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Tammy Ben-Yaacov Tommy Ive Chris G. Van de Walle Umesh K. Mishra James S. Speck Steven P. Denbaars 《Journal of Electronic Materials》2010,39(5):608-611
We investigated the properties of indium-doped zinc oxide layers grown by metalorganic chemical vapor deposition on semi-insulating GaN(0001) templates. Specular and transparent films were grown with n-type carrier concentrations up to 1.82 × 1019 cm−3 as determined by Hall measurements, and all In-doped films had carrier concentrations significantly higher than that of a comparable undoped film. For low In flows, the carrier concentration increased accordingly with trimethyl-indium (TMIn) flow until a maximum carrier concentration of 1.82 × 1019 cm−3 was realized. For higher In flows, the carrier concentration decreased with increasing TMIn flow rate. Sheet resistance as low as 185 Ω/sq was achieved for the In-doped films, which is a significant decrease from that of a comparable undoped ZnO film. Our n-type doping studies show that In is an effective dopant for controlling the n-type conductivity of ZnO. 相似文献
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This article examines the spatial relationships between avatars (i.e., graphical identities or icons) over time in a 2-dimensional online chat environment. The Spatial Distance Analysis Program (SDAP) was developed to measure the distance between avatars in a specially designed Palace environment. Correlations between distance and interpersonal communication constructs of (1) conversational appropriateness, (2) social attraction, and (3) uncertainty reduction indicate that distance effects are significant in an online environment. Specifically, it was found that general conversational appropriateness mediated between uncertainty reduction and specific conversational appropriateness for individuals who moved closer together and farther apart over time, respectively. Furthermore, the relationship between social attraction and distance indicated a significant positive parabolic function; that social attraction (i.e., liking) decreased at middle distances and increased at low and high distances. This finding suggests that there are three interpersonal distance zones in online communication. 相似文献
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This investigation consolidated the recent research on gender differences in self-concept among children and youth by conducting a systematic meta-analysis of research published since 1980, particularly involving self-concept as a multidimensional phenomenon. Through a comprehensive search process, 22 studies representing over 19,000 child and adolescent participants were analyzed. The articles included participant samples from 7 nations: the US, Australia, Northern Ireland, South Africa, Finland, Norway, and Canada. Participants ranged from 1st grade through 12th grade. Mean effect size estimates across dimensions showed a complex pattern of gender differences and similarities, some of which were consistent across grade levels and others of which were not. Although some of the findings defied stereotypes, several were consistent with previous notions regarding differences in self-concept based on gender. The direction and complexity of these results emphasizes the importance of discussing developmental differences in self-concept in a thoughtful and careful manner and argues against the use of simplistic global generalizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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Barry Christopher T.; Frick Paul J.; DeShazo Tammy M.; McCoy Monique; Ellis Mesha; Loney Bryan R. 《Canadian Metallurgical Quarterly》2000,109(2):335
This study focused on the use of callous–unemotional (CU) traits to identify a subgroup of children with both attention deficit/hyperactivity disorder (ADHD) and a conduct problem diagnosis (oppositional defiant disorder [ODD] or conduct disorder [CD]) who show characteristics similar to adults with psychopathy. In a clinic-referred sample of children aged 6 to 13 years (N?=?154), those with diagnoses of both ADHD and ODD/CD were divided on the basis of teacher ratings of CU traits. Children high on these traits showed features typically associated with psychopathy, such as a lack of fearfulness and a reward-dominant response style. Furthermore, children with CU traits seemed less distressed by their behavior problems. These findings are consistent with research on adults showing that impulsivity and antisocial behavior alone are insufficient to document persons who fit the construct of psychopathy. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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