排序方式: 共有30条查询结果,搜索用时 15 毫秒
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R. Pfaff B. M. Young W. Benenson J. Clayton D. J. Morrissey N. A. Orr T. Reposeur M. Thoennessen J. A. Winger 《Zeitschrift für Physik A Hadrons and Nuclei》1993,347(1):67-70
A comparison has been made between the production of high energy (E γ≧30 MeV)γ rays from the bombardment of124Sn and112Sn targets withE/A= 10 MeV12C ions. The results are well explained by then-p bremsstrahlung model and do not indicate the need for any new processes. 相似文献
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O. I. Kolodiazhnyi E. V. Grishkun S. Sheiko O. Demchuk H. Thoennessen P. Jones R. Schmutzler 《Russian Chemical Bulletin》1999,48(8):1568-1573
Chiral C2-symmetrical dialkyl phosphites and C3-symmetrical trialkyl phosphites, derived from (−)-borneol, (−)-menthol, and 1,2∶5,6-di-O-isopropylidene-α-d-glucofuranose, were studied as the starting reagents for the preparation of chiral organophosphorus compounds. The reactions
of C2-symmetrical dialkyl phosphites and C3-symmetrical trialkyl phosphites with aldehydes and amines or aldehydes are accompanied by asymmetrical induction at the α-carbon
atom to yield optically active α-aminoalkylphosphanates or α-hydroxyalkylphosphonates, respectively. The stereoselectivity
of the reaction depends on the structure of the starting compounds and the reaction conditions.
Translated fromIzvestiya Akademii, Nauk, Seriya Khimicheskaya, No. 8, pp. 1588–1593, August, 1999. 相似文献
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C.R. Hoffman T. Baumann D. Bazin J. Brown G. Christian D.H. Denby P.A. DeYoung J.E. Finck N. Frank J. Hinnefeld S. Mosby W.A. Peters W.F. Rogers A. Schiller A. Spyrou M.J. Scott S.L. Tabor M. Thoennessen P. Voss 《Physics letters. [Part B]》2009
The decay energy spectrum for neutron unbound states in 24O (Z=8, N=16) has been observed for the first time. The resonance energy of the lowest lying state, interpreted as the 2+ level, has been observed at a decay energy above 600 keV. The resulting excitation energy of the 2+ level above 4.7 MeV, supplies strong evidence that 24O is a doubly magic nucleus. The data is also consistent with the presence of a second excited state around 5.33 MeV which can be interpreted as the 1+ level. 相似文献
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Lunderberg E DeYoung PA Kohley Z Attanayake H Baumann T Bazin D Christian G Divaratne D Grimes SM Haagsma A Finck JE Frank N Luther B Mosby S Nagi T Peaslee GF Schiller A Snyder J Spyrou A Strongman MJ Thoennessen M 《Physical review letters》2012,108(14):142503
Evidence for the ground state of the neutron-unbound nucleus (26)O was observed for the first time in the single proton-knockout reaction from a 82 MeV/u (27)F beam. Neutrons were measured in coincidence with (24)O fragments. (26)O was determined to be unbound by 150(-150)(+50) keV from the observation of low-energy neutrons. This result agrees with recent shell-model calculations based on microscopic two- and three-nucleon forces. 相似文献
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J.P. Seitz B.B. Back M.P. Carpenter I. Diszegi K. Eisenman P. Heckman D.J. Hofman M.P. Kelly T.L. Khoo S. Mitsuoka V. Nanal T. Pennington R.H. Siemssen M. Thoennessen R.L. Varner 《Nuclear Physics A》2005,750(2-4):245-255
The giant dipole resonance built on excited states was observed in very fissile nuclei in coincidence with evaporation residues. The reaction 48Ca + 176Yb populated evaporation residues of mass A=213–220 with a cross section of 200 μb at 259 MeV. The extracted giant dipole resonance parameters are in agreement with theoretical predictions for this mass region. 相似文献
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M. B. Chadwick M. Hussein E. Ramakrishnan T. Baumann A. Azhari R. A. Kryger R. Pfaff M. Thoennessen S. Yokoyama J. R. Beene M. L. Halbert P. E. Mueller D. W. Stracener R. L. Varner G. van Buren R. J. Charity P-F. Hua D. G. Sarantites L. G. Sobotka 《Acta Physica Hungarica A》1995,2(3-4):347-353
New experimental data has been obtained for the208Pb(α, α′) reaction induced by 160 MeV alpha particles, for inelastic scattering to forward angles. We use these data to investigate the applicability of the multistep scattering theory of Feshbach, Kerman, and Koonin for describing this reaction. The mechanism we study, following the work of Gadioli et al. [1], is of the incident alpha particle remaining intact throughout the scattering process, exciting nucleon particle-hole pairs through multistep process. We conclude that this mechanism, combined with compound nucleus decay at low emission energies, can account for much of the observed data. However, there are indications that other processes also contribute at energies above the compound nucleus emission regime, and we outline future theoretical analyses that are needed. 相似文献
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M. Thoennessen 《Acta Physica Hungarica A》2004,21(2-4):379-384
Reaching the limits of nuclear stability offers unique opportunities to understand basic nuclear properties. New shell structures close to the driplines can change the existence of neutron-rich nuclei. A new search for 16Be confirmed the previous limit for particle stable Be isotopes at A=14. Single proton knock-out reactions offer the potential for more sensitive searches of very weakly bound nuclei. In order to extend the knowledge of the neutron dripline beyond Z=8 requires new accelerator developments. The proposed new rare isotope accelerator has the potential to push the limit of the neutron dripline to at least Z=25. 相似文献
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