bluuebunny/crossref_metadata_2025_split huggingface dataset:
Kernreaktionen durch Deuteronen von 52 MeV
Authors: Duelli B. , Mairle G. , Schmidt-Rohr U. , Turek P. , Wagner G. 
Published: March 2015

The nuclear reactions of 52 MeV deuterons have been studied at some medium weight and heavy nuclei. The angular distributions of elastically scattered deuterons show sharp structures which are smoothed out — similar to the results at lower deuteron energies — for target nuclei near A = 100. The optical model analysis gives good fits with parameters extrapolated from the best values at lower energies. The „Smoothed Cut-off“ models do not describe the results properly. The influence of the nuclear interior on the elastic scattering is important.
The proton spectra from the (d, p) and (d, pn) reactions are dominated by a broad „break up“ maximum. From the width of the maximum and the A-dependence of the cross section it is concluded that nuclear break up is more frequent at 52 MeV than COULOMB break up. The spectra of deuterons and tritons from the (d, d′) and (d, t) reactions show maxima up to Q-values of — 15 MeV. With these reactions it should be possible to study collective excitation up to high excitation energies and to get information about inner shells. The intensity of low energy inelastic deuterons is surprisingly large.
Elektrolytische Stofftrennung in Kapillarrohren als präparative Methode
Authors: Wagener K. , Bilal B. A. 
Published: March 2015

Es werden die Eigenschaften und die Verwendbarkeit von Kapillarrohren zur Stofftrennung durch Gegenstromelektrolyse beschrieben. Eine experimentelle Ausführungsform sowie einige Trennergebnisse werden als Beispiele mitgeteilt.
Das Verfahren zeichnet sich durch Einfachheit in der Ausführung, Vielseitigkeit in der Anwendbarkeit und hohe Trennschärfe aus und ist für Produktmengen bis zu etwa 1/100 Mol geeignet. Es können grundsätzlich alle lonengemische getrennt werden, deren Komponenten einen Unterschied in der lonenwanderungsgeschwindigkeit zeigen. Auf einige kernchemische Anwendungsmöglichkeiten wird besonders hingewiesen.
Photochemical Studies by Means of a Field Ion Mass Spectrometer
Authors: Okabe H. , D. Beckey H. , Groth W. 
Published: March 2015

A mass spectrometric investigation was carried out on the direct photolyses of propene, 1-butene, and hydrazine at 1849 A with a field ion source in a flow system. Comparisons were made with Pt tip and wire emitters. It was found that, without illumination, mass spectra obtained with the wire were accompanied by a number of fragment peaks amounting to almost 1%. Since these peaks interfere with those produced photochemically, the tip emitter was used mostly for the photochemical studies although it gave 100 times less current and was less stable. The photochemical products formed at a gas pressure of 10 μ by a low pressure mercury lamp were detected after approximately 10 m sec. The three main peaks observed in the propene photolysis were at masses 27, 28, and 56, indicating the processes:
C3H6+hv→C2H3+CH3, C3H6+hv→C2H4+CH2, CH2+C3H6→C4H8.
The photolysis of 1-butene gave four main peaks at masses 40, 41, 42, and 70, suggesting steps, C4H8+hv→C3H4+ (H+CH3) or CH4, C4H8+hv→C3H5+CH3, C4H8+hv→C3H6+CH2, CH2+C4H8C5H10.
The only peak found with the photolysis of hydrazine was at mass 17, indicating the step, N2H4+hv→NH3+NH.
The possibility of forming these products by secondary processes is discussed.
Über die Feldstärkeabhängigkeit der Winkelverteilung feldemittierter Elektronen und Ionen
Authors: Beckey H. D. , Dahmen J. , Knöppel H. 
Published: March 2015

The angular distribution of atoms and molecules field ionized at Platinum tips is determined. First, with negative polarity of the tip the angular distribution of the field emitted electrons is measured in order to determine he radius of curvature and the shape of the tip, using calculations of DRECHSLER and HENKEL 2.
Then the angular distribution of field ionized Argon is measured at a tip temperature of about 400 °K. The curve agrees qualitatively with one derived from GOMER’s 6 equations on field ion currents as a function of field strength.
In contrast with this curve which shows a continuous decay with polar angle, the angular distribution curve of field ionized n-hexane, acetone, water and methanol shows a side-maximum lying at a polar angle of about 40°. This is explained as the consequence of adsorption and particle supply phenomena.
Extremaleigenschaft thermodynamischer Gleichgewichtszustände bei Ähnlichkeitstransformationen
Authors: Lenk Richard 
Published: March 2015

