bluuebunny/crossref_metadata_2025 huggingface dataset:
Die Aktivitätskoeffizienten des Hg im Indiumamalgam beim Übergang von der festen zur flüssigen Phase / The activity coefficients of hg in in-amalgams at the solid-liquid phase transition
Authors: Franck Günter
Published: February 2015

By 2537 Å resonance absorption the temperature dependency of mercury partial pressure of dif­ferent In-amalgams is measured. - The Hg-concentrations of the investigated amalgams are 1.9 - 20 atomic per cent. The temperature interval is 30 -160 °C. In the solid + liquid two-phase region the activity coefficient of mercury is strongly diminuted with growing temperature. For tem­peratures higher than 130 °C the Hg-vapour pressure in the two-phase region falls with growing temperature.

With the help of a generalized Clausius-Clapeyron formula for a three phase system with two components the mercury vapour pressure in the liquid + solid two-phase region is calculated. There is a good agreement with our experimental results
Zur Erweiterung der Poulet-Loudon-Näherung in der Theorie der optischen Gitterschwingungen
Authors: Merten L. , Lamprecht G.
Published: February 2015

In einachsigen Kristallen sind die Frequenzen der sog. außerordentlichen optischen Gitterschwingungen richtungsabhängig (Richtungsdispersion). Diese Richtungsabhängigkeit wurde in der Literatur bisher fast ausnahmslos durch die Poulet-Loudon-Näherung beschrieben. Im folgenden werden zwei erweiterte Näherungslösungen angegeben. Da inzwischen auch die exakten Lösungen (im Rahmen der harmonischen Näherung) bekannt sind, läßt sich die Genauigkeit dieser beiden Näherungen wie auch der Poulet-Loudon-Näherung jetzt gut beurteilen.

Als Beispiele werden je zwei Schwingungszweige starker Richtungsdispersion von a-Quarz und dem tetragonalem BaTiO3 im einzelnen diskutiert.
Die Molekülstruktur des Chlor-Isocyanats ClNCO
Authors: Oberhammer Heinz
Published: February 2015

Die Molekülstruktur des Chlor-Isocyanats in der Gasphase wurde mit Hilfe der Elektronen­-beugung bestimmt. Dabei ergeben sich zwei mögliche Strukturmodelle, zwischen denen auf Grund der Elektronenbeugung alleine nicht unterschieden werden kann. Im Modell 1 ist die NCO-Gruppe linear, die N-C-und C-O-Bindungslängen weichen stark von den für ähnliche Moleküle bestimmten "Werten ab. Im Modell 2 ist die NCO-Gruppe um einen Winkel von ca. 10° geknickt, die N-C-und C-O-Bindungslängen stimmen gut mit den für ähnliche Moleküle bestimmten Werten überein. Außerdem ergibt sich für das Strukturmodell 2 ein um ca. 5° kleinerer ClNC-Winkel als für Modell 1. Unter Hinzunahme der aus mikrowellenspektroskopischen Messungen bekannten Rota­tionskonstanten kann eine Entscheidung zwischen den beiden Modellen zugunsten von Modell 2 getroffen werden. Audi semiempirische MO-Rechnungen sprechen für eine geknickte NCO-Gruppe in diesem Molekül.
Fluctuations in the Radial Distribution Function for Simple Liquids
Authors: Woodcock L. V.
Published: February 2015

Radial fluctuation functions which convey information about liquid microstructure are defined, determined from computer generated configurations, and discussed.
Studies on the PMR Spectra of Oxetanes
Authors: Jokisaari Jukka , Rahkamaa Erkki , Malo Heikki
Published: February 2015

The 60 MHz PMR spectra of 2 -(4-iodophenyl) oxetane, 2-(4-bromophenyl) oxetane, 2-(4-fluoro-phenyl) oxetane, and 2-(4-chlorophenyl) oxetane have been analysed for the oxetane ring protons and the phenyl protons. In the three first mentioned compounds the spectra show a coupling of 0.46 - 0.63 Hz between the benzyl proton and the phenyl protons in ortho position relative to the oxetane ring, the other proton-proton couplings between the oxetane and phenyl parts being zero in the error limits. In the oxetane part, the halogen substituent in the para position of the phenyl ring mainly affects the chemical shifts of the protons with a slight effect on the proton-proton couplings. The ortho and meta couplings of the phenyl protons increase and the para coupling decreases with growing electronegativity of the substituent, in the order iodine, bromine, fluorine. The phenyl protons in 2-(4-chlorophenyl) oxetane produce a sharp singlet, which shows that they are chemically equivalent. This proves that chlorine and the oxetane group affect the shieldings of the phenyl protons similarly, which is supported by comparing the chemical shift differences in 2-(4-halophenyl) oxetanes to the ones in para-dihalo-substituted benzenes.
Über die Konzentrationsdepolarisation der Photolumineszenz von Lösungen
Authors: Bojarski C. , Dudkiewicz J.
Published: February 2015

Die Emissionsanisotropie der Photolumineszenz von Rhodamin 6 G in Wasser-Glycerin wurde im Konzentrationsbereich 5 · 10-6 bis 8 · 10-2 M/1 gemessen. Bei Konzentrationen c > 10-2 M/l wurde ein Repolarisationseffekt festgestellt. Die Meßergebnisse wurden mit der Theorie der Konzen­ trationsdepolarisation, die die Löschung der Fluoreszenz durch nicht lumineszierende Dimere berücksichtigt, verglichen.
Streuung von Ionen. II. Regenbogeneffekt bei der elastischen Streuung von Protonen an Helium, Neon, Krypton, Xenon und von He+ an Helium
Authors: Weise H.-P. , Mittmann H.-U. , Ding A. , Henglein A.
Published: February 2015

Differential scattering cross sections of H+ on various noble gases and of He+ on He were measured at various energies between 3 eV-80 eV. The rainbow structure and the superimposed rapid oscillations were resolved. Differential cross sections were calculated in WKB approximation and compared with experimentally obtained cross sections. Agreement was obtained by using the modified Morse potential:

U = exp{2 G1 G2(1 -ρ)} -2 exp{G1 G2(1-ρ)} , G2 = 1 for ρ>1,

whit ρ=r/rm, and U=V/ε. G2 ≠ 1 for ρ ≧1,

The fitting procedure discussed in part I was applied in order to obtain the parameters ε,rm, G1 and G2. Calculations with the modified Lennard-Jones potential described in part I gave the same values for ε and rm .

