bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Methode der Korrelationsfunktion in der Theorie der Supraleitung
Authors: Lüders Gerhart
Published: March 2015

The BOLTZMANN equation, which was conjectured and applied in previous papers of this series, is derived from an integral equation given by EDWARDS, ABRIKOSOV, and GORKOV. In an appendix, we present the quasi-classical approximation for the calculation of GREEN functions.
Improved Precision in the Evaluation of Ion-Sensitive Photoplates by a Computer Program
Authors: Franzen J. , Schuy K. D.
Published: March 2015

An algorithm is presented to be used in the computer evaluation of ion-sensitive photographic plates in spark source analyses by mass spectroscopy. It is shown that this algorithm permits the attainment of the precision of photoplate evaluation demanded by theory, i. e. a precision of 0.015 relative standard deviation of the measured ion density for a mass spectral line of area 0.05 mm2.
Elektronenoptischer Phasenkontrast
Authors: Reimer L.
Published: March 2015

Mit der BORNschen Näherung als Ausgangspunkt wird die Wirkung des Öffnungsfehlers und einer Defokussierung auf den Phasenkontrast eines phasenschiebenden Scheibchens von 5 bis 40 A Durchmesser berechnet und die Frage diskutiert, inwieweit derartige Objekte durch Phasenkontrast abgebildet werden können. Es wird ferner der Versuch unternommen, den Phasenkontrast auch quantitativ auf der Basis der Elektronenstreutheorie zu erfassen. Bei derartig kleinen Objekten muß man auch den Aufbau aus Einzelatomen berücksichtigen. Die Diskussion zeigt, daß man jedoch bei den kleinen Aperturwinkeln, die zur Abbildung benutzt werden, keinen nennenswerten Einfluß des atomaren Aufbaues findet. Die Annahme einer phasenschiebenden Scheibe mit einem inneren Potential stellt bei Scheiben mit 10 bis 20 A Durchmesser aus einer Monolage von Atomen noch eine befriedigende Näherung dar.
A New Mass Spectrograph with Very Large Dispersion
Authors: Matsuda H. , Fukumoto S. , Kuroda Y. , Nojiri M.
Published: March 2015

A new type of mass spectrograph with large mass dispersion has been constructed. The distinguishing feature of this apparatus is that the mass dispersing action of a r-l magnetic field is utilized. The instrument has a r-1 magnetic field of 198.1° sector type (22 cm mean radius) as the dispersing field, a toroidal electric field of 118.7° sector type (30 cm mean radius) and a 30° uniform magnetic field (120 cm mean radius) as the focusing fields. The principle, the design and important parts of the apparatus are described. The dispersion on the photographic plate was estimated to be 14 cm for 1% mass difference and the maximum resolving power of about 500,000 was obtained.
Über den Ionennachweis mit Photoplatten
Authors: Franzen J. , Maurer K.-H. , Schuy K. D.
Published: March 2015

Part I. The transparency curve, produced by ions of 10 - 100 keV, can be described by

T=Ts+(1-Ts)

T = transparency, Ts = transparency at saturation, e = photographic sensitivity, N = number of ions incident per unit area, V = parameter of the size-frequency distribution of the AgBr grain impact areas. The equation is derived from basic principles by suitably modifying Kinoshita’s assumptions 1. Agreement with experimental curves is demonstrated.

Part II. The shape of the transparency curve (T vs. log of ion density) was investigated for several developers at various developing temperatures and developing times, for the improved Ilford Q2 emulsion. Plates were exposed with 28 keV Kr+-ions.

For short developing times, only those grains are developed which have been struck by r and more ions, r in the order of 50. With increasing developing time, r tends towards 1.

This statistical effect, observed for all developers, is superimposed by two developer-dependent effects: in regions of high density of developable grains, the developing action is hampered by local consumption of developer reagents; furthermore, some developers result in a superposition of curves of very different values of r: the transparency curves appear “flatter” than those demanded by theory.

Part III. The consideration of background fog necessitates the differentiation of two types of background: a fog due to light quanta or plate storage, and a surface fog due to particles with limited penetration depth into the emulsion. Equations are derived correcting measured transparencies for both types of background.

Background fog reduces the photographic sensitivity. A theoretical equation gives the loss of photographic sensitivity for ion-produced fog. A similar equation is valid for light- and plate storageproduced fog; it then contains a parameter which has to be determined experimentally.

Agreement with experiment is demonstrated.

Part IV. Grain size and grain density of Ilford Q2 emulsions are determined from photometric measurements of statistical fluctuations of the blackening for various developing conditions. For most developers, the grain density increases with increasing developing time, the grain size remaining constant. The maximum attainable precision of photometer transparency and ion current density measurements for a given line area is stated.
The Isotopic Composition of Atmospheric Neon
Authors: Walton J. R. , Cameron A. E.
Published: March 2015

“Absolute” values for the isotopic abundance ratios of atmospheric neon have been determined by mass spectrometry. Calibration standards were prepared by mixing of nearly pure separated nuclides of neon. The percentage abundance of the three nuclides of neon are:

20Ne = 90.514 ± 0.031, 21Ne = 0.266 ± 0.005, 22Ne =9.220 ± 0.029.