Some inequalities are derived from the extremal properties of thermodynamic equilibrium states. Nonequilibrium states with the same volume and entropy as the equilibrium state are constructed by scale transformations from the equilibrium distributions to other values of volume and entropy.
A volume-changing scale transformation gives the virial theorem and a stability condition for any system. An entropy-changing scale transformation yields the equipartion theorem and the condition C ν Cν
id for classical systems. A combined scale transformation gives a new stability condition which is more stringent than the condition belonging to the virial theorem. The latter degenerates to an identity for ideal systems, the former for a classical plasma.
The Wannier Functions of the Lattice Electron in a Uniform Magnetic Field
Authors: Jannussis A. 
Published: March 2015

In this paper a generalization of the WANNIER functions is performed for the case of the lattice electron moving in a uniform magnetic field.
In the case of the free electron moving in a uniform external magnetic field, the WANNIER function may be obtained directly by the Schrauben-function, if the wave vector k is substituted by the vector potential — (1/c) A (ai).
Gruppentheoretische Betrachtung zum Torsions-Rotations-Spektrum von Wasserstoffperoxyd
Authors: Dreizler H. 
Published: March 2015

Es wird die Invarianzgruppe eines bekannten HAMILTON-Operators, der die Torsion und Rotation von H2O2 beschreibt, gegeben. Dabei erweist es sich als notwendig, den Basisbereich des Torsionswinkels η mit 4 π zu wählen. Mit dieser Gruppe wird eine Klassifizierung der Energieterme durchgeführt und Auswahlregeln abgeleitet.
Die Ergebnisse sollten auch für Strukturanaloge des Wasserstoffperoxyds anwendbar sein.
Zur Temperaturabhängigkeit der Felddissoziation von Molekülionen
Authors: Knöppel H. , Beckey H. D. 
Published: March 2015

The temperature dependence of field dissociation of organic molecular ions as described in this paper can be interpreted qualitatively by means of simple models.
Very fast decomposition processes, occurring about 10-12 sec after field ionization, are not only due to the lowering of the dissociation energy by the field, but also due to fluctuation of vibrational energy, especially at higher temperatures.
The fragment ion insensities are increased by formation of adsorbed layers on the tip anode at low temperatures, especially with substances having high dipole moments.
In the case of molecules containing a polar group and an alkyl chain, only the former is ordered preferrentially, with the dipole moment parallel to the field lines, whereas the latter is relatively mobile in the electric field.
The relative fragment ion intensities depend on the orientation of the alkyl chain relatively to the polar group, however, this effect does not depend appreciably on temperature because of the mobility of the alkyl chain. The only exception from this rule was observed with pentanol. The pentanol molecules are adsorbed at the tip anode with the alkyl chains preferrentially parallel to each other. This leads to a preferred formation of C2H5
+ fragment ions. With increasing temperature, the adsorbed layer is removed and a statistical orientation of the alkyl chain becomes more important, thus reducing the relative C2H5
+ abundance.
Die kinetische Energie ionisierter Molekülfragmente
Authors: Fuchs R. 
Published: March 2015

It is well known that in the initial energy spectra of hydrocarbon fragment ions formed by electron impact, satellite ion groups occur which are believed to be mainly due to the fragmentation of doubly charged ions into two singly charged fragments. By using an electron energy of 150 eV a new type of satellite was observed in the initial energy spectra of C1Hk
+ and C2Hl+ fragment ions from hydrocarbons with three and more carbon atoms. The n-paraffins were investigated systematically up to n-decane. Because the initial energy of these satellites is nearly twice the initial energy of the already well known “first” satellites, it is suggested that these newly discovered “second” satellites are due to an analogous fragmentation process of the type
A+++→B+ + C++.
Therefore, a careful search was made for the corresponding doubly charged fragment ions of high kinetic energy. Well pronounced satellite groups of doubly charged fragment ions were, indeed, found. Their momentum approximately equals the momentum of the corresponding “second” satellites of singly charged fragments, which supports the suggested mechanism.
Zur Ultrarot-Dispersion zweiachsiger und einachsiger Kristalle I
Authors: Merten L. 
Published: March 2015