With exception of the system H+ -Xe, a single set of parameters could describe the rainbow structure and the fine structure at all ion energies. The values for ε and rm agree fairly well with ab-initio calculations. The reduced potentials have about the same shape, G1 being between 2.7 and 2.2, G2 being between 0.8 and 0.9.

In the case of H+ -Xe, ε increases significantly with decreasing proton energy, while G1 and G2 have only slightly to be changed. The potential well is narrower than for the other systems mentioned above. These effects are attributed to the crossing of the potential curves of the systems H+ -Xe and H-Xe+ .
Zum Kornwachstum beim reinen und dotierten polykristallinen Selen / Grain Growth of Pure and Doped Poly crystalline Selenium
Authors: Weyrich C.
Published: February 2015

Grain Growth of Pure and Doped Poly crystalline Selenium Samples of vitreous high-purity selenium as well as vitreous chlorine-and thallium-doped selenium have been brought into the polycrystalline form by annealing. The dependence of grain size on annealing time tu was measured. In high-purity selenium and in chlorine-doped selenium the mean grain diameter increases essentially ~ tu
1/2 , in thallium-doped selenium ~ tu
1/2 , as is expected from the laws of grain growth. The proportionality between electrical conductivity and specific grain surface reported by other authors could not be verified.
Diffusion Processes in TlCl
Authors: Friauf Robert J.
Published: February 2015

Pure single crystals have been used for measurements of ionic conductivity (160° -425 °C ) , CI diffusion (275° - 415 °C ) , and Tl diffusion (290° - 400 °C ) . Conductivity measurements were made with a capacitance bridge at 1 to 10 kHz, and diffusion coefficients were obtained with radioactive tracers and the sectioning technique. It is found that D*(Cl) is 10 to 40 times larger than D* (Tl) . An empirical fit gives

D*(CI)=0.031 exp [ - (0.771 ± 0.010) /k T] ,

D*(Tl)=0.62 e x p [- (1.101 ± 0 . 0 2 0 ) /k T]

with D in cm2/s and the energy in eV. The conductivity has an activation energy of 0.76 eV for 230°-330 ° C , increasing to 0.87 eV for 375° - 425 ° C . For several reasons the conductivity is believed to be entirely ionic. The Nernst-Einstein relation is generally well obeyed, but there is a significant excess diffusion of 10 t o 15%.

The results show that the defect structure consists primarily of Schottky defects with highly mobile anion vacancies. The excess diffusion can be accounted for by the presence of up to 20% of either vacancy pairs or next nearest neighbor jumps into single vacancies; there is no clear preference for either mode. With a Schottky formation energy of 1.36 + 0.03 eV from other work, the mobility energies are 0.104 ± 0.005 eV for CI for either model, and 0.56 ± 0.04 or 0.44 ± 0.02 eV for Tl, respectively. Comparisons are made to observations of conductivity and diffusion by other workers near r o om temperature and in the melt.
Untersuchungen zum Gültigkeitsbereich der zweiten Näherung der Betheschen Theorie der Elektronenbeugung
Authors: Herzberg B.
Published: February 2015

The validity of the second BETHE approximation 1 (dynamical 2-beam theory using Bethe's potential with weak-beam corrections) was tested for various situations of systematic and accidental interactions. For this test the structure potential V002 of MgO was measured from the fine structure of the diffraction spot which one observes in a single crystal wedge experiment. In the Bethe potentials 119 weak reflections were taken into account; the electron accelerating voltage was 56 - 6 7 keV. Except in the neighbourhood of low-indexed zone axes, e.g. [110] , the second Bethe approximation allowed to determine the structure potential V002 to be 6.90 V within an accuracy of about 2%. This was in good agreement with the result of GOODMAN and LEHMPFUHL
2
Functional Quantum Theory of Free Relativistic Scalar Fields
Authors: Bauhoff W.
Published: February 2015

Dynamics of quantum field theory can be formulated by functional equations. Starting with the Schwinger functionals of the free scalar field, functional equations and corresponding many particle functionals are derived. To establish a complete functional quantum theory, a scalar product in functional space has to be defined as an isometric mapping of physical Hilbert space into the functional space.
Optisches Pumpen an Mangan
Authors: Assfalg A. , Fricke J. , Haas J. , Tilgner R. , Lüscher E.
Published: February 2015

The 6 S5/2 ground state of Mn 55 was polarized by spin exchange collisions with an optically pumped Cs-vapour. The rf induced transitions between Zeeman subleves of Mn were detected as a change in the Cs pumping light transmission. To estimate the effectiveness of direct optical pumping or of detection with resonance light the absorption probabilities for circlarly polarized light are given as functions of 〈Sz〉.
Calibration of a Slotted Disk Velocity Selector Using Supersonic Molecular Beams
Authors: Cantini P. , Dondi M. G. , Torello F.
Published: February 2015

A new calibration method for slotted disk velocity selectors is presented and is compared with other calibration procedures.

It is based on the measurement of the velocity distribution of a supersonic molecular beam produced by a room temperature source.

The error due to the assumed theoretical distribution and to experimental procedure is discussed. It is shown that the velocity scale is known to within 0.8%.
Binary Systems Containing Hydrocarbons IV. Miscibility Gaps in 18 Nitromethane + 1-, 2-, 3-and 4-alkenes
Authors: Ferloni Paolo , Geangu-Moisin Angela , Franzosini Paolo , Rolla Mario
Published: February 2015

Liquid-liquid equilibria in binary systems of nitromethane with 1-(C8-C9)-, trans-2-(C5-C9)-, trans-3-(C6-C9)-, trans-4-(C8-C9)-, 3-methyl-1-(C5)-, 2-methyl-2-(C5-C7)- and cis-2-(C6)-alkenes were investigated. Some regularities obeyed by the critical temperatures and compositions, as well as the possibility of foreseeing (on empirical basis) the two liquids region boundaries are discussed.
Optische Kern-Spin-Polarisation in Molekül-Kristallen
Authors: Schuch H. , Stehlik D. , Hausser K. H.
Published: February 2015

This paper deals with the polarisation of nuclei in molecular crystals due to their hyperfine interaction with optically excited triplet states and excitons, a phenomenon which is termed optical nuclear polarisation (ONP).

