Dissertation com aug 1997 (2 Ergebnisse)

Taschenbuch. Zustand: Neu. Neuware - This study investigated young children's expectations regarding others' potential reactions to their emotional displays. These expectations were considered precursors to the display rules for emotional expression evident in middle childhood. Possible gender differences in the children's expectancies for the expression of anger, sadness and fear were examined.Preschool and early grade school children (ages 4.3-6.4 & 7.0-8.7, respectively) were presented with eight hypothetical narratives illustrated with felt puppets. The identity of an audience figure accompanying the protagonist of each narrative varied between subjects in three experimental conditions: mother, father, and same-sex peer. The narratives also varied the social context within which the protagonist expressed an emotion. The scenarios were qualitatively coded to assess if children expected favorable or unfavorable reactions from the audience figure to the protagonist's emotional display.The expression of anger elicited substantial unfavorable expectancies from children in both age groups but the expression of sadness and fear did not. It was theorized that the display rules for these emotions have different developmental timelines. Anger receives early socialization pressure while sadness and fear are not sanctioned until after approximately age 8. Children expected peers and parents to respond equally unfavorably to expressions of anger, suggesting that both groups are important agents in emotional socialization at this age. Unlike the preschoolers, the early grade school children used social information about a provocateur's status and intentions to mediate their expectations regarding audience reactions to anger. The only significant gender difference to emerge was that the older girls expected mothers to be more disapproving of anger than fathers or peers. It was suggested that gender role requirements for emotional expression may not be enforced until children reach grade school ages and that the same-sex parent may come to be the primary socialization agent for these roles. Asian-American children held fewer unfavorable expectancies for the expression of anger than children of other ethnicities. African-American girls held more unfavorable expectancies for the expression of anger than African-American boys. Future research should elaborate upon the specific content and developmental timelines associated with different cultures' emotional display rules.…

Taschenbuch. Zustand: Neu. Neuware - This study is a theoretical investigation of the electronic and optical properties of intrinsic semiconductors using the orthogonal empirical tight binding model. An analysis of the bulk properties of semiconductors with the zincblende, diamond and rocksalt structures has been carried out. We have extended the work of others to higher order in the interaction integrals and derived new parameter sets for certain semiconductors which better fit the experimental data over the Brillouin zone. The Hamiltonian of the heterostructures is built up layer by layer from the parameters of the bulk constituents.The second part of this work examines a number of applications of the theory. We present a new microscopic derivation of the intervalley deformation potentials within the tight binding representation and computes a number of conduction-band deformation potentials of bulk semiconductors. We have also studied the electronic states in heterostructures and have shown theoretically the possibility of having barrier localization of above-barrier states in a multivalley heterostructure using a multiband calculation. Another result is the proposal for a new 'type-II' lasing mechanism in short-period GaAs/AlAs superlattices. As for our work on the optical properties, a new formalism, based on the generalized Feynman-Hellmann theorem, for computing interband optical matrix elements has been obtained and has been used to compute the linear and second-order nonlinear optical properties of a number of bulk semiconductors and semiconductor heterostructures. In agreement with the one-band elective mass calculations of other groups, our more elaborate calculations show that the intersubband oscillator strengths of quantum wells can be greatly enhanced over the bulk interband values.…