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101.
U. Greife F. Gorris M. Junker C. Rolfs D. Zahnow 《Zeitschrift für Physik A Hadrons and Nuclei》1995,351(1):107-112
Thed(d, n) 3He andd(d,p)t fusion reactions have been studied at center-of-mass energies E=1.6 to 130 keV using intense beam currents from 30, 100, and 450 kV accelerators in combination with detectors in close and far geometry. The cross sesction ratio,R(E)=σ(d,n)/σ(d, p), approaches unity (within 2%) at low energies; thus there is no experimental evidence for the Oppenheimer-Phillips effect at subcoulomb energies. The cross sections of d(d, p)t at E≦10keV show clear evidence for electron screening effects. However, the observed cross section enhancement is significantly larger than can be accounted for from available atomic physics models. 相似文献
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Fission barriers for even-even nuclei in the region (Th ... Ku) are calculated in the framework of the Strutinsky method and using the concept of dynamic fission paths. The single particle states are calculated in a deformed Woods-Saxon potential including axial asymmetry at the inner barrier and deviation from reflection symmetry at the outer barrier. It is shown that in the present model also the mass symmetric outer barrier is unstable against axially asymmetric (γ) distortions. 相似文献
104.
F. Raiola L. Gang C. Bonomo G. Gyürky M. Aliotta H. W. Becker R. Bonetti C. Broggini P. Corvisiero A. D’Onofrio Z. Fülöp G. Gervino L. Gialanella M. Junker P. Prati V. Roca C. Rolfs M. Romano E. Somorjai F. Strieder F. Terrasi G. Fiorentini K. Langanke J. Winter 《The European Physical Journal A - Hadrons and Nuclei》2004,19(2):283-287
The electron screening effect in the d(d,p)t reaction has been studied for deuterated metals, insulators, and semiconductors, i.e. 58 samples in total. As compared to measurements performed with a gaseous D2 target, a large effect has been observed in most metals, while a small (gaseous) effect is found, e.g., for the insulators, semiconductors, and lanthanides. The periodic table provides the ordering of the observed small and large effects in the samples. An explanation of the large effects in metals is possibly provided by the classical plasma screening of Debye applied to the quasi-free metallic electrons. The data also provide information on the solubility of hydrogen in the samples.Received: 25 July 2003, Revised: 15 September 2003, Published online: 23 December 2003PACS:
25.10. + s Nuclear reactions involving few-nucleon systems - 25.45.-z 2H-induced reactions - 95.30.-k Fundamental aspects of astrophysicsFor the LUNA Collaboration; supported in part by BMBF (06BO812 and 05CL1PC1/1), GSI (Bo-Rol), DFG (Ro429/31-1 and 436Ung113), OTKA (T034259, T042733, F043408), and Dynamitron-Tandem-Laboratorium Bochum. 相似文献
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Gruber O Kallenbach A Kaufmann M Lackner K Mertens V Neuhauser J Ryter F Zohm H Bessenrodt-Weberpals M Büchl K Fiedler S Field A Fuchs C Garcia-Rosales C Haas G Herrmann A Herrmann W Hirsch S Köppendörfer W Lang P Lieder G Mast K Pitcher CS Schittenhelm M Stober J Suttrop W Troppmann M Weinlich M Albrecht M Alexander M Asmussen K Ballico M Behler K Behringer K Bosch HS Brambilla M Carlson A Coster D Cupido L DeBlank HJ De Pena Hempel S Deschka S Dorn C Drube R Dux R Eberhagen A Engelhardt W 《Physical review letters》1995,74(21):4217-4220
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109.
We extended prior studies on the influence of impeller type on fermentation performance to include a novel low-power-number,
high-efficiency radial flow impeller, the CD-6, possessing six curved blades on a disk turbine. Dual impeller combinations
of CD-6/CD-6, CD-6/Maxflo T, and CD-6/HE-3 were compared with Rushton/Rushton and Maxflo T/Maxflo T base cases. Qualitative
comparisons of unaerated and aerated power draw in both water and glycerol were conducted. These suggested minimal power drops
with aeration for dual CD-6 impellers and hybrids containing the CD-6 impeller design. We also examined fermentation performance
for Streptomyces and Glarea secondary metabolite fermentations. A qualitative comparison of the data suggested that dual CD-6 impellers and hybrids containing
the CD-6 impeller design resulted in reasonable power draws, improved mass transfer rates with airflow increases, and acceptable
peak titers. These arrangements may warrant further study under a wider range of production conditions. 相似文献
110.
A dynamic diastereomer differentiating cyclisation is the key step in a new large-scale synthesis of both enantiomers of the cyclic sulfonimidates 1 (Aldrich no. 54099-4) and ent-1 (Aldrich no. 54412-4). These are valuable starting materials in the asymmetric synthesis of chiral oxa- and azaheterocyclic compounds. NMR spectroscopic studies on the reacting system reveal N-chloro sulfinamides to be reactive intermediates in the oxidative chlorination of sulfinamides with tert-butyl hypochlorite and allow for the inspection of the configurational behaviour of the involved sulfonimidoyl chlorides and sulfonimidoyl bromides. 相似文献