Symmetry of superconducting states with two orbitals on a tetragonal lattice: application to LaO1−xFxFeAsLaO_{1-x}F_{x}FeAs

We use group theory to classify the superconducting states of systems with two orbitals on a tetragonal lattice. The orbital part of the superconducting gap function can be either symmetric or anti-symmetric. For the orbital symmetric state, the parity is even for spin singlet and odd for spin triplet; for the orbital anti-symmetric state, the parity is odd for spin singlet and even for spin triplet. The gap basis functions are obtained with the use of the group chain scheme by taking into account the spin-orbit coupling. In the weak pairing limit, the orbital anti-symmetric state is only stable for the degenerate orbitals. Possible application to iron-based superconductivity is discussed.Comment: published versio

Investigating types of delinquents in a non-Western country: a group-based model approach

This study focuses on the empirical status for theories of types of delinquents in a non-Western country: Taiwan. Based on the theories and current empirical status of them, current study tries to answer three main questions: (1) How many groups of delinquent trajectories in Taiwan? (2) What factors distinguish between trajectory groups? Do empirical findings support common factors argument or trajectory-specific argument? (3) Do the covariates of delinquency work differently for trajectory groups in different timing?;Using five-year prospective longitudinal research in Taiwan, current research applies Nagin\u27s group-based models to exploring these questions. In group-based models, results show three trajectory groups (never, early and late starters) for boys and two (never and early starters) for girls. It corresponds to what has already found in Western literature for boys, but not for girls. In the risk factor analysis, common risk factor argument gains much support than trajectory-specific argument. Last, in time-varying covariate analysis, the results support the timing argument that covariates work best in later waves for late starters, while they work similar for early starters across time.;Limitations and discussions are provided in the conclusion section. Suggestions for possible intervention and future research are also provided

The disappearance of a narrow Mg II absorption system in quasar SDSS J165501.31+260517.4

In this letter, we present for the first time, the discovery of the disappearance of a narrow Mg II $\lambda\lambda2796,2803$ absorption system from the spectra of quasar SDSS J165501.31+260517.4 ($z_{\rm e}=1.8671$). This absorber is located at $z_{\rm abs} =1.7877$, and has a velocity offset of $8,423\rm ~km~s^{-1}$ with respect to the quasar. According to the velocity offset and the line variability, this narrow Mg II $\lambda\lambda2796,2803$ absorption system is likely intrinsic to the quasar. Since the corresponding UV continuum emission and the absorption lines of another narrow Mg II $\lambda\lambda2796,2803$ absorption system at $z_{\rm abs}=1.8656$ are very stable, we think that the disappearance of the absorption system is unlikely to be caused by the change in ionization of absorption gas. Instead, it likely arises from the motion of the absorption gas across the line of sight

The Critical Success Factors and Integrated Model for Implementing E-business in Taiwan’s SMEs

Purpose - To date, identifying barriers and critical success factors (CSFs) and integrating business model in implementing e-business for SMEs have not been systematically investigated. Few existing studies have derived their CSFs and business model from large companies\u27 perspectives and have not considered the needs of integration for smaller businesses. This paper is aimed to bridge this gap. Design/methodology/approach - Existing studies on CSFs and e-business model were reviewed and their limitations were identified. By integrating insights drawn from these studies as well as adding some new factors, the author proposed a set of 18 CSFs which is believed to be more useful for SMEs. The importance of the proposed CSFs was theoretically discussed and justified. In addition, a case study was conducted to evaluate the extent of success of this proposition. Findings - The overall results from the case study assessment were positive, thus reflecting the appropriateness of the proposed CSFs and integrated model. Practical implications - The set of CSFs and integrated model can act as a list of items and an easy to follow model for SMEs to address when adopting e-business. This helps to ensure that the essential issues and factors are covered during implementation. For academics, it provides a common language for them to discuss and study the factors crucial for the success of e-business in SMEs. Originality/value - This study is probably the first to provide an integrative perspective of CSFs and integrated model for implementing e-business in the SME sector. It gives valuable information, which hopefully will help this business sector to accomplish e-business visions