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1.
The Burgers vectors of the so-called threading screw dislocations (a total of 28 dislocations) in 4H-SiC were determined by large-angle convergent-beam electron diffraction. A new type of TSD, that is, b = c + 2a dislocation, was identified. Thus, all of the four types of TSD predicted by Onda et al. [Phil. Mag. Lett. 93 (2013) p.591] were identified.  相似文献   

2.
The deformation microstructure of single crystals of 4H-SiC resulting from microindentations on a prismatic surface was investigated by TEM. Indentations were performed at 400 and 675°C, i.e. below the brittle to ductile transition temperature of 4H-SiC (temperature close to 1100°C). TEM analysis reveals dissociated dislocations as well as extended stacking faults in the basal plane. In addition, perfect edge dislocations are observed on prismatic planes. From the observations, it is assumed that perfect dislocations are nucleated in the prismatic plane and cross-slip on the basal one where they dissociate.  相似文献   

3.
Defects in highly nitrogen-doped 4H-SiC deformed by cantilever bending at 550°C have been identified by weak-beam and high-resolution transmission electron microscopy techniques. The induced-defects consist of double stacking faults (DSFs) whose expansion produces a local 4H?→?3C phase transformation. Each DSF is bound by two identical 30° Si(g) partial dislocations which glide on two adjacent basal planes. The DSFs belong to three different populations which differ by their extension as a function of the applied-stress and the 30° Si(g) characteristics (line direction L , Burgers vector b , glide planes and glide direction). The external mechanical stresses are the main driving forces involved in the DSF expansion. However, extra driving forces such as thermodynamic or electronic forces are also likely to be involved.  相似文献   

4.
Krist Vaesen 《Synthese》2011,181(3):515-529
The Credit Theory of Knowledge (CTK)—as expressed by such figures as John Greco, Wayne Riggs, and Ernest Sosa—holds that knowing that p implies deserving epistemic credit for truly believing that p. Opponents have presented three sorts of counterexamples to CTK: S might know that p without deserving credit in cases of (1) innate knowledge (Lackey, Kvanvig); (2) testimonial knowledge (Lackey); or (3) perceptual knowledge (Pritchard). The arguments of Lackey, Kvanvig and Pritchard, however, are effective only in so far as one is willing to accept a set of controversial background assumptions (for instance, that innate knowledge exists or that doxastic voluntarism is wrong). In this paper I mount a fourth argument against CTK, that doesn’t rest on any such controversial premise, and therefore should convince a much wider audience. In particular, I show that in cases of extended cognition (very broadly conceived), the most salient feature explaining S’s believing the truth regarding p may well be external to S, that is, it might be a feature of S’s (non-human, artifactual) environment. If so, the cognitive achievement of knowing that p is not (or only marginally) creditable to S, and hence, CTK is false.  相似文献   

5.
The visual fields of rhesus monkeys have been studied perimetrically before and after removal of parts of the striate cortex. The operations produced visual field defects of the expected size, shape, and position but an animal's ability to respond to a flash of light which appeared in the defective part of the field was diminished rather than abolished. It is suggested that this residual ability enables an animal to detect changes in illumination, which might be cues to other visual events. A study of fixation indicates that the animals probably do not recognize or respond to objects when they lie within the impaired region of the visual field. The results are compared with those found in earlier studies of simian and human subjects.  相似文献   

6.
7.
There is a growing realization in cognitive science that a theory of embodied intersubjectivity is needed to better account for social cognition. We highlight some challenges that must be addressed by attempts to interpret ‘simulation theory’ in terms of embodiment, and argue for an alternative approach that integrates phenomenology and dynamical systems theory in a mutually informing manner. Instead of ‘simulation’ we put forward the concept of the ‘extended body’, an enactive and phenomenological notion that emphasizes the socially mediated nature of embodiment. To illustrate the explanatory potential of this approach, we replicate an agent-based model of embodied social interaction. An analysis of the model demonstrates that the extended body can be explained in terms of mutual dynamical entanglement: inter-bodily resonance between individuals can give rise to self-sustaining interaction patterns that go beyond the behavioral capacities of isolated individuals by modulating their intra-bodily conditions of behavior generation.  相似文献   

