240 research outputs found
Cross-cultural differences in temperament: Comparing paternal ratings of US and Dutch infants
This study conducted longitudinal comparisons of US and Dutch paternal ratings of temperament, measured via the Infant Behaviour Questionnaire-Revised, at 4 months (US n = 99; Dutch n = 127) and 12 months (US n = 66; Dutch n = 112) of age. US fathers rated their infant higher in the broad temperament trait Surgency, and its subscales vocal reactivity, high-intensity pleasure, and activity level. US fathers also rated their infants higher in negative emotionality, and its subscales of sadness, distress to limitations, and fear. Dutch infants received higher ratings in falling reactivity. Though the cultures did not differ in ratings of Orienting/regulatory capacity, US infants were higher on the subscale duration of orienting, and lower in soothability. Significant culture-by-age and culture-by-gender interactions were also noted. Overall, results are largely consistent with those reported for Dutch mothers and speak to considerable differences in early temperament development between cultures viewed as largely similar because of their Western/individualistic orientations
Model ab initio study of charge carrier solvation and large polaron formation on conjugated carbon chains
Using long C_{N}H_{2} conjugated carbon chains with the polyynic structure as
prototypical examples of one-dimensional (1D) semiconductors, we discuss
self-localization of excess charge carriers into 1D large polarons in the
presence of the interaction with a surrounding polar solvent. The solvation
mechanism of self-trapping is different from the polaron formation due to
coupling with bond-length modulations of the underlying atomic lattice
well-known in conjugated polymers. Model ab initio computations employing the
hybrid B3LYP density functional in conjunction with the polarizable continuum
model are carried out demonstrating the formation of both electron- and
hole-polarons. Polarons can emerge entirely due to solvation but even larger
degrees of charge localization occur when accompanied by atomic displacements
Correlated theory of triplet photoinduced absorption in phenylene-vinylene chains
In this paper we present results of large-scale correlated calculations of
triplet photoinduced absorption (PA) spectrum of oligomers of
poly-(para)phenylenevinylene (PPV) containing up to five phenyl rings. In
particular, the high-energy features in the triplet PA spectrum of oligo-PPVs
are the focus of this study, which, so far, have not been investigated
theoretically, or experimentally. The calculations were performed using the
Pariser-Parr-Pople (PPP) model Hamiltonian, and many-body effects were taken
into account by means of multi-reference singles-doubles configuration
interaction procedure (MRSDCI), without neglecting any molecular orbitals. The
computed triplet PA spectrum of oligo-PPVs exhibits rich structure consisting
of alternating peaks of high and low intensities. The predicted higher energy
features of the triplet spectrum can be tested in future experiments.
Additionally, theoretical estimates of exciton binding energy are also
presented.Comment: To appear in Phys. Rev.
The Global Temperament Project: Parent-Reported Temperament in Infants, Toddlers and Children from 59 Nations
Data from 83,423 parent reports of temperament (Surgency, Negative Affectivity, and Regulatory Capacity) in infants, toddlers and children from 341 samples gathered in 59 countries were used to investigate the relations among culture, gender and temperament. Between-nation differences in temperament were larger than those obtained in similar studies of adult personality, and most pronounced for Negative Affectivity. Nation-level patterns of Negative Affectivity were consistent across infancy, toddlerhood and childhood; and patterns of Regulatory Capacity were consistent between infancy and toddlerhood. Nations that previously reported high Extraversion, high Conscientiousness, and low Neuroticism in adults were found to demonstrate high Surgency in infants and children; and countries reporting low adult Openness and high adult Neuroticism reported high temperamental Negative Affectivity. Negative Affectivity was high in Southern Asia, Western Asia and South America; and low in Northern and Western Europe. Countries in which children were rated as high in Negative Affectivity had cultural orientations reflecting Collectivism, high Power Distance, and Short-Term Orientation. Surgency was high in Southeastern and Southern Asia and Southern Europe, and low in Eastern Asian countries characterized by philosophies of Long-Term Orientation. Low personal income was associated with high Negative Affectivity. Gender differences in temperament were largely consistent in direction with prior studies, revealing higher Regulatory Capacity in females than males and higher Surgency in males than females; with these differences becoming more pronounced at later ages
C-axis optical properties of high Tc cuprates
A review is given of the experimental status of the interlayer coupling
energy in the cuprates. A second c-axis plasmon is identified in the double
layer compound Y123 for various dopings. The anomalous transport properties
along the c-direction and in the planar directions are compared to model
calculations based on strongly anisotropic scattering. An excellent description
of the optical data at optimal doping is obtained if an anomalously large
anisotropy of the scattering rate between cold spots and hot spots is assumed.
This raises questions as to the physical meaning of these parameters.Comment: 4 pages, LaTeX, espcrc2.sty, 3 figures in encapsulated postscript
forma
Charge carrier solvation and large polaron formation on a polymer chain revealed in model ab initio computations
When an excess charge carrier is added to a semiconducting polymer chain, it
is well known that the carrier may self-trap into a polaronic state accompanied
by a bond length adjustment pattern. A different mechanism of self-localization
is the solvation of charge carriers expected to take place when the polymer
chain is immersed in polar media such as common solvents. We use
state-of-the-art ab initio computations in conjunction with the Polarizable
Continuum Model to unequivocally demonstrate solvation-induced self-consistent
charge localization into large-radius one-dimensional (1D) polarons on long
carbon chains with the polyynic structure. Within the framework
used, the solvation results in a much more pronounced charge localization. We
believe this mechanism of polaron formation to be of relevance for various 1D
semiconductors in polar environments
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