100,731 research outputs found
High-resolution investigation of the Sb-121(p,t)Sb-119 reaction and quasiparticle-phonon model description
No full textThe Sb-121(p,t)Sb-119 reaction has been measured in a high-resolution experiment at an incident energy of 21 MeV. Accurate measurement of the (p,t) reaction angular distributions for the transitions to the levels of Sb-119 allows us to determine energies of 59 levels, 23 of which have been identified for the first time, and to assign the angular momentum transfer values and a well-defined range for the J values. DWBA analysis has been performed in a finite-range approximation, assuming a dineutron cluster pickup mechanism, by using conventional Woods-Saxon potentials for the entrance proton and exit triton channel. The present (p,t) data have been supplemented by microscopic calculations in the framework of the quasiparticle-phonon model, giving a reasonably good description of the experimental fragmentation of the integrated cross sections and the absence of (p,t) strength above 2.9 MeV
Study pf the 119Sb via the 121Sb(p,t)119Sb reaction
No full textAccurate measurement of the (p,t)
reaction angular distributions for the transitions to the levels of 119Sb
allows us to confirm or determine energies of 59 levels, 23 of which have been
identified for the first time and to assign the angular momentum transfer values
and a well-defined range for the J values. By using conventional Woods-Saxon
potentials for the entrance proton and exit triton channel, the DWBA analysis
has been performed in a finite range approximation, assuming a dineutron cluster
pickup mechanism. The present (p,t) data have been supplemented by microscopic
calculations in the framework of QPM, giving a reasonably good description
of the experimental fragmentation of the cross sections and the absence of (p,t)
strength above 2.9 MeV
The 123Sn(p,t)118Sn reaction : level structure of 118Sn and microscopic DWBA calculations
No full textThe 120Sn(p,t)118Sn reaction has been studied in a high resolution experiment at an incident energy of 21 MeV. Differential cross sections for 37 transitions to levels of 118Sn up to an excitation energy of about 3.6 MeV have been measured. Cluster and microscopic DWBA analysis and shell model calculations have been carried out
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
118Sn levels studied by the 120Sn( p, t) reaction : high-resolution measurements, shell model, and distorted-wave Born approximation calculations
No full textCross-section angular distributions of 38 (p, t ) transitions to final states of 118Sn up to an excitation energy
of 3.597 MeV have been measured in a high-resolution experiment at an incident proton energy of 21 MeV. A
distorted-wave Born approximation (DWBA) analysis of the 38 experimental differential cross sections, carried
out by using conventionalWoods-Saxon potentials, allowed us either 18 confirmations of previous spin and parity
values or new assignments of spin and parity to 14 states of 118Sn. A shell-model calculation has been performed
by using a realistic two-body effective interaction derived from the CD-Bonn nucleon-nucleon potential. The
doubly-magic nucleus 132Sn is assumed as a closed core, with 14 valence neutron holes occupying the five levels
of the 50–82 shell. Within this model space the calculations are performed by employing the seniority scheme
including states with seniority up to 4. The energy spectrum of 118Sn has been calculated and compared with
the experimental one. The theoretical two-neutron spectroscopic amplitudes are used in the microscopic DWBA
calculations of some cross-section angular distributions
Handwritten biographical information on Paulina T. McClung Merritt
No full textA handwritten biography of Paulina T. McClung Merritt by an unknown author, 1892.
Heterogeneous and tissue-specific regulation of effector T cell responses by IFN-gamma during Plasmodium berghei ANKA infection.
No full textIFN-γ and T cells are both required for the development of experimental cerebral malaria during Plasmodium berghei ANKA infection. Surprisingly, however, the role of IFN-γ in shaping the effector CD4(+) and CD8(+) T cell response during this infection has not been examined in detail. To address this, we have compared the effector T cell responses in wild-type and IFN-γ(-/-) mice during P. berghei ANKA infection. The expansion of splenic CD4(+) and CD8(+) T cells during P. berghei ANKA infection was unaffected by the absence of IFN-γ, but the contraction phase of the T cell response was significantly attenuated. Splenic T cell activation and effector function were essentially normal in IFN-γ(-/-) mice; however, the migration to, and accumulation of, effector CD4(+) and CD8(+) T cells in the lung, liver, and brain was altered in IFN-γ(-/-) mice. Interestingly, activation and accumulation of T cells in various nonlymphoid organs was differently affected by lack of IFN-γ, suggesting that IFN-γ influences T cell effector function to varying levels in different anatomical locations. Importantly, control of splenic T cell numbers during P. berghei ANKA infection depended on active IFN-γ-dependent environmental signals--leading to T cell apoptosis--rather than upon intrinsic alterations in T cell programming. To our knowledge, this is the first study to fully investigate the role of IFN-γ in modulating T cell function during P. berghei ANKA infection and reveals that IFN-γ is required for efficient contraction of the pool of activated T cells
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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