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  • 1
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    Call number: K 95.0066 ; K 95.0067
    In: Geologische Karte
    Pages: 1 Kt. + Erl.-H. (52 S.)
    Edition: unveränd. Nachdr., 1995
    Branch Library: GFZ Library
    Branch Library: GFZ Library
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  • 2
    Call number: K 95.0074 ; K 95.0075
    In: Geologische Karte
    Pages: 1 Kt. + Erl.-H. (125 S.)
    Edition: 2., neubearb. Aufl., unveränd. Nachdr., 1995
    Branch Library: GFZ Library
    Branch Library: GFZ Library
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  • 3
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    Call number: K 95.0056 ; K 95.0057
    In: Geologische Karte
    Pages: Kt. + Erl.-H. (108 S.)
    Edition: 2. Aufl.
    Branch Library: GFZ Library
    Branch Library: GFZ Library
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  • 4
    Call number: K 95.0058 ; K 95.0059
    In: Geologische Karte
    Pages: Kt. + Erl.-H. (122 S.)
    Edition: 2. Aufl.
    Branch Library: GFZ Library
    Branch Library: GFZ Library
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  • 5
    ISSN: 1612-1112
    Keywords: High performance gel permeation chromatography ; Liquid scintillation counter ; On-line detection ; Fructan oligomers
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary 1-F-Fructan/1-F-Fructan-Fructosyltransferase (FFT, EC 2.4.1.100) catalyses the transfer of a single fructose residue of an inulin-type fructan as donor to an acceptor. The donor must have a degree of polymerisation (DP) of at least 3 and the acceptor a DP of at least 2. High Performance Gel Permeation Chromatography (HPGPC) combined with an on-line Liquid Scintillation Counter was employed as an efficient and quick method for the separation and detection of the oligosaccharides produced by the catalytic action of FFT. Quantification of specific enzymatic activity and its selective detection was achieved by the use of radioactive substrates.
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  • 6
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Description / Table of Contents: Summary Orientation and theological fibre strength during spinning of monofilaments from the melted mass are investigated in dependency on the heat transmission coefficient. The analysis is based in free convection on six series of measurements published in the literature on PET and PA6, and forced convection in one range of measurements, kindly made available by the courtesy of Zimmer AG in Frankfurt/Main. In the fibre strength and spinning orientation, the molecular weight of the polymere reduces during fibre formation. In order to find the dynamic viscosity in the polymere jet the equation $$\eta _p = \bar M_n^a \cdot t_p^{ - b} $$ was introduced, which is based on the measured values of the dynamic viscosity depending on the molecular weight and the temperature of the polymere melted mass. Equations are given for calculation of the exponentsa andb.The equation for ∌ p, is extended to an average temperature $$\bar t_p $$ in the polymere jet. There thus results in respect of this an average viscosity of $$\bar \eta _p $$ . This is identical with the fibre tension a during fibre formation processes. The spinning orientation results directly proportionally as $$\bar \eta _p $$ or a respectively. Fibre diameter $$\bar d$$ , heat transmission coefficient $$\bar \alpha $$ , spinning pathx s , until the glass transformation temperature tG is reached