A theory is presented which extends the mechanisms of dynamic nuclear polarisation (Overhauser effect) to the case of spin systems containing triplet states with S = 1 and nuclei with I = 1/2. In this mechanisms the optical electron polarisation (OEP) caused by symmetry selection rules for intersystem crossing to and from the magnetic triplet sublevels is assumed to be transferred to the nuclear magnetic substates by efficient hyperfine relaxation transitions.

The adiabatic fast passage is used to detect the nuclear polarisation. The advantages and conditions of this technique as compared to other nmr techniques are discussed.

ONP results at room temperature are given as a function of the external field H0, its orientation with respect to the crystalline axes, the intensity and frequency of the exciting light and the concentration and types of guest molecules. In phenazine crystals relative polarisation factors up to 50 are found with marked orientation dependencies even in fields as high as 11 kG. These results can be interpreted in principle in terms of the presented theory. However, in low fields (0 - 200 G) where ONP caused by hyperfine relaxation vanishes, large polarisations are found in doped crystals of fluorene and anthracene. The maximum absolute polarisation in fluorene doped with acridine is 3.6 · 10-4 at H0 = 80 G corresponding to a relative polarisation factor of ~ 104. The effect of doping is discussed.. Reference is made to a possible ONP mechanism 3 which is able to produce large nuclear polarisations at low fields
Untersuchungen zur Diffusion von Tritium in Übergangsmetallen
Authors: Sicking G. , Buchold H.
Published: February 2015

Investigations of the diffusion of tritium in transition metals have been carried out by using "time-lag" methods.

The β-radiation, originating from tritium decay within a thin layer near the external surface of the metal, was taken as the signal to follow the change of tritium concentration with time in this layer. No passage of tritium atoms through the phase boundary is necessary for this method; the influence of energy barriers, which might retard this passage, can therefore not interfere.

Measurements with palladium at temperatures between 16.5 °C and 50 °C and vanishing hydrogen content in the Pd yielded:

D0
T = (10.5 ± 3.0) • 10-3 • exp{- (6350 ± 300)/RT} cm2 s-1, (R T in cal/mole).

The observed isotope effects in the diffusion of H, D and T in palladium are discussed. At 25 °C diffusion coefficients of tritium in Pd/Ag-alloys of different compositions (0 - 70 atom-% Ag) were determined. They first decrease slowly with rising silver content up to 30% and then drop sharply to very low values at higher Ag-contents.

Measurements with tantalum at 25 °C yielded: DT = (0.50 ±0.25) • 10-6 cm2 s-1
On Schwarzschild's Stability Criterion
Authors: Lortz Dietrich
Published: February 2015

The stability of a gas in an external gravitational field Φ is investigated for arbitrary initial conditions. It is shown that Schwarzschild's entropy criterion ds/dΦ > 0 is both necessary and sufficient for the spatial quadratic mean of a linear disturbance to be bounded in time. The variational principle usually applied is not always sufficient for stability
Driftgeschwindigkeit und Beweglichkeit von Elektronen in Silicium bei 4,2 °K in Abhängigkeit vom elektrischen Feld / Driftvelocity and Mobility of Electrons in Silicon at 4.2 °K in Dependence of Electric Field
Authors: Deimel P.
Published: February 2015

The pulse rise times of an n-type silicon surface barrier detector were measured at 4.2 °K. At this temperature the detector was fully depleted even at very low bias and the measured pulse rise times gave direct information about the driftvelocity and the mobility. Instead of E-0.5, an E-0.8 dependence of the mobility at moderate electric fields was found. At high electric fields agreement exists with theory.
Gleichzeitige Messung von Hyperfeinstruktur, Stark-Effekt und Zeeman-Effekt des 87RbF mit einer Molekülstrahl -Resonanzapparatur / Simultaneous Measurement of Hyperfine Structure, Stark-Effect and Zeeman-Effect of 87RbF with a Molecular Beam Resonance Apparatus
Authors: Heitbaum J. , Schönwasser R.
Published: February 2015

The electric and magnetic properties of the molecule 87RbF in the rotational state J = 1 and the vibrational states v = 0, 1 were studied by a molecular beam resonance apparatus. The rotational state (J, mJ) was separated by an electric quadrupole lense as A-field and focused to the detector by a similar lense as B-field. The vibrational states could be resolved by their different Stark-effect-energies. In the transition region homogeneous electric and magnetic fields were superimposed. The observed (ΔmJ = ±1) transitions were induced electrically.

The measured spectra permitted the calculation of the following molecular constants: the electric dipole moment µel, the rotational magnetic dipole moment µJ/J, the scalar and tensor nuclear dipole-dipole-interaction dS and dT the nuclear spin-rotational interactions cRb and cF , the nuclear quadrupole interaction e q QRb the nuclear magnetic moment µ(1 - σs)Rb, the anisotropy of the diamagnetic susceptibility (ξ⊥- ξ∥) the anisotropy of the diamagnetic shielding of the external field by the electrons at the position of the nuclei (σ⊥-σ∥]).

The results were (J = 1, v = 0) :
Electron-Spin-Resonance of Eu2+ in Ca-and Yb-Metal
Authors: Schmidt H.
Published: February 2015

ESR measurements of Eu2+ (concentration ≦ 1%) in Ca- and Yb-metal in the temperature range from 5 °K to 30 °K at microwave frequencies of 35 GHz and 9.6 GHz are reported. In Ca a “bottleneck” was observed, whereas in Y b the resonance condition is determined by the "dynamical effect". By adding Ca-impurities to Yb the influence of the dynamical effect was lowered. The measurements can be adequately described by the formulas of Hasegawa, yielding an exchange integral for Eu2+ in Yb of J =+ 0.09 eV.
Pressure Broadening of Multiply Ionized Carbon Lines
Authors: Bogen P.
Published: February 2015

