of 2.8 than that obtained with an infinitely strong magnetic field. When the interaction with the potassium atoms and the COULOMB interaction are taken into account as well the conductivity in the magnetic field varies by about 20%.
Messung hoher Elektronendichten mit einer neuartigen Mikrowellen-Reflexionssonde an einem linearen z-Pinch
Authors: Hermansdorfer H.
Published: March 2015

A microwave reflection probe method allowing the local measurement of electron densities well above the critical density is described. Measurements in the 35 Gc/s band on a z-pinch show its applicability. A rectangular waveguide with a dielectric aperture window serves as a probe. The interferometer for measuring the reflection coefficient is presented. It indicates phase angle and amplitude automatically without using modulators or frequency translators. Electron densities between about 1013 cm-3 and 1016 cm-3 could be measured, facilitated by the transforming action of a dielectric λ/4-window.
Matrix Representation for Calculation of the Second-Order Aberration in Ion Optics
Authors: Takeshita Isao
Published: March 2015

The matrix representation for calculating the ion trajectory is extended to include the secondorder aberration terms.

Properties of the matrix and relations between its elements are discussed.

As an example of the application of the matrix method, the second-order coefficients of a homogeneous magnetic field of arbitrary shape are derived and the relations between the matrix elements and Hinterberger's notations are shown.
A Note on the Theory of Decaying Systems and the Computation of Decay Rates
Authors: Kümmel H.
Published: March 2015

The theory of decaying systems of FRANZ 1— which seems finally to settle the basic questions left open so far—has been reformulated assuming a slightly altered initial situation. The currently used formulae for the decay rates (see MANG2) have been derived as an approximation to this practically rigorous theory.
Zur Theorie der Entstehung der Atomkerne unseres Sonnensystems
Authors: Suess Hans E.
Published: March 2015

Im allgemeinen hält man die Schwierigkeiten, die den Theorien der Elemententstehung anhaften, durch die Annahme für überwunden, daß die Elemente unseres Sonnensystems Mischungen darstellen von Kernsorten, die auf verschiedene Weise, zu verschiedenen Zeiten und an verschiedenen Orten entstanden sind. Gegen diese Vorstellung läßt sich jedoch u. a. ein grundlegender Einwand erheben : Durch Wahl einer geeigneten Klassifizierung der Kernsorten läßt sich zeigen, daß in bestimmten Massengebieten die Kernhäufigkeiten mit dem Gang der Kernbindungsenergien nach MATTAUCH et al.1, zum Beispiel mit den Bindungsenergien der letzten α-Teilchen, in einem, wenn auch derzeit nicht quantitativ deutbaren, augenfälligen Zusammenhang stehen.
Der Mond als Mutterkörper der Bronzit-Chondrite
Authors: Wänke H.
Published: March 2015

Knowing the cosmic ray exposure ages of a sufficiently large number of meteorites and using the earth as analyser with special assumptions, criteria can be found to distinguish between a lunar or asteroidal origin of meteorites. Several of the following arguments are based on new and unpublished results of rare gas measurements by HINTENBERGER, SCHULTZ und WÄNKE70.

Bronzite-chondrites :

1. Arguments for an origin near the surface of the parent body. a) Porosity of the chondrites 0—20%. b) Many bronzite-chondrites contain light primordial rare gases, originating from the exposure of the single meteorite grains to the solar wind. c) Primordial rare gas content always connected with light-dark structure. d) In the distribution of the cosmic ray exposure ages certain groupings can be distinguished. The age distribution of bronzite-chondrites with light primordial rare gases is identical with the distribution of the cosmic ray exposure ages of all bronzite-chondri-tes. The bronzite-chondrites containing primordial gas therefore are probably coming from the very upper layers, and the other bronzite-chondrites from somewhat deeper layers of their parent body.

2. Arguments for an origin close to the earth’s orbit. a) Bronzite-chondrites with high cosmic ray exposure ages show a slight tendency to fall in the afternoon (noon until midnight) . b) For the bronzite-chondrites, which are morning falls (midnight until noon), diffusion losses of 3He and 4He are higher and more frequent compared to the afternoon falls. The reason for this can be found in a closer approach to the sun of the first ones. Hypersthene-chondrites do not show this effect. c) Bronzite-chondrites with light primordial rare gas content concentrate among the afternoon falls. d) The mean cosmic ray exposure age of the bronzite-chondrites is considerably lower than that of the hypersthene-chondrites.