in fibre and volume V of the polymere jet are calculated with equations published at an earlier date. A variable νω, which corresponds for each number the expression of specific weight · volume/throughput volume $$\dot m$$ of the monofilament and which is equated with the quotient from the average speed in the jet and fibre removal speed, characterizes the flow reaction during fibre formation and is used in the calculation of fibre strength and spinning orientation. PET resulted in $$\Delta n = k_2 \cdot f \cdot \bar \alpha ^3 $$ and PA6 in $$\Delta n = k_3 \cdot f \cdot \bar \alpha ^3 $$ .f corresponds with the theological fibre strength at the polymere jet,k 2 the valueq Me · In 10/g andk 3 the valueq Me · loge/g.q Me is the mechanical heat equivalent of a gram calory andg the gravitation constant. The fibre strength, which results from the measurement of the spinning orientation and calculation of the heat transmission coefficient, is given for all numbers in the measuring series 1 to 7 in the tables 5 to 11. Spinning orientation depending on the spinning normalityS corresponds with the relationk 4 ·f · S z . Numerical valuesk 4, and exponent z of each measuring series are summarized in table 12. Fibre strength and spinning orientation in dependency on the heat transmission coefficient are investigated in section 14. With PET there results the fibre strength $$f = \frac{{q^2 Me}}{g} \cdot \log e \cdot \frac{1}{{U_w }} \cdot \bar a^y $$ and spinning orientation $$\Delta n = \frac{{q^3 Me}}{{g^2 }} \cdot \frac{1}{{U_w }} \cdot \bar a^{3 + y.} $$ The exponent y is a function of the spinning normality. For the measuring series 1 to 4, which apply to free convection and PET, the data for calculation ofy is summarized as table 13. For forced convection with PET, in which the fibre is blown transverse to the running direction,y has the value 3. Thereafter applicable to forced convection $$f = \frac{{q^2 Me}}{g} \cdot \log e \cdot \frac{1}{{U_w }} \cdot \bar a^3 and\Delta n = \frac{{q^3 Me}}{{g^2 }} \cdot \frac{1}{{U_w }} \cdot \bar a^6 $$ with an average fluctuationɛs = ± 8.9% for the numbers 36 to 41. With PA6, measuring series 6 there resulted for the exponenty, in addition to the spinning normality, an influence exerted by the fibre removal speed. Equations are given for calculation of y for the measuring series 6 and 7. A reduction ofy signifies an increase in fibre strength with increasing fibre removal speed. With PA6 the equations $$f = \frac{{q^2 Me}}{g} \cdot \log e \cdot \frac{1}{{U_w }} \cdot \bar a^y and\Delta n = \frac{{q^3 Me}}{{g^2 }} \cdot \log ^2 e \cdot \frac{1}{{U_w }} \cdot \bar a^{3 + y} $$ are applicable. The average fluctuation of they value for all measuring values in every series of measurements in the calculation of fibre strength and spinning orientation with the equations given lies with PET between ± 5.3% and 14.7%, and with PA6 between ± 5.0% and 18.2% and the numerical value 3 +y between 5 and 6. The exponent y shows the tendency to drop with increasing molecular weight. A high spinning orientation during fibre formation results from lower molecular weight $$\bar M_n $$ , low value of the quotient νω arising from average speed $$\bar w_p $$ in the polymere jet and fibre removal speedω, high polymere temperaturet p at ejection from the nozzle, greater heat transmission coefficient $$\bar \alpha $$ , lower diameter of the capillary boreD and smaller spinning normalityS, which exists with lower throughput volume $$\dot m$$ of the elementary fibre and higher fibre removal speed ω.
