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151.
Wilhelm Hummeltenberg 《European Journal of Operational Research》1985,21(3):318-329
Capital budgeting problems with different interest rates for borrowing and lending and with possible limits on borrowing are applied to dual and primal decomposition. While the former fails if a dual gap exists, the latter becomes attractive. The paper elaborates dual and primal decomposition to capital budgeting models and discusses variants of the Benders scheme. A computer implementation is described and results of extensive computer runs with different strategies are reported which give proof of the efficiency of the implemented decomposition procedure. 相似文献
152.
Wolf von der Osten Hans Peisl Wilhelm Waidelich 《Zeitschrift für Physik A Hadrons and Nuclei》1966,193(3):400-411
The formation of defects in AgCl single crystals under UV and X-ray exposure and their thermal annealing are studied by measuring the optical density, the lattice parameter change, the X-ray Ag-reflection and by electronmicroscopical observations. Specks of crystalline silver are found to be produced at the surface of the crystals as well as in the interior. According to surface and volume darkening the isochronal annealing curves exhibit two stages. The activation energy for stage I, (0,59±0,08) eV, is suggested to be the energy for the thermal formation of electrons and Ag 0 + -ions from Ag-aggregates. Stage II appears when the crystal is annealed in chlorine at above 523 °K. It is due to the regeneration of silver at the surface, where chlorine was able to leave the crystal during exposure. 相似文献
153.
Wilhelm Spannhake 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1958,9(5-6):642-647
Summary A diagramm is developed by means of which any flow through axisymmetric spaces with and without exchange of energy can be
followed up. The flow, too, is assumed to be axisymmetric which, in the case of turbomachines, means that an infinite number
of blades is assumed and the average values of the meridian components of the velocities are introduced. In all cases the
absolute flow is discussed.
相似文献
154.
A generalized companion matrix of a polynomial is introduced; the concept is applied to estimates of polynomial roots and to the explicit determination of the characteristic equation of matrix. 相似文献
155.
Zusammenfassung Actinomycin D (250 /ml) hemmt in Suspensionskulturen vonPhysarum polycephalum spezifisch die RNS-Synthese, während die DNS- und Proteinsynthese innerhalb der ersten drei Stunden nur wenig beeinträchtigt werden. Die Auslösung einer synchronen Kernteilung in Makroplasmodien kann durch 250 /ml Actinomycin D verhindert oder stark verzögert werden, sofern der Hemmstoff spätestens zu Beginn des letzten Drittels der Interphase ( 2 Stdn. vor Prophase) dem Medium zugesetzt wird. Die Mitosehemmung ist durch Auswaschen des Hemmstoffes reversibel. Die Ergebnisse sprechen dafür, daß zur Vorbereitung einer Mitose während des größten Teiles der Interphase DNS-abhängige RNS neu gebildet werden muß, die möglicherweise als Informationsüberträger die Synthese mitosespezifischer Proteine kontrolliert. Es wird eine Arbeitshypothese diskutiert, nach der die Mitose als ein durch Genregulation gesteuerter Vorgang aufzufassen wäre.
Mit 4 Abbildungen
Herrn Prof. Dr.Hermann Bretschneider zum 60. Geburtstag gewidmet. 相似文献
Actinomycin D (250 /ml) specifically inhibits RNA synthesis in suspension cultures ofPhysarum polycephalum whereas DNA and protein synthesis are less affected within the first three hours. Onset of synchronous mitoses in macroplasmodia is prohibited or largely delayed by 250 /ml actinomycin D if the inhibitor is added to the medium at or prior to the beginning of the last third of interphase ( 2 hrs. prior to prophase). Removal of the inhibitor from the medium reverses the inhibitory effect on mitosis. The results indicate that preparation of mitosis requires synthesis of DNA dependent RNA during the major part of interphase. These RNA molecules possibly carry information for the synthesis of proteins specifically involved with mitosis. A working hypothesis is discussed suggesting that mitotic activities may by controlled by gene regulation.
Mit 4 Abbildungen
Herrn Prof. Dr.Hermann Bretschneider zum 60. Geburtstag gewidmet. 相似文献
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Based on the principle of supramolecular preorganization, a new type of oligofunctional amphiphile, of which compounds 1-4 are representative structures, has been designed and synthesized. The typical feature of their structure is a highly rigid and geometrically well-defined central unit composed of ethynylene substituted aromatic spacers with different numbers of amphiphilic segment groups (also of a rigid geometric design) attached to it. The molecules form well-defined Langmuir films when spread from a solution at the air/water interface or when a 10(-4) M aqueous CaCl2 solution was used as the subphase. By analysis of the surface pressure-surface area (pi-A) isotherms, information on the packing behavior and orientation of the amphiphilic molecules depending on the molecular structure could be obtained. Morphological characterization of the dynamic process of monolayer compression at the air/water interface was carried out by Brewster angle microscopy, illustrating several phase states visualized as snap shots. Thin monolayer films produced on a 10(-4) M aqueous CaCl2 subphase can be transferred to a mica solid support by the Langmuir-Blodgett technique. Tapping mode atomic force microscopy reveals a surface topography of the monofilms composed of 1 and 3 that differ in roughness and also in the properties of elasticity, hardness and adhesive strength. X-Ray crystal structure analysis of three relevant intermediate compounds of the synthesis were successfully determined giving an indication of the potential structural features inherent in the new amphiphiles. 相似文献