The calculated atomic weight of neon on the unified physical and chemical atomic weight scale (12C=12) is 20.1794 ± 0.0030.
Skalare Kern-Elektronen-Wechselwirkungen zwischen verschiedenen Molekülen in Lösungen
Authors: Müller-Warmuth W.
Published: March 2015

The dynamic polarization of the 19F nuclei in free radical solutions of C6F6, C6H5F and C6H4F2 is much less negative than expected from investigations of the proton polarization in similar systems. In the limits of “extreme narrowing” the enhancement factor is of the order of —100 instead of —350; in strong magnetic fields it is even posiitve. Data obtained in fields of 16.2, 176 and 3230 gauss are interpreted in terms of a combined dipole-dipole and scalar coupling between nuclear and electron spins. For the time dependence of the dipolar interaction the model of an independent "translational" random diffusion of spin-carrying molecules is used whilst the scalar interaction is described by a spectral function proportional to τSk/(1+ω2τSk
2). The results are compared with measurements of RICHARDS in strong magnetic fields and with theoretical models of HUBBARD for the scalar interaction. Diffusional and scalar correlation times, the relative contribution of the scalar interaction and the order of the coupling constant are calculated.
Ionization Potentials of Aromatic Molecules Determined by Analytical Interpretation of Electron Impact Data
Authors: Eland J. H. D. , Shepherd P. J. , Danby C. J.
Published: March 2015

The analytical technique proposed by MORRISON 1 has been tested on ionization efficiency curves obtained using an unmodified mass spectrometer. Ionization potentials of a series of aromatic amines have been found by this method and have been used to determine the best parameters for use in calculations by the STREITWIESER ω-technique.
Electromigration in Molten and Solid Binary Sulfate Mixtures: Relative Cation Mobilities and Transport Numbers
Authors: Ljubimov Vladislav , Lundén Arnold
Published: March 2015

The electrolytic displacement of the two cations relative to each other has been studied in solid (Li, Ag)2SO4 (93 eq. % Li) at 700 °C, solid (Li, K)2SO4 (91% Li) at 575 °C and molten (Li, K)2SO4 (41 — 90% Li). For melts containing more than about 52% Li the Li ions have a higher mobility (at about 740 °C) than the K ions, while the latter have the highest mobility in mixtures where K is the more abundant cation. The relative difference (Δb/b) between the mobilities of the two cations exceeds 15% already at concentrations some 8% off from the equimobility concentration. For the eutectic composition, 80% Li, Δb/b was about 60% independent of the temperature (590 — 835 °C). For mixtures containing 90% Li it was established that Δb/b changes its sign at the melting point. Thus, the mobility of the Li ion was of the order of half the mobility of the other ion in the solid systems, while it was about twice as large in the melt. The cation transport numbers (relative to the anion) were calculated for all experiments ,and for the melts also the difference between the cation mobilities. An estimation is made of the obtainable accuracy of electromigration experiments.

The experiments with melts were analysed for isotope effects. The light isotopes were always enriched towards the cathode, independent of whether Li or K had the higher mobility. The magnitude of the isotope effects shows a concentration dependence, i. e. the mass effect (relative difference in mobility divided by relative difference in mass) tends to increase when an ion is dilute, as previously found for other systems. Thus for the melts with 80% Li, the mass effect is higher for K than for Li.
Nachwirkungserscheinungen am keramischen Bariumtitanat
Authors: Wild Bertram
Published: March 2015

An grobkristallinem Bariumtitanat wurden im Temperaturbereich 10 bis 110 °C und im Zeitintervall von 2 bis 107 sec Nachwirkungsströme gemessen, ebenso Ausheizströme bis zu Temperaturen über 600 °C. Dabei ergaben sich drei Relaxationsmechanismen: der rein ferroelektrische, ein von den normalen Randschichten der Kristallite verursachter und schließlich eine Nachwirkung auf Grund der Randschichten, die durch einseitige Diffusion von Elektrodenatomen entstehen.
Feldverdampfung von Platin bei hohen Temperaturen im Ultrahochvakuum und in Gegenwart von Sauerstoff: massenspektrometrische Analyse der Oberflächenkomplexe
Authors: Vanselow R. , Schmidt W. A.
Published: March 2015

Bei der Feldverdampfung von spektralreinem Platin im UHV (p≦5 · 10-8 Torr) wurden bei Temperaturen bis zu 1200°C die Ionen Pt+, Pt2+ und Pt3
2+ nachgewiesen; durch Verunreinigungen (Begleitmetalle, gelöste Gase und Restgase) bedingt, wurden daneben PtFeO2+, PtCuO2+, Pt2FeO2+, Pt2CuO2+, PtC+, PtO+, Pt20+, Pt202+, Pt3O2+ und Pt4O2+ gefunden.

Wurde die Feldverdampfung von Platin in Gegenwart von Sauerstoff (po2=7 · 10-4 Torr) im Temperaturbereich 600—1150°C durchgeführt, so traten sauerstoffreichere Molekülionen auf, z. B. wurden die Ionen PtO+, PtO2+, Pt3O4
3+, Pt2O3
2+, PtO2
+ und PtO3+ nachgewiesen.

Die Methode eignet sich zur Spurenanalyse, besonders wenn eine flächenspezifische Anreicherung auf der Oberfläche der Probe erfolgt und dient als Hilfsmittel, bei Oberflächenreaktionen gebildete Komplexe zu bestimmen.
Some Interesting Aspects of Particle Physics at Super High Energies
Authors: C. L. Yuan Luke
Published: March 2015

A brief account is given on some specific aspects of particle physics at super high energies which are of major importance to the understanding of nature of matter with the expectation that the related experiments can be carried out when these high energies become available. The discussions include 1) Asymptotic Behavior, 2) Dispersion Relations, 3) Broken Symmetry, 4) Heavy Triplets, and 5) Intermediate Bosons.
Die Struktur der Invarianzgruppe für lineare Feldtheorien
Authors: Steudel H.
Published: March 2015

The LIE algebra U of the invariance group of any field theory with a homogeneous quadratic Lagrangian shows a remarkable structure: If D1, D2, D3 are any three elements of U then the expression ½ (D1 D2 D3 +D3 D2 D1) also belongs to U.

