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51.
52.
F. Vanderbist P. Leleux C. Angulo E. Casarejos M. Couder M. Loiselet G. Ryckewaert P. Descouvemont M. Aliotta T. Davinson Z. Liu P. J. Woods 《The European Physical Journal A - Hadrons and Nuclei》2006,27(2):183-186
The 15O(α,α)15O elastic scattering is investigated using a 15O radioactive beam and a He gas cell limited by Mylar windows. The width of a 19Ne state at an excitation energy of 5.35MeV is measured as Γα = 3.2±1.6keV, in agreement with charge symmetry estimate. 相似文献
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54.
Strong Direct Magnetic Coupling in a Dinuclear CoII Tetrazine Radical Single‐Molecule Magnet 下载免费PDF全文
Toby J. Woods Dr. Maria Fernanda Ballesteros‐Rivas Sergei M. Ostrovsky Andrew V. Palii Oleg S. Reu Sophia I. Klokishner Dr. Kim R. Dunbar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(29):10302-10305
The ligand‐centered radical complex [(CoTPMA)2‐μ‐bmtz.?](O3SCF3)3 ? CH3CN (bmtz=3,6‐bis(2′‐pyrimidyl)‐1,2,4,5‐tetrazine, TPMA=tris‐(2‐pyridylmethyl)amine) has been synthesized from the neutral bmtz precursor. Single‐crystal X‐ray diffraction studies have confirmed the presence of the ligand‐centered radical. The CoII complex exhibits slow paramagnetic relaxation in an applied DC field with a barrier to spin reversal of 39 K. This behavior is a result of strong antiferromagnetic metal–radical coupling combined with positive axial and strong rhombic anisotropic contributions from the CoII ions. 相似文献
55.
Belmessieri D Joannesse C Woods PA MacGregor C Jones C Campbell CD Johnston CP Duguet N Concellón C Bragg RA Smith AD 《Organic & biomolecular chemistry》2011,9(2):559-570
The catalytic activity and enantioselectivity in the kinetic resolution of (±)-1-naphthylethanol with a range of structurally related 3,4-dihydropyrimido[2,1-b]benzothiazole-based catalysts is examined. Of the isothiourea catalysts screened, (2S,3R)-2-phenyl-3-isopropyl substitution proved optimal, giving good levels of selectivity in the kinetic resolution of a number of secondary alcohols (S values up to >100 at ~50% conversion). Low catalyst loadings (0.10-0.25 mol%) of the optimal isothiourea can be used to generate enantiopure alcohols (>99% ee) in good yields. 相似文献
56.
This paper proposes a model and a mechanism for explaining the mechanical behavior of extruded powder aluminum at elevated temperature. This behavior is significantly different from that of ingot-cast and drawn aluminum which is subjected to the same tests. Powder aluminum exhibits a strain-softening effect which is evident in a decrease of stress with increasing strain in uniaxial test specimens when the experiment proceeds into the postyield region. Similar behavior is observed in the shear response during biaxial tension-torsion loading. For these tests, the shear stress is additionally reduced with increased axial extension. A model and mechanism are proposed, based on the relative motion of the extruded aluminum particles, to explain this effect. Equations are derived which relate the axial and shear stresses and strains. These equations are fitted to data obtained in a matrix of experiments, which include combined loadings from uniaxial tension to simple shear. Results are presented graphically and are in good agreement with the proposed models. 相似文献
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Three different series of edge emission bands, associated with donor—acceptor recombination, have been observed at 10 K in crystals of zinc selenide grown in a continuous flow of argon or in sealed capsules in the presence of excess zinc or selenium. It is tentatively suggested that two of these series are associated with random and preferential pairing of the same donors and acceptors. 相似文献
59.
The radiative decay of free excitons with the emission of 0, 1, or 2LO phonons has been observed in electroluminescence in Cds MIS diodes operated in forward bias at temperatures in the range 40 – 77K. The line shapes and temperature dependence of the ILO and 2LO phonon assisted replicas are discussed in terms of the distribution of kinetic energy of the excitons with an effective temperature equal to that of the lattice. 相似文献
60.
T.J. Woods 《Physics letters. [Part B]》1974,50(3):302-304
It is proposed that T< states which strongly mix with analog states to give states of mixed isospin results in the enhancement of the probability of proton decay from highly excited nuclear states. Such considerations are shown to explain the anomalies observed in the () reactions. 相似文献