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排序方式: 共有421条查询结果,搜索用时 15 毫秒
291.
292.
E. Mergel C.M. Petrache G. Lo Bianco H. Hübel J. Domscheit D. Roßbach G. Schönwaßer N. Nenoff A. Neußer A. Görgen F. Becker E. Bouchez M. Houry A. Hürstel Y. Le Coz R. Lucas Ch. Theisen W. Korten A. Bracco N. Blasi F. Camera S. Leoni F. Hannachi A. Lopez-Martens M. Rejmund D. Gassmann P. Reiter P.G. Thirolf A. Astier N. Buforn M. Meyer N. Redon O. Stezowski 《The European Physical Journal A - Hadrons and Nuclei》2002,15(4):417-420
The even-even nucleus 136Nd was studied via in-beam γ-ray spectroscopy using the 16O + 125Te reaction at 100 MeV and the EUROBALL array. One new dipole band was observed. Together with a previously identified dipole
band, whose position in the level scheme is revised, the new band forms a doublet structure similar to the recently observed
chiral bands in the odd-odd neighboring nuclei. This would be the first case of a chiral doublet in an even-even nucleus.
Received: 23 May 2002 / Accepted: 30 September 2002 / Published online: 27 November 2002
RID="a"
ID="a"e-mail: costel.petrache@unicam.it
RID="b"
ID="b"Present address: Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA.
RID="c"
ID="c"Present address: Gesellschaft für Schwerionenforschung D-64291 Darmstadt, Germany.
Communicated by C. Signorini 相似文献
293.
Ilievski S Aumann T Boretzky K Elze TW Emling H Grünschloss A Holeczek J Holzmann R Kozhuharov C Kratz JV Kulessa R Leistenschneider A Lubkiewicz E Ohtsuki T Reiter P Simon H Stelzer K Stroth J Sümmerer K Wajda E Waluś W;LAND Collaboration 《Physical review letters》2004,92(11):112502
Differential cross sections for electromagnetic fission of 238U projectiles (500 MeV/u) in C, Sn, and Pb targets are measured and analyzed in terms of single- and multiphonon giant resonance excitations as doorway states to fission. A novel experimental method exploits the linear relationship between neutron multiplicity and the primary 238U excitation energy. Multiphonon states contribute up to 20% of the cross section; a component at high excitation energies is indicated that may arise from three-phonon dipole and two-phonon GDR x GQRiv giant resonance excitations. 相似文献
294.
A series of N-methylated polyarylurea oligomers have been reduced with potassium metal in HMPA. These reductions result in the transient formation of arylurea anion radicals, which undergo reductive elimination of the urea linkages. The aryl moieties appear in the products as the anion radicals of oligoaryl systems. The reaction is intramolecular, and the sequencing in the polyaryl anion radical remains the same as in the polyarylureas due to the urea-enforced pi-pi stacking interactions. 相似文献
295.
Reiter P Khoo TL Ahmad I Afanasjev AV Heinz A Lauritsen T Lister CJ Seweryniak D Bhattacharyya P Butler PA Carpenter MP Chewter AJ Cizewski JA Davids CN Greene JP Greenlees PT Helariutta K Herzberg RD Janssens RV Jones GD Julin R Kankaanpää H Kettunen H Kondev FG Kuusiniemi P Leino M Siem S Sonzogni AA Uusitalo J Wiedenhöver I 《Physical review letters》2005,95(3):032501
In-beam gamma-ray spectroscopic measurements have been made on 253/102No. A single rotational band was identified up to a probable spin of 39/2planck, which is assigned to the 7/2(+)[624] Nilsson configuration. The bandhead energy and the moment of inertia provide discriminating tests of contemporary models of the heaviest nuclei. Novel methods were required to interpret the sparse data set associated with cross sections of around 50 nb. These methods included comparisons of experimental and simulated spectra, as well as testing for evidence of a rotational band in the gammagamma matrix. 相似文献
296.
We investigated the kinetics of autophobic dewetting, caused by differences in entropy, of a polymer melt slipping on a monolayer of end-grafted identical molecules (polymer brush). From simultaneous measures of the dewetted distance and the width of the resulting rim, we obtained in real time and quantitatively the slippage length and the contact angle, a measure of the "incompatibility" between identical molecules. Furthermore, we could directly relate a decrease in the slippage length in the course of the experiments at elevated temperatures to temporal or permanent attachment of polymers from the melt to the brush. 相似文献
297.
298.
Kurth TL Lewis FD Hattan CM Reiter RC Stevenson CD 《Journal of the American Chemical Society》2003,125(6):1460-1461
The one-electron reduction of tertiary N,N'-dimethyl-N,N'-diarylureas (aryl = phenyl, beta-naphthyl, alpha-naphthyl), in HMPA, results in anion radicals that undergo novel intramolecular reductive elimination reactions leading to the formation of the anion radicals of the corresponding biaryls. These results are due to face to face pi-pi stacking interactions involving the two aromatic rings in the urea systems. The overlapping p(pi)() orbitals on the ipso carbons of opposing aryl groups evolve into a sigma bond leading to the formation of the biaryl anion radical. In the case of the N,N'-dimethyl-N,N'-di-2-pyrenylurea system, there is a node in the LUMO of the number 2 carbon, and the parent anion radical remains intact. 相似文献
299.
300.
I.U. Heilmann R.J. Birgeneau Y. Endoh G. Reiter G. Shirane S.L. Holt 《Solid State Communications》1979,31(9):607-610
By means of neutron scattering, we have measured magnetic excitations in the linear-chain antiferromagnet TMMC at T =1.8 K. An energy gap is observed at q=0 associated with zz-spin correlations, thus giving direct evidence for the importance of the dipolar xy anisotropy for the spin dynamics at low temperatures. A finite magnetic field applied perpendicular to the chains creates a second q=0 gap. There are substantial discrepancies between field dependence of the spin-wave dispersion and the predictions of linear spin-wave theory. 相似文献