    Notes: Zusammenfassung Orientierung und rheologische Fadenkraft beim Erspinneu monofiter Fäden aus der Schmelze werden abhängig von der Wärmeübergangszahl untersucht. Die Analyse beruht bei der freien Konvektion auf sechs Meßreihen, die in der Literatur für PET und PA6 veröffentlicht sind, und bei der erzwungenen Konvektion auf einer Meßreihe,, welche die Zimmer AG in Frankfurt/Main dankenswerterweise zur Verfügung gestellt hat. In die Fadenkraft und Spinnorientierung geht bei der Fadenbildung das Molekulargewicht des Polymers ein. Um die dynamische Viskosität im Polymerstrahl zu finden, wird die Gleichung $$\eta _p = \bar M_n^a \cdot t_p^{ - b} $$ eingeführt, die auf Meßwerten der dynamischen Viskosität abhängig vom Molekulargewicht und von der Temperatur der Polymerschmelze beruht. Zur Rechnung der Exponenten a und b sind Gleichungen angegeben. Die Gleichung für∌ p wird auf eine mittlere Temperatur $$\bar t_p $$ im Polymerstrahl erweitert. Daraus folgt für ihn eine mittlere dynamische Viskosität $$\bar \eta _p $$ . Diese ist mit der Fadenspannung abeim Fadenbildungsvorgang identisch. Die Spinnorientierung ergibt sich zu $$\bar \eta _p $$ bzw.σ direkt proportional. Fadendurchmesser $$\bar d$$ , Wärmeübergangszahl $$\bar \alpha $$ , Spinnwegx s bis zum Erreichen der Glasumwandlungstemperaturt G im Faden und Volumen V des Polymerstrahles sind mit früher veröffentlichten Gleichungen gerechnet. Eine veränderliche Größe νω, die für jede Nummer dem Ausdruck spezifisches Gewicht · Volumen/Durchsatzmenge $$\dot m$$ des monofilen Fadens entspricht und dem Quotienten aus mittlerer Geschwindigkeit im Strahl und Fadenabzugsgeschwindigkeit gleichgesetzt ist, charakterisiert den Fließvorgang bei der Fadenbildung und findet bei der Rechnung von Fadenkraft und Spinnorientierung Anwendung. Für PET hat sich $$\Delta n = k_2 \cdot f \cdot \bar \alpha ^3 $$ und für PA6 $$\Delta n = k_3 \cdot f \cdot \bar \alpha ^3 $$ ergeben.f entspricht der theologischen Fadenkraft am Polymerstrahl,k 2 dem Wertq Me , · In 10/g undk 3 dem Wertq Me , · loge/g.q Me , ist das mechanische Wärmeäquivalent einer Grammkalorie und g die Gravitationskonstante. Die Fadenkraft, die sich aus der Messung der Spinnorientierung und der Rechnung der Wärmeübergangszahl ergeben hat, ist für alle Nummern der Meßreihen 1 bis 7 in den Tabellen 5 bis 11 angegeben. Die Spinnorientierung abhängig vom Spinntiter S entspricht der Beziehungk 4, ·f · νω/g -S z. Zahlenwertk 4 und Exponent z jeder Meßreihe sind in der Tabelle 12 zusammengestellt. Im Abschnitt 14 wird die Fadenkraft abhängig von der Wärmeübergangszahl, ebenso die Spinnorientierung unter sucht. Bei PET ergibt sich die Fadenkraft $$f = \frac{{q^2 Me}}{g} \cdot \log e \cdot \frac{1}{{U_w }} \cdot \bar a^y $$ und die Spinnorientierung $$\Delta n = \frac{{q^3 Me}}{{g^2 }} \cdot \frac{1}{{U_w }} \cdot \bar a^{3 + y} $$ . Der Exponenty ist eine Funktion des Spinntiters. Für die Meßreihen 1 bis 4, die für freie Konvektion und PET gelten, sind die Angaben zur Rechnung vony als Tabelle 13 zusammengestellt. Die mittlere Schwankung für alle Meßwerte jeder Meßreihe bei der Rechnung von Fadenkraft und Spinnorientierung mit den vorstehenden Gleichungen liegt zwischen ± 6,8 und ± 14,7%, und der Zahlenwert 3 +y zwischen 5 und 6. Für die erzwungene Konvektion mit PET, bei der die Fäden quer zur Ablaufrichtung angeblasen sind, haty den Wert 3. Danach gilt für die erzwungene Konvektion $$f = \frac{{q^2 Me}}{g} \cdot \log e \cdot \frac{1}{{U_w }} \cdot \bar a^3 und\Delta n = \frac{{q^3 Me}}{{g^2 }} \cdot \frac{1}{{U_w }} \cdot \bar a^6 $$ mittleren Schwankungɛ = ± 8,9% für die Nummern 36 bis 41. Bei PA6, Meßreihe 6 zeigt sich für den Exponenteny neben der Abhängigkeit vom Spinntiter ein Einfluß durch die Fadenabzugsgeschwindigkeit. Zur Rechnung vony sind für die Meßreihen 6 und 7 Gleichungen angegeben. Eine Abnahme vony bedeutet eine Zunahme der Fadenkraft bei steigender Fadenabzugsgeschwindigkeit. Bei PA6 haben die Gleichungen $$f = \frac{{q^2 Me}}{g} \cdot \log e \cdot \frac{1}{{U_w }} \cdot \bar a^y $$ und $$\Delta n = \frac{{q^3 Me}}{{g^2 }} \cdot \log ^2 e \cdot \frac{1}{{U_w }} \cdot \bar a^{3 + y} $$ Gültigkeit. Für die Meßreihe 6 hat sich als mittlere Schwankung der Wert ɛ = ± 5,0% und die Meßreihe 7 ɛ = ± 18,2% ergeben.