This general property allows, starting with known invariance transformations or conservation laws, to derive an infinite number of conservation laws.
A General Formulation for the Evaluation of Two-center Moment Integrals
Authors: Yeranos Walter A.
Published: March 2015

The mathematical formulation necessary for the evaluation of two-center integrals for SLATER-type orbitals has been presented. The formulation takes into consideration the arbitrary orientation of the two centers and presents a general expression involving the three quantum numbers, the effective charge of each of the two orbitals, the internuclear distance, and the usual A and B integrals. A flow chart for digital computer programming is also presented.
Die Bestimmung von Molekülkonstanten aus nicht aufgelösten Bandenspektren am Beispiel des PO-β-Systems
Authors: Meinel H. , Krauss L.
Published: March 2015

For 2∑-2Πa transitions (e. g. PO β-system), a method is described for calculation of rotational constants B (ν) from the doublet splitting of the bandheads. In that way the classification of both the violet and the red shaded PO β-bands (some 30 bands are new analysed) into one system can be shown, which seemed to be doubtful recently. From the discrepancies between the observed and the calculated additional heads in some subbands the rotational constant D has been evaluated, which plays an important part particularly for higher values of J as correction term in our calculation. Small systematic deviations in the graph of the rotational constant B (ν) for some sequences Δν=ν′-ν″ are interpreted as an indication for the interaction between electronic and nuclear motion; the effect corresponds to a deformation in the flanks of the potential curve in the order of 0.001 Å for higher vibrational quantum numbers (ν>5). The potential curves for the PO β- and γ-system have been computed, and from their relative position the observed perturbation of the level ν′=10 (β-system) and the range of perturbation starting at ν′=0 (γ-system) is explained. By calculation of the band origins a cubic equation for the vibrational levels of the B2∑-state is deduced. The extrapolation of the differences between two successive vibrational levels yields a new value of dissociation energy D0
0 (PO) =5.15 eV.
Das Mikrowellenrotationsspektrum des PbSe
Authors: Hoeft J. , Manns K.
Published: March 2015

Im Frequenzbereich 12—30 GHz wurden bei Temperaturen zwischen 700 und 750°C Rotationsübergänge von 15 Isotopenkombinationen des PbSe gemessen. Es werden Rotationskonstanten, Potentialkoeffizienten, Kernabstände und Massenverhältnisse von Blei- und Selenisotopen mitgeteilt. Als Mittelwert über alle isotopen Molekeln ergibt sich ein Kernabstand re = (2,402223 ± 0,000032) Å. Unter Annahme eines MoRSE-Potentials folgt für die Dissoziationsenergie D =(4,17 ± 0,05) eV.
Zur Analyse des Schwingungsspektrums von Triphenylen aus Raman- und Infrarotdaten
Authors: Mecke R. , Witt K.
Published: March 2015

Die IR-Spektren von Triphenylen im Bereich von 200—3200 cm-1 in verschiedenen Aggregatzuständen werden verglichen mit der Polarisation der Banden in orientierten kristallinen Schichten. Die Zuordnung der IR-aktiven E′- und A2"-Banden kann fast vollständig gegeben werden. Pulveraufnahmen an einem RAMAN-Spektrometer mit Anregung durch die He-Linie 5876,6 A ergaben den größten Teil der totalsymmetrischen A1′-Banden. Weniger vollständig gelang das Auffinden der IR-verbotenen Banden der Rassen A2', A1'' und E″, bei denen Unklarheiten vor allem bei tiefen Frequenzen blieben.

Aus Gas- und Lösungsspektrum ergibt sich bereits eine merkliche Abweichung von der D3h-Symmetrie (am Beispiel der 620 cm-1-E′-Bande). Beim Übergang zum kristallinen Zustand treten neue Banden auf, die für eine Verstärkung der Deformation in diesem Aggregatzustand sprechen.
Zur Kinetik des monomolekularen Zerfalls organischer Ionen in hohen elektrischen Feldern
Authors: Beckey H. D. , Knöppel H.
Published: March 2015

The kinetics of unimolecular decomposition of organic ions in the presence of electric fields up to 108 V/cm is discussed. The results are deduced from the mass spectra obtained by field ionization of organic molecules. The time interval between formation and decomposition of the ions can be derived from the shape of the mass lines. It is shown that field induced decomposition can occur at a minimum time of about 3 · 10–14 sec after field ionization. The optimum time resolution with these experiments, 10–12 sec, is given by the resolving power of the mass spectrometer.

The results can be interpreted in terms of five different mechanisms :

1. Field induced dissociation. Excitation of the molecular ion to a state above the dissociation limit is possible at high enough fields. Spontaneous dissociation within one vibrational period will then be possible because the excitation energy is contained in the reaction coordinate.

2. Field induced dissociation by tunneling of radicals through the potential barrier. This may occur after excitation of the molecular ion to a state lying in an interval between the dissociation limit and about half a vibrational energy quantum below this, provided the field strength is high enough. The maximum observable life time of ions resulting from this process is about 6·10–12 sec.

3. Field induced dissociation, delayed by re-orientation of the molecular ion. Certain orientations of the molecular ion are favoured with respect to field dissociation. The maximum re-orientation time for a favourable position is of the order 3·10–12 sec.

4. Field induced statistical dissociation. This is due to fluctuation of energy within the ion, as in the case of common reaction kinetics, but with lowering of the dissociation limit by the field. The time intervall for these processes lies between about 10–13 and 10–11 sec.

5. Statistical decomposition in the space of low or zero field strength. This process is due to energy fluctuation within the molecular ion excited to a state above the dissociation limit, lowered only by a minute amount by the weak field. The range of life times is about 10–11 to 10–8 sec. Processes of the same type, occurring at zero field strength within about 10–8 and 10–6 sec, are called — as usually — “metastable” processes.