Die Kopplung der optischen Gitterschwingungen (unter Berücksichtigung ihrer Dämpfung) mit den elektromagnetischen Lichtwellen läßt sich für doppelbrechende kristallographisch zweiachsige und einachsige Kristalle ähnlich wie für kubische Kristalle vollständig im Rahmen einer phänomenologischen Theorie beschreiben. Es ergibt sich eine Dispersionsformel, die auf die äußere Form der FRESNELSchen Normalengleichung gebracht werden kann, in der die dielektrischen Konstanten durch dielektrische Resonanzglieder (LORENTZ-Terme) ersetzt sind. Aus der Dispersionsgleichung erhält man insbesondere die Richtungsabhängigkeit der optischen Konstanten (Brechungsindex n, Absorptionskoeffizient k) und damit der optischen Spektren im Reststrahlgebiet.
Für n→∞ (k=0) ergeben sich die reinen Gitterschwingungen. Ihre Frequenzen gehorchen gewissen Summations- und Produktregeln.
Experimentelle und theoretische Untersuchungen zum plastischen Verhalten kubisch-flächenzentrierter Vielkristalle
Authors: Schwink Ch. , Vorbrugg W. 
Published: March 2015

Für die Bereiche 1 und 2 der in früheren Untersuchungen 9-11 gewonnenen Einteilung der Verfestigungskurve kubisch-flächenzentrierter Vielkristalle, die bis zum Beginn dynamischer Erholungsvorgänge (Quergleitung) reichen, wird eine Versetzungstheorie entwickelt und experimentell geprüft. Sie führt die Spannungs-Dehnungskurve quantitativ auf den mittleren Laufweg der die Verfestigung verursachenden Versetzungen zurück. Unsere Einzelergebnisse sind:
1. Für Bereich 1 wird zur Berechnung des Versetzungslaufwegs eine geeignete Definition des mittleren Korndurchmessers gegeben und gezeigt, wie sich dessen Zahlenwert aus Schliffbildern ermitteln läßt.
2. Das Gleitlinienbild wird an Nickelproben für eine tiefe (85°K) und eine höhere (295°K) Verformungstemperatur elektronenmikroskopisch studiert, Gleitliniendichte und Mehrfachgleitung werden quantitativ erfaßt. Die mittlere Gleitlinienlänge als Funktion der Spannung σ erweist sich als eine charakteristische, doppelt gekrümmte Kurve.
3. Die Verfestigung in Bereich 1 läßt sich theoretisch beschreiben, wenn man für den verfestigungsbestimmenden Versetzungslaufweg den oben definierten mittleren Korndurchmesser wählt und außerdem berücksichtigt, daß dieser mit zunehmender Spannung σ langsam abnimmt.
4. In Bereich 2 wird die Verfestigung durch den infolge von Versetzungsreaktionen im Korninneren abnehmenden Versetzungslaufweg bestimmt. Er stimmt hier mit der mittleren Gleitlinienlänge überein. Die aus den Gleitlinienmessungen mit unserer Theorie gefolgerten Verfestigungsparameter stimmen mit den unmittelbar gemessenen sehr gut überein.
5. Physikalische Überlegungen und der Vergleich mit den Experimenten legen es nahe, daß der sogen, mittlere Orientierungsfaktor in Bereich 1 Werte um 2,7, in Bereich 2 dagegen Werte um 2.3. nahe dem Sachs sehen Wert, annimmt.
UR- und UV-spektroskopische Untersuchungen einiger Azomethine
Authors: Krauss Walther , Wagner Claus G. J. 
Published: March 2015

Die Lage und die integrale Intensität der UR-(C=N)-Valenzschwingung parasubstituierter Benzalaniline in verschiedenen Lösungsmitteln werden untersucht. Die verwendeten Lösungsmittel üben keinen signifikanten Einfluß auf beide Größen aus. Die HAMMETTSchen σ-Konstanten können Abschätzungen über Substituenteneffekte auf die Intensität und umgekehrt erlauben.
Bei Konjugation der (C=N) · zu einer (C=C)-Bindung tritt eine Bandenaufspaltung auf. Es wird versucht, dies durch eine symmetrtische und antisymmetrische Valenzschwingung des Gerüstes zu interpretieren.
Die UV-Spektren der Azomethine und einiger Komplexe werden vermessen, wobei als Intensitätsmaß die Oszillatorenstärke dient. Auf Grund der UR- und UV-Messungen wird der Versuch unternommen, die Bandendaten durch ein System zu deuten, bei dem der Kettenstickstoff als Begrenzung angenommen wird. Zum Vergleich werden entsprechende Aldehyde herangezogen. Der Annahme eines starken Herausdrehens des Anilinringes aus der Gerüstebene können wir uns nicht ohne weiteres anschließen.
Edelgasmessungen an Eisenmeteoriten
Authors: Schultz L. , Hintenberger H. 
Published: March 2015

