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981.

{111} stacking faults and nanotwins in epitaxial BaTiO3 thin films on MgO substrates have been investigated by high-resolution transmission electron microscopy. In many cases, the stacking faults and nanotwins were found to be accompanied by partial dislocations. These partial dislocations can be classified as two different types, analogous to the situation in the fcc structure. One is of the Shockley type with the Burgers vector (a/3)<112>. The other is of the Frank type with the Burgers vector (a/3)<111>. The movements of both types of partial can lead to the {111} stacking faults and the {111} twins observed in these films.  相似文献   
982.
The nucleation of voids at the initial stage of hollow nanoshell formation is described in terms of the thermodynamics of nucleation in systems of finite size (or small systems) pumped with vacancies by interdiffusion-driven vacancy influx. Crossovers from suppressed nucleation to metastable nucleus formation and then to stable nucleus formation are analysed, describing, in particular, the possibility of significant supersaturations with vacancies of the metallic core. It is shown that at higher temperatures it becomes more favourable to nucleate at once a large single void instead of multiple tiny voids.  相似文献   
983.
An inverse “smaller is stronger” trend is predicted on the basis of molecular dynamics simulations of α-titanium (Ti) single-crystal nanopillars orientated for double prismatic slips when the nanopillars are less than 7?nm wide. This trend is attributed to a significant increase in the surface energy due to the nucleation and propagation of edge dislocations on the surface of the pillars.  相似文献   
984.
Abstract

Regenerative medicine (RM) in Japan lays strong emphasis on a specific trajectory of its development, which deploys human induced pluripotent stem (iPS) cells as the primary sources for the technology. The technique to create these stem cells was developed in 2006 by a Japanese stem cell scientist, Shinya Yamanaka, and since its applicability to human cells was established about a year later, this new type of cells has become to be considered as a potential substitute for human embryonic stem cells. While the clinical value of these cells are yet to be confirmed, the Japanese Ministry of Education, Culture, Sports, Science and Technology decided to concentrate its support on iPS cells research and turned it into a national project. This decision reflected the state's vision of initiating the transition to a knowledge-based society, which was adopted in the 1990s to tackle the prolonged deflation in the country. As the research became intertwined with this policy vision, however, the Ministry came to see bringing its success as more important than ever, while other trajectories of RM were left underrated and largely unsupported. Industrial actors counteracted this situation and developed an initiative to recognize existing technical capability in the country, but its impact has been so far negligible. This indicates that the nation is locked in the particular trajectory of RM. Hence, this Japanese RM research enterprise presents an interesting case to understand how states' commitment may not only shape the course of scientific research but also reduce flexibility in technological development.  相似文献   
985.
In this study, 63 observations of secular IQ changes (both Flynn and anti-Flynn effects) are collected from three demographically diverse studies of the Dutch population for the period 1975–2005 (representing the 1950–1990 birth cohorts), along with data on g loadings and subtest reliabilities. The method of correlated vectors is used to explore the association between Flynn and anti-Flynn effect magnitudes, both independently and together, and the g loadings of subtests. Despite a positive vector correlation the Flynn effects are not associated with the Jensen effect (r = .307, ns, N = 36), however the anti-Flynn effects are (r = .406, P = .05, N = 27). Combined, the vector correlation becomes negative but non-significant (r = −.111, ns, N = 63). Declines due to the anti-Flynn effect are estimated at −4.515 points per decade, whereas gains due to the Flynn effect are estimated at 2.175 points per decade. The N-weighted net of these is a loss of −1.350 points per decade, suggesting an overall tendency towards decreasing IQ in the Netherlands with respect to these cohorts. The Jensen effect on the anti-Flynn effect suggests that it may be related to bio-demographic changes within the Netherlands which have reduced ‘genetic-g’, despite the presence of large, parallel gains on subtests that may be relatively more sensitive to cultural-environmental improvements.  相似文献   
986.
The relationship between the Flynn effect and ability differentiation is investigated in a reanalysis of published data on Estonian student cohorts tested in 1933/36, 1997/98 and 2006 on the National Intelligence Test (Must, te Nijenhuis, Must, & van Vianen, 2009). To determine whether there was a relationship we computed the vector correlation between the Flynn effects (d) and the change in the g loading (Δg) between measurement occasions for each of the 10 NIT subtests and for each of the seven cohort comparisons, giving a total N of 70 effect sizes. The association between d and Δg was robustly negative (indicating that the Flynn effects were negatively associated with changes in the g loading of subtests) for all cohort comparisons, with values of r ranging from −.100 to −.461 (N = 10). When all effect sizes were analyzed together, the vector correlation was found to be −.281 (p ? .05, N = 70). This indicates a significant association between the Flynn effect and ability differentiation. Possible causes of this association are discussed.  相似文献   
987.
In this study we attempt to determine whether dysgenic fertility is associated with the Jensen effect. This is investigated with respect to a US population representative sample of 8110 individuals from the National Longitudinal Survey of Youth for whom there exists complete data on IQ and fertility. In addition to the general sample, the sample was also broken out by race and sex so as to examine whether or not the Jensen effect manifested amongst different sub-populations. The method of correlated vectors revealed significant Jensen effects in five of the seven samples, and in all cases the effect was in a direction indicating that subtests with higher g-loadings were associated with larger dysgenic fertility gradients. The magnitude of the difference between Spearman’s ρ and Pearson’s r was non-significant in all cases, suggesting that biasing factors were minimally influencing the result. This finding suggests that dysgenesis occurs on the ‘genetic g’ at the heart of the Jensen effect nexus, unlike the Flynn effect, which is ‘hollow’ with respect to g. Finally, the finding is discussed in the context of two converging lines of evidence indicating that genotypic IQ or ‘genetic g’ really has been declining over the last century.  相似文献   
988.
989.
Using data from the longitudinal NICHD Study of Early Child Care and Youth Development (N = 1364), this study examined the association between mothers' sensitivity and children's externalizing behavior from preschool to preadolescence. Externalizing behavior declined on average across this period with a slowing of this decline around middle childhood. Maternal sensitivity remained relatively stable on average, and there was significant variation across mothers. A decrease in maternal sensitivity from ages 3 to 11 was related to an increase in externalizing behavior from ages 4 to 12. A model-based test of the direction of the effect suggested that the association between changes in maternal sensitivity and externalizing behavior from ages 4 to 11 was driven by child effects on mothers and not vice-versa. Between late preschool age and preadolescence, the behavior problems of children appear to strongly influence the sensitive support of mothers. Practical implications were discussed in light of these findings.  相似文献   
990.
Abstract

The aim of this study was to analyse the psycholinguistic variables of the attributes and concepts involved in the recall of a concept. One hundred and twenty adults (18–40 years old) participated. A lexical recall task was administered by presenting a successive list of defining attributes. Forty concepts from different semantic categories were used. The attributes were obtained empirically from local Semantic Features Production Norms. The influence of the characteristics and attributes of the concepts on the number of participants who accessed the name of the concept and the correct guess trend was analysed. Significant values for Age of Acquisition, Presence of Distinctive Attributes and Presence of Taxonomic Attributes were observed. Results show that concepts which are acquired earliest are more easily recalled; presenting taxonomic categories narrows the search and the presence of distinctive attributes allow differentiating between such concepts within a category.  相似文献   
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