The processes described here are derived mainly from the FI mass spectra of paraffins, alcohols, ethers and ketones. Dissociation is hindered, in some cases, by high electric fields.
Eine erweiterte Intensitätsfunktion für Elektronenbeugung an Gasen und ihre Interpretation durch kinematische Asymmetrien 1.Mitteilung
Authors: Freyland Werner , Haase Joachim , Zeil Werner
Published: March 2015

Es wurden eine erweiterte Intensitätsfunktion und eine erweiterte Radialverteilungsfunktion für Elektronenbeugung an Gasen berechnet. Die Bestimmung der Atombewegung in einem Molekül mit Hilfe der Elektronenbeugung wird in diesem Zusammenhang von neuen Gesichtspunkten aus diskutiert. Eine aus den Erweiterungen resultierende Korrektur für die gemessenen Atomabstände wird angegeben.
Eine Methode zur Verbesserung der Monochromasie bei Röntgen-Kleinwinkel-Untersuchungen
Authors: Jupe K.
Published: March 2015

Es wird eine Beziehung für die gestreute Intensität bei Röntgen-Kleinwinkelaufnahmen an Systemen polydisperser Partikel angegeben. Daraus ergeben sich 2 Werte für die optimale Präparatdicke, von denen der eine maximale Streuintensität liefert, während der andere optimale Monochromasie der gestreuten Strahlung ermöglicht.
Degree of Ionization of a Plasma in Equilibrium
Authors: Ecker G. , Kröll W.
Published: March 2015

Previous investigations derived the SAHA equation for a plasma in equilibrium applying the free-bound concept valid for an isolated electron-ion pair. In our investigation of the “adapted free-bound model” (I) we have shown that due to the free-bound interaction the demarcation between free and bound states is shifted by Δχ=—e2/r0 . We study the influence of this shift of the ionization limit on the effective ionization energy in SAHA’S equation. At the same time we account by interpolation for the contributions of the quasi-free highly correlated particles. The lowering of the free-bound limit causes an increase of the effective lowering of the ionization energy in SARA’S equation beyond the well-known e2/D-term resulting from the free-free interaction. This additional term itself is of the order O (e2/D) and therewith much stronger than the correction found from higher order correlations of the free particles. On the other hand it is much smaller than the lowering of the free-bound limit.
Uniform Description of Core and Sheath of a Plasma Column
Authors: Ecker G. , Kanne H.
Published: March 2015

Weakly ionized plasmas bounded by insulated walls have been studied for the limiting cases of very low and very high pressure in numerous papers. These investigations base the particle kinetics either on the model of “collision dominated motion” or on the model of “inertia dominated motion”. Corresponding model regions are matched neglecting the transition region.

We consider a weakly ionized plasma bounded by insulated walls. Its particle production is due to electron collisions and its particle destruction due to wall recombination. Describing the electrons as in quasiequilibrium and ion-neutral interaction by constant mean free time collisions it is possible to derive for arbitrary plasma pressure an integrodifferential equation valid throughout the plasma core, the transition region and the sheath. No matching of model regions is required. The well-known LANGMUIR and SCHOTTKY theories are shown to be asymptotic solutions of this general treatment.
Ein Verfahren zur Herstellung dünner ebener Einkristallschichten
Authors: KlEndl H.
Published: March 2015

A procedure is described for preparing thin plane single crystal foils from the solid suitable for transmission electron diffraction. The essential point is to thin down the foils by mechanical polishing to thicknesses of about 1 μm before applying chemical or sputtering procedures.
Die Streuung niederenergetischer Elektronen an Methan. Das zweite Ionisierungspotential
Authors: Ehrhardt H. , Linder F.
Published: March 2015

Measurements are made of the inelastic scattering of electrons from methane into large scattering angles. The results show the appearance of a collision process at 19.5 ± 0.2 eV. From the measured angular dependence of the differential scattering cross section, this collision process is identified as an optically forbidden transition. The classification of this transition (2 sa1 → 3 sa1) and a value of the second appearance potential of methane (between 23.5 and 24 eV) are deduced from analogous transitions in neon.
Messung der Zerfallszeiten von Molekülionen
Authors: Ottinger Ch.
Published: March 2015

The time interval between the ionization of a molecule by electron impact and its dissociation was determined from the kinetic energy of the fragment ions. This technique allows a direct differential sampling of the dissociation rate at various times, in contrast to previous, integral methods. The use of a disc-shaped molecular beam of 28 μ half-width and a draw-out field of 10 000 V/cm in the ionization region resulted in a minimum measured time interval of 7.4·10-9 sec. The longest times measured were between 5 and 6 μsecs. The time dependence of the decomposition rate was measured for two decompositions in butane, five in heptane, three in benzene, one in CD4 and one in CO2++, with rather similar results. It was established that the decay is not exponential. All decay curves, plotted semi-logarithmically, were found to have an increasing slope towards shorter times, indicating contributions from a variety of rate constants, in agreement with the predictions of the statistical theory of ion decompositions. 50 delayed decompositions in the μsec region were investigated, about half of which had not been reported previously. For these measurements the detection limit was about 10-5 of the base peak intensity. In particular, such "metastables" were found in methane and the deutero-methanes. They were explained by considering the external rotation of the ion. Small fragmentation energies set free during the decomposition can be determined from the kinetic ion energy. The detection limit is as low as 5 mV for the total fragmentation energy, since the method is unaffected by thermal translational energy. Some rules concerning these energies were found.
Binary Systems Containing Hydrocarbons
Authors: Rolla Mario , Franzosini Paolo , Riccardi Riccardo , Bottelli Luigi
Published: March 2015

The miscibility gaps (which can be represented through a unique generalized curve on the Td/Tmax vs. z plane) in the binary liquid systems of nitromethane with 13 (C5 —C9)-alkanes have been measured. Moreover, it has been shown that for the title systems and for those of MeOAc or MeOH with alkanes the temperatures Tmax obey a simple additive rule, at least as a first approximation.
Ringstrom bei cyclischen Polyenen mit alternierenden und ausgeglichenen Bindungsabständen
Authors: Baer F. , Kuhn H. , Regel W.
Published: March 2015

The ring current effect in NMR has generally been used to distinguish between equal and alternant bonds in cyclic π-electron systems, assuming a strong ring current in equal-bonds-hydrocarbons and no ring current in alternant-bonds-hydrocarbons. A calculation of the ring current is presented based on the one dimensional electron gas model. The effect of bond alternation is considered by a sine curve potential.