In a helium plasma with carbon impurity, the pressure broadened profiles of seven C III and two C IV lines have been measured. The plasma which was produced by magnetic compression had typically an electron density of 4 · 1017 cm-3, a temperature of 60 000°K, and a life time of about 0.1 μs. Electron densities have been deduced from the width of the He II λ= 3203 Å line. If ΔEii′ ≪ kT {ΔEii′ = energy difference between perturbed level i and perturbing level i′) the classical straight line non-adiabatic theory gives values being in good agreement (error < ± 25%) with measured widths for six lines. For two lines the deviations are larger. For the C IV resonance line (λ = 1550 Å) with ΔEii′ >k T, the profile can be explained by hyperbolic path, adiabatic collision theory. The semiempirical Gaunt-factor approximation gives a rough estimate of the width, but normally the values obtained are too low.
Schubnikow—de Haas-Effekt und Bandstruktur-Untersuchungen an Wismut—Antimon-Legierungen / Shubnikov-de Haas-Effect and Band Structure Investigations in Bismuth — Antimony Alloys
Authors: Schneider Detlef
Published: February 2015

Magnetoresistance, Hall effect, and susceptibility have been investigated in Te-doped Bi95Sb3 single crystals. The experimental results establish the occurrence of both longitudinal and transversal SdH-oscillations over a wide temperature range up to T = 77 °K. Dingle-temperatures, cyclotron masses, spin splitting, and the effective mass tensor of the electrons at the Fermi level and the band edge were calculated from the temperature and angular dependence of the SdH-oscillations. The results are discussed in respect of various models of the electron band structure. The behaviour of the small Fermi surface cross sections is in agreement with the ENP-model, however in the long direction of the quasi ellipsoids a slight variation of the effective mass must be assumed.
Berücksichtigung der Gitterperiodizität bei der Elektron-Plasmon-Streuung. II / Consideration of Lattice Periodicity at the Electron Plasmon Scattering. II.
Authors: Münchmeyer W
Published: February 2015

It is shown that the existence of the additional inelastic scattering processes described in part 1 is caused by lattice periodicity and depends upon the form of the Fermi surface. An estimate of that part of the anomalous absorption resulting from this scattering process is given.
Zur charakteristischen Streuung langsamer Elektronen an Ni(111) und ihrer Temperaturabhängigkeit im Bereich des ferromagnetischen Curie-Punktes / Characteristic Scattering of Low Energy Electrons from Ni(111) and its Temperature Dependence in a Range Containing the Ferromagnetic Curie-point
Authors: Heimann B , Hölzl J
Published: February 2015

Characteristic energy losses (CEL) of slow electrons scattered from a Ni ( 111 ) surface were studied using primary energies Ep in the range 150 ≦ Ep 600 ≦ eV. Special attention was given to the cleanliness of the crystal surface. In particular, CEL were studied as function of temperature T in the range containing the Curie-temperature Tc . The volume loss energy ħωp shows an anomalous variation in the region of Tc superimposed on a linear decrease from T = 100 °C to T = 700 °C, while the surface loss energy ħωs remains constant in this range within the error of measurement ( ±0.1eV); ħωs and ħωs could be identified in connection with optical measurements of VEHSE and ARAKAWA14. A possible explanation of the variation of loss energy ħωp is given in terms of electronic band structure changes.
Elektronenbeugung an Vizinalflächen und an Kugelflächen von Einkristallen / Electron Diffraction of Vicinals and of Spherically Shaped Crystal Surfaces
Authors: Melle H , Menzel E
Published: February 2015

The reciprocal lattice of a periodic terrace-ledge surface is calculated by Fourier transformation. This formalism is applied to spherical crystals. In that case the reciprocal lattice consists of bundles of finite streaks; their vertices are situated on the reciprocal lattice points of the bulk crystal. That confirms a model formerly used to discuss LEED experiments with spherical crystals. The calculation is generalized to describe terraces composed of several monolayers.
Determination of a Static Hyperfine Interaction Following Recoil into Vacuum
Authors: Dar Y. , Engelstein P. , Gerber J. , Levy R. , Vivien J.P.
Published: February 2015

By means of using a plunger time-differential technique, spin precessions from a static free hyperfine interaction have been observed for low-energy 152Sm nuclei recoiling into vacuum.
Bewegungen der CH3 -Gruppen in Methyl-Naphthalin-Kristallen
Authors: Schütz J.U. , Noack F.
Published: February 2015

The temperature and frequency dependencies of the proton spin relaxation in methyl naph-thalenes discussed in a preceding paper can be described quantitatively by assuming a rotatory jump model of the methyl groups in connection with a Cole-Davidson distribution of jumping times. The observed activation barriers are derived in good approximation from a Buckingham potential.
Massenspektrometrie am negativen Glimmlicht einer zylindrischen Hohlkathode / Mass Spectrometric Studies of the Negative Glow of a Cylindrical Hollow Cathode Discharge
Authors: Pähl M. , Lindinger W. , Howorka F.
Published: February 2015

Positive ions were extracted from the negative glow (NG) of a cylindrical hollow cathode discharge (h.c.d.) through a plane sampling probe (diameter 1 mm, orifice dia. 50 [xm, Molyb-denum) and analyzed in a 60° mass spectrometer. The discharge was operated in pure Argon with an admixture of about 0.1% of H20. The principal ions were Ar+, Ar++,r2
+, ArH+ , H20+ and H3O+ . The individual ion currents were measured as functions of the probe potential U\>, at dif-ferent discharge currents (2 - 7 mA) and of the gas pressure (0,05 - 0,5 torr).

The reaction scheme for the production and conversion of these ions in the NG could be established. In general, the ions were extracted from the axis of the h.c.d. When the sampling probe was mounted excentrically (3 mm out of the axis), the ratio of secondary to primary ions was higher in the axis.

At probe potentials above +15 v referred to anode no ions from the NG reached the probe, but electrons were accelerated so that ionization of the neutral gas could arise in and behind the orifice. The Ar++ current as a function of Ub together with other results suggested the presence of very fast electrons (energy > 100 v) in the sampling orifice. They could be identified as electrons from the cathode fall region which were scattered into the orifice.

Studies of the ion currents from Ar-H2 mixture proved the sampling probe suitable as an electron impact ion source.
Ein Röntgen-Diffraktometer mit vertikaler Achse zur Strukturuntersuchung von flüssigem Natrium
Authors: Schierbrock R. B. , Langner G , Fritsch G , Lüscher E
Published: February 2015

Es wird eine automatische Röntgen-Streuapparatur zur Untersuchung von flüssigem Natrium be-schrieben. Zum Unterschied früherer Messungen an freien Natriumoberflächen wurde eine senkrecht-stehende Meßkammer mit Beryllium als Röntgen-Fenstermaterial verwendet.

