Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract. The neutron transfer in a very heavy asymmetric nuclear system, in 206 Pb + 118 Sn has been measured using particle- $\gamma$ coincidence techniques with position-sensitive detectors, 5 EUROBALL-Cluster detectors (EB) and the Heidelberg-Darmstadt NaI-CRYSTAL BALL (CB). The fragments are identified via the known $\gamma$ -decays of the lowest excited states using the high resolution of EB. Using the unique feature of the set-up with the CB, transfer to well-defined final channels with known quantum numbers is selected using the high-efficiency multiplicity filter of the CB with no second $\gamma$ -ray, i.e. without feeding. The enhancement in the two-neutron transfer is deduced, for population of the low-lying super-fluid 2 + states in 120 Sn and 116 Sn, while the 2n-transition remains in the ground state for the recoiling 20X Pb-nuclei. Large enhancements up to EF $\simeq 10^3$ are observed. This is the first observation of neutron pair-transfer enhancement for a heavy nuclear binary system with superfluid properties with experimentally separated levels.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Angular and energy correlations betweenα-particles and quasi-elastic projectile-like heavy ions have been measured for36Ar+197Au collisions atE LAB=380MeV. The majority of the observed coincident events can be understood in terms of a statistical emission process whereas only a small fraction of the events, mainly at forward angles, can be attributed to a direct process.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1434-601X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Angular and energy correlations betweenα-particles and deep-inelastic projectile-like fragments were measured for the system36Ar+197Au atE Lab=380 MeV. At most half of the coincident events can be attributed to statistical emission ofα-particles from the fully accelerated projectile-like fragments. The remainder of the events may be due to direct emission during the first 10−22 s of the scattering process and to preequilibrium processes taking place within some 10−21 s.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1434-601X
    Keywords: PACS:21.10.-k Properties of nuclei; nuclear energy levels – 21.10.Dr Binding energies and masses – 25.70.Hi Transfer reactions – 27.20.+n 6 ≤ A ≤ 19
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract: New information has been obtained on excited states of the neutron-rich boron isotopes 14B, 15B and 16B, using the reactions 12C(14C,12N)14B, 13C(14C,12N)15B and 14C(14C,12N)16B at about 24 MeV/A. The mass excess of 16B has been measured for the first time, it is 37.08(6) MeV. This means that 16B is unbound by only 0.04(6) MeV. Furthermore, the nucleus 13B has been investigated with the four reactions 16O(14C,17F), 12C(14C,13N), 12C(13C,12N) and 12C(15N,14O). Choosing different target-projectile combinations, it was possible to populate states with different selectivity. New states are observed in 13B at excitation energies above the threshold for two-neutron decay.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1432-2277
    Keywords: Key words Extracellular matrix ; Liver transplantation ; Acute rejection ; Early chronic rejection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have previously observed changes at the extracellular matrix (ECM) which significantly correlated with the extent of preservation and reperfusion injury. In the present study, we attempted to investigate whether the ECM may be also involved in the pathophysiological sequelae of acute and chronic rejection. Of 81 patients monitored for the ECM parameters laminin, hyaluronic acid, fibronectin receptor, and transforming growth factor (TGF)-β , 28 patients developed acute rejection (〈 1 month), in 14 patients (17.4 %) acute rejection was steroid resistant, 4 patients (4.5 %) developed early chronic rejection following acute steroid-resistant rejection. Acute and chronic rejection were confirmed by established clinical and histological criteria. Laminin levels were significantly increased in patients experiencing acute steroid-resistant rejection (4204 ± 133 ng/ml; P K 0.01) compared with patients with steroid-sensitive rejection (1059 ± 27.3 ng/ml) and with an uneventful postoperative course (1214 ± 17.4 ng/ml). No increase in laminin was observed in those four patients who developed early chronic rejection (1099 ± 58.7 ng/ml). Hyaluronic acid, fibronectin receptor, and TGF-β levels also increased in patients with acute steroid-resistant rejection; hyaluronic acid: 290 ± 10.8 μg/l vs 154 ± 13.6 μg/l and 131 ± 11.7 μg/l in patients with steroid-sensitive and no rejection, respectively; fibronectin receptor: 1003 ± 23.5 ng/ml vs 573 ± 24.8 ng/ml and 428 ± 13.6 ng/ml in patients with steroid-sensitive and no rejection, respectively; and TGF-β : 393 ± 14.9 pg/ml versus 315 ± 10.7 pg/ml and 233 ± 8.9 pg/ml in patients with steroid-sensitive and no rejection, respectively. A further increase in hyaluronic acid levels was observed in patients who developed early chronic rejection, while fibronectin receptor and TGF-β levels remained low, similarly to laminin levels. The increase in laminin, hyaluronic acid, fibronectin receptor, and TGF-β during acute steroid-resistant rejection may be stimulated by the rejection-related release of cytokines and adhesion molecules which paralleled the increase in ECM parameters. The lack of increase in laminin and fibronectin receptor levels in those patients who developed early chronic rejection may reflect an inability to recover from acute rejection.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1434-601X