Proceeding from a model with equal bonds to a model with alternant bonds the ring current is strongly reduced in rings with more than 10 members; it is reduced by 24% and 51% only in 6 and 10 membered rings, respectively. In non-HücKEL type rings with 4 to 16 carbon atoms the ring current is directed opposite to the classical current and is strongest in cyclobutadiene. The contribution of the π-electrons to the susceptibility of these compounds is therefore paramagnetic and ring current shifts opposite to those in HÜCKEL rings are to be expected. These results are confirmed by the proton chemical shifts in the NMR spectrum of [16]-Annulene.
Composition Dependence of the Thermal Diffusion Factor in Binary Gas Mixtures
Authors: Mathur B. P. , Saxena S. C.
Published: March 2015

The thermal diffusion factor, αT, for the gas systems He—Ar, He—Ne, Ne—Kr and Ne —Xe is measured as a function of composition in a glass two bulb apparatus, operating with its hot and cold bulbs at 373.9° and 273.3°K respectively. Gas samples are analysed with a sensitive and specially designed differential thermal conductivity analyser. The αT data are compared with similar values of other vorkers and a smooth set is recommended. The data are further compared with the predictions of rigorous theory in conjunction with realistic intermolecular potentials. An approximate prediction of the theory concerning the composition dependence of αT has been checked.
Eine Berechnung des H2O-Moleküls
Authors: Hamel D.
Published: March 2015

Das H2O-Molekül wird nach der Valenzstrukturmethode mit Konfigurationswechselwirkung behandelt. Für den Aufbau der Zustandsfunktion wird eine Minimalbasis von einfachen oder linear kombinierten SLATER-Funktionen gewählt. Als Konfigurationen werden solche benutzt, die beim Sauerstoffkern stets zwei ls-Elektronen sowie zwei 2p-Elektronen in der zur Molekülebene senkrechten Richtung enthalten. Neben der ausführlichen Berechnung des Grundzustandes werden Rechnungen zu allen auftretenden Kombinationen von Symmetrie und Gesamtspin durchgeführt. Zu den besten Näherungen werden außer der Gesamtenergie auch Zustandsfunktionen mit einer graphischen Darstellung der Elektronendichte in der Molekülebene, Dipolmomente und Kernschwingungsfrequenzen angegeben.
Gas-Solid Interaction: Study of the Systems C6H6—γ-Αl2Ο3, CCl4—γ-Αl2Ο3 and cyclo-C6H12—γ-Αl2Ο3 by Means of the B.D.D.T. Equation
Authors: Sanesi Manlio , Wagner Vittoriano
Published: March 2015

Gas-solid adsorption was experimentally investigated at 25°C for the title systems, which all exhibit isotherms of type IV with a hysteresis loop.

The B.D.D.T. equation was employed for the treatment of the experimental data, and the values obtained for its four constants have been discussed and compared with values derived by independent methods. In particular, for C6H6—γ-Al2O3 a good agreement was found between the calculated value of the interaction energy in monolayer and calorimetric data.
Self-Transport, Electro-Convection and Effective Self-Diffusion in Liquid Rubidium Metal
Authors: Norden A. , Lodding A.
Published: March 2015

Isotope electrotransport in liquid Rb has been measured. Results of earlier measurements of the mass effect μ have been confirmed and their accuracy further improved. μ ranges from 2 x 10-5 at the m.p. to 10-4 at 400°C. Up to about 200°C the temperature dependence of μ is similar to that of the (theoretically computed) self-diffusion coefficient. At higher temperatures the apparent “activation energy” increases.

With the aid of electrotransport, electro-convection in the liquid metal has been studied. Analysis of data at three different currents indicates that in horizontal 0.5 mm i.d. capillaries, at less than some 9 Amps, the main source of electro-convection in Rb is an I2 sensitive mechanism, probably electro-osmosis. At higher currents an I4 dependent mechanism may become dominant. A relatively small current independent term may influence the effective self-diffusion. The zero-current values of the effective self-diffusion coefficients are computed. Between 333° and 500°K they can be represented by (Deff) 0=5.7 x 10–4 exp (-1910/R T), with about 15 percent error margin in “activation energy”. These values are in good agreement with self-diffusion coefficients as calculated from experimental viscosity.
Messung der Druckverbreiterung von Linien der 2. Lyman-Serie des Heliumions
Authors: Hessberg H. , Bötticher W.
Published: March 2015

In einer gepulsten Kapillarentladung wird ein Heliumplasma hoher Elekronendichte (ne=2 bis 4·1018 cm-3) und Temperatur (T =50 000-55 000°K) erzeugt. Die Plasmadaten werden aus Messungen der Linienbreite sowie des Intensitätsverhältnisses Linie/Kontinuum der He II-Linie 4686 A bestimmt. Mit Hilfe dieser Daten werden aus den gemessenen Profilen die normierten Profile der im Vakuumultravioletten liegenden He II-Linien bei λ=1640, 1215 und 1085 Å ermittelt. Wegen der guten Reproduzierbarkeit und der hohen Dichte des emittierenden Plasmas eignet sich die Lichtquelle als Strahlungsnormal bei 1640 Å.
Ungeladene Bruchstücke aus einfachen aromatischen Molekülen bei Elektronenstoß
Authors: Genzel H. , Osberghaus O.
Published: March 2015

A mass spectrometer was used to study the primary neutral fragments produced by 200 eV electrons from C6H6, C6H5F and C6H5CH3 at pressures of 10-5 torr. In the case of C6H5 an attempt was made to measure quantitatively the relative production rates of different neutral fragments and to determine the relative importance of ionic and neutral decays. Ionisation potentials of C6H5, C6H4 and C6H2 were measured.
Die kritische Schubspannung kubischer Kristalle mit Fehlstellen tetragonaler Symmetrie
Authors: Frank Werner
Published: March 2015

In kubischen Kristallen treten zwischen Fehlstellen tetragonaler Symmetrie (elastischen Dipolen) und Versetzungen starke elastische Wechselwirkungskräfte auf. Deshalb tragen elastische Dipole zur kritischen Schubspannung τo bei, indem sie sich in den Spannungsfeldern der Versetzungen energetisch möglichst günstig ausrichten (induzierter SNOEK-Effekt). Dieser τo-Beitrag auf Grund weitreichender elastischer Versetzungs-Dipol-Wechselwirkungen wird für mehrere Gleitsysteme und Dipolorientierungen berechnet, welche in kubischen Kristallen vorkommen, und zwar für beliebige Verformungstemperaturen.
Elektrotransport in Wolfram
Authors: Neumann G. M. , Hirschwald W.
Published: March 2015

