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1.
The superheating behaviour of embedded particles induced by semicoherent interfaces has been observed in many circumstances. In this paper, a phenomeno‐ logical model for melt nucleation on misfit dislocations at a semicoherent interface is proposed. A kinetic limit for semicoherent-interface-induced superheating, which is in good agreement with the results of experiments and computer simulations, is derived from this model. Calculations and analyses based on the model reveal that melting prefers to initiate at the semicoherent interface and that superheating of embedded particles is possible for a melt nucleation contact angle less than 90°. Among the matrix-dependent parameters, the contact angle and the shear modulus of the matrix are found to be dominant in determining the superheating of embedded particles.  相似文献   

2.
Intuitively it has seemed to many that our concepts conscious state and conscious creature are sharp rather than vague, that they can have no borderline cases. On the other hand, many who take conscious states to be identical to, or realized by, complex physical states are committed to the vagueness of those concepts. In the paper I argue that conscious state and conscious creature are sharp by presenting four necessary conditions for conceiving borderline cases in general, and showing that some of those conditions cannot be met with conscious state. I conclude that conscious state is sharp, and the conclusion is then extended to conscious creature. The paper ends with a brief discussion of some implications.
Michael V. AntonyEmail:
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3.
Around the 1960s, political psychology was developed as a field of knowledge that attempted to interrelate scientific psychology and political phenomena. However, social and academic conditions are very different today. More and more, political psychology is becoming a protagonist, as much in the internal context of psychology as in the external context of its relations with the social world. Thus, political psychology can now be seen as a resource relating psychological knowledge to social practice, and relating psychological processes to social action. Political psychology is the interface that puts psychology and society in contact. The development of political psychology in Spain provides an example of this alternative view of the field.  相似文献   

4.
A phase field model accounting for plasticity has been developed using an homogenization scheme for interpolating the constitutive laws within the diffuse interface. The influence of plasticity on the growth of a misfitting spherical precipitate, controlled by solute diffusion has been investigated: plasticity in the matrix slows down the transformation. Moreover, an excellent agreement with the corresponding analytical sharp interface solutions has been achieved.  相似文献   

5.
A meta-analytic test of intergroup contact theory   总被引:9,自引:0,他引:9  
The present article presents a meta-analytic test of intergroup contact theory. With 713 independent samples from 515 studies, the meta-analysis finds that intergroup contact typically reduces intergroup prejudice. Multiple tests indicate that this finding appears not to result from either participant selection or publication biases, and the more rigorous studies yield larger mean effects. These contact effects typically generalize to the entire outgroup, and they emerge across a broad range of outgroup targets and contact settings. Similar patterns also emerge for samples with racial or ethnic targets and samples with other targets. This result suggests that contact theory, devised originally for racial and ethnic encounters, can be extended to other groups. A global indicator of Allport's optimal contact conditions demonstrates that contact under these conditions typically leads to even greater reduction in prejudice. Closer examination demonstrates that these conditions are best conceptualized as an interrelated bundle rather than as independent factors. Further, the meta-analytic findings indicate that these conditions are not essential for prejudice reduction. Hence, future work should focus on negative factors that prevent intergroup contact from diminishing prejudice as well as the development of a more comprehensive theory of intergroup contact.  相似文献   

6.
Auvray M  Philipona D  O'Regan JK  Spence C 《Perception》2007,36(12):1736-1751
Whenever we explore a simulated environment, the sensorimotor interactions that underlie our perception of space may be modified. We investigated the conditions under which it is possible to acquire the mastery of new sensorimotor laws and thereby to infer new perceptual spaces. A computer interface, based on the principles of minimalist sensory-substitution devices, was designed to enable different possible links between a user's actions (manipulation of a mouse and/or keys of a keyboard) and the resulting pattern of sensory stimulation (visual or auditory) to be established. The interface generated an all-or-none stimulus whose activation varied as a function of the participant's exploration of a hidden form. In this study we addressed the following questions: What are the conditions necessary for participants to understand their actions as constituting a displacement in a simulated space? What are the conditions required for participants to conceive of sensations as originating from the encounter with an object situated in this space? Finally, what are the conditions required for participants to recognise forms within this space? The results of the two experiments reported here show that, under certain conditions, participants can interpret the new sensorimotor laws as movements in a new perceptual space and can recognise simple geometric forms, and that this occurs no matter whether the sensory stimulation is presented in the visual or auditory modality.  相似文献   

