5,394 research outputs found
Isovector channel of quark-meson-coupling model and its effect on symmetry energy
The non-relativistic approximation of the quark-meson-coupling model has been
discussed and compared with the Skyrme-Hartree-Fock model which includes spin
exchanges. Calculations show that the spin-exchange interaction has important
effect on the descriptions of finite nuclei and nuclear matter through the Fock
exchange. Also in the quark-meson-coupling model, it is the Fock exchange that
leads to a nonlinear density-dependent isovector channel and changes the
density-dependent behavior of the symmetry energy.Comment: 20 pages, 9 figures and 1 table, accepted for publication in Nuclear
Physics
On the "Security analysis and improvements of arbitrated quantum signature schemes"
Recently, Zou et al. [Phys. Rev. A 82, 042325 (2010)] pointed out that two
arbitrated quantum signature (AQS) schemes are not secure, because an
arbitrator cannot arbitrate the dispute between two users when a receiver
repudiates the integrity of a signature. By using a public board, they try to
propose two AQS schemes to solve the problem. This work shows that the same
security problem may exist in their schemes and also a malicious party can
reveal the other party's secret key without being detected by using the
Trojan-horse attacks. Accordingly, two basic properties of a quantum signature,
i.e. unforgeability and undeniability, may not be satisfied in their scheme
Alternate proof of the Rowe-Rosensteel proposition and seniority conservation
For a system with three identical nucleons in a single- shell, the states
can be written as the angular momentum coupling of a nucleon pair and the odd
nucleon. The overlaps between these non-orthonormal states form a matrix which
coincides with the one derived by Rowe and Rosensteel [Phys. Rev. Lett. {\bf
87}, 172501 (2001)]. The propositions they state are related to the eigenvalue
problems of the matrix and dimensions of the associated subspaces. In this
work, the propositions will be proven from the symmetric properties of the
symbols. Algebraic expressions for the dimension of the states, eigenenergies
as well as conditions for conservation of seniority can be derived from the
matrix.Comment: 9 pages, no figur
Calculation of the spectrum of 12Li by using the multistep shell model method in the complex energy plane
The unbound nucleus Li is evaluated by using the multistep shell model
in the complex energy plane assuming that the spectrum is determined by the
motion of three neutrons outside the Li core. It is found that the ground
state of this system consists of an antibound state and that only this
and a and a excited states are physically meaningful
resonances.Comment: 9 pages, 5 tables, 7 figures, printer-friendly versio
The influence of social capitalism on construction safety behaviors: An exploratory megaproject case study
Health and safety issues are critical factors influencing the sustainable development of mega construction projects. The impact of social capitalism on health and safety activities has been widely discussed in sustainability domains; nevertheless, its influence towards workers' safety behaviors in mega construction projects remains largely unknown. To address this research gap, the current study aims to determine the influence of social capitalism on safety behaviors from a two-fold perspective between project managers and construction workers. An exploratory case study was adopted from a mega construction project in Tianjin, China. The results reveal that (a) the social network between project managers and construction workers manifests itself as close communication and contact, trust and emotional identification, common language, vision, and values; (b) project managers' management behaviors show stronger influences on construction workers' safety compliance behaviors, while their leadership behaviors show stronger influences on construction workers' safety participation behaviors; and (c) the practice of social capitalism promotes enforcement of commands and compulsory norms and plays a positive regulatory role on safety behaviors. These findings provide new insights into the use of social capitalism for improving safety behaviors and ultimately facilitate the attainment of the broader goal of sustainability in mega construction projects
Technical Review: Analysis and Appraisal of Four-Dimensional Building Information Modeling Usability in Construction and Engineering Projects
Building information modeling (BIM) fundamentally requires the importation of a three-dimensional (3D) model with a series of repository data. Numerous studies have been conducted to clarify the philosophy of BIM and promote its adoption in construction and engineering projects. The primary contributions of this research to the construction engineering and management body of knowledge are the technical review, analysis, and appraisal of various issues concerning the usability of four-dimensional (4D) BIM. The research aims to determine the readiness and development of 4D BIM. A technical literature review was conducted of various BIM software websites, journal articles, brochures, and videos about required 4D elements. A comparative analysis was conducted to compare the technical (TECA) and project-planning functionality (PPFA) aspects of developing 4D models with features provided by available BIM software. This analysis yielded matrices that can be used to guide decision making on which BIM software to invest in. The results reveal that all of the software packages in their way serve the purpose of developing a 4D BIM model
Molecular structure of highly-excited resonant states in Mg and the corresponding Be+O and C+C decays
Exotic Be and C decays from high-lying resonances in Mg are
analyzed in terms of a cluster model. The calculated quantities agree well with
the corresponding experimental data. It is found that the calculated decay
widths are very sensitive to the angular momentum carried by the outgoing
cluster. It is shown that this property makes cluster decay a powerful tool to
determine the spin as well as the molecular structures of the resonances.Comment: 17 pages, no figur
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