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131.
This research examined the association between relationship satisfaction and later breakup status, focusing on the temporal changes in satisfaction ratings of individuals in newly formed dating relationships. Growth curve analytic techniques were used in 2 longitudinal studies to create 4 predictors: each participant's initial level of satisfaction, linear trend in satisfaction over time, degree of fluctuation in satisfaction over time, and mean level of satisfaction. Consistent with hypotheses, individuals who exhibited greater fluctuation in their repeated satisfaction ratings were more likely to be in relationships that eventually ended, even after controlling for overall level of satisfaction. Individuals with fluctuating levels of satisfaction also reported relatively lower commitment. The results are discussed in terms of conditions that promote versus undermine relationship stability.  相似文献   
132.
The affective consequences of social comparison were examined in 2 field studies among nurses and related to the 3 dimensions of professional burnout: emotional exhaustion, reduced personal accomplishment, and depersonalization. Study t was conducted in a sample of 99 nurses of a psychiatric hospital, and Study 2 in a sample of 237 nurses employed in various settings In general, upward comparisons evoked more positive and less negative affect than did downward comparisons. However, the affective consequences of social comparison were different for those high and low in burnout. Those low in personal accomplishment reported higher levels of negative affect from upward comparisons and higher levels of positive affect from downward comparisons than did those high in personal accomplishment. In addition, in Study 2, those high in depersonalization and emotional exhaustion derived more positive affect from downward comparisons than did those with lower levels of burnout.  相似文献   
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The effectiveness of tetraethylammonium (TEA) and high-frequency stimulation (HFS) in inducing long-term synaptic modification is compared in CA1 and dentate gyrus (DG) in vitro. High-frequency stimulation induces long-term potentiation (LTP) at synapses of both perforant path-DG granule cell and Schaffer collateral-CA1 pyramidal cell pathways. By contrast, TEA (25 mM) induces long-term depression in DG while inducing LTP in CA1. The mechanisms underlying the differential effect of TEA in CA1 and DG were investigated. It was observed that T-type voltage-dependent calcium channel (VDCC) blocker, Ni2+ (50 microM), partially blocked TEA-induced LTP in CA1. A complete blockade of the TEA-induced LTP occurred when Ni2+ was applied together with the NMDA receptor antagonist, D-APV. The L-type VDCC blocker, nifidipine (20 microM), had no effect on CA1 TEA-induced LTP. In DG of the same slice, TEA actually induced long-term depression (LTD) instead of LTP, an effect that was blocked by D-APV. Neither T-type nor L-type VDCC blockade could prevent this LTD. When the calcium concentration in the perfusion medium was increased, TEA induced a weak LTP in DG that was blocked by Ni2+. During exposure to TEA, the magnitude of field EPSPs was increased in both CA1 and DG, but the increase was substantially greater in CA1. Tetraethylammonium application also was associated with a large, late EPSP component in CA1 that persisted even after severing the connections between CA3 and CA1. All of the TEA effects in CA1, however, were dramatically reduced by Ni2+. The results of this study indicate that TEA indirectly acts via both T-type VDCCs and NMDA receptors in CA1 and, as a consequence, induces LTP. By contrast, TEA indirectly acts via only NMDA receptors in DG and results in LTD. The results raise the possibility of a major synaptic difference in the density and/or distribution of T-type VDCCs and NMDA receptors in CA1 and DG of the rat hippocampus.  相似文献   
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These studies examined the relations among performance satisfaction, choice of social comparison targets, and subsequent performance in a classroom setting. Previous research has shown that comparison with high performers helps academic performance. In 2 field studies, this relation was moderated by satisfaction with initial performance. After learning their scores on the first exam of the semester, students indicated their satisfaction with the scores and performance level of someone with whom they would like to compare exams. Comparison with poor performers was beneficial when coupled with dissatisfaction. Dissatisfied students who preferred comparison with poor performers improved over the semester.  相似文献   
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The concept of capacity has become increasingly important in discussions of working memory (WM), in so far as most models of WM conceptualize it as a limited-capacity mechanism for maintaining information in an active state, and as capacity estimates from at least one type of WM task—complex span—are valid predictors of real-world cognitive performance. However, the term capacity is also often used in the context of a distinct set of WM tasks, change detection, and may or may not refer to the same cognitive capability. We here develop maximum-likelihood models of capacity from each of these tasks—as well as from a third WM task that places heavy demands on cognitive control, the self-ordered WM task (SOT)—and show that the capacity estimates from change detection and complex span tasks are not correlated with each other, although capacity estimates from change detection tasks do correlate with those from the SOT. Furthermore, exploratory factor analysis confirmed that performance on the SOT and change detection load on the same factor, with performance on our complex span task loading on its own factor. These findings suggest that at least two distinct cognitive capabilities underlie the concept of WM capacity as it applies to each of these three tasks.  相似文献   
139.
Microstructure and deformation mechanisms at a nanoindentation in the lamellar colony of high Nb containing TiAl alloy have been studied using the focused ion beam and the transmission electron microscopy. Considerable deformation twins are observed around the nanoindentation, and a strain gradient is generated. A continuous change in the bending angle of the lamellar structure can be derived, and a strain-induced grain refinement process is observed as various active deformations split the γ grains into subgrains. In addition to all possible deformation mechanisms (ordinary dislocation, super-dislocation and deformation twining) activated due to the heavy plastic deformation, a 6-layer hexagonal (6H) long-period stacking ordered structure is identified for the first time near the contact zone and is thought to be closely related to the glide of partial dislocations.  相似文献   
140.
The plastic stability of bimetals composed of a Ti-based metallic glass composite (MGC) and a pure titanium (PT) under tension has been investigated. The results reveal that the plastic stability of the MGC/PT bimetal is strongly dependent on the thickness fraction of the MGC: when the thickness fraction of the MGC decreases to a critical value, a homogeneous plastic deformation occurs in the MGC/PT bimetals, i.e. the strain localization and necking of the MGC is effectively suppressed. This unique phenomenon is explained using the normalized strain-hardening rate, and the quantitative relationship between the normalized strain-hardening rate of the MGC/PT bimetals and the thickness fraction of the MGC is thereby established.  相似文献   
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