The spallogenic isotopes of helium, neon, and argon have been measured in 36 iron meteorites using a statically operated double focusing mass spectrometer. The following relations were found between the concentration ratios of the cosmic ray produced isotopes 3He, 4He, 21Ne, and 38Ar:

3He/4He = (36.0 ± 0.9) 21Ne/4He+ (0.148 ± 0.015),

38Ar/21Ne= (9.4±0.8) x 10-3
4He/21Ne+ (2.06±0.04).
From the 38 Ar/21Ne ratio a parameter n was calculated for each sample which according to GEISS, OESCHGER und SCHWARZ is a number measuring the effective irradiation hardness. Relations between n, 3He/4He, 3He/21Ne, and 4He/21Ne have been studied.
A slight variation of the 36Ar/38Ar has been found which is correlated to the effective irradiation hardness. The spallation yield of 36Ar relative to the total isobaric yield does not depend on the effective irradiation hardness.
Die Hochfrequenz-Resonanz-Sonde
Authors: Peter Günter 
Published: March 2015

Dc and ac currents to a rf resonance probe were investigated experimentally in the frequency range from 1 to 100 Mc/s in a quiescent Cesium plasma. The measurements in the plasma are explained by calculations and measurements with a lumped-constant equivalent network (“plasma simulator”).
It is shown that the ac current to the probe is strongly influenced by the capacitance of the cable leading to the probe. A device to compensate this cable-capacitance is developed and used. Furthermore, it is shown for the first time that the double (or devided) main resonance maximum, occurring frequently with dc and ac currents to the resonance probe, is generally due to the influence of a second reference electrode.
A simple and direct (“focus”) method for very precise plasma density determination (from the intersection point of the rf-current-vs.-frequency curves with probe voltage as parameter) is developed and compared with ac transmission current and LANGMUIR probe measurements at plasma densities between 2 × 106 and 3 × 107 cm–3. Agreement is obtained between these three experimental methods within their margins of error. The comparison leads to a better understanding of the measured LANGMUIR characteristic and of the Cs-plasma of the “Alma I” device.
γ-Radiolyse von flüssigem Kohlenoxid bei —196°C
Authors: Buschmann H. W. , Groth W. 
Published: March 2015

The radiation chemistry of liquid carbon monoxide at —196°C and mixtures of CO with various gases has been investigated. In the γ-radiolysis of pure CO CO2 is formed with G(CO2) =0.18. The addition of CH4, C2H4, O2, and NO leads to the formation of C3O2 which is not observed in the γ-radiolysis of pure CO.
In the case of CO—CH4 mixtures the following reacting products were identified: C2H6, C2H2, H2CO, H2C2O (Ketene), CO2 and C3O2. Results of experiments with CO —CH4
—13CH4 and CO—CH4—CD4 mixtures and measurements of the dependence of G(CO2), G(C3O2), G(C2H2) and G (C2H6) on the concentration of CH4 have shown that ethane is formed by energy transfer from CO to CH4 or by reaction of CH4 with excited CO and that C3O2 and C2H2 are formed by reaction of free carbon atoms which are formed in the presence of methane.
Zur Theorie der Supraleitung in planparallelen Schichten geringer Dicke
Authors: Raufuss Henning 
Published: March 2015

The GORKOV equations are solved for ideal planar films of superconductors. For the purpose of comparison, two different formulations of the self-consistency condition are used; the first is characterised by a cut-off factor in the energy integral, the second by the termination of the ω summation at the same cut-off value. Certain values of the film thickness (those corresponding to resonance intervalls in the sense of THOMPSON and BLATT) are excluded, but they are not decisive to this treatment. By this means, a fairly accurate check of the error in the approximation is made possible. This allows a quantitative comparison of the critical temperatures and of the two forms of the gap function calculated from the two formulations of the basic equations.
At absolute zero, both formulations of the theory become equivalent and lead to essentially identical relations between the gap function and film thickness. However, the critical temperature which results from the termination of the ω summation is noticeably higher than that calculated with the help of the energy cut-off.
Über den Einfluß der Adsorption auf die Feldionisierung organischer Substanzen
Authors: G. Metzinger H. , Beckey H. D. 
Published: March 2015

