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861.
Bo Zhou Anna Konstorum Thao Duong Kinh H. Tieu William M. Wells Gregory G. Brown Hal S. Stern Babak Shahbaba 《Psychometrika》2013,78(2):260-278
We propose a hierarchical Bayesian model for analyzing multi-site experimental fMRI studies. Our method takes the hierarchical structure of the data (subjects are nested within sites, and there are multiple observations per subject) into account and allows for modeling between-site variation. Using posterior predictive model checking and model selection based on the deviance information criterion (DIC), we show that our model provides a good fit to the observed data by sharing information across the sites. We also propose a simple approach for evaluating the efficacy of the multi-site experiment by comparing the results to those that would be expected in hypothetical single-site experiments with the same sample size. 相似文献
862.
在匹配了情绪刺激的效价和唤醒度后,检验了情绪的动机程度对注意范围的影响。研究采用Navon字母任务,通过被试对整体字母和局部字母的反应考察了注意范围的变化。结果显示,被试在中性状态下出现整体加工偏向;在低动机程度的正性和负性情绪下偏向加强,注意范围扩大;在高动机程度的正性和负性情绪下偏向减弱,注意范围缩小。因此,在同一效价内动机程度的不同仍会影响注意加工,高动机程度窄化注意范围,低动机程度反之。 相似文献
863.
864.
865.
The wetting behaviour and associated pressure effect of water in single-walled carbon nanotubes (SWCNTs) are investigated through molecular dynamics (MD) simulations. It is found that water molecules can enter SWCNTs via surface diffusion, and the effective infiltration rate increases with pressure. The effect of pressure on infiltration rate is highly non-linear, exhibiting characteristics of both hydrophilic and hydrophobic surfaces. There exists a nominal infiltration pressure that is dependent on the SWCNT size, above which the water flux is significantly increased. 相似文献
866.
867.
It is usually difficult to undercool Ti–Al alloys on account of their high reactivity in the liquid state. This results in a serious scarcity of information on their thermophysical properties in the metastable state. Here, we report on the surface tension of a liquid Ti–Al alloy under high undercooling condition. By using the electromagnetic levitation technique, a maximum undercooling of 324 K (0.19 T L) was achieved for liquid Ti-51 at.% Al alloy. The surface tension of this alloy, which was determined over a broad temperature range 1429–2040 K, increases linearly with the enhancement of undercooling. The experimental value of the surface tension at the liquidus temperature of 1753 K is 1.094 N m?1 and its temperature coefficient is ?1.422 × 10?4 N m?1 K?1. The viscosity, solute diffusion coefficient and Marangoni number of this liquid Ti–Al alloy are also derived from the measured surface tension. 相似文献
868.
Abstract The local translational order of the icosahedral quasicrystalline phase in rapidly solidified V41Ni36Si23 has been investigated by means of selected-area electron diffraction and high-resolution electron microscopy. Experimental results show that translational order always occurs in the twofold direction and can be observed when the quasicrystal is examined along its fivefold and threefold as well as twofold axes. Sometimes it occurs in two or three coplanar twofold directions simultaneously. In these cases some crystalline islands exist in the icosahedral quasicrystal and this corresponds to the initial stage of transformation from a quasicrystal to the stable crystalline phase. 相似文献
869.
In daily life, people frequently need to observe dynamic objects and temporarily maintain their representations in visual working memory (VWM). The present study explored the mechanism underlying the binding between perceptual features and locations of dynamic objects in VWM. In three experiments, we measured and compared the memory performance for feature-location binding of multiple dynamic and static objects. The results showed that the feature-location binding was impaired for the dynamic objects compared with the static objects. The impairment persisted when the global spatial configuration of the objects remained intact during the motion, as well as when the binding task was relatively easy, such as binding between single-feature objects and coarse locations. The results indicate that object features and locations are not maintained in VWM as well-integrated object files; rather, the formation of feature-location binding may require additional processes, which are disrupted by the constant change of locations in dynamic circumstances. We propose a consolidation process as possible underlying mechanism, and discuss factors that may influence the strength of feature-location binding in dynamic circumstances. 相似文献
870.
民间教门在中国历史上长期存在,不仅影响渗透到中国社会的各个领域,控制着千百万下层群众生活,时刻威胁着封建政权,而且延续到现实的社会生活。当今一些邪教和黑社会组织,与它们有着一定的渊源关系。民间教门是民间神灵信仰的组织化和团体化.具有宗教性与叛逆性双重属性。根据民间教门历史演变轨迹呈现出的阶段性特征.可划分为发生发展、活跃发展、繁盛发展、分化转折等四个历史阶段。教门文化既有精华又有糟粕,随着历史条件的变迁,到晚清和民国时期,总体上演变为对抗民主与科学、阻挡社会进步的最顽固、最落后的腐朽文化。用马克思主义唯物史观和宗教观研究中国民间教门与教门文化。对深入开展同邪教组织的斗争,可从多方面获得智慧和启示。 相似文献