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  • 1975-1979  (6)
  • 1965-1969  (3)
  • 1925-1929  (2)
  • 1
    Electronic Resource
    Electronic Resource
    A treatment of the non-local exchange potential in the classical theory of heavy ion reactions (1976)
    Springer
    The European physical journal 276 (1976), S. 79-83 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract A method is presented how to incorporate the non-local exchange potential in the classical description of heavy-ion reactions. Along the line of the Ehrenfest theorem Hamilton's canonical equations are derived. A possible way of constructing the classical hamiltonian in terms of the matrix elements in the complex generator-coordinate method is proposed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01414598
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  • 2
    Electronic Resource
    Electronic Resource
    Refinement of Harrison's normal table for the morula and blastula of the axolotl (1977)
    Springer
    Development genes and evolution 181 (1977), S. 89-93 
    Details
    ISSN: 1432-041X
    Keywords: Cleavage ; Normal table ; Axolotl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Films of cleaving embryos of the axolotl,Ambystoma mexicanum, taken by the “double camera” technique, were used in order to arrive at a more detailed staging based on quantitative criteria. Drawings were made of the animal hemispheres just prior to the start of each cleavage cycle from the 6th to the 15th cleavage. The number of cells intersected either by the (apparent) “egg diameter” (up to the 10th cleavage) or by “half the diameter” (from the 10th cleavage onwards) was determined. The cell numbers for each cleavage cycle did not overlap with those of the previous or succeeding cycles. On the basis of these cell numbers, in place of the four Harrison stages 6–9, 10 successive stages were established each of which corresponds to one cleavage cycle.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00857270
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  • 3
    Electronic Resource
    Electronic Resource
    The cleavage pattern of the axolotl egg studied by cinematography and cell counting (1977)
    Springer
    Development genes and evolution 181 (1977), S. 73-87 
    Details
    ISSN: 1432-041X
    Keywords: Cleavage ; Cinematography ; Cell dissociation ; Cell numbers ; Axolotl
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary The temporal pattern of cleavage in the egg of the axolotl,Ambystoma mexicanum, was studied 1. by time-lapse microcinematography, and 2. by counting the total number of blastomeres dissociated at successive stages. Eggs were filmed from the one-cell stage till the early gastrula either (A) simultaneously from above and below with a “double-camera” assembly, or (B) from the side with a single camera. The animal blastomeres divide synchronously from the 2nd up to and including the 10th cleavage. The cycle length is roughly constant from the 3rd till the 10th cleavage. The cycle from the 2nd to the 3rd cleavage is slightly longer, while that from the 1st to the 2nd cleavage is about 20% longer. After the 10th cleavage the synchrony of divisions is lost owing to variable lengthening of cell cycles in individual blastomeres. Gastrulation starts around the onset of the 15th cleavage in the animal blastomeres. The analysis of films taken in side view reveals seven recurring “cleavage waves”, from the 5th till the 11th cleavage. Cells in the animal, equatorial and vegetative regions in sequence repeatedly pass through the three successive phases of the cleavage cycle—rounding-up, division, and relaxation—but with a shift in phase. The start of the 10th cleavage division of the slowest vegetative cells more or less coincides with that of the 11th division of the animal cells; from then on the cleavage waves become increasingly obscured. Morulae and blastulae were dissociated by placing them in 1/15 M phosphate buffer (pH 7.8) for the duration of 2–3 cleavage cycles and then removing the vitelline membrane. In this solution cell divisions continued without disturbance of the temporal cleavage pattern. The dissociated cells were fixed either just prior to the onset of the next cleavage (up to the 10th cleavage) or at those times when cleavageswould have been expected, had there been no lenthening of cleavage cycles (beyond the 10th cleavage). The total cell number was counted, dividing cells being scored as two. Prior to the 11th cleavage the total cell number increased exponentially. Beyond the 10th cleavage the rate of increase was considerably lower. At the time when gastrulation would have started if the egg had not been dissociated, the total cell counts were 13,000–15,000, whereas the number anticipated without lengthening of cleavage cycles would be of the order of 130,000 (217). The application of Balfour's rule to amphibian eggs is criticized.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00857269
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  • 4
    Electronic Resource
    Electronic Resource
    Cinematographic Observation of “Post-Fertilization waves” (PFW) on the zygote ofXenopus laevis (1977)
    Springer
    Development genes and evolution 181 (1977), S. 189-192 
    Details
    ISSN: 1432-041X