A new effect was observed: The overall field ion current generated by thin wires or tips changes with the average work function of the metal if different organic substances are adsorbed.
The shift of the tunneling probability versus voltage curve with change of work function and of ionization potential for molecules such as heptane, and heptene is calculated.
This is compared with the shift of the experimental current-voltage curves with change of work function and ionization potential when supplying different organic compounds into the field ionization chamber and after addition of small amounts of another organic substance to the substance under discussion.
Physically adsorbed substances on platinum, like n-paraffins, are always shifting these curves to higher voltages. This corresponds to a lowering of the average work function. The shift is more pronounced with alcohols on platinum because of the large work function change due to the polar groups. The higher aliphatic alcohols — starting with pentanol — are forming two dimensional condensed phases as postulated by KEMBALL. This was proven by detection of stepwise increase of dimeric ions in the FI mass spectra of pentanol as compared with the lower alcohols. The hydrocarbon chains of the alcohol molecules are ordered perpendicular to the metal surface in these phases.
Benzene, ethylene and acetylene additives are shifting the FI-curves of paraffins to lower voltages, thus indicating a chemisorption process of these unsaturated compounds increasing the average work function of the platinum surface.
Investigation of a Caesium Plasma Diode Using an Electron Beam Probing Technique 1, 2
Authors: Ott Werner 
Published: March 2015

The plasma in a plane caesium diode with a hot emitter and a cold collector was investigated experimentally with a ribbon-shaped electron beam. The ribbon beam is projected through the diode at an angle of 45 degrees to its axis and allowed to strike a fluorescent screen. Variations in the axial electric field of the diode cause the ribbon beam to be distorted. The image of the distorted beam as seen on the fluorescent screen then constitutes a plot of the axial electric field along the axis of the diode.
The field plots so obtained are compared with a theory in which the collisions of the charge carriers are neglected. By means of this comparison it is possible to evaluate the neutralization parameter, the plasma density, and an average drift energy of the charge carriers.
The results show that the theory correctly describes the different modes of the potential distribution and especially the transitions between modes of operation as long as the diode is free of oscillations.
The stability of the different possible static potential distributions was also investigated. It was found experimentally that the system is unstable if the electron emission is less than the ion emission and the collector potential is positive.
Isometry Groups with Surface-Orthogonal Trajectories
Authors: Schmidt Bernd 
Published: March 2015

It is shown that the trajectories of an isometry group admit orthogonal surfaces if the sub-group of stability leaves no vector in the tangent space of the trajectories fixed. A necessary and sufficient condition is given that the trajectories of an Abelian group admit orthogonal surfaces.
In spacetimes which admit an Abelian G2 of isometries, the trajectories admit orthogonal 2-surfaces if a timelike congruence exists with the following properties: the curves lie in the trajectories and are invariant under G2; ωα and üα are linearly independent and orthogonal to the trajectories.
Mikrowellenspektrum, Struktur und Dipolmoment von Trichiorsilan und Methyltrichlorsilan
Authors: Mitzlaff M. , Holm R. , Hartmann H. 
Published: March 2015

The rotational spectrum of several isotopic species of HSiCl3 and CH3SiCl3 was studied in the region from 8 to 40 Gc. From the derived rotational constants the following structural parameters were obtained using KRAITCHMAN'S equations:
dSi-H= (1.4655±0.0002) A, dSi-Cl= (2.0118±0.0009) A, ∢ Cl—Si—Cl= (110,60±0.25)°.
Furthermore the constants for centrifugal distortion DJ= (1.2 ± 0.4) kc for HSiCl3 and DJ= (0.19 ± 0.04) kc for CH3SiCl3, for the quadrupole coupling e Q Vzz= + 12.8 Mc and the dipole moment μ= (0.86 ± 0.01) D for HSiCl3 and μ= (1.91 ± 0.01) D for CH3SiCl3 were determined. The interaction of the overall-rotation with the internal rotation is discussed for CH3SiCl3, and the hindering barrier is estimated to be less than 200 cm-1.
Die Thermokraft von kubisch stabilisiertem Zirkonoxid zwischen Sauerstoffelektroden
Authors: Fischer W. 
Published: March 2015

The thermoelectric power Δφ/ΔT [mV/grad] of cells of the type O2 | T stabilized zirconia | T + ΔT O2 has been determined as a function of oxygen partial pressure p [Torr] in the temperature range 960°K ≦ T ≦ 1310°K. The experimental results can be described by the equations
-Δφ/ΔT=0,492+0,0220 ln(159/p) for (ZrO2)0,88(CaO)0,12 and
-Δφ/ΔT=0,460+0,0219 ln (159/p) for (ZrO2)0,91(Y2O3)0,09.
The change of Δφ/ΔT with oxygen partial pressure corresponds to the change of partial molar entropy of O2.
The heats of transfer of oxygen ions are estimated from experimental results and thermodynamic data. From the negative sign of the heat of transfer it is concluded, that oxygen ions migrate by a vacancy mechanism, which has been established also by experiments of other authors.