Messungen am flüssigen Natrium wurden bei einer Temperatur von 114,3 °C durchgeführt und aus den Streudaten die statische Strukturfunktion und die atomare Dichteverteilung ermittelt. Die Ergebnisse werden mit den bisher bekannten Messungen am flüssigen Natrium verglichen
Elektrisches dipolmoment von InCl / Electric dipole moment of incl
Authors: Tiemann E. , Hoeft J. , Törring T.
Published: February 2015

Stark-effect measurements on the rotational transition J = 1 → 2 of InCl are described. The vapour pressure in the absorption cell was chosen so that the quadrupole hyperfine structure due to the Cl-nucleus could not be resolved. Thus we neglect this coupling in the calculation of the Stark-effect. The derived electric dipole moment in the ground vibrational state is:

115In35Cl : | μ0= (3.79 ± 0.10) D.

The electric dipole moment of 205Tl19F : | μ0 | = 4.2282 (8) D was used for the calibration of the electric field
Isotherme galvanomagnetische Transport- koeffizienten bei Streuung quasifreier Ladungsträger an Dipolen / Isothermic galvanomagnetic transport coefficients of quasi-free carriers scattered, at dipole centres
Authors: Rachmann J
Published: February 2015

It has been observed that in several semiconductors an in-crease in total impurity concentration leads to an increase in the low-temperature mobility due to pairing effects. The trans port coefficients rʜ, rQ' and rQ necessary for the analysis of the Hall effect and the magnetoresistance, in the event of di-pole scattering, are derived for the cases k a ≫ 3 and k a ≪ 3 (k = wave number of the quasi-free charge carrier, a = dipole length). For k a ≫ 3 the coefficients are dependent on tempe-rature, effective mass, and dipole length, whereas for k a ≪ 3 they are constant
Quantum Condensation, Thermodynamic Limit, and Dimensionality
Authors: Lüders Gerhart
Published: February 2015

The analysis presented recently for the interacting boson gas is repeated for the interacting fermion gas. It is shown that quantum condensation does not occur in finite systems and even not if the thermodynamic limit is formed with respect to one or two space dimsnsions only.
Das Mikrowellenspektrum Der Fluor Wasserstoffassoziate Im X- Und K-Band / The Microwave Spectrum Of The Hydrofluoric Associate In The X And K Band
Authors: Reichert U. V. , Hartmann H.
Published: February 2015

Es wird das Mikrowellenspektrum von Fluorwasserstoffassoziaten im X-und K-Band bei -70 °C und 0,01 Torr gemessen und analysiert. Dazu wird ein erstelltes Frequenzprogramm für den asymmetrischen Kreisel verwendet, sowie ein Extrapolationsprogramm, das eine in der Literatur angegebene druck-und temperaturabhängige Verteilung der Fluorwasserstoffassoziate auf für Mikrowellenspektroskopie geeignete Drücke und Temperaturen umzurechnen erlaubt. Es zeigt sich, daß planare hexamere und heptamere Fluorwasserstoffassoziate vorliegen mit F-F-F-Winkeln von etwa 104° und H-F-Bindungslängen von 0,9997 Å bzw. 0,9640 Å. Die Längen der Wasserstoff brücken sind 1,4998 Å bzw. 1,6105 Å. Ein Vergleich der Bindungslängen zeigt, daß bei Anlagerung von H-F an (HF)6 eine Kontraktion der Fluorwasserstoffbindung um 3,5% und eine Dilatation der Wasserstoffbrückenbindung um 1% stattfindet. Dieses Ergebnis steht im Einklang mit der oben erwähnten Assoziatverteilung, die eine Minderung der Kettenstabilität beim Übergang von hexamerer zu heptamerer Kette erwarten läßt.
Calculations of Eigenvalues in Functional Nonlinear Spinor Theory
Authors: Dammeier K
Published: February 2015

A differential equation of third order for spinor potentials is proposed, that modifies the dynamics of the nonlinear spinor theory. We derive a symmetrical eigenvalue equation using functional integration techniques. This equation and a momentum symmetrized equation - a simplified form of the mass eigenvalue equation proposed by Stumpf - are applied to calculate mass eigenvalues. By a special combination of both methods it is possible to weaken the regulari-zation dipole in Heisenberg's theory and thereby produce better boson masses. Finally, the modified theory allows a self-consistent calculation of the fermion propagator
On the Functional Definition and Calculation of Global Observables in Nonlinear Spinor Field Quantum Theory
Authors: Stumpf H
Published: February 2015

Nonlinear spinor theory contains unobservable field operators which cannot be identified with free field operators. Therefore for the comparson with experiment a theory of observables for nonlinear spinor fields is required. This theory is developed for global observables by means of a map into functional space, and leads to a functional quantum theory of nonlinear spinor fields
Eigenfrequencies and Eigenvectors of Polaritons with Application to LiNbO3. II. Polaritons of Small Wave Vectors k (k ≦ 104 cm-1)
Authors: Merten L , Borstel G
Published: February 2015

In this second paper the region of strong dispersion of extraordinary polaritons (k ≈ 103 - 104 cm-1) and the limiting case k ￫ 0 is treated. The dependence on k of the eigenfrequencies ω, of the quasi-normal coordinates Qi, of the electric field E and of the electric polarization P is discussed in detail for four branches of LiNbO3 as examples. The behaviour of eigenfrequencies and eigen-vectors in the vicinity of the crossing points of the vibrational branches is of special interest. It is shown in the appendix that the coupled harmonic oscillator formalism due to Onstott and Lucovsky is equivalent to our theory in the special case k ￫ ∞, ε⊥
∞ = ε||
∞
Zur paramagnetischen Elektronenresonanz metallorganischer Sandwich-Verbindungen, Teil II / The Magnetic Resonance Properties of Some Sandwich Compounds, part II
Authors: Krieger Robert , Voitländer Jürgen
Published: February 2015