7.
E Greene 《Perception》1988,17(1):65-70
With the classic Poggendorff illusion a set of parallel 'induction lines' will cause a set of oblique line segments to look misaligned even though they are collinear. A different kind of misalignment can be produced by placing the induction lines so that they form a corner. Under these conditions the obliques will appear to be angled slightly, one relative to the other. The effects are small, but can be seen and reliably reported by a group of naive subjects. The influence of the induction lines drops sharply as their relative position is moved from parallel to orthogonal, but there is a small residual influence which may be called the corner Poggendorff effect.  相似文献   

8.
A survey of the published literature on undercooled metallic and oxide melts suggests that phase selection during solidification can be categorized as nucleation controlled or growth controlled. Common characteristics governing the phase-selection pathway have been identified for various alloy systems. It is recognized that when competing stable and metastable phases share the same crystalline characteristics and have comparable interface kinetic coefficients, the principle of nucleation control applies for primary phase formation in a deeply undercooled melt. However, there can be a difference of two or three orders of magnitude in the interface kinetic coefficients for competing phases, either between an ordered intermetallic compound and a disordered solid solution, or between a crystalline phase with a high level of complexity and a simple crystal. In such cases, the principle of growth control will apply; more specifically, the phase with the faster growth kinetics should be favoured and the competing counterpart with sluggish interface kinetics should be suppressed at high undercoolings. Some simple predictions are suggested on the basis of this principle when considering stable and metastable phase diagrams. The specific conditions under which the present categorization is applicable are outlined. Future work is required to elucidate phase competition under conditions of very rapid solidification.  相似文献   

9.
It is shown that initially sharp interface in AB diffusion couple, above the ordering temperature, can shift with anomalous kinetics, i.e. deviations from the parabolic growth kinetics are possible. The initial slopes of the shift versus time functions can be even unity for large diffusion asymmetry (the ratio of diffusion coefficients of the parent materials in orders of magnitude) and gradually decrease to 0.5 at larger distances (longer times). This is in accordance with earlier results obtained in phase separating systems. It is shown that from the results of simulations the crossover thickness, X*, between the linear and parabolic regimes can also be calculated, and the applicability of the linear–parabolic law is confirmed. Furthermore, it is illustrated that the crossover thickness depends exponentially on the diffusion asymmetry parameter, with the exponent close to the value obtained from analytical estimations.  相似文献   

10.
In this paper I offer a counterexample to the so called vagueness argument against restricted composition. This will be done in the lines of a recent suggestion by Trenton Merricks, namely by challenging the claim that there cannot be a sharp cut-off point in a composition sequence. It will be suggested that causal powers which emerge when composition occurs can serve as an indicator of such sharp cut-off points. The main example will be the case of a heap. It seems that heaps might provide a very plausible counterexample to the vagueness argument if we accept the idea that four grains of sand is the least number required to compose a heap—the case has been supported by W. D. Hart. My purpose here is not to put forward a new theory of composition, I only wish to refute the vagueness argument and point out that we should be wary of arguments of its form.
Tuomas E. TahkoEmail:
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11.
Experiments are described showing that Octopus can be trained to distinguish by touch between a cube and a sphere, a surprising result since previous work has always indicated that octopuses cannot take proprioceptive information into account in learning. It can be shown, however, that the cube/sphere discrimination is made by detecting the distortion imposed on the rims of individual suckers in contact with the corners of the cube. Thus it is shown (1) that a cube with the corners even slightly rounded is less readily distinguishable from a sphere than a cube with sharp corners and, more important, (2) that a narrow rod is readily accepted in place of the cube by trained animals. Indeed, the rod seems to be a “better” cube than the original, and errors of discrimination decrease when it replaces the cube, presumably because it lacks flat surfaces liable to be confused with the surface of the sphere by a system depending on information from sense organs arranged in circles on the rims of the suckers.  相似文献   

12.
Recent research suggests that eye contact can lead to enhanced self-awareness. A related phenomenon, the sense of agency deals with the notion of the self as the origin of our actions. Possible links between eye contact and agency have been so far neglected. Here, we investigated whether an implicit sense of agency could be modulated by eye gaze. We asked participants to respond (button press) to a face stimulus: looking or not at the participant (experiment 1); or displaying distinct eye gaze before or after a mask (experiment 2). After each trial, participants estimated the time between their key press and the ensuing effects. We found enhanced intentional binding for conditions that involved direct compared to averted gaze. This study supports the idea that eye contact is an important cue that affects complex cognitive processes and suggests that modulating self-processing can impact the sense of agency.  相似文献   