    Keywords: 25.70.Jj ; 25.85.Ge
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Energy spectra and multiplicities of neutrons from the reaction system 838 MeV32S projectiles on197Au have been measured in coincidence with binary fragmentations. Neutron detection was performed simultaneously in a 4π scintillator sphere and by time-of-flight. The linear momentum transfer (LMT) and the excitation energyE CN * are deduced with the folding angle technique. Neutron multiplicities are compared for consistency and discussed as a measure of LMT andE CN * . The saturation ofM 4π (E CN * ) beyondE CN * ≈400 MeV seen for several systems of high fissility (x≧0.8) is attributed to the spreading of the folding angle distribution and the increasing competition of charged particle evaporation.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1434-601X
    Keywords: 24.10.-i ; 24.10.Eq ; 24.20.Ht ; 25.70.Cd
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Elastic, inelastic scattering as well as one-neutron transfer channels have been measured over a wide angular range for systems16O+16O at the incident energy of 350 MeV and20Ne+12C at 390 MeV, respectively, using the Q3D magnetic spectrometer. In both cases differential cross sections have been measured down to about 50 nb/sr (or dσ/dσ R≤10−4) at large angles. For the16O+16O system refractive contributions are found at the level of these cross sections, whereas in the20Ne+12C case a steeper decrease of the differential cross section with the angle is observed and the refractive contribution can not be determined. The elastic scattering data have been analyzed using standard Woods-Saxon potentials and potentials calculated in different versions of the double-folding model. Some properties of these potentials are tested in the calculations for inelastic scattering and one-neutron transfer within the DWBA. With the refractive pattern observed for the16O+16O system, the scattering and transfer data are found to be sensitive to the interaction potential at small internuclear distances down to about 2.5 fm.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1434-601X
    Keywords: 24.10-i ; 25.70.Cd
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Proton and neutron transfer populating low-lying states have been studied in the system144Sm+88Sr at an energy below the Coulomb barrier. The experimental cross sections for the single proton transfer are well reproduced by DWBA-calculations using spectroscopic information from light ion reactions. The two-proton transfer appears enhanced relative to the uncorrelated sequential transfer of single protons. The same holds for the transfer of proton pairs, the enhancement is kept for the second pair. This is interpreted as a supercurrent between two superfluid nuclear proton-pair wave functions: more mass and charge is transported per time unit in pairs than by single nucleons. Neutron transfer is observed with large cross sections and is found to contribute to the energy loss observed in the transfer reactions. For mixed proton-neutron transfers the sequential nature of the transfer reactions is established in a similar way as for the two-proton and two-neutron transfer; in the latter case no enhancement is observed.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 1434-601X
    Keywords: 21.10.Dr ; 25.70.Cd ; 27.20.+n
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The mass of 13 Be has been measured with the reaction 13 C(14 C,14 O)13 Be at E Lab =337 MeV. A Q-value of Q 0=−37.02(5) MeV was obtained and the mass excess is M.E.=35.16(5) MeV. If the observed line corresponds to the ground state,13 Be is particle unstable with respect to the oneneutron emission by 2.01 MeV. The observed line width of 0.3(2) MeV supports an assignment ofJ π=5/2+ or 1/2−, but excludesJ π=1/2+. An excited state is seen at 3.12(7) MeV; there are indications of a second excited state at 6.5(2) MeV.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    ISSN: 1434-601X
    Keywords: 21.10.Dr ; 25.70.Cd ; 27.20.+ n
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract The mass of10Li has been measured with two different reactions:9Be(13C,12N)10Li,E Lab=336 MeV, and13C(14C,17F)10Li,E Lab=337 MeV. The mass excess of 33.445(50) MeV is deduced from theQ-value measurement.10Li is found to be particle-unstable with respect to one-neutron emission by 0.42(5) MeV. In the analysis of the first reaction a low lying excited state is found at 0.38(8) MeV. This state and the ground state can be most probably identified as the 1+/2+-doublet coupled from the [π 1p3/2 ⊗ν 1p 1/2] configuration, the 1+-state being the ground state. The (13C,12N)-reaction populates the 1+-state strongly due to a spin-isospin-flip character of the dominant part of the transition amplitude. The 2+-member corresponds to the mass given by Wilcox et al. A second excited state is observed at 4.05(10) MeV with a width of 0.7(2) MeV, it can be associated with theν 1d 5/2-strength. The second reaction is fully supporting the interpretation of the ground state doublet. The excited state at 4.05 MeV is not observed in this reaction and indeed it should not, because the reaction does not populate in first order excited neutron configurations. The levels are well described by mean field calculations including pairing correlations. The lowest resonance in the calculations is theν 1/2−-configuration, whereas theν 1/2+-configuration shows at the neutron threshold a strong non-resonant contribution.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...