In part II the magnetic resonance properties of the lowest lying excited triplet state of ferrocene has been investigated theoretically. As in the case of the ground state of chromocene (part I) we studied the splitting of the orbitally degenerate triplet state by the combined action of spin-orbit coupling and low-symmetry perturbation. The results explain the fact that no ESR spectrum has been observed in the lowest lying triplet state of ferrocene until now. There is also given an estimation of the lifetime of this state. The g-values and parameters of hyperfinestructure of the orbitally degenerate doublet ground state of cobaltocene are calculated and compared with the experimental results. The wave functions used for the calculations were obtained by a self-consistent-charge extended Hückel method.
Electronic Structure of Octacyanides of Molybdenum IV and V According to the SCCC MO Method. The D2d Case
Authors: Gołębiewski A. , Nalewajski R.
Published: February 2015

The electronic structure of dodecahedral octacyanides of molybdenum IV and V is described in terms of SCCC molecular orbitals. Five MO's resemble d orbitals of the central atom. The splitting of appropriate levels is almost exactly the same as that following from the crystal field theory for G4/G2 ~ 0.7. According to the theory stable Mo(CN)8
4- is dodecahedral and stable MO(CN)8
3- is antiprismatic. In the dodecahedron the A-type ligands are bonded more strongly than the B-type ligands.
Das Emissionsspektrum der stillen elektrischen Entladung in Ammoniak-und Hydrazin-Dampf / The Emission Spectrum of the Silent Electric Discharge in the Vapours of Ammonia and Hydrazine
Authors: Weisbeck R. , Rühle D.
Published: February 2015

Below 5000 Å the silent electric discharge in ammonia essentially reveals the same emission spectrum as the glow discharge. Between 5000 and 8000 Å in discharges in NH3 as well as in N2H4 there appear besides the Schuster band and the Ha line especially 3 new diffuse peaks with maxima of intensity at about 5253, 6380 and 7560 Å. These emissions are caused presumably by a more than 2atomic molecule (NH3, N2H2, N2H3 or N2H4). The behaviour of the intensities of the Hα line and the Schuster band favours the hypothesis H + N2H3 → N2H4* → N2H4 + h v for the formation of the Schuster band already put forward some time ago.
Konzentrationsabhängigkeit der Thermodiffusion in D2 -H2 , HD-H2 und D2 —HD bei 85 °C / Dependence on Composition of Thermal Diffusion in D2 -H2 , HD-H2 and D2 -HD at 85 °C
Authors: Müller K.P. , Klemm A
Published: February 2015

Measurements of the thermal diffusion factor (α) result in the relations

D2 - H2 : α= (0.182-0.057 γ) ±0.003 ,

HD - H2: α= (0.116-0.036 γ) ±0.003 ,

D2-HD: α= (0.064-0.017 γ) ±0.002

with γ the molar fraction of the heavy molecule. Earlier measurements on tritium systems are corrected and discussed in view of these results.
The d2 and d8 Noncubic Ligand Field Spectrum. I. The Complete Theory of Quadrate, Trigonal, and Cylindrical Ligand Fields
Authors: Perumareddi Jayarama
Published: February 2015

The complete theory of Liehr and Ballhausen for d2 and d8 electronic configurations immersed in cubic fields has been extended to include noncubic ligand fields of quadrate, trigonal, and cylindrical symmetry. The complete set of symmetry adapted eigenvectors for the three symmetries have been derived in various coupling schemes in which the spin-orbit interaction, electron cor-relation, and ligand field in turn are varied from minor to dominant perturbations. The cor-responding energy matrices as a function of the parameters of the ligand field, electron correlation, and spin-orbit constant have been constructed in all the representations. Unitary transformations connecting different formalisms were obtained. The energy matrices have been solved for representative sets of parametric values and energy diagrams have been plotted in all the symmetries as well as in the square planar limit of the quadrate crystalline field. The secular determinants, the eigenfunctions, the energy diagrams, and the unitary transformations presented here are extremely useful in the study of the various aspects of spectroscopic, magnetic, and other properties of appropriate systems. The theory is applicable to quadrately distorted or substituted, trigonally distorted or substituted, octahedral and tetrahedral complexes and to compounds of cylindrical symmetry of d2 and d8 electronic configurations.
Determination of Gradient-Elastic Constants in Cubic Solids
Authors: Hackeloer H. J. , Kanert O.
Published: February 2015

The effect of static elastic stress on the NMR signal in LiCl35 , Rb85Cl35 , and Rb87Br is used to determine the gradient elastic constants relating the electric field gradient at the given nucleus to the elastic deformation. In contrast to previous experiments the quadrupole distortion produced by internal lattice distortion (point defects, dislocations etc.) is considered. Neglecting these distortions leads to an error in the determination of the gradient elastic constants by an order of magnitude.
Infrarotmessungen zur Ring-Ketten-Struktur des amorphen Selens
Authors: Gobrecht H. , Willers G. , Wobig D. , Zirre J.
Published: February 2015

The infra-red spectrum of red amorphous selenium has been studied in the region of 1 μm to 25 μm. The formation of Se8-ring molecules as well as polymeric chains Sen has been observed by investigating non-fundamental vibrations. Additional absorption bands at 7.85 μm (1274 cm-1), 8.95/9.35 μm (1117/1070 cm-1) and 12.35 μm (810 cm-1) are reported. They are assigned to multiphonon processes of the type E fundamental of Sen at 74.1 μm (135 cm-1).
Untersuchungen an CdS-Dünnschicht-Solarzellen / Investigations on CdS Thin Film Solar Cells
Authors: Küfe L. , Schneider G.
Published: February 2015

CdS thin film solar cells with a p-Cu2S - n-CdS-heterojunction were made by vacuum evaporation of CdS films on Mo substrates and dipping of these films into Cu+-ion solution. The influence of various annealing times and repeated dipping into Cu+-ion solution were investigated and discussed. Etching the CdS films with various etchants gave different results. In this way the solar cells yielded efficiencies up to 5.2%. The influence of interfaces of Ag and Zn between the Mo-substrat and the CdS film was studied.
Microwave Spectrum and Dipole Moment of Dimethylnitrosamine
Authors: Scappini F. , Guarnieri A. , Dreizler H. , Rademacher P.
Published: February 2015

