排序方式: 共有31条查询结果,搜索用时 0 毫秒
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A. Malki J. P. Coffin G. Guillaume F. Jundt K. Krishan F. Rami P. Wagner P. Fintz M. Zahar M. Gonin B. Heusch M. Ohta B. Rastegar D. Rebreyend F. Merchez J. Mistretta S. Kox 《Zeitschrift für Physik A Hadrons and Nuclei》1991,339(2):283-292
In an attempt to separate preequilibrium and thermalised emissions of light particles in low impact parameter heavy-ion collisions, the40Ar+24Mg reaction has been studied at 27.5 MeV/nucleon. Exclusive measurements have permitted us to examine, in some detail, heavy fragments and charged particles (p, d, t,-particle). The fragments recognized as evaporation residues have been selected and, due to inverse kinematic conditions, the related preequilibrium and statistical emissions of light particles resulting from incomplete fusion reaction appear to be distinguishable to a fair extent. This separation is fully supported by Monte Carlo calculations. Some experimental characteristics of the light particles have been examined and compared to the predictions of dynamical calculations. These calculations, associating a preequilibrium (interpreted as prompt emitted particles) model with a statistical-decay model, follow the evolution of the collision from the point of contact between the projectile and the target to the final evaporation-residue formation on an event by event basis. The predictions of these calculations have been compared to experimental data and satisfactory agreement is achieved for fragment-mass distribution, proton-energy spectra, and proton-angular distribution. 相似文献
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Ban G Bodek K Daum M Henneck R Heule S Kasprzak M Khomutov N Kirch K Kistryn S Knecht A Knowles P Kuźniak M Lefort T Mtchedlishvili A Naviliat-Cuncic O Plonka C Quéméner G Rebetez M Rebreyend D Roccia S Rogel G Tur M Weis A Zejma J Zsigmond G 《Physical review letters》2007,99(16):161603
In case a mirror world with a copy of our ordinary particle spectrum would exist, the neutron n and its degenerate partner, the mirror neutron n', could potentially mix and undergo nn' oscillations. The interaction of an ordinary magnetic field with the ordinary neutron would lift the degeneracy between the mirror partners, diminish the n' amplitude in the n wave function and, thus, suppress its observability. We report an experimental comparison of ultracold neutron storage in a trap with and without superimposed magnetic field. No influence of the magnetic field is found and, assuming negligible mirror magnetic fields, a limit on the oscillation time taunn' > 103 s (95% C.L.) is derived. 相似文献
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Dr. Yann Gloaguen Christophe Rebreyend Dr. Martin Lutz Pravin Kumar Dr. Martina Huber Dr. Ir. Jarl Ivar van der Vlugt Prof. Dr. Sven Schneider Prof. Dr. Bas de Bruin 《Angewandte Chemie (International ed. in English)》2014,53(26):6814-6818
Photochemical activation of [(PNNH)Rh(N3)] (PNNH=6‐di‐(tert‐butyl)phosphinomethyl‐2,2′‐bipyridine) complex 2 produced the paramagnetic (S=1/2), [(PNN)Rh?N.‐Rh(PNN)] complex 3 (PNN?=methylene‐deprotonated PNNH), which could be crystallographically characterized. Spectroscopic investigation of 3 indicates a predominant nitridyl radical (.N2?) character, which was confirmed computationally. Complex 3 reacts selectively with CO, producing two equivalents of [(PNN)RhI(CO)] complex 4 , presumably by nitridyl radical N,N‐coupling. 相似文献
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A. Ignatov V. Bellini J.P. Bocquet M. Capogni M. Casano A. D’Angelo J.-P. Didelez A. Fantini G. Gervino B. Girolami A. Giusa M. Guidal V. Kouznetsov A. Lapik A. Lleres A. Mushkarenkov L. Nicoletti D. Rebreyend N. Rudnev G. Russo M.-L. Sperduto M.-C. Sutera 《Progress in Particle and Nuclear Physics》2008,61(1):253-259
New experimental approach to study meson photoproduction in nuclei is discussed. It is based on the measurement of the recoil nucleon as a tagger for identification of the initial step of reaction. Propagation of mesons and nucleons within a nucleus is described by the Intra-Nuclear Cascade (INC) model. Simulations and preliminary experimental data for the deuteron target obtained at GRAAL are presented. 相似文献
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M. Zahar A. Malki M. Bozin P. Wagner F. Rami J. P. Coffin G. Guillaume F. Jundt P. Fintz B. Rastegar D. Rebreyend F. Merchez J. Mistretta S. Kox 《Zeitschrift für Physik A Hadrons and Nuclei》1991,339(4):465-473
Protons, deuterons, tritons,α-particles and Li have been studied in coincidence with evaporation residues produced at low impact parameter for the40Ar(1100 MeV)+13C reaction. Experimental characteristics of the light particle — heavy residue correlations, and among them an effect of left-right asymmetry, are analyzed and discussed in some detail on the basis of Monte Carlo simulations. This reaction appears to be governed by an incomplete fusion process. Due to transverse emission of preequilibrium particles, the compound nuclei associated with light-particle-evaporation-residue coincidence events recoil at a non-zero degree lab. angle with some dispersion around this direction. When these effects are introduced into statistical decay calculations, it is then possible to reproduce various experimental results and to understand features like the asymmetry effect. Discrimination of light particles of preequilibrium and of evaporative origin appears possible. 相似文献
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Z. Chowdhuri M. Fertl M. Horras K. Kirch J. Krempel B. Lauss A. Mtchedlishvili D. Rebreyend S. Roccia P. Schmidt-Wellenburg G. Zsigmond 《Applied physics. B, Lasers and optics》2014,115(2):257-262
We report on a comparison of spin relaxation rates in a 199Hg magnetometer using different wall coatings. A compact mercury magnetometer was built for this purpose. Glass cells coated with fluorinated materials show longer spin coherence times than if coated with their hydrogenated homologues. The longest spin relaxation time of the mercury vapor was measured with a fluorinated paraffin wall coating. 相似文献
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J. Julien M. Boloré H. Dabrowski J. M. Hisleur V. Bellini A. S. Figuera R. Fonte A. Insolia G. F. Palama G. V. Russo M. L. Sperduto J. Chauvin P. De Saintignon D. Lebrun D. Rebreyend 《Zeitschrift für Physik A Hadrons and Nuclei》1988,330(1):83-86
Inclusive production of neutral pions has been studied in16O +27Al,197Au reactions at 38 MeV/u and20Ne +27Al reaction at 200 MeV/u. A setup of 10 Pb glass Cherenkov detector telescopes was used to detect the twoγ rays from theπ 0 decay. 相似文献