8.
Monocular visual field defects were studied in two monkeys. In one, the macular retina was destroyed by photocoagulation, producing a central scotoma and consistent 5° eccentric fixation. In a second animal the effects of removal of macular projection area in striate cortex and subsequent photocoagulation of the macula were compared. The cortical operation produced a partial field defect, i.e. a region of diminished sensitivity but not a scotoma, which became with practice much smalle than the region of retina whose primary projection area had been ablated. A 10° eccentric fixation was observed. Following the second, retinal, operation a macular scotoma was demonstrated whose size and position corresponded closely with the area of retinal destruction as determined by photography of the fundus and later histological examination of the retina.  相似文献   

9.
This study is an extended replication of the Larsen and Seidman study (1986) on the Bem Sex-Role Inventory (BSRI) as a measurement instrument for gender-schematic processing. Using a Dutch sample and the GRAS (Groninger Androgyny Scale)—a Dutch sex-role inventory—responses to this inventory were factor-analysed separately for sex-typed and non-sex-typed groups. The extremity of response style on GRAS items and the degree of self-indicated cross-situational variability on GRAS items were used as additional indices for gender-schematic processing. Similar to Larsen and Seidman's (1986) study, bipolar factors were found for the sex-typed groups and unipolar factors for the non-sex-typed groups. Similar to a study conducted by Bem (1981) into differences among the sex-types in their response latencies to the attributes of the BSRI, sex-typed subjects showed more extremity of response style on attributes of the GRAS when making schema-consistent judgements about themselves, and showed less extremity of response style when making schema-inconsistent judgements about themselves. The data on cross-situational variability were less equivocal. It is concluded that the degree of gender-schematic processing in individuals can be well measured by means of a sex-role inventory.  相似文献   

10.
This study investigated the relationship between culture, structural aspects of the nuclear and extended family, and functional aspects of the family, that is, emotional distance, social interaction, and communication, as well as geographical proximity. The focus was on the functional aspects of family, defined as members of the nuclear family (mother, father, and their children) and the extended family (grandmother/grandfather, aunt/uncle, cousins). Sixteen cultures participated in this study, with a total number of 2587 participants. The first hypothesis, that the pattern of scores on the psychological measures and the behavioral outcomes are similar across cultures, an indication of cultural universality, was supported. The second hypothesis, that functional relations between members of the nuclear family and their kin are maintained in high‐affluent and low‐affluent cultures, and that differences in functional relationships in high‐ and low‐affluent cultures are a matter of degree, was also supported by the findings. The results suggest that it is less meaningful in cross‐cultural family studies to ask questions about the structure of the family, than to ask about the functional relationships between members of the nuclear family and their kin. In looking only at the nuclear family, one focuses only on those residing in the household, but ignores those important members of the extended family who may reside nearby and their significant relationships with the members of the nuclear family.  相似文献   

11.
When a stick is used to extend the boundaries of the world perceived by touch, haptic parallels to visual angle and size constancy appear. In a pilot study, Ss using a stick to feel an out-of-reach gap were more likely to underestimate its size than were Ss feeling a nearby gap with the index finger, but size constancy was relatively high with the stick. The main study, comparing judgments of gaps at intermediate and far positions, confirmed these findings. Errors were greater for the more distant gap, but constancy was high in both positions. Correlations between far and intermediate judgments indicated that Ss were consistent in the type of error made. Similar findings emerged from a partial replication with blind and partially sighted Ss.  相似文献   

12.
I argue that examining the explanatory power of the hypothesis of extended cognition (HEC) offers a fruitful approach to the problem of cognitive system demarcation. Although in the discussions on HEC it has become common to refer to considerations of explanatory power as a means for assessing the plausibility of the extended cognition approach, to date no satisfying account of explanatory power has been presented in the literature. I suggest that the currently most prominent theory of explanation in the special sciences, James Woodward's contrastive-counterfactual theory, and an account of explanatory virtues building on that theory can be used to develop a systematic picture of cognitive system demarcation in the psychological sciences. A major difference between my differential influence (DI) account and most other theories of cognitive extension is the cognitive systems pluralism implied by my approach. By examining the explanatory power of competing traditions in psychological memory research, I conclude that internalist and externalist classificatory strategies are characterized by different profiles of explanatory virtues and should often be considered as complementary rather than competing approaches. This suggests a deflationary interpretation of HEC.  相似文献   

