Time filter

Source Type

Li J.J.,Lanzhou University | Li J.J.,University Paris - Sud | Li J.J.,University Claude Bernard Lyon 1 | Long W.H.,Lanzhou University | And 5 more authors.
Physical Review C - Nuclear Physics | Year: 2016

The occurrence of the bubble-like structure has been studied, in the light of pseudospin degeneracy, within the relativistic Hartree-Fock-Bogoliubov (RHFB) theory. It is concluded that the charge/neutron bubble-like structure is predicted to occur in the mirror system of {Si34,Ca34} commonly by the selected Lagrangians, due to the persistence of Z(N)=14 subshell gaps above which the π(ν)2s1/2 states are not occupied. However, for the popular candidate Ar46, the RHFB Lagrangian PKA1 does not support the occurrence of the bubble-like structure in the charge (proton) density profiles, due to the almost degenerate pseudospin doublet {π2s1/2,π1d3/2} and coherent pairing effects. The formation of a semibubble in heavy nuclei is less possible as a result of small pseudospin-orbit (PSO) splitting, while it tends to appear at Z=120 superheavy systems which coincides with large PSO splitting of the doublet {π3p3/2,π2f5/2} and couples with significant shell effects. Pairing correlations, which can work against bubble formation, significantly affect the PSO splitting. Furthermore, we found that the influence on semibubble formation due to different types of pairing interactions is negligible. The quenching of the spin-orbit splitting in the p orbit has been also stressed, and it may be considered the hallmark for semibubble nuclei. © 2016 American Physical Society.


Li J.J.,Lanzhou University | Li J.J.,University Claude Bernard Lyon 1 | Li J.J.,University Paris - Sud | Margueron J.,University Claude Bernard Lyon 1 | And 3 more authors.
Physics Letters, Section B: Nuclear, Elementary Particle and High-Energy Physics | Year: 2016

The formation of new shell gaps in intermediate mass neutron-rich nuclei is investigated within the relativistic Hartree-Fock-Bogoliubov theory, and the role of the Lorentz pseudo-vector and tensor interactions is analyzed. Based on the Foldy-Wouthuysen transformation, we discuss in detail the role played by the different terms of the Lorentz pseudo-vector and tensor interactions in the appearing of the N=16, 32 and 34 shell gaps. The nuclei 24O, 48Si and 52,54Ca are predicted with a large shell gap and zero (24O, 52Ca) or almost zero (48Si, 54Ca) pairing gap, making them candidates for new magic numbers in exotic nuclei. We find from our analysis that the Lorentz pseudo-vector and tensor interactions induce very specific evolutions of single-particle energies, which could clearly sign their presence and reveal the need for relativistic approaches with exchange interactions. © 2015 The Authors.


Gao L.-F.,Lanzhou University | Gao L.-F.,Key Laboratory of Special Function Materials and Structure Design | Xu J.-Y.,Lanzhou University | Zhu Z.-Y.,Lanzhou University | And 6 more authors.
Nanoscale | Year: 2016

Ultrathin BP QDs with a uniform size of ∼3.4 nm were prepared via small molecule-assisted liquid phase exfoliation and they exhibited superior broadband nonlinear saturable absorption promising for nonlinear optical applications. Laser photolysis measurement implied that the nonlinear response origin was related to the long-lived electron-hole pairs delocalized within the BP QDs. © 2016 The Royal Society of Chemistry.


Wu H.,Lanzhou University | Wu H.,Key Laboratory of Special Function Materials and Structure Design | Li P.,China Academy of Engineering Physics | Pan D.,Lanzhou University | And 7 more authors.
PLoS ONE | Year: 2016

The interactions between contaminations of U(VI) and silicon oxide nanoparticles (SONPs), both of which have been widely used in modern industry and induced serious environmental challenge due to their high mobility, bioavailability, and toxicity, were studied under different environmental conditions such as pH, temperature, and natural organic matters (NOMs) by using both batch and spectroscopic approaches. The results showed that the accumulation process, i.e., sorption, of U(VI) on SONPs was strongly dependent on pH and ionic strength, demonstrating that possible outer- and/or inner-sphere complexes were controlling the sorption process of U(VI) on SONPs in the observed pH range. Humic acid (HA), one dominated component of NOMs, bounded SONPs can enhance U(VI) sorption below pH∼4.5, whereas restrain at high pH range. The reversible sorption of U(VI) on SONPs possibly indicated that the outer-sphere complexes were prevalent at pH 5. However, an irreversible interaction of U(VI) was observed in the presence of HA (Fig 1). It was mainly due to the ternary SONPs-HA-U(VI) complexes (Type A Complexes). After SONPs adsorbed U(VI), the particle size in suspension was apparently increased from ~240 nm to ~350 nm. These results showed that toxicity of both SONPs and U(VI) will decrease to some extent after the interaction in the environment. These findings are key for providing useful information on the possible mutual interactions among different contaminants in the environment. © 2016 Wu et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


Liu B.,Lanzhou University | Shi K.,Lanzhou University | Shi K.,Key Laboratory of Special Function Materials and Structure Design | Ye G.,Lanzhou University | And 3 more authors.
Microchemical Journal | Year: 2016

A convenient method was developed for rapid determination of Pu in environmental water samples. The analytical procedure involves preconcentration of Pu using TEVA extraction chromatography implemented in a vacuum box setup, and measurement of 239+240Pu by low background liquid scintillation counter (LSC). Chromatographic behaviors of plutonium, uranium, thorium, and americium were investigated, and the size of chromatographic column, concentration and flow rate of uploaded medium/washing liquid, and composition of eluent of Pu(Cl-)6 2--on TEVA column were explored. The results show that all the above factors affect the adsorption and desorption of Pu(Cl-)6 2--on TEVA column. Decontamination factors of more than 1×104 for uranium and 1×103 for thorium and americium were achieved. Chemical yields of plutonium in the overall procedure range from 70% to 98% and a detection limit of 6×10-3 Bq L-1 in 60min counting time for 5L of water samples were obtained. The method has been successfully applied for rapid and effective determination of low level Pu in water samples. The analytical results show a good agreement with the values obtained using the conventional method. Compared with the conventional analytical procedure, the time consumption and labor intensiveness of the new procedure were greatly reduced and the analysis throughput was greatly increased with low analysis cost. The method is applicable to routine and emergency radiometric assays. © 2015 Elsevier B.V.


