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When individuals reach very old age, accumulating negative conditions represent a serious challenge to their capacity to adapt and are likely to reduce the quality of life. By examining happiness and its determinants in centenarians, this study investigated the proposal that psychological resilience may come to an end in extremely old age. Data from the population-based Heidelberg Centenarian Study indicated high levels of happiness. Basic resources (i.e., job training, cognition, health, social network, extraversion) explained a substantial proportion of variance in happiness, but some resource effects were mediated through self-referent beliefs (e.g., self-efficacy) and attitudes toward life (e.g., optimistic outlook). Results challenge the view that psychological resilience reaches a critical limit or that the self-regulatory adaptation system loses its efficiency in very advanced age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Efficient fabrication of structurally and functionally diverse nanomolecular devices and machines by organizing separately prepared DNA origami building blocks into a larger structure is limited by origami attachment yields. A general method that enables attachment of origami building blocks using ‘sticky ends' at very high yields is demonstrated. Two different rectangular origami monomers are purified using agarose gel electrophoresis conducted in solute containing 100 × 10?3 m NaCl, a treatment that facilitates the dissociation of most of the incorrectly hybridized origami structures that form through blunt‐end interactions during the thermal annealing process and removes these structures as well as excess strands that otherwise interfere with the desired heterodimerization reaction. Heterodimerization yields of gel‐purified monomers are between 98.6% and 99.6%, considerably higher than that of monomers purified using the polyethylene glycol (PEG) method (88.7–96.7%). Depending on the number of PEG purification rounds, these results correspond to about 4‐ to 25‐fold reduction in the number of incorrect structures observed by atomic force microscopy. Furthermore, the analyses of the incorrect structures observed before and after the heterodimerization reactions and comparison of the purification methods provide valuable information on the reaction mechanisms that interfere with heterodimerization.  相似文献   
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Everyday leisure activities in adulthood and old age have been investigated with respect to constructs such as successful aging, an engaged lifestyle, and prevention of age-related cognitive decline. They also relate to mental health and have clinical value, as they can inform diagnosis and interventions. In the present study, the authors enhanced the content validity of the Victoria Longitudinal Study activity questionnaire by adding items on physical and social activities and validated a shortened version of the questionnaire. The proposed leisure activity model included 11 activity categories: 3 types of social activities (i.e., activities with close social partners, group-centered public activity, religious activities), physical activities, developmental activities, experiential activities, crafts, game playing, TV watching, travel, and technology use. Confirmatory factor analyses validated the proposed factor structure in 2 independent samples. A higher order model with a general activity factor fitted the activity factor correlations with relatively little loss of fit. Convergent and discriminant validity for the activity scales were supported by patterns of their correlations with education, health, depression, cognition, and personality. In sum, the scores derived from of the augmented Victoria Longitudinal Study activity questionnaire demonstrate good reliability, and validity evidence supports their use as measures of leisure activities in young, middle-aged, and older individuals. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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货运船是全球货物运输中的主要交通工具。随着全球贸易量的不断增长,有超过90%的贸易运输是横跨世界各大海洋来完成的。这种趋势朝着载量更大,速度更快的方向发展。即使海洋运输是各种运输方式中最为有效的一种方式,但货运船只所消耗的燃料和排放的CO,总量也在继续上升。  相似文献   
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In this research, the authors investigated the specific and shared impact of personal resources and selection, optimization, and compensation (SOC) life-management strategies (A. M. Freund & P. B. Baltes, 2002) on subjective well-being. Life-management strategies were expected to be most relevant when resources were constrained, particularly in very old age. In Study 1 (N = 156, 71-91 years), age-differential predictive patterns supported this assumption: Young-old individuals' well-being was predicted independently by resources and SOC, whereas SOC buffered the effect of restricted resources in old-old individuals. Study 2 replicated the findings longitudinally with resource-poor and resource-rich older individuals (N = 42). In both studies, specific SOC strategies were differentially adaptive. Results confirm that resources are important determinants of well-being but that life-management strategies have a considerable protective effect with limited resources. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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A novel selective catalytic reduction method of tertiary phosphine oxides to the corresponding phosphines has been developed. Notably, the reaction proceeds smoothly with low catalyst loadings of 1–5 mol% even at low temperature (70 °C). Under the optimized conditions various phosphine oxides could be selectively reduced and the desired phosphines were usually obtained in excellent yields above 90%. Furthermore, we have developed a one‐pot reaction sequence for the preparation of valuable phosphine⋅borane adducts. Simple addition of BH3⋅THF subsequent to the reduction step gave the desired adducts in yields up to 99%.

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In this study, the authors investigated the role of activities and self-referent memory beliefs for cognitive performance in a life-span sample. A factor analysis identified 8 activity factors, including Developmental Activities, Experiential Activities, Social Activities, Physical Activities, Technology Use, Watching Television, Games, and Crafts. A second-order general activity factor was significantly related to a general factor of cognitive function as defined by ability tests. Structural regression models suggested that prediction of cognition by activity level was partially mediated by memory beliefs, controlling for age, education, health, and depressive affect. Models adding paths from general and specific activities to aspects of crystallized intelligence suggested additional unique predictive effects for some activities. In alternative models, nonsignificant effects of beliefs on activities were detected when cognition predicted both variables, consistent with the hypothesis that beliefs derive from monitoring cognition and have no influence on activity patterns. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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