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731.
The aim of this study was to look at motivations behind altruistic behavior in virtual communities by studying the sharing of game tips by experienced gamers. We examine several possible motivations (pure altruism, generalized reciprocity, and reputation) and qualitatively analyze tip types in terms of usefulness, visibility, and skill level. We found that in games that do not support a "performance stage" for skill demonstration, players often share game tips as a strategy to attract attention. To a certain degree, reciprocity can be used to explain small favor exchanges, but earning social reputation is often a much stronger motivating factor. 相似文献
732.
Neuronal substrates of relapse to cocaine-seeking behavior: role of prefrontal cortex 总被引:2,自引:0,他引:2
The return to drug seeking, even after prolonged periods of abstinence, is a defining feature of cocaine addiction. The neural circuitry underlying relapse has been identified in neuropharmacological studies of experimental animals, typically rats, and supported in brain imaging studies of human addicts. Although the nucleus accumbens (NAcc), which has long been implicated in goal-directed behavior, plays a critical role in this circuit, the prefrontal cortex (PFC) appears to process the events that directly trigger relapse: exposure to acute stress, cues previously associated with the drug, and the drug itself. In this paper, we review animal models of relapse and what they have revealed about the mechanisms underlying the involvement of the NAcc and PFC in cocaine-seeking behavior. We also present electrophysiological data from PFC illustrating how the hedonic, motor, motivational, and reinforcing effects of cocaine can be analyzed at the neuronal level. Our preliminary findings suggest a role for PFC in processing information related to cocaine seeking but not the hedonic effects of the drug. Further use of this recording technology can help dissect the functions of PFC and other components of the neural circuitry underlying relapse. 相似文献
733.
Zhang J Wieczorek WF Jiang C Zhou L Jia S Sun Y Jin S Conwell Y 《Suicide & life-threatening behavior》2002,32(4):370-379
As China opens its door to the world, suicide research is making rapid progress using methods and instruments developed in the West. This is a feasibility study of the psychological autopsy methodology applied in China, with its emphasis on the social and cultural environments. With samples of 66 completed suicides and 66 community normal living controls, the authors found that it is feasible to interview at least two informants for each suicide case and each control, between 2 and 6 months after the suicide. With the Chinese-cultivated contacting method of recruiting cases, the refusal rate is nearly zero. The Western-developed methodology per se proved to be valid in the Chinese culture. Ethical considerations in the context of Chinese culture are as important as in the West. Psychological autopsy technique is shown to be an equally applicable method for the study of completed suicides in Chinese culture as it is in the West. Future epidemiological research on Chinese suicide should use the psychological autopsy method to collect data from larger samples in order to increase our understanding of the risk factors for Chinese suicides. 相似文献
734.
A new decagonal quasicrystal (the D phase) with a period of about 1.6 nm was found to form in conventionally solidified and heat-treated Al75Ni15Ru10 alloys. The electron diffraction patterns of the Al-Ni-Ru D phase exhibit a large number of quite sharp diffraction spots located at precise decagonal symmetry positions, indicating a highly ordered decagonal quasicrystal with a long-range quasiperiodic correlation. The D phase is formed with a composition close to Al74Ni15Ru11, as determined by energy-dispersive X-ray analysis. By means of high-resolution electron microscopy, the structural features of the Al-Ni-Ru D phase, which are obviously different from that of the Al-Pd D phase (a typical decagonal quasicrystal with 1.6 nm periodicity reported previously), have been revealed. 相似文献
735.
The mechanical properties of periodic composites containing identical spherical particles are investigated using the principles of micromechanics and homogenization procedures. The averaged strain and stress fields are derived in terms of an eight-particle interaction. The effective elasticity with the cubic symmetry tensor is explicitly obtained. If the interaction term is dropped, then one recovers the conventional Mori–Tanaka model. With further approximations, the dilute model and the self-consistent model can also be obtained within the proposed framework. It is observed that the particle interactions make no contribution to the effective bulk modulus, a result that is consistent with other models and experiments for composites with cubic lattices. 相似文献
736.
H. Wei J.J. Liang P. Peng Q. Zheng X.F. Sun B.Z. Sun 《Philosophical Magazine Letters》2013,93(5):299-311
The valence band structures of the NiAl–Mo alloy was investigated by photoelectron spectroscopy. The valence band spectra of the NiAl–Mo alloy was shifted away from the Fermi level so that the Ni-d-band centroid moved to a higher energy by 0.22 eV as Mo was added. A possible explanation lied in the overlap of Ni-d bands in the energy with Mo-d and Al-p bands. The participation of Mo-d bands was correlated with the site preference of Mo in NiAl alloys. 相似文献
737.
An ordered structure, which was found in a decagonal quasicrystal with 0.4 nm periodicity in a conventionally solidified Al70Ni20Ru10 alloy, has been examined theoretically by the projection of an ordered body-centred (CsCl-type) hypercubic lattice. The ordered structure can be characterized as an ordered arrangement of two kinds of atom columnar cluster with different directions of pentagonal symmetry. Two lattices, which are constructed by connecting the atom clusters in the same directions, can be interpreted as ordered sublattices formed by each of vertex and body-centred positions of the CsCl-type hypercubic lattice. Diffraction patterns calculated from the ordered and disordered body-centred hypercubic lattices replicate well the electron diffraction patterns observed from the Al-Ni-Ru and other decagonal quasicrystals. 相似文献
738.
739.
Hee Sun Park Doshik Yun Hye Jeong Choi Hye Eun Lee Dong Wook Lee Jiyoung Ahn 《International journal of psychology》2013,48(5):922-934
The social identity of another person, in addition to the social identity of self, can be an important factor affecting the types of attribution judgments and emotions that individuals indicate for the other person. In April 2007, the perpetrator of the shooting incident on the Virginia Tech University campus was identified as a person who emigrated to the USA from Korea at a young age. The current study compared non‐Korean Americans, Korean Americans, Koreans in the USA, and Koreans in Korea in terms of their attributions and emotions concerning the perpetrator and the shooting incident. Participants were asked to indicate (1) the extent to which they attributed the cause of the incident to either American society or the perpetrator, (2) their emotions (e.g., upset), and (3) the extent to which they categorized the perpetrator as an American, a Korean American, or a Korean. The results indicated that non‐Korean Americans were most likely to attribute the cause of the incident to the perpetrator as opposed to American society. Non‐Korean Americans, Korean Americans, and Koreans in the United States had more negative emotions (e.g., unhappy, sad, and upset) about the incident than Koreans in Korea did. The results also indicated that individuals differed in their attributions and emotions depending on how they categorized the perpetrator. For example, categorizing the perpetrator as being a Korean was positively related to Americans’ tendency to hold the perpetrator responsible, while categorizing the perpetrator as being an American was negatively related to the tendency to hold the perpetrator responsible among Koreans in Korea. The findings may imply that social identity theory, intergroup emotion theory, and cultural orientations (e.g., individualism and collectivism) can provide insights into people's reactions to a tragic incident. 相似文献
740.
运用双任务实验范式,比较了三种认知负荷主观评价量表的灵敏度与效度。结果发现:在本研究任务条件下,次任务反应时的稳定性、抗干扰性较好,可以作为认知负荷主观评价的标尺;WP量表与PAAS量表的敏感性均较好,其中WP量表的敏感性、诊断性高于后者,TLX量表的敏感性较弱;WP量表与PAAS量表的效度较好,且好于TLX量表。综合各项指标,在中低难度任务下,WP量表是目前认知负荷较为理想的测量工具。 相似文献