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191.
In this letter, the dislocation patterns on the common primary slip plane in a fatigued [1-34]-[182-7] copper bicrystal with a Sigma=19b grain boundary (GB) have been investigated using the electron channelling contrast technique in a scanning electron microscope. The results show that the two-phase dislocation structure, such as veins and persistent slip band (PSB) walls, embedded within veins, can be clearly seen on the common primary slip plane. In particular, the interactions of PSBs with the GB are clearly revealed. It is found that there are three kinds of interaction mode between the GB and the dislocations during cyclic deformation, and those are discussed. It is suggested that the dislocations carried by PSBs cannot transfer through the GB continuously even though the bicrystal has a common primary slip plane and its surface slip bands are continuous across the GB. 相似文献
192.
The microstructure and crystallization behaviour of melt-spun Al88Ni9Ce2Fe1 amorphous alloy and nanophase composites have been studied by means of X-ray diffraction, transmission electron microscopy and scanning and isothermal calorimetry. The diffraction patterns from Al88Ni9Ce2Fe1 amorphous alloys are diffuse, indicating a basically amorphous structure but contain two rings presumed to be associated with quenched-in nuclei. In the cases of Al88Ni9Ce2Fe1 nanophase composites, nanoscale precipitated particles are homogeneously dispersed in an amorphous matrix, and the crystallite diameter and volume fraction are sensitive to quenching conditions. During thermal crystallization, a two-step phase transformation occurs in the amorphous alloy and nanocomposites, which is characterized by a diffusion-controlled precipitation of nanoscale Al particles and the growth of a Al3(Ni, Fe) nanophase prior to a Al11Ce3 nanophase. This study gives insight into structure-control for obtaining nanophases dispersed in an amorphous matrix by rapid quenching. 相似文献
193.
Magnesium oxide (MgO) films and particles have been collected by pressurised filtration of a Mg-8.6wt%Al-0.67wt%Zn (AZ91D) alloy melt. The morphology of the oxides and their interfaces with the α-Mg phase were investigated by high-resolution transmission electron microscopy. It was found that the oxide films consisted of large numbers of sub-micrometre-sized MgO particles, and that melt shearing can effectively break up the oxide films and disperse the oxide particles. For the first time, orientation relationships (ORs) of OR I: [1?1?1]MgO～2° from (0?0?0?1)α-Mg and (0?1?1)MgO?//[2?1?1?0)α-Mg; and OR II: (1?1?1)MgO//(1?1?0?1)α-Mg and [0?1?1]MgO//[1?2?1?1]α-Mg, were observed between the MgO particles and the α-Mg matrix. The calculated Bramfitt planar disregistries were 5.5% and 2.5% for the two ORs, respectively, indicating good lattice matching between MgO and α-Mg at the interface. With the evidence of grain refinement effect observed in the sheared AZ91D magnesium alloy, the possibility of MgO particles to act as potent nucleants for heterogeneous nucleation of α-Mg grains is discussed in terms of the crystallographic criterion. 相似文献
194.
We examine special extended spin S?=?1/2 fermionic and hard core bosonic t–Jz models with nearest neighbour and next nearest neighbour interactions to find exact ground states. Some of these models display an exponentially large degeneracy with diagonal stripe-like patterns. 相似文献
195.
Y. Wang S.L. Shang H. Zhang L.-Q. Chen Z.-K. Liu 《Philosophical Magazine Letters》2013,93(12):851-859
To understand the Invar anomalies, such as negative thermal expansion and spontaneous magnetization, we have applied our recently developed thermodynamic framework for a system with itinerant-electron magnetism to the ordered Fe3Pt. The framework has coherently predicted the finite temperature intermixing between the fully ferromagnetic (FM) configuration and the spin-flipping configurations (SFCs). We have also discovered a tri-critical point at which a high-temperature second-order phase transition, between the fully ordered FM phase and the paramagnetic phase which is disordered due to SFCs, becomes first order at low temperatures. 相似文献
196.
Michelle L. West Victoria Z. Lawson Jillian Grose-Fifer 《Basic and applied social psychology》2013,35(2):133-144
There are concerns that if neuroscientific deception detection evidence becomes admissible in court, jurors may weigh it inappropriately. We investigated whether mock jurors were influenced more by electrophysiological than behavioral evidence that a defendant in a criminal trial was lying. Participants’ perceptions of evidence quality predicted verdict choice, and quality ratings were higher for neuroscientific than for behavioral evidence. However, both types of evidence increased guilty verdicts similarly, and the inclusion of neuroimages had no additional impact. These findings suggest that neuroscientific evidence may be processed differently than other types of deception evidence, but it is not necessarily more persuasive. 相似文献
197.