3. Arguments concerning the size of the parent body. Light primordial rare gas and their connection with light-dark structure indicate a parent body of the size of the moon or a large asteroid.

None of these arguments are strictly conclusive. In some cases they are based on observations, which can only be obtained by using statistical methods. Most of these effects are close to the mean error. Adding, however, all observations together, a lunar origin of the bronzite-chondrites becomes nearly undoubtable. A lunar origin of stone meteorites was in recent times first proposed by URET 3.

Hypersthene-chondrites :

Hypersthene-chondrites with low cosmic ray exposure ages are rare among the morning falls. Their parent body therefore probably has to be found outside the earth’s orbit. Their distribution of the cosmic ray exposure ages may also lead to this conclusion. As proposed by ANDERS 4, the Mars asteroids could possibly be the parent bodies for the hypersthene-chondrites. Mars itself might however be considered also. A lunar origin of the hypersthene-chondrites seems to be completely out of question.
Die Produktionsraten von 36Cl und 39Ar in Metall- und Steinphase des Chondriten Leedey
Authors: Begemann F. , Vilcsek E. , Wänke H.
Published: March 2015

The production rates of 36Cl and 39Ar by the cosmic radiation on Fe and Ca +K have been determined in the chondrite Leedey. The values of

19.4 atoms/min · kg ≦ PFe (36Cl) ≦ 26.6 atoms/min · kg and PFe (39Ar) = (23.6 ± 1.8) atoms/min · kg are in good agreement with those found in iron meteorites of comparable size. A large contribution of Ca+K to the production of both isotopes is indicated by the ratios

9.2 ≦ PCa + K (36Cl) /PFe (36Cl) ≦ 13.6 and PCa + K (39Ar) /PFe (39Ar) = 12.1 ± 1.6. The bearing of these results on the interpretation of 39Ar-data obtained on other chondrites is being discussed.
Die Isotopenbeweglichkeiten und deren Temperaturabhängigkeit in geschmolzenem KCl, RbCl und RbBr
Authors: Jordan S. , Klemm A.
Published: March 2015

Die kationischen und anionischen Masseneffekte der Beweglichkeiten μ+ ≡ მ ln bp-/მ In mp und μ - ≡ მ In bn + / ln mn sowie deren Abhängigkeit von der absoluten Temperatur T wurden bestimmt zu

Es zeigt sich, daß bei den drei Salzen nicht nur die Masseneffekte μ ±, sondern in drei von vier prüfbaren Fällen auch die reduzierten Masseneffekte μ±=μ±/ (z± D± F2/RT Λ) mit der Temperatur ansteigen. Dies weist auf ein Kleinerwerden der ladungstragenden zusammengesetzten Bewegungseinheiten mit steigender Temperatur hin.
Die Abtragung von Silicium im System Si-Cl-H
Authors: Seiter Hartmut , Sirtl Erhard
Published: March 2015

Die verschiedenen Möglichkeiten der Anätzung von Silicium mit Hilfe chlor- und wasserstoffhaltiger Gasgemische lassen sich an Hand von Gleichgewichtsberechnungen diskutieren. Es werden dabei die Reaktionen von Chlorwasserstoff mit oder ohne Zugabe eines Chlorsilans sowie Transportreaktionen im Temperaturgefälle behandelt. Für den letzteren Fall wird eine einfache apparative Anordnung beschrieben, in der der Übergang von Transport zu Pyrolyse in einem Gasgemisch von gleichbleibender Zusammensetzung technisch genutzt werden kann.
Flächengitter in geschmolzenem Zinn und Silber sowie in festem amorphem Selen nach der Fourier-Analyse
Authors: Richter H. , Breitling G.
Published: March 2015

