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61.
Does sentence generation and/or stimulus emotionality enhance verbal memory in patients with neurological impairment? This question was addressed by testing 40 patients with unilateral stroke (20 with left-brain and 20 with right-brain damage) and 20 healthy control participants for recall and recognition of 48 target words. During encoding, emotional and nonemotional words were either presented in sentences (read condition) or used to form sentences (generate condition). Both word emotionality and generative processing improved memory performance in all groups. The authors suggest that a similar influence (i.e., cognitive activation) underlies both of these memory-enhancing effects, although the putative origins of the 2 effects are quite different. Neuropsychological underpinnings and clinical implications of these phenomena are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
62.
Isolated rat hearts were subjected to 15, 45, or 60 minutes of global ischaemia and then fixed by perfusion at 37°C with glutaraldehyde containing various amounts of oxygen. This either had been bubbled with 100% oxygen (PO2 620 mm Hg) or with 100% nitrogen (PO2 40 mm Hg) immediately before use, or it had been routinely prepared and stored exposed to atmospheric oxygen (PO2 245 mm Hg). The ultrastructure of myocytes and endothelial cells subjected to 15 minutes of ischaemia was not affected by the treatment of the fixative. However, when the tissue subjected to longer periods of ischaemia was fixed with routinely prepared or oxygen-bubbled glutaraldehyde, ultrastructural changes characteristic of reoxygenation damage were uniformly evident in both the microvasculature and myocytes. These qualitatively distinct changes included mitochondrial swelling, cell swelling, endothelial bleb formation, and narrowing of capillary lumina. These abnormalities were not observed in tissue fixed with nitrogen-bubbled glutaraldehyde. These findings indicate that deliberate steps should be taken to reduce or eliminate dissolved oxygen from the fixatives used to study ischaemic tissues. Otherwise artefactual reoxygenation damage in vitro may occur and make valid ultrastructural interpretation difficult or impossible.  相似文献   
63.
This paper details the deformation mechanism and low‐cycle fatigue life of eutectic solder alloys at high temperature (around 0.8Tm). Grain boundary sliding generally nucleates a wedge‐type cavity that reduces the low‐cycle fatigue life of metals. In this study, grain boundary sliding has promoted intergranular failure contributing to the reduction in fatigue life of Sn–Ag–Cu alloy. However, grain boundary sliding has exerted no deleterious effects on fatigue resistance of eutectic Pb–Sn and Bi–Sn alloys. The phase boundary sliding with very fine microstructure induces exceptional ductility in these alloys leading to superior low‐cycle fatigue endurance for theses eutectic Pb–Sn and Bi–Sn alloys.  相似文献   
64.
65.
The Modified Embedded Atom Method model for Pu metal is revised so that it more accurately captures the behavior of the Ziegler-Biersack-Littmark model of ion-ion interactions. Two revision are tested with somewhat different stiffnesses in the 2-1000 eV range. The revised models show higher damage levels at 20 KeV than an earlier model, suggesting that the behavior of the models above 100 eV is dominating damage production, at least in the earlier stages of the cascade. Work was performed at Los Alamos National Laboratory under the auspices of the US Department of Energy, under contract DE-AC52-06NA25396.  相似文献   
66.
Boundary objects are a critical, but understudied, theoretical construct in CSCW. Through a field study of aircraft technical support, we examined the role of boundary objects in the practical achievement of safety by service engineers. Their resolution of repair requests was preserved in the organization’s memory via three compound boundary objects. These crystallizations did not manifest a static interpretation, but instead were continually reinterpreted in light of meta-negotiations. This suggests design implications for organizational memory systems which can more fluidly represent the meta-negotiations surrounding boundary objects.  相似文献   
67.
This paper will introduce experimental studies and numerical calculation onturbulent boundary layer of water flow along curved surface in our country in recent years.Onthe basis of the experimental studies,the effects of curvature and roughness on velocitydistribution and pressure distribution and the change of turbulent flow boundary layer onoverflow bucket concave surface is discussed.We proposed the empirical formula of velocity,pressure and the change of turbulent flow boundary layer on outlet bucket concave.According tothe momentum principle,we have deduced the momentum integral equation full water depthboundary layer and using the element as control unit inside the boundary layer on concavesurface of bucket.Combining with continuity equation,we have computed the boundary layerdevelopment on the bucket of a spillway.Compared with the field experimental data,thecalculation results are available.Under polar coordinates,a mathematical model for simulatingtime-averaged flow characteristics in concave surface of bucket is established.The turbulent flowfield on concave surface of bucket is calculated by SIMPLE method and this mathematicalmodel.The flow velocity field,pressure field,distribution of turbulent kinetic energy,distribution of turbulent energy dissipating rate and distribution of shear stress are available.Thecalculation value is consistent with measured test data.  相似文献   
68.
本文对最基本的HCMOS器件(反相器和与非门)作了γ辐射损伤实验。通过器件性能变化,分析了γ辐射对电路的作用。  相似文献   
69.
李克平  张同俊 《激光技术》1997,21(3):174-178
梯度功能材料是一种界面连续化的新型复合材料,本文研究了激光加热在合成Al2O3/Ti系梯度功能材料过程中的作用和机理,同时用激光大光斑加热方法制备出直径11mm厚度3mm完整的FGM试样并加以分析,以及首次采用在试样中埋设微细热电偶成功地测出了激光加热造成的温度梯度分布。  相似文献   
70.
饱和—非饱和土体非稳定渗流数值分析   总被引:56,自引:0,他引:56  
吴梦喜  高莲士 《水利学报》1999,30(12):0038-0043
本文对一般的非饱和渗流有限元计算方法加以改进,有效地消除了非饱和渗流数值计算中存在的数值弥散现象。同时还提出了一种简便有效的逸出面处理新方法,并给出了非饱和非稳定渗流计算的实例。  相似文献   
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