Jacob Z. Hess Danielle Rynczak Joseph D. Minarik Joycelyn Landrum‐Brown 《Journal of community & applied social psychology》2010,20(2):156-166
Given the polarization of the early 21st century political atmosphere in the U.S., intergroup dialogue has emerged as a unique alternative setting, with intentions of facilitating a more productive and thoughtful citizen engagement. Although cross‐partisan dialogue efforts are underway in community contexts, they have been slower to reach academic settings. This paper is an exploratory study of our own liberal‐conservative dialogue course at the University of Illinois–the first of its kind, to our knowledge. After describing basic features of the course, we identify themes from student journals and final evaluations suggesting both dialogue benefits and challenges. Finally, we discuss the growing literature around dialogue, questions of its long‐term impact, and larger potential barriers to participation in liberal‐conservative dialogue, specifically. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
198.
Irwin Z. Hoffman Ph.D. 《Psychoanalytic Dialogues》2013,23(6):721-731
Jeremy D. Safran feels that my views regarding the relative merits of case studies and systematic empirical research are unnecessarily polarizing. I feel that, on the contrary, I'm offering bridges between my perspective and those of researchers on psychoanalytic process and outcome in two ways. One is through my own constructivist critique of traditional positivist case studies and theorizing based upon clinical experience. The second is through conceptualizing the place of systematic research within a constructivist paradigm. I am arguing that its place can be no different than that of case studies. Both generate possibilities for any particular analyst or analytic therapist to have in mind as he or she works with a particular patient at a particular moment. Safran locates the destructive effects of scientism with “biologically oriented researchers and cognitive therapists.” In my view, it might be convenient if the problem could be located exclusively with them, but the fact is that psychoanalytic researchers, as I demonstrate, are working largely within the same paradigm as their adversaries in the research world. That paradigm erroneously privileges systematic research as hypothesis-testing, whereas case studies are relegated to the status of anecdotal, hypothesis-generating work. I describe what I call “nonlinear constructivist learning” as the kind of “generalization” that case studies can yield and that is optimal for our field. 相似文献
199.
Irwin Z. Hoffman Ph.D. 《Psychoanalytic Dialogues》2013,23(3):315-323
Within his evolutionary framework, Slavin elaborates eloquently on the dialectic of construction of meaning and anticipation of death. Also within that framework he highlights the emergence of the universal dialectic of self-interest and care for others, perhaps finding its most poignant expression in the relation of parents and children. I raise questions about Slavin's attribution of a “sense of loss” to humans who allegedly long for the experience of evolutionarily earlier species, particularly their sense of automatic connectedness and automatic ways of relating to the world free of the burdens of uncertain, self-conscious choice. A longing for earlier states in human development is easier to grasp than a longing for the experience of less advanced species from which humans evolved. Nevertheless, Slavin's views and my own are otherwise deeply compatible, particularly his sense of what emerges as the uniquely human challenge of intersubjective construction of meaning in the context of individual self-interest and in the face of death. Slavin is also emphatic that the pervasiveness of absolute belief systems that preempt awareness of ambiguity, the anxiety of freedom, and the dread of death, does not gainsay their defensive nature. I argue, in accord with Altman, Butler, and others, that denial of death may promote dissipation of communal sensibility and replacement of it in a capitalist world (and perhaps others as well) with destructive splitting and fetishistic, competitive pursuit of money and power. 相似文献
200.
Luis Xavier Rangel‐Ortiz 《Studies in Ethnicity and Nationalism》2011,11(3):384-403
This article explores the role played by a growing community of Mexican national entrepreneurs who are crafting a new form of Mexican nationalism in San Antonio, Texas. This population of Mexican business people is growing in size and influence in the city. The experiences of Mexican entrepreneurs differ from understood forms of Mexican immigration and acculturation to the United States. They differ from previous waves of affluent groups of political and religious Mexican refugees that flourished in San Antonio from 1908 through the 1940s. The integration and cultural adaptation experiences of Mexican entrepreneurs represent a new form of Mexican nationalism that engages both Mexican and American nationalisms in a bidirectional acculturation process. Blending attitudes, values, beliefs, and behaviours of both countries represent a new form of Mexican and American culture emerging in San Antonio at the beginning of the twenty‐first century. To better understand the experiences and dynamics of these business people, this study builds on Pierre Bourdieu's principles of capital and power. 相似文献