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51.
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Ordinary and thermal diffusion of moisture in activated alumina are investigated using a new diffusion cell design and scheme of analysis reported earlier. The specific form of the mass flux equation has a pronounced effect on the magnitude of the associated thermal diffusion ratio. In the case of activated alumina-moist air, if a partial pressure gradient is used, then the thermal diffusion term is small if not zero.Free, Knudsen and surface diffusion all play a part in the diffusion through activated alumina. However, surface diffusion makes the major contribution and for this reason the model in this case can be simplified to a two parameter surface model.The activation energy for surface diffusion is constant and is approximately equal to the mean isosteric heat of absorption. In addition, mean pore radius, turtuosity, and other physical constants are computed from the least square fit of experimental data. Furthermore, the model is theoretically consistent over the entire concentration range (0≦ CACAsat).A new fact about activated alumina (Grade F1) it that it does not transfer moisture in a nonisothermal condition so long as the partial pressures of moisture on the two sides of the pellet are the same. There appears to be no previous report of this fact in the periodical literature.  相似文献   
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Two important sets of performance indicators have become established in the United Kingdom: research quality ratings and teaching quality ratings. The research quality ratings and, to a lesser extent, the teaching quality ratings, influence the level of government funding provided to higher education institutions. This paper considers the correlation between the two ratings and the possible consequences of policies that reshape the higher education sector by concentrating research resources in a limited number of institutions. Comparisons are made between quality assurance/assessment approaches in the United Kingdom and those in the United States.  相似文献   
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Using Sonstroem, Harlow, and Josephs' (1994) expanded version of the Exercise and Self-Esteem Model (EXSEM; Sonstroem &; Morgan, 1989), we explored how 9 older adults (6 women and 3 men, aged 65–72 years) involved in a resistance training program experienced and perceived changes in physical self-worth (i.e., improved strength, functional competency, physical condition, and body satisfaction). We conducted three in-depth interviews with each participant over the course of the program. In individual log books, participants recorded the weight lifted and the number of repetitions for each exercise. Our findings showed the course of changes in physical self-perceptions in these older adults and how actual individual changes in strength performance related to perceived changes in important psychological outcomes.  相似文献   
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Two Web-based breastfeeding programs were developed to provide new parents with necessary information on proper breastfeeding techniques. One version was plain text and the other version combined text with graphics. The computer was viewed as a valuable learning tool. The breastfeeding program that contained graphics was preferred over the text-only program. Educators are encouraged to use Web-based graphic programs to provide breastfeeding education to new parents.  相似文献   
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Two experiments with goldfish were performed to investigate the role of stimulus-reinforcer vs. response-reinforcer relationships in omission training and the role of stimulus localizability in a positive behavioral contrast paradigm. The directed behavior of fish, like that of pigeons and rats in other studies, was greatly influenced by positive stimulus-reinforcer correlations, as evidenced by maintained contacts of a signal for food, even though such responses terminated the signal and cancelled reinforcement delivery. Goldfish exhibited positive behavioral contrast when the signals for reinforcement and nonreinforcement were displayed directly on the response key, but no contrast was observed when variations in a diffuse houselight stimulus were used as signals for reinforcement or nonreinforcement. Analysis of sequential-trial data yielded effects analogous to Pavlovian positive and negative induction. Theoretical and methodological problems were briefly considered.  相似文献   
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This study investigated HyperCard as a tool for assessment in science education and determined whether or not a HyperCard assessment instrument could differentiate between expert and novice student performance (balancing stoichiometric equations) in science education. Five chemical equations were presented by traditional pen-paper and by a HyperCard (Hyperequation) program. Thirty honors (expert) and 30 regular (novice) chemistry students were randomly divided into HyperCard and traditional pen-paper groups of 15 students each. Scoring was based on five dependent variables: performance scores, number of attempts, rate of attempts, time on task, and correctness. Correlation results indicated that students with high performance scores correctly balanced more equations, required fewer attempts to balance equations, and required less time per attempt than did students with low performance scores. MANOVA results showed that performance scores and correctness scores for both experts and novice were significantly higher on HyperCard compared to pen-paper assessment; the novice scores on HyperCard nearly equaled the expert pen-paper assessment scores. Significant interactions were found for time on task and for correctness. The results suggest that HyperCard can be a suitable tool for assessment in science education and that such an instrument can differentiate between expert and novice student performance.  相似文献   
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