Der Elektrotransport in Wolfram wurde mit Hilfe des radioaktiven Isotops Wolfram-185 im Temperaturbereich 1950 bis 2100°C an polykristallinen Wolframproben (Korngröße 0,1-0,2 mm) untersucht. In Übereinstimmung mit theoretischen Vorstellungen wurde ein Transport des Wolframs zur Kathode beobachtet. Die Aktivierungsenergie des Elektrotransportes ΔHE = 91,5 kcal stimmt mit der Aktivierungsenergie der Selbstdiffusion in dem untersuchten Material überein.
IR-Untersuchungen heterocyclischer Verbindungen
Authors: Joeckle R. , Lemperle E. , Mecke R.
Published: March 2015

Wie bei Benzol- und Pyridinderivaten besteht auch bei 2-substituierten Thiophenderivaten ein funktioneller Zusammenhang zwischen den Intensitäten der CH-Valenzschwingungen lCH und den TAFTschen Substituentenparametern σI (X). Die ICH-Werte nehmen mit wachsender Elektronenakzeptorwirkung des Substituenten ab. Ihre Empfindlichkeit gegenüber Substituenteneffekten haben wir durch das Verhältnis der CH-Intensitäten der Methyl- zur Chlorverbindung ausgedrückt. Sie nimmt bei den bisher untersuchten Verbindungsreihen in der Reihenfolge Benzol (3,0), Pyridin (2,5) und Thiophen (1,5) ab.
The Decomposition of Benzene and Deuterated Benzenes under Electron Impact
Authors: Jennings K. R.
Published: March 2015

Metastable transitions have been observed in the mass spectra of benzene, hexadeutero-benzene, 1,4-dideuterobenzene and 1,3,5-trideuterobenzene using a double-focusing mass spectrometer. Decomposition maps have been obtained for each substance and decomposition reactions leading to the production of all significant fragment ions have been suggested. Metastable transitions of several doubly-charged species were found. Loss if identity by the H and D atoms of the partly-deuterated benzenes was observed in metastable transitions in their mass spectra, indicating that rapid isomerization occurs before fragmentation.
The Electrical Conductivity of Pure Molten Alkali Sulphates and Molten Equimolar Alkali Sulphate Mixtures
Authors: Kvist Arnold
Published: March 2015

The electrical conductivity of pure Na2SO4, Rb2SO4 and Cs2SO4 and of the nine equimolar mixtures LiNaSO4, LiRbSO4, LiCsSO4, NaKSO4, NaRbSO4, NaCsSO4, KRbSO4, KCsSO4 and RbCsSO4 has been measured up to 1145°C. From the measurements we have estimated the number of cations taking part in cooperative motions in these salts. The relation between the TOBOLSKY parameter and the conductivities is discussed.
Rare Gas Mobility in Pure and Doped Potassium Bromide
Authors: Matzke Hj.
Published: March 2015

The mobility of the inert gases argon and xenon in pure and doped single crystals of KBr was studied. The gases were introduced by ion bombardment. The recently established system of stages was used to interpret the results. Normal volume diffusion was found for xenon at low gas concentration, the activation enthalpy being 1.4 ± 0.2 eV. This release was independent of doping, thus favoring a transport process for xenon independent of single vacancies. As most probable alternative, a mobility via small vacancy clusters, e. g. vacancy pairs was suggested. Trapping of xenon was found at higher xenon concentrations. This retarded release was shown to depend on doping and was more pronounced in crystals with an excess of cation vacancies. The diffusion of argon occurred with a similar activation enthalpy, but was most probably due to an interstitial motion.
Mikrowellenspektrum und partielle rs-Struktur des Tertiärbutylchloracetylens (1-Chlor-3,3-Dimethyl-butin-1)°
Authors: Bodenseh Hans-Karl , Gegenheimer Richard , Mennicke Jürgen , Zeil Werner
Published: March 2015

Das Mikrowellenspektrum des Tertiärbutylchloracetylens wurde im Bereich zwischen 8000 und 24 000 MHz untersucht. Durch Vermessen der Mikrowellenspektren einer Reihe von isotopensubstituierten Molekülen im natürlichen Vorkommen konnten nach der Methode der rs-Strukturbestimmung die Gesamtlänge der linearen Kette sowie die Abstände C—Cl und C—C ≡ C bestimmt werden. Die Quadrupolfeinstruktur konnte zum Teil aufgelöst und die Kernquadrupolkopplungskonstante ermittelt werden.

Obwohl das Molekül einem symmetrischen Kreisel entspricht, ist das Spektrum sehr komplex durch das Auftreten sehr vieler angeregter Schwingungsfreiheitsgrade. Es gelang, fast alle stärkeren angeregten Schwingungsfreiheitsgrade zuzuordnen, wobei aus den Intensitätsverhältnissen die entsprechenden Schwingungsfrequenzen ermittelt werden konnten.

Die Ergebnisse stimmen befriedigend mit den früher von uns vermessenen Ultrarot- und Raman-Spektren überein. Die Strukturdaten entsprechen der gleichzeitig von uns mittels Elektronenbeugung bestimmten Struktur.
Zum Mikrowellenspektrum des Pyridazins
Authors: Werner W. , Dreizler H. , Rudolph H. D.
Published: March 2015

The rotational spectrum of pyridazine in the vibrational ground state is reported for the parent species and three isotopically substituted species. The rs coordinates of the ring atoms have been reliably determined with the exception of the α coordinate of the Cl and the C4 atoms which is obviously too small for the application of KRAITCHMAN’S equations. The dipole moment was calculated from the STARK effect as μα=4.22 D. The quadrupole coupling constants, from hfs measurements, are χαα=— 4.64, χbb=1.38, χcc=3.27 MHz. The only non-diagonal quadrupole coupling tensor element has been less accurately determined from the variation of the hfs upon rotation of the principal axes system by isotopic substitution of one N15 nucleus.
Zum Mikrowellenspektrum des Isobutyronitrils
Authors: Herberich G. E.
Published: March 2015

The microwave spectrum of isobutyronitrile has been investigated in the region from 5 — 30 GHz. A and C type transitions have been observed. No splittings due to internal rotation of the methyl groups could be detected and a lower bound of 2.6 kcal/mole for the barrier height is established.