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  • 7
    ISSN: 1434-601X
    Keywords: 12.38.Qk Experimental tests ; 13.40.-f Electromagnetic processes and properties ; 13.60.Le Meson production
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. An experiment on the radiative π{+}-meson photoproduction from the proton ( γp → γπ{+}n) was carried out at the Mainz Microtron MAMI in the kinematic region 537MeV 〈 Eγ 〈 817MeV, 140°≤ $ \theta_{{\gamma \gamma ^{\prime }}}^{{{{\rm cm}}}}$ ≤180°. The π{+}-meson polarizabilities have been determined from a comparison of the data with the predictions of two different theoretical models, the first one being based on an effective pole model with pseudoscalar coupling while the second one is based on diagrams describing both resonant and nonresonant contributions. The validity of the models has been verified by comparing the predictions with the present experimental data in the kinematic region where the pion polarizability contribution is negligible ( s1 〈 5mπ2) and where the difference between the predictions of the two models does not exceed 3%. In the region, where the pion polarizability contribution is substantial ( 5 〈 s1/mπ2 〈 15, -12 〈 t/mπ2 〈 - 2), the difference $\ensuremath{(\alpha -\beta )_{\pi^{+}}}$ of the electric (α) and the magnetic (β) polarizabilities has been determined. As a result we find $\ensuremath{(\alpha -\beta )_{\pi^{+}}=(11.6\pm 1.5_{{\rm stat}}\pm 3.0_{{\rm syst}}\pm 0.5_{{\rm mod}})\times 10^{-4}{}{\rm fm^{3}}}$ . This result is at variance with recent calculations in the framework of chiral perturbation theory.
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  • 8
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The Hartree-Fock-Bogolyubov-Equations of the cranking model are used to give a description of nuclear rotations in a general single particle model. Numerical results for some rare earth nuclei are presented.
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  • 9
    ISSN: 1434-601X
    Keywords: PACS:21.30.Fe Forces in hadronic systems and effective interactions – 25.20.Lj Photoproduction reactions – 27.20.+n 6 ≤ A ≤ 19
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: The angular distribution of nucleons emitted in the 12C(γ,pn) reaction has been measured using tagged photons at the Mainz microtron MAMI. The variation of the reaction strength with the polar angles of the two emitted nucleons is reported for Eγ=120−150 MeV. The proton angular distribution peaks at more backward angles than the 2H(γ,p) differential cross section indicating a departure from the simple quasi-deuteron model of 2N photo-emission. The distribution shape is in reasonable agreement with microscopic theoretical models which include both π- and ρ-exchange.
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  • 10
    Electronic Resource
    Electronic Resource
    Springer
    The European physical journal 243 (1971), S. 409-417 
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract It is shown that the stability of spherical HFB states against deformation may be completely altered if angular momentum conservation is taken into account exactly, leading to a smooth transition from spherical to deformed nuclei. Furthermore the close connection between the stability matrix in HFB theory and the RPA matrix is destroyed by angular momentum projection.
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