Die 4 π r [ρ (r) —ρ0] -Kurven von geschmolzenem Sn bei 250° und 750°C zeigen, daß in der Schmelze zwei Strukturen vorkommen, die dichteste Kugelpackung mit r1=3,15 bzw. 3,18 Å (Literaturwert r12=3,16 Å) und die Flächengitter-Struktur mit r1′=3,01 bzw. 3,03 A als Kantenlänge einer quadratischen Gitterzelle. Dabei ist r1′[r1] G=3,02 A, also gleich dem kürzesten Gitterabstand. In der Ag-Schmelze tritt die dichteste Kugelpackung in Form von Flächengittern mit der (111)kub.- bzw. (001) hex.-Ebene als Basis auf. Die Abmessungen der zugehörigen hexagonalen Gitterzelle sind r1=2,94 A und φ=120°. Überraschenderweise zeichnen sich in der 4 π r [ρ (r) — ρ0]-Kurve lediglich die Abstände der Zickzackkette ab, die von den Atomabständen r1=2,94 Å und r1 √3 =5,09 Å gebildet wird. Die Flächengitter-Struktur besteht bei Ag wie bei Sn aus einer quadratischen Gitterzelle, und zwar mit r1′=2,72 Å als Kantenlänge. Danach ist die Ag-Schmelze ein Haufwerk von Flächengittern mit hexagonaler und mit quadratischer Gitterzelle; Gleiches gilt für die Schmelzen von Au, Pb und Tl. Auch in den 4 π r [ρ (r) —ρ0] -Kurven von geschmolzenem Na und Cs bildet sich die Zickzackkette der dichtesten Kugelpackung ab. Die Alkalimetallschmelzen stehen damit dem geschmolzenen Au, Ag, Pb und Tl sehr nahe, weniger dagegen dem geschmolzenen Sn, Ga und Bi.

Die Zickzackkette wird auch bei den festen amorphen Stoffen erhalten. So zeichnet sich in der 4 π r2 [ρ (r) —ρ0] -Kurve von festem amorphem Se die ebene Zickzackkette ab, die sich aus den Gitterabständen [r1] G=2,32 Å und [r3]G=3,69 Å (Bindungswinkel φ=105°) aufbaut. Bei großen Abstandswerten ist selbst hier wegen der Lagestreuung der Atome eine deutliche Abstandsverkürzung wie bei geschmolzenem Au, Ag, Pb und Tl zu beobachten.
Über die Wirkungsweise und den Aufbau von Protonen-Wendellinearbeschleunigern mit variabler Endenergie
Authors: Dänzer, H. , Herminghaus H. , Klein H.
Published: March 2015

Die Wirkungsweise des Protonen-Wendellinearbeschleunigers und sein prinzipieller Aufbau werden kurz beschrieben und Angaben über die erreichbare Parallelimpedanz gemacht. Es wird gezeigt, wie durch sektionsweisen Aufbau eine variable Endenergie erzielt und die Kühl- und Fokussierprobleme gelöst werden können. Zwei Konstruktionsbeispiele für kontinuierlichen und gepulsten Betrieb werden näher ausgeführt.
Zur Frage der Bestimmung des Frequenzspektrums in festen Körpern durch die unelastische Streuung von kalten Neutronen
Authors: Kley W.
Published: March 2015

The various possibilities are examined how to measure the frequency distribution of solids by the inelastic scattering of thermal and subthermal neutrons. Particular attention is drawn on measuring-techniques that allow the determination of the frequency distribution even if the scattering cross section of the target material is not totally incoherent but a mixture of a coherent and an incoherent component. It is shown how the frequency distribution of solids can be measured even if the cross section is totally coherent by the use of a doping technique. Atoms as H and V, that have an almost entirely incoherent scattering cross section, are used as impurities in the solid of interest, serving as a probe of the host lattice vibrations. By studiing the difference of the two independent inelastic scattering experiments, one with the pure, the other with the impure solid, it is possible to derive the frequency distribution function of the host lattice itself. Examples are given for Vanadium and Niobium. In addition, evidence is given how the best experimental conditions are selected for this type of inelastic neutron scattering experiments.
Experimentelle Probleme physikalischer Weltraumforschung
Authors: Rawer K.
Published: March 2015