Qi B.,Shandong University | Zhang N.-B.,Shandong University | Sun B.-Y.,Lanzhou University | Sun B.-Y.,Key Laboratory of Special Function Materials and Structure Design | And 2 more authors.
Research in Astronomy and Astrophysics | Year: 2016

We study the dimensionless spin parameter j ≡ cJ/(GM2) of different kinds of uniformly rotating compact stars, including traditional neutron stars, hyperonic neutron stars and hybrid stars, based on relativistic mean field theory and the MIT bag model. It is found that jmax ∼ 0.7, which had been suggested in traditional neutron stars, is sustained for hyperonic neutron stars and hybrid stars with M > 0.5 M⊙. Not the interior but rather the crust structure of the stars is a key factor to determine jmax for three kinds of selected compact stars. Furthermore, a universal formula j = 0.63(f/fK) - 0.42(f/fK)2 + 0.48(f/fK)3 is suggested to determine the spin parameter at any rotational frequency f smaller than the Keplerian frequency fK. © 2016 National Astronomical Observatories, Chinese Academy of Sciences and IOP Publishing Ltd.


Liu B.,Lanzhou University | Shi K.,Lanzhou University | Shi K.,Key Laboratory of Special Function Materials and Structure Design | Ye G.,Lanzhou University | And 3 more authors.
Analytical Methods | Year: 2015

An analytical method for rapid determination of 239+240plutonium in environmental water samples was developed. The separation of plutonium from matrices and interfering elements was performed using anion exchange chromatographic columns in a vacuum box system. Under the optimized conditions, the chemical yield of plutonium is better than 90% and the decontamination factors for uranium, thorium and americium ranged from 103 to 104 for 5 L water samples. The concentration of plutonium was measured by detecting the α decay of 239+240plutonium using low background liquid scintillation counting (LSC). The analytical results of the plutonium in water samples were in good agreement with the values obtained by the conventional method, indicating that the proposed method is reliable and can be used for low level plutonium analysis in environmental water samples. © 2015 The Royal Society of Chemistry.


Qi B.,Shandong University | Zhang N.-B.,Shandong University | Wang S.-Y.,Shandong University | Sun B.-Y.,Lanzhou University | Sun B.-Y.,Key Laboratory of Special Function Materials and Structure Design
Chinese Physics Letters | Year: 2015

Based on the equations of state from the relativistic mean field theory without and with the inclusion of strangeness-bearing hyperons, we study the dimensionless spin parameter j = cj/(GM2) of uniformly rotating neutron stars. It is shown that the maximum value of the spin parameter jmax of a neutron star rotating at the Keplerian frequency fK is jmax ∼ 0.7 when the star mass M > 0.5⊙, which is sustained for various versions of equations of state without and with hyperons. The relationship between j and the scaled rotation frequency f/K is found to be insensitive to the star mass or the adopted equation of state in the models without hyperons. However, the emergence of hyperons in neutron stars will lead to an uncertainty of the spin parameter j, which in turn could generate a complexity in the theoretical study of the quasi-periodic oscillations observed in disk-accreting compact-star systems. © 2015 Chinese Physical Society and IOP Publishing Ltd.


Zhao Q.,Lanzhou University | Zhao Q.,Key Laboratory of Special Function Materials and Structure Design | Sun B.Y.,Lanzhou University | Sun B.Y.,Key Laboratory of Special Function Materials and Structure Design | And 2 more authors.
Journal of Physics G: Nuclear and Particle Physics | Year: 2015

The density dependence of nuclear symmetry energy is studied within the covariant density functional (CDF) theory in terms of the kinetic energy, isospin-singlet, and isospin-triplet potential energy parts of the energy density functional. When the Fock diagram is introduced, it is found that both isospin-singlet and isospin-triplet components of the potential energy play an important role in determining the symmetry energy. At high densities, a strong density-dependent behavior is revealed in the isospin-triplet potential part of the symmetry energy. In addition, the inclusion of the Fock terms in the CDF theory reduces the kinetic part of the symmetry energy and may lead to negative values at the supranuclear density region, which is regarded partly as the effect of the nuclear tensor-force components. The results demonstrate the importance of the Fock diagram in the CDF theory on the isospin properties of the in-medium nuclear force at high densities, especially from the isoscalar-meson coupling channels. © 2015 IOP Publishing Ltd.


Xu J.-Y.,Lanzhou University | Xu J.-Y.,Key Laboratory of Special Function Materials and Structure Design | Gao L.-F.,Lanzhou University | Hu C.-X.,Lanzhou University | And 6 more authors.
Chemical Communications | Year: 2016

Ultrathin uniform BP nanosheets with lateral dimensions of up to several tens of micrometers were prepared via a small molecule-assisted liquid phase exfoliation method, which exhibited attractive electron accepting abilities from photosensitizers and was thus promising in diverse applications such as photocatalysis and photovoltaics. © The Royal Society of Chemistry 2016.

Loading Key Laboratory of Special Function Materials and Structure Design collaborators
Loading Key Laboratory of Special Function Materials and Structure Design collaborators