bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
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.
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.
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.
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.
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.
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.
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.
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 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.
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.
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.
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.
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.
Über den Einfluß der Adsorption auf die Feldionisierung organischer Substanzen
Authors: Metzinger H. G. , Beckey H. D. 
Published: March 2015

The dependence of neutral particle supply to the emission centres of a field ion emitter on adsorption and surface diffusion is investigated.
An equation is derived relating the field ion current to the adsorption energy of organic adsorbates. It follows from this equation that the ion current increases with increasing adsorption energy.
This was confirmed experimentally by a set of seven heptane isomers where the ion current increases with increasing boiling points.
The ion intensities of a series of n-paraffins as a function of molecular weights are also discussed.
Das Mikrowellenrotationsspektrum des GeTe
Authors: Hoeft J. , Nolting H.-P. 
Published: March 2015

Im Frequenzbereich 11—20 GHz wurden bei Temperaturen zwischen 570 und 600°C Rotationsübergänge von 19 isotopen Molekeln des GeTe gemessen. Es werden Rotationskonstanten, Kernabstände, Koeffizienten der Potentialfunktionen nach DUNHAM und MORSE und Massenverhältnisse von Germanium- und Tellurisotopen mitgeteilt. Als Mittelwert für den Gleichgewichtsabstand der Kerne ergibt sich
re = (2,340 157 ± 0,000 026) A.
Ein weiterer Hauptsatz über das Messen als Grundlage der Hilbert-Raumstruktur der Quantenmechanik
Authors: Ludwig Günther 
Published: March 2015

In einer früheren Arbeit1 des Verfassers wurden Hauptsätze über das Messen formuliert und diskutiert, die HILBERT-Raum-ähnliche Strukturen zu Folge haben. Das in 1 vorgeschlagene System von Axiomen läßt aber wahrscheinlich noch andere Realisationen als den HILBERT-Raum zu. In dieser Arbeit wird ein weiterer Hauptsatz so formuliert, daß im „endlich dimensionalen Fall“ (siehe Axiom l η endlich aus 1) als irreduzible Lösungen nur noch HILBERT-Räume über dem Körper der reellen oder komplexen Zahlen oder der Quaternionen übrig bleiben. Der formulierte Hauptsatz ist im wesentlichen eine Art modulares Postulat, wie es von vielen an die „Propositions“ gestellt wurde [siehe 2 „loi de couverture“ (siehe Anm. 3), Theorem 8 und Axiom 12].
Man kann aber dieses Postulat als Aussage über Gesamtheiten so formulieren, daß es sich leicht und anschaulich physikalisch interpretieren läßt. Ebenso läßt es sich sofort auf den unendlich dimensionalen Fall übertragen, so daß der Verband der abgeschlossenen Teilräume des HILBERT-Raumes (der bekanntlich nicht modular ist!) alle Axiome erfüllt.