高校乒乓球教学中专项意识的培养

乒乓球的专项意识不是自发产生的 ,它是在大量的练习和比赛中获得的。学生在练习中不受正确的意识指导 ,就会受错误的意识支配。教师在教学中应注重对学生进行乒乓球专项意识的培养 ,加速运动技能的形成。     

Environmentally-induced stone decay: the cumulative effects of crystallization–hydration cycles on a Lincolnshire oopelsparite limestone

An investigation has been undertaken at St Andrew’s church, Walpole St Andrew, Norfolk, to establish the underlying causes of the observed stone decay to the upper parts of the six stone piers. The stone decay was first recorded in the early 1930s. The salt-contaminated masonry within the church has been shown to undergo severe salt decay during the summer, with little damage occurring over the winter months. The south aisle piers have been shown to decay 2.5 times faster than the north aisle piers. Although crystallization–hydration cycles have been identified, the rate of decay is at its greatest when the cycling is relatively infrequent. This was not the expected trend. Furthermore, it has been shown that during extended periods where the ambient relative humidity is less than 75%, the rate of decay reaches a maximum. It is the length of this ‘drying’ period that apparently has the greatest influence on the rate of decay and could explain the significant difference in the rate of decay between the south and north aisle piers. The results have serious implications for passive conservation, where it is often recommended to lower the ambient relative humidity to well below the equilibrium relative humidity of the salt contaminant, to avoid crystallization–hydration cycles. Since, at the time of building, the church was situated on the coast, it is possible that the sodium chloride contamination occurred during the building process (1440–1520), particularly since the area was prone to sea-flooding at this time. Alternatively, the salt could have been applied as a treatment during the general restoration of 1897. Whatever the source of the salt, it seems likely that the ambient environment was changed by the insertion of a sealed floor in 1897, which could account for the onset of the salt decay.     

Educational and Employment Testing: Changing Concepts in Measurement and Policy

How will the expansion of the concept of construct validity affect validation practice in employment testing? How does the need for consequential validity differ in educational and employment testing? How do the research bases differ for performance assessment in these settings? Are there parallel trends in policies for test use in education and industry?     

Characteristics of early adopters of end-user online searching in the health professions

This paper examines end-user, online searching using data from a questionnaire mailed to 150 Canadian health professionals in practice settings. The response rate was 83% (n = 124). The data provide a demographic profile of early adopters of end-user searching in the health care community. Positive correlations with the user's level of implementation of end-user searching were found for the following variables: amount of time spent in research activities, amount of system training received, and use of Medical Subject Headings (MeSH). There was a negative association between the amount of time spent in patient care and implementation level. General practitioners and family physicians had lower implementation levels than physicians in other specialties. Successful implementers were more likely to be computer literate and to place a high value on formal information sources such as books, journals, and libraries. Health professionals using so-called "user-friendly" or menu-based software had lower levels of personal commitment to using online databases, as measured by a combination of continuance of use, willingness to pay personally, type of recommendations made to colleagues, and hardware ownership.     

ADONIS—latest developments and its role in the changing publisher/library relationship

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Exporting the American (information) revolution: the international impact of the National Library of Medicine

The National Library of Medicine has had an enormous impact on health information services all over the world. Although NLM is primarily a national institution, it has become an important international resource by responding to requests from the international community. NLM has been influential in three major ways. First, NLM has provided a model for other national and regional health information services. Second, it has been a catalyst, in that MEDLARS and other services it provides formed the nucleus of many regional networks. NLM helped such networks get started by giving advice on how to set up services and build collections and by "training the trainers" on the MEDLARS system. Third, NLM has supported national and regional operations by providing the additional training and materials needed for day-to-day service.