道德规范与国书馆事业

美国图书馆协会的<职业道德规范声明>提出了以图书馆事业为中心的具体原则,其<图书馆权利法案>则明确了图书馆的责任和义务.目前,美国社会和政治环境的变化为图书馆职业带来了越来越多的忧虑和压力."9·11"后出台的<爱国者法案>明显与图书馆职业道德规范中所阐述的重要原则相冲突.因此,美国图书馆协会决心抵制<爱国者法案>对知识、信息自由开放以及行使个人隐私权的限制.     

Optimizing segmental movement in the jumping header in soccer

This study looks at segmental movements in the jumping header from an optimization viewpoint. Investigations on the header so far have focused on head restriction in the movement but have not clarified how and to what extent body segments influence the performance of the skill. In the present study a biomechanical model was used to analyze the jumping header in simulated competition to give a clear picture of an optimized header. Skilled soccer players headed balls at speeds of 13 m x s(-1) the results indicated that the head moves as a free non-restricted segment in the jumping header and should be allowed to do so, even though much soccer literature says otherwise to prevent injuries. The arm movement showed individual characteristics and gave no general advantages in optimizing ball speed after impact in the header The movement of the legs was, on the other hand, the single most important factor in the skill. Therefore, coaches and players shouldfocus on developing muscle strength in the stomach, back and pelvis and should put no restrictions on head and arm movement to optimize the jumping header.     

The Penultimate Teaching Machine

This paper discusses the possibility of building an electronic transducer to take the place of the existing teaching machines. The tasks that can be performed by such a machine as well as the advantages and risks involved are discussed.