Values for the rotational constants are 7.940 95 ± 0.000 04, 3.968 039 ± 0.000 010 and 2.901 030 ± 0.000 010 GHz.

The nuclear quadrupole coupling constants are χαα=—3.905±0.010 MHz, χbb=2.077±0.02 MHz and χcc=1.828±0.017 MHz.
Untersuchung des Barkhausen-Effekts während des Zerfalls von Nickelhydrid
Authors: Bauer H. J. , Pfrenger E. , Stierstadt K.
Published: March 2015

The size distribution of Barkhausen discontinuities was measured along the hysteresis cycle during the decomposition of non-ferromagnetic nickel hydride at room temperature. The results confirm our earlier conception that this process is comparable to the precipitation of alloys. During the decomposition, firstly superparamagnetic particles are formed. They increase in size to monodomain and multi-domain particles successively, and finally grow together to compact nickel.
Die Ionenbahnen dritter Näherung in magnetischen Sektorfeldern einschließlich ihrer Streufelder
Authors: Ludwig Rainer
Published: March 2015

Für das homogene magnetische Sektorfeld mit gekrümmten Feldbegrenzungen und schrägem Ein- und Austritt wird die Gleichung des Nebenstrahls eines Ionenbündels mit radialer und axialer Öffnung relativ zu dessen Mittelstrahl in dritter Näherung bestimmt. Damit werden die Bildfehlerkoeffizienten 3. Ordnung gewonnen. Die Streufeldeinwirkungen werden ebenfalls in dritter Näherung behandelt, wobei die im Streufeldbereich stattfindende Gesamtablenkung durch das Modell eines „Ersatzstrahlenganges“ mit Knickung und Versetzung des Strahls an einer zu bestimmenden „Ersatzfeldgrenze“ beschrieben wird. Numerische Beispiele werden angegeben. Bisher 1-12 waren entsprechende Rechnungen nur bis in 2. Näherung durchgeführt.
Eine anomale Temperaturabhängigkeit der Schwelle bei einem quasikontinuierlich betriebenen Rubinlaser
Authors: Zeidler G.
Published: March 2015

Kurze Rubinstäbe wurden quasikontinuierlich bei variabler Kühlmitteltemperatur betrieben. Der Temperaturgang von Schwelle, Wirkungsgrad und Emissionsspektrum wurde gemessen. Dabei ergab sich ein unerwarteter Effekt: Bei einem VERNEUILLE-Stab nahm die Schwelle unterhalb einer Kühlmitteltemperatur von — 5°C stark zu, während sie bei einem nach dem CZOCHRALSKI-Verfahren gezogenen Stab den Erwartungen gemäß abnahm. Erklärungsmöglichkeiten sind Anregungsprozesse in hochliegenden Energieniveaus und vom Herstellungsverfahren abhängige, durch das Pumplicht induzierte Absorptionszentren, deren Lebensdauer mit sinkender Temperatur zunimmt.
Quadrupole - Quadrupole and Dipole - Octupole Dispersion Forces Between Axially Symmetric Molecules
Authors: Van Der Merwe Alwyn J.
Published: March 2015

Formulas are derived that express the contributions of the electric quadrupole-quadrupole and dipole-octupole forces, respectively, to the dispersion energy of two unexcited molecules possessing axial symmetry. The formulas are valid in situations where the optical dispersion curve of each molecule is adequately characterized by a pair of resonance frequencies.
Näherungsmethode für die Berechnung der Dichtematrix von Gitterelektronen
Authors: Jannussis A. D.
Published: March 2015

Es wird eine Näherungsmethode für die Berechnung der Dichtematrix von Gitterelektronen entwickelt. Das Gitterpotential wird als Störung betrachtet, und als ungestörte Funktion wird eine lineare Kombination von verschobenen Green-Funktionen des freien Teilchens verwendet. Diese Funktion berücksichtigt die Translations-Symmetrie des Gitters.

Die Näherungsmethode ist der BLocnschen Methode „Methode der Festbindung“ ähnlich, und in Analogie zur Blochschen Summe von Atomeigenfunktionen treten die verschobenen Green-Funktionen des freien Teilchens auf.

Die Methode läßt sich erweitern für den Fall, daß ein äußeres homogenes Magnetfeld auftritt.
Oxide and Hydroxide Activity Determination in Oxide Doped Lithium Fluoride
Authors: Trevisan G. , Pizzini S.
Published: March 2015

Oxide and hydroxide activities in solid lithium fluoride at high temperatures have been evaluated by measuring the equilibrium partial pressures of water and hydrofluoric acid.

Results concerning the lithium hydroxide solubility have been discussed on the basis of the phase diagram of the LiF—LiOH system and the concentration of the dissolved lithium hydroxide has been calculated.
Energiemessung von Photoelektronen und Franck— Condon-Faktoren der Schwingungsübergänge einiger Molekülionen
Authors: Spohr Reimar , Von Puttkamer Ewald
Published: March 2015

The energy of photoelectrons ejected by 21.21 eV quanta of the He resonance line is measured with a retarding potential method at a resolution of 40 meV. Vibrational structure of the molecular ions H2
+, D2
+, O2
+, N2
+, NO+, CO2
+, N2O+ H20, and HC ≡ CH+ is resolved and experimental values of the FRANCK-CONDON factors for the transitions into these vibrational levels are given.
Adsorption von Sauerstoff an spektralreinem Platin: Messungen nach der „flash-filament“-Methode im Feldionen-Massenspektrometer
Authors: Vanselow R. , Schmidt W. A.
Published: March 2015

Mit einem Feldionen-Massenspektrometer als Partialdruckmesser wurden nach der „flash-filament“-Methode adsorptionskinetische Daten für das System Sauerstoff —Platin bestimmt. Es wurde die Bedeckung und der Haftkoeffizient in Abhängigkeit von der Adsorptionsdauer ermittelt. Bei einem Gleichgewichtsdruck von 8·10-7 Torr betrug die Zahl der bei Sättigung adsorbierten O2-Moleküle Nad=2,1·1014 Moleküle/cm2, die Zahl der beim Erhitzen auf 1500°C desorbierten 02-Moleküle dagegen nur Ndes=5,8·1013 Moleküle/cm2. Der maximale Haftkoeffizient bei beginnender Adsorption ergab sich zu smax = 4,6·10-2 für Tpt≈400°C.