13.
The purpose of the current study is to examine the relationship between religion and post death contact among older Mexican Americans. Four major themes emerged from 52 in-depth interviews that were conducted with Older Mexican Americans residing in Texas. First, many older study participants told us they had contact with the dead, but others indicated this was not possible. Second, the form in which contact with the dead was made varied greatly. Some older Mexican Americans reported they had visual contact with the dead, while others said they only made contact with the dead through dreams. Third, although some older Mexican American study participants believed that it was in the best interests of the dead to contact the living, others felt the dead should instead be in Heaven with God. Fourth, the participants in our study reported that having contact with the dead provides a number of important social and psychological benefits. In the process of discussing these themes, an emphasis is placed on how beliefs and experiences with the dead interface with religion. In addition, we also explore how post death contact may be associated with health and well-being in late life.  相似文献   

14.
te Vrugt  Michael 《Synthese》2021,199(5-6):12891-12921

The special composition question (SCQ), which asks under which conditions objects compose a further object, establishes a central debate in modern metaphysics. Recent successes of inductive metaphysics, which studies the implications of the natural sciences for metaphysical problems, suggest that insights into the SCQ can be gained by investigating the physics of composite systems. In this work, I show that the minus first law of thermodynamics, which is concerned with the approach to equilibrium, leads to a new approach to the SCQ, the thermodynamic composition principle (TCP): Multiple systems in (generalized) thermal contact compose a single system. This principle, which is justified based on a systematic classification of possible mereological models for thermodynamic systems, might form the basis of an inductive argument for universalism. A formal analysis of the TCP is provided on the basis of mereotopology, which is a combination of mereology and topology. Here, “thermal contact” can be analyzed using the mereotopological predicate “self-connectedness”. Self-connectedness has to be defined in terms of mereological sums to ensure that scattered objects cannot be self-connected.

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15.
Green's functions for magnetoelectroelastic medium with an arbitrarily oriented half-plane or bimaterial interface are presented in this paper. The derivation is based on an extended Stroh's formalism and coordinate-transform technique. In particular, a new coordinate variable is introduced to handle vertical or other boundary problems. These Green's functions satisfy related boundary or interface conditions. The Green's functions obtained can be used to establish boundary-element formulation and to analyse fracture behaviour involving half-plane boundaries or bimaterial interfaces.  相似文献   

16.
A simple input and output circuit is described that allows users to sense contact closures and to drive relays from a Digital Equipment Corporation LSI-11 DRV 11 parallel interface board or a signal-compatible equivalent.  相似文献   

17.
The propagation of shear horizontal waves between the interface of two magneto-electro-elastic materials with an magneto-electro-mechanical imperfect contact has been studied. Mechanical, electrical and magnetical imperfections are modelled by means of a spring, a capacitor and an inductor, respectively. A general expression for the dispersion relation is given in an explicit form. Some limit cases are analysed in detail. The influence of imperfect contacts is shown in some numerical results.  相似文献   

18.
以321名少数民族大学生为被试,考察了民族接触(与汉族)、交往态度、民族认同、民族本质论、民族刻板印象和群际焦虑等变量,以整合的视角探讨了民族接触促进民族交往的机制问题。研究结果表明:民族接触通过降低群际焦虑和民族认同、减弱消极刻板印象和民族本质论而间接促进了民族交往,民族认同在民族接触和民族本质论之间、消极刻板印象在民族接触和群际焦虑之间存在中介作用。这项整合的研究理论上丰富了群际接触减少偏见的机制研究,发现了新的中介变量,对促进民族交往的实践具有指导意义。  相似文献   

19.
The interaction of light with surfaces results in a number of lighting effects that may serve as valuable visual cues. Previous research on shadows has shown them to be effective in determining the three-dimensional (3-D) layout of a scene, but interreflections have been ignored as cues for spatial layout. Interreflections as well as shadows may help to disambiguate the 3-D layout of objects by providing information about an object's contact with a surface. We generated computer images of a box on an extended textured ground plane that was either in contact with the ground or was slightly above the ground. Images were rendered for four conditions: (1) no shadow + no interreflection, (2) shadow only, (3) interreflection only, and (4) shadow + interreflection. A photometrically incorrect condition was also included. The participants rated the degree of contact for each image on a scale, which was used to generate receiver operating characteristic (ROC) curves and a measure of sensitivity. In the images with no shadows or interreflections, the participants performed at chance levels. Interreflections, shadows, and a combination of interreflections and shadows all resulted in high sensitivity for judging object contact. More important, information from shadows and interreflections can be combined, resulting in near-perfect judgment of surface contact. Interreflections and shadows can be effective cues for object contact.  相似文献   

20.
A classifier based on the linear regression model was developed to automatically detect sharp transients in EEG, matching the definition of spikes and sharp waves accepted by IFSECN. Practical applications proved the accuracy of the method which succeeded in detecting 84% of sharp transients previously found by an experienced electronencephalographer. Computerized search for sharp transients in EEG records will be particularly useful in long term EEG records obtained from epileptic patients.  相似文献   

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