13.
This article provides an overview and analysis of recent work on the extended self, demonstrating that the boundaries of selves are fluid, shifting across biological, artifactual, and sociocultural structures. First, it distinguishes the notions of minimal self, person, and narrative self. Second, it surveys how philosophers, psychologists, and cognitive scientists argue that embodiment, cognition, emotion, consciousness, and moral character traits can be extended and what that implies for the boundaries of selves. It also reviews and responds to various criticisms and counterarguments against the extended self. The main focus is on the link between the extended mind and extended self, which has received the most attention in recent literature. But accounts of the extended self developed independently of the extended mind are also briefly discussed. This article ends by drawing out some of the conceptual, methodological, and normative implications of the extended self and suggesting some directions for future research.  相似文献   

14.
Differential partitioning of extended experiences   总被引:1,自引:0,他引:1  
This article focuses on the effect of the perceived cohesiveness of experiences, whether composed of single or multiple parts, on their overall hedonic evaluations. Four experiments demonstrate the effects of partitioning on decision makers’ evaluation of extended experiences. First, patterns (i.e., improving vs. deteriorating trends) strongly influence how experiences are evaluated. Second, increased partitioning of an experience reduces the effect of the overall trend and results in more equal weighting of its parts. Third, breaking experiences at strategic points (i.e., local maxima and minima) influences the overall evaluation of experiences as well as the prediction of their future levels. These results suggest that components of sequences are evaluated similarly to the way whole sequences are evaluated and that experiences composed of multiple components are evaluated relatively more on the basis of their individual intensity and less based on their overall pattern.  相似文献   

15.
16.
Five experiments were designed to investigate the influence of three-dimensional (3-D) orientation change on apparent motion. Projections of an orientation-specific 3-D object were sequentially flashed in different locations and at different orientations. Such an occurrence could be resolved by perceiving a rotational motion in depth around an axis external to the object. Consistent with this proposal, it was found that observers perceived curved paths in depth. Although the magnitude of perceived trajectory curvature often fell short of that required for rotational motions in depth (3-D circularity), judgments of the slant of the virtual plane on which apparent motions occurred were quite close to the predictions of a model that proposes circular paths in depth.  相似文献   

17.
Over the past 12 years, a wide variety of neurodegenerative diseases has been linked to mutations in mitochondrial genes located in either the mitochondrial DNA (mtDNA) or the nuclear DNA (nDNA). These disorders encompass an array of unorthodox inheritance patterns and a plethora of symptoms ranging from lethal neonatal multi-symptom disorders to later onset myopathies, cardiomyopathies, movement disorders, and dementias. The bases for the genetic and phenotypic variability of mitochondrial diseases lie in the multiplicity of the mitochondria genes dispersed across the human genome and the variety of cellular pathways and functions in which the mitochondria play a central role.  相似文献   

18.
This paper will defend the cognitivist view of cognition against recent challenges from Andy Clark and Richard Menary. It will also indicate the important theoretical role that cognitivism plays in understanding some of the core issues surrounding the hypothesis of extended cognition.  相似文献   

19.
Using horizontal rotational motions of a hand-held rod, participants in four experiments probed the aperture between two blocks separated in depth. The farther block could be either on the outer or on the inner side of the hand-rod system, defining apertures of opposite sense. The participants reported the perceived size of the in-depth intervals by adjusting, with the nonprobing hand, the lateral separation between two blocks or the egocentric distances of two blocks. Over variations in hand and geometric arrangement of stimulus and report blocks, perceived aperture size depended on the aperture's sense: Apertures with the farther edge on the outer side of the hand-rod were reported as being larger than their mirror image counterparts. The effect was not observed in judgments of a single edge distance (Experiment 5); it was configuration dependent. The sense effect would not be expected from the physical quantity accommodating perceived frontal apertures. Possible expansions of the physical model are discussed.  相似文献   

20.
An extension of Buss’s device for measuring human aggression is described, and the status of aggressive response latency as an indicator of aggressive motivation is discussed. An experiment is described in which measures of latency correlated negatively with those of shock intensity, and both discriminated between Ss who were motivated to aggress and those who were not.  相似文献   

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