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131.
H. Hübel R. M. Diamond P. Aguer C. Ellegaard D. B. Fossan H. Kluge C. Schück S. Shih F. S. Stephens U. Smilanski 《Zeitschrift für Physik A Hadrons and Nuclei》1982,304(3):225-230
Average lifetimes of unresolved transitions deexciting very high spin states populated in28Si(136, 129Xe,xn)164? x, 157?xEr reactions have been determined by a Doppler shift attenuation method. We find that the yrast bump region between 1.0 and 1.6 MeV contains a majority of strongly collectiveE2 transitions with very short lifetimes (a few tens of fsec) in the well deformed nuclei around159Er and, with less certainty, almost comparably short lifetimes in the more spherical nuclei around152Er. In the high energy region of 2.0–3.2 MeV we observe transitions which depopulate longer lived states in the nuclei nearN=82 than in the well deformed systems. 相似文献
132.
Total syntheses of 1α- and 1β-methyl thienamycin are reported. 1β-Methyl thienamycin retains the antibacterial activity of thienamycin and is highly resistant to hydrolysis by DHP-I enzyme. 相似文献
133.
Journal of Optimization Theory and Applications - Optimal modal feedback control laws are synthesized from the modal equations which are obtained by eigenfunction expansion of the diffusion... 相似文献
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135.
Prof. Dr.-Ing. J. Siekmann Mr. Shih -Chih Chang M.S. 《Archive of Applied Mechanics (Ingenieur Archiv)》1968,37(2):99-109
Summary The problem of hydroelastic sloshing of a liquid, partially filling a cylindrical tank with rigid side walls and a flat flexible bottom, has been investigated. The liquid is assumed to be inviscid, homogeneous and incompressible; the flexible bottom is assumed to be a stretched membrane. An approximate solution is given and numerical examples are discussed. The data obtained show good agreement with experimental results reported by other authors.
Paper presented in part at the Canadian Congress of Applied Mechanics, Centennial Year 1967, 22–26 May 1967, Lavai University at Quebec City. This work was performed under National Aeronautics and Space Administration Grant No. NsG-542 to the University of Florida. Numerical calculations were carried out at the University of Florida computing center. 相似文献
Übersicht In der vorliegenden Arbeit wird das hydroelastische Problem des Schwappens von flüssigem Treibstoff in einem kreiszylindrischen Tank mit starrer Wand und ebenem, flexiblem Boden untersucht. Die Flüssigkeit wird als reibungsfrei, homogen und inkompressibel, der Boden als gespannte Membran angenommen. Eine Näherungslösung wird angegeben und numerische Rechnungen werden diskutiert. Die erhaltenen Resultate zeigen gute Übereinstimmung mit experimentellen Befunden anderer Autoren.
Paper presented in part at the Canadian Congress of Applied Mechanics, Centennial Year 1967, 22–26 May 1967, Lavai University at Quebec City. This work was performed under National Aeronautics and Space Administration Grant No. NsG-542 to the University of Florida. Numerical calculations were carried out at the University of Florida computing center. 相似文献
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137.
In the Proceedings of the 1982 Tri-Service Cathode Workshop, the authors described studies of the reactivations of tungsten-based dispenser cathodes following poisonings of the kind expected during shelf storage of a microwave tube [Appl. Surface Sci. 16 (1983) 73]. Further work on the problems of reactivation following such poisoning is described here. In addition to coated (“M”) and uncoated tungsten matrix cathodes, the tungsten-iridium mixed metal matrix (“MM”) cathode has been studied. In general reproducible results have been obtained from different examples of the same type of “M” and uncoated cathodes. However, although some “MM” cathodes have exhibited good reactivation characteristics, a large variation has been observed between different examples of “MM” cathodes. The composition of the impregnant in the dispenser cathodes has been found to be an important factor in determining the reactivation rate of a cathode. As the barium oxide concentration in the impregnant increases, the cathode will recover faster from a poisoning exposure. Studies of the poisoning caused by combinations of different gases suggest that poisoning will occur if there is a sufficient exposure of a poisoning agent, regardless of the total exposure. The exposures necessary to poison a cathode are so small, that poisoning of the cathode appears probable during shelf storage of a microwave tube. The reactivation results have been summarised in terms of the times and temperatures required to achieve both a given current density and a given degree of reactivation from a poisoned cathode. The studies also indicate that the limiting step during the reactivation process involves the dispensing of fresh material to the cathode surface rather than the desorption or conversion of a poisoned surface layer. 相似文献
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Analysis of the plasma emission from a low-pressure microwave cavity discharge through flowing hydrogen peroxide vapor showed that both H and OH were produced in proportions which varied with the applied power. When the dissociated vapor was condensed at 195 K only water was obtained; at 77 K, H2O2 and H2O4 were also obtained. Their formation could not be increased by increasing the H atom or OH radical concentration in the plasma. When the reaction time of the dissociated vapor between the plasma exit and the cold surface was increased, the rate of H2O2 formation increased mostly at the expense of water formation. It appears that, as in the case of the reaction of H with O2, the rate of H2O2 formation is dependent on the concentration of O2 produced in the spatial afterglow by the gas-phase reactions of the hydroxyl radicals. 相似文献