    Keywords: Xenopus egg ; Fertilization ; Surface wave ; Time-lapse cinematography
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary In fertilizedXenopus eggs, shortly after egg rotation but well before the occurrence of the cleavage-associated “surface contraction waves”, two circular dark zones originate consecutively from the pigment spot marking the site of sperm entrance. They expand and travel centrifugally over the egg surface.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848442
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  • 5
    Electronic Resource
    Electronic Resource
    Changes in the differentiation tendencies of the hypoblast-free Hensen's node during “Gastrulation” in the chick embryo (1975)
    Springer
    Development genes and evolution 177 (1975), S. 89-100 
    Details
    ISSN: 1432-041X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Hensen's node was isolated from chick blastoderms of medium-streak to headfold stages from which the endodermal layer had previously been removed. The isolates were culturedin vivo by means of the intra-coelomic grafting technique. Node pieces with the endodermal layer intact served as controls. Endodermal differentiation tendencies gradually decreased from the medium-streak to the pre-head-process stage and completely disappeared at the head-process stage, whereas the controls gave rise to endodermal structures throughout all stages. “Cranial” structures such as oesophagus and trachea, often together with thyroid, parathyroid and/or thymus, were only found in grafts of younger stages, while gizzard, intestine and/or pancreas were observed in many gut-containing grafts throughout all stages. There was a constant high incidence of notochord, muscle, and cartilage formation. The incidence of mesonephric structures, sometimes accompanied by adrenal gland, rose steadily throughout all stages both in experimentals and controls. Neural differentiation tendencies (rhombencephalon and/or spinal cord) were always present in the nodes isolated (with or without endoderm) from the definitive primitive-streak stage onwards, but in nodes from earlier stages the incidence of neural differentiation was significantly lower. The results are discussed in relation to the possible location and determination of the prospective endoderm and mesoderm.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848524
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    Paper (German National Licenses)
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  • 6
    Electronic Resource
    Electronic Resource
    über den Einflu\ der Heizung des N. splanchnicus auf den Druck und die Durchströmungsgrö\e in der Pfortader der Katze (1929)
    Springer
    Pflügers Archiv 222 (1929), S. 350-355 
    Details
    ISSN: 1432-2013
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zusammenfassung Splanchnicusreizung bewirkt zunÄchst einen Abfall des Pfortaderdruckes und der Durchströmungsmenge, und nach Aufhören der Reizung einen Anstieg beider Grö\en. Die Abnahme des Pfortaderdruckes erklÄrt sich durch die Verengerung der EingeweidegefÄ\e wÄhrend der Splanchnicusreizung. Der Anstieg des Pfortaderdruckes beruht im wesentlichen auf einer Kontraktion der LebergefÄ\e, zu einem geringen Teil wird er auch durch die erhöhte Blutzufuhr zur Leber nach Aufhören der Reizung bedingt. Diese Zunahme der Durchströmungsmenge ist die Folge davon, da\ durch die Splanchnicusreizung der Blutdruck steigt.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01755121
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  • 7
    Electronic Resource
    Electronic Resource
    Über die Hemmung der Schweißsekretion nach Reizung der hinteren Wurzel; zugleich als ein Beitrag über die Wirkungsweise der sogenannten antidromen Nervenerregung (1929)
    Springer
    Pflügers Archiv 221 (1929), S. 692-694 
    Details
    ISSN: 1432-2013
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Zusammenfassung Die vonO. Foerster an der menschlichen Haut gefundene Hemmung der Schweißsekretion nach Reizung der hinteren Wurzeln kann am Pfotenballen der Katze bestätigt werden. Gleichzeitig wird auch die Gefäßverengerung auf Sympathicusreizung gehemmt. Die Versuche weisen daher nicht auf Hemmungsnerven für die Schweißdrüsensekretion hin. Es wird die Hypothese erörtert, daß die Hemmung darauf beruht, daß bei antidromer Reizung histaminähnliche Stoffe freiwerden, die eine hemmende Wirkung auf Schweißdrüsen und Gefäßmuskulatur ausüben.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01794023
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  • 8
    Electronic Resource
    Electronic Resource
    Adhesion of polyethylene (1969)
    Springer
    Colloid & polymer science 229 (1969), S. 4-7 
    Details
    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: Zusammenfassung Die Oxydation durch gasförmigen Sauerstoff katalysiert mit Kobalt-Azetat ließ sich als wirksame Methode zur Einführung polarer Gruppen in Polyäthylen anwenden. Die meisten polaren Gruppen wurden als Carbonylgruppen in Ketonform eingeführt. Die scheinbare Aktivierungsenergie der flüssigen Phasen-Oxydation beträgt 25,6 kcal/mol und liegt etwa zwischen ozon-katalysierter Oxydation und Oxydation durch rauchende Salpetersäure. Der Abbau der Polymeren während der Oxydation wurde ebenfalls durch die Abnahme des Molekulargewichts beobachtet.