The microwave spectrum of the (CH3)2NNO and (CH3)2
15N15NO species have been studied and the rotational constants evaluated. By comparison of the inertia defects of the two species it can be stated that the nuclear frame of the molecule is planar, which is in agreement with the reported electron diffraction results. The dipole moment of the (CH3)2
15 N15NO species has been determined. Further studies on the internal rotation of the two methyl tops are in progress together with the analysis of the spectra of other isotopically substitued species.
Zur Geometrie des Spinnen-Netzes
Authors: Peters Hans M.
Published: February 2015

Das Kreuzspinnen-Netz wird als Gegenstand einer biologischen Gestalt-Geometrie untersucht. In den verschiedenen Netzen und in den verschiedenen Regionen eines und desselben Netzes beobachtet man immer wieder andere Abstände der Klebfäden. Dieser Mannigfaltigkeit liegt jedoch eine ganz einfache rationale Ordnung zugrunde. Unter gewissen definierten geometrischen Grundbedingungen tendiert die Spinne nämlich dahin, die Abstände von der Peripherie des Netzes in Richtung auf das Zentrum konstant zu halten, unter anderen aber die Abstände so zu wählen, daß das Höhen-Breiten-Verhältnis der von je zwei benachbarten Klebfadenabschnitten und den zugehörigen Radialfadenabschnitten umgrenzten Flächenelemente (Segmente) konstant bleibt. Es wird ein geometrisches Verfahren angegeben, mit dem man diese Gesetzmäßigkeiten nachweisen kann.
Untersuchungen über die Befruchtungsstoffe der Regenbogenforell
Authors: Hartmann Max , Medem Fred Graf , Kuhn Richard , Bielig Hans-Joachim
Published: February 2015

Die Methoden zum biologischen Nachweis der Androgamone AI und AII sowie der Gynogamone GI und GII werden beschrieben. Als Farbstoffe der Eier von Salmo irideus wurden Astaxanthin, β-Carotin, Lutein und Lactoflavin aufgefunden und quantitativ bestimmt. Astaxanthin, C40H52O4 (Schmp. 216°), ist GI-wirksam. Es aktiviert die Spermatozoen der Regenbogenforelle, wirkt chemotaktisch auf sie und ist Antagonist des im Sperma vorkommenden AI. Aus den Eiern wurde ferner ein thermolabiles Proteid gewonnen, das aus einem globulinartigen Protein + Phosphatid besteht. Es agglutiniert die Spermatozoen bis zu einer Verdünnung von 1:5 000 000 000. Das die Wirkung des Agglutinins (GII) aufhebende AII des Spermas ist thermostabil.
Untersuchungen über den Wasserhaushalt der Pflanzen bei Stickstoffmangel
Authors: Gessner Fritz , Schumann-Petersen Maria
Published: February 2015

Stickstoffmangel erzeugt bei Tradescantia und Impatiens in Wasserkultur Verände- rungen in Richtung auf zunehmende Sukkulenz. Damit ist eine sehr erhebliche Ab- nahme der Transpiration verbunden, die darauf zurückzuführen ist, daß die Schließ- zellen weitgehend die Fähigkeit verloren haben, sich zu öffnen. Das Protoplasma der N-Mangelpflanzen zeigt eine größere Viskosität; damit steht jedenfalls die Tatsache im Zusammenhang, daß die Kälteresistenz bei N-Hunger gegenüber den normal ernähr- ten Pflanzen erheblich gesteigert ist.
Richtwirkung verschiedener Ionen auf anisotrope Kolloide
Authors: Thiele Heinrich , Lück Hans
Published: February 2015

Anisodiametrische Teilchen von Solen können durch oberflächenaktive Stoffe, durch Phasengrenzen oder durch Elektrolyte ausgerichtet werden.

Gemessene und berechnete Diffusionspotentiale der ionogenen Stoffe ergeben eine Beziehung zwischen der Aufladung des Gelrandes, bedingt durch die verschiedene Diffusionsgeschwindigkeit der Ionen, und dem Vorzeichen der Doppelbrechung.

Durch die positive oder negative Aufladung des Gelrandes werden die Teilchen im Sol durch Anziehung oder Abstoßung radial oder tangential ausgerichtet - und in dieser Lage fortschreitend fixiert.
Die cytologischen Grundlagen des Crossing-over bei Oenothera
Authors: Renner Otto
Published: February 2015

Eine bisher dem Aliel p (ungetupfter Stengel) zugeschriebene pollenletale Wirkung des albicans-Komplexes der Oe. biennis wird nach einer Analyse der Oe. (biennis × Hookeri) albihookeri auf das Gen an (androletal oder androkton) zurückgeführt, das einwärts von s (sulfurea, schwefelgelbe Blüte) und auswärts von p (ohne rotes Pigment) liegt. Doppeltes Crossing-over auf der Strecke p-s bzw. P-S ist nicht beobachtet. Die pollenaktive Kombination pS-hHookeri, jetzt als p An S zu verstehen, kommt nur in zwei Crossing-over-Schnitten zustande, die sich über zwei Generationen verteilen. Das Segment pS von flavens der Oe. suaveolens, das an Stelle von PS in velans von Oe. Lamarckiana eingegliedert werden kann, enthält keinen Pollenletalfaktor; so ist p-velans in pollenaktiver Form durch eine einzige Überkreuzung zu gewinnen.

Die Vermutung, daß das genetische Crossing-over bei Oenothera mit den interstitiellen, bis zur Anaphase erhalten bleibenden Chiasmen (den „Querarmen“) zusammenhängt, wird durch folgende Erfahrungen gestützt: 1. Formen, in denen das Crossingover häufig ist, haben viele Dauerchiasmen, und Formen mit seltenem Austausch sind arm an Chiasmen. 2. Oe. (Lamarckiana vetaurea × biennis) velutirubata, mit den Allelen vet - Vet (altgold gegen hochgelb) und r - R (weiß- gegen rotnervig) im einzigen freien Chromosomenpaar, zeigt in diesem Paar bis zu 5% Querarme und brachte 2% vet R-Crossovers. 3. So wie doppeltes Crossing-over nie beobachtet wurde, so sind Chiasmen immer einfach.

