Subjects: Physics >> Nuclear Physics submitted time 2017-08-22
Abstract: The stability of excited superheavy nuclei (SHN) with 100 Z 134 against neutron emission and fission is investigated by using a statistical model. In particular, a systematic study of the survival probability against fission in the 1n-channel of these SHN is made. In present calculations the neutron separation energies and shell correction energies are consistently taken from the calculated results of the finite range droplet model which predicts an island of stability of SHN around Z = 115 and N = 179. It turns out that this island of stability persists for excited SHN in the sense that the calculated survival probabilities in the 1n-channel of excited SHN at the optimal excitation energy are maximized around Z = 115 and N = 179. This indicates that the survival probability in the 1n-channel is mainly determined by the nuclear shell effects.
Peer Review Status:Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2017-08-22
Abstract: Halo phenomenon in deformed nuclei is studied by using a fully self-consistent deformed relativistic Hartree-Bogoliubov model in a spherical Woods-Saxon basis with the proper asymptotic behavior at large distance from the nuclear center. Taking a deformed neutron-rich and weakly bound nucleus 44Mg as an example and by examining contributions of the halo, deformation effects, and large spatial extensions, we show a decoupling of the halo orbitals from the deformation of the core.
Peer Review Status:Awaiting Review
Subjects: Physics >> Nuclear Physics submitted time 2017-07-30
Abstract: With the relativistic Coulomb wave function boundary condition, the energies, widths and wave functions of the single proton resonant orbitals for 17Ne are studied by the analytical continuation of the coupling constant (ACCC) approach within the framework of the relativistic mean field (RMF) theory. Pairing correlations and contributions from the single-particle resonant orbitals in the continuum are taken into consideration by the resonant Bardeen-Cooper-Schrieffer (BCS) approach, in which constant pairing strength is used. It can be seen that the fully self-consistent calculations with NL3 and NLSH effective interactions mostly agree with the latest experimental measurements, such as binding energies, matter radii, charge radii and densities. The energy of π2s1/2 orbital is slightly higher than that of π1d5/2 orbital, and the occupation probability of the (π2s1/2)2 orbital is about 20%, which are in accordance with the shell model calculation and three-body model estimation.
Peer Review Status:Awaiting Review
Subjects: Physics >> Interdisciplinary Physics and Related Areas of Science and Technology submitted time 2016-05-08
Abstract: Sequence-function爎elations for爏mall燫NA (sRNA)-mediated爂ene爏ilencing爓ere quantified for爐he爏RNA RyhB and some of its mRNA targets爄n燛scherichia coli. Numerous mutants of RyhB and its targets were generated and their爄n爒ivo functions characterized at various levels of target and RyhB expression. Although a core complementary region is required for repression燽y燫yhB, variations爄n爐he燾omplementary sequences of爐he燾ore region gave rise to a continuum of repression strengths, correlated exponentially with爐he燾omputed free energy of RyhB-target duplex formation. Moreover,爏equence爒ariations爄nthe爈inker region known to interact with爐he燫NA chaperone Hfq also gave rise to a continuum of repression strengths, correlated exponentially with爐hecomputed energy cost of keeping爐he爈inker region open. These results support爐he燼pplicability of爐he爐hermodynamic model爄n爌redicting sRNA-mRNA interaction and suggest that sequences at these locations may be used to fine-tune爐he燿egree of repression. Surprisingly, a truncated RyhB without爐he燞fq-binding region is found to repress multiple targets of爐he爓ild-type RyhB effectively, both爄n爐he爌resence and absence of Hfq, even though爐he爁ormer is required for爐he燼ctivity of wild-type RyhB itself. These findings challenge爐he燾ommonly accepted model concerning爐he爁unction爋f Hfq爄n爂ene爏ilencing-bothin爌roviding stability to爐he爏RNAs and爄n燾atalyzing爐he爐arget mRNAs to take on active conformations-and raise爐he爄ntriguing question of why many endogenous sRNAs subject their functions to Hfq-dependences.
Peer Review Status:Awaiting Review