Die von der Laborphysik erheblich abweichenden Bedingungen von Weltraumexperimenten werden grundsätzlich diskutiert und am Beispiel der Messung der Plasmadichte erläutert. Die behandelten Problem-Stellungen sind: Meßgeräte, Meßgrößen, störende Einflüsse, Experimentier-Bedingungen. *
Anisotropie-Effekte in der Gravitationstheorie Einsteins
Authors: Ruffer Joachim
Published: March 2015

The use of an EUCLIDean space in astronomy corresponds in the framework of general relativity to the introduction of an EUCLIDean “space of comparison”. We generalize this method till now used only in special cases and analyse the motion of test particles in the EUCLIDean space of comparison. The inertial mass of test particles is a tensor in the space of comparison. Independent of any CORIOLIS force the mass tensor is able to cause anisotropy effects that can be observed on principle.
Die Methode der Korrelationsfunktion in der Theorie der Supraleitung
Authors: Lüders Gerhart
Published: March 2015

The method of correlation function is extended to the case of paramagnetic impurities. The BOLTZMANN equation is obtained and subsequently applied to a derivation of the concentration dependence of the transition temperature, of the linearized GINZBURG—LANDAU equation, and of the diffusion approximation.
Elektronen-Geschwindigkeitsverteilungsfunktionen für kraftfreie bzw. teilweise kraftfreie Magnetfelder
Authors: Moratz E. , Richter E. W.
Published: March 2015

Based on the VLASOV equation a method is derived to deliver velocity distributions in the case of a one-component plasma which produces a force-free or in part force-free magnetic field. This formalism is applied to simple fields of the type H=(Hx(z), Hγ(z), 0) .
Spektroskopische Untersuchungen an elektrischen Entladungen in Strahlen aus kondensiertem Wasserstoff
Authors: Klingelhöfer R. , Röhl H. , Wüst J.
Published: March 2015

Das Emissionsspektrum eines mit Wasserstoff-cluster-Strahlen erzeugten Plasmas wird längs der Strahlrichtung untersucht. Bei einem Elektrodenabstand von 26 cm wird in einem Bereich von 14 cm nur die Emission des Wasserstoffs beobachtet, in Elektrodennähe treten auch Linien des Elektrodenmaterials auf.
Coherent Bremsstrahlung and Pair Production in the Diamond Crystal in Graphical Representation between 1 and 40 GeV
Authors: Lutz G. , Timm U.
Published: March 2015

The paper supplies numerical information on coherent effects of bremsstrahlung and electron pair production in diamond crystals in the energy range from 1 to 40 GeV. The information is collected in a number of graphs and tables showing the intensity and polarization of bremsstrahlung and the cross section and asymmetry ratio for pair production as a function of crystal orientation. The basic formulas for the interpretation of the diagrams are given. The experimental problem of a precise orientation of the crystal, which is closely connected with the production of coherent radiation, is discussed on the basis of these formulas.
Graphische Methoden zur Abschätzung von Enthalpie- und Entropiewerten gasförmiger anorganischer Verbindungen
Authors: Sirtl Erhard
Published: March 2015

Die atomaren Bildungsenthalpien gasförmiger Verbindungen, ΔH*298, zeigen innerhalb einer Gruppe des Periodischen Systems eine lineare Abhängigkeit von der Ordnungszahl des elektronegativeren Bindungspartners. Eine ähnliche Gesetzmäßigkeit beobachtet man bei den entsprechenden Standardentropien, S298
0, wenn man sie im doppeltlogarithmischen Koordinatensystem gegen die Molekulargewichte aufträgt. Die Genauigkeit interpolatorisch ermittelter Daten wird hier durch Vergleich mit einer zweiten Methode erhöht, die sich auf die Beziehung zwischen S (MXn
1) und S (MXn
2) stützt. Abschließend wird eine Zusammenstellung von Entropie- und Enthalpiewerten der wichtigsten gasförmigen Verbindungen gegeben. Die Tabellen, ergänzt durch Inter- bzw. Extrapolation mit Hilfe der angegebenen Schätzmethoden, entsprechen dem Stand von 1965.