    Notes: Summary Liquid phase oxidation by oxygen gas catalysed with cobalt acetate is employed as effective method for introduction of polar groups to polyethylene. Main polar groups introduced were carbonyl groups in ketone form. Apparent activation energy of liquid phase oxidation 25.6 Kcal/mole is intermediate between these ozone catalyzed oxidation and fuming HNO3 oxidation. Degradation of polymer during oxidation was also recognized by the decrease of molecular weight.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01542497
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  • 9
    Electronic Resource
    Electronic Resource
    Adsorption of polymers at the solution-solid interface (1969)
    Springer
    Colloid & polymer science 229 (1969), S. 17-21 
    Details
    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: Zusammenfassung Die Adsorption von Polyvinyl-Azetat als Lösung an Glaspulver wurde untersucht. Die Adsorption ist unabhängig vom Molekulargewicht, und man kann sagen, daß das Polymere flach auf der Adsorbens-Oberfläche liegt. Andererseits hängt das Ausmaß der Adsorption stark von der Art des Lösungsmittels in einer Weise ab, welche mit Hilfe von Lösungsmittelparametern und Gestalt des Polymerknäuels in der Lösung diskutiert werden kann. Gute lineare Beziehungen wurden zwischen der maximalen Adsorption und der Differenz der Lösungsmittel-Parameter zwischen Polymeren und Lösungsmittel gefunden. Und ebenfalls eine lineare Abhängigkeit wurde erhalten, wenn das spezifische Volumen des Polymeren gegen das Maximum der Adsorption aufgetragen wurde. Die maximale Adsorption nahm ab mit steigendem spezifischen Volumen. Man kann sagen, das Polymere wird an der festen Oberfläche adsorbiert und bedeckt eine Fläche, die proportional zur Größe des Knäuels in der Lösung ist.
    Notes: Synopsis The adsorption of polyvinyl acetate from solution onto glass powders was studied. The adsorption is independent of molecular weight and it can be said that polymer lies flat on the adsorbent surface. On the other hand, the extent of adsorption depends strongly upon the sort of the solvent in a manner which can be discussed with solubility parameter and size of the polymer coil in the solution. Good linear relation was obtained between maximum adsorption and difference of the solubility parameter between polymer and solvent. And also a straight line was obtained when specific volume of the polymer was plotted against maximum adsorption. Maximum adsorption decreases with increasing specific volume. It would be said that polymer is adsorbed on the solid surface with its occupied area which is proportional to the size of coil in the solution.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01542500
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  • 10
    Electronic Resource
    Electronic Resource
    Coupling of a quasi-particle to the pairing vibrations (1968)
    Springer
    The European physical journal 209 (1968), S. 428-439 
    Details
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The intermediate coupling model of odd nuclei, where a nucleon is coupled to the surface vibration of an even system, has been successfully used in explaining various nuclear properties. In this paper, it is pointed out that a similar picture is applicable to improve the BCS approximation for seniority-one states in the pairing force model by considering coupling of a quasi-particle to the pairing normal modes. It is shown that this model is, in part, equivalent to the variational approach which takes the blocking effect into account. Several models are compared numerically.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01380548
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