595 research outputs found
Renormalization-group exponents for superconducting phases in two-leg ladders
In previous studies, we proposed a scaling ansatz for electron-electron
interactions under renormalization group transformation. With the inclusion of
phonon-mediated interactions, we show that the scaling ansatz, characterized by
the divergent logarithmic length and a set of renormalization-group
exponents, also works rather well. The superconducting phases in a doped
two-leg ladder are studied and classified by these renormalization-group
exponents as demonstration. Finally, non-trivial constraints among the
exponents are derived and explained.Comment: 4 pages, 3 figures; minor revisions with references adde
Spatial trends of noncollinear exchange coupling mediated by itinerant carriers with different Fermi surfaces
We study the exchange coupling mediated by itinerant carriers with spin-orbit interaction by both analytic and numeric approaches. The mediated exchange coupling is noncollinear and its spatial trends depend on the Fermi-surface topology of the itinerant carriers. Taking Rashba interaction as an example, the exchange coupling is similar to the conventional Ruderman-Kittel-Kasuya-Yosida type in weak coupling. On the other hand, in the strong coupling, the spiral interaction dominates. In addition, inclusion of finite spin relaxation always makes the noncollinear spiral exchange interaction dominant. Potential applications of our findings are explained and discussed
Generational Differences in Household Car Ownership
The stagnation of car demand had been observed in many countries. A similar phenomenon had emerged in Taiwan. From the perspective of socio-demographic characteristics, this study employs quantile regression for count data to investigate generational differences in household car ownership in Taiwan. The results show that the socio-demographic characteristics affected household car ownership. Due to the seniority effects, households in the later life-cycle stages and households with a higher proportion of elderly members would reduce car demand. But, households with the middle-aged heads owned more cars due to their better economic ability. The income effects are greater for higher income households. Household car ownership varied across
generations, which was related to the income effects, the life course, and household structure. Hence, the demographic changes and generational differences in travel preferences should be considered in urban transportation planning. Seamless transportation and senior-friendly facilities would be important for transportation demand management
The effects of a peer-tutoring strategy on children’s e-book reading comprehension
Reading competence is one of the most critical skills for children’s academic success. In the study reported on here we proposed an integrated peer-tutoring strategy for reading comprehension that employs e-books for elementary school students. The effects of this strategy on children’s reading comprehension were investigated using a quasi-experimental design. Three classes of 11–12-year-old students (n = 73) participated in the study for 12 weeks. Compared to the control group, students in the experimental group, who engaged in peer tutoring with e-book reading, showed significant gains in reading comprehension. Students’ perceptions of the benefits of the peer-tutoring resources to their reading are discussed. The findings demonstrate that the integration of peer tutoring in e-book reading results in an effective instructional model for the enhancement of elementary school students’ reading.
Keywords: e-book; elementary school children; mobile learning; peer tutoring; reading comprehensio
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