Ob die normalen Endbindungen der Diakinesechromosomen bei Oenothera immer terminalisierte Chiasmen darstellen, wird noch genauer zu prüfen sein.
Quantitative Analyse der Krebsentstehung
Authors: Druckrey Hermann , Küpfmüller Karl
Published: February 2015

In quantitativen Versuchen an 700 Ratten mit dem krebserregenden Farbstoff „Buttergelb" ergaben sich folgende Beziehungen zwischen der Dosis und der Wirkung:

1. Die Latenzzeit bis zum Auftreten der ersten Lebergeschwülste ist eine einfache Funktion der täglich gegebenen Dosis.

2. Zur Geschwulsterzeugung ist eine bestimmte Gesamtdosis „Buttergelb“ erforderlich, ohne Rücksicht darauf, über welche Zeit sie zwischen 34 Tagen und einem Jahr verteilt wird. Die Latenzzeit ist in diesem Bereich der Höhe der täglichen Dosis umgekehrt proportional.

3. Bei längerer Versuchsdauer, die sich über die ganze Lebenszeit der Ratten erstreckt, genügt sogar eine kleinere Gesamtdosis. Das deutet auf eine Zunahme der Krebs-Disposition im Alter hin.

4. Die Größe der zur Krebsauslösung notwendigen Gesamtdosis „Buttergelb“ kann als Maß für die Größe der vorhandenen Krebsdisposition dienen.

5. Die Streuung der Versuchsergebnisse ist mit nicht mehr als 10% auffällig gering. Daraus ergibt sich die Folgerung, daß zum Geschwulstwachstum eine Mindestzahl von erzeugten Krebszellen vorhanden sein muß.

6. Die Effekte auch der kleinsten Einzeldosen bleiben bei diesem Farbstoff über die ganze Lebenszeit der Ratten voll summationsfähig bestehen.

7. Da in dieser Zeit häufig Zellteilungen stattgefunden haben, müssen die gesetzten Effekte auf die Tochterzellen übertragen worden sein. Die Zellbestandteile, an denen die cancerogene Wirkung ansetzt, haben also die Fähigkeit zur Selbstproduktion, d. h. der Effekt ist erblich.

8. Nach den vorliegenden Ergebnissen bestehen zwischen krebsiger Entartung und genetischer „Mutation“ zumindest quantitative Unterschiede.

9. Der einfache reaktionskinetische Ansatz erweist sich für die Wirkung cancerogener Agenzien auf den fraglichen Zellbestandteil anwendbar. Er erklärt eine Reihe bisher unerklärbarer Phänomene zwanglos und führt zu weiteren klaren Problemstellungen.

10. Die „Treffertheorie“ wird auf den gleichen reaktionskinetischen Ansatz zurückgeführt.

11. Die krebserzeugende Wirkung unterliegt genau so bekannten physikalisch-chemischen Gesetzmäßigkeiten wie jede andere Wirkung auch.

12. Der Farbstoff „Buttergelb“ ist bei dauernder Zufuhr auch in kleinsten Dosen schädlich und deshalb als Lebensmittelfarbstoff abzulehnen.
Strahlung und Stoffwechsel, II. Mitteilung: Die Wirksamkeit der Ultraviolett- und Ultrarotstrahlung einschließlich des sichtbaren Lichtes
Authors: Giersberg Hermann , Lotz Robert G. A.
Published: February 2015

Bestrahlung mit UV und UR einschließlich sichtbaren Lichts bedingt bei weißen Mäusen und Hühnern eine Senkung im Gasstoffwechsel von durchschnittlich 25% und im Dauerversuch eine deutliche Herabsetzung des Grundstoffwechsels, während Lichtmangel bei weißen Mäusen den Stoffwechsel erhöht.

Sichtbares Licht, UV oder UR allein bewirken keinen Stoffwechselabfall.

Für die Stoffwechselerniedrigung nach Bestrahlung ist eine bestimmte Kombination von UV und UR notwendig.

Die Wirkung der Bestrahlung beruht mit großer Wahrscheinlichkeit auf einer Senkung des Tonus des Sympathicus und einer Verschiebung der vegetativen Regulationslage zur Vagotonie.

Eigenbestrahlungsversuche (G.) zeigten eine gleiche Senkung des durch Hyperthyreose erhöhten Grundstoffwechsels.
Über die Einwirkung von Tyrosinase auf Proteine
Authors: Kausche Gustav-Adolf , Hahn Friedrich
Published: February 2015

Durch kolorimetrische Tyrosin-Bestimmung wurde die Wirkung der Tyrosinase auf verschiedene Substrate verfolgt. In den untersuchten Proteinen: Eialbumin, Casein, Tabakmosaikvirus-Protein und Spaltprotein aus Tabakmosaikvirus ist das im Peptidverband enthaltene Tyrosin durch Tyrosinase nicht oxydierbar. Die fermentative Aktivität von Pepsin wird durch Tyrosinase-Einwirkung nicht spezifisch gehemmt.
Ein einfaches Verfahren zur Messung kleinster Jodkonzentrationen, Jod- und Natriumthiosulfatmengen in Lösungen
Authors: Ehmert Alfred
Published: February 2015

Es wird ein einfaches und sehr empfindliches Verfahren zur quantitativen Messung der Depolarisationsfähigkeit von Lösungen angegeben und seine Handhabung an Beispielen eines darauf aufgebauten Jodmeters erläutert, das einen der Konzentration proportionalen Ausschlag liefert. Es eignet sich u. a. auch besonders für die Verwendung als Coulombmeter für kleine Ladungsmengen. Weiter kann man damit geringe Konzentrationen von Jod oder Natriumthiosulfat mit rein elektrischen Mitteln, d. h. ohne Normallösungen sehr genau bestimmen. Die Meßgrenze liegt bei 1 ccm Lösung unter 1/1000 γ Jod.
Zum Wirkungsprinzip schwefelhaltiger tuberkulostatischer Chemotherapeutica
Authors: Liebermeister Kurt
Published: February 2015

Es wird nachgewiesen, daß die tuberkulostatisch wirksamen Chemotherapeutica Tb I bzw. Tb 6 und Badional Kupferkomplexbildner sind und daß diese Kupferverbindungen eine gleichartige Hemmwirkung ausüben wie die ursprünglichen Stoffe. Dimethyldithiocarbamat (MTC) ist Tb I und Badional im Kupferbindungsvermögen überlegen und damit — ebenso wie sein Kupfersalz — auch in den keimhemmenden Eigenschaften.

Die sich hieraus ergebenden Folgerungen werden kurz besprochen.