Daneben wurde die Adsorption der Restgaskomponenten CO, H2O und CO2 untersucht. Für CO wurden an dem bereits für Sauerstoffadsorptionsmessungen benutzten Pt-Draht bei einem Druck von 6·10-7 Torr — in Gegenwart von ca. 4% O2 — Nad≈Ndes = 4,4·1014 Moleküle/cm2 und für Tpt≈150°C smax=5·10-2 bestimmt. Es konnte die Chemisorption von H2O, nicht aber die von CO2 an Platin nachgewiesen werden.
IR-Untersuchungen heterocyclischer Verbindungen
Authors: Joeckle R. , Lemperle E. , Mecke R.
Published: March 2015

Messungen der CH-Valenzschwingungen des Rings und der Methylgruppe methylierter heterocyclischer Verbindungen zeigen, daß die Wirkung der Heteroatome auf die Gruppenintensitäten und -frequenzen in der Reihenfolge O, NH, S, Se abnimmt. Aus einem Vergleich der Intensitätswerte von 2-Methyl-, 3-Methyl- und 2,5-Dimethylderivaten mit den unsubstituierten Stammsubstanzen geht hervor, daß der Effekt der Heteroatome auf die Elektronendichteverteilung in 2- (bzw. 5-) Stellung von CH- und CH3-Gruppe wesentlich größer ist als in 3- (bzw. 4-) Position.
Tritium-Diffusionsmessungen an protonenbestrahlten Proben des Eisenmeteoriten Sikhote-Alin
Authors: Fechtig H. , Festag J. G. , Schultes H.
Published: March 2015

Samples of the iron meteorite Sikhote Alin were irradiated in the synchrocyclotron at CERN by 600 MeV protons. A concentration of the radioactive isotopes Ar37 and tritium was produced by spallation from iron and nickel nuclei. Diffusion and extraction experiments showed a lack of the produced tritium which may either have been dissolved in the iron at higher temperatures or escaped by diffusion during the irradiation. Also some grains were completely dissolved chemically. The results were that most of the tritium diffused out of the samples during the irradiation, while only a neglectible amount of argon was lost by diffusion during the irradiation. Based on this result we could determine the diffusion parameter D/a2 at room temperature to be in the order of 10-9 sec-1. The activation energy is in the vicinity of 10 kcal/mol. From these values for the diffusion parameters it can be concluded that the meteorite lost most of the tritium within a few weeks after its fall.
Helium- und Neonisotope in Eisenmeteoriten und der Tritiumverlust in Hexaedriten
Authors: Hintenberger H. , Schultz L. , Wänke H. , Weber H.
Published: March 2015

The He- and Ne-contents as well as their isotopic composition have been measured of 40 iron meteorites, including 12 hexahedrites. These hexahedrites were of particular interest because many of them showed a definite 3He-deficiency which we explain by a loss of tritium. This effect was already found by us previously for the hexahedrite Braunau. The tritium loss depends on the temperature the meteorites were exposed to, hence, on their orbital elements. Some of the hexahedrites have lost practically all their tritium produced during their exposure to the cosmic rays, indicating that they always had been in the vicinity of the Earth or even closer to the Sun. Two octahedrites, Anoka and Staunton, suffered an appreciable loss of tritium too.

From the rare gas data of meteorites with a nearly complete loss of tritium the cross-section ratios of the direct production of tritium, 3He, and 4He by the cosmic rays in iron meteorites could be calculated.

In the ataxite Washington County a portion of the rare gas content was identified to be of primordial origin.
Zur Prüfung allgemein-relativistischer Rotationseffekte mittels eines Ringlasers
Authors: Dehnen H.
Published: March 2015

Es werden die optischen Konsequenzen der Rotation der Erde, besonders hinsichtlich allgemeinrelativistischer Effekte, untersucht. Es zeigt sich, daß letztere Effekte so klein sind, daß sie auch mit Hilfe eines Ring-Lasers z. Zt. nicht nachgewiesen werden können.
Relaxation und dynamische Kernpolarisation von Protonen in freien Radikalen
Authors: Stehlik D. , Hausser K. H.
Published: March 2015

In all dynamic nuclear polarisation (DNP) experiments in liquids carried out so far the electronic spin belonged to the paramagnetic molecule while the proton was part of the diamagnetic solvent molecule. In this paper the relaxation and DNP of protons inside free radicals in protonfree solvents is studied.

A calculation of the DNP coupling parameter ξ is given for mixed scalar and dipolar intramolecular interaction with simultaneous time dependences by electron spin relaxation, electron spin exchange and molecular motion on the basis of the formalism of ABRAGAM and SOLOMON.

Experimental results at 12.5 kGauß were obtained for the t-butyl-protons in the three radicals tri-t-butyl-phenoxyl (TBP), COPPINGER'S Radical (CR) or Galvinoxyl and di-t-butyl-nitroxide (DBNO). The experimental technique differs from the usual NMR-detection in the use of pulse technique and of a dielectric resonator in the microwave equipment.

DNP enhancements from high positive to high negative values could be observed corresponding to mixed proton-electron-coupling from dominantly scalar to dominantly dipolar interaction. All results can be at least qualitatively explained by the theory of the intramolecular interaction since the essential parameters and